<RECORD 1>
Accession number:20184506039297
Title:Experiment on single root tensile mechanical properties of typical herb species in loess region of Xining Basin
Authors:Liu, Yabin (1, 2, 3); Li, Shuxia (1, 2, 3); Yu, Dongmei (1, 2); Hu, Xiasong (1, 4); Yang, Youqing (1, 2, 3)
Author affiliation:(1) Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining; 810008, China; (2) Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes, Xining; 810008, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China; (4) Department of Geological Engineering, Qinghai University, Xining; 810016, China
Corresponding author:Hu, Xiasong(huxiasong@tsinghua.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:157-166
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To further explore the mechanical effects of roots of herb species on soil reinforcement and slope protection in loess region of Xining Basin, in this study, 3 kinds of herbs i.e. Elymus nutans Griseb., Agropyron trachycaulum Linn. Gaertn. and Medicago sativa L., which were planted in the self-established testing area in Xining Basin, were selected as the research objects and the growth time was 150 d. Under the condition of different root diameter levels, single root tensile force, single root tensile strength and single root limit extensile rate of 3 kinds of herbs were assessed via single root tensile test. Furthermore, the stress-strain characteristics of 3 kinds of herbs during the tensile process were further analyzed. The test results are as follows: Under the 5 levels of root diameters i.e. (0.10, 0.20], (0.20, 0.30], (0.30, 0.40], (0.40, 0.50] and (0.50, 0.60] mm, the single root tensile force of M. sativa, E. nutans and A. trachycaulum ranges from (2.28±0.67) to (12.00±3.89) N, from (1.75±0.43) to (7.66±0.72) N and from (1.82±0.46) to (7.95±0.47) N, respectively; the single root tensile force of M. sativa is averagely 1.32 times higher than E. nutans and 1.26 times higher than A. trachycaulum; the single root tensile strength of M. sativa, E. nutans and A. trachycaulum is from (49.21±17.06) to (124.88±46.63) MPa, from (35.33±1.76) to (84.87±15.93) MPa and from (35.96±2.46) to (73.32±19.56) MPa, respectively; the single root tensile strength of M. sativa is averagely 1.30 times higher than E. nutans and 1.31 times higher than A. trachycaulum; the single root limit extensile rate of E. nutans ranges from 50.36%±15.52% to 76.4%±3.05%, which is averagely 1.13 times higher than A. trachycaulum (from 45.84%±11.56% to 73.28%±10.82%) and 2.16 times higher than M. sativa (from 25.74%±8.05% to 36.09%±7.78%); in addition, when the root diameter is from 0.10 to 0.60 mm, the single root tensile force of the 3 kinds of herbs increases with the root diameter increasing, with a power relationship between single root tensile force and root diameter. Meanwhile, the single root tensile strength of the 3 kinds of herbs increases with the root diameter decreasing, and a power relationship exists between single root tensile strength and root diameter; moreover, the single root limit extensile rate of the 3 kinds of herbs increases with the increasing of the root diameter, but there is no significant functional relationship between them. The 3 kinds of herbs show 2 types of stress-strain curves (Ⅰand Ⅱ) during the single root tensile test; both of 2 types of stress-strain curves for the 3 kinds of herbs can be divided into 4 stages: elastic deformation, elastic-plastic deformation, strain hardening and fracture failure; in addition, the stress-strain curves of Type Ⅱ have the phenomenon of double peaks, which is due to the epidermis of root broken earlier than its internal tissue; the stress-strain curves of Type Ⅱ are found in the single root tensile process of E. nutans and A. trachycaulum, but not in M. sativa, which means the stress-strain process of root epidermis and its internal tissue of M. sativa has a relatively significant synchronism during the single root tensile test; it can also be concluded that, among the 3 kinds of herbs, M. sativa has the most significant effect on enhancing soil shear strength, followed by A. trachycaulum and E. nutans. These conclusions have a theoretical and practical significance in preventing soil erosion, shallow landslide and other geological hazards in cold and arid environment.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Stress-strain curves
Controlled terms:Biomechanics - Elastic deformation - Elastoplasticity - Mechanical properties - Plants (botany) - Sediments - Shear flow - Shear strength - Slope protection - Soil testing - Soils - Strain - Strain hardening - Stresses - Tensile strength - Tensile testing - Tissue - Vegetation
Uncontrolled terms:Arid environments - Elastic-plastic deformation - Functional relationship - Herbs - Root tensile strength - Stress strain characteristics - Tensile mechanical properties - Xining Basin
Classification code:461.2 Biological Materials and Tissue Engineering - 461.3 Biomechanics, Bionics and Biomimetics - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 537.1 Heat Treatment Processes - 631.1 Fluid Flow, General - 951 Materials Science
Numerical data indexing:Size 1.00e-04m to 6.00e-04m
DOI:10.11975/j.issn.1002-6819.2018.15.020
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 2>
Accession number:20184506039282
Title:Construction of visco-elasto-plasticity contact model of vibratory screening and its parameters calibration for wheat
Authors:Liu, Fanyi (1); Zhang, Jian (1); Chen, Jun (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China
Corresponding author:Chen, Jun(chenjun_jdxy@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:15
Issue date:August 1, 2018
Publication year:2018
Pages:37-43
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to better simulate the screening process of wheat, a visco-elasto-plasticity contact model was constructed based on the existing discrete element method (DEM) contact model. The modelling process was based on the application programming interface (API) of the EDEM 2.7 software, which allowed users to create customized contact model, particle factory and coupling interface by the C++ programming language. The normal contact model was created by adding the viscous dissipation term of the Kuwabara and Kono non-linear viscoelasticity model to the Thornton hysteretic model. The simplified Thornton tangential model was used to calculate the tangential force and the calculation of rolling friction was the same as that used in the Hertz-Mindlin (no slip) model. The calibration of the parameters of the visco-elasto-plasticity contact model was based on a uniaxial loading-unloading test, collision test and rotating drum test. Specifically, the uniaxial loading-unloading test was conducted to determine the yield overlap of wheat as the loading rate was slow (1 mm/min) and it could be regarded as a quasi-static process in which the viscous dissipation term can be neglected. In this work, the sum of squared errors of the contact force at all sampling points was calculated and the regression equation was developed, representing the relationship between the sum of squared errors of the contact force and the yield overlap of wheat. The result showed that the difference between the experimental and simulated values was the least when the yield overlap was 7.63×10<sup>-6</sup> m. Then the wheat-wheat/steel collision tests were respectively conducted to calibrate the wheat-wheat/steel coefficients of viscidity as the coefficient of restitution measured in these collision tests can reflect the energy dispassion of collision. Specifically, the double-pendulum test was used to calibrate wheat-wheat coefficient of viscosity and the inclined plate test was used to calibrate wheat-steel coefficient of viscosity. The regression equations describing the relationship between the wheat-wheat/steel coefficients of restitution and coefficients of viscosity were also developed. Solving the equations with the measured wheat-wheat/steel coefficients of restitution, the wheat-wheat/steel coefficients of viscosity were calibrated to be 190.68 and 306.65. In DEM parameters calibration, the dynamic angle of repose measured in rotating drum tests was often used as it could well reflect the flow regime of particles. The wheat particles in screening process were dynamic, and thus the rotating drum test was also conducted to calibrate the coefficients of static friction and rolling friction. The results of extensive pre-experiments showed the wheat-wheat/steel rolling friction had little influence on the dynamic angle of repose. So only the wheat-wheat/steel coefficient of static friction was calculated. The calibration results showed that the difference between the simulated and measured angles of repose was the least when the wheat-wheat/wall coefficients of static friction were 0.40 and 0.44, respectively. In order to verify whether the newly constructed visco-elasto-plasticity contact model and the calibrated parameters could well simulate the vibration screening process of wheat, a vibratory screening test was conducted. The screened wheat particles were collected and weighted by a material box with 7 sections, from which the undersize distribution of wheat in simulation was found to have similar trends with the realistic test and the wheat particles were mainly distributed in the first 3 sections. In order to evaluate whether the difference between the simulated and measured mass friction was significant, a paired T-test was performed by the SPSS software, and no significant difference was found between the simulated and experimental results. Moreover, the simulated and experimental results had a high correlation coefficient (0.98). The validation result showed that the model and the parameters can well simulate the screening process. This research can not only simulate the visco-elasto-plasticity characteristics of wheat, but also provide guidance for developing visco-elasto-plasticity models and their parameters calibration of other crops.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Software testing
Controlled terms:Application programming interfaces (API) - Application programs - C++ (programming language) - Calibration - Computer simulation - Crops - Elastoplasticity - End effectors - Finite difference method - Modeling languages - Models - Pendulums - Plasticity - Stiction - Unloading - Viscosity - Viscous flow
Uncontrolled terms:Coefficient of restitution - Coefficient of viscosity - Contact modeling - Correlation coefficient - Non-linear viscoelasticity - Parameters calibrations - Viscoelastoplasticity - Wheat
Classification code:631.1 Fluid Flow, General - 691.2 Materials Handling Methods - 723 Computer Software, Data Handling and Applications - 731.5 Robotics - 821.4 Agricultural Products - 921.6 Numerical Methods - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2018.15.005
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 3>
Accession number:20184506039287
Title:Cotton moisture stress diagnosis based on canopy temperature characteristics calculated from UAV thermal infrared image
Authors:Zhang, Zhitao (1, 2); Bian, Jiang (1, 2); Han, Wenting (2); Fu, Qiuping (3); Chen, Shuobo (1, 2); Cui, Ting (1, 2)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Key Laboratory of Agricultural Soil and Water Engineering in the Ministry of Education, Northwest A&F University, Yangling; 712100, China; (2) Institute of Water Saving Agriculture in Arid Regions of China, Yangling; 712100, China; (3) College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Urumqi; 830052, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:77-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The canopy temperature can indicate crop water stress condition, but the traditional method of canopy temperature measurement is based on ground point measurement, time-consuming and laborious. The calculation of crop water stress index (CWSI) requires more ground data monitoring and the crop water deficit physiological indicators are also difficult to measure in specific practical application, so it is difficult to popularize widely in agriculture. With the rapid development of unmanned aerial vehicle (UAV) platforms and thermal infrared sensors, the thermal infrared technology of UAV can monitor crop canopy temperature quickly and effectively and obtain a large area of crop canopy temperature with fast, dynamic monitoring, all-weather operation advantages, and further diagnose the water stress condition of agricultural crops. To solve the problem of low precision of the current UAV thermal infrared remote sensing for the diagnosis of crop water stress, in this paper, the 4 water treatment plots I<inf>1</inf>, I<inf>2,</inf> I<inf>3</inf> and I<inf>4</inf> with 50%, 65%, 80% and 95%-100% of field holding water as the upper limit were set up, each treatment plot had 3 repeated tests, a total of 12 treatment plots, and the cotton at flower boll period under 4 kinds of water treatments was selected as the test object. A six-rotor unmanned aerial vehicle was used to carry the thermal infrared sensor, and the high resolution thermal infrared images of cotton canopy at 13 o'clock at noon were collected in 5 consecutive days. First, the custom coordinates for thermal infrared images are defined in order to make the image have the same operating position, and Canny edge detection algorithm is used to obtain the edge feature raster image of cotton canopy. Then, the edge feature raster images are processed in ArcGIS and ENVI (environment for visualizing images) software to obtain a polygon vector layer, including the cotton canopy edge feature raster image converting to polyline vector layers and the polyline vector layers converting to polygon vector layers. Finally, use the polygon vector layer to clip, mask statistics and draw the canopy temperature histogram. Through the Canny edge detection algorithm, the thermal infrared image of the soil background is effectively removed, and the application of canopy temperature histogram verifies the elimination effect. The number, position and size of the original temperature histogram's peaks correspond to different matter pixels. If the temperature histogram is a single peak histogram for the high coverage crop canopy, the crop canopy with low coverage will be characterized by double or triple peaks. According to the canopy temperature histogram, the temperature characteristics of cotton canopy are calculated, including standard deviation of canopy temperature (CTSD) and canopy temperature coefficient of variation (CTCV). The relationships between cotton canopy temperature characteristics and cotton leaf stomatal conductance (Gs), transpiration rate (Tr), crop water stress index (CWSI) and soil water content (SWC) were studied, and the applicability of canopy temperature characteristics to diagnose cotton water stress was analyzed. The results showed that the cotton canopy temperature characteristics were correlated with the physiological and physical indices representing cotton water stress, and the maximum determining coefficient (R<sup>2</sup>) was 0.88. The determining coefficients of CTSD and CTCV with Gs, Tr, CWSI and SWC were 0.884, 0.625, 0.673, 0.550 and 0.853, 0.583, 0.620, 0.520, respectively. The CTSD was more sensitive to crop water stress condition, which could be used as a new index to diagnose crop water stress. However, the correlation between CTCV and physiological and physical indicators of crop water deficit is not ideal. Compared with CWSI, Gs, Tr and SWC which are traditional diagnostic indicators of crop water stress, this method greatly simplifies the calculation of crop diagnostic indicators. In this research, it suggests that the calculation method of canopy temperature characteristics only needs the thermal infrared image data of UAV and does not require any meteorological factors, so the canopy temperature characteristics are more easily promoted for use in agricultural water-saving irrigation. It has great potential to be used in the diagnosis of crop water stress compared with other water stress indices.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Temperature
Controlled terms:Antennas - Cotton - Crops - Edge detection - Geometry - Graphic methods - Infrared detectors - Infrared devices - Infrared imaging - Infrared radiation - Physiology - Plants (botany) - Rasterization - Remote sensing - Signal detection - Soil moisture - Statistical methods - Temperature measurement - Unmanned aerial vehicles (UAV) - Vectors - Water - Water conservation - Water resources
Uncontrolled terms:Canopy temperature - Crop water stress indices - Leaf stomatal conductance - Physiological indicators - Temperature characteristic - Thermal infrared - Thermal infrared remote sensing - Thermal infrared sensors
Classification code:444 Water Resources - 461.9 Biology - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 652.1 Aircraft, General - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 746 Imaging Techniques - 821.4 Agricultural Products - 921 Mathematics - 921.1 Algebra - 922.2 Mathematical Statistics - 944.6 Temperature Measurements - 944.7 Radiation Measuring Instruments
Numerical data indexing:Percentage 5.00e+01%, Percentage 6.50e+01%, Percentage 8.00e+01%, Percentage 9.50e+01% to 1.00e+02%
DOI:10.11975/j.issn.1002-6819.2018.15.010
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 4>
Accession number:20184506039288
Title:Dynamic response evaluation of hydraulic performance based on sediment deposition sensitivity to flow rate of dripper emitter
Authors:Wang, Xinduan (1); Bai, Dan (1); Song, Lixun (2); Guo, Lin (1)
Author affiliation:(1) Institute of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an; 710048, China; (2) School of Science, Xi'an Polytechnic University, Xi'an; 710048, China
Corresponding author:Bai, Dan(baidan@xaut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:85-91
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The performance of dripper irrigation emitter is of great concern in the emitter design and use. Generally, there are two important methods to estimate the performance of dripper emitters: their hydraulic performance and their anti-clogging performance. The hydraulic performance is always calculated in rinsing experiments; but in practice, although deposition and filtration techniques are adopted, fine sand particles can still penetrate into dripper emitters. This may change the forms and roughness of the flow channel. As a result, the hydraulic performance of dripper emitters in the field may greatly differ from initial rinsing tests. In addition, inlet pressures of dripper emitters may differ with different position in the field pipe network because of the influence of the topographical height difference and the head loss. So it is not particularly accurate to use the decrease in the rate of discharge under a fixed working pressure as usual to estimate the anti-clogging performance of dripper emitter. In order to overcome this discrepancy, we proposed a method to estimate the performance of dripper emitters that accounted for the influence of inlet pressure changes and sediment deposition on their hydraulic performance. We selected 3 bidirectional flow channels and 1 labyrinth channel for our study. Rinsing experiments were carried out at 50, 75, and 100 kPa to calculate the flow index of the dripper emitters. Periodic intermittent drip irrigation tests were also carried out to measure the changes of flow discharge using muddy water containing sediment particles with different sizes (all less than 0.125 mm); the sediment particles were formulated to 30 g/L of muddy water. The results showed that the flow indexes of selected dripper emitters in the muddy water experiment were bigger than the values in the rising experiment. This means that the hydraulic performance of the 4 types of dripper emitters got worse, which indicated, not surprisingly, that sediment deposits worsened the hydraulic performance. The increase in flow rates of No.0, No.1, No.2, and No.3 dripper emitters were 74.85%, 38.47%, 41.26%, 46.25%, respectively. After the muddy water experiment, the hydraulic performances of the bidirectional flow channels were still better than the contrastive labyrinth channel because the anti-clogging performance of bidirectional flow channels were better. The hydraulic performance of the 4 types of dripper emitters got worse and worse as muddy water irrigation frequency increased, which indicated that the larger the cumulative effect of sediment deposition could result in the greater influence on hydraulic performance. When the inlet pressure increased from 50 kPa to 100 kPa, the rates of discharge changes of No.0, No.1, No.2, and No.3 dripper emitters in the muddy water experiment were 40.43%, 17.23%, 19.43%, 22.33% higher than those in the rinsing experiment. The sensitivity of discharge to inlet pressure changes of the 4 types of drip emitters got bigger, which caused the hydraulic performance to drop. There were significant differences in hydraulic performance and anti-clogging performance among the bidirectional flow channels with different structural parameters; this indicated that structural parameters were the main factors affecting the overall performance of dripper emitters. Our method, using the dynamic response of hydraulic performance to sediment deposition in muddy water irrigation to evaluate the overall performance of dripper emitters, can improve dripper emitter development and provide a method guidance for measuring the overall performance of dripper emitters.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Sediments
Controlled terms:Channel flow - Deposition - Dynamic response - Flow rate - Irrigation - Pressure
Uncontrolled terms:Anti-clogging - Bi-directional flows - Dripper irrigation emitter - Filtration techniques - Hydraulic performance - Irrigation frequency - Sediment deposition - Structural parameter
Classification code:483 Soil Mechanics and Foundations - 631 Fluid Flow - 631.1 Fluid Flow, General - 802.3 Chemical Operations - 821.3 Agricultural Methods - 931.1 Mechanics
Numerical data indexing:Mass_Density 3.00e+01kg/m3, Percentage 1.72e+01%, Percentage 1.94e+01%, Percentage 2.23e+01%, Percentage 3.85e+01%, Percentage 4.04e+01%, Percentage 4.13e+01%, Percentage 4.62e+01%, Percentage 7.48e+01%, Pressure 5.00e+04Pa to 1.00e+05Pa, Size 1.25e-04m
DOI:10.11975/j.issn.1002-6819.2018.15.011
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 5>
Accession number:20184506039315
Title:Selection of nitrite and bioamine-degrading bacteria and its improvement of fish sausage quality
Authors:Xu, Nü (1); Li, Tiantian (1); Jia, Ruijuan (1); Zhang, Hao (1); Wang, Rufu (1)
Author affiliation:(1) Food Science and Engineering College, Shanxi Agricultural University, Taigu; 030801, China
Corresponding author:Wang, Rufu(wrf558@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:304-312
