<RECORD 1>
Accession number:20201008270964
Title:Construction and spatiotemporal variation of dump reclamation disturbance index
Title of translation:煤矿排土场复垦干扰指数构建及其时空分异
Authors:Xie, Miaomiao (1, 2); Gao, Shuting (1); Li, Shaoling (1); Zhou, Yan (1); Bai, Zhongke (1, 2); Zhang, Yu (3)
Author affiliation:(1) College of Land Science and Technology, China University of Geosciences, Beijing; 100083, China; (2) Key Laboratory of Land Consolidation and Rehabilitation, Ministry of Land and Resources, Beijing; 100035, China; (3) Geoshare Information Technology Co, Ltd, Beijing; 100013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:258-265
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Dumps in coal mine occupy huge areas of land and cause many problems, therefore, dumps reclamation become an important issue in ecological restoration. The reconstructed ecosystem of the reclamation dump is affected by various disturbance factors, which causes it to be unstable and prone to degradation. The disturbance influences the stability of reconstructed ecosystem and decides the success or failure of the ecological restoration in coal mine. Therefore, it is important to evaluate the recovery process of the reconstructed ecosystem. Based on the MODIS global disturbance index (MGDI) and vegetation disturbance index, which are based on MODIS data, we constructed the dump reclamation disturbance index (DRDI) by combing land surface temperature (LST) and enhanced vegetation index (EVI) using Landsat data. DRDI can provide higher spatial resolution than MGDI and VDI. EVI indicates the vegetation structure, and LST indicates the function of vegetation. The best status of reconstructed ecosystem is estimated by the maximum EVI and minimum LST, which is compared with the status of every year. DRDI is used to measure the vegetation recovery process and the degree of disturbance of vegetation in dumps. This study calculated the disturbance index of Antaibao opencast coal mine dump in Shanxi province, China for 28 years. This study combined remote sensing analysis with field validation data to analyze the spatial and temporal dynamics of characteristics for reconstructed vegetation restoration and interference. The results indicated that: in the early stage of reclamation, the areas with great disturbance showed highly spatial aggregated. The areas with disturbances had been gradually decreasing and took about 10 years for the vegetation structure and function to recover to the natural state in the reclamation dump, when the disturbed area could be reduced to the degree between 1.32% and 17.76%. DRDI could reflect the reclamation process and reveal spatial heterogeneity. The four dumps in Antaibao coal mine showed different stability periods and distribution characters of disturbance, which were influenced by dumping (coal gangue), reclamation strategy and vegetation reconstruction mode, as well as topography. Due to the spontaneous combustion of coal gangue, South Dump was more unstable than other dumps. Inner Dump began to reclaim later than other dumps but has entered a stable state relatively quickly, which was because of fine topography condition. The Western dump and its expansion area showed a degradation and great disturbance, where the surface vegetation covers mostly wasteland, grassland and cultivated land. DRDI can effectively identify the spatial extent and severity of disturbances for vegetation in reclamation dumps. DRDI is intuitive, effective and easy to implement. Its data can be easily obtained, and the calculation method is simple. It can effectively monitor the restoration properties of the reconstructed ecosystem for post-review evaluation of land reclamation. The quantitative analysis between influencing factors and disturbance index will be a key point in future research. Applying DRDI in evaluating the effect of reclamation in dumps will provide references to optimizing reclamation strategy and improving the efficiency of reclamation. For future research, DRDI can be combined with VDI to distinguish the causative factors of restoration character.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Reclamation
Controlled terms:Atmospheric temperature - Coal - Coal combustion - Coal mines - Coal reclamation - Ecosystems - Function evaluation - Land reclamation - Land surface temperature - Land use - Radiometers - Remote sensing - Restoration - Spontaneous combustion - Surface measurement - Surface properties - Topography - Vegetation
Uncontrolled terms:Disturbance index - Dump - Enhanced vegetation index - LANDSAT - Remote sensing analysis - Spatio-temporal variation - Spontaneous combustion of coals - Vegetation structure and functions
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 443.1 Atmospheric Properties - 454.3 Ecology and Ecosystems - 503.1 Coal Mines - 521.1 Fuel Combustion - 524 Solid Fuels - 921.6 Numerical Methods - 943.2 Mechanical Variables Measurements - 944.7 Radiation Measuring Instruments - 951 Materials Science
Numerical data indexing:Age 1.00e+01yr, Age 2.80e+01yr, Percentage 1.32e+00% to 1.78e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.032
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 2>
Accession number:20201008271037
Title:Increasing the real-time dynamic identification efficiency of sugarcane nodes by improved YOLOv3 network
Title of translation:改进YOLOv3网络提高甘蔗茎节实时动态识别效率
Authors:Li, Shangping (1); Li, Xianghui (1); Zhang, Ke (2); Li, Kaihua (1); Yuan, Honglei (1); Huang, Zongxiao (2)
Author affiliation:(1) School of Information Science and Engineering, Guangxi University for Nationalities, Nanning; 530006, China; (2) School of Mechanical Engineering, Guangxi University, Nanning; 530004, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:185-191
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To popularize the technology of sugarcane pre-cutting seed, and cultivation with good method, combine with the development of intelligent transverse sugarcane pre-cutting seed-cutting machine, and realize the continuous and dynamic intelligent recognition of sugarcane seed characteristics by sugarcane seed-cutting device, in this study, an intelligent recognition convolution neural network model based on improved YOLOv3 network was established by continuously and dynamically collecting the surface data of the whole sugarcane through the camera built in the black box of the sugarcane cutting machine. The real-time location and recognition of the image features of the whole sugarcane cane nodes in the input recognition system was carried out by the camera inside the system. Compared with the recognition information, the improved network timely updated the sugarcane nodes data, identified and marked the position of the sugarcane nodes, and then got real-time sugarcane nodes information through data processing, which was transmitted to the multi-tool cutting table for real-time cutting. In this paper, based on the improved YOLOv3 network, a sugarcane nodes recognition system was established. The image acquisition was carried out by the camera in the sugarcane cutting system. The video data of sugarcane was collected before the training of this network, and then the image data was processed to establish training set, validation set and test set. The training data sets of different improved models were tested and the best model was selected as the model in this paper. Through the training and test, the measured results showed that the recognition accuracy of the model for sugarcane nodes was 96.89%, the recall rate was 90.64%, average recognition accuracy AP was 90.38%, and the average recognition time of pictures was 28.7 ms. Compared with the original network, the AP was improved by 2.26 percentage point, the accuracy was decreased by 0.61 percentage point, and the recognition time was shortened by 22.8 ms. At present, the recognition of sugarcane nodes still remained in single or basic image processing and recognition, and there was still a lack of fast processing methods for the whole sugarcane image. In this study, we proposed to use the improved YOLOv3 network to recognize and locate sugarcane features, and to establish the recognition model of sugarcane nodes through network training. On the basis of the accuracy and speed of the original network identification and location, the speed of identification, detection and the recognition rate were further improved. The whole sugarcane can be identified and processed quickly in real time, which can meet the needs of various sugarcane seed cutting. Combining with the other parts of the intelligent sugarcane cutting machine system designed by our research group, the whole cutting process can be mechanized and intellectualized, which can greatly improve the quality of sugarcane cutting, reduce the labor intensity and time, and greatly improve the production efficiency. It provides a research basis for the industrialized production of sugarcane pre-cutting and realizes the sugarcane production. Continuous and real-time dynamic identification of sugarcane seeds lays the application foundation for the development of intelligent transverse cutting machine for sugarcane pre-cutting.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Molasses
Controlled terms:Cameras - Computer vision - Convolution - Convolutional neural networks - Cutting - Cutting tools - Data handling - Efficiency - Identification (control systems) - Image processing - Machinery - Models
Uncontrolled terms:Convolution neural network - Industrialized production - Intelligent recognition - Production efficiency - Real-time location - Recognition accuracy - Recognition systems - Seed characteristics
Classification code:603.2 Machine Tool Accessories - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 731.1 Control Systems - 742.2 Photographic Equipment - 822.3 Food Products - 913.1 Production Engineering
Numerical data indexing:Percentage 9.04e+01%, Percentage 9.06e+01%, Percentage 9.69e+01%, Time 2.28e-02s, Time 2.87e-02s
DOI:10.11975/j.issn.1002-6819.2019.23.023
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 3>
Accession number:20201008270982
Title:Extraction of geometric parameters of soybean canopy by airborne 3D laser scanning
Title of translation:基于机载三维激光扫描的大豆冠层几何参数提取
Authors:Guan, Xianping (1); Liu, Kuan (1); Qiu, Baijing (1); Dong, Xiaoya (1); Xue, Xinyu (2)
Author affiliation:(1) Key Laboratory of Crop Protection Engineering, Ministry of Agriculture and Rural Affairs, Jiangsu University, Zhenjiang; 212013, China; (2) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture and Rural Affairs, Nanjing; 210014, China
Corresponding author:Qiu, Baijing(qbj@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:96-103
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Accurate acquisition and analysis of crop geometric information is an important basis for the implementation of precision agriculture. Canopy height and volume are important decision parameters for variable sprayer application rate. In the field environment, the large change of ambient light has an important influence on the measurement of canopy geometry information by sensors. At the same time, there are few researches on the problems of remove the effect of ground roughness and difficulty in distinguishing individual plants due to branches and leaves crossing under the ridge planting mode of field soybean. Therefore, it is necessary to design an information acquisition system that is less affected by light conditions and an algorithm to improve the ability to extract geometric information from individual crops. In this study, a crop phenotype detection system based on airborne lidar was constructed and its accuracy was verified. A method of extracting individual plant based on local geometric feature segmentation and mean shift algorithm was proposed. In the process of soybean plant and ground classification, firstly, the local geometric features constructed in the optimal neighborhood are classified into 2D and 3D local shape features according to their dimensions. Secondly, in order to select 5 feature combinations that are strongly related to classification, all features were evaluated using Gini index algorithm, Chi-square algorithm, ReliefF algorithm, and random forest method. Finally, according to different feature combinations, a random forest classifier is selected to predict the test set data. In the process of extracting a single soybean plant, the point cloud data of different plants were used to obtain the point cloud data of a single plant using the mean shift algorithm to complete the extraction of a single soybean plant. In the process of obtaining geometric information of single plants, the height of plants was defined as the height difference from the intersection point of soybean stem and ground to the highest point of crops. In actual measurement, because the laser beam was blocked by branches and leaves, it is difficult to obtain the intersection point of soybean stem and ground, so the paper used the method of projecting the center of gravity of single point cloud to the ground fitting surface to estimate the intersection point. Furthermore, the plant height of single plant was obtained by subtracting the estimated intersection point from the maximum point. The experimental results showed that the maximum relative errors of the lidar scanning measurement system along the carrier moving direction, vertical moving direction and vertical ground direction were 0.58% (5.8 cm), -1.75% (-7.0 cm) and -1.74% (-3.4 cm), respectively. In the process of soybean crop and ground classification, the AUC (area under curve) value of the classification index ROC (receiver operating characteristic) curve was 0.994, achieving a good classification effect based on feature combination which was selected from 26 features using random forest algorithms. The relative error was 11.83% between the number of artificially counted plants and the number of manual measurements, and the distribution correlation was the highest with R=0.675 when the mean shift algorithm parameter is 20 cm. The average relative error of the height estimated method in this paper was 5.14%, which was better than RANSAC algorithm. This paper can provide reference for crop segmentation and yield statistics. Future research should focus on converting the obtained target crop information into a prescription map and storing it in a server for application in online spraying.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Classification (of information)
Controlled terms:Crops - Data handling - Data mining - Data processing - Decision trees - Errors - Extraction - Geometry - Laser beams - Lasers - Object recognition - Optical radar - Plants (botany) - Random forests
Uncontrolled terms:Average relative error - Geometric parameter - Information acquisition system - Maximum relative errors - Point cloud - Random forest algorithm - Random forest classifier - Receiver operating characteristics
Classification code:716.1 Information Theory and Signal Processing - 716.2 Radar Systems and Equipment - 723.2 Data Processing and Image Processing - 744.1 Lasers, General - 744.8 Laser Beam Interactions - 802.3 Chemical Operations - 821.4 Agricultural Products - 921 Mathematics - 961 Systems Science
Numerical data indexing:Percentage 1.18e+01%, Percentage 5.14e+00%, Size -3.40e-02m, Size -7.00e-02m, Size 2.00e-01m, Size 5.80e-02m
DOI:10.11975/j.issn.1002-6819.2019.23.012
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 4>
Accession number:20201008271038
Title:Automatic identification and counting of leaf stomata of monocotyledonous crops
Title of translation:单子叶作物叶片气孔自动识别与计数技术
Authors:Sun, Zhuangzhuang (1); Jiang, Dong (1); Cai, Jian (1); Wang, Xiao (1); Zhou, Qin (1); Huang, Mei (1); Dai, Tingbo (1); Cao, Weixing (1)
Author affiliation:(1) Regional Technique Innovation Center for Wheat Production, Ministry of Agriculture, Nanjing Agricultural University, Nanjing; 210095, China
Corresponding author:Jiang, Dong(jiangd@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:170-176
