<RECORD 1>
Accession number:20181605031921
Title:Experimental study and numerical simulation of hydraulic characteristics of Tai Chi fishway
Authors:Qie, Zhihong (1); Guo, Liyun (1); Wu, Xinmiao (1); Ran, Yanli (1)
Author affiliation:(1) College of urban and rural construction, Agricultural University of Hebei, Baoding; 071001, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:182-188
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Once the fishway is completed in the traditional style and the flow condition is basically fixed. It will be hard for a variety of fish to go through it at the same time. To solve the problem, in this paper, we developed a Tai Chi fish-way, which can form a rich flow regime and adapt to the migration of many fishes. Based on the ancient Taoist philosophy of "Tai Chi Eight Diagrams", Tai Chi fishway created a flow changing environment when the eight diagrams rolled, which can offset the general fishway's shortcoming, "once built, water conditions were basically fixed". The pool room of the Tai Chi fishway was arc-shaped, which was connected by a reverse arc smoothly. Through the diffusion and aggregation of water, it can help the water flow more smoothly, and reduce the adverse effects of turbulence, vortex and so on. The wall of the pool room was provided with external eight diagrams (groyne type clapboards), which offered resistance to the water flow and helped change its direction when flowing through. The migratory fishes may rest below the external eight diagrams. Tai Chi disk was also set in the pool room and the S shaped channel on the disk had the function of dispersing water flow and dissipating energy. The Tai Chi disk and internal eight diagrams partition can rotate in certain cycles which were combined into different operating conditions at different times to create conditions for the polymorphism of the stream. For Tai Chi fishway had its unique pool room structure, the physical model test alone was difficult to capture the flow structure in detail, and it was time-consuming, too. We used a method combined with the physical model test and numerical simulation to study the flow characteristics of Tai Chi fishway in different conditions. Physical model test was used to study the variation of water level along the course and the basic flow pattern of water flow, and the CFD numerical simulation method was applied to determine the distribution of the surface and internal flow fields which were difficult to be measured by the physical model. Then the water level and flow pattern were compared and verified with each other after being obtained via the two methods. In accordance with the relevant norms of fishway designs and gravity similarity criteria, the fishway physical test models were made. Before the installation of the Tai Chi disc and external and internal eight diagrams, a water test and a measurement of the water depth along the center line were conducted. After the installation of Tai Chi disc, the test was divided into two groups to measure the water depth along the center line. The S shaped channel was approximately parallel and vertical to the flow. In each case, Tai Chi disk placement angle was consistent. The above three situations were simulated by numerical calculation. The results showed that they had a same trend. The maximum error was 13.6%, within the allowable range of 15%. Therefore, the calculation model was reliable and can be used to simulate the complex flow field of the pool room. Therefore, the surface velocity, bottom velocity and critical cross section velocity were further analyzed. The results showed that the Tai Chi fishway had significant energy dissipation reduction effect. The shallowest water depth was about twice of that of the corresponding shallowest water depth without the Taichi disk. Average maximum velocity of cross section decreased by about 50%, the flow presented polymorphism, Tai Chi disk's different positions also made flow change, which can provide more suitable conditions for migratory fish.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Computational fluid dynamics
Controlled terms:Energy dissipation - Fish - Fisheries - Fishways - Flow fields - Flow of water - Flow patterns - Flow velocity - Graphic methods - Hydraulics - Hydrodynamics - Lakes - Models - Numerical methods - Numerical models - Testing - Velocity - Water levels
Uncontrolled terms:CFD numerical simulations - Different operating conditions - Flow charac-teristics - Flow condition - Hydraulic characteristic - Mathematical simulations - Tai chis - Variation of water level
Classification code:525.4 Energy Losses (industrial and residential) - 631 Fluid Flow - 632.1 Hydraulics - 723.5 Computer Applications - 921 Mathematics - 921.6 Numerical Methods
Numerical data indexing:Percentage 1.36e+01%, Percentage 1.50e+01%, Percentage 5.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.025
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 2>
Accession number:20181605031927
Title:Design and implementation of smart supervisory system for sewage emission in swine breeding industry
Authors:Wu, Xinmei (1, 2); Xu, Aijun (1, 2); Zhou, Suyin (1, 2)
Author affiliation:(1) School of Information Engineering, Zhejiang A&F University, Hangzhou; 311300, China; (2) Zhejiang Provincial Key Laboratory of Forestry Intelligent Monitoring and Information Technology, Zhejiang A&F University, Hangzhou; 311300, China
Corresponding author:Zhou, Suyin(zsy197733@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:226-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Swine effluent poses not only serious threats to the environment and soil but also affect the sustainable development of livestock industry. So the treatment and supervision of swine sewage is imperative. In this paper, we divided the swine treatment methods into ecological treatment, industrial treatment and centralized treatment. To realize the remote monitoring and illegal discharge warning of swine effluent disposed by the three treatment methods, a smart supervisory system and real time data supervisory strategy was designed and proposed. Based on Internet, the newly developed system collected and monitored the effluent information such as rainfall, level, flow, location, chemical oxygen demand and biochemical oxygen demand in water, ammonia concentration and so on through data acquisition system. The system was mainly comprised of sensors, microprocessors, and GPRS wireless transmission module. The collected data were transmitted to the cloud server as real-time data for the entire supervisory system. According to the change rules of data and the practical demand of supervision, real-time data was obtained every 10 minutes. In addition, to determine the credit rating of the industries and push the alarm information in different conditions, the system would select the principle identity as the primary index of warning decision, while for the real-time warning, industry credit rating, alarm grade, and alarm processing time as the secondary indexes were used. Furthermore, the index system of warning-push was proposed in this paper. Combing the real time data and index system of warning-push, the system could realize functions of real time data monitoring, video monitoring, site management, equipment management, data statistic and early warning management. A lower inter-module coupling and a higher cohesion between the functions were designed to improve its scalability and flexibility, and to ensure that the modules could be interrelated in the logical structure and independent in the physical structure. In the centralized treatment, the system used the GPS data and basic information of sewage disposal plant to judge whether the tank car took the sewage to the designated place to discharge it or not. Based on fuzzy reasoning theory, the supervisory system of industrial treatment with five monitoring subsystems, which had two inputs and one output variables, was established. In this fuzzy supervisory system, suspended solid difference, ammonia-nitrogen difference, biochemical oxygen demand difference, chemical oxygen demand difference, total phosphorus difference and its variation rate were selected as input variables, and corresponding warning rank as an output variables. Also, symmetry triangle was selected as the membership function of input and output variables to ensure the sensitivity and robustness of the system. According to the effluent discharge standards of the livestock and poultry industry, fuzzy reasoning rules of the subsystem can be generated. To monitor the ecological treatment of swine effluent, in this paper, we constructed the corresponding supervision strategy and ecological mathematical model. Based on the principle of the supervisory strategy, the model predicted and analyzed the real-time data by qualitative and quantitative method to calculate the discharging interval during rainy days and to judge whether there existed the phenomenon of night discharge, stealing and leaking, overflowing and so on. Through the simulation test, the results showed that the system's average warning accuracy reached 96.17%, the average error time was 33.22 s, the illegal discharge capacity caused by error time was 15.77 L. Therefore, this supervisory system could meet the requirements of swine effluent discharge regulation and improve the supervision efficiency significantly.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Information management
Controlled terms:Agriculture - Alarm systems - Ammonia - Biochemical oxygen demand - Computer aided software engineering - Crime - Data acquisition - Design - Effluent treatment - Effluents - Emission control - Membership functions - Oxygen - Rating - Sewage - Structural design - Sustainable development - Waste disposal
Uncontrolled terms:Data acquisition system - Design and implementations - Fuzzy reasoning - Real-time data monitoring - Smart supervision - Supervisory systems - Swine production - Wireless transmi-ssion modules
Classification code:408.1 Structural Design, General - 451.2 Air Pollution Control - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 723 Computer Software, Data Handling and Applications - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 971 Social Sciences
Numerical data indexing:Percentage 9.62e+01%, Time 3.32e+01s, Time 6.00e+02s, Volume 1.58e-02m3
DOI:10.11975/j.issn.1002-6819.2018.02.031
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 3>
Accession number:20181605031912
Title:Effect of soil fracture priority flow on soil ammonium nitrogen transfer and soil structure in mining area
Authors:Yan, Jiaping (1); Chen, Xiaoyang (2); Cheng, Fangkui (1); Huang, He (2); Fan, Tingyu (2)
Author affiliation:(1) School of Surveying and Mapping, Anhui University of Science and Technology, Huainan; 232001, China; (2) School of Earth and Environment, Anhui University of Science and Technology, Huainan; 232001, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:120-126
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:North China Plain is the main coal production area with sedimentary deposit coal seam overlaid by the thicker soil layer above. The decrease of land surface elevation typically occurs at the rate in centimeters per year. Subsidence causes permanent inundation, especially topography gradient increase on the boarder of subsidence, surface runoff change, soil and water loss, and soil quality decline. It is critical to study the relationship among subsidence, surface runoff and soil quality change, and find the key factors that control the water and soil loss. In this paper, a two-dimensional undisturbed soil field experiment is performed, simulating subsidence process during coal mining. The data monitored in the experiment include surface subsidence, soil structure development, ammonia concentration and particle size change of soil during the rainfall-runoff process. Results show that underground mining not only changes surface topographic gradient and soil structure significantly but also aggravates the transport intensity of nutrient and particle in soil with runoff in the horizontal direction. Moreover, the soil crack produced by surface subsidence forms a series of groundwater preferential flow paths and promotes nutrient transport towards deeper layer. Firstly, in the horizontal direction, the ammonia content decreases by 14% on average in the subsidence with a length of 1.2 m and a slope of 2.1° after simulated rainfall of 122 mm. Secondly, in the vertical profile, the original ammonia peak value in the surface layer is 8. 8 mg/kg, migrating a depth of 30 cm downwards. Thirdly, soil texture changes ununiformly in different subsidence parts. On the sloping bottom over the distance of 1.2 m, the fine-grained soil clay (≤ 2 μm) content decreases from 2.5% to 2.1%, and the average rate of soil clay loss is 16%; coarse-grained sand (≥50μm) increases from 3.2% to 3.8%, and the average increase rate is 3.6%. Reversely, the amount of clay at the bottom increases from 2.5% to 2.8% and the cumulative increase rate of clay content is 12%. This study shows that during the development of the subsidence basin, the soil crack experiences an evolution process of soil force changing from tension to compression. Preferential flow of soil crack has become an important driving factor for soil erosion in coal mining subsidence areas. In the tension stage of the crack development, the surface runoff would move deeper directly where the preferential flow paths are dominant. Part of the ammonia and soil particles in the soil would transport through these shortcuts with the runoff and infiltration. Furthermore, this process of crack preferential flow decreases the amount of lateral migration of soil nutrients and particles in the runoff and infiltration process and enhances profile transport. This process causes a rapid decline of soil fertility than usual. Fine particles move to the deeper layer and coarse particle proportion increases. The water and soil loss are strengthened. Therefore, the decrease of the quality of the soil caused by mining subsidence is completely different from the horizontal erosion type runoff erosion in the area where natural slope is predominant. Soil degradation caused by mining subsidence is more serious, and the soil crack preferential flow is the important driving factor to reduce the soil quality in coal mining subsidence area. It does matter to carry out control technology research for soil quality and improve the soil quality and land utilization efficiency in mining area.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Infiltration
Controlled terms:Ammonia - Coal - Coal deposits - Coal mines - Cracks - Cutting machines (mining) - Erosion - Groundwater - Groundwater flow - Nitrogen - Nutrients - Particle size - Quality control - Rain - Runoff - Soils - Subsidence - Underground mine transportation
Uncontrolled terms:Ammonia concentrations - Ammonia nitrogen - Coal mining subsidences - Control technologies - Priority flow - Rainfall-runoff process - Soil structure - Topographic gradients
Classification code:443.3 Precipitation - 444.1 Surface Water - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 502.2 Mine and Quarry Equipment - 503 Mines and Mining, Coal - 503.1 Coal Mines - 524 Solid Fuels - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 913.3 Quality Assurance and Control
Numerical data indexing:Percentage 1.20e+01%, Percentage 1.40e+01%, Percentage 2.50e+00% to 2.10e+00%, Percentage 2.50e+00% to 2.80e+00%, Percentage 3.20e+00% to 3.80e+00%, Percentage 3.60e+00%, Size 1.20e+00m, Size 1.22e-01m, Size 2.00e-06m, Size 3.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.02.016
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 4>
Accession number:20181605031926
Title:Prediction of wind turbine key load based on SCADA data
Authors:Zhou, Shidong (1); Xue, Yang (1); Ma, Xiaojing (1); Wang, Wenzhuo (1)
Author affiliation:(1) State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems, China Electric Power Research Institute, Beijing; 100192, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:219-225
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The accurate prediction of wind turbine load at crucial positions is of great importance for wind turbines' structural safety and scheme of operation and maintenance. Traditional load measurements using strain gauges are not suitable for long-term load monitoring because such measurements are labor-intensive, costly and time-consuming. Load simulation using software represented by GH bladed is not applicable to the evaluation of wind turbines' load because of the failure to get comprehensive information of wind in real time. Therefore, it is necessary to develop an economical and feasible assessment method for wind turbine load. The prediction of wind turbine load may be achieved by establishing the relationship between SCADA data and load measurements. In view of the complicated load condition and coupling relationship among loads, BP (back propagation) neural network is used to construct the relationship between SCADA data and load indicators. The load indicator used in this study is fatigue equivalent load. The SCADA data used as input parameters are selected by calculating the correlation coefficients between SCADA data and load indicators. The numbers of hidden layers and neurons are determined by trial-and-error approach. Taking blade edgewise blending moment as the example, when the rest of parameters of neural network remain fixed, the predicted outputs by the BP neural network with 1 hidden layer and 6 neurons are the most accurate. For other BP neural network models, 1 hidden layer is used and the number of neurons is determined by trial-and-error approach. In order to prove the validity of the model, load measurements at 7 crucial locations of a 2.5 MW wind turbine are carried out. The accuracy of the relationship model is judged by comparing the predicted outputs by the model with the measured values. The coefficient of determination and the arithmetic mean value of relative errors between model outputs and measured values are used to characterize the accuracy. The arithmetic mean values of relative errors are between 1.28% and 15.6%, and the coefficients of determination are between 0.882 and 0.951, which show that the predictions are in good agreement with measurements. Therefore, establishing the approximate relationship between SCADA data and load indicators by BP neural networks can be used as an effective means to achieve the long-term monitoring and evaluation of wind turbine load at crucial locations. In the consideration of the fact that the wind farm seldom has the wind measurement mast and anemometer mounted in nacelle is often affected by the rotating blades, this study has abandoned the wind speed in the load prediction. Using BP neural network, hub rotating speed, pitch angle and active power are used to predict wind speed. The predicted values agree well with the measured value, which indicates that wind speed is not indispensable for the accurate load prediction. The study also shows that better prediction accuracy can be achieved by increasing reasonable input parameters. When there are many SCADA data that can be used as model input, the correlation coefficient approach is more efficient than the trial-and-error approach in selecting model inputs.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Wind turbines
Controlled terms:Backpropagation - Blending - Computer software - Electric load management - Errors - Forecasting - Information dissemination - Models - Neural networks - Neurons - Rotating machinery - Speech recognition - Wind - Wind power
Uncontrolled terms:BP (back propagation) neural network - Coefficient of determination - Comprehensive information - Equivalent load - Load predictions - Operation and maintenance - Parameter selection - Scada datum
Classification code:443.1 Atmospheric Properties - 461.9 Biology - 601.1 Mechanical Devices - 615.8 Wind Power (Before 1993, use code 611 ) - 706.1 Electric Power Systems - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 751.5 Speech - 802.3 Chemical Operations - 903.2 Information Dissemination
Numerical data indexing:Percentage 1.28e+00% to 1.56e+01%, Power 2.50e+06W
DOI:10.11975/j.issn.1002-6819.2018.02.030
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 5>
Accession number:20181605031917
Title:Quantitative retrieval of soil salt content based on Sentinel-1 dual polarization radar image
Authors:Ma, Chi (1)
Author affiliation:(1) Liaoning College of Communication, Shenyang; 110122, China
Corresponding author:Ma, Chi(machi1001@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:153-158
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The soil in midwest of Songnen Plain is becoming increasingly more salinized, which highlights the importance of rapid and precise monitoring and evaluation on salinization of soil. With great advantages, the microwave remote sensing becomes an emerging method with huge potential in detecting composition of soil. With the Sentinel-1 image covering the region with salinized soil in Songnen Plain as data source, combined with the assay data of total salt content in the sampled soil from the region of interest, the technology and method of soil salinization information extraction are investigated based on dual polarization radar image. Firstly, 64 soil samples are collected in the study area, and the total salt content of soil samples is tested in the laboratory. Fifty-two soil samples are taken as modeling samples, and 12 samples are taken as test samples. Saline-alkaline soil is divided into light salinization soil (with salt content of 1-3 g/kg), medium salinization soil (with salt content of 3-5 g/kg), heavy salinization soil (with salt content of 5-7 g/kg) and saline-alkaline soil (with salt content > 7 g/kg). The Speckle Filtering of S1TBX software is used to filter Sentinel-1 image to eliminate the influence of noise in the image on information extraction. Radiometric calibration is made for image using Radiometric-Calibrate tool to eliminate the absorption and scattering of atmospheric aerosol for imaging process so as to obtain the true back scattering coefficient of topographical surface feature. The image is subjected to geometrical correction by Terrain Correction tool. Then, by analyzing the quantitative relations between radar image VH and VV polarization modes, back scattering coefficient of polarization combination of VV+VH, VV/VH, (VV+VH)/(VV-VH), and (VV<sup>2</sup>+VH<sup>2</sup>)/(VV<sup>2</sup>-VH<sup>2</sup>), and soil salt content, the optimized polarization combination mode of the inversion model is determined. Lastly, the prediction model for soil salinity in the region of interest is established using multiple regression technique, and the relative error and root mean square error (RMSE) between predicted value and actual value of salinity in test sample of soil are compared to evaluate the precision of inversion model. The inversion model of soil salinity is used to inverse topsoil salinity in region of interest and the inversion result chart of soil salinity is drawn for the region of interest. The findings are: The back scattering coefficient of Sentinel-1 image VH polarization mode is strongly responsive to medium salinization soil, heavy salinization soil and saline-alkaline soil, and the back scattering coefficient of VV polarization mode is strongly responsive to all degrees of saline-alkaline soil; the back scattering coefficient of polarization mode of (VV<sup>2</sup>+VH<sup>2</sup>)/(VV<sup>2</sup>-VH<sup>2</sup>) can well separate non-salinized soil, light salinization soil, medium salinization soil, heavy salinization soil and saline-alkaline soil. The coefficient of determination R<sup>2</sup>for the established model reaches 0.872, and the RMSE is 0.988. Model checking results show that, the maximal relative error between predicted value and actual value of sample's salinity is 4.87%, and the minimum relative error is only 0.91%. In the scatter plot, inverse value and measured value of sample salt content after checking are evenly distributed on both sides of 1:1 straight line, and coefficient of determination R<sup>2</sup>is up to 0.98, and RMSE is 0.412, showing that the inversion model has a high precision in prediction of soil salt content in the research area. The graphical result of the inversion shows that: light salinization soil is widely distributed in the research area; medium salinization soil is mainly distributed in the western and southern Daqing City and western and northern Datong District, and concentrates around the rivers and lakes in the research area; heavy salinization soil, saline-alkaline soil and medium salinization soil are incidentally distributed, and mainly distributed in western and southern Datong District. This method can meet the need for monitoring soil salinization in large region, and provide reference for research on extraction of composition of soil based on Sentinel-1 radar data.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Soil surveys
Controlled terms:Artificial intelligence - Atmospheric aerosols - Backscattering - Data mining - Errors - Image segmentation - Information filtering - Information retrieval - Inverse problems - Mean square error - Model checking - Polarization - Radar - Radar imaging - Radiometry - Remote sensing - Salinity measurement - Soils
Uncontrolled terms:Absorption and scatterings - Coefficient of determination - Dual polarization radars - Inversion - Microwave remote sensing - Multiple regression techniques - Radiometric calibrations - Sentinel-1
Classification code:443.1 Atmospheric Properties - 483.1 Soils and Soil Mechanics - 716.2 Radar Systems and Equipment - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723.2 Data Processing and Image Processing - 723.4 Artificial Intelligence - 903.1 Information Sources and Analysis - 903.3 Information Retrieval and Use - 922.2 Mathematical Statistics - 944.8 Radiation Measurements
Numerical data indexing:Percentage 4.87e+00%, Percentage 9.10e-01%
DOI:10.11975/j.issn.1002-6819.2018.02.021
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 6>
Accession number:20181605031906
Title:Establishment and validation of flow rate prediction model for drip irrigation emitter based on support vector machine
Authors:Guo, Lin (1); Bai, Dan (1); Wang, Xinduan (1); Wang, Cheng (1); Zhou, Wen (2); Cheng, Peng (2)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an; 710048, China; (2) School of Water Conservancy, North China University of Water Resources and Electric Power, Zhengzhou; 450011, 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:2
Issue date:January 15, 2018
Publication year:2018
Pages:74-82
