<RECORD 1>

Accession number:20151700790330
Title:Analysis of farmland consolidation implementation status in China based on Ward hierarchical clustering
Authors:Xiang, Xiaomin (1); Jin, Xiaobin (1); Du, Xindong (1); Sun, Wei (1); Zhou, Yinkang (1)
Author affiliation:(1) College of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, China
Corresponding author:Jin, Xiaobin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:257-265
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Analyzing implementing characteristics and spatial pattern of land consolidation scientifically is of great theoretical and practical value for improving land consolidation scientific decision-making. In order to make sure the implementation status of farmland consolidation in China and its gap with planning objectives, based on the data acquired from the dataset of consolidation project management from 2006 to 2012, this paper analyzes the implementation status of farmland consolidation at county level by three indices i.e. the intensity, the potential and the difficulty of engineering. Then the Ward hierarchical clustering method is used to produce a comprehensive regionalization of farmland consolidation implementation in China. Finally combined with the established national planning objectives, a quantitative analysis is made macroscopically on the farmland consolidation implementation status in China from 2006 to 2012. The conclusions can be summarized as the following: 1) In terms of the implementation status based on itemized index, the North China Plain, the Sanjiang Plain, the Yellow River Delta, the Yangtze River Delta and other traditional agricultural regions are the main consolidation areas with high intensity during the study period; the consolidation areas with high potential are mainly in semi-humid and semi-arid region, including Inner Mongolia and pastoral areas along the Great Wall, Qinggan agricultural and pastoral areas, the Loess Plateau, etc; the consolidation areas with high difficulty are mainly located in the Loess Plateau, Qilian Mountain region, Qinba Mountains, Yunnan-Guizhou Plateau and other more complex terrain regions. 2) The implementation status of farmland consolidation in China during the study period can be divided into five types consisted of "medium high - low - medium" (Class I), "medium - medium low - medium" (Class II), "medium high - medium high - medium high" (Class III), "low - medium - high" (Class IV) and "high - medium low - medium" (Class V). The Class III is the most concentrated type, mainly distributed in Shanxi, Gansu and China's other western provinces, and characterized by higher implementation levels of the intensity, the potential and the difficulty of engineering; then Class I and II follow, and they are mainly distributed in some areas where natural resources and agricultural production conditions are appropriate, such as the Northeast Plain, the North China Plain, the Middle-lower Yangtze Plain, the Sichuan Basin. This class shows relatively high intensity, low potential and medium difficulty of implementation characteristics. While Class IV and V are small numbers and scattered, Class IV is mainly distributed in Shanghai, Guangdong and other coastal developed areas and western plateau mountainous, and its characteristics on the performance are lower intensity, medium potential and higher difficulty; Class V is mainly distributed in the hilly area of southwestern Zhejiang, Chengdu Plains, agricultural and pastoral areas of northern Inner Mongolia, and its intensity, potential and difficulty of engineering are all at medium and lower levels. 3) In terms of the coordination between implementation status and consolidation planning, there is a certain deviation in the specific implementation of major tasks containing key areas of farmland consolidation, demonstration counties of well-facilitated capital farmland and major consolidation projects of capital farmland. As far as the comparison of consolidation implementation in the different areas be concerned, which is characterized as the economic development, grain production and land consolidation activities, the regional difference is not very significant, and key points of farmland consolidation are still not highlighted. The findings suggest that the guiding role of national land consolidation planning should be strengthened to standardize the provincial farmland consolidation projects; especially in the key areas, the project arrangement and investment of farmland consolidation should be optimized at spatial pattern and implementation structure. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Farms
Controlled terms:Agriculture - Arid regions - Consolidation - Decision making - Economics - Engineering education - Investments - Land use - Landforms - Planning  - Project management - Sediments
Uncontrolled terms:Agricultural productions - Coordination - Farmland - Hier-archical clustering - Hierarchical clustering methods - Implementation status - Implementation structure - Land consolidation planning
Classification code:403 Urban and Regional Planning and Development - 443 Meteorology - 444 Water Resources - 481.1 Geology - 483 Soil Mechanics and Foundations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.2 Education - 911.2 Industrial Economics - 912.2 Management
DOI:10.3969/j.issn.1002-6819.2015.06.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 2>

Accession number:20151700790326
Title:Analysis of effective diffusivity of sludge in superheated steam drying based on Fourier number method and optimization method
Authors:Zhang, Xukun (1); Yao, Bin (1); Wu, Qi (1); Luo, Jun (1); Xu, Gang (2); Xu, Jianguo (2)
Author affiliation:(1) Mechanical and Electrical Equipment Institute of Nanchang Hangkong University, Nanchang, China; (2) Jiangxi Academy of Sciences, Nanchang, China
Corresponding author:Zhang, Xukun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:230-237
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The production of sewage sludge from wastewater treatment plants has been continuously increasing in China. One way to manage sewage sludge is drying, which yields a solid with low humidity. This solid can be easily stored, recycled and transported to other facilities. The drying of sewage sludge has been proved to considerably reduce solid volumes. Using superheated steam in the drying process can lead to substantial energy, if the vapour evaporating from the materials is used elsewhere in overall process. Therefore, superheated steam drying is an attractive drying process for industrial use especially if the cost energy for the drying is a major part of the cost of manufacture such as sewage sludge drying process. In order to further study the moisture diffusion mechanism and effective diffusivity of thin layer of sludge in superheated steam drying, this paper ignoring the influence of sample's moisture content change on effective diffusivity when determining the effective diffusivity through drying method, and adopts Fourier number method and optimization method respectively to calculate the effective diffusivity of sludge thin layers with the thickness of 2, 4, 6 and 10 mm at superheated steam temperature from 120 to 280, respectively. Relations of the effective diffusivity with superheated steam temperature and the thickness of thin layer were analyzed. The results showed that the effective diffusivity values derived from Fourier number method and optimization method were basically identical, and the effective diffusivity values and change characteristics of thin layer sludge in superheated steam drying were more accurately reflected based on these two methods. Calculation results derived from the Fourier number method and optimization method showed that the effective diffusivity of sludge with the thickness at 4 mm were 2.52&times;10&lt;sup&gt;-10&lt;/sup&gt;-2.93&times;10&lt;sup&gt;-9&lt;/sup&gt; m&lt;sup&gt;2&lt;/sup&gt;/s and 2.75&times;10&lt;sup&gt;-10&lt;/sup&gt;-3.32&times;10&lt;sup&gt;-9&lt;/sup&gt; m&lt;sup&gt;2&lt;/sup&gt;/s respectively at the temperature 120-280,and the effective diffusivity of sludge with thicknesses of 2, 4, 6 and 8 mm were 3.85&times;10&lt;sup&gt;-10&lt;/sup&gt;-2.28&times;10&lt;sup&gt;-9&lt;/sup&gt; m&lt;sup&gt;2&lt;/sup&gt;/s and 4.40&times;10&lt;sup&gt;-10&lt;/sup&gt;-2.72&times;10&lt;sup&gt;-9&lt;/sup&gt; m&lt;sup&gt;2&lt;/sup&gt;/s respectively at the temperature of 160. The effective diffusivity increased gradually with the increase of superheated steam temperature and the thickness of thin layer, and had a linear relationship with the two parameters. By using the multiple linear regression method, simplified expressions that reflect the relationship between effective diffusivity and drying temperature and thickness of layer were established respectively according to Fourier number method and optimization method, with the corresponding determination coefficient of 0.9982 and 0.9956. The calculation results can provide a valuable reference for the analysis of moisture diffusion process and effective diffusion coefficient of thin sludge layer in superheated steam drying. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Diffusion
Controlled terms:Drying - Fourier transforms - Linear regression - Moisture - Optimization - Regression analysis - Sewage sludge - Sewage treatment plants - Sludge disposal - Steam  - Waste disposal - Wastewater disposal - Wastewater treatment
Uncontrolled terms:Determination coefficients - Effective diffusion coefficients - Effective diffusivities - Fourier numbers - Multiple linear regression method - Sewage sludge from wastewater treatment plants - Superheated steam - Superheated steam temperature
Classification code:452.2 Sewage Treatment - 452.4 Industrial Wastes Treatment and Disposal - 614 Steam Power Plants - 642.1 Process Heating - 801.4 Physical Chemistry - 921.3 Mathematical Transformations - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.06.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 3>

Accession number:20151700790325
Title:Effects of covering materials and sawdust covering depths on ammonia and greenhouse gase emissions from cattle manure during storage
Authors:Zhu, Haisheng (1); Zuo, Fuyuan (1); Dong, Hongmin (2); Luan, Dongmei (3)
Author affiliation:(1) Department of Animal Science, Rongchang Campus of Southwest University, Chongqing, China; (2) Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China; (3) College of animal science and Technology, Northeast Agricultural University, Harbin, China
Corresponding author:Zhu, Haisheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:223-229
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Livestock production is the important source of gaseous emissions (NH&lt;inf&gt;3&lt;/inf&gt; and greenhouse gases) from agriculture. Storage of animal manure is reported to be an important agricultural source of the environmentally harmful gases. Generally, ammonia and greenhouse gas emissions from stored animal manure can be affected by environmental factors (temperature and wind speed) and storage stacking configuration. Most studies have focused on the emission of ammonia and greenhouse gases from slurry during storage. However, information of gaseous emissions from solid manure stored is limited. Material covering is expected to be an effective method to reduce gaseous emissions from the stored manure. Thus, two experiments were set up to study gaseous emissions during storage of the solid cattle manure, and the effect of covering depth (1, 3 and 5 cm) and two different covering materials (sawdust and straw) on emissions of ammonia and greenhouse gases. Polyvinylchloride cylindrical (30 cm in diameter and 90 cm in height) static vessels were designed and built to measure ammonia and greenhouse gas emissions in the laboratory experiment. Fresh cattle manure was collected from practicing farm of Rongchang Campus of Southwest University in Chongqing. After fully mixed, manure was filled into 12 barrels (24.2 cm in diameter and 15 cm in height). Barrels were enveloped by static vessels while measuring gaseous emissions. The stacking process commenced on May 29, 2014, and was measured for 49 days. In Experiment 1, the emissions of NH&lt;inf&gt;3&lt;/inf&gt;, CH&lt;inf&gt;4&lt;/inf&gt;, N&lt;inf&gt;2&lt;/inf&gt;O and CO&lt;inf&gt;2&lt;/inf&gt; from an uncovered and three sawdust-covering heaps of solid cattle manure were compared. Considering that the stacking of solid manure was only 10 cm height (about 4 kg), sawdust covering depths of 1, 3 and 5 cm were selected. In Experiment 2, the emissions of NH&lt;inf&gt;3&lt;/inf&gt;, CH&lt;inf&gt;4&lt;/inf&gt;, N&lt;inf&gt;2&lt;/inf&gt;O and CO&lt;inf&gt;2&lt;/inf&gt; were quantified using solid cattle manure (about 10 kg, 25cm stacking height) covered with sawdust (2 cm depth, 250 g) and straw (6 cm depth, 250 g) by using the method of static chamber. In Experiment 1, sawdust covering decreased cumulative NH&lt;inf&gt;3&lt;/inf&gt; emissions by 15.28%-58.13% and cumulative CO&lt;inf&gt;2&lt;/inf&gt; emissions by 4.61%-13.14% from cattle manure compared with that uncovered (P&lt;0.05). However, sawdust covering simultaneously increased cumulative N&lt;inf&gt;2&lt;/inf&gt;O emissions by 6.57%-20.02% and cumulative CH&lt;inf&gt;4&lt;/inf&gt; emissions by 29.82%-36.84% (P&lt;0.05). The emission of NH&lt;inf&gt;3&lt;/inf&gt;, N&lt;inf&gt;2&lt;/inf&gt;O and CO&lt;inf&gt;2&lt;/inf&gt; decreased and the emission of CH&lt;inf&gt;4&lt;/inf&gt; increased with the increasing of sawdust covering depth in three treatments of sawdust covering. Considering that the indirect global warming potential of NH&lt;inf&gt;3&lt;/inf&gt;-N per kilogram was calculated on the basis of an emission of 0.01 kg N&lt;inf&gt;2&lt;/inf&gt;O-N and global warming potential in 100-year scale for CH&lt;inf&gt;4&lt;/inf&gt; and N&lt;inf&gt;2&lt;/inf&gt;O, cumulative greenhouse gas emissions (based on CO&lt;inf&gt;2&lt;/inf&gt;) were 103.80, 108.61, 103.57 and 101.36 g/kg of manure weight for uncovered treatment, sawdust covering treatments with the covering depths of 1, 3, and 5 cm, respectively. Total greenhouse gas emissions showed a downward trend with the increasing of covering depth for covering treatments. In Experiment 2, both sawdust covering and straw covering reduced cumulative NH&lt;inf&gt;3&lt;/inf&gt; and CO&lt;inf&gt;2&lt;/inf&gt; emissions from solid cattle manure compared with that without covering during storage (P&lt;0.05), but increased cumulative CH&lt;inf&gt;4&lt;/inf&gt; emission (P&lt;0.05). Compared with uncovered treatment, sawdust covering increased cumulative N&lt;inf&gt;2&lt;/inf&gt;O emission from solid cattle manure (P&lt;0.05). However, straw covering decreased cumulative N&lt;inf&gt;2&lt;/inf&gt;O emission (P&lt;0.05). Compared with straw covering, sawdust covering decreased cumulative NH&lt;inf&gt;3&lt;/inf&gt; emission by 16.14% from solid cattle manure. Cumulative N&lt;inf&gt;2&lt;/inf&gt;O emission from solid cattle manure increased significantly by using sawdust covering compared with straw covering (P&lt;0.05), 33.39 mg/kg for sawdust covering and 22.30 mg/kg for straw covering, respectively. Cumulative CH&lt;inf&gt;4&lt;/inf&gt; emissions from solid cattle manure covered with straw was significantly higher than that from solid cattle manure covered with sawdust (P&lt;0.05), 2.53 vs. 2.07 g/kg, respectively. However, cumulative CO&lt;inf&gt;2&lt;/inf&gt; emissions from solid cattle manure covered with straw was significantly lower than that from solid cattle manure covered with sawdust (P&lt;0.05), 32.62 vs. 34.65 g/kg, respectively. Cumulative greenhouse gas emissions were 94.14, 101.51 and 109.46 g/kg of manure weight based on CO&lt;inf&gt;2&lt;/inf&gt; for uncovered, sawdust covering and straw covering, respectively. Compared with sawdust covering, straw covering increased significantly total greenhouse gas emissions from solid cattle manure. The results show that the treatments with thicker sawdust-covering (3 and 5 cm) have better effect of reduction emission for greenhouse gases. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Gas emissions
Controlled terms:Agriculture - Ammonia - Animals - Gases - Global warming - Greenhouse effect - Greenhouse gases - Manures - Sawdust - Scales (weighing instruments)  - Storage (materials) - Straw - Wind
Uncontrolled terms:Agricultural sources - Covering depth - Covering material - Environmental factors - Global warming potential - Laboratory experiments - Livestock production - Stacking configurations
Classification code:443.1 Atmospheric Properties - 451.1 Air Pollution Sources - 694.4 Storage - 804.2 Inorganic Compounds - 811.2 Wood and Wood Products - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 931.2 Physical Properties of Gases, Liquids and Solids - 943.3 Special Purpose Instruments
DOI:10.3969/j.issn.1002-6819.2015.06.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 4>

Accession number:20151700790311
Title:Simulation of agricultural water supply and demand at irrigation district under climate change using STELLA
Authors:Feng, Dongpu (1); Wei, Xiaomei (1); Jiang, Ya'nan (1); Li, Ping (1)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&amp;F University, Yangling, China
Corresponding author:Wei, Xiaomei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:122-128
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Climate change has significant influences on irrigation water demand (IWD) and available irrigation water supply (IWS), which poses grave challenges to farmers and administrators of agriculture and water resources. Due to the complexity and uncertainties from climate, agriculture and water systems, only a few studies have combined these systems together, especially at irrigation district scale. Furthermore, most climate change scenarios (CCS) are continuous time series with uncertainties, meanwhile the corresponding CCS of the typical hydrological years are deficient. Thus it is difficult for the administrators from water sectors and agriculture to make positive responses to climate change. The object of the study was to provide an approach to estimate and assess the influences of climate change on IWS and IWD systems in irrigation district. The study area was a typical northern irrigation district of China, the Baojixia Irrigation District. The model considering IWD, IWS and CCS was developed using system dynamics software i.e. structure thinking experimental learning laboratory with animation (STELLA). There were four function modules: IWDM, IWSM, CCSM and WSDBI. CCSM included the reference crop evapotranspiration (ET&lt;inf&gt;0&lt;/inf&gt;) and the climate factors of future typical hydrological years. Climate factors (i.e. precipitation, air temperature, wind speed, relative humidity and sunshine duration) were predicted using historical data and hydrological frequency calculation principle of inconsistent series. ET&lt;inf&gt;0&lt;/inf&gt; was calculated by Penman-Monteith equation from the Food and Agriculture Organization of the United Nations (FAO) based on the predicted climate factors. IWDM calculated the irrigation water demands of main crops (wheat, maize, cotton, cole and apple). Crop water requirement was calculated by a simple soil water balance model including effective precipitation, crop coefficient (Kc) and ET&lt;inf&gt;0&lt;/inf&gt;. Net irrigation water demand (NIWD) was the sum of crop water requirements multiplied by their planting areas. IWD was NIWD divided by coefficient of irrigation water effective utilization. IWS was the available irrigation water supply which consisted of ground water and surface water (runoff of Weihe River and reservoirs). The runoff was estimated by historical data and hydrological frequency calculation principle of inconsistent series. The outputs were IWD, IWS and a water supply-demand balance index (WSDBI, i.e. the ratio of IWD and IWS), which were used to evaluate the effects of climate change. The model was verified by historical hydro-meteorological and agriculture data from 2000 to 2010. After validation the predicted CCS and IWS were used as inputs for the simulation of the future irrigation water balance conditions. The conclusions of this research are: 1) The water supply and demand model based on STELLA has a good performance and can be a steady approach for agriculture and water resource simulation. The mean relative errors for IWD and WSDBI are both 3.13%. The mean absolute errors for IWD and WSDBI are 3.9&times;10&lt;sup&gt;-7&lt;/sup&gt; m&lt;sup&gt;3&lt;/sup&gt; and 0.06, respectively. 2) The runoff of Weihe River at Linjiacun station had a significant downward trend at the 0.05 level from 1954 to 2010. It was a jump type of change with its jump range of about -1.43&times;10&lt;sup&gt;-9&lt;/sup&gt; m&lt;sup&gt;3&lt;/sup&gt; occurred in 1989. Compared with the runoff values of different typical hydrological years from 1954 to 2010, the predicted values from 1989 to 2030 were declined by 40%-55% which caused a large reduction of agricultural water supply. The mean temperature and maximum temperature significantly increased meanwhile relative humidity and wind speed significantly decreased at the 0.05 level during 1981-2010. 3) Compared with 2010, the simulation values of IWD in 2030 for wet year (P=25%), normal year (P=50%) and dry year (P=75%) increased by 1.08&times;10&lt;sup&gt;-8&lt;/sup&gt;, 1.29&times;10&lt;sup&gt;-8&lt;/sup&gt; and 1.21&times;10&lt;sup&gt;-8&lt;/sup&gt; m&lt;sup&gt;3&lt;/sup&gt; respectively, meanwhile the corresponding values of WSDBI increased by 14.46%, 11.70% and 9.06% respectively. The simulation indicated that the IWD and WSDBI increased dramatically under the synthetic action of meteorological factors in future. The supply could not meet the demands except wet years and the situation could be worse over the time, so effective measures should be taken in water resource and agriculture planning and management. This research can provide the reference for assessing the effect of climate change on agricultural water supply and demand in the irrigation district. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Climate change
Controlled terms:Agricultural runoff - Agriculture - Animation - Atmospheric humidity - Climate models - Continuous time systems - Crops - Economics - Errors - Groundwater  - Irrigation - Models - Reservoirs (water) - Runoff - Soil moisture - Surface waters - Water - Water resources - Water supply - Wind
Uncontrolled terms:Climate change scenarios - Food and agriculture organizations - Irrigation districts - Penman-Monteith equations - Reference crop evapotranspirations - STELLA - Water resource simulation - Water supply and demands
Classification code:441.2 Reservoirs - 443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 921 Mathematics - 961 Systems Science - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.06.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 5>

Accession number:20151700790299
Title:Design and laboratory test of control system for depth of furrow opening
Authors:Zhao, Jinhui (1); Liu, Lijing (2); Yang, Xuejun (2); Liu, Zhongjun (2); Tang, Jingxuan (2)
Author affiliation:(1) Chinese Academy of Agricultural Mechanization Sciences, Beijing, China; (2) Modern Agricultural Equipment Co. Ltd., Beijing, China; (3) Collaborative Innovation Center for Southern Grain and Oil Crop, Changsha, China; (4) National Engineering Laboratory for Agricultural Production Machinery and Equipment, Beijing, China
Corresponding author:Yang, Xuejun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:35-41
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Seeding depth is one of the indicators required by agricultural seeding technology. Seeding depth too large, too small or not consistent will cause low germination rate, slow seedling growth and other problems. It will affect late crop growth and finally reduce yield. In China, conventional tillage is widely used. But with the development of modern agricultural science and technology, the quality of soil in conventional tillage can not meet the requirements of the crop growth. Under the circumstances, conservation tillage arises in china, but the residues on surface of conservation tillage and the surface roughness is larger than conventional tillage. So working depth control is one of the keys for planter design. In order to control working depth constantly, profiling mechanism was adopted in planter for furrow opener, which was one of the most important ways to control working depth. Profiling mechanism mainly included whole profile modeling and unit profile modeling, of which whole profile modeling was simple, but the stability of its working depth was poorer. So whole profile modeling and unit profile modeling were adopted in most planter to keep working depth constantly. At present, the passive regulating mode was more used to control working depth in domestic, such as adjusting spring and parallelogram linkage. In other countries, in order to control working depth, besides the passive regulating mode, the active regulating mode was also adopted, which was controlled by electro-hydraulic technology and could realize the accurate control of working depth. Therefore, in order to improve the stability of no-till planter seeding depth, a depth of furrow opening control system was designed. The system included a surface height detection mechanism, four-connecting-rod profiling mechanism, PLC control system and hydraulic system. In the system, working depth was controlled by feedback and synchronization of profiling in real-time, the surface height by checking could reach 200 mm, and the capacity of profile modeling was 370 mm. In hydraulic system, through analyzing the work load and the speed of the system, it was determined that the rated system pressure was 10 MPa and the rated flow was 40 L/min. The average speeds of rise and fall of furrow opener were 78.7 and 102.8 mm/s, respectively. Through various tests on the depth control system, the working parameters of the control system were obtained. The system response time was 0.12 s, and working depth stability was more than 90%. In the speed of 5 km/h and working depths of 30, 50 and 70 mm, the stabilities of working depth were 90.98%, 91.45% and 92.32%, respectively, and the measurement error of the system was less than or equal to 0.54%. Therefore, it can meet the requirements of the standard on working depth stability. The research of the depth of furrow opening control system provides the reference for designing planter and understanding its furrow opening depth control mechanism. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Depth profiling
Controlled terms:Agricultural machinery - Agriculture - Control systems - Crops - Design - Hydraulic equipment - Hydraulic machinery - Machine design - Machinery - Seed  - Soil conservation - Stability - Surface roughness - System stability
Uncontrolled terms:Agricultural science and technologies - Agriculture machinery - Conservation tillage - Conventional tillage - Depth of furrow opening - Opening control system - Planter - System response time
Classification code:408 Structural Design - 601 Mechanical Design - 632.2 Hydraulic Equipment and Machinery - 731.1 Control Systems - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.06.005
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 6>