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the quality and food safety of Chinese fermented fish sausages, the activities of nitrite and biogenic amines degradation and related genes distribution in 19 Lactobacillus plantarum strains from different sources were investigated. The results showed that all strains had the ability of nitrite degradation with the reducing rate of 36%-95%. Among them, L. plantarum CP3 and MP1 (isolated from cupei and milk product respectively) had the strongest nitrite reducing ability, and the degrading rate could reach above 95% after 72 h. PCR (polymerase chain reaction) test suggested that all strains contained HP (hypothetical protein) gene. Detection rates of the other 2 nitrite degradation related genes GR (glutathione reductase) and ORD (oxidoreductase) were 47.36% and 42.10% respectively. There are few reports on genes of nitrate reductase in lactic acid bacteria. In future, the 3 genes encoding proteins sequence, enzyme activities and gene expression regulation should be studied in depth. Additionally, Suf I (multicopper oxidases) gene could be detected in all 19 strains. However, the biogenic amine degrading rate was so different, from 20% to 77%. There were 6 strains showing the degrading activity to all 8 tested biogenic amines. Ten strains (tryptamine degradation), 2 strains (putrescine degradation), 7 strains (tyramine degradation) and 3 strains (tyramine degradation, arginine degradation and spermidine degradation respectively) exhibited degradation rate of more than 50%. Also, we proved that the excellent target strain (L. plantarum CP3) did not contain potential harmful biogenic amines producing genes such as hdc (histidine decarboxylase gene), tdc (tyrosine decarboxylase gene) and odc (ornithine decarboxylase gene). Further, the effects of L. plantarum CP3 on nitrosamines, biogenic amines, microorganism and physico-chemical index of fish sausages were researched. The results showed that L. plantarum CP3 had a high inhibitory effect on all 4 N-nitrosamines: N-nitrosodiethylamine (NDEA), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR) and N-nitrosomethylamine (NMEA). Moreover, this ability could be synergistically enhanced when inoculated with L.saki M4 (another excellent strain for sausage fermentation in our previous study, which could produce bacteriocin). After 48 h fermentation, the putrescine, cadaverine and tyramine content were reduced by 76.83%, 93.33% and 88% respectively in the test group. Moreover, the results clearly demonstrated that due to the L. plantarum CP3 and L.saki M4 inoculation, lactic acid bacteria rapidly became dominant flora and the growth of food-borne pathogens, such as Enterobacteria spp. and Pseudomonas spp., was completely inhibited during sausages fermentation. Additionally, the pH values, thiobarbituric acid (TBA) and total volatile basic nitrogen (TVB-N) content were sharply reduced in inoculated sausages. In conclusion, L. plantarum CP3 can be considered as excellent candidate for microbial culture starters in fermented sausage production to inhibit nitrosoamines and biogenic amines accumulation and improve the product quality and safety.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Biodegradation
Controlled terms:Amines - Amino acids - Bacteria - Degradation - Enzyme activity - Fermentation - Fish - Food safety - Gene encoding - Gene expression - Gene expression regulation - Lactic acid - Meats - Nitrosamines - Polymerase chain reaction
Uncontrolled terms:Glutathione reductase - Lactobacillus plantarum - N-nitrosodiethylamine - N-nitrosodimethylamine - Nitrite - Ornithine decarboxylase - Total volatile basic nitrogens - Tyrosine decarboxylase
Classification code:461.8.1 Genetic Engineering - 461.9 Biology - 801.2 Biochemistry - 802.2 Chemical Reactions - 804.1 Organic Compounds - 822.3 Food Products
Numerical data indexing:Percentage 2.00e+01% to 7.70e+01%, Percentage 3.60e+01% to 9.50e+01%, Percentage 4.21e+01%, Percentage 4.74e+01%, Percentage 5.00e+01%, Percentage 7.68e+01%, Percentage 8.80e+01%, Percentage 9.33e+01%, Percentage 9.50e+01%, Time 1.73e+05s, Time 2.59e+05s
DOI:10.11975/j.issn.1002-6819.2018.15.038
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 6>
Accession number:20184506039301
Title:Detection of dairy cow lameness based on fitting line slope feature of head and neck outline
Authors:Song, Huaibo (1, 2, 3); Jiang, Bo (1, 2, 3); Wu, Qian (1, 2, 3); Li, Tong (1, 2, 3); He, Dongjian (1, 2, 3)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) Key Laboratory for Agricultural Internet of Things, Ministry of Agriculture and Rural Affair, Yangling; 712100, China; (3) Key Laboratory of Agricultural Information Perception and Intelligent Services, Yangling; 712100, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:190-199
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Lameness diseases could cause high elimination rate of the worthless dairy cow, and early detection of dairy cow lameness disease is a significant research field of dairy farming. In this research, a lameness detection method of dairy cows with the fusion of LCCCT (local circulation center compensation tracking) and DSKNN (distilling data of k-nearest neighbor) was proposed. By using the normal background statistical model (DNBSM), the dairy cow videos were decomposed into image sequences, and segmented to target region and backgrounds. Then, the obtained pixel area of the upper contour of the cow body was extracted by the LCCCT. In the detected region, DSKNN were used to extract the slope data of the head, neck and the back connected to the neck region. Firstly, the DNBSM model is used to separate the target dairy cow's pixel area and background from the dairy cow's sequence image. Since the frontal movement of dairy cow body is greater than the back movement of the dairy cow body, the DNBSM algorithm is used to lead to a better detection of the front body pixels for the dairy cow. Then, the LCCCT model is used to track and extract the pixel area of the front dairy cow body, and the DSKNN model is used to extract the target's head and neck for slope data of contour line fitted. The changes in the slope data of the fitted straight line of the dairy cow's head and neck were used as the basis for the detection of lameness of dairy cows. The characteristics of the slope data of head-neck fit lines of different dairy cows are different. Compared with other body parts of dairy cows, the head and neck area data of dairy cows are relatively easy to obtain. When dairy cows stand or walk, the head and neck characteristics can be extracted stably, which is the basis for judging lameness. The upper contour of the dairy cow's body starts from the tip of the dairy cow's head and ends beyond the neck line. If the extracted contour line belongs to a defined area range, it is considered to be a valid contour line. Outside this range, it is considered that the extracted contour line is abnormal or has an error. The videos were divided into 3 slope data sets with 3 kinds of labels including slight lameness, moderate-severe lameness, and normal based on large sample video sequence frame data. In order to verify the validity of the algorithm, a total of 18 videos of dairy cows were processed. The slope data set was obtained from fitting line at the junction of the head, neck and back region. On the original data set, SVM, Naive Bayes algorithm and KNN classification algorithm were used to test the accuracy of dairy cow lameness detection, and the detection correct rates of SVM and Naive Bayes algorithm were both 82.78%, which were higher than that of KNN algorithm which was 81.67%. Test result illustrates that the slope feature of fitting line at the junction of the head, the neck and the back can be used to detect dairy cow lameness diseases. After cleaning the original data set, the correct detection rate of lameness classification by KNN classification algorithm was 93.89%, and the correct detection rates of SVM classification and Naive Bayes classification algorithm were 91.11%, and 86.11%, respectively. The results show that the KNN classification algorithm can get better results using cleaned data set. The results of this research can provide the reference for the prevention and diagnosis of lameness disease of dairy cows.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Data mining
Controlled terms:Barium compounds - Chemical detection - Classification (of information) - Classifiers - Contour measurement - Diagnosis - Feature extraction - Image processing - Learning algorithms - Models - Nearest neighbor search - Pixels - Statistical tests - Text processing
Uncontrolled terms:Algoritms - Cassification - Dairy cow - Lameness detection - Tracking algorithm
Classification code:461.6 Medicine and Pharmacology - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 801 Chemistry - 802.1 Chemical Plants and Equipment - 903.1 Information Sources and Analysis - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 8.17e+01%, Percentage 8.28e+01%, Percentage 8.61e+01%, Percentage 9.11e+01%, Percentage 9.39e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.024
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 7>
Accession number:20184506039308
Title:Design and performance test of concentration solar PV/TE compound power generation system
Authors:Wang, Lishu (1); Feng, Guanghuan (1); Zhang, Xu (1); Sun, Shida (1); Li, Xinran (1)
Author affiliation:(1) Institute of Electrical and Information, 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:15
Issue date:August 1, 2018
Publication year:2018
Pages:246-254
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the 21st century, the intensive use of fossil fuels has inevitably brought extreme damage to our living environment. The air pollution of many cities is grave, and the global greenhouse effect is increasing unknowingly. All those problems have had a tremendous impact on human production and life, which also make it urgent to solve energy problems. Solar energy is one of the most promising, the most realistic, the most renewable and cleanest energy sources that can be exploited on a large scale in the world today. With the increasing environmental pollution and the increasing scarcity of energy, the development and use of solar energy have become an urgent task for human development. But, the efficiency is low, and there is a waste of heat energy. Therefore, in order to solve the problems about large-scale energy consumption of conventional energy resources in modern greenhouses, lower solar energy utilization efficiency and waste of waste-heat energy, based on the photoelectric conversion and the photothermal conversion, a concentration solar photovoltaic(PV)/thermoelectric(TE) compound power generation system was designed. Photovoltaic cells use the photovoltaic effect principle to generate electricity. The parabolic concentrator converges solar energy to the surface of photovoltaic cells and enhances solar radiation intensity. The thermoelectric cells are attached to the back panel of photovoltaic cells, and the thermoelectric cells are used to simultaneously convert the excess heat generated by photovoltaic cells to electricity energy. A triangular heat pipe is treated as heat transfer element, and a certain amount of water is used to effectively transfer the remaining heat. The following objectives have been accomplished: Some of the heat generated during the operation of photovoltaic cells was used to increase the temperature of hot side on thermoelectric cells; the other heat was transferred to heat storage tank by the convection of water in heat pipe and reused in heat storage tank. In order to test the electrical performance and thermal performance of this compound system, the corresponding electrical/thermal mathematical model was established in this paper, and the energy conversion of the system was analyzed to obtain the effect of different solar radiation intensities and different flow quantities on the system. At the same time, the system's test platform was set up, and annual tests were conducted in spring, summer, autumn and winter. Tests were conducted from 09:00 to 15:00 when the intensity of solar radiation was the strongest on the test day. The results show that the electrical efficiency and thermal efficiency of concentration solar PV/TE compound power generation system are greater than those by single power generation method, so the gradient utilization of energy can be realized by the system. During the winter test, the electrical efficiency of this compound system could reach 20.98%, the thermal efficiency could reach 39.81%, and the energy efficiency could reach 32.5%. It can be seen that the concentration solar PV/TE compound power generation system has better power property than a PV-TE hybrid power generation system without concentration solar energy. Moreover, the power obtained by operating this system can be supplied for environmental monitoring and lighting systems of the greenhouse. Especially in winter, the heat energy obtained can provide heat for the growth of crops in the greenhouse.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Energy efficiency
Controlled terms:Cells - Cytology - Energy conversion - Energy utilization - Fossil fuels - Greenhouse effect - Greenhouses - Heat pipes - Heat pump systems - Heat storage - Heat transfer - Photoelectrochemical cells - Photovoltaic cells - Photovoltaic effects - Pollution - Problem solving - Solar energy - Solar equipment - Solar power generation - Solar radiation - Tanks (containers) - Temperature - Testing - Thermoelectric energy conversion - Waste heat - Waste heat utilization
Uncontrolled terms:Environmental pollutions - Generation - Hybrid power generation systems - Photo-thermal conversions - Photoelectric conversion - Power generation methods - Power generation systems - Solar radiation intensity
Classification code:451 Air Pollution - 461.2 Biological Materials and Tissue Engineering - 525 Energy Management and Conversion - 615.2 Solar Power - 615.4 Thermoelectric Energy - 616.1 Heat Exchange Equipment and Components - 619.1 Pipe, Piping and Pipelines - 619.2 Tanks - 641.1 Thermodynamics - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 702.1 Electric Batteries - 821.6 Farm Buildings and Other Structures
Numerical data indexing:Percentage 2.10e+01%, Percentage 3.25e+01%, Percentage 3.98e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.031
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 8>
Accession number:20184506039293
Title:Suitability analysis of TRMM satellite precipitation data in regional drought monitoring
Authors:Chen, Shaodan (1, 2); Zhang, Liping (1, 2); Guo, Mengyao (1, 2); Liu, Xin (1, 2)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan; 430072, China; (2) Hubei Provincial Collaborative Innovation Center for Water Resources Security, Wuhan; 430072, China
Corresponding author:Zhang, Liping(zhanglp@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:126-132
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Drought is one of the most frequent and widespread natural disasters and has a tremendous impact on agriculture, ecology, society, and economy. Because the causes of drought are complex and there are many influencing factors, the applicability of drought indices has obvious regional and time-scale constraints. Among many drought indices, SPI (standardized precipitation index) using monthly precipitation data is simple to calculate and has multi-scale characteristics. And SPI is an indicator of the probability of precipitation occurring in a certain period. Moreover, SPI uses the probability density function to solve the cumulative probability and further normalizes the cumulative probability, eliminating the temporal and spatial distribution of precipitation. Therefore, the selected drought index is suitable for drought monitoring and evaluation of the climate above the monthly scale. In addition, the precipitation data are easily accessible and widely used in drought monitoring research. The drought index generally needs the observation data of the ground meteorological site for calculation. However, in practical applications, due to the spatial and temporal differences in the distribution of precipitation, limited ground station observations are difficult to truly reflect the spatial heterogeneity of precipitation, especially in areas where observation sites are sparse. Under these circumstances, the drought index calculated based on the data from meteorological site produced an error. With the rapid development of remote sensing technology, a series of precipitation products based on satellite remote sensing have emerged. Satellite-derived precipitation monitoring at high spatial resolution is essential for assessing the water and energy cycles at the global and regional scale. The Tropical Rainfall Measurement Mission (TRMM) satellite was successfully launched on November 27, 1997, and was the first meteorological satellite to measure tropical and subtropical precipitation. The TRMM 3B43 dataset used in this study was synthesized from the TRMM satellite data and other data. The spatial resolution of the TRMM 3B43 products is 0.25°×0.25° and extends from the latitude 50° S to 50° N. In order to evaluate the applicability of high spatial-temporal resolution satellite remote sensing precipitation products in drought monitoring, based on the tropical rainfall satellite products and station-based meteorological data, the SPI values at different time scales (1, 3, 6, and 12 months), which only used precipitation and could monitor both dry and wet conditions, were calculated during the period of 1998-2016 in Henan Province. The results showed that the monthly precipitation data of TRMM 3B43 have the high correlation with the observed data of meteorological stations, and the correlation coefficient is higher than 0.9. Except a few cases, TRMM 3B43 slightly overestimates the precipitation. In addition, there is a good agreement between the different time scales (1, 3, 6 and 12 months) calculated by the 2 data sources, and the fluctuation amplitude decreases with the increase of timescale. In addition, droughts occurred in the years of 1999, 2001, 2012 and 2013. Moreover, the correlative analysis was performed based on the SPI values at different time scales from the 2 data sources. The correlation coefficient was higher than 0.7. The consistency of the SPI values calculated by the 2 data sources at different time scales was high, indicating that TRMM data can replace site observation data for drought monitoring and evaluation. Therefore, our study on the suitability of the TRMM satellite precipitation data in regional drought monitoring can provide a new way for effective monitoring of meteorological and agricultural drought.<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:Agriculture - Disasters - Drought - Image resolution - Precipitation (chemical) - Probability density function - Probability distributions - Rain - Rain gages - Remote sensing - Satellites - Time measurement - Tropics
Uncontrolled terms:Cumulative probabilities - Henan Province - Remote sensing technology - Satellite remote sensing - Standardized precipitation index - Temporal and spatial distribution - TRMM 3B43 - Tropical rainfall measurement missions
Classification code:443 Meteorology - 443.3 Precipitation - 655.2 Satellites - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.1 Probability Theory - 943.3 Special Purpose Instruments
Numerical data indexing:Age 1.00e+00yr, Age 5.00e-01yr
DOI:10.11975/j.issn.1002-6819.2018.15.016
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 9>
Accession number:20184506039281
Title:Mathematical model establishment and validation of bionic irregular plantar surface of goat's hoof
Authors:Zhang, Fu (1, 2); Wang, Yafei (1); Ma, Tianle (1); Wang, Jiajia (1); Xu, Ruiliang (3); Guo, Zhijun (3)
Author affiliation:(1) College of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang; 471003, China; (2) Collaborative Innovation Center of Machinery Equipment Advanced Manufacturing of Henan Province, Luoyang; 471003, China; (3) Colleg of Vehicle &Transportation Engineering, Henan University of Science and Technology, Luoyang; 471003, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:30-36
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Goat is a typical quadrupedal animal which can walk steady and fast on complex terrain environment. The irregular surface topography of goat's hoof bottom is one of the key factors affecting the stability of goat walking on the rough terrain. The study on the irregular surface characteristics of the goat's hoof bottom will help to apply this superior feature to the 4-legged walking robots of goat-like agricultural, in order to solve the problem of poor walking stability of the agricultural 4-legged walking robots on rough pavement. In this study, male Boer goat's hoofs of 6 months were selected. In order to get the exact surface of the hoof, the hoof was sprayed with contrast intensifying agent and pasted mark points before the experiments, and the hoof point cloud data was obtained by using a 3D stereo scanner. The Geomagic Studio software was used to perform point cloud denoising, sampling, encapsulation and surface treatment to obtain the precise surface of the goat's hoof. The surface deviation analysis was carried out. The bottom surface of goat's hoof were divided into 2 parts according to the goat's hoof structure. The Digitized Shape Editor module in Catia software was used to filter the dense point clouds of the 2 surfaces and preserve the features of the curved surface, and the three-dimensional coordinate data of 2 regional feature points were derived. The 3D coordinate data of point cloud of feature surface were fitted by using cftool toolbox of Matlab software. The fitting equations of 2 surfaces, the residual square (SSE), standard deviation (RMSE) and the determination coefficient R<sup>2</sup> were obtained respectively. In order to verify the mathematical model of irregular surface at the bottom of goat's hoof, other 3 goat's hoof of the model were selected as the verification sample. The x and y coordinates of the characteristic surfaces of the three samples were substituted into the mathematical model respectively, and the mathematical model was validated. Research results show that the standard deviation for the surface of the hoof was 1.402 2 mm. The fitting result of the left curved surface on the bottom of the goat's hoof showed that the sum of squares for residuals (SSE), the standard deviation (RMSE) and the determination coefficient (R<sup>2</sup>) were 359, 0.792 9 and 0.988 9, respectively. The fitting result of the right curved surface on the bottom of the goat's hoof showed that the residual square (SSE), the root mean square error (RMSE) and the determination coefficient (R<sup>2</sup>) were 256.2, 0.725 3 and 0.987 9, respectively. The mathematical model validated results showed that the residual of model 1 ranged from 0.18 to 4.86, the residual of model 2 ranged from 0.13 to 5.25. The maximum relative error between the fitted and the actual values of the model were 8.63% and 9.58%, respectively, The error were 4.32% and 4.73%, respectively. The relative error was range of ±5%, which means the calculated values of the 2 mathematical models were in good agreement with the actual values. The validity of the model was verified and the transformation of irregular surface from biological model to mathematical model at the bottom of goat's hoof was realized. This research will provide theoretical foundation for the application of bionics to the surface morphology of the surface of goat's hoofs, and provide references for the study of the agricultural quadruped walking robots using bionics technology.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Surface topography
Controlled terms:Agriculture - Biomimetics - Bionics - Biophysics - Errors - Mathematical transformations - MATLAB - Mean square error - Mobile robots - Models - Reverse engineering - Statistics - Surface treatment - Walking aids
Uncontrolled terms:Characteristic surfaces - Determination coefficients - Maximum relative errors - Plantar surfaces - Quadruped walking robot - Root mean square errors - Theoretical foundations - Three dimensional coordinate
Classification code:461 Bioengineering and Biology - 731.5 Robotics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 921.3 Mathematical Transformations - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Age 5.00e-01yr, Percentage 4.32e+00%, Percentage 4.73e+00%, Percentage 8.63e+00%, Percentage 9.58e+00%
DOI:10.11975/j.issn.1002-6819.2018.15.004
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 10>
Accession number:20184506039291
Title:Effect of man-made forest on soil moisture of different slopes in upper and lower reaches of small watershed of Loess Plateau
Authors:Huang, Yanli (1, 2); Li, Zhanbin (1, 3, 4); Su, Hui (5); Bai, Lanfeng (4); Sun, Baoyang (1); Liu, Chenguang (1)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dry-land Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A& F University, Yangling; 712100, China; (2) College of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo; 454000, China; (3) Key Laboratory of Northwest Water Resources and Environment Ecology of Ministry of Education, Xi'an University of Technology, Xi'an; 710048, China; (4) Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling; 712100, China; (5) School of Life Science and Technology, Xinxiang University, Xinxiang; 453003, China
Corresponding author:Li, Zhanbin(zhanbinli@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:108-116