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To carry out the prediction and calculation of the flow rate for further study the hydraulic performance and the structure optimization of the flow channel in drip irrigation emitter is of great significance. In order to predict and calculate the flow rate of the emitter accurately, in this study, the prediction and calculation method of Support Vector Machine (SVM) with strong generalization ability was introduced, and the flow rate prediction model of the SVM was built. We chose six working pressures and eight geometric parameters of the flow channel as factors, and arranged 300 sets of emitter schemes as training sample of SVM according to the orthogonal experimental design method, and 30 sets of schemes as test sample. Based on these, the prediction model sample set of flow rate of SVM was established. The flow rate of the emitter was simulated by the SST k-ω model with high precision in the sample set, and compared with the predicted value of flow rate of the SVM. The pressure and geometric parameter of the emitter was taken as the input item, and the flow rate was taken as the output item of SVM. The prediction and simulation of the flow rate were carried out in State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area, Xi'an University of Technology. In order to eliminate the impact of each factor on the predicted results, the input and output item in the emitter sample were normalized before predicting flow rate. At the same time, the Genetic Algorithm was used to optimize the C and δ parameter in the Radial Basis Function (RBF) kernel of the SVM, and then the minimum error between the predicted value and simulated value of flow rate was obtained. The results showed that the relative error between the predicted value of flow rate using SVM and the simulated value was from 0.09% to 6.43%, the average relative error was 1.91%, and the determination coefficient was 0.98 when the optimal values of SVM parameter C and δ were 100 and 20, respectively. The predicted value of flow rate of SVM had a good correlation with the simulated value, which satisfied the predicted demand for the flow rate of the emitter. However, when the regression fitting method was adopted and calculated, the relative error between the predicted value and the simulated value was from 0.15% to 26.69%, the average relative error was 6.45%, and the determination coefficient was 0.93, which indicated excellent superiority based on SVM. To further verify the reliability of SVM, the five experimental verification schemes were chosen, and manufactured by using high-precision engraving technology. The flow rate value of experimental verification sample was tested under different pressure range, and was compared with the predicted value of flow rate. The relative error between the predicted value of flow rate using SVM and the experimental value was from 0.14% to 5.13%, and the average relative error was 2.25%, which were within the error range, verifying the accuracy and reliability of predicting flow rate using SVM. The establishment of the flow rate prediction response surface based on SVM can effectively improve the development efficiency of the emitter, and provide the evidence and guidance for the hydraulic performance evaluation, the flow channel structure design and optimization.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Support vector machines
Controlled terms:Channel flow - Errors - Flow rate - Fluid mechanics - Forecasting - Genetic algorithms - Geometry - Hydraulic machinery - Irrigation - Models - Numerical analysis - Optimization - Radial basis function networks - Shore protection - Structural design - Structural optimization
Uncontrolled terms:Determination coefficients - Drip irrigation - Geometric parameter - Orthogonal experimental design method - Prediction and simulations - Radial Basis Function(RBF) - University of technologies - Working pressures
Classification code:407.1 Maritime Structures - 408.1 Structural Design, General - 631 Fluid Flow - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 723 Computer Software, Data Handling and Applications - 821.3 Agricultural Methods - 921 Mathematics - 931.1 Mechanics
Numerical data indexing:Percentage 1.40e-01% to 5.13e+00%, Percentage 1.50e-01% to 2.67e+01%, Percentage 1.91e+00%, Percentage 2.25e+00%, Percentage 6.45e+00%, Percentage 9.00e-02% to 6.43e+00%
DOI:10.11975/j.issn.1002-6819.2018.02.010
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 7>
Accession number:20181605031919
Title:Quantitative method for freezing-thawing environment of concrete in Qinghai-Tibet plateau
Authors:Li, Xuefeng (1); Fu, Zhi (1); Wang, Hualao (1)
Author affiliation:(1) Research Institute of Highway Ministry of Transportation, Beijing; 100088, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:169-175
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Owing to the higher annual solar radiation and the thinner atmosphere compared to the plain area, plus and minus temperature appear alternately day and night in the Qinghai-Tibet Plateau. Therefore, concrete cast in the Qinghai-Tibet Plateau should have an excellent anti-frost durability. However, current proposed approaches to quantitatively evaluate the number of freeze-thaw cycles of concrete per year are mainly based on the freezing-thawing environment of the plain area. In this paper, firstly in order to compare the freezing-thawing environment difference between the Qinghai-Tibet Plateau and plains, according to the determining criterion of freezing-thawing environment listed in Code for durability of concrete structure, 3 groups of cities from different areas located in the Qinghai-Tibet Plateau and the plains respectively were selected, which had the same freezing-thawing environmental grade. In the meanwhile, because the freeze-thaw damage of concrete usually takes place on the surface and physical thermal parameters between concrete and soil are nearly equal to each other, the land-surface temperature is in good agreement with the concrete-surface temperature. Then the land-surface temperature was utilized to replace the concrete-surface temperature, and the air temperature and land-surface temperature of the 3 groups of cities were compared. The results demonstrate that in the Qinghai-Tibet Plateau the number of freeze-thaw cycles of concrete per year is more, the diurnal range of temperature is much larger and the lowest temperature is much lower than those of the plains. Due to without considering the freezing-thawing environmental difference between the Qinghai-Tibet Plateau and plains mentioned above, it was found that current calculating methods could underestimate the number of freeze-thaw cycles of concrete per year and are insufficient for durability design for concrete in Qinghai-Tibet Plateau. Based on the above analysis, the quantitative method for the freezing-thawing environment of concrete in Qinghai-Tibet Plateau was proposed. In the method, the concrete-surface temperature was replaced by the land-surface temperature and the conditions for occurrence of freezing-thawing damage of concrete were that the uninterrupted time of lowest temperature of less than or equal to-3℃ and temperature of more than 0℃ were not less than 2 h respectively. Then, the number of freezing-thawing cycles of concrete per year in Qinghai-Tibet Plateau was counted on the basis of corresponding meteorological data from 20 weather stations in 1971-2003 using the method mentioned above, and a calculation formula, related to the average temperature of the coldest month and annual solar radiation, was created to calculate the number of freezing-thawing cycles of concrete per year in the Qinghai-Tibet Plateau by regression analysis. With the formula the number of freeze-thaw cycles of concrete per year in the main region of the Qinghai-Tibet Plateau could be estimated approximately. The results indicate that in the Qinghai-Tibet Plateau the number of freeze-thaw cycles of concrete per year is generally more than 150, and even reaches 200 in some regions. Therefore, the demand for the durability of freezing-thawing resistance of concrete constructed is more exigent in the Qinghai-Tibet Plateau than in the plain. Based on the quantitative method for the frost environment of concrete in Qinghai-Tibet Plateau proposed in this paper, the design process method for the freeze-thaw durability of concrete structure and the recommended design grade of freezing resistance for concrete in the Qinghai-Tibet Plateau are given at the end of this paper.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Atmospheric temperature
Controlled terms:Concrete buildings - Concrete construction - Concretes - Durability - Freezing - Frost resistance - Landforms - Meteorology - Regression analysis - Solar radiation - Structural design - Surface measurement - Surface properties - Temperature - Thawing
Uncontrolled terms:Average temperature of coldest month - Durability of concrete structure - Environmental difference - Freezing thawing cycles - Freezing-thawing - Freezing-thawing resistances - Land surface temperature - Qinghai Tibet plateau
Classification code:408.1 Structural Design, General - 412 Concrete - 443.1 Atmospheric Properties - 481.1 Geology - 641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 922.2 Mathematical Statistics - 943.2 Mechanical Variables Measurements - 951 Materials Science
Numerical data indexing:Time 7.20e+03s
DOI:10.11975/j.issn.1002-6819.2018.02.023
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 8>
Accession number:20181605031908
Title:<sup>3</sup>He tube neutron moisture measurement device improving measuring accuracy
Authors:Zhang, Jie (1); Liu, Gang (1); Li, Baoguo (1); Li, Guitong (1)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China
Corresponding author:Liu, Gang(liug@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:90-97
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a significant part of water resources in the ecosystem cycle, soil moisture plays an extremely important role in the process of matter and energy exchange between the surface and the atmosphere. But it is very difficult to accurately measure large scale soil moisture. Cosmic-ray neutron method is a promising way to measure soil moisture for intermediate spatial scales. This method bridges the scale gap between point measurements of soil moisture and remote sensing, making significant contribution to the measurement of soil moisture within a regional level. In 2008, Zreda et al. introduced a method to measure average soil water content over a larger area with a cosmic-ray neutron sensor (CRS). The footprint of a CRS covers a circle with an approximate radius of 300 m and the effective measurement depth varies between 10 and 70 cm below the soil surface. Desilets et al. proposed an equation with three constant shape parameters (a<inf>0</inf>, a<inf>1</inf>, a<inf>2</inf>) and one calibration parameter (N<inf>0</inf>), which needs to be calibrated with soil moisture values determined by oven-drying method from field soil samples in 2010. Franz et al. (2013) developed a universal calibration function for determination of soil moisture with cosmic-ray neutrons that takes into account three influencing factors including pressure, incoming neutron flux and water vapor in the air. Meanwhile, other scholars have explored other factors that influence the soil moisture content, including the depth and range of detection, the lattice water, soil organic carbon and vegetation biomass. In this study, experiments were conducted in China Agricultural University Experiment Station with commercial cosmic-ray neutron sensors (CRS1000) and self-assembly<sup>3</sup>He tube neutron moisture detector (<sup>3</sup>He tube). In order to verify the accuracy and stability of these two instruments, we compared the soil moisture content data with the result from oven-drying method. Meanwhile, we made a comparison between the sensitivity of these two instruments for the response of precipitation event. Before using the two instruments, we needed to calibrate the N<inf>0</inf>from neutron conversion equation. And the calibration was based on soil moisture content derived directly from soil samples taken within the footprint of the sensor. After one correction, N<inf>0</inf>had certain stability over a long time. The intensity of the incoming neutron was one factor that affected the neutron count of the instruments, and it was necessary to calibrate the intensity of the incoming neutron when the solar activity was intense. Oven-drying method was used to measure the average moisture content within the footprint of the sensors. Then we used the average moisture content data to verify the stability of the two kinds of measurement. Comparing the soil moisture content data obtained from oven-drying method, it can be calculated that the root mean square error of the two instruments were respectively 0.036 and 0.015 cm<sup>3</sup>/cm<sup>3</sup>. It showed that the measurement results of two instruments were more accurate. The original neutron counts per hour of<sup>3</sup>He tube were about 10 times more than CRS1000, so we can conclude that the former was far more accurate than the latter. After corrected, soil moisture measurement results of CRS1000 and<sup>3</sup>He tube were more consistent. When precipitation event occurred, the change in<sup>3</sup>He tube was even more pronounced than CRS1000, showing that<sup>3</sup>He tube was more sensitive than CRS1000. At the same time, the cost of self-assembly<sup>3</sup>He tube neutron moisture detector was about half of commercial cosmic-ray neutron sensors. So<sup>3</sup>He tube will have a better application prospect.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soil surveys
Controlled terms:Calibration - Cosmic rays - Cosmology - Drying - Mean square error - Moisture - Moisture control - Moisture determination - Moisture meters - Neutrons - Organic carbon - Ovens - Remote sensing - Self assembly - Sensors - Soil moisture - Soils - Solar energy - Tubes (components) - Water resources
Uncontrolled terms:Application prospect - Calibration parameters - CRS1000 - Precipitation events - Root mean square errors - Soil moisture measurement - Soil organic carbon - Universal calibration
Classification code:444 Water Resources - 483.1 Soils and Soil Mechanics - 619.1 Pipe, Piping and Pipelines - 657 Space Physics - 804.1 Organic Compounds - 922.2 Mathematical Statistics - 944.1 Moisture Measuring Instruments - 944.2 Moisture Measurements - 951 Materials Science
Numerical data indexing:Size 1.00e-01m to 7.00e-01m, Size 3.00e+02m
DOI:10.11975/j.issn.1002-6819.2018.02.012
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 9>
Accession number:20181605031910
Title:Microphysical features of raindrop and rainfall energy based on particle imaging transient measurement technology
Authors:Zhan, Xiaoyun (1, 2); Guo, Minghang (1, 2); Zhao, Jun (1, 2); Shi, Haijing (1, 2); Shui, Junfeng (1, 2)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling; 712100, China; (2) Institute of Soil and Water Conservation, CAS & MWR, Yangling; 712100, China
Corresponding author:Guo, Minghang(mhguo@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:107-113
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Microphysical features of raindrop and rainfall energy are the key parameters for study of rainfall physics, which also have great significance in quantitative analysis of soil erosion and in soil erosion prediction model. The existing measurement methods include splash method, immersion method and so on, but most of them have many disadvantages, such as, labor and time consuming, poor real-time response, low precision and so on. Therefore, a new method should be developed urgently. In order to obtain physical properties of raindrops, in this study, the particle imaging transient visual measurement technology, light field and imaging system were designed, image identification, extraction and measurement were investigated, and finally the particle imaging transient visual measurement technology and computer vision identification technology were used to obtain the microphysical features of natural raindrop. The principle of the system could be described as below: a Fresnel lens was installed in the front of the light source. When the lights were passing through the Fresnel lens, the lights from point source would become parallel lights, which would shine on a projecting screen, and then the raindrop would project on the screen during its falling. Specifically, the system consisted of three parts: projection system, image capture system, and image control system. In the image capture system, two cameras were used to capture the raindrop image, one with a fast speed to obtain static image, and the other worked slowly to capture the tailed image. Based on the two images, we calculate the diameter and the fall velocity of raindrops. In order to obtain a clear raindrop image, we must remove the noise in the images. Basically, the image noise removal involved four steps. First, it was statistical filtering; second, the rolling filtering; third, the smooth filtering, and finally, it was the image binarization. Based on the static image and the corresponding tailed image mentioned above, geometric mean value algorithm and outer contour algorithm were used to calculate the diameter and fall velocity of raindrop. In our previous research, we found that the measurement technology had small relative error and it was suitable for the measurement of microphysical features of raindrop. Meanwhile, rainfall intensity was recorded by siphonic pluviograph. The results showed that medium-sized particles were the predominant contributor in the single rainfall. Raindrop diameter and fall velocity in our study were, on average, 1.52 mm and 3.47 m/s, respectively. Specifically, the proportion of raindrops with diameter ranged from 1.00 to 3.00 mm was up to 87.21%. Fall velocity was strong logarithmically related to raindrop diameter, and more precisely, fall velocity grew rapidly with an increase in rainfall diameter when the diameter was below 1.5 mm. As the raindrops fatten, the growth rate of fall velocity was reduced. Moreover, rainfall energy calculated in the present study was compared with the classic statistical model, and the relative error was averaged as 7.28%. In all, microphysical features of raindrop and rainfall energy can be measured precisely by the technique in this study, which sets the basis of estimating rainfall splash erosion.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Image processing
Controlled terms:Drops - Erosion - Light sources - Optical instrument lenses - Physical properties - Rain - Transient analysis - Velocity
Uncontrolled terms:Identification technology - Image identification - Measurement technologies - Particle imaging - Raindrop - Rainfall intensity - Statistical filtering - Transient measurement
Classification code:443.3 Precipitation - 741.3 Optical Devices and Systems - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 7.28e+00%, Percentage 8.72e+01%, Size 1.00e-03m to 3.00e-03m, Size 1.50e-03m, Size 1.52e-03m, Velocity 3.47e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.02.014
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 10>
Accession number:20181605031935
Title:Effects of packaging methods and materials on quality of prepared crisp grass carp (Ctenopharyngodon idellus C. et V) fillets during cold storage
Authors:Lin, Wanling (1); Ding, Mo (1, 2); Wang, Jinxu (1); Zhai, Honglei (1); Yang, Xianqing (1); Li, Laihao (1, 3); Wu, Yanyan (1); Hao, Shuxian (1); Huang, Hui (1)
Author affiliation:(1) National Research and Development Center for Aquatic Product Processing, South China Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou; 510330, China; (2) College of Food Science and Technology, Shanghai Ocean University, Shanghai; 201306, China; (3) Key Laboratory of Fishery Ecology and Environment, Guangzhou; Guangdong Province; 510300, China
Corresponding author:Li, Laihao(laihaoli@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:284-291
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Crisp grass carp (Ctenopharyngodon idellus C. et V) is a grass carp fed with broad bean as the sole food, but it is very different from ordinary grass carp and famous for its unique taste (more compact and crisper than ordinary grass carp). However, the shelf life of the products is limited due to the high protein content. The study was to investigate the effects of packaging methods and packaging materials on the quality of prepared crisp grass carp fillets, which were marinated in the water extract from Perilla leaf during the storage at 4℃. The results showed that the total bacteria count grew the fastest in prepared crisp grass carp with air-conditioned packaging (AP), whereas the lowest count of total bacteria was found in the sample with modified atmosphere packaging (MAP) during chilled storage at 4℃. On the 15th day during the storage, the average of total bacteria count of the fillets with MAP reached 5.61 log CFU/g, which didn't exceed the limitation at the end of the shelf life of aquatic products, while the total bacteria counts of the fillets with other 2 packaging methods, i. e. vaccum packaging (VP) and AP exceeded that limitation. At the end of the storage, the drip loss rate, TVB-N (total volatile basic-nitrogen) value and TBA (thiobarbituric acid) value of the prepared crisp grass carp fillets packaged with MAP were lower than that with VP and AP. For these samples packaged with MAP and PVC (polyvinyl chloride) taken as the material, the drip loss rate reached 5.07% on the 15th day. At the same time, the TVB-N value reached 13.91 mg/100 mg, which was less than the secondary freshness in national standard. The preservation life of prepared crisp grass carp fillets was more than 15 d with MAP during chilled storage at 4℃. In addition, TBA values of the fillets with MAP were lower than that with VP and AP by 16.40% and 46.46%, respectively. During the whole storage, the texture of samples with MAP decreased more slowly than that with VP and AP. Moreover, the hardness of prepared crisp grass carp fillets with MAP at the end of storage was 26.41% and 27.08% higher than that of the other 2 groups, respectively. For sensory evaluation, the sensory scores of fillets were not significantly different between MAP and VP. However, the average scores of MAP and VP were about 2.00 higher than that with AP. For packaging materials, the differences of the quality among them were very significant. The differences of hardness, drip loss rate, TBA value and sensory score between different packaging materials were significant during chilled storage at 4℃. More importantly, packaging material is one of the most important factors affecting the quality of prepared crisp grass carp fillets, and the prepared crisp grass carp packaged with the NY/EVOH/PET composites possessing high barrier properties had the best freshness. In summary, this paper provides the reference for the application of MAP and the material with high barrier properties in the preservation of prepared crisp grass carp fillets. MAP and the material with high barrier properties are more conducive to keeping the quality of prepared crisp grass carp fillets during chilled storage at 4℃.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Modified atmosphere packaging
Controlled terms:Air conditioning - Bacteria - Chlorine compounds - Cold storage - Food processing - Hardness - Packaging materials - Packing - Polyvinyl chlorides - Quality control - Sensory perception - Water quality
Uncontrolled terms:Barrier properties - Crisp grass carp - National standard - Packaging methods - Protein contents - Thiobarbituric acid - Total volatile basic nitrogens - Vaccum packaging
Classification code:445.2 Water Analysis - 461.4 Ergonomics and Human Factors Engineering - 643.3 Air Conditioning - 694 Packaging - 815.1.1 Organic Polymers - 822.2 Food Processing Operations - 913.3 Quality Assurance and Control - 951 Materials Science
Numerical data indexing:Percentage 1.64e+01%, Percentage 2.64e+01%, Percentage 2.71e+01%, Percentage 4.65e+01%, Percentage 5.07e+00%
DOI:10.11975/j.issn.1002-6819.2018.02.039
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 11>
Accession number:20181605031898
Title:Design and experiment of chopping-type maize straw returning machine
Authors:Wang, Qingjie (1); Liu, Zhengdao (1); He, Jin (1); Li, Hongwen (1); Li, Wenying (1); He, Jianhuai (1); Yan, Xionglei (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Li, Hongwen(lhwen@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:10-17
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In annual double cropping areas in northern China, the straw is directly returned to the field after maize harvest, and the wheat is sown by no-tillage planter. However, the high water content and strong toughness of maize straw result in the low qualification rate of traditional rotary flail knife type returning machine, which can easily lead to straw blocking and thereby affect wheat sowing quality. To address the above problems, in this paper, a chopping method based on the principle of four-bar linkage mechanism was put forward. The maize straw was chopped using ground as the support. A chopping-type straw returning machine, composed of the frame, pressure roller, transmission device and straw cutting device, was developed. The pressure roller was located at the front of the machine, and was designed to press the standing or lying straws forward in the direction of machine movement. The cutting device was at the back of the roller, and was designed to cut the lying parallel straw into segments. To avoid straw blocking, maize straw was chopped into segments with the length less than 6 cm, and the length was half of the narrow row spacing of wheat. Based on theoretical calculation and motion simulation, the size of 4-link mechanism of cutting device was designed and the cutters' movement trajectory was optimized. In 4-link mechanism, the minimum transmission angle was 70°, the maximum swing angle of rocker was 20°, the eccentric distance of eccentric wheel was 80 mm, and the lengths of cutter holder (connecting rod) and rocker were 267.375 and 460.702 mm, respectively. The distance between the rotation center of eccentric wheel and the hinge point of rocker on frame was 526.627 mm. According to the finite element static analysis by using ANSYS software, the maximum stress of the cutter was calculated as 162 MPa generated near the bolt holes on both sides, which met the design requirements. The field performance experiment was conducted in Hebei Province to compare the chopping-type straw returning machine and traditional flail knife type machine. The comparison and research objects included the unqualified rate of straw length, working stability, soil physical property and the subsequent sowing operation effect. The experiment results showed that the average length of the straw with the designed machine was 4.8 cm, the unqualified rate was 6% and the coefficient of variation was 0.209, which were all superior to the traditional machine. The vibration of the designed one was slightly larger than that of traditional one with no significant difference, and both of the machines worked stably. The cutting depth of new cutter reached 7.71 cm averagely, and soil bulk density in 0-10 cm depth decreased obviously. The subsequent wheat seeding experiments were carried out, and the results showed that there was no straw blocking during seeding when the seeder operated on the surface on which the chop-cutting straw returning machine worked, and the coefficient of sowing depth was 92.5% and it was significantly higher than another one. This study provides a new equipment for the maize straw returning in the double cropping areas in northern China, and it is also conducive to the popularization of straw returning technology.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Finite element method