Accession number:20151700790306
Title:Optimization and experiment on piston motion law of four-stroke free-piston engine
Authors:Lin, Jiming (1); Xu, Zhaoping (2); Yan, Hao (2)
Author affiliation:(1) College of Mechanical Engineering and Automation, Huaqiao University, Xiamen, China; (2) School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, China
Corresponding author:Lin, Jiming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:82-88
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The free-piston engine has an advantage of changeable piston motion trajectory because of its lack of mechanical constraint. The motion law of a four-stroke ignited free-piston engine was studied in order to improve the efficiency of the system. Based on analyzing the working principle of the system and setting boundary constraints and path constraints of the system, an optimized model of the piston motion was established. The working cycle of the free-piston engine was composed of intake, compression, combustion, expansion and exhaust phases. Based on the characteristics of separate phase of the piston motion, a trajectory optimal method called gauss pseudospectral method (GPM) was used to separate the states and control variables. In this method, the piston position, the piston velocity, the in-cylinder gas pressure and the in-cylinder gas temperature were set as the state variables and the electromagnetic forces were set as the control variables. Then the optimal problem of piston motion was discretized to nonlinear programming problem. Then the nonlinear programming problem was solved by the sequential quadratic programming method (SQP). Furthermore, the parameters of the 462 engines were taken as the computing parameters. The fuel used in the simulation was gasoline. The simulation results showed that by adjusting the separate electromagnetic force and optimizing the piston position and velocity curves, the output work increased while the heat-transfer loss reduced with the rapid piston motion. It indicated that the efficiency reached as high as 45.3% in the simulation. During the compression process, the applied time of the optimized electromagnetic force was delayed compared with the original. And the time spent in the optimized compression process was shorter than the original. During the early expansion process,the optimized amplitude of the electromagnetic force was bigger than the original, which made the in-cylinder combustion close to constant volume combustion and the gas pressure and temperature increase quickly. During the middle expansion process, the electromagnetic force was not applied, which made the piston move fast and avoid more losses of heat transfer under the condition of high temperature and high pressure. During the late expansion process, the big electromagnetic force was applied in order to meet the target expansion length. Then comparison experiments of different piston trajectories were studied under the natural aspirate. The intake air pressure was 0.1 MPa, the temperature was 303 K and the excess air coefficient was 1.05. The results were derived from repeat experiments, which validated that the optimal method was feasible and valid. The in-cylinder peak pressure had a notable increase when the electromagnetic forces were applied by separate phase. The output electrical efficiency reached 31.2% and the system performance was remarkably improved. The output electric power had a small increase, because the cycle period was extended. As a result, the proposed optimization method of the piston motion law has an important significance for the system development. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Engine pistons
Controlled terms:Air intakes - Atmospheric pressure - Combustion - Efficiency - Engines - Free piston engines - Heat transfer - Models - Nonlinear programming - Optimization  - Pistons - Quadratic programming - Separation - Trajectories
Uncontrolled terms:Constant-volume combustions - Excess air coefficient - Free piston - Gauss pseudo-spectral methods - High temperature and high pressure - Motion law - Nonlinear programming problem - Sequential Quadratic Programming method
Classification code:404.1 Military Engineering - 443.1 Atmospheric Properties - 521.1 Fuel Combustion - 612 Engines - 631.1 Fluid Flow, General - 641.2 Heat Transfer - 802.3 Chemical Operations - 902.1 Engineering Graphics - 913.1 Production Engineering - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.06.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 7>

Accession number:20151700790300
Title:Dynamic simulation and high-speed photography experiment on corn-ear husking
Authors:Zhu, Zhongxiang (1); Yue, Xiaowei (1); Du, Yuefeng (1); Song, Zhenghe (1); Mao, Enrong (1); Wang, Bo (2)
Author affiliation:(1) Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment, China Agricultural University, Beijing, China; (2) Shandong Changlin Group Agricultural Equipment Co. LTD, Linshu, China
Corresponding author:Mao, Enrong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:42-48
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The moisture content of corn kernel is generally 25%-40% when corn ear is harvested in China, which makes it not suitable for using direct way of threshing and harvesting. As an important part of harvesting, corn ear husking plays a great role in the harvest performance. At present, research on the performance of corn ear husker is commonly implemented by field experiments and bench tests. However, these approaches are restricted by the various kinds of corn and the shortage of harvesting time. Therefore, there are limitations on the test results. To deal with the problems mentioned above, a method combining theory analysis, virtual prototyping technology with high-speed photography was proposed in this paper to study the motion pattern of the corn ear on the husking device. First of all, to obtain the main influence factors of husking rate, efficiency and damage rate, the force and movement of corn ear in husking mechanism was analyzed in theory. Secondly, the three-dimensional (3D) model of husking mechanism was established using 3D design software, and then the 3D model was imported to ANSYS/LS-DYNA. After that the finite element model of corn ear and corn husker was set up by setting the material model and adding constraint and load. The velocity of corn ear in the direction of husking roller, the angular speed of corn ear around its own axis and the force of corn ear corresponding to the performance of the corn husker, were obtained by simulation analysis. The simulation results showed that the movement speed of corn ear along husking roller rose from 0.2 to 0.4 m/s with the increase of husking roller rotating speed; the angular velocity of corn ear ranged from 0 to 15 rad/s when the rotating speed of husking roller increased from 350 to 550 r/min; meanwhile, the force which was applied to corn ear increased and showed strong fluctuations, and the maximum stresses under three kinds of working conditions were about 11.9, 14.5 and 16.3 N, respectively. Finally, the husking test bench was built in the basis of the 3D model. The husking experiment was carried out with different rotating speeds of husking roller using high-speed photography. The test bench was made up of base frame, husking device, transmission mechanism, variable frequency motor (rated power of 3 kw), frequency converter, NI National Instruments data acquisition card, computer and high-speed photography (Phantom v9.1). The test condition was mainly consistent with the simulation condition. In order to avoid the influence of different sizes of corn ear, corn ear in the experiment was similar to that in the simulation in length and diameter size. At the same time, for reducing the influence of accidental factors on test results, the experiment was carried out three times. Taking the actual velocity and acceleration of corn ear in the direction of husking roller as validation arguments, the simulation data were compared with the high-speed photography test data. It was found that the simulation results agreed well with the actual results, which verified the validity and accuracy of the simulation model. The result also indicates that the simulation model could be a better alternative to the physical test, which can reduce the development cycle and the number of physical prototype test. The research output will play a significant role in carrying out the optimization design of the corn husker and provide a new method to develop a new husking mechanism. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:High speed photography
Controlled terms:Accidents - Agriculture - Angular velocity - Computer simulation - Crops - Data acquisition - Finite element method - Harvesting - Kinematics - Machinery  - Photography - Rollers (machine components) - Rotating machinery - Speed - Virtual prototyping
Uncontrolled terms:Agriculture machinery - Combining theory analysis - Corn-ear - Husking - Husking device - Three dimensional (3-D) modeling - Variable frequency motors - Virtual prototyping technologies
Classification code:601 Mechanical Design - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 742.1 Photography - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 914.1 Accidents and Accident Prevention - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.06.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 8>

Accession number:20151700790308
Title:Simultaneous optimization design of vehicle chassis integrated control system based on particle swarm optimization algorithm
Authors:Liu, Xiangui (1); Chen, Wuwei (2); Luo, Shanming (1); Zhong, Ming'en (1)
Author affiliation:(1) School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China; (2) School of Mechanical and Automobile Engineering, Hefei University of Technology, Hefei, China
Corresponding author:Liu, Xiangui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:97-104
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the application of active control technology in vehicle, the performances of vehicle such as riding comfort, active safety and handling stability were greatly improved in recent years. However, most of these control systems were aimed to improve individual performance of vehicle respectively. In fact, the improvement of the overall vehicle dynamics performance not only depends on the cooperative work among these various control subsystems but also depends on the coupling interferences of the mechanical structure and control system of vehicle in the running process. In order to remove the coupling interferences between the mechanical structure and control system of vehicle chassis system and to further enhance the overall performance of vehicle, the method of simultaneous optimization of mechanical structure and controller parameters of vehicle chassis system based on Particle Swarm Optimization Algorithm is presented in this paper. According to the fundamental principle of vehicle dynamics, a half car mode of active suspension system and anti-lock braking systems established at first. Then the linear quadratic gauss controller of the active suspension system and sliding mode controller of anti-lock braking system are designed. Taking controllers designed for active suspension system and anti-lock braking system as bottom controllers, the upper coordinated control logic of the systems is put forward and the upper PID coordinated controller is designed on the basis of analyzing the coupling conflict between active suspension system and anti-lock braking system. Finally, a Particle Swarm Optimization Algorithm was adopted for simultaneous optimization of mechanical structure and controller parameters of vehicle chassis integrated control system, because the traditional design method of a vehicle system is always to design control parameters following structure parameters and it can not obtain the global optimal performances for the system. In order to verify the effectiveness of the algorithm, the simultaneous optimization program is developed based on Particle Swarm Optimization Algorithm in MATLAB environment while the mechanical structure and control parameters of chassis control system are set as optimization variables and the overall vehicle dynamics performance is set as objective function. Simulation result shows that the pitching angular acceleration of vehicle is reduced and vehicle riding comfort performance is improved after optimized. Braking distance and dynamic load of front and rear wheels of vehicle are also reduced significantly which indicating vehicle active safety is improved dramatically. The vehicle road test was also carried out based on integrated controller is development of anti-lock braking system and active suspension system using ARM7 when vehicle speed is 40 km/h under braking condition. The road test also shows that the dynamic load of front and rear wheels of vehicle are reduced by 34.20% and 34.10%, braking time and braking distance of vehicle were reduced by 2.31% and 4.50% respectively, the response of vehicle pitching angular acceleration at braking condition is decreased by 15.10% after optimized, and both vehicle active safety and riding comfort are improved at different levels.. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Anti-lock braking systems
Controlled terms:Acceleration - Active suspension systems - Airships - Algorithms - Automobile suspensions - Braking - Chassis - Control systems - Controllers - Design  - Dynamic loads - Dynamics - Experiments - Integrated control - Locks (fasteners) - MATLAB - Optimization - Parameter estimation - Particle swarm optimization (PSO) - Roads and streets  - Shape optimization - Sliding mode control - Structural optimization - Suspensions (components) - Vehicle performance - Vehicle wheels - Vehicles - Wheels
Uncontrolled terms:Active control technologies - Chassis control systems - Co-ordinated control - Coordinated controllers - Global optimal performance - Particle swarm optimization algorithm - Simultaneous optimization - Sliding mode controller
Classification code:406.2 Roads and Streets - 408 Structural Design - 408.1 Structural Design, General - 432 Highway Transportation - 601.2 Machine Components - 601.3 Mechanisms - 602 Mechanical Drives and Transmissions - 632.1 Hydraulics - 652.5 Balloons and Gliders - 663.1 Heavy Duty Motor Vehicles - 663.2 Heavy Duty Motor Vehicle Components - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 732.1 Control Equipment - 901.3 Engineering Research - 921 Mathematics - 921.5 Optimization Techniques - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.06.014
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 9>

Accession number:20151700790324
Title:Comparison of calculation methods for wind shear exponent in complex terrain at altitude above 1000 meters
Authors:Deng, Shengxiang (1); Chen, Gang (1); Chen, Guibao (1)
Author affiliation:(1) School of Energy Science and Engineering, Central South University, Changsha, China; (2) Key Laboratory of Renewable Energy Electric-Technology of Hunan Province, Changsha University of Science &amp; Technology, Changsha, China
Corresponding author:Deng, Shengxiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:218-222
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Among all uncertainty factors affecting the wind power assessment at a site, wind speed extrapolation is probably one of the most critical, particularly if considering the increasing of the size of modern multi-Megawatt wind turbines, and therefore of their hub height. Wind measurements are generally performed below wind turbine hub heights due to avoiding higher measurement and tower costs. In order to obtain the wind speed at the hub height of the turbine, the measurements are extrapolated, assuming that the wind shear exponent is constant. So it is important to calculate the wind shear exponent accurately. The wind shear exponents of different areas are different because of the influence of roughness. What's more, the wind shear exponent may change in the same area at different time. Therefore, to obtain an accurate value of the wind shear exponent in a certain area at a certain time, only the local wind speed data can be used to calculate it. Here, the situation is set as some complex terrain above 1000 meters. There are many different methods to calculate the wind shear exponent, and in this paper, four different methods are chosen, which are: the Panofsky and Dutton (PD) method, annual average wind speed method, wind profile method and all of the data method. The PD method is based on Monin-Obukhov similarity theory, and Panofsky and Dutton proposed the semiempirical formulation to estimate the wind shear exponent as a function of stability and roughness. First of all, according to the classification method of Pasquill, the stability can be calculated. Then, choose the right formulation based on the value of stability to calculate the wind shear exponent. Method 2 and 4 use the wind speed and the exponential formula to calculate wind shear exponent. Method 3 uses wind profile fitting to calculate the wind shear exponent. Choose the example of actual wind speed data within a complete year on three wind measurement heights at an anemometer tower of some complex terrain above 1000 meters in Hunan Province. Four different results of the wind shear exponent can be calculated. Thus, the wind speed at the known height can be extrapolated through the power law, then by comparing the extrapolated value and actual value, the methods which produce smaller errors can be chosen. The results show that due to the impact of ground roughness and the topography, wind shear exponents are different not only in different areas, but also when calculated by different methods even in the same area at the same time. And the results calculated by the PD method and the annual average wind speed method are more accurate than the all of the data method and wind profile method. The PD method is more accurate than the annual average wind speed method, and the results are very close. The result calculated by using all of the data is better than using the wind profile, while the wind profile method is the most accurate in flat topography. Therefore, these methods should be comprehensively used to choose the most accurate wind shear exponent. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Wind
Controlled terms:Applications - Calculations - Extrapolation - Landforms - Speed - Wind effects - Wind power - Wind turbines
Uncontrolled terms:Complex terrains - PD methods - Power-law - Wind profiles - Wind shears
Classification code:443.1 Atmospheric Properties - 451.2 Air Pollution Control - 481.1 Geology - 615.8 Wind Power (Before 1993, use code 611 ) - 721 Computer Circuits and Logic Elements - 723 Computer Software, Data Handling and Applications - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.06.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 10>

Accession number:20151700790335
Title:Aerodynamic characteristics of lotus seed mixtures and test on pneumatic separating device for lotus seed kernel and contaminants
Authors:Ma, Qiucheng (1); Lu, Ange (1); Gao, Lianxing (2); Wang, Zhenggen (1); Tan, Zehua (1); Li, Xianqi (2)
Author affiliation:(1) School of Mechanical Engineering, Xiangtan University, Xiangtan, China; (2) College of Engineering, Shenyang Agricultural University, Shenyang, China
Corresponding author:Ma, Qiucheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:297-303
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Lotus seed hulling is the first process in rough processing, which is removing the tough shell that covers lotus seed kernel. Generally, it can utilize the mechanical processing method. After processing, the mixtures of lotus seed kernel, lotus seed shell, kernel debris and a small amount of imperfectly shelled lotus seed can be yielded. Because the lotus seed shell, kernel debris and other contaminants are easy to block the entrance of next working position (kernel coring process), a separating process for shell and kernel after the hulling process would be necessary and crucial. Pneumatic separating method is commonly used in separating equipment in agriculture products. However, there is limited academic research on pneumatic separating technology for lotus seed mixtures. In this paper, a negative pressure, pneumatic separating method was proposed to separate lotus seed kernel and shell. Firstly, the density parameter, the moisture content and the shape parameter of lotus seed mixture constituent were measured. The test results showed that the density parameters of lotus seed kernel, lotus seed, shell and kernel debris were 1 080, 1 042, 1 210 and 1 163 kg/m&lt;sup&gt;3&lt;/sup&gt; respectively, the moisture content of lotus seed kernel, unhulled lotus seed (with imperfectly shelled lotus seed), shell and kernel debris were 7.35%, 3.91%, 12.36% and 12.45% respectively. The shape of lotus seed kernel, lotus seed and the imperfectly shelled lotus seed could be abstracted as the spherical, and the grain diameter could be represented by maximum cross section. Secondly, the theoretical analysis and aerodynamics characteristics test of lotus seed mixtures were carried out. The results showed that the drag coefficient of lotus seed mixtures was within the Newton area, and the drag coefficient was 0.44. The ranges of theoretical suspension velocity of lotus seed kernel, lotus seed and imperfectly shelled lotus seed calculated were 14.134-16.115, 14.745-17.327 and 15.763-17.623 m/s respectively. The ranges of actual suspension velocity of lotus seed kernel, lotus seed shell, kernel debris, lotus seed and lotus seed which is shelled imperfectly were 11.230-14.680, 2.511-4.891, 6.505-7.865, 12.573-16.289 and 12.533-16.017 m/s respectively. The range of suitable air flow velocity for separation was confirmed as 7.865-11.23 m/s. There was no overlaps between the ranges of suspension velocity of lotus seed kernel and contaminants such as kernel debris and shell. Therefore, it's suitable to use pneumatic separating method to separate lotus seed kernel and contaminants. According to the comparison of test results and theoretical calculation results, the shape correction coefficient of products which was used in theoretical calculation was corrected. The ranges of shape correction coefficient of lotus seed kernel, lotus seed and lotus seed which was shelled imperfectly were 1.46-1.76, 1.29-1.66, 1.65-1.81 respectively. Thirdly, the negative pressure, pneumatic separating device for lotus seed kernel and shell, which matched the lotus seed huller with multiple working positions, had been designed and manufactured. This device consists of centrifugal fan, separation channel, cyclone separator, frame and inverter. Single factor test and orthogonal test were carried out. The effect law of factors on test indices was studied through the single factor test, and the influential factor and level were identified. The key parameters of separating processing of the device, which was identified and corrected by the orthogonal test, were as follows: inclination angel of inlet tube was 60&deg;, inclination angle of separation channel was 35&deg;, air flow velocity of separation channel was 7.881 m/s, length of inlet tube was 220 mm, and feed rate was 6 grains every time. Verification test on the optimum scheme was carried out and the result showed that the separating ratio could reach 98.283%. The result of this study in this paper can be taken as theoretical basis and reference for the research and development on separating equipment for lotus seed kernel and contaminants. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Testing
Controlled terms:Aerodynamics - Air - Contamination - Debris - Drag - Drag coefficient - Equipment - Fans - Flow velocity - Grain (agricultural product)  - Inlet flow - Mixtures - Moisture - Moisture determination - Optimization - Pneumatics - Processing - Separation - Shells (structures) - Tubes (components)  - Velocity
Uncontrolled terms:Aerodynamic characteristics - Lotus seeds - Mechanical processing - Mixed materials - Pneumatic separations - Research and development - Suspension velocity - Theoretical calculations
Classification code:408.2 Structural Members and Shapes - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 616.1 Heat Exchange Equipment and Components - 618.3 Blowers and Fans - 631 Fluid Flow - 631.1 Fluid Flow, General - 632.3 Pneumatics - 651.1 Aerodynamics, General - 714.2 Semiconductor Devices and Integrated Circuits - 801.4 Physical Chemistry - 802.3 Chemical Operations - 804 Chemical Products Generally - 821.4 Agricultural Products - 821.5 Agricultural Wastes - 901 Engineering Profession - 913.4 Manufacturing - 921.5 Optimization Techniques - 931.1 Mechanics - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2015.06.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 11>

Accession number:20151700790319
Title:Wind erosion prediction based on soil particle size characteristics and strong wind days
Authors:Meng, Zhongju (1); Gao, Yong (1); Wang, Huailiang (2); Ren, Xiaomeng (3)
Author affiliation:(1) Wind Erosion Key Laboratory of Central and Local Government, Ecological and Environmental College, Inner Mongolia Agricultural University, Huhhot, China; (2) HeBei Extenrion and Experiment Center For Water Technology, Shijiazhuang, China; (3) Meteorological Sciences Institute of Inner Mongolia, Huhhot, China
Corresponding author:Gao, Yong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:186-192
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wind erosion is a severe environmental problem in arid, semi-arid region of the world, and it occurs frequently in northwest part of China and leads to soil degradation. Inner Mongolia is located in Northern China as a very important ecological barrier with various of landforms including desert, grassland and forest. In order to quantify the regional soil degradation degree and predict potential wind erosion risk, 5 typical sites of wind erosion, i.e. Jilantai Gebi, Ulan Buh desert, Mu Us sandy land, Wuchuan farmland and Xilamuren Grassland were chosen as experimental sites. Based on digital image technology, the pictures of these 5 sites were taken using Canon EF24-105 mm, and the grey scale information of the images was analyzed by Erdas-Image software; an area compensation equation was established to obtain the actual particle size, and then the residual amount of coarse surface was calculated. On the basis of wind erosion estimation model of Inner Mongolia Houshan Area, surface un-erodible particle (&gt;0.84 mm) was chosen as key indicator combined with local strong wind days, and then an applicable soil erosion potential risk exponential equation was established and the soil potential wind erosion risk was evaluated. The results suggested that wind erosion was a physical process of erodible particle loss, as a result, serious degradation surface kept a high content of coarse grains. Jilantai Gebi and surface around shrub has experienced severe wind erosion, for there existed a large proportion of coarse particles, indicating that the area was in late period of the coarsening process with strong anti-erosion ability, and the average anti-erosion indices were 91.40% and 81.40% respectively. Soil particles of Ulan Buh Desert showed obvious spatial heterogeneous characteristics due to the effect of few shrub communities, and the soil anti-wind erosion ability was Artemisia xerophytica Krasch plot &gt; Artemisia arenaria DC.plot &gt; Nitraria tangutorum plot. In Mu Us Sandy land, aeolian material was the main component and the vegetation coverage was less than 5%; the area was dominated by barchan, and soil particle content showed intensive spatial heterogeneity with variation coefficient of 37%, which was mainly caused by different position of sand dunes. The anti-erosion index was only 13.40% indicating that wind erosion occurred easily in this site. In terms of typical farming land, surface fine material was maintained at a high level due to frequent plow activities, which led to a lower anti-erosion index of 29.40%; on the contrary, due to long-term wind erosion, much fine particle of abandoned farmland got lost, at last soil surface was covered by coarsening grains mostly, and the anti-wind erosion index was greater than that of farming land. Soil particle turned to show obvious spatial heterogeneity in deserted grassland, un-erodible particle decreased along with the distance far away from the tourist area, and the regional average anti-erosion index was 45.20%. Poor soil and strong wind were the main factors contributing to the sand dust in the tested areas. Based on the potential wind erosion risk equation, Jilantai Gebi was in the lowest potential wind erosion risk among the 5 sites, and it showed that soil surface reached a new stable balance. The potential wind erosion risk of shrub communities in Ulan Buh Desert was contrary to anti-wind erosion ability. However, based on the analysis effect, potential wind erosion risk was farmland &gt; abandoned land &gt; shift sand dune, which seemed to be a little bit abnormal. This was because farmland surface was looser than others, and there were different strong wind days among these areas. As a simple prediction equation, it was applicable in different sites of arid areas, especially in small scale predication, as was shown in the results. Farmland and grassland were in higher wind erosion risk and was becoming a new sand source, and human disturbance played an important role in this process. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Erosion
Controlled terms:Arid regions - Farms - Forecasting - Geosynthetic materials - Land use - Landforms - Particle size - Risk assessment - Risk perception - Sand  - Soils - Wind
Uncontrolled terms:Anti winds - Digital image technology - Erodibility - Heterogeneous characteristic - Numerical images - Soil erosion potential - Wind erosion predictions - Wind erosions
Classification code:403 Urban and Regional Planning and Development - 407 Maritime and Port Structures; Rivers and Other Waterways - 443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 922.1 Probability Theory - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.06.025
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 12>