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil moisture is a key limiting factor of agricultural production and ecological restoration on the Loess Plateau. The comparative study on the soil moisture under the influence of different ecological managements at a small watershed scale as the basic unit of ecological restoration is of great significance to evaluate ecological effects and predict soil water accurately. Most importantly, it is essential for ecological planning and layout. In order to compare the soil water content (SWC) in the artificial forest watershed and natural restoration watershed and determine the relative deficit situation of the former, soil samples within the 120 cm profile in the 2 basins named Yangjiagou (Y) and Dongzhuanggou (D) were simultaneously taken to measure SWC of 9 layers every 4 days in August 2016. Both Y and D were inside the Nanxiaohegou watershed located in the Loess Gully Area of eastern Gansu Province and the former is of Robinia pseudopodia plantation, whereas the latter was of natural restoration. Of the 2 basins, the basic conditions such as zone, slope aspect and slope position of sampling slopes and sampling points were well contrasted. The SWC of different zones, slope aspects, slope positions and soil layers in each basin was analyzed by classical statistical methods. And a new indicator, difference ratio of soil moisture (DRSM) between the 2 different basins was used to quantitatively compare the SWC in Y and D. The results showed that: 1) In D, the SWC in the upper reaches was higher than that in the lower reaches, the SWC in the eastern slope was larger than that in the western slope, its ranking in the different slope positions from highest to lowest was toe-slope (16.96%) > waist-slope (14.34%) > shoulder-slope (11.80%), and there was significant difference between the different zones and slope aspects (P<0.05). The SWC continued to increase in the 20-120 cm soil layer after a brief decrease in the 0-20 cm soil layer down the profile. 2) In Y, as the plantation consumed soil water and regulated evaporation, the SWC decreased significantly and its distribution pattern was changed compared with that in D. Specifically, the soils in the lower reaches and eastern slope were more humid than that in the upper reaches and western slope, the SWC of the toe-slope was significantly higher than that of the waist-slope and shoulder-slope (P<0.05), and down the soil profile, it decreased continuously first in the 0-100 cm layer and then increased in the 100-120 cm layer. 3) The spatial variability followed the order of D (29.19%) > Y (23.51%), while the order of time variability was Y (10.99%) > D (8.76%). 4) The upper reaches, eastern slope, waist-slope and 60-120 cm soil layers were the main areas or layers with soil water deficit in Y, and the DRSM between Y and D was bigger. All the above results revealed spatial heterogeneity in soil desiccation caused by the Grain for Green at the small watershed scale and are expected to serve as the basis for the allocation and layout of vegetation in the ecological construction on the Loess Plateau.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Soil moisture
Controlled terms:Conservation - Ecology - Forestry - Landforms - Restoration - Sediments - Soil testing - Vegetation - Watersheds
Uncontrolled terms:Agricultural productions - Distribution patterns - Ecological construction - Ecological managements - Ecological restoration - Natural restoration - Soil water content - Spatial heterogeneity
Classification code:444.1 Surface Water - 454.3 Ecology and Ecosystems - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics
Numerical data indexing:Age 1.10e-02yr, Percentage 1.10e+01%, Percentage 1.18e+01%, Percentage 1.43e+01%, Percentage 1.70e+01%, Percentage 2.35e+01%, Percentage 2.92e+01%, Percentage 8.76e+00%, Size 0.00e+00m to 1.00e+00m, Size 0.00e+00m to 2.00e-01m, Size 1.00e+00m to 1.20e+00m, Size 1.20e+00m, Size 2.00e-01m to 1.20e+00m, Size 6.00e-01m to 1.20e+00m
DOI:10.11975/j.issn.1002-6819.2018.15.014
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 11>
Accession number:20184506039280
Title:Design and experiment of auto spreading and raking fascicles device for straw braiding machine
Authors:Liu, Dawei (1, 2, 3); Xie, Fangping (1, 2, 3); Wu, Bei (1); Wang, Xiushan (1); Xie, Jinfan (1)
Author affiliation:(1) College of Engineering, Hunan Agricultural University, Changsha; 410128, China; (2) Collaborative Innovation Center of Southern Chinese Grain and Oilseed, Changsha; 410128, China; (3) Hunan Provincial Engineering Technology Research Center for Modern Agricultural Equipment, Changsha; 410128, China
Corresponding author:Xie, Fangping(hunanxie2002@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:19-29
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Straw is a rich resource in quantity, but large amount of waste rice straw has been burned in the field, which causes waste of resource and environmental pollution at the same time. Straw is an important production resource, and the straw mats are widely used as a protective tool for bricks, buildings, agaric production and vegetable greenhouse, etc. According to literature and data reviewed, rice straw abroad is mainly used for field return and recycling, and straw mats braiding machine are rarely reported abroad. While in China, a type of mature flat straw braiding machine was widely used in the north. This kind of machine relies on human spreading and needs operators to stand on either side of the machine to continuously lay straws onto the conveyor surface regularly. It has many problems, such as high labor intensity, poor working conditions and so on. With the increase of labor cost, the demand for the automatic spreading conveyor of the machinery becomes more and more imperative. In order to realize mechanical feeding, improve working performance of the straw braiding machine and reduce the labor intensity, an automatic spreading and raking fascicles device for straw has been developed by simulating the actions of humans, which can be used as the matching equipment of the existing flat braiding machine. The device is composed of 2 parts: dip-angle bisecting spreading and multi-link raking fascicles. Straw can be proportionately fed into the braiding machine. Kinematic analysis of key components and parameter optimization are carried out by using ADAMS software. However, there are no available standards for the performance test of the weaving machines. In addition, the weaving quality of the straw mats are related to weaving speed, straw quality, evenness of laying and many other factors, and there are also many uncontrollable factors. While considering these, experimental tests have been firstly performed to find out the relationship between weaving speed and needle frequency (f<inf>z</inf>) of the flat straw braiding machine, and taking laying thickness as the index, to test the working performance of the auto spreading and raking fascicles device. Prototype testing were carried out at different weaving speeds, and the operating frequency range of 3 components, which are the dip-angle bisecting spreading, multi-link raking fascicles and knitting lock device, were obtained. In order to test the working condition of the automatic device and the weaving quality of the straw mats, fascicles rate (F<inf>s</inf>) and leak rate (L<inf>b</inf>) are used as the evaluation indexes which have been contrastively analyzed at 3 different weaving speeds and corresponding operating frequencies during the complete machine performance test. The results indicated that mean thickness of the spreading straws is less than 40 mm from auto spreading and raking fascicles device, which can accord with the design requirements for the following weaving process. And used with the flat straw braiding machine, the fascicles rate (F<inf>s</inf>) of the straw is 92.12% and the leak rate (L<inf>b</inf>) is 5.44%, when the needle frequency (f<inf>z</inf>) is 0.8 Hz, weaving speed (v<inf>b</inf>) is 90 m/h, and setting the frequencies of the dip-angle bisecting spreading (f<inf>t</inf>) and multi-link raking fascicles (f<inf>p</inf>) as 0.8 Hz and 1.13 Hz respectively, which can meet the use requirements. Compared with traditional manual feeding method, the use of the device reduces labor cost and improves production efficiency. It can reduce 2 workforces at the constant weaving speed, increase the annual income by nearly 8 640 yuan for each machine. In addition, the device is driven by link motion, shock and vibration will occur during the weaving process. In this experiment, the influences of velocity and acceleration changes of each component on straw spreading efficiency and whole machine properties need to be further analyzed and verified.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Weaving
Controlled terms:Agricultural machinery - Conveyors - Cost accounting - Efficiency - Employment - Experiments - Needles - Quality control - Speed - Straw - Wages
Uncontrolled terms:Braiding machines - Environmental pollutions - Parameter optimization - Production efficiency - Raking fascicles - Spreading - Straw mats - Uncontrollable factors
Classification code:692.1 Conveyors - 819.5 Textile Products and Processing - 821.1 Agricultural Machinery and Equipment - 821.5 Agricultural Wastes - 901.3 Engineering Research - 911.1 Cost Accounting - 912.4 Personnel - 913.1 Production Engineering - 913.3 Quality Assurance and Control
Numerical data indexing:Frequency 1.13e+00Hz, Frequency 8.00e-01Hz, Percentage 5.44e+00%, Percentage 9.21e+01%, Size 4.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.15.003
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 12>
Accession number:20184506039289
Title:Influence of red loam particles, fertilizer concentration and irrigation method on clogging of different irrigation emitters
Authors:Yu, Yang (1); Xu, Wenqi (1); Song, Shiyu (1); Yang, Haolin (1); Zhang, Yijie (1)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Yunnan Agricultural University, Kunming; 650201, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:92-99
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is important to study the factor of clogging of emitter, which is the prerequisite for drip fertigation technology to be used and promoted in Yunnan red loam. In this paper, we chose three different irrigation emitter types (drip irrigation belt embedded with inner patch, 2-hole flow adjustable emitter and 8-hole flow adjustable emitter) as study subject under the water quality condition combined with three fertilization concentrations (0, 0.6 and 1.2 g/L) and three sediment particles size range were applied on root area infiltration irrigation and surface drip irrigation. The irrigation experiment of 5 min each time was conducted under working pressure of 20 kPa for three days. The difference in weight of the flowerpots before and after irrigation was the amount of water irrigated. After the experiment, the irrigation amount of emitters was recorded. If the relative flow rate of emitter was below 75%, the test stopped and then recorded effective irrigation times. The results showed that there was a very significant interaction between the soil particle size and emitter types, fertilizer concentration and emitter types, irrigation types and emitter types (P<0.01), but there was no significant interaction between them (P>0.05). The bigger Yunnan red loam particle size, the easier clogging was made on flow adjustable emitter. Such as 2-hole flow adjustable emitter on surface drip irrigation,when the application rate of fertilizer was 0 g/L, the effective irrigation times of muddy water with three different particles size range were 11, 8 and 5, respectively. As for drip irrigation belt embedded with inner patch, Yunnan red loam particle size ranging 0.0385 - 0.074 mm was the easiest to cause clogging and the particle size ranging 0 - 0.0385 mm was the least to cause clogging. The fertilization has a significant influence on the clogging of the emitter. When the fertilizer concentration was less than 0.6 g/L, the large impact of fertilizer application on emitter was most obvious. When the fertilizer concentration was more than 0.6 g/L, the number of effective irrigation times did not have obvious change. However, the trend of the relative flow rate of the emitter increased, indicating that the blockage of the emitter increased. The irrigation type was an important factor affecting the clogging of emitter and it had different effects on different emitter. For 8-hole flow adjustable emitter, the anti-blocking performance of the surface drip irrigation was better than the root area infiltration irrigation. Under the surface drip irrigation, when the application rate of fertilizer was 0, the total effective irrigation times with three different particle sizes were four times more than root area infiltration irrigation. When the application rate of fertilizer was 1.2 g/L, the total effective irrigation times with 3 different particle sizes were 18 times and the root area infiltration irrigation were 15 times. For 2-hole flow adjustable emitter and drip irrigation belt embedded with inner patch, two different irrigation types did not have abviously different for effective irrigation times. Under the condition of fertilizing in muddy water, the performance of different emitter on clogging was different. The most clogged emitter was 8-hole flow adjustable emitter, followed by 2-hole flow adjustable emitter and the last was drip irrigation belt embedded with inner patch. This paper provides a theoretical basis for the application and familiarization of drip fertigation technology in Yunnan red loam.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Infiltration
Controlled terms:Fertilizers - Irrigation - Particle size - Water quality
Uncontrolled terms:Blocking performance - Clogging - Different particle sizes - Emitters - Fertigations - Fertilizer applications - Sediment particles - Surface drip irrigations
Classification code:445.2 Water Analysis - 804 Chemical Products Generally - 821.3 Agricultural Methods
Numerical data indexing:Mass_Density 0.00e+00kg/m3, Mass_Density 1.20e+00kg/m3, Mass_Density 6.00e-01kg/m3, Percentage 7.50e+01%, Pressure 2.00e+04Pa, Size 0.00e+00m to 3.85e-05m, Size 3.85e-05m to 7.40e-05m, Time 3.00e+02s
DOI:10.11975/j.issn.1002-6819.2018.15.012
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 13>
Accession number:20184506039304
Title:Influence factors of batch dry anaerobic digestion for corn stalks-cow dung mixture
Authors:Yu, Jiadong (1); Zhao, Lixin (1); Feng, Jing (1); Yao, Zonglu (1); Huang, Kaiming (1); Luo, Juan (1)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture, Beijing; 100125, China
Corresponding author:Zhao, Lixin(zhaolixin5092@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:215-221
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The batch dry anaerobic digestion (AD) has the characteristics of increasing raw material handling capacity, and reducing energy consumption, and the biogas residue can be directly used for producing organic fertilizer, but its methane production efficiency needs to be further improved. Previous study of the batch dry AD is limited to only one or two factors, but there is still no systematic study on multi-factor interactions to improve methane production efficiency. In order to further improve the methanogenic efficiency of the batch dry AD process of agricultural waste in China, this paper studied the various environmental factors affecting the efficiency of the batch dry AD. It further clarified the characteristics of dry AD and microbial community characteristics of the corn stalks mixed with cow dung under different factors, and identified the important influence factors and their interactions. The experiment was designed using the method of Plackett-Burman. A total of 12 experiments were carried out at a digestion temperature of (38±0.5) ℃ for 40 d. The results showed that when the dry digestion system had a solid content of 25%, the TS (total solid) ratio of corn stalks to cow dung was 3:7, the inoculum concentration (TS mass fraction) was 50%, the particle size of corn stalks was 1 cm, and the spray strategy was with the interval of 2 h and with the amount of 4 L, the volumetric methane production efficiency was significantly increased (P<0.05), and a large amount of propionic acid accumulation occurred in the acidified reactor. The reactors A, C, D, E and L produced methane significantly, and the methane production rate by the reactor E with the TS ratio of corn stalks to cow dung of 3:7 was significantly increased by 2.3 times compared with that by the reactor A with the ratio of 7:3. When the spraying frequency in the reactor L was 4 times that of the reactor E, the volume methanogenic rate was increased by 2.7 times. Properly increasing the spray frequency, inoculum concentration and proportion of cow dung in the raw material ratio can be conducive to promoting the improvement of methane production efficiency. And the high-efficient methane production can last for 27 d, and the volumetric methane yield is 0.70 L/(L•d). By analyzing the contribution, it is showed that the spray frequency and inoculum concentration played a key role in promoting the volumetric methanogenic rate of the batch dry AD, with the contributions of 30.84% and 24.96%, respectively. The bacterial community had a significant effect on the methane production characteristics of the batch dry AD (P<0.05). Properly increasing the spraying frequency and increasing the inoculum concentration promoted the abundance of Ruminofilibacter, Hydrogenispora and Ruminiclostridium as well as the microbial community structure and diversity. The abundance of the 3 kinds of microbes in the reactor A, C, D, E, and L with obvious methane formation was 9.30%-33.70%, 6.30%-11.00%, and 8.50%-14.90%, respectively, which had a significant synergistic relationship with methane production and an important regulatory effect on improving the batch dry AD environment. This study provides a theoretical reference for optimizing the key factors of the dry AD of agricultural waste.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Anaerobic digestion
Controlled terms:Agricultural wastes - Agriculture - Bacteria - Energy efficiency - Energy utilization - Fertilizers - Manures - Materials handling - Methane - Particle size - Propionic acid - Straw
Uncontrolled terms:Dry anaerobic digestions - Environmental factors - Influence factors - Inoculum concentrations - Microbial communities - Microbial community structures - Propionic acid accumulations - Reducing energy consumption
Classification code:525.2 Energy Conservation - 525.3 Energy Utilization - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes
Numerical data indexing:Percentage 2.50e+01%, Percentage 3.08e+01%, Percentage 5.00e+01%, Percentage 8.50e+00% to 1.49e+01%, Percentage 9.30e+00% to 3.37e+01%, Size 1.00e-02m, Time 7.20e+03s, Volume 4.00e-03m3
DOI:10.11975/j.issn.1002-6819.2018.15.027
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 14>
Accession number:20184506039306
Title:Industrial chain optimization of circular agricultural garden based on analysis of material flow and energy flow
Authors:Yuan, Xuefeng (1); Yao, Yichen (1); Song, Chengjun (2); Liu, Tianchi (3); Dong, Qiang (3); Tian, Yishui (2)
Author affiliation:(1) School of Earth Science and Resources, Chang'an University, Xi'an; 710054, China; (2) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agriculture Waste, Ministry of Agriculture, Beijing; 100125, China; (3) Tianshui National Agricultural Science and Technology Park Management Committee, Tianshui; 741030, China
Corresponding author:Tian, Yishui(yishuit@yahoo.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:228-237
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Circular agricultural park can be an important measure to enhance the construction of ecological civilization and the green development of agriculture, and it is also an essential trend of green development theory in the field of agriculture. In the analysis of this paper, the material and energy flow (MEFA) were used to clarify the industrial structure of the park, master the practical operations of the industrial chain, optimize the resource allocation, promote the productivity efficiency of resources and energy, add the complementary chain of circular economy, increase the recycling utilization rate of the waste, which could make the economy of the agricultural park develop, promote the sustainable utilization of resource and environment protection as well. The Gansu National Agricultural Science and Technology Park was investigated in this study, the general information of the park and detailed data like the enterprise input, output and etc were obtained. Under field investigation, the material and energy flow in the park and appropriate index evaluation system were built to understand the status of the circular agriculture, and then the main factors that restrict the circular economy development in the park were analyzed. Based on that, we put forward the change approach of industrial chain, estimated the future status of circular agriculture in the park and analyzed the feasibility of the new circular economy development pattern. The research results showed that: 1) The resource productivity was 5 400 RMB/t, the ratio of recycled material was 51.75% and energy consumption for each unit of GDP was 0.038 t per thousand RMB, which indicated that the ratio of the clean resource utilization was relatively low and it was hard to reach a balance between economic development and ecological conservation. The productivities of some industries were limited, the resource allocation was not reasonable and the industry coupling was of low magnitude. 2) The park could enlarge the current productivity by importing food processing industry, promoting photovoltaics, biogas and processing projects for densified biomass fuel. And it could also increase the income and the production efficiency of resources and energy, decrease the environmental damage, boost the circular economy development of the whole park. 3) Based on the enlarging the industry scale and adjusting the industrial structure, the park should implement measures as followed: First, the environmental supervision and the distribution of new energy sources should be strengthened, and the clean energy such as photovoltaic power, biomass, etc., is encouraged to use; Secondly, it should have revolution on supply side, which meant that the economic orientation should be decided by the market demand, and blind production and bubble economy under saturated market should be avoided; Thirdly, it must pay more attention to make products demand-lead and avoid the superfluous administrative intervention; Fourthly, it should improve the scientific innovation of the park to make a good example under the 'enterprise-university-research' cooperation. Based on the above research results, the industrial structure after adjustment can not only give a resolution to the inherent waste, but also significantly promote the utility efficiency of the resources and energy of the whole park. It has reference significance to the development, planning and evaluation of circular economy of other industrial parks.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Energy efficiency
Controlled terms:Agriculture - Chains - Commerce - Ecology - Economic analysis - Economic and social effects - Energy utilization - Food processing - Industrial research - Optimization - Photovoltaic cells - Productivity - Recycling - Resource allocation
Uncontrolled terms:Agricultural parks - Agricultural science and technologies - Energy flow - Environmental supervision - Food processing industry - Industrial chain - Material and energy flows - Material Flow
Classification code:452.3 Industrial Wastes - 454.3 Ecology and Ecosystems - 525.2 Energy Conservation - 525.3 Energy Utilization - 602.1 Mechanical Drives - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.2 Food Processing Operations - 911.2 Industrial Economics - 912.1 Industrial Engineering - 912.2 Management - 921.5 Optimization Techniques - 971 Social Sciences
Numerical data indexing:Percentage 5.18e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.029
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 15>
Accession number:20184506039279
Title:Development of automatic depth control device for semi-feeding four-row peanut combine harvester