Controlled terms:Design - Mechanization - Optimization - Rollers (machine components) - Static analysis - Wheels
Uncontrolled terms:Chopping-type - Coefficient of variation - Eccentric distances - Movement trajectories - Soil physical property - Theoretical calculations - Transmission devices - Working stabilities
Classification code:601 Mechanical Design - 601.2 Machine Components - 723.5 Computer Applications - 921.5 Optimization Techniques - 921.6 Numerical Methods
Numerical data indexing:Percentage 6.00e+00%, Percentage 9.25e+01%, Pressure 1.62e+08Pa, Size 0.00e+00m to 1.00e-01m, Size 2.67e-01m, Size 4.61e-01m, Size 4.80e-02m, Size 5.27e-01m, Size 6.00e-02m, Size 7.71e-02m, Size 8.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.02.002
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 12>
Accession number:20181605031922
Title:Evaluation on applicability of daily solar radiation model in Northwest China based on meteorological data
Authors:Zhang, Qingwen (1); Cui, Ningbo (1, 2); Feng, Yu (1, 3); Jia, Yue (1); Li, Chen (1); Gong, Daozhi (3); Hu, Xiaotao (4)
Author affiliation:(1) State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, Chengdu; 610065, China; (2) Provincial Key Laboratory of Water-Saving Agriculture in Hill Areas of Southern China, Chengdu; 610066, China; (3) State Engineering Laboratory for Efficient Water Use and Disaster Loss Reduction of Crops, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agriculture Science, Beijing; 100081, China; (4) Institute of Water-saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling; 712100, China
Corresponding author:Cui, Ningbo(cuiningbo@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:189-196
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Complete and accurate global solar radiation data at a specific region are highly crucial to regional crop modeling, evapotranspiration estimation, irrigation system development and utilization of solar energy resources. In order to improve the utilization efficiency of facility agriculture technology on radiation resources, daily climatic data in 10 meteorological stations in Northwest China from 1993 to 2016 were used to calculate daily global solar radiation. The applicability of 6 solar radiation models based on sunshine (Ångström-Prescott, Ogelman, Bahel, Louche, Almorox-Hontoria and Glower-McCulloch model) and 3 solar radiation models based on temperature (Hargreaves-Samani, Annandale and Bristow-Campbell model) was evaluated using the coefficient of determination (R<sup>2</sup>), root mean square error (RMSE), normalized root mean square error (nRMSE), Nash-Sutcliffe coefficient (NS), mean absolute error (MAE) and relative error (RE). In addition, the parameters of Bristow-Campbell (B-C) model were calibrated based on least square method using the daily meteorological data from 1993 to 2010, and the daily meteorological data from 2011 to 2016 were adopted to evaluate the applicability of B-C model. The results showed that the estimated and measured daily global solar radiation had statistically significant correlations (P<0.01) for all the 9 models at the 10 stations. Generally, the models based on sunshine (with R<sup>2</sup>ranging from 0.875 to 0.954 for the 10 stations) were more accurate to estimate daily global solar radiation than the models based on temperature (with R<sup>2</sup>from 0.652 to 0.813). In Northwest China, the Bahel model showed the best performance for daily global solar radiation estimation among the 6 models based on sunshine, followed by Ogelman model and Glower-McCulloch model, with average RMSE of 2.282, 2.309 and 2.313 MJ/(m<sup>2</sup>·d), average nRMSE of 14.0%, 14.2% and 14.2%, average MAE of 1.666, 1.701 and 1.697 MJ/(m<sup>2</sup>·d), and average NS of 0.905, 0.903 and 0.902, respectively. The best model based on temperature for estimation of daily global solar radiation was the calibrated B-C model, followed by Hargreaves-Samani model and Annandale model, with average RMSE of 3.819, 4.167 and 4.368 MJ/(m<sup>2</sup>·d), average nRMSE of 23.3%, 25.5% and 26.6%, average MAE of 2.680, 3.068 and 3.378 MJ/(m<sup>2</sup>·d), and average NS of 0.741, 0.688 and 0.656 respectively. On the monthly scale, the estimated and measured monthly average daily global solar radiation had good agreement, and the monthly average daily global solar radiation all increased from January to June and decreased from July to December. The Bahel model also showed the best performance for monthly average daily global solar radiation estimation among the 6 models based on sunshine, followed by Ogelman model and Glower-McCulloch model, with average RE of 5.350%, 5.375% and 5.679%, respectively. The calibrated B-C model had the best estimation accuracy among the models based on temperature, with average RE of 4.254%. It meant that the B-C model was more accurate than the Bahel model for global solar radiation estimation in monthly scale. Overall, the Bahel model is recommended to estimate daily global solar radiation when the sunshine hours are available, and the calibrated B-C model is recommended to estimate daily global solar radiation in Northwest China when only temperature data are available. This paper provides valuable information for global solar radiation estimation method in Northwest China, and also provides the theoretical basis and technical support for accurate estimation of daily global solar radiation.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Solar radiation
Controlled terms:Errors - Least squares approximations - Mean square error - Meteorology - Models - Solar energy - Temperature
Uncontrolled terms:Coefficient of determination - Daily global solar radiation - Global solar radiation data - Nash-Sutcliffe coefficient - NorthWest China - Parameter calibration - Root mean square errors - Sunshine duration
Classification code:641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.40e+01%, Percentage 1.42e+01%, Percentage 2.33e+01%, Percentage 2.55e+01%, Percentage 2.66e+01%, Percentage 4.25e+00%, Percentage 5.35e+00%, Percentage 5.38e+00%, Percentage 5.68e+00%
DOI:10.11975/j.issn.1002-6819.2018.02.026
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 13>
Accession number:20181605031901
Title:Intake throttling control strategy based on DPF active regeneration temperature for diesel
Authors:Wang, Jan (1); Cao, Zheng (1); Zhang, Duojun (2); Liu, Shengji (1)
Author affiliation:(1) School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) Wuxi Wabertec Automobile Technology Co., Ltd., Wuxi; 214000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:32-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Diesel engines are widely applied in the field of transportation and manufacturing because of its better power and fuel economic performances. However, diesel engine emits huge quantities of particulate matter (PM) which pose a great threat to the human health and environment. As emission regulations are becoming gradually stricter, it is imperative to stringently control diesel PM emission with a feasible after-treatment technic. Diesel particulate filter (DPF) is considered as the most effective mean to reduce diesel PM emission. The core of DPF regeneration is the control of upstream temperature of DPF. DPF regeneration is mainly divided into active and passive regeneration, the regeneration temperature is mainly controlled by the air management and injection strategy for the active regeneration. Air management is mainly by changing the intake throttle valve to control the intake air flow, and then controlling the exhaust temperature, which is important to match and improve the low temperature performance of the after treatment system, but the change of intake air flow will inevitably affect performances of the engine. So the control strategy of air management needs to be studied in depth. In order to obtain the intake throttling control strategy based on DPF active regeneration temperature under the whole working area of diesel engine, three typical working conditions were designed, including low-speed light load (working condition A: 1250 r/min 25% load), middle-speed medium load (working condition B:2000 r/min 40% load) and high-speed heavy load (working condition C: 3000 r/min 70% load), and the effects of intake throttle opening on pumping loss, exhaust thermal condition, in-cylinder combustion and emission characteristics of diesel engine were studied. The experimental results showed that the throttle effect was enhanced, the air intake flow gradually reduced under the different working conditions with the increasing of the throttle valve opening, which lead to the deterioration of combustion in cylinder, the decrease of the maximum combustion pressure, the increase of the BSFC, CO, NO<inf>X</inf>and smoke emissions. However, the decrease of the intake air flow delayed the start timing of combustion, prolonged the ignition delay period and increased the combustion temperature as well as the exhaust temperature, which inhibited the generation of HC effectively. When the intake throttle valve opening was reduced to 20%, the reduction rate of air intake flow was greater under the low-speed light load condition, the increase rate of exhaust temperature was more significant as much as 63%, while under the heavy load conditions, the exhaust temperature was slightly increased, but the pumping loss was increased by up to 19.2%, which seriously deteriorate the fuel economic performance. Based on the experimental results, the intake throttle valve opening was set respectively 35%-45%, 50%-60% and 70%-80% range according to the increasing potential for the exhaust temperature and performance deterioration under working conditions A, B, C in this paper. Moreover, the intake throttling strategy was given within the scope of all working conditions based on exhaust temperature distribution of the engine that light loads adopted the larger intake throttle valve opening, with the increasing of load, the throttle valve opening was gradually increased to the full open state.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Diesel engines
Controlled terms:Air - Air intakes - Automobile engines - Combustion - Deterioration - Emission control - Engine cylinders - Health risks - Ignition - Intake valves - Particulate emissions - Temperature
Uncontrolled terms:Active regenerations - Control strategies - Diesel particulate filters - Exhaust temperature - Intake throttle - Low temperature performance - Maximum combustion pressures - Performance deterioration
Classification code:451.1 Air Pollution Sources - 451.2 Air Pollution Control - 461.7 Health Care - 521.1 Fuel Combustion - 612.1.1 Internal Combustion Engine Components - 612.2 Diesel Engines - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 661.1 Automotive Engines - 804 Chemical Products Generally - 951 Materials Science
Numerical data indexing:Percentage 1.92e+01%, Percentage 2.00e+01%, Percentage 2.50e+01%, Percentage 3.50e+01% to 4.50e+01%, Percentage 4.00e+01%, Percentage 6.30e+01%, Percentage 7.00e+01%, Percentage 7.00e+01% to 8.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.005
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 14>
Accession number:20181605031899
Title:Development of mobile soil rotary steam disinfection machine
Authors:Wang, Xiaochan (1, 2); Li, Chengguang (1); Yang, Zhenjie (1); Sun, Guoxiang (1, 2); Shi, Yinyan (1); Zhao, Bo (1)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing; 210031, China; (2) Jiangsu Province Engineering Laboratory for Modern Facilities Agricultural Technology and Equipment, Nanjing; 210031, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:18-24
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China has been a great producer and consumer of vegetables all the time, and with the continuous development of vegetable cultivation, a series of problems have appeared, which have caused the tremendous pressure on the soil. For example, a tremendous use of fertilizer has led to many terrible results, like soil nutrient imbalance, soil continuous cropping barriers, imbalance of soil physical and chemical properties, soil consolidation, and so on. Every issue would cause serious damages to vegetable growth, yield and quality. In order to deal with the problem of vegetable planting caused by soil continuous cropping obstacle, a kind of steam disinfection machine was designed. This machine combined the rotary tillage device with the steam sterilizer effectively, and made it possible to complete the disinfection work while doing the soil rotary tillage. It was mainly composed of 6 parts: the rotary tiller, the steam generator, the water supply device, the steam delivery system, the disinfection cover and the detachable disinfection capillary. Compared with chemical disinfection, soil steam disinfestation was an ecological technique used in intensive agriculture to reduce soil pests before planting crops, which had the advantages of safe operation. Soil steam disinfection made high temperature water vapor into the soil, and could kill most bacterias and weeds in the soil so as to achieve the effect of disinfection. Also, high temperature steam sent the residual nitrogen and phosphorus under the effective tillage layer through the pore of the soil; at this time, the pore of the soil would also be heated by the high temperature water vapor, and the pore of the soil was enlarged with the dredging of the water vapor simultaneously. Therefore, this soil vapor disinfection increased the permeability and drainage of the soil, which was beneficial to the improvement of soil texture. By the way, it could be learnt through the analysis of the heat balance that the steam power required for the soil disinfection at 60℃ was 87.78 kW when the soil body was 120 cm wide and 15 cm deep, while when the steam generator outlet pressure of the steam sterilizer was 0.6 MPa and the temperature was 158.86℃, the steam power of the steam generator was 97.35 kW and the system loss was 0.61 kW, which could meet the heat demand of soil disinfection. And through the plot experiments, the main parameters affecting the steam disinfection performance of soil, including steam pressure, speed of machine running, diameter of capillary tube and spacing between tubes were determined, and relevant theoretical analysis was performed at the same time. Plot experiments showed that under the steam pressure of 0.6 MPa, the temperature of 158.86℃, and the rotary working speed of 0.035 m/s, 15 cm depth of soil temperature can reach 58. 9-70.6℃ under the condition of the capillary tube diameter of 15 mm and separation distance of 180 mm. This study provides not only a reference for further improving the performance of soil steam sterilizer, but also a choice for the farmers using the soil steam disinfection system.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Steam
Controlled terms:Agricultural machinery - Capillary tubes - Cultivation - Descaling - Design - Disinfection - Machine design - Soil mechanics - Soil moisture - Soils - Steam generators - Sterilizers - Vegetables - Water supply - Water vapor
Uncontrolled terms:Continuous cropping obstacles - Continuous development - Ecological techniques - High-temperature water - Mobile - Nitrogen and phosphorus - Rotary tillages - Soil physical and chemical properties
Classification code:446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 614.2 Steam Power Plant Equipment and Operation - 619.1 Pipe, Piping and Pipelines - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Power 6.10e+02W, Power 8.78e+04W, Power 9.74e+04W, Pressure 6.00e+05Pa, Size 1.20e+00m, Size 1.50e-01m, Size 1.50e-02m, Size 1.80e-01m, Velocity 3.50e-02m/s
DOI:10.11975/j.issn.1002-6819.2018.02.003
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 15>
Accession number:20181605031916
Title:Long-term effect of deep application of rice husk improving physical and chemical properties of soda alkaline soil
Authors:Wang, Qiuju (1, 2); Liu, Feng (1); Chang, Benchao (1); Ken, Araya (3); Liu, Yanxia (4); Jiang, Hui (5); Jiao, Feng (6)
Author affiliation:(1) Institute of Soil Fertilizer and Environment Resources, Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China; (2) Heilongjiang Key laboratory of Soil Environment and Plant Nutrition, Harbin; 150086, China; (3) NICH Laboratory, Sapporo; 079-01, Japan; (4) Remote Sensing Technique Centre of Heilongjiang's Academy of Agricultural Science, Harbin; 150086, China; (5) Heilongjiang Academy of Agricultural Sciences, Scientific Research Department, Harbin; 150086, China; (6) Heilongjiang Bayi Agricultural University, Daqing; 163319, China
Corresponding author:Jiao, Feng(jiaofeng1980@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:147-152
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Saline soil is an important soil resource in China. The area of saline soil in China is 9.91×106 hm2. The total area of saline soil in Heilongjiang province is 2.43×106 hm2, and the area cultivated for cultivated land is 1.6×106 hm2. The saline soil in Heilongjiang province is mainly distributed in Anda, Zhaodong, Zhaoyuan, Daqing in the Songnen Plain, and the Sanjiang plain also has a small amount of distribution. Because of the high content of exchange base in saline soil, it is harmful to the growth of crops. Therefore, governments at all levels and scientific research departments have spent great amount of resources to the improvement of saline soil, and have developed various techniques and methods for improving saline soil, such as subsoiling, gypsum, soil conditioner, salt pipe disposal and so on. However, there are some problems with these methods. Rice husk deep application technology is the technology for improving saline soil developed by our research group for many years. Rice husk has many advantages, such as ample source of material, low cost and resistance to decay. In this study, soda alkaline soil of Heilongjiang province was used as test soil, and rice husk was embedded in 20-30 cm soil layer by a special machine, and the single mechanical tillage without rice husk was used as the control. The results of two years' investigation showed that rice husk deep application had significant effects on improving soil physical and chemical properties and forage yield. Based on that, field with rice husk amendment conducted eight years ago was investigated for soil physical and chemical properties. The results showed that after eight years of deep application of rice husks, the effects on the physical and chemical properties of the modified soda alkaline soil were still obvious. The soil organic carbon, available nitrogen, phosphorus and potassium content of rice hull deep application showed an increasing trend compared with treatments without rice husk applications. The total amount of exchange base decreased in 0-30 cm soil layer, and the pH value of each layer decreased by 0.37-0.41, and the content of Na<sup>+</sup>decreased by 40.68-212.35 mg/kg soil. After eight years of deep application of rice husk, the soil solid phase rate was still in a downward trend, the solid phase of soil was about 40% and decreased 3.68% -8.86% than control soil. The total soil porosity increased between 57.38%-60.58%. The proportion of effective pores is large, accounting for 22.7%-26.8% of the total porosity. The soil aeration and water permeability were obviously higher than those of control, and were 10-1215 times and 118-1735 times as much as those of the control. The reservoir capacity of 0-30 cm soil layer was increased, 18.58 mm higher than that of the control. The available reservoir capacity was 33.19 mm, 10.71 mm higher than that of the control. Rice hull deep application has long lasting effect, and the improved effect of soda alkaline soil is obvious. The effectiveness of rice husk application with single mechanical tillage is a technique suitable for the improvement of saline soil and can be achieved by mechanical means.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Soil surveys
Controlled terms:Agricultural machinery - Agriculture - Alkalinity - Cultivation - Ion exchange - Landforms - Organic carbon - Porosity - Reservoirs (water) - Salts - Soil conditioners - Soil testing - Soils - Water aeration
Uncontrolled terms:Alkaline soils - Application technologies - Physical and chemical properties - Pore - Rice husk - Scientific researches - Soil organic carbon - Soil physical and chemical properties
Classification code:441.2 Reservoirs - 445.1 Water Treatment Techniques - 481.1 Geology - 483.1 Soils and Soil Mechanics - 801.1 Chemistry, General - 802.2 Chemical Reactions - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Size 1.07e-02m, Size 1.86e-02m, Size 2.00e-01m to 3.00e-01m, Size 3.32e-02m, Percentage 2.27e+01% to 2.68e+01%, Percentage 3.68e+00% to 8.86e+00%, Percentage 4.00e+01%, Percentage 5.74e+01% to 6.06e+01%, Size 0.00e+00m to 3.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.02.020
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 16>
Accession number:20181605031915
Title:Improving biological traits by soda alkali-saline land diking for fish
Authors:Fan, Fu (1, 2); Zhang, Qinguo (1); Ma, Yulu (1); Hou, Mihong (1); Sa, Rula (1); Ma, Jinhui (1); Lü, Xiuyan (1)
Author affiliation:(1) College of Agronomy, Inner Mongolia University for Nationalities, Tongliao; 028043, China; (2) Inner Mongolia Autonomous Region Feed Crop Engineering Technology Research Center, Tongliao; 028000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:142-146
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soda saline-alkali land is one of the main types of salinized land resources in China. Due to the influence of semi-arid monsoon climate, groundwater condition and geochemical process of element migration in Tongliao City of Inner Mongolia, a large area of saline-alkali soil has been formed. The low-lying saline-alkali land in the West Liaohe River Basin belongs to the soda alkaline soil with high alkalinity. And for most of the barren bare alkaline soil, soil productivity was very low. Planting rice after embankment and fish culture in saline-alkali soil was one of the effective ways of improving saline-alkali soil. In order to investigate the improvement effect of embankment and fish culture on saline-alkali soil, the biological traits and respiration of various soil samples were tested in 2016. The pH value of soil samples was 9.52, and soil respiration was 1.10 mg/g. The activity of soil enzyme and the amount of soil microorganism were the important indices to indicate the soil fertility level. The biological traits included the numbers of microorganisms (nitrite bacteria, cellulose decomposing bacteria, phosphorus bacteria), which were counted with dilution flat plate coating method, and the soil enzyme activity included phosphatase, urease, cellulase, polyphenol oxidase, and catalase, which were determined by colorimetric method and titration method. Additionally, the soil respiration was measured by alkali absorption titration method. The soil samples were taken from the ponds in Horqin Left Middle Banner, Tongliao City, where fish culture lasted for 3, 5 and 8 years, respectively, and rice was planted after 5-year fish culture and bare alkaline soil was taken as the control. The results showed that among the fish culture of different years, planting rice after 5-year fish culture had the most obvious improvement effect on the microorganism. Compared with the bare saline soil, the numbers of soil bacteria, cellulose decomposing bacteria, rice nitrite bacteria, and phosphorus bacteria were increased respectively by 2.60×10<sup>6</sup>, 0.66×10<sup>4</sup>, 7.84×10<sup>5</sup>, and 0.55×10<sup>5</sup>cfu/g. It was not that the longer the fish culture time, the better the improvement effect on the soda saline-alkali land. Except the activity of polyphenol oxidase that was the highest in the bare alkaline soil, all the other enzyme activities had the most obvious improvement in the soil of fish culture for 5 years. The activities of urease, phosphatase, catalase and cellulase were increased respectively by 0.008 mg/g every 24 h, 0.153 mg/g every 24 h, 2.035 mg/g every 20 min and 0.399 mg/g every 72 h. The release amount of CO<inf>2</inf>was the highest in the soil of fish culture for 8 years, 7.41 mg/g higher than that in the bare alkaline soil. Only bacteria number was positively correlated with soil respiration (P<0.05). There was no correlation between soil biological properties and soil respiration. The research has a certain reference value to the regional follow-up use of the saline-alkali land. In the early stage of utilization, we should pay attention to the improvement of fertilizer, increase the application of organic manure, rationally arrange irrigation, and make the utilization of soda salinized soil develop in a benign direction. We will study the effect of different ages on the nitrogen, phosphorus and potassium of the soda saline-alkali soil after embankment and fish culture. It will provide a reliable basis for the protection and utilization of soda saline-alkali land resources.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Soils
Controlled terms:Alkalinity - Aquaculture - Bacteria - Cellulose - Embankments - Enzyme activity - Enzymes - Fertilizers - Fish - Groundwater - Microorganisms - Natural resources - pH - Phosphatases - Phosphorus - Soil surveys - Titration
Uncontrolled terms:Biological traits - Colorimetric methods - Groundwater conditions - Protection and utilizations - Soil biological properties - Soil enzyme activity - Soil fertility levels - Soil micro-organisms
Classification code:405 Construction Equipment and Methods; Surveying - 444.2 Groundwater - 461.9 Biology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 801 Chemistry - 801.1 Chemistry, General - 804 Chemical Products Generally - 811.3 Cellulose, Lignin and Derivatives - 821.3 Agricultural Methods
Numerical data indexing:Age 5.00e+00yr, Age 8.00e+00yr, Time 1.20e+03s, Time 2.59e+05s, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2018.02.019
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 17>
Accession number:20181605031907
Title:Optimization of backwashing speed based on transient simulation of water volume fraction in sand filter layer