Accession number:20151700790321
Title:Forecasting wheat aphid with remote sensing based on relevance vector machine
Authors:Tang, Cuicui (1); Huang, Wenjiang (1); Luo, Juhua (4); Liang, Dong (1); Zhao, Jinling (1); Huang, Linsheng (1)
Author affiliation:(1) Key Laboratory of Intelligent Computing &amp; Signal Processing, Ministry of Education, Anhui University, Hefei, China; (2) School of Electronic and Information Engineering, Anhui University, Hefei, China; (3) Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China; (4) Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
Corresponding author:Huang, Wenjiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:201-207
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The prevalence of aphid in winter wheat field has a significant impact on the production of winter wheat. An effective and timely forewarning of the scope and severity of the disease at a regional scale will not only reduce yield losses but also alert the stakeholders to take effective preventive measures. Forecasting aphid occurrence with Remote Sensing has great advantages over traditional methods and meteorological data, such as lower cost, simpler operation, more real-time and higher resolution. Chinese HJ-1A/1B data which have a high revisit frequency (&lt;4 days) as well as 30 m spatial resolution, in addition to a full band set covering visible, near-infrared, short-wave infrared, mid-infrared and thermal infrared spectral ranges, which thus significantly expand opportunities of remote sensing application in predicting crop diseases and pest. According to the literature research and field investigation found that apart from crops growth status was closely related to wheat aphid occurrence, development, and dispersal, the environmental conditions of field, such as temperature and humidity,also have a certain impact on its susceptibility to pest. In this study, we retrieve two parts of information from multi-temporal HJ-CCD optical data and HJ-IRS thermal infrared data, including Ratio vegetation index (RVI) and Normalized Difference Vegetation Index (NDVI) representing grow status of wheat, Perpendicular Drought Index (PDI) and Land Surface Temperature (LST) that represent the environmental characteristics. An independent t-test analysis was used to test the difference between pest and healthy samples based on calibration data. Those vegetation and environmental factors that failed to show a statistical significant (p-value &lt;0.001) were eliminated. Five remotely sensed variables (NDVI-T1, RVI-T1, LST-T1, LST-T2, and PDI-T2) were identified as optimal explanatory variables for developing the pest forecasting model. The relevance vector machine (RVM) model was established to predict aphid occurrence of filling stage of wheat in the Beijing suburbs, which is a machine learning algorithm and commonly used to improve business decisions, detect disease, and forecast weather credit to its superior learning ability when on a small datasets. The results obtained from the RVM model are compared with prediction models developed using logistic regression (LR) and support vector machine (SVM) techniques. Goodness-of-fit values of the calibrated models were evaluated through the p-value of Spearman test. In addition, the association between observed outcome of pest occurrence and predicted outcome of pest occurrence was evaluated by using three different measures: Somers'D, Goodman-Kruskal gamma, and Kendall's Tau-c. The RVM model produced a higher Spearman p-value than that the LR model and the SVM model did, indicating that the RVM model had a better performance to predict the aphid than the other two models. Moreover, the values of Somers'D, Goodman-Kruskal Gamma, and Kendall's Tau-c were all higher with the RVM model than those with the remaining model, which further demonstrated the better performance of the RVM model on the training datasets. To further evaluate the difference of performances of the three types of models, we obtain accuracy of models respectively based on validation samples. The results showed that: accuracy by using RVM algorithm is the highest among the three methods, with lower omission and commission than the other two algorithms. Furthermore, the overall prediction accuracy and the kappa coefficient of the RVM model are 87.5%, 0.71respectively, have shown better performance over the SVM model (79.2%,0.55) and the LR model (75.0%,0.44). Additionally, the RVM model needs less computation work and faster prediction speed. These results revealed that the RVM model with high accuracy level and prediction efficiency is much more favorable in forecast the pest occurrence at a regional scale effective and timely. It indicated that the result of this research can be used in different regions. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Weather forecasting
Controlled terms:Artificial intelligence - Atmospheric temperature - Crops - Forecasting - Infrared devices - Infrared radiation - Learning algorithms - Learning systems - Meteorology - Regression analysis  - Remote sensing - Satellite imagery - Support vector machines - Vectors - Vegetation
Uncontrolled terms:Environmental characteristic - Logistic regressions - Normalized difference vegetation index - Perpendicular drought indices (PDI) - Relevance Vector Machine - Support vector machine techniques - Thermal infrared spectral range - Wheat aphid
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 731.1 Control Systems - 741.1 Light/Optics - 741.3 Optical Devices and Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921.1 Algebra - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.06.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 13>

Accession number:20151700790322
Title:Application of cabin intelligent compartments based on expert system in fishing vessel
Authors:Zheng, Jianli (1); Liu, Ping (1); Zhang, Zhuli (1); Zhang, Jingdang (2)
Author affiliation:(1) Key laboratory of Fishery Equipment and Engineering, Fishery Machinery and Instrument Research Institute, Chinese Academy of Fishery Sciences, Shanghai, China; (2) College of Shipbuilding Engineering, Harbin Engineering University, Harbin, China
Corresponding author:Zhang, Zhuli
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:208-212
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The ship compartment partition and arrangement is the constantly repetitive work with a broad range of knowledge. Most of the previous ways are using man-machine interaction provided by software, complete the ship compartments partition by repeated design and stepwise refinement, or build equipment graphics library based on menu management through secondary development of some aided softwares, and finish the ship compartment partition by calling the graphics. Computer aid design/made (CAD/CAM) application has improved the design accuracy and contributed to improve the ship design and construction efficiency, but still these are try design methods. With the intelligent technology, expert system on ship compartment partition and arrangement design is established. Cabin intelligent design expert system based on parallel design method is a combined design process and evaluation process, and it unifies the knowledge engineering and computer aided software which is mainly based on the knowledge of the expert system, and the use of computer aided software realizes the intelligent ship design. This paper provides a theoretical basis for the solution of the main design parameters, laid a theoretical and technical foundation for seeking a new way of ship compartment arrangement design. Due to too much repetitive work, wide range of knowledge, and rules and regulations in design process being often ignored by designer, this paper puts forward an intelligent design method of fishing vessel cabin compartments, explores the cabin intelligent design method based on expert system applied in the design of the fishing vessel, provides a design method for a ship compartment design. In this paper, the overview of the development and its application in shipbuilding is analyzed, and domestic and international situation and development trend of intelligent design technology system as well as the basic theory and key technology of intelligent design such as composition, acquisition, representation and usage of knowledge are studied. According to the design features of ship compartment partition and arrangement, using expert system to solve such problems is proposed. And the theory and application genetic algorithm is introduced. Knowledge base and reasoning systems on ship compartment partition and arrangement is built. And compartments channel design is optimized using genetic algorithm. CATIA V5 software is secondary development in this system of knowledge engineering module. The overall structure and basic process framework of intelligent design is built according to compartment design features, and knowledge-based intelligent design system of ship compartments partition is developed using VB (visual basic), which is then applied to a 49.5 m tuna fishing vessel design and its accuracy and practicability of the procedures is verified. The development of the program realizes that the less data is needed to input to promote the rapid modeling ability, make the compartment in the fishing rules satisfy the specification at the same time, and at least can shorten the whole ship design cycle by 5-10 working days. It provides the theory and technology reference for the intelligent design of fishing boats. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Computer aided design
Controlled terms:Airships - Algorithms - Computer aided software engineering - Computer software - Computer systems - Design - Expert systems - Fisheries - Fishing vessels - Genetic algorithms  - Knowledge based systems - Knowledge engineering - Shipbuilding - Ships
Uncontrolled terms:Cabin compartments - Computer aid designs - Intelligent design systems - Intelligent designs - Intelligent technology - Knowledge - Rules and regulations - Secondary development
Classification code:408 Structural Design - 471.5 Sea as Source of Minerals and Food - 652.5 Balloons and Gliders - 671 Naval Architecture - 672 Naval Vessels - 673.1 Shipbuilding - 674 Small Craft and Other Marine Craft - 723 Computer Software, Data Handling and Applications
DOI:10.3969/j.issn.1002-6819.2015.06.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 14>

Accession number:20151700790301
Title:Cottonseed particle motion Law in 3-DOF hybrid vibration screen surface
Authors:Wang, Chengjun (1); Liu, Qiong (2); Ma, Lzhong (3); Li, Long (2)
Author affiliation:(1) Mining Engineering Post-doctoral Mobile Station, Anhui University of Science and Technology, Huainan, China; (2) School of Mechanical Engineering, Anhui University of Science and Technology, Huainan, China; (3) School of Mechanical Engineering, Jiangsu University, Zhenjiang, China
Corresponding author:Wang, Chengjun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:49-56
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To further study and reveal material movement rule and penetrating screening mechanism on multidimensional vibrating screen as well as to design a hybrid vibrating screen of three degrees of freedom (3-DOF), the paper, based on topological structure theory in mechanism, has constructed a complete decoupling 3-DOF hybrid organization of 2PRRR-P(2R) as the main body of vibration mechanism in the 3-DOF hybrid vibrating screen and has designed an experiment prototype of the 3-DOF hybrid vibrating screen. The simulation test of screen movement on the screen surface was carried out and analyzed. Cotton seed particles of ellipsoid were taken as the typical materials. Movement rule of material particle group on the screen surface of the 3-DOF hybrid vibrating screen was analyzed. D-H transformation matrix was used to deduce motion trace equation on the screen surface. The kinematics simulation was carried out with ADAMS software, and the feasibility of the mechanism design has been verified. Based on the discrete element method, the paper used optimal selection of difficult ellipsoid cotton seed particles of ellipsoid that is difficult in screening in agricultural materials as the screening objects, and carried out simulation analysis on screening process of cotton seed particle group on the screen surface of the 3-DOF hybrid vibrating screen. In the simulation test, optimal screen size is 280 mm &times; 160 mm and contact model between cotton seeds and screen surface belongs to the Hertz model. Set in the rectangle form of 140 mm &times; 80 mm, particle factory produced 10 000 cotton seed particles and particle generation rate was 5, 000 per second. The simulation time was 8 s. In the experiment, reciprocating motions in Z, XZ and XYZ directions were respectively added on the screen surface. Based on truncation technique, the average values of three-coordinate in borderless particles collision were respectively extracted and the particle group displacement time curve on the screen surface was drawn. Simulation test results showed that when the screen surface vibrated in XYZ direction, three-direction displacement curve of cotton seeds displayed periodicity and the X and Y directions showed the larger throwing displacement. After 3.6 s, particles penetrating screening completed. When the screen surface vibrated in Z direction only, there was a small amount of displacement fluctuation in cotton seed particles in the X and Y directions. After 6.4 s of particles' penetrating screening, the average penetrating screening time increased by 77% compared with vibrating particles group on the screen surface in XYZ direction. When the screen surface vibrated in XZ direction, cotton seeds particles in X direction had the relatively great throwing displacement. After 5.1 s, particles' penetrating screening completed. The average penetrating screening time was shortened to 38% compared with particles group on screen surface in Z direction only. Average penetrating screening time increased by 43% compared with particles group vibration in XYZ direction on the screen surface. Simulation test results showed that the increase of freedom movement on the screen surface in X and Y directions could increase the particles group's throwing displacement in X and Y directions correspondingly, which was conducive to dispersing particles group on the screen surface, reducing average particles' penetrating screening time and improving the screening efficiency. The dispersion and efficiency of cottonseed particles on three translations of 3-DOF vibration screen surface was verified by testing in the multi-dimensional vibration screening test stand, and the test results were in agreement with the simulation. Research showed that 3-DOF hybrid vibrating screen could realize three-dimensional independent vibration along the X, Y and Z directions. The vibration parameters such as degrees of freedom of vibration, amplitude, frequency could be adjusted conveniently; 3-DOF vibration on the screen surface was conducive to dispersing particles materials on the screen surface and could significantly improve the screening efficiency. The paper provides the reference for further study on the multidimensional vibration principle and for prototype development of 3-DOF hybrid vibrating screen. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Hybrid materials
Controlled terms:Agriculture - Computer software - Cotton - Degrees of freedom (mechanics) - Dispersions - Efficiency - Equations of motion - Linear transformations - Machine design - Machinery  - Mechanics - Mechanisms - Oilseeds - Testing - Vibrating screens
Uncontrolled terms:3-DOF - Agriculture machinery - Particle groups - Three-dimensional Discrete Element Methods - Vibrations
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 601 Mechanical Design - 601.3 Mechanisms - 605.1 Small Tools, Powered - 712 Electronic and Thermionic Materials - 723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 913.1 Production Engineering - 921.3 Mathematical Transformations - 931.1 Mechanics - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 15>

Accession number:20151700790332
Title:Effect of magnetoelastic biosensors' size on sensitivity for detecting Salmonella typhimurium
Authors:Hu, Jing (1); Hu, Jiajia (1); Guntupalli, R. (2); Chin, Bryan A. (2)
Author affiliation:(1) Jiangsu Key Laboratory of Materials Surface Technology, School of Materials Science and Engineering, Changzhou University, Changzhou, China; (2) Food Detection and Safety Center, Department of Materials Engineering, Auburn University, Auburn; AL, United States
Corresponding author:Hu, Jing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:277-281
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mass-sensitive, magnetoelastic resonance sensors have a characteristic resonant frequency that can be determined by monitoring the magnetic flux emitted by the sensor in response to an applied time-varying magnetic field. This magnetostrictive platform has a unique advantage over conventional sensor platforms in that measurement is wireless and remote. In this study, antibody-based magnetoelastic (ME) biosensor specific to Salmonella typhimurium has been developed by immobilizing bio-recognition element onto the physical transducer. Rabbit polyclonal antibody, which was a protein called immunoglobulin related to immune system, was used as the bio-recognition. A magnetoelastic platform was served as the transducer, since it offered wireless or remote detecting, which was a unique advantage over conventional sensor platforms. Amorphous magnetostrictive alloy was mechanically polished using fine grit paper to reduce the thickness to 15 &micro;m for decreasing the initial mass, and magnetostrictive strips were made with different sizes using an auto controlled micro-dicing saw. Then the diced sensors were ultrasonically cleaned in methanol solution to remove grease and debris left by the dicing process. And antibody was immobilized on the magnetostrictive platform using Langmuir-Blodgett (LB) technique, in which seven mono layers containing antibody were transferred onto the magnetostrictive sensor surface using an LB film balance KSV 2200 LB. Due to the magnetoelastic nature of the amorphous magnetostrictive alloy, the sensor exhibited a physical resonance when it underwent a time-varying magnetic field, and a shift in resonance frequency of the magnetostrictive sensor depended only on the mass change when testing environmental parameters are invariable. In this study, the environment was kept constant, and the changes in the resonance frequency of biosensors attributing to the binding of Salmonella typhimurium were recorded by HP network analyzer 8751A over the testing period, and the binding was also confirmed by scanning electron microscopy (SEM) micrographs. According to the shift in resonance frequency due to the binding of Salmonella typhimurium, the binding density bound on the biosensor was calculated. In order to confirm the binding, up to ten different regions of each sensor surface were examined and photographed using SEM, the number of cells bound to the sensor surface was directly counted from the SEM images and statistically converted to an area density of bacteria attached to the sensor surface, and compared with that calculated from the shift in resonance frequency. The results showed that the developed magnetostrictive biosensors could be applied for detecting Salmonella typhimurium; there existed a detection limit, which was defined as the lowest concentration that could be sensitively detected, and it was found that the detection limit was closely related to the size of the biosensor, and the rule was that the smaller the size of the biosensor, the lower the detection limit. And the higher frequency shift could be obtained while detecting the same solution by using smaller size of biosensor. The detection limits of 5&times;10&lt;sup&gt;3&lt;/sup&gt;, 10&lt;sup&gt;5&lt;/sup&gt; and 10&lt;sup&gt;7&lt;/sup&gt; CFU/mL were obtained for the biosensors with the sizes of 2 mm&times;0.4 mm&times;15 &micro;m, 5 mm&times;1 mm&times;15 &micro;m and 25 mm&times;5 mm&times;15 &micro;m, respectively. Good agreement was obtained between the physical densities of bacterial cells obtained from SEM images and the theoretical densities calculated from the measured frequency shift, with less than 10% difference in between. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Biosensors
Controlled terms:Antibodies - Frequency shift keying - Langmuir Blodgett films - Magnetic fields - Magnetostrictive devices - Natural frequencies - Resonance - Salmonella - Scanning electron microscopy - Sensitivity analysis  - Transducers
Uncontrolled terms:Environmental parameter - Langmuir Blodgett techniques - Magnetostrictive alloys - Magnetostrictive material - Magnetostrictive sensors - Magnetostrictive strips - Salmonella typhimurium - Time-varying magnetic fields
Classification code:461.9 Biology - 461.9.1 Immunology - 701 Electricity and Magnetism - 701.2 Magnetism: Basic Concepts and Phenomena - 704 Electric Components and Equipment - 711.1 Electromagnetic Waves in Different Media - 714 Electronic Components and Tubes - 715 Electronic Equipment, General Purpose and Industrial - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 732 Control Devices - 741.1 Light/Optics - 801.4 Physical Chemistry - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.06.038
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 16>

Accession number:20151700790295
Title:Query about theory and technical properties of trace quantity irrigation
Authors:Zhang, Guoxiang (1); Zhao, Aiqin (2)
Author affiliation:(1) China Irrigation &amp; Drainage Technology Development Corporation, Beijing, China; (2) Postdoctoral Research Stations Chinese Academy of Agricultural Engineering, Beijing, China
Corresponding author:Zhao, Aiqin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:1-7
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In past few years, a new irrigation method is developed, which is trace quantity irrigation. Trace quantity irrigation is based on the capillary phenomena and membrane filtration technology, can completely solve the problem of emitter clogging and achieve the "self-adaptive irrigation" (water supply following crop demand), and has higher water utilization efficiency. In this study, we queried about theory and technical properties of trace quantity irrigation. The analysis showed that: 1) According to the basic characteristics of the capillary, and the actual condition of trace quantity irrigation emitters and low flow point-water source, the capillary force cannot be the basis for irrigation systems; 2) Soil water potential is not equivalent to negative pressure, the former is not yet be perceived by dripper outlet, and the "adaptive irrigation" that trace quantity irrigation realizes the match of crop water requirement with irrigation amount was still lack of evidence; 3) It was hasty to draw the conclusion that filter membranes and fiber emitter channel cannot be clogged for a long time; 4) As a subsurface irrigation method, the effects of water-saving, anti-clogging, and yield-increasing of trace quantity irrigation should be confirmed in a long term experiment (at least 4-5 years based on experience); and 5) According to the common perception of international micro-irrigation field, the irrigation product with flow not greater than 12 L/h is referred to as the dripper, and thus the trace quantity irrigation should be attributed to subsurface drip irrigation with the dripper of membrane and fiber bundle structure. It is no double that the trace quantity irrigation is a good try for the lower flow water supply and membrane filtration in subsurface irrigation systems. However, the statements that the trace quantity irrigation can achieve the "self-adaptive irrigation", which will revise the field of crop cultivation and water conservancy of agricultural field, and lead the next round of innovations for irrigation technique are questionable. In summary, the trace quantity irrigation as a technique is of many shortcomings in the theory and techniques, and has a high risk of failure. This technique is currently in a stage of principle exploring. The urgency is to clarify its theory and verify it in small areas. The technique is still far from pilot production and large-area promotion. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:7
Main heading:Irrigation
Controlled terms:Algorithms - Crops - Cultivation - Filtration - Membrane technology - Membranes - Microfiltration - Pilot plants - Soil moisture - Soils  - Subirrigation - Water conservation - Water filtration - Water management - Water supply
Uncontrolled terms:Basic characteristics - Capillary force - Crop water requirements - Long-term experiments - Soil water potential - Subsurface drip irrigation - Trace quantity - Water - savings
Classification code:402.1 Industrial and Agricultural Buildings - 444 Water Resources - 446 Waterworks - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 723 Computer Software, Data Handling and Applications - 802.3 Chemical Operations - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921 Mathematics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 17>

Accession number:20151700790331
Title:Undertaking industrial land spatial suitability evaluation based on hierarchical fuzzy matter element model
Authors:Fan, Shuping (1); Liu, Youzhao (1); Zhang, Hongmei (2); Hou, Changli (2); Chang, Dongyin (2)
Author affiliation:(1) College of Public Administration, Nanjing Agricultural University, Nanjing, China; (2) Anhui Provincial Institute of Land Surveying and Planning, Hefei, China
Corresponding author:Liu, Youzhao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:266-276
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is of vital importance for the central and western regions to distinguish the undertaken industrial types as well as land space layout on the basis of transferring industry, ecological environment and land development strategy. In this paper, Chizhou City, the typical representative of undertaking industrial types, from the perspectives of location quotient and comparative labor productivity, constructs industrial transfer identification model and identifies regional undertaken industrial type. From four criterion layers of natural environment, infrastructure, development degree and development benefit, construct the identification model and the evaluation index system and its city domain and the classical domain; using analytic hierarchy process (AHP) and fuzzy matter element analysis method and mathematical software such as Matlab7.0, Arcgis and Excel, identify the regional industrial types undertaken and evaluate the industrial land development suitability. Research shows that Chizhou City industry location quotient varies from the maximum value of 10.5421 to the minimum value of 0.0315, which demonstrates that the degree of industrial agglomeration is relatively high while the comparative labor productivity is low overall, only 5 types of industry more than 1. Industry location quotient and comparative labor productivity are low, which shows that industrial development difference is small and without obvious hierarchical gradient. According to industry transfer identification model, the Chizhou industry is classified into 4 types, of which the numbers of competitive advantage industry and weak industry respectively reach 12 and 15, and stay out industry and undertaken industry account for only 5 and 2. Based on the advantages of the three core resources, i.e. mineral resource, ecological resource and tourism resource, five categories of industry including mineral mining industry, textile and garment industry, equipment manufacturing industry, wood furniture industry and food processing industry will be identified to be undertaken and fostered in the future. Land development suitability in the city is generally low, and the regional difference is obvious. The areas with higher land development suitability is concentrated around the city areas and around the towns along the river belt like Juanqiao, Wusha, Dongliu, Xiangyu, and is also gathered around Rongcheng Town, Lingyang Town and Xinhe Town surrounding Qingyang County. On the contrary, other types of industrial land have rather low development suitability degree. As a result, the undertaken industry and the space corridor of industrial development is only limited to the city areas and town zones along the river; to other regions, it is a good choice to develop green environmental tourism industry and ecological agriculture relying on the natural ecological environment, which is not suitable for large-scale land and space development. It has completed the evaluation of the five categories industrial land, overcame the subjective sideness in the multi-angle and multi-factor assessment, and followed a certain ambiguity and extension of the result itself. Scientific evaluation of industrial land suitability, clear developing direction of future industrial development type and expansion of land space in Chizhou, with rational industrial layout mode to drive the optimal allocation of regional land resources, are the effective ways to realize industrial projects guarantee. This idea and method in this paper can provide a reference for similar regions to evaluate the undertaken industry's land spatial suitability. In addition, the research results will also scientifically guide the industrial land space layout and further promote the regional land resource development and industrial coordination development. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Mineral industry
Controlled terms:Analytic hierarchy process - Competition - Ecology - Food processing - Industrial research - Industry - Land use - Mineral resources - Natural resources - Productivity  - Textile industry
Uncontrolled terms:Analytic hierarchy process (ahp) - Chizhou city - Coordination development - Equipment manufacturing industries - Food processing industry - Fuzzy-matter-element analysis methods - Matter-element model - Suitability evaluation
Classification code:403 Urban and Regional Planning and Development - 454.3 Ecology and Ecosystems - 501 Exploration and Prospecting - 819.6 Textile Mills, Machinery and Equipment - 822.2 Food Processing Operations - 911 Cost and Value Engineering; Industrial Economics - 911.2 Industrial Economics - 912 Industrial Engineering and Management - 912.1 Industrial Engineering - 913 Production Planning and Control; Manufacturing - 913.1 Production Engineering - 921 Mathematics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.06.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 18>