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Stomata is the dominant gate for water and gas exchange for plant leaves, and thus plays key roles in plants in response to the fluctuations of the environmental variables. Observation and counting stomata amounts is generally one of the obligatory determinants in the research of plant ecology and physiology. The classic measurement protocol of leaf stomata usually includes the capture of leaf stomata by a microscope, followed by manually identifying and counting of the target stomata. This method is well-known in disadvantages of both time and labor consuming, and of low accuracy. Although some algorithms for stomata recognition have been proposed at present, their recognition abilities showed limitation, and they could not realize the full effect of automatic recognition. Thereafter, we developed an automatic identification and counting technique based on YOLOv3, one of the high speed convolutional neural networks (CNN) algorithm in the present study. We acquired pictures of leaf stomata after the third leaf occurred and during grain filling stage of wheat (Triticum aestivum), in which, 138 pictures were taken from the method of nail polish printing, and another 117 pictures were taken from the method of portable microscopy. After that, we created separate data sets and then trained the corresponding models respectively. During the training process, we visualized the loss and average loss which were the most important training parameters, and finally stopped the training at 1 200 times. To better describe the parameters of both models, we used the key metrics to evaluate the models, such as precision, recall and F1. The precision, recall and F1 reached 0.96, 0.98 and 0.97 in the method of nail polish printing, whereas reached 0.95, 0.98 and 0.96 in the method of portable microscopy. Secondly, this algorithm could count stomata amounts accurately, and showed excellent robustness. By linear regression between the labeled and predicted stomata amounts in pictures from test sets, we found that this algorithm showed strong correlation, R<sup>2</sup> were 0.980 1 and 0.962 5, respectively. What’s more, this algorithm also showed high performance in high-throughput and real-time, since it identified stomata with a speed of 30 frames per second. With this technique, we optimized the objective identifying performance, which conferred accurate identification performance of stomata in the microscope pictures of leaf stomata. Firstly, compared with the method of nail polish printing, the method of portable microscopy showed low precision and F1, but was harmless to samples. Secondly, YOLOv3 algorithm exhibited the merits of accuracy, high efficiency, as well as real-time, long-time and dynamic detection. Thirdly, this technique was high compatible due to its power in accurately identifying stomata of other monocotyledonous crops such as barley (Hordeum vulgare), rice (Oryza sativa) and maize (Zea mays). Lastly, in order to facilitate the use of more researchers, we not only opened source of the detailed Python code, but also encapsulated the method in a relatively complete way. It could provide an interface for relevant researchers to detect their stomata photo or video files. The files in our stomata project could be consulted and downloaded in Github (https://github.com/shem123456/).<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Automatic identification
Controlled terms:Computer vision - Convolution - Convolutional neural networks - Crops - Deep learning - Deep neural networks - Ecology - Gas plants - Grain (agricultural product) - Models - Plants (botany)
Uncontrolled terms:Automatic recognition - Environmental variables - Measurement protocol - Real-time detection - Recognition abilities - Rice (oryza sativa) - Stomata counting - Training parameters
Classification code:454.3 Ecology and Ecosystems - 522 Gas Fuels - 716.1 Information Theory and Signal Processing - 723.5 Computer Applications - 821.4 Agricultural Products
DOI:10.11975/j.issn.1002-6819.2019.23.021
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 5>
Accession number:20201008271046
Title:Characteristics of runoff on biological soil crust slope in different rainfall durations
Title of translation:生物结皮坡面不同降雨历时的产流特征
Authors:Yang, Kai (1, 2); Zhao, Jun (2); Zhao, Yunge (2, 4); Zhang, Zihui (1); Sun, Hui (3); Gu, Kangmin (1); Guo, Yali (1); Wang, Shanshan (4)
Author affiliation:(1) College of Natural Resources and Environment, Northwest A&F University, Yangling; 712100, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China; (3) College of Forestry, Northwest A&F University, Yangling; 712100, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Zhao, Yunge(zyunge@ms.iswc.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:135-141
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The Loess Plateau in China is one of the most severely eroded regions of the world. Since the implementation of "Grain for Green" ecological restoration project, biological soil crusts (biocrusts) were widely distributed in this region, which significantly affected surface runoff. Numerous studies have explored the effect of biocrusts on runoff. However, the conclusions were still widely different. In the Loess Plateau region, rainfall is mostly concentrated in June to September, and the rainfall duration is not fixed, which may affect the runoff characteristics of biocrust slopes. This study investigated characteristics of runoff from biocrust slope in different rainfall durations in the Loess Plateau region by using artificial simulated rainfall experiment. The experiment was conducted in the revegetated grassland of northern Shaanxi Provence, China. The experiment site was about 80 m×20 m, and the slope gradient was approximately 15°. The biocrust types were mainly moss crust and moss cyanobacteria mixed crust in this site and their average coverage was 79.2%. The dimensions of the experimental plots were 10 m×2.1 m (length×width).Canopy of higher plants in the plots was removed with scissors. According to the range of local biocrust coverage, two treatments were set: 1) slopes with undisturbed biocrust as a high coverage biocrust (the average biocrust coverage were 79.2%); 2) the slopes with removal of a part of the biocrusts by shovels, which simulated the low biocrust cover situation (the average biocrust coverage were 43.6%). Meanwhile, ploughing plots were set as the control group. The rainfall intensity was set as 90mm/h and the duration was1 hour. The results showed that the initial runoff time of biocrust slope was significantly reduced compared to the bare soil slope. The initial runoff yield time of bare soil was 1.59-3.04 times that of the biocrust slopes. There was a significant negative correlation between biocrust coverage and initial runoff generation time; Conclusion of the influence of biocrusts on runoff yield was contradictory during the first 15 min and 60 min. For 90 mm/h rainfall intensity, runoff from biocrust slope increased by 75.42% compared to bare soil when the rainfall duration was the 15 min. While, runoff from biocrust slope was decreased by 52.42% compared to the bare soil when the rainfall lasted to 60 min; the infiltration rate of soil moisture was affected by biocrusts. The infiltration rate of bare soil slope with 60 min rainfall was 34.30% lower than that with 15 min. The infiltration rate of high coverage biocrust slope with 60 min rainfall was only 6.38% lower than that with 15 min, which may cause the difference of runoff yield between bare soil slope and biocrust slope; the effect of biocrust on slope infiltration and runoff is closely related to rainfall duration. Different periods of rainfall are likely to lead to inconsistent conclusions. Therefore, the duration of rainfall experiment considering the factors of biocrust should be no less than 45 min. The study provides scientific evidences for explaining the differences in the effect of biocrusts on infiltration and runoff, and further clarifies the hydrological effect of biocrusts in arid and semi-arid areas.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Infiltration
Controlled terms:Hydrodynamics - Landforms - Rain - Runoff - Sediments - Soil moisture
Uncontrolled terms:Arid and semi-arid areas - Artificial simulated rainfall - Biological soil crusts - Ecological restoration - Initial runoff time - Negative correlation - Runoff characteristics - Runoff coefficients
Classification code:442.1 Flood Control - 443.3 Precipitation - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics
Numerical data indexing:Percentage 3.43e+01%, Percentage 4.36e+01%, Percentage 5.24e+01%, Percentage 6.38e+00%, Percentage 7.54e+01%, Percentage 7.92e+01%, Time 2.70e+03s, Time 3.60e+03s, Time 9.00e+02s
DOI:10.11975/j.issn.1002-6819.2019.23.017
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 6>
Accession number:20201008270963
Title:Construction of reaction rate equation of biomass based on integral method improvement
Title of translation:积分方法改进的生物质热解反应速率模型构建
Authors:Liu, Xuanzuo (1); Yao, Zonglu (2); Zhao, Lixin (3); Song, Jinchun (1); Cong, Hongbin (3); Huo, Lili (3); Ren, Yawei (3)
Author affiliation:(1) School of Mechanical Engineering and Automation, Northeastern University, Shenyang; 110819, China; (2) Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing; 100081, China; (3) Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture and Rural Affairs, Chinese Academy of Agricultural Engineering, Beijing; 100125, China
Corresponding author:Yao, Zonglu(yaozonglu@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:242-249
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aiming at the problem that the temperature integral term cannot be integrated in the classical Arrhenius integral equation, a method that assumes the biomass conversion rate in the pyrolysis process as a function of time t and temperature T was suggested, making the temperature integral term can be integrated and effectively avoiding the computational errors caused by the simplification of the temperature integral term in the isoconversional integration method. The idea of combining the isoconversional method and the model fitting method to analyze the biomass pyrolysis kinetics was proposed: Using the isoconversional linear integral method to solve the reaction activation energy E based on class II thermodynamic equation, the activation energy E obtained by the model fitting method was compared with that obtained by the isoconversional method to select the optimal reaction mechanism function, then the selected mechanism function was re-substituted into the class II thermodynamic equation to obtain the value of the pre-factor A. The above analysis method was used to analyze the pyrolysis kinetics of five kinds biomass (corn cob, corn straw, sorghum straw, peanut shell and beech wood), verifying the feasibility of this analysis method. Non-isothermal thermogravimetric experiments with 7 linear heating programs were performed for each biomass, the obtained experimental data were linearly fitted based on class I and class II thermodynamic equations, respectively. The fitting correlation coefficients of the two classes of thermodynamic equations were all more than 0.95. The results showed that the activation energy E solved by class II thermodynamic equation was more sensitive to temperature, and the difference between the experimental data and the calculated value obtained by the kinetic parameters, which solved by the class II thermodynamic equation, was lower than that of the class I thermodynamic equation. Hence, the TG value calculated by the kinetic parameters of the class II thermodynamic equation was more close to the experimental data than that of the class I thermodynamic equation, and the accuracy of the kinetic parameters calculated by the class II thermodynamic equation was higher. According to the characteristics of the pyrolysis reaction that the activation energy E had a high linear fit with the logarithm of A and the activation energy with a conversion rate of 0.05-0.85 has a little fluctuation, the pyrolysis kinetic parameters solved by the isoconversional method can be simplified to a set of kinetic parameters corresponding to a specific conversion rate. Taking the conversion rate corresponding to the maximum pyrolysis rate as the dividing point, the TG values obtained from three sets of representative pyrolysis kinetic parameters (less than, equal to and higher than this point) were compared with the experimental data. The results showed that the TG values solved by the pyrolysis kinetic parameters of the maximum pyrolysis rate were closest to the experimental data. Using the kinetic parameters of the maximum pyrolysis rate as the kinetic parameters of the whole pyrolysis process can reduce the number of kinetic parameters while ensuring the calculation accuracy, thereby can reduce the computational cost of numerical simulation and provide a basis for numerical simulation of pyrolysis reactions in engineering.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Integral equations
Controlled terms:Activation analysis - Activation energy - Bioconversion - Biomass - Cost engineering - Integration - Kinetic parameters - Kinetics - Numerical models - Pyrolysis - Reaction kinetics - Temperature - Thermogravimetric analysis
Uncontrolled terms:Arrhenius equation - Calculation accuracy - Fitting correlations - Iso-conversional method - Model fitting method - Temperature integral - Thermo-gravimetric experiments - Thermodynamic equations
Classification code:641.1 Thermodynamics - 801 Chemistry - 802.2 Chemical Reactions - 911 Cost and Value Engineering; Industrial Economics - 921 Mathematics - 921.2 Calculus - 931 Classical Physics; Quantum Theory; Relativity
DOI:10.11975/j.issn.1002-6819.2019.23.030
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 7>
Accession number:20201008271031
Title:Passive regeneration characteristics and mechanism of CDPF for diesel engine
Title of translation:柴油机CDPF被动再生特性及机理分析
Authors:Chen, Zhaohui (1); Zhang, Wei (1); Li, Zehong (1); Kong, Mengxi (1); Pan, Mingzhang (2)
Author affiliation:(1) Faculty of Transportation Engineering, Yunnan Key Laboratory of Internal Combustion Engine, Kunming University of Science and Technology, Kunming; 650500, China; (2) College of Mechanical Engineering, Guangxi University, Nanning; 530004, China
Corresponding author:Zhang, Wei(koko_575@aliyun.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:80-86