Authors:Chen, Zhikai (1); Wu, Huichang (1); Zhang, Yanhua (1); Peng, Baoliang (1); Gu, Fengwei (1); Hu, Zhichao (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing; 210014, China
Corresponding author:Hu, Zhichao(zchu369@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:10-18
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the increase in labor costs and the development of peanut large-scale production in China, the demand for high-efficient peanut combine harvesters has become increasingly urgent. 4HLB-4 type semi-feeding four-row peanut combine harvester can harvest 2 ridges (4 rows) at one time, whose productive efficiency is more than twice that of the existing semi-feeding two-row peanut combine harvester. At present, simple mechanical depth-control devices such as depth-control plates and depth-control wheels have been widely used on the semi-feeding peanut combine harvester, but in practice, it is found that simple mechanical depth-control devices are difficult to meet the requirements of precision and high efficiency. In the application of semi-feeding four-row peanut combine harvester, there are many problems such as slow response and poor accuracy, which easily result in high peanut leakage rate and breakage rate. In order to overcome the above problems, in this paper, a set of automatic depth control device for 4HLB-4 type semi-feeding four-row peanut combine harvester was designed by adopting electronic sensor technology, hydraulic driving technology and microprocessor control technology comprehensively. The device was composed of a depth-control profiling mechanism, an excavation depth adjustment mechanism, a hydraulic execution system, a microprocessor control system and a control software. The working principle of the device is as follows: The depth-control profiling mechanism senses the change of the ridge top undulation, converts the fluctuating changing amount into the angle information, and then transmits it to the angle encoder. The angle encoder converts the angle information into a digital signal and transmits it to the controller. Based on the compiled program, the controller analyzes the angle signal and then outputs the solenoid valve control signal to open the hydraulic cylinder to drive oil circuit. The hydraulic cylinder drives the excavation depth adjustment mechanism to adjust the height of the excavating shovel. At the same time, an articulated linear displacement sensor installed in parallel with the hydraulic cylinder of the harvesting platform is used to measure the displacement of the hydraulic cylinder and feed it back to the controller. According to the processing result of the displacement, the controller adjusts the output control signal to ensure that the depth of excavation is stable so that the entire automatic depth-control system forms a closed loop feedback system. In this system, the controller is a single-chip microprocessor IAP15W4K58S4. The control software program adopts the fixed dual-threshold dead-zone PID (proportion, integral, derivative) control algorithm, and is compiled by C language in Keil uVision4. It increases system noise immunity, avoids frequent shocks of control action, and improves control stability. The field harvesting test showed that the automatic depth-control system was stable and reliable. After 4HLB-4 type semi-feeding four-row peanut combine harvester adopted the system, the average leakage rate was 1.08%, the average breakage rate was 0.94%, and the average excavation depth was 123 mm. Compared with the artificial depth-control harvesting test results, it was found that the average leakage rate decreased by 2.13 percentage points, the average breakage rate decreased by 1.4 percentage points, the average excavation depth deviation decreased by 11 mm, and the excavation depth deviation was more stable. This study can provide some reference for the development of automatic depth-control systems for other under-soil fruit harvesting machines.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Controllers
Controlled terms:Agricultural machinery - C (programming language) - Combines - Control engineering - Cylinders (shapes) - Depth profiling - Efficiency - Excavation - Feeding - Harvesters - Harvesting - Hydraulic machinery - Mechanical actuators - Oilseeds - Proportional control systems - Sensors - Signal encoding - Solenoid valves - Wages
Uncontrolled terms:Automatic depth controls - Closed-loop feedback system - Combine harvesters - Intelligen - Linear displacement sensor - Microprocessor control system - Productive efficiencies - Single chip microprocessor
Classification code:619 Pipes, Tanks and Accessories; Plant Engineering Generally - 632.2 Hydraulic Equipment and Machinery - 691.2 Materials Handling Methods - 716.1 Information Theory and Signal Processing - 723.1.1 Computer Programming Languages - 731.1 Control Systems - 732.1 Control Equipment - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 912.4 Personnel - 913.1 Production Engineering
Numerical data indexing:Percentage 1.08e+00%, Percentage 9.40e-01%, Size 1.10e-02m, Size 1.23e-01m
DOI:10.11975/j.issn.1002-6819.2018.15.002
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 16>
Accession number:20184506039292
Title:Estimation of greenhouse cucumber evapotranspiration in different seasons based on modified dual crop coefficient model
Authors:Yan, Haofang (1); Wu, Haimei (1); Zhang, Chuan (2); Acquah, Samuel Joe (1); Zhao, Baoshan (1); Huang, Song (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang; 212013, China; (2) Institute of Agricultural engineering, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:117-125
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to estimate the transpiration of greenhouse cucumber and evaporation beneath the canopy in greenhouses, in this study, we modified basic crop coefficient (K<inf>cb</inf>) as well as soil evaporation coefficient (K<inf>e</inf>) based on the Modified Dual Crop Coefficient model recommended by FAO-56 by applying measured meteorological data, leaf area index (LAI) and soil moisture data in a greenhouse. The greenhouse reference crop evapotranspiration (ET<inf>0</inf>) was determined by FAO-56 modified Penman-Monteith (P-M) model. Hence, the greenhouse evapotranspiration (ET<inf>c</inf>) and transpiration (T<inf>r</inf>) were estimated. A field experiment was conducted from March to July (spring-summer) and August to November (autumn-winter) in 2017. By measuring the growth status of cucumber plants in different planting seasons (spring-summer, autumn-winter) in a Venlo-type greenhouse and measuring the ET<inf>c</inf> and T<inf>r</inf> of cucumber by lysimeter and stem flow meter, the Modified Dual Crop Coefficient model predictions were validated. The results showed that the ET<inf>c</inf> and T<inf>r</inf> calculated by the Modified Dual Crop Coefficient model were in good agreements with the measured values. The measured and estimated values of ET<inf>c</inf> during the whole growing period of greenhouse cucumber in spring-summer were 2.94 and 3.05 mm/d, and the measured and estimated values of ET<inf>c</inf> during the whole growth period of greenhouse cucumber in autumn-winter were 2.76 and 2.53 mm/d, respectively. The coefficient of determination (R<sup>2</sup>), the root mean square error (RMSE), and the model efficiency coefficient (E<inf>ns</inf>) of the Modified Dual Crop Coefficient model in predicting spring-summer cucumber ET<inf>c</inf> were 0.95, 0.41 mm/d and 0.93, respectively, while the results of error analysis of predicting autumn -winter ET<inf>c</inf> were 0.91 (R<sup>2</sup>), 0.48mm/d (RMSE), and 0.90 (E<inf>ns</inf>). Based on the modification of Dual Crop Coefficient model,the basal crop coefficient of each growing stage of cucumber for spring-summer season were adjusted as 0.17-0.25 (the initial season stage), 1.05 - 1.10 (the middle season stage), 0.33 - 0.68(the late season stage), and the corresponding values for autumn-winter season were adjusted as 0.14 - 0.36 (for the initial season stage), 0.99 - 1.16 (the middle season stage), 0.45 - 0.71 (the late season stage). The measured and estimated daily T<inf>r</inf> values by the Modified Dual Crop Coefficient model for spring -summer season were 2.19 and 2.37 mm/d, and the measured and estimated average daily T<inf>r</inf> values by the Modified Dual Crop Coefficient model for autumn-winter season were 1.34 and 1.43 mm/d, respectively. Based on the result of estimation, the ratio of average daily T<inf>r</inf> to ET<inf>c</inf> was the highest in the middle season stage with the values of 84.36% (spring-summer season) and 84.79% (autumn-winter season), respectively. The ratio of average daily T<inf>r</inf> to ET<inf>c</inf> was the lowest in the initial season stage with the values of 28.98% (spring-summer season) and 17.64% (autumn-winter season). During the whole growing period, the ratio of average daily T<inf>r</inf> to ET<inf>c</inf> for spring-summer and autumn-winter seasons were 64.62% and 68.59%, respectively. Therefore, the Modified Dual Crop Coefficient model can accurately estimate the T<inf>r</inf> of greenhouse cucumber and evaporation beneath the canopy in greenhouses. The study results not only provide the theoretical basis for formulating accurate greenhouse cucumber irrigation system, but also have important significance for controlling greenhouse environment and reducing invalid soil evaporation in greenhouses.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Evapotranspiration
Controlled terms:Crops - Flow measurement - Flowmeters - Forecasting - Greenhouses - Mean square error - Meteorology - Plants (botany) - Soil moisture - Soil surveys - Transpiration
Uncontrolled terms:Basal crop coefficients - Coefficient of determination - Crop coefficient - Greenhouse environment - Leaf Area Index - Reference crop evapotranspirations - Root mean square errors - Stem flow
Classification code:461.9 Biology - 483.1 Soils and Soil Mechanics - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures - 922.2 Mathematical Statistics - 943.1 Mechanical Instruments - 943.2 Mechanical Variables Measurements
Numerical data indexing:Percentage 1.76e+01%, Percentage 2.90e+01%, Percentage 6.46e+01%, Percentage 6.86e+01%, Percentage 8.44e+01%, Percentage 8.48e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.015
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 17>
Accession number:20184506039295
Title:Soil-bin experiment on effects of contour ridge tillage for controlling hillslope soil erosion in black soil region
Authors:Wang, Lei (1); He, Chao (1); Zheng, Fenli (1, 2); Bian, Feng (3); Qin, Chao (1); Xu, Ximeng (1)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China; (2) Institute of Soil and Water Conservation CAS & MWR, Yangling; 712100, China; (3) College of Natural Resource and Environment, Northwest A&F University, Yangling; 712100, China
Corresponding author:Zheng, Fenli(flzh@ms.iswc.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:141-148
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ridge tillage is the most common tillage method in Mollisol region of Northeast China, and contour ridge tillage is one of the practices to promote soil and water conservation on the farmland. However, the effects of contour ridge tillage for controlling hillslope soil erosion and its erosion process under different rainfall intensities have not been fully investigated. Studying the hillslope soil erosion controlling effects of contour ridge can provide basic information for designing hillslope soil conservation practices. A simulated rainfall experiment was designed to study the effects of contour ridge tillage for controlling hillslope soil erosion in balck soil region of northeast China, three rainfall intensities (50, 75 and 100 mm/h), one slope gradient (5°), two surface treatments of contour ridge tillage and flat tillage were conducted, and a soil box with 8 m long and 3 m wide was used in this study. The results showed that contour ridge tillage has a significant effect on erosion prevention under rainfall intensity of 50 mm/h, and there was almost no runoff and soil loss compared with flat hillslope. In 75 and 100 mm/h treatments, the runoff and soil loss processes on contour ridge hillslope obviously had abrupt changes before and after the ridge failure. Compared with the flat tillage hillslope, before contour ridges failure, the contour ridge tillage reduced more than 97.7% of runoff and soil loss, runoff intensities and erosion rates were 0.01 - 0.06 times and 0.01 - 0.02 times lower than that of flat hillslope, respectively, and water storage capacities for contour ridge hillslope under three rainfall intensities were greater than 97.2%, which indicated that contour ridge tillage had a satisfactory effect for controlling hillslope soil erosion. However, when contour ridges failure occurred, soil loss greatly increased and correspondingly effects of contour ridge tillage for controlling hillslope sharply decreased. Hillslope soil loss was closely responding to runoff rate after ridges failure. The runoff and soil loss after ridges failure increased by 23.3- 25.9 and 136.8-171.5 times than that before ridges failure, respectively; and water storage capacity respectively decreased 50% and 10% under 75 and 100 mm/h rainfall intensities, while soil loss increased by 63.7% and 35.8%. Hillslope soil loss of the treatment with contour ridge tillage was 2.7 - 3.6 times higher than the flat tillage under the rainfall intensities of 75 and 100 mm/h. Contour ridge tillage might have a better effects for controlling hillslope soil erosion under the rainfall intensities less than 50 mm/h, but contour ridges failure occurred frequently under the high rainfall intensities, resulting in a dramatic decrease of the erosion control effect. Although ridge failure occurred under large rainfall intensity treatments, the water volume intercepted (including infiltration and impoundment) was still remarkable. It was found that the ridge stability improved in wide-ridge tillage system in field survey, and the popularization of the wide-ridge tillage was expected to further improve the effect of erosion control. Therefore, the future work should be focused on the improvement of contour ridge tillage to better control the hillslope erosion in Mollisol region of northeast China, and more research should be conducted on contour ridges failure to better understand and predict this process in ridge tillage systems of the balck soil region.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Soil conservation
Controlled terms:Agriculture - Erosion - Rain - Runoff - Soil structure interactions - Soils - Water conservation
Uncontrolled terms:Erosion control - Ridge failure - Ridge tillage - Simulated rainfall - The balck soil region
Classification code:443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 483.1 Soils and Soil Mechanics - 483.2 Foundations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.00e+01%, Percentage 3.58e+01%, Percentage 5.00e+01%, Percentage 6.37e+01%, Percentage 9.72e+01%, Percentage 9.77e+01%, Size 3.00e+00m, Size 8.00e+00m
DOI:10.11975/j.issn.1002-6819.2018.15.018
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 18>
Accession number:20184506039305
Title:Effects of composition ratios on burning stability and laminar burning characteristics of biogas
Authors:Zeng, Wen (1); Liu, Jing (1); Liu, Yu (1); Liu, Aiguo (1)
Author affiliation:(1) School of Aerospace Engineering, Shenyang Aerospace University, Shenyang; 110136, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:222-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For the purposes of reducing CO<inf>2</inf> emissions during combustion of fossil fuels and removing wastes due to environmental and health concerns, biomass derived gas (biogas), an attractive and potentially renewable energy source from wood, waste, landfill, and alcohol fuels via gasification, pyrolysis or fermentation processes, has been widely studied as a supplement for fossil fuels. At present, the fuel used for the gas turbine for power generation is generally natural gas or light diesel. For the gas turbine using natural gas as fuel, when the fuel is changed from natural gas to biogas, the fuel composition changes, and the calorific value decreases. Moreover, the requirements of environmental protection, as well as the reliability and economy of the gas turbine need to be met. At the same time, the content of each component in biogas varies significantly due to the influence of many factors (such as pyrolysis temperature and feedstock), which have a significant effect on its calorific value, ignition characteristics, and combustion characteristics. Therefore, it is very necessary to have a full understanding of the effects of the main compositions ratios on the combustion characteristics of biogas (such as the flame propagation characteristics, the combustion stability, laminar and turbulent combustion velocities etc.) in order to adjust and improve the combustion chamber structure and operating parameters of the gas turbine. The experimental methods used to measure the combustion characteristics of fuel included the hedging flame, Bunsen burner, and the constant volume bomb method. Compared with other testing methods, the constant volume bomb method has been widely applied because it can conveniently analyze the flame stretching effect and flame stability during flame propagation. In this paper, the effects of the main compositions ratios on the combustion stability and laminar burning characteristics of biogas, the flame propagation characteristics of biogas over the equivalence ratio range of 0.8-1.3, the pressure range of 0.1-0.3 MPa, the temperature of 320 K, and the methane volume fractions of 47%, 55.5% and 59% were measured in the constant volume bomb. Furthermore, the effects of main compositions ratios on the combustion stability and burning velocity of biogas in laminar combustion were investigated. The results showed that the flame front was kept smoothly and quasi-spherical outward was developed at the conditions that the initial temperature was 320 K, the equivalence ratio was 1.0, the initial pressure was 0.1 MPa, and different methane volume fractions. With the initial pressure increasing to 0.2 MPa, cracks and flame bumps appeared on the flame front at different methane volume fractions and the preferential diffusion instability would appear. With the initial pressure increasing to 0.3 MPa, the preferential diffusion instability would become obvious and the buoyancy instability would initial appear. At the same time, increasing the equivalence ratio or decreasing the initial pressure or increasing the methane volume fractions increased the Markstein length and the stability of the flame front was increased. With the equivalence ratio increasing, the unstretched flame propagation speed and the laminar burning velocity illustrated an increase initially and then decreased gradually, and the maximum values were measured at the condition of the equivalence ratio was 1.1 at all conditions. Furthermore, the unstretched flame propagation speed and the laminar burning velocity of biogas increased with the initial pressure decreasing or the methane volume fractions increasing.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Waste incineration
Controlled terms:Alcohol fuels - Biogas - Bombs (ordnance) - Calorific value - Combustion - Combustion chambers - Convergence of numerical methods - Flammability - Fossil fuels - Gas emissions - Gas turbines - Ignition - Methane - Natural gas - Pyrolysis - Renewable energy resources - Single crystals - Stability - Testing - Velocity - Volume fraction - Wood fuels
Uncontrolled terms:Combustion characteristics - Flame propagation speed - Fuel composition changes - Ignition characteristics - Laminar burning velocity - Markstein lengths - Preferential diffusion - Renewable energy source
Classification code:404 Civil Defense and Military Engineering - 452.4 Industrial Wastes Treatment and Disposal - 521.1 Fuel Combustion - 521.4 Flame Research - 522 Gas Fuels - 524 Solid Fuels - 525.1 Energy Resources and Renewable Energy Issues - 612.3 Gas Turbines and Engines - 641.1 Thermodynamics - 654.2 Rocket Engines - 802.2 Chemical Reactions - 804.1 Organic Compounds - 921.6 Numerical Methods - 933.1 Crystalline Solids
Numerical data indexing:Percentage 4.70e+01%, Percentage 5.55e+01%, Percentage 5.90e+01%, Pressure 1.00e+05Pa, Pressure 1.00e+05Pa to 3.00e+05Pa, Pressure 2.00e+05Pa, Pressure 3.00e+05Pa, Temperature 3.20e+02K
DOI:10.11975/j.issn.1002-6819.2018.15.028
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 19>
Accession number:20184506039313
Title:Feature selection of electronic nose signal for vinegar discrimination based on multivariable analysis
Authors:Yin, Yong (1); Zhao, Yuzhen (1); Yu, Huichun (1)
Author affiliation:(1) College of Food & Bioengineering, Henan University of Science and Technology, Luoyang; 471023, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:290-297
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to enhance discrimination ability of electronic nose (E-nose) for six kinds of vinegars, a multi-features representation strategy for E-nose data of vinegar samples based on multivariable analysis is proposed in this paper. Firstly, initial feature matrix, which was composed of six kinds of features extracted from E-nose data, was dealt with loadings analysis so as to optimize gas sensors, and then kept 12 gas sensors for next analysis. For eliminating correlation between response signals of gas sensors, feature matrix of 12 sensors array was carried out with principal component analysis (PCA), and generated principal component (PC) variables (PC variable(s) for short) for constructing Wilks Λ-statistic. Subsequently, Wilks Λ value of each PC variable was obtained. As we all known, the smaller the value of Λ, the higher separation ability of the calculated PC variables; in other words, some PC variables corresponding to larger Λ values should be eliminated due to their lower separation ability. Generally speaking, Wilks Λ-statistic was adopted to get principal component sub-matrix that was beneficial to identification of vinegar samples. On the basis of obtaining principal component sub-matrix, considering that each PC variable was a linear combination of all original feature variables, as for each original feature variable, the contribution quantity of original feature variable to all obtained PC variables may be as choosing criterion. So taking each original feature variable as an object, and the sum of absolute values of combination coefficients corresponding to each original feature variables would be calculated according to obtained principal component sub-matrix, and the sums corresponding to different original feature variables were sorted from large to small, and the greater the sum, the higher possibility for the corresponding original feature variables to be chosen. Meanwhile, according to different designation values for the sum of coefficient absolute values of each original feature variable to all picked PC variables, different original feature variable sets could be formed. With the help of Fisher discriminant analysis (FDA), after correct discrimination rates of different original feature variable sets were calculated and compared, optimal original feature variables set was determined. The results showed that representation feature variables for gas sensors were extremely different from initial ones. In view of the proposed feature selection strategy, 48 features were selected to characterize E-nose signals of vinegar samples at final. In order to verify and explain the application effect of feature selection strategy and the rationality of selected 48 characteristic parameters for vinegar samples, FDA and back propagation neural network (BPNN) were employed to discriminate six kinds of vinegar samples, and correct discrimination rates of FDA and BPNN were over 93% and 98% in training sets, respectively; corresponding test sets were also over 90% and 93%, respectively. In addition, Bhattacharyya distance was also employed further to explain the separability between six kinds of vinegar samples and illustrate the reliability of FDA and BPNN results. As a result, the proposed feature selection strategy is effective and feasible, which provides a new idea for multi-features representation of E-nose data.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Principal component analysis