Accession number:20151700790298
Title:Hydraulic failure diagnosis of tractor hydro-mechanical continuously variable transmission in shifting process
Authors:Wang, Guangming (1); Zhang, Xiaohui (1); Zhu, Sihong (2); Zhang, Haijun (2); Shi, Lixin (2); Zhong, Chengyi (2)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Shandong Agricultural University, Tai'an, China; (2) College of Engineering, Nanjing Agricultural University, Nanjing, China; (3) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture, Nanjing, China
Corresponding author:Zhang, Xiaohui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:25-34
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Unlike conventional mechanical transmission with manual shift, the hydro-mechanical CVT (continuously variable transmission) shifts from one range to another automatically under the control of hydraulic system, however, some faults of this hydraulic system can affect the establishment of clutch engagement pressure and affect the shift quality further. In order to improve the reliability of the hydro-mechanical CVT in shifting process and avoid safety accident, the problem of fault diagnosis on this hydraulic system was studied in this paper. First, a measurement and control system for the hydro-mechanical CVT was built, including the transmission, clutch hydraulic control system, sensors, transmission control unit and IPC (industrial personal computer). Software developed under Labview can build the communication between the IPC and the sensors, and record the feedback data from sensors to the table file with a frequency of 62.5 Hz. Then, 5 fault modes were defined in this paper, i.e. normal state, piston seizure, seal ring damage, oil passages clog and pipeline sealing failure. Through experiments, 60 groups of feedback data from pressure gauges and flowmeter with different fault modes were acquired. Thirty groups of the testing data were selected as training samples and the other 30 groups were selected as testing samples. For each sample, 6 kinds of statistic features such as root mean square value of sample data in a second were calculated. Because any combination of the 6 statistic features could not classify the fault sample directly in a low-dimensional space, it was necessary to map the sample to a higher dimensional space and to find the hyperplane of demarcation. So, a projection vector was calculated using the method of kernel based on the rule of Fisher. According to this projection vector, the sample data which was difficult to classify in original space could be transferred to feature space, in which the sample data could be classified with a simple linear function. After the kernel calculation, the methods to reduce the computation complexity were studied. Based on the rough set theory, the kernel features were found and the FAI (fisher based attribute importance function) value was calculated. The kernel features and the non-kernel features with a high FAI value were selected as the training features. Based on the heuristic algorithm, the training sample data corresponding to the minimum component in projection vector could be deleted in turn. Finally, in order to test the robustness of the algorithm, 10 groups of training set and testing set were rebuilt through random sample selection. The results revealed that the training and testing sample data could be classified correctly using the method of kernel, and proper reduction on features and training samples could reduce the computation complexity of fault diagnosis without accuracy loss. In addition, The average fault diagnostic accuracies of the random samples under the 5 modes were 99.67%, 100%, 99%, 98% and 99%, respectively, and the variation range for each group of sample was from 96.7% to 100%. The results indicated a high robustness of the algorithm used in this paper. The study of this paper provides a method to improve the reliability of the hydro-mechanical CVT. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Classification (of information)
Controlled terms:Algorithms - Computer control systems - Computer programming languages - Control systems - Failure analysis - Fault detection - Heuristic algorithms - Hydraulic equipment - Hydraulic machinery - Machinery  - Personal computers - Quality control - Robustness (control systems) - Rough set theory - Sampling - Seals - Set theory - Tractors (truck) - Transmissions - Variable speed transmissions  - Vector spaces
Uncontrolled terms:Agriculture machinery - Continuously variable transmission - Hydraulic control systems - Industrial personal computers - Kernel methods - Measurement and control systems - Mechanical transmission - Transmission control units
Classification code:422 Strength of Building Materials; Test Equipment and Methods - 601 Mechanical Design - 602.2 Mechanical Transmissions - 619.1.1 Pipe Accessories - 632.2 Hydraulic Equipment and Machinery - 663.1 Heavy Duty Motor Vehicles - 716.1 Information Theory and Signal Processing - 722.4 Digital Computers and Systems - 723.1 Computer Programming - 723.1.1 Computer Programming Languages - 731.1 Control Systems - 913.3 Quality Assurance and Control - 921 Mathematics - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory
DOI:10.3969/j.issn.1002-6819.2015.06.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 19>

Accession number:20151700790307
Title:Key parameters' correlation analysis on high-speed solenoid valve electromagnetic force under overall operating conditions
Authors:Fan, Liyun (1); Xu, De (1); Fei, Hongzi (1); Feng, Lidong (2); Liu, Peng (1); Zhou, Wei (1)
Author affiliation:(1) College of Power and Energy, Harbin Engineering University, Harbin, China; (2) Xi'an Power Station Engineering Branch Company of Shanxi Diesel Engine Heavy Industry Co. Ltd, Xi'an, China
Corresponding author:Fan, Liyun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:89-96
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Electronic unit pump (EUP) is a timing controlled fuel injection system used in diesel engines to meet the increasingly strict exhaust emission regulation and improve the economy of the fuel injection. As the key actuator of EUP, high-speed solenoid valve (HSV) determines the fuel injection timing and quantity in EUP. The electromagnetic force of HSV has a significant influence on the response speed and the stability of EUP, which depends greatly on the structure parameters of HSV. However, it is still not comprehensive in the parameter analysis of HSV for most experiments and simulations on the influence rules of single parameter on electromagnetic force or the parameters' influence rules for only one operating condition of HSV. In order to improve effectiveness of HSV's parameters' design and matching, six parameters' influence rules and the parameters' interaction principles on electromagnetic force under overall operating conditions were revealed by correlation analysis. Coils, armature and iron core were the most important parts for generating the electromagnetic force of HSV, and the 3D numerical simulation model of HSV was established in Ansoft Maxwell according to the three parts' actual structures, moreover the accuracy of the model was verified at different working air gaps and driving currents by experiment. Pole length, coil turns, coil location, armature thickness, damping hole location and damping hole radius were selected as the six key parameters of HSV and every parameter's three levels were determined based on their actual values. Due to HSV's working characteristics, the overall operating condition of HSV was dispersed into nine operating condition points to approximate HSV's entire working process. Based on the three levels of each of the six parameters, 47 sample points of the parameters combinations were obtained effectively and accurately by the method of design of experiments (DOE), in which the electromagnetic force was determined as a response variable and the six parameters were selected as experimental factors. Then the electromagnetic force of 423 sample points were got by using the 3D numerical simulation model of HSV to do experiment with the same times. At last, the correlation coefficients of first and second order factors formed by the six key parameters with electromagnetic force were explored under overall operating conditions according to the thought of correlation analysis. By making correlation analysis, the influence rules of the first order factors on electromagnetic force were revealed under overall operating conditions. The rules showed that one factor with significant correlation to electromagnetic force was coil turns, and the correlation decreased with the increase of driving current and increased with the increase of working air gap under different working conditions; the other factor with significant correlation to electromagnetic force was armature thickness, and the correlation increased with the increase of driving current and decreased with the increase of working air gap under different working conditions. The correlations of second order factors to electromagnetic force tended to be very complicate under overall operating conditions. In addition, the interaction principles of coil turns with armature thickness, armature thickness with damping hole location and damping hole location with damping hole radius were revealed. The electromagnetic force of HSV is determined by the complex interactions of characteristic parameters. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Finite element method
Controlled terms:Correlation methods - Damping - Design of experiments - Diesel engines - Factor analysis - Fuel economy - Fuel injection - Fuels - Models - Numerical models  - Solenoid valves - Solenoids - Structural design - Valves (mechanical)
Uncontrolled terms:3-D numerical simulation - Correlation coefficient - Electromagnetic forces - Electronic unit pump (EUP) - Fuel injection systems - High-speed solenoid valve - Interaction - Overall operating conditions
Classification code:408.1 Structural Design, General - 521 Fuel Combustion and Flame Research - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 612.2 Diesel Engines - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 704.1 Electric Components - 901.3 Engineering Research - 902.1 Engineering Graphics - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.06.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 20>

Accession number:20151700790314
Title:Effect of residual film on soil infiltration under drip irrigation
Authors:Li, Yuanqiao (1); He, Wenqing (1); Yan, Changrong (1); Mao, Lili (1); Liu, Shuang (1)
Author affiliation:(1) Institute of Environment and Sustainable Development in Agricultural, Chinese Academy of Agricultural Sciences, Beijing, China; (2) Key Laboratory of Dryland Agriculture of Ministry of Agriculture, Beijing, China; (3) Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Shanghai, China
Corresponding author:He, Wenqing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:145-149
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Large tracts of farmland are polluted by residual film with the mulching film widely applied. The residual film has become a major environmental factor which significantly affects agricultural production. Based on lab experiments of infiltration with different residual film, the influence of residual film on soil infiltration was analyzed. Six treatments were designed including T0, T1, T2, T3, T4, T5, which represented for six levels of residual film 0, 45, 90, 180, 360, 720 kg/hm&lt;sup&gt;2&lt;/sup&gt; respectively. Experimental apparatus consisted of Marriotte bottle, water tube and soil tank. The water applied in the experiment was 0.65 L/h which equaled 1.95 L/h of the drip irrigation. Total water used in one experiment was 1.90 L. During the experiment the numerical value of Marriotte bottle and wetting area were monitored continuously in 1, 2, 3, 6, 10, 15, 25, 35, 50, 65, 80, 95, 110, 125, 150, 175 minutes. The results indicated that residual film could hinder the movement of wetting front. when residual film levels were between 0 and 360 kg/hm&lt;sup&gt;2&lt;/sup&gt;, residual film had a significantly influence on horizontal distance of wetting front. In 50 minutes when wetting front moved to 0-10 cm soil, T2 treatment showed minimum horizontal distance and three horizontal distances of T2, T3 and T4 were gradually increasing due to the preferential flow with more residual film in 0-10 cm soil. While in 175 minutes when wetting front moved to 10-20 cm soil, treatments with increased residual film gave rise to decreases in horizontal distance. Residual film could also affecte the vertical distance of wetting front heavily, however, the vertical distance had no obvious difference among T1, T2, T3 and T4, T5 treatment while it diminished greatly between T0 and T1 treatment in 175 minutes (F=4.53, P&lt;0.05). The soil wetting rate was amplified due to residual film, which the drip irrigation needs to be applied with more water or short dripper distance to achieve proper drip irrigation uniformity in polluted farmland. While the irrigation was stopped, the steady infiltration rate increased from 12.2 mm/h to 16.9 mm/h with the residual film increased from 0 to 360 kg/hm&lt;sup&gt;2&lt;/sup&gt;. Steady infiltration rate showed significant difference between T0.and T1, T2, T3 T4 treatment. Therefore, it is concluded that residual film can make soil wetting body smaller and maintain more water in the soil wetted volume, and the random distribution of residual film affects water general movement, which crops will be difficult in absorbing soil water. The soil infiltration of residual film could be well described by the Kostiakov Function, which the correlation coefficient was over 0.989. When the residual film attained to 720 kg/hm&lt;sup&gt;2&lt;/sup&gt;, excessive amounts of residual film add soil macropore heavily, which lead to preferential flow in total 0-20 cm soil causing increase of the wetting distance, at the same time that decreased the wetting rate and steady infiltration. This research will provide fundamental theory for the control of residual film polluted farmland in term from soil water movement. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Infiltration
Controlled terms:Agriculture - Bottles - Farms - Groundwater flow - Irrigation - Soil moisture - Soils - Wetting
Uncontrolled terms:Agricultural productions - Correlation coefficient - Environmental factors - Experimental apparatus - Preferential flows - Residual films - Steady infiltration rate - Wetting fronts
Classification code:444.2 Groundwater - 483.1 Soils and Soil Mechanics - 694.2 Packaging Materials - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.06.020
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 21>

Accession number:20151700790309
Title:Effects of outlet pipe transition circular arc on properties of reactive muffler and its application
Authors:Chu, Zhigang (1); Kuang, Fang (1); Gao, Xiaoxin (1); Kang, Runcheng (4)
Author affiliation:(1) State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing, China; (2) College of Automotive Engineering, Chongqing University, Chongqing, China; (3) College of Mechanical Engineering, Chongqing University, Chongqing, China; (4) Technical Center, Dongfeng Motor Corporation, Xiangyang, China
Corresponding author:Chu, Zhigang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:105-112
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Based on the layout principles of inlet and outlet pipes, using the cavity acoustic modes to design muffler can get good acoustic attenuation, and for the inlet and outlet pipes are not coaxial, the pressure loss is larger when it is caused by the blocked air flow. Taking the expansion chamber and flow-reversing chamber as examples, firstly, comparative study about the effects of chamfer transition and circular arc transition on the pressure loss and transmission loss were made based on the finite element method. The results showed that the smooth transition of outlet pipe could decrease the pressure loss and did not affect the transmission loss at the same time; moreover, the properties of muffler with circular arc transition were much better than those of chamfer transition. On this basis, the coupling influences of transition circular arc radius and muffler size on the pressure loss and transmission loss were analyzed. It turned out that the transition circular arc of outlet pipe almost had no effect on the transmission loss but could effectively decrease pressure loss; moreover, this is a universal law and will not be changed with the change of type and size of the muffler. And with the increase of transition circular arc radius, the change rates of the pressure loss were decreasing. Further, under the premise of keeping the overall size, an automobile muffler was made a preliminary improvement by applying the layout principles of inlet and outlet pipes based on the cavity acoustic modes. After the preliminary improvement, the average transmission loss was increased by 15.8 dB in the frequency range of 750-1500 Hz, but the pressure loss was increased by 7.78% with the inlet velocity of 60 m/s. In order to decrease the pressure loss on the base of good acoustic attenuation performance, the further improvement of car muffler was made. The first chamber and third chamber of muffler could be seen as two simple flow-reversing mufflers, and 10 mm transition circular arcs were added at the entrance of outlet pipes on the basis of the preliminary improvement. Compared with the original muffler, the average transmission loss of final improved muffler in the frequency range of 750-1500 Hz was increased by 15.3 dB and slightly lower than that of preliminary improved muffler, however, the pressure loss was reduced by 25.20% with the inlet velocity of 60 m/s. In conclusion, the properties of muffler have been greatly improved after the further improvement. Integrated use of the layout principle of inlet and outlet based on the cavity acoustic modes and the effect laws of outlet pipe transition circular arc on the pressure loss can guide the muffler design. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Pressure effects
Controlled terms:Automobile mufflers - Finite element method - Inlet flow - Noise pollution - Noise pollution control - Pipe - Pollution control - Wave transmission
Uncontrolled terms:Acoustic attenuation - Acoustic attenuation performance - Comparative studies - Expansion chamber - Improvement - Pressure loss - Smooth transitions - Transmission loss
Classification code:454.2 Environmental Impact and Protection - 461.7 Health Care - 619.1 Pipe, Piping and Pipelines - 631.1 Fluid Flow, General - 663.2 Heavy Duty Motor Vehicle Components - 711 Electromagnetic Waves - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.06.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 22>

Accession number:20151700790327
Title:Risk assessment of drought and chilling injury of maize in Northeast China
Authors:Wang, Chunyi (1); Cai, Jingjing (1); Zhang, Jiquan (4)
Author affiliation:(1) Chinese Academy of Meteorological Sciences, Beijing, China; (2) Hainan Meteorological Service, Haikou, China; (3) Shenzhen Air Traffic Management Station, Civil Aviation Administration of China, Shenzhen, China; (4) College of Urban and Environmental Sciences/Natural Disaster Research Institute, Northeast Normal University, Changchun, China
Corresponding author:Wang, Chunyi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:238-245
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Northeast China is the important commodity grain base of China, but the characteristics of the climate resources in this area show insufficient heat and great differences in regional and seasonal distribution of precipitation, which could lead to the chilling injury, drought and other agriculture meteorological disasters. During the production, especially at the stages of crop growth, the disaster-inducing factor for a particular agriculture meteorological disaster may occur with some disaster-inducing factors for other disasters simultaneously or successively. So the final output of the crop was also influenced by various factors together. Therefore, it was of more practical significance to consider the major disasters comprehensively and analyze their effects on the growth of crop. In this study, the meteorological data from 1961 to 2010, maize growth data from 1981 to 2010, production area data from 1961 to 2010 in 35 agriculture meteorological stations, disaster record for the latest 50 years in 3 provinces of Northeast China, and social and economic statistics for the latest 10 years in the counties of these 3 provinces were employed. The drought and chilling injury at two stages of the maize including emergence-tasseling and tasseling-mature was studied based on the theory of natural disaster risk analysis, and the risk of the drought and cold injury to corn in Northeast China was evaluated by emphasizing the creation of the risk assessment index system and risk assessment model. The indices of drought and chilling injury risk assessment model of the maize included hazard, vulnerability, exposure, and emergency response and recovery. Combined the evaluation from disaster index and the record of typical disastrous year, the weights of hazards were made according to the actual drought and chilling damage conditions. The contributions of the compound disaster risk to the whole growth and development of the maize at the early and late stage were 0.347 and 0.6527, respectively. The weights of hazard, vulnerability, exposure and emergency response and recovery ability were explained and provided objectively. These given weights showed that hazard and emergency response and recovery ability were the two most important factors in the model. The risk assessments for the maize drought and chilling damage at different growth and development stages were listed as below: at the early stage, the high values of risk index were distributed in the northwest of Heilongjiang Province, the east of Jilin Province and the northeast of Liaoning Province, while in the southwest of Heilongjiang Province, the west of Jilin and the southwest of Liaoning, the risk index values were relatively low; at the later growth stage, the distribution of the risk index changed, and the risk index values for west Heilongjiang Province and northwest Jilin increased, but decreased considerably in the east of Jilin and northeast of Liaoning. For the whole growth and development period of the maize, the high values of risk index were in the southwest and northeast of Heilongjiang Province and the west of Liaoning Province, with the value of above 0.8; the moderate values were found in the northwest and southeast of Jilin Province and the northeast of Liaoning Province, with the value of between 0.6 to 0.7; the low values were in the central south of Liaoning Province and Liaoning peninsula, with the value of around 0.3. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Risk assessment
Controlled terms:Agriculture - Crops - Damage detection - Disasters - Drought - Emergency services - Hazards - Meteorology - Recovery - Risk analysis
Uncontrolled terms:Assessment index system - Chilling injury - Growth and development - Maize - Meteorological disasters - Meteorological station - Risk assessment models - Seasonal distributions
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 443 Meteorology - 444 Water Resources - 531 Metallurgy and Metallography - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 914 Safety Engineering - 914.1 Accidents and Accident Prevention - 922 Statistical Methods
DOI:10.3969/j.issn.1002-6819.2015.06.033
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 23>

Accession number:20151700790338
Title:Optimization of fermentation process of removal of cadmium in rice powder using lactic acid bacteria
Authors:Fu, Yaping (1); Liao, Luyan (2); Liu, Yang (1); Wu, Weiguo (1)
Author affiliation:(1) College of Food Science and Technology, Hunan Agricultural University, Changsha, China; (2) Orient Science and Technology College of Hunan Agricultural University, Changsha, China
Corresponding author:Wu, Weiguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:319-326
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, along with our country cadmium pollution in rice is increasingly serious, the safety and quality of rice in China has been under serious threat. Contamination of rice with cadmium also draws great attention because of its serious threat to food safety and its potential harm to human health. Thus, it's very important and necessary for food industry to find a method to decrease the degree of cadmium pollution in polished rice. Cadmium in rice has been demonstrated that it mainly bonded with protein and little cadmium accumulated in starch and other nutritional ingredients. And processing of soaking, heating, washing can reduce the content of cadmium in rice powder, but the effect of cadmium removal is not obvious. Hence, it also was proved that the amount of heavy metals in rice dropped significantly after fermentation using lactic acid bacteria. Therefore, in order to resolve the problem of "excessive cadmium" polished rice utilization, this paper tried to reduce the content of cadmium in "excessive cadmium" polished rice(cadmium content of 0.6479mg/kg) by lactic acid bacteria and produce safe fermented rice products, and the fermentation conditions were studied and optimized. The mixed strains of Lactobacillus plantarum and Pediococcus pentosaceus(2:1,v/v) were selected as the suitable fermentation strain by comparative test. The effects of rice powder size, fermentation time, fermentation temperature and inoculum size of mixed strains on the removal rate of cadmium in polished rice also were evaluated by single-factor experiment. The results showed that fermentation time, fermentation temperature and inoculum size of mixed strains could significantly affect the removal rate of cadmium(P&lt;0.05). However, the effect of rice powder size(20-100 mesh) on the removal rate of cadmium was not significant(P&gt;0.05). Then, fermentation time, fermentation temperature and inoculum size of mixed strains were further researched using a three-variable, three level Box-Benhnken design to optimize the fermentation conditions. The results indicated that the interaction effects of fermentation temperature and fermentation time, fermentation temperature and inoculum size of mixed strains on the removal rate of cadmium were extremely significant (P&lt;0.01). Moreover, the significant degree of three factors was in order as fermentation temperature (A, P&lt;0.01)&gt;fermentation time (B, P&lt;0.01)&gt;inoculum size of mixed strains (C, P&lt;0.01). When rice powder size was selected as 40 mesh, the optimum fermentation conditions were obtained with fermentation temperature of 40.8, fermentation time of 23.4 h, and the inoculum size of 3%. In this optimal conditions, the verification test demonstrated that the removal rate of cadmium in polished rice powder was 85.73%, and the content of cadmium in fermented rice noodle was 0.0925 mg/kg and met the national food sanitation standard (0.2 mg/kg). In addition, the verification test showed that there was a good fit between the experimental and the predicted values, relative standard deviation was 0.918. Therefore, the results indicated that this method could efficiently remove cadmium in polished rice and provide a reference for industrial production of fermented rice noodle. The results of research also can provide a theoretical basis for further study on the mechanism on cadmium removal in rice by lactic acid bacteria. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Chemical contamination
Controlled terms:Bacteria - Cadmium - Fermentation - Health risks - Heavy metals - Lactic acid - Optimization - Pollution - Powder metals - Strain
Uncontrolled terms:Fermentation conditions - Fermentation temperature - Lactic acid bacteria - Lactobacillus plantarum - Relative standard deviations - Removal rate - Response surface method - Single-factor experiments
Classification code:421 Strength of Building Materials; Mechanical Properties - 454.2 Environmental Impact and Protection - 461.7 Health Care - 461.9 Biology - 531 Metallurgy and Metallography - 536 Powder Metallurgy - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 802.2 Chemical Reactions - 822.3 Food Products - 921.5 Optimization Techniques - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.044
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 24>

