<RECORD 1>
Accession number:20151800797513
Title:Power matching on loader engine and hydraulic torque converter based on typical operating conditions
Authors:Xu, Lichao (1); Hou, Xueming (1)
Author affiliation:(1) Huaiyin Institute of Technology, Huai'an, China; (2) School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang, China
Corresponding author:Xu, Lichao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:80-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to avoid the deficiencies of obtaining net engine torque in several common methods, and realize more scientific and reasonable matching between engine and hydraulic torque converter, a hydraulic test system for wheel loader was established, the performances of three sensors were calibrated, and a quantitative relationship was obtained between outlet pressure of hydraulic pump and engine torque consumed by the pump. Some actual tests were performed under typical operating conditions, and the test data were processed by a series of procedures, including segmentation, mergence, filtration, elimination of abnormal value and weighted average calculation with nSoft software, and the engine torque actually consumed by loader hydraulic system was obtained when comprehensively considering operation materials and their corresponding proportions, then a matching scheme between engine and hydraulic torque converter was put forward based on typical operating conditions. According to the original feature data of the tested loader engine, the deducted empiric values of engine torque for full power matching and partial power matching, and the actual engine torque value consumed by loader hydraulic system, three kinds of different characteristic curves of net engine torque were obtained by using a data fitting method. After fitting the original feature data of tested loader hydraulic torque converter, according to the characteristic curves of hydraulic torque converter between efficiency, torque coefficient, moment coefficient and rotational speed ratio, the corresponding torque coefficient, moment coefficient and rotational speed ratio were obtained when the torque converter efficiency was the highest; and according to the matching principle of engine with torque converter and load calculation formula of torque converter, the corresponding torque converter diameters of matching schemes for full power, experimental power and partial power were calculated. On the basis of determining jointly working points of different engine and torque converter matching schemes, and combined with the parameter relationships between pump impeller and turbine of hydraulic torque converter, the jointly working output characteristics of engine and torque converter were obtained, then the average turbo-shaft output power and the average engine fuel consumption rate of turbine working in high efficient area for experimental power matching scheme were calculated by using integral average method, and a contrast analysis of the corresponding calculated values had been carried out among the matching schemes of experimental power, original power and partial power. The results showed that the average turbo-shaft output power of experimental power matching scheme was respectively 17.02% and 42.59% higher than those of original scheme and partial scheme, and the average engine fuel consumption rate of experimental power matching scheme was respectively 3.80% and 8.72% lower than those of original scheme and partial scheme. Therefore, the proposed matching scheme is superior to several kinds of matching schemes commonly used in power matching at present, which provides a reference for optimum design of hydraulic torque converter and proper matching between engine and hydraulic torque converter. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Torque
Controlled terms:Construction equipment - Curve fitting - Data handling - Data processing - Engines - Hydraulic equipment - Hydraulic motors - Hydraulic torque converters - Loaders - Loading - Pumps - Software testing - Turbines
Uncontrolled terms:Characteristic curve - Converter efficiency - Data fitting method - Integral average method - Output characteristics - Parameter relationships - Power matching - Typical operating conditions
Classification code:405.1 Construction Equipment - 421 Strength of Building Materials; Mechanical Properties - 612 Engines - 612.3 Gas Turbines and Engines - 618.2 Pumps - 632.2 Hydraulic Equipment and Machinery - 672 Naval Vessels - 691.1 Materials Handling Equipment - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.07.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 2>
Accession number:20151800797535
Title:Temporal-spatial transformation characteristics of land use types in composite area of ore-agriculture-urban in Loess Area
Authors:Cao, Yingui (1); Zhang, Xiaoran (1); Bai, Zhongke (1); Zhou, Wei (1); Chen, Xiaohui (1); Sun, Qi (1); Ding, Xiang (1)
Author affiliation:(1) School of Land Science and Technology, China University of Geosciences, Beijing, China; (2) Key Lab of Land Consolidation, Ministry of Land and Resources, Beijing, China
Corresponding author:Bai, Zhongke
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:238-246
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The transformation of land use type occurs frequently in the composite area of ore-agriculture-urban driven by industrialization, urbanization and urban-rural integration. This transformation is especially affected by the government policy of returning marginal cultivated land to forest and grassland, and reclamation of urban and rural construction occupied land and opencast mining site. This study aimed at revealing the process, characteristics and major causes of land use type transformation in nearly 30 years in the composite area of ore-agriculture-urban in the Loess region. With transformation maps of land use types in the periods of 1986-1996, 1996-2000, 2000-2004, 2004-2009 and 2009-2013, the important values, areas and space distribution of main transformation types were analyzed. The zoning of land use type transformation during 1986-2013 was divided, and the causes of land use type transformation were discussed. The results showed that the differences of transformation types in different periods were obvious and the number of transformation types was increased. There were 17 transformation types in the period of 1986-2013 and the sum of important values of the dominate transformation types was 94.58%, and the other transformation types were 22 and the sum of important values were 5.42%. The sum of important values in different periods presented decreasing trend. The transformation types gradually presented from the state of transformation in farmland to the coexistence of transformation in farmland, transformation between farmland and construction land, transformation between farmland and damage land. The results also showed that all transformation types presented the trends of convergence and diversity in regional distribution. In Xiangyangbao county, Jingping town, Baitang county, transformation from cultivated land into construction land was significant. In the southeast of Jingping town, the northwest of Taocun county, and the middle part of Yuling county, a great amount of cultivated lands became damage lands. Transformation among cultivated land, forestland and grassland was noticeable in the east, the southeast and the north of the studied area. The study area has been divided into regions of farmland transformation to construction land, farmland transformation to damage land, and region of farmland transformation to farmland transformation. Meanwhile, the region of farmland transformation was divided into region of cultivated land transformation to forest land, region of cultivated land transformation to grassland. The areas were nearly balanced on cultivated land transformation to forest land and cultivated land transformation to grassland in the period of 2009-2013. In addition, the results showed farmland decrease was mainly due to the reduction of cultivated land. The cultivated land was the dominant land use type in the transformation by converting into forestland, grassland, rural residential and stripped land, impacted by returning cultivated land to forest land and grassland, occupied construction land and opencast mining damage. The area was 1.01×10<sup>4</sup> hm<sup>2</sup> on cultivated land transformation to forest land and grassland in the period of 1986-2013. The increase of construction land was promoted by urban expansion and land demand for farmers building new houses for improving the living condition and illegal building houses for more land requisition compensation. The area was 0.24 ×10<sup>4</sup> hm<sup>2</sup> on cultivated land transformation to construction land in the period of 1986-2013. Damage land growth was related to the scale enlargement of coal production. The area was 0.37× 10<sup>4</sup> hm<sup>2</sup> on cultivated land transformation to damage land in the period of 1986-2013. The findings can provide references for land sustainable use and protection of ecological environment to the research area. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Land reclamation
Controlled terms:Agriculture - Construction - Farms - Forestry - Land use - Ores - Remote sensing - Rural areas - Sediments - Urban growth - Urban planning
Uncontrolled terms:Driving forces - Ecological environments - Forest and grassland - Regional distribution - Space distribution - Spatial transformation - Transformation types - Urban-rural integrations
Classification code:403.1 Urban Planning and Development - 405 Construction Equipment and Methods; Surveying - 442.2 Land Reclamation - 483 Soil Mechanics and Foundations - 502 Mines and Quarry Equipment and Operations - 504 Mines and Mining, Metal - 505 Mines and Mining, Nonmetallic - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.0 Woodlands and Forestry
DOI:10.3969/j.issn.1002-6819.2015.07.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 3>
Accession number:20151800797537
Title:Layout optimization for county rural residents in Huang-Huai-Hai plain area and its remediation strategies
Authors:Zhou, Ning (1); Hao, Jinmin (1); Meng, Peng (1); Chen, Li (1); Hong, Shuman (1); Pareti, Muhabaiti (2)
Author affiliation:(1) College of Resources Environmental Sciences, China Agricultural University, Beijing, China; (2) College of Humanities and Development Studies, China Agricultural University, Beijing, China
Corresponding author:Hao, Jinmin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:256-263
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to provide the guidance for migration and combination in land consolidation and new rural construction, this paper analyzed layout optimization scheme of rural residential patches in Quzhou county, both in terms of rural residential patches' development conditions and of spatial interaction between adjacent patches. Centrality index from Christaller's Central Place Theory was employed to quantitatively calculate development conditions of rural residential patches. To achieve this, an evaluation index system which fitted the characteristics of Huang-Huai-Hai plain was built. The paper obtained the centrality indices of 247 main residential patches in Quzhou county using comprehensive judgment method of various factors, which derived from 342 administrative villages and consisted of 242 rural residential patches and 5 urban residential patches. The paper regarded the rural residential patches as the study units and merged the adjacent rural residents belonging to different administrative villages.. Then, field-strength was used to recognize the rural residential patches greatly influenced by cities and towns, and the improved gravity model was employed to find out the spatial interaction between rural residential patches. The 242 main rural residential patches were divided into 4 levels according to the values of centrality index, and most of high-level patches were located along arterial traffic and towns. Based on the higher value of field strength given by 5 urban residential patches, 21 rural residential patches were defined as urbanization-oriented type. In these rural residential patches, the second and third industry developed rapidly and employment structure changed gradually. The paper drew the largest gravity connection line between the patches, based on which the 59 consolidation units were confirmed and spatial interaction relationship was known. According to the characteristics of spatial organization between the patches in one unit, the paper recognized 4 types, including tandem type, parallel type, aggregation type and dual-core type. There were 21 out of 242 rural residential patches which were urbanization-oriented type, and the remaining rural residential patches were deeply divided into 3 types, including key development type, restricted expansion type and combined migration type, on the basis of centrality index of rural residential patches and spatial interaction between the patches. Finally, the paper put forward the policy suggestions aiming at every type of layout optimization. Quzhou county, Hebei province is located in the Heilonggang Basin of Huang-Huai-Hai plain. People living in the study area prefer to reside and gather together. For example, one rural residential patch from Henantuan town, had a population of 3.2 thousand. This rural residential patch was divided into 3 administrative villages, including 1<sup>st</sup> Malantou village, 2<sup>nd</sup> Malantou village and 3<sup>rd</sup> Malantou village. The paper eliminated the influence of administrative village boundary by taking rural residential patches as the research unit. This had implications for the study of rural resident layout in the other areas of Huang-Huai-Hai plain. The paper took both centrality index and spatial interaction into consideration when studying the layout optimization scheme in Quzhou county. However, the relationship between the two as well as different trip modes between urban residents and peasants, deserves further study. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Rural areas
Controlled terms:Consolidation - Housing - Land use - Landforms - Optimization
Uncontrolled terms:Central place theories - Evaluation index system - Field strengths - Gravity model - New rural constructions - Nodality index - Remediation strategies - Rural residential areas
Classification code:403 Urban and Regional Planning and Development - 403.1 Urban Planning and Development - 481.1 Geology - 483 Soil Mechanics and Foundations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.07.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 4>
Accession number:20151800797533
Title:Microorganism screening for ethanol production using gasification gas from agricultural residue
Authors:Wang, Fengqin (1); Zhang, Yanda (1); Xie, Hui (1); Peng, Yiding (1); Song, Andong (1)
Author affiliation:(1) Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture, Henan Agricultural University, Zhengzhou, China
Corresponding author:Song, Andong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:221-226
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ethanol is one of the most important alternative biofuels, which provides a net energy gain, has environmental benefits and is economically competitive. Ethanol production from syngas anaerobic fermentation appears to be a potential and promising technology compared to the existing chemical conversion techniques. Currently, syngas fermentation is being developed as one option towards the production of bio-ethanol from biomass. Agricultural residue biomass such as corn stalks and wheat stalks, has been an important part of the biomass resource in the world. Much attention has been attracted on the conversation and utilization of these biomasses with high value. The gasification of the agricultural residue biomass is a mature and industrialized technology up to now. Gasification of agricultural lignocellulosic residue followed by syngas fermentation to produce bio-ethanol is being explored owing to the low cost and availability of agricultural residue feedstock. The process can not only change trash to treasure but also be of benefit to reduce environmental pollution, which will promote the sustainable development of agriculture and improve the rural environment. It has been found that some anaerobic bacteria can be used to convert syngas to ethanol and acetic acid, such as Clostridium ljungdahlii and C. autoethanogenum. But the excellent strains are still very limited and their productivity levels are not high. According to the fact that bio-ethanol production from syngas in anaerobic conditions still can not be industrialized, special emphasis has been given to obtain the efficient microorganism fermenting that transfers syngas to ethanol. In order to obtain strains for high efficient ethanol production by syngas generated from agricultural residue, ethanol fermentations taking syngas as the sole carbon source and energy source were carried out. Ethanol production potentials were compared among the mixed-cultures A-fm4, B-fm4, G-fm4 and LP-fm4 and the reported strains Clostridium carboxidivorans P7, Clostridium sp. P11, C. ljungdahlii and C. autoethanogenum DSM10061. Meanwhile, microbial mixed-cultures A-fm4, B-fm4, G-fm4 and LP-fm4 were isolated from animal faeces samples of alpaca, papion, lesser panda and gibbon respectively under strict anoxic condition in 200 mL bottle. Batch fermentations were done in 300 mL serum bottles each containing 60 mL fermentation medium. 10% (v/v) of inoculum was transferred to fresh media. The 240 mL syngas was injected into the 300 mL serum bottle by syringe. Experiments were conducted for 7 days. The results showed that all of the cultures/mixed-cultures can transform syngas into biofuel ethanol. The net ethanol production and specific cell growth rate were 179. 23, 152.92, 115.08 mg/L and 1.46, 1.66, 1.18 d<sup>-1</sup>, respectively, for culture/mixed-cultures LP-fm4, Clostridium sp. P11 and A-fm4. Their specific ethanol production rate and ethanol production amount per cell were 3.50, 2.05, 0.78 d<sup>-1</sup> and 2252.90, 1450.20, 1132.37 mg/g (dry cell weight, DCW), respectively. These parameters were significantly higher than those of other treatments. Duncan analysis and dendrogram of cluster analysis also agreed that mixed-culture/strain LP-fm4 and Clostridium sp. P11 were the ideal microorganisms for ethanol production by syngas generated from agricultural residue, and mixed-culture A-fm4 was a potential candidate. The research results will provide excellent microorganisms for fermentation of syngas generated from agricultural residue in the future. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Ethanol
Controlled terms:Agricultural wastes - Agriculture - Bacteria - Bioethanol - Biofuels - Biomass - Body fluids - Bottles - Clostridium - Cluster analysis - Fermentation - Gasification - Microbiology - Microorganisms - Sustainable development - Synthesis gas
Uncontrolled terms:Anaerobic fermentation - Bio-ethanol production - Clostridium ljungdahlii - Environmental benefits - Environmental pollutions - Ethanol fermentation - Lignocellulosic residues - Syn-gas
Classification code:461 Bioengineering and Biology - 522 Gas Fuels - 523 Liquid Fuels - 694.2 Packaging Materials - 723 Computer Software, Data Handling and Applications - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 911.2 Industrial Economics - 922 Statistical Methods
DOI:10.3969/j.issn.1002-6819.2015.07.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 5>
Accession number:20151800797518
Title:Effects of maize straw mulching on runoff and sediment process of slope
Authors:Zhang, Yifu (1); Li, Hongwen (1); He, Jin (1); Wang, Qingjie (1); Li, Wenying (1); Chen, Wanzhi (1); Zhang, Xinyue (2)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China; (2) College of Engineering, Heilongjiang Bayi Agricultural University, Daqing, China
Corresponding author:Li, Hongwen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:118-124
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Straw mulching is a main method to reduce soil erosion and improve soil moisture. However, overmuch straw mulching may lower the anti-blocking capacity of no-till planter, affecting seeding quality and grain production in conservation tillage system in North China Plain. So, more researches should be conducted to investigate the suitable straw mulching quantity in conservation tillage system. Aiming at achieving suitable straw mulching conditions for high-performance planting of no-till planter and efficient soil and water conservation, this paper studied the effects of straw mulching on slope runoff and sediment yield process under different simulated rainfalls, and quantified the straw mulching rate for different conditions. A rainfall simulation experiment was carried out at Zhuozhou Experimental Station of China Agricultural University, Hebei province, from October 2013 to May 2014. The soil-bin (length: 1m, width: 1 m, slope rate: 9%) was filled with sandy loam soils according to natural soil structure in North China Plain. The surface was covered by chopped (less than 100 mm) maize straws collected after maize harvesting (early October). A rainfall simulator (model: DIK-6000, made in Japan) was used to produce different rainfall intensity. In this experiment, eight kinds of rainfall intensity (10, 20, 30, 40, 50, 60, 70, and 80 mm/h) and five kinds of straw mulching rate (0, 15%, 30%, 60%, and 90%) were considered as two independent variables in experimental design (three replications). Each simulated rainfall lasted for 1 h. The results showed that under different straw mulching rates, runoff time and rainfall intensity varied as power functions in conservation tillage fields in North China Plain. Straw mulching significantly (P<0.05) delayed runoff time in each simulation, and compared with uncovered treatments, straw mulching treatments with a coverage of 15%, 30%, 60% and 90% delayed runoff time by 1.0-15.4, 2.1-22.1, 3.4-48.2, and 5.9-73.6 min, respectively. Furthermore, straw mulching restrained runoff and reduced total runoff and total sediment yield. Compared with no straw mulching treatment, 30% straw mulching treatment significantly reduced total runoff by 17.9%-38.7%, but the positive effect in 15% straw mulching treatment was negligent. For sediment yield, the value in 30% straw mulching treatment was 34.1%-48.0% lower than that in no straw mulching treatment under total 8 kinds of simulated rainfall conditions. However, significant reduction (15.6%-34.7%) in 15% straw mulching treatment could only be founded in heavy rainfall (50-80 mm/h) experiments. The results above demonstrated that > 30% straw mulching rate could significantly reduce soil erosion and improve soil water retention capacity. However, in North China Plain, the annual output of maize straw is about 7000 kg/hm<sup>2</sup>. In conservation tillage fields, if the straw mulching rate is over 60%, and this heavy straw cover condition will affect no-till planter's anti-blocking capacity. So, in conservation tillage system, 30%-60% maize straw mulching (1.4-3.1 t/hm<sup>2</sup>) is recommended to achieve high performance of planting and high efficient soil and water conservation, which provides the valuble information for suitable straw mulching rate of maize in North China Plain during the application of conservation tillage practice. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Soil conservation
Controlled terms:Agricultural machinery - Agriculture - Design of experiments - Erosion - Rain - Runoff - Sediments - Seed - Soil moisture - Soils - Straw - Water conservation
Uncontrolled terms:Conservation tillage - Conservation tillage systems - Experimental stations - Independent variables - Rainfall simulations - Sediment yields - Soil and water conservation - Soil water retention
Classification code:443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research
DOI:10.3969/j.issn.1002-6819.2015.07.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 6>
Accession number:20151800797504
Title:Dynamic modeling of leveling system of paddy field laser leveler
Authors:Chen, Jiaqi (1); Zhao, Zuoxi (1); Shi, Lei (1); Ke, Xinrong (1); Wu, Zhiwei (1); Liu, Xiong (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China
Corresponding author:Zhao, Zuoxi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:18-23
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Modern paddy rice planting requires the field with high smoothness since it is conducive to reducing water consumption and improving the crop yields. A paddy land leveler is a complex mechanical system connected to the tractor by hanging. With both plow leveling and working height adjustment mechanisms, the paddy land leveler can automatically adjust the height and leveling of the land-leveling plow to attain high paddy field flatness. In order to improve the control precision, stability and responsiveness of a laser leveler in varying paddy field environment, a dynamic model of the leveling system is proposed in this paper. Considering that the leveling system of paddy field laser leveler is a typical electro-hydro-mechanical system, the dynamic model takes the proportional valve's solenoid current as the input, and the tilt of the plow as the output. Firstly, based on the electro-hydro-mechanical structure and the working principle of the paddy field leveler, an abstract, simplified dynamic model with the diagrams of force analysis is derived, which is composed of a hydraulic subsystem and a mechanical subsystem connected in series, and the hydraulic part generates hydraulic flow rate due to the proportional valve's solenoid current, followed by the mechanical subsystem mainly consisting of a hydraulic cylinder, an installation platform and a plow. A series of differential algebraic equations (DAE) about the two subsystems are then proposed and analyzed based on the diagrams. A typical paddy field leveler is used to demonstrate how to numerically solve these DAEs, and various parameters of the subsystems like resonant frequency, viscosity coefficient of friction, rotation inertia and damping ratio are experimentally determined. Secondly, to verify the model, with the proportional valve's solenoid current as the input and the tilt of the plow as the output, a sine signal response simulation is conducted, and a sine signal response experiment with the actual physical system is done, in which the input is also the proportional valve's solenoid current and the output is the tilt of the plow. The simulation results are then compared with the experimental results of actual physical system. The actual physical system has time delay in the hydraulic system and a certain gap between the mechanicals, and therefore the simulation curve has a little difference from the empirical curve. Overall the experimental result shows that the model proposed behaves in good agreement with the actual tests though with some imperfections. The model represented by DAEs, the way to derive it and the way to numerically solve it, can be used for both hydro-mechanical design and control algorithm design for the leveler, and the modeling principles may be applied to the design of similar electro-hydro-mechanical agricultural operation machines. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Leveling (machinery)
