<RECORD 1>
Accession number:20182405313514
Title:Effect of different positions of grass strips on hydrological connectivity in slope-gully system
Authors:Ma, Yongyong (1); Li, Zhanbin (1, 2); Ren, Zongping (1); Li, Peng (1); Lu, Kexin (1); Li, Cong (3); Tang, Shanshan (1); Wang, Tian (1)
Author affiliation:(1) State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an; 710048, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Yangling; 712100, China; (3) Henan Yellow River Hydrological Survey and Design Institute, Zhengzhou; 450004, China
Corresponding author:Ren, Zongping(renzongping@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:170-176
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to investigate the effects of different slope grass strips patterns on hydrological connectivity of the slope-gully system, we selected topographic convergence index and topographic wetness index as structural connectivity indicators, and the simplified hydrograph and derived relative surface connection function as functional connectivity indicators which were used to analyze the hydrological connectivity of groove system in different grass strip patterns (upper, middle, lower and foot slopes). In this paper, we used artificial simulated rainfall experiment which was conducted in the State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China at Xi'an University of Technology from July to August 2014. According to the loess plateau typical geomorphic features design indoor slope gully system model, the model for steel soil bin, groove width was 1 m, including Liang Mao slope gradient of 12°, slope 8 m long; groove was 25° slope degree, slope length 5 m. Liang Mao slope and gully slope ratio was roughly control in 1.6: 1.0, representing the proportion of slope gully loess plateau region. The experimental rainfall intensity was set at 1.5 mm/min, and the rainfall space was evenly distributed to more than 80% before the experiment began. We started to count the time after the rainfall was produced. All the muddy water samples were collected in every minute to calculate the runoff volume per minute. After 30 minutes of runoff, the rainfall experiment stopped. The results showed that different grass strip patterns had different influence on the connection process of slope ditch system. The closer to gully the grass strip was located, the longer the initial runoff time was. The total runoff was small in the grass strip layout in the middle and lower slope position. The lower slope and the foot slope had great influence on the runoff collection. The structural connectivity of grass strip was arranged on the placement of the middle and upper slopes which were superior to that of other positions, and were more conducive to the connection of water system after rainfall. The distribution of topographic convergence index was similar to normal distribution, while the distribution of the terrain moisture index was in line with the positively skewed distribution. The topography of the grass strip position which was arranged on the placement of the middle and upper slope was more conducive to the confluence than other patterns. In the middle and upper slope, the average topoqraphic wetness index of the grass strips after rainfall decreased by 10.59%. The closer the grass strip was to the top of the slope, the better the functional connectivity was, but the saving capacity of precipitation was poor. Compared with other patterns, the grass strip in the upper slope needed less water to produce flow and the functional connectivity was the best. When the rainfall stopped, there were about 70% of the total rainfall was used for saving with the grass strip laid in the lower and foot slope, while the one located in the middle and upper parts were only 50%. This study can provide reference for the prevention and treatment of slope gully in the Loess Plateau, China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Landforms
Controlled terms:Erosion - Hydrology - Normal distribution - Rain - Runoff - Sediments
Uncontrolled terms:Artificial simulated rainfall - Connection function - Convergence indices - Functional connectivity - Hydrological connectivity - Structural connectivity - Topographic wetness index - University of technologies
Classification code:442.1 Flood Control - 443.3 Precipitation - 481.1 Geology - 483 Soil Mechanics and Foundations - 922.1 Probability Theory
Numerical data indexing:Percentage 1.06e+01%, Percentage 5.00e+01%, Percentage 7.00e+01%, Percentage 8.00e+01%, Size 1.00e+00m, Size 5.00e+00m, Size 8.00e+00m, Time 1.80e+03s
DOI:10.11975/j.issn.1002-6819.2018.08.022
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 2>
Accession number:20182405313524
Title:Characteristics of nitrogen and phosphorus content and analysis of its influencing factors in feces and wastewater of livestock farms in Beijing suburb
Authors:Zhang, Shuai (1); Lu, Peng (1, 2); Chen, Shuo (1); Wu, Jianfan (3); Ren, Kang (4); Shi, Wenqing (4); Chen, Qing (1)
Author affiliation:(1) Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China; (2) Beijing Jeegreen Environmental Technology Company Limited, Beijing; 102200, China; (3) Beijing Low Carbon Agriculture Association, Beijing; 100107, China; (4) Beijing Animal Husbandry Station, Beijing; 100029, China
Corresponding author:Chen, Qing(qchen@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:244-251
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the increasing demand of meat products, animal husbandry industry had been rapidly developed in China in the past decade, especially the intensive livestock farms, increased from 16% to 52% in the total amount, from the year 1999 to 2015. Large amount of animal manures have been produced at the same time, which would be serious pollutant sources to the soil and water if they were discharged without any appropriate treatment. However, there is no suitable technology to deal with these wastes to realize recycling of nutrients, e.g. nitrogen (N) and phosphorus (P) in feces livestock farms, which must lead to serious environmental pollution. Because of the increasing amount of feces and shortage of treatment methods, it is meaningful to assess their potential impacts and the influencing factors in the intensive livestock farms, together with the research of treatment methods. Based on the questionnaire inquiry and samples collection, this study collected 41 questionnaires and 218 examples from 19 scale pig farms and 22 scale cattle farms in different districts of Beijing suburb. Then the concentrations of N and P in 86 wastewater samples and 132 manure samples were analyzed. And taking one of the pig farms as an example, the main influencing factors that changed the nutrients content were analyzed. The results indicated that, in the livestock farms investigated in this study, the average contents of the total N (TN) in manures from pig livestock farms and cattle livestock farms were 29.1 and 17.8 g/kg, respectively; the total P (TP) were 15.1 and 6.8 g/kg, respectively. It also suggested that more variation of TN and TP contents were observed in pig manure than that in cattle manure. The average contents of TN in wastewater of pig livestock farms and cattle livestock farms were 892 and 540 mg/L, and the TP were 82.4 and 53.3 mg/L, respectively. That was similar with the manure nutrient content, more variation of TN and TP contents were observed in wastewater from pig livestock farm. The TN and TP contents in pig manure in the large-scale pig farm were mainly attributed to the feed formula. TN and TP contents of manures had less effect on TN and TP contents of wastewater under the current methods of feeding and disposal of manure due to the fodder and water usage. For the solid manure selected in pig farms, content of TN and TP were more influenced by their feed formulas, rather than other factors. While for the wastewater in pig farms, the content of TN and TP were more influenced by their manure management process and feed formulas rather than solid manure even though most of N and P in the wastewater come from solid manure. The seasonal variation of N and P in wastewater were observed in the large-scale pig farms with more than ten thousand pigs and the proportion of inorganic P was increased with the time of wastewater storage. Results of this study provide reference for not only land use of manures and wastewater, but also decision-making on regional gross control of animal feeding and distribution of livestock farming.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Agriculture
Controlled terms:Animals - Decision making - Emission control - Environmental technology - Fertilizers - Land use - Manures - Nitrogen - Nutrients - Phosphorus - Surveys - Wastewater disposal - Water pollution
Uncontrolled terms:Beijing suburb - Environmental pollutions - Livestock farming - Manure nutrient content - Nitrogen and phosphorus - Questionnaire inquiry - Seasonal variation - Wastewater samples
Classification code:403 Urban and Regional Planning and Development - 451.2 Air Pollution Control - 452.4 Industrial Wastes Treatment and Disposal - 453 Water Pollution - 454 Environmental Engineering - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 912.2 Management
Numerical data indexing:Mass_Density 5.33e-02kg/m3, Mass_Density 5.40e-01kg/m3, Mass_Density 8.24e-02kg/m3, Mass_Density 8.92e-01kg/m3, Percentage 1.60e+01% to 5.20e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.032
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 3>
Accession number:20182405313496
Title:Optimization of working parameters on soil removal of stover pickup baler by vibration
Authors:Fu, Qiankun (1, 2); Fu, Jun (1, 2); Chen, Zhi (2, 3); Cheng, Chao (1, 2); Ren, Luquan (1, 2)
Author affiliation:(1) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun; 130022, China; (2) College of Biological and Agricultural Engineering, Jilin University, Changchun; 130022, China; (3) China National Machinery Industry Corporation, Beijing; 100080, China
Corresponding author:Fu, Jun(fu_jun@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:26-33
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Yellow silage corn stover is taken as a kind of important feedstuff for animal husbandry. Corn stover pickup balers are used to collect the stover and bundle it into straw bale in the harvest process of yellow silage corn stover. But in Northeast China, the soil has strong adhesiveness when it is in high moisture content. And when the moisture content is low, the soil disperses into fine particles which are easily carried in the miscellaneous branches of stover. It is a fleeting moment when stover is gathered and transported into baler. Soil adhered to stover and carried by the branches can't be removed in this short process. As a result, high soil content reduces feed quality of yellow silage corn stover. In order to solve the problem of high soil content of yellow silage corn stover, the paper proposed to remove the soil adhered and included in stover by means of vibration. The soil removal mechanism of stover pickup baler by vibration was fitted on the bottom of the machine. It is connected between the pickup unit and the cutting and rubbing unit. Stover can be picked up and delivered to the vibrating conveying screen to remove the soil. Then, the stover would be robbed, cut and bundled. The operating principle of the test-bed was clarified through the design of the test-bed and analysis of high-speed camera. Collision between stover and screen and internal friction of stover could release soil in the stover. Stover thickness, vibration time, vibration amplitude and vibration frequency were 4 influencing factors acting on performance of soil removal in the tests. Taking the soil removal rate and the stover loss rate as indices, single factor experiments were conducted to determine the value range of each parameter on the whole-plant stover (long stover) and chopped stover (short stover) on the ground respectively. The result showed that the soil removal rate and the stover loss rate increased with the increase of vibration time, vibration amplitude, and vibration frequency. But the soil removal rate and the stover loss rate dropped with the increase of stover thickness. It was given that the focus ranges of values of all parameters were vibration time from 10 to 14 s, vibration amplitude from 10 to 20 mm, vibration frequency from 4 to 6 Hz for long stover, and vibration time from 12 to 16 s, vibration amplitude from 10 to 20 mm, vibration frequency from 4 to 6 Hz for short stover. Through the three-factor orthogonal polynomial regression test, the author found the change laws of the soil removal rate and the stover loss rate determined by vibration frequency, vibration amplitude and vibration time. Four regression equations were induced according to experiment and analysis above. Then, a comprehensive index indicating soil removal rate and stover loss rate toward the optimum synchronously was made to evaluate the effect of soil removal. By analyzing the regression equations and the comprehensive index, an optimal solution was obtained. The optimal combination of soil removal from corn stover by vibration was as follows: For the long stover, the vibration amplitude was 15 mm, the vibration frequency was 4.5 Hz, and the vibration time was 14 s; for the short stover, the vibration amplitude was 20 mm, the vibration frequency was 4 Hz, and the vibration time was 12 s. Verification tests were conducted on the test-bed to verify the results above. Through calculating with the regression equations, the soil removal rate and the stover loss rate of long stover were 4.71% and 0.34%, respectively, and for short stover, the calculating results were 4.44% and 1.42% respectively. In the verification tests, the results were 4.80% and 0.38% for long stover and 4.72% and 1.53% for short stover. By comparing the simulated and the experimental result, it was found that the relative errors of the soil removal rate and the stover loss rate were acceptable. It was believed that the result of mathematical model matched the test result well. This study provides references not only for removing soil from stover by vibration, but also for the improvement of corn stover pickup baler design.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Soils
Controlled terms:Agricultural machinery - Agriculture - Equipment testing - Experiments - High speed cameras - Moisture - Moisture determination - Optimization - Pickups - Regression analysis
Uncontrolled terms:Comprehensive indices - Experiment and analysis - High moisture contents - Orthogonal polynomial - Single-factor experiments - Soil removal - Stover - Vibrations
Classification code:483.1 Soils and Soil Mechanics - 742.2 Photographic Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 901.3 Engineering Research - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 944.2 Moisture Measurements
Numerical data indexing:Frequency 4.00e+00Hz, Frequency 4.00e+00Hz to 6.00e+00Hz, Frequency 4.50e+00Hz, Percentage 1.42e+00%, Percentage 1.53e+00%, Percentage 3.40e-01%, Percentage 3.80e-01%, Percentage 4.44e+00%, Percentage 4.71e+00%, Percentage 4.72e+00%, Percentage 4.80e+00%, Size 1.00e-02m to 2.00e-02m, Size 1.50e-02m, Size 2.00e-02m, Time 1.00e+01s to 1.40e+01s, Time 1.20e+01s
DOI:10.11975/j.issn.1002-6819.2018.08.004
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 4>
Accession number:20182405313498
Title:Design and experiment of electrical drive side deep hill-drop fertilization system for precision rice hill-direct-seeding machine
Authors:Wang, Jinwu (1); Li, Shuwei (1); Zhang, Zhao (1); Li, Qichao (1)
Author affiliation:(1) Engineering College, Northeast Agricultural University, Harbin; 150030, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:43-54
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problems of the excessive application of fertilizer and the low utilization rate of fertilizer in the process of rice direct-seeding with synchronous fertilizing, according to the agronomic requirements, a set of electrical drive side deep hill-drop fertilization system for precision rice hill-direct-seeding machine was developed. The omni-directional profiling system was designed by hydraulic self-balance way, and the machine could adapt to the operation environment and accomplish the real-time and automatic adjustment; The design of fertilizer furrow opener was completed by circle function curve, and the opened smooth fertilizer furrow was with 50 mm width, with adjustable depth and at a lateral distance of 30 mm from bud row; The electrical outer slot wheel fertilizer applicator was designed by electrical drive way, which were connected with the electric parts. According to the work requirements, each fertilizer applicator can be adjusted separately, the fertilizer was applied onto the bottom of fertilizer furrow. Field experiments carried out in the Northeast Agricultural University test base in Suihua of Heilongjiang province, with the optimal working condition: machine speed was 2.48 km/h, the seed-metering device and fertilizer applicator both worked at a rotation speed of 29 r/min, the fertilizing depth was 50 mm, qualification rates of seeds and fertilizers in each hill were 86.73% and 87.49%. The fertilizing hill spacing matched seeding hill spacing, the variation coefficients of seeding and fertilizing hill spacing were 17.2% and 16.5%. The broken bud seed rate was 0.31%. During the feasibility experiment, the seed metering device and fertilizer applicator both worked at different rotation speeds such as 15, 20, 25, 30, 35 r/min. Test results showed that fertilization system could be matched with precision rice hill-direct-seeding machine, at the same time the synchronization of ditching furrows, side deep hill-drop fertilization, covering mud, forming ridges and precision rice hill-direct-seeding were achieved. The performance indexes could satisfy agronomic requirements of rice hill-direct-seeding as well as fertilization, so as to provide a reference for the design and evaluation of key fertilization components for precision rice hill-direct-seeding machine.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Fertilizers
Controlled terms:Agricultural machinery - Agronomy - Applicators - Cloud seeding - Crops - Depth profiling - Drops - Hydraulic machinery - Petroleum reservoir evaluation - Pneumatic materials handling equipment - Shafts (machine components)
Uncontrolled terms:Application of fertilizers - Design and evaluations - Direct-seeding - Feasibility experiments - Fertilizing - Seed metering devices - Side deep hill-drop fertilization - Variation coefficient
Classification code:443.3 Precipitation - 512.1.2 Petroleum Deposits : Development Operations - 601 Mechanical Design - 601.2 Machine Components - 632.2 Hydraulic Equipment and Machinery - 632.4 Pneumatic Equipment and Machinery - 801 Chemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.65e+01%, Percentage 1.72e+01%, Percentage 3.10e-01%, Percentage 8.67e+01%, Percentage 8.75e+01%, Rotational_Speed 2.90e+01RPM, Rotational_Speed 3.50e+01RPM, Size 3.00e-02m, Size 5.00e-02m, Velocity 6.89e-01m/s
DOI:10.11975/j.issn.1002-6819.2018.08.006
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 5>
Accession number:20182405313516
Title:Area change monitoring of winter wheat based on relationship analysis of GF-1 NDVI among different years
Authors:Wang, Limin (1); Liu, Jia (1); Yao, Baomin (1); Ji, Fuhua (1); Yang, Fugang (1)
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing; 100081, China
Corresponding author:Liu, Jia(liujia06@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:184-191
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to achieve fast monitoring of regional winter wheat area change, reduce monitoring difficulty, and improve monitoring efficiency and accuracy, the paper proposes a monitoring method based on the relationship analysis of normal difference vegetation index (rNDVI). By selecting 3 counties i.e. Huanghua, Mengcun, and Haixing County, Hebei Province as the study area, and by taking GF-1/WFV data of 2 dates i.e. April 14th, 2014 and April 26th, 2017, the paper conducted the monitoring in the study area by extracting the increased and decreased areas of winter wheat planting areas. Based on rNDVI, the paper built a two-dimensional space with two-year NDVI values of sample points, and thus obtained the monitoring threshold values of the changing areas of the winter wheat by employing the least squares fit method to obtain the upper and lower envelope equations of unchanged ground objects. The result shows that, the overall accuracy of rNDVI algorithm is 90.60%, with the Kappa coefficient of 0.84. Compared with the traditional method of making maximum likelihood classification and then extracting changed winter wheat planting areas, the overall accuracy of this method and its Kappa coefficient are improved by 6.6 percentages and 16.7% respectively. Analysis of the monitoring results on the change of the winter wheat increased area and decreased area shows that, the monitoring method based on rNDVI can effectively improve the identification ability on the change of the land areas such as bare land, linear roads, and fragmented winter wheat areas, and improve monitoring accuracy. The monitoring on the winter wheat changed area was conducted based on 2 pairs of GF-1/WFV data of March 1st, 2014 and March 12th, 2017, as well as May 17th, 2014 and May 20th, 2017. The result shows that the monitoring accuracy of March is relatively low, and the overall accuracies of May and April are close. The above study results show that, fast monitoring method of winter wheat change based on rNDVI can effectively monitor the change of the regional winter wheat planting area. The algorithm used in this method is simple and effective, and it can maintain relatively high accuracy for the sample planting structure of winter wheat planting area, and it can also meet the demand for fast acquisition of crop remote sensing monitoring information.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Monitoring
Controlled terms:Crops - Least squares approximations - Maximum likelihood - Remote sensing - Space optics
Uncontrolled terms:Change detection - GF-1 - NDVI - Recognition - Relationship analysis - Winter wheat
Classification code:656.1 Space Flight - 821.4 Agricultural Products - 921.6 Numerical Methods - 922.1 Probability Theory
Numerical data indexing:Percentage 1.67e+01%, Percentage 9.06e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.024
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 6>
Accession number:20182405313523
Title:Effects of temperature and sieving treatments on physicochemical characteristics and cadmium adsorption capacity for biochars derived from pig manure and rice straw
Authors:Huang, Shuang (1); Dong, Caiqin (1); Huang, Jiesheng (1); Deng, Yiyi (1); Jiang, Jinlong (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan; 430072, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:235-243