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To explore the regeneration performance and mechanism of the catalyzed diesel particulate filter (CDPF), an engine bench test was carried out to study the regeneration characteristics for three groups of CDPFs with catalyst loading of 0, 530(CDPF1) and 636 g/m<sup>3</sup>(CDPF2) under endurance cycle conditions in this paper. The endurance cycle tests consist of 26 operating conditions, and each test cycle lasted 5 hours, which equivalent to the vehicle traveling 800 km on the actual road. The test results showed that exhaust pressure drop across CDPF during the test was significantly lower than that of DPF. When the inlet temperature reaches 500℃, the pressure drop between CDPF1 and CDPF2 was about 14 kPa lower than that of DPF. From the 8th operating condition of endurance cycle to the 25th, CDPF could almost completely oxidize the trapped soot. Passive regeneration consumes NO<inf>2</inf>, and the NO<inf>x</inf> concentration of CDPF1 with 530 g/m<sup>3</sup> catalyst loading was lower than that of the front end under heavy load conditions. The CDPF2 with 636 g/m<sup>3</sup> catalyst loading produced higher concentration of NO<inf>2</inf> with the increase of catalyst loading, and generated amounts of oxidation components were higher than consumed amounts of passive regeneration. Therefore, regeneration efficiency of CDPF was greatly increased compared with DPF, the regeneration efficiency for endurance cycle of CDPF1 was 87.5%, and that of the CDPF2 was 93.1%. Because the soot emitted by diesel engines have 11 kinds of polycyclic aromatic hydrocarbons, and phenanthrene is composed of 3 ring aromatics accounts for the largest proportion, so the density functional theory (DFT) in quantum chemistry was used to construct the oxidation reaction model of phenanthrene and NO<inf>2</inf> to produce CO and CO<inf>2</inf> on the Pt (111) crystal plane in the paper. DFT calculation results showed that O<inf>1</inf> atom in NO<inf>2</inf> was continuously slipped on the Pt(111) crystal plane, and chemical double bond of the N=O was gradually elongated and broken, and dissociated produced the active oxygen O<inf>1</inf>. The C=C double bond was produced by C<inf>1</inf> and C<inf>2</inf> atoms of phenanthrene radical, and the C-C single bond was elongated between C<inf>1</inf> and C<inf>10</inf> atoms. The C<inf>1</inf> atom was dissociated from phenanthrene radical after C-C bond was broken. The dissociated C<inf>1</inf> and active O<inf>1</inf> atoms continued to slip on Pt crystal plane and approach each other, gradually producing a C-O single bond and finally generating CO molecule. The activation energy of C<inf>1</inf> atom oxidized to CO was 234 kJ/mol, and reaction rate coefficient was 1.34×10<sup>18</sup>/s. When the C<inf>1</inf> atom was completely oxidized to CO<inf>2</inf>, two NO<inf>2</inf> molecules were required to dissociate, and produces two active O atoms which were O<inf>1</inf> and O<inf>2</inf>, respectively. These two active O and C<inf>1</inf> atoms were slipped on Pt crystal plane, and were close to each other to generate O=C=O chemical bond. The activation energ of C<inf>1</inf> atom oxidized to CO<inf>2</inf> was 218 kJ/mol, and reaction rate coefficient was 5.63×10<sup>16</sup>/s. Based on chemical reaction kinetic parameters calculated by DFT, a one-dimensional regeneration model of CDPF1 was constructed to calculate the exhaust pressure drop during passive regeneration, and the error range between simulation value and test value was within 3%. This also verified the accuracy of DFT calculation results. The study of combining engine bench test with DFT calculation of Soot-NO<inf>2</inf> reactions, which was not only reveals passive regeneration characteristics of soot from a macroscopic perspective, but also reflected passive regeneration process of soot from a microscopic perspective. This study can provide theoretical basis and engineering guidance for improvement of CDPF regeneration efficiency.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Catalyst regeneration
Controlled terms:Activation energy - Anthracene - Atoms - Carbon dioxide - Catalysts - Chemical bonds - Combustion - Crystals - Density functional theory - Design for testability - Diesel engines - Drops - Dust - Free radical reactions - Ionization of gases - Molecules - Nitrogen oxides - Oxidation - Platinum - Pressure drop - Quantum chemistry - Reaction rates - Road vehicles - Soot - Testing
Uncontrolled terms:Catalyzed diesel particulate filters - CDPF - Characteristics and mechanisms - Reaction rate coefficients - Regeneration efficiency - Regeneration mechanisms - Regeneration performance - Regeneration process
Classification code:451.1 Air Pollution Sources - 547.1 Precious Metals - 612.2 Diesel Engines - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 931.3 Atomic and Molecular Physics - 933.1 Crystalline Solids
Numerical data indexing:Mass_Density 5.30e-01kg/m3, Mass_Density 6.36e-01kg/m3, Percentage 3.00e+00%, Percentage 8.75e+01%, Percentage 9.31e+01%, Pressure 1.40e+04Pa, Size 8.00e+05m, Time 1.80e+04s
DOI:10.11975/j.issn.1002-6819.2019.23.010
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 8>
Accession number:20201008271023
Title:Hyperspectral remote sensing estimation of pasture crude protein content based on multi-granularity spectral feature
Title of translation:多粒度光谱特征的牧草粗蛋白含量高光谱遥感估算
Authors:Kang, Xiaoyan (1, 2); Zhang, Aiwu (1, 2)
Author affiliation:(1) Key Laboratory of 3D Information Acquisition and Application, Ministry of Education, Capital Normal University, Beijing; 100048, China; (2) Engineering Research Center of Spatial Information Technology, Ministry of Education, Capital Normal University, Beijing; 100048, China
Corresponding author:Zhang, Aiwu(zhangaw@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:161-169
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rapid and accurate estimation of crude protein (CP) content in pasture plays an important role in the monitoring and management of the forage growth on a wide range of grassland. Crude protein contents of pastures are ideal for characterization using hyperspectral data. In view of the limitation of ground and satellite remote sensing, in this paper, we attempted to achieve an accurate estimation of CP content in forage by unmanned aerial vehicle (UAV)-based hyperspectral remote sensing images with high spatial resolution of the pasture canopy. Although the hyperspectral data of the forage have a large number of bands, the reflectance of the canopy spectrum at each band contains information of various parameters which are from atomic level to plant community level. So, when estimating a physicochemical parameter using the spectral data, we may achieve low prediction accuracy because the spectra are affected by other parameters. Compared with the original spectra, multi-granularity spectral features can provide more sensitive features for inversion of chemical parameters. More importantly, multi-granularity spectral features can extract some hidden weak spectral information, which is of great significance for inversion of low-content physical and chemical indicators. However, in current inversion methods of pasture CP content, there is a lack of effective utilization of spectral multi-granularity information. In view of this, we first proposed a novel multi-granularity spectral feature extraction approach named multi-granularity spectral segmentation (MGSS) to segment each canopy spectrum into multiple spectral features. Second, by using the sequential forward selection method, sensitive components of each feature under a granularity can be selected. Finally, based on these selected components of different features, the inversion models of pasture CP content can be established using two regression methods, i.e., the stepwise multivariate linear regression (SMLR) and the partial least squares regression (PLSR). Taking a typical meadowland in Qinghai Plateau as an example, the detailed experimental analyses have been conducted. Results showed that under the same quantity sensitive components for MGSS and sensitive bands for the raw spectra, on the estimation accuracy of pasture CP content, MGSS was superior to the raw spectra. So the validity of MGSS in improving the accuracy of hyperspectral estimation of CP content in forage was verified. Specifically, under Granularity 23 (G23) of MGSS, the PLSR model achieved the best performance. Its determining coefficient (R<sup>2</sup>) was 0.937 which was 0.06 higher than that of the optimal model of the raw spectra. And the root mean square error (RMSE) and the mean relative error (MRE) were 1.906 (g/m<sup>2</sup>) and 8.82%, respectively, which were 0.75 (g/m<sup>2</sup>) and 1.37 percentage points lower than those of the optimal model of raw spectra. Moreover, on the single and combined components sensitive to CP content in forage, there were three characteristics among the selected components of MGSS, i.e., the agglomeration within the Red Edge range, the dispersion of non-Red Edge range, and the sparsity of strongly sensitive components, which can be helpful for selecting sensitive components. In conclusion, the proposed MGSS achieved the high performance estimation of CP content in forage by UAV hyperspectral imagery. And compared with the raw spectra, MGSS had better performance. This study provides a new technical means for the accurate estimation of CP content in grasslands in large areas.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Remote sensing
Controlled terms:Agriculture - Antennas - Feature extraction - Hyperspectral imaging - Indicators (chemical) - Least squares approximations - Mean square error - Proteins - Regression analysis - Spectroscopy - Spectrum analysis - Unmanned aerial vehicles (UAV)
Uncontrolled terms:Crude proteins - Forage grass - Hyperspectral remote sensing - Hyperspectral Remote Sensing Image - Multivariate linear regressions - Partial least squares regressions (PLSR) - Qinghai Lake - Spectral feature
Classification code:652.1 Aircraft, General - 801 Chemistry - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 8.82e+00%
DOI:10.11975/j.issn.1002-6819.2019.23.020
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 9>
Accession number:20201008271121
Title:Spatial distribution and cause of salinization of shallow groundwater in plain terrain of the Yarkant River Basin, Xinjiang
Title of translation:新疆叶尔羌河流域平原区浅层地下水咸化空间分布及成因
Authors:Zhang, Jie (1, 2); Zhou, Jinlong (1, 2); Nai, Weihua (3); Zeng, Yanyan (1, 2); Chen, Yunfei (1, 2); Wei, Xing (1, 2)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Xinjiang Agricultural University, Urumqi; 830052, China; (2) Xinjiang Hydrology and Water Resources Engineering Research Center, Urumqi; 830052, China; (3) No 2 Hydrogeology and Engineering Geology Party of Xinjiang Bureau of Geology and Mineral Resources Exploration and Development, Changji; 831100, China
Corresponding author:Zhou, Jinlong(zjzhoujl@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:126-134
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to understand the characteristics and causes of groundwater salinization in the plain area of Yarkant River Basin, the water quality evolution of the shallow groundwater (buried depth ≤100 m) was analyzed by means of multivariate statistics, geostatistics, remote sensing technology and geochemical methods. The groundwater pH value ranged from 6.91 to 8.07, which mainly occurred under neutral to alkaline environment in the study area. Groundwater types in single structure unconfined groundwater were mainly HCO<inf>3</inf>•SO<inf>4</inf>-Ca•Mg, SO<inf>4</inf>•HCO<inf>3</inf>-Na•Ca, and unconfined groundwater in confined area were SO<inf>4</inf>•Cl-Na•Ca and SO<inf>4</inf>•Cl-Na•Mg, while Cl•SO<inf>4</inf>-Na, SO<inf>4</inf>•Cl-Na•Ca and HCO<inf>3</inf>•SO<inf>4</inf>-Ca•Mg were dominant in shallow confined groundwater. The calculation results of salinization coefficient(SC) showed that the proportion of SC≤1, between >1 and 2, >2 in the water samples with single structure unconfined groundwater (17 groups of groundwater samples) were 47.06%, 29.41% and 23.53%, respectively, and the degree of salinization was high. The proportion of SC≤1 in unconfined groundwater of confined area (22 groups of groundwater samples) was 50.00%. The proportion of Sc between >1 and 2 was 36.36%, the proportion of SC>2 was 13.64%, and the degree of salinization was low. The SC≤1, >1-2 and > 2 of shallow confined groundwater (33 groups groundwater samples) was 42.43%, 15.14% and 42.43% respectively, which the salinization degree was the highest. Kolmogorov-Smirnov tests were carried out on Cl<sup>-</sup>, SO<inf>4</inf><sup>2-</sup>, TDS of unconfined and shallow confined groundwater, and the results obeyed normal distribution. To examine the degree of spatial correlation, the ratio of nugget to sill was advised generally. The nugget/sill≤0.25, > 0.25-0.75, and > 0.75 were the conditions in which spatial structures were supposed to be strong, moderate, and weak, respectively. In this study, the ratio of nugget to sill for all parameters of Cl<sup>-</sup>, SO<inf>4</inf><sup>2-</sup>, TDS of unconfined and shallow confined groundwater were < 0.25, suggested the strong spatial correlation for the studied regionalized variable. The trend of Cl<sup>-</sup>, SO<inf>4</inf><sup>2-</sup>, TDS in unconfined groundwater was generally low in the South and high in the North, while that of shallow confined groundwater was characterized by the distribution of high and low values. Factor analysis was carried out on 14 hydrochemical indices of 72 groups of groundwater samples. The results showed that the contribution rates of main factors F1, F2 and F3 were 49.383%, 19.528% and 13.520% respectively, and the contribution rate of cumulative variance was 82.431%. Cluster analysis showed that GW1 (controlled by hydrogeological conditions) groundwater accounted for 58.33% of the all groundwater samples, which was widely distributed and mainly affected by natural processes. The saturation indices (SI) of carbonate minerals tended to be saturated, while the SI of evaporite minerals was unsaturated. The ion concentration was mainly controlled by the dissolution of evaporite minerals. GW2 (affected by groundwater chemical environment) groundwater accounted for 15.28%, mainly distributed in grassland, and hydrochemical environment had a relatively large impact on groundwater salinization. Sodium adsorption ratio (SAR) was positively correlated with total dissolved solids (TDS) (R<sup>2</sup>=0.770), which showed that Na<sup>+</sup> in groundwater had obvious ion exchange with Ca<sup>2+</sup> and Mg<sup>2+</sup> in aquifer medium. 26.39% of the all groundwater samples belong to GW3 (affected by human activities), mainly distributed in cultivated land and construction land, and groundwater salinization was significantly affected by human activities. Unconfined groundwater was greatly affected by agricultural irrigation, domestic sewage and industrial sewage, however, the pollution degree of shallow confined groundwater was relatively low.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Hydrochemistry
Controlled terms:Alkalinity - Aquifers - Chemical analysis - Cluster analysis - Computational complexity - Factor analysis - Groundwater pollution - Groundwater resources - Hydrogeology - Ion exchange - Landforms - Minerals - Multivariant analysis - Normal distribution - Remote sensing - River pollution - Rivers - Sewage - Water quality - Watersheds
Uncontrolled terms:Agricultural irrigation - Geo-statistics - Groundwater salinizations - Hydrogeological conditions - Kolmogorov-Smirnov test - Remote sensing technology - River basins - Sodium adsorption ratio
Classification code:444.1 Surface Water - 444.2 Groundwater - 445.2 Water Analysis - 452.1 Sewage - 453 Water Pollution - 481.1 Geology - 481.2 Geochemistry - 482.2 Minerals - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723 Computer Software, Data Handling and Applications - 801.1 Chemistry, General - 802.2 Chemical Reactions - 922 Statistical Methods
Numerical data indexing:Percentage 1.35e+01%, Percentage 1.36e+01%, Percentage 1.51e+01%, Percentage 1.53e+01%, Percentage 1.95e+01%, Percentage 2.35e+01%, Percentage 2.64e+01%, Percentage 2.94e+01%, Percentage 3.64e+01%, Percentage 4.24e+01%, Percentage 4.71e+01%, Percentage 4.94e+01%, Percentage 5.00e+01%, Percentage 5.83e+01%, Percentage 8.24e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.016
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 10>
Accession number:20201008270961
Title:Water quality evaluation of Erhai drainage ditch based on improved grey-mode identification model
Title of translation:改进灰色模式识别模型评价洱海雨季灌排沟渠水质
Authors:Xie, Kun (1, 3); Luo, Yuan (1, 2, 3); Feng, Yiyang (1, 2, 3); Wu, Fan (1, 3); Wang, Guiyun (1); Zhang, Keqiang (1, 3); Shen, Shizhou (1, 3); Wang, Feng (1, 3)
Author affiliation:(1) Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin; 300191, China; (2) College of Resources and Environment, Yunnan Agricultural University, Kunming; 650201, China; (3) Dali Agro-Environmental Science Station, Ministry of Agriculture and Rural Affairs, Dali; 671004, China
Corresponding author:Wang, Feng(wangfeng_530@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:234-241