Accession number:20151700790318
Title:Evaluation in soil carbon and nitrogen characteristics under long-term cropping regimes in black soil region of Northeast China
Authors:Guo, Jinrui (1); Song, Zhenwei (3); Peng, Xianxian (1); Zhu, Ping (2); Gao, Hongjun (2); Peng, Chang (2); Zhang, Weijian (1)
Author affiliation:(1) Institute of Applied Ecology, Nanjing Agricultural University, Nanjing, China; (2) Institute of Agricultural Resource and Environment, Jilin Academy of Agricultural Sciences, Changchun, China; (3) Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing, China
Corresponding author:Zhang, Weijian
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:178-185
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil carbon and nitrogen are of importance to evaluate soil fertility. To clarify the comprehensive effects of cropland management measures on soil carbon and nitrogen dynamic will provide theoretical and technical support to soil fertility cultivation and land sustainable utilization. Commercial grain production in Northeast China plays a crucial role in Chinese food security. However, long-term intensive maize cropping with chemical fertilizer application has resulted in great decrease of soil organic carbon and rapid decline of soil fertility in this region. During the past decades, many efforts have been paid on the impacts of plant patterns on soil organic carbon and soil chemical conditions in order to improve soil fertility, but little is known about the integrated impacts on soil aggregation and soil organic carbon situation, soil nitrogen and their relationship. Therefore, based on the long-term field experiment started in 1990 in Gongzhuling, Jilin Province, China, an investigation was performed to compare the differences in soil carbon, soil nitrogen, and their relationship among the different cropping regimes (continuous maize cropping, maize-soybean rotation and continuous soybean cropping, the three were with organic manure application, fallow). Soil samples were taken at 20 cm intervals from 0 to 100 cm soil depth after maize was harvested in October 2010 for analysis. The results showed that, within the 0-100 cm soil profile, soil organic carbon, total nitrogen, and available nitrogen decreased significantly with soil depth under all treatments. There were significant correlations between soil organic carbon and total nitrogen, and available nitrogen (P&lt;0.01), suggesting that higher soil organic carbon could promote soil nitrogen concentration. In the topsoil layer (0-20 cm), soil organic carbon, total nitrogen and available nitrogen under continuous maize cropping, maize-soybean rotation and continuous soybean cropping treatments were higher than those under fallow treatment by 23.5%-46.8%, 4.9%-64.3% and 35.4%-121.9%, respectively. Furthermore, the highest values in soil organic carbon, total nitrogen and available nitrogen occurred in the continuous maize cropping treatment (P&lt;0.05). Soil microbial biomass carbon and soil microbial biomass nitrogen under continuous maize cropping treatment in topsoil layer were significantly higher than those under maize-soybean rotation and continuous soybean cropping treatments by 23.1%-41.4% and 37.8%-135.3%, respectively (P&lt;0.05). Continuous maize cropping achieved the greatest organic carbon associated by soil aggregate in the &gt;2 000, &ge;250-2 000, &ge;53-250 and &lt;53 &mu;m aggregate fractions (P&lt;0.05). However, high labile organic carbon under continuous maize cropping treatment was significantly higher than those under fallow, maize-soybean rotation and continuous soybean cropping treatments (P&lt;0.05), and the chemical activity index was significantly higher than that under maize-soybean rotation treatment as well (P&lt;0.05), resulting that soil organic carbon is more sensitive to the external environment changes under continuous maize cropping treatment. Present study indicates that long-term continuous maize cropping with organic manure amendment can increase soil organic carbon and nitrogen availability. However, more efforts should be paid to adopt reasonable cultivation measures to reduce the risk of soil organic carbon decomposition under continuous maize cropping. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Organic carbon
Controlled terms:Aggregates - Carbon - Cultivation - Decay (organic) - Fertilizers - Food supply - Manures - Nitrogen - Risk assessment - Rotation  - Soil surveys - Soils
Uncontrolled terms:Black soil region of northeast chinas - Long-term field experiments - Monoculture - Organic manure - Soil microbial biomass carbons - Soil microbial biomass nitrogens - Soil organic carbon and nitrogen - Sustainable utilization
Classification code:404.2 Civil Defense - 406 Highway Engineering - 483.1 Soils and Soil Mechanics - 601.1 Mechanical Devices - 804 Chemical Products Generally - 804.1 Organic Compounds - 811.2 Wood and Wood Products - 821.3 Agricultural Methods - 821.5 Agricultural Wastes - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.06.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 25>

Accession number:20151700790316
Title:Effects of irrigation methods and rice planting densities on yield and photosynthetic characteristics of matter production in cold area
Authors:Zhao, Liming (1); Li, Ming (1); Zheng, Dianfeng (3); Gu, Chunmei (2); Na, Yongguang (2); Xie, Baosheng (2)
Author affiliation:(1) College of Agriculture, Northeast Agricultural University, Harbin, China; (2) Rice Research Institute of Heilongjiang Academy of Land Reclamation Sciences, Jiamusi; Heilongjiang, China; (3) College of Plant Science, Heilongjiang August First Land Reclamation University, Daqing; Heilongjiang, China
Corresponding author:Li, Ming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:159-169
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This research aims at discussing the influence of irrigation method and planting density on the rice yields in cold zone and production characteristics of photosynthetic substances, and the interaction effect, which has important meaning for the guidance of high yield of rice and high-efficiency cultivation. The experiment is carried out in the land for growing field crops, and takes Kendao 24 (A rice cultivar widely planted in rice production in china, which had high grain yield, extensive adaptability, and with growth duration of 130-135 days from sowing to maturity) as the experimental material. Deal the rice with three kind of irrigation method, heavy irrigation of alternation of wetting and drying (W&lt;inf&gt;1&lt;/inf&gt;), light irrigation of alternation of wetting and drying (W&lt;inf&gt;2&lt;/inf&gt;) and irrigation with shallow water(W&lt;inf&gt;3&lt;/inf&gt;), and the planting distance respectively adopts 30 cm&times;10 cm (D&lt;inf&gt;1&lt;/inf&gt;), 30 cm&times;12 cm (D&lt;inf&gt;2&lt;/inf&gt;), and 30 cm&times;14 cm (D&lt;inf&gt;3&lt;/inf&gt;). It will analyze the influence of the water and density on the yield formation of rice and production characteristics of photosynthetic substances. The results show that the overall effects of each way of irrigation on the dry matter accumulation, production of photosynthetic substance, yield components and yield present W&lt;inf&gt;2&lt;/inf&gt;&gt;W&lt;inf&gt;3&lt;/inf&gt;&gt;W&lt;inf&gt;1.&lt;/inf&gt; W&lt;inf&gt;2&lt;/inf&gt; treatment has greatly improved the rice yield, and increases the 1000-grain weight and seed setting rate of rice. Compared with W&lt;inf&gt;3&lt;/inf&gt; and W&lt;inf&gt;1&lt;/inf&gt; treatment, the actual yield respectively increased by 5.05% and 27.89%; W&lt;inf&gt;2&lt;/inf&gt; treatment has effectively controlled the ineffective tillering, greatly improved percentage of earbearing tiller, and reduced the height of plant and length of the third and forth internode from the top while the growth speed of blade is slower than W&lt;inf&gt;3&lt;/inf&gt; treatment. Under all the conditions of density, the one resulting in the best effect in biological yield after head sprouting, dry matter transmission in the stem-sheath and the final grain yield is D&lt;inf&gt;2&lt;/inf&gt; treatment; the blade under D&lt;inf&gt;3&lt;/inf&gt; treatment grows faster than D&lt;inf&gt;2&lt;/inf&gt; and D&lt;inf&gt;1&lt;/inf&gt; treatment, and new leaves will grow. Under the interaction of different ways of irrigation and densities, each kind of way of irrigation and density treatment will cause significant or extremely significant interaction effect on the leaf age, number of stem and tiller, percentage of earbearing tiller, ratio of grain-leaf during heading period, dry matter accumulation, dry matter transmission in stem-sheath after heading sprouting and production of photosynthetic substance, yield components, and yield. The best effect appears under the light irrigation of alternation of wetting and drying and planting distance of 30 cm&times;10 cm(W&lt;inf&gt;2&lt;/inf&gt;D&lt;inf&gt;1&lt;/inf&gt;). Compared with other treatments, it realizes the production increase by 5.0%-8.5%, Yield increasing way of W&lt;inf&gt;2&lt;/inf&gt;D&lt;inf&gt;1&lt;/inf&gt; treatment is achieved by the high ratio of grain-leaf, high leaf area index(LAI), more photosynthetic substance accumulation, high grain weight and harvest index, and the formation of high quality population; great dry matter accumulation at the late growth stage, high crop growth rate(CGR) and net assimilation rate(NAR), strong production capacity of photosynthetic substance, reasonable output and transmission of substances in stem-sheath, and great number of effective panicles, high 1000-grain weight and seed setting rate, which causing high grain yield. The comprehensive analysis shows that the treatments of light irrigation of alternation of wetting and drying and planting distance of 30 cm&times;10 cm are more suitable for the cultivation of rice in cold zone with high yield and high efficiency. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:46
Main heading:Grain (agricultural product)
Controlled terms:Crops - Cultivation - Density (specific gravity) - Drying - Grain growth - Irrigation - Photosynthesis - Plants (botany) - Population statistics - Wetting
Uncontrolled terms:Cold rice - Comprehensive analysis - Dry matter accumulation - Experimental materials - Net assimilation rates - Photosynthetic characteristics - Production characteristics - Yield
Classification code:461.9 Biology - 642.1 Process Heating - 741.1 Light/Optics - 821.3 Agricultural Methods - 821.4 Agricultural Products - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids - 933.1.2 Crystal Growth
DOI:10.3969/j.issn.1002-6819.2015.06.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 26>

Accession number:20151700790320
Title:Verification of high-resolution land surface temperature by blending ASTER and MODIS data in Heihe River Basin
Authors:Yang, Guijun (1); Sun, Chenhong (1); Li, Hua (4)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China; (2) Key Laboratory of Agri-informatics, Ministry of Agriculture, Beijing, China; (3) College of Geomatics, Xi'an University of Science and Technology, Xi'an, China; (4) Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing, China
Corresponding author:Yang, Guijun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:193-200
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land surface temperature (LST) is a key parameter in investigating environmental, ecological processes and climate change at various scales, and is also valuable in the studies of evapotranspiration, soil moisture conditions, surface energy balance, and urban heat islands. However, it is difficult to acquire satellite LSTs with both high spatial and temporal resolutions due to tradeoffs between these parameters. The Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) algorithm was initially designed to predict surface reflectance and is based on the assumption that MODIS and Landsat surface reflectance are highly consistent over homogeneous areas. However, the ESTARFM method prediction results degrade somewhat when the method is used for heterogeneous fine-grained landscapes. This research extended the ESTARFM model from reflectivity range to thermal infrared for estimation of daily temperature at 90 m resolution combined MODIS and ASTER. The implementation of ESTARFM requires input of the search window size, selection of spectrally similar pixels, determination of the weight of similar pixels, and computation of the correction coefficient and temporal weight. The calculation of weights for spectrally similar pixels involves weighing the contribution of neighboring pixels to the computation of a central pixel. Using a local moving window, neighboring spectrally similar pixels were included for the computation of the LST corresponding to a central pixel with the temporal weights of the two dates. In this study, we used multiple bands, i.e., red, NIR, and LST bands, as the input variables and generated high spatial-temporal resolution land surface temperature, combining temporal change information from multi-temporal MODIS with high-resolution spatial resolution from ASTER. The objective of this paper was to evaluate the ESTARFM method using ground measurements coordination with ASTER LST products collected in an arid region of Northwest China during the first thematic Multi-Scale Observation Experiment on Evapotranspiration (MUSOEXE) over heterogeneous land surfaces in 2012, as part of the Heihe Watershed Allied Telemetry Experimental Research (HiWATER).We didn't modified the model even if the linear hypothesis was directly applied in LST prediction, which may result in uncertainty and errors. The remote sensing data were acquired with from Jun to September in 2012. The results showed that ESTARFM was positively and linearly related with the actual measured TIR. The correlation coefficient values were all found to be greater than 0.71. The mean absolute error and root mean square error were all below 2.00 K and 2.60 K, respectively. From the feature of scattering plots between the predicted and observed LST, the data points fell close to the diagonal line in each panel, indicated that the predictions were all in good agreement with the observations. Overall, the values of mean absolute error and root mean square error between the predicted and the observed LST were quiet small; whereas the correlation coefficient values between the predicted LSTs and ASTER LST products were all found to be greater than 0.95.It should be noted that some pixels in the scatter plots showed differences between the predicted and observed LSTs. These discrepancies revealed a major limitation to the method; i.e., ESTARFM does not capture land cover that has been altered between two imaging dates. Thus, changes in land cover or other surface conditions can lead to prediction errors. In addition, the fusion results showed that value of correlation coefficient was better in non-vegetation area than vegetation and water area, and up to 0.91 especially in the August 27, 2012. However, the application of the ESTARFM and its variants to LST prediction is immature in terms of methodology. Many critical issues have not been solved, especially with respect to the determination of the search window size, conversion coefficient improvement, and thermal landscape heterogeneity. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Atmospheric temperature
Controlled terms:Arid regions - Blending - Climate change - Errors - Evapotranspiration - Forecasting - Image resolution - Mean square error - Pixels - Radiometers  - Reflection - Remote sensing - Satellite imagery - Soil moisture - Surface measurement - Surface properties - Temperature - Uncertainty analysis - Vegetation
Uncontrolled terms:Conversion coefficients - Correction coefficients - Heterogeneous land surfaces - High spatial resolution - Land surface temperature - Landscape heterogeneities - Multi-Sources - Spatial and temporal resolutions
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 711 Electromagnetic Waves - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 742 Cameras and Photography - 742.2 Photographic Equipment - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 922.1 Probability Theory - 943.2 Mechanical Variables Measurements - 944.7 Radiation Measuring Instruments - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 27>

Accession number:20151700790337
Title:Residual heat and quick-freezing energy saving technologies of frozen cooked noodles
Authors:Pan, Zhili (1); Wang, Tao (1); Wang, Na (1); Xie, Xinhua (1); Suo, Biao (1); Ai, Zhilu (1)
Author affiliation:(1) Quick-frozen Food Made of Wheat Flour and Rice and Frozen Prepared Food of Henan Province Engineering Laboratory, College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China; (2) College of Food Science, Northeast Agricultural University, Harbin, China; (3) Collaborative Innovation Center of Henan Grain Crop, Zhengzhou, China
Corresponding author:Ai, Zhilu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:311-318
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the effective utilization of resources and solve the problem of energy consumption in the production, using residual heat (reducing the boiling time of noodles and then allowing them to stand and using residual heat to continue to cook) and changing the frozen condition were applied in developing energy-saving technologies of frozen noodles. Instead of boiling, which generally requires constant heating, utilization of residual heat in a closed pot following boiling is a well-known approach for cooking noodles but has never been investigated. The process parameters were optimized from the quality-related indices of textural properties, whiteness, pasting properties, and water distribution, and energy consumption and sensory evaluation were determined by texture analyzer, differential scanning calorimetry and low-field nuclear magnetic resonance. The usage of residual heat could not only increase the gelatinization ratio of noodles, but also decrease the cooking time and energy consumption. The whiteness values of frozen noodles gradually increased with the extension of standing time, but the differences were not obvious. There were no significant differences of the whiteness values with prolonged standing time both for 4 min in the case of boiling for 2 min and for 2 min in the case of boiling for 3 min. The textural properties of frozen noodles i.e. hardness, firmness and break strength increased firstly and then decreased with prolonged standing time. In the case of boiling for 2 min, the textural properties and whiteness values with standing for 6 min after that were higher than those of other standing time, whose gelatinization ratio reached 97%. For boiling for 3 min, the textural properties and whiteness values with standing for 4 min after that were higher than those of other standing time, whose gelatinization ratio reached 98%. There were significant differences of the textural properties (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, break strength and firmness) and relaxation time between the quick-freezing temperature of -40 and the temperature of -30. There were significant differences of the textural properties and relaxation time at different frozen time in the range of 15-25 min at -30. Similarly, there were significant differences of the textural properties and relaxation time at different frozen time in the range of 10-20 min at -40. The lightness, redness, yellowness and whiteness of noodles had significant differences between -40 and -30 during from 10 to 20 min. Along with the standing time extending, the lightness and whiteness values of frozen noodles appeared to increase, while the redness and yellowness values had opposite tendencies at the same frozen temperature. Again, the lightness, redness, yellowness and whiteness had significant differences at different frozen time from 15 to 25 min at -30, and also at different frozen time in the range of 10-20 min at -40. Overall, there were no significant differences in textural properties, whiteness and moisture distribution between freezing for 20 and 30 min at the temperature of -40 (traditional thawing pattern). Considering the energy and sensory evaluation, the processing of noodles that were boiled for 3 min followed by standing for 4 min and freezing for 20 min at -40 was chosen as energy-saving technology with the optimized parameters. The results showed that the energy-saving process cost 3.47 kW&middot;h electric power per kilogram of product with the energy saving reaching 17.18% comparing with traditional technology. The total sensory score of energy-saving process was 85.5 and there were no significant differences in the sensory indicators including color, performance status, palatability, smoothness and taste between optimized and traditional technologies. Therefore, under the premise of guaranteeing the quality, the usage of residual heat and reduction of freezing time are partly effective for energy saving. This processing cost was analyzed by simulation calculations, in which the production cost saving was &yen;805 per ton of frozen cooked noodles. The method and data stated in this study are valuable and useful to the industry and can provide reference for further studies, of energy-saving technologies of frozen noodles. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Energy conservation
Controlled terms:Costs - Differential scanning calorimetry - Energy utilization - Freezing - Gelation - Hardness - Parameter estimation - Processing - Quality control - Relaxation time  - Sensory analysis - Textures - Water quality - Water supply systems
Uncontrolled terms:Effective utilization of resources - Energy-saving technologies - Frozen noodle - Heat preservation - Low field nuclear magnetic resonance - Moisture distribution - Simulation calculation - Water conditions
Classification code:421 Strength of Building Materials; Mechanical Properties - 446.1 Water Supply Systems - 453.2 Water Pollution Control - 525.2 Energy Conservation - 525.3 Energy Utilization - 731.1 Control Systems - 801 Chemistry - 802.3 Chemical Operations - 911 Cost and Value Engineering; Industrial Economics - 913.3 Quality Assurance and Control - 913.4 Manufacturing - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.043
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 28>

Accession number:20151700790328
Title:Sensitivity analysis of double-rice yield under climate change in Hunan Province
Authors:Liu, Shengli (1); Xue, Jianfu (1); Zhang, Ran (1); Chen, Zhongdu (1); Chen, Fu (1); Hu, Saijing (2); Zhang, Hailin (1)
Author affiliation:(1) Key Laboratory of Farming System, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China; (2) Ningxiang Agricultural Bureau, Changsha, China
Corresponding author:Zhang, Hailin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:246-252
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Global warming is a concern for policy makers, scientists and farmers around the world. It is widely accepted that climate change has had great impacts on agricultural production and farmers' income. Thus, there is a conundrum of how to balance the tradeoffs between food demand, increasing population, and scarce agricultural resources in the changing climate. Sensitivity and vulnerability of crop production to climate change are highly important for agriculture adaptation, but uncertainty still exists in previous research among diverse regions. Rice production may face huge risk because of the frequent extreme weather in China, therefore, a sensitivity analysis of rice production under the impacts of climatic change in different growth stages will contribute to optimizion of rice cultivation management for adapting to the changing conditions. In this study, we selected the recorded rice phonological observations at 10 agro-meteorological experiment stations, and the corresponding weather and statistical yields from 1980-2012 in Hunan Province, China. These data were used to analyze rice sensitivity to climate change using a panel model combined with multiple regression methods. The relationship of climate and yield trend was computed with the least square method, and the possible relationship between climatic factors and double-rice yield was analyzed by partial correlation analysis. The results showed that the double-rice region in Hunan Province experienced a warming trend over the last three decades, and the average temperature during the early rice and late rice seasons were 0.47 and 0.33 &lt;sup&gt;o&lt;/sup&gt;C/(10a) higher. An increase in temperature of 0.76 &lt;sup&gt;o&lt;/sup&gt;C/(10a) was observed during the vegetative stage of the early rice season, while the late rice season experienced a relatively slower increase in temperature. Precipitation and radiation during the growth stage of early rice tended to increase unnoticeable, but radiation in the vegetative stage and the reproductive stage of early rice changed with the trend -0.40 and 0.40 MJ/(m&lt;sup&gt;2&lt;/sup&gt;&middot;d&middot;10a), while the trend was opposite for the late rice. Yield changes in the early rice were significantly correlated with precipitation and radiation during the ripening stage and the whole growth stage (P&lt;0.01), but only the average temperature was significantly correlated to the yield for the late rice (P&lt;0.05). Whatever the model adopted, the yield sensitivity of double-rice to climate change showed great differences among different growth stages, ranging from -280.11 to 118.20 kg/hm&lt;sup&gt;2&lt;/sup&gt;. Temperature, precipitation and radiation in the vegetative stage were most sensitive to the yield for both the early rice and late rice. The rising temperature increased yield of the early rice, while we observed the opposite effect for the late rice. From 1980 to 2012, temperature increase, decrease of precipitation and radiation changed the early rice yield by -0.24% to 3.18%, and temperature increase during vegetative stage increased the early rice yield by 2.63%, and even accelerated the early rice yield by 157.10 kg/hm&lt;sup&gt;2&lt;/sup&gt;. The late rice experienced a severe yield decrease by -4.98% with only temperature change in consideration. The historical climatic change impacted the yield of the early rice and late rice by 2.59% and -6.02%, respectively. These results suggest that the historical climate change during different rice growth stages has changed yields of double-rice in Hunan Province, especially if temperature rose during the growth stages. There is a strong need to assess historical climate change to project possible impacts in the future and identify adaptive technologies for double-rice production in this region. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Climate change
Controlled terms:Agriculture - Climate models - Correlation methods - Cultivation - Global warming - Least squares approximations - Regression analysis - Risk assessment - Sensitivity analysis - Temperature
Uncontrolled terms:Agricultural productions - Agricultural resources - Different growth stages - Double-rice - Hunan province , China - Multiple regression methods - Rice yield - Temperature increase
Classification code:443 Meteorology - 451 Air Pollution - 641.1 Thermodynamics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 921 Mathematics - 921.6 Numerical Methods - 922.1 Probability Theory - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.06.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 29>

Accession number:20151700790329
Title:Characterizations of physico-chemical changes of corn biomass by steam explosion
Authors:Su, Tongfu (1); Zhao, Guozhong (2); Ren, Tianbao (3); Xu, Cuilian (1); Gong, Changrong (3); Chen, Gang (1)
Author affiliation:(1) Department of Chemistry, Henan Agricultural University, Zhengzhou, China; (2) Department of Physics, Capital Normal University, Beijing, China; (3) Department of Tobacco, Henan Agricultural University, Zhengzhou, China
Corresponding author:Chen, Gang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:253-256
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Scanning electron microscopy (SEM) and terahertz time domain spectroscopy (THz-TDS) were employed to investigate the effects of steam-explosion on biomass, and the surface images, micro-analysis and terahertz spectra were obtained. SEM analysis of the surface showed that the parenchyma cell and epidermis of corn stem were smashed and separated by steam-explosion, which suggests a great increase in specific surface area and potentially enhanced speed of fermentation in the production of biogases and biofuels. Terahertz spectra of stover showed that their absorption coefficients increase with increasing frequency. Steam explosion may cause a subtle chemical change in biomass according to obviously different absorption coefficients between the steamed and original samples, which could also be proved by micro-analysis. Moreover, two resonance peaks were detected in the absorption curves of parenchyma cell, with notable frequency shift between curves of the steamed and original parenchyma cells. Assignments of the two vibrational peaks must be explored by further studies. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Chemical analysis
Controlled terms:Biomass - Explosions - Microanalysis - Scanning electron microscopy - Steam - Straw - Terahertz spectroscopy - Time domain analysis - X rays
Uncontrolled terms:Absorption co-efficient - Absorption curves - Parenchyma cells - Physical performance - Physico-chemical changes - Steam explosion - Terahertz spectra - Terahertz time domain spectroscopy
Classification code:502.1 Mine and Quarry Operations - 614 Steam Power Plants - 801 Chemistry - 821.5 Agricultural Wastes - 921 Mathematics - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 932.1 High Energy Physics
DOI:10.3969/j.issn.1002-6819.2015.06.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 30>