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this study, to investigate the impacts of feedstocks, pyrolysis temperature and sieving treatments (before pyrolysis and after pyrolysis) on biochar properties and cadmium adsorption capacity, as well as the relationship between biochar properties and cadmium adsorption capacity, two kinds of agricultural solid wastes (pig manure, and rice straw) were pyrolyzed at five temperatures (300, 400, 500, 600, 700℃). The effects of different treatments on the physicochemical properties such as yield, ash content, pH, element composition (C, H, N, O) and BET specific surface area of biochars were investigated. The biochars were also characterized by scanning electron microscopy(SEM), X-ray diffraction (XRD) and Fourier transform infrared spectro graph (FTIR). The cadmium adsorption capacity of biochars with different treatments was determined by a batch experiment. The relationship between physicochemical properties and cadmium adsorption capacity of biochars was also analyzed. The results showed that: 1) With increasing pyrolysis temperature, the yield, N, H, O content and H/C molar ratio of biochars decreased, and the pH, ash content and BET specific surface area increased. At the same pyrolysis temperature, the yield and ash content of pig manure (PM) biochars were higher than that of rice straw (RS) biochars, while the pH value and BET specific surface area were opposite. Biochars with different treatments had lower O/C and (O+N)/C molar ratios than that of raw materials, indicating that the polarity of biochars was weakened during pyrolysis process. 2) The effect of raw material on the cadmium adsorption capacity of biochar was significant. The cadmium adsorption capacity of rice straw biochar (the maximum adsorption capacity was 69.2 mg/g) were better than pig manure biochar (the maximum adsorption capacity was 36.4 mg/g), and increased with the pyrolysis temperature. The cadmium adsorption capacity of PMCA (PM is pig manure, C expresses biochar, A expresses biochar sieved by 0.25 mm) was not significantly increased with pyrolysis temperature. The higher pH value and BET specific surface area may be responsible for its better cadmium adsorption capacity of straw biochar. There was no obvious tendency for the cadmium adsorption capacity of biochars with different sieved treatments (before and after pyrolysis). 3) Correlations between the yield and ash content of different biochars were significantly negatively correlated, and yield showed highly significant and positive correlation with H/C. The ash content of biochars was positively correlated with pH value. Rice straw biochar, with higher pH value, had lower ash content than that of pig manure biochar, which can be explained by the different composition of ash contents, as XRD results showed that the minerals of rice straw biochar mainly consisted of sylvine. 4) The cadmium adsorption capacity of biochars (RSCB, RSCA and PMCB, RS is rice straw, B expresses raw material sieved by 0.25 mm befre pgrolysis) was significantly negatively correlated with yield and H/C molar ratio. There were positive correlation coefficient between adsorption capacity and ash and BET specific surface area, and the cadmium adsorption capacity of RSCB was significantly correlated with its ash content, and that of RSCA was significantly correlated with its BET specific surface area. The cadmium adsorption capacity of RSCA, RSCB had high correlation with pH value. It indicated that the yield and H/C were important for the cadmium adsorption capacity of these three kinds of biochars, and ash content, the BET specific surface and pH were of secondary importance. However, the cadmium adsorption capacity of PMCA was not correlated to all physicochemical properties, which may contribute to the inhomogeneity of the raw materials.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Adsorption
Controlled terms:Cadmium - Fertilizers - Fourier transform infrared spectroscopy - Heavy metals - Manures - pH - Pyrolysis - Scanning electron microscopy - Specific surface area - Straw - Surface properties - Temperature - X ray diffraction
Uncontrolled terms:BET specific surface area - Bio chars - Cadmium adsorption - Effects of temperature - Fourier transform infra reds - Physicochemical characteristics - Physicochemical property - Pyrolysis temperature
Classification code:531 Metallurgy and Metallography - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 641.1 Thermodynamics - 801 Chemistry - 801.1 Chemistry, General - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 821.5 Agricultural Wastes - 951 Materials Science
Numerical data indexing:Size 2.50e-04m
DOI:10.11975/j.issn.1002-6819.2018.08.031
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 7>
Accession number:20182405313517
Title:Classification and recognition for major vegetable pests in Southern China using SVM and region growing algorithm
Authors:Pan, Chunhua (1); Xiao, Deqin (1); Lin, Tanyu (1); Wang, Chuntao (1)
Author affiliation:(1) College of Mathematics and Informatics, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Xiao, Deqin(deqinx@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:192-199
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As vegetable safety is a rather important issue related to people's health and life, it is fundamental to ensure the vegetable safety by supervising the whole procedure of vegetable production. This requires to control the use of pesticides via accurate pesticide spraying according to the pest situation, which is the best strategy for vegetable safety. The key issue achieving this objective is to find out the species, quantity, and distribution of pests and the harm degree of vegetables. Although the pest identification via image processing has been widely used in recent years, it merely handles small pests of vegetables in the laboratory, and the number of pest species simultaneously processed is also limited to 1 or 2. To better recognize pests, this paper proposes a new algorithm to identify a number of vegetable pests such as striped flea beetle, whiteflies, diamondback moth, and thrips by deploying the support vector machine (SVM) and the region growing algorithm. This scheme integrates the recognition process into the segmentation one and uses the grid method to select seed points for region growing, which in turn simplifies stages of image processing. In performance assessment, 100 samples are adopted for each test pest, among which 60 are for training and the others for testing. Experimental results show that the proposed scheme can correctly identify the aforementioned major 4 vegetable pests in south China with a recognition rate of more than 93%. This implies that the proposed scheme achieves classification of several pests and thus would be promising in practical applications.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Vegetables
Controlled terms:Classification (of information) - Image segmentation - Pesticides - Support vector machines
Uncontrolled terms:Classification and recognition - Image segementation - Performance assessment - Recognition - Recognition process - Region growing - Region growing algorithm - Vegetable productions
Classification code:716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 803 Chemical Agents and Basic Industrial Chemicals - 821.4 Agricultural Products
Numerical data indexing:Percentage 9.30e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.025
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 8>
Accession number:20182405313507
Title:Prediction of frost-resisting critical strength of plateau concrete based on measured apparent activation energy
Authors:Li, Xuefeng (1, 2); Wang, Hualao (1); Diao, Bo (2)
Author affiliation:(1) Research Institute of Highway Ministry of Transportation, Beijing; 100088, China; (2) School of Transportation Science and Engineering, Beihang University, Beijing; 100191, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:117-123
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Accurately estimating the development of concrete compressive strength and avoiding suffering from negative temperature before concrete compressive strength reaches the frost-resisting critical strength is an important issue for concrete construction in the Qinghai-Tibet Plateau. When predicting the strength of concrete based on the traditional maturity method, there exists low prediction accuracy because the apparent activation energy is treated as constant value in the entire process of forecasting strength. In fact, the apparent activation energy value is influenced by many factors, such as curing temperature, degree of hydration and type of cementitious material. There is not any unique value that can precisely predict the concrete strength throughout the curing period. In view of the above shortcomings, an improved maturity method is proposed through modifying the determined value of apparent activation energy. And the specific methods are as follows: Firstly, according to the typical service environments of concrete structures, the durability requirements of the environment for the concrete are determined, and then the predicted target strength and the corresponding prediction range can be determined. Secondly, 3 temperatures are selected to maintain the concrete at a constant temperature, one of which is the standard curing temperature (usually 20℃). The compressive strength of concrete at different ages under different curing temperatures is tested. By assuming apparent activation energy values, the test ages at the other 2 temperatures except the standard curing temperature are converted to the ages under the standard curing temperature. Then the apparent activation energy and the corresponding parameters in the strength-age curve are obtained when the error between the actual strength and the predicted strength of the concrete within the range of target strength is minimized. At last the calculated parameters are utilized to predict the concrete strength at different ages. In order to verify the accuracy of the modified method, 4 groups of concrete with different mixing proportions were designed and were cured under 3 constant temperatures (5, 20 and 35℃ respectively). Meanwhile, one group of concrete with fly ash (F10) was subjected to variable temperature curing. The design of curing temperature refers to the characteristics of ambient temperature in the Qinghai-Tibet Plateau. The compressive strength of concrete with different ages was tested and the traditional maturity method and the modified maturity method were respectively used to predict the concrete strength within the target strength range. The results show that among the 24 groups of predicted values of the compressive strength of the concrete in the target strength range using the traditional method, the error between the predicted and measured values in the 20 groups is more than 10%, and the predicted value is generally greater than the measured value. When using the modified maturity method, there are 30 groups whose prediction errors for the target strength are lower than 10% in 36 groups, and the accuracy of the strength prediction is improved remarkably compared with the traditional maturity method. Thus, this improved method can be used to predict the strength development of concrete in the Qinghai-Tibet Plateau to prevent early-freezing of the concrete.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Compressive strength
Controlled terms:Activation energy - Concrete construction - Concrete mixing - Concrete testing - Concretes - Curing - Errors - Fly ash - Forecasting - Temperature
Uncontrolled terms:Apparent activation energy - Cementitious materials - Compressive strength of concrete - Concrete compressive strength - Critical strength - Negative temperatures - Plateau - Qinghai Tibet plateau
Classification code:412 Concrete - 641.1 Thermodynamics - 802.2 Chemical Reactions
Numerical data indexing:Percentage 1.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.015
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 9>
Accession number:20182405313515
Title:Classification of land cover in high-resolution remote sensing images based on Space-LDA model
Authors:Li, Yang (1, 2, 3); Shao, Hua (4); Jiang, Nan (1, 2, 3); Shi, Ge (1, 2, 3); Ding, Yuan (1, 2, 3)
Author affiliation:(1) Key Laboratory of VGE, Ministry of Education, Nanjing Normal University, Nanjing; 210023, China; (2) Cultivation Base of State Key Laboratory of Geographical Environment Evolution, Jiangsu Province, Nanjing; 210023, China; (3) Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing; 210023, China; (4) College of Geomatics Science and Technology, Nanjing Tech University, Nanjing; 211800, China
Corresponding author:Shao, Hua(shaohua@njtech.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:177-183
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Automatic classification of high-resolution remote sensing image has been a hot topic in remote sensing image analysis and related areas. Object-oriented image analysis method exploits segmentation object as the basic unit of analysis, avoiding the "salt and pepper" phenomenon in the traditional classification method. However, the major limitation is the uncertainty of segmenting semantically meaningful object as the basic unit of analysis. The traditional classifiers to discriminate objects in the underlying feature spaces cannot adapt to the complexity of different features with different imaging mechanisms, leading to large differences within classes and the imbalance between different classes. Probabilistic topic model shows a great success in the field of natural language processing with solid mathematical theoretical foundation. Its inherent characteristics are extremely consistent with the demand of remote sensing information extraction. In this paper, the classic probabilistic topic model, latent dirichlet allocation (LDA) model, is used as the main model. LDA model is introduced into high-resolution remote sensing image classification research. Bag-of-words model can produce a valid information expression of remote sensing images, but the studies regarding this model are still limited in low-level features which mean the word vector space. The proposed LDA model in this paper would be applicable to the further exploitation of remote sensing data. This paper was going to establish some sort of spatial model oriented to the classification of high-resolution remote sensing images, and meanwhile the improved model was based on the traditional LDA model. The expression of remote sensing images based on the bag-of-words model is a basic of probabilistic topic model. Considering the requires of patterns classification, we were going to create the "Document-Words" mapping of high-resolution remote sensing images by using multi-scale segmentation algorithm and study on the key technology of building the bag-of-words model. It created the visual dictionary with a fast clustering algorithm based on the density peak to get rid of the dependence of original clustering center and identify the noise. After building the bag-of-words model, we tried to introduce the popularity and content of spatial topic as the latent topic of data and the prior distribution of words in the topic. Moreover, the variational expectation maximization (EM) inference algorithm of this model was built and the tests would verify the advantage of improved model. QuickBird images of Wuxi were used in the experiment, whose spatial resolution was 0.6 m with 4 bands. LDA and Space-LDA model were compared in the classification of land use types. Space-LDA model had higher classification accuracy than traditional LDA, and reached the highest accuracy when the visual dictionary size was 480. At last, when topic size was fixed at 40, both overall classification accuracy and Kappa's coefficient showed that Space-LDA model achieved better results than LDA model. The spatial region information provides reasoning information from both the theme popularity and the thematic content at the same time, so the model has a more flexible structure.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Remote sensing
Controlled terms:Clustering algorithms - Data mining - Flexible structures - Image analysis - Image classification - Image enhancement - Image segmentation - Inference engines - Information retrieval - Information retrieval systems - Land use - Maximum principle - Models - Natural language processing systems - Space optics - Statistics - Uncertainty analysis - Vector spaces
Uncontrolled terms:High resolution remote sensing images - Latent dirichlet allocations - Lda models - Object oriented - Object-oriented image analysis - Probabilistic topic models - Remote sensing information - Spatial relationships
Classification code:403 Urban and Regional Planning and Development - 408.2 Structural Members and Shapes - 656.1 Space Flight - 723.2 Data Processing and Image Processing - 723.4.1 Expert Systems - 903.1 Information Sources and Analysis - 903.3 Information Retrieval and Use - 921 Mathematics - 922.1 Probability Theory - 922.2 Mathematical Statistics
Numerical data indexing:Size 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.08.023
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 10>
Accession number:20182405313493
Title:Simulation of dust emissions in Hebei Province based on CLM4.5 soil wind erosion model
Authors:Wang, Xiaowei (1, 2); Wang, Wei (1)
Author affiliation:(1) College of Resources and Environment Science, Hebei Normal University, Hebei Key Laboratory of Environmental Change and Ecological Construction, Shijiazhuang; 050016, China; (2) Hebei Women's Vocational College, Shijiazhuang; 050051, China
Corresponding author:Wang, Wei(wangwei@mail.hebtu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:1-9
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the continuous development of the economy and society, the problem of air pollution in China is becoming more and more serious especially in Hebei Province. Currently, Hebei Province has been one of the most serious areas of air pollution in China. The wind-blown dust, emitted from the earth's surface to the atmosphere, has become one of the main components of air pollutants. The wind-blown dust has significant impacts on atmospheric phenomena and consequently on air quality. The wind-blown dust not only causes atmospheric pollution, but also changes the radiation balance of the ground and the acidity or alkalinity of the aerosol. It not only affects human health but also causes changes in the global climate system and ecosystem. In order to evaluate the PM<inf>10</inf>of atmospheric pollutants in Hebei Province caused by wind-blown dust, the article set up parameters system of wind-blown dust production by Community Land Model 4.5 (CLM4.5) using remote sensing data, the ground meteorological data, the Land Data Assimilation System data and the land surface characteristic parameters production data with 1 km spatial resolution. The factors affecting the wind-blown dust include soil texture, wind speed, soil moisture, surface roughness, and the proportion of bare soil determined by vegetation coverage, surface freezing ratio, snow cover ratio, lakes and wetland ratio. Wind speed, soil moisture, vegetation coverage, snow cover area and freezing ratio change greatly with the seasons, so they are the sensitive factors of the wind-blown dust. This study provides the first estimates of the fine-scale spatial and temporal distribution of dust emissions from Hebei Province. The result shows that: The wind-blown dust annual emission flux of PM<inf>10</inf>is 1.02 t/hm<sup>2</sup>in 2013. The highest monthly emission flux is 0.28 t/hm<sup>2</sup>in March, accounting for 27.6% of the whole year, and the lowest is July, accounting for only 0.2%. The dust emission flux of spring is 0.55 t/hm<sup>2</sup>, the summer is 0.015 t/hm<sup>2</sup>, the autumn is 0.18 t/hm<sup>2</sup>, and the winter is 0.28 t/hm<sup>2</sup>. That shows spring is the highest season and summer is the lowest season for wind-blown dust emission flux. There are obvious regional differences about wind-blown dust emissions in Hebei Province, the coastal plain of Cangzhou and Bashang plateau are the highest areas for dust emission flux, annual emission flux of which is 5.365 and 3.542 t/hm<sup>2</sup>respectively, and Taihang Mountain piedmont plain is the lowest area, annual emission flux of which is 0.20 t/hm<sup>2</sup>. The result above shows CLM4.5 wind-blown dust model can well simulate the characteristics of spatial and temporal change in Hebei Province. Comparing the initial data of CLM4.5 with our study data, it presents the spatial resolution of initial data is very low, and not suitable for the simulation of the small area, in contrast, the local parameters we used including vegetation coverage, wind speed, soil moisture, the proportion of bare soil, lakes and wetland ratio data with high spatial resolution (1 km) have improved the accuracy of the simulation result. This paper is not only meaningful for evaluating the PM<inf>10</inf>from wind-blown dust in Hebei Province, but also the first application to estimate wind-blown dust in the fine scale by CLM4.5 model.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Dust
Controlled terms:Air quality - Earth atmosphere - Erosion - Freezing - Image resolution - Lakes - Models - Remote sensing - Snow - Soil moisture - Soils - Surface roughness - Vegetation - Wetlands - Wind
Uncontrolled terms:CLM4.5 - Dust emission - Hebei Province - Land data assimilation systems - Land surface characteristics - PM10 - Spatial and temporal changes - Spatial and temporal distribution
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 451.1 Air Pollution Sources - 451.2 Air Pollution Control - 483.1 Soils and Soil Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 2.00e-01%, Percentage 2.76e+01%, Size 1.00e+03m
DOI:10.11975/j.issn.1002-6819.2018.08.001
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 11>
Accession number:20182405313520
Title:Effect of molding and burning temperature on ash physicochemical characteristics of refuse derived fuel
Authors:Li, Tao (1); Xiong, Zuhong (1); Lu, Min (1); Xie, Sen (1); Xiong, Peipei (1)
Author affiliation:(1) Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou; 510640, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:214-219
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Waste to energy (WTE) is one of the most reasonable managements for solving impacts of rubbish on our environment. Methods of WTE are major in incineration and gasification, by which to release thermal energy from organic substances. WTE plants have some more serious problems to solve because of the complexity of raw refuse. Refuse derived fuel (RDF) with specific pretreatment is confirmed as an optimum feedstock with higher efficient and more stable performance for incineration and gasification than the raw refuse. However, the RDF ash is still about 20% of original weight after burning. It needs to be considered how to dispose RDF ash in the right way. It is worth mentioned that RDF ash has specific property, such as low toxicity, well-distributed and inorganic nature. Therefore, some experts indicated that RDF ash could be used as source materials of building wall or road basement. This study focused on the characteristics of RDF ash such as weight, particle size, chemical composition, and discussed the mechanism of reaction change during the combustion. In this experiment, refuse from a WTE plant in Guangdong Foshan was made into RDF by screening and smashing process. Pelleted RDF made by additional extrusion and forming process. Ash samples were obtained from both pelleted and non-pelleted RDF burned at temperature of 600, 700, 800, 900, 1 000 and 1 100℃ in muffle furnace, respectively. The weight, particle size and chemical composition of these samples were analyzed. The results showed that chemical compounds of the RDF ash have decomposition reaction mainly below 1 000℃, such as decomposition of organic residue, chloride, sulfate, thus particle size decreased. While the burning temperature was rising over 1 000℃, combination reaction turned to be dominant during the whole reaction, the higher temperature is, the more serious reaction happened, which resulted in the products with composite silicates. Meanwhile, particle size increased and even formed into massive structure because more and more ash substances melted and bonded at or over their melting points. As a result, lump amounts increased after temperature returned back. Some compounds containing non-metallic elements such as C, Cl, S decomposed and turned into gaseous compounds, which escaped from the base-ash, so the ash weight reduced. High temperature burning reduced the weight of RDF ash. Compared with non-pelleted RDF ash, ash of pelleted RDF has more active at the same temperature, because of its higher density which means that there is shorter distance among reaction substances causing lower resisting force to overcome. Pelleted RDF ash contained more crystal substance quantities than the non-pelleted one, so it has bigger particle size, but the weight of the pelleted RDF ash is less than that of non-pelleted RDF ash.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Pelletizing