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This study investigated the comprehensive impacts of alternate distribution of farmland production and rural living units on the water quality of irrigation and drainage channels and the contribution rate of pollutants in the Erhai Basin. Different sections of typical irrigation and drainage ditches in the farmland of the Erhai Basin were selected for continuous sampling observation. Chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), NH<inf>4</inf><sup>+</sup>-N, NO<inf>3</inf><sup>-</sup>-N, total dissolved phosphorus (TDP), and particle phosphorus (PP) concentrations of runoff in different sections of the ditch were measured for water quality evaluation. The "centralization" method was used as dimensionless treatment method of data in the gray pattern recognition model. At the same time, the correlation coefficient formula based on the point-to-interval distance was introduced into the model, and the absolute difference in the model calculation was newly defined as intervals. The comprehensive average pollution index was used to calculate the proportion and weight of pollutant pollution in the runoff water quality of the ditch, and it combined the 2 models to objectively and accurately comprehensively evaluate the changes in the water quality categories of different sections of the typical irrigation and drainage ditch in the farmland. The results showed that the TP and TDP concentrations in the runoff from different sections of the typical irrigation and drainage ditch in the farming area of the watershed were continuous increased along the direction of the ditch flow. The TN and NO<inf>3</inf><sup>-</sup>-N concentrations in the runoff form different sections of the ditch showed a pattern of increasing first and then stabilizing. The NH<inf>4</inf><sup>+</sup>-N and COD concentrations in the runoff from the monitoring section of different farmland outlet sections in a typical irrigation and drainage ditch were reduced by 13.43%-57.88% and 2.88%-19.33%. The concentration in the runoff from irrigation and drainage ditches flowing through the monitoring sections of different village sections was increased. The water quality of runoff from the different sections of the ditch along the direction of the water flow were classified as III, II, IV, IV, V and V. The calculation of water quality pollutants of the ditch by the comprehensive average pollution index method showed that TN and COD in the ditch of the basin were the main factors causing water pollution. The NO<inf>3</inf><sup>-</sup>-N was a main form of TN in water body. This study can reveal the sources and contributions of nitrogen and phosphorus pollution in the Erhai Basin. By comparing 4 water quality evaluation methods of traditional gray correlation evaluation method, single factor evaluation method, comprehensive pollution index method and Nemerow pollution index method, we foud that improved water quality evaluation methods could objectively and accurately evaluate water quality. The improved water quality evaluation method is suitable for water quality evaluation of farmland irrigation and drainage ditches, and provides technological support for clarifying the main pollution factors of non-point source pollution control.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Quality control
Controlled terms:Catchments - Chemical oxygen demand - Dissolved oxygen - Farms - Flow of water - Irrigation - Nitrogen - Pattern recognition - Phosphorus - Runoff - Rural areas - Water pollution - Water pollution control - Water quality
Uncontrolled terms:Agricultural non-point source pollutions - Drainage ditches - Erhai Basin - Mode identification - Pollution index
Classification code:442.1 Flood Control - 445.2 Water Analysis - 453 Water Pollution - 453.2 Water Pollution Control - 631.1.1 Liquid Dynamics - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 913.3 Quality Assurance and Control
Numerical data indexing:Percentage 1.34e+01% to 5.79e+01%, Percentage 2.88e+00% to 1.93e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.029
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 11>
Accession number:20201008271017
Title:Development of on-line detection device for grain moisture contentusing microwave reflection method
Title of translation:基于微波反射法的谷物含水率在线检测装置研制
Authors:Zhang, Wei (1); Yang, Gang (1); Lei, Junbo (1); Liu, Chengliang (1); Tao, Jianfeng (1); Qin, Chengjin (1)
Author affiliation:(1) School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai; 200240, China
Corresponding author:Lei, Junbo(jblei@sjtu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:21-28
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Moisture content is one of the important indicators in grain harvesting, trading, storage and processing. High moisture content will lead to a series of problems of grain such as mildew, deterioration, shortened storage time, lower transaction price and higher processing cost. With the development of precision agriculture, accurate detection of grain moisture content can also accurately assess the growing situation of crops, and then provide guidance for the next season’s crop planting. Compared with the drying method, the capacitance method and the electric resistance method, the microwave method is easy to realize the non-destructive measurement of the grain moisture content, which is an important direction of moisture content detection. In the field of on-line detection of moisture content of rice and wheat in combine harvesters, foreign related research started earlier, and enterprises have commercialized, but this technology is still in the research stage in China. Aiming at the problem that the rice-wheat combine harvester is difficult to accurately measure the moisture content of wheat and rice during harvesting operation, this paper studied a non-destructive on-line detection method of grain moisture content based on microwave reflection method, established the grain moisture content measurement model, designed a non-destructive on-line detection device for grain moisture content used on rice-wheat combine harvesters. The device used a 450 MHz microwave measurement module to measure the moisture content of rice and wheat non-destructively. The voltage conversion circuit was designed to convert microwave parameters into voltage signals, and the average filtering algorithm was used for signal filtering to reduce the impact of interference factors. Finally, the moisture content detection model of rice and wheat, which was established by the calibration experiment, was used to calculate the moisture content. The calculation result was displayed on the display in real time via CAN bus communication. Due to the insufficient installation space in rice-wheat combine harvester, the structure of the detecting device was designed and optimized, and the circuit portion and the sampling mechanism were integrated in a compact structure. Based on the above theoretical research, technology development and structural design, this paper carried out laboratory static experiments and field harvesting experiments. The laboratory static experiment used rice and wheat to illustrate the establishment process of the grain moisture content detection model: 30 groups of rice and 30 groups of wheat samples were prepared, moisture contents and voltages calibration experiment was completed, the rice and wheat moisture content detection models was established and the experimental results were analyzed. The field harvesting experiment was verified the practicability and reliability of the grain moisture content detecting device with rice as the test object. The experiment results show that the performance standard deviations of the laboratory static experiment and the field harvest experiment are 0.458 3% and 1.078 0%, respectively, and the relative error are around 2.5% and 5%, respectively. Moisture content measuring range of the detection device for rice and wheat is 14%-34%, which meets the project requirements.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Grain (agricultural product)
Controlled terms:Agricultural machinery - Calibration - Capacitance - Combines - Crops - Deterioration - Harvesters - Harvesting - Low temperature drying - Microwave filters - Microwaves - Moisture - Moisture determination - Signal filtering and prediction - Structural design
Uncontrolled terms:Average filtering - Calibration experiments - Experimental study - High moisture contents - Non-destructive measurement - On-line detection method - Technology development - Wheat combine harvesters
Classification code:408.1 Structural Design, General - 701.1 Electricity: Basic Concepts and Phenomena - 703.2 Electric Filters - 711 Electromagnetic Waves - 716.1 Information Theory and Signal Processing - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 944.2 Moisture Measurements - 951 Materials Science
Numerical data indexing:Frequency 4.50e+08Hz, Percentage 1.40e+01% to 3.40e+01%, Percentage 2.50e+00%, Percentage 5.00e+00%
DOI:10.11975/j.issn.1002-6819.2019.23.003
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 12>
Accession number:20201008270975
Title:Force characteristics of gas-liquid two-phase centrifugal pump
Title of translation:气液两相离心泵受力特性分析
Authors:Luo, Xingqi (1); Yan, Sina (1); Feng, Jianjun (1); Zhu, Guojun (1); Sun, Shuaihui (1); Chen, Senlin (1)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an; 710048, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:66-72
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Centrifugal pumps are widely used in various fields because of their high head, high efficiency and simple structure. It will be accompanied by instability phenomena, such as vibration and noise, when a centrifugal pump is operated at gas-liquid two-phase conditions. Uneven force on impeller is an important reason for these unstable phenomena of pump. The variable radial force will make the bearing of pump subject to alternating stress and produce directional deflection of pump shaft, so that the clearances of seal become uneven, leading to leakage. The impeller is also moved axially by axial force. Therefore, it is very important to study the force acting on gas-liquid two-phase centrifugal pump. In this study, a gas-liquid two-phase centrifugal pump was studied by computational fluid dynamics (CFD) to analyze the unsteady force characteristics. The CFX-18.0 was used to solve the three-dimensional turbulent flow field of the gas-liquid two-phase centrifugal pump. The inhomogeneous Eulerian-Eulerian two-fluid model was used to capture the distribution of each phase and its influence on the pressure and velocity fields. The SST (Shear Stress Transmission) model was adopted as turbulence model in the process of numerical simulation. The transient characteristics of the pump under different gas volume fraction conditions were studied. The results showed that the numerical simulation results were coincident with the experimental data. IGVF affected the magnitude of the axial force. The magnitude of axial force at gas-liquid two-phase flow conditions was 2.4 times that of water single-phase flow condition. Under gas-liquid two-phase conditions, the unsteady axial force acting on the impeller was produced a large amplitude fluctuation under some frequency. And the magnitude of the amplitude was increased exponentially with the increase of the IGVF. IGVF had a great influence on the magnitude and direction of radial force. Under water single-phase condition, the magnitude of the radial force on the impeller was the largest, and the direction of radial force on the impeller's rotating circle distributed in an elliptical shape. Under gas-liquid two-phase condition, the impeller radial force magnitude changed dramatically, and the vector diagram of each working condition had an irregular polygonal distribution. IGVF affected the number of radial force fluctuation period. There were 5 wave peaks and troughs of periodic fluctuation for one impeller cycle which was the same as the number of impeller blades at the condition of 0, 1% and 7% IGVF, while it was four for the condition of 3% and 5% IGVF. IGVF also affected the radial force fluctuation of impeller. The peak value of radial force coefficient at 7% IGVF was 1.6 times that of 0 IGVF and 2.6 times that of 1% IGVF. IGVF affected the gas liquid two phase flow pattern. It was isolated bubble flow at the 1% IGVF, the flow pattern was unstable gas-pocket formed by the aggregation of some small bubbles under the3% and 5% IGVF, and the gas-pocket becomed large and more stable which occupying most of the area of the flow channel as IGVF increased to 7%. Therefore, the impeller flow field had undergone a process from stability to slight oscillation, then to drastic change and finally to stability as IGVF increased from 0 to 7%, which was accompanied by the change of radial force. In addition, the distribution law of vorticity in impeller was consistent with that of gas-liquid two-phase distribution. The large vorticity in gas accumulation area resulted in uneven pressure gradient distribution in impeller and uneven force distribution in impeller.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Two phase flow
Controlled terms:Axial flow - Centrifugal pumps - Channel flow - Computational fluid dynamics - Computer simulation - Flow fields - Flow patterns - Gases - Impellers - Liquids - Numerical models - Oscillating flow - Pumps - Shear stress - Turbulence models - Turbulent flow - Velocity - Vorticity
Uncontrolled terms:Axial forces - Gas - liquid two-phase flows - Gradient distributions - Periodic fluctuations - Radial forces - Single-phase conditions - Three dimensional turbulent flow field - Transient characteristic
Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 723.5 Computer Applications - 921 Mathematics
Numerical data indexing:Percentage 0.00e+00% to 7.00e+00%, Percentage 1.00e+00%, Percentage 3.00e+00%, Percentage 5.00e+00%, Percentage 7.00e+00%
DOI:10.11975/j.issn.1002-6819.2019.23.008
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 13>
Accession number:20201008271012
Title:Design and experiment of air-assisted high speed precision maize seed metering device
Title of translation:气送式高速玉米精量排种器设计与试验
Authors:Gao, Xiaojun (1, 2); Xu, Yang (1, 2); Zhang, Dongxing (1, 2); Yang, Li (1, 2); Lu, Bing (1, 2); Su, Yuan (1, 2); Xia, Guoyi (1, 2); Cui, Tao (1, 2)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) Key Laboratory of Soil-Machine-Plant System Technology of Ministry of Agriculture, Beijing; 100083, China
Corresponding author:Cui, Tao(cuitao850919@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:9-20
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to meet the requirements of maize precision seeding under high-speed conditions, from the working principle, we designed a high-speed precision seed metering device that could fundamentally solve the problems of poor filling performance and complex structure caused by high-speed operation. The device used the centrifugal force generated by high-speed operation to fill and clean seeds, and traditional seed stacking was changed into a gas-filled seed by means of gravity filling. Theoretical analysis and parameter design were carried out on the shape of seed tray, hole insert and seed plate. Seed supply mechanism was used for seed supply, and venturi tube was used for orderly gas blowing, and plug of type hole was matched with seed plate to fill and carry seeds, and changed width of the seed plate to clean seeds, and gravity of seeds and driving force of airflow were used for seeding. Single factor test was carried out on working speed of seed meter device, seed feeding speed and wind pressure. The qualified index, missing index and multiple index were used as test indicators to obtain the influence of various factors on seeding performance. The principle and structure of seed metering device was different from conventional seed metering device. In the case of increasing working speed of seed metering device, it did not increase missing index, but decreased and basically went to zero. When wind pressure was 130 Pa and seed feeding speed was 1 kg/min, the seeding performance was best when working speed was 9.8 km/h. When wind pressure was 130 Pa and working speed was 14.4 km/h, the seeding performance was best when seed feeding speed was 1.2 kg/min. When seed feeding speed was 1.5 kg/min and working speed was 14.3 km/h, the seeding performance was best when wind pressure was 465 Pa. In order to obtain the best performance parameter combination of seed metering device, the ternary quadratic regression orthogonal rotation combination test was carried out with above factors and test indexes, and the mathematical model between test index and test factor was established, and working principle and structure were obtained. Working speed had no significant effect on missing index for this metering device. The multi-objective optimization of the regression equation was carried out by using the response surface method. The optimal parameter range was: working speed was 9 km/h, seed feeding speed was 1.91 kg/min, and wind pressure was 492.17 Pa. Qualified index was 93.14%, missing index was 1.00%, and multiple index was 5.86%. It was verified by experiments and basically consistent with optimization results. It can be seen that working principle and structure of metering device had a low missing index, and missing index was not increased due to increase of working speed. It showed that this air-assisted high-speed maize precision seed metering device solved the problem of difficult to fill in high-speed operation, and its seed cleaning structure was simple, and could maintain good seeding performance under high-speed working conditions. It provided a reference for design and optimization of high-speed precision metering devices.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Speed