Controlled terms:Agricultural machinery - Agriculture - Algorithms - Computer systems - Delay control systems - Differential equations - Dynamic mechanical analysis - Dynamic models - Dynamics - Friction - Hydraulic equipment - Hydraulic machinery - Lasers - Mechanics - Mechanisms - Natural frequencies - Solenoid valves - Solenoids - Time delay - Valves (mechanical)
Uncontrolled terms:Agricultural operations - Complex mechanical system - Differential algebraic equations - Hydro-mechanical systems - Leveler - Mechanical sub-systems - Paddy fields - Viscosity coefficient
Classification code:421 Strength of Building Materials; Mechanical Properties - 601.2 Machine Components - 601.3 Mechanisms - 603.1 Machine Tools, General - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 632.2 Hydraulic Equipment and Machinery - 704.1 Electric Components - 711.1 Electromagnetic Waves in Different Media - 713 Electronic Circuits - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 744.1 Lasers, General - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 921.2 Calculus - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.07.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 7>
Accession number:20151800797505
Title:Influence of hanging farm implement on vibration of tractor with electro-hydraulic hitch system
Authors:Cheng, Jian (1); Chi, Ruijuan (1); Mao, Enrong (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Chi, Ruijuan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:24-32
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the increase of the speed of high-power tractors, the tractor's vibration problem has become more and more prominent in recent years, since tractors often travel on rugged roads. High-power tractors mostly work with farm implements hung by hydraulic hitch system. The hanging farm implements are raised to the highest point in transit. When the tractor is travelling on the rugged road, the vibration of the tractor with a farm implement will be more intense for the existence of the hanging farm implement sometimes would bring a great pitch vibration. This paper discussed the effect of the existence of the farm implement on the vibration characteristics of the tractor. For the first time, the movement and stress distribution of the hitch system and the farm implements were analyzed in detail, besides that of the tractor's body. The mathematical vibration model of the tractor with a farm implement was established. And then the incentive mathematical model of the concrete barriers was established and the process of the tractor driving over obstacles was simulated with the Matlab based on the mathematical model. Variation curves of each key point were got and some conclusions were obtained by the simulation. The front tire's dynamic load and dynamic load coefficient increased significantly because of the existence of the farm implement. The front tire's dynamic load coefficient increased from 0.26 to 0.55, which seriously affected the safety of the driving. When the tractor encountered obstacles, low frequency vibration had obviously been strengthened. In both cases of load and no-load, the first vibration mode of the tractor was the body's vertical vibration, and the second vibration mode of the tractor was the body's pitch vibration. Without the farm implement, the tractor's vertical vibration frequency was 3 Hz, and it became 2.5 Hz with the farm implement. In case of no-load, the tractor's pitch vibration was hardly apparent. When the farm implement was hung up, the tractor's pitch vibration was significantly enhanced by the farm implement, and the frequency of that was 4.8 Hz. Because of the nonlinear coupling between the vibration of the tractor and the motion of the hitch system, the third vibration mode appeared under certain conditions, the frequency of which was between 10 and 15 Hz. Both the performances of the second and the third vibration mode of the tractor with farm implement would be harmful to the driver's comfort and the safety of the tractor. The vibration of the farm implement made the force of the lower pull rod's hinge point of the electro-hydraulic hitch system changed correspondingly. There was a good linear relationship between the vertical component of the force and the vertical acceleration of the farm implement's centroid. Therefore, we could use the vertical force instead of the acceleration to represent the vibrational state of the tractor when we designed the active vibration control system of the tractors later on. The simulation results agreed well with the experimental results, which verified the correctness of the mathematical model. The methodology and conclusion provide a theoretical basis for the tractor vibration control. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Tractors (agricultural)
Controlled terms:Agricultural implements - Agricultural machinery - Dynamic loads - Loads (forces) - Mathematical models - MATLAB - Mechanisms - Suspensions (fluids) - Tractors (truck) - Vibration analysis - Vibration control
Uncontrolled terms:Active vibration control systems - Linear relationships - Low-frequency vibration - Simulation - Vertical accelerations - Vibration characteristics - Vibration modes - Vibrations
Classification code:408 Structural Design - 408.1 Structural Design, General - 421 Strength of Building Materials; Mechanical Properties - 601.3 Mechanisms - 663.1 Heavy Duty Motor Vehicles - 731.3 Specific Variables Control - 804 Chemical Products Generally - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.07.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 8>
Accession number:20151800797543
Title:Preparation and property analysis of cellulose nano-fibril and nano-silicon dioxide composites
Authors:Li, Huiyuan (1); Wu, Qinglin (2); Zhou, Dingguo (1)
Author affiliation:(1) College of Material Science and Technology, Nanjing Forestry University, Nanjing, China; (2) School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, United States
Corresponding author:Zhou, Dingguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:299-303
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this study, cellulose nano-fibril (CNF)/nano-silicon dioxide composites were prepared by mimicking the fast paper-making method. Mechanical property, thermal degradation and moisture adsorption of the composites were studied. The results revealed that tensile strength and modulus decreased as the loading of nano-silicon dioxide increased. The measured density value of CNF was 1 305.04 kg/cm<sup>3</sup> while the density of CNF with 20% nano-silicon was only 1 132.9 kg/cm<sup>3</sup>. Tensile strength of CNF was 120.98 MPa and Modulus was 6.41 GPa. As the loading of nano-silicon dioxide increased, the tensile strength and modulus decreased sharply. When the content of nano-silicon dioxide reached 20%, the tensile of nano-composite was 49.41 MPa and the modulus was 2.96 GPa. The thermal stability of nano-composite was improved after adding nano-silicon dioxide. The onset cellulose decomposition temperature was around 270 and weight loss in this period was around 4%. Although the onset decomposition temperature of nanocomposites did not increase, the lower weight loss indicated less initial decompositions in this stage. In addition, as the content of silica became higher, the char residue increased. The amount of dry plain CNF was 23%, noticeably smaller than that of corresponding CNF/nano-silicon dioxide samples which ranged from 30% and 65%. Degradation models including the Kissinger, modified Coats-Redfern and Flynn-Wall-Ozawa (F-W-O) methods were utilized to calculate the activation energy. The Kissinger method led to an apparent activation energy ranging from 150 to 225 for all films. NFC with inorganic silica normally showed a higher activation energy than the control, high clay content also resulted in high activation energy. Results from the modified Coats-Redfern and F-W-O methods were similar (activation energy ranged from 180 to 220) to the observations. Nano-silicon dioxide provides barrier to the oxygen which leads to an improvement in flame retardant property. Limiting oxygen index of the tested CNF was 21.8 which is similar to normal paper but lower than CNF with nano-silicon dioxide. Limiting oxygen index of the CNF with 20% nano-silicon dioxide was 24.20%. The CNF/nano-silica dioxide composites were placed in a container with relative humidity 95% for 24 hours and moisture content of composites increased as the time continued. Among all composites, CNF/nano-silicon dioxide showed more moisture sensitivity than plaint CNF. The higher the nano-silica dioxide content was, the more moisture was absorbed. The final moisture content (FMC) of CNF was around 20% while the FMC of CNF with 20% nano-silica dioxide was around 26%. Contact angle was used to determine surface wettability of these nanocomposites. The contact angle of plain CNF was 55.9°. As the nano-silicon dioxide content increased, the contact angle of nanocomposites decreased. When the loading of nano-silicon dioxide was lower than 10%, the contact angle of nanocomposite was similar with CNF. However, as the loading of nano-silicon dioxide increased to 15%, the contact angle of the nanocomposite was only 45.4°. When the content of nano-silicon dioxide was 20%, the contact angle decrease to 40.4°. In conclusion, mechanic and water adsorption properties of cellulose nano-fibril were affected by added nano-silicon dioxide amount, but the thermos property of the cellulose nano-fibril/nano-silicon dioxide was stable. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Silica
Controlled terms:Activation energy - Adsorption - Cellulose - Chemical activation - Contact angle - Decomposition - Flame retardants - Mechanical properties - Moisture - Moisture determination - Nanocomposites - Nanofibers - Oxygen - Polymer blends - Tensile strength - Thermodynamic properties - Thermodynamic stability
Uncontrolled terms:Apparent activation energy - Cellulose decomposition - Final moisture content - Flame retardant properties - High activation energy - Moisture absorption - Nano silicon dioxide - Onset decomposition temperatures
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 631.1.1 Liquid Dynamics - 641.1 Thermodynamics - 761 Nanotechnology - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 812 Ceramics, Refractories and Glass - 815.1.1 Organic Polymers - 816.1 Processing of Plastics and Other Polymers - 933 Solid State Physics - 944.2 Moisture Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.07.042
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 9>
Accession number:20151800797532
Title:Characteristics of flue gas emissions during large wood pellet combustion
Authors:Chen, Guohua (1); Li, Yunquan (1); Peng, Haobin (1); Li, Yuesheng (2); Jiang, Zhiming (2)
Author affiliation:(1) School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou, China; (2) Shunde Detection, Special Equipment Inspection Institute of Guangdong Province, Shunde, China
Corresponding author:Chen, Guohua
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:215-220
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Due to the influence of the mass and heat transfer, some obvious differences in flue gas emissions may occur during the combustion of wood powders and pellet. However, many studies report on the characteristics of flue gas emissions during wood powder combustion, and researches on the single wood pellet combustion and its flue gas emission are limited. The aim of this work was to obtain dynamic data on the release of CO, NO, and SO<inf>2</inf> during single large wood pellet combustion by performing experiments in a tube furnace under different temperatures (800, 900, 1 000, 1 100, and 1 200) and air flow rates (3, 4, and 5 L/min). The results from the experiment can serve as an important reference for efficient and clean combustion of biomass. The total emissions and their conversions from biomass combustion can be quantified with these data. The experimental results showed that CO emission curve present a double-peak shape at 800, mainly because of its slow devolatilization and combustion in low temperature. With increasing temperature, CO emission time decreased, indicating that it needed shorter time during devolatilization and char burnout. Because of sufficient burning, the peak CO concentrations and total CO emissions almost decreased as the temperature grown in 4,5 L/min air flow rate. NO was released to the gas phase in significant amounts at 900, while decreased with increasing temperature or reducing air flow rate. A part of NO was transformed to N<inf>2</inf> with the reductive gas of CO as the temperature increased. At temperatures of 1 100 and 1 200, NO forming through HCN and NH<inf>3</inf> declined because of inadequate oxygen supply in 3 L/min air flow rate. The change tendencies of NO emissions in 4 L/min air flow rate were similar to the change tendencies in 5 L/min air flow rate, probably associated with CO emissions in 4, 5 L/min air flow rate. Fuel-N conversion rate reached the minimum and maximum values (12.32%, 41.79%) in 3 L/min air flow rate under the combustion temperature of 1 200 and 5 L/min air flow rate under the combustion temperature of 900, respectively. During wood pellet sufficient burning, no SO<inf>2</inf> was released to the gas phase, since sulfur mainly converted to sulfate stored in ashes or discharged with the flue gas at high temperature. Above 1 100, SO<inf>2</inf> emission was observed presumably by organic sulfur oxidation or sulfate dissociation in 3 L/min air flow rate, mainly because of the low conversion of SO<inf>2</inf> transformed to sulfates under the condition of lean oxygen. Calculations indicated that 33.78% and 25.99% of the fuel-S was released to the gas phase as SO<inf>2</inf> at 1 100 and 1 200, respectively. On the contrary, most sulfur in the wood pellet discharged with the forms of H<inf>2</inf>S, CaS, etc. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Gas emissions
Controlled terms:Air - Biomass - Combustion - Flow rate - Flue gases - Flues - Gases - Heat transfer - Nobelium - Oxygen - Oxygen supply - Pelletizing - Sulfur - Sulfur compounds - Temperature - Wood
Uncontrolled terms:Biomass combustion - Change tendencies - CO concentrations - Combustion temperatures - High temperature - Increasing temperatures - Mass and heat transfers - Wood pellet
Classification code:451.1 Air Pollution Sources - 521 Fuel Combustion and Flame Research - 521.1 Fuel Combustion - 525.1 Energy Resources and Renewable Energy Issues - 622.1 Radioactive Materials, General - 631 Fluid Flow - 641.1 Thermodynamics - 641.2 Heat Transfer - 802.3 Chemical Operations - 804 Chemical Products Generally - 811.2 Wood and Wood Products - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.07.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 10>
Accession number:20151800797529
Title:Intelligent monitoring system for aquaculture dissolved oxygen in pond based on wireless sensor network
Authors:Ma, Congguo (1); Zhao, Dean (2); Wang, Jianguo (1); Chen, Yajuan (1); Li, Yazhou (1)
Author affiliation:(1) Huaiyin Institute of Technology, Huai'an, China; (2) School of Electrical Information Engineering, Jiangsu University, Zhenjiang, China
Corresponding author:Ma, Congguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 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:In order to facilitate DO (dissolved oxygen) monitoring for a scaled aquaculture pond, a DO intelligent monitoring system was developed based on a wireless sensor network, which could realize distribution measurement, intelligent control, and centralized management. The system consists of a three-layer structure including data acquisition and control, water quality monitoring, and water management. The data acquisition and control layer was composed of data acquisition and control terminals, routing nodes, and a coordinator node based on ZigBee technology. They were deployed in the sensing area for an aquaculture pond's waters, and they constituted a wireless monitoring network for water quality environmental parameters by self organization to collect water quality parameters and adjust control devices. The water quality monitoring layer included a water quality monitoring terminal and a communication computer, which realized water quality supervision and aquaculture equipment intelligent control. The water quality management layer contained mainly a water quality management terminal, a system database, and a Web server end. The water quality management end was responsible for analysis and processing for the water quality data. The monitoring system concentrated wireless data acquisition, intelligent control, and centralized management for water quality parameters to improve scale aquaculture benefit and information management level. Aiming at low adaptive ability for conventional fuzzy PID controller, a variable universe fuzzy PID controller was proposed, which comprises an adjustment unit for expansion factors, variable universe fuzzy control unit and PID controller, the extension factor α<inf>1</inf>, α<inf>2</inf> and β for input and output domain of fuzzy control unit were adjusted constantly by an expansion factor regulating unit according to DO error and DO error change rate. PID controller parameters were tuned online by a variable universe fuzzy control unit to realize the purpose for DO adaptive control. According to the DO change characteristics with nonlinear, large delay and large inertia in a pond, the cascade control system was constituted by a variable universe fuzzy PID controller and an aerator speed PID controller. DO was the main controlled variable, and the aerator speed was the secondary controlled variable. If the DO concentration deviates from the setting value, a DO control loop will operate. Its output is the control loop input of the aerator speed, and the output of the aerator regulator changes the aerator speed to make DO concentration fast track the setting value of system target. The cascade control system can timely and accurately adjust the DO concentration to meet aquacultural needs. According to the changing trend of the DO data sequence for multiple pond monitoring sites, a combination grey DO forecasting model was constructed based on grey theory and weights to predict DO concentration and the feedback value for a variable universe fuzzy PID controller. This achieved DO prediction control and beforehand adjustment, and DO overshooting was well restrained. The test pond and the contrast pond respectively used a variable universe fuzzy PID controller and a fuzzy PID controller to regulate DO in the ponds, and the DO target value was 7.10 mg/L. In the dynamic response phase, DO response time for the contrast pond extended about 15 min more than the test pond, and the overshooting expanded 2.96 times. After the system entered steady process, the standard deviation, the mean variance, and the maximum error and minimum error enlarged by 3-4 times. The testing results showed that the adjustment process for the test pond had characteristics with fast response, small overshooting, high control precision, and good stability compared with the contrast pond. The adjusting factors for the variable universe fuzzy PID controller better solved contradictions between the quantity of fuzzy control rules and DO control precision, and realized self tuning for PID parameters, and improved dynamic performance, and raised steady accuracy and quality of the fuzzy PID controller. It can effectively restrain many uncertain factors of interference affecting DO stability to meet aquaculture requirements for DO and provide a new control method to solve control problem for complex objects with a nonlinear and large time delay. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Quality control
Controlled terms:Aquaculture - Biochemical oxygen demand - Cascade control systems - Complex networks - Control systems - Control theory - Controllers - Data acquisition - Delay control systems - Dissolved oxygen - Dissolved oxygen sensors - Dynamic response - Electric control equipment - Forecasting - Fuzzy control - Information management - Intelligent control - Lakes - Monitoring - Oxygen - Proportional control systems - Quality management - Sensor nodes - Social networking (online) - Three term control systems - Time delay - Water conservation - Water management - Water quality - Wireless sensor networks - Zigbee
Uncontrolled terms:Fuzzy - pid controls - Gray forecasting - Intelligent monitoring systems - Variable universe - Variable universe fuzzy controls - Water quality monitoring - Water quality parameters - Wireless data acquisitions
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 408.1 Structural Design, General - 444 Water Resources - 445 Water Treatment - 445.2 Water Analysis - 446 Waterworks - 453 Water Pollution - 453.2 Water Pollution Control - 713 Electronic Circuits - 722 Computer Systems and Equipment - 722.3 Data Communication, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 732.1 Control Equipment - 801 Chemistry - 804 Chemical Products Generally - 821.3 Agricultural Methods - 903.2 Information Dissemination - 913.3 Quality Assurance and Control - 921 Mathematics - 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
DOI:10.3969/j.issn.1002-6819.2015.07.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 11>
Accession number:20151800797517
Title:Ridge-furrow planting with biodegradable film mulching over ridges for rain harvesting improving root growth and yield of maize
Authors:Zhou, Changming (1); Li, Yuannong (1); Yin, Minhua (1); Guo, Xiaobo (1); Zhao, Xi (1)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A and F University, Yangling, China; (2) Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A and F University, Yangling, China
Corresponding author:Li, Yuannong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:107-117
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plastic film mulching can reduce soil evaporation and improve water use efficiency, thereby relieving water shortage and steadily increasing crop productivity in arid and semi-arid region of China. For such reasons, plastic mulching film has been increasingly used, which leads to many negative effects such as environment pollution and land degeneration. Biodegradable film is considered to be a promising way to solve such problems caused by plastic film without compromising its positive effects. Many studies focus on the effects of biodegradable film mulch on soil water storage and maize growth, but few has dedicated to the effect of biodegradable film mulching combined with planting patterns on maize growth. Therefore, this study aimed to investigate the effects of biodegradable film with plating patterns on soil water storage, maize root growth and maize yield. A field experiment was carried out from June to November in 2013 and 2014, respectively. Four kinds of treatments were designed using complete randomized block design with three replicates, respectively: flat planting without mulching (CK), flat planting with biodegradable film mulching (M1), ridge-furrow planting with biodegradable film mulching over ridge only (M2) and ridge-furrow planting with biodegradable film mulching over ridges (M3). The maize variety was Luodan 9 for the two-year experiments. Soil moisture of 0-200 cm depth during different growth stage and before and after a rainfall, maize yield and root growth (including root length, root surface area, root volume and total root dry weight) in the maize mature stage under different mulching patterns were measured. The correlation between soil water storage capacity and root indicators, water use efficiency and yield was analyzed. Results showed that degradation of films under different plating patterns was similar. The mulching treatments all played an important role in rainfall harvesting. With the degradation of biodegradable film, the capacity of rainwater harvesting under all mulching treatments reduced. Average soil water storage of two years under M1, M2 and M3 was significantly (P<0.05) higher than that under CK in 2013 and 2014, and increased by 7.40%, 9.54% and 13.21% than CK respectively. Water consumption under three mulching treatments in 2013 and 2014 was significantly (P<0.05) lower than that of CK, mainly due to the fact that biodegradable mulching film reduces land surface evaporation effectively. The root length, root surface area, root volume and total root dry weight under three mulching treatments were all significantly (P<0.05) higher than those under CK, and root length density for maize in mature periods under M1, M2 and M3 were improved by 9.23%, 13.85% and 16.92% compared to CK, respectively. The reason of such a difference between CK and three treatments might be the improvement of water storage capacity and root growth of maize under three mulching treatments. The correlation coefficient between water storage capacity and total root length was 0.83, while the correlation coefficient between water storage capacity and root surface area was 0.77. Compared to CK, the average yield in 2013 and 2014 under treatments of M1, M2 and M3 increased by 16.03%, 18.53%, 40.22%, average water use efficiency in the two years increased by 21.29%, 26.57%, 57.27%, and average rainfall use efficiency increased by 13.98%, 19.57%, 35.65%, respectively. Water storage capacity had significant positive correlation with grain yield and water use efficiency and the correlation coefficient was 0. 91 and 0.86 respectively. Evapotranspiration had significant negative correlation with grain yield and water use efficiency and the correlation coefficient was 0.77 and 0.86, respectively. Comparably, M3 was best among the three treatments in improving soil water storage, root growth and yield of maize, and ridge-furrow planting with biodegradable film mulching over ridges could be an effective method for maize cultivation in drought area. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Film growth