Controlled terms:Ashes - Chemical analysis - Chlorine compounds - Combustion - Decomposition - Extrusion - Gasification - Particle size - Refuse derived fuels - Refuse incineration - Silicates - Sulfur compounds - Temperature - Wastes
Uncontrolled terms:Chemical compositions - Combination reactions - Decomposition reaction - High-temperature burning - Non-metallic elements - Physicochemical characteristics - Physicochemical property - Specific properties
Classification code:452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 452.3 Industrial Wastes - 641.1 Thermodynamics - 802.2 Chemical Reactions - 802.3 Chemical Operations
Numerical data indexing:Percentage 2.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.028
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 12>
Accession number:20182405313510
Title:Decomposing characteristics of maize straw returning in Songnen Plain in long-time located experiment
Authors:Gong, Zhenping (1); Deng, Naizhen (1); Song, Qiulai (2); Li, Zhongtao (1)
Author affiliation:(1) College of Agriculture, Northeast Agricultural University, Harbin; 150030, China; (2) Institute of Cultivation and Crop Tillage Research, Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:139-145
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The Songnen Plain is located in the provinces of Heilongjiang and Jilin, and which is an important spring maize producing area in China. Excess maize straw resource causes large amounts of straw to be burned in the open air, which causes serious environmental pollution. Straw returning can not only solve the problem of environmental pollution caused by incineration of straw, but also return various nutrient elements contained in straw to the soil and increase the supply of soil nutrients. The straw returning is the development direction of maize production. It has great significance to study the characteristics of maize straw decomposition and nutrient release. The nylon bag method was used, the size of the nylon mesh bag was 34 cm×36 cm and the aperture was 80 mesh. The maize straw was crushed and cut into 5 to 10 cm segments after drying, 80 g of the maize straw were put into a nylon net bag and sealed with a nylon thread. The experiment set up two maize straw returning methods: buried and covered ground, with located observation for four years, both treatment fields were planted with maize in no-tillage manner. In the buried soil treatment, the nylon mesh bag was buried vertically in the ridge body, and the upper end of the mesh bag was level with the ground surface, which was basically the same as the depth of the mixed straw in the production field. The covered treatment was to lay the nylon mesh bag in the ditch, fixed with iron wire. The results showed that: 1) The maize straw decomposition rate and nutrient release rate in buried treatment were higher than that of covered treatment. The decomposition of straw was mainly concentrated in the first three years of returning to the soil, with the fastest decomposition rate in the first year, the total decomposition rate of buried and covered straw reached 60.63% and 45.53%, and the three-year decomposition rate was 91.70% and 81.96%. 2) The order of nutrient release in maize straw was K>P>C>N. For buried and covered treatment, in the first year of returning to the soil, the K release rate reached 96.26% and 84.04%, respectively; In the first year, the release rate of P was 61.63% and 54.30%, and the release rate of P of three-year was 92.03% and 83.29%; In the first year, the release rate of C was 57.58% and 45.32%, and the release rate of C of three-year was 90.96% and 82.06%; In the first year, the release rate of N was 52.65% and 41.33%, and the release rate of N of three-year was 91.70% and 81.96%. 3) The decomposition rate of hemicellulose in maize straws was faster than cellulose, and the lignin was the slowest. Among them, the hemicellulose decomposed rate of buried and covered straw was 73.70% and 54.72% in the first year and 88.78% and 86.30% of two-year, respectively; Cellulose was 59.29% and 45.31% in the first year and 80.42% and 70.86% of two-year, respectively; Lignin was 28.10% and 23.65% in the first year and 46.64% and 40.65% in two-year and 78.63% and 66.48% of three-year, respectively.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Nutrients
Controlled terms:Cellulose - Decomposition - Incineration - Lignin - Mesh generation - Pollution - Polyamides - Rayon - Soils - Straw
Uncontrolled terms:Decomposition rate - Development directions - Environmental pollutions - Experiment set-up - Maize - Nutrient elements - Production fields - Returning method
Classification code:483.1 Soils and Soil Mechanics - 723.5 Computer Applications - 802.2 Chemical Reactions - 811.3 Cellulose, Lignin and Derivatives - 815.1.1 Organic Polymers - 819.2 Synthetic Fibers - 821.5 Agricultural Wastes
Numerical data indexing:Mass 8.00e-02kg, Percentage 2.36e+01%, Percentage 2.81e+01%, Percentage 4.06e+01%, Percentage 4.13e+01%, Percentage 4.53e+01%, Percentage 4.55e+01%, Percentage 4.66e+01%, Percentage 5.26e+01%, Percentage 5.43e+01%, Percentage 5.47e+01%, Percentage 5.76e+01%, Percentage 5.93e+01%, Percentage 6.06e+01%, Percentage 6.16e+01%, Percentage 6.65e+01%, Percentage 7.09e+01%, Percentage 7.37e+01%, Percentage 7.86e+01%, Percentage 8.04e+01%, Percentage 8.20e+01%, Percentage 8.40e+01%, Percentage 8.63e+01%, Percentage 8.88e+01%, Percentage 9.10e+01%, Percentage 9.17e+01%, Percentage 9.20e+01%, Percentage 9.63e+01%, Size 5.00e-02m to 1.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.08.018
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 13>
Accession number:20182405313494
Title:Effects of vibration mode and frequency on vibration harvesting of apricot trees
Authors:San, Yunlong (1); Yang, Huimin (2); Wang, Xuenong (2); Niu, Changhe (2); Guo, Wensong (1); Hou, Shulin (1)
Author affiliation:(1) College of Engineering, China Agriculture University, Beijing; 100083, China; (2) Agricultural Mechanization Institute, Xinjiang Academy of Agricultural Sciences, Urumqi; 830091, China
Corresponding author:Hou, Shulin(hsl010@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:10-17
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the response state of apricot after being stimulated by different vibrations and the optimal vibratory harvest frequency of apricot tree and provide a theoretical basis for the design of the vibration harvesting machinery of tree fruit, we established a response model of apricot tree excited by single eccentric and symmetrical double-eccentric vibration, and an apricot tree - harvester dynamics model for the main apricot variety "Kumati" in Xinjiang. The apricot tree was simplified into a fixed cantilever beam structure at one end. In this way, the apricot tree could be regarded as a system that could be discretely divided into a finite number of degrees of freedom. The trunk was regarded as an isometric, and uniform-section cylindrical beam. The apricot tree canopy was considered as a mass group and was located in a movable cylinder. We analyzed the vibration response status of apricot trees at different positions after being stimulated by the single eccentric vibration and the symmetric double eccentricity vibration. The theoretical analysis and experiments showed that when apricot trees were excited by a single eccentric vibration, they mainly showed a torsional vibration, and the clamping position trajectory was circular while the trunk trajectory was similar to an inverted cone. When they were excited by a symmetrical double-eccentric vibration, they mainly performed a bending vibration with the reciprocating movement of the clamping position in the horizontal direction, the trajectory of which was straight, and the trunk trajectory was similar to a sector. The data obtained from the accelerometers installed in the clamp positions of the trunk, in the x and y directions, showed that the theoretical motion trajectory of the trunk brace position was consistent with the actual motion trajectory. LabView vibration test software was used and acceleration sensors were installed along the main trunk of the apricot tree to detect the vibration acceleration data of the apricot tree clamping position, the secondary branches and the third-level branches. The vibration acceleration response curve showed that the vibration was transmitted along the trunk upward from the clamping position. The time from the bottom to the top of the vibration initiated by the single eccentric vibration was: 0.135, 0.181, and 0.191 s. The symmetrical double-eccentric was 0.052, 0.219, and 0.224 s. The Fourier fitting analysis of the data within 0.1 s after reaching the vibration steady state in MATLAB showed that the branches detection points at all levels were periodical harmonic motions, and the single eccentric vibrational excitation period was 0.05 s which varied from the bottom to the top. The R<sup>2</sup>values were: 0.912 1, 0.928 6, and 0.981 9, respectively. The symmetric double-eccentric vibration period was 0.1 s, and the R<sup>2</sup>values at different positions from the bottom to the top were: 0.906 2, 0.939 8, and 0.93, respectively. The above values indicated a higher degree of function fitting. At the same time, the acceleration fitting curves and vibration response formulas at different positions were obtained. The frequency spectrum analysis of 0-50 Hz acceleration showed that the acceleration value of each detection point was maximum when the apricot was excited by 11.56 Hz vibration, and the acceleration of the single eccentric vibration clamping position was greater than that of the branches at all levels. When the symmetrical double-eccentric vibration was transmitted to the third-level branch, the acceleration was higher than that of the clamping position. At the same frequency, the acceleration response of the branches at the symmetrical double-eccentric vibration was greater than that of the single eccentric vibration, which made the vibration recovery more conducive. The results of this study could provide references for the design and the optimization of harvesting machinery parameters for the apricot and other varieties of forest fruits.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Vibration analysis
Controlled terms:Acceleration - Agricultural machinery - Computer programming languages - Curve fitting - Degrees of freedom (mechanics) - Dynamic response - Excited states - Forestry - Fruits - Harvesting - Machine design - MATLAB - Models - Orchards - Software testing - Spectrum analysis - Trajectories
Uncontrolled terms:Acceleration response - Acceleration sensors - Apricot - Frequency spectrum analysis - Fruit trees - Vibration acceleration - Vibrational excitation - Vibrations
Classification code:601 Mechanical Design - 723.1.1 Computer Programming Languages - 723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.6 Numerical Methods - 931 Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Frequency 0.00e+00Hz to 5.00e+01Hz, Frequency 1.16e+01Hz, Time 1.00e-01s, Time 1.91e-01s, Time 2.24e-01s, Time 5.00e-02s
DOI:10.11975/j.issn.1002-6819.2018.08.002
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 14>
Accession number:20182405313502
Title:Load spectrum compiling for wheel loader semi-axle based on mixed distribution
Authors:Zhai, Xinting (1); Zhang, Xiaochen (1); Jiang, Zhujin (1); Li, Yingying (2); Zhang, Qiang (3); Wang, Jixin (1)
Author affiliation:(1) School of Mechanical Science and Engineering, Jilin University, Changchun; 130025, China; (2) Tianjin Research Institute of Construction Machinery, Tianjin; 300384, China; (3) Liugong Machinery Co., Ltd., Liuzhou; 545000, China
Corresponding author:Wang, Jixin(jxwang@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:78-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Working in harsh environments and bumpy roads, ground vehicles such as the agricultural vehicle and construction machinery often suffer from random load which may obey different load distributions. Aiming at the problem that the single distribution is difficult to fit the multi-peak form of the load, the traditional load spectrum compiling method is improved to obtain the load spectrum that reflects actual working conditions. During the field test of wheel loader, the semi-axle load data, the speed and the bucket cylinder displacement are collected through sensors and data acquisition system. The operation modes of wheel loader can be reflected by the above data. Then the semi-axle load data are divided into 6 sections according to the operation modes of wheel loader. The 6 sections are no load forward section, spading section, full load backward section, full load forward section, unloading section and no load backward section. The load mean, load amplitude and their corresponding frequency are obtained after conducting rain-flow counting for each section. Both the single distribution and the mixed distribution are applied to fit the load mean and load amplitude in each section. The maximum likelihood estimation method is used for single distribution estimation, and the maximum expectation algorithm is used for mixed distribution estimation. The log-likelihood function values and decision coefficients are applied to the fitting test. The larger the log-likelihood function value and the decision coefficients, the better the fitting results. The fitting test results show that the fitting effects of the mixed distribution for both load mean and load amplitude are better than those of the single distribution in no load forward section, spading section, full load backward section, unloading section and no load backward section. The decision coefficients of the mixed distribution for load mean are 32%, 2.3%, 25.1%, 40.1% and 160.8% respectively larger than the corresponding decision coefficients of the single distribution. The decision coefficients of the mixed distribution for load amplitude are 8.3%, 6.7%, 1.4%, 6.2% and 1.2% respectively larger than the corresponding decision coefficients of the single distribution. For the load mean in full load forward section, the corresponding fitting test values of the mixed distribution are larger than those of the single distribution, which shows the fitting effect of the mixed distribution is better. Different conclusions are obtained for the load amplitude in the full load forward section. The fitting test values of the load amplitude are -1 417.10 and 0.995 9 for the single distribution, while -143 0.50 and 0.962 2 for the corresponding mixed distribution. The above values show that the fitting effects of the single Weibull distribution with the parameters of (8.717 1, 0.887 1, 9.344 1) for the load amplitude are better. It is clear to demonstrate that the load data of different sections may present different characteristics and obey different distributions. Furthermore, the load spectrum can be affected by the fitting effect caused by the distribution type according to the compiling procedure. In this paper, the load spectrum compiling method is improved. The comparisons of fitting effects of different distributions are added before deciding the distribution function. Based on the distribution which has good fitting effects in each section, the maximum values of the load mean and load amplitude of each section are determined. The joint probability density functions are also obtained. Then the frequency extrapolation and synthesis are carried out. Next the two-dimensional load spectrum is obtained. According to the Goodman theory and the fatigue damage theory, the two-dimensional load spectrum is converted into a one-dimensional load spectrum with load mean of 0. The proposed method is helpful to solve the problem of fitting multi-peak form of the load and contributes to compile the load spectrum that reflects actual semi-axle load conditions of wheel loader.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Weibull distribution
Controlled terms:Axles - Construction equipment - Data acquisition - Distribution functions - Fatigue damage - Loaders - Loads (forces) - Maximum likelihood estimation - Mining machinery - Models - Parameter estimation - Probability density function - Rain - Testing - Tractors (agricultural) - Unloading - Vehicles - Wheels
Uncontrolled terms:Data acquisition system - Different distributions - Joint probability density function - Load spectrum - Log-likelihood functions - Maximum likelihood estimation method - Mixed distribution - Rain flows
Classification code:405.1 Construction Equipment - 408 Structural Design - 443.3 Precipitation - 502.2 Mine and Quarry Equipment - 601.2 Machine Components - 663.1 Heavy Duty Motor Vehicles - 691.1 Materials Handling Equipment - 691.2 Materials Handling Methods - 723.2 Data Processing and Image Processing - 922 Statistical Methods - 951 Materials Science
Numerical data indexing:Percentage 1.20e+00%, Percentage 1.40e+00%, Percentage 1.61e+02%, Percentage 2.30e+00%, Percentage 2.51e+01%, Percentage 3.20e+01%, Percentage 4.01e+01%, Percentage 6.20e+00%, Percentage 6.70e+00%, Percentage 8.30e+00%
DOI:10.11975/j.issn.1002-6819.2018.08.010
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 15>
Accession number:20182405313500
Title:Structural parameters optimization of swirling jet mixer based on reducing effective length
Authors:Song, Haichao (1, 2); Xu, Youlin (1); Zheng, Jiaqiang (1); Dai, Xiang (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) College of Mechanical Engineering, Nanjing Institute of Industry Technology, Nanjing; 210023, China
Corresponding author:Xu, Youlin(youlinxu@njfu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:62-69
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The pesticide solutions include both fat soluble and water soluble. The permeability of fat soluble pesticides is greater than that of water soluble pesticides. So its infiltration effect is better than that of water soluble pesticides. It is necessary to break up the oil into a fine oil bead by the intense mechanical agitation when fat soluble pesticide mixed with water. However, the emulsion oil droplet dispersion degree is not high. During the storage period, it is very easy to produce oil beads and break the emulsion, and after that, it's hard to recover. Inline mixed pesticides can reduce the harm of pesticides to operators, the environment, and non-target organisms. At present, the mixed pesticide is mainly mixed with water soluble pesticides. It is difficult to study the inline mixing of fat soluble pesticides due to their insolubility in water. The purpose of this study was to determine the effective length of the mixer under the condition of uniform mixing of fat soluble pesticide (rapeseed oil). Comparative analysis was made for the different diffusion angle, different injection methods, different contraction angle, and different mixing tube length. The main components of swirling jet mixer were shrink tube and diffuser. When the shrinkage and diffusivity were determined, the influencing factors of the effective length of the mixer were the contraction angle, the length of the mixing tube and the diffusion angle of the diffuser. Structure parameters of the mixer were optimized by orthogonal experiments with three factors and three levels, including the contraction angles of 19°, 22° and 25°, the mixing tube length of 20, 12 and 8 mm, and the diffusion angle of 10°, 14° and 18°. To confirm the content of the study, the experiments were conducted in which the fluorescent tracers were mixed with the pesticides to enable the camera to track the mixing process in the transparent chamber. According to different physical and chemical properties of pesticides, rapeseed oil was used as substitute for fat soluble pesticide, and it was added with oily fluorescent agent LUYOR-6100. The orthogonal experiment results showed that the probabilities of the three factors were 0.206, 0.004, and 0.025, respectively. The mixing tube length of swirling jet mixer for mixing uniformity was the most significant, followed by diffusion tube diffusion angle, no significant effect was the contraction angle shrink tube. The order of the three levels of the contraction angle of the contraction tube on mixing uniformity was 25°, 19°, and 22°. The order of the three levels of the mixing tube length on mixing uniformity was 20 mm, 12 mm, and 8 mm. The order of the three levels of the diffusion tube diffusion angle on mixing uniformity was 18°, 14°, and 10°. On the premise of fat soluble pesticide mixing, the effective length of the swirling jet mixer of 25°, 20 mm, and 18° was relatively short. The mix combination of 25°, 20 mm, and 18° was better because its effective length was shorter in the realization of fat soluble pesticide (rapeseed oil) uniform mixing. Its effective length is 69 mm, the contraction angle is 25°, the mixing tube length is 20 mm and the diffusion angle is 18°. In conclusion, swirling jet mixing device 252018 (25°, 20 mm, and 18°) can be used as a shorter mixing device structure in the experiments of studying the adaptability of the sprayer and nozzle structures.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Pesticides
Controlled terms:Birefringence - Diffusion - Emulsification - Fluorescence - Mixers (machinery) - Mixing - Oilseeds - Optimization - Spray nozzles - Structural optimization - Testing - Tubes (components) - Vegetable oils
Uncontrolled terms:Comparative analysis - Effective length - Fluorescent tracers - Mechanical agitation - Non-target organism - Orthogonal experiment - Physical and chemical properties - Structural parameter
Classification code:619.1 Pipe, Piping and Pipelines - 631.1 Fluid Flow, General - 741.1 Light/Optics - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 821.4 Agricultural Products - 921.5 Optimization Techniques
Numerical data indexing:Size 1.20e-02m, Size 2.00e-02m, Size 6.90e-02m, Size 8.00e-03m
DOI:10.11975/j.issn.1002-6819.2018.08.008
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 16>
Accession number:20182405313530
Title:Analysis on quality of soymilk processed from different soybean cultivars and evaluation model
Authors:Chen, Chen (1); Guo, Shuntang (1); Li, Jingyan (1); Xu, Jingting (1); Wang, Ruican (1); Zhang, Xinyan (1); Xie, Laichao (1); Shi, Xiaodi (1); Zhang, Hui (1); Wang, Shuming (2); Wang, Qianyu (3)