Controlled terms:Acetic acid - Backpropagation - Discriminant analysis - Electronic nose - Feature extraction - Fisher information matrix - Gas detectors - Matrix algebra - Multivariable systems - Neural networks - Sensor arrays - Signal analysis
Uncontrolled terms:Back-propagation neural networks - Bhattacharyya distance - Discrimination ability - Electronic nose (e-nose) - Fisher discriminant analysis - Multi features - Multivariable analysis - Vinegar
Classification code:716.1 Information Theory and Signal Processing - 723.4 Artificial Intelligence - 801 Chemistry - 804.1 Organic Compounds - 914.1 Accidents and Accident Prevention - 921.1 Algebra - 922 Statistical Methods - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Percentage 9.00e+01%, Percentage 9.30e+01%, Percentage 9.80e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.036
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 20>
Accession number:20184506039290
Title:Modeling of multiple ions coupling transport for salinized soil in oasis based on COMSOL
Authors:Jiao, Huiqing (1); Sheng, Yu (2); Zhao, Chengyi (2); Li, Baoguo (1)
Author affiliation:(1) Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture, and Key Laboratory of Land Quality, Ministry of Land and Resources, Beijing; 100193, China; (2) Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi; 830011, China
Corresponding author:Li, Baoguo(libg@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:15
Issue date:August 1, 2018
Publication year:2018
Pages:100-107
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil salinization constrains sustainable development of agriculture in arid area. Understanding dynamics of soil salt ions is helpful for the comprehensive treatment and high-efficient utilization of salt-affected soils. COMSOL is a flexible numerical simulation software based on finite element theory, with which one can freely define any type of function capable of describing material properties, sources or sinks, and boundary conditions. In addition, one can define a unique set of partial differential equations for describing certain physics phenomena that are not included in the preset modules in COMSOL. Based on these strengths, we reported a modeling study of SO<inf>4</inf><sup>2-</sup>, Ca<sup>2+</sup>, Na<sup>+</sup>, Cl<sup>-</sup>, and Mg<sup>2+</sup> dynamics in salt-affected soil using COMSOL. Soil water flow was described using the Richards equations in porous media and subsurface flow module. Salt ions transports were simulated by the advection-dispersion equations in the presence of cation exchange, precipitation and dissolution of calcium sulfate, which were built in the user-defined partial differential equations module. The cation exchange was described by the Gapon equation, and the chemical reaction between Ca<sup>2+</sup> and SO<inf>4</inf><sup>2-</sup> was described using the second-order equation. We further verified the model with an example of mulched drip irrigation with different irrigation amounts. The simulated soil water contents and ion concentrations in soil solution were generally in good agreement with the experiment measurement. The mean absolute error values for soil water contents ranged from 0.023 to 0.033 cm<sup>3</sup>/cm<sup>3</sup>, and the root mean square error values for those ranged from 0.030 to 0.040 cm<sup>3</sup>/cm<sup>3</sup>. For all the ions in soil solution, the mean relative error values ranged from 9.15% to 28.57%, and the coefficients of determination ranged from 0.41 to 0.88. It indicated that the model was capable of describing the dynamics of soil salt ions under field conditions. In the mulched drip irrigation system, all the concentrations of salt ions in soil solution decreased in the upper layer (around 40 cm) of the mulched soil after the irrigation, and then increased gradually due to water uptake of root and chemical reaction, or both. As Ca<sup>2+</sup> and SO<inf>4</inf><sup>2-</sup> in soil solution were replenished by the dissolution of calcium sulfate, their concentrations increased more rapidly than those of Cl<sup>-</sup> and Na<sup>+</sup>, which indicated that Cl<sup>-</sup> and Na<sup>+</sup> were leached more easily. However, all the ions gradually accumulated on the exposed soil surface, and the accumulation amount of Cl<sup>-</sup> was the biggest due to its strong mobility in soil. In addition, the simulation results based on different activity coefficient equations, i.e., Davies equation and the exponential equation fitted from the measured values, were compared. The activity coefficient values calculated from the Davies equation were generally larger than those calculated from the fitted exponential equation. As a result, the simulated Ca<sup>2+</sup>, SO<inf>4</inf><sup>2-</sup>, Na<sup>+</sup>, and Mg<sup>2+</sup> concentrations in soil solution based on the Davies equation were generally lower than those based on the fitted exponential equation, especially for Ca<sup>2+</sup> and SO<inf>4</inf><sup>2-</sup>. The results suggest that the calculation method of activity coefficient has obvious effect on the model accuracy, and general activity coefficient equation might lead to considerable simulation errors for saline soil.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Soil pollution
Controlled terms:Activity coefficients - Boundary conditions - Calcium compounds - Chemical reactions - Computer software - Dissolution - Driers (materials) - Errors - Flow of water - Irrigation - Mean square error - Models - Partial differential equations - Porous materials - Positive ions - Precipitation (chemical) - Soil moisture - Soils - Solution mining - Sulfur compounds
Uncontrolled terms:Advection-dispersion equation - COMSOL - Finite element theories - Mulched drip irrigations - Numerical simulation software - Root mean square errors - Salt ions - Second-order equation
Classification code:483.1 Soils and Soil Mechanics - 502.1 Mine and Quarry Operations - 631.1.1 Liquid Dynamics - 723 Computer Software, Data Handling and Applications - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 821.3 Agricultural Methods - 921.2 Calculus - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 9.15e+00% to 2.86e+01%, Size 4.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.15.013
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 21>
Accession number:20184506039303
Title:Moving object detection algorithm in rural substation based on time-space-frequency-domain
Authors:Liu, Yifan (1); Cai, Zhenjiang (1); Si, Yongsheng (2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Hebei Agricultural University, Baoding; 071000, China; (2) College of Information Science and Technology, Hebei Agricultural University, Baoding; 071000, China
Corresponding author:Cai, Zhenjiang(czj65@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:207-214
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rural substation in China usually has large scale, but the electrical equipment has low automation and intelligentization. So the substation maintenance in the daily operation requires high amount of man powers. The staffs need to enter the substation to complete the daily patrol, check and maintenance. Video monitor system can be used, however, for remote and real-time monitoring to protect the on duty staff (moving targets) from danger. Moving target detection is one of the critical issues in video monitor system. In order to overcome the disadvantages of the commonly used object detection algorithm, in this paper, we proposed a moving object detection algorithm in rural substation based on multi-domain (time-domain space-domain and frequency-domain fusion TSFF). At first, the consecutive multi-frames were observed in time domain. Then a time-domain signal was constituted by multiple frames pixels in the same location to observe the amplitude of frequency variation by use of short time Fourier transform in frequency domain. Then the horizontal and vertical four directions extension neighborhood of each target pixel was selected in space domain. The amplitude of frequency variation of the pixels in transverse and longitudinal section was also calculated. Eventually the target pixel was detected as the background, noise, or moving target, to complete the moving object segmentation. Comparing with these kinds of algorithm, inter-frame difference (IFD) method can remove noise effectively (mean of accuracy rate was 96.73%), but the object information retention performed poorly (mean of recall rate was 44.14%). The FPCP algorithm performed generally in all aspects (mean of accuracy rate was 65.95% and mean of recall rate was 77.73%). The GRASTA algorithm performed poorly in object information retention when the background noise disturbance was large (the lowest recall rate was 21.83%). The GMM algorithm had the high mean of accuracy rate (85.31%), but for object information reserving had its shortcomings to a certain extent when the back-ground noise disturbance was large (the lowest recall rate was 78.18%). The ViBe algorithm had the low recall rate (mean of recall rate was 65.05%). The TSFF algorithm showed stable performance with different conditions and higher robustness. The TSFF algorithm had the optimal mean recall rate (86.10%) and mean accuracy rate (96.68%). The TSFF algorithm was not only to overcome the RPAC method affected by lights, shadows, and noise, but also to reserve the object information to the maximum compared with the inter-frame difference method and overcome the difficulty in dealing with the high frequency noise compared with the adaptive background modeling algorithm. The experiment results showed that the proposed algorithm reserve the object information well, and maximum removed the background. The TSFF algorithm was suitable for real-time and monitoring substation staff in different circumstances.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Object detection
Controlled terms:Algorithms - Frequency domain analysis - Image segmentation - Monitoring - Object recognition - Pixels - Signal detection - Time domain analysis
Uncontrolled terms:Frequency domains - Moving objects detection - Space domain - Time domain - Video
Classification code:716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 921 Mathematics - 921.3 Mathematical Transformations
Numerical data indexing:Percentage 2.18e+01%, Percentage 4.41e+01%, Percentage 6.50e+01%, Percentage 6.60e+01%, Percentage 7.77e+01%, Percentage 7.82e+01%, Percentage 8.53e+01%, Percentage 8.61e+01%, Percentage 9.67e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.026
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 22>
Accession number:20184506039299
Title:Prediction of Avian pasteurellosis based on ZINB model and meteorological factors
Authors:Gao, Xiang (1); Xiao, Jianhua (1); Wang, Hongbin (1)
Author affiliation:(1) Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Northeast Agricultural University, Harbin; 150030, China
Corresponding author:Wang, Hongbin(wanghb1960@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:176-182
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:According to reliable data, the epidemic of poultry infectious diseases causes billions of economic losses every year in China. It not only seriously threatened the healthy development of the poultry industry, but also had a serious impact on the food security and human health. Compared with the developed countries, the problem of the poultry disease prevention in China is that farmers always ignore the importance of comprehensive management and control, and, tend to excessive reliance on vaccines and antibiotics for the infectious diseases. Experience has shown that without the daily management, only relying on antibiotics and vaccines can't effectively control the spread of infectious disease. This is because that although vaccines can improve the immunity of animal, they can't kill pathogenic microorganism which have already existed in animal and farm. At the same time, in the face of new infectious diseases due to continuous mutation of pathogenic microorganism, the development of a new novel vaccines always have a lag period. In this case, evaluation of the risk factors which can affect the spread of the disease will help to develop and to strengthen chicken farm management, resulting effective disease control measure. As for antibiotics, the problem of drug-resistant has produced serious influence on the treatment of related diseases. In addition, antibiotics in animal waste ended in environment also have been reported to cause problems in ecosystems and to human health. The purpose of this paper is to study the effect of meteorological factors on the prevalence of Avian pasteuretlosis by using a variety of statistical methods and mathematical model. Data for poultry infectious diseases between Jan., 2006 to Dec., 2016 were obtained from China National veterinary. Provincial meteorological data were obtained from China State Meteorological Administration. By using seasonal analysis, time series analysis method and the zero-inflated negative binomial model, trend analysis and evaluation model of Avian pasteuretlosis have been conducted. This study included: 1) By using seasonal analysis and time series analysis, we studied the epidemic tendency of Avian pasteuretlosis. From the results, we found that the Avian pasteuretlosis, which have been included in the "Official Veterinary Bulletin", was influenced by the seasonal factors and the number of disease cases. 2) By using Zero-inflated negative binomial model, disease data of Avian pasteuretlosis in months and the provincial level meteorological data in every month of the whole country during research period, we reviewed the relationship between meteorological factors and Avian pasteuretlosis cases. Results indicated that there was a high possibility of Avian pasteuretlosis when the weather conditions with high temperature and air humidity and low wind speed. In summary, we studied the epidemic trend of Avian pasteuretlosis and the effect of meteorological factors on this poultry disease. The study offered a reliable theory for setting up the early warning system of Avian pasteuretlosis, and it also provided a reference to the control of other poultry infectious diseases. In further research work, more risk factors, such as the economy, traffic and the migration of migratory birds, should be considered in the analysis to improve the accuracy of the model prediction.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Diseases
Controlled terms:Agricultural wastes - Animals - Antibiotics - Controlled drug delivery - Disease control - Food supply - Harmonic analysis - Losses - Meteorology - Microorganisms - Models - Risk analysis - Risk assessment - Time series analysis - Vaccines - Wind
Uncontrolled terms:Avian pasteuretlosis - Comprehensive managements - Early Warning System - Meteorological factors - Negative binomial models - Pathogenic microorganisms - Seasonal analysis - Web-GIS
Classification code:443.1 Atmospheric Properties - 461.6 Medicine and Pharmacology - 461.9 Biology - 821.5 Agricultural Wastes - 822.3 Food Products - 911.2 Industrial Economics - 914.1 Accidents and Accident Prevention - 921.6 Numerical Methods - 922 Statistical Methods - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2018.15.022
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 23>
Accession number:20184506039314
Title:Preparation of cellulose nanocrystals coated soft packaging material and evaluation of its oxygen barrier performance
Authors:Hu, Yunfeng (1); Wei, Zengyu (1); Li, Fei (1); Du, Wei (1); Yan, Ruixiang (2)
Author affiliation:(1) State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin; 300457, China; (2) College of Packaging and Printing Engineering, Tianjin University of Science and Technology, Tianjin; 300222, China
Corresponding author:Li, Fei(li.fei@tust.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:298-303
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, the preparation process of nanofibers with oxygen barrier materials was studied and the oxygen barrier effect of cellulose nanocrystals (CNs) coatings on 4 kinds of flexible packaging substrate was compared. The preparation process was as follows: First, the nanocellulose crystal with 1% content was prepared by the method of acid hydrolysis, and then a suitable amount of nanoscale crystal was dissolved in the distilled water by ultrasonic dissolution. When it became clear and transparent, the nanoscale coating solution with a concentration of 8% was obtained. The corresponding composite film was prepared by placing 4 kinds of substrate on a coating machine and the coating liquid was uniformly applied to the surface of the substrate at a coating speed of 2.5 mm/s. The obtained composite film was observed under an atomic force microscope. The results showed that the nanocellulose was evenly coated on 4 kinds of substrate to form a dense composite membrane structure. Moreover, the surface roughness of coated materials was significantly reduced, making it difficult for microorganisms to pollute the membrane. Based on the evaluation of the basic properties of the composite film, it was found that the coefficient of friction on the surface of the coated material was significantly lower than that of the original substrate except the oriented polypropylene (OPP) film, making the resulting composite membrane easier to mass-produce on high-speed packaging machines. The CNs coating method did not improve the optical properties of the composite film very well, and its optical performance was not significantly different from that of the original substrate. Evaluation of the oxygen barrier performance of the composite membrane revealed that CNs coating greatly increased the oxygen barrier properties of the substrate. The oxygen barrier performance of the original basement membrane was greatly improved by the composite film coated with CNs. The oxygen transmission of all composite films decreased by more than 98%, except the composite film made by OPP substrate. The application of the composite membrane on fresh-cut apples showed that the 4 kinds of oxygen-insulating composite membranes could effectively prevent the infiltration of oxygen, which effectively inhibited the decrease of the color of fresh-cut apple slices and the loss of its nutrients. The experimental results also showed that the oxygen isolation effect of oriented polyamide (OPA) film coated with CNs was the best, and the oxygen isolation coefficient was 0.003 cm<sup>3</sup>•μm/(m<sup>2</sup>•d•kPa). Compared to PET (polybutylene terephthalate), CELL (celluloid) and OPP film, the oxygen coefficient of OPA film was increased significantly, respectively. The fresh-cut apple was stored for 4 d under the temperature of 3-5℃. On the 4th day, compared with the control group, the luminance value of the OPA based oxygen insulating composite membrane was increased by 11.7%, and the contents of titratable acid, vitamin C and soluble solids increased by 105%, 42.6% and 36.2% respectively. This study provides a completely new process for the preparation of oxygen barrier membranes and a new method for preventing browning and preservation of fresh-cut apples.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Composite films
Controlled terms:Atomic force microscopy - Cellulose - Cellulose derivatives - Chip scale packages - Coated materials - Coatings - Composite membranes - Film preparation - Films - Friction - Fruits - Insulating materials - Membranes - Nanocellulose - Nanocrystals - Optical properties - Packaging - Packaging materials - Polypropylenes - Surface roughness
Uncontrolled terms:Cellulose nano-crystals - Coefficient of frictions - Flexible packaging substrates - Fresh-cut apples - Oriented polypropylene films - Oxygen barrier properties - Oxygen transmissions - Polybutylene terephthalates
Classification code:413 Insulating Materials - 694.1 Packaging, General - 694.2 Packaging Materials - 714.2 Semiconductor Devices and Integrated Circuits - 741.1 Light/Optics - 741.3 Optical Devices and Systems - 761 Nanotechnology - 811.3 Cellulose, Lignin and Derivatives - 813 Coatings and Finishes - 813.2 Coating Materials - 815.1.1 Organic Polymers - 821.4 Agricultural Products - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 1.00e+00%, Percentage 1.05e+02%, Percentage 1.17e+01%, Percentage 3.62e+01%, Percentage 4.26e+01%, Percentage 8.00e+00%, Percentage 9.80e+01%, Velocity 2.50e-03m/s
DOI:10.11975/j.issn.1002-6819.2018.15.037
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 24>
Accession number:20184506039294
Title:Simulation and verification of overhanging soil layers stability of gully heads in Yuanmou Dry-hot Valley based on moment method
Authors:Zhang, Baojun (1, 2); Xiong, Donghong (1); Zhang, Guanghui (3); Wu, Han (1); Zhang, Su (1); Yuan, Yong (1); Dong, Yifan (1)
Author affiliation:(1) Key Laboratory of Mountain Hazards and Earth Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu; 610041, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Research Center of Soil & Water Conservation and Ecological Environment, Chinese Academy of Sciences, Yangling; 712100, China; (3) Faculty of Geographical Science, Beijing Normal University, Beijing; 100875, China
Corresponding author:Xiong, Donghong(dhxiong@imde.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:133-140
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Gully erosion is one of the major contributors to severe land degradation in the Yuanmou Dry-hot Valley Region of Southwest China, due to the frequent erosive precipitation events in the rainy season and special lithological conditions. Most active gullies in the study area are characterized by steep gully headcut, and headward erosion has been recognized as the main process of gully expansion. In particular, scour holes are often developed in the open side of gully headcut, which cause the frequent collapse of overhanging layers of gully heads in the process of headward erosion, and thus accelerate gully headward development. It is, therefore, of great significance to carry out the study on the collapse of overhanging layers of gully heads during the gully headward processes. In this study, based on the field investigations, a generalized physical model of active gully head was established. Then, the stability of overhanging layer of active gully head was studied by the momental analysis method, considering the main factors i.e. headcut height, the shape of scour hole and the development of tension crack at gully head. The results showed that the stability of overhanging layer of gully head was affected by various factors, such as the soil water content, the height of scour hole, the location and depth of tension crack. The results also indicated the difficulty in studying the mechanism of the gully head collapse process. When other parameters were assigned with default values, the stability of overhanging layer of gully head was decreased with soil water content and depth of tension crack (p<0.001) as an exponential function, and decreased with height of scour hole (p<0.001) as a linear function. As the distance between the tension crack and the headcut wall increased, the stability of overhanging layer increased significantly (p<0.001). Furthermore, to test the reliability of the evaluation of stability of overhanging layers, 4 gully heads molded by man with scour holes and the flow scouring experiments were employed in the field. When the collapse of overhanging layers of gully heads occurred, soil water contents of the whole collapse soil and the collapse surface soil were determined by oven-dry method with 6 repetitions. The results showed that the measured soil water contents of the whole collapse soil and the collapse surface soil were 69.8%-87.6% and 82.0%-95.5% of the model estimated values, separately. The small difference in soil water contents between the measured values and estimated values also indicated that this evaluation model was very valuable for the prediction of the collapse of overhanging layers of gully heads in the Yuanmou Dry-hot Valley Region. Moreover, the soil water content of the collapse surface soil was much closer to the model estimated value, which demonstrated that the development of tension crack on the overhanging layers of gully heads did affect their stability. These results are helpful to supplement meaningful theories to the erosion mechanism study and conservation practices implementation of active gully heads in the Yuanmou Dry-hot Valley Region. However, due to the complexity and uncertainty of the collapse of overhanging layers, further studies are needed to focus on the process of collapse of active gully heads, which can further improve the evaluation reliability of the stability model.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Landforms