Controlled terms:Arid regions - Biodegradable polymers - Efficiency - Evaporation - Evapotranspiration - Films - Forestry - Harvesting - Plastic films - Rain - Soil moisture - Soils - Water supply
Uncontrolled terms:Degration - Root - Summer maize - Water use efficiency - Yield
Classification code:443 Meteorology - 443.3 Precipitation - 444 Water Resources - 446.1 Water Supply Systems - 454 Environmental Engineering - 483.1 Soils and Soil Mechanics - 712.1 Semiconducting Materials - 802.3 Chemical Operations - 817.1 Polymer Products - 821.0 Woodlands and Forestry - 821.3 Agricultural Methods - 913.1 Production Engineering - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2015.07.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 12>
Accession number:20151800797530
Title:Optimum ratio of pig manure to edible fungi residue improving quality of organic fertilizer by composting
Authors:Zhou, Jiangming (1); Wang, Litong (2); Xu, Qinghua (2); Jiang, Xinyou (1)
Author affiliation:(1) The Agricultural Technique Popularization Centre of Jiangshan City, Jiangshan, China; (2) Zhejiang TianPeng Animal Husbandry Ltd, Jiangshan, China
Corresponding author:Zhou, Jiangming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 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:In order to solve the current problems about environmental pollution of agricultural waste and explore the technology of producing organic fertilizer by composting with pig manure and edible fungi residue, an experiment was conducted to study dynamic changes of several parameters including heat, pH value, organic carbon (C), germination index (GI), nutrient nitrogen (N), phosphorus (P) and potassium (K) during the natural fermentation. The experiment was based on the four ratios of 9:1, 8:2, 7:3 and 6:4 of pig manure and edible fungi residue in high-temperature composting experiment. The results showed as followed. The temperatures of all disposals were over 50 degrees centigrade at about the 3<sup>rd</sup> day. It maintained a high temperature for from 25 to 32 d, and then began to decrease. Duration of the high-temperature composting was longer while the ratio of the mushroom residue got more. From the experiment, we could see that the high-temperature duration of the disposal with the ratio of 6: 4 was 7 d longer than the disposal with the ratio of 9:1. The pH values of all disposals, ranging from 6.83 to 8.62, increased rapidly and then decreased smoothly in the 22 d. Total N of the nutrient decreased with the loss of ammonia in the early, and then the relative quality of the total N began to rise while the total mass was reducing along with the loss of C content. At the end of the composting, the total N contents of the disposals A and B decreased by 2.9 and 1.0 g/kg, respectively, but the disposals C and D increased by 1.6 and 1.9 g/kg, respectively. The total P and total K contents have been on a slow upward trend, until the end of the composting they increased by 14.2%-36.4% and 28.1%-34.7% respectively. The organic C content decreased in general. At the end of the composting, the organic C contents of all disposals respectively decreased by 16.3%, 14.5%, 13.6% and 11.9%. Due to the rich source of N in the early time, microbes multiplied and let out large-scale ammonia N, which resulted in the rapid increase in the C/N ratio, and then the average ratio declined; and the 4 disposals decreased by 0.67, 2.08, 4.48 and 4.49 respectively in the end. Except the disposal with the ratio of 6: 4, the GI of all disposals respectively reached 80% on the 23<sup>rd</sup>, 33<sup>rd</sup>, 47<sup>th</sup> day. At the same time, the toxicity of the piles extract liquid increased on plants due to the accretion of the ratio of fungi residue. The total nutrient contents of N, P and K were in a flat or a small decline and then continued to rise in the early period (in about 19 d), which were respectively 5.93%, 5.57%, 5.64% and 5.13% for all disposals at the end of the composting. In addition, the disposal with the ratio of 6: 4 was less than 5% in the most period of the composting (within 45 d), but the rest disposals were more than 5% after about 21-25 d. Considering the factors of the compost quality and production cycle comprehensively, the appropriate ratio of manure to mushroom residue is 8:2 for making scale production of organic fertilizer. Furthermore, on account of the low C/N ratio of manure and mushroom residue, it is better to add some annexing agent with high C/N ratio such as rice bran for improving the efficiency of composting. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Waste treatment
Controlled terms:Agricultural wastes - Agriculture - Ammonia - Composting - Environmental technology - Fertilizers - Fungi - Manures - Nitrogen fertilizers - Nutrients - Organic carbon - pH - Waste disposal
Uncontrolled terms:Edible fungi residues - Environmental pollutions - Germination index - High temperature - Nutrient contents - Organic fertilizers - Production cycle - Relative qualities
Classification code:452.4 Industrial Wastes Treatment and Disposal - 454 Environmental Engineering - 454.3 Ecology and Ecosystems - 801.1 Chemistry, General - 801.2 Biochemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.07.029
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 13>
Accession number:20151800797509
Title:Performance experiment on spray atomization and droplets deposition of wind-curtain electrostatic boom spray
Authors:Jia, Weidong (1); Hu, Huachao (1); Chen, Long (1); Chen, Zhigang (1); Wei, Xinhua (1)
Author affiliation:(1) Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, Jiangsu University, Zhenjiang, China
Corresponding author:Jia, Weidong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:53-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To solve the problem of less liquid deposition on the middle and lower plant canopy and uneven distribution of particle diameter by traditional pesticide application methods, this paper conducted the exploratory research about the application of the technology of pneumatic auxiliary spray combined with electrostatic spray. The charge-to-mass ratios of the droplets under different spray pressures and voltages were measured by measurement system. The results indicated that the charge-to-mass ratio increased as the voltage increased and then tended to be stable, yet decreased with the increase of spray pressure. The particle diameter spatial distribution of the droplets under charging or not was measured by Winner318B laser particle size analyzer; the horizontal and longitudinal stent in the system could move precisely so as to adjust the position of the nozzle relative to the measuring line of the laser particle size analyzer. The results showed that the volume median diameters (VMD) of the droplets decreased and then tended to increase when the nozzle moved from 0 to 3 in the horizontal stent; in the condition of no charging, the VMD of the droplets was 108.48 μm and the coefficient of variation of droplet sizes was 11.96%, while in the condition of charging, the VMD of the droplets was 83.67 μm and the coefficient of variation of droplet sizes was 7.48%; and the VMD of the droplets increased when the nozzle moved from 6 to 4 in the longitudinal stent. For analyzing the influence of wind-curtain, spray pressure and voltage on droplets deposition performance, the wind-curtain electrostatic boom spray system was set up and the experiment on droplet deposition performance was conducted. The system used cochineal solution as spraying liquid, and used radermachera hainanensis merr. as simulation target. Layout the film on the upper, middle, lower position plant canopy for collecting the droplets deposited. In order to ensure the accuracy of the experimental data, the droplet collection started after spray being stable with the duration of 20 s, and the film sample was eluted by 50 ml distilled water, the absorbance of the eluant was measured by UV-2100PCS UV-VIS spectrophotometer and then converted into the concentration based on the curve equation. Finally, calculate the unit area droplets deposited amount (UADDA) on plant canopy. The wind-curtain effect (the wind-curtain outlet wind speed was 20 m/s) could improve the UADDA under spray pressure of 0.2 MPa and no voltage, in which the coefficient of variation of droplet deposition distribution under wind-curtain was 0.645, and compared with no wind-curtain, the coefficient of variation declined by 25.95%. The electrostatic effect could also improve the UADDA when spray pressure was 0.2MPa and the wind-curtain outlet wind speed was 20 m/s, in this case, the coefficient of variation of droplet deposition distribution decreased from 0.645 to 0.321, reduced by 50.2%; when droplets were charged, the coefficient of variation of droplet deposition distribution increased as the spray pressure increased. This study provides the theory and design basis for the development of innovative wind-curtain electrostatic boom sprayer and offers the experience for the field test which will be conducted next. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Spray nozzles
Controlled terms:Deposition - Drops - Electrostatic devices - Electrostatics - Elementary particles - Liquids - Nozzles - Particle size - Particle size analysis - Pressure effects - Spraying - Stents - Wind
Uncontrolled terms:Charge-to-mass ratios - Coefficient of variation - Distribution of particles - Electrostatic effect - Laser particle size analyzer - Performance experiment - Pesticide applications - UV-Vis spectrophotometers
Classification code:443.1 Atmospheric Properties - 462.4 Prosthetics - 631.1 Fluid Flow, General - 701.1 Electricity: Basic Concepts and Phenomena - 813.1 Coating Techniques - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.07.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 14>
Accession number:20151800797528
Title:Analysis of heat transfer characteristics for parabolic trough solar collector
Authors:Wang, Jinping (1); Wang, Jun (1); Zhang, Yaoming (1); Bi, Xiaolong (3)
Author affiliation:(1) Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology, School of Energy and Environment, Southeast University, Nanjing, China; (2) Solar Energy Technology Research Center, College of Energy and Environment Engineering, Southeast University, Nanjing, China; (3) College of Energy and Power Engineering, Nanjing Institute of Technology, Nanjing, China
Corresponding author:Wang, Jun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:185-192
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Parabolic trough solar collector (PTC) is one of the most mature technologies in the medium and high temperature solar thermal utilization field, and PTC is the key component which transforms solar radiation into heat. PTC performance directly affects the performance of solar energy heat utilization system. In order to improve the thermal efficiency and provide the theoretical basis for PTC design, this paper analyzes the heat transfer characteristics of PTC. One-dimensional heat transfer mathematical model of PTC is established, and using this model, heat transfer characteristics for PTR70 2008 type PTC are analyzed. The result shows solar radiation heat absorbed by PTC is significantly affected by the solar incident angle. Heat absorbed by PTC is calculated by direct normal irradiance data in September 21st and October 25th, and the mean direct solar radiation data of October 25th is higher than the data in September 21st by 37.5894 W/m<sup>2</sup>, solar radiation heat absorbed by PTC in September 21st is higher than the data in October 25th by 196.644 W/m. The heat transferred from the outer absorber surface to the inner absorber surface increases with the increase of temperature difference of the outer and inner absorber surface, decreases with the increase of the ratio of outer absorber diameter to inner absorber diameter. When the ratio of outer absorber diameter to inner absorber diameter is greater than 1.05, the thermal resistance increases to 0.00046-0.00047 K/ (Wm). Convection and radiation heat transfer occur between the absorber and the glass envelope. The heat transferred across the evacuated annulus from the outer absorber surface to the inner glass surface through radiation increases with the increase of the temperature of the outer absorber surface. The convection heat transfer between the absorber and glass envelope is very small and plays a negligible role. The heat is associated with annulus gas type, and heat transfer of annulus hydrogen is greater than annulus air and heat transfer of annulus air is greater than annulus argon. The heat transfers from the glass envelope to the atmosphere by convection and radiation. The convection will either be forced or natural, depending on whether there is wind. Radiation heat loss occurs due to the temperature difference between the glass envelope and the sky. Radiation heat loss increases by 105 W when ambient temperature drops by 10. The convection heat increases by 116 W when wind speed increases from 0.5 to 6 m/s under the glass envelope outer surface temperature of 50. The value reaches 340 W when the glass envelope outer surface temperature is 80. The transient thermal efficiency of PTC is significantly affected by heat transfer fluid (HTF) temperature. The transient thermal efficiency decreases with the increase of the temperature of HTF, and increases with the increase of the direct solar radiation. PTC thermal efficiency is calculated by using the mathematical model established in this paper, and compared with the experimental data of the national renewable energy laboratory (NREL) in America, and the results show that the maximum deviation is about 3%. It shows that the mathematical model can reflect the heat transfer law of PTC. The characteristics of heat transfer mathematical model can provide theoretical basis for PTC design and system operation. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Heat transfer
Controlled terms:Argon - Atmospheric temperature - Collector efficiency - Glass - Heat convection - Heat losses - Heat radiation - Incident solar radiation - Mathematical models - Radiation - Solar collectors - Solar energy - Solar equipment - Solar radiation - Sun - Surface properties - Wind
Uncontrolled terms:Direct normal irradiances - Direct solar radiation - Heat transfer characteristics - National Renewable Energy Laboratory - One-dimensional heat - Parabolic trough solar collectors - Temperature differences - Transient thermal efficiency
Classification code:443.1 Atmospheric Properties - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 702.3 Solar Cells - 804 Chemical Products Generally - 812.3 Glass - 921 Mathematics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.07.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 15>
Accession number:20151800797534
Title:Updating model for land use database based on multi-layer perceptron network and its application
Authors:Ji, Yazhou (1); Gu, Hehe (1); Li, Baojie (2)
Author affiliation:(1) School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, China; (2) City and Environment College, Jiangsu Normal University, Xuzhou, China
Corresponding author:Ji, Yazhou
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:227-237
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land use database is the basis for the government departments at all levels to regulate land use, and the currency and quality of land use database directly determine the level and effect of land supervision. However, at present, the land use database updating technology and means are not advanced enough yet. The currency of the land use database significantly lags our economic development level. In light of the automatic matching complexity of change type and update strategy, artificial neural network is introduced into update strategy judgment field. According to the structure and main updating content, from the horizontal, land use database adaptive updating model is divided into land class polygon, linear feature and isolated feature. Then, in accordance with annual update implementation program of land use database and current updating progress, methods and habits, from the vertical, the above-mentioned updating model is divided into spatial analysis layer, input layer, change type judgment layer, spatial update strategy judgment layer and attribute update strategy judgment layer. Land class polygon is the first and the most important layer for land use database to update, so its updating model is designed on the top of the land use database adaptive updating model. To judge the change type and update strategy, 3 input conditions and 12 neurons are set up in land class polygon updating model, among which 4 neurons are responsible for judging the change type, 6 neurons are responsible for judging the spatial strategy, and 2 neurons are responsible for judging attribute strategy. Compared with land class polygon, linear feature updating model is more complicated. Therefore, linear feature updating model has 6 input conditions and 12 neurons, among which the distribution of neurons is the same as that of neurons in land class polygon updating model. Isolated feature belongs to one-dimensional element, so its updating model is relatively simple. In isolated feature updating model, 4 neurons are arranged to judge the change type, 3 neurons to judge spatial strategy, and 2 neurons to attribute strategy. The same-type neurons of adaptive updating model are organized into a network layer, and all layers are organized into a multi-layer perception network in an all-connected way. In addition, in order to realize the judgment of change type and update strategy, a threshold activation function is arranged in each neuron, and between the neurons connection weight is set up to adjust the input of neuron active function. All kinds of training methods of multi-layer perception neuron network are analyzed in a comprehensive and deep way. Change sample data of each element are collected so that updating model training can be carried out. Spatial and attribute update rules of various land use elements under the conditions of different topological relationships and different properties should be studied. And the knowledge and experience are organized into an update knowledge database. When new change survey data are input into model again, topology, property and linkage effect of the input sample are gained through the spatial analysis function, and then are organized in the form of vector. According to topological, property and linkage characteristics of new input sample together with learned experience, adaptive updating model draws a correct inference to spatial update strategy and attribute update strategy of new input sample, and eventually offers corresponding update strategy of sample in the form of vector. After the research subject is finished, updating application and technology tests are carried out respectively in 7 test bases, including Laoshan, Laixi, Huangdao of eastern Shandong, Liuyang and Yizhang of central Hunan and Chengdu and Wenjiang of western Sichuan, and the desired effect has been achieved. The tests show: Firstly, adaptive updating model of the land use features that the paper constructs can quickly complete change type's judgment of land class polygon, linear feature and isolated feature under any condition, and correctly offer spatial update strategy and attribute update strategy of all features. Compared with all test bases' software, our new software based on this updating model can comprehensively improve the updating efficiency by about 30%, and enhance one-time updating correct rate by more than 5%. Secondly, adaptive updating model of the land use features that the paper constructs has a strong adaptability. When update rules vary, it only needs to conduct a second sample training of the model, and the correct update strategy will be given without modifying software, thus improving soft adaptability. Thirdly, different from common updating software, in the adaptive updating model that the paper presents, the update strategies of all features are given not by man, but by experts' knowledge database. Meantime, change methods model need not be driven by man, but automatically driven by update strategy, thus bettering software automation level. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Topology
Controlled terms:Complex networks - Database systems - Economics - Geometry - Intelligent agents - Land use - Network layers - Neural networks - Neurons - Software testing - Spatial variables measurement
Uncontrolled terms:Activation functions - Economic development - Government departments - Knowledge and experience - Multi layer perceptron networks - Multi-layer perception - Software automation - Topological relationships
Classification code:403 Urban and Regional Planning and Development - 461.1 Biomedical Engineering - 461.9 Biology - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 921 Mathematics - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 943.2 Mechanical Variables Measurements - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.07.033
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 16>
Accession number:20151800797531
Title:Spatio-temporal differentiation and environmental risk assessment of fertilization in Shandong Province, China
Authors:Liu, Qinpu (1); Lin, Zhenshan (2); Zhou, Liang (3)
Author affiliation:(1) School of Environmental Science, Nanjing Xiaozhuang University, Nanjing, China; (2) School of Geographic Science, Nanjing Normal University, Nanjing, China; (3) School of Geographic and Oceanographic Science, Nanjing University, Nanjing, China
Corresponding author:Liu, Qinpu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:208-214
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Studies on spatio-temporal differentiation and environmental risk of fertilization in Shandong Province were conducted to reveal potential threats of fertilizers to the ecological environment, and strengthen environmental risk awareness and management. Such factors as fertilization intensity, fertilization efficiency, fertilization environmental safety threshold, weight of fertilizer effect on environment, multiple cropping index were introduced into the Fertilization Environmental Risk Index Model (FERIM). The model set up the risk index values between 0 and 1 to assess the fertilization environmental risk of Shandong. Based on the proportion of 1: 0.5: 0.5 for N: P: K in Shandong and the standard of 250 kg/hm<sup>2</sup> for the construction of ecological counties sponsored by Chinese government, the numbers of 125, 62.5, and 62.5 kg/hm<sup>2</sup> was considered as environmental safety thresholds for N, P, and K, respectively. Analytic hierarchy process (AHP) was used to determine the weights of N, P, and K. Results were shown as follows. 1) The rate of farmland fertilizer in Shandong was 634.1 kg/hm<sup>2</sup>, which was 2.5 times as many as the standard of 250 kg/hm<sup>2</sup> with the regional difference from the maximum of 878.7 kg/hm<sup>2</sup> to the minimum of 473.7 kg/hm<sup>2</sup>. The proportion of 1: 0.5: 0.5 for N: P: K was reasonable for crops in Shandong with little regional differentiations. 2) Environmental risk index of Shandong was 0.75 at medium risk degree, with sub-regions of Yantai at serious risk degree at 0.81 risk index and Weifang, Jining and Zaozhuang at severe risk degree in the range of risk index from 0.76 to 0.78. As for nitrogen fertilizer environmental risk, Yantai and Zaozhuang were at severe degree in the range of risk index from 0.78 to 0.80, except for the rest 15 regions at medium degree in the range of risk index from 0.70 to 0.75, while the environmental risk situation for phosphorus use was serious, with Yantai at extreme risk in 0.86 risk index, seven regions of Qingdao, Rizhao, Weifang, Dongying, Zaozhuang, Jining and Liaocheng at serious degree in the range of risk index from 0.81 to 0.84, the rest 9 regions at severe degree in the range of risk index from 0.76 to 0.80. But the environmental risk situation for potash use is relatively light, with southeast part of Shandong where there were seven regions at medium degree in the range of risk index from 0.68 to 0.75 and northwest part where there were ten regions at light degree in the range of risk index from 0.56 to 0.65.3) Overload fertilizers had resulted in serious environmental problems in Shandong. It made the concentration of NO<inf>3</inf>-N increasing in the groundwater and acidification of soil in the pH value of less than 5.5 for 63% orchard land in some regions, which was not suitable for apple tree growth. Therefore, governments at all levels in Shandong should regulate the fertilizer use with laws or rules, control the total amount of fertilizers' use and guideline farmers' fertilization according to local conditions in order to assure the sustainability of agriculture. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Soil pollution control
Controlled terms:Agriculture - Analytic hierarchy process - Ecology - Farms - Fertilizers - Groundwater - Nitrogen fertilizers - Pollution control - Risk assessment - Risk perception - Safety engineering - Soil pollution - Sustainable development
Uncontrolled terms:Analytic hierarchy process (ahp) - Ecological environments - Environmental problems - Environmental risk assessment - Environmental risk indices - Multiple cropping index - Shandong province - Spatio-temporal differentiations