Author affiliation:(1) Beijing Key Laboratory of Plant Protein and Cereal Processing, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing; 100083, China; (2) Soybean Research Institute, Jilin Academy of Agricultural Sciences, Changchun; 130033, China; (3) Jiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi; 154000, China
Corresponding author:Guo, Shuntang(shuntang@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:291-302
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Northeast is one of the main producing areas of Chinese soybeans, and an important base of raw materials for traditional soybean products. 47 soybean cultivars in northeast China were selected as the materials to clarify the characteristics of different soybean cultivars and the quality of the soymilk processed from them. The physicochemical indexes of the seeds including the crude protein, crude oil, lipoxygenase, fatty acid, calcium and phosphorus contents and the quality indexes of the soymilk such as the soymilk yield, soymilk viscosity, soluble protein contents, total solid contents, sensory evaluation and odor substances were determined. The cultivars with relatively high and low contents of each constituent had also been screened. The correlation between the quality of soymilk and the characteristics of soybean raw materials showed that the flavor of soymilk was positively correlated with LOX activity, oleic acid, linoleic acid and linolenic acid contents. The fat content was negatively correlated with the flavor activity ratio. Factor analysis was used to establish the soymilk quality evaluation model, extracting equations of 4 main factor, calculating the contribution to the comprehensive product quality. The coefficients of the model could be adjusted according to the purpose of processing. The 5 varieties with the highest comprehensive scores were JI45 (9.52), JIYU70 (9.43), JIQING1 (9.28), JIYU66 (9.27), and JIYU102 (9.21). Combining the ranks of soybean physical and chemical indexes, it was found that soymilk quality was the result of comprehensive effects of soybean components. The higher the protein content was, may not the product the better. The varieties with high fat content may not suitable for processing soymilk. This research realized the comprehensive discrimination of soymilk quality and provided the standardization integration of basic data of soybean cultivars in Northeast China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Quality control
Controlled terms:Agricultural products - Crude oil - Linoleic acid - Processing - Proteins
Uncontrolled terms:Comprehensive effect - Comprehensive qualities - Evaluation modeling - Northeast China - Phosphorus contents - Quality evaluation models - Soybean cultivars - Total solid content
Classification code:512.1 Petroleum Deposits - 804.1 Organic Compounds - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 913.4 Manufacturing
DOI:10.11975/j.issn.1002-6819.2018.08.038
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 17>
Accession number:20182405313499
Title:Design and experiment of bionics pit shape grinding roller for improving wear resistance and crushability
Authors:Xi, Peng (1); Cong, Qian (1); Teng, Fengming (1); Guo, Huaxi (1)
Author affiliation:(1) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun; 130025, China
Corresponding author:Cong, Qian(congqian@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:55-61
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Cement is a basic material, which plays an important role in ensuring national economic construction. Cement grinding roller press plays an important role in cement production and grinding process. The grinding roller is the key component on the grinding roller press and the abrasion loss is quite large. Therefore, increasing the wear resistance and reducing abrasion loss of the grinding roller press will bring huge economic benefits to cement production. Organisms have evolved a large number of non-smooth surface structures in the process of natural selection. Such as the scale structure on the surface of the pangolin, the fringe structure on the shell surface, the blocky protuberance structure on the surface of the lizard, etc. These non-smooth structures play an important role in improving wear resistance and reducing abrasion of biological surfaces. In order to improve the wear resistance and fragmentation of cement grinding roller press. Based on the excellent wear resistance and drag reduction characteristics of the non-surface structure. Guided by bionics non-smooth theory. According to the working principle and actual size of the grinding roller press. The bionic pit shape structure with different depth, different diameter, different axial spacing and different circumferential angle designed on the surface of grinding roll. Each factor selected at two levels. The factors of the pits arranged according to the orthogonal experimental design method. The grinding roller machined according to orthogonal experimental design. To do the wear test of the grinding roller after processing carried out. The composition and structure of the test bench are basic the same as the actual roller press. Two relatively rotating grinding rollers driven by an electric motor. The grinding rollers extruded the abrasive quartz sand in the middle of them. The wear condition judged by measuring the quality loss. The test results showed that the reasonable bionic pit structure could significantly improve the wear resistance of the grinding roller. The wear resistance of the grinding roller improved by 29.06% compared with the standard grinding roller. In order to explore the wear mechanism of bionic grinding roller, the force analysis of the grinding roller analyzed by finite element software. The reasonable bionic pit shape structure could effectively reduce the stress in the inner surface and the stress distribution of grinding roller surface. It can also reduce the stress gradient and optimize the force on the grinding roller surface, reduce abrasion and improve wear resistance. The crushing test of the grinding roller carried out according to the orthogonal experimental design. The fragmentation rate of quartz sand used as a criterion for evaluating crushability. The bionic pit structure can effectively improve the crushability of the grinding roller according to the test results. Its crushability increased by 18.7% compared with the standard grinding roll. Combined with the explicit dynamic finite element method to explore the crushing process of grinding roller. It found that the maximum extrusion pressure was an important factor affecting the crushability of grinding roller. It found that the maximum extrusion pressure was an important factor affecting the crushability of grinding roller. It was the best grinding roller with both wear resistance and breakage when the diameter of the pit is 8 mm, the depth of the pit is 2 mm, the distance of the axial pit is 16 mm and the number of circumferential pit is 12. The single particle crush test of the bionic grinding roller carried out and the whole process of quartz sand breakage recorded by high-speed camera. Compared with the standard grinding roll, the bionic pit shape grinding roller can seize quartz sand quickly, form transient stability structure, reduce the sliding probability of quartz sand on the grinding roller surface. Reduced the probability of scratch on the grinding roll surface by the quartz sand. The bionic pit shape structure makes the single point support become multi-point support in the process of extruding quartz sand by grinding roller. The extrusion force dispersed which was the important reason to improve the abrasion resistance and crushability of the grinding roller press.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Tungsten ore treatment
Controlled terms:Abrasion - Biomimetics - Bionics - Biophysics - Cements - Crushing - Design - Design of experiments - Extrusion - Finite element method - Grinding (machining) - High speed cameras - Presses (machine tools) - Quartz - Rollers (machine components) - Sand - Statistics - Surface structure - Testing - Tribology - Wear resistance
Uncontrolled terms:Circumferential angles - Crushability - Economic constructions - Explicit dynamic finite element method - Finite element software - Orthogonal experimental design - Orthogonal experimental design method - Pit shape
Classification code:412.1 Cement - 461.1 Biomedical Engineering - 461.9 Biology - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 533.1 Ore Treatment - 601.2 Machine Components - 603.1 Machine Tools, General - 604.2 Machining Operations - 742.2 Photographic Equipment - 901.3 Engineering Research - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 931 Classical Physics; Quantum Theory; Relativity - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 1.87e+01%, Percentage 2.91e+01%, Size 1.60e-02m, Size 2.00e-03m, Size 8.00e-03m
DOI:10.11975/j.issn.1002-6819.2018.08.007
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 18>
Accession number:20182405313529
Title:Parameter optimization of ultrasonic-heat extraction process of bovine bone oil
Authors:Liu, Wenyuan (1); Jia, Wei (1); Li, Xia (1); Zhang, Chunhui (1, 2); Zheng, Qiankun (2); Li, Yuanliang (3); Li, Min (2); Zhang, Zhaojing (3)
Author affiliation:(1) Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing; 100193, China; (2) Delisi Group Co. LTD, Weifang; 262216, China; (3) Shandong Fengxiang Co., Ltd, Liaocheng; 252400, China
Corresponding author:Zhang, Chunhui(dr_zch@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:283-290
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As an important by-product of poultry industry, bone consisting of bone marrow and the mineralized osseous tissues, is a good source of nutrients such as proteins, fats and minerals. It has long been noted that the improper treatment of bone by-products, such as totally discarded, may cause serious environmental issues. Thus, converting bones into high value-added products has gained more attention in order to reduce the adverse environmental impacts as well as increase the economic benefits. For the traditional heat extraction process of bovine bone oil in current food industry, the extraction rate of oil was low. Ultrasound was capable of producing the cavitation that generated the secondary effects, such as thermal effect and mechanical effect, which resulted in accelerating the diffusion and dissolution of oil components. In order to improve the extraction rate of oil from bovine bones in industrialization production, the ultrasonic-heat technique was investigated. Influences of different operation parameters on the oil recovery were evaluated. And the conditions of the ultrasonic-heat technique used for extraction were optimized by response surface methodology to maximum the oil recovery. Meanwhile, the acid value, the peroxide value and the composition of fatty acid (FA) of bovine oil were analyzed. The obtained results showed that the order of all the factors that affected the extraction rate of bovine bone oil was as follows: heat extraction temperature>heat extraction time>ultrasonic time>ultrasonic temperature>ultrasonic power>the ratio of material to liquid, and the effects of heat extraction temperature and heat extraction time on the extraction rate of bone oil were much higher than that of other factors, and the effect of the ratio of material to liquid on the extraction rate of bone oil was much smaller (P<0.05). The results of the response surface methodology showed that the optimum technological conditions of ultrasonic-heat extraction process of bovine bone oil were as follow: ultrasonic power, 300 W; ultrasonic time, 50 min; ultrasonic temperature, 100℃; heat extraction temperature, 125℃; heat extraction time, 90 min; the ratio of material to liquid, 1: 1. Under these conditions, the bovine oil extraction rate was 98.86%. Compared with the heat extraction process of bovine bone oil in current food industry, the bone oil extraction rate increased by about 12% for the ultrasonic-heat extraction process. Meanwhile, under the optimum technological conditions of ultrasonic-heat extraction process, the acid value (0.80<2.5 mg/g) and the peroxide value (0.03<0.20 g/100g) of bovine oil were both less than the national standard of GB10146-2015. And the contents of FAs of bone oils in the optimum technological conditions were above or equal to those in the traditional heat extraction process (except for C18: 1n9c and the unsaturated fatty acid (UFA)). In bone oils, there were 17 FAs determined, and C18: 1n9c, C16: 0 and C18: 0 were the major FAs of bovine bone oil, approximately accounting for 44%, 23% and 19% of the total FA, respectively. The ratio of UFA and saturated fatty acid (SFA) in bone oil was about 1: 1, and the content of UFA was slightly higher than SFA. This extraction method provides a theoretical and technical guidance for the industrialization production of oils from bovine bones.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Extraction
Controlled terms:Agricultural products - Bone - Byproducts - Environmental impact - Liquids - Mammals - Oil well flooding - Oils and fats - Oxidation - Peroxides - Saturated fatty acids - Surface properties - Ultrasonic testing - Ultrasonics - Unsaturated fatty acids
Uncontrolled terms:Adverse environmental impacts - Bovine bone - Heat extraction - Heat extraction process - Hydrothermal methods - Optimum technological conditions - Parameter optimization - Response surface methodology
Classification code:454.2 Environmental Impact and Protection - 461.2 Biological Materials and Tissue Engineering - 511.1 Oil Field Production Operations - 753.1 Ultrasonic Waves - 753.3 Ultrasonic Applications - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.4 Agricultural Products - 951 Materials Science
Numerical data indexing:Percentage 1.20e+01%, Percentage 1.90e+01%, Percentage 2.30e+01%, Percentage 4.40e+01%, Percentage 9.89e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.037
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 19>
Accession number:20182405313505
Title:Mechanical model for frost heave damage of large-sized canal considering bi-directional frost heave of frozen soil and lining plate frozen shrinkage
Authors:Xiao, Min (1, 2); Wang, Zhengzhong (1, 2, 3); Liu, Quanhong (1, 2); Wang, Yi (1, 2); Ge, Jianrui (1, 2); Wang, Xingwei (1, 2)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; 712100, China; (2) Cold and Arid Regions Water Engineering Safety Research Center, Northwest A&F University, Yangling; 712100, China; (3) State Key Laboratory of Frozen Soil Engineering, Cold and Arid Region Environmental and Engineering Research Institute, CAS, Lanzhou; 730000, China
Corresponding author:Wang, Zhengzhong(wangzz0910@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:100-108
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In vast and cold permafrost regions, concrete lining canals are highly vulnerable to frost heave damage because of the freezing and expansion of foundation soil. Frost heave deformation of canal foundation frozen soil is orthotropic, namely bi-directional frost heave. Bi-directional frost heave of foundation soil consists of frost heave both parallel to temperature gradient direction and perpendicular to temperature gradient direction. As large-sized concrete lining trapezoidal canals have larger cross-section dimension and longer canal slope lining plate than ordinary canals, the mechanism of frost heave damage of large-sized canals is different from medium or small sized ones. Both storage effect of tangential frost heave force along canals concrete lining plates and frozen shrinkage stress of canals concrete lining plates are significant. The reasons for frost heave damage of canals concrete lining plates in cold regions consist of frost heave of canal foundation frozen soil and frozen shrinkage of canals concrete lining plates. As low rainfall and no water diversion in winter in north-western cold and arid regions in China, initial moisture content of canal foundation soil is extremely low. In specific regions with specific meteorological conditions and soil quality conditions, groundwater replenishment becomes dominant influence factor which determines frost heave intensity of each point on canal concrete lining plates. By combining Winkler elastic foundation assumption for canal foundation frozen soil and considering orthotropy of frost heave deformation of frozen soil namely bi-directional frost heave of frozen soil, calculating methods to determine distribution of normal frost heave force and tangential frost heave force on canals concrete lining plates in open-system conditions were proposed. Eventually calculation formulas of internal force of canal concrete lining plates were carried out. Analytic formulas to calculate frozen shrinkage stress of canal lining plates were deduced based on elastic foundation beam theory, and methods for crack resistance checking computations of canal lining plates of large-sized concrete lining trapezoidal canal were proposed. By taking a trapezoidal canal in Gansu Jinghui irrigation district as prototype, the distribution of internal force and frozen shrinkage stress of each section of lining plates were determined. Then the distribution of maximum tensile stress (namely, tensile stress on upper surface of canal lining plates) on canal lining plates and the position coordinate of the most dangerous section were calculated. Contrast analysis results between the situation considering both bi-directional frost heave and frozen shrinkage stress and the situation only considering normal frost heave force irrespective of frozen shrinkage stress showed that the calculated value of maximum section tensile stress according to the latter was notably less than the previously calculated value. Therefore, taking no consideration of the effects caused by bi-directional frost heave of canal foundation frozen soil and lining plate frozen shrinkage in mechanics analysis and frost heave resistance designs of large-sized concrete lining canal was unsafe. While considering both bi-directional frost heave and frozen shrinkage stress, the maximum cross-section tensile stress on shady-slope plate was 2.134 MPa. While considering normal frost heave only and irrespective frozen shrinkage stress, the maximum cross-section tensile stress on shady-slope plate was 1.494 MPa. Thus it can be seen that the calculated values would be smaller if considering normal frost heave only and irrespective frozen shrinkage stress. The research results can provide references for mechanics analysis and frost heave resistance designs of large-sized concrete lining canal.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Canal linings
Controlled terms:Canals - Concretes - Deformation - Flood control - Foundations - Frost effects - Groundwater - Irrigation canals - Linings - Models - Permafrost - Replenishment (water resources) - Shrinkage - Soil mechanics - Stresses - Tensile stress - Thermal gradients
Uncontrolled terms:Concrete linings - Frost heave - Mechanic model - Soil engineering - Temperature stress
Classification code:407.2 Waterways - 412 Concrete - 442.1 Flood Control - 444 Water Resources - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 483.2 Foundations - 641.1 Thermodynamics - 951 Materials Science
Numerical data indexing:Pressure 1.49e+06Pa, Pressure 2.13e+06Pa
DOI:10.11975/j.issn.1002-6819.2018.08.013
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 20>
Accession number:20182405313519
Title:Biogas production and H<inf>2</inf>S content control on semi-continuous anaerobic digestion of rural solid waste
Authors:Zhan, Yong (1); Huang, Ting (1); Dong, Bin (2); Xiong, Dan (1); Zhang, Huanhuan (1)
Author affiliation:(1) School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai; 200093, China; (2) School of Environmental Science and Engineering, Tongji University, Shanghai; 200092, China
Corresponding author:Dong, Bin(dongbin@tongji.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:206-213
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The treatment and disposal technology of rural solid waste (RSW) through anaerobic digestion has become a hot research at home and abroad. However, the generation of foul odors, especially H<inf>2</inf>S, seriously affects the utilization rate of biogas and the service life of equipment, and causes environmental pollution during the anaerobic digestion process. This paper made an in-depth study on the anaerobic digestion of rural solid waste and the inhibition of H<inf>2</inf>S production. Completely stirred tank anaerobic reactors were used to carry out anaerobic digestion experiments on rural solid waste. The effects of different organic loading rate (OLR) on the degradation performance, gas production and stability of the anaerobic digestion system were studied, to find the optimum organic loading rate of anaerobic digestion of rural solid waste. At the same time, in order to reduce the H<inf>2</inf>S content of the malodorous gas produced by the anaerobic digestion process, the batch anaerobic digestion experiment with different proportions of solid waste and concentrated sludge (CS) was designed to observe the changes of H<inf>2</inf>S content in biogas. The results show that when the organic loading rate is 3 to 6 g/(L·d), the anaerobic digestion of the solid waste in the reactor can be stably operated, and the balance between the acid-producing phase and the methanogenic phase can be achieved. When the organic loading rate is 7 g/(L·d), the methane production rate is reduced to 325 mL/g and the volatiles solid degradation rate is 62.55%. At this time, the VFA<inf>S</inf>/TA is maintained between 0.4 and 0.8, and acidification may occur not very stable. Until the organic loading rate increased to 8 g/(L·d), the pH value decreased significantly, volatile fatty acid increased sharply, and the system started to run rancid and could not be operated stably. When the organic loading rate is 4 g/(L·d), the microbial degradation of the added solid waste is relatively sufficient, and the utilization rate of microorganisms is relatively high. Therefore, the increase of methane production is the most significant, the system is stable and the utilization rate of organic loading rate is higher when the organic loading rate is 4 g/(L·d). With the increase of the concentration of concentrated sludge, the content of H<inf>2</inf>S decreases obviously. When the concentration of VS<inf>RSW:</inf>VS<inf>CS</inf>were 1: 0.25, 1: 0.5, 1: 0.75, the degradation rate of H<inf>2</inf>S were 85.15% and 88.18%, 96.20%, respectively. The addition of sludge has a strong inhibitory effect on the production of H<inf>2</inf>S in the system, which has a significant effect on the utilization of biogas during the anaerobic digestion of domestic waste. Combined with the analysis of the composition of rural solid waste and concentrated sludge, the metal contents of the two materials are not obvious difference, but the humus content in the concentrated sludge was more than that of the rural solid waste, therefore, the humus content in the sludge may affect the production of H<inf>2</inf>S in the anaerobic digestion system.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Loading
Controlled terms:Anaerobic digestion - Biodegradation - Biogas - Concentration (process) - Degradation - Digestive system - Fermentation - Methane - Sludge digestion - Soils - Solid wastes - Sulfur compounds - Volatile fatty acids - Waste disposal - Wastes