Controlled terms:Agricultural machinery - Air cleaners - Crops - Design - Feeding - Machine design - Multiobjective optimization - Plates (structural components) - Pneumatic materials handling equipment - Regression analysis - Structural dynamics - Testing - Wind effects
Uncontrolled terms:Centripetal force - Design and optimization - High Speed - Maize - Performance parameters - Precision seed-metering devices - Regression equation - Response surface method
Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 443.1 Atmospheric Properties - 451.2 Air Pollution Control - 601 Mechanical Design - 691.1 Materials Handling Equipment - 691.2 Materials Handling Methods - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
Numerical data indexing:Mass_Flow_Rate 1.67e-02kg/s, Mass_Flow_Rate 2.00e-02kg/s, Mass_Flow_Rate 2.50e-02kg/s, Mass_Flow_Rate 3.18e-02kg/s, Percentage 1.00e+00%, Percentage 5.86e+00%, Percentage 9.31e+01%, Pressure 1.30e+02Pa, Pressure 4.65e+02Pa, Pressure 4.92e+02Pa, Velocity 2.50e+00m/s, Velocity 2.72e+00m/s, Velocity 3.97e+00m/s, Velocity 4.00e+00m/s
DOI:10.11975/j.issn.1002-6819.2019.23.002
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 14>
Accession number:20201008271019
Title:Preparing and charactizing starch-based potassium releasing superabsorbent polymer, and optimizing water absorption and potassium release
Title of translation:淀粉基赋钾保水剂的制备表征与保水释钾性能优化
Authors:Bai, Wenbo (1); Shen, Huiyou (2); Liu, Hongjie (3); Lü, Guohua (1); Fan, Liren (2); Song, Jiqing (1)
Author affiliation:(1) Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing; 100081, China; (2) Faculty of Materials Science and Chemistry, China University of Geosciences (Wuhan), Wuhan; 300057, China; (3) Shangqiu Academy of Agriculture and Forestry Sciences, Shangqiu; 476000, China
Corresponding author:Song, Jiqing(songjiqing@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:151-160
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To prepare the cassava starch-based potassium releasing superabsorbent polymer (AM-SAP), an orthogonal experiment and range analysis were applied to optimize the synthesis conditions for the best water absorbency and potassium release capacity. A comprehensive feasibility study on the potassium release amount and release rate by activated muscovite (AM) sample was investigated as a function of cosolvent dosage, reaction temperature and reaction time. The water absorbency, repeated water absorbency, water holding capacity, water absorption swelling process and cumulative potassium release amount of AM-SAP samples were all compared with different AM dosages. The structural and morphological characteristics of the raw muscovite (RM), AM and AM-SAP samples were compared by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope analysis (SEM). The results showed that the RM samples were best activated as reaction temperature and time of 950℃ and 2 h, respectively, with the mass ratio of NaCl and muscovite was 2:1. Under such condition, the potassium release amount and release rate could reach by 92% and 32.4 mg/g, respectively. The maximum water absorbency of AM-SAP sample was 358 g/g in the distilled water and 155 g/g in the tap water, respectively, which was determined as the starch content, crosslinking agent, initiator, acrylamide and neutralization degree were 20%, 0.02%, 0.4%, 25% and 80%, respectively. The AM amount, that affected the water absorption and potassium release capacity of AM-SAP sample were quite different. Compared with the pure cassava starch-based superabsorbent polymer, the repeated water absorbency of AM-SAP sample was obviously larger than that of the former with the AM amount of 20%. While the cumulative potassium release amount of AM-SAP sample was increased with the increasing of AM dosage. After 9 d immersion at the temperature of 25℃, the cumulative potassium release amount and release rate were increased by 2.59 and 3.64 times, respectively. The AM-SAP sample could maintain more than 40% of the initial water content after 25 h later, even at the temperature of 40℃. The swelling process of AM-SAP sample conformed to the non-Fickian diffusion, which was determined by the diffusion of water molecules and the relaxation process of polymer chain segments. The FTIR data confirmed that AM existed in the AM-SAP in the form of physical filling, and some powder reacted with organic matter in the process of polymerization. The SEM showed that the rough surface of the AM-SAP sample was beneficial to the performance of water absorption and potassium release. It was preliminarily concluded that the AM-SAP is expected to be widely used in agricultural production due to its capacities of water retention, repeated water absorption and slow releasing and promotion of potassium.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Water absorption
Controlled terms:Agriculture - Amides - Diffusion in solids - Fourier transform infrared spectroscopy - Mica - Molecules - Plants (botany) - Potassium - Scanning electron microscopy - Sodium chloride - Starch
Uncontrolled terms:Agricultural productions - Initial water contents - Morphological characteristic - Potassium release - Structural characterization - Superabsorbent polymer - Swelling process - Water holding capacity
Classification code:482.2 Minerals - 549.1 Alkali Metals - 801 Chemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.3 Atomic and Molecular Physics
Numerical data indexing:Percentage 2.00e+01%, Percentage 2.00e-02%, Percentage 2.50e+01%, Percentage 4.00e+01%, Percentage 4.00e-01%, Percentage 8.00e+01%, Percentage 9.20e+01%, Time 7.20e+03s, Time 9.00e+04s
DOI:10.11975/j.issn.1002-6819.2019.23.019
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 15>
Accession number:20201008270993
Title:Modeling and experiment of feeding rate for full-feed peanut pickup harvester
Title of translation:全喂入花生捡拾收获机喂入量建模与试验
Authors:Wang, Shenying (1); Hu, Zhichao (1); Wu, Feng (1); Yu, Zhaoyang (1); Cao, Mingzhu (1); Gao, Xuemei (1)
Author affiliation:(1) Nanjing Institute of Agricultural Mechanization, Ministry of Agriculture and Rural Affairs, Nanjing; 210014, China
Corresponding author:Hu, Zhichao(nfzhongzi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:29-36
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problem of performance degradation and even mechanical failure caused by fluctuation of feeding rate during the operation of full-feed peanut combine harvester in China, and the lack of basic research on feeding rate of full-feed peanut combine harvester, the structure and working principle of the pickup bench of the 4HLJ-3000 full-feeding peanut combine harvester developed by the author team were analyzed in this paper. The pickup bench is mainly composed of limited depth wheel, pressure rod, slide plate, pickup elastic teeth and screw conveyor. Based on the analysis of structure and working principle, a monitoring method of feeding rate based on the torque of power input shaft of pickup bench was proposed. Through the force analysis of the pickup bench, the mathematical relationship between the power input shaft torque and the feeding rate of the pickup bench was obtained. A working condition monitoring system of the speed input, shaft speed, torque and power of the power input shaft was designed, and the system was mainly composed of sensor unit, data acquisition, and data storage analysis. The sensor unit converts the torque and speed of the power input axis of the pickup bench into frequency signals, and the data acquisition module converts the frequency signals into torque and speed values and displays them, and transmits them to the computer for storage and analysis through RS485 bus and RS485 to USB. The data of torque and rotate speed of pickup bench power input shaft, forward speed of pickup harvester and feeding rate were obtained in different operating conditions by road monitoring tests. Linear function, power function, exponential function and quadratic function fitting regression analysis were used to obtain the function indicated the change of feeding rate with various torque based on the test results. The results showed that the quadratic function model had higher fitting precision, and its determination coefficient was 0.990. The fitting curve of quadratic function was analyzed, and the results showed that when the feeding rate was less than 3 kg/s, the torque increased slowly with the increase of feeding rate, while the torque increased sharply and the rotation speed decreased with the increase of feeding rate. The model verification experiments were proposed, and the results showed that the established quadratic function model had good accuracy. The absolute deviation rate ranged from 0.42% to 2.43%, and the average deviation rate was 1.40%. The deviation rate increased with increasing the feeding rate. The field experiments also proved that there was a quadratic function relationship between feed rate and torque, and the torque deviation rate ranged from 1.90% to 3.58%, and the average deviation rate was 2.65% compared with the calculated results. This study can provide reference for the optimization design of the structure of full-feeding peanut picker and other crop pickers and the intelligent measurement and control of feed rate.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:45
Main heading:Feeding
Controlled terms:Agricultural machinery - Combines - Condition monitoring - Curve fitting - Data acquisition - Digital storage - Experiments - Exponential functions - Failure (mechanical) - Fits and tolerances - Harvesters - Models - Oilseeds - Pickups - Regression analysis - Speed - Torque
Uncontrolled terms:Condition monitoring systems - Data acquisition modules - Determination coefficients - Different operating conditions - Feeding rate - Mathematical relationship - Peanut - Performance degradation
Classification code:691.2 Materials Handling Methods - 722.1 Data Storage, Equipment and Techniques - 723.2 Data Processing and Image Processing - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 901.3 Engineering Research - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Mass_Flow_Rate 3.00e+00kg/s, Percentage 1.40e+00%, Percentage 1.90e+00% to 3.58e+00%, Percentage 2.65e+00%, Percentage 4.20e-01% to 2.43e+00%
DOI:10.11975/j.issn.1002-6819.2019.23.004
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 16>
Accession number:20201008271015
Title:Comparison of winter wheat yields estimated with UAV digital image and hyperspectral data
Title of translation:基于无人机数码影像和高光谱数据的冬小麦产量估算对比
Authors:Tao, Huilin (1, 2, 3, 4); Feng, Haikuan (1, 3, 4); Yang, Guijun (1, 3, 4); Yang, Xiaodong (1, 3, 4); Miao, Mengke (1, 3, 4, 5); Wu, Zhichao (1, 3, 4, 5); Zhai, Liting (1, 3, 4, 5)
Author affiliation:(1) Key Laboratory of Quantitative Remote Sensing in Agriculture, Ministry of Agriculture and Rural Affairs, Beijing Research Center for Information Technology in Agriculture, Beijing; 100097, China; (2) School of Geodesy and Geomatics, Anhui University of Science and Technology, Huainan; 232001, China; (3) National Engineering Research Center for Information Technology in Agriculture, Beijing; 100097, China; (4) Beijing Engineering Research Center for Agriculture Internet of Things, Beijing; 100097, China; (5) School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo; 454000, China
Corresponding author:Feng, Haikuan(fenghaikuan123@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:111-118
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Accurate estimation of crops yield is of great significance in agricultural production and has a strong guiding significance for agricultural managers. It is necessary to use an effective technical means to estimate the yield of field crops quickly and accurately. Taking winter wheat in Xiaotangshan National Precision Agricultural Research Demonstration Base as the research object, this study compared the performance of unmanned aerial vehicle (UAV) digital image and hyperspectral data in winter wheat yield estimation. The field surveys and campaigns were conducted in three typical winter wheat growth stages including flagging, flowering and filling stages. The digital images and hyperspectral data were respectively acquired by digital camera and Cubert UHD 185 Firefly imaging spectrometer, which were mounted on a UAV platform. The wheat yield data were collected during harvest. Firstly, the typical digital image indices and hyperspectral parameters were extracted from UAV digital image and hyperspectral data, respectively. Then the correlation analyses between wheat measured yield and digital image indices and hyperspectral parameters were carried out. Nine digital image indices and hyperspectral parameters with high correlation were selected for each growth stages, respectively. The selected digital image indices and hyperspectral parameters were used as modeling factors and the yield were estimated by multiple linear regression (MLR) and random forest (RF), and the models constructed by the two remote sensing data were compared to optimize the remote sensing data and model. The results showed that the digital image indices and hyperspectral parameters had significant correlation with the wheat measured yield. Among them, the correlation of the best index of different growth stages was the reflectance of the red and the best hyperspectral parameter of the three growth stages were transformed chlorophyll absorption reflectance index optimized soil adjusted vegetation index (TCARI/OSAVI), simple ratio vegetation (SR), and TCARI/OSAVI, respectively. Through the digital image indices, analyzing the effect of the modeling set, the accuracy of the MLR model was significantly better than the RF model in different growth stages, and the estimation accuracy of the two models was the highest during the filling stage and the lowest during the flagging stage. The best R<sup>2</sup> of the MLR model was 0.71 (RMSE = 730.66 kg/hm<sup>2</sup>, NRMSE = 12.79%), and the best R<sup>2</sup> of the RF model was 0.57 (RMSE = 894.16 kg/hm<sup>2</sup>, NRMSE = 15.65%), indicating that the advantages of the MLR model were more obvious. MLR and RF model verification effect and modeling effect remain the same. The performance of MLR and RF models had gradually increased to the filling stage to achieve the best. NRMSE reached 13.56% and 17.22%, respectively. The yield effect was estimated based on the spectral index. For MLR and RF models, the accuracy of model modeling was gradually improved, and the fitting effect was getting better and better. Among them, the best R<sup>2</sup> of the MLR model was 0.77 and the NRMSE was 10.32%; the best R<sup>2</sup> of the MLR model was 0.61, NRMSE was 14.79%, the estimation accuracy of MLR model was better than RF model in different growth stages. As the growth stage progresses, the verification R<sup>2</sup> gradually increased, and RMSE and NRMSE gradually decreased. This result was consistent with the effect of the modeling set, indicating that the validation effect was relatively stable. So using UAV hyperspectral remote sensing data, the estimation model of winter wheat yield established by the MLR method can quickly and easily predict the yield of crops, and can effectively monitor the growth of crops and the performance of yield estimation models in different growth stages.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Hyperspectral imaging