Classification code:444.2 Groundwater - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911.2 Industrial Economics - 914 Safety Engineering - 914.1 Accidents and Accident Prevention - 921 Mathematics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.07.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 17>
Accession number:20151800797510
Title:Numerical analysis and test on cavitation of jet mixing apparatus
Authors:Zhou, Liangfu (1); Zhou, Lixin (1); Xue, Xinyu (1); Kong, Wei (1)
Author affiliation:(1) Key Laboratory of Modern Agricultural Equipment, Ministry of Agriculture, Ministry of Agriculture, Nanjing, China
Corresponding author:Xue, Xinyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:60-65
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The jet mixing apparatus (JMA) is a vitally important part for mixing water with a pesticide, including a working nozzle, suction inlet, diffuser, thumb lock, case, end cap, one-way ball, inserts, etc. The Jet Mixing Apparatus is a simple device with no moving parts, where a high velocity flow (water) is used to pump a second fluid (pesticide). It was broadly used in large plant protection machinery. Its main property is efficiency and stability of the mixing ratio. Cavitation is a physical phenomenon in a Jet Mixing Apparatus happening at low pressure, seriously affecting the performance and wasting energy. In order to acquire the characteristic curve of the relation on the mixing ratio and pressure ratio, experimental and numerical analyses were used to measure the mass flow rate of working, intake, and mixed fluid. The test was conducted in the Key Laboratory of Modern Agricultural Equipment in accordance with the JB/T9782-1999 general test method for plant protection machinery. The outlet pressure was regulated to different levels (0.25, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.35 MPa) by a throttle valve, an electronic scale for mass flow rate, a U mercury manometer for vacuum, which was at 2.0 MPa working pressure and normal atmosphere intake. The computational fluid dynamics (CFD) software ANSYS fluent 15.0 was used for numerical simulation of the cavitation. The Zwart-Gerber-Belamri cavitation model in mixture model was adopted to capture cavitation, and obtained the internal static pressure distribution and gas distribution contour under different outlet pressures. Water was set as the main phase, with density of 1000 kg/m<sup>3</sup>, and dynamic viscosity of 0.001 kg/(ms). Water vapor was set as the second phase, with density of 0.02558 kg/m<sup>3</sup>, dynamic viscosity of 1.26×10<sup>-6</sup>, and the bubble radius of 0.01 mm. Cavitation pressure was set 3 540 Pa. The two inlet boundary condition was set at pressure-inlet, turbulence intensity of 2%, and hydraulic diameter of 14 mm. The outlet boundary condition was set at pressure-outlet, turbulence intensity of 2%, and hydraulic diameter of 9 mm. A double precision solver and pressure velocity coupling algorithm was adopted. The pressure equation was discrete with two-order upwind, and other equations with the QUICK method. Calculation of residual was set for 10<sup>-6</sup>, using hybrid initialization to initialize. The experimental values and the simulated values were compared for fitting analysis, and the mathematical relationship between the experimental values and the simulated values was established. The fitting coefficient R<sup>2</sup> was 0.9618, which verified the accuracy of the model. The results showed that JMA has poor performance even backflow when the pressure ratio was greater than 0.6. The static pressure on the central axis had no significant difference in a working nozzle at the different outlet pressures, negative pressure appeared at the nozzle exit, and the negative pressure zone increased with the decrease of the pressure ratio. The mixing ratio was negatively correlated with the pressure ratio when the pressure was between 0.4 to 0.6. The mixing ratio and pressure ratio were independent when the pressure ratio was less than 0.4, which was the cavitation mixing ratio. The cavitation happened at the outlet pressure of 0.8 MPa, and the lower the outlet pressure, the more severe the cavitation, which was under working pressure 2.0 MPa, and suction pressure zero. Numerical and experiment research of cavitation is a meaningful area for research for improving the efficiency of a jet mixing apparatus. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Computational fluid dynamics
Controlled terms:Agricultural machinery - Agriculture - Boundary conditions - Cavitation - Computer software - Electronic scales - Equipment - Flow rate - Fluid dynamics - Gases - Hydraulic machinery - Inlet flow - Jets - Manometers - Mass transfer - Mixing - Nozzles - Numerical analysis - Pesticides - Turbulence - Viscosity - Water distribution systems
Uncontrolled terms:Agricultural equipment - Experimental and numerical analysis - Mathematical relationship - On-line mixing - Outlet boundary condition - Plant protection - Pressure-velocity coupling - Static pressure distributions
Classification code:446.1 Water Supply Systems - 631 Fluid Flow - 632.2 Hydraulic Equipment and Machinery - 641.3 Mass Transfer - 715 Electronic Equipment, General Purpose and Industrial - 723 Computer Software, Data Handling and Applications - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 901 Engineering Profession - 921 Mathematics - 921.6 Numerical Methods - 931.2 Physical Properties of Gases, Liquids and Solids - 944.3 Pressure Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.07.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 18>
Accession number:20151800797542
Title:Identification of cold resistance of squash and cucumber fruits by electrical conductivity and Logistic equation
Authors:Xie, Yue (1); Zhang, Min (1); Liang, Feixia (1); Yuan, Haitao (1); Huang, Ruguo (1); Zhu, Saisai (1)
Author affiliation:(1) College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
Corresponding author:Zhang, Min
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:292-298
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The present study was undertaken to investigate cold-sensitive fruits' cold resistance at low temperatures. Squash and cucumber were two typical kinds of cold-sensitive fruits, and they were very sensitive to low temperatures and easily suffered from chilling injury for inappropriate cold storage. Therefore, the research took squash, Jinyou cucumber and Shenqing cucumber as samples, and analyzed the changes of electrolyte leakage rate at different low temperatures (2, 8, 12 and 20) for different days (2, 4, 6, 8, 10 and 12 d). Because the changes in cell membrane permeability were significantly earlier than other chilling injury symptoms, such as the index of internal browning, but the changes between different varieties of cold-sensitive fruits were not always the same. That was the reason why the research took two different kinds of cucumbers as samples. The electrolyte leakage rate was often taken to identify cold-sensitive fruit's cold resistance. In addition, it has achieved some progress and breakthroughs at home and abroad in resent years. The electrolyte leakage rate was tested and documented every two days. Storage temperature and time, maturity, penetration time, measurement unit were considered as major influential factors on the research for electrolyte leakage rate. Among all the factors, penetration time and measurement unit were the most innovative and unique ones. Semi-lethal temperatures were determined by the logistic equation and they were taken as the important basis to judge whether cold-sensitive fruits suffered from chilling injury or not and the order of cold resistance. The result showed that the electrolyte leakage rate achieved stable when penetration time reached 90 minutes. At the same storage temperature, for the growth of the electrolyte leakage rate, there was little difference between the two varieties. With the extension of the storage time, the growth of the electrolyte leakage rate increased and showed significant difference (P<0.05). At the end of the storage time, the growth of the electrolyte leakage rate became stabilized, indicating that the cell membrane permeability had been completely destroyed at this moment. That was to say, the lower the storage temperature, the longer the storage time, the higher the electrolyte leakage rate, the worse the fruits' quality. Meanwhile, semi-lethal temperature of squash was between 5.37-6.56, Jinyou cucumber was between 6.69-7.86 and Shenqing cucumber was between 8.04-8.96. That was to say, these cold-sensitive fruits would have maintained a high quality when they were stored at this temperature range. They were confirmed individually and accurately. The tendency of the electrolyte leakage rate followed the Logistic equation and had a linear relationship with semi-lethal temperature. The result of semi-lethal temperature showed significant difference between different varieties, with the extension of duration time at low temperatures, the value of semi-lethal temperature increased and had a positive correlation with the duration time (P<0.05). The order of cold-sensitive fruit's cold resistance from high to low was squash, Jinyou cucumber, Shenqing cucumber and it had no significant relationship with fruits' maturity. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Fruits
Controlled terms:Cell membranes - Cold storage - Cytology - Electrolytes - Frost protection - Models - Temperature - Units of measurement
Uncontrolled terms:Cell membrane permeability - Cold resistance - Electrical conductivity - Electrolyte leakage - Linear relationships - Logistic equations - Positive correlations - Storage temperatures
Classification code:461.2 Biological Materials and Tissue Engineering - 641.1 Thermodynamics - 694.4 Storage - 702 Electric Batteries and Fuel Cells - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products - 902.1 Engineering Graphics - 902.2 Codes and Standards
DOI:10.3969/j.issn.1002-6819.2015.07.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 19>
Accession number:20151800797524
Title:Mosaic and repair method of locust slices based on feature extraction and matching
Authors:Li, Li (1); Guo, Shuangshuang (1); Mei, Shuli (1); Zhang, Nannan (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China
Corresponding author:Li, Li
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:157-165
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Because of the influence of the environment and the characteristics of the locust slices, locust slices obtained from experiments are always incomplete or folded. To match and reconstruct this folded area, the slice in the sequences adjacent to the slice which needs to be repaired is used as the reference image, and in this way, the slice is repaired successfully. The image mosaic and repair algorithm used in the article has the following steps: image preprocessing, feature extraction, feature matching, coordinate transformation and image mosaic and repair. Firstly, as there is some noise in the slice image that can influence the repairing effect, we use wavelet denoising on images to reduce the effect of noise on feature extraction before searching the feature points; secondly, as there are no related materials about how to match or repair locust slices, in order to find more suitable feature extraction methods for locust slices, we compare the scale-invariant feature transform (SIFT) with speed-up robust features (SURF) algorithm which are already widely used in computer vision and image registration, and then generate the image feature vectors to complete the feature extraction from the initial slice image, record the scale, position and direction of the feature points at the same time, and finish the preliminary matching between the two slices; thirdly, as the preliminary matching can not completely remove the error matching points, random sample consensus (RANSAC) algorithm is used to correct the matching errors and eliminate the error matching points by repeatedly choosing a group of random subsets of the data, finally leaving the correct matching points; fourthly, the homography matrix is calculated by using the least square method based on all the correct matching points, which makes full use of existing points to calculate and therefore makes the results have more universal adaptability; finally, the locust slices mosaic is finished using the correct matching points and the homography matrix, the corresponding matching block for the folded part is found out using space mapping model and the slice repair is completed. The experiment adopts two groups of positive images of locust slice obtained from the experimental environment under the microscope. What's more, statistical results of contrast experiment with SIFT and SURF algorithm are obtained, each of which shows the running time, the number of matching points and matching rate. The experimental results show that: the matching rates reach 72.2% and 34.0% using SIFT algorithm and SURF algorithm, respectively, which means that SIFT algorithm can meet the requirements of image mosaic more precisely compared with SURF algorithm. As the matching rate doesn't perform as well as expected, the error sources such as the change of content or the effect from the fold are briefly analyzed. The registration algorithm provides the reference for the later work of the folded area's opening on the slice image and the three-dimensional reconstruction of locust. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Image matching
Controlled terms:Algorithms - Computer vision - Extraction - Feature extraction - Image processing - Image reconstruction - Iterative methods - Least squares approximations - Matrix algebra - Random errors - Repair - Vector spaces
Uncontrolled terms:Feature extraction and matching - Feature matching - Image mosaic - Locust slices - Random sample consensus - Random sample consensus (RANSAC) algorithm - Scale invariant feature transforms - Three-dimensional reconstruction
Classification code:716 Telecommunication; Radar, Radio and Television - 741 Light, Optics and Optical Devices - 741.2 Vision - 802.3 Chemical Operations - 913.5 Maintenance - 921 Mathematics - 922 Statistical Methods
DOI:10.3969/j.issn.1002-6819.2015.07.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 20>
Accession number:20151800797525
Title:Design and test of remote monitoring equipment for bactrocera dorsalis trapping based on internet of things
Authors:Xiao, Deqin (1); Fu, Junqian (2); Deng, Xiaohui (2); Feng, Jianzhao (2); Yin, Jianjun (2); Ke, Xinrong (3)
Author affiliation:(1) Key Laboratory of Modern Agricultural Equipment, Ministry of Agriculture, Nanjing, China; (2) College of Informatics, South China Agricultural University, Guangzhou, China; (3) College of Engineering, South China Agricultural University, Guangzhou, China
Corresponding author:Xiao, Deqin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:166-172
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For bactrocera dorsalis field monitoring, the current method had some disadvantages: a heavy workload, low efficiency, poor reliability, low accuracy, and it could not large-scale and fast monitor the orchard pest situation in real time. Agriculture experts eager to have a solution to automatically count the number of bactrocera dorsalis and remotely observe the trapping result in real time to reduce their labor so that they could focus more on the study of the characteristics of insects. Therefore, combining the image target detection technology and the target tracking technology to develop an automated counting system by using a video image sensor would be necessary. In order to realize the real-time monitoring, the bactrocera dorsalis trapping, and a rapid diagnosis, an IOT-Based remote monitoring equipment for bactrocera dorsalis trapping was provided in this paper. The equipment included a trap monitoring device, a solar power supply device, and the monitoring control device. The trap monitoring device was comprised of a top cover, a transparent funnel, a trap bottle, a LED, and a camera; the solar energy device was comprised of a solar panel, a storage battery, and a solar panel bracket; the bactrocera dorsalis monitoring control system device was comprised of a Fit-pc controller, a 3G communication module, and the independent software for counting bactrocera dorsalis' numbers. This equipment combined machine vision technology and telecommunication technology with solar power technology. The purpose of the equipment was to achieve a whole function for bactrocera dorsalis trap monitoring with plant diseases and insect pests information collection, together with processing, transmission, and self-supply. It could monitor the trapping process and precise calculation of the number of bactrocera dorsalis anytime and anywhere, and also automatically transmit the results to the remote server or store it in a local storage card. For object extraction, this paper used an HSV color space for image filtering, then used median filtering and morphological filtering for the image to reduce white noise, eliminating holes in the target area to improve the image quality, and then divided the image into blocks based on the adjacent pixels of the image and used these blocks for Geometric feature matching, so that the bactrocera dorsalis area could be extracted. Finally, this paper used the watershed algorithm based on weight for an image segment to get the tracking object and tag the object. For bactrocera dorsalis tracking, this paper used a Kalman filter to predict the target movement position, narrowing the range of target searching and target matching, reducing the amount of calculation of the target matching; and established a cost model by using centroid Euclidean distance, survival time, and the color difference of the target between two consecutive frames; updated the cost model of each tracked target, and handled the missing target to ensure the stability and accuracy of the tracking algorithm. For bactrocera dorsalis metering, this paper studied a counting strategy for moving targets. This equipment was tested in the laboratory environment. There were 138 bactrocera dorsalis entered in the equipment in 830 s, the detected result of the system was 131, and the detection success rate was 94.9%. Also this equipment was tested in the Yangtao Park for more than a year (from November 2013 to December 2014), and the system hardware and software could work cooperatively and stably. The system stopped running only when there was a shortage of solar power, rendering it ineffective under grim weather for lack of the light. The IOT-Based remote monitoring equipment for bactrocera dorsalis trapping could automatically track and count the number of bactrocera dorsalis. It could also provide simple and effective monitoring information to the regional monitoring personnel, improve work efficiency, greatly improve the performance of the monitoring system, and had a wide range of applications in agriculture. This equipment had important practical applications. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Monitoring
Controlled terms:Agriculture - Bottles - Color - Color matching - Colorimetry - Computer control systems - Computer vision - Controllers - Design - Diagnosis - Electric power supplies to apparatus - Equipment - Feature extraction - Image matching - Image processing - Image segmentation - Internet - Internet of things - Light emitting diodes - Median filters - Real time control - Remote control - Software testing - Solar cell arrays - Solar concentrators - Solar energy - Target tracking - Tracking (position) - White noise
Uncontrolled terms:Bactrocera dorsalis - Count - Machine vision technologies - Monitoring control systems - Plant diseases and insect pests - Telecommunication technologies - Trapping - Visual perception
Classification code:408 Structural Design - 461.6 Medicine and Pharmacology - 615.2 Solar Power - 694.2 Packaging Materials - 702.3 Solar Cells - 711 Electromagnetic Waves - 715.2 Industrial Electronic Equipment - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 732 Control Devices - 732.1 Control Equipment - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 801 Chemistry - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession - 941 Acoustical and Optical Measuring Instruments - 941.4 Optical Variables Measurements - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.07.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 21>
Accession number:20151800797507
Title:Multi-objective adaptive control model of foreign fiber cleaner used in seed cotton
Authors:Li, Hui (1); Wang, Haopeng (1)
Author affiliation:(1) Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, Shandong University, Ji'nan, China; (2) Shandong Police College, Ji'nan, China
Corresponding author:Wang, Haopeng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:39-46
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Foreign fiber cleaner was widely used in the field of cotton processing industry for its good cleaning efficiency. However, with the improvement of cotton processing level, how to improve the foreign fiber's cleaning efficiency and reduce the fiber's damage had become a growing concern, which was taken as the research object in the paper. This paper designed four-factor quadratic orthogonal rotation test. The four factors were the capacity of foreign fiber cleaner, the regain of seed cotton, the winding roller speed and the wind speed. The cleaning efficiency of foreign fiber and the damage of fiber length were objective functions. For the multi-factor test, orthogonal test design was an effective method of scientific experiments where part of the ones can reflect the comprehensive experiments. Through these factors quadratic orthogonal rotation test, the multi-objective optimal control model of foreign fiber cleaner was established. The results revealed that the remarkable factors which influenced the cleaning efficiency of linear foreign fiber were the winding roller speed, the regain of seed cotton and the wind speed, while the capacity of foreign fiber cleaner was not remarkable. The regain of seed cotton and winding roller speed had significantly interactive effect for the cleaning efficiency of linear foreign fiber. Higher winding roller speed, wind speed and lower regain of seed cotton would improve the cleaning efficiency. The effects on the cleaning efficiency of linear foreign fiber were in order of winding roller speed > wind speed > regain of seed cotton > capacity of foreign fiber cleaner. The effects on the cleaning efficiency of flake foreign fiber were in order of wind speed > winding roller speed > regain of seed cotton > capacity of foreign fiber cleaner. All of the factors were the remarkable factors. The effects on the damage of fiber length were in order of winding roller speed > regain of seed cotton > wind speed > capacity of foreign fiber cleaner. The remarkable factors which influenced the damage of fiber length were the winding roller speed, the regain of seed cotton and the wind speed. The model in this paper has been applied in the multi-objective optimization control of foreign fiber cleaner. Users could adjust the parameters of foreign fiber cleaning machine according to their demand in the actual production. In the conditions of this study, Compared with a fixed value control method, the cleaning efficiency of linear foreign fiber by using multi-objective adaptive control method was increased on average by about 9.4%, the cleaning efficiency of flake foreign fiber was increased on average by about 3.3%, and the damage of fiber length was reduced on average by about 0.051%. Cleaning effect was satisfactory. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Cleaning
Controlled terms:Adaptive control systems - Automation - Control - Cotton - Cotton fibers - Cultivation - Efficiency - Fibers - Multiobjective optimization - Regain - Rollers (machine components) - Speed - Wind - Winding
Uncontrolled terms:Adaptive Control - Adaptive control methods - Cleaning efficiency - Foreign fiber - Multi-objective optimal control - Orthogonal test design - Quadratic orthogonal rotation - Scientific experiments
Classification code:443.1 Atmospheric Properties - 601.2 Machine Components - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 732 Control Devices - 802.3 Chemical Operations - 812 Ceramics, Refractories and Glass - 817 Plastics and Other Polymers: Products and Applications - 819.1 Natural Fibers - 819.3 Fiber Chemistry and Processing - 821.3 Agricultural Methods - 913.1 Production Engineering - 921.5 Optimization Techniques - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.07.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 22>
Accession number:20151800797536
Title:Cultivated land quality evaluation of land consolidation project based on agricultural land gradation
Authors:Xu, Kang (1); Jin, Xiaobin (1); Wu, Dingguo (2); Zhou, Yinkang (1)
Author affiliation:(1) School of Geography and Ocean Sciences, Nanjing University, Nanjing, China; (2) Lingshui Bureau of Land Environment and Resources, Lingshui, 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:7
Issue date:April 1, 2015
Publication year:2015
Pages:247-255