Uncontrolled terms:Anaerobic digestion process - Different proportions - Environmental pollutions - Humic acid - Hydrogen sulphate - Microbial degradation - Organic loading rates - Treatment and disposal
Classification code:452.2 Sewage Treatment - 452.4 Industrial Wastes Treatment and Disposal - 461.2 Biological Materials and Tissue Engineering - 461.8 Biotechnology - 483.1 Soils and Soil Mechanics - 522 Gas Fuels - 691.2 Materials Handling Methods - 802.2 Chemical Reactions - 804.1 Organic Compounds
Numerical data indexing:Percentage 6.25e+01%, Percentage 8.52e+01%, Percentage 8.82e+01%, Percentage 9.62e+01%, Specific_Volume 3.25e-01m3/kg
DOI:10.11975/j.issn.1002-6819.2018.08.027
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 21>
Accession number:20182405313513
Title:Coupling coordinative degree analysis on benefit of water and soil erosion control and development of ecological agriculture
Authors:Zhang, Huili (1); Cai, Jie (1); Xia, Xianli (1)
Author affiliation:(1) College of Economic & Management, Northwest A&F University, Yangling; 712100, China
Corresponding author:Xia, Xianli(xnxxli@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:162-169
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:High importance has been put by government on the issues of water and soil erosion which are the key factors for sustainable development of agriculture in the Loess Plateau. There is a considering number of models to resolve this problem after several year's practice. From the perspective of relationship and coupling of agricultural eco-economic system, some crisis is hidden in the process of establishing benign coupling relationship of agricultural eco-economic system. To achieve sustainable development in the area of Loess Plateau, it is necessary to build win-win situation among ecology, economy and society. In this study, we selected panel data from 16 prefecture-level cities in Shaanxi, Gansu and Ningxia Province from 2007 to 2014. On the basis of previous researches, the subjective and objective comprehensive weighting method named Analytic Hierarchy Process (AHP) and Variation Coefficient Method (CPA) were adopted to measure the weights of the evaluation indicators from the qualitative and quantitative perspectives. Based on the coupling degree model, the degree of mutual influence between the water and soil erosion management system and the ecological agriculture development system was explored from the perspective of the geomorphological features and prefecture-level cities for understanding the consistency of the system development situation as a whole. Based on the coordination degree model, the internal elements relationship between water and soil erosion management system and ecological agricultural development system was explored from the perspective of geomorphological features and prefecture-level cities for understanding the interaction relationship and coordination of every factor under different coupling stages. Using the bivariate spatial autocorrelation model, the coupling coordinative degree between the benefits of soil and water loss treatment and the level of ecological agriculture were taken as a measurement index. The index of measuring level of coupling degree of water and soil erosion control efficiency and ecological agriculture development: global and local degree Moran I indexes were calculated using Geoda software. Combined with LISA clustering analysis, in this paper, we analyzed the spatial distribution correlation of coupling degree between water and soil erosion control efficient benefits and ecological agriculture development to explore the coupling coordination state and development trend between water and soil erosion management and ecological agriculture development. Also, in this paper, we wanted to find the general laws of coupling and coordination between two subjects in order to provide scientific basis for policy development. The results indicated that the coupling level of water and soil loss erosion control benefits and the development level of ecological agriculture were generally high in the research area, but the degree of coordination was low and the development trend of coupling and coordination was slow, it presented a "low level equilibrium" state. The overall spatial agglomeration was gradually strengthened, but the two levels were severely differentiated. There was a lack of necessary "radiation hubs" between the "high-high" agglomeration areas and "low-low" agglomeration areas. New agglomeration poles were badly needed to be trained. Based on the above conclusions, we proposed the following policy recommendations: 1) maintaining the momentum of coupling development, 2) radiating development models, technology, and experience actively, 3) increasing mutual support and cooperation among regions, 4) strengthening pilot research, 5) exploring key factors that stop coordinated development from multiple perspectives, 6) breaking through the bottleneck of coordinated development, 7) cultivate new agglomeration poles, 8) increasing system resilience, and 9) easing spatial agglomeration.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Soil conservation
Controlled terms:Agglomeration - Agriculture - Analytic hierarchy process - Autocorrelation - Couplings - Ecology - Environmental protection - Erosion - Landforms - Planning - Poles - Sediments - Soil surveys - Soils - Spatial variables measurement - Sustainable development - Water treatment
Uncontrolled terms:Coordinative degree - Eco agricultures - Shaanxi, Gansu and Ningxia - Soil erosion controls - Spatial autocorrelations
Classification code:408.2 Structural Members and Shapes - 445.1 Water Treatment Techniques - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 912.2 Management - 921 Mathematics - 943.2 Mechanical Variables Measurements - 961 Systems Science
DOI:10.11975/j.issn.1002-6819.2018.08.021
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 22>
Accession number:20182405313508
Title:Characteristics of soil moisture infiltration in shrub land and terraces dryland in Karst peaks hillslopes
Authors:Xu, Qinxue (1, 2); Li, Chunmao (2); Chen, Hongsong (1); Fu, Zhiyong (1); Wu, Pan (2); Wang, Kelin (1)
Author affiliation:(1) Key Laboratory of Agro-ecological Process in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Science, Changsha; 410125, China; (2) Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin; 541004, China
Corresponding author:Chen, Hongsong(hbchs@isa.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:124-131
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Vulnerable ecosystems in Karst area are sensitive to external environmental changes, and human activities have affected the vegetation environment and hydrological water cycle to some extent. It is of great significance to formulate soil and water conservation measures and groundwater management measures, predict soil erosion, and explore the impacts of human activities and disturbance levels on the soil infiltration in the fragile ecology in the Karst area. Peak cluster sloping field in Karst area is a typical landform in the southwest in China; due to natural, historical and artificial reasons, the economic benefits of agriculture are relatively backward, and the ecosystem has seriously deteriorated to the fragile state due to the impact of rocky desertification. In order to expand the benefit of agricultural production, the villagers spontaneously carried out the behaviors of changing slope cropland into terraces, and converting farmland to slope cropland. Therefore, a unique landscape pattern has also been formed, which produces good ecological benefits. In this paper, the infiltration process of different soil layers in shrub land and terraced field was determined by ring method, and the influencing factors of soil infiltration were analyzed by measuring the soil properties. In addition, the infiltration process was fitted by different mathematical models. The results showed that: 1) Shrub land has better infiltration performance than terraces, and the average infiltration coefficient (0.84) of natural slopes is 1.3 times that of terraced fields (0.66). The average initial infiltration rate and average stable infiltration rate of terraces at 30-60 cm are only 4.3% and 4.4% of the shrub land respectively. There is distinct infiltration barrier at 30-60 cm soil layer in the terraced field, and the reason is mainly as follows: Firstly, terraces land itself has enough soil clay content; secondly, artificial tillage will make the upper and lower soil mixed, so the finer particles migrate easily down; lastly, under the action of gravity, the soil is transported or migrated to the underground space along the path of the dissolving channel that develops on the surface of the bedrock. 2) The infiltration properties of shrub land and terraced fields are significantly correlated with soil properties. The contents of sand and organic matter in the shrub land were significantly higher than those in the terraced fields. The differences of soil properties between different soil layers in shrub land are not distinct, while the soil properties at 0-30 and 30-60 cm soil layers in terraced farmland are obviously different, which means the soil bulk density of the lower layer is very large and the soil porosity is small. 3) The fitting effect of Horton model on shrub land and terraced farmland is better, and the general accuracy for the upper layer is better than that for the lower layer, while the Kostiakov model and Philip model are poor in fitting effect. Infiltration models can better reflect the different infiltration processes. This research can provide a theoretical basis for further study on the soil moisture management and hydrological models in Karst sloping fields, and promote understanding of the relationship between soil infiltration and human activities.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Infiltration
Controlled terms:Ecosystems - Farms - Groundwater - Landforms - Models - Porosity - Soil conservation - Soil moisture - Water conservation - Water management
Uncontrolled terms:Agricultural productions - Groundwater management - Infiltration coefficients - Karst - Soil and water conservation measures - Terraces - Vegetation environments - Vulnerable ecosystems
Classification code:444 Water Resources - 444.2 Groundwater - 454.3 Ecology and Ecosystems - 481.1 Geology - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 4.30e+00%, Percentage 4.40e+00%, Size 3.00e-01m to 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.08.016
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 23>
Accession number:20182405313512
Title:Monitoring model of slope internal deformation and instability based on smart magnetic rock
Authors:Jiang, Shenghua (1, 2); Liu, Xiaochun (3); Sun, Weihe (1); Song, Yunhao (1); Hu, Man (1); Wang, Shiji (1)
Author affiliation:(1) College of Engineering and Technology, Southwest University, Chongqing; 400715, China; (2) School of Civil and Environmental Engineering, Nanyang Technological University, Singapore; 639798, Singapore; (3) School of Civil Engineering, Central South University, Changsha; 410075, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:156-161
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There exist a number of slope deformation monitoring methods, but as for most of methods, only the surface deformation can be used to measure slope, while in the practical engineering the slope internal deformation is very important to determine the sliding surface of a slope. Although the slope internal deformation can be monitored by means of few technologies, it is very difficult to arrange and maintain these sensors. Also, the existing slope internal deformation sensors are easily influenced by extreme harsh environment, and the arrangement of equipment is not convenient for the internal deformation monitoring. In this study, slope deformation monitoring system was combined with smart magnetic rock and full tensor magnetic gradiometer. Accordingly, the simplified algorithm of magnetic survey was given for slope deformation monitoring method based on the magnetic gradient tensor and magnetic dipole, and consequently, the three dimensional positions of smart magnetic rock can be obtained in real time. Through the displacement change of smart magnetic rock in the deep internal position of slope, the sliding process and instability of slope can be evaluated. The thrust load was crucial for slope sliding when the slope sliding was the driving force type or caused by the load on the slope top. Therefore, the physical model test by driving force was used as landslide simulation system to verify the slope internal deformation monitoring system by means of smart magnetic rock and full tensor magnetic gradiometer. The landslide simulation system was established by aluminum alloy model box, separated jack and force sensor, and the sliding of slope was realized by applying driving force at the back of slope. The results showed that when the driving force was 2 500 N, there existed the turning on the curve of driving force versus critical points' horizontal displacements measured by soft film size. When the driving force was ranged from 2 500 to 3 100 N, six critical points' horizontal displacements increased drastically with instability failure of slope. With regard to the smart magnetic rock, there also existed the turnings on the curve of the relative distances from smart magnetic rock to reference points and smart magnetic rock's horizontal displacements versus driving force. And then both the relative distances from smart magnetic rock to reference points and smart magnetic rock's horizontal displacements changed sharply. It showed that the slope deformation development and slope instability evaluation can be judged by relative distances from smart magnetic rock to reference points and smart magnetic rock's horizontal displacements, and the results were in accord with the monitoring assessment by soft film size, which can be used as reference in the further study and practical engineering monitoring. It also showed that the simplified algorithm of magnetic survey for three dimensional positions of smart magnetic rock and slope internal monitoring were effective and useful. And it was suggested that the magnetic interaction of smart magnetic rocks should be studied in order that the smart magnetic rock network can be established for slope internal deformation monitoring in the practical engineering.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Monitoring
Controlled terms:Aluminum alloys - Deformation - Geological surveys - Landslides - Magnetic fields - Magnetism - Magnetometers - Rocks - Slope protection - Slope stability - Tensors
Uncontrolled terms:Horizontal displacements - Magnetic gradient tensor - Magnetic interactions - Magnetic rocks - Monitoring assessment - Physical model test - Practical engineering - Simplified algorithms
Classification code:406.2 Roads and Streets - 481.1 Geology - 541.2 Aluminum Alloys - 701.2 Magnetism: Basic Concepts and Phenomena - 921.1 Algebra - 942.3 Magnetic Instruments
DOI:10.11975/j.issn.1002-6819.2018.08.020
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 24>
Accession number:20182405313522
Title:Characterization and risk assessment of heavy metal pollution in agricultural soils in Three Gorge Reservoir Area
Authors:Wang, Jinxia (1, 2); Li, Xieling (2); He, Qingming (3); Chen, Yucheng (1); Cai, Qing (2); Luo, Le (2); Zhao, Xue (2)
Author affiliation:(1) Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Southwest University, Chongqing; 400715, China; (2) Chongqing Vocational Institute of Engineering, Chongqing; 400037, China; (3) Taizhou University, Taizhou; 225300, China
Corresponding author:Chen, Yucheng(372505096@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:227-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Over the past several decades, a large amount of agricultural production materials (such as chemical fertilizers, organic fertilizers, pesticides and agricultural films) has been used to increase the output of agricultural products. Therefore, the problems of soil pollution, especially heavy metal pollution in soils, have become problems. Those problems have exerted direct or indirect adverse effects on food safety, and health of human and ecosystem. Therefore, the problem of heavy metal pollution in agricultural soils has become a research hot spot in environmental studies and has since received more attention. Chongqing is an important agricultural production base in the Three Gorges Reservoir Area. The environmental quality of soils in Chongqing area directly affects the food safety and health of the local residents. Although there have been some studies on the quality of agricultural soils, few studies have investigated the status of heavy metal pollution in the agricultural areas of Chongqing. In order to understand the status of heavy metal pollution and the level of its environmental risk in typical agricultural areas in Chongqing, 160 surface soil samples (0 - 20 cm) were collected from the farm field of eight agricultural areas (Tongliang, Yunyang, Wanzhou, Fengdu, Chengkou, Dianjiang, Nanchuan and Jiangjin) based on the "Technical Specifications for Soil Environmental Monitoring (HJ/T 166-2004)". The concentrations of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in these soil samples were analyzed according to the "Environmental quality standard for soils GB 15618-1995". The status and differences in pollutions of these weight heavy metals among various regions were compared. In addition, geo-accumulation index and potential ecological risk index were used to evaluate the accumulation characteristics and potential environmental risk levels of heavy metals in the studied regions. The results showed that the average contents of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in the soils of the typical agricultural areas in Chongqing were respectively 6.110, 0.146, 96.860, 35.346, 0.050, 30.596, 24.723, and 77.286 mg/kg soil. The average concentration of all these eight heavy metals in the agricultural soils of studied areas did not exceed the Tier II limit specified in GB 15618-1995. In addition, compared with the background level of the soils, the levels of Cd, Cr, Cu, Hg and Zn showed significant (P < 0.01) differences, while the levels of As, Ni and Pb showed insignificant (P > 0.05) differences. Furthermore, the levels of Cr in all areas showed significant (P < 0.05) differences. Moreover, the concentrations of all these eight heavy metals in soil from Chengkou County showed significant (P < 0.05) differences and the geoaccumulation index values, i.e., the average value of geo-accumulation index, of all eight heavy metals were less than 0, indicating that the overall condition of the soils was not polluted. However, the geoaccumulation index values of certain individual samples were between 0 and 1, indicating that the heavy metals were accumulated at some sampling points. In particular, the level of Pb accumulation was the lowest, with the presence of mild pollution in 3.75% of the samples. The proportions of samples showing mild pollution of Cd, Ni, Hg, As, Zn and Cr were 8.75%, 11.25%, 11.25%, 12.5%, 12.5% and 15%, respectively, but the highest proportion of samples (42.5%) showed mild pollution of Cu. Therefore, the level of potential ecological risk posed by individual heavy metals was Hg> Cd> As> Hg> Cu> Ni> Cr> Zn. Specifically, as a heavy metal with a medium level of ecological risk, the average Eir value of Hg was 43.8, greater than 40. In addition, the average Eir values of all other heavy metals were less than 40, indicating the level of ecological risk posed by them was low. The overall mean potential ecological risk index (RI) of the eight heavy metals was 108, less than 135, which was at a level of low ecological risk. The results of this comprehensive study showed that Cd, Cr, Cu, Hg and Zn were accumulated to a certain extent in the typical agricultural areas of Chongqing and were manifested as a combined accumulation of multiple heavy metals. In particular, the accumulation of Cr was widely found, while Hg was the main element affecting the comprehensive ecological risk posed to the agricultural soils in Chongqing. Nevertheless, the overall ecological risk posed to the soils of typical agricultural areas in Chongqing was low. Based on a relatively large-scale and updated investigation and assessment of the environmental quality of heavy metals in the soils of typical agricultural areas in Chongqing, in this study, we analyzed the status of heavy metal pollution in the soils of Chongqing, and would provide a scientific basis for the prevention and treatment of soil pollution in Chongqing.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Soil pollution
Controlled terms:Agricultural products - Chromium - Fertilizers - Films - Food safety - Heavy metals - Mercury (metal) - Pollution - Risk assessment - Safety engineering - Soil surveys - Soils - Zinc
Uncontrolled terms:Accumulation characteristics - Agricultural areas - Agricultural productions - Environmental quality standards - Potential ecological risk - Technical specifications - Three Gorge reservoir - Three gorges reservoir area
Classification code:461.6 Medicine and Pharmacology - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 543.1 Chromium and Alloys - 546.3 Zinc and Alloys - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 804 Chemical Products Generally - 821.4 Agricultural Products - 914 Safety Engineering - 914.1 Accidents and Accident Prevention
Numerical data indexing:Percentage 1.12e+01%, Percentage 1.25e+01%, Percentage 1.50e+01%, Percentage 3.75e+00%, Percentage 4.25e+01%, Percentage 8.75e+00%, Size 0.00e+00m to 2.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.08.030
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 25>
Accession number:20182405313521
Title:Dissolved oxygen prediction in aquaculture based on ensemble empirical mode decomposition and reconstruction using run test method
Authors:Huan, Juan (1); Cao, Weijian (1); Qin, Yilin (1, 2); Wu, Fan (1)
Author affiliation:(1) School of Information Science & Engineering, Changzhou University, Changzhou; 213164, China; (2) Changzhou Technical Institute of Tourism & Commerce, Changzhou; 213023, China
Corresponding author:Qin, Yilin(qinyilin101@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:220-226