Controlled terms:Drying - Erosion - Exponential functions - Function evaluation - Lithology - Method of moments - Soil moisture - Soils - Stability - Water content
Uncontrolled terms:Conservation practices - Dry-hot valleys - Evaluation of stability - Gully head - Headcuts - Precipitation events - Scour holes - Scouring experiments
Classification code:481.1 Geology - 483.1 Soils and Soil Mechanics - 921 Mathematics - 921.6 Numerical Methods
Numerical data indexing:Percentage 6.98e+01% to 8.76e+01%, Percentage 8.20e+01% to 9.55e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.017
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 25>
Accession number:20184506039286
Title:Active modulation of torque distribution for dual-motor front- and rear-axle drive type electric vehicle based on slip ratio
Authors:Wu, Zhongbin (1); Xie, Bin (1); Chi, Ruijuan (1); Du, Yuefeng (1); Mao, Enrong (1)
Author affiliation:(1) Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment, China Agricultural University, Beijing; 100083, China
Corresponding author:Xie, Bin(xiebincau@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:66-76
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Research and development of electric vehicles (EVs) are being rapidly performed to cope with the latest environmental and energy issues. Studies of techniques for the efficient use of electrical energy are very important for the development of EVs. To this end, it is necessary to develop EVs that can deliver efficient running performance on various road surfaces. As we all know, the vehicle performances such as the drivability, the stability and the economics, are strongly influenced by its driveline architectures. New driveline architectures with 2 motors respectively installed at the input of the front and rear axles have yielded a new generation of four-wheel-drive vehicle, which is known as the front- and rear-wheel-independent drive type electric vehicle (FRID EV). Benefit from the mechanical layout, the longitudinal forces on the front and rear wheels can be adjusted flexibly according to the road and the driving conditions. This allows to design active control systems that are capable of altering the behavior of the vehicle and make it possible to achieve excellent driving performances via the reasonable control method that uses the structural features of the FRID EV. Therefore, in order to improve the traction performance and avoid the excessive slip of the driving wheels, which is also beneficial to energy saving during running, an active torque distribution method in consideration of the optimal slip ratio control for the front- and rear-wheel-independent drive type electric vehicle, which is based on the friction coefficient / slip ratio curve, was put forward in this paper. The pattern of the control method was designed as 2 levels, the top gives the total driving torque assignable in consideration of the driver's expectations and various road surfaces, and the underlying is responsible to reasonably distribute the torque given by the top level between the front and rear axles. Taking the longitudinal, lateral, the yawing modes of motion and the revolving of each wheel into consideration, the seven-degree-of-freedom dynamic model of an FRID EV was set up in this paper. In view of the advantages of sliding mode control (SMC) that can overcome the uncertainty of the system and is robust to external noise disturbances, the parameter perturbation and imprecise-model dynamics, especially for nonlinear systems, the SMC controller for the front and rear drive motors was designed to optimize the slip ratio of each wheel on the basis of the dynamic model. Using the exponential approach law, the approach motion (non-sliding mode) reached the switch surface in finite time, and buffeted less in the process of approaching by introducing a continuous function instead of the sign function. The correctness of this design was verified by the acceleration simulation tests on a split-μ and a joint road surface based on the MATLAB/Simulink software (SIL) platform and the hard-ware-in-the-loop (HIL) simulation system, respectively. The simulation results on the split-μ road surface show that the slip ratio of each wheel can be kept stably within the level of 0.12 around by actively modulating the distribution of the torque between the front and rear motors, which therefore inhibits effectively the excessive slip that may be caused by the wheels on the road with low friction coefficient, although the terminal velocity after 8 seconds is close to the case of equal torque distribution. But when it comes to the joint road surface, the acceleration performance is improved remarkably with the terminal velocity increased by 9.9%. Besides, during the process of turning on a uniform low-μ road surface, the slip ratio of inner wheels is limited within 0.2, which improves the steering capability of the vehicle. Besides, the simulation results of SIL and HIL are essentially in good agreement.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Vehicle wheels
Controlled terms:All wheel drive vehicles - Automobile drivers - Control engineering - Degrees of freedom (mechanics) - Drive axles - Dynamic models - Electric traction - Electric vehicles - Energy conservation - Friction - Front axles - MATLAB - Memory architecture - Models - Modulation - Rear axles - Roads and streets - Sliding mode control - Software testing - Torque - Traction control - Traction motors - Vehicle performance - Vehicles
Uncontrolled terms:Acceleration performance - Four-wheel-drive vehicles - Hardware in loop - Low friction coefficients - Matlab/Simulink software - Research and development - Sliding mode control(SMC) - Torque distribution
Classification code:406.2 Roads and Streets - 432 Highway Transportation - 525.2 Energy Conservation - 601.2 Machine Components - 662.1 Automobiles - 662.4 Automobile and Smaller Vehicle Components - 722 Computer Systems and Equipment - 723.5 Computer Applications - 731.1 Control Systems - 731.2 Control System Applications - 921 Mathematics - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 9.90e+00%, Time 8.00e+00s
DOI:10.11975/j.issn.1002-6819.2018.15.009
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 26>
Accession number:20184506039298
Title:Wheat powdery mildew monitoring based on GF-1 remote sensing image and relief-mRMR-GASVM model
Authors:Huang, Linsheng (1); Ruan, Chao (1, 2); Huang, Wenjiang (1, 2); Shi, Yue (2); Peng, Dailiang (2); Ding, Wenjuan (1)
Author affiliation:(1) National Engineering Research Center for Agro-Ecological Big Data Analysis & Application, Anhui University, Hefei; 230601, China; (2) Key Laboratory of Digital Earth Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing; 100094, China
Corresponding author:Huang, Wenjiang(huangwj@radi.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:167-175
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wheat powdery mildew is one of the most serious diseases in wheat, so timely and effective monitoring of wheat powdery mildew is necessary for improving wheat yield and quality. The selection of suitable modeling method and feature selection algorithm play an important role in improving the performance of remote sensing monitoring of crop diseases. In this study, the GF-1 remote sensing image was used to extract 14 characteristic variables, including 4 band reflectance variables and 10 vegetation indices. An approach combining relief and minimum redundancy maximum relevance (mRMR) algorithm (relief+mRMR) is proposed for improving the ability to remove redundancy of relief algorithm. First, the relief algorithm was used to calculate the weight of each feature and filter out the disease independent features. Then the mRMR algorithm was used to remove the redundant features. Finally, the optimal feature set including NIR(near-infrared reflectance), SR (simple ratio index) and NDVI (normalized difference vegetation index) was as the input variables. Meanwhile, the other 2 feature sets such as SR, GNDVI (green normalized difference vegetation index) and TVI (triangular vegetation index) by relief algorithm and TVI, RTVI (ratio triangular vegetation index) and RDVI (re-normalized difference vegetation index) by mRMR algorithm were also obtained. Support vector machine (SVM) is a machine learning method based on statistical learning theory, and its working principle is to minimize the structural risk as the core, and it can improve the generalization ability, and resolve problems such as nonlinearity, small samples. Penalty factor and nuclear parameter should be considered in establishing monitoring model for wheat powdery mildew, and traditional parameter selection was mostly through multiple experiments. Presently, the commonly used grid search (GS) algorithm obtains the optimal parameters, but its efficiency is low and workload is large. The advantage of the genetic algorithm (GA) is to solve the global optimal problem, which is robust and can be independent of the domain of the problem when searching quickly. Therefore, the algorithm of SVM optimized by GA (GASVM) was used to monitor wheat powdery mildew in Hebei, China. For comparison and validation, SVM method, the approach of SVM optimized by GS algorithm (GSSVM), and 3 existing monitoring methods of wheat powdery mildew i.e. AdaBoost, particle group optimized least square support vector machine (PSO-LSSVM) and random forest (RF) were also been used. The results illustrated that the performance of models constructed using the feature set through relief+mRMR algorithm outperformed the models established using the feature set through only relief algorithm or only mRMR algorithm. The result demonstrated that the combination of relief and mRMR algorithms can effectively remove the redundancy between features while selecting high correlated features with disease. Additionally, in 3 monitoring models based on the features selected by relief+mRMR, the relief-mRMR-GASVM monitoring model had the highest overall accuracy of 85.7%, which increased by 21.4 and 7.2 percentage points compared with relief-mRMR-SVM and relief-mRMR-GSSVM monitoring models. The result indicated that the relief-mRMR-GASVM approach can effectively improve the monitoring accuracy and consistency of the wheat powdery mildew model, and further strengthen the reliability of the model in practical application. Furthermore, the monitoring accuracy of GF-1 data combined with relief-MRMR-GASVM model increased by 21.4, 14.3 and 7.1 percentage points compared with AdaBoost, PSO-LSSVM and RF methods, respectively. These results reveal that the GF-1 data combined with the relief-mRMR-GASVM model can be used for remote sensing monitoring of wheat powdery mildew.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Genetic algorithms
Controlled terms:Adaptive boosting - Decision trees - Diseases - Fungi - Infrared devices - Least squares approximations - Monitoring - Particle swarm optimization (PSO) - Redundancy - Reflection - Remote sensing - Support vector machines - Vegetation
Uncontrolled terms:Green normalized difference vegetation index - Least square support vector machines - Minimum redundancy-maximum relevances - Normalized difference vegetation index - Powdery mildew - Relief algorithm - Statistical learning theory - Wheat
Classification code:723 Computer Software, Data Handling and Applications - 921.6 Numerical Methods - 961 Systems Science
Numerical data indexing:Percentage 8.57e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.021
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 27>
Accession number:20184506039300
Title:Adaptive image enhancement algorithm for wild animal monitoring based on Retinex theory
Authors:Zhang, Junguo (1); Cheng, Zhean (1); Hu, Chunhe (1); Chen, Chen (2); Bao, Weidong (3)
Author affiliation:(1) School of Technology, Beijing Forestry University, Beijing; 100083, China; (2) Department of Electrical and Computer Engineering, University of North Carolina, Charlotte; 28223, United States; (3) School of Biological Sciences and Technology, Beijing Forestry 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:15
Issue date:August 1, 2018
Publication year:2018
Pages:183-189
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wildlife monitoring images can be used to conduct accurate estimation of species diversity, quantity and inhabit attribution, offering scientific proofs for wildlife resource conservation.However, the quality and availability of acquired wildlife monitoring images were usually weakened due to different illumination variations in wild environments. To address this drawback, an adaptive image enhancement method based on Retinex theory was proposed in this paper.We utilized wildlife monitoring images collected at Saihanwula Nature Reserve in Inner Mongolia as experimental samples.These monitoring images were acquired from several field experimentsfrom 2010 to 2014 by using the infrared trigger cameras and they were classified into 4 illumination conditions, namely sufficient illumination condition, low illumination condition, shadow condition and overexposure condition. Firstly, we analyzed the pseudo halo phenomenon in illuminance component image estimation process caused by the traditional guided filter. The global smoothing factor of guided filtercan notbalance the halo elimination and image detail information preservation in illumination abruptchanging image regions. Therefore, we introduced the composite gradient of images to improve the guided filter algorithm. By calculating the composite gradient image, the local adaptive smoothing factor of the guided filter was obtained to achieve the joint optimal performances of the pseudo halo elimination and the dynamic range compression. In view of the over enhancement problem in conventional Retinex algorithm, a contrast adaptive stretching method based on Otsu threshold was then proposed to realize the correction of illumination component. By calculating the Otsu threshold in illumination component images, the estimated illumination component images could reach the optimal brightness extension effect at the threshold and realize the brightness improvement in dark image regions, and it could limit the over enhancement degree of the bright image regions.And it enhanced the adaptability of the algorithm to different illumination conditions. Lastly, in order to maintain the color information of enhanced images, the single channel illumination component of the corrected images and the 3 color channels of the original images were used to conduct separate calculation to maintain the correlation of the 3 color channels. It was validated that it did not increase the complexity of the algorithm. In order to prove the superiority of this algorithm, 50 wild animal monitoring images were selected randomly for validation. This algorithm was compared with MSRCR(multi-scale Retinex with color restoration) algorithm, bilateral filter Retinex algorithm and guided filter Retinex algorithm to test its quality performance of image enhancement. Compared with the other 3 algorithms, the average hue fidelity was increased by 81.00%,5.24% and 3.58%, respectively; the average information entropy was increased by 6.76%,6.23% and 2.61%, respectively; the average PSNR (peak signal to noise ratio) was improved by 53.43%,5.36% and -2.85%, respectively; the running time was reduced by -29.03%,78.51% and 28.68% respectively. Above promising results can greatly demonstrate that the proposed method is effective in addressing the over enhancement, the fogging effect and halo phenomenon in existing algorithms, and it can achieve robust illumination adaptive enhancement of wildlife monitoring images.It makes significant contribution to further automatic identification of wildlife monitoring images as well as the improvement of information and automation level in wildlife protection.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Image enhancement
Controlled terms:Algorithms - Animals - Automation - Color - Computational complexity - Image acquisition - Luminance - Monitoring - Signal to noise ratio
Uncontrolled terms:Automatic identification - Dynamic range compression - Guided filters - Illumination components - Information preservations - PSNR (peak signal to noise ratio) - Retinex theory - Wildlife monitoring
Classification code:716.1 Information Theory and Signal Processing - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 741.1 Light/Optics
Numerical data indexing:Percentage -2.85e+00%, Percentage -2.90e+01%, Percentage 2.61e+00%, Percentage 2.87e+01%, Percentage 3.58e+00%, Percentage 5.34e+01%, Percentage 6.76e+00%, Percentage 8.10e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.023
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 28>
Accession number:20184506039312
Title:Optimal design of photovoltaic power storage system hybrid refrigeration system of refrigerator car based on chaotic ant algorithm
Authors:He, Ren (1); Yang, Liu (1)
Author affiliation:(1) School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:282-289
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A hybrid refrigeration system of refrigerator car was designed in this paper. Photovoltaic energy storage system was the auxiliary power source of the refrigeration system and it drove the refrigerator during refrigerator car parking for a long time midway or at night. Engine drove refrigerator when refrigerator car was driving. The experimental analysis of hybrid refrigeration system of refrigerator car found that power generation of solar panels could only keep electric compressor working for 4.13 hours in one day. The power generation was not enough to support refrigeration system working for all night and this would affect the quality of cargo in the refrigerated carriage. In order to solve this problem, on the one hand, the energy consumption of refrigeration system needed to be reduced. On the other hand, the power generation capacity should be increased. Firstly, mathematical model of the hybrid refrigeration system of refrigerator car was established. Then, experiments about photovoltaic energy storage system and refrigeration system have been down. Correctness of the model was verified by comparing experimental data and simulation data. On this basis, the refrigeration efficiency and economic coefficient of photovoltaic power generation were put forward as the system evaluation indexes in this paper. The refrigeration efficiency was the ratio of energy consumption to cooling capacity and represented the energy consumption of the refrigeration system. If the refrigeration efficiency is lower, the energy saving of the refrigeration system is more. The economic coefficient of photovoltaic power generation is the ratio of power generation of solar panels to the power capacity of batteries and it represents the power generation capacity of per-unit cost of photovoltaic energy storage system. If the economic coefficient of photovoltaic power generation is greater, the power generation capacity per unit cost of photovoltaic power generation system is more. The two evaluation indexes were unified as the objective function. Nine constraints were enumerated. Based on chaotic ant colony algorithm, the hybrid refrigeration system of refrigerator car was optimized. The results after optimization showed that the energy consumption of the refrigeration system was reduced by 238.63 W, the cooling capacity was increased by 103.11 W and the refrigeration efficiency was reduced from 0.542 to 0.402. The optimized refrigeration system was more energy-saving. The volume of optimized refrigeration system was smaller, which made refrigeration system easier to install on the refrigerator car. Also, the power capacity of batteries was decreased by 2.67 kW•h, the whole day power generation capacity of solar panels was increased from 4.45 to 5.82 kW•h and the economic coefficient of photovoltaic power generation was increased from 0.464 to 0.840. In summary, the optimized hybrid refrigeration system of refrigerator car was more energy-efficient and economical. The optimization method and encouraging results in this paper will provide a fundamental reference for optimization design of the research on solar refrigeration system.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Refrigeration
Controlled terms:Ant colony optimization - Costs - Design - Digital storage - Electric batteries - Energy conservation - Energy efficiency - Energy storage - Energy utilization - Optimization - Photovoltaic cells - Refrigerating machinery - Refrigerator cars - Refrigerators - Solar cell arrays - Solar concentrators - Solar energy - Solar power generation - Thermal management (electronics)
Uncontrolled terms:Ant algorithms - Chaotic ant colony algorithms - Experimental analysis - Photovoltaic power - Photovoltaic power generation - Photovoltaic power generation systems - Power generation capacities - Refrigeration system
Classification code:525 Energy Management and Conversion - 615.2 Solar Power - 644.1 Refrigeration Methods - 644.3 Refrigeration Equipment and Components - 657.1 Solar Energy and Phenomena - 702.1 Electric Batteries - 702.3 Solar Cells - 722.1 Data Storage, Equipment and Techniques - 911 Cost and Value Engineering; Industrial Economics - 921.5 Optimization Techniques
Numerical data indexing:Power 1.03e+02W, Power 2.39e+02W, Time 1.49e+04s
DOI:10.11975/j.issn.1002-6819.2018.15.035
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 29>
Accession number:20184506039283
Title:Deformation simulation and structural improvement design for floating collar of deep-water aquaculture net cage
Authors:Huang, Xiaohua (1); Liu, Haiyang (1); Hu, Yu (1); Tao, Qiyou (1); Wang, Shaomin (1); Yuan, Taiping (1)
Author affiliation:(1) Guangdong Cage Engineering Research Center, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou; 510300, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:44-49