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To improve the quality of cultivated land was one of the core tasks of land consolidation. But for a long time, increasing the number of arable land was the only goal, and therefore it was an urgent requirement to effectively and quickly evaluate the consolidated farmland's quality for the research and practice on the basis of ready data. To stabilize the amount of arable land, improve the quality of arable land and ensure food security were the main objectives and focuses of the agricultural land consolidation in China currently. Monitoring the changes in number and quality of arable land was objective requirement to guarantee the orderly development of the system. Agricultural land classification (ALC) fully ascertained the distribution of Chinese farmland quality level and established a unified national database of cultivated land quality grades. The Ministry of Land and Resources (MLR) deployed the dynamically updated work of cultivated land quality grade change in 2012, which provided solid foundation for the scientific management of land quality. But ALC mainly characterized the quality of farmland at macro level, and the application of the results faced some restrictions on the scale of the project. Therefore, the evaluation system of classification needed to be corrected. Land consolidation included four projects: land leveling project, irrigation and drainage project, field road project, farmland protection and eco-environment maintaining project. This paper analyzed the impact of these four projects to the farmland quality, distinguished the sensitive factors and stable factors, supplied the modified factors for natural quality and production condition through comparing with the ALC. Combined the factors of natural quality and ALC, the corresponding weights were set by AHP (analytic hierarchy process) and Delphi, the natural quality evaluation system was constituted based on project scale, and natural quality score was recalculated. Light and temperature potential, yield ratio coefficient, utilization coefficient and economic coefficient were regarded as constant values. The natural quality index was recalculated, and the natural grade of arable land on project scale was classified. Follow the idea of revising coefficient, compare the scores of the production factors before and after the consolidation, calculate the correction coefficients of utilization and redraw the utilization grades. Because land consolidation projects did not directly affect agricultural production technology and management level of arable land, this study did not involve economic correction. Finally, combined with field survey data in the study area, the correlation between the obtained results and the actual output was analysed, and the validity of this evaluation results was verified. Taking Lingshui county, Hainan province as an example, this article analyzed typical land consolidation project. The research results demonstrated that the comprehensive nature grade increased from 4.7 to 4.2, the comprehensive utilizable grade increased from 4.3 to 3.2 and the correlation coefficient between consolidated utilizable grade index and actual output of benchmark crops was 0.86, which was higher than the one before the revision 0.82, indicating that the constructed cultivated land quality evaluation system can effectively reflect the land consolidation's impact on the farmland quality and the analysis results meet the need of objectively evaluating the change of farmland quality. This study can provide the reference for cultivated land quality evaluation. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Quality control
Controlled terms:Agriculture - Benchmarking - Classification (of information) - Consolidation - Farms - Food supply - Grading - Land use - Macros - Scales (weighing instruments)
Uncontrolled terms:Agricultural land - Agricultural productions - AHP (analytic hierarchy process) - Correction coefficients - Correlation coefficient - Cultivated land qualities - Projects - Quality evaluation system
Classification code:403 Urban and Regional Planning and Development - 404.2 Civil Defense - 483 Soil Mechanics and Foundations - 716.1 Information Theory and Signal Processing - 723.1 Computer Programming - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 912 Industrial Engineering and Management - 913 Production Planning and Control; Manufacturing - 913.3 Quality Assurance and Control - 943.3 Special Purpose Instruments
DOI:10.3969/j.issn.1002-6819.2015.07.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 23>
Accession number:20151800797541
Title:Processing technology combining degumming with oil pressing for flaxseed
Authors:Huang, Qingde (1); Deng, Qianchun (1); Xu, Jiqu (1); Zhu, Zhengwei (1); Cao, Weiwei (1)
Author affiliation:(1) Oil Crops Institute of Chinese Academy of Agricultural Science, Wuhan, China
Corresponding author:Huang, Qingde
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:287-291
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the present, oil pressing is still the main process for extracting oil from flaxseed in China, but it cannot achieve efficient utilization of functional materials in flaxseed, such as flaxseed gum and lignin secoisolariciresinol diglycoside (SDG). So a comprehensive process that produces multiple products from flaxseed needs to be developed. On the basis of the structural characteristics that the flaxseed gum is in the outermost layer of flaxseeds, the grinding degumming technology using high-speed rotating sand roller grind flaxseed surface is studied before in our laboratory. Model 150 flaxseed degumming machine was designed and manufactured according to this technology, it is composes of motor, sand roller, sieve, gum powder collector etc. Electronic motor is used in the machine to drive the sand roller with high-speed rotation inner the sieve to grind flaxseed, the gum powder flow out the sieve and is collected, the sand roller length and diameter is 800 and 146 mm, the cylindrical sieve diameter is 158 mm with uniform distribution of Φ 1.5 mm sieve size. In this paper, the feasibility of Model 150 flaxseed degumming machine was studied. Based on that, the research work of flaxseed degumming and oil pressing co-process was carried out with the commodity flaxseed from Gansu as the research material. The results showed that: the machine was able to obtain flaxseed gum-powder successfully when flaxseed flow rate was controlled at 40 to 220 kg/h. The rate of gum-powder grinded from flaxseed was 6.5?Ddamp;plusmn;0.3%. The viscosity of the defatted gum-powder was (5100±520) mPas. The oil contents of flaxseed and the degummed flaxseed were 39.30?Ddamp;plusmn; 0.25% and 41.62?Ddamp;plusmn;0.22%, respectively. By using the method of adding 30% flaxseed cake to degummed flaxseed, the oil of degummed flaxseed can be screw pressed successfully. The oil yield pressed from degummed flaxseed was 34.65?Ddamp;plusmn;0.43%, higher than that pressed twice from flaxseed (33.94?Ddamp;plusmn;0.43%) when the flaxseed was pressed with the screw pressing machine without degumming. By the combination of degumming and screw-pressing for flaxseed processing, two benefits were achieved, they were: increase number of products and high pressed oil yield. The research results can provide reference for flaxseed processing. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Flax
Controlled terms:Degumming - Functional materials - Oil shale - Oilseeds - Pressing (forming) - Processing - Rollers (machine components) - Sand - Screws - Sieves - Technology
Uncontrolled terms:Electronic motors - Flaxseed - High speed rotation - High-speed rotating - Processing technologies - Secoisolariciresinol - Structural characteristics - Uniform distribution
Classification code:505 Mines and Mining, Nonmetallic - 512.1 Petroleum Deposits - 535.2.2 Metal Forming Practice - 601.2 Machine Components - 605 Small Tools and Hardware - 819.1 Natural Fibers - 821.4 Agricultural Products - 822.2 Food Processing Operations - 901 Engineering Profession - 913.4 Manufacturing - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.07.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 24>
Accession number:20151800797508
Title:Crop line recognition algorithm and realization in precision pesticide system based on machine vision
Authors:Diao, Zhihua (1); Zhao, Mingzhen (1); Song, Yinmao (1); Wu, Beibei (1); Wu, Yuanyuan (1); Qian, Xiaoliang (1); Wei, Yuquan (1)
Author affiliation:(1) Electric Information and Engineering Department, Zhengzhou University of Light Industry, Zhengzhou, China; (2) Henan Key Lab of Information Based Electrical Appliances, Zhengzhou, China
Corresponding author:Song, Yinmao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:47-52
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The identifying of a center line in a crop and the realization of an automatic alignment of a spraying nozzle is the key technology in a precision pesticide. Machine vision has great advantage in path automatic identification, and has been widely used in the study of modern precision agriculture. To overcome the low adaptability in a navigation line extraction algorithm, we used middle growing corn as the goal of the research and got an algorithm with a higher adaptability. In this paper, the image background segmentation was the first part. In this part, the comparison of a traditional gray transformation and an improved one was realized, and showed the effect of the traditional method and an improved method, the results showed that the improved algorithm had certain advantages in the processing of such images, so we used the improved gray-scale transformation as the first step of segmentation. Then the improved middle filter algorithm was used to filter the noise in an image which has been changed in the method of obtaining the middle value to reduce the processing time. Then the image was binarized by an OTSU algorithm instead of the threshold method, which processed automatically with little interference and made the crop row black, and the background white, so to achieve the image background segmentation. Crop line extraction was the second part. The purpose was to use the line to indicate the crop rows, so we used the following method to extract a line in a binary image as far as possible to represent the crop rows and the central position of the image. We used a morphological algorithm to remove the noise, and the 3×3 template of erosion and dilation to operate on the two value image, and determined the number of erosion and dilation by experiment, and then the thinning algorithm and scanning filtration was adopted to keep the middle of the crop rows only, in order to represent navigation information and reduce the computation in line recognition. The third part was deviation calculation. We fit out the navigation line, and got the navigation information by a randomized Hough transform that determined a point in the parameter space by any two points in an image space and transformed the dispersed mapping of one to many to merge the mapping of many to one, which reduced the amount of computation effectively and improved the velocity of calculation. According to the transformation between the world coordinate system and the image coordinate system and the deviation distance between bottom center of crop rows, the pixel center of the image and the spray nozzle position relative to the information of camera, we could get the actual deviation in this image. Finally, we realized the hardware structures and composition of this system. And the experimental results suggested that this algorithm had better generality, and it had a certain advantage in background segmentation, crop line, and navigate information extraction. We have proved that the algorithm can effectively avoid the effects of weeds by the experiment of different images and process, and it can adapt to the line extraction of different crops. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Image processing
Controlled terms:Algorithms - Automation - Binary images - Computer vision - Crops - Erosion - Feature extraction - Hough transforms - Image segmentation - Mapping - Navigation - Pesticides - Spray nozzles
Uncontrolled terms:Automatic identification - Background segmentation - Morphological algorithms - Navigation in formation - Precision Agriculture - Randomized Hough transform - Row recognition - World coordinate systems
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 483 Soil Mechanics and Foundations - 631.1 Fluid Flow, General - 716 Telecommunication; Radar, Radio and Television - 716.3 Radio Systems and Equipment - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 731.6 Robot Applications - 732 Control Devices - 803 Chemical Agents and Basic Industrial Chemicals - 821.4 Agricultural Products - 902.1 Engineering Graphics - 921 Mathematics - 921.3 Mathematical Transformations
DOI:10.3969/j.issn.1002-6819.2015.07.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 25>
Accession number:20151800797511
Title:Experiment of vehicle passive skyhook damping suspension system
Authors:Nie, Jiamei (1); Zhang, Xiaoliang (1)
Author affiliation:(1) School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang, China
Corresponding author:Nie, Jiamei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:66-71
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, the inerter was used to different mechanical vibration networks to improve the vibration isolation performance. In order to improve the vehicle suspension system's performance of vibration isolation and develop passive suspension system, the suspension system with inerter was studied. A passive realization method was presented for ideal skyhook damping to solve the technical problem in connecting the damper with the inertial reference system. This method took use of the anti-resonance phenomenon in the inerter-spring-mass system. The passive realization method of ideal skyhook damping was applied to the vehicle suspension system. Based on the inerter-spring-damper mechanical system, a passive skyhook damping suspension system with inerter was proposed, which could achive the main function of the ideal skyhook damping suspension. There was two-stage structure in the passive skyhook damping suspension system. The first stage had a coil spring and a damper in parallel, the same as the conventional passive suspension. The second stage had a coil spring, a damper and an inerter in parallel which could realize the ideal skyhook damping performance. The experimental prototype of passive skyhook damping suspension was designed and installed to the back of the test vehicle instead of the conventional passive suspension. The two-stage series passive skyhook damping suspension needed more vertical space when installed to the vehicle than the conventional passive suspension. So it was not suitable for the car. In order to solve the problem, the two-stage series suspension was folded in half to reduce the total height. Then the improved suspension was installed to the test vehicle with a rocker arm. The rocker arm was an equal armed lever which could change the direction of force but not change the magnitude. The test system was designed based on the MTS 320 type simulator with four-channel road coupled by tire. A gyroscope was used to acquire the body vertical, pitch and roll acceleration signal. Two PCB acceleration sensors were used to acquire the left rear body vertical acceleration and the left rear wheel vertical acceleration signals. Frequency response characteristics test of rear suspension, bump pulse response test, random excitation response test were carried out. And the test results were compared to the conventional passive suspension in order to verify the characteristics of the passive skyhook damping suspension. The test results of frequency response characteristics of rear suspension showed that the resonant peak value of the left rear body vertical acceleration was reduced by 35.7% within the frequency of 1-3 Hz. At the same time, the left rear wheel vertical acceleration had no significant deterioration. The test results of bump pulse response showed that the peak-to-peak values of body vertical acceleration, body pitch acceleration and left rear wheel vertical acceleration were reduced by 7.52%, 11.82% and 31.48% respectively. The test results of random excitation response showed that the power spectral densities of body vertical, body pitch, body roll, left rear body vertical and left rear wheel vertical acceleration were reduced obviously within the frequency of 1-3 Hz. In different roads the root mean square (RMS) of body vertical acceleration was reduced by about 12% with different speeds. The RMS of body pitch, body roll, and left rear wheel vertical acceleration were all reduced by no more than 10%. It was shown from the test results that the low frequency response characteristics of vehicle could be improved by the proposed passive skyhook damping suspension. Meanwhile, the vertical, pitch and roll vibration of vehicle body within the frequency of 1-3 Hz could be inhibited obviously. So, the vehicle performance of ride comfort could be improved markedly. Compared with the conventional passive suspension, the passive skyhook damping suspension had better performance. The test results also indicated that the passive realization method of ideal skyhook damping was correct and feasible. The conclusion provides an important reference for the investigation of new passive suspension system with inerter. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Suspensions (components)
Controlled terms:Acceleration - Airships - Automobile bodies - Automobile suspensions - Damping - Frequency response - Polychlorinated biphenyls - Power spectral density - Research aircraft - Spectral density - Springs (components) - Suspensions (fluids) - Testing - Vehicle performance - Vehicle suspensions - Vehicles - Vibrations (mechanical) - Wheels
Uncontrolled terms:Bench tests - Inerter - Ride comforts - Sky-hook damping - Vibrations
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 432 Highway Transportation - 601.2 Machine Components - 632.1 Hydraulics - 652.1 Aircraft, General - 652.5 Balloons and Gliders - 663.1 Heavy Duty Motor Vehicles - 663.2 Heavy Duty Motor Vehicle Components - 711 Electromagnetic Waves - 731.1 Control Systems - 804 Chemical Products Generally - 804.1 Organic Compounds - 921 Mathematics - 931.1 Mechanics - 941 Acoustical and Optical Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.07.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 26>
Accession number:20151800797540
Title:Distribution of beef tenderness grading based on texture features by hyperspectral image analysis
Authors:Zhao, Juan (1); Peng, Yankun (1)
Author affiliation:(1) National R and D Center for Agro-processing Equipment, College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Peng, Yankun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:279-286
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Due to high protein, low fat, high vitamin and mineral content, beef is regarded as an important meat item which is consumed by human in regular basis. In addition, with the improvement of people's living standard, different quality parameters such as beef tenderness, water retention and other edible quality indicators have become important factors to consumers' satisfaction. Sensory evaluation and shear force measurement are primarily two methods for measurement of beef tenderness, which are now considered as traditional methods. However, with improvement in technology, optical methods are playing important role for rapid, real-time, non-destructive and accurate detection of meat quality parameters. Near-infrared method and hyperspectral imaging method are important methods for non-destructive measurement of beef tenderness. This study focused on the application of hyperspectral image analysis for non-destructive detection of beef tenderness at different points of the sample. Considering the measurement complexity due to complex beef structure as well as the disadvantage of near infrared spectrum for single point detection, this study made use of hyperspectral imaging system to obtain three-dimensional information from each sample. Fifty-six beef samples were obtained from the slaughter house Yuxiangyuan in Beijing and were cut into 3 cm thick slices, vacuum packaged and then stored in 4 environment before hyperspectral image acquisition. Reflectance spectrum was obtained for each sample from acquired images. Stepwise regression and genetic algorithm (GA) were used to identify the feature wavelengths, thus reducing the high dimensionality of the hyperspectral data. Eight feature wavelengths were selected, which were used to develop prediction model for measuring the shear force value at each point in the sample. By the principal component analysis (PCA), every sample could acquire 5 PCA images. Gray level co-occurrence matrix (GLCM) was applied to extract 8 main texture parameters from the characteristic band image and the 3 PCA images. Eight wavelengths were extracted from these 8 texture characteristic parameters respectively, with a total of 64 texture variables. Also, from five PCA images 40 texture variables were extracted. These parameters were used to establish a model based on linear discrimination analysis (LDA) and support vector machine (SVM) for beef tenderness. Because the number of principal components has a greater impact on the accuracy of discriminant model, before the training of SVM model, it first needed to select the appropriate number of principal components. Finally, three PCA images which included 95.37% information of every sample were chosen to extract texture parameters. With texture parameters of band images, the prediction set's accuracy of the discriminant model was 88.89%. There had some shortcomings that on one hand, the band images had great influence on the result, and on the other hand, some information may be missed with selected band images, so the texture features of the image of sample main component were used to establish classification model. After analysis and comparison, the accuracy of main component model was 94.44%, which was higher than that of band image model. In addition, the LDA method was more applied to establish classification model than SVM method. The results show that the image texture features can determine the distribution of beef tenderness. The results can provide the theoretical reference for the research on rapid non-destructive detection technique of beef tenderness. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Image texture
Controlled terms:Algorithms - Beef - Classification (of information) - Genetic algorithms - Grading - Image acquisition - Image analysis - Image processing - Image retrieval - Infrared devices - Meats - Models - Near infrared spectroscopy - Optical data processing - Principal component analysis - Spectroscopy - Support vector machines - Textures - Water quality
Uncontrolled terms:Beef tenderness - Feature bands - Gray level co occurrence matrix(GLCM) - Hyper-spectral images - Linear discrimination analysis - Number of principal components - Texture features - Three-dimensional information
Classification code:453.2 Water Pollution Control - 716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 741.3 Optical Devices and Systems - 801 Chemistry - 822.3 Food Products - 902.1 Engineering Graphics - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2015.07.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 27>
Accession number:20151800797526
Title:Obstacle detection based on point clouds in application of agricultural navigation
Authors:Ji, Changying (1); Shen, Ziyao (1); Gu, Baoxing (1); Tian, Guangzhao (1); Zhang, Jie (1)
Author affiliation:(1) Engineering College, Nanjing Agricultural University, Nanjing, China
Corresponding author:Ji, Changying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:173-179
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Various sensors are utilized to ensure safety in the vicinity of an intelligent robot while it is walking, with the development and wide application of intelligent navigation. Among them, stereo cameras are prevalent in recent years due to their capability of distance measurement. Due to the limitation of traditional detection methods in stereo vision, a method based on point clouds was presented to meet the demand of obstacle detection on a robot while planning its path. Point clouds of an environment's space with an obstacle involved was taken as the object, and a validity box was applied into the space to eliminate point clouds in irrelevant regions. From a top view, the area was divided into grids, and the number of points in each grid was denoted as the density of point clouds. Once the point cloud density in different ranges was calculated, a curve that fitted the distribution of density, decreasing due to the range was figured out. It indicated that obstacles far from the camera created fewer point clouds than the close ones, leading to a mismatch and the recognition of obstacles. In order to compensate for the sparse point clouds of obstacles in the long range view, the density was compensated for according to a curve of the density-range relationship. And obstacles were able to be recognized by setting a threshold, so the distance could be measured. The specific space that an obstacle occupied was confirmed by setting one more validity box. Therefore, its shape and size could be measured after projecting it onto a front view. Experiments were conducted on the campus of Nanjing Agricultural University, Nanjing, Jiangsu Province, and source codes were programmed and compiled by Matlab software. Experimental results showed that this method could restore the obstacle information of point clouds effectively, while in the distance measurement test, it showed a maximum detection range of 28 m and an average error of 2.43%. Several experiments in various environments and weather were conducted as well, which indicated its robust performance with illumination changing. While in the size measurement tests, it showed a maximum range of 10 meters and the average error in length and height were 2.59% and 2.01%, respectively. In summary, this article was based on a density map of a point cloud and density-compensation algorithm to measure both the distance and the size of obstacles in the vicinity of the camera. Unlike conventional image processing methods, it converted three dimensional point cloud data to two dimensional, using the density of point clouds and applying a grid map to significantly decrease the calculation amount. Additionally, it functioned well under different weather conditions, in both an indoor and outdoor environment, showing a robustness over traditional methods that separate obstacles from the background in image processing. Because there were still some deficiencies to be improved, the current method and programming platform are still too time-consuming to fulfill the demands of real-time detection, but this appears to be a fruitful approach for future study in this field. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Stereo image processing