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Dissolved oxygen (DO) is one of the key water quality parameters for water products, which reflects changes in water quality in aquaculture. To increase prediction accuracy of dissolved oxygen (DO) in aquaculture, a hybrid model based on ensemble empirical mode decomposition (EEMD), reconstruction using runs test method, the appropriate forecasting method and superposition by BPANN was proposed. Firstly, the dissolved oxygen sequence was decomposed into a series of components by EEMD. EEMD performs very well in noise reduction and detail features extraction. Original dissolved oxygen datasets were decomposed to 9 IMFs and a Res. Then these components were reconstructed into high frequency component, intermediate frequency and low frequency component by the runs test method, which centralized the characteristic information and reduced the difficulty of predicting. Thirdly, based on the changed characteristics of each sequence, the appropriate prediction method was selected. According to the characteristics of high frequency component, which fluctuated violently and varied complicatedly, the least squares support vector machine (LSSVM) optimized by particle swarm optimization (PSO) was used to predict this term because this method had high accuracy and adaptability to predict. Intermediate frequency component was forecasted by extreme learning machine (ELM) because this component presented a periodic characteristic. The fluctuation of low frequency term was gentle and periodic, so it could be modeled by nonlinear regression method. Finally, the predicted values of DO datasets were calculated by using BPANN to reconstruct the forecasting values of all components, which ensured good fitting effect and stability. The model adopted BPANN nonlinear superposition to replace simple adaptive superposition, which achieved better fitting effect. This model was tested in Daitou Huangjiadang Special Aquaculture Farm in Liyang City, Jiangsu Province. Based on the prediction model, the dissolved oxygen changing was predicted for aquaculture pond during June 23 to June 24, 2016. The experimental results demonstrated that the proposed combinatorial prediction model had better prediction effect than the ELM and LSSVM. When it predicted the next 12, 24, 36 h dissolved oxygen values by using the proposed combinatorial prediction model, the root mean square error (RMSE) of the proposed combination prediction model was 0.088 6, 0.093 1 and 0.095 7, respectively, mean absolute errors (MAE) were 0.066 6, 0.071 2 and 0.076 9, respectively; and mean absolute percentage errors (MAPE) were 0.008 9, 0.013 1 and 0.014 2. When dissolved oxygen values of next 48 h were predicted, the RMSE, MAPE, and MAE of the proposed combination prediction model were 0.099 2, 0.078 and 0.015 5, respectively. The RMSE, MAPE and MAE for dissolved oxygen value of the standard extreme learning machine (ELM) were 0.1581, 0.111 2 and 0.027 6, respectively. Three indexes of LSSVM were 0.134 4, 0.102 6 and 0.021 3, respectively, under the same experimental conditions. The proposed model performs well in terms of all the evaluation indexes, so the proposed model is highly competitive with the compared models. It is obvious that the proposed hybrid model has high forecast accuracy and is proven to be an effective way to predict DO.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Dissolved oxygen
Controlled terms:Aquaculture - Biochemical oxygen demand - Dissolution - Errors - Forecasting - Knowledge acquisition - Least squares approximations - Mean square error - Models - Noise abatement - Particle swarm optimization (PSO) - Petroleum reservoir evaluation - Regression analysis - Support vector machines - Testing - Water quality
Uncontrolled terms:Ensemble empirical mode decomposition - Ensemble empirical mode decompositions (EEMD) - High frequency components - Least squares support vector machines - Mean absolute percentage error - Non-linear regression method - Prediction model - Runs tests
Classification code:445.2 Water Analysis - 512.1.2 Petroleum Deposits : Development Operations - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 751.4 Acoustic Noise - 802.3 Chemical Operations - 821.3 Agricultural Methods - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Time 1.30e+05s, Time 1.73e+05s
DOI:10.11975/j.issn.1002-6819.2018.08.029
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 26>
Accession number:20182405313528
Title:Performance of cold storage with ethylene glycol as secondary refrigerant and its application on preservation of 'Huangguan' pear
Authors:Sun, Jing (1, 2); Chen, Quan (1, 2); Wang, Ping (1); Wang, Xizhuo (1, 2); Sun, Jie (1, 2); Cheng, Qinyang (1, 2); Cao, Jiankang (3)
Author affiliation:(1) Institute of Agriculture Product Processing Engineering, Chinese Academy of Agricultural Engineering, Beijing; 100121, China; (2) Key laboratory of Agro-Products Postharvest Handling, Ministry of Agriculture, Beijing; 100121, China; (3) College of Food Science and Nutritional Engineering, China Agricultural University, Beijing; 100083, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:276-282
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The cold storage facility exhibited features of energy wasting and higher running cost. In underdeveloped regions that became one of the most important reasons to backward construction of storage and preservation facility of fruit and vegetable. This problem was obstacle for sound development of storage and keeping-fresh industry of fruit and vegetable in China. In order to solve the problem above, and accelerate the construction of cold storage facility in site of production, it would build new energy-saving cold storage facility. The cold storage with ethylene glycol as secondary refrigerant was developed. The newly developed cold storage was composed of 3 circle systems, i.e. compressor refrigeration system, secondary refrigerant cycle system, and cold storage room refrigeration system. The phase-changed material was ethylene glycol, which was widely used in ice-storage air-condition. For exploring possibility of cold storage with ethylene glycol as secondary refrigerant for storage and preservation of fruit, performance, storage and preservation effects, and running cost of the new cold storage were analyzed. To detect performance, temperatures at different sites in the cold storage room and evaporator output draught were measured. Over the period of the experiments, average temperature at 5 test sites of the newly developed freezer is 0.18-0.32℃, while the same index of control cold storage is -0.10-1.00℃. The maximum temperature difference of the newly developed refrigerator among test sites is 0.8℃, less than 1.5℃ of control cold storage. Temperature fluctuation range of evaporator output draught of the newly developed cold storage is -0.8 - -0.2℃, less than that of control cold storage. All these results indicate that cold storage with ethylene glycol as secondary refrigerant shows preferable temperature stability and uniformity, which is useful to guarantee good storage quality of fruit. To analyze storage and preservation effects, both newly developed freezer and control cold storage were used to store Huangguan pear, and the postharvest quality was detected, such as weight loss, soluble solids content, rot rate, and brown heart rate. Weight loss and brown heart rate of Huangguan pear stored by the newly developed refrigerator are smaller than those by control cold storage, and there is no significant difference between cold storage with ethylene glycol as secondary refrigerant and control cold storage in storage effects of Huangguan pear. The power consumption of a cold storage with ethylene glycol as secondary refrigerant with 30 t capacity is about 7 523.12 kW·h, which is a little higher than that of control cold storage. Using peak and valley price, electricity bill of developed cold storage is only 75% of that of control cold storage. Overall, compared with control cold storage, the newly developed cold storage with ethylene glycol as secondary refrigerant shows good performance, satisfactory fresh-keeping effect, and lower running cost, which indicates this developed storage facility is suitable for storage and preservation of fruit in area using peak and valley price policy.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Cold storage
Controlled terms:Costs - Energy conservation - Ethylene - Ethylene glycol - Evaporators - Freezing - Fruits - Heart - Polyols - Quality control - Refrigerants - Refrigeration - Refrigerators - Temperature - Vegetables - Wood preservation
Uncontrolled terms:'Huangguan' pear - Cold-storage facilities - Maximum temperature differences - Refrigeration system - Secondary refrigerant - Soluble solids content - Temperature fluctuation - Temperature stability
Classification code:461.2 Biological Materials and Tissue Engineering - 525.2 Energy Conservation - 641.1 Thermodynamics - 644.1 Refrigeration Methods - 644.3 Refrigeration Equipment and Components - 802.1 Chemical Plants and Equipment - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 811.2 Wood and Wood Products - 821.4 Agricultural Products - 911 Cost and Value Engineering; Industrial Economics - 913.3 Quality Assurance and Control
Numerical data indexing:Percentage 7.50e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.036
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 27>
Accession number:20182405313506
Title:Improving frost resistance of concrete mixed with aeolian sand powder based on microscopic characteristics
Authors:Li, Genfeng (1); Shen, Xiangdong (1); Zou, Yuxiao (1); Gao, Bo (1)
Author affiliation:(1) Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot; 010018, China
Corresponding author:Shen, Xiangdong(ndsxd@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:109-116
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this study, the utilization of aeolian sand cementitious properties, the development of new cementitious materials, and the durability of concrete under sulfate environment are combined together. Based on the test of compressive strength and splitting tensile strength of aeolian sand powder concrete, the effect of freezing thawing and salt leaching coupling on the microscopic characteristics of aeolian sand powder concrete was studied. The aeolian sand powder concrete specimens (100 mm × 100 mm × 400 mm) with strength grade of C35 and C25 were used to perform the freezing resistance test after immersed in 0%, 3% and 6% magnesium sulfate solution (20±2℃) for 4 d, and the initial dynamic elastic modulus and mass were measured. Then the minimum and maximum temperature of the specimens center were set at -17 and 5℃, respectively, each freeze-thaw cycle was ensured to be completed within 3 h, and the transition time between freezing and thawing was 8 min; and the relative dynamic elastic modulus and mass loss rate were measured after 25 freeze-thaw cycles. When the specimen relative dynamic elastic modulus decreased to 60% or the mass loss rate by 5%, the trial was stopped. At the same time, to observe the morphology and hydration products, the solidified slurry was selected at the central part of the test block before and after the freeze-thaw cycle test, then the hydration of samples was terminated by ethanol, and then the samples were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). NMR (nuclear magnetic resonance) analysis was performed for aeolian sand powder concrete (diameter × height: 50 mm × 50 mm), and then its microscopic pore characteristics were analyzed. The results show that the incorporation of aeolian sand powder can significantly improve the frost resistance of concrete, and to increase the strength grade appropriately is beneficial to improve the frost resistance of aeolian sand powder concrete. The aeolian sand powder concrete with strength grade C35 in 6% magnesium sulfate solution was subject to 425 freeze-thaw cycles, the appearance was intact, and the relative dynamic elastic modulus decreased to 43.9%. The relative elastic modulus of aeolian sand powder concrete decreased with the number of freeze-thaw cycles at the beginning and then turned to stable, and finally declined to the destruction. Compared with the reference group, the ettringite (AFt) and the calcined hydrated product gypsum (CaSO<inf>4</inf>) were produced. With the swelling properties of ettringite and gypsum, cracks in aeolian sand powder concrete due to frost heaving stress were filled, and the number of harmful and more hazardous holes in concrete was 29.78% lower than that in ordinary concrete. In 6% magnesium sulfate solution, the porosity of C35-15 aeolian sand powder concrete was 40.9% lower than that of the reference group, the irreducible fluid saturation was 32.7% higher, the permeability was lowered by 98.7%, the total pore volume was reduced, the proportion of small holes was increased, the impermeability was improved, the density of the structure was significantly improved, and the frost resistance was enhanced. This has very important social and practical significance for the development of aeolian sand industries, environmental governance and improvement, and the application of aeolian sand powder concrete in water conservancy and hydropower projects. It has significant economic benefits in the contemporary era.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Concrete testing
Controlled terms:Calcium compounds - Compressive strength - Concretes - Elastic moduli - Energy dispersive spectroscopy - Field emission microscopes - Freezing - Frost resistance - Gypsum - Hydration - Indium compounds - Magnesium compounds - Magnesium powder - Microstructure - Nuclear magnetic resonance - Sand - Scanning electron microscopy - Sodium sulfate - Spectrum analysis - Sulfur compounds - Tensile strength - Thawing - Water management
Uncontrolled terms:Durability of concretes - Energy dispersive spectroscopies (EDS) - Energy spectrum analysis - Environmental governances - Field emission scanning electron microscopy - Magnesium sulfate solution - Microscopic characteristics - Splitting tensile strength
Classification code:412 Concrete - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 542.2 Magnesium and Alloys - 741.3 Optical Devices and Systems - 804.2 Inorganic Compounds - 951 Materials Science
Numerical data indexing:Percentage 0.00e+00%, Percentage 2.98e+01%, Percentage 3.00e+00%, Percentage 3.27e+01%, Percentage 4.09e+01%, Percentage 4.39e+01%, Percentage 5.00e+00%, Percentage 6.00e+00%, Percentage 6.00e+01%, Percentage 9.87e+01%, Size 4.00e-01m, Size 5.00e-02m, Time 1.08e+04s
DOI:10.11975/j.issn.1002-6819.2018.08.014
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 28>
Accession number:20182405313525
Title:Evaluation on livability of living space based on multiple functions of land use at county level
Authors:Huang, An (1, 2); Xu, Yueqing (1, 2); Liu, Chao (1, 2); Hao, Jinmin (1, 2); Sun, Piling (1, 2); Zheng, Weiran (1, 2); Lu, Longhui (1, 2)
Author affiliation:(1) College of Land Science and Technology, China Agricultural University, Beijing; 100193, China; (2) Key Laboratory for Agricultural Land Quality, Monitoring and Control, Ministry of Land and Resources, Beijing; 100193, China
Corresponding author:Xu, Yueqing(xmoonq@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:252-261
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The livability evaluation of living space was an important topic, which had important guiding significance for improving the livability of living space.This study aimed to explore the theoretical logical relationship between the multi-function of land use and livability of living space, and make use of the research about multi-function of land use for the optimization practice of livability of living space. So, this paper discussed the theoretical logical relationships between multiple functions of land use and livability of living space from the perspective of human needed products and services supplied by land use, and the evaluation index system was built based on the relationship and previous research. And then, the scheme of index spatialization was designed based on the technology of geographical information system(GIS) and remote sensing(RS). At the same time, multi-source data like remote sensing, survey, statistical and other spatialdataset were integrated by analytic hierarchy process (AHP) to quantify the spatial distribution of living space in ZhangbeiCounty, Hebei Province. The results showed that the livability of living space in ZhangbeiCounty presented the trend that the high value center was concentrated in the ZhangbeiTown and the subcenterwas distributed in Ertai-ShagouTown. The living space area above relatively strong levelwas only 2.42% of all county area.The spatial distribution characteristics of 3 types of land use were significantly difference;livingbearing function presented a trend like network distribution takingmain traffic trunk line as high value axis and ZhangbeiCounty as high value center. Living support function presented 2 groupsof high value centerscontaining the ZhangbeiTownand the north of YoulougouTown, and Ertai-shagouTown. The high value center of mental purification function was distributed in the ZhangbeiTown and the subcenterwas distributed in the area along the southwest of ZhangbeiTown to DaheTown and Ertai-shagouTown. There was a large difference in the distribution of livability between towns and villages. Most of the areas of livability space in town land were above the moderate level, especially, the area the livability level of which belonged to the higher and highest accounted for 78.37% of the total area of the town land, and meanwhile, accounted for 74.94% of the total area with higher and highest level of living space. This area was mainly distributed in the town of Zhangbei, Ertaiand Shagou, and YoulougouVillage. Most of the livability areas in rural land were under the moderate level, and the area oflower and lowest level accounted for 78.39% of the total area of the rural land, whatwas more, accounted for 95.32% of the total area with lower and lowest level of living space. This area was mainly concentered in the town ofHailiutu, Erquanjing, Dahe, Danjinghe, and Liangmianjing. The spatial difference of the functional elements of land use was the main reason to the difference in livability of living space. So, according to the above results, some conclusions can be drawn in this research. The villages, which containlarge lower and lowest livability space area, are the key areas of primary concern inthe implementation process of the "Revitalizing the countryside" strategy; what's more, the theory and method of land use multi-function can be applied to the study of livability evaluation of living space.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Land use
Controlled terms:Analytic hierarchy process - Function evaluation - Information systems - Information use - Remote sensing - Rural areas - Space optics - Spatial distribution
Uncontrolled terms:Geography information systems - Livability evaluation - Living spaces - Multiple function - Rural regions - Zhangbei county
Classification code:403 Urban and Regional Planning and Development - 656.1 Space Flight - 903.3 Information Retrieval and Use - 921 Mathematics - 921.6 Numerical Methods - 961 Systems Science
Numerical data indexing:Percentage 2.42e+00%, Percentage 7.49e+01%, Percentage 7.84e+01%, Percentage 9.53e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.033
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 29>
Accession number:20182405313501
Title:Simulation and verification of effect of throttle opening on temperature rise characteristic of Helmholtz pulsating burner
Authors:Pan, Sipu (1); Zhou, Hongping (1); Jiang, Xuesong (1); Chen, Qing (1); Li, Pingping (2)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) College of Biology and Environment, Nanjing Forestry University, Nanjing; 210037, China
Corresponding author:Zhou, Hongping(hpzhou@njfu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:70-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pulsating combustion has the advantages of high combustion intensity, high heat transfer coefficient, and low pollutant emission, and therefore it has been widely used to enhance the heat transfer process, such as aeromodelling's power, material drying, and pest control. In recent years, pulsating combustion heater, such as hot water boiler or steam boiler, has become another new application of pulsating combustion technology. Pulsating combustion heater employs the pulsating burner as the heat source, and the main components such as combustion chamber and tail pipe are immersed in heating medium (such as oil and water). When the pulsating burner works, heat is transferred to the heating medium through the high temperature outer wall of the combustion chamber and tail pipe, and then the heating medium is heated to the temperature required by the process. The efficiency and the economy of the pulsating combustion heater were related to the temperature increasing process of the heating medium. In order to investigate the characteristics of temperature distribution of airflow field outside combustion chamber of the pulsing burner, a two-dimensional unsteady numerical model was established. The increasing-temperature process in the central cross section of combustion chamber was simulated by Fluent software under the conditions of 5 different kinds of oil consumption (30°, 60°, 90°, 120°, and 150° throttle opening), employing a self-excited and self-suction Helmholtz pulsing burner as the heat source. Temperature increasing process of the pulsating burner in the heating medium was difficult to obtain, but it was easier to obtain in the air. The temperature increasing process of the heat source in the air was obtained by an infrared thermal cameral under all kinds of different oil consumption. Formula fitting was carried out for the increasing-temperature process. The fitted values and measured values were in good agreement. The maximum temperature difference between the fitted data and measured results was 5.2℃ and the maximum relative error was 2.2%. The temperature increasing law of the heat source was added to the numerical model by UDF (user-defined function) interface. A series of tests were performed to investigate the accuracy of the numerical model. It was found the simulation values were matched with the test data quite well, and the average relative error was between 2.68% and 5.54%. Temperature elevation of airflow field outside combustion chamber showed an "S" shape. In the beginning, air temperature increased rapidly. After a period of time, the temperature tended to be stable. With the increase of throttle opening, there was little difference in temperature increasing process for one single test point. The closer the distance to the combustion chamber in the same direction, the shorter the time it took to reach the maximum temperature, and the higher the temperature increasing speed and the maximum temperature. The test points above the combustion chamber got the higher temperature increasing speed and the higher maximum temperature than the test points which were at the right and the bottom of the combustion chamber when they were in the same distance to the combustion chamber. The 4 test points above the combustion chamber reached the highest temperature at 1.25 min, but the time required for the test points at the right and the bottom of the combustion chamber varied from 2 to 5 min when the throttle opening was 120°. The airflow outside the combustion chamber was driven upward from the bottom under the influence of density difference. Karman vortex street was observed when the airflow passed the combustion chamber, and the airflow temperature field above the combustion chamber oscillated periodically. As the vortices moved upward, their influence on the airflow temperature field was gradually weakened, and the temperature amplitude gradually decreased. This paper can be helpful to further understand the heating process of internal temperature field of the pulsating combustion heater when using oil or water as heating medium, and it also can provide references to optimize heat source structure design inside the pulsating combustion heater.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Combustion chambers
Controlled terms:Boilers - Computer simulation - Engines - Heat transfer coefficients - Heating - Models - Numerical models - Process monitoring - Temperature - Vortex flow