Controlled terms:Antennas - Crops - Decision trees - Estimation - Filling - Image analysis - Least squares approximations - Linear regression - Random forests - Reflection - Remote sensing - Unmanned aerial vehicles (UAV) - Vegetation
Uncontrolled terms:Digital image - HyperSpectral - Partial least square (PLS) - Winter wheat - Yield
Classification code:652.1 Aircraft, General - 691.2 Materials Handling Methods - 821.4 Agricultural Products - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Percentage 1.28e+01%, Percentage 1.36e+01%, Percentage 1.48e+01%, Percentage 1.57e+01%, Percentage 1.72e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.014
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 17>
Accession number:20201008271036
Title:Three dimensional point cloud reconstruction and body size measurement of pigs based on multi-view depth camera
Title of translation:多视角深度相机的猪体三维点云重构及体尺测量
Authors:Yin, Ling (1, 2); Cai, Gengyuan (2, 3); Tian, Xuhong (1); Sun, Aidong (4); Shi, Shuai (1); Zhong, Haojie (1); Liang, Shihao (1)
Author affiliation:(1) College of Mathematics and Informatics, South China Agricultural University, Guangzhou; 510642, China; (2) National Engineering Research Center for Swine Breeding Industry, Guangzhou; 510642, China; (3) College of Animal Science, South China Agricultural University, Guangzhou; 510642, China; (4) Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing; 210014, China
Corresponding author:Sun, Aidong(sunad2002@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:201-208
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Body size measurement is a major way to understand the key parameters of livestock for precision livestock farming (PLF) and effective management of large numbers of livestock. Manual measurement is one of the most commonly used methods to obtain the growth status of livestock. However, manual measurements can be time-consuming, costly, and sometimes harmful to animals and feeders. In addition, due to the lack of mature technology in effective data acquisition, robust registration and accurate estimation of multi-body parameters, non-contact measurement of live pigs is often a difficult task. Therefore, the application of automatic measurement technology of livestock and poultry body size parameters in actual breeding has great challenge. To solve these problems, a new 3D reconstruction and measurement system is proposed. Three consumer-grade depth cameras are set on the right, left and top of the data acquisition channel. When the pig passes the best shooting area of the channel, the camera synchronously obtains the point cloud data. Using filtering methods such as Gaussian curvature, outliers of three-dimensional images such as balustrade and other point clouds that do not belong to the pig contour are extracted from the original point cloud, and then the preprocessed point cloud in the three views is reconstructed based on the sample consistency (SAC), and then the pig body size parameters including body length are used. The body height, chest circumference and abdomen circumference are measured by the accurate estimation technology of body condition. In different experimental analysis, we compared 5 groups of body size measurement data at different speeds in the laboratory, and compared the body size measurement results of 25 pigs in the pig farm. In the laboratory, pig models were moved at 0, 0.3, 0.6, 0.9 and 1.2m/s. The results show that the average relative error between the body length measurement and the manual measurement is 1.77%. The average relative errors of height, chest width and abdominal circumference were 1.36%, 2.74% and 2.17%, respectively. In addition, the detection value was highly correlated with the manual measurement value of 25 pigs in the pigsty. The average relative error of body length is 2.56%. The average relative errors of height, chest width and abdominal circumference were 2.32%, 3.89% and 4.51%, respectively. In addition, in the farm, the accuracy of body size parameters is in accordance with the results of the laboratory. The experimental results show that the study is helpful to evaluate the body condition of pigs fed with concentrate and managed by breeders automatically and accurately.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Parameter estimation
Controlled terms:Agriculture - Algorithms - Anthropometry - Cameras - Data acquisition - Errors - Image processing - Image reconstruction - Mammals - Models - Three dimensional computer graphics
Uncontrolled terms:Body sizes - Data acquisition channels - Kinect V2 - Noncontact measurements - Precision livestock farming - Three dimensional images - Three-dimensional point clouds - Three-dimensional reconstruction
Classification code:461.3 Biomechanics, Bionics and Biomimetics - 723.2 Data Processing and Image Processing - 742.2 Photographic Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.36e+00%, Percentage 1.77e+00%, Percentage 2.17e+00%, Percentage 2.32e+00%, Percentage 2.56e+00%, Percentage 2.74e+00%, Percentage 3.89e+00%, Percentage 4.51e+00%, Velocity 1.20e+00m/s, Velocity 9.00e-01m/s
DOI:10.11975/j.issn.1002-6819.2019.23.025
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 18>
Accession number:20201008270992
Title:Vision pre-positioning method for litchi picking robot under large field of view
Title of translation:大视场下荔枝采摘机器人的视觉预定位方法
Authors:Chen, Yan (1, 2); Wang, Jiasheng (1, 2); Zeng, Zeqin (1, 2); Zou, Xiangjun (1, 2); Chen, Mingyou (1, 2)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou; 510642, China; (2) Key Lab of Key Technology on Agriculture Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Zou, Xiangjun(xjzou1@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:48-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Litchi picking robot is an important tool for improving the automation of litchi picking operation. The spatial position information of litchi cluster needs to be acquired when the robot picks litchi normally. In order to guide the robot moving to the picking position and improve the picking efficiency, the vision pre-positioning method of litchi picking robot under large field of view is proposed in this paper studied. Firstly, using the binocular stereo vision system composed of two industrial cameras that have been calibrated, 250 pairs of litchi cluster images under large field of view was taken in the litchi orchard in Guangzhou, the spatial positions of key litchi clusters were recorded by using a laser range finder, and the results were compared with those tested in the paper. In order to expand the sample size, the original image and the polar line correction image were randomly cropped and scaled in a small range, and the final image data set was 4 000 sheets. After that, by using LabelImg, the data set of the target detection network was created. Secondly, by using the YOLOv3 network and the DenseNet classification network, combined with the characteristics of single target and single scene of litchi cluster detection task (only for orchard environment), the network structure was optimized, a Dense Module with a depth of 34 layers and a litchi cluster detection network YOLOv3-DenseNet34 based on the Dense Module was designed. Thirdly, Because of the the complexity of the background image under large field of view, the dense stereo matching degree of the whole image is low and the effect is poor, at the same time, some litchi clusters can not appear in the public view of the image at the same time, therefore, a method for calculating sub-pixel parallax was designed, peer-to-peer sequential consistency constraint matching method was proposed. By solving the quadratic curve composed of parallax and similarity, the parallax under sub-pixel was used to calculate the spatial positions of the litchi cluster. Through the comparison with the original network of YOLOv3, the test network performance of the paper was tested, and found that the YOLOv3-DenseNet34 network improved the detection accuracy and detection speed of the litchi cluster, the mAP (mean average precision) value was 0.943, the average detection speed was 22.11 frame/s and the model size was 9.3 MB, which was 1/26 of the original network of YOLOv3. Then, the detection results of the method were compared with the results of the laser range finder. The max absolute error of the pre-positioning at the detection distance of 3 m was 36.602 mm, the mean absolute error was 23.007 mm, and the average relative error was 0.836%. Test results showed that the vision pre-positioning method studied in this paper can basically meet the requirements of vision pre-positioning under large field of view in precision and speed. And this method can provide reference for other vision pre-positioning methods under large field of view of fruits and vegetables picking.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Stereo image processing
Controlled terms:Convolutional neural networks - Errors - Geometrical optics - Image processing - Object detection - Object recognition - Orchards - Pixels - Radar equipment - Robots - Stereo vision
Uncontrolled terms:Average relative error - Binocular stereo vision system - Classification networks - Fruits and vegetables - Large field of views - Litchi picking - Robs - Sequential consistency
Classification code:716.2 Radar Systems and Equipment - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 731.5 Robotics - 741.1 Light/Optics - 741.2 Vision - 821.3 Agricultural Methods
Numerical data indexing:Percentage 8.36e-01%, Size 2.30e-02m, Size 3.00e+00m, Size 3.66e-02m
DOI:10.11975/j.issn.1002-6819.2019.23.006
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 19>
Accession number:20201008270958
Title:Regional differences and dynamic evolution of cultivated land pressure in Hubei Province
Title of translation:湖北省耕地压力的区域差异及动态演进分析
Authors:Lu, Xinhai (1, 2); Liu, Ruihong (1); Kuang, Bing (1)
Author affiliation:(1) College of Public Administration, Central China Normal University, Wuhan; 430079, China; (2) College of Public Administration, Huazhong University of Science and Technology, Wuhan; 430074, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:266-272
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to fully research the regional differences and dynamic evolution of cultivated land pressure to ensure food security in Hubei Province, the revised cultivated land pressure index was used to measure the pressure of cultivated land in Hubei Province and its 17 cities. The difference of cultivated land pressure variation in Hubei Province from time series and spatial level was analyzed. The kernel density estimation method was used to describe the dynamic evolution of cultivated land pressure. The results showed that: 1) During the period 2000-2016, the cultivated land pressure index and the minimum cultivated land area per capita showed a decrease trend. The average cultivated land pressure index was 1.011 in Hubei Province; the cultivated land pressure was warning pressure. The minimum per capita arable land area and per capita actual supply area were small. 2) During the period 2000-2016, the change of cultivated land pressure in Hubei Province is inconsistent. The temporal and spatial changes of cultivated land pressure were obvious, and the situation of cultivated land pressure was severe in the central area of Hubei Province, Wuhan in particular. The cultivated land pressure in western area was weaker than that of eastern area of Hubei Province, and the situation of cultivated land pressure in Xiangyang City was the best. The trend of cultivated land pressure in 17 urban areas was different, but the current situation of cultivated land pressure in Hubei was optimistic and the change was small. At the same time, the pressure of cultivated land in western and eastern Hubei Province was different. In the eastern region, such as Wuhan, E'zhou and Huangshi, they had higher pressures on cultivated land, but Huanggang and Xianning had better pressure of cultivated land. Only the pressure of cultivated land in Xiangyang City reached the best. The pressure on cultivated land in the other four cities was higher than medium pressure; the annual pressure of cultivated land in Shiyan City was higher than high pressure. 3) The overall level of cultivated land pressure gradually decreased during the sample survey period, but the regional gap increased, and the polarization phenomenon was quite obvious. 4) From the perspective of different regions, the overall level of cultivated land pressure in the eastern Hubei was continuously decreasing, the regional gap was large, and the polarization phenomenon was more prominent; the pressure level of cultivated land in central Hubei was low, the regional gap was not large, and the polarization was not obvious; the pressure of cultivated land in western Hubei horizontally centered, there was a regional gap, and polarization was not obvious as the eastern region.<br/> © 2019, 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:Food supply - Models - Polarization - Statistics
Uncontrolled terms:Cultivated lands - Dynamic evolution - Hubei Province - Kernel Density Estimation - Pressure index
Classification code:403 Urban and Regional Planning and Development - 822.3 Food Products - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2019.23.033
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 20>
Accession number:20201008271029
Title:Effects of super-chilled conditions on quality and shelf life of beef during long term storage
Title of translation:不同冰温条件对长期贮藏牛肉品质和货架期的影响
Authors:Chen, Xue (1); Luo, Xin (1, 2); Liang, Rongrong (1); Yang, Xiaoyin (1); Dong, Pengcheng (1); Zhu, Lixian (1); Mao, Yanwei (1); Han, Mingshan (3); Hao, Jiangang (4); Zhang, Yimin (1)
Author affiliation:(1) Lab of Beef Processing and Quality Control, College of Food Science and Engineering, Shandong Agricultural University, Tai'an; 271018, China; (2) Jiangsu Synergetic Innovation Center of Meat Production and Processing Quality and Safety Control, Nanjing; 210000, China; (3) National Beef Cattle Industrial Technology System, Tongliao Station, Tongliao; 028100, China; (4) National Beef Cattle Industrial Technology System, Wulagai Station, East Ujimqin, 026321, China
Corresponding author:Zhang, Yimin(ymzhang@sdau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:305-311
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Fresh beef is perishable product, which is an ideal substrate for the growth of spoilage microorganisms. Thus, it is essential to apply adequate preservation technologies to retard the bacterial spoilage and maintain beef quality and safety. Super-chilled storage with an intense microbial growth delay, less protein denaturation and structural damage, was considered as an advantageous technology for meat products. Currently, this technology has been successfully applied in the preservation of beef, extending the shelf life up to 20 to 30 weeks. Excellent temperature control is critical to enable a long shelf life; Subtle differences in super-chilled temperature might exert a significant effect on shelf life of meat products. The application of super-chilled storage in domestic meat industry is scarce, due to the restriction of technology and equipment in China. Temperature fluctuation is the major issue in domestic commercial super-chilled condition, which may affect the meat products quality during storage. However, little information is available looking at the effects of commercial super-chilled condition on beef quality during long term storage. Therefore, this study aimed to explore the effects of commercial super-chilled condition (-4-4℃) on beef quality during long term storage, with the comparison of the ideal super-chilled condition under lab control (-2-0℃). Physicochemical, microbial counts and sensory attributes of vacuum-packaged beef stored under two conditions were analyzed during 20 weeks. The results showed that the L*, a* and b* values increased gradually over the entire storage time for both ideal and commercial super-chilled samples. Moreover, thiobarbituric acid reactive substances (TBARS) values of both samples exhibited slight changes over time, and were in the range of 0.19-0.35 mg/kg. Noteworthy, the different growth rates for total viable counts (TVC) and lactic acid bacteria (LAB) counts were found in different storage treatments. The TVC counts of the samples stored at commercial super-chilled condition grew more rapidly as compared to that in samples under ideal super-chilled condition, reaching 7.09 lg CFU/cm<sup>2</sup> after 9 weeks. Whereas, the samples under ideal super-chilled condition were below the spoilage thresholds (7 lg CFU/cm<sup>2</sup>) during the entire storage period. For sensory evaluation, samples under ideal super-chilled condition showed better sensory attributes than those in commercial super-chilled condition at the 20th weeks of storage. One noticeable point in the present study was that samples from both storage treatments maintained high consumer acceptance (scores higher than 60) after 20 weeks storage, and exhibited longer shelf-life in term of sensory attributes. In addition, the TVB-N values of samples under commercial super-chilled condition exceeded the threshold (≤15 mg/100 g) at 9 weeks, reaching 15.59 mg/100 g. Compared to commercial super-chilled condition, ideal super-chilled condition exerted a better preservative effect for beef cuts, the TVB-N values reached 16.66 mg/100 g at 12 weeks. The present results here indicated that the acceptable shelf life of super-chilled beef cuts under ideal super-chilled and commercial super-chilled conditions were less than 12 weeks and 9 weeks, respectively, according to the national standard. Differences in temperature fluctuations during super-chilled storage and large temperature fluctuations during transportation had significant influences on beef quality and shelf life.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Quality control