Controlled terms:Agriculture - Algorithms - Cameras - Computer vision - Image processing - Intelligent robots - MATLAB - Obstacle detectors - Processing - Robot programming - Robots - Stereo vision
Uncontrolled terms:Density compensation - Image processing - methods - Intelligent navigation - Obstacle detection - Outdoor environment - Point cloud - Real-time detection - Three-dimensional point clouds
Classification code:681.3 Railroad Signals and Signaling - 723 Computer Software, Data Handling and Applications - 723.1 Computer Programming - 731.5 Robotics - 731.6 Robot Applications - 741 Light, Optics and Optical Devices - 742.2 Photographic Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.4 Manufacturing - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.07.025
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 28>
Accession number:20151800797519
Title:Effect of narrow terrace on gully erosion in Northern Shaanxi Loess area
Authors:Zhang, Yan (1); Yang, Song (1); Li, Zhen (1); Li, Hongjun (1); He, Yuanmei (1)
Author affiliation:(1) Key Laboratory of Soil and Water Conservation and Desertification Combating, Ministry of Education, Beijing Forestry University, Beijing, China
Corresponding author:Zhang, Yan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:125-130
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Gully erosion is one of main forms of soil erosion threatening land resources. Conservation practices that can reduce rill and inter-rill erosion would be effective on control gully erosion but there is a lack of quantitative assessments. In order to access the effect of terrace on gully erosion, 32 small watersheds were selected randomly on the hilly and gully loess plateau in northern Shaanxi province, where cropland was returned to woodland or grassland in 2001 and terrace was the major conservation practices. Based on two QuickBird images with a 9-year interval and digital elevation model (DEM) with pixel size of 5 m, valley shoulder line and distribution of terrace and land-uses in the small watersheds was extracted by visual interpretation and with GIS technology. Average vegetation cover, local slope upslope drainage area and changes of the gully area from 2004 to 2013 were calculated to access the factors influencing gully growth. Gully area growth with cropland on terrace, woodland on narrow terrace, or grassland on narrow terrace on the upslope drainage area and gully area growth without terrace on the upslope drainage area were compared with statistical analysis method. The results showed that the proportion of terrace area on the upslope drainage area in the 32 small watersheds increased from 39.43% to 59.39% during the period from 2004 to 2013 with woodland on narrow terrace increased by 11.76% on average, cropland on terrace increased by 9.91% and grassland on narrow terrace decreased slightly. The gully area in 32 investigated small watersheds in 2013 increased by 0 to 6% with the average of 4.18%, as compared to 2004. Among the three factors related to gully growth rate investigated in this study, the terrace proportion in upslope drainage area was the most important. Gully area growth rate correlated significantly with terrace proportion in upslope drainage area and average vegetation coverage at the level of 0.01, with the Pearson's correlation coefficients were -0.801 and 0.671, respectively; while the geomorphologic factors (AS2, where S is local slope gradient and A is drainage area), which was considered the predictor of gully initiation, were not related significantly to gully area growth rate owing to high vegetation coverage and high terrace proportion on the upslope drainage area, which reduced the kinetic energy of concentrated overland flow. 32 small watersheds were classified into 5 groups according to terrace proportion and vegetation types. Gully area growth rate in 5 groups of small watersheds increased in the following order: woodland on narrow terrace> grassland on narrow terrace> cropland on terrace> multiple vegetation on terrace> multiple vegetation without terrace. It indicates that the combination of engineering measures such as terrace and conservation vegetation achieves better effect than the single one. The results of this study can provide valuble information for evaluating the full effect of terrace on controlling soil erosion and making plan for gully control. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Landforms
Controlled terms:Catchments - Correlation methods - Drainage - Erosion - Forestry - Geographic information systems - Geomorphology - Growth rate - Kinetic energy - Kinetics - Land use - Sediments - Soil conservation - Surveying - Vegetation - Watersheds
Uncontrolled terms:Digital elevation model - Gully - Loess area - Pearson's correlation coefficients - Quantitative assessments - QuickBird imageries - Statistical analysis methods - Terrace
Classification code:401 Bridges and Tunnels - 403 Urban and Regional Planning and Development - 405.3 Surveying - 406 Highway Engineering - 442 Flood Control; Land Reclamation - 444 Water Resources - 444.1 Surface Water - 481.1 Geology - 481.1.1 Geomorphology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 502 Mines and Quarry Equipment and Operations - 723.3 Database Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics - 933.1.2 Crystal Growth
DOI:10.3969/j.issn.1002-6819.2015.07.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 29>
Accession number:20151800797502
Title:Regional types and regulating strategy of changes for rural residential land in China
Authors:Qiao, Luyin (1); Liu, Yansui (1); Yang, Ren (4)
Author affiliation:(1) Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, China; (2) College of Resources Science and Technology, Beijing Normal University, Beijing, China; (3) University of Chinese Academy of Sciences, Beijing, China; (4) School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
Corresponding author:Liu, Yansui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The change of rural residential land dominates rural land use transformation. Understanding the dynamic change and spatial pattern and developing targeted macro regulating strategy accordingly can provide guidelines for promoting rural land consolidation, rural development and optimizing distribution pattern of towns and villages. In recent years, some studies use single index method especially the net change scale or net change rate, and many of them are on macro perspective. Such method is difficult to depict the complicated types of change for rural residential land. Based on the comprehensive perspective including km-grid, county and province level, this paper used grid data of rural residential land (1 km×1 km) and put forward a new research framework to analyze the quantitative characteristics and to classify the regional types of rural residential land change. The comprehensive indicator method consisted of total change rate, net change rate and share modifying. Then the spatial autocorrelation analysis method was used to explore the spatial distribution and agglomeration features. Based on the above analysis, regulating strategies for rural residential land were proposed finally. First, all provinces or counties nationwide were classified into four regional types by the comprehensive indicator method. The increased active regions included 786 counties and districts which mainly distributed in Huang-Huai-Hai plain, northeast plain, Yangtze River delta, Sichuan basin, etc. The increasing and decreasing balanced active regions consisted of 297 counties which was the least among the four types. The decreased active regions involved 352 counties and districts and mainly concentrated in mountain areas and the transition section between plain and mountain area. The final type was named as the changed slowly regions which had 926 counties and districts, accounting the most in the four types, and almost all of them distributed in the western China. Second, compared with single index method, the comprehensive indicator method was able to identify the special types of increasing and decreasing balanced active regions, and avoided the defect that the change rates of some counties might be overestimated or underestimated due to the regional difference of the original scale of rural residential land by share modifying. Therefore, the new method in this paper was more scientific for classifying change types. Third, the spatial autocorrelation analysis showed that the four types had significant space correlation. The high-high clusters mainly distributed in plains and areas around large cities, and the low-low clusters concentrated in those regions with poor natural and geographical conditions in central and southwest China and the Qinghai-Tibet Plateau. Fourth, each change type should have targeted regulating strategy. The increasing active regions were the core areas for urbanization and rural-urban development transformation, in which the typical feature of rural residential land was rapidly increased. The key point of regulating strategy in those regions was the exited and revitalized mechanism innovation. The increasing and decreasing balanced active regions were the important areas with fertile arable land for protecting national food security. The regulation of rural residential land in those regions should pay attention to improving living conditions and environment for rural residents and promoting rural space reconstruction by land consolidation. The decreasing active regions were the main areas of rural residential land reclamation. The local governments should guide rural population for centralized residence with a moderate scale and should push forward the obsolete housing land reclamation to arable land or woodland. The changed slowly regions were in the most ecologically vulnerable and under developed rural area. Under the preconditions to strictly protect the ecological environment, these regions should combine land consolidation, rural development and village renovation, and then build typical eco-village. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Rural areas
Controlled terms:Agriculture - Autocorrelation - Consolidation - Food supply - Geographical regions - Housing - Land reclamation - Land use - Landforms - Regional planning - Spatial distribution - Spatial variables measurement - Urban growth
Uncontrolled terms:China - Ecological environments - Geographical conditions - Indicator methods - Quantitative characteristics - Regulating strategy - Rural residential - Spatial autocorrelation analysis
Classification code:403.1 Urban Planning and Development - 403.2 Regional Planning and Development - 404.2 Civil Defense - 442.2 Land Reclamation - 481.1 Geology - 483 Soil Mechanics and Foundations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.4 Impact of Technology on Society - 921 Mathematics - 922 Statistical Methods - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.07.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 30>
Accession number:20151800797506
Title:Mechanical and ecological tillage pattern improving soil quality and crop yields
Authors:Zhang, Yinping (1); Du, Ruicheng (1); Diao, Peisong (1); Geng, Duanyang (1)
Author affiliation:(1) Department of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, China
Corresponding author:Du, Ruicheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:33-38
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Tillage was the key factor affecting soil quality, and plowing, rotary tillage and subsoiling etc. were the important links of tillage pattern. Years of plowing, trying to make the soil crushing and creating a good growth environment were the essence of traditional farming in China. But excessive tillage caused the damage to the vegetation, made the soil lose protection, caused soil erosion, dust wreaking havoc and fertility decline in the end. However, long-term no tillage was also inconducive to the sustainable high yield of crops. In order to solve this problem, through comprehensive consideration, the advantages of different tillage patterns were took and combined reasonably. Then a rotational period of mechanical and ecological tillage pattern was established in wheat/corn double-cropping system and compared with the patterns of years of plowing and years of no tillage. The mechanical and ecological tillage pattern was set as Treatment W, the years of plowing pattern was Treatment F, and the years of no tillage pattern was Treatment N. The rotational period was set to be 5 years. For Treatment W, different agricultural machines were combined suitably for moderate tillage on soil in the 5 years. In the first year, the soil was ploughed with the splintery straw mulch on the soil after harvesting corn, and no tillage the next year; in the third and the fourth year subsoil interleaved, and in the last year no tillage as well. For Treatment F the soil was ploughed every year after harvesting corn and no tillage for Treatment N. In order to study the effects of different patterns on soil and yield, the soils of 0-10, > 10-20, > 20-30 cm layer were collected and tested for soil organic content, moisture content and bulk density, and yields of wheat and corn were recorded as well every year in the period for all treatments. Then the results were compared. The comparison results showed as follows: in the period of five-year test, Treatment W effectively improved soil organic content at all 3 layers, and the largest improvement was 0.2% at 0-10 cm soil layer; Treatment N also significantly improved soil organic content at 0-10 cm soil layer at the first 3 years, but reduced at the last 2 years; however, soil organic content was reduced for Treatment F at 0-10 cm layer, yet that at > 20-30 cm soil layer was significantly improved at the first 3 years, and then reduced at the last 2 years. The soil moisture contents from the highest to the lowest were Treatment W, Treatment N and Treatment F, and the difference between Treatment W and the two other treatments was more significant (P<0.05) with the increasing of the year. At 0-10 cm soil layer, the soil bulk densities of Treatment W and N were significantly lower than Treatment F at 5% level. The yields of Treatment W and N were significantly higher than Treatment F, and the order from the highest to the lowest was Treatment W, Treatment N and Treatment F; the difference was most significant in 2014, wheat yields of Treatment W was 30.8% higher than Treatment F and 22.5% than Treatment N, and yields of corn was 28.4% higher than Treatment F and 20.9% than Treatment N. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Soils
Controlled terms:Agricultural machinery - Agriculture - Crops - Cultivation - Ecology - Machinery - Mechanization - Moisture - Moisture determination - Soil moisture
Uncontrolled terms:Agricultural machine - Bulk density - Comparison result - Double cropping - Soil bulk density - Soil organic content - Tillage patterns - Yields
Classification code:454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 801.4 Physical Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2015.07.005
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 31>
Accession number:20151800797520
Title:Modeling heteroscedasticity of reference evapotranspiration series with GARCH family models
Authors:Sun, Huaiwei (1); Yan, Dong (1); Chen, Haorui (3); Zhou, Jianzhong (1); Zhang, Yongchuan (1)
Author affiliation:(1) School of Hydropower and Information Engineering, Huazhong University of Science and Technology, Wuhan, China; (2) State Key Laboratory of Soil and Sustainable Agriculture, Chinese Academy of Sciences, Nanjing, China; (3) China Institute of Water Resources and Hydropower Research, Beijing, China
Corresponding author:Sun, Huaiwei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:131-136
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:More effective methods are needed to evaluate the water demand to improve water resource management as the population and economy grow leading to water shortage. Time series models are useful tools in the estimation and forecasting of reference evapotranspiration series and their changes. However, due to the dynamic nature of reference evapotranspiration, accurate estimation of variance has been being a challenging task and requires new modelling approaches in application. The Generalized Autoregressive Conditional Heteroscedasticity (GARCH) family models, which provide an appropriate framework for focusing on the conditional variance remaining in the residuals of the time series models, were applied in this study to comply with the estimation. Daily climate data including average air pressure, air temperature, relative humidity, wind speed, and saturation deficit were provided by the Chinese National Climatic Data Center (CDC). The observed meteorology dataset from 1953-2007 in Yichang station in Hubei province in China was chosen as the selected station for its data available. The FAO Penman-Monteith method was applied to obtain the potential reference evaporation series. Then, for deseasonalization of the seasonal variation in the series, a Seasonal Autoregressive Moving Average (SARMA) model was set up to estimate the conditio nal mean of the potential reference evaporation. Besides, four types of GARCH models (GARCH, Threshold GARCH, Exponential GARCH, and Power GARCH models) were investigated to take the advantages of GARCH family models to simulate the conditional variance of the potential reference evaporation series. Also, six criteria were utilized to compare the model performance. It was shown that the data of potential reference evaporation series in Yichang Station had skewness, and right tail on an annual cycle, indicating the necessary of SARMA model used in this study. The final SARMA model was chosen by the minimum of AIC values. The results of SARMA model showed that it was efficient for modelling the monthly mean total daily reference evaporation series as a small redisudal mean square error (RMSE) between the observed and estimated values (0.089 mm). However, the heteroscedasticity was present in the residuals of SARMA model according to the Engle test, which suggested the necessary of GARCH models used for modeling of reference evaporation series. Results of GARCH models showed its ability to remove the heteroscedasticity from the reference evaporation residuals. The asymmetric effects of solar radiation series were also confirmed by the application of GARCH family models for estimating the residuals of SARMA model. Among the SARMA and GARCH models, the EGARCH model was best to predict the series because the prediction of the EGARCH model had a narrower confidence level. The better interval estimation would provide more useful information for analysis of hydrological processes and was undoubtedly more favorable to further uncertainty analysis in water resource management. The multi-criteria evaluation for model performance also proved that the EGARCH model was best among SARMA and GARCH models, and it was recommended to use the EGARCH model to estimate the potential reference evaporation series in practice. In conclusion, the results indicated that the application of GARCH family models would be a promising alternative over the traditional approaches in the estimation of potential reference evaporation series, and can be a useful tool to existing water resources management. Further studies about the comprehensive application of GARCH models should focus on the model performances with different observed dataset among stations. It also suggests to use more GARCH models to estimate the hydrological series and the results of accuracy estimation should be linked with water risk analysis. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Uncertainty analysis
Controlled terms:Atmospheric pressure - Evaporation - Evapotranspiration - Forecasting - Hydrology - Information management - Mean square error - Models - Natural resources management - Radiation effects - Resource allocation - Risk analysis - Risk assessment - Risk perception - Statistical methods - Sun - Time series - Water management - Water resources - Water supply - Wind
Uncontrolled terms:Autoregressive moving average - Generalized autoregressive conditional heteroscedasticity - Heteroscedasticity - Multi-criteria evaluation - National climatic data centers - Reference evapotranspiration - Water resources management - Waterresource management
Classification code:443.1 Atmospheric Properties - 444 Water Resources - 446.1 Water Supply Systems - 657.2 Extraterrestrial Physics and Stellar Phenomena - 711 Electromagnetic Waves - 744 Lasers - 802.3 Chemical Operations - 902.1 Engineering Graphics - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 914 Safety Engineering - 922 Statistical Methods
DOI:10.3969/j.issn.1002-6819.2015.07.019
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 32>
Accession number:20151800797516
Title:Numerical simulation and test verification on diversion pier rectifying flow in forebay of pumping station for asymmetric combined sluice-pump station project
Authors:Luo, Can (1); Qian, Jun (2); Liu, Chao (1); Chen, Feng (1); Xu, Jian (1); Zhou, Qinglian (3)
Author affiliation:(1) School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou, China; (2) Qinhuai River Water Conservancy Management Department, Nanjing, China; (3) Lianyungang Water Resources Planning and Designing Institute Co. Ltd., Lianyungang, China
Corresponding author:Liu, Chao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:100-108
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the combined sluice-pump station project, adverse flow pattern always happens in the forebay, which will result in the unfavorable inflow pattern on the inlet section of the passage intake. Based on this, the physical experiment device and computational domain are prepared separately, which share the same dimensions and parts containing a diversion canal, passage intake, forebay, diversion pier and, check gate, so that the flow in the forebay is predicted and verified by the test data at the model water level which is 0.125 m, corresponding to the prototype water level of 2.5 m. The velocities of the measure points on the chosen sections in the forebay is measured with a LGY- intelligent velocity instrument and recorded. To gain the steady flow in the test rig, the flow rate was adjusted depending on the valve and electromagnetic flowmeter. In order to better understand the inner detail flow structure in the forebay, several analysis planes which are the surface plane, the bottom plane, the inlet of passage intakes 1#, 4#, and 5#, and the plane before the passage intake are sliced. In the original case, the crosswise velocity of the main forward flow around the diversion pier is large which leads to a deflective flow. With the effect of viscous force, the neighboring water changes its direction, and brings out a larger scale bias flow. Then the water changes its direction again, due to the low pressure zone, and across flow occurs once more whose direction is opposite to the initial cross flow. At last, the water moves along the diversion pier to the inlet of forebay, where a mixed flow takes place and the steady large circulation zone starts from the isolated pier to the cross-section which is close to the inlet of the passage intake in the forebay is produced. The axial velocity distribution is uniform and left-right & up-down symmetry on the inlet of passage intake 1#, the high velocity area is in the center of the section. The axial velocity distribution is not uniform on the inlet of passage intake 5#, and the high velocity area is on the left of the inlet. To solve the problem, a single long diversion pier and the combined measures of "long diversion pier + short diversion pier" were put forward which were marked as improvement scheme 1 and 2. Compared with the original case, the recirculation zone was decreased and advanced with both measures, and the water could be smoothly guided into passage intake 4#. The axial velocity distribution on the inlet of passage intake with both rectification measures was well improved. For passage intake 1#, 4#, and 5#, axial velocity distribution increased 2.6%, 7.8%, and 3.6% respectively with improvement scheme 1, as well as 2.7%, 18%, and 1.8% with improvement scheme 2. As a whole, rectification results with improvement scheme 2 were better than improvement scheme 1, but the structure of improvement scheme 1 is simple and convenient for construction. By discussing the calculated and test average axial velocity, the maximum and minimum relative error was 6.29% and 0.63% respectively. After a single long diversion pier was installed, the standard deviation of calculated and test axial velocities decreased. The calculated results were well satisfied with test results and the prediction well verified and credible. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Inlet flow
Controlled terms:Computer simulation - Flow patterns - Flowmeters - Numerical models - Piers - Pumps - Velocity - Velocity distribution - Water levels
Uncontrolled terms:Axial-velocity distribution - Computational domains - Electromagnetic flow meters - Forebay - Initial cross flows - Physical experiments - Pump station - Recirculation zones
Classification code:407.1 Maritime Structures - 407.2 Waterways - 618.2 Pumps - 631.1 Fluid Flow, General - 723.5 Computer Applications - 921 Mathematics - 931.1 Mechanics - 931.3 Atomic and Molecular Physics - 943.1 Mechanical Instruments - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.07.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 33>
Accession number:20151800797527
Title:Buffer algorithms for operation area measurement based on global navigation satellite system trajectories of agricultural machinery
Authors:Liu, Hui (1); Meng, Zhijun (2); Wang, Pei (2); Wei, Xueli (2); Han, Yu (2)
Author affiliation:(1) Information Engineering College, Capital Normal University, Beijing, China; (2) National Research Center of Intelligent Equipment for Agriculture, Beijing, China
Corresponding author:Meng, Zhijun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:180-184