Uncontrolled terms:Average relative error - Combustion intensities - Heat transfer process - Increasing temperatures - Maximum relative errors - Maximum temperature differences - Pulsating combustion - User Defined Functions
Classification code:614 Steam Power Plants - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 654.2 Rocket Engines - 723.5 Computer Applications - 913.1 Production Engineering - 921 Mathematics
Numerical data indexing:Percentage 2.20e+00%, Percentage 2.68e+00% to 5.54e+00%, Time 1.20e+02s to 3.00e+02s, Time 7.50e+01s
DOI:10.11975/j.issn.1002-6819.2018.08.009
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 30>
Accession number:20182405313518
Title:Bag of words feature multi-PCA subspace adaptive fusion for cucumber diseases identification
Authors:Qin, Lifeng (1, 2); He, Dongjian (1, 2); Song, Huaibo (1, 2)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) Key Laboratory of Agricultural Internet of Things, Ministry of Agriculture, Yangling; 712100, China
Corresponding author:He, Dongjian(hdj168@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:200-205
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Cucumber disease identification in greenhouse is of great significance to cucumber production. The traditional recognition method based on colour and texture features with single classifier has low accuracy in diagnosing many kinds of diseases. In view of this problem, a cucumber disease identification method based on Bag of Words (BoW) model and multi classifiers adaptive fusion on PCA-subspaces, BoW-mPCA, was proposed. First, for each category disease images, the SIFT points were extracted and clustered into a certain number of clusters, and the centres, called visual words (VW), were gathered to establish the category-related BoW (CR-BoW) model. Considering that the image data in the remote transmission can reduce the real-time of the disease recognition, and the disease location plays a decisive role in disease identification, so we cut the diseases location of the sample images by hand into sub-images of different size (minimum 58×68, maximum 562×487), which were collected as the dataset for CR-BoW model construction and experiments. To present the images based on the CR-BoW model, every SIFT point of each image was presented by the nearest VW in the VW space. Then each image was presented as a histogram of the VWs appearing on the image. To solve the problem of the high-dimension BoW-feature of disease images, PCA (Principal Component Analysis) method was adopted to reduce the feature dimensionality to series of subspaces of different size, and on each subspace a BP network was trained. During the identification process, a self-adaptive strategy for classifiers combination was built based on the idea that each single type of disease should be classified on one optimal PCA-subspace. The diseases image was classified by the BP net trained on the smallest PCA-subspace. If the distance of the highest two scores was higher than a given threshold, the image was classified into the category corresponding to the highest score. If not, the image was classified again by the BP net trained on the next larger PCA-subspace, and the scores were confused with the former ones and the highest two were compared to decide the final result. Repeating this process until the highest two scores were obviously discrepant or all the BP nets were used. The experiments were carried on a dataset containing five types of cucumber diseases, angular leaf spot, corynes pora, powder, downy and anthrax. The results showed that the average classification precision of five kinds of cucumber diseases in two PCA subspace fusion with preservation of 75%, and 85% energy, respectively, was 90.38%, higher than the single colour, texture and colour-texture mix feature by 6.97, 26.15, 13.02 percent respectively. Although for single disease of angular leaf Spot, corynes pora and anthrax, BoW-2PCA obtained precisions of 86.96% and 88.00%, slightly lower than colour features (89.78% and 93.20%), the precision on downy was 89.13% comparing to 64.20% from colour feature. This result indicated that BoW-2PCA could deal with the situation that the traditional methods can hardly handle. Moreover, the BOW-2PCA algorithm showed more stability in classification precision over all five types of diseases than the other three traditional methods. These results showed that the proposed CR-BoW model and BoW-mPCA algorithm was effective for diagnosing greenhouse cucumber disease.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Image classification
Controlled terms:Backpropagation - Classifiers - Color - Diagnosis - Diseases - Greenhouses - Information retrieval - Models - Principal component analysis
Uncontrolled terms:Bag-of-words models - BP networks - Classifier fusion - Multi subspace - Recognition
Classification code:461.6 Medicine and Pharmacology - 723.4 Artificial Intelligence - 741.1 Light/Optics - 802.1 Chemical Plants and Equipment - 821.6 Farm Buildings and Other Structures - 903.3 Information Retrieval and Use - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.30e+01%, Percentage 6.42e+01%, Percentage 7.50e+01%, Percentage 8.50e+01%, Percentage 8.70e+01%, Percentage 8.80e+01%, Percentage 8.91e+01%, Percentage 8.98e+01%, Percentage 9.04e+01%, Percentage 9.32e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.026
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 31>
Accession number:20182405313527
Title:Detection of vitamin C content in head cabbage based on visible/near-infrared spectroscopy
Authors:Li, Hongqiang (1, 2); Sun, Hong (1); Li, Minzan (1)
Author affiliation:(1) Key Laboratory of Modern Precision Agriculture System Integration Research, China Agricultural University, Beijing; 100083, China; (2) School of Science, Hebei Institute of Architecture and Civil Engineering, Zhangjiakou; 075000, China
Corresponding author:Li, Minzan(limz@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:269-275
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The experiment was conducted to study the rapid detection method of soluble sugar content in head cabbage by near infrared spectroscopy, partial least squares (PLS) regression and stepwise regression (SR). The experiment collected a total of 71 samples of head cabbage. The spectral data were measured by the spectrometer of ASD FieldSpec<sup>®</sup>Handheld™ 2 made in ASD Company, USA, and the vitamin C (Vc) was measured by the 2, 6 two chloro indigo titration method. The kennard-stone (K-S) method was used to divide all samples into a calibration set and a validation set according to the given ratio. First derivative (FD) and second derivative (SD) pretreatment methods were used to improve the S/N ratio so as to find the better one from them. The coefficient of determination (R<sup>2</sup>), root mean squared error of cross validation (RMSECV), and root mean squared error of prediction (RMSEP) were used to evaluate models. The samples were divided into calibration set (60 samples) and validation set (11 samples) according to the ratio of 6: 1 by K-S method. Six PLS models were established by using original, FD, and SD preprocessed spectral data of preflectance and absorbance, respectively. The modeling results showed that the spectral preprocessing method using FD could well improve modeling accuracy, the R<sup>2</sup>of the validation set with which increased from 0.85 to 0.93, and this method was thought to be the better spectral data pretreatment method in this experiment. For the spectrum after the FD treatment, 5 confidence levels (0.95, 0.975, 0.99, 0.995, 0.999 5) were set up, and SR method was used to select modeling wavelength. With the increase of confidence level, the number of selected wavelength variables decreased from 14 to 3, and then 5 multiple linear regression models were established by 5 sets of preferred wavelengths corresponding to 5 confidence levels. The R<sup>2</sup>values were 0.91, 0.83, 0.77, 0.7 and 0.61, respectively, and the RMSECV values were 2.362 2, 3.316 3, 3.841 1, 4.125 2 and 4.962 5 mg/100 g respectively for calibration set, while the R<sup>2</sup>values were 0.82, 0.71, 0.72, 0.75 and 0.69, respectively, and the RMSEP values were 2.121 9, 2.983 6, 2.902 4, 2.751 6 and 3.021 5 mg/100 g respectively for validation set. According to the determination coefficient and the root mean square error analysis of the calibration set and the validation set, the multiple linear regression models corresponding to 8, 6 and 5 wavelength variables were established, and the model performance was consistent for the calibration set and the validation set. The average R<sup>2</sup>was 0.78, the average RMSECV was 3.760 9 mg/100 g for calibration set, and the average R<sup>2</sup>was 0.73, the average RMSEP was 2.879 2 mg/100 g for validation set, which meant that using fewer wavelength variables to predict Vc content in head cabbage was practical. So the visible / short wave near infrared spectra could be used for quantitative detection of vitamin C content in head cabbage. For the PLS model, it had many wavelength variables, the information was large, and so the detection precision was high. For the multiple linear regression models with 8, 6 or 5 selected wavelength variables, with the reduction of number of wavelength variables, the R<sup>2</sup>decreased, which could yet provide technical support for the development of portable testing instrument. Using near infrared spectroscopy analysis technique, the prediction model for the content of Vc in cabbage was established, and it could improve the working efficiency of the internal quality evaluation of the cabbage. The research provides a new approach for quality evaluation of head cabbage.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Least squares approximations
Controlled terms:Calibration - Errors - Finite difference method - Forecasting - Infrared devices - Instrument testing - Linear regression - Mean square error - Near infrared spectroscopy - Quality control - Silicon compounds - Spectrometers - Spectrum analysis - Titration - Vitamins
Uncontrolled terms:Head cabbage - Multiple linear regression models - Near-infrared spectroscopy analysis - Nondestructive detection - Partial least squared regression - Partial least-squares regression - Stepwise regression - Visible/near-infrared spectroscopies
Classification code:741.3 Optical Devices and Systems - 801 Chemistry - 913.3 Quality Assurance and Control - 921.6 Numerical Methods - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2018.08.035
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 32>
Accession number:20182405313509
Title:Inhibitory effect of soil pH value and moisture on soil nitrification by nitrapyrin application
Authors:Gu, Yan (1, 2); Wu, Lianghuan (1, 2, 3); Hu, Zhaoping (3)
Author affiliation:(1) Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou; 310058, China; (2) Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou; 310058, China; (3) State Key Laboratory of Nutrition Resources Integrated Utilization, Kingenta Ecological Engineering Group Co., Ltd., Linyi; 276000, China
Corresponding author:Wu, Lianghuan(lhwu@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:132-138
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nitrification inhibitors such as nitrapyrin (2-chloro-6-(tricholoromethyl)-pyridine, CP) are co-applied with nitrogen fertilizers to prevent nitrification and improve the efficiencies of fertilizers in cropland, but its effectiveness depends on a number of soil characteristics. Nitrapyrin was reformulated by new technology and its purity has achieved 98%. The effectiveness improved a lot because of the greatly reduced impurities. In order to study the effects of soil pH value and soil moisture on the inhibition efficacy of new reformulated nitrapyrin, soil incubation experiments were carried under dark and aerobic conditions (25℃ constant temperature and 80% humidity) to discuss the implications of nitrapyrin on dynamic changes of inorganic nitrogen, nitrification intensity and nitrification inhibition rates' changing rules in different soil regime. Results indicated that ammonium concentrations decreased while nitrate concentrations and apparent nitrification rates had an ascending tendency as pH value increased. Nitrogen application combined with nitrapyrin significantly decreased the amount of disappeared ammonium and inhibited nitrification at all pH levels. At the 9th day, nitrification inhibition rate at pH value of 7.70 was highest, up to 91.53%. However, nitrification inhibition rates at low pH value decreased slower than that at high pH value. At the 45th day, nitrification inhibition rate at pH value of 4.66 was 36.43%, higher than other treatments. Nitrate concentration and apparent nitrification rate were highest in soils with 60% of the maximum water holding capacity (WHC). Nitrapyrin application inhibited nitrification at all soil moisture levels. Nitrification inhibition rate in soils of moisture levels was 40%WHC>60%WHC>80%WHC. In conclusion, nitrapyrin should be more suitable for application in acidic soil and upland soil. Results in our study are expected to provide scientific basis for the optimal soil conditions in practical application of new nitrapyrin.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Nitrification
Controlled terms:Moisture determination - Nitrates - Nitrogen - Nitrogen fertilizers - pH effects - Soil moisture - Soils
Uncontrolled terms:Ammonium concentrations - Nitrapyrin - Nitrate concentration - Nitrification inhibitions - Nitrification inhibitor - Nitrification rates - pH value - Water holding capacity
Classification code:483.1 Soils and Soil Mechanics - 801.1 Chemistry, General - 802.2 Chemical Reactions - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 944.2 Moisture Measurements
Numerical data indexing:Percentage 3.64e+01%, Percentage 6.00e+01%, Percentage 8.00e+01%, Percentage 9.15e+01%, Percentage 9.80e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.017
Funding Details: Number; Acronym; Sponsor: 31172032; NSFC; National Natural Science Foundation of China
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 33>
Accession number:20182405313497
Title:Design and test of double crank multi-rod hill-drop potato planter on plastic film
Authors:Sun, Wei (1); Liu, Xiaolong (1); Wang, Hucun (1); Zhang, Hua (1); Wu, Jianmin (1); Yang, Xiaoping (1); Wang, Guanping (1)
Author affiliation:(1) College of Electromechanical Engineering, Gansu Agricultural University, Lanzhou; 730070, China
Corresponding author:Wang, Guanping(wangguanping@gsau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:34-42
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Potato is one of the dominant crops in the rain-fed agriculture area of the Loess Plateau in the northwest. To inhibit evaporation and retain soil moisture, the potato planting normally adopts drought resisting and water-saving technology with plastic film mulching in this area. Potato film mulching cultivation is divided into two kinds according to the operating procedure. One is the first sowing then mulching film, and covered with a layer of 3-5 cm soil on the film, relying on the soil mass and buds naturally move upward so that seedlings automatically rupture of film and natural emergence. The advantages of this approach are to solve the problem of artificial seedlings. But the disadvantage is that the film warming effect is weakened after the film is covered with soil, and it cannot be planted when the spring drought is serious. The other approach is the first mulching film then sowing, and this approach can be ridged and mulched in the autumn of previous year or in the spring of that year. It has the advantages of storing autumn moisture, resisting spring drought, raising ground temperature, etc. which can effectively solve the problem of sowing due to serious spring drought. Therefore, this approach is mostly used in this area. At present, due to the lack of matching hill-drop planter, the approach needs manual sowing, poor quality control, and labor-intensive operation, which urgently needs to be mechanized. After decades of development, China's mechanized mulching film planting technology has made great progress. The mechanism of roller wheel, vertical insertion, rotary type has been developed, and the sowing on film of corn, peanut, cotton and other crops has been realized. However, the depth of potato planting is much higher than these crops, which requires the hill-drop mechanism has a large vertical displacement and small horizontal displacement in the hill-drop process, as such to avoid tearing and picking film. Therefore, a potato hill-drop planter was designed for the potato cultivation mode with two drills sowing on ridges in the rain-fed agriculture area of the Loess Plateau in the northwest. The key components of the potato prototype was analyzed and designed, the kinematic model of the hill-drop mechanism with double crank multi-rod was established, the structure and working parameters of the hill-drop mechanism with double crank multi-rod, covering soil device and lifting soil device were determined. The scheme of transmission system was established and the working mechanism of core components was analyzed. Field experiments showed that the qualified rate of sowing depth under the film, the rate of hole dislocation, the qualified rate of hole spacing, the qualified rate of covering soil on hole and mechanical damage degree of plastic film day lighting surface were 92%, 5%, 88%, 93% and 52.1 mm/m<sup>2</sup>, respectively. Field performance experiment indexes had reached the requirements of the national and industry standards. Moreover, the results met the design requirements, which can realize integrated operation of potato hill-drop planting on film and covering soil on hole.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Cultivation
Controlled terms:Agricultural machinery - Crops - Design - Drops - Drought - Kinematics - Landforms - Mechanization - Plastic films - Rain - Sediments - Soil moisture - Water conservation - Water resources
Uncontrolled terms:Covering soil device - Horizontal displacements - Labor-intensive operations - Large vertical displacement - Plastic film mulching - Potato planter - Structure and working parameters - Water saving technology
Classification code:443.3 Precipitation - 444 Water Resources - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 817.1 Polymer Products - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.1 Mechanics
Numerical data indexing:Percentage 5.00e+00%, Percentage 8.80e+01%, Percentage 9.20e+01%, Percentage 9.30e+01%, Size 3.00e-02m to 5.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.08.005
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 34>
Accession number:20182405313495
Title:Characterizing energy transfer of litchi branches and working parameters of destemmed vibrational picking
Authors:Li, Bin (1); Lu, Huazhong (1, 2); Lü, Enli (1, 2); Li, Jun (1, 2); Qiu, Guangjun (1); Yin, Hongchao (1); Ma, Yakun (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou; 510642, China; (2) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Li, Jun(autojunli@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:18-25
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The planting area and production of litchi in China rank the first in the world. Currently, manual harvesting of fresh litchi is the main way. Harvest mechanization of litchi is limited by many factors such as mountainous topography, traditional cultivation patterns, biological characteristics and uniform ripening of fruit. However, the adoption of simple mechanical tools to aid harvesting has begun to experiment as a labor-saving approach. To improve the harvesting efficiency and reduce the labor intensity, a hybrid shaking-fixed combo picker for litchi was developed as a canopy vibrational shaker. Understanding of the harvesting performance and postharvest litchi quality of the proposed picker is imperative. The technical possibility of the picker was proved by the energy transfer experiments. The postharvest fruit quality for vibrational picking and manual picking was compared. The experimental results showed that the dissipation of vibration energy was smaller if the excitation point was close to the branch at the position of the lateral crown. The vibration energy could be applied efficiently for harvesting if the fruiting branches that were relatively immobilized at the head of branch were shaken as the principle of hybrid shaking-fixed combo picker. The three-factor three-level orthogonal test was conducted. The results showed that the smallest damage ratio was obtained at vibration frequency of 20 Hz, spacing of fixed comb of 10 mm and swing angle of shaking comb of 30°. When the vibration frequency, spacing of fixed comb and swing angle of shaking comb were respectively 26.67 Hz, 20 mm and 50°, the picking efficiency was the highest with the damage ratio of 7.18%. Considering the effect of picking efficiency and damage ratio on picking performance index comprehensively, a synthetic weight grade method was proposed to analyze the experimental results for evaluating and determining the best operation parameters of the hybrid shaking-fixed combo picker. It is indicated that the best operation parameters of the litchi picker are vibration frequency of 26.67 Hz, spacing of fixed comb of 20 mm, swing angle of shaking comb of 40°. The replication experimental results showed that the productivity is 4.1 kg/min and the damage ratio is 5.05% under this condition. During the postharvest quality test, the harvested litchi fruits by vibrational picking and hand picking were both pre-cooled for 15 min at 5℃. Sample fruits of each harvesting method were packed with polythene film bags with 20 bags per group. Each fresh-keeping bag included 15 fruits. The packaged fruits were stored in a fresh-keeping container for 8 d with temperature of 6℃, oxygen volume fraction of 3%-6% and relative humidity of 90%-95%. Every 48 h, one bag was randomly taken out as to each harvesting method. The color difference (a*, b*, L*), titratable acid and soluble solids were tested. No significant difference was found between vibrational harvest and manual harvest in the total soluble solid content, color difference (a*, b*, L*) and titratable acidity. It was found that vibrational harvesting has no effect on the fruit quality. This study can provide a reference for the design and optimization of litchi harvester.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Harvesting
Controlled terms:Color - Colorimetry - Energy transfer - Fruits - Machinery - Mechanization
Uncontrolled terms:Biological characteristic - Design and optimization - Destemmed picking - Litchi - Operation parameters - Postharvest quality - Total soluble solids - Vibrations
Classification code:601 Mechanical Design - 741.1 Light/Optics - 821.3 Agricultural Methods - 821.4 Agricultural Products - 941.4 Optical Variables Measurements
Numerical data indexing:Frequency 2.00e+01Hz, Frequency 2.67e+01Hz, Mass_Flow_Rate 6.83e-02kg/s, Percentage 3.00e+00% to 6.00e+00%, Percentage 5.05e+00%, Percentage 7.18e+00%, Percentage 9.00e+01% to 9.50e+01%, Size 1.00e-02m, Size 2.00e-02m, Time 1.73e+05s, Time 9.00e+02s
DOI:10.11975/j.issn.1002-6819.2018.08.003
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 35>
Accession number:20182405313511
Title:Effect of standing and shattered stalk residue mulching on soil respiration during growing-season of maize (Zea mays L.)