Accession number:20151700790302
Title:Nondestructive testing and pull shear performance experiment on bionic heterogeneous compound materials interface
Authors:Tian, Limei (1); Li, Ziyuan (1); Ke, Qingpeng (1); Jin, E (1); Dong, Shiyun (2)
Author affiliation:(1) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun, China; (2) National Key Laboratory for Remanufacturing, Academy of Armord Forces Engineering, Beijing, China
Corresponding author:Tian, Limei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:57-63
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Bionic form heterogeneous composite material (BCHCM), which is inspired by the dolphin skin and formed by the compounding of polyurethane (PU) and cast iron, can be used as drag reduction material. However, PU and cast iron belong to completely different materials. When they are combined together, defects are easily formed on the interface, and these defects will affect their mechanical properties, and so will limit their application in engineering. The purpose of this study was to investigate interfacial nondestructive testing method and pull shear performance of these materials, and provide practical engineering application technology for them. The BCHCM in this study was composed of the surface material (PU) and basal material (cast iron). The elasticity surface material was mixed of polyurethane pre polymers (PUP) (C10H8N2O2&bull;C6H14O3) and curing agent (C13H12N2CL2), and the contents of them were measured by quality ratio. In order to understand the effect of above two components on the shear stress, three kinds of quality ratios were considered, which were 100:10, 100:12 and 100:14.6 respectively. The basal material of cast iron and the bionic form were composite together using the casting and compressive moulding method. Nondestructive testing method for this composite material was investigated using EUT-101B ultrasonic flaw detector, and the dual probes were put on two sides of the BCHCM. One probe transmitted signal and the other probe received signal, and defect was judged through the changes of transmission acoustic intensity. The results showed that the transmission acoustic intensity of good interface was larger than that of defective interface. This was due to the thin layer of air existed on the defective interface that hindered the transmission of sound wave, which made the transmission acoustic intensity relatively small. So during the process of detection, the region where transmission acoustic intensity was significantly lower than other places can be considered to be defect, otherwise, there were no defects. After that, pull shear performance test of 3 samples which were believed to have good interfaces and 3 samples with flaw interfaces using above nondestructive testing method was carried out. The test results showed that the pull shear curves of good interface samples were better than those of flaw interface samples, which had a certain repeatability and the repeatability was good. However, for the flaw interface samples, the pull shear performance was greatly reduced, and the curves of them had no rules to follow. The results of above experiment verified the feasibility and effectiveness of the double probe nondestructive testing method for the BCHCM. In addition, pull shear performance of the BCHCM was tested using the orthogonal experiment optimization design with two factors and three levels. The two factors were ratio of surface material and morphology of composite interface. The experimental results with range analysis showed that the primary and secondary factors influencing pull shear performance of the BCHCM were interface morphology and surface material ratio respectively under the premise of the composite interface without defects. When the surface material ratio was 100:12 and the composite interface was bionic morphology, the maximum pull shear stress was 1233.83 N. This study provides basic nondestructive testing method for the BCHCM and also provides a reference for the practical application in engineering. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Interfaces (materials)
Controlled terms:Acoustic intensity - Bionics - Bridge decks - Cast iron - Composite materials - Iron - Iron compounds - Materials testing - Mechanical properties - Morphology  - Nondestructive examination - Optimization - Polyurethanes - Probes - Shear flow - Shear stress - Surface defects - Testing - Ultrasonic applications - Ultrasonic testing
Uncontrolled terms:Heterogeneous composite materials - Heterogeneous compounds - Interface morphologies - Nondestructive testing method - Practical engineering applications - Shear performance - Transmission of sounds - Ultrasonic flaw detectors
Classification code:401.1 Bridges - 415 Metals, Plastics, Wood and Other Structural Materials - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 422.2 Strength of Building Materials : Test Methods - 423 Non Mechanical Properties and Tests of Building Materials - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 545.1 Iron - 545.2 Iron Alloys - 731.1 Control Systems - 751.2 Acoustic Properties of Materials - 753.3 Ultrasonic Applications - 804.1 Organic Compounds - 811 Cellulose, Paper and Wood Products - 815.1.1 Organic Polymers - 921.5 Optimization Techniques - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 31>

Accession number:20151700790304
Title:Impact of blade outlet angle on acoustic of centrifugal pump as turbine
Authors:Dong, Liang (1); Dai, Cui (2); Kong, Fanyu (1); Fu, Lei (3); Bai, Yuxing (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China; (2) School of Energy and Power Engineering, Jiangsu University, Zhenjiang, China; (3) College of Mechanical and Electrical Engineering, Sichuan University of Science &amp; Engineering, Zigong, China
Corresponding author:Dai, Cui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:69-75
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a kind of energy saving technology by recovery of residual pressure, the centrifugal pump as turbine (PAT) has been widely used in many fields. To improve the efficiency of energy recovery, the PAT is gradually developing for high power. The flow-induced noise becomes one of the most important issues that cause negative effect on reliability. The flow-induced noise consists of flow-borne noise and flow-induced structure noise from dipole source. In order to identify the effect of blade outlet angle on flow-induced noise of the PAT, a single-stage end-suction centrifugal pump as turbine was chosen as research model. The blade outlet angles were set to 20&deg;, 30&deg; and 40&deg; respectively, while the rest geometric parameters of impeller and volute were kept unchanged. The flow-induced interior/exterior acoustics of the PAT were studied experimentally and numerically. A synchronous acquisition of performance parameters and noise signals were realized on the basis of INV3020C data acquisition system and performance test system in an open test loop. The liquid was pressurized through booster pump, and then impacted the turbine's impeller to make it rotate. The dynamometer consumed and measured the turbine's energy. The operating condition was adjusted by regulating the converter's frequency to change the booster pump's capacity. Experimental studies on acoustic characteristics at downstream of the PAT were carried out on the test bench at variable flow rates. The flow-induced noise signals were collected using hydrophone at a sampling frequency of 25 600 Hz. The signals were amplified and recorded by INV3020C data acquisition system, and Fast Fourier Transform was used to compute the spectra with the Hanning window for reducing the spectrum leakage. The computational fluid dynamics (CFD) numerical simulation was firstly performed to obtain noise-generating fluid forces. In this step, the k-&Epsilon; turbulence model was used to solve transient flow field in the PAT, and a time series for pressure fluctuations at fluid-wall interface was obtained. Then, the boundary element method (BEM) was applied to study flow-borne noise caused by impeller and casing dipole sources in interior acoustics of the PAT. Meanwhile, the finite element method/automatically matched layer (FEM/AML) technology was used to study exterior acoustics considering the structure's vibration due to casing source. The interior acoustics were calculated and compared with experimental results, showing that the k-&Epsilon; turbulence model combined with the BEM for flow-borne interior noise computation was verified. And in the validation of finite element model of casing structure, the exterior acoustics were investigated. In order to investigate the sound's spatial distribution around the PAT, 3 monitoring planes and 36 monitoring points were arranged every 1 meter farther from the center of impeller, and noise directivity distribution was obtained by using FEM/AML calculation. Then, the impact of blade outlet angle on interior/exterior acoustics of the PAT was investigated. Results showed that flow-borne noise due to casing source could reflect joint action of multiple sources. Its spectrum curve agreed well with experimental result, with an error of 3.7% at blade passing frequency (BPF) by the BEM. With the increase of outlet angle, the efficiency within overall flow range reduced. Taking one-third octave A-weighted sound pressure level and sound power level as criteria, the outlet angle had a certain influence on interior/exterior acoustics. Considering both hydraulic performance and noise, a suitable blade outlet angle of 30&deg; exists which ensures a better comprehensive performance of the PAT. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Acoustic noise
Controlled terms:Acoustic wave propagation - Acoustics - Boundary element method - Centrifugal pumps - Computational fluid dynamics - Data acquisition - Energy conservation - Fast Fourier transforms - Finite element method - Hydraulic motors  - Impellers - Models - Pumps - Sailing vessels - Turbine components - Turbines - Turbomachine blades - Turbulence models
Uncontrolled terms:Acoustic characteristic - Blade passing frequency - Comprehensive performance - Data acquisition system - Energy-saving technologies - Flow induced structure - Outlet angle - Synchronous acquisition
Classification code:443.1 Atmospheric Properties - 525.2 Energy Conservation - 601.2 Machine Components - 617 Turbines and Steam Turbines - 618 Compressors and Pumps - 618.2 Pumps - 632.2 Hydraulic Equipment and Machinery - 674.1 Small Marine Craft - 723.2 Data Processing and Image Processing - 751 Acoustics, Noise. Sound - 902.1 Engineering Graphics - 921.3 Mathematical Transformations - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.06.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 32>

Accession number:20151700790305
Title:Effect of blade tail's shape on hydraulic performance of bidirectional bulb turbine
Authors:Zheng, Xiaobo (1); Weng, Kai (1); Wang, Lingjun (1)
Author affiliation:(1) Department of Hydraulic Power Engineering, Xi'an University of Technology, Xi'an, China
Corresponding author:Zheng, Xiaobo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:76-81
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Tidal power is pollution-free renewable energy and an effective way to reduce coal consumption and guarantee normal social electricity consumption in China. Bidirectional bulb turbine is widely used in tidal power station. Scholars at home and abroad have carried out extensive researches in bidirectional tubular turbine in terms of internal blade clearance flow, the occurrence and location of cavitation and blade airfoil optimization.Scholars in China firstly put forward improving the operating efficiency of the bidirectional tubular turbine under the reverse working condition by means of setting rear guide vanes. In order to solve the low efficiency problem under the reverse condition in bidirectional bulb turbine, how blade tail affected the units' hydraulic performance under reverse working condition by studying bade tails of different shapes and different thickness on the basis of a bidirectional bulb turbine unit with rear vanes was analyzed. The profile of computational domain was built with modeling software UG and the grid division was done with software ICEM, also the grid independence verification for runner parts was conducted. Based on the CFX software, the SST turbulence model was adopted to conduct numerical simulation on runners with blade tails of different shapes and thickness. Results showed, under reverse conditions, the efficiency of the units with circular blade tail was 59.55%, which was higher than 58.4% and 58.01% of units with rectangular and arched tailing edge respectively, indicating that the impact loss of runner with rectangular tail and curved tail was bigger. Moreover, increasing the thickness of the blade tail could improve the efficiency of the turbine relatively obvious under the reverse condition, and the efficiency could reach at 79%, but the method no longer worked when the blade tail thickness increased to a certain degree. The increase of the tail thickness changed pressure distribution on the blade suction surface, and the minimum pressure value reduced by 1 200 000 Pa under reverse condition on the blade tail, which greatly affected the cavitation performance under the reverse condition. Increasing the thickness of blade tail caused squeezing action to the passage channel, which increased the positive condition efficiency but the effect was not obvious. However, the increase of blade's tail thickness decreased the frequency of the Karman vortex at the tail outlet under positive conditions, as the frequency of the unit components was usually low frequency, the probability of the occurrence of Karman vortices on positive condition was increased. The results showed that compared with rectangular blade tail and arched blade tail, the unit with circular blade tail performed the best under reversal conditions. We can conclude that in order to improve the units efficiency under the reverse condition, thickness of blade tail can be appropriately increased. But that could been donein the premise of ensuring Karman vortices resonance wouldn't occur with other components of the unit under positive conditions. The research results provided references for optimization design of blade tail shape under the reverse condition in bidirectional turbine. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Turbine components
Controlled terms:Arches - Bulb turbines - Cavitation - Computer software - Efficiency - Hydraulic motors - Models - Tidal power - Tubular turbines - Turbines  - Turbomachine blades - Turbulence models - Verification - Vortex flow
Uncontrolled terms:Blade suction surface - Blade tail - Cavitation performance - Computational domains - Electricity-consumption - Hydraulic performance - Reverse condition - SST turbulence models
Classification code:408.2 Structural Members and Shapes - 615.6 Wave Energy - 617 Turbines and Steam Turbines - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 632.2 Hydraulic Equipment and Machinery - 723 Computer Software, Data Handling and Applications - 902.1 Engineering Graphics - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2015.06.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 33>

Accession number:20151700790313
Title:Multiple inverse models for estimating soil hydraulic parameters based on field-scale moisture content observation
Authors:Liu, Zhao (1); Yang, Wenyuan (1); Zha, Yuanyuan (1); Yang, Jinzhong (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China
Corresponding author:Yang, Jinzhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:135-144
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Unsaturated zone hydrological processes played an important role between the processes of surface and groundwater hydrology. The Richards' equation was widely utilized to describe unsaturated zone flow due to its solid physical foundation. It was essential to know the parameters of this equation before simulation, and these parameters were also called as soil hydraulic parameters in this paper. Comparing with experimental methods, the inverse method was a more realistic way to obtain parameters. Universal Inverse Code (UCODE) using gradient-type minimization method provided users with flexibility in estimating parameters of forward models. However, there were many numerical methods to solve Richards' equation, and four representative numerical models discussed in this paper were Ross model, Picard-&theta; model, Picard-mix model and Picard-h model, respectively. It had been known that the Ross model was of the most computational efficiency, while Picard-h model may lead to serious mass balance problem. Based on the combination of UCODE and four numerical models of Richards' equation, four different inverse models of unsaturated flow were constructed in this paper to optimize three parameters of Richards' equation, i.e., K&lt;inf&gt;s&lt;/inf&gt; (Saturated Hydraulic Conductivity), &alpha; (Reciprocal of Air Entry Pressure) and n (Grain Size Distribution Parameter). In this paper, a ten days infiltration test was conducted in a 7.77 m &times;29.38 m area located in Wuhan University Water Conservancy and Water Environmental Laboratory (China), and observed data was the soil water content measured by TRIME-PICO IPH system. Every 24 hours was as an irrigation-measurement period. The upper boundary flux R&lt;inf&gt;a&lt;/inf&gt;[L/T] changed with time. More specifically, R&lt;inf&gt;a&lt;/inf&gt; was 80 mm/d during the first 3 hours, while it was 0 mm/d in the last 21 hours. Before the infiltration test, K&lt;inf&gt;s&lt;/inf&gt; was measured directly by 29 double rings, and the others parameters were measured by centrifugal method (4 filled samples and 36 undisturbed samples). The parameters K&lt;inf&gt;s&lt;/inf&gt; and &alpha; significantly varied in space, while the variance of soil water content decreased with time due to uniform upper boundary in space. The measured soil hydraulic parameters were used as initial value, and then K&lt;inf&gt;s&lt;/inf&gt;, &alpha; and n were respectively estimated by the four inverse models based on the soil water content observed in the field scale. Several indexes, i.e. R&lt;sup&gt;2&lt;/sup&gt; (Coefficient of Determination), RMSE (Root Mean Squared Error), BIAS, IA (Index of Agreement), were used to evaluate the precision that the simulated model results matched the observed variables. By comparison of these indexes, the precision order of the four inverse models and measured parameters from high to low was as follows: Ross inverse model (RMSE: 0.0123), Picard-&theta; inverse model (RMSE: 0.0124), Picard-mix inverse model (RMSE: 0.0125), Picard-h inverse model (RMSE: 0.0128) and measured parameters (RMSE: 0.0138). The reason for the minimal differences of soil water content data simulated by the four models was that water retention curves (or unsaturated hydraulic conductivity curves) described by the four groups of optimized parameters were close to each other. Besides, the precision of the four inverse models were marginally improved with smaller grid size. In addition, the parameter equal finality was discussed in this paper. A group of parameters, by which RMSE is less than 0.0128 in this paper, can be called equivalent parameters. It can be noticed that the curves intersected in the soil water moisture interval where there were more observation values. The equal finality zone was defined as the envelopes of water retention curves or unsaturated hydraulic conductivity curves described by equivalent parameters. We discussed equal finality zones at three cases (RMSE&le;0.128, RMSE&le;0.128, RMSE&le;0.125 and RMSE&le;0.124) and pointed out that the width of equal finality zone became narrower with the demand of higher precision. The equal finality zone was also used to illustrate the fact that the precision of the filled samples were much higher than that of undisturbed samples. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Infiltration
Controlled terms:Computational efficiency - Curve fitting - Grain size and shape - Groundwater - Hydraulic conductivity - Inverse problems - Laboratories - Mean square error - Models - Moisture  - Numerical methods - Numerical models - Parameter estimation - Soil moisture - Soils - Solute transport - Water management
Uncontrolled terms:Coefficient of determination - Environmental laboratories - Inverse modeling - Parameter equal finality - Richards 'equation - Saturated hydraulic conductivity - Soil hydraulic parameters - Unsaturated hydraulic conductivity
Classification code:444 Water Resources - 444.2 Groundwater - 446 Waterworks - 483.1 Soils and Soil Mechanics - 632.1 Hydraulics - 731.1 Control Systems - 801 Chemistry - 801.4 Physical Chemistry - 902.1 Engineering Graphics - 921 Mathematics - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.06.019
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 34>

Accession number:20151700790334
Title:Design and experiment of wine grape threshing mechanism with flexible combing striping monomer
Authors:Li, Chao (1); Xing, Jiejie (1); Xu, Liming (1); He, Shaolin (1); Li, Shijun (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Xu, Liming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:290-296
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, the rapid growth of China's wine industry is promoting the increase of vineyards. However, the wine grapes are harvested entirely depending on hand picking in China with high cost. The old harvesting method restricts the widespread popularization and planting of wine grapes. Research on picking machine and picking mechanism of wine grapes is in its infancy in China. A study was conducted to change the artificial harvesting status of the wine grapes, promote the mechanization of the wine grapes thread mechanism, and establish the theoretical guidance and design basis for the picking machine of wine grapes for Chinese national conditions. First, a new-type wine grape thread mechanism by flexible combing striping mode was designed. The mechanism mainly consists of the multiple flexible pole teeth, a pair of combing rollers and a supporting power control system. The flexible pole teeth are the core component. It is U-structure and consists of the steel wire rope and silicone tube. The steel wire rope can change the bending stiffness of the flexible pole tooth by change its diameter. The silicone tube sleeves the steel wire rope, which can reduce the harm on grapes, and increase the friction between grape berries and the pole teeth. At the same time, the flexible pole teeth are fixed on a pair of counter-rotating combing rollers in a certain way. When the mechanism works, it threads the grapes by the flexible pole teeth. The main threshing form of grapes is that the grape brush pulls out from the grape berry. Second, for an in-depth analysis of the stripping mechanism, the parameterized model was established, and the flexible simulation model of the flexible pole teeth and stalks, which are discrete rigid bodies through a flexible BUSH connection, was built. By using the generalized force to establish the connection force between grape berry and stalk, and the sensor to monitor fracture condition, the grape threshing process was realized under the action of external force control, which solved the key problems of threshing simulation process control of multiple objects. The influences of three factors, i.e. the rotational speed, the bending stiffness and the distance of rotary shafts were analyzed through the simulation during the wine grape threading process. And it was found that they all could influence the threading process in certain degree. Last but the most important, based on the above simulation and analysis, the rotational speed, the bending stiffness and the distance of rotary shafts were taken as the orthogonal test factors. The rotating speed of combing roller selected three levels including 120, 160 and 200 r/min. The bending stiffness selected three levels including 0.029, 0.067 and 0.09 N&middot;m&lt;sup&gt;2&lt;/sup&gt;. The distance of rotary shafts selected three levels including 280, 300 and 320 mm. The threshing time and the broken rate were selected as indices in the orthogonal test. The results showed that there were some errors between the actual and the simulated experiment results, which needed the further research. The flexible pole tooth's bending stiffness was the only significant factor for the index of breakage and threshing time. In addition, the effect of the bending stiffness on wine grape picking was analyzed by the experiment. When the rotating speed of combing roller was 160 r/min, the bending stiffness of flexible pole tooth was 0.067 N&middot;m&lt;sup&gt;2&lt;/sup&gt; and the distance of combing rollers was 280 mm, the results showed that the threshing time was 1.73 s and the broken rate was 3.51%, which was the best. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Process control
Controlled terms:Agriculture - Crops - Fruits - Harvesting - Machinery - Mechanization - Mooring - Poles - Rollers (machine components) - Rope  - Rotating machinery - Silicones - Stiffness - Tubes (components) - Wine - Wire - Wire rope
Uncontrolled terms:Agriculture machinery - External force control - Flexible combing - Simulated experiments - Simulation - Simulation and analysis - Stripping mechanisms - Thresh
Classification code:408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 535 Rolling, Forging and Forming - 535.2 Metal Forming - 601 Mechanical Design - 616.1 Heat Exchange Equipment and Components - 672 Naval Vessels - 731 Automatic Control Principles and Applications - 816 Plastics and Other Polymers: Processing and Machinery - 817 Plastics and Other Polymers: Products and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 35>