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Due to various environmental issues and coastal zone resource conflicts in recent years, cage aquaculture has been increasingly developed in more exposed sea water where the water depth exceeds 20 m and the water quality is much better than the one close to the shore line. As an important part of deep-water net cage, the floating collar made of high-density polyethylene (HDPE) may undergo great deformation resulting from strong winds, waves and current. Site observations have confirmed that the deformation of larger net cage in open sea is more severe than that of smaller cage. The floating collar may deform to a large extent that normal functionality is disabled, causing heavy economic loss to farming enterprises. Therefore, the aim of this study is to analyze the dynamic deformation of the floating collar of a net cage under the combined influence of waves and current in order to help improve the design to increase the bearing capacity of a net cage. In this study, a numerical model was established through a commercial program, Orcaflex, and applied to simulate the dynamic behavior of a floating net cage in waves and current. The program is able to perform dynamic analysis of a wide range of offshore systems, typically including boundary conditions such as vessels, buoys, etc., as well as finite element modeling of line structures. The whole cage system, composed of a floating collar, fishing net and mooring lines, was modeled by a combination of line elements, three and six degree of freedom buoys. For the surface collar, lines were connected by six degree of freedom buoys, which transferred rotational and translational motion to represent the bending stiffness of the material. For the fishing net and mooring lines connecting the collar, line segments were connected by three degree of freedom buoys with no moment contributions, considering that the bending stiffness was insignificant, which can be set to zero. To validate the numerical model, we considered a case based on the motions of the net cage under regular waves and current, from which we calculated and compared it with the simulated results. The comparison of the results indicated a good agreement. Afterwards, the numerical model was used to simulate the dynamic deformation of the floating collar of a net cage with a circumference of 80 m, which was connected by an eight-point mooring system. This type of net cage is used extensively in the South China Sea. Regular waves with different wave heights (5, 6, or 7 m), wave periods (9, 11, or 13 s), and current velocities (0.6, 1.0, or 1.5 m/s) were set as the sea conditions for the calculations. We considered the von Mises strain and stress at the mooring line connection point on the floating collar to represent the deformation of the floating collar. The results showed that deformation occurred when the collar was exposed to sea loads, and became greater as the wave height or current velocity increased. However, the maximum strain on the collar did not change significantly as the wave period increased, which indicated that the effect of the wave period on collar deformation was small. When the net cage was subjected to the sea loads with waves (height 7 m and period 9 s) and current velocity of 1.5 m/s, the maximum strain on the floating collar was equal to 2.47%, which was the largest among all of the waves and current conditions. The largest value for the von Mises stress was very close to the yield stress of 24 MPa, which may increase the likelihood of plastic deformation. Therefore, to reduce the risk of plastic deformation, we designed a casing pipe measuring 0.5 m in length with an outer diameter of 0.355 m and a thickness of 15 mm. The casing pipes were installed and fixed at each position of the mooring line connection point on the floating collar. The deformation results demonstrated that the maximum strain on the cage collar with casing pipes was much smaller than that without casing pipes, and thus using casing pipes can greatly reduce the local deformation of the cage collar to ensure the structural safety in severe sea conditions.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Mooring cables
Controlled terms:Buoys - Degrees of freedom (mechanics) - End effectors - Finite element method - Fisheries - High density polyethylenes - Losses - Mooring - Numerical models - Offshore oil well production - Oil well casings - Plastic deformation - Plastic pipe - Seawater - Stiffness - Water quality - Water waves - Yield stress
Uncontrolled terms:Deep Water - Deformation simulation - Dynamic deformation - Floating collar - High density polyethylene(HDPE) - Structural improvements - Three degree of freedoms - Translational motions
Classification code:445.2 Water Analysis - 471.4 Seawater, Tides and Waves - 511.1 Oil Field Production Operations - 511.2 Oil Field Equipment - 619.1 Pipe, Piping and Pipelines - 731.5 Robotics - 815.1.1 Organic Polymers - 911.2 Industrial Economics - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science
Numerical data indexing:Percentage 2.47e+00%, Pressure 2.40e+07Pa, Size 1.50e-02m, Size 2.00e+01m, Size 3.55e-01m, Size 5.00e-01m, Size 7.00e+00m, Size 8.00e+01m, Time 1.30e+01s, Time 9.00e+00s, Velocity 1.50e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.15.006
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 30>
Accession number:20184506039284
Title:Design and optimization of variable stiffness spring for pump valve based on numerical simulation
Authors:Dong, Shimin (1); Zhu, Ge (1)
Author affiliation:(1) School of Mechanical Engineering, Yanshan University, Qinhuangdao; 066004, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:50-57
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Automatic poppet valve is a key component of reciprocating pump, which directly influences its performance and lifespan by controlling flow direction of fluid. Many researchers focus mainly on constant stiffness coefficient springs, due to its widespread application in the automatic poppet valve. Previous research already proves that spring plays an important role in the dynamic properties of poppet valve. The main function of spring is to balance inertia force. Studies also suggest that impact velocity and lag height gradually decreases with the increases of stiffness coefficient and preload. However, the increases of stiffness and preload makes head loss rise. Therefore, only by adjusting different combinations of spring stiffness and preload, it is difficult to reduce impact velocity and lag height while reducing head loss. This contradiction restricts the further improvement of reciprocating pump performance. In addition, the determination of the preload and stiffness of spring is often based on empirical formulas in the design process about constant stiffness coefficient spring. To solve these problems, application of variable stiffness coefficient spring on the pump valve was proposed in this paper. In the meantime, a new optimization design method for it was established. The main research contents of this paper included: (i) A mathematical model on the motion properties of valve disc was established under the condition which spring stiffness coefficient was variable. In this model, dynamics differential equation of valve disc motion, continuous flow equation of fluid between valve gaps and initial condition were all considered about. Based on above mathematical model, a computer simulation program was compiled to solve this simulation model by using of Runge-Kutta method. (ii) In order to verify accuracy of simulation model, two contrast tests were carried out. Firstly, lift of valve disc was compared between simulation results and measured results when stroke frequency was 74 min<sup>-1</sup>. In the process of measurement, the lift of valve disc was measured by lift sensor and pressure in the liquid cylinder was measured by semiconductor pressure transducers. The contrast result showed that the error was less than ±8%. Secondly, by changing parameter of stroke frequency, maximum lift was compared under different stroke frequencies, the error was less than ±10%. In summary, the above comparison showed that simulation model met the requirement of precision. (iii) According to above simulation model, we selected many different combinations of stiffness and preload for the constant stiffness coefficient spring for simulation comparison. After calculation, there was a mutual contradiction between impact velocity, lag height and head loss. In other words, impact velocity and lag height would increase with head loss reduced. Subsequently, in response to above deficiencies, three common types of spring: stiffness decreasing type, stiffness increasing type and stiffness constant type were chosen in the simulation. By comparing with curves of lift, velocity and head loss, it was demonstrated that stiffness decreasing type can improve the suction performance of reciprocating pump, while impact velocity and lag height were not significantly increased. (iv) Based on the numerical simulation model of valve disc motion properties, optimization simulation model of variable stiffness spring parameters was established. In this optimization model, the objective function was that maximum head loss was minimum. The constraint condition was that impact velocity satisfied the theory of no impact. Genetic algorithm and pattern search were used to solve this optimization model. In the end, compared with the constant stiffness coefficient spring, the maximum head loss for variable stiffness spring was reduced by 20.85%. In conclusion, variable stiffness coefficient spring can be used for improving suction performance of reciprocating pump and alleviating the occurrence of cavitation. Besides, this optimization method has a certain guiding significance for guiding design process of spring parameters on the pump valve.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Stiffness
Controlled terms:Computer simulation - Design - Differential equations - Flow of fluids - Genetic algorithms - Numerical models - Optimization - Pumps - Reciprocating pumps - Runge Kutta methods - Velocity
Uncontrolled terms:Design and optimization - Dynamics differential equations - Guiding significances - Optimization-simulation models - Poppet valve - Simulation comparison - Stiffness coefficients - Variable stiffness spring
Classification code:618.2 Pumps - 631.1 Fluid Flow, General - 723.5 Computer Applications - 921 Mathematics - 951 Materials Science
Numerical data indexing:Percentage 2.09e+01%
DOI:10.11975/j.issn.1002-6819.2018.15.007
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 31>
Accession number:20184506039285
Title:Calculation of pipe water hammer pressure with liquid column separation by improved two-fluid model
Authors:Fu, You (1); Jiang, Jin (2); Li, Yanhui (2); Yin, Rui (2)
Author affiliation:(1) School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; (2) Key Lab of Hydraulic Machinery Transients, MOE, Wuhan University, Wuhan; 430072, China
Corresponding author:Jiang, Jin(jiangjing423@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:58-65
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, we improved an existed two-fluid model for simulating the transient flow with liquid-column separation in the pipeline system. An improved NND numerical algorithm was proposed to ensure the accuracy and stability of the model. The finite relaxation and the infinite relaxation methods were compared. It was concluded that when using the finite relaxation calculation method, the relaxation coefficient was too large, resulting in the reverse correction for vapor-liquid phase pressure difference in the equation, which would cause the interruption of calculation. When the calculation method of the infinite relaxation coefficient was used, a stable calculation could be performed without setting the initial concentration of the foam particles, whilst the transient phenomenon could be described more accurately with increasing intensity. In the meantime, due to the forced correction of the void fraction and internal energy distribution after each time step, the method would often produce a larger void fraction and void fraction residue. The water hammer transient tests in two different laboratories were compared to verify the accuracy and applicability of the improved gas-liquid two-phase two-fluid model. We found that for the calculation using the finite relaxation parameters, the phase changes due to cavitation needed to be considered, and also needed to select reasonable bubble concentration to ensure the accuracy of calculation. For the calculation using infinite relaxation parameters, the cavitation model can be neglected, but the model could be used to directly analyze the phenomenon of liquid column separation caused by water hammer phenomenon. As the infinite pressure relaxation calculation method was a kind of mandatory correction calculation method, after each time step, it was considered that the gas phase and the liquid phase pressure reached the equilibrium state, and in fact, the relaxation time of the pressure was usually 1 ms. If the calculation time step was less than 1 ms, due to the forced correction of the calculation method, the two-phase flow in the unbalanced state was forced to be in equilibrium, which led to the correction of the void volume became too large, making reduction of the cavitation model in the low pressure area. The use of improved two-fluid gas-liquid two-phase flow calculation model with a reasonable numerical calculation method and infinite relaxation parameters can be used to predict the transient phenomenon of gas-liquid two-phase pipelines with obvious liquid column separation. The method had high calculation accuracy and it was suitable for water hammer protection in industrial pipelines calculation with a better value of application.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Two phase flow
Controlled terms:Cavitation - Liquids - Models - Numerical methods - Pipelines - Pressure - Transition flow - Void fraction - Water hammer
Uncontrolled terms:Gas - liquid two-phase flows - Liquid columns - Numerical calculation methods - Relaxation coefficients - Transient flow - Water hammer phenomenon - Water hammer pressure - Water hammer protections
Classification code:619.1 Pipe, Piping and Pipelines - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 632.2 Hydraulic Equipment and Machinery - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science
Numerical data indexing:Time 1.00e-03s
DOI:10.11975/j.issn.1002-6819.2018.15.008
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 32>
Accession number:20184506039307
Title:Design and experiment on RO brine desalination system by solar vacuum membrane distillation in cold region
Authors:Liu, Juan (1, 2, 3); Tian, Juncang (1, 2, 3)
Author affiliation:(1) School of Civil and Hydropower Engineering, Ningxia University, Yinchuan; 750021, China; (2) Ningxia Research Center on Technology of Water-Conservation Irrigation and Control of Water Resources Utilization, Yinchuan; 750021, China; (3) Project Research Center of China Ministry of Education on Utilization of Water Resources for Agricultural Purposes in the Dry Areas, Yinchuan; 750021, China
Corresponding author:Tian, Juncang(slxtjc@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:238-245
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problems of zero discharge of reverse osmosis (RO) brine, the coupling matching of solar collector and membrane distillation, the cooling water reduction and phase change heat recovery in the steam condensation process of membrane distillation system, the RO brine desalination system by solar vacuum membrane distillation in cold area was designed and verified in the test. The system consists of RO concentrated tank, membrane distillation module, solar collector, condensing unit, circulation pump, vacuum pump, fresh water tank, and so on. The condensing devices are self-made stainless steel heat exchange coil placed in the RO freshwater pool and geothermal coil placed in the underground of the greenhouse. The components of the system are designed in detail, and the self-made condensing device is the focus in the design. The system is placed in a greenhouse in Xinrong Village, Helan County, Yinchuan City, Ningxia. The front end of the system is an RO system for greenhouse irrigation. Since RO concentrated water cannot be discharged, it is further diluted by vacuum membrane distillation. In order to reduce energy consumption, the RO concentrated water treated by membrane distillation is heated by a solar collector. The fresh water vapor produced by membrane distillation is cooled by the stainless steel heat exchange coil in the RO fresh water tank and the greenhouse geothermal coil, which solves the problem of cooling water reduction in the steam condensation process of the membrane distillation system, and realizes phase change heat recovery and heats the greenhouse. Through measuring the relevant parameters of each component of the system, the solar collector effect, the RO brine desalination effect of the vacuum membrane distillation, the condensation effect of the condensing device and the heating effect of the greenhouse crop were tested and analyzed. The tests show that under the test conditions, the selected collector area can basically meet the heat requirement of membrane distillation for the whole year, the length of the stainless steel heat-dissipating coil designed in the greenhouse fresh-water tank can meet the steam condensation requirement, and the geothermal coils laid in 30-40 cm depth below the surface can meet condensation requirements and greenhouse heating requirements. The amount of freshwater produced by membrane distillation increases with the increase of the inlet temperature of the RO brine on feeding side and the vacuum pressure on the permeate side. When the inlet temperature of the RO brine on feeding side is 80°C and the vacuum pressure of permeate side is -0.080 MPa, the water production is 37.62 L/h. When the operating time of the vacuum membrane distillation system reaches 240 h, the membrane fouling increases and the water production decreases. When the hollow fiber membrane is cleaned, the water production after washing is increased by nearly 1.5 times compared with that before washing. It has been verified by experiments that the RO concentrated water desalination system by solar vacuum membrane distillation in cold area can basically meet the requirements for use. This study has important significance for reducing the energy consumption of membrane distillation system, realizing the zero discharge of RO brine, and reducing the concentration of brine in the environment.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Membranes
Controlled terms:Concentration (process) - Condensation - Cooling water - Desalination - Distillation - Distillation equipment - Energy utilization - Geothermal energy - Greenhouse effect - Greenhouses - Heat exchangers - Membrane fouling - Reverse osmosis - Solar collectors - Solar energy - Stainless steel - Steam condensers - Steel heat treatment - Washing - Waste heat - Water - Water filtration - Water tanks - Water treatment
Uncontrolled terms:Cold area - Condensation effects - Desalination systems - Hollow fiber membranes - Membrane distillation - Reduce energy consumption - Vacuum membrane distillation - Water desalination
Classification code:445.1 Water Treatment Techniques - 446.1 Water Supply Systems - 451 Air Pollution - 481.3.1 Geothermal Phenomena - 525.3 Energy Utilization - 525.4 Energy Losses (industrial and residential) - 545.3 Steel - 616.1 Heat Exchange Equipment and Components - 657.1 Solar Energy and Phenomena - 802.3 Chemical Operations - 821.6 Farm Buildings and Other Structures - 951 Materials Science
Numerical data indexing:Size 3.00e-01m to 4.00e-01m, Temperature 3.53e+02K, Time 8.64e+05s, Pressure -8.00e+04Pa
DOI:10.11975/j.issn.1002-6819.2018.15.030
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 33>
Accession number:20184506039278
Title:Current situation of foreign organic greenhouse horticulture and its inspiration for sustainable development of Chinese protected agriculture
Authors:Liu, Nihong (1); Jiang, Xianping (1); Cheng, Junfeng (1); Li, Huiling (1); Li, Wei (2); Xue, Kunpeng (1); Hou, Lu (2); Xiong, Zheng (2)
Author affiliation:(1) Guangdong Institute of modern Agricultural Equipment, Guangzhou; 510640, China; (2) Guangdong Hongke Agricultural Machinery Research & Development Co., Ltd, Guangzhou; 510530, China
Corresponding author:Xiong, Zheng(xiongz109@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 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:Protected agriculture was one of the highest forms of modern agriculture, which had been the focus of world agricultural development in each country. The demand for organic fruit and vegetables accounted for around 30%-40% of the global demand, but the total area for organic vegetable production was only 0.5% of the total area of vegetables grown in the world. Although it was generally considered that the output of organic agriculture was 10%-20% lower than that of conventional agriculture, it exceeded conventional agriculture in terms of economic benefits, environmental impact, and social benefits. It also had a positive performance in providing nutrition, adapting to climate change, promoting soil health, protecting biodiversity, increasing employment and creating new economic model. In the face of rapid population growth, climate change and environmental degradation in the 21st century, new organic greenhouse horticulture was the major force for sustainable agricultural development. The total area for organic greenhouse horticulture was estimated to be over 8302 hm<sup>2</sup> (1.8% of total vegetable greenhouse area). There were 5236 hm<sup>2</sup> in European Union and 3066 hm<sup>2</sup> in Non-European Union. With the rapid development of agriculture in the world, the organic greenhouse horticulture had been shown to be sustainable, productive and profitable in foreign countries, but the standards of organic greenhouse horticulture were still a blank in China. This paper introduced the background, definition, origin, objectives, area of organic certification, yield and profitability, the basic forms of organic greenhouse horticulture and the rules of certification, and analyzed the feasibility and problems on the organic greenhouse horticulture in China: 1) Certification standards of organic greenhouse horticulture were lacked. 2) Greenhouse ecological environment had been deteriorated. 3) Plant varieties for greenhouse were scarce. 4) There were only a few studies on organic greenhouse horticulture. The feasibility of the development of organic greenhouse horticulture in China was further analyzed. It was suggested that organic greenhouse horticulture should be actively developed in China, but organic greenhouse horticulture cannot be simply equivalent to "greenhouse + organic planting". It should be an integration with sustainable development, which consisted of greenhouse climate control, planting material, soil fertility, water management, disease and pest management, energy conservation and sustainability. However, to promote the development of organic greenhouse horticulture in China, we need to implement it based on national conditions and learn the rules of the foreign organic greenhouse horticulture. Moreover, the basic research of the biological agriculture in our country should be strengthened: 1) Strengthen the formulation of organic farming laws and industry standards in China, and point out the development goals and technical requirements of organic greenhouse horticulture. 2) Strengthen basic research in bio-agriculture to propose novel theories, technologies and equipment for protected agriculture. 3) Strengthen the development of agricultural machinery for organic greenhouse horticulture. The aim was to compensate for the lack of manpower, increase production efficiency and transform people's bias that organic agriculture has low yield and inefficiency. 4) Strengthen the demonstration and promotion of organic facilities horticultural technology integration. We need to construct a diversified organic facility horticultural extension service system with national public welfare promotion institutions as the main body, scientific research units, colleges and universities, agriculture-related enterprises, professional cooperative organizations and consumers participating in it. The system can provide information and technical services for farmers and consumers, which can ensure the sustainable development of the protected agriculture industry in China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:97
Main heading:Greenhouses
Controlled terms:Biodiversity - Climate change - Climate models - Disease control - Economic and social effects - Environmental impact - Environmental protection - Industrial plants - Planning - Population statistics - Profitability - Soil conservation - Sustainable development - Vegetables - Water conservation - Water management
Uncontrolled terms:Agricultural development - Colleges and universities - Conventional agricultures - Cooperative organization - Ecological environments - Greenhouse climate control - Plant factory - Sustainable agricultural development
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 454 Environmental Engineering - 454.2 Environmental Impact and Protection - 483.1 Soils and Soil Mechanics - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures - 911.2 Industrial Economics - 912.2 Management - 921 Mathematics - 971 Social Sciences
Numerical data indexing:Percentage 1.00e+01% to 2.00e+01%, Percentage 1.80e+00%, Percentage 3.00e+01% to 4.00e+01%, Percentage 5.00e-01%
DOI:10.11975/j.issn.1002-6819.2018.15.001
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 34>
Accession number:20184506039311
Title:Soil heavy metal sources analysis and risk evaluation of Zhundong coal mine in Xinjiang
Authors:Yang, Lei (1, 2); Xiong, Heigang (3)
Author affiliation:(1) College of Resources & Environmental Science, Xinjiang University, Urumqi; 830046, China; (2) College of Management, Xinjiang Agricultural University, Urumqi; 830052, China; (3) College of Arts and Sciences, Beijing Union University, Beijing; 100083, China