Authors:Li, Jinghai (1, 2); Cai, Jiumao (3); Zhai, Guoliang (3); Liu, Qingxia (1); Zhang, Wenzheng (3)
Author affiliation:(1) Anyang Institute of Technology School of Civil and Architectural Engineering, Anyang; 455000, China; (2) Water Resources Management Committee Office of Anyang City, Anyang; 455000, China; (3) Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang; 453002, China
Corresponding author:Zhai, Guoliang(275580557@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:83-89
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The volume fraction of water is an important parameter which affects the backwashing effect of quartz sand filter layer. In order to analyze flow field of the volume fraction of water and to determine the reasonable range of backwashing speed in the backwashing process of quartz sand filter layer, numerical simulation method was used in this paper to simulate the dynamic process of the volume fraction of water in the filter layer. For this, the geometric model of quartz sand filter was established and the mesh division of the geometric model was carried out through Gambit software. Because the backwashing process of quartz sand filter layer is a solid-liquid multiphase flow system composed of water and quartz sand, we can conclude that the mixture model is suitable for the numerical simulation of the volume fraction of water by comparing the applicability of the current multiphase flow numerical simulation models such as Eulerian model, mixture model and VOF (volume of fluid ) model. At the same time, because the backwashing process of quartz sand filter layer is both a dynamic and a stable process, the transient simulation solver was adopted. The simulation objects were 3 kinds of quartz sand filter layers whose thickness was all 400 mm, and the equivalent particle diameter was 1.06, 1.2 and 1.5 mm respectively. In order to verify the reliability of simulation results, laboratory experiments of backwashing were conducted with the 3 different quartz sand filter layers in Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, which is located in Xinxiang City, Henan Province, China. The parameters such as the backwashing speed and the total height of the filter layers were measured during the experiments. And the simulation results were compared with the experimental results. Comparison results showed that the maximum simulation error of the volume fraction of water was 5.64%. It was proved that the numerical simulation results were reliable. When the flow field of the volume fraction of water was analyzed with the simulation data, in order to draw a more general conclusion, the concept of fluidization ratio of backwashing was introduced. On this basis, 3 cross-sections, whose heights were 15, 25 and 35 cm respectively, were selected in each filter layer and the fluctuation rule of the volume fraction of water on the sections with time was analyzed when the fluidization ratio of backwashing was 1.1, 1.3, 1.5, 1.7 and 1.9 respectively. Then the mean and the standard deviation of the volume fraction of water were calculated. And their variation trend with the backwashing speed of quartz sand filter layer was analyzed. In the condition that the volume fraction of water in the 3 cross-sections is basically the same, the stability of filter layer can be determined according to the standard deviation. Therefore, it was concluded that the critical value of the fluidization ratio of backwashing was 1.7 for these 3 filter layers. It is said that the standard deviation is modest and the backwashing effect is ideal when the range of the fluidization ratio of backwashing is 1-1.7. The results showed that the fluidization ratio of backwashing decided whether the backwashing effect was ideal. The research results above provide not only a theoretical basis but also a technical support for the operation of the sand filter in the process of backwashing.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Sand
Controlled terms:Bandpass filters - Computer simulation - Flow fields - Fluidization - Geometry - Irrigation - Models - Multiphase flow - Numerical methods - Numerical models - Quartz - Stability criteria - Statistics - Volume fraction
Uncontrolled terms:Back washing - Laboratory experiments - Multi-phase flow systems - Numerical simulation method - Quartz sand - Transient simulation - VOF (volume of fluid) - Water volume fraction
Classification code:482.2 Minerals - 483.1 Soils and Soil Mechanics - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 703.2 Electric Filters - 723.5 Computer Applications - 802.3 Chemical Operations - 821.3 Agricultural Methods - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Percentage 5.64e+00%, Size 1.20e-03m, Size 1.50e-03m, Size 2.50e-01m, Size 3.50e-01m, Size 4.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.02.011
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 18>
Accession number:20181605031936
Title:Mechanical characterization and establishment of its model for crunchiness of surimi gels
Authors:An, Yueqi (1, 2); Zhao, Siming (1); Liu, Ru (1, 2); Liu, Youming (1, 2); You, Juan (1, 2); Xiong, Shanbai (1, 2)
Author affiliation:(1) College of Food Science and Technology, Huazhong Agricultural University, Wuhan; Hubei; 430070, China; (2) National R&D Branch Center For Conventional Freshwater Fish Processing (Wuhan), Wuhan; 430070, China
Corresponding author:Xiong, Shanbai(xiongsb@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:292-298
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Surimi gels, one of the deeply processed aquatic products, have received wide attention due to their unique texture and high nutrition. Surimi gels with less MTGase show soft and elastic mechanical properties, while the textural properties of surimi gels are transferred from elastico-viscous body to elastico-crispy body if surimi was set with much MTGase at a low temperature for a long time owing to the excessive cross-links. When excessively cross-linked, surimi gels become easier to be broken and show "fracture properties", also called "crunchiness" or "brittleness". Sensory evaluation is the most commonly used method for evaluating food brittleness. However, sensory sensations can be affected by some instable factors such as preference, mood and health of panelists. Therefore, it is necessary to focus on the instrument measurement to evaluate the crunchiness. In this paper, frozen fresh-water surimi (AAA grade) was used as material. Surimi gels with different crunchiness were produced under different setting time and MTGase addition. Uniaxial compression test, three-point bending test and puncture test were used to realize a mechanical characterization of the sensory crunchiness of surimi gels with different cross-linking extent. It was found that surimi gels with different cross-linking extents showed different mouth feel, and the sensory score of crunchiness of surimi gels increased with the cross-linking extent. Moreover, when the cross-linking extent was less than 30%, surimi gel was not crunchy, while when the cross-linking extent was more than 30%, crunchiness appeared and increased significantly as cross-linking extent increased. When the cross-linking extent was over 75%, the sensory crunchiness did not increase significantly anymore. In uniaxial compression test, surimi gels with lower cross-linking extent (<30%) could not be broken. With the increase of cross-linking extent, the fracture stress, compression constant, initial cutting coefficient and Young's modulus all increased. In three-point bending test, the brittle fracture stress and elasticity modulus increased first and then decreased, reaching the maximum at 50% cross-linking extent. When the cross-linking extent was less than 30%, the fracture work showed an increasing trend, while when the cross-linking extent was over 30%, the fracture work decreased with the increasing of crunchiness. In puncture test, the deformation of surimi gels did not show obvious change regulation. Additionally, the breaking force, rising slope and decreasing slope increased as cross-linking extent increased. Multiple regression analysis was applied to model the sensory crunchiness by mechanical indices of surimi gels with the cross-linking extent of 30%-75.5%. It was showed that the sensory crunchiness of surimi gels could be characterized by breaking force, fracture work, fracture stress, compression constant and initial cutting coefficient. The crunchiness characterization equation was obtained, which was proved to be accurate and precise, and there was no significant difference between the predicted and measured values of surimi gels crunchiness (P>0.05). The research provides new ideas and methods for the evaluation of the surimi gel products.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Brittle fracture
Controlled terms:Aquaculture - Brittleness - Characterization - Compression testing - Elastic moduli - Fracture mechanics - Gels - Monitoring - Plasticity - Quality control - Regression analysis - Sensory analysis - Steam turbines - Temperature - Water quality
Uncontrolled terms:Crunchiness - Cutting coefficients - Elastic mechanical properties - Mechanical characterizations - Multiple regression analysis - Surimi gels - Three-point bending test - Uni-axial compression tests
Classification code:445.2 Water Analysis - 617.2 Steam Turbines - 641.1 Thermodynamics - 804 Chemical Products Generally - 821.3 Agricultural Methods - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics - 931.1 Mechanics - 951 Materials Science
Numerical data indexing:Percentage 3.00e+01%, Percentage 3.00e+01% to 7.55e+01%, Percentage 5.00e+01%, Percentage 7.50e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.040
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 19>
Accession number:20181605031909
Title:Signal intensity of stem diameter fluctuation diagnosing alternate furrow irrigation maize water deficit
Authors:Du, Bin (1); Ran, Hui (1); Hu, Xiaotao (1); Wang, Wen'e (1); Zhou, Shiwei (1)
Author affiliation:(1) Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling; 712100, China
Corresponding author:Ran, Hui(huiran@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:98-106
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to evaluate the feasibility of applying signal strength to the diagnosis of alternate furrow irrigation of maize, and find out the most suitable growth period of water deficit index, the experiment was conducted in the experiment station of Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Area of Ministry of Education, Northwest Agriculture and Forestry University from July to September in 2016. In the experiment, the treatments of conventional furrow irrigation (CFI), alternate furrow irrigation of high water (AFIH) and alternate furrow irrigation of low water (AFIL) were set, and the irrigation amounts of AFIH and AFIL were 2/3 and 1/2 respectively of CFI at every turn. The soil moisture content, stem diameter changes, air temperature, radiation and other meteorological factors were measured. Responses in maximum daily stem shrinkage (MDS) and stem daily increase (DI) to soil water content and meteorological factors were analyzed, 2 signal irrigation indices (SI<inf>MDS</inf>and SI<inf>DI</inf>, which were signal MDS and signal DI) were established, and the signal values were calculated by the ratio of measured values to reference values. The reference values were obtained by the regression equation of plant stem diameter indicators and meteorological factors under no water stress condition. However, water-stress index variability may increase with the increase of water stress; high variability index requires multiple measurements to reduce the error, which increases the cost, so the variability (noise value) of index and the intensity also should be considered. High signal value means the change of the indicators derived from stem diameter for soil moisture response is stronger, and high signal value means the variability of the indicators caused by the water difference is acceptable. When soil moisture changes, the signal-to-noise ratio (SNR) in the short term is greater, indicating that the index is more suitable for diagnosing the water status of plants. At the same time, if the large signal value changes can be recorded shortly after rehydration, then the change of stem diameter is more sensitive to soil moisture, that is, the sensitivity of the index is stronger. The SNR and the suitability of indices (SI<inf>MDS</inf>, SI<inf>DI</inf>) in each growth period were evaluated. The results showed that MDS and DI were easily affected by meteorological factors, and there was a weak response for the above 2 indices to soil water content. SI<inf>MDS</inf>and SI<inf>DI</inf>could exclude the interference of meteorological factors. The SI<inf>MDS</inf>and SI<inf>DI</inf>showed a better linear relationship with soil moisture. Stem diameter signal indicator could be used in corn moisture status diagnosis under the alternate furrow irrigation. In the different periods, signal indicator and water sensitivity showed significant differences; in jointing period, the SNR of SI<inf>DI</inf>was larger, and the decrease range of signal intensity after rehydration was greater than the SI<inf>MDS</inf>, so SI<inf>DI</inf>was more suitable for moisture diagnosis in jointing stage. In heading stage and maturity stage, the SNR of SI<inf>MDS</inf>was larger than SI<inf>DI</inf>, and the sensitivity and correlation with the soil moisture content were better than SI<inf>DI</inf>, so SI<inf>MDS</inf>was more suitable for corn moisture diagnosis in heading and maturity stage.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Irrigation
Controlled terms:Atmospheric temperature - Forestry - Moisture - Moisture determination - Plants (botany) - Shrinkage - Signal analysis - Signal processing - Signal to noise ratio - Soil moisture
Uncontrolled terms:Agriculture and forestry universities - Alternate furrow irrigation - Arid and semi-arid areas - Linear relationships - Maximum daily stem shrinkages - Meteorological factors - Ministry of Education - Multiple measurements
Classification code:443.1 Atmospheric Properties - 483.1 Soils and Soil Mechanics - 716.1 Information Theory and Signal Processing - 821.3 Agricultural Methods - 944.2 Moisture Measurements - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2018.02.013
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 20>
Accession number:20181605031920
Title:Response of induced flow speed to fish body length and its application in flow design of fish passage facilities
Authors:Cai, Lu (1); Wang, Weiying (2); Wang, Hailong (3); Hu, Wangbin (1); Zhao, Ping (1); Zhao, Na (1); Hou, Yiqun (1); Chen, Shengli (2); Chen, Hao (3); Zhang, Peng (1)
Author affiliation:(1) Key Laboratory of Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem of Ministry of Water Resources, Institute of Hydroecology, Ministry of Water Resources and Chinese Academy of Sciences, Wuhan; 430079, China; (2) Kunming Engineering Corporation Limited of Power Construction Corporation of China, Kunming; 650051, China; (3) Huaneng Lancang River Hydropower Corporation Limited, Kunming; 650206, China
Corresponding author:Zhang, Peng(zhang860214@foxmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:176-181
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There is a global boom in dams. Although dams bring a huge economic benefit, they obstruct fish migrations and gene exchange. Fish passages are being designed and constructed to mitigate the influence of the dams on fish migration and gene exchange. Fish behavior researches are useful to the design of fish passages. A large amount of research about critical swimming speed and burst speed, which were related to velocity design in the high velocity region of fish passages such as the entrance, was reported worldwide. However the reports about velocity design in the low velocity region of fish passages were limited. To study fish behavior and provide information for the velocity design in the low velocity region, induced flow speed of 5 fishes in the Lancang River was investigated with the fish behavior measurement equipment and a stepped velocity test was carried out in spring when fish migrated. Before testing, fish body length was measured and the test fish was allowed to adapt to experimental conditions at 0.5 bl/s (bl meant body length of fish) for 2 h. At the initial flow velocity (approximately 0.06 m/s), the fish was nearly motionless along the flow direction. The water velocity was increased by approximately 0.01 m/s at 5 s interval and, when the fish was no longer able to hold station and began to swim actively, the flow velocity was reported as induced flow speed. Results included: 1) The induced flow speed of the fish ranged from 0.40 to 1.18 bl/s (or from 0.07 to 0.23 m/s) at 11.1-22.6℃, which was similar to other references (0.4-1.5 bl/s or 0.05-0.15 m/s). 2) Lateral line receptors detected small changes in flow, and swimming was induced in fish when the stimulus from lateral line receptors was sufficient. The relatively induced flow speed (bl/s) was negatively correlated with fish body length and the absolutely induced flow speed (m/s) was positively correlated with fish body length, whether each species was considered individually or all species were considered together. The above relationships were consistent to both the relationship between critical swimming speed and body length, and the relationship between burst speed and body length. The relationship could be used to forecast swimming performance of fishes that were captured with difficulty or had small quantity. 3) Overmuch decreasing or increasing the designed velocity of fish passages would increase the difficulties for the engineering design and increase the cost for construction. The relationship between percentage of fish swimming trend and flow speed was obtained in this study, which could provide the reference to balance the fish demand and flow design. Based on the data of fish induced flow speed, the designed minimum velocity of the fish passages should be more than 0.2 m/s in order that 95% of fish could pass the passages successfully, if both the difficulties for the engineering design and the cost of construction were neglected, and if the effectiveness of fish passages was considered uniquely. The release site for the fish lifting machine and fish transport boats was set in the upstream, far away the dam site. If the velocity at the release site was too low, the fish lost orientation even went back to the downstream, resulting in the fail of fish passages. Therefore, the site where the velocity is higher than fish induced flow speed should be selected for releasing fish. The principle can be also applied to the selection of exit site in fish passages.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Fish
Controlled terms:Behavioral research - Cost engineering - Facilities - Fishways - Flow velocity - Genes - Hydrodynamics - Rivers - Site selection - Velocity
Uncontrolled terms:Economic benefits - Engineering design - Experimental conditions - Low velocity region - Minimum velocities - Rheotaxis - Swimming capability - Swimming performance
Classification code:461.2 Biological Materials and Tissue Engineering - 631 Fluid Flow - 911 Cost and Value Engineering; Industrial Economics - 971 Social Sciences
Numerical data indexing:Percentage 9.50e+01%, Time 5.00e+00s, Time 7.20e+03s, Velocity 1.00e-02m/s, Velocity 2.00e-01m/s, Velocity 5.00e-02m/s to 1.50e-01m/s, Velocity 6.00e-02m/s, Velocity 7.00e-02m/s to 2.30e-01m/s
DOI:10.11975/j.issn.1002-6819.2018.02.024
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 21>
Accession number:20181605031904
Title:Flowing and pressure-balancing characteristics of clearance field in helical grooved piston-copper sleeve pair of piston pump
Authors:Tong, Baohong (1); Yang, Wen (1); Liu, Qingyun (1); Ye, Xiaohua (1); Shi, Liping (1)
Author affiliation:(1) School of Mechanical Engineering, Anhui University of Technology, Maanshan; 243032, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:55-63
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to investigate the effect of helical grooved structure on the clearance flow and pressure balancing characteristics of the piston -copper sleeve pair, the flow field numerical simulation of pair was carried out by using the computational fluid dynamics method. Combined with the actual structure of a specific type of swashplate pump, 6 kinds of pistons were designed with different surface structures distinguished from length and location of helical groove. At different rotate velocity, oil supply pressure, piston location, oil film pressure distribution, tilting torque size and clearance flow characteristics of 6 kinds of piston-copper sleeve pairs were analyzed and compared. The results showed that the oil film pressure distribution of helical grooved piston-copper sleeve pairs became more uniform and stable due to the effect of helical groove, and the maximum value and rangeability of tilting torque decreased observably. Specifically, when the rotating speed was 1000 r/min and the plunger position was 90°, relative to the non-grooved plunger, their change amplitude of circumferential pressure decreased by 24.05%-55.77% at axial position of 25 mm, and the maximum tilting torque reduced by 49.01%-103.14%. In all groove design proposals, compared to the single-turn circle groove, oil film pressure distribution of single-ring helical groove was more conducive to piston's stable work. Then, pressure balancing characteristic of the single-ring helical groove would be more effective as the distance between the starting point of groove and the end face of the piston increased. Furthermore, compared to the single-ring helical groove, multi-ring helical groove possessed superior balance pressure characteristics. Especially, when multi-ring helical groove was arranged continuously, the uniformity and stability of oil film would be enhanced further. In addition, the pressure balancing effect of the helical grooved structure could reduce the flow resistance of the oil in the clearance, and was good for the oil to fill the whole clearance, so the characteristics of pressure balance and lubrication would be promoted. But the sealability of piston -copper sleeve pair would be worse and the leakage would be increased by 22.73%-267.53% in the condition of high pressure and low speed. The design scheme of the three-ring helical groove obviously improved the pressure lubrication characteristics, but it seriously affected the sealing of the piston pair, which did not satisfy the working requirement of the piston pump. The size of the pressure flow in clearance increased with the depth of the groove, and the increasing speed gradually elevated before the depth reached 0.9 mm, and then the linear change rule appeared after it. Meanwhile, the flow characteristics of the helical groove were also changed with the depth of the groove. Therefore, by selecting groove size reasonably, lubrication and leakage could be controlled, which was helpful to improve piston work quality. Moreover, a method combining dynamic and static conditions was proposed in this study for proving the rationality of the numerical simulation. On the one hand, a theoretical formula was used to calculate the flow rate of concentric annular clearance at different piston velocities, and the result was compared with the flow rate obtained by the dynamic numerical simulation. On the other hand, the measurement test of clearance flow of the helical grooved piston in the static state was carried out to verify the rationality of specific helical grooved piston's numerical simulation. Probative results showed that simulation method accorded with the need of research rationality. Firstly, the calculation results of formula were in good agreement with the simulation. Then, the value difference of simulation and test was relatively large, but the change trends in comparison were consistent. The study was aimed at providing a reference for the helical grooved piston design that synthetically considered the tightness and pressure uniformity. And the groove type piston was expected to obtain good lubrication characteristics while the leakage dose did not affect the piston pump work efficiency. To promote the practical application of the helical groove type piston, the relevant research of dynamic test method and platform needs to be further performed.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Pistons
Controlled terms:Computational fluid dynamics - Computer simulation - Copper - Engines - Fluid dynamics - Friction - Lubricating oils - Lubrication - Numerical methods - Numerical models - Pressure distribution - Pressure effects - Reciprocating pumps - Structural design - Testing
Uncontrolled terms:Characteristics of pressures - Clearance flow - Computational fluid dynamics methods - Flow field numerical simulations - Helical grooves - Lubrication characteristics - Oil film pressure distribution - Pressure characteristics
Classification code:408.1 Structural Design, General - 544.1 Copper - 607.1 Lubricants - 607.2 Lubrication - 612.1.1 Internal Combustion Engine Components - 618.2 Pumps - 723.5 Computer Applications - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics
Numerical data indexing:Percentage 2.27e+01% to 2.68e+02%, Percentage 2.41e+01% to 5.58e+01%, Percentage 4.90e+01% to 1.03e+02%, Rotational_Speed 1.00e+03RPM, Size 2.50e-02m, Size 9.00e-04m
DOI:10.11975/j.issn.1002-6819.2018.02.008
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 22>
Accession number:20181605031905
Title:Effect of down wash airflow in hover on droplet motion law for multi-rotor unmanned plant protection machine
Authors:Yang, Fengbo (1); Xue, Xinyu (1); Cai, Chen (1); Zhou, Qingqing (1)
Author affiliation:(1) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture, Nanjing; 210014, China
Corresponding author:Xue, Xinyu(735178312@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:64-73