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The rapid development of modern agriculture in China has put forward higher requirements for agricultural machinery operation. In order to meet the requirement of agricultural machinery scale management and market service, operation area should be measured by using a kind of accurate, real-time and convenient method. The GNSS (global navigation satellite system) receiver installed in agricultural machinery can provide operation trajectory data in real time. The paper reports a vector buffer algorithm and a raster buffer algorithm for operation area measurement based on GNSS trajectories of agricultural machinery. The vector buffer algorithm calculates the area of operation buffer polygon which is generated by intersecting and merging the part line buffers based on trajectory segments using data analysis method of the GIS (geographic information system). The raster buffer algorithm calculates the area of entire operation buffer which is covered by a certain number of unit grids with known area value. At present operation area is measured by using the conventional distance algorithm based on the product of swath width and distance of trajectory segments. The tests of full-width operations and overlap operations were carried out to compare area measurement accuracy of these two buffer algorithms with the distance algorithm in three different GNSS positioning accuracies of RTK (real time kinematic), decimeter-level and single-point. Full-width operation was implemented in the control of automatic navigation system for agricultural machinery. Overlap operation was achieved by setting up different overlapping rates of 5%, 10%, 15%, 20% and 25%. The results showed that in the full-width operation tests the distance algorithm had higher area measurement precision in any GNSS positioning accuracy, and the mean of relative error was 0.72%. Compared with the distance algorithm, the two buffer algorithms precisely measured operation area only in differential GNSS positioning accuracy. Using RTK GNSS positioning, the relative errors of the vector buffer algorithm and the raster buffer algorithm were 0.31% and 0.18%, respectively. Using decimeter-level GNSS positioning, the relative errors of the two buffer algorithms were 2.43% and 1.44%, respectively. However, in overlap operation tests the relative error of the distance algorithm increased significantly with the increasing of overlapping rate in any GNSS positioning accuracy. Area measurement precisions of the buffer algorithms were not affected by the overlaps. The relative errors of the vector buffer algorithm in GNSS positioning accuracies of RTK, decimeter-level and single-point were 0.48%, 3.13% and 5.52%, respectively. The relative errors of the raster buffer algorithm in GNSS positioning accuracies of RTK, decimeter-level and single-point were 0.11%, 2.77% and 5.33%, respectively. In China it cannot avoid the operation overlaps while agricultural machineries are controlled by drivers, and therefore the buffer algorithm can provide more accurate and convenient method for operation area measurement. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Global positioning system
Controlled terms:Agricultural machinery - Agriculture - Algorithms - Communication satellites - Errors - Geodesy - Geographic information systems - Information systems - Navigation systems - Satellites - Surveying - Trajectories - Vectors
Uncontrolled terms:Area measurement - Automatic navigation systems - Data analysis methods - GIS (geographic information system) - Global Navigation Satellite Systems - Modern agricultures - Real time kinematic - Trajectory segments
Classification code:405.3 Surveying - 434.4 Waterway Navigation - 655.2 Satellites - 655.2.1 Communication Satellites - 716 Telecommunication; Radar, Radio and Television - 716.3 Radio Systems and Equipment - 717 Optical Communication - 723 Computer Software, Data Handling and Applications - 723.3 Database Systems - 731 Automatic Control Principles and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 903.2 Information Dissemination - 921 Mathematics - 921.1 Algebra
DOI:10.3969/j.issn.1002-6819.2015.07.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 34>
Accession number:20151800797522
Title:Extraction of farmland classification based on multi-temporal remote sensing data
Authors:Li, Xiaodong (1); Jiang, Qigang (1)
Author affiliation:(1) College of Geo Exploration Science and Technology, Jilin University, Changchun, China; (2) Baicheng Normal College, Baicheng, China
Corresponding author:Jiang, Qigang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:145-150
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Both artificial visual interpretation and computer automatic classification were the mainly remote sensing methods used to extract farmland information. At present, it is still difficult to entirely replace the artificial visual interpretation for the computer automatic classification to extract farmlands' type information of the remote sensing image, because the automatic method needs more efforts to improve the precision of the classification results, so the problem became the key link of the automatic classification extraction. How to extract farmlands' type information in the western part of Jilin is one of the major problems which the paper attempts to solve to distinguish paddy field from dry land. A new solution to extract the farmland information has been designed for the remote sensing automatic classification, based on the spatial variation theory. The classification scheme was carried out by operating in an R language platform and the remote sensing software ERDAS platform. The farmland type of Zhenlai in the western of Jilin was extracted and monitored by making use of four indexes, the range of NDVI series, the local variance of image texture, the modified soil adjusted vegetation index, and the normalized difference water index, which have significant meaning for the farmland cover type in the transition zone between the cropping area and the nomadic area. These variances with clear physical meaning information (including the vegetation, water, soil drought conditions) and phonological information were used to build a multi-dimensional feature space classification data set. The results indicated that: 1) the dry field of which an area of 1065.337 km<sup>2</sup> was cultivated in the study area was the largest farmlands' type, and also was one of the most important ecological landscape types. It's the spatial distribution characteristic of the study area that is a relatively dispersed dry field, and a relatively concentrated paddy field; 2) based on the multidimensional space data set, the algorithm of a support vector machine (SVM) was chosen to automatically extract the farmland types' data of the paddy field and the dry land. The overall classification accuracy of the algorithm was 94%, the Kappa coefficient of the classification was 0.87, and the extracted accuracy of the paddy field was 98.3%, while the extracted accuracy of the dry land was 98%. The existing automatic extraction approach was implemented to obtain a comparatively ideal classification result; 3) through the farmland's regional analysis, a depression that has more lowland and easy seeper is suitable for the reclamation of paddy field. It's noted that the extracted classification has an obvious regional farmland type, and the regional features were consistent with the farming cultivation characteristics in the northeast plains; 4) both rice and corn were typical unimodal type growth crops, and the similar growth peak, but the result of the range (rice, 3.8±0.4; upland crops, 3.4±0.3;) noted that: the phenology information of different vegetation types has its own characteristics; this characteristic of the NDVI seasonal variation curve is real. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:12
Main heading:Classification (of information)
Controlled terms:Automatic indexing - Crops - Data mining - Extraction - Farms - Forestry - Image processing - Image reconstruction - Image texture - Regional planning - Remote sensing - Space optics - Support vector machines - Vector spaces - Vegetation
Uncontrolled terms:Automatic classification - Distribution characteristics - Dry land - Multi-temporal remote sensing - Normalized difference water index - Paddy fields - Semi-variances - Western of Jilin
Classification code:403.2 Regional Planning and Development - 716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 741.1 Light/Optics - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.07.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 35>
Accession number:20151800797512
Title:Fractional order model of viscoelastic suspension for crawler vehicle and its vibration suppression analysis
Authors:Li, Zhanlong (1); Sun, Dagang (1); Yan, Bijuan (2); Sun, Bao (2); Zhang, Wenjun (2)
Author affiliation:(1) School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, China; (2) College of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan, China
Corresponding author:Sun, Dagang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:72-79
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Viscoelastic suspension is a newly applicable suspension for a large power and heavy crawler vehicle. The viscoelastic suspension can support a heavy load efficiently when walking and working on the off road, raise the adhesion property of a vehicle, and decrease the impact vibration level of the vehicle. The suspension consists of a metal part and viscoelastic material which are spaced and arranged to notably control vibration by transforming vibration energy into thermal energy to dissipate it into the air due to the hysteretic characteristic of viscoelastic materials. To predict and accurately study the dynamic behavior of viscoelastic suspension and evaluate its vibration damping capability, fractional calculus was introduced because of the facts that the fractional calculus exhibits global correlation and data-fitting well when describing rheological phenomenon. In this context, a fractional order Kelvin-Voigt model considering the geometric factors i. e. A radius-thickness ratio incorporated into a dynamic model of viscoelastic suspension for crawler vehicle was established. In this model, the viscoelastic part was represented by a parallel-combination of a spring whose stress is in direct proportion to the strain and a spring pot whose stress is in direct proportion to the fractional derivative of the strain differentiating from the conventional damping pot with stress being proportional to the first derivative of the strain. A numerical solution was obtained by adoption of a Grumwald-Letnikov fractional derivative definition and a matrix function theory and its calculating codes were programming in Matlab. A history correlation coefficient was achieved to embody the afore-history influence of the viscoelastic suspension on its dynamic behavior. Parameters of a fractional model was acquired by fitting data using a least-square method based on a viscoelastic material tensile test carried out on a Testometric M350-10kN according to GB/T 528-1998 and GB/T 9865.1. For a pragmatic study case, a heavy crawler tractor installed with 8 viscoelastic suspensions was considered to analyze its vibration control effect by establishing its fractional model. Also the parameter influence on the vibration control effect, including exciting frequency, fractional order, and ratio of radius to thickness, was examined. The results showed that, compared with rigid suspension, the viscoelastic suspension exhibited remarkable vibration control capability, especially at the resonant frequency of about 4. 5 Hz by reducing the response magnitude of the vehicle body by 64. 10% in max value and 66. 40% in RMS, thus satisfying the supporting and stable demands of the crawler tractor walking and working on the off road. Radius-thickness has a negative influence on the response magnitude of viscoelastic suspension, that is to say there is an effective way to reduce the vibration by introducing a geometry-modified viscoelastic suspension with higher thickness and lower action aero. Fractional order, however, exhibits a positive correlation to the behavior of the response magnitude, which inspires another valid method of altering the viscoelastic material parameter to perfect the vibration of the crawler tractor. The history-dependent factor gives evidence of the long range correlation of the fractional model, i. e., the system response at current time relates to the whole history whose influence increases with time closer to the current time. This research provides an essential theoretical basis for multi-objective optimization and dynamic design of a viscoelastic suspension for a higher power and heavy load crawler vehicle. Experiment study is an essential procedure as a further study. So our future work will stress the indoor test of a dynamic mechanical analysis (DMA) of viscoelasitc materials, deriving a fractional constitutive model considering the temperature-frequency effect of viscoelastic material, and carrying out an in-situ test of a real crawler vehicle establishing a different-parameter viscoelastic suspension to investigate stable/dynamic stiffness, fatigue features, and vibration control capability under working conditions of cutting, pulling, digging, and crossing over an obstacle. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Vibrations (mechanical)
Controlled terms:Airships - Automobile suspensions - Beams and girders - Calculations - Crashworthiness - Damping - Dynamic mechanical analysis - Dynamic models - Least squares approximations - MATLAB - Multiobjective optimization - Natural frequencies - Research aircraft - Roads and streets - Stiffness - Stresses - Suspensions (components) - Suspensions (fluids) - Tensile testing - Thermography (temperature measurement) - Tractors (agricultural) - Tractors (truck) - Vehicles - Vibration analysis - Vibration control - Viscoelasticity
Uncontrolled terms:Correlation coefficient - Crawler vehicles - Dynamic mechanical analysis (DMA) - Fractional order models - Hysteretic characteristics - Long range correlations - Radius thickness ratios - Viscoelastic suspensions
Classification code:406.2 Roads and Streets - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 422.2 Strength of Building Materials : Test Methods - 432 Highway Transportation - 601.2 Machine Components - 652.1 Aircraft, General - 652.5 Balloons and Gliders - 663.1 Heavy Duty Motor Vehicles - 663.2 Heavy Duty Motor Vehicle Components - 711.1 Electromagnetic Waves in Different Media - 731.3 Specific Variables Control - 804 Chemical Products Generally - 921 Mathematics - 931.1 Mechanics - 943.2 Mechanical Variables Measurements - 944.6 Temperature Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.07.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 36>
Accession number:20151800797515
Title:Comprehensive assessment methodology of characteristics of soil fertility under different fertilization regimes in North China
Authors:Wen, Yanchen (1); Li, Yanqing (1); Yuan, Liang (1); Li, Juan (1); Li, Wei (1); Lin, Zhian (1); Zhao, Bingqiang (1)
Author affiliation:(1) National Engineering Laboratory for Improving Quality of Arable Land/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
Corresponding author:Zhao, Bingqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:91-99
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil fertility is a typical index to evaluate the soil ability of supplying the proper conditions for plant growth. This study focused on the differences among soil physical, chemical, and biological properties under different long-term fertilization strategies and the results of those properties were analyzed synthetically to establish the suitable fertilization strategy to improve soil fertility. A 26 years long-term experiment was conducted in the Dezhou station of Chinese Academy of Agriculture Sciences. Six treatments included no fertilizer and manure (CK), half conventional dosage of organic manure and half of chemical fertilizer (MF), conventional dosage of organic manure (CM), conventional dosage of chemical fertilizer (CF), and high dosage of organic manure (HM) and high dosage of chemical fertilizer (HF). The indicators of soil physical, chemical and biological characteristics under the different fertilization treatments were determined to clarify the effects of fertilization on soil fertility. Principal component and cluster analyses were applied to get a comprehensive assessment on the effects of different fertilization strategies on soil fertility. The results showed that: 1) The significant differences of soil properties were found among the fertilization treatments. Compared with chemical fertilizer, long-term application of organic manure or combination of organic and inorganic fertilizers reduced soil bulk density by 5.0%-11.0%, and increased soil total porosity by 4.1%-9.9%, increased soil organic carbon, total nitrogen, available phosphorus and available potassium by 95%-136%, 69%-137%, 500%, and 81%-103%, respectively. In addition, the soil pH in the treatments of organic manure or combination of organic and inorganic fertilizer was lower than that of chemical fertilizer treatments by 0.15-0.47. 2) According to principal component analysis, soil fertility indexes could be classified into two principal components. The first component (PC1) consisted of soil organic carbon (C), total nitrogen (N), organic N, microbial biomass N, microbial biomass C, total phosphorus (P), available P, available potassium (K), organic P, soil bulk density, and total porosity and pH, which had high loadings about 83.73%. In the second component (PC2), however, soil total K had high minus loadings, and the proportion of total K in the component was only 8.49%. 3) Cluster analysis classified the indexes into 4 classes of CM and MF, CF and HF, CK, and HM. Based on the analyses above, we concluded that the high application rate of organic manure could lead to the best impacts on the soil fertility. The effects of all fertilization strategies on soil fertility presented the descent orders as: HM > CM > MF > HF > CF > CK. Thus, the contents of soil nutrients increased more effectively under the treatments with organic manure or combination of organic and chemical fertilizer than chemical fertilizer. Moreover, the treatments with organic manure or combination of organic manure and chemical fertilizer could also alter the balance of soil nutrients, enhance soil fertility comprehensively in the aspects of soil physical, chemical and biological fertilities, and improve the supply ability of soil nutrients. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Fertilizers
Controlled terms:Carbon - Chemical analysis - Cluster analysis - Indicators (chemical) - Manures - Nitrogen - Nitrogen fertilizers - Nutrients - Organic carbon - Phosphorus - Porosity - Potassium - Principal component analysis - Soils
Uncontrolled terms:Biological properties - Chemical and biologicals - Comprehensive assessment - Fertilization regimes - Inorganic fertilizers - Long-term experiments - Long-term fertilization - Soil fertility
Classification code:452.3 Industrial Wastes - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 723 Computer Software, Data Handling and Applications - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.2 Agricultural Chemicals - 922 Statistical Methods - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.07.014
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 37>
Accession number:20151800797514
Title:Impeller-volute interaction around tongue region in centrifugal pump under rotating stall condition
Authors:Zhou, Peijian (1); Wang, Fujun (1); Yao, Zhifeng (1)
Author affiliation:(1) China College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China
Corresponding author:Wang, Fujun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:85-90
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The impeller-volute interaction around the tongue region in centrifugal pump is always very strong, which usually causes vibration and noise. The tongue region is one of the most critical regions for pressure fluctuation, and in order to reveal the impeller-volute interaction around this region under rotating stall condition, a volute-type centrifugal pump was chosen as the research object to investigate by numerical simulation. A number of reference locations were arranged in the near-tongue region for recording the pressure fluctuations. The entire computational domain including impeller and volute was divided into 4.2 million grid cells, and the time step was set as 2.3×10<sup>-4</sup> s, totally 360 time steps per impeller revolution.. Corresponding to a Courant number, which was estimated to be smaller than 1.0. Large eddy simulation was applied to simulate the three-dimensional unsteady viscous incompressible flow in the centrifugal pump. The predictions of the numerical model were compared with experimental results of flow-head curve. Good agreement between the simulated and experiment results was obtained. The largest head deviation under different flow rates was 8%, due to the smooth wall assumption during the simulations. Several flow rates were chosen ranging from 100% to 25% of the nominal flow rate for determining the stall point. The internal flow field and pressure fluctuation characteristics at different operating points were obtained. Spectra of pressure pulsation signals were analyzed, and the frequency was normalized by the rotation frequency. The regions with lower values in the pressure field were referred as rotating cells in that the stall was always accompanied by pressure reduction. It has been found that the rotating stall phenomenon occurred as the flow rate was decreased to 0.70 of nominal flow rate. Three stall cells near the entrance of passages could be observed in the pressure distribution. As the flow rate was further decreased, the area of stall cells was larger. Under the rotating stall condition, 50% of the blade passing frequency (i. e. 3 times of rotation frequency) was presented due to the alternate stalled and unstalled passages. When the rotating stall occurred, the amplitude of pressure fluctuation was much higher than that at unstalled points. Stall cells had significant effect on the pressure fluctuations in the volute. The maximum amplitude of dominant frequency was located at the tongue whether it was under rotating stall or unstalled condition. The amplitudes at the other locations were reduced gradually along the flow direction. Furthermore, a vortex always appeared in the fixed position (near the tongue) when the blade passed the tongue. It could be called "fixed stall" phenomenon, which was caused by the non-uniform pressure distribution on the volute and strong adverse pressure gradient in the tongue region. At 0.50 of nominal flow rate, the rotating stall cells played the leading role. The dominant frequency was 3 times of rotation frequency, which was 50% of the blade passing frequency. However, when the flow rate was decreased to 0.25 of nominal flow rate, the "fixed stall" cells played the leading role. The dominant frequency was 6 times of rotation frequency, which was the blade passing frequency. This research can provide useful reference for the secure and stable operation of centrifugal pumps. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Large eddy simulation
Controlled terms:Cells - Centrifugal pumps - Computer simulation - Cytology - Flow rate - Impellers - Incompressible flow - Models - Numerical models - Pressure distribution - Rotation
Uncontrolled terms:Adverse pressure gradient - Blade passing frequency - Computational domains - Impeller volute interactions - Pressure fluctuation - Rotating stalls - Tongue - Viscous incompressible flows
Classification code:461.2 Biological Materials and Tissue Engineering - 601.2 Machine Components - 618.2 Pumps - 631 Fluid Flow - 723.5 Computer Applications - 902.1 Engineering Graphics - 921 Mathematics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.07.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 38>
Accession number:20151800797503
Title:Design and experiment of pneumatic-typed precision centralized metering device for rapeseed
Authors:Li, Zhaodong (1); Lei, Xiaolong (1); Cao, Xiuying (1); Liao, Yitao (1); Liao, Qingxi (1); Li, Shanshan (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China
Corresponding author:Liao, Qingxi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:9-17
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To improve mechanical direct seeding level, a kind of precision centralized metering device for rapeseed with a reliable performance was designed, applying for high speed and broad width. The wheel type metering device with holes had a simple structure, low rape seeds of uniform granularity, and good spherical degree which could be better utilized, thus easily realizing a centralized seeding operation; otherwise, it had a high damage rate, and therefore thus would affect seeding performance. To solve the problem of the wheel type metering device with holes because of the difficulty of precisely controlling the seeding rate on rape seeding, the seeding type holes were punched in a pyramidal shape. The device used a combination of air clearing seed and air pressure protecting seed, so the device was a kind of pneumatic-typed precision centralized metering device for rapeseed. This subject introduced the working principle of a pneumatic-typed centralized metering device. It determined the main parameters of the centralized metering device, and established the mechanical model of clearing an area and protecting an area. The tests on the influences of clearing pressure and protecting pressure and seeding metering rotating speed were carried out. For seeding performance, the evaluation indexes were stability variability coefficient of the full seeding quantity, the apiece row consistency, variability coefficient of seeding quantity, and damage rate of the rapeseed. Results showed that under the condition that the seeding cylinder diameter was 100 mm, the hole shape was punched in a pyramid shape, the number of holes were 27, while the clearing pressure was 250 Pa, the protecting pressure was 150 Pa, the seed layer thickness was 49.4 mm, the clearing seed angle was 53°, and the protecting seed angle was 90°, the rotating speed varied from 20 to 70 r/min. The whole index and damage rate increased with the rise of the rotating speed of the cylinder. When the speed was not more than 40 r/min, the index changed into good range and had not much variation. When it was from 40 to 50 r/min, the damage rate of the rapeseed rarely changed, while the stability of the full seeding quantity and the apiece row consistency of seeding quantity obviously had a rising trend. If was no less than 50 r/min, the seeding performance was obviously getting worse. Thus, a seeding cylinder speed of 20-40 r/min was much better. For the stability variability coefficient of the full seeding, quantity was less than 2%. The apiece row consistency variability coefficient of seeding quantity was not more than 2%, and the damage rate was less than 0.3%. The field experiment showed that in conditions of clearing pressure 100 Pa, protecting pressure 300 Pa and seeding roller speed 26 r/min, the rape seed field seeding uniformity coefficient variation of the collecting seeding system was 38.76%, and the average emergence distance was 75 mm which satisfied agronomy planting requirements. This seeding method is suitable for small seed metering, and provides a basis for research on the design of this type metering device. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Speed