Accession number:20151700790333
Title:Development and test of continuous combined mid-infrared with hot air drying equipment
Authors:Xie, Xiaolei (1); Zhang, Chunhui (1); Jia, Wei (1); Li, Xia (1); Wang, Zhaojin (2); Mu, Guofeng (3)
Author affiliation:(1) Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China; (2) Tai Zhou Sheng Tai-ke Infrared Technology Co. Ltd, Taizhou, China; (3) Inner Mongolia Meng Du Sheep Food Co. Ltd, Chifeng, China
Corresponding author:Zhang, Chunhui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:282-289
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Drying efficiency was always considered to be the most important factor by factories, however, low thermal conductivity and case hardening of the material slowed the moisture migration in hot air drying, and resulted in more time and energy consumption. So to solve the existing problems of present drying equipment, a continuous drying equipment of combined mid-infrared and hot air (CMIHA) was developed in this paper. This drying equipment included feed section, heating sections and cooling section, of which each heating section was made up of four parts, i.e. conveying system, heating system, convective circulation system and control system. As we all know, since infrared energy is converted into heat only when material absorbs the radiation, it was essential to select a heat source emitting radiation with the range in which the material to be processed had maximum absorption. So, the radiation wavelength of infrared was selected by the infrared spectra of meats, and the radiation intensity could be controlled by changing the amount of working lamps to make good use of the radiation energy. At the same time, this equipment was developed by calculating the main technological parameters of convection system, cooling system and heating system, and then the production verification test was also done to compare the difference between CMIHA drying and hot air drying on beef jerky. Results showed that, in the same conditions (heating power 105 kW, heating temperature 70, wind velocity 1 m/s, cooling wind velocity 3 m/s, heating distance 8 cm), compared with hot air drying, the continuous CMIHA drying equipment could speed up muscle protein denaturation, reduce activation energy, reduce the energy that jerky needed to accelerate moisture migration, and improve drying efficiency. The time consumption that the beef samples in the first row on the conveyor dehydrated from raw to weight reduction by 50% for CMIHA drying equipment was 120 min, and the production efficiency was 120 kg/h, if the working time of equipment was more than 10 h every day. However, the time consumption and production efficiency of hot air drying equipment were 280 min and 40 kg/h, respectively. Besides, compared with hot air drying equipment, CMIHA drying equipment could reduce the case hardening of jerky, significantly decrease (P&lt;0.05) the value of shear force and shrinkage rate, and increase (P&lt;0.05) the values of chewiness of jerky, and the chewiness, shear force and shrinkage rate were 44.79 N, 143.59 N and 45.48%, respectively, but those of hot air drying were 35.87 N, 182.69 N and 55.0%, respectively. As we all know, different kinds of myoglobin can make meat have different colors, of which myoglobin is kermesinus, oxymyoglobin is bright red and metmyoglobin is taupe brown. Compared with hot air drying equipment, CMIHA drying equipment could increase the content of oxymyoglobin, and reduce the content of metmyoglobin, which made jerky have better color. The values of a* (redness value), C* (chroma value) and H* (hue value) of jerky dried with CMIHA were significantly higher (P&lt;0.05) than hot air. Besides, the sensory evaluation of jerky dried with CMIHA drying had higher scores than hot air drying. This study can provide valuable information for designing and developing this new continues combined mid-infrared and hot air drying equipment that can be used for solving the problems that low drying efficiency and poor quality of jerky. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Infrared drying
Controlled terms:Activation energy - Agricultural machinery - Air - Case hardening - Chemical activation - Conveyors - Cooling - Drying - Energy efficiency - Energy utilization  - Equipment - Hardening - Heating - Heating equipment - Image quality - Infrared devices - Meats - Metal drawing - Moisture - Shrinkage  - Solar dryers - Thermal conductivity - Thermal processing (foods) - Wind
Uncontrolled terms:Circulation systems - Drying efficiency - Heating temperatures - Low thermal conductivity - Midinfrared - Production efficiency - Radiation wavelength - Technological parameters
Classification code:443.1 Atmospheric Properties - 525.2 Energy Conservation - 525.3 Energy Utilization - 535.2 Metal Forming - 537.1 Heat Treatment Processes - 641.2 Heat Transfer - 642.1 Process Heating - 642.2 Industrial Furnaces and Components - 643.1 Space Heating - 692.1 Conveyors - 741 Light, Optics and Optical Devices - 741.3 Optical Devices and Systems - 801.4 Physical Chemistry - 802.1 Chemical Plants and Equipment - 804 Chemical Products Generally - 821.1 Agricultural Machinery and Equipment - 822.2 Food Processing Operations - 822.3 Food Products - 901 Engineering Profession
DOI:10.3969/j.issn.1002-6819.2015.06.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 36>

Accession number:20151700790315
Title:Simulation on potential effects of drought on winter wheat in Huang-Huai-Hai Plain from 1981 to 2010
Authors:Xu, Jianwen (1); Ju, Hui (2); Mei, Xurong (2); Liu, Qin (2); Yang, Jianying (2)
Author affiliation:(1) Dalian Meteorological Service Center, Dalian, China; (2) State Key Engineering Laboratory of Crops Efficient Water Use and Drought Mitigation, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Science, Beijing, China; (3) Key Laboratory of Agricultural Environment, Ministry of Agriculture, Beijing, China; (4) Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Beijing, China
Corresponding author:Liu, Qin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:150-158
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Grain yields of rainfed winter wheat in the Huang-Huai-Hai Plain are often low and vary substantially from season to season. In the past several decades, amount of precipitation in the Huang-Huai-Hai Plain has fallen dramatically. By contrast, agricultural water consumption is so great that water resource is insufficient, leading to excessive exploitation of underground water, in which case irrigation water is far from enough. Under the backdrop of great climate changes, lack of irrigation water and severe drought will have potential impact on winter wheat yield. Simulating the effect of drought on winter wheat has been identified as an important contributor to agricultural production in such environments. In this paper, based on meteorological data and field observations of 6 typical meteorological stations from six agricultural sub-regions of the Huang-Huai-Hai Plain from 1981 to 2010, the yield reduction rate of potential drought in critical growth stages of winter wheat was determined in the Huang-Huai-Hai Plain. Then the probability distribution of yield reduction of 6 typical sites and the relationship between variation of soil moisture and yield in typical wet and dry years were analyzed. The results showed that the regional simulation capability was acceptable and the 3H could be the representative variety of winter wheat in Huang-Huai-Hai Plain for simulation. Regional distribution of yield reduction rate was gradually growing serious from south to north in jointing-heading stage, and the yield reduction rates in agricultural region I, II and  were more than 40%, and in Region IV, V and VI were 38%, 27% and 13% respectively. The regional distribution of yield reduction rate of each agricultural region was mainly caused by the climatic factors. In addition, the probability of the same level of yield reduction rate in jointing-heading stage was much larger than that in filling stage. The probability of the same level of yield reduction rate in northern region was much larger than that in partial southern area. In the drought years, irrigation was needed to provide water for the soil surface layer to meet the demand of winter wheat. If drought happened in the jointing-heading stage and the deep-layer soil water was insufficient, the wheat had to rely on irrigation to provide sufficient water for its later growth stage. If drought happened in the filling stage, the wheat root systems had to grow down deeper to get more water, which would cause the reduction in the wheat yield. China has insufficient water resource, which is especially true in North China. The limited water resource should be applied in critical regions and stages. Water saving and drought prevention are a long-term task. Prediction shall be made on water stress in key growth stages and simulation analysis shall be performed on crop models to determine potential yield reduction due to drought, thereby to make reasonable and scientific irrigation measures. This will have referential value for evading drought risks and developing water-saving agriculture under climate changes. The results are expected to provide basic information for drought management and rational irrigation of winter wheat in the Huang-Huai-Hai Plain by focusing on the potential drought in critical growth stages of winter wheat. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Water resources
Controlled terms:Agriculture - Climate change - Crops - Cultivation - Drought - Geographical distribution - Groundwater - Irrigation - Meteorology - Models  - Probability - Probability distributions - Soil moisture - Soil surveys - Soils - Water - Water conservation - Water supply
Uncontrolled terms:DSSAT - Growth stages - Huang-Huai-Hai Plain - Winter wheat - Yield
Classification code:443 Meteorology - 444 Water Resources - 444.2 Groundwater - 446.1 Water Supply Systems - 451 Air Pollution - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.06.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 37>

Accession number:20151700790317
Title:Photosynthetic response of yield enhancement by nitrogen fertilization in winter wheat fields with drip irrigation
Authors:Zhang, Yanqun (1); Wang, Jiandong (1); Gong, Shihong (1); Sui, Juan (1)
Author affiliation:(1) Department of Irrigation and Drainage, China Institute of Water Resources and Hydropower Research, Beijing, China
Corresponding author:Wang, Jiandong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:170-177
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is essential to understand the underlying physiological regulation of the effects of nitrogen fertilization to yield. Exploring the characteristics of flag leaf photosynthesis after the headed stage is of importance since the flag leaf assimilation product of this stage are the main sources of yield. In this research, winter wheat fields with sufficient drip irrigation and different nitrogen fertilization treatments were selected as the object of the study. Three nitrogen fertilization levels were designed. Net photosynthetic rate to photo active radiation (PAR) curves of different stages were measured with Li-cor 6400 portable photosynthesis system, to get the capacity of photosynthesis, i.e. the maximum photosynthetic rate (A&lt;inf&gt;max&lt;/inf&gt;) and the apparent quantum yield (&alpha;). The specific leaf mass (SLA), leaf nitrogen content per leaf mass (N-mass), leaf nitrogen content per leaf area (N-area) and &lt;sup&gt;13&lt;/sup&gt;C carbon isotope discrimination rate (&Delta;) were also determined by analyzing the leaf samples after photosynthesis measurements. Yield and water use efficiency were also estimated. The light curves were fit using a non-rectangular hyperbolic regression to obtain the relevant parameters for a comparison among treatments. Linear fitting was used for the light data at 0-150 &mu;mol/(m&lt;sup&gt;2&lt;/sup&gt;&middot;s), the slope of the line was &alpha; and the intercept was the respiration rate (R&lt;inf&gt;d&lt;/inf&gt;). The results showed that the more nitrogen fertilization significantly increased the parameters of A&lt;inf&gt;max&lt;/inf&gt; and &alpha; (P=0.046), extended the duration of the better photosynthesis function, especially for the highest nitrogen treatments (N3, 221 kg/hm&lt;sup&gt;2&lt;/sup&gt;). R&lt;inf&gt;d&lt;/inf&gt; and PAR&lt;inf&gt;c&lt;/inf&gt; showed no significant differences among treatments for the measurements on May 21&lt;sup&gt;st&lt;/sup&gt;-23&lt;sup&gt;rd&lt;/sup&gt; and June 2&lt;sup&gt;nd&lt;/sup&gt; -3&lt;sup&gt;rd&lt;/sup&gt;. The mean values of R&lt;inf&gt;d&lt;/inf&gt; of the three measurements were 1.54, 1.98 and 1.90 &mu;mol/(m&lt;sup&gt;2&lt;/sup&gt;&middot;s), respectively. The A&lt;inf&gt;max&lt;/inf&gt; values gradually decreased over the duration of the field trial. The A&lt;inf&gt;max&lt;/inf&gt; of N3, N2 and N1 treatments on June 2&lt;sup&gt;nd&lt;/sup&gt;-3&lt;sup&gt;rd&lt;/sup&gt; were 14.0%, 28.9% and 39.9% lower than the A&lt;inf&gt;max&lt;/inf&gt; values measured on May 4&lt;sup&gt;th&lt;/sup&gt;-5&lt;sup&gt;th&lt;/sup&gt;, respectively. The A&lt;inf&gt;max&lt;/inf&gt; of the high N treatment, i.e. the N3 treatment, was kept fairly high even at the end of the milky stagy in the June 2-3 measurement. That's the reason of the highest yield of the N3 treatment. However, the evapotranspiration were not affected significantly by nitrogen treatments in this study. In this case, the water use efficiency of the N3 treatments was the highest. The yield of winter wheat for N3, N2 and N1 were 6646.5, 6 302.2 and 5810.2 kg/hm&lt;sup&gt;2&lt;/sup&gt;, respectively. Y of N3 was 14.4% higher than that of N1 with significantly difference (P=0.046). The WUEa values of N3, N2 and N1 treatments were 14.34, 13.41 and 12.25 kg/(hm&lt;sup&gt;2&lt;/sup&gt;&middot;mm) respectively. The enhancement of A&lt;inf&gt;max&lt;/inf&gt; were related to the SLA, N-mass, N-area and &Delta;. Except that A&lt;inf&gt;max&lt;/inf&gt; was with marginally significant linear correlation with &Delta; (P=0.057) for N1 treatment, under all other treatments, there were significant linear relationships between A&lt;inf&gt;max&lt;/inf&gt; and SLA, &Delta;, N-mass and N-area. N treatments affected those relationships significantly. With the decreased N fertilization, absolute values of slopes of the regression lines were increased, suggesting that A&lt;inf&gt;max&lt;/inf&gt; is highly sensitive to the above parameters if lower N applied. In the relationships between A&lt;inf&gt;max&lt;/inf&gt; and leaf N content, the absolute value of Y-intercept of the N3 treatment was the highest and the slope was the lowest, suggesting that the A&lt;inf&gt;max&lt;/inf&gt; of N3 were higher at a given leaf N content, both at the mass and area basis. This may be interpreted as a result of changes in nitrogen partitioning in the photosynthetic apparatus. The results of this study explained the underlying photosynthetic regulation of yield enhancement by nitrogen fertilization in winter wheat fields. Moreover, the photosynthesis and leaf traits parameters determined in this study are readily to be used in some crop models to increase the accuracy of estimation under conditions of nitrogen treatments. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Nitrogen fertilizers
Controlled terms:Crops - Efficiency - Irrigation - Isotopes - Nitrogen - Photosynthesis - Physiology - Water supply
Uncontrolled terms:Carbon isotope discrimination - Leaf nitrogen content - Net photosynthetic rate - Nitrogen fertilization - Photosynthetic apparatus - Photosynthetic response - Water use efficiency - Yield
Classification code:446.1 Water Supply Systems - 461.9 Biology - 741.1 Light/Optics - 804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2015.06.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 38>

Accession number:20151700790323
Title:Forest stand spatial structure measurement method using handheld tree measurement smart station
Authors:Feng, Zhongke (1); Xu, Weiheng (2); Yang, Liyan (1)
Author affiliation:(1) Beijing Key Laboratory of Precision Forestry, Beijing Forestry University, Beijing, China; (2) Computer and Information Institute, Southwest Forestry University, Kunming, China
Corresponding author:Xu, Weiheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:213-217
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Spatial structure is an important characteristic of forest and spatial distribution pattern is one part of researches on population spatial behavior.Based on the relationship of neighborhood trees, three kinds of stand spatial structure parameters including uniform angle index,mingling and dominance was proposed by Professor Gangying Hui. In the past decade, stand spatial structure parameters are widely used to analyze stand spatial structure, calculate trees dominance, judge competition among trees, measure species diversity and recover or reconstruct stand structure at domestic and international study.. Measurement accuracy of spatial structural parameters (uniform angle index, mingling degree, and dominance) has a significant role in studying stand spatial structure. In the traditional direct interpretation method(DIM), it is difficult to measure the angle between reference tree and 4 nearest neighbor trees. For this method, the error derived from tree diameters at breast height is not considered in the process of measurement, so uniform angle index value is inaccurate. Moreover, based on DIM, other two parameters of mingle degree and dominance measurement required at least two operators, one person completed measurement and the other recorded field data, thus it is impossible to calculate the observing results immediately In this paper, a new measuring method named as HSSM was proposed using handheld smart station to measure stand spatial structure parameters in order to enhance measurement precision and accuracy, decrease field investigation workload. For measuring uniform angle index, the angle between reference tree and four nearest neighbor trees is not measured directly. Firstly, X-Y coordinates of reference tree and four nearest neighbor trees are measured using handheld smart station. Secondly, the diameters at breast height of five trees are measured corresponding with each tree, specifically, diameters at breast height measurement is to obtain center coordinates of five selected trees so as to increase angle calculation accuracy. Finally, reference tree as central point, intersection angles between four nearest neighbor trees are resolved according to the law of cosines. According to the above-mentioned measurement method, experiment was carried out in one stand forest plot (100 m&times;100 m) which located at Beijing Olympic Forest Park by three operators. The relative error of uniform angle index average value of HSSM was 2% less than that of DIM, average time-consuming (single person) of HSSM was 90.1s more than that of DIM (double person, 40.7 s), and measurement efficiency of HSSM was 8% lower than that of DIM. The mingle measurement result of HSSM were as the same as that of DIM, but the average time-consuming (single person) of HSSM was 21.5s less than that of DIM (double person, 32.2 s), measurement efficiency of HSSM was about 3 times that of DIM. The results of dominance relative error was 4% between HSSM and DIM, but the average time-consuming (single person) of HSSM was 74.8s more than that of DIM (31.05 s for double person), measurement efficiency of HSSM was 20% lower that of DIM. HSSM had the advantages of single person operation, display and storage directly by the equipment. Moreover, compared with the DIM, HSSM resolved the problem that DIM could not measure the tree center coordinate at breast height of reference tree and nearest neighbor tree, and for HSSM, the distribution of reference tree and nearest neighbor tree could draw conveniently and visually display according to measuring data in the process of interior work. This research can provide references for measuring forest spatial structure measurement accurately and efficiently. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:12
Main heading:Spatial variables measurement
Controlled terms:Data visualization - Digital storage - Efficiency - Forestry - Measurements - Parameter estimation
Uncontrolled terms:Diameters at breast heights - Forest spatial structure - Four-nearest-neighbors - Measurement efficiency - Spatial distribution patterns - Spatial structure - Tree diameters at breast heights - Trees
Classification code:722.1 Data Storage, Equipment and Techniques - 723.5 Computer Applications - 731.1 Control Systems - 821.0 Woodlands and Forestry - 913.1 Production Engineering - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 943.2 Mechanical Variables Measurements - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.06.029
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 39>

Accession number:20151700790310
Title:Effects of seeding date on yield, growth period and utilization of temperature and sunshine of mechanical transplanting rice in different ecological regions
Authors:Sun, Jianjun (1); Zhang, Hongcheng (1); Yin, Haiqing (2); Chen, Bo (1); Guo, Baowei (1); Wei, Haiyan (1); Dai, Qigen (1); Wang, Shengxuan (2); Cheng, Xiangong (2); Jiang, Yuanhua (1); Jiang, Mingbo (3); Du, Yuanzhong (3); Xia, Yan (2)
Author affiliation:(1) Innovation Center of Rice Cultivation Technology in Yangtze Valley, Ministry of Agriculture, Yangzhou University, Yangzhou, China; (2) Cereal Crops Institute, Henan Academy of Agricultural Sciences, Zhengzhou, China; (3) Luoshan Institute of Agricultural Sciences, Luoshan, China
Corresponding author:Zhang, Hongcheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:113-121
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This study was conducted to investigate the effects of seeding date and variety type on yield, growth period and utilization of temperature and sunshine under the rice-wheat cropping system in different ecological regions of Henan Province. Taking conventional medium-maturing medium Japonica rice variety, conventional and hybrid late-maturing medium Japonica rice varieties, conventional early-maturing late Japonica rice variety and hybrid late-maturing medium indica rice variety as experimental materials, high-yield cultivation method of mechanization planting of carpet seedlings was used in three different sites, i.e. Luoshan rice-growing district along the Huai River in,southern Henan Province, Xincai in central Henan Province and Yuanyang rice-growing district along the Yellow River in northern Henan Province. The effects of different seeding dates on yield, growth period and utilization of temperature and sunshine of mechanized planting rice were comparatively analyzed. Within the set range of seeding date in the experiment, except that the yields of conventional medium-maturing medium Japonica rice variety were highest for Luoshan and Xincai in the second sowing period (On May 16) and for Yuanyang in the first sowing period (On May 11), the yields of conventional and hybrid late-maturing medium Japonica rice varieties, conventional early-maturing late Japonica rice variety and hybrid late-maturing medium indica rice variety were all highest in the first seeding period (On May 11) for every site, and it showed a trend of gradual decline along with the seeding date delaying(P&lt;0.01), but significance differences were all different among different variety types and sites. With the delaying of seeding date, yield differences among variety types gradually increased in the same site(P&lt;0.01), of which grain yield of hybrid late-maturing medium Japonica rice variety was the highest in every site, and was significantly higher than other variety types in each period. With the delaying of seeding date, the periods of jointing, heading and maturity of all varieties were correspondingly delayed, and whole growth period, and its accumulated temperature, sunshine hours and utilization rate of TPS all showed a significant decreasing trend (P&lt;0.01). And the reduction of growth period along with the delaying of seeding date, was mainly in vegetative growth phase, i.e. from seeding to jointing stages. Therefore, under the condition of rice-wheat cropping system with mechanical planting in Henan Province, the preferred variety that was firstly chosen should be hybird and conventional late-maturing medium Japonica rice varieties in southern Henan, and the variety that was secondly chosen should be conventional early-maturing late Japonica rice variety, and their suitable seeding dates were all from May 11 to May 25. In the northern Henan, the preferred varieties should be the conventional late-maturing medium Japonica rice variety and medium-maturing medium Japonica rice variety, followed by conventional late-maturing medium Japonica rice variety, and their suitable seeding dates were all from May 11 to May 21. The result will provide a reference for the scientific division and the distribution of different rice variety types under mechanical high-yield cultivation and the choosing of its possible seeding date in different ecological areas in Henan Province. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Seed
Controlled terms:Cloud seeding - Cultivation - Ecology - Hybrid materials - Machinery - Temperature
Uncontrolled terms:Growth period - Mechanical transplanting rice - Seeding dates - Using of temperature and sunshine - Yield
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 443.3 Precipitation - 454.3 Ecology and Ecosystems - 601 Mechanical Design - 641.1 Thermodynamics - 712 Electronic and Thermionic Materials - 821.3 Agricultural Methods - 821.4 Agricultural Products - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2015.06.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 40>

Accession number:20151700790340
Title:Non-dimensional mathematical model of magnetized sugarcane juice by micro-filtration membrane separation
Authors:Ma, Sen (1); Gao, Junyong (2)
Author affiliation:(1) College of Grain Oil and Food Science, Henan University of Technology, Zhengzhou, China; (2) Guangzhou Sugarcane Industry Research Institute, Guangdong Key Lab of Sugarcane Improvement &amp; Biorefinery, Guangzhou, China
Corresponding author:Ma, Sen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:333-337
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The physical properties of liquid and the filtration performance of membrane was easily modified by the magnetization process. It meant that the process of membrane separation was difficult to be analyzed because of applying the magnetic field technology. It was also hard to make clear the relationships of all the influence factors just by a simple mathematical derivation, so a suitable non-dimensional mathematical model of membrane flux was used, in order to simulate the separation process of micro-filtration membrane for the magnetized mixed sugarcane juice. The parameters of micro-filtration membrane, operating conditions and flow characteristics of feed liquid were chosen as the main factors in this process, and mathematical statistics were done aiming at the involved parameters and dimensions. A non-dimensional mathematical model was established according to the &pi; theorem, the dimensional consistency principle and the hydromechanics affinity theory. The results showed that the non-dimensional mathematical model mainly consisted of three important dimensionless parameters. The first one was Reynolds number, which represents the characteristics of fluid during the operating process. The second one was Euler number, which represents the characteristics of micro-filtration membrane. The last one was a new Sy number, which shows the group of dimensionless factors associated with physical property parameters of liquid and intensity of magnetic field. In order to verify the accuracy and the practicability of the model, the mixed sugarcane juice was used as a raw material for solving the non-dimensional mathematical model. The magnetic field intensities of 0.1, 0.2, 0.3 and 0.4 T were applied to deal with the mixed sugarcane juice, and the total reflux experiments were used in the process. The membrane flux was determined under the changed conditions of pressure difference between inlet and outlet of membrane, and flow rate, brix and viscosity of feed liquid. All of these parameters and membrane flux were calculated using the established model. The results showed that the coefficient of determination R&lt;sup&gt;2&lt;/sup&gt; of the multivariate regression model was 0.905, and the standard error was 0.173. The F value of variance analysis was 413.604, and the significance probability was 3.911&times;10&lt;sup&gt;-134&lt;/sup&gt;. The P values of q, Reynolds number (x&lt;inf&gt;1&lt;/inf&gt;), Euler number (x&lt;inf&gt;2&lt;/inf&gt;) and two groups of dimensionless factors (x&lt;inf&gt;3&lt;/inf&gt; and x&lt;inf&gt;4&lt;/inf&gt;) in the model were 7.217&times;10&lt;sup&gt;-96&lt;/sup&gt;, 7.174&times;10&lt;sup&gt;-127&lt;/sup&gt;, 4.420&times;10&lt;sup&gt;-6&lt;/sup&gt;, 0.283 and 8.129&times;10&lt;sup&gt;-24&lt;/sup&gt;, respectively. The influence order of model factors from high to low was as follows: x&lt;inf&gt;1&lt;/inf&gt;, q, x&lt;inf&gt;4&lt;/inf&gt;, x&lt;inf&gt;2&lt;/inf&gt; and x&lt;inf&gt;3&lt;/inf&gt;. The results showed that the main flow velocity, operating temperature, intensity of magnetic field and characteristic parameters of membrane tube had great influence on the membrane flux, and the regression analysis model had a high precision. The applied scopes of the model were as follows: 0.050-0.130 MPa pressure difference, flow rate of 2.6-3.9 m/s, brix of 14.5%-16.6%, pH value of 5.00-5.90, operating temperature of 25-60, magnetic field intensity of 0-0.4 T, membrane pore size of 0.20-0.45 &micro;m. The model can predict the membrane flux of magnetic mixed sugarcane juice in the micro-filtration membrane separation process under certain parameters, which provides a simple calculation method for the micro-filtration membrane device design and the operating process conditions. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Filtration
Controlled terms:Flow rate - Flow velocity - Inlet flow - Liquids - Magnetic fields - Magnetism - Magnetization - Membranes - Microfiltration - Models  - Physical properties - Pore size - Regression analysis - Reynolds number - Separation - Statistics - Temperature
Uncontrolled terms:Cane mixed juice - Ceramic micro-filtration membranes - Coefficient of determination - Micro-filtration membranes - Multivariate regression models - Physical property parameters - Regression analysis models - Significance probabilities
Classification code:631 Fluid Flow - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 701.2 Magnetism: Basic Concepts and Phenomena - 802.3 Chemical Operations - 902.1 Engineering Graphics - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.046
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 41>