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Recently, multi-rotor unmanned aerial vehicle (UAV) becomes more and more irreplaceable in the field of plant protection. Multi-rotor unmanned plant protection machine has been widely used in pesticide spraying, pollination operation, and so on, however, the unclearness of wind field distribution leads to non-uniform deposition problem. In this paper, the influence of the down wash flow on the motion distribution of droplet group was studied for the multi-rotor UAV in hovering state. Based on the N-S equation and realizable k-Ε turbulence model, the three-dimensional numerical model was established for six-rotor unmanned plant protection machine under 3 kg load condition. In the numerical calculation, 12 observation points were set at 2 heights directly below each rotor, and the wind velocity value at each point was observed. When the computing time reached 2.28 s, the wind velocity tended to be stable, and the 12 stable wind velocity pulsation values were obtained. The wind velocity of the down wash flow was tested one by one at the 12 observation points for the multi-rotor UAV in hovering state. Comparative analysis showed that the relative error of the velocity at the z direction between the experimental measurement and numerical simulation for characteristic points was less than 9% when the down wash flow was stable, and the reliability of the wind field numerical calculation was verified. Under the rotation of airfoil and the extrusion of the external atmospheric pressure, the "shrinkage-expansion-shrinkage" phenomenon appeared in the longitudinal main section; under the influence of wing interference caused by the opposite velocity of adjacent rotor, the turbulent effect of down wash flow was obvious, and the "airflow inlet" and "airflow outlet" region appeared between the wings area at the cross section. Droplet discrete phase was introduced to N-S equation, the momentum and energy equations were also corrected for continuous phase to establish two-phase flow model, then the two-phase flow model with droplet discrete phase was established for the nozzle, and the feasibility and validity of the two-phase flow model to calculate the trajectory of the droplets were also verified combined with the spray test. The advantages of easy boundary setting in numerical computation were used to discuss the influence law of droplet size on droplet motion for the atomization nozzle. Numerical results showed that the droplet distribution was basically circular, and the area of droplets with the highest concentration was the medium-sized droplet sedimentation area, which had the maximum differential ratio. Moreover, the numerical simulation results also showed that the smaller the droplet size, the smaller the droplet spray amplitude; the larger the droplet size of the droplet, the larger the final sub-velocity value at the vertical direction. Then the three-dimensional two-phase flow model was established for six-rotor unmanned plant protection machine, and the analysis showed that droplets were mainly distributed in the 3 "airflow inlet" areas and 3 "airflow outlet" areas where wing interference was obvious. The droplets in the inner side of down wash area were interlaced, and the horizontal travel of large particles was greater and they were distributed in the outside periphery of down wash area. When the diameter was less than 200 m, the droplet movement range could not cover all the "airflow inlet" area, and the droplets were mostly distributed in the center down wash area. When the diameter was greater than 250 m, the droplet motion region gradually covered all the "airflow inlet" and "airflow outlet". The result can lay a foundation for the research of drifting and deposition of droplets under the disturbance of vertical wind flow, down wash flow and instantaneous transverse wind during the flight spraying.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Two phase flow
Controlled terms:Air - Antennas - Atmospheric pressure - Deposition - Drops - Models - Navier Stokes equations - Numerical models - Reliability analysis - Shrinkage - Spray nozzles - Spraying - Turbulence models - Unmanned aerial vehicles (UAV) - Velocity - Wind
Uncontrolled terms:Air flow - Discrete phase - K-epsilon turbulence model - Motion law - Numerical calculation - Numerical computations - Three-dimensional numerical modeling - Wind field
Classification code:443.1 Atmospheric Properties - 631.1 Fluid Flow, General - 652.1 Aircraft, General - 802.3 Chemical Operations - 804 Chemical Products Generally - 921 Mathematics - 921.2 Calculus - 951 Materials Science
Numerical data indexing:Size 2.00e+02m, Size 2.50e+02m, Time 2.28e+00s, Mass 3.00e+00kg, Percentage 9.00e+00%
DOI:10.11975/j.issn.1002-6819.2018.02.009
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 23>
Accession number:20181605031931
Title:Land use pattern change and influential factors analysis of Songnen Plain in 1979-2015
Authors:Wang, Panpan (1); Song, Ge (1)
Author affiliation:(1) Institute of Land Management, Northeast University, Shenyang; 110169, China
Corresponding author:Song, Ge(songgelaoshi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:256-264
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A series of ecological and socioeconomic problems were caused by the change of land use pattern. In order to clarify the characteristics of the change of land use pattern and the mode of action of the influence factors in Songnen high plain, this paper, taking Bayan County, Heilongjiang Province as a case, on the basis of the characteristics of land use patterns in the study area during 1979-1991, 1991-2003 and 2003-2015, recognized the main influencing factors of land use pattern change in 3 periods and made clear temporal evolution of the strength and direction of the factors on land use patterns based on the canonical correlation analysis and radial basis function neural network. The results showed that, firstly, during 1979-1991, 1991-2003 and 2003-2015, the land use types in the study area varied in magnitude and the areas of dry land, paddy field and other land use types varied greatly. The area of dry land increased by 11514.56 hm<sup>2</sup>, and the area of other land use types reduced by 6445.57 hm<sup>2</sup>and the land use area changed the most in 1991-2003. Secondly, the change of land use pattern in the study area was influenced by both natural and human factors. The key factors that affected the change of land use pattern were different in the 3 different periods, and the influence intensity, direction and manner of the key influence factors on land use pattern changed. During 1991-2003, the correlation coefficients between key factors as slope, soil type, soil texture, soil fertility, soil moisture, GDP, population, location index, concentration degree, diversity index, land use intensity and the first sort axis were-0.3866,-0.5594,-0.3423, 0.6483, 0.3526, 0.1871, 0.0918, 0.3936, 0.4170, 0.3888, and-0.5833, respectively, which were higher than those in 1979-1991 and 2003-2015, and resulted in frequent conversion of land use types and large change in land use area during this period. The influence of elevation, slope and landform types on the land use pattern in the study area was greater, and the impact intensity increased firstly and then decreased, the strongest in 1991-2003; soil type, soil texture and soil fertility had great influence on land use pattern, and the soil factors of land use pattern in 1991-2003 were more; distance factors, i. e. distance from town center and distance from river had great influence on land use pattern, and the change of intensity was not significant; the land use degree factors, i. e. location index, degree of centralization, diversity index and land use intensity of land use pattern in the research area were very strong, and the impact strength increased firstly and then decreased, the strongest in 1991-2003. Thirdly, the main factors that affected the change of land use types were different. Moreover, the effects, intensities, directions and ways of different factors on land use types were different. Under the combined effects of various factors, the area change of land use types was different. The change of dry land was greatly affected by the intensity of land use. The land use intensity caused by the change of dry land decreased obviously in the 1991-2003 years. The influence coefficient was 0.4854, 0.3384 and 0.3355 respectively in 3 different periods, which promoted the intensity of land use change in dry land. The intensity of land use decreased significantly in the 1991-2003 years, which was the main reason to the increase of dry land area during this period. The change of paddy field was increased due to the influence of the distance from water areas and the soil moisture. The influence coefficient increased from 0.1441, 0.3323 in 1979-1991 to 0.295, 0.343 in 2003-2015 respectively. The conclusion is that: In 3 different periods, the key factors on the intensity, direction and way of the land use pattern have changed more or less, which leads to the obvious differentiation characteristics of land use pattern in the study area.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Land use
Controlled terms:Correlation methods - Factor analysis - Forestry - Functions - Impact strength - Landforms - Radial basis function networks - Remote sensing - Soil moisture
Uncontrolled terms:Bayan counties - Canonical correlation analysis - Influence factor - Land consolidations - Radial basis function neural networks
Classification code:403 Urban and Regional Planning and Development - 481.1 Geology - 483.1 Soils and Soil Mechanics - 921 Mathematics - 922.2 Mathematical Statistics
Numerical data indexing:Age 1.99e+03yr to 2.00e+03yr
DOI:10.11975/j.issn.1002-6819.2018.02.035
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 24>
Accession number:20181605031929
Title:Effect of different leakage speeds on plants in carbon capture and storage by simulation in chamber
Authors:Ji, Xiang (1, 2); Ma, Xin (1); Han, Yaojie (1); Yu, Mengying (1); Meng, Chunchun (1)
Author affiliation:(1) Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing; 100081, China; (2) Department of Life and Environmental Science, Kashgar University, Kashgar; 844000, China
Corresponding author:Ma, Xin(maxin02@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:242-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Carbon capture and storage (CCS) is an effective means to reduce greenhouse gas emissions, which sequesters anthropogenic CO<inf>2</inf>in deep geological formations and avoids emissions into the atmosphere while supporting coal use. Thus, the technology is an attractive way of controlling greenhouse gases in economies heavily dependent on coal energy, such as China, whose goal is to reach an emissions cap by 2030. Currently, more than 12 CCS demonstration projects are in development in China. Preliminary estimates show that reservoirs, such as saline aquifers, depleted oil and gas reservoirs, and un-mineable coal seams, have a CO<inf>2</inf>storage capacity with hundreds of billions of tons. However, there are risk of CCS-stored CO<inf>2</inf>leaking out of the storage reservoirs, and the quick leakage such as failure of injection wells and slow leakage from geological aisle, which shows different environmental impacts. The most visible impact of CCS leakage is the degradation of plant cover. To know the impact of elevated soil CO<inf>2</inf>flux in near-surface ecosystems and the plants' responses to different CO<inf>2</inf>leaking rates, and to assess and address the risks of elevated soil CO<inf>2</inf>flux, we simulated quick and slow CO<inf>2</inf>leakage, at a rate of 2000 g/(m·d) and 60% of the soil CO<inf>2</inf>concentration, and compared the differences of maize plant height, root length, leaf number, leaf photosynthetic rate and soil pH value. The experimental device was the self-made combination with gas chambers and soil chambers on top. CO<inf>2</inf>was injected into the bottom of the cultivation container at different flux rates by manually control. The results indicated that, under the quick CO<inf>2</inf>leaking at a rate of 2000 g/(m·d), the maize photosynthetic rate was decreased from (22.86±0.89) µmol/(m·s) of CK treatment to (0.1±0.08) µmol/(m·s), while the height of maize was dropped from (206±10.20) cm to (93.67±4.78) cm and maize root length was decreased by 75%, from (109±16.83) cm to (20.73±3.73) cm. And the number of plant leaves was decreased significantly, which was 16 in the control group, but only 9 to 11 in the rapid leakage control, and the withered leaf number were significantly increased in the rapid leakage test. Slow leakage under 60% of the soil CO<inf>2</inf>concentration did not inhibit the growth of maize. The height of maize plants in the control group (SCK) was (153.25±13.27) cm, and the plant height at slow leakage treatment was (154 ± 8.09) cm. The root length, the number of leaves and net photosynthetic rate of maize also were not significant difference, separately. Only the soil pH value in the vicinity of leaking source was decreased slightly, however, soil pH value remained within a reasonable range of maize growth and therefore did not have a significant impact on maize growth. The different response of plant to quick and slow stored CO<inf>2</inf>leakage will provide useful information for decision maker to formulate countermeasures.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Carbon capture
Controlled terms:Aquifers - Carbon dioxide - Coal - Coal deposits - Coal storage - Decision making - Environmental impact - Gas emissions - Greenhouse gases - Hydrogeology - Petroleum reservoir engineering - pH - Plants (botany) - Risk assessment - Soils
Uncontrolled terms:Carbon capture and storages (CCS) - Demonstration project - Emissions into the atmosphere - Experimental devices - Net photosynthetic rate - Oil and gas reservoir - Plant response - Plants
Classification code:444.2 Groundwater - 451.1 Air Pollution Sources - 454 Environmental Engineering - 454.2 Environmental Impact and Protection - 481.1 Geology - 483.1 Soils and Soil Mechanics - 503 Mines and Mining, Coal - 512.1.2 Petroleum Deposits : Development Operations - 524 Solid Fuels - 801.1 Chemistry, General - 804.2 Inorganic Compounds - 912.2 Management - 914.1 Accidents and Accident Prevention
Numerical data indexing:Percentage 6.00e+01%, Percentage 7.50e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.033
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 25>
Accession number:20181605031913
Title:Characteristics of soil erosion and nutrients evolution under coal mining disturbance in aeolian sand area of Northwest China
Authors:Nie, Xiaojun (1); Gao, Shuang (1); Chen, Yongliang (2); Zhang, Hebing (1)
Author affiliation:(1) School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo; 454000, China; (2) Halagou coal mine, China Shenhua Shendong Group, Yulin; 719315, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:127-134
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Deterioration of the local ecological environment due to coal mining is serious in the aeolian sand area, Northwest China. A better understanding of the evolution of aeolian sandy soil under coal mining disturbance is essential prior to the initiation of restoration of local ecological environment. In this study, the<sup>137</sup>Cs tracing technique was used to investigate the characteristics of soil erosion and nutrients in coal mining disturbed lands of Shendong mining area, Northwest China. A plot without being disturbed by coal mining activities near Shendong mining area was selected as the control plot. As for the mining disturbed lands, an unexploited plot and 5 subsidence plots were selected as the study sites. The 5 subsidence plots include 4 self-recovery subsidence plots and one vegetation restoration plot. The 4 self-recovery subsidence plots (1ySP, 2ySP, 4ySP, 8ySP) have undergone stabilization for 1, 2, 4, and 8 years, respectively after surface subsidence. The vegetation restoration plot has experienced a 13-year duration of stabilization after surface subsidence, and has been planted with almond trees for 12 years. It was found that<sup>137</sup>Cs inventories from the unexploited plot, subsidence plots and control plot were 32%-55% lower than local<sup>137</sup>Cs reference inventory (726 Bq/m<sup>2</sup>), which demonstrates the background of severe wind erosion desertification in the study area. In comparison with the control plot, the<sup>137</sup>Cs inventories in the unexploited plot, 1ySP, 2ySP, 3ySP and 4ySP decreased by 8%, 16%, 29%, 34%, and 10%, respectively. Changes in the nutrients, including soil organic carbon (SOC), microbial biomass carbon (MBC), total nitrogen (TN), available nitrogen (AN) and total phosphorus (TP), showed a similar trend to the<sup>137</sup>Cs variation. Unlike SOC, MBC, TN, AN, and TP, available phosphorus showed higher concentrations in the unexploited plot and the 4 self-recovery subsidence plots than that in the control plot. In addition, the<sup>137</sup>Cs, SOC and TN concentrations increased in the vegetation restoration plot in comparison with that in the control plot. Overall, there were significant correlations between SOC, MBC, TN, AN, TP and<sup>137</sup>Cs within the mining disturbed lands. It was also found that the coal-mining disturbed lands exhibited smaller ratios of MBC to SOC but greater ratios of SOC to TN (i. e. C/N) than the control plot. These results suggested that the intensity of soil erosion firstly increased and then decreased after surface subsidence in the aeolian sand area. Soil erosion increased sharply in the first 2 years after surface subsidence. The evolution of soil nutrients is closely associated with soil erosion evolution under coal mining disturbance. The present study provides evidences for the acceleration of soil erosion and nutrients depletion in unexploited lands of mining area by coal mining disturbance. As a consequence, there would be a considerable underestimation of the impact of mining subsidence on soil evolution when using unexploited plots as the control. Our study also suggested that vegetation restoration may effectively weaken soil erosion and improve soil nutrients in subsidence lands. Therefore, ecological restoration in subsidence lands of the aeolian sand area, Northwest China, should combat against earlier soil erosion after surface subsidence, and a plant-microorganism integrated remediation approach should be adopted to promote the positive succession of soil and vegetation.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Soils
Controlled terms:Coal - Coal mines - Cutting machines (mining) - Ecology - Erosion - Nitrogen - Nutrients - Organic carbon - Phosphorus - Recovery - Restoration - Sand - Stabilization - Subsidence - Vegetation
Uncontrolled terms:Aeolian sand - Ecological environments - Ecological restoration - Microbial biomass carbon - Mining subsidence - Tracing method - Vegetation restoration - Wind erosion desertifications
Classification code:454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 502.2 Mine and Quarry Equipment - 503.1 Coal Mines - 524 Solid Fuels - 804 Chemical Products Generally - 804.1 Organic Compounds
Numerical data indexing:Percentage 1.60e+01%, Percentage 2.90e+01%, Percentage 3.20e+01% to 5.50e+01%, Percentage 3.40e+01%, Percentage 8.00e+00%, Age 1.20e+01yr, Age 1.30e+01yr, Age 2.00e+00yr, Age 8.00e+00yr, Percentage 1.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.017
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 26>
Accession number:20181605031914
Title:Spatial wind speed and surface wind erosion characteristics of farm-shelter forest network in arid sandy area
Authors:Zuo, Zhong (1); Pan, Zhanbing (1); Zhang, Andong (1, 2); Yu, Dian (3); Zhou, Jingyu (3)
Author affiliation:(1) Desertification Controlling Institute, Agriculture and Forestry Sciences of Ningxia Academy, Yinchuan; 750002, China; (2) College of Life Sciences, Sichuan University, Chengdu; 610065, China; (3) Habahu Natural Nature Reserve Bureau of Ningxia, Yanchi; 751500, China
Corresponding author:Pan, Zhanbing(624151845@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:135-141
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To accurately understand and evaluate the spatial distribution of wind speed and the erosion characteristics of farm-shelter forest network in a typical strong wind environment, the research on space wind speed and surface wind erosion characteristics of farmland shelterbelts in Yanchi County, Ningxia Hui Autonomous Region in arid sandy area is carried out. The spatial distribution of wind speed within 50 and 200 cm vertical space above the ground and the erosion characteristics have been studied at the different distances from the farm-shelter forest network with portable anemometer and trapping method respectively. The result shows that: With the increase of monitoring distance, the amount of wind erosion increased first and then decreased, while the wind speed changed in the opposite direction. The wind speed changes at 50 and 200 cm height are the same, which show a very regular inverted parabolic linear change of first gradually decreasing and then gradually rising. The effect of wind reduction at 12H height (12 times shelter forest height, the same below) is the most obvious. Wind speeds decreased by 51% and 46% at 50 and 200 cm height respectively. With the increase of the distance, the wind-break potency presented the tendency of increasing at first and then decreasing. The wind-break potency was the best at the 200 cm height from 12H, and the value was 53.65%. The amount of wind erosion was positively correlated with the distance from the farm-shelter forest network. The erosion modulus in the farm-shelter forest network was the least, and the order was 1H < 12H < 3H and 7H. The value at 3H height was the biggest, 21944.62 t/km<sup>2</sup>. The sand diameters were about 73.99, 87.99 and 104.6 μm, 82.53%-99.93% was under 248.9 μm, and the sand was the fine sand. However, the sand diameters of the bare land were about 104. 6-148 μm. These reflected that the sandy irrigated farmland was the main dust source. So configurating the farm-shelter forest network scientifically and reducing the bare soil could prevent sand disaster effectively in the arid sandy area. Thus, even in the early growth of tree leaves, farmland shelterbelts in arid and sandstorm areas are also very effective in slowing wind speed during typical windy days. However, due to the rich source of sand in the forest network, the wind erosion is still serious and has a great impact on the local sandstorms. The farmland shelterbelt network is set scientifically to minimize the occurrence of wind erosion and sand damage as much as possible during the wind-affected season for farmland. This study can have certain technical reference to accurately grasp the wind erosion of the local forest network, and scientifically evaluate the forest network protection function.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Farms
Controlled terms:Disaster prevention - Erosion - Forestry - Sand - Soils - Spatial distribution - Speed - Storms - Wind
Uncontrolled terms:Erosion characteristics - Farmland shelterbelts - Inverted parabolic - Network protection - Strong wind environment - The arid sandy area - Trapping methods - Wind erosions
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 914.1 Accidents and Accident Prevention - 921 Mathematics
Numerical data indexing:Percentage 4.60e+01%, Percentage 5.10e+01%, Percentage 5.36e+01%, Size 1.05e-04m, Size 2.00e+00m, Size 2.49e-04m, Size 5.00e-01m, Size 6.00e-06m to 1.48e-04m, Size 8.80e-05m
DOI:10.11975/j.issn.1002-6819.2018.02.018
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 27>
Accession number:20181605031897
Title:Research progress on Terahertz technology and its application in agriculture
Authors:Li, Bin (1, 2, 3, 4); Long, Yuan (1, 2, 3); Liu, Huan (1, 2, 3); Zhao, Chunjiang (1, 2, 3, 4)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing; 100097, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing; 100097, China; (3) Key Laboratory of Quantitative Remote Sensing in Agriculture, Ministry of Agriculture, Beijing; 100097, China; (4) Beijing Key Lab of Digital Plant, Beijing; 100097, China
Corresponding author:Zhao, Chunjiang(zhaocj@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:1-9
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Terahertz (THz) radiation is an electromagnetic radiation whose frequency lies between the microwave and infrared regions of the spectrum. THz remains the least explored region mainly due to the technical difficulties involved in making efficient and compact THz sources and detectors. The lack of suitable technologies leads to the THz band being called the "THz gap". Until 1980s, the advent of the femtosecond laser started the advancement in THz generation and detection technologies. THz equipment was then developed by researchers in different labs and commercialized by companies, such as TeraView Ltd. (Cambridge, UK), and Picometrix LLC. (Ann Arbor, MI, USA). With the superior THz equipment, researchers from different disciplines were able to study THz and explored its potential applications in different areas. THz has unique properties in detecting weak intermolecular interaction, and is sensitive to the properties of target objects on both amplitude and phase. THz spectroscopy and imaging techniques are the focuses of current research in this area. Terahertz time-domain spectroscopy (THz-TDS) has been used to evaluate the spectral properties of an object in terahertz range and is being applied in many areas, such as security, semiconductor manufacturing process, communication, and biomedicine. The coherent detection scheme together with the resulting time-domain signal of the terahertz pulse lead to the high sensitivity and excellent contrast that can be achieved in terahertz imaging, which makes terahertz imaging attractive for industrial applications, like metal contacts of a packaged integrated circuit chip, tree-ring analysis, polymer composites and flames, etc. Recently, terahertz techniques have been gradually applied to many fields, including security imaging detection, aerospace, and explosives molecular detection. Experts in field of agricultural research have also actively participated in the application of terahertz technology and have made great progresses. In current paper, the generation and detection methods, sample-making methods, data acquisition and analysis methods of THz spectroscopy and imaging were first systematically summarized and presented. Since there are many factors in agriculture area may influence the THz data acquisition, such as air moisture, samples' thickness, diameter of samples' powder, crop's vulnerability and so on, experimental parameters' determination methods and some testing cases were introduced and demonstrated, which provided a reference for other THz research groups. Afterwards, the research and applications progress of terahertz spectroscopy and imaging technology in agricultural area were carefully reviewed, including agricultural bio-molecular material detection, quality and safety detection of agricultural products, physiology inspection of crops and pollutions detection in agricultural environment, which revealed its great potential and application prospects of terahertz technology in agriculture. The presented explorative studies in agricultural area showed that THz is a promising technology and will definitely play a critical role in many active research areas of agriculture, such as food quality control, crop inspection, and pollutions detection in agricultural environment. However, there are still some problems deserve more attentions in future, such as, what is the 'killer application' of THz in agriculture, how to make the equipment smaller, cheaper, and portable for on-the-spot measurements, etc. which indicated the research directions of THz technology.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:66