Authors:Jia, Honglei (1, 2); Li, Sensen (1, 2); Wang, Gang (1, 3); Zhang, Yu (3); Liu, Huili (1); Walsh, Michael J. (4)
Author affiliation:(1) College of Biological and Agricultural Engineering, Jilin University, Changchun; 130022, China; (2) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun; 130022, China; (3) College of Electronic Science & Engineering, Jilin University, Changchun; 130012, China; (4) Department of Biological and Environmental Engineering, Cornell University, Ithaca; NY; 14853, United States
Corresponding author:Wang, Gang(wangganggoodman@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:146-155
Language:English
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Cropland soil respiration (Rs) is an important part of global CO<inf>2</inf>cycling. The growing-season Rs has great influence on the crop yield, and Rs can be affected by crop residue mulching. Two prevailing crop residue mulching methods, which were shattered residue mulching (SH) and standing residue mulching (ST) were applied after harvesting in this study since 2000. The measurement was initiated in the year of 2013, and the measurements included the soil frost depth, snow accumulation, CO<inf>2</inf>fluxes, soil temperature and soil moisture. Total Rs are divided into heterotrophic respiration (HR) and rhizospheric respiration (RR). Radiocarbon signature technology combining with mathematical equations were utilized to calculate the CO<inf>2</inf>fluxes of HR and RR. The experimental results showed that average snow accumulation increased by 44%, maximum soil-frost-depth reduced by 18% and the frozen soil thawing completely hastened by about 10 to 27 d of ST compared that with SH. The average CO<inf>2</inf>fluxes were 16.55 and 14.02 mmol/m<sup>2</sup>h for ST and SH, respectively. In terms of the growing season, the Rs difference between SH and ST was relatively small at the introductory and final stage, while the Rs difference was relatively larger in the middle stage. The average Rs of ST was 3.3 mmol/m<sup>2</sup>h larger than that of SH. The HR was the dominant contributor to Rs in ST treatment, while RR only contributed about 10% to the total Rs. Redundancy analyses revealed that the Rs and HR were positively correlated with soil temperature and snow accumulation, but they were negatively correlated with the soil frost depth. These results indicated that applying ST can result in higher growing-season Rs compared with SH, the higher Rs means the higher CO<inf>2</inf>supplement to maize for photosynthesis, which is benefit for crop yield improvement.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:52
Main heading:Carbon dioxide
Controlled terms:Agricultural wastes - Crops - Frozen soils - Grain (agricultural product) - Snow - Soil moisture - Soils - Temperature
Uncontrolled terms:Growing season - Heterotrophic respiration - Respiration - Rhizospheric respiration - Shattered residue mulching - Standing residue mulching
Classification code:443.3 Precipitation - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 804.2 Inorganic Compounds - 821.4 Agricultural Products - 821.5 Agricultural Wastes
Numerical data indexing:Percentage 1.80e+01%, Percentage 4.40e+01%
DOI:10.11975/j.issn.1002-6819.2018.08.019
Funding Details: Number; Sponsor: 801171030419; China Postdoctoral Science Foundation
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 36>
Accession number:20182405313504
Title:Rapid prediction of sudden water pollution accident in main canal of Shandong section of East Route of South-to-North Water Transfer Project
Authors:Zhao, Ranhang (1); Peng, Tao (1); Wang, Haofang (1); Zhang, Lianzhou (2); Qi, Zhen (1)
Author affiliation:(1) School of Civil Engineering and Hydraulic Engineering, Shandong University, Jinan; 250061, China; (2) Water Conservancy Research Institute of Shandong Province, Jinan; 250014, China
Corresponding author:Wang, Haofang(whf29@sdu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:93-99
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The East Route of the South-to-North Water Transfer Project is a trans basin, long distance, large and comprehensive water diversion project to alleviate the contradiction between the supply and demand of water resources in the eastern part of China and support the sustainable development of the national economy and society in this region. Since the construction of the South-to-North Water Transfer Project, water safety and water quality guarantee have been a hot issue. In the middle line project, there has been a large number of researches concentrated in the source and the Beijing section. While in the east line project, the Shandong section, has already carried out the risk assessment of water transportation safety and the simulation of hydrodynamic water quality. In Shandong section, canals are mostly open type, crossing several local traffic roads, and some of the rivers and lakes bear the task of shipping. Therefore, the water conveyance safety is threatened by many potential water pollution accidents. In order to take effective emergency control and disposal measures in case of an emergency, it is necessary to carry out rapid prediction of the sudden water pollution events in the South-to-North Water Transfer project. Literature retrieval shows that, at present, many scholars at home and abroad have established a large number of simulation models with the aid of model software, but all of them need a large amount of basic data, and the operation of the model needs a lot of time. The sudden water pollution accident often happened suddenly, with random and acute. Once the sudden water pollution accident occurs, it is urgent to make a decision, and there is no time to run the simulation model to predict. So the rapid prediction is still an important problem for the scholars at home and abroad to study the sudden water pollution events. At present, there is no model to predict the process of the changes of pollutants quickly and accurately. Considering about all the situations above, based on the risk identification of water pollution incident in the main water transfer canal of Shandong section of the South-to-North Water Transfer Project, this study simulated some typical water pollution accidents in different canals of Shandong section. Also based on the transport and transformation of empirical formula of pollution, this study established a rapid prediction model of sudden water pollution accidents, and determined the parameters of the fast prediction model by using the simulation results of the main channel of the Shandong section of the South-to-North Water Transfer project. Finally, we used the results of computer numerical simulation to test the prediction results of the rapid prediction model. The test results showed that the relative error of influencing time and influencing range predicted by rapid prediction model were 0.52%-4.83% and 0.23%-7.15%, none of them were more than 10%. So it conclude that the established rapid prediction model can accurately predict the sudden water pollution accidents in the trunk section of the Shandong Section of the South to North Water Transfer project.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Water pollution control
Controlled terms:Canals - Computer software - Economics - Flood control - Forecasting - Models - Oil spills - Pollution - Risk assessment - River pollution - Tectonics - Water quality - Water resources
Uncontrolled terms:Literature retrieval - Pollution incidents - South to North Water Transfer Project - Sudden water pollutions - Transport and transformation - Water diversion project - Water pollution accidents - Water transportation
Classification code:407.2 Waterways - 444 Water Resources - 445.2 Water Analysis - 453 Water Pollution - 481.1 Geology - 723 Computer Software, Data Handling and Applications - 914.1 Accidents and Accident Prevention - 971 Social Sciences
Numerical data indexing:Percentage 1.00e+01%, Percentage 2.30e-01% to 7.15e+00%, Percentage 5.20e-01% to 4.83e+00%
DOI:10.11975/j.issn.1002-6819.2018.08.012
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 37>
Accession number:20182405313526
Title:Evaluation model of urban land intensive use based on nighttime light remote sensing data
Authors:Cheng, Xin (1); Shao, Hua (1); Li, Yang (2, 3, 4); Wang, Yahua (2, 3, 4); Yuan, Yuan (2, 3, 4)
Author affiliation:(1) School of Geomatics Science and Technology, Nanjing Tech University, Nanjing; 211800, China; (2) Key Laboratory of Virtual Geographic Environment, Nanjing Normal University, Ministry of Education, Nanjing; 210023, China; (3) Cultivation Base of State Key Laboratory of Geographical Environment Evolution, Jiangsu Province, Nanjing; 210023, China; (4) Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing; 210023, China
Corresponding author:Shao, Hua(shaohua@njtech.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:262-268
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the acceleration of the urbanization, urban land intensive use becomes necessary for the development of city. In the traditional study of urban land intensive use, all kinds of socio-economic statistical data are used and evaluation indicators based on analytic hierarchy process are built for the analysis of the land intensive use. However, there are many difficulties, such as data collection, data "monopoly" and data distortion. Under the background of new urbanization, it is important to optimize the structure of land resource utilization, improve the utilization efficiency of land resources and rationally control the scale of urban construction land. Jiangsu Province is taken as an example for the urban land intensive use in this research. Nighttime light data are considered as a good data source in the many studies of society and economy, because they can objectively reflect the social and economic activities. Before using nighttime data, a series of pre-processing work is needed to ensure the accuracy of the experimental result. Nighttime light data and built-up area data from 1996 to 2012 in Jiangsu Province are used to construct the allometric growth model of city light intensity - urbanization of land based on order space at the scale of prefecture-level city. And then the nighttime light data and built-up area data in 2015 are used to construct the model based on phase space at county scale. The allometric growth index is used to analyze the growth relation between city light intensity and urbanization of land based on the city scale of Jiangsu Province. At the same time, the effect of time lag of urban light on urban land is considered, and the allometric growth model is improved by adding lag term. A new allometric growth model is constructed. By selecting typical cities with different development levels, restrictive relations between urban light and the stock urban land and the new urban land are assessed separately based on the lag term coefficient. The result shows that the land intensive use level is significantly different from north to south. The new model considering the lag effect is better in analysis of relationship between city light and urban land growth. There is exactly a lagging phenomenon of urban light relative to the urbanization of land. The light of most cities mainly concentrates on the stock land, and the light of the new urban land has lag phenomenon to a certain extent. The new functional area pattern of "1+3" in Jiangsu Province also has obvious regional characteristics of allometric growth. The intensive use level in Yangtze River urban agglomeration is higher than other zones obviously. This study validates the rationality of the strategy of "1+3" functional areas and has a certain reference value to the change of Jiangsu's economic pattern. This study takes advantage of the urban nighttime light remote sensing data in long time series and large scale, which avoids the cumbersome and time-consuming data collection process in traditional land intensive use evaluation system. It can effectively evaluate the land intensive use level of cities with different development degrees. Therefore, this method can provide a reliable reference guide for the utilization of land resources in China..<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Urban growth
Controlled terms:Data acquisition - Economic analysis - Models - Natural resources - Phase space methods - Remote sensing - Space optics
Uncontrolled terms:Allometric growth - Data collection process - Evaluation indicators - Land utilization - Night-time lights - Regional characteristics - Urbanization - Utilization efficiency
Classification code:403.1 Urban Planning and Development - 656.1 Space Flight - 723.2 Data Processing and Image Processing - 911.2 Industrial Economics - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2018.08.034
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 38>
Accession number:20182405313503
Title:Influence mechanism of alternating temperature on friction torque of aerospace bearings
Authors:Ning, Fengping (1); Fan, Xiaoqin (1); Chen, Ran (2); An, Jingtao (3); Zhao, Yongsheng (3)
Author affiliation:(1) Department of Mechanical Engineering, North University of China, Taiyuan; 030051, China; (2) China Academy of Space Technology, Aerospace Electromechanical Equipment Institute, Tianjin; 300301, China; (3) Parallel Robot and Mechatronic System Laboratory of Hebei Province, Yanshan University, Hebei; 066004, China
Corresponding author:Zhao, Yongsheng(yszhao@ysu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:8
Issue date:April 15, 2018
Publication year:2018
Pages:85-92
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the further development of the Beidou navigation satellite network, high precision, high reliability and high security issues of shaft assembly in interstellar link antenna drive unit have been paid more and more attention by the researchers. As the absolutely necessary key components in spacecraft mechanism, the reliability of space bearing is one of the main difficulties in the world's space technology. Due to the harshness, extremeness and uncertainty of the space environment, the alternating temperature first seriously affects the size and stability of the space bearing friction torque. Secondly, the operation reliability is affected in space bearing while temperature changes. Then, the life, accuracy and reliability of the spacecraft mechanism are affected by the space environment. Space bearing is the sensitive and key problem related to the reliability of spacecraft mechanisms. The reliability of space bearing is the basic guarantee of the normal operation of spacecraft mechanisms, the realization of the intended function and the design life. The friction torque of the bearing reflects the operation of the precision shaft system and will affect the function and accuracy of the shaft system. The improper friction torque of the space bearing will cause the spacecraft mechanism to failure, so the dynamic performance of the friction torque is an important factor to restrict the life and reliability of spacecraft mechanism. Aiming at the space ambient temperature alternating between -60 and 80℃ influencing the friction torque issue of space bearing, the mathematical model of friction torque of solid lubricating bearing is established by using contact mechanics and kinematics theory. Then, the friction torque of inner and outer rings is analyzed. Based on the elastic mechanics, thermotics and deformation coordination, the influence law of alternating temperature on the interference and preload force of space bearing is analyzed. On the basis of changing law of the interference and preload force, the influence mechanism of alternating temperature on the friction torque of space bearing is studied by combining the friction torque model. The relationships between the interference and friction torque, the preload force and friction torque, the alternating temperature and the friction torque are investigated by theory and experiment. Meanwhile, the experiment is carried out to verify the theoretical analysis. The results show that the alternating temperature is negatively correlated with the inner ring interference, and the alternating temperature is positively related to the outer ring interference. The increased amount of the friction torque of the inner ring, caused by the increase of the interference, is larger than that of the outer ring. The preload force of space bearing increases with the alternating temperature. Comparing with the preload force at room temperature, the change range of preload force is -40-40 N, while the alternating temperature increases from -60 to 80℃. The increase of preload force or ambient temperature leads to the increase of the friction torque. The friction torque increases with the increase of the alternating temperature, and decreases with the decrease of the alternating temperature. The friction torque cannot reach the maximum and minimum of the initial time. By analyzing the influence law of the alternating temperature on the friction torque of space bearing, the method to reduce or eliminate the influence of the alternating temperature on the friction torque is explored, which provides a theoretical basis for slowing the change of the friction torque.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Tribology
Controlled terms:Antennas - Assembly - Bearings (structural) - Deformation - Friction - Models - Radio navigation - Reliability - Spacecraft - Temperature - Torque
Uncontrolled terms:Bearing friction torque - Deformation coordination - Friction torque - Friction torque model - Influence mechanism - Navigation satellites - Operation reliability - Spacecraft mechanisms
Classification code:401.1 Bridges - 641.1 Thermodynamics - 655.1 Spacecraft, General - 716.3 Radio Systems and Equipment - 931 Classical Physics; Quantum Theory; Relativity - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Force -4.00e+01N
DOI:10.11975/j.issn.1002-6819.2018.08.011
Database:Compendex
Compilation and indexing terms, Copyright 2018 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
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- 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
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- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
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- ASABE
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- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
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