Controlled terms:Bacteria - Beef - Energy storage - Lactic acid - Meats - Spoilage - Temperature distribution
Uncontrolled terms:Lactic acid bacteria - Preservation technologies - Quality and safeties - Shelf life - Spoilage microorganisms - Technology and equipments - Temperature fluctuation - Thiobarbituric acid reactive substances
Classification code:461.9 Biology - 525.7 Energy Storage - 641.1 Thermodynamics - 804.1 Organic Compounds - 822.3 Food Products - 913.3 Quality Assurance and Control
Numerical data indexing:Age 1.73e-01yr, Age 2.30e-01yr, Age 3.84e-01yr, Age 3.84e-01yr to 5.75e-01yr
DOI:10.11975/j.issn.1002-6819.2019.23.037
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 21>
Accession number:20201008271045
Title:Design and experiment of wedge churning device for pneumatic cylinder-type seed metering device for hybrid rice
Title of translation:杂交稻气力滚筒集排式排种器楔形搅种装置设计与试验
Authors:Wang, Baolong (1, 2); Wang, Zaiman (1); Luo, Xiwen (1); Zhang, Minghua (1); Fang, Longyu (1); Liu, Shuncai (1); Xu, Peng (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China; (2) College of Horticulture, Hainan University, Haikou; 570228, China
Corresponding author:Wang, Zaiman(wangzaiman@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To meet the requirement of the precise direct-seeding for hybrid rice, the study aimed to design the wedge type churning device, which on the basic of pneumatic cylinder-type seed metering device. As the shape of rice seed is slender, long and sharp, with edges, villus, and poor fluidity, the wedge-shaped churning device was designed to improve suction accuracy. The previous experimental results show that the installation of an electromagnetic vibration device at the bottom of the seed box can help the cylinder metering device to suck seeds, but it is not suitable for field use. A directional churning device and a linear churning device for a vertical disc rice pneumatic metering device was designed, the experimental results show that the directional churning device can improve the seed suction precision of the metering device according the previous research of the author’s team. According to the triaxial size of typical hybrid rice varieties, three kinds of churning devices with thickness of 1 mm, 2 mm and arc-shaped churning device with slope thickness from 1mm to 2 mm were designed, which was made of ABS plastic and fixed on the outer surface of the cylinder, with two suction holes on both sides of the churning device. The straight-line distance between the two ends of churning device is 10mm, and five groups in the cylinder axial direction, eight groups in the cylinder circumference In order to test the churning performance, the virtual simulation was investigated by means of discrete element method, the model of the seed metering device was drawing out by 3D cad design software. According to the average triaxial size, the rice seed model made by multi-spherical particles with radius from 0.2 mm to 1 mm were packed and filled in EDEM software. The mass, volume and moment of inertia were calculated automatically by EDEM model. The average normal contact force and triaxial resultant velocity towards to the cylinder of the rice seed near suction holes were compared. The average normal contact forces produced by seed agitator on rice population were respectively -1.37×10<sup>-5</sup>, -1.42×10<sup>-5</sup> and 7.54×10<sup>-6</sup> N. The results showed that the churning effect of arc-shaped churning device with slope thickness from 1mm to 2 mm was better than the others. Taking the Jingliangyou 1212 rice seeds as the experiment material, using three factors and five level orthogonal rotatory experiment for arc-shaped churning device, the influence of negative pressure of the suction chamber, rotation velocity of cylinder, and cleaning distance (distance between the cleaning device and the hole edge) on the suction performance were studied. The results showed that the prediction optimal parameters of the regression model were as follows: the negative pressure was 1.60 kPa, rotation velocity of cylinder was 10 r•min<sup>-1</sup>, the cleaning distance was 1.94 mm, with the qualified rate of 84.67%, the over sucked rate of 7.92% and rate of seed empty of 7.41%. The test results showed that the qualified rate was 86.00%, the over sucked rate was 8.47%, and the rate of seed empty was 5.53% under condition with optimal parameters. The results showed that the arc-shaped churning device with slope thickness from 1 mm to 2 mm for cylinder-type seed metering device had a significant effect on the separation, agitation and suction for the hybrid rice, which could improve the seed suction performance, and provide a reference for the further optimization.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Computer aided design
Controlled terms:ABS resins - Agricultural machinery - Cleaning - Crops - Cylinders (shapes) - Experiments - Finite difference method - Pneumatic materials handling equipment - Pneumatics - Regression analysis - Software testing
Uncontrolled terms:Churning - Cylinder circumference - Electromagnetic vibrations - Hybrid rice - Normal contact force - Resultant velocities - Seed metering devices - Virtual simulations
Classification code:632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 723.5 Computer Applications - 802.3 Chemical Operations - 815.1.1 Organic Polymers - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 901.3 Engineering Research - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 5.53e+00%, Percentage 7.41e+00%, Percentage 7.92e+00%, Percentage 8.47e+00%, Percentage 8.47e+01%, Percentage 8.60e+01%, Pressure 1.60e+03Pa, Size 1.00e-02m, Size 1.00e-03m, Size 1.00e-06m2 to 2.00e-03m2, Size 1.94e-03m, Size 2.00e-03m, Size 2.00e-04m to 1.00e-03m
DOI:10.11975/j.issn.1002-6819.2019.23.001
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 22>
Accession number:20201008270965
Title:Real time color recognition of moving raisin based on OpenCV
Title of translation:基于OpenCV的动态葡萄干色泽实时识别
Authors:Liu, Xingxing (1); Wang, Shuoshuo (1); Xu, Liming (1); Yuan, Quanchun (1); Ma, Shuai (1); Yu, Changchang (1); Niu, Cong (1); Chen, Chen (1); Yuan, Xunteng (1); Zeng, Jian (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Xu, Liming(xlmoffice@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:177-184
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to realize the automatic colour and lustre recognition of "seedless white" raisins in Turpan, Xinjiang, in this paper, OpenCV open source function library was used as an image processing tool, a multi-channel moving raisin color and lustre real-time recognition algorithm was proposed. In order to ensure the accuracy of raisin colour and lustre feature extraction, it is necessary to preprocess every image acquired in real time. In this paper, component method was used to obtain the gray scale image of each image, the gray histogram of RGB image components was obtained by OpenCV open source function library, and finally the B-channel gray scale image was selected for threshold segmentation through observation. Through the B-channel gray histogram, 55 was selected as the segmentation threshold, and the image after threshold segmentation was obtained, i.e. binary image. Through morphological operation, the binary image was processed by etching first and then expanding, and the smooth and burr free binary image of raisin was obtained. A method to remove the incomplete raisin outline at the two sides of each binary image was proposed. The complete color information of raisin was obtained by the image boundary expansion, overflow filling and image clipping of binary image. The pper and lower area mask were established, and each frame image was processed separately by the mask, the image segmentation was realized, and the raisins on the two conveyor belts was recognized at the same time, and the recognition processing efficiency was improved. The rightmost contour of upper and lower region was found by traversing every raisin contour in the image, and only the rightmost raisin was recognized in the process of processing each frame of the image (the synchronized conveyor belt was transported from left to right), so as to simplify the data processing. In HSV space, the mean value of each channel was extracted from the first raisin on the rightmost of the two synchronized conveyor belt, and 40 raisins of green, yellow and brown were tested for value taking. Statistical data were analyzed and plotted with MATLAB, the results were that the threshold value of H component was 23, and that of V component was 80, which were used to identify and sort the raisins of three colors. 150 raisins of each color were selected were selected for the validation test, and each color was divided into three groups, 50 raisins in each group, 9 groups of tests were conducted. The results showed that the average recognition accuracy of green raisins was 89.33%, that of yellow raisins was 92.00%, and that of brown raisins was 96.67%, the recognition efficiency was 21 s/100 raisins, the method was simple and effective. The recognition efficiency of this method was higher than 110 s / 100 raisins of manual sorting, but the recognition accuracy was lower than 100% of manual sorting. Compared with the existing research methods, the recognition accuracy of this method for brown raisins was higher, but the recognition accuracy for yellow and green raisins was lower. The current raisin grading equipment in the market can hardly distinguish the yellow and green raisins, the paper provides a better method to distinguish the yellow and green raisins. The raisin colour and lustre recognition algorithm based on OpenCV open source function library was feasible and accurate, the coordinate information, colour and lustre information of the identified raisins were obtained, which provided the algorithm basis for the construction of the subsequent sorting actuator and control system, and provides the reference for the commercialization of raisin colour and lustre selection.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Color image processing
Controlled terms:Belt conveyors - Binary images - Color - Efficiency - Etching - Grading - Graphic methods - Image enhancement - Image processing - Image segmentation - Mathematical morphology - Open systems - Sorting
Uncontrolled terms:Agriculture products - Color recognition - Color space - OpenCV - Raisin
Classification code:692.1 Conveyors - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 802.2 Chemical Reactions - 913.1 Production Engineering
Numerical data indexing:Percentage 1.00e+02%, Percentage 8.93e+01%, Percentage 9.20e+01%, Percentage 9.67e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.022
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 23>
Accession number:20201008270962
Title:Effects of C/N ratio of wilted maize straw on wet storage process and subsequent methane production
Title of translation:碳氮比对干黄秸秆贮存及后续甲烷产量的影响
Authors:Cui, Xian (1); Zhang, Leping (1); Sun, Hui (1); Wen, Xiaoyu (1, 2); Guo, Jianbin (1); Dong, Renjie (1, 3)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) Graduate college, Party School of the CPC Central Committee, Beijing; 100091, China; (3) Yantai Research Institute, China Agricultural University, Yantai; 264670, China
Corresponding author:Guo, Jianbin(jianbinguo@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:250-257
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In northern China, large amounts of wilted maize straw as agricultural waste are produced annually due to the cropping system, harvesting method and so on. Straw-biogas-fertilizer has become one of the promoted utilization modes in major grain-maize producing areas of northern China. Straw is anaerobically digested to produce methane while digestate (effluent of anaerobic digestion process) is utilized as organic fertilizer. Wet storage is always reported as a preferred strategy to preserve energy crops for methane production. It can control microbial activity by a combination of an anaerobic environment and a natural fermentation of sugars by lactic acid bacteria on the crop to achieve lower dry matter loss compared to hay or open-air storage. However, the C/N ratio of wilted maize straw is generally 100-60:1, not only affects the microbial activity during storage, but also is not conducive to the anaerobic digestion. In this study, the effects of adjusting the C/N ratio of wilted maize straw by adding sucrose and soybean meal on the storage quality and subsequent methane production were studied. Wilted maize straw has been stored for 60 days with five treatments, including CK group (without additives), S group (only sucrose and water were added where the water-soluble carbon content and moisture content were adjusted to 3.5% and 65%, respectively), S-SM1 group (sucrose, soybean meal and water were added where, the water-soluble carbon content, C/N ratio and moisture content were adjusted to 3.5%, 30:1 and 65%, respectively), S-SM2 group (sucrose, soybean meal and water was added where the water-soluble carbon content, C/N ratio and moisture content were adjusted to 3.5%, 25:1 and 65%, respectively), S-SM3 group (sucrose, soybean meal and water were added where the water-soluble carbon content, C/N ratio and moisture content were adjusted to 3.5%, 20:1 and 65%, respectively). The results of 60-day wet storage experiment showed that, when the C/N ratio of wilted maize straw was adjusted to 30:1, 25:1 and 20:1, there was no significant effect (P>0.05) on pH value and dry matter loss but decreased the hemicellulose content compared to S group. At the same time, the lactic acid content was increased by 19.0%, 22.2% and 31.7%, respectively. The acetic acid content was increased by 20.0%, 30.0% and 30.0%, respectively. The butyric acid content was decreased by 55.0%, 65.0% and 65.0%, respectively. The relative abundance of lactic acid bacteria (Lactobacillus, Weissella, Enterococcus, Pediococcus) was increased by 13%, 45% and 63%, respectively. The relative abundance of Clostridium was reduced to 0%. The results of LEfse analysis showed that Lactobacillus and Cellulosimicrobium become biomarker when the C/N ratio of wilted corn straw was 20:1. The results of biomethane potential test showed that, the specific methane yield of CK group, S group, S-SM1 group, S-SM2 group and S-SM3 group was increased by 5.2%, 3.7%, 3.9%, 6.1% and 10.8%, respectively, compared with treatment groups before wet storage. Simulating the anaerobic digestion performance by the modifying Gompertz equation shows that adjusting the C/N ratio of straw can reduce the lag period. In summary, by adding water-soluble carbon and protein nitrogen to adjust the C/N ratio of wilted maize straw, it can effectively improve the storage quality, biodegradability and specific methane yield of wilted corn straw. In practical engineering applications, in order to reduce the cost of the project, it is appropriate to supplement other agricultural wastes with high nitrogen content for mixed storage.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Anaerobic digestion