Main heading:Terahertz spectroscopy
Controlled terms:Agricultural products - Agriculture - Crops - Data acquisition - Electromagnetic waves - Excitons - Explosives detection - Forestry - Inspection - Moisture determination - Molecular imaging - Monitoring - Plasma diagnostics - Pollution - Semiconductor device manufacture - Spectrum analysis - Terahertz waves - Time domain analysis
Uncontrolled terms:Agricultural environments - Experimental parameters - Integrated circuit chips - Research and application - Semiconductor manufacturing process - Terahertz time domain spectroscopy - THz technology - Weak intermolecular interactions
Classification code:711 Electromagnetic Waves - 714.2 Semiconductor Devices and Integrated Circuits - 723.2 Data Processing and Image Processing - 746 Imaging Techniques - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921 Mathematics - 931.1 Mechanics - 932.3 Plasma Physics - 944.2 Moisture Measurements
DOI:10.11975/j.issn.1002-6819.2018.02.001
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 28>
Accession number:20181605031933
Title:Optimization experiment on two-stage drying process of high and low temperatures for cassavas
Authors:Yang, Xiaoxiao (1); Cong, Kunlin (1); Zhang, Yanguo (1); Li, Qinghai (1)
Author affiliation:(1) Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University-University of Waterloo Joint Research Center for Micro/Nano Energy & Environment Technolog, Department of Energy and Power Engineering, Beijing; 100084, China
Corresponding author:Li, Qinghai(liqh@tsinghua.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:272-277
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Cassava is widely distributed in tropical and subtropical regions of the world. Cassava, potato and sweet potato are known as the world's 3 major potatoes. Cassava is native to the Amazon basin, which are now widely grown in China and Southeast Asia. Cassava is mainly used in food, medicine, industry and other fields, and known as the king of starch. Cassava has to be dried in a period of short time prior to storage or transportation, since the water content of the fresh cassava is as much as 65%-70% at harvest. Up to now, many scholars have done a lot of research on cassava. However, there are few studies on the drying process, drying technology and drying equipment for cassava. In order to develop and optimize drying process of cassava, the effects of the thickness of cassava slices and the temperature of drying process were experimentally investigated. Fresh cassavas were obtained from Rongxian County, Guangxi Zhuang Autonomous Region. They were washed and dried before being stored in a fridge at 2-5℃. Cassavas were cut into 5-9 mm pieces, and then were placed in a drying oven with a preset temperature that could be adjusted from 60 to 100℃ with a 10℃ interval for different cases. The drying process by hot air was simulated with an electric drying oven with forced convective air flow. The samples were taken from the oven every 5 min during the experiment. The cassava slices taken from the drying oven were placed in a silica gel dryer. The cassava slices were cooled to room temperature and weighed with an electronic balance. The moisture of cassava was calculated according to the actual weight change. The effects of different temperatures and different thicknesses on the drying process of cassava were compared. The results showed that cassavas were denatured due to the high temperature, however, the low temperature made water evaporation incomplete. The slice with thinner thickness was prone to be broken up, and on the contrary, the thicker thickness prolonged the drying time to reach the targeted water content. The experimental results show that the drying temperature of 80-100℃ and the thickness of 6-8 mm are better. It was found that the cassava drying process was fitted well with the Wang and Singh model. Based on the water content curves on dry basis, the critical water contents of cassava with different thicknesses were obtained. The experimental results show that the one-stage scheme with constant temperature can only reduce the water content of cassava to about 35% when being dried for 70 min, and fails to reduce moisture content of cassava to safe moisture in the limited short time. In order to avoid the undesired sharp decrease in the drying rate as the water content reached the critical value during single-stage drying process, an optimal two-stage drying scheme of first low temperature and then high temperature was proposed. According to the two-stage drying scheme, the cassava drying process was also proposed. The equipment of the proposed drying process mainly includes the fan, the feeder, the first drying section, the second drying section, the heat exchanger, and so on. The cassava slices of 6-8 mm in thickness were fed into the first drying section by feeder. After the moisture content was reduced to a certain value, the cassavas were fed into the second drying section. Finally, the cassava slices eventually reached the safe moisture content. This cassava drying process provides a good solution for cassava drying and production.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Drying
Controlled terms:Dryers (equipment) - Electronic scales - Moisture - Moisture control - Moisture determination - Ovens - Plants (botany) - Quality control - Silica - Silica gel - Temperature - Water content
Uncontrolled terms:Cassava - Constant temperature - Critical water content - Drying temperature - Electric drying oven - Electronic balances - Single-stage-drying - Subtropical regions
Classification code:641.1 Thermodynamics - 804 Chemical Products Generally - 913.3 Quality Assurance and Control - 944.2 Moisture Measurements
Numerical data indexing:Percentage 3.50e+01%, Percentage 6.50e+01% to 7.00e+01%, Size 5.00e-03m to 9.00e-03m, Size 6.00e-03m to 8.00e-03m, Time 3.00e+02s, Time 4.20e+03s
DOI:10.11975/j.issn.1002-6819.2018.02.037
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 29>
Accession number:20181605031911
Title:Hysteresis characteristics of soil solid-liquid contact angle measured by sessile drop method during wetting-drying cycles
Authors:Yang, Song (1); Ma, Zehui (1); Wang, Lei (1); Luo, Maoquan (1)
Author affiliation:(1) College of Water Conservancy, 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:2
Issue date:January 15, 2018
Publication year:2018
Pages:114-119
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The contact angle hysteresis is one of the main causes of soil water characteristic curve (SWCC) hysteresis in unsaturated soil, the hysteresis of SWCC is a remarkable feature of soil under wetting and drying cycles. In this study, we prepared soil samples with different contact angles by adding repellent agents (octadecylamine) and found that the more the content of the water repellent agents, the greater the contact angle between the soil particles and the pore water. Contact angle measurement test were designed at the same time, drying-wetting cycles of soil were reflected in the test. Droplet 1 was the initial state of the droplet, droplet 2 was a little drop formed after droplet 1 evaporation immediately, and droplet 3 was a little drop formed 24 hours after droplet 2 evaporation. The test results showed that, the contact angles of sand were greater than the clay with the same water repellent agents content, this was mainly because of the geometrical shapes of the soil particles. In all of the soil samples, the contact angles of soil particles and the pore water decreased continuously during the evaporation process, until the contact angle became 0. At this time, the droplets were completely vaporized. The change of the contact angle on clay surface had a linear relation with time, but it was a nonlinear on sand surface. In the same samples, the evaporation time of droplet 1 was longer than droplet 2 and droplet 3 with the same liquid volume, the time spent in droplet 2 and droplet 3 complete evaporation was relatively close, but droplet 3 took a little more time to evaporation than droplet 2, this meant initial contact angle may affect the evaporation velocity of the soil. The larger the initial contact angle, the longer the evaporation time of the droplet would be. Either sand or clay, the contact angle of droplet 1 was greater than droplet 2 and droplet 3. This was because that the contact angle of droplet 1 was measured on the fully dry sample surface. The contact angle of droplet 2 was measured on the sample surface when soil particles were covered by water films from the droplet 1. The contact angle of droplet 3 was measured on the state in which the free water was evaporated completely. The initial contact angle of the three droplets reflected the contact angle of the soil under different initial conditions of wetting drying cycles. The water films of soil particles which the droplet 1 correspond to were the thinnest and droplet 2 correspond to be the thickest. There were three stages of droplet evaporation on a continuous solid surface: Initial stage, pinning stage and slipping stage. The evaporation mode of soil particles only existed in the initial stage and pinning stage, and there was no slip stage. That was, no matter how lager the initial soil contact angle was, by the end of the droplet evaporation, contact angle would be 0. In the whole evaporation process, the three-phase contact line did not move, and the solid-liquid area remained unchanged. The experiment confirmed that it was reasonable to suppose the contact angle was zero during soil drying, the contact angle hysteresis was one of the reasons why SWCC hysteresis loops became small during wetting-drying cycles.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Drops
Controlled terms:Contact angle - Drying - Evaporation - Flow of water - Hysteresis - Liquids - Magnetic bubbles - Soil moisture - Soil surveys - Soils - Waterproofing - Wetting
Uncontrolled terms:Contact angle hysteresis - Hysteresis characteristics - Soil-water characteristic curve - Three-phase contact line - Unsaturated soil - Water repellent agents - Wetting and drying cycles - Wetting drying cycles
Classification code:483.1 Soils and Soil Mechanics - 631.1.1 Liquid Dynamics - 701.2 Magnetism: Basic Concepts and Phenomena - 802.3 Chemical Operations - 931.2 Physical Properties of Gases, Liquids and Solids - 961 Systems Science
Numerical data indexing:Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2018.02.015
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 30>
Accession number:20181605031938
Title:Influence of multi intermittence radiation by LED on flavor components in Tieguanyin tea
Authors:Chen, Shousong (1); Jin, Xinyi (1, 2); You, Fangning (1); Zhou, Ziwei (1); Li, Xinlei (1); Hao, Zhilong (1, 2); Sun, Yun (1, 2)
Author affiliation:(1) College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou; 350002, China; (2) Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou; 350002, China
Corresponding author:Sun, Yun(sunyun1125@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:308-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Light is an important factor, which decides joyful aroma and mellow taste in Oolong tea. Solar withering is the first and essential process, and a large number of primary and secondary metabolites are induced and regulated under several minutes of radiation during Oolong tea manufacturing. However, rainy days usually take place in fastigium production period, and thus quality of Oolong tea has no fruit floral odor and taste is niffy. In recent years, many scholars selected LED (light emitting diode) as an artificial light source to improve quality of special tea. In order to explore the influence of multi intermittence radiation radiation with different times by LED on quality in Oolong tea, in this study, Tieguanyin was taken as research material, and dark treatment (CK) was used as control. Meanwhile, 3 treatments were performed by white LED, one time radiation (S-1), which was conducted before the first assignment in turning over process, the other two treatments (S-2, S-3) were designed by adding radiation for 1 time and 2 times before the second and third assignment in turning over process, respectively. The parameters of environment were set as follows: Photosynthetically active radiation (PAR) was set as (400±10) μmol/(m<sup>2</sup>·s), duration of illumination was set as 30 min for each time, temperature was set as 25℃, relative humidity was set as 60%, and thickness of leaves was set as 10 mm. Then, 4 samples of primary tea were made following technological process of fen-flavor Tieguanyin, and were frozen in refrigerator at-20℃. Catechins, amino acids, aroma and sensory evaluation in Tieguanyin primary tea were performed for all samples by UPLC-QqQ-MS and HS-SPME-GC-MS. Firstly, the multi intermittence radiation device by LED in Oolong tea was developed by ourselves. The device mainly included LED panel, heat pump, rocking device, transfer platform, ventilating slot, superior lobe device, and transmission mechanism. Several set devices would perform cycle operation of different times in light radiation and turning over process. Secondly, compared to control treatment, contents of all nongallated and gallated catechins including C (catechin), EC (epicatechin), GC (gallocatechin), EGC (epigallocatechin), GCG (gallocatechin gallate), ECG (epicatechin gallate), EGCG (epigallocatechin gallate) were significantly reduced in different times of radiation. The contents of total catechins in 4 samples with ascending order were showed as follows: S-2, S-3, S-1, CK. The contents of catechins were very dramatically decreased in S-2 and S-3 by LED, and it showed a reduction of 29.6 % and 24.4 %, respectively, and had a lower bitterness in primary tea. However, the total content of amino acids was enhanced, especially in S-2 and S-3 treatment, and it showed a rise of 20.5 % and 15.4 %, respectively. The content of total amino acids in 4 samples with ascending order was showed as follows: CK, S-1, S-3, S-2. Several aromatic and fresh-sweet amino acids including Trp, Glu, Asp showed an obvious increasing trend, which resulted in more brisk and sweet taste in primary tea. Accordingly, the ratio of phenols to amino acids showed a decrease variation, and can improve taste sensory in primary tea. Thirdly, volatile components of different treatments were assayed by gas chromatography mass spectrometry (GC-MS). Principal component analysis method was also used to evaluate the results. Relative content of alpha-farnesene and nerolidol in 4 samples with ascending order was showed as follows: CK, S-3, S-1, S-2. In contrast to the CK, the relative contents of alpha-farnesene and nerolidol in S-2 treatment were increased by 56.28% and 62.51%, respectively. The comprehensive evaluation score of volatile quality in S-2 treatment was the highest, approached to 9.88, S-3 treatment ranked the second and the CK ranked the last. The sensory evaluation results of quality in primary tea showed a similar sort to principal component analysis of volatiles. In conclusion, the taste and volatile of Oolong tea can be regulated and improved by adding the appropriate times of light radiation, especially in S-2 treatment. It can be a promising technology, especially for the factorization and standardization on rainy days during Oolong tea manufacturing.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Principal component analysis
Controlled terms:Amino acids - Flavonoids - Gas chromatography - Heat radiation - Image quality - Light emitting diodes - Mass spectrometry - Metabolites - Odors - Phenols - Quality control - Radiation - Sensory analysis - Testing - Vitamins
Uncontrolled terms:Comprehensive evaluation - Epigallocatechin gallate - Gas chromatography-mass spectrometries (GC-MS) - Multi intermittence - Photosynthetically active radiation - Principal component analysis method - Tieguanyin - Volatile components
Classification code:641.2 Heat Transfer - 714.2 Semiconductor Devices and Integrated Circuits - 801 Chemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.54e+01%, Percentage 2.05e+01%, Percentage 2.44e+01%, Percentage 2.96e+01%, Percentage 5.63e+01%, Percentage 6.00e+01%, Percentage 6.25e+01%, Size 1.00e-02m, Time 1.80e+03s
DOI:10.11975/j.issn.1002-6819.2018.02.042
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 31>
Accession number:20181605031937
Title:Optimization of short-path molecular distillation technology for refining essential oil from Eucalyptus grandis leaves
Authors:Hu, Xuefang (1, 2); Tian, Zhiqing (1, 2); Pei, Haisheng (1, 2); Zhang, Zhimin (1, 2); Wang, Shikui (1, 2)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Beijing; 100125, China; (2) Key Laboratory of Agro-Products Postharvest Handling, Ministry of Agriculture, Beijing; 100121, China
Corresponding author:Wang, Shikui(wosk1963@shou.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:299-307
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:1,8-cineole and α-pinene are the main constituents of eucalyptus essential oil and important medicine and chemical raw materials. The primary eucalyptus essential oil was refined by short-range molecular distillation, and the separation characteristics of 1,8-cineole and α-pinene of substances under different temperature and pressure conditions were studied, so as to provide technical method for the fractionation and application of eucalyptus essential oil. Using eucalyptus grandis leaves as material, the primary eucalyptus essential oil was extracted and purified by supercritical CO<inf>2</inf>extraction and molecular distillation method respectively. Taking the distillate yield, the content of 1,8-cineole and the content of α-pinene in the distillates, the content of 1,8-cineole and the content of α-pinene in the residues as experimental indices, two-stage molecular distillation purification was carried out. Response surface methodology (RSM) based on a two-variable and five-level center composite rotation design (CCRD) was employed to evaluate the purification effects. Using the free path theory, the effects of different distillation temperatures and distillation pressures on the content of 1,8-cineole and α-pinene in distillates and residues were investigated. The optimization of the process of eucalyptus essential oil refining by molecular distillation was studied. The distillation temperature and distillation pressure had significant influence on the effect of 1,8-cineole and α-pinene fractionation, and the experimental results were optimized by the optimization method of multi response values. Taking distillate as the target product, the optimum conditions were as follows: distillation temperature 38℃, distillation pressure 41 Pa, and 1,8-cineole and α-pinene content in distillates of 60.80% and 31.58%, respectively, and the yield of the distillates was 82.06%, which were well matched with the predicated values 61.97%, 33.37% and 86.38% obtained from the models. The smaller error between experimental and predicted values indicated the optimization experiment was successful. The results of variance analysis showed that the regression equations and models were reliable to predict the influences of factors on the distillate yield, and the content of 1,8-cineole and α-pinene in distillates and residues. Molecular distillation purification can effectively purify the eucalyptus oil. The CCRD is suitable for the process optimization of molecular distillation of eucalyptus essential oil. The experimental process did not introduce any organic solvents, and was carried out in low temperature environment, protecting the material composition and characteristics of the structure. The contents of 1,8-cineole and α-pinene were increased by 77.62% and 56.72% respectively after the secondary molecular distillation. Through the investigation of the change of the content of 1,8-cineole and α-pinene with the distillation temperature and the distillation pressure, the effects of distillation temperature and distillation pressure on the content of 1,8-cineole were significantly higher than those of α-pinene. Meanwhile, the effect of distillation pressure on the content of 1,8-cineole oil was higher than that of distillation temperature. In contrast, for α-pinene, the effect of distillation temperature on its content was more significant, and the interaction of temperature and pressure had no significant effect on the content of α-pinene. The result provides a technical reference for the separation and purification of 1, 8-cineole and α-pinene.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:49
Main heading:Distillation
Controlled terms:Essential oils - Fractionation - Monoterpenes - Olefins - Optimization - Petroleum refining - Pressure - Pressure effects - Process control - Purification - Temperature
Uncontrolled terms:1 ,8-cineole - Distillation temperature - Low temperature environment - Response surface methodology - Separation and purification - Separation characteristics - Supercritical CO2 extraction - Temperature and pressures
Classification code:513.1 Petroleum Refining, General - 641.1 Thermodynamics - 802.3 Chemical Operations - 804.1 Organic Compounds - 921.5 Optimization Techniques - 931.1 Mechanics
Numerical data indexing:Percentage 3.16e+01%, Percentage 3.34e+01%, Percentage 5.67e+01%, Percentage 6.08e+01%, Percentage 6.20e+01%, Percentage 7.76e+01%, Percentage 8.21e+01%, Percentage 8.64e+01%, Pressure 4.10e+01Pa
DOI:10.11975/j.issn.1002-6819.2018.02.041
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 32>
Accession number:20181605031903
Title:Experiment of flow induced vibration of mixed-flow pump based on Hilbert-Huang transform
Authors:Li, Wei (1); Ji, Leilei (1); Shi, Weidong (1); Yang, Yongfei (1); Ping, Yuanfeng (1); Zhang, Wenquan (1)
Author affiliation:(1) National Research Center of Pumps, 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:2
Issue date:January 15, 2018
Publication year:2018
Pages:47-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The vibration induced by flow is one of the important factors to the instability of the mixed-flow pump. With the increase of the capacity and the size of mixed-flow pumps, the vibration of the hydraulic components attracts more attention from researchers and engineers. In order to study the vibration of mixed-flow pump induced by hydrodynamic force, based on the Bentley 408 data acquisition system, vibration signals in 3 directions (X, Y and Z) on the base under unloaded and designed flow conditions of the mixed-flow pump are tested and then analyzed using Hilbert-Huang transform (HHT). The original vibration signal is decomposed by EMD (empirical mode decomposition) using the Hilbert-Huang transform, and the spectral distribution of the different mode function components is obtained. The decomposed signal contains intrinsic modulus with 11 different orders and one residual. The acquired intrinsic modulus represents vibration signal with different frequencies, except the Intrinsic mode function 11 and the residual, which show no periodic characteristics. The results show that the vibration under loaded condition is significantly increased compared with the unloaded operating condition, but the vibrations caused by the hydraulic excitation differ in different directions. When the mixed-flow pump is working under designed operating condition, the low frequency vibration occupies the main vibration energy distribution, making the main mode of the different mode function components move to the low frequency direction, and the hydraulic induced vibration is dominated by the middle and low frequency vibration. In the X direction, the vibration spectrum distribution is similar in the 2 cases, while in the Y and Z direction and on the base of mixed-flow pump the frequency distribution of the waveform is narrowed and the energy distribution is concentrated under loaded condition. Under both loaded and unloaded conditions, the main frequency of the spectrum moves toward the low frequency region with the increase of the modulus order. The difference of the frequency spectrum under loaded and unloaded conditions is more obvious for the intrinsic modulus with lower order, namely Intrinsic mode function 1-3. Under unloaded condition, frequency spectrum of the Intrinsic mode function 1-3 reaches the highest value near 600 Hz; while under loaded operating condition, the position for the peak values moves from 900 to 300 Hz for the spectrum of the intrinsic modulus of the first 3 orders. For the other intrinsic moduli, the peak of the frequency spectrum is distributed below 200 Hz, which indicates that the vibration induced by flow is mainly composed of low and middle frequency vibrations. Compared with the frequency spectrum of vibration signal under unloaded condition, the distribution of vibration spectrum under loaded operating condition is narrower, and the power distribution of the vibration is more concentrated, indicating that the vibration induced by flow increases the vibration of the pump and the hydraulic vibration makes the main frequency of the pump vibration move toward the low frequency region in the frequency spectrum. In the original spectrum under loaded operating condition, the amplitude of the vibration spectrum is higher in the region of 200-600 Hz, which indicates that the vibration power is high in this frequency section, and the vibration caused by hydraulic force is greater there. According to the original vibration signal on the base of the pump, it was found that in the frequency region from 0 to 400 Hz, the amplitude of the vibration spectrum under loaded operating condition is 2 times higher than that of other frequencies, which indicates that low frequency vibration occupies the vibration on the base of the mixed-flow pump. The research results have important engineering application value and theoretical guidance for effectively reducing or preventing the vibration of mixed-flow pumps.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Vibration analysis
Controlled terms:Data acquisition - Mathematical transformations - Pumps - Signal analysis - Signal processing - Spectroscopy
Uncontrolled terms:Empirical Mode Decomposition - Engineering applications - Hilbert Huang transforms - Intrinsic Mode functions - Middle-frequency vibration - Mixed flow pump - Unloaded condition - Vibrations
Classification code:618.2 Pumps - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 921.3 Mathematical Transformations
Numerical data indexing:Frequency 0.00e+00Hz to 4.00e+02Hz, Frequency 2.00e+02Hz, Frequency 2.00e+02Hz to 6.00e+02Hz, Frequency 9.00e+02Hz to 3.00e+02Hz
DOI:10.11975/j.issn.1002-6819.2018.02.007
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 33>
Accession number:20181605031928
Title:Earthworm photophobic movement under different light conditions and quantitative analysis of mechanical separating vermicompost parameters