Accession number:20151700790297
Title:Design and experimental analysis of 4U2A type double-row potato digger
Authors:L, Jinqing (1); Tian, Zhongen (1); Yang, Ying (1); Shang, Qinqin (1); Wu, Jin'e (1)
Author affiliation:(1) Department of Engineering, Northeast Agricultural University, Harbin, China
Corresponding author:L, Jinqing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:17-24
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The domestic potato planting shows the main characteristics that it is distributed in scattered plots and hilly mountains regions with less acreage in the south of China. For some large foreign potato harvesters can be used in only few areas. According to the characteristics of domestic potato planting, the most way of harvesting potato is two-stage harvesting, so the digging model of potato harvester is common in the domestic potato diggers and is used in most areas in China. According to the regional users' feedback information and related field trials, it was found that problems of soil plug and weeds winding often appeared in the process of harvesting, and phenomenon of soil plug was more serious especially in northern cohesive soil. In the north, most of heavy soil not only restricts the development of potato harvest mechanization but also causes the damage of equipment and hence directly affects harvesting efficiency. Soil separation effect of chain elevator parts of potato digger is poor. The technology to prevent weeds winding, soil plug, jams, failure rate and mechanical damage is backward, which causes the damage to machines and tools and affects the efficiency of potato harvest greatly. It can not meet the requirement of the production of heavy soil, and severely restricts the healthy development of potato industry in the regions with heavy soil. So measures should be taken to improve the present situation. There are a lot of potato digger models in domestic, but afore-mentioned problems are almost universal. So designing a machine which can solve the soil plug of potato harvester and weeds winding around on the machine is very necessary. This paper aimed at the problems of chain elevator potato harvester in the process of potato two-stage harvesting, i.e. great resistance, failure rate, high mechanical damage rate and some key technical problems, and the 4U2A type of potato digger was designed. The harvester's structure and working principle were illustrated and its anti-blockage mechanism was theoretically analyzed, which consists of digging shovel, stone gate, front wheel, wheel for pressure grass and chain elevator, and the performance of the whole machine was tested at last. To obtain specific performance parameters, the machine was compared with the old one. The performance indices (obvious rate, injury rate, abrasion rate and productivity) in harvesting of this machine were 98.8%, 0.76%, 1.02% and 0.51 hm&lt;sup&gt;2&lt;/sup&gt;/h, better than the old one (92.21%, 4.92%, 8.45%, and 0.31 hm2/h). Experiment results show that this machine solves the potato harvester's problems such as great resistance, high failure rate, grass winding, jams and soil plug in the process, which not only reduces the energy consumption of the tractor and machine failure rate, improves the efficiency and quality of potato harvest, but also provides the reference for solving the problem of anti-blocking mechanism design of potato harvest machinery. It is helpful for farmers to solve problems encountered in the process of the harvest and promote the development of potato production mechanization in China. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Problem solving
Controlled terms:Agriculture - Chains - Crops - Elevators - Energy efficiency - Energy utilization - Failure (mechanical) - Failure analysis - Harvesters - Harvesting  - Machine design - Machinery - Mechanization - Soils - Wheels - Winding
Uncontrolled terms:Agriculture machinery - Anti-blocking mechanisms - Field experiment - Performance indicators - Potato digger
Classification code:421 Strength of Building Materials; Mechanical Properties - 483.1 Soils and Soil Mechanics - 525.2 Energy Conservation - 525.3 Energy Utilization - 601 Mechanical Design - 601.2 Machine Components - 602.1 Mechanical Drives - 692.2 Elevators - 816.1 Processing of Plastics and Other Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.06.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 42>

Accession number:20151700790336
Title:Effects of two enzymes on qualities of non-fermented dough after freeze-thaw circles
Authors:Yang, Xuan (1); Ye, Xiaofeng (1); Han, Yongbin (1); Li, Yang (2); Lu, Jun (2); Mo, Bin (2)
Author affiliation:(1) Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China; (2) Yangzhou Mingjia Food Limited Company, Baoying, China
Corresponding author:Han, Yongbin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:304-310
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the effect of enzymes on the quality of non-fermented dough after freeze-thaw cycles, the transglutaminase and xylanase were chosen and their effects on the quality of non-fermented dough after freeze-thaw circles were investigated. The low-field nuclear magnetic resonance (LF-NMR), texture profile analyzer and a rheometer were used to observe the changes of frozen non-fermented dough in quality during freeze-thaw cycles. The water loss rate, water distribution and mobility, protein fraction content, textural and rheological properties of the dough samples were evaluated in the experiment. The results showed that: compared with the control group, the additions of transglutaminase and xylanase could change the contents of different protein fractions. Transglutaminase addition could reduce the gliadin and gluten content (P&lt;0.05), and raise the glutenin macropolymer content in the dough, while adding xylanase could increase the gliadin content but reduce glutenin content. The effect of transglutaminase on water extractable arabinoxylan content was not significant (P&gt;0.05), however, the effect of xylanase was significant (P&lt;0.05) compared with the control group, and with the increase of addition dose, the water extractable arabinoxylan content increased. Though transglutaminase addition could accelerate dehydration of the non-fermented dough after freeze-thaw cycles, xylanase significantly reduced water loss rate (P&lt;0.05). Relaxation time T&lt;inf&gt;2(1)&lt;/inf&gt; remained at 1.75 ms except the addition of 10 g/kg transglutaminase which significantly decreased T&lt;inf&gt;2(1)&lt;/inf&gt; to 1.32 ms, and relaxation timeT&lt;inf&gt;2(2)&lt;/inf&gt; were all reduced with the addition of two enzymes. The addition of transglutaminase gradually increased the relative content of deep bound water of the non-fermented dough after freeze-thaw cycles, and its content became to 33.05% when the addition of transglutaminase was 10 g/kg; while the effect of xylanase was opposite. The firmnness, toughness and hardness of samples were significantly decreased (P&lt;0.05) with the addition of xylanase when compared with the control group. The xylanase improved the sample's texture profile better than the transglutaminase. The transglutaminase improved the sample's adhesiveness, elasticity and cohesiveness, and the xylanase decreased hardness and improved elasticity. To optimize the rheological properties of dough, the transglutaminase significantly increased the storage of moduliand the loss of moduli (P&lt;0.05), and more addition more increased. On the contrary, the xylanase had a negative impact. Therefore, the addition of transglutaminase and xylanase played the roles in different aspects to improve the quality of non-fermented dough after freeze-thaw circles. The results provide the theoretical basis for the two enzymes widely application to the frozen non-fermented flour products. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Thawing
Controlled terms:Elasticity - Enzymes - Freezing - Hardness - Nuclear magnetic resonance - Proteins - Rheology - Textures - Water supply systems
Uncontrolled terms:Improvement - Low field nuclear magnetic resonance (LF NMR) - Non-fermented dough - Rheological property - Transglutaminases - Water distributions - Water-extractable arabinoxylan - Xylanases
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 446.1 Water Supply Systems - 804.1 Organic Compounds - 822.2 Food Processing Operations - 931.1 Mechanics - 932.2 Nuclear Physics - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.042
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 43>

Accession number:20151700790339
Title:Recovering protein from surimi wash water after isoelectrically precipitate by chitosan flocculation
Authors:Qi, Xiangming (1); Wang, Lu (1); Lu, Shenjie (1); Wan, Tianwei (2)
Author affiliation:(1) College of Food Sciences and Engineering, Ocean University of China, Qingdao, China; (2) Qingdao Longeasy Biotechnology Co. Ltd., Qingdao, China; (3) Bingzhou Taiyu Wheat Industry Co. Ltd., Bingzhou, China
Corresponding author:Qi, Xiangming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:327-332
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a wastewater, surimi wash water is rich in nutrients, mainly protein. It means both waste of material and pollution to environment. To maximize protein recovery from surimi wash water by eco-friendly techonolgies, purify surimi wash water and increase the utilization efficiency of aquatic resources simultaneously, a combined protein-recovery technology of fractional isoelectric precipitation and chitosan occulation was adopted. The surimi wash water produced from Alaska pollock processing was isoelectrically precipitated fractionally in two points of pH values, which were determined by isoelectric focusing result tested in polyacrylamide gels before. And then the low-concentration supernatant protein was occulated using chitosan. Influences of some dynamic (flocculation time) and thermodynamic (internal factors such as dosage and deacetylation degree of chitosan, and external factors such as temperature and pH value of solution) factors on the occulating process were explored centrally. Thereafter, a 3-factor 3-level experiment of Box-Benhnken design was executed, so as to find out if there was any interactive influence between the factors and obtain optimal occulating conditions. It showed that the isoelectric points of proteins in surumi wash water of Alaska pollock were located around 4.30 and 5.50, which indicated that fractional isoelectric precipitation was feasible in the solution. Total protein recovery up to 77.70% was recorded from isoelectric precipitation fractionally at the pH values of 5.50 and 4.30, which was more efficient than single isoelectric precipitation as reported before. Herein the protein content was decreased from 7.00 to 1.56 mg/mL, and the chemical oxygen demand (COD) was cut down from 8 960 to 3 916 mg/L. Single-factor experiments in the pretreated surimi wash water of 1.56 mg/mL protein showed that, in chitosan occulating process, the increase of flocculation time had a positive effect before 90 min. However, after 90 min, protein flocculating recovery lowered down with time increasing. Chitosan dosage rising led to flocculating recovery increasing before 250 mg/L, almost the same as used in original surimi wash water, and then the influence of this factor became to be a little negative. As to deacetylation degree of chitosan, higher degree gave out more flocculating recovery. The pH value of solution was a key factor of the chitosan occulation, and proper pH value, such as 8.0, got 87.8% flocculating recovery, other than pH values of 4.0-4.5, flocculation could hardly be achieved. As an important thermodynamic factor, temperature of solution had a remarkable effect only when it was above 50. Finally flocculating time and deacetylation degree of chitosan were fixed at 90 min and 95% respectively, and Box-Benhnken experiment was designed with 3 factors i.e. chitosan dosage, pH value and temperature (the range was limited to &lt;40 under consideration for industrial practice) of solution. According to results of response surface analysis, there were significant interactive influences between dosage and pH value, and dosage and temperature respectively. The condition was optimized as pH value of 8.04, chitosan dosage of 369 mg/L and temperature of 19.6. Under the condition, protein recovery up to 94.75% could be achieved, while content of residue protein was decreased to 0.37 mg/mL. Meanwhile 3 040 mg/L COD remained in the cleaned water, which indicated that there were other materials contributing to COD value. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Proteins
Controlled terms:Acetylation - Chemical oxygen demand - Chitin - Chitosan - Electrophoresis - Flocculation - Optimization - pH - Recovery - Surface analysis  - Temperature - Wastewater treatment
Uncontrolled terms:Isoelectric focusing - Isoelectric precipitation - Response surface analysis - Single-factor experiments - Soluble proteins - Surimi - Thermodynamic factors - Utilization efficiency
Classification code:423 Non Mechanical Properties and Tests of Building Materials - 452.4 Industrial Wastes Treatment and Disposal - 531 Metallurgy and Metallography - 641.1 Thermodynamics - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804.1 Organic Compounds - 921.5 Optimization Techniques - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.06.045
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 44>

Accession number:20151700790303
Title:Integration and experiment of clip bale knotter
Authors:Zhang, Ji (1); Geng, Hao (1); Geng, Aijun (1); Li, Ruxin (1)
Author affiliation:(1) Shandong Provincial Key Laboratory of Horticultural Machineries and Equipments, College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, China
Corresponding author:Li, Ruxin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:64-68
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Knotter is in the key position of the rectangular baler, and it's working quality is in direct relation to the job performance of the baler. D type knotter is now used more widely in the rectangular baler, and most of them used in domestic are imported from abroad. It is not only expensive but inconvenient in use and maintenance because of the complicated organization. Therefore, a new clip bale knotter was developed in order to develop independent intellectual property rights and meet the needs of the country. The paper was focused on analyzing the structures and working principles of D type knotter of rectangular baler and food packaging clipper machine to form a new kind of knotter. The main innovation of the new design was that the impacting clip action replaced the original knotting action of D type knotter through the U type clip punching device. To evaluate the knotter device, the architecture and working principles of the clip bale knotter were described and some experimental results of knotter applicability were verified. The clip bale knotter was composed of two parts. One part was based on the fan-shape dentate cam disc of D type knotter, for which the original knotter hook and corresponding meshing teeth of the fan-shape dentate cam disc were dismantled and the clipping rope and cutting rope organization were retained. The other part was added with U type clip punching device, U type clip feed mechanism and the driving machinery of punching. By designing U type clip punching device, driving mechanism of punching as well as U type clip feed mechanism, combining the calculation of the motion sketch of the cam swing rod mechanism, the integration of the clip bale knotter was finished. When the knotter worked, rope was sent to the above of the clipping rope disc by the sending rope needle powered by spindle, then the clipping rope disc was rotated to grip the rope, and the swing shaft of the knotter organization was made to swing by spindle cam through the deep-groove ball bearing. By the cooperation between U type clip feed mechanism and related artifacts of the punching device, U type clip was impacted to form a taut knot in the rope. In the process, the cutter swang to be just above the rope knot, and cutting the rope would end the knotting process. The driving machinery of punching and U type punching device moved back with the work of the swing shaft return spring and pushing rope plate respectively. To test the knotter's applicability, a bedstand was made. The knotting rate was used as the judgment standard. Three kinds of normal U type clips and 3 kinds of ropes were chosen to do the orthogonal experiments. The experimental results showed that when the spindle rotation speed was determined to be 90 r/min, it finished impacting clip within 0.7 s, and the rate of knotting and locking of the new knotter reached 99% and 100% respectively. During the experiment, delivering rope, clipping rope, impacting rope and cutting rope operated at an appropriate time sequence which ensured the knotting process to be finished. Compared with D type knotter, the new device had simpler structure, lower manufacturing difficulty and cost, and the operation and maintenance were more convenient. The results show that the knotter design is feasible and lays the foundation for further optimizing the structure and working parameters of the knotter and its evaluation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Rope
Controlled terms:Agricultural machinery - Ball bearings - Cams - Deep groove ball bearings - Disks (machine components) - Experiments - Intellectual property - Laws and legislation - Locks (fasteners) - Maintenance  - Mechanisms - Structural design
Uncontrolled terms:Baler - Clip - Knotter - Performance - Rectangular bale
Classification code:408.1 Structural Design, General - 535 Rolling, Forging and Forming - 601.2 Machine Components - 601.3 Mechanisms - 821.1 Agricultural Machinery and Equipment - 901.3 Engineering Research - 902.3 Legal Aspects - 913.5 Maintenance
DOI:10.3969/j.issn.1002-6819.2015.06.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 45>

Accession number:20151700790296
Title:Review of multi-scale evapotranspiration estimation and spatio-temporal scale expansion
Authors:Zhang, Baozhong (1); Xu, Di (1); Liu, Yu (1); Chen, He (1)
Author affiliation:(1) State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China; (2) National Center of Efficient Irrigation Engineering and Technology Research-Beijing, Beijing, China
Corresponding author:Zhang, Baozhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:8-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Information of evapotranspiration (ET) at different spatial-temporal scales over croplands is the basis of high-efficient water consumption control and water-saving irrigation management. However, evapotranspiration theory or model parameter at certain scale is highly relied upon the scale. Due to the lack of knowledge of the multi-scale ET spatio-temporal coupling, an incomprehensive understanding to the agricultural water evaluation may lead to incorrect irrigation regime. Therefore, researches on conversion methods for ETs at various spatio-temporal scales are of significant importance for improving regional irrigation regime and maintain sustainable development of agricultural water resources. This study systematically reviewed the measurement and estimation methods for ETs at various spatio-temporal scales, and evaluated the applicability and pros/cons of each method. A further review of the conversion method for ETs at various spatio-temporal scales was given, presenting future study highlights, including the current research focuses such as cooperation &amp; coupling response mechanism of crops for multi-factors, the integration technology of multi-source ET data from various methods at different spatio-temporal scales, the theoretic conversion model at various spatio-temporal scales, and spatio-temporal coupling scales and water-heat-carbon in a unified system. And the future research emphasises were detailed shown as follow: 1) Three aspects of research highlights on ET estimation method were listed below. Firstly, the research highlights on ET estimation model mainly focus on integrating the response mechanism of the crops to many factors such as water, fertilizer, air, heat, light, soil and living beings, building up a regulation &amp; control equation for quantitative coupling and developing the ET estimation method of heterogeneous underlying surfaces in several combination modes including partial irrigation and film covering. On the other hand, the key research on ET measuring method comprises the methods for improving the performance and optimizing the layout of the sensors as well as promoting the ET precision of remote-sensing monitoring area, including the higher parameter precision of the characteristics of the underlying surface in remote-sensing inversion, inversion error analysis and quantitative attributes. Furthermore, the fusion technology of multi-source ET monitoring data at several methods and multi-time/space dimensions, and real-time water shortage diagnosis and precisely controlled irrigation for the crops based on ET information. 2) For conversion methods for time-space dimensions of ET, the following research highlights needs to be paid more attention. Building up the theoretical formula for ET conversion between the dimensions with physical meaning including leaf, single plant, field block, farmland and region (irrigation area) are the key research focuses on conversions among space dimensions of ET. While, for conversion of time dimension of ET, the key researches mainly aims at quantizing the error and uncertainty of the conversion of time dimension of ET in different climates, different crop types, different irrigation systems and different managing modes, and optimizing and recommending the conversion function of time dimension for different regions. With regard to the coupled conversion of time and space dimensions of ET, the development of coupled conversion method for time and space dimensions of ET with physical meaning is the pivot in future. The last but not least, with regard to the expansion and application of the conversion of time and space dimensions for ET, the key research need focus on the evaluation of water utilization efficiency in agriculture at different time and space dimensions as well as the coordinated multi-dimension improvement mode for high-efficient water utilization in agriculture. Over all, the integration of water, heat and carbon in one unified system and the development of ET conversion systems at corresponding time and space dimensions will become the hot spot in this field. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:82
Main heading:Space optics
Controlled terms:Agriculture - Carbon - Crops - Evapotranspiration - Irrigation - Remote sensing - Water conservation - Water resources - Water supply
Uncontrolled terms:Scale expand - Scales - Spatial scale - Spatio temporal - Temporal scale
Classification code:444 Water Resources - 444.1 Surface Water - 446.1 Water Supply Systems - 731.1 Control Systems - 741.1 Light/Optics - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.06.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 46>

Accession number:20151700790312
Title:Improved simulation algorithm for soil colloid fractal aggregation based on unparallel Brownian motion
Authors:Xiong, Hailing (1); Yang, Zhimin (3); Li, Hang (2)
Author affiliation:(1) College of Computer and Information Science, Southwest University, Chongqing, China; (2) Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing, China; (3) College of Resources and Environment, Southwest University, Chongqing, China; (4) Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Southwest University, Chongqing, China
Corresponding author:Yang, Zhimin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:6
Issue date:March 15, 2015
Publication year:2015
Pages:129-134
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The cluster-cluster aggregation (CCA) model bridges the study of colloid aggregation by computer simulation and laboratory experiment. Two distinct and limiting regimes of irreversible colloid aggregation have been identified by computer simulation with the CCA model. One regime is diffusion-limited cluster aggregation (DLCA) corresponding to the rapid colloid aggregation. The other is reaction-limited cluster aggregation (RLCA) corresponding to the slow colloid aggregation. The simulations of the two regimes are both start with N non-overlapping identical particles distributed randomly in a cubic box with side-lengths of L. A three dimensional array, hypothetically named Cube[L][L][L], was usually used to represent the cubic box. Each particle in the cubic box occupies an element of the three dimensional array and are labeled with a different integer. When particles and/or clusters collide and aggregate, all particles in the resulting cluster are modified with the same label (one of them). The progression of Brownian movement and aggregation are realized by updating the labels of the corresponding array elements. However, a critical issue in this kind of simulation is how to efficiently distinguish all of the particles in any selected cluster only based on the three dimensional array Cube[L][L][L] when the cluster is to be moved. Similarly, there are difficulties in the process of collision detection to locate all neighboring positions of the cluster. The traditional method must perform exhaustive search in the whole system, what's more, this kind of exhaustive search will repeated over and over again in the simulation progression. In this paper, the traditional on-lattice CCA algorithm is optimized by improving the storage structure to reduce the time complexity, in which the simulation system is represented by a three dimensional array, while the clusters in the system are simultaneously stored by the linked lists respectively in programming. Another one dimensional array Cluster[N] is used to organize the linked lists and store the basic attributes of the clusters in the system. Initially, N linked lists, each only has one node, are created for the N randomly placed particles. After a cluster is moved, its particles is examined to determine whether any other clusters have been contacted via nearest neighbor occupancy. If aggregation does occur after the collision detection, the simple operation is to link the corresponding clusters. After an aggregation, the array Cluster should be indexed simultaneously because there may be some vacant linked lists. In the later random selection for the potential movement, these vacant linked lists should not be in the candidate lists. For the indexing, a one dimensional array Index[N] is used to store the non-vacant linked list subscripts of the array Cluster[N]. The current length of the Index is the number of the remaining clusters in the system. For example, if the new generated random number for the random selection is k, the label of the next moving cluster should be Index [k], and the linked list of this cluster is exactly linked by Cluster [Index[k]]. From this entry, all the particles in the cluster can be easily accessed. And then, the positions of the six neighboring boxes of each particle in the cluster can also be accessed by the element subscripts of the array Cube, which is needed for the collision detection. Brownian motion, collision detection and aggregation as the basic operations in the CCA simulation are all improved based on the compounded data structure. The results show that the new algorithm achieves linear time complexity from three cubed time complexity. This is a great contribution for researchers in large scale simulation of fractal aggregation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Clustering algorithms
Controlled terms:Algorithms - Brownian movement - Colloids - Data structures - Digital storage - Fractals - Geometry - Models - One dimensional - Random number generation  - Soils
Uncontrolled terms:Cluster-cluster aggregation - Diffusion limited cluster aggregation - Fractal aggregation - Laboratory experiments - Large scale simulations - Linear time complexity - Three dimensional arrays - Time complexity
Classification code:483.1 Soils and Soil Mechanics - 721 Computer Circuits and Logic Elements - 722.1 Data Storage, Equipment and Techniques - 723.3 Database Systems - 801.3 Colloid Chemistry - 902.1 Engineering Graphics - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.06.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.