Corresponding author:Xiong, Heigang(heigang@buu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:273-281
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:During the process of opencast and underground coal mining, a variety of rock types with different compositions are exposed to atmospheric conditions and undergo accelerated weathering. These materials are often deposited nearby as mine waste rocks and mine dust. Heavy metal pollution is the representative environmental pollution which is caused by heavy metals or their compounds. It has wide range, long duration, non-degradability, and some other features. The accumulation of heavy metals in soil will destroy the physical and chemical properties of soil, cause irreversible pollution of environment, and further threaten human health. For mining area, influenced by human exploitation, the top soil is thin and is easily affected by atmospheric dust fall. To study the origin of heavy metals in soils and ecological risk in Zhundong area, we analyzed heavy metal (As, Hg, Pb, Cr, Cu and Zn) content with 27 soil samples in three buffers (every 42 km from Zhundong Diggings to Fukang City was divided into a area, area A, area B and area C). The risk analysis of heavy metals was carried out by means of pollution index method, land accumulation index method and potential ecological risk index method. The results showed that: 1) In addition to the overall average value of Cr is 53.03 mg/kg, which is higher than the background value of soil (49.3 mg/kg) in Xinjiang, the contents of other heavy metals are lower than their background values. The figures of spatial distribution of soil heavy metals indicate that: High values of Cu and Hg content was distributed in the area C, high values of other heavy metal content appeared in soils near Zhundong mining area (area A), the heavy metal content in the three buffers are basically the same, the coefficient of variation decreased with the increasing of distance to the mining area. 2) Through the analysis of pollution sources, in Zhundong area, 89.31% of Hg comes from coal burning, 40.1% of Pb comes from transportation, 19.65% of As comes from atmospheric dust. The main source of Cu and Cr is coal dust and its contribution rates are 60.23% and 81.6%, respectively, 29.7% of Cu comes from the soil parent material, and 75.1% of Zn comes from the soil parent material. There are still unknown sources of heavy metals in soil except Zn. 3) The soil pollution risk in the study area was evaluated by means of pollution index method, land accumulation index method and potential ecological hazard index method. The pollution level of soil in Zhundong area is mild-moderate, single element pollution degree from high to low is Hg>As>Pb>Cr>Cu>Zn. The farther away from the mining area, the lighter the heavy metal pollution is. The rank of Regional ecological risks of As, Hg, Pb and Cr elements was A >B >C, the farther away from the mining area, the lower the ecological risk is. The potential ecological risk index is consistent with the order of single factor ecological risk of heavy metals. The mining of coal results in the pollution of heavy metals in the surrounding soil, which seriously affects people undefined cultivation and life, and also affects the ecological environmental system. Therefore, it is necessary to establish a system of environmental protection and strictly manage of mining in mining areas.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Soil pollution
Controlled terms:Air pollution - Atmospheric chemistry - Coal - Coal dust - Coal mines - Coal transportation - Copper - Heavy metals - Metal analysis - Mine dust - Risk analysis - Risk assessment - Soil surveys - Soils - Weathering
Uncontrolled terms:Ecological risks - Environmental pollutions - Mining areas - Physical and chemical properties - Pollution of heavy metals - Potential ecological hazards - Potential ecological risk - Source analysis
Classification code:443.1 Atmospheric Properties - 451 Air Pollution - 451.1 Air Pollution Sources - 483.1 Soils and Soil Mechanics - 503.1 Coal Mines - 524 Solid Fuels - 531 Metallurgy and Metallography - 544.1 Copper - 914.1 Accidents and Accident Prevention - 922 Statistical Methods
Numerical data indexing:Percentage 1.96e+01%, Percentage 2.97e+01%, Percentage 4.01e+01%, Percentage 6.02e+01%, Percentage 7.51e+01%, Percentage 8.16e+01%, Percentage 8.93e+01%, Size 4.20e+04m
DOI:10.11975/j.issn.1002-6819.2018.08.034
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 35>
Accession number:20184506039310
Title:Zoning method for well-facilitated farmland construction based on improvement of ecological services
Authors:Liu, Chunfang (1, 2); Wu, Yahan (1, 2); Wang, Chuan (1, 2)
Author affiliation:(1) College of Geography and Environmental Science, Northwest Normal University, Lanzhou; 730070, China; (2) Gansu Engineering Research Center of Land Utilization and Comprehension Consolidation, Lanzhou; 730070, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:264-272
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Improving the ecosystem service function and production function of cultivated land is the main objective of well-facilitated farmland construction, while well-facilitated farmland zoning and regulation design aimed to improve ecological service function is the fundamental premise for the effective implementation of ecological farmland construction. At present, the emphasis of well-facilitated farmland construction is to achieve the goal of good quality of cultivated land, centralized and continual cropland, infrastructure supporting, rational ecological landscape pattern and stable spatial distribution through engineering technology and other measures. On the basis of the existing goals, taking Yuzhong County, Gansu Province as a typical case, the paper tried to explore the theory and method of ecological farmland construction zoning in loess hilly region. Firstly, taking village as the basic research unit, based on InVEST model, the paper evaluated 4 different values of ecosystem services which are habitat quality, soil retention, carbon sequestration, and food supply. Then the paper analyzed the spatial differentiation of various types of ecosystem services, and found out the low-value ecosystem service types for each research unit. Secondly, the paper identified obstacle factors which affect regional ecosystem services, and divided them into controllable factors and un-controllable factors. Thirdly, through the relationship framework between well-facilitated farmland construction measures and ecosystem service functions, combined with the controllable obstacle factors, the construction directions of well-facilitated farmland in different regions are determined, as well as the measures of ecological well-facilitated farmland construction zoning and regulation. The main contribution of the paper is to discuss the relationship between well-facilitated farmland construction measures and ecosystem service functions, and to put forward a set of ideas and methods for delineating ecological well-facilitated farmland construction zoning based on ecosystem services evaluation. Results show that, Yuzhong County's ecosystem services have obvious spatial difference. Among them, the habitat quality shows a decreasing trend from southwest to northwest area. The spatial difference of soil erosion is large, which is controlled by topography and vegetation cover and other factors. The high value area is mainly distributed in the loess hilly area and the northwest area, and the low value area is mainly located in the southern mountainous area and the central valley basin area. Similar to the habitat quality, the spatial distribution of carbon sequestration services also shows spatial characteristics of decreasing from south to north. Because of the better soil and water conditions in the central valley basin, the spatial distribution of food supply services shows that it is low in the north and south mountains, and high in the central basin. On the basis of the spatial difference of ecosystem services and the identification of controllable obstacle factors, 4 zoning types of ecological well-facilitated farmland construction in Yuzhong are obtained, which are habitat quality improvement zone, food supply and carbon sequestration service promotion zone, habitat quality and carbon sequestration service promotion zone, and habitat quality, food supply and carbon sequestration service promotion zone. Corresponding regulation and control measures are put forward for different types of ecological well-facilitated farmland construction zoning. The construction division can effectively promote the ecological function of "fields, water, roads and forests", which is the effective mode to achieve the simultaneous improvement of ecological service functions and production, and it also can provide important basis for theoretical thinking and practical innovation of ecological civilization construction.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Ecosystems
Controlled terms:Carbon - Farms - Food supply - Land use - Landforms - Petroleum reservoir evaluation - Quality control - Sediments - Soils - Spatial distribution - Zoning
Uncontrolled terms:Construction measures - Ecosystem service functions - Farm land - Regulation and control - Regulation strategy - Relationship frameworks - Spatial characteristics - Spatial differentiation
Classification code:403 Urban and Regional Planning and Development - 454.3 Ecology and Ecosystems - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 512.1.2 Petroleum Deposits : Development Operations - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 913.3 Quality Assurance and Control - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2018.15.033
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 36>
Accession number:20184506039309
Title:Comparison on evolution of rural farmland use in poverty-stricken counties between flat and mountainous areas based on remote sensing and GIS
Authors:Xie, Zhen (1, 2); Zhang, Fengrong (1, 2); Gao, Yang (1, 2); Zhang, Tianzhu (1, 2); Zhang, Bailin (3); Zhou, Jian (4)
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; (3) School of Management, Tianjin Polytechnic University, Tianjin; 300387, China; (4) Center for Land Resources Research in Northwest China, Shaanxi Normal University, Xi'an; 710119, China
Corresponding author:Zhang, Fengrong(frzhang@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:15
Issue date:August 1, 2018
Publication year:2018
Pages:255-263
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Recognizing the evolution and transformation progress of rural farmland under different terrain conditions is the basis of modernization management of agriculture, which will also help the targeted poverty alleviation in rural areas. Remote sensing and GIS (geographic information system) technology were used to analyze the farmland use in national-level poverty-stricken county of Horqin Left Wing Rear Banner in the flat area and Youyang County in the mountainous area. The analysis mainly focused on the variation of the quantity, quality, spatial distribution, configuration characteristic, distribution of topographic region and planting structure of farmland land from 2001 to 2015 when there is an enormous amount of migration from rural to urban areas. The results are as follows: 1) Compared with the mountainous county, the farmland per capita labor is more abundant in the plain county, but continuous expansion of farmland still occurs in the flat county while the shrink exists in the mountainous county. 2) The farmland quality of poverty-stricken county in the flat area is generally low and the inferior farmland changes obviously, by contrast, in the mountainous county, it is higher and the farmland of low and middle quality increases obviously. 3) The distribution of farmland in these 2 counties tended to cluster together; the farming radius in the flat county was expanding but it shrank in the mountainous county. The number of farmland patches and largest patch index increased in the flat county, while the number of farmland patches declined sharply and the largest patch index increased a little in the mountainous one. The mean patch size of farmland in the flat county was much larger than that in the mountainous county, but varying degrees were both increased. There was a raise of area-weighted patch fractal dimension of farmland in the flat county but a reduction in mountainous county. In the flat county, the low terrain niche range was the priority areas for development of farmland and there existed no significant change, while the middle-low terrain niche range was not the priority areas for development of farmland in the mountainous county. Meanwhile the advantage degree of farmland increased in the middle-low terrain niche range. 4) Generally, farmers in the flat counties prefer to plant food crops which are land-intensive agricultural products because of the man-earth relationship of wide land and few people, while commercial crops with greater weight are planted in mountainous county by contrast because of big population holding little tillable land. The results show that terrain and farmland resource are the critical factors influencing the difference of comparative advantage of regional production, which, to some extent, makes the pattern of farmland use and agricultural production various. Therefore, the investment and policy-making for agricultural modernization and targeted poverty alleviation must make the best use of the circumstances. The agricultural development mode in flat areas should change from extensive use of resources to protective utilization, so as to avoid the phenomenon of "land reclamation along with land desertification", which causes the soil desertification and the farmland quality decline. The development of agriculture in mountainous areas must change the traditional agricultural production mode to improve agriculture multifunction for the more value of "land economic output per unit area" through technological reformation and marketization.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Farms
Controlled terms:Agricultural products - Climatology - Crops - Fractal dimension - Geographic information systems - Land reclamation - Land use - Landforms - Remote sensing - Rural areas - Weathering
Uncontrolled terms:Farmland use - Horqin Left Rear Banner - Poverty-stricken county - Terrain - Youyang county
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 443 Meteorology - 481.1 Geology - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 903.3 Information Retrieval and Use - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2018.15.032
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 37>
Accession number:20184506039296
Title:Relationship between rill erosion morphology and hydraulic characteristics and sediment yield on artificial soils slope with different textures
Authors:Ni, Shimin (1); Feng, Shuyue (1); Wang, Junguang (1); Cai, Chongfa (1)
Author affiliation:(1) Research Center of Water and Soil Conservation, Huazhong Agricultural University, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) in Ministry of Agriculture, Wuhan; 430070, China
Corresponding author:Wang, Junguang(jgwang@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:149-156
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil erosion is one of serious environmental problems in China. Rill erosion is the most important process of water erosion and sediment production. The sediment yield of rill erosion accounts for most of the total sediment yield. The formation of rill is the result of the interaction between water hydraulic characteristic and soil resistance. Soil particle composition plays an important influence on soil erosion resistance that hinders rill formation and development. The objectives of this study were to clarify the relationship between the rill morphology and sediment yield for soil-sand mixture with different sand contents, which were selected as experimental materials. The indoor water scouring experiment was conducted on the basis of the experimental settings including the experimental combination of 2 slopes (5°, 15°), 4 discharges (2, 4, 6, 8 L/min) and 5 remodeling slopes (sand content of 0, 30%, 50%, 70%, 100%) by a moving steel flume (3 m long, 1 m wide and 0.35 m high). Before the experiment, stones, roots and other impurities were removed from the soil material, followed by air-drying of the soil and sifting through a 5 mm sieve. And the bulk density was controlled at 1.35 g/cm<sup>3</sup>. Prior to each experiment, the flume was pre-wetted using the 30 mm/h rainfall intensity to moisture saturation with the flume covered with a gauze. The experiment was started when the moisture content reduced to 30% as measured by a soil moisture meter. Mean rill depth, mean rill width and rill width-depth ratio were used as basic rill morphological parameters. The relationship between rill morphology, hydraulic characteristics and sediment yield was analyzed and the prediction equation of slope erosion of different soil particle compositions was established. The results showed that: 1) Mean rill depth increased and mean rill width decreased with the increase of slope gradient, but the impact on discharges was not obvious. The rill cross-section morphology exhibited an obvious regularity that width-depth ratio decreased with the increase of slope gradient and discharges also gradually presented a narrow-deep form.2) Rill cross-section morphology tended to be wide-shallow form with the increase of slope sand content, and rill cross-section morphology of different slope sections tended to be wide-shallow form from up slope to low slope. 3) Unit stream power and stream power had the closest relationship with the rill morphology parameters (r>0.784, p<0.01). There was a non-significant relationship between mean rill width and hydraulic parameters. 4) Mean rill depth and rill morphology comprehensive quantification parameters had satisfying effect on the forecasting of sediment yield (R<sup>2</sup>>0.747, p<0.01; Nash coefficient was larger than 0.755). 5) The slope erosion prediction equation with preferable reliability was established by the introduction of soil clay content, which facilitated the higher prediction accuracy (R<sup>2</sup>>0.879, p<0.01; Nash coefficient was larger than 0.887). The results provide a theoretical basis for the study of slope erosion prediction and soil erosion mechanism.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:55
Main heading:Erosion
Controlled terms:Buoyancy - Forecasting - Hydraulics - Morphology - Sand - Sediments - Soil moisture
Uncontrolled terms:Cross-section morphology - Environmental problems - Experimental materials - Hydraulic characteristic - Morphological parameters - Quantification parameters - Sediment yields - Slope erosion
Classification code:483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 632.1 Hydraulics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Mass_Density 1.35e+03kg/m3, Percentage 1.00e+02%, Percentage 3.00e+01%, Percentage 5.00e+01%, Percentage 7.00e+01%, Size 1.00e+00m, Size 3.00e+00m, Size 3.50e-01m, Size 5.00e-03m
DOI:10.11975/j.issn.1002-6819.2018.15.019
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 38>
Accession number:20184506039302
Title:Optimized operation of energy storage systems of wind power based on demand response and cost model
Authors:Tian, De (1); Chen, Zhonglei (1); Deng, Ying (1)
Author affiliation:(1) State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing; 102206, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:15
Issue date:August 1, 2018
Publication year:2018
Pages:200-206
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, the global energy shortage and environmental pollution become more and more serious. There is growing concern for the development of the power grid is facing more severe challenge. Therefore, it is important to research economic optimal operation problem of wind power/energy storage systems, and make the comprehensive economic benefits of power grid achieve the top level. At present, the trend in the global energy sector has turned to a new type of clean power source that is environmentally friendly. In China, while the scale of renewable energy development continues to expand, it has caused the problem of the mismatch between growth in power installation capacity and growth in demand-side electricity consumption. In addition, the renewable energy consumption market is in an immature stage of development, the export channel is not smooth, and there exist other factors causing that the renewable energy output is limited and the abandonment of wind/photovoltaic energy resource is serious. With the development and application of new power sources in the actual power grid, this also puts forward new requirements for the planning and operation of traditional power grids. This paper analyzes the structure of wind power/energy storage systems, and summarizes the key techniques of optimal operation which are demand-side response technology and energy storage technology. There are 2 steps in the establishment of models, and the details are as follow: First, a model of demand-side response is built, which depends on load reduction, load reduction climb rate and total reduction. The second model is the total principal balance model of wind power. In addition, the third one is the energy storage cost model for the life of energy storage equipment. It just ends up with a model which combines the second one and the third one-optimized operation model of electric distribution network for wind power/energy storage. It is constrained by power balance, transmission power between systems, and operation behavior for energy storage systems. In order to solve the established model, this paper mentions a differential evolution algorithm (DEA). After introducing the basic DEA, some steps are described in detail. The steps include the data initialization, DEA mutation operation, cross operation and selection operation. In this paper, an improved differential evolution algorithm (IDEA) is put forward. This greatly improves the economic benefit and the life of energy storage. The problem of early maturity may be solved by solving group transformation. The IDEA was used to solve the model and then the optimal scheduling strategy was developed. Finally, the electric distribution network for wind power/energy storage is simulated. In this study, IDEA was programmed by MATLAB and its results were compared with the basic DEA results. It is proved that IDEA is more beneficial than DEA to maintain population diversity and avoid convergence to local optimum effectively. To illustrate the advantage of IDEA, genetic algorithm (GA) was selected for comparison. The scheduling cost of IDEA scheme is less than that of GA scheme, so the IDEA scheme is better.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Electric power transmission networks
Controlled terms:Digital storage - Economic and social effects - Electric energy storage - Electric network parameters - Electric power distribution - Electric power system economics - Energy policy - Energy utilization - Genetic algorithms - MATLAB - Models - Optimization - Scheduling - Wind power
Uncontrolled terms:Demand side response - Development and applications - Differential evolution algorithms - Improved differential evolutions - Optimal scheduling - Optimal scheduling strategies - Renewable energy development - Storage systems
Classification code:525.3 Energy Utilization - 525.6 Energy Policy - 615.8 Wind Power (Before 1993, use code 611 ) - 703.1 Electric Networks - 706 Electric Transmission and Distribution - 722.1 Data Storage, Equipment and Techniques - 912.2 Management - 921 Mathematics - 921.5 Optimization Techniques - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2018.15.025
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
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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
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- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
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