Authors:Lin, Jiacong (1, 3); Liu, Zhigang (2); Xing, Hang (1, 3); Luo, Shuai (1, 3); Yuan, Qiaoxia (1, 3); Cao, Hongliang (1, 3)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China; (2) School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang; 212013, China; (3) Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture, Wuhan; 430070, China
Corresponding author:Yuan, Qiaoxia(qxyuan@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:235-241
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The vermicomposting has shown to be efficient in processing the organic solid waste like crop straw, dump of poultry and municipal sludge. It is of necessity to separate the earthworm from vermicompost before resulting product is marketed and further developed. But the problems of labor and time intensity, which induce poor earthworm separating efficiency, are urgent to be solved in the stage of vermicomposting. The light separation method has been widely recognized and applied to separate vermicompost. After the earthworm disappeared in the vermicompost pile under the simulated light, there is fixed thickness of vermicompost near the pile surface that can be scraped out. In this way the pure vermicompost can be collected without hurting earthworm. Nowadays, for lacking mechanization and relevant quantitative parameters, the task of earthworm separation is still done by manual labor, which had a higher cost. In this study, the mature earthworms were evenly distributed on the surface of fixed mirco-vermicompost pile. Different monochromatic lights including white light, yellow light, green light, red light, and incandescent light, and the light intensity from 10 to 270 lx, were applied to investigate the earthworm photophobic movement. In order to compare the effect between natural light environment and artificial light, the controlled experiments of indoor light, outdoor light, and direct sunlight were conducted in real environment. The time all earthworms disappeared from the surface of mirco-vermicompost pile was measured and the layer without earthworm was collected. Typically, the study discussed the reason of forming the layer without earthworm through analyzing the pattern of illumination attenuation in the vermicompost. The result indicated that no matter what light qualities were, when the light intensity was less than 10 lx, the earthworm showed almost no reaction; when the light intensity changed from 10 to 30 lx, the earthworm showed weak photophobic reaction; when the light intensity changed from 30 to 210 lx, the extent of earthworm photophobic reaction got increased with the increase of light strength; when the light intensity was over 210 lx, the extent of earthworm photophobic reaction reached the maximum. The white light and direct sunlight had the most significant influence compared with the other light environments, and the disappearing time was 6.5 and 5 min, respectively. After disappearing for 5 min the thickness of the layer without earthworm reached 15 mm, showing no significant difference with other time gaps (10, 15 and 20 min) after disappearing. The red light exerted the weakest impact on earthworm, and the disappearing time was over 20 min in the experiment replicates under different light intensities. With the light intensity increasing, the disappearing time of earthworm dropped logarithmically. When it came to the application for the white light and sunlight with light intensity over 210 lx, 10-15 mm layer without earthworm could be formed. The study calculated the earthworm reaction and responding time under different illumination conditions, which can offer reference for earthworm cultivation. The results of disappearing time, light environment and the thickness of layer without earthworm can be treated as process parameters to provide reference for designing the separating machine.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Piles
Controlled terms:Chemical analysis - Fertilizers - Light - Machinery - Manures - Municipal solid waste - Separation
Uncontrolled terms:Controlled experiment - Illumination conditions - None earthworm thickness - Organic solid wastes - Photophobic movement - Quantitative parameters - Separating efficiency - Vermi-composting
Classification code:408.2 Structural Members and Shapes - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 741.1 Light/Optics - 802.3 Chemical Operations - 804 Chemical Products Generally - 821.5 Agricultural Wastes
Numerical data indexing:Illuminance 1.00e+01lx, Illuminance 1.00e+01lx to 2.70e+02lx, Illuminance 1.00e+01lx to 3.00e+01lx, Illuminance 2.10e+02lx, Illuminance 3.00e+01lx to 2.10e+02lx, Size 1.00e-02m to 1.50e-02m, Size 1.50e-02m, Time 1.20e+03s, Time 3.00e+02s, Time 3.90e+02s, Time 9.00e+02s
DOI:10.11975/j.issn.1002-6819.2018.02.032
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 34>
Accession number:20181605031925
Title:Wolfberry image segmentation based on morphological multi-scale reconstruction and concave points matching
Authors:Wang, Xiaopeng (1); Yao, Lijuan (1); Wen, Haotian (1); Zhao, Junjun (1)
Author affiliation:(1) School of Electronic and Information Engineering, Lanzhou Jiaotong University, 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:2
Issue date:January 15, 2018
Publication year:2018
Pages:212-218
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The traditional Chinese wolfberry classification usually adopts manual grading in terms of the wolfberry characteristics of size, color, surface defects, and so on. It is a time-consuming and inefficient work. Fortunately, machine vision provides an efficient and fast way to improve the classification efficiency and accuracy. During the process of wolfberry classification by machine vision, the first and important task is to segment wolfberry particles from the image, and then classify them into different grades according to their characteristics. However, the accuracy of wolfberry image segmentation process is often hindered by a number of constraints including noise, inhomogeneous intensity, complex adherent and overlapped particles, which easily cause the decline of segmentation accuracy, and subsequently affect the wolfberry classification effect. For the purpose to improve the accuracy and efficiency of wolfberry image segmentation, a method for efficient segmentation of adherent wolfberries based on morphological multi-scale reconstruction and concave points matching is hereby proposed. Firstly, the red component of the original color image is extracted to partially remove the shadow noise around or inside the wolfberries, and then the red component image is reconstructed by morphological multi-scale mixture opening-closing reconstruction to further smoothen the interior of wolfberries while preserving the contour edge information. Since such reconstruction operation can effectively retain the interesting contour edge of wolfberry particles and eliminate the irregular details, the influence of wolfberries edge contours blur and location offset on the subsequent classification will be greatly reduced. The binary regions of wolfberries are extracted from the reconstructed image by the method of maximum between-cluster variance, and the holes in the interior of wolfberries are filled by morphological filling operator. In the filled binary image, there are 2 kinds of wolfberries. One kind consists of single non-adherent wolfberries particles, and can be extracted by morphological area opening operation without further processing. The other kind mainly contains adherent or overlapped wolfberries particles, and needs to further segment, so 8-neighborhood tracking algorithm is used to extract the edge of single pixel contours of the adherent wolfberries. Taking into account that the shape of wolfberry is ellipsoid, the concave points usually locate in the edges where they are touched or overlapped with each other. Therefore the circular template is used to detect these edge concave points. For the incorrect concave point's pairs matched by the shortest Euclidean distance as fitting condition, they can be modified according to the unequal pixel distance between the middle point of the connecting line and the boundary point since the length-to-width ratio of the wolfberry is obvious. When all the concave points' pairs of the adherent wolfberries are confirmed, adherent wolfberries are clearly segmented. The final segmentation results are the combination of single non-adherent and adherent or overlapped wolfberries. The simulation results show that this method can achieve more accurate segmentation results and lower over-segmentation rate compared with the methods of mark-controlled watershed, direct concave points matching, and watershed combined with concave point segmentation, and is especially suitable for the segmentation of adherent wolfberries. The highest accurate segmentation rate is 96% while over-segmentation rate less than 2%.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Image segmentation
Controlled terms:Binary images - Computer vision - Crops - Efficiency - Grading - Image acquisition - Image enhancement - Image reconstruction - Pixels - Surface defects - Watersheds
Uncontrolled terms:Classification efficiency - Concave points matching - Edge extraction - Image segmentation process - Maximum between-cluster variances - Multi-scale reconstruction - Opening-and-closing reconstruction - Reconstruction operations
Classification code:444.1 Surface Water - 723 Computer Software, Data Handling and Applications - 821.4 Agricultural Products - 913.1 Production Engineering - 951 Materials Science
Numerical data indexing:Percentage 2.00e+00%, Percentage 9.60e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.029
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 35>
Accession number:20181605031923
Title:Nondestructive evaluation method for saline-alkaline tolerance of maize based on marginal spectral entropy of electric signal in leaf
Authors:Liu, Kai (1); Zhao, Yanyan (2); Xi, Gang (1); Yang, Yunjing (3); Du, Guangyuan (3)
Author affiliation:(1) Institute of Science, Xi'an University of Technology, Xi'an; 710054, China; (2) Basic Teaching Department, Zhengzhou University of Industry Technology, Zhengzhou; 451100, China; (3) Institute of Science, Northwest A&F University, Yangling; 712100, China
Corresponding author:Xi, Gang(xig@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:197-204
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Saline-alkaline stress (SAS) is one of the major abiotic stresses affecting the growth of plants. It has been a severe problem that restricts plant production and even the development of the ecological environment. The improvement of plant saline-alkaline tolerance and selection of saline-alkaline tolerance plant varieties are becoming hot spots for research. To develop and select saline-alkaline tolerance plants, an evaluation method that can accurately judge the plant saline-alkaline tolerance must be first established. In the present study, the evaluation of saline-alkaline tolerance of plants is generally based on morphological indicators and physiological and biochemical indicators. These evaluation methods require a large number of samples and long cycle, and cannot be early diagnosed. Moreover, many of the indicators must be obtained through the destructive measurement of test-tube experiments, which are not nondestructive testing. Therefore, the traditional evaluation method has many disadvantages. In order to explore the methods of early, sensitive, in situ and nondestructive testing saline-alkaline tolerance of plants, a complex solution consisting of NaCl, Na<inf>2</inf>SO<inf>4</inf>, NaHCO<inf>3</inf>and Na<inf>2</inf>CO<inf>3</inf>with pH value of 9.09 was used to stress 2 kinds of maize variety seedlings of Zhengdan 958 with poor saline-alkaline tolerance and Mingyu 20 with strong saline-alkaline tolerance. Time-domain waveforms of leaf electrical signals of Zhengdan 958 and Mingyu 20 seedlings during saline-alkaline stress were collected. The marginal spectra of 2 kinds of maize leaf electrical signals were obtained by Hilbert-Huang transformation (HHT). The changes of marginal spectrum entropy (MSE) of maize leaf electrical signals and the biological significance were analyzed. The results showed that the MSE of leaf electrical signals from maize variety Zhengdan 958 continued to decline in the process of saline-alkaline stress, while the MSE of leaf electrical signals from maize variety Mingyu 20 changed in volatility. It was indicated that the ion transport of leaf cells in Zhengdan 958 was inhibited under saline-alkaline stress, and there was complex metabolic regulation in leaf cells of Mingyu 20 to maintain the dynamic balance of ion transport and normal functional status of leaf cell. The study also found that the malondialdehyde (MDA) content in leaf of Zhengdan 958 was increasing in the process of saline-alkaline stress, and the MDA content in leaves of Mingyu 20 began to increase significantly after 4 days of stress. This phenomenon suggested that there was membrane lipid peroxidation in leaves of Zhengdan 958 in the early stages of saline-alkaline stress, and it was more and more serious with the process of the stress, however, there was significant membrane lipid peroxidation in leaves of Mingyu 20 after 4 days of stress. The membrane lipid peroxidation of leaf cells caused by saline-alkaline stress could be the reason to the decrease of MSE about maize leaf electrical signals. Due to that the variation of the MSE from 2 maize varieties with different saline-alkaline tolerance under saline-alkaline stress was different, the response index (RI) of electrical signal based on the MSE was defined in this paper. The results showed that the RI values of maize varieties Zhengdan 958 and Mingyu 20 were obviously different in the processes of saline-alkaline stress. The influence of saline-alkaline stress on the ion transport and cell membrane injury of maize leaf cell could be sensitive and early quantitatively diagnosed according to the size of RI, and then to achieve in situ measurement and nondestructive evaluating saline-alkaline tolerance of maize seedlings. Since the RI based on plant electrical signals has not relationship with the species, the method proposed in this paper to evaluate the saline-alkaline tolerance of maize seedlings may also have a wide range of applicability. It is expected that the evaluation method about saline-alkaline tolerance of plant proposed in this paper can be verified through a large number of experiments.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:51
Main heading:Alkalinity
Controlled terms:Cells - Crops - Cytology - Entropy - Ions - Lipids - Mathematical transformations - Nondestructive examination - Oxidation - Oxidative stress - Physiological models - Plants (botany) - Seed - Sodium bicarbonate - Sodium Carbonate - Sodium chloride - Sodium sulfate - Stresses - Time domain analysis
Uncontrolled terms:Electrical signal - Evaluation - Hilbert Huang Transformation - Maize - Marginal spectrum - Membrane lipid peroxidation - Non-destructive evaluation methods - Plant electrical signals
Classification code:461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 641.1 Thermodynamics - 801.1 Chemistry, General - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.4 Agricultural Products - 921 Mathematics - 921.3 Mathematical Transformations
Numerical data indexing:Age 1.10e-02yr
DOI:10.11975/j.issn.1002-6819.2018.02.027
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 36>
Accession number:20181605031930
Title:Object-oriented land use/cover classification based on texture features of Landsat 8 OLI image
Authors:Pei, Huan (1, 2, 3); Sun, Tianjiao (1); Wang, Xiaoyan (1, 2, 3)
Author affiliation:(1) College of Information Science and Engineering, Yanshan University, Qinhuangdao; 066004, China; (2) Hebei Provincial Key Lab of Computer Virtual Technology and System Integration, Qinhuangdao; 066004, China; (3) Hebei Provincial Key Lab of Software Engineering, 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:2
Issue date:January 15, 2018
Publication year:2018
Pages:248-255
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Remote sensing image classification is the main approach for rapidly obtaining regional land use/cover information and it has always been an important part in the field of remote sensing. How to improve the classification accuracy of remote sensing images is an urgent problem to be solved in remote sensing research. In traditional classification, only the spectral features of remote sensing image are used, while the texture and other features are ignored. Therefore, it is very common to see the object confusion in the classification result. In this paper, we took the Shijiazhuang Landsat 8 OLI remote sensing image data as the research area, and systematically studied object-oriented classification based on the spatial texture features of remote sensing images. Firstly, Gray Level Co-occurrence Matrix (GLCM) texture features and Gist texture features based on Gabor filter were compared and analyzed. The average J-M distance method was used to evaluate the sample separability and to choose optimal texture features of GLCM. Subsequently, the optimum index factor (OIF) was applied to obtain the best combination of the two texture features. Secondly, the segmentation scale of object-oriented classification was studied in detail, meanwhile, the concept of "the optimal overall segmentation scale" was proposed, which was based on the ratio between maximum area and the number of the objects in classification result. Finally, two object-oriented classification methods, K-Nearest Neighbor (KNN) method and Support Vector Machine (SVM) method, were used to classify the texture data and the original data, and the accuracy of assessment results were compared using three traditional supervised classification methods. The results indicated that the fusion of texture features could improve the accuracy of classification to some extent. The overall classification accuracy based on texture data using object-oriented SVM and object-oriented KNN increased by 3.67 and 3.33 percentage points, respectively, compared with the results based on original data. Object-oriented SVM method based on texture data had the highest classification accuracy with overall classification accuracy of 85.67%, and with Kappa index of 0.81. Although the classification accuracy of the texture-based supervised classification was improved compared with the supervised classification based on original data, the accuracy was far lower than the value with object-oriented method. For original data, the overall classification accuracy of object-oriented KNN increased by 4.33%, 3.99% and 2.00%, respectively, compared with Maximum Likelihood Classification (MLC), Mahalanobis Distance Classification (MDC) and SVM method. The overall classification accuracy of object-oriented SVM increased by 8.33%, 7.99% and 6.00%, respectively, compared with three supervised methods. After fusing Gist texture features, the overall classification accuracy of object-oriented KNN had increased by 6.33%, 4.66% and 2.66% respectively compared with MLC, MDC and SVM. Whereas the overall classification accuracy of object-oriented SVM increased by 10.67%, 9% and 7.00%, respectively, compared with three supervised methods. Object-oriented SVM method is more sensitive to texture features with the maximum increase of classification accuracy. In future study, more texture features need to be considered to extend the application range of remote sensing classification. In summary, the texture feature has positive effect on improving the accuracy of remote sensing classification, and the application of Gist textures have great potential in object-oriented classification. Moreover, it can also be found that object-oriented method is suitable for classifying medium resolution remote sensing image. The research method in this paper not only gives a valuable reference for other kinds of remote sensing images, but also provides an effective approach for the extraction of regional land use/cover information.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Classification (of information)
Controlled terms:Forestry - Gabor filters - Image classification - Image enhancement - Image texture - Information use - Land use - Maximum likelihood - Nearest neighbor search - Remote sensing - Supervised learning - Support vector machines
Uncontrolled terms:Gist features - Gray level co occurrence matrix(GLCM) - Maximum likelihood classifications - Object oriented classification - Remote sensing classification - Remote sensing image classification - Supervised classification - Texture features
Classification code:403 Urban and Regional Planning and Development - 703.2 Electric Filters - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 903.1 Information Sources and Analysis - 903.3 Information Retrieval and Use - 921.5 Optimization Techniques - 922.1 Probability Theory
Numerical data indexing:Percentage 1.07e+01%, Percentage 2.00e+00%, Percentage 2.66e+00%, Percentage 3.99e+00%, Percentage 4.33e+00%, Percentage 4.66e+00%, Percentage 6.00e+00%, Percentage 6.33e+00%, Percentage 7.00e+00%, Percentage 7.99e+00%, Percentage 8.33e+00%, Percentage 8.57e+01%, Percentage 9.00e+00%
DOI:10.11975/j.issn.1002-6819.2018.02.034
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 37>
Accession number:20181605031918
Title:Spatial distribution characteristics and scale effects of regional soil organic carbon
Authors:Zhang, Shiwen (1); Ge, Chang (1); Chen, Xiaohui (2); Li, Zhen (3); Shen, Qiang (4); Zhang, Lanlan (5); Nie, Chaojia (1); Huang, Yuanfang (3)
Author affiliation:(1) School of Earth and Environment, Anhui University of Science and Technology, Huainan; 232001, China; (2) Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing; 100101, China; (3) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China; (4) Faculty of Surveying and Mmapping, Anhui University of Science and Technology, Huainan; 232001, China; (5) College of Agriculture, Anhui Science and Technology University, Bengbu; 230002, China
Corresponding author:Huang, Yuanfang(yfhuang@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:2
Issue date:January 15, 2018
Publication year:2018
Pages:159-168
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Combined with the current research progress and shortcomings on spatial distribution characteristics and scale effects of soil properties, using a combination of variogram theory, spatial autocorrelation theory, multi-fractal theory and other methods from the aspects of the spatial variability of soil properties and the structure, the paper gradually revealed the spatial distribution characteristics of SOC (soil organic carbon) and its scale effects under 4 kinds of scales. The results showed that: Ratio of nugget to sill of SOC under 15, 25, 35 and 45 km scales were 61.78%, 42.65%, 49.98% and 39.34%, respectively, which showed a moderate spatial correlation. The spatial correlation from high to low was 45, 25, 35 and 15 km in turn. Except the 15 km scale, the spatial variability caused by random factors including representative measurement error and the micro-scale process, was less than the structure variance, namely the ratio of nugget to sill was less than 50%, the structural factors were dominant, and spatial variability from the random part showed a decreasing trend with the scale increasing. The variation function couldn't be described with discrete characteristics (i. e. spatial negative correlation), which was also impossible to make a significant test for variable range. As the separation distance increased, the Moran index decreased from full positive to negative, then the positive and negative values alternately occurred, and eventually the values turned out to be negative totally. Nearer positive correlation distance represents the spatial correlation distance, which is the first cross point of positive and negative conversion under different scales, and were 1607, 7520, 8649 and 9053 m for 15, 25, 35, and 45 km scale. With the scale increasing, the spatial correlation distance increased, and compared to the change range in the semi-variation function, it became smaller with varying degree under different scales except 15 km scale. The order for standardized statistic under different scales was 15 km < 45 km <35 km < 25 km, which increased firstly and then decreased with the scale, and standard statistics under 4 scales were larger than 1. 96. All random scale accounted for less than 5%, and on the whole each scale had good spatial structure. The multidimensional fractal parameter value under 25 km scale was the largest, indicating that the SOC content in this scale was mainly concentrated in a dense area. The magnitude of variation of Rayleigh dimension of SOC under 4 kinds of scales was consistent with that of width of multidimensional spectrum. The spatial distribution of SOC is a typical fractal dimension. Multifractal method is a tool for describing the spatial heterogeneity of SOC. It can reveal the scale variation characteristics of spatial heterogeneity of SOC. No matter what kind of scale, specific value of the measured value based on the Mkrige method agreed well with the predicted value, and the coverage ratio of specific value was above 85%. Spatial distribution characteristics of SOC were deeply revealed through combining variation function, spatial autocorrelation, multi-fractal and Mkrige method from spatial variability, spatial correlation and spatial structure in research area. The results can provide a method to the research on the spatial distribution characteristics of SOC in relatively flat agricultural region. However, due to the different combinations of artificial and natural factors, the spatial variability, correlation and structure will vary with scale change.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:51
Main heading:Spatial distribution
Controlled terms:Autocorrelation - Forestry - Fractal dimension - Organic carbon - Soil surveys - Soil testing - Soils - Spatial variables measurement
Uncontrolled terms:Distribution characteristics - Multi-dimensional fractals - Positive correlations - Scales - Semivariances - Spatial autocorrelations - Spatial variability of soil properties - Variation characteristics
Classification code:483.1 Soils and Soil Mechanics - 804.1 Organic Compounds - 921 Mathematics - 943.2 Mechanical Variables Measurements
Numerical data indexing:Percentage 3.93e+01%, Percentage 4.26e+01%, Percentage 5.00e+00%, Percentage 5.00e+01%, Percentage 6.18e+01%, Percentage 8.50e+01%, Size 1.50e+04m, Size 2.50e+04m, Size 3.50e+04m, Size 4.50e+04m, Size 8.65e+03m, Size 9.05e+03m
DOI:10.11975/j.issn.1002-6819.2018.02.022
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 38>
Accession number:20181605031902
Title:Design method for series airfoil based on mean camber line consisting of double ellipse arcs
Authors:Zhang, Sen (1); Xi, Deke (1); Liu, Zhibin (2); Chen, Baofeng (2)