Controlled terms:Agricultural machinery - Agriculture - Atmospheric pressure - Cylinders (shapes) - Design - Machine design - Oilseeds - Pneumatics - Rotating machinery - Seed - Wheels
Uncontrolled terms:Cylinder diameters - Direct-seeding - Metering devices - Rapeseed - Reliable performance - Seed layer thickness - Seeding performance - Simple structures
Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 443.1 Atmospheric Properties - 601 Mechanical Design - 632.3 Pneumatics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.07.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 39>
Accession number:20151800797521
Title:AWRA-L model for simulating interception of rainfall loss in large scale
Authors:Lu, Xinjian (1); He, Kangning (1); Wang, Hui (1); Wang, Wenyi (2); Zhao, Lijuan (2); An, Guocai (2)
Author affiliation:(1) Key Laboratory of Soil and Water Conservation and Desertification Combating, Ministry of Education, Beijing Forestry University, Beijing, China; (2) Baoku Forestry Farm, Xining, China
Corresponding author:He, Kangning
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:137-144
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The application of the Gash model to simulate canopy interception is mostly on the study plot or a specified forest, and the application in a landscape scale is only reported in the Australian Water Resource Assessment system (AWRA-L). This study introduced the AWRA-L model, and aimed to simulate the interception loss of the natural secondary forest of birch (Betula platyphylla Suk.) during 2013 in China. The GLASS LAI data and submerging method were used to get the canopy capacity for different periods. The leaf area index (LAI) value obtained before germination was assumed to be the area of branches and trunks. While the LAI value obtained after germination was the area of the leaves, branches and trunks. The differences between the LAI values after and before germination were the area of leaves when the growing of branches and trunks was ignored. The submerging method showed that the water capacity of leaves and stems per unit area were 0.17 and 0.33 mm, respectively. The capacity of branches and trunks was 0.23 mm. The capacity of leaves was 0.04-0.51 mm. The mean canopy capacity was 0.60±0.14 mm. The intercept method showed the canopy capacity and the trunk capacity were 0.62 and 0.04 mm, respectively. The whole capacity of the birch forest in its over ground parts was 0.66 mm. The canopy capacity by the submerging method and the intercept method was not significantly different (P=0.23). Considering of the high canopy cover fraction of the birch forest, both the simulating results of AWRA-L model based on Van model and the AWRA-L (1979) model based on Gash (1979) model were discussed in the paper. For the 25 rain events measured during the experiment, the simulating errors of the cumulative interception loss obtained from the AWRA-L model and the AWRA-L (1979) model were -9.2 and -1.7 mm, respectively. The relative errors were -14.8% and -2.8%, respectively. Both the AWRA-L model and the AWRA-L (1979) model underestimated the interception loss. When the rain event on June 8 with the biggest simulating error was eliminated, the cumulative simulating errors of the AWRA-L model and the AWRA-L (1979) model were -4.4 and 1.5 mm, respectively. The relative errors were -8.7% and 3.0%, respectively. The mean errors of the simulating interception loss for single rain event by these two models were -0.15 and -0.03 mm, respectively. The simulating value and measured was not significantly different. The results illustrated that the canopy capacity obtained by the data of GLASS LAI and submerging method could be used to determine the canopy capacity and the results could be used for simulating of interception loss by the AWRA-L model. The AWRA-L model is reliable to simulate both the cumulative interception loss for a long period and the interception loss for a single rain event in a landscape scale. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Rain
Controlled terms:Cultivation - Errors - Forestry - Glass - Models - Remote sensing - Water resources
Uncontrolled terms:AWRA-L - Betula platyphylla Suk - Canopy interception - Gash - Leaf Area Index
Classification code:443.3 Precipitation - 444 Water Resources - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 812.3 Glass - 821.0 Woodlands and Forestry - 821.3 Agricultural Methods - 902.1 Engineering Graphics - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.07.020
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 40>
Accession number:20151800797523
Title:Analyzing space-time characteristics of Xiangshan trawling based on Beidou Vessel Monitoring System Data
Authors:Zhang, Shengmao (1); Cui, Xunsen (1); Wu, Yumei (1); Zheng, Qiaoling (1); Wang, Xiaoxuan (1); Fan, Wei (1)
Author affiliation:(1) Key Laboratory of East China Sea and Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Chinese Academy of Fishery Sciences, Shanghai, China; (2) College of Marine Sciences, Shanghai Ocean University, Shanghai, China
Corresponding author:Fan, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:151-156
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:More than fifty thousand fishing vessels have installed the terminal unit of the Beidou satellite positing system since the Ministry of Agriculture of China started to construct fishing vessels monitoring system in Nansha islands in 2006. This system mainly aims to manage vessel fishing, fishery safety and emergency rescue. The data sent by the terminal unit have a temporal resolution of 3 minutes, and a spatial resolution of 10 meters. Thus, after carrying out these fishing services almost for 9 years, the system has recorded billions of historical cruising data for each vessel, such as time, position, speed, direction and rate of turn. These data can be analyzed deeply by big data mining technology. To deeply mine the fishery information from the historical data, the cooperation has been carried out between East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences (ECSFRI) and several Beidou operators. Performing statistical computations for traditional fishing effort takes much time and effort, and the macro fishing intensity cannot be accessed immediately. Through the Beidou satellite vessel position monitoring system, the position, course, speed and other information of vessels can be got and used to data mining. The information of every point position of trawlers includes speed, course, time and other information. With the information, the state of trawlers can be determined. In this paper, the speed threshold of each vessel's fishing condition is obtained by the statistics of navigational speed. And fishing state points can be judged by combining the speed thresholds. When the speed and course are in the range of threshold value, the trawler is in the state of fishing. The fishing effort in the grid is calculated based on the cumulative fishing time in fishing state points of each vessel. There may be many trawlers in one fishing grid. The work of one trawler in fishing is divided into many hauls. In general, a haul lasts a few hours. When a haul is over, the next haul will get under way after some interval of time. Every haul has several discrete points of vessel position. The first summation is the cumulative fishing for one haul; the second summation is the cumulative fishing for several hauls of one trawler in a period of time; the third summation is the cumulative fishing of all trawlers in one fishing grid. The cumulative fishing is the product of the cumulative fishing time and the vessel power (kW·h). This method has the characteristics of real-time, large-scale, fast and high resolution, which can provide good service in fishery resource protection. Ship position, heading, speed and other information obtained from the Beidou Vessel Monitoring System can work for mining the trawler status, calculating cumulative fishing time and effect, as well as analyzing temporal and spatial characteristics on the basis of fishing effort. In 2013, trawling fishing effort of Xiangshan Harbor in offshore area could be divided into 3 periods which were from February to May, from June to September and from October to December and January. From a spatial perspective, fishing effort formed approximate concentric circles, centering on the fisheries near Xiangshan Harbor and expanding from high to low. From the perspective of trawling time, there were annual inshore fisheries, spring-autumn inshore fisheries, spring-autumn off-sea fisheries and spring-autumn outer edge fisheries. The duration of 6 net times were manually recorded at sea investigation. And the Beidou data have also been used to calculate the time. The relative error between them is less than 5%. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Fishing vessels
Controlled terms:Agriculture - Big data - Computer systems - Data mining - Fisheries - Monitoring - Radio navigation - Satellites - Speed
Uncontrolled terms:Beidou satellites - Data mining technology - Fishing effort - Position monitoring system - Space-time characteristics - Statistical computations - Temporal and spatial - Vessel monitoring systems
Classification code:471.5 Sea as Source of Minerals and Food - 655.2 Satellites - 716.3 Radio Systems and Equipment - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.1 Mechanics - 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
DOI:10.3969/j.issn.1002-6819.2015.07.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 41>
Accession number:20151800797538
Title:Biochar addition inhibiting nitrification of reclaimed soils in coal-mining subsidence area
Authors:Zhu, Jirong (1); Wei, Xuhao (1); Zhu, Pengfei (1); Yu, Hongmei (2); Shu, Liangzuo (1); Xu, Zhiheng (1); Chen, Deyi (1)
Author affiliation:(1) Anhui Province Key Laboratory of Plant Resource and Biology, School of Life Science, Huaibei Normal University, Huaibei, China; (2) College of Geography and Environment Science, Zhejiang Normal University, Jinhua, China; (3) School of Resources and Environmental Engineering, Anhui University, Hefei, China
Corresponding author:Shu, Liangzuo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:264-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The soil structure was severely destroyed, and the content of organic matter and fertility was extremely low in reclaimed soil in the coal-mining subsidence area. How to improve the soil fertility and recover soil productivity was a critical problem for sustainable agriculture in this area. Nitrogen fertilizer was one of the largest amounts of fertilizers used in agricultural production, and the nitrification of ammonium to nitrate was an important nitrogen transformation process in dryland soil. Numerous evidences showed that biochar could improve soil fertility and affect nitrogen transformation in soil. However, little attention was paid to compare the difference in nitrogen transformation affected by biochar addition in soils with different fertility levels, especially in the extremely infertile reclaimed soil in the coal-mining subsidence area. In this paper, the effect of biochar addition on the nitrification in the reclaimed soil from a coal-mining subsidence area was examined by using a laboratory aerobic incubation method with constant temperature and controlled humidity under different nitrogen supply levels. In addition, vegetable soil with high fertility was used as the comparation. The experimental factors included three levels of biochar (0, 1.5% and 3%), two levels of nitrogen (at the rates of 200 and 400 mg/kg, respectively), and two kinds of soil (vegetable soil and reclaimed soil with extremely low fertility). In addition, soils without any biochar or nitrogen addition were cultured at the same condition to provide background nitrification information. Nitrate nitrogen and ammonium nitrogen concentration in soils were monitored during the cultivation period. The variation of nitrate nitrogen concentration in the cultivated soils was simulated by Logistic function and the significance values of the model were analyzed. It showed that, compared with the vegetable soil, the nitrification was slow in the reclaimed soil. The maximum rate of nitrification in the reclaimed soil was only 17.32% of that in the vegetable soil, and the time the maximum nitrification rate occurred delayed 4.2 days in the reclaimed soil compared with the vegetable soil. The inhibition of biochar addition on the nitrification was obvious especially in nitrification acceleration stage, and was affected interactively by nitrogen supply level and soil type. Compared with low nitrogen supply, biochar exerted greater inhibition on the nitrification so that the nitrification acceleration stage extended 6 days (for the reclaimed soil) or 11 days (for the vegetable soil) in the soil with high nitrogen supply. However, the nitrification acceleration stages were all terminated before the 18<sup>th</sup> day under both of the two nitrogen supply levels. In the reclaimed soil, especially under high nitrogen supply, the time the maximum nitrification rate occurred was obviously delayed as the increasing of biochar amount, but the maximum rate of nitrification was not affected by biochar and nitrogen supply level. However, in the vegetable soil, the value of maximum rate of nitrification was significantly affected by nitrogen or biochar supply. Hence, biochar addition could suppress soil nitrification, and this suppression was especially obvious in the nitrification acceleration stage, which could be affected interactively by nitrogen level and soil type. The outcome of this research will provide a theoretical guide for improving the fertility of the reclaimed soil in the coal-mining subsidence area. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Soils
Controlled terms:Agriculture - Coal - Coal mines - Cultivation - Cutting machines (mining) - Fertilizers - Humidity control - Land reclamation - Nitrates - Nitrification - Nitrogen - Nitrogen fertilizers - Reclamation - Subsidence - Vegetables
Uncontrolled terms:Agricultural productions - Bio chars - Coal mining subsidences - Constant temperature - Controlled humidities - Nitrogen transformations - Sustainable agriculture - Vegetable soil
Classification code:402 Buildings and Towers - 442.2 Land Reclamation - 452.4 Industrial Wastes Treatment and Disposal - 483.1 Soils and Soil Mechanics - 503.1 Coal Mines - 504 Mines and Mining, Metal - 524 Solid Fuels - 802.2 Chemical Reactions - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.07.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 42>
Accession number:20151800797544
Title:Experiment and dynamics of dehydration and inactivation of enzyme of potato slices by simultaneous infrared dry-blanching
Authors:Ma, Haile (1); Wang, Juan (1); Liu, Bin (2); Pan, Zhongli (1); Wu, Bengang (1); Hong, Chen (1); Ding, Yingpan (1); Liu, Rui (1)
Author affiliation:(1) School of Food and Biology Engineering, Jiangsu University, Zhenjiang, China; (2) Chinese Academy of Agricultural Mechanization Sciences, Beijing, China; (3) Processed Foods Research Unit, Western Regional Research Center, 800 Buchanan St. Albany, United States; (4) Department of Biological and Agricultural Engineering, University of California, Davis One Shields Ave, Davis, United States
Corresponding author:Pan, Zhongli
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 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:A simultaneous infrared dry-blanching and dehydration (SIRDBD) method utilizes infrared dry heat to blanch fruits and vegetables and simultaneously remove a certain amount of moisture. This study investigated the effects of three processing parameters, e. g. distance between infrared emitter and material (9.5, 12.5 and 15.5 cm), thickness (0.8, 1 and 1.3 mm, and the diameter was 6 cm) and processing time which was determined based on the complete inactivation of polyphenol oxidase (PPO), on blanching and dehydration of potato slices. The measured performance parameters were temperature, moisture ratio (MR), drying rate, relative residual PPO and surface color change (ΔE). In the test, the surface temperatures of all samples increased to predetermined temperatures within 1 min and then were kept at those temperatures for the rest of processing. In general, the tests showed that the radiation distance decreased from 15.5cm to 9.5 cm and the thickness of samples decreased from 1.3 mm to 0.8 mm, which would lead to an increase of the maximum dehydrating rates of potato slices from 0.24 g/(g·s) to 0.59 g/(g·s), a decrease of the reduction time of PPO inactivation from 364 s to 152 s, and a reduction of the color difference value Δ E from 5.26 to 1.66. Therefore, the test results indicated that the thin slices and narrow distance between the infrared emitter and sample were desirable for the quick moisture reduction, fast inactivation of enzymes and less color change. The residual PPO activities after application of various processing conditions were between 0-8.51%, which corresponded to a moisture reduction from 37.96% to 55.42% (w. b.), and a processing time from 150 s to 420 s. This indicated that infrared heating could blanch fruits and vegetables and simultaneously remove a certain amount of moisture. In addition, when the thickness of potato slices increased, the activation energies of potato slices decreased, but the effective moisture diffusivities increased. The reduced distance between infrared emitter and sample improved effective moisture diffusivities of potato slices. The effective moisture diffusivities of potato slices under different processing conditions were between 3.37×10<sup>-10</sup> m<sup>2</sup>/s and 6.36×10<sup>-10</sup> m<sup>2</sup>/s (R<sup>2</sup>=0.974-0.983), and the activation energies of potato slices ranged from 20. 34 kJ/mol to 32.59 kJ/mol (R<sup>2</sup>=0.951-0.996). First-order kinetics fitted well for PPO inactivation (R<sup>2</sup> was from 0.926 to 0.988), and the predicted kinetic parameters provided useful information for the blanching processing. The rate constants of PPO inactivation under different infrared radiation conditions were between 0.0063 s<sup>-1</sup> and 0.0151 s<sup>-1</sup>, and the reduction times ranged from 152 s to 364 s. The best processing parameters for the infrared heating mode were 9.5 cm radiation distance, 0.8 and 1 mm potato slice thickness and 150 and 180 s corresponding processing time, which resulted in 8.51% and 2.44% residual of PPO, 55.44% and 61.49% moisture content (w. b.), 1.66 and 2.24 Δ E, respectively. It has been concluded that SIRDBD method can be used as an alternative to manufacture blanched and partially dehydrated fruits and vegetables. For infrared dry-blanching, a narrow distance between infrared emitter and material with high temperature should is recommended. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Infrared drying
Controlled terms:Activation energy - Atmospheric temperature - Blanching - Chemical activation - Color - Colorimetry - Dehydration - Diffusion - Drying - Enzymes - Fruits - Infrared devices - Infrared heating - Infrared radiation - Models - Moisture - Rate constants - Thermal processing (foods) - Vegetables
Uncontrolled terms:Color difference values - Effective moisture diffusivity - Fruits and vegetables - Partial drying - Performance parameters - Potato - Processing parameters - Surface color changes
Classification code:443.1 Atmospheric Properties - 741.1 Light/Optics - 741.3 Optical Devices and Systems - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804.1 Organic Compounds - 821.4 Agricultural Products - 822.2 Food Processing Operations - 902.1 Engineering Graphics - 931.1 Mechanics - 931.3 Atomic and Molecular Physics - 941.4 Optical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.07.043
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 43>
Accession number:20151800797539
Title:Degradation and residue of EDTA used for soil repair in heavy metal-contaminated soil
Authors:Guo, Xiaofang (1); Wei, Zebin (2); Wu, Qitang (2)
Author affiliation:(1) School of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, China; (2) College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China
Corresponding author:Wu, Qitang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:7
Issue date:April 1, 2015
Publication year:2015
Pages:272-278
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:According to the bulletin of the national soil pollution reported by Ministry of Environmental Protection and Ministry of Land and Resources of the Peoples Republic of China, the total above standard rate is 16.1% in national soil, and above standard soils of Cd, Zn, Pb and Cu are 7.0%, 0.9%, 1.5% and 2.1%, respectively. Soil washing with chelating agents and phytoextraction by chelator-enhanced is potentially useful technique for remediating the heavy metal-contaminated soils. EDTA is the most frequently cited chelating agent in these techniques because of its strong chelating ability for different heavy metals. However, the slow degradation rate and persistence of residual EDTA in soil potentially increases the metal leaching risk which may cause groundwater contamination. But the environmental risk of EDTA reported in literature is from pot and column leaching experiments in laboratory scale. In order to understand the environmental risk of residual EDTA in the remediation of metal-contaminated soil, the field investigation and the incubation experiments were conducted to investigate the residue and degradation of EDTA in soil. The results of Lechang field investigation revealed that EDTA residue was not detected in the topsoil and deep soil after EDTA applied for 6 years. In Fogang field, the concentration of EDTA in soil was 0.039-0.056 mmol/kg soil, which was 2% to 5% of the applied amount in the 4th month after application. However, the EDTA was not detected in soil after 1 year. In Wengyuan field, the concentration of EDTA in topsoil was approximately 50% of added amount (3.3 mmol/kg soil) after 45 d of EDTA application, while it was only 2.6% of added amount after application in one year. EDTA residue was detected in the deep soil. However, the EDTA was not detected in groundwater. In addition, the concentration of heavy metals in groundwater was not increased after EDTA application. The deep soils have considerable fixation capacity for the heavy metal-chelator complexes, which help preventing the metal-chelator complexes from leaching down to groundwater. Incubation experiments were carried out to evaluate the degradation of EDTA in different soils. The air-dried soil (2 kg with < 5 mm particle size) was placed in plastic pots with the rate of 10 mmol/kg soil EDTA addition. Soils were incubated at room temperature and about 60%-70% soil water-holding capacity. Then soil samples were taken in 0, 3, 10, 20, 30, 50 and 72 d after incubation. The results indicated that degradation of EDTA in soils followed the first-order kinetic equation. Degradation rate constant of EDTA in latosolic red soil, cinnamon soil and metal-contaminated soil was 4.6×10<sup>-3</sup>, 1.4×10<sup>-2</sup> and 5.8×10<sup>-3</sup>, and the half-life was 71, 25 and 53 d for each soil, respectively. The half-life of EDTA had a good correlation with the organic matter content and CEC in soil. Microorganisms had a marked influence on the degradation of EDTA in soils. The finding suggested that EDTA-enhanced remediation technology can be used on remediating heavy metals-contaminated soil, but the added amount should be controlled. As such, the environmental risk of EDTA is minimum. ©, 2015, Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Soil pollution
Controlled terms:Chelation - Contamination - Degradation - Environmental protection - Groundwater - Groundwater pollution - Heavy metals - Integral equations - Leaching - Metals - Particle size - Plants (botany) - Pollution - Pollution control - Rate constants - Remediation - Repair - Soil moisture - Soil pollution control - Soils
Uncontrolled terms:Column leaching experiments - Degradation rate constants - EDTA degradation - Environmental risks - First order kinetic equations - Groundwater contamination - Heavy metal contaminated soils - Peoples Republic of China
Classification code:444.2 Groundwater - 454.2 Environmental Impact and Protection - 461.9 Biology - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 802.2 Chemical Reactions - 802.3 Chemical Operations - 913.5 Maintenance - 921.2 Calculus - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.07.038
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
- 邮编 100125
- 电话 010－59197078/7077/7076
- 邮箱 tcsae@tcsae.org
微信公众号
二维码
友情链接
- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
- 中华人民共和国农业农村部-MARA
- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
- 期刊界
- CNKI
- 万方数据
- 维普