Author affiliation:(1) Institute of Aeronautics, Northwestern Polytechnical University, Xi'an; 710072, China; (2) Shanxi Anrui Fan Electric Co., Ltd, Yuncheng; 044402, China
Corresponding author:Xi, Deke(xideke@nwpu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:40-46
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Airfoil, as a product of aviation technology, has been widely used in the design of fluid machinery products. The aerodynamic characteristics of airfoils are a key factor in determining the performance of fluid machinery. When the existing airfoils are not able to meet the engineering requirements, it is necessary to redesign or trim the original airfoils. In this research, 2 ellipse arcs were used to form the mean camber line of the airfoil, and the corresponding equation was deduced. This equation controls the shape of the mean camber line by changing the maximum camber and the relative position of maximum camber, and adjusts the local shape by changing the 2 shape factors of the mean camber line. The mean camber line constructed by this method is smooth and continuous, and there is no knee point. Then the thickness distribution of the existing airfoil was superposed with the distribution function of mean camber line, and a thickness scale factor was introduced to adjust the thickness distribution. Ultimately, the design method for a series of airfoils based on mean camber line of double ellipse arcs is achieved, which is called DEA (double ellipse arcs) airfoil. The airfoil profile function constructed by this method has definite physical meaning, simple and reliable, and it is easy to realize serialization. In order to study the influence of airfoil characteristic parameters on aerodynamic performance of the DEA airfoil, the Clark-Y airfoil was taken as the basic airfoil, and a number of DEA airfoils were designed using the thickness distribution of the Clark-Y airfoil. Then the aerodynamic characteristics of the designed airfoils were solved by the X-foil software to study the influence of the maximum camber, the relative position of the maximum camber, the maximum thickness and the shape factors of the mean camber line on the DEA airfoil aerodynamic performance. There are 5 characteristic parameters in all that influence the shape of the DEA airfoil. We selected one of the 5 characteristic parameters as variable and fixed the other 4 characteristic parameters to design different DEA airfoils. And the aerodynamic characteristics were achieved at Reynolds number of 1.0×10<sup>5</sup>. The calculation results of the 4 DEA airfoils with different values of maximum camber show that the increase of the maximum camber can improve the lift coefficient and ameliorate the characteristics of the lift-drag ratio. The calculation results of the 4 DEA airfoils with different values of relative position of the maximum camber show that as the relative position of the maximum camber moves forward, the lift coefficient under small angles of attack is improved, and the range of efficient lift-drag ratio gets broadened. The calculation results of the 4 DEA airfoils with different values of maximum thickness show that the increase of the maximum thickness can increase the maximum lift coefficient and the stall angle. At the same time, with the increase of thickness, the range of efficient lift-drag ratio also gets broadened. The calculation results of the DEA airfoils with different shape factors of the mean camber line also were achieved. At small attack angle, the change of the leading shape factors of the mean camber line has little influence on lift coefficient. With the decrease of the leading shape factors of the mean camber line, the interval of efficient lift-drag ratio has a tendency to move to high attack angle range. With the decrease of the trailing shape factors of the mean camber line, the lift coefficient and lift-drag ratio decrease gradually. Moreover, the interval of efficient lift-drag ratio also decreases and the decrease is mainly at the range of small attack angle. According to the adjustment principle of the above parameters, a new airfoil can be designed or modified to meet the needs of the target task.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Lift drag ratio
Controlled terms:Airfoils - Angle of attack - Cambers - Design - Distribution functions - Drag - Geometry - Lift - Machine design - Machinery - Numerical analysis - Product design - Reynolds number - Thickness control
Uncontrolled terms:Aero-dynamic performance - Aerodynamic characteristics - Airfoil aerodynamics - Aviation technology - Double ellipse arcs - Maximum lift coefficient - Mean camber line - Thickness distributions
Classification code:601 Mechanical Design - 631.1 Fluid Flow, General - 651.1 Aerodynamics, General - 652.1 Aircraft, General - 731.3 Specific Variables Control - 913.1 Production Engineering - 921 Mathematics - 921.6 Numerical Methods - 922.1 Probability Theory
DOI:10.11975/j.issn.1002-6819.2018.02.006
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 39>
Accession number:20181605031900
Title:Influence of water content on anti-pressing properties of corn ear
Authors:Li, Xinping (1); Xiong, Shi (1); Geng, Lingxin (1); Ji, Jiangtao (1)
Author affiliation:(1) College of Agricultural 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:2
Issue date:January 15, 2018
Publication year:2018
Pages:25-31
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The corn threshing without cob fracture can greatly simplify cleaning link. The rupture of corn ear can directly affect the effect of the core threshing without cob fracture. In order to study the anti-pressing properties and rupture laws of corn ear and explore the effect of water content on anti-pressing properties, the static compress experiments were carried out on the electronic universal testing machine. The analysis of the biological characteristics of corn ear showed that the wooden ring form had compact structure and its strength was big. And the core pulp and the glume shell had loose structure and small strength. The corn varieties selected by experiment were Zhongdan 868 and Zhenghuangnuo No. 2. The water content of each variety was treated as 5 criteria. Four tests were done for each test level. The corn variety and the water content of corn cob were used as test factors. The maximum load and the maximum stress of corn ear were used as the test indices. The experimental data were analyzed by MATLAB software and the function relation between water content of corn cob and test indices was obtained. The relationship between water content of corn cob and fracture strain of corn ear indicated that the plasticity of corn ear was firstly enhanced and then declined with the increase of the water content of corn cob. Through the analysis of the fitting curves between the water content of corn cob and the test indices, it was known that the water content of corn cob had a tremendous effect on the anti-pressing properties of corn ear. When the water content was below 13%, with the decrease of water content, the plasticity of corn ear decreased and the compressive strength increased slowly, which resulted in a slow enhancement of the anti-pressing ability of corn ear. When the range of water content was 13%-25%, with the increase of water content, the plasticity and the compressive strength of corn ear both increased, which resulted in the enhancement of the anti-pressing ability. When the water content was higher than 25%, the plasticity of corn ear was weakened and the compressive strength decreased with the increase of water content, which resulted in a sharp decline of the anti-pressing ability. To observe the internal fracture process of corn ear, samples were cut in radial direction and then the cut samples were put on the test bench to do experiment. Using the radial section of corn ear as the observation window, the whole process of corn ear compression test was recorded by camera. Through the analysis of the photos of corn ear in the process of compression, it was known that the core pulp firstly ruptured and the crack was extended in vertical direction. Then the crack gradually approached to the wooden ring form. Finally, the wooden ring form ruptured and corn ear presented obvious deformation. The analysis of the strain-stress curves indicated that stress gradually increased and corn ear showed plastic deformation with the increase of strain. Stress began to decline after peak. Curves showed jagged wave and the yield stage was entered. The rupture of the wooden ring form led to the decline of stress curves. So the wooden ring form was the main anti-pressing part of corn ear. In the process of compression, corn ear showed the phenomenon of grains falling. The radial balance equations of grain were established by force analysis. Analysis indicated that pressure would be transmitted to the grains in the circumferential distribution. The increase of the pressure between grains would destroy the radial force balance of grains, resulting in the fracture of the carpopodium. Test results showed that the anti-pressing ability of corn ear was the strongest when the water content of corn cob was 25%, and this water content of corn cob was the most suitable for the corn threshing without cob fracture. The rupture of corn ear was a gradual rupture process by the inside-out. Applying pressure less than 610 N to corn ear could not only prevent the fracture of corn ear but facilitate threshing. The research results can provide data reference and theoretical support for the further research of the corn threshing without cob fracture.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Grain (agricultural product)
Controlled terms:Compression testing - Compressive strength - Cracks - Crops - Curve fitting - Experiments - Fracture - High pressure effects - MATLAB - Moisture - Pressure - Pulp - Software testing - Water content
Uncontrolled terms:Biological characteristic - Corn ear - Influence of water - Observation window - Pressing property - Strain stress curve - Universal testing machines - Vertical direction
Classification code:723.5 Computer Applications - 811.1 Pulp and Paper - 821.4 Agricultural Products - 901.3 Engineering Research - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science
Numerical data indexing:Percentage 1.30e+01%, Percentage 1.30e+01% to 2.50e+01%, Percentage 2.50e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.004
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 40>
Accession number:20181605031934
Title:Migration rules of Zn from nano-ZnO modified LDPE food packaging films
Authors:Huang, Hao (1); Li, Li (1); Qin, Yu (1); Luo, Zisheng (1); Chen, Hangjun (2); Ru, Qiaomei (3)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou; 310058, China; (2) Zhejiang Academy of Agricultural Sciences, Hangzhou; 310021, China; (3) Hangzhou Wanxiang Polytechnic, Hangzhou; 310023, China
Corresponding author:Luo, Zisheng(luozisheng@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:278-283
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the migration of Zn from low-density polyethylene (LDPE) films modified with nano-ZnO, according to the European Union regulation NO. 10/2011, distilled water, 30 g/L acetic acid, 95% ethanol (v/v) and 10% ethanol (v/v) were chosen as the neutral, acidic, fatty and alcoholic food simulants, respectively. Nanoparticle modified films (NMFs) were prepared by blending LDPE with nano-ZnO. Film characterization was conducted by transmission electron microscope (TEM) and the migration of Zn was measured by ICP-MS (inductively coupled plasma-mass spectrometry). Migration tests of Zn into 4 kinds of food simulants were performed under 40℃ for 2 h, 1 d, 4 d and 7 d, as well as 70℃ for 2 h. The effect of different temperatures on the migration was studied. Moreover, the influences of microwave and ultraviolet treatment were also studied. The size of nano-ZnO was observed to be about 100 nm in TEM image. This result indicated that particles in the NMFs still possessed nano size. It was obvious that NMFs had relatively higher content of Zn compared to the control in all kinds of food simulants. For NMFs in neutral simulant, the migration amount of Zn in 40℃ for 7 d was 10% higher than that in 40℃ for 1 d. While in acidic simulant, the migration amount of Zn in 40℃ for 7 d was 31% higher than that in 40℃ for 1 d. Migration amount of Zn in 40℃ for 7 d were 4% and 9% higher than that in 40℃ for 1 d, respectively, in alcoholic and fatty simulants (P<0.05). Results showed that the highest migration amount of Zn was in acidic simulant, followed by neutral, fatty and alcoholic simulants. The amounts of migration rose with the increase of temperature. In neutral simulant, the migration amount of Zn in 70℃ for 2 h was 1245% higher than that in 40℃ for 2 h. When in acidic simulant, the migration amount of Zn in 70℃ for 2 h was 1047% higher than that in 40℃ for 2 h. Migration amounts of Zn in 70℃ for 2 h were 902% and 1524% higher than that in 40℃ for 2 h in alcoholic and fatty simulants, respectively (P<0.05). Microwave treatment could promote the migration. In neutral simulant, compared to the control, microwave treatment of 250 and 600 W increased the migration amount of Zn by 22% and 53%, respectively. While in acidic simulant, migration amount of Zn was enhanced by 22% and 53%, under microwave treatment of 250 and 600 W, respectively (P<0.05). However, ultraviolet treatment could not promote the migration of Zn. The amounts of Zn migrated into food simulants ranged from 0.52 to 14.17 mg/kg. The highest migration amount of Zn was beyond the limitation of 5 mg/kg in the European Union regulation No. 10/2011. The results of migration test indicated that LDPE films modified with nano-ZnO might not be a kind of safe food packaging film, and it still needs further investigation.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Fatty acids
Controlled terms:Ethanol - II-VI semiconductors - Inductively coupled plasma mass spectrometry - Low density polyethylenes - Microwave heating - Microwaves - Packaging machines - Packing - Plastic films - Transmission electron microscopy - Ultraviolet lamps - Zinc oxide
Uncontrolled terms:European Union regulations - Film characterizations - Low Density Polyethylene (LDPE) - Microwave treatment - Migration - Migration tests - Nano-ZnO - Ultraviolet treatment
Classification code:694.3 Packaging Equipment - 707.2 Electric Lamps - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 801 Chemistry - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 815.1.1 Organic Polymers - 817.1 Polymer Products
Numerical data indexing:Mass_Density 3.00e+01kg/m3, Percentage 1.00e+01%, Percentage 1.05e+03%, Percentage 1.24e+03%, Percentage 1.52e+03%, Percentage 2.20e+01%, Percentage 3.10e+01%, Percentage 4.00e+00%, Percentage 5.30e+01%, Percentage 9.00e+00%, Percentage 9.02e+02%, Percentage 9.50e+01%, Power 2.50e+02W, Power 6.00e+02W, Size 1.00e-07m, Time 7.20e+03s
DOI:10.11975/j.issn.1002-6819.2018.02.038
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 41>
Accession number:20181605031924
Title:Image recognition method of multi-cluster kiwifruit in field based on convolutional neural networks
Authors:Fu, Longsheng (1, 2); Feng, Yali (1); Elkamil, Tola (3); Liu, Zhihao (1); Li, Rui (1); Cui, Yongjie (1, 2)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) Key Laboratory of Agricultural Internet of Things, Ministry of Agriculture, Yangling; 712100, China; (3) Precision Agriculture Research Chair, King Saud University, Riyadh; 11451, Saudi Arabia
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:205-211
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China is the largest country for cultivating kiwifruit, and Shaanxi Province provides the largest production, which accounts for approximately 70% of the production in China and 33% of the global production. Harvesting kiwifruit in this region relies mainly on manual picking which is labor-intensive. Therefore, the introduction of robotic harvesting is highly desirable and suitable. The fast and effective recognition of kiwifruit in the field under natural scenes is one of the key technologies for robotic harvesting. Recently, the study on kiwifruit recognition has been limited to a single cluster and multi clusters in the field have seldom been considered. In this paper, according to growth characteristics of kiwifruit grown on sturdy support structures, an RGB (red, green, blue) camera was placed around 100 cm underneath the canopy so that kiwifruit clusters could be included in the images. We proposed a kiwifruit image recognition system based on the convolutional neural network (CNN), which has a good robustness avoiding the subjectivity and limitation of the features selection by artificial means. The CNN could be trained end to end, from raw pixels to ultimate categories, and we optimized the critical structure parameters and the training strategy. Ultimately, the network was made up of 1 input layer, 3 convolutional layers, 2 sub-sampling layers, 1 full convolutional layer, and 1 output layer. The CNN architecture was optimized by using batch normalization (BN) method, which normalized the data distribution of the middle layer and the output data, accelerating the training convergence and reducing the training time. Therefore, the BN layers were added after the 1, 3 and 5th convolutional layer (Conv1, Conv3, and Conv5 layer) of the original LeNet network. The size of all convolutional kernels was 5×5, and that of all the sub-sampling layers was 2×2. The feature map numbers of Conv1, Conv3, and Conv5 were 6, 16 and 120, respectively. After manual selection and normalizing, the RGB image of kiwifruit was transferred into a matrix with the size of 32×32 as the input of the network, stochastic gradient descent was used to train our models with mini-batch size of 100 examples, and momentum was set as 0.9. In addition, the CNN took advantages of the part connections, the weight sharing and Max pooling techniques to lower complexity and improve the training performance of the model simultaneously. The network used rectified linear units (ReLU) as activation function, which could greatly accelerate network convergence. The proposed model for training kiwifruit was represented as 32×32-6C-2S-16C-2S-120C-2. Finally, 100 images of kiwifruit in the field (including 5918 fruits) were used to test the model, and the results showed that the recognition ratios of occluded fruit, overlapped fruit, adjacent fruit and separated fruit were 78.97%, 83.11%, 91.01% and 94.78%, respectively. The overall recognition rate of the model reached 89.29%, and it only took 0.27 s in average to recognize a fruit. There was no overlap between the testing samples and the training samples, which indicated that the network had a high generalization performance, and the testing images were captured from 9 a. m. to 5 p. m., which indicated the network had a good robustness to lightness variations. However, some fruits were wrongly detected and undetected, which included the fruits occluded by branches or leaves, overlapped to each other and the ones under extremely strong sunlight. Particularly, 2 or more fruits overlapped were recognized as one fruit, which was the main reason to the success rate not very high. This phenomenon demands a further research. By comparing with the conventional methods, it suggested that the method proposed obtained a higher recognition rate and better speed, and especially it could simultaneously identify multi-cluster kiwifruit in the field, which provided significant support for multi-arm operation of harvesting robotic. It proves that the CNN has a great potential for recognition of fruits in the field.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Fruits
Controlled terms:Algorithms - Convolution - Deep learning - Harvesting - Image processing - Image recognition - Neural networks - Optimization - Robotics - Stochastic models - Stochastic systems
Uncontrolled terms:Convolutional kernel - Convolutional neural network - Convolutional Neural Networks (CNN) - Generalization performance - Growth characteristic - Image recognition system - Kiwifruits - Stochastic gradient descent
Classification code:716.1 Information Theory and Signal Processing - 731.5 Robotics - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921.5 Optimization Techniques - 922.1 Probability Theory - 961 Systems Science
Numerical data indexing:Percentage 3.30e+01%, Percentage 7.00e+01%, Percentage 7.90e+01%, Percentage 8.31e+01%, Percentage 8.93e+01%, Percentage 9.10e+01%, Percentage 9.48e+01%, Size 1.00e+00m, Time 2.70e-01s
DOI:10.11975/j.issn.1002-6819.2018.02.028
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 42>
Accession number:20181605031932
Title:Monitoring spatio-temporal changes of water area in Hongjiannao Lake from 1957 to 2015 and its driving forces analysis
Authors:Wang, Ying (1); Yan, Zhenglong (2); Gao, Fan (3)
Author affiliation:(1) The Second Monitoring and Application Center, China Earthquake Administration, Xi'an; 710054, China; (2) Shaanxi Administration of Surveying, Mapping and Geoinformation, Xi'an; 710054, China; (3) College of Water Conservancy and Civil Engineering, Xinjiang Agricultural University, Urumqi; 830052, China
Corresponding author:Gao, Fan(gutongfan0202@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:2
Issue date:January 15, 2018
Publication year:2018
Pages:265-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The changes of lake water resources record the impacts of climate changes and human activities on the regional hydrological processes in the changing environment. Especially for inland areas with less precipitation, timely and accurate information on changes in lake water resources are recorded. Environmental evolution has an important reference value. With China's largest desert freshwater lake-Hongjiannao Lake as an example, based on the 3S (RS, GIS, and GPS, which are remote sensing, global position system, geographic information system) technology, lake water surface area change was analyzed, which provided important scientific guidance for the restoration, protection and utilization of ecological and economic functions of Hongjiannao Lake. However, due to the different sources of data, the uneven technology, the discontinuous time series and the generally short time series, as well as the different monitoring phases, the result analysis on the change of water area of Hongjiannao Lake is quite different and systematic study and overall analysis of long time series of the entire river basin are lacking. Fifteen periods of both basic and RS data collected for Hongjiannao Lake, such as DRG, DLG, DOM, remote sensing images, and paper maps, were selected for analysis over a recent 60-year period (from 1957 to 2015), together with field annotation data and relevant attributes. All the data and images above have passed the geometric correction of digital elevation model data from Shaanxi Surveying and Mapping Archives and Geological Information Bureau of State Bureau of Surveying and Mapping, which have good quality. Different data can meet the high-precision registration requirements of water body information extraction in the study area. Among them, NDWI (normalized difference water index) with better extraction effect was used to extract water body information, which could restrain the vegetation soil while enhance the water body information. To analyze characteristics in spatio-temporal variations and identify trends of the change in lake water area over the period, we comprehensively utilized RS and GIS techniques and adopted spatial data processes, extracted and interpreted information, constructed a massive database, and conducted integrated management and analysis. We also explored major causes that triggered spatio-temporal variations of lake water area by combining climate change and anthropogenic factors from the same period. Results indicated that in a recent 60-year period, the area covered by water significantly changed in the study area. During 1957-1976, the water area continuously increased from 37.6 to 55.53 km<sup>2</sup>, and reached the maximum value over the entire record of study with increased amplitude of 47.69%. The growth rates in northern and southeastern areas of the lake were relatively fast, followed by other regions. During 1977-1999, the overall water area was stable, approximately 50 km<sup>2</sup>. During 2000-2015, water area showed a decreasing trend year by year, from 50.27 to 31.05 km<sup>2</sup>with decreased amplitude of 38.23%, and all regions showed this shrinking trend except waters near Qibusu River in 2005, in which the reverse occurred and the water area slightly increased. In general, over the last 60 years, the revolution process of the water area of Hongjiannao Lake could be divided into 3 phases corresponding to the annual variability of water area: expanding period (1957-1976), stabilizing period (1977-1999), and shrinking period (2000-2015), showing an overall shrinking trend. The area of lakes and waters has experienced a dynamic trend of expansion-stabilization-atrophy in the recent 60 years, and has shown a significant atrophy situation since 1999 and a strong signal of ecological and hydrological deterioration, deserving attention. Trends in both warming and drying climate may be the major factors, which affect lake water area variation in both expanding and stabilizing periods, and the superimposition of these trends with anthropogenic effects (i. e. a water conservation project construction in the upper streams, coal mining, pavement construction around the lake, and water consumption for irrigation) may be the essential factor leading to water area variations during the shrinking period.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Climate change
Controlled terms:Data mining - Ecology - Extraction - Geographic information systems - Lakes - Mapping - Monitoring - Remote sensing - Rivers - Shrinkage - Surveys - Time series - Time series analysis - Water conservation
Uncontrolled terms:Digital elevation model data - Global position systems - Human activities - Normalized difference water index - Protection and utilizations - Spatio-temporal changes - Spatio-temporal variation - Water body information extractions
Classification code:405.3 Surveying - 443.1 Atmospheric Properties - 444 Water Resources - 454.3 Ecology and Ecosystems - 723.2 Data Processing and Image Processing - 802.3 Chemical Operations - 903.3 Information Retrieval and Use - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Age 6.00e+01yr, Area 3.76e+07m2 to 5.55e+07m2, Area 5.00e+07m2, Area 5.03e+07m2 to 3.10e+07m2, Percentage 3.82e+01%, Percentage 4.77e+01%
DOI:10.11975/j.issn.1002-6819.2018.02.036
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
- 邮编 100125
- 电话 010－59197078/7077/7076
- 邮箱 tcsae@tcsae.org
微信公众号
二维码
友情链接
- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
- 中华人民共和国农业农村部-MARA
- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
- 期刊界
- CNKI
- 万方数据
- 维普