Controlled terms:Additives - Agricultural wastes - Bacteria - Biodegradability - Butyric acid - Carbon - Cost engineering - Crops - Effluents - Fermentation - Fertilizers - Lactic acid - Methane - Moisture - Moisture determination - Nitrogen - pH - Straw - Sugar (sucrose)
Uncontrolled terms:Anaerobic digestion process - Anaerobic environment - Biomethane potential (BMP) - C/N ratio - Digestion performance - Maize straw - Practical engineering applications - Wet storage
Classification code:452.3 Industrial Wastes - 801.1 Chemistry, General - 801.2 Biochemistry - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.4 Agricultural Products - 821.5 Agricultural Wastes - 822.3 Food Products - 911 Cost and Value Engineering; Industrial Economics - 944.2 Moisture Measurements
Numerical data indexing:Age 1.64e-01yr, Percentage 0.00e+00%, Percentage 1.00e+00%, Percentage 1.08e+01%, Percentage 1.30e+01%, Percentage 1.90e+01%, Percentage 2.00e+01%, Percentage 2.22e+01%, Percentage 3.00e+01%, Percentage 3.17e+01%, Percentage 3.50e+00%, Percentage 3.70e+00%, Percentage 3.90e+00%, Percentage 4.50e+01%, Percentage 5.20e+00%, Percentage 5.50e+01%, Percentage 6.10e+00%, Percentage 6.30e+01%, Percentage 6.50e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.031
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 24>
Accession number:20201008270968
Title:Effects of blade number on flow induced vibration and noise in centrifugal pump
Title of translation:叶片数对离心泵振动噪声性能的影响
Authors:Tan, Minggao (1); Lu, Youdong (1); Wu, Zejin (1); Wu, Xianfang (2); Liu, Houlin (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang; 212013, China; (2) School of Energy and Power Engineering, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:73-79
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The number of blades is one of the main geometric parameters of centrifugal pump, which is widely used in agricultural machinery, and it has an important influence on the vibration and noise of centrifugal pumps. Both vibration and noise can affect the centrifugal pump performance and its life, and the sources of vibration and noise may lie in hydraulic or mechanical aspects. In fact, most previous works for vibration and noise of centrifugal pumps mostly focused on theoretical and experimental studies. However, these studies seem to simulate the volute and impeller interactions only, without consideration of the leakage flow paths. The leakage flow paths between the rotating impeller and the stationary housing play an important role in centrifugal pumps. Therefore, understanding the influence of the blade number and the leakage flow paths in centrifugal pump is an urgent problem to be solved. In this paper, the vibration and sound radiation of volute under flow excitation was simulated by FEM/BEM acoustic-vibration method. The experiment was carried out to study the effects of blade number on the vibration and noise based on a centrifugal pump with a single entry and a single volute. Comparing the different performances of centrifugal pump with various blade numbers, it was found that with the increase of blade number, the head and shaft power increased gradually, and the efficiency increased first, then decreased and increased with the increase of blade number. In addition, the numerical simulation results of volute with and without leakage flow paths were compared. The vibration and noise induced by inner flow of the pump with different blade number were analyzed under design flow condition. It was found that the results of simulation were validated by the vibration acceleration of the monitoring points on volute compared with the experimental vibration acceleration. The numerical simulation method proposed in this paper could be used to predict flow-induced vibration and acoustic radiation of volutes under design conditions. The errors value of head, efficiency and shaft power between numerical calculation and experiments were within 5.06%, 5.34% and 5.68% respectively. The amplitudes of simulation with the leakage flow paths were coincident with the experimental results than the results without the leakage. The peak error between the simulation amplitude with and without leakage flow paths was 13.5%. To reveal the effects of the blade number on pressure fluctuation and vibration, the contrast with different blade numbers was considered objectively. As the number of blades decreased, the pressure fluctuation and vibration displacement of the volute of centrifugal pump increased. High amplitude regions appeared at the volute tongue, the first and second hydraulic profile of the volute and the eighth hydraulic profile were close to the diffuser. The maximum vibration displacement mainly concentrated at the eighth hydraulic profile. According to the analysis, the significant high levels of vibration velocity can mainly classify in three regions, around the tongue, between the fourth and the sixth hydraulic profile of the volute, and the eighth hydraulic profile was close to the diffuser. However, the variation of the velocity disagreed with the displacement. That meant the vibration velocity was not only relative to the displacement, but also relative to the frequency. In terms of the noise on these impeller with diverse blade number, the vibration speed and radiated sound pressure level of the volute surface first increased and then decreased with the increase of the number of blades, besides, when the impeller was five blades, the vibration speed and noise reached the maximum value. The region of high noise level mainly appears in the vertical direction. The results can provide a reference for the further analysis on vibration and noise reduction design of centrifugal pump.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Vibration analysis
Controlled terms:Acoustic noise - Acoustic wave propagation - Acoustic wave transmission - Centrifugal pumps - Computer simulation - Efficiency - Impellers - Noise abatement - Numerical methods - Numerical models - Pressure - Well pumps
Uncontrolled terms:Leakage flow - Noise - Number of blades - Numerical simulation method - Radiated sound pressure - Vibration - Vibration and noise reduction - Vibration displacements
Classification code:601.2 Machine Components - 618.2 Pumps - 723.5 Computer Applications - 751.1 Acoustic Waves - 751.4 Acoustic Noise - 913.1 Production Engineering - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics
Numerical data indexing:Percentage 1.35e+01%, Percentage 5.06e+00%, Percentage 5.34e+00%, Percentage 5.68e+00%
DOI:10.11975/j.issn.1002-6819.2019.23.009
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 25>
Accession number:20201008270966
Title:Heat and moisture transfer and heat storage and release performance of assembled soil sandwich wall in solar greenhouse
Title of translation:日光温室装配式土质夹心墙体热湿迁移及蓄放热性能
Authors:Wang, Shaojie (1, 2); Zhang, Guangpeng (1); Liu, Xin (1); Wu, Kun (1, 3); Liu, Fusheng (1); Wei, Min (2); Hu, Yuqiu (1)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Shandong Agricultural University, Tai'an; 271018, China; (2) College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an; 271018, China; (3) Shandong Transport Vocational College, Weifang; 261206, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:209-217
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solar greenhouse is a unique type of greenhouse in China. It can absorb solar energy through the back wall to achieve heat storage and release, maintain the temperature in the greenhouse to meet the growth of vegetable crops, and effectively solve the problem of winter fruit and vegetable supply in northern cold region of China. In order to solve the problems of excessive thickness, easy collapse and low land-use efficiency of traditional soil wall, an assembled heterogeneous composite soil sandwich wall was developed. Prefabricated ordinary reinforced concrete slabs and light energy-saving thermal insulation slabs were used on both sides of the wall, respectively. The thickness of the soil sandwich layer could be flexibly adjusted according to the different needs of different crops for temperature. The interior and exterior wall panels are backfilled with soil and tied with reinforcements. The exterior insulation panels can effectively prevent heat transfer. In order to deeply and systematically study the heat and moisture transfer and heat storage and release performance of assembled soil sandwich wall in solar greenhouse, and reveal the hysteretic effect of filling on the response of temperature change, indoor model tests were carried out. The test wall is 1.2 m long and 0.6 m high with a total thickness of 600 mm. CF autoclaved ceramic powder aerated concrete slab with excellent heat preservation and insulation characteristics is used outdoors with a thickness of 100 mm. The filling material in the wall is taken locally, and the cultivated land with good heat storage and heat release performance is tamped, with a thickness of 440 mm. The indoor side is made of ordinary reinforced concrete slab with a thickness of 60 mm, which is effectively supported and retained. While supporting the wall, it has high thermal conductivity and fast heat transfer. Considering the actual indoor and outdoor hygrothermal environment of solar greenhouse and the technical parameters of the self-developed controllable coupled heat and moisture test bench, two test groups were designed under seven cases. The temperature and relative humidity changes of the indoor and outdoor walls were accurately controlled by the test bench, and the temperature and humidity sensors embedded in the wall were used in advance. The data acquisition system is used to measure and analyze the steady-state distribution and transient change of temperature and relative humidity in the wall. The thermal storage and release performance of the wall is calculated and analyzed quantitatively through theoretical formula deduction. On the basis of experimental research, the numerical analysis method of thermal performance of the layered heterogeneous composite wall is revised and established. The results show that the heat and moisture transfer of the composite wall with layered heterogeneous structure is coupled but not significant; the filling in the wall keeps high humidity (more than 90%) all the time, which is conducive to the heat storage and release of the wall, and is the main heat storage and release body of the wall; the thermal insulation efficiency of the outer wall panel is remarkable, and the change of the outdoor environment affects the thermal insulation and storage performance of the wall. The heat release in the wall has a lag effect in time and space, the longest lasting time is 6 days and 6.5 hours, but the heat release in the fast exothermic period (within 4 days and 8 hours) accounts for 85.64% to 91.21% of the total heat release, and the 280 mm thick wall on the indoor side responds quickly to the change of indoor temperature. The numerical analysis method can provide reference for the design and construction of similar walls with different thickness, and has guiding significance for production. The new wall design concept is advanced. The outer wall is thermal insulation layer and the inner wall is heat storage and release layer. It has excellent heat storage and release performance, and it can be quickly assembled, reused and returned to the field in situ. It is suitable for wide application in China.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Heat transfer performance
Controlled terms:Autoclaved aerated concrete - Concrete slabs - Crops - Data acquisition - Digital storage - Energy conservation - Environmental testing - Filling - Greenhouse effect - Greenhouses - Heat storage - Humidity control - Land use - Numerical analysis - Numerical methods - Reinforced concrete - Soils - Solar energy - Solar heating - Storage (materials) - Temperature - Thermal conductivity - Thermal insulation - Vegetables
Uncontrolled terms:Assembled wall - Moisture migration - Release performance - Solar greenhouse - Walls
Classification code:403 Urban and Regional Planning and Development - 412 Concrete - 413.2 Heat Insulating Materials - 451 Air Pollution - 483.1 Soils and Soil Mechanics - 525.2 Energy Conservation - 641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 691.2 Materials Handling Methods - 694.4 Storage - 722.1 Data Storage, Equipment and Techniques - 723.2 Data Processing and Image Processing - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures - 921.6 Numerical Methods
Numerical data indexing:Age 1.10e-02yr, Age 1.64e-02yr, Percentage 8.56e+01% to 9.12e+01%, Percentage 9.00e+01%, Size 1.00e-01m, Size 1.20e+00m, Size 2.80e-01m, Size 4.40e-01m, Size 6.00e-01m, Size 6.00e-02m, Time 2.34e+04s, Time 2.88e+04s
DOI:10.11975/j.issn.1002-6819.2019.23.026
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 26>
Accession number:20201008271027
Title:Transient mathematical modeling of circulation counter-flow rice drying system
Title of translation:稻谷逆流循环干燥瞬态解析模型
Authors:Fang, Zhuangdong (1); Li, Changyou (1); Zhao, Yikun (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment Ministry, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Li, Changyou(lichyx@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:286-295
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The circulation dryer consists of drying, tempering, preheating and discharging stages, is the main equipment for rice drying in southern China. During circulation drying process, grain flows from top to bottom and returns to the top by elevator; air passes through the drying stages after being heated and carries away the vapor form grain; high temperature gas from boiler transfers heat to the air through the heating exchanger, and the flue gas passes through the heating tube in the preheating stage. Drying system may behave unexpectedly because of fluctuations of heat supply, medium flow, material flow and environmental state. In order to achieve greater drying capacity, milling quality, and energy efficiency, matching drying parameters with the system states dynamically is necessary. Due to the complexity of drying process, it is difficult to measure the system states accurately and comprehensively by sensors, therefore, it is meaningful to propose a mathematical model to predict the behavior of drying system. In this study, a transient mathematical models of various stages were developed for circulation counter-flow rice drying system based on heat and mass balance. The models consists of partial differential equations involving moisture content, grain temperature, humidity and air temperature. As the coupling of variables, analytic solutions of the PDEs could not be obtained, it was solved by finite difference method with first order upwind difference scheme. A algorithm was programmed on MATLAB and the distribution of moisture content, grain temperature, humidity and air temperature throughout drying bed varied with time was presented. The numerical simulation results showed that in counter-flow drying stages, moisture content decreased and grain temperature rise along the grain-flow, humidity increased and air temperature decreased along the air-flow; high moisture grain versus low temperature air, low moisture grain versus high temperature air, which accorded with demand of drying energy. When the operation condition was constant, moisture content alternated between descent-phase and plateau-phase with position in drying bed and time; grain temperature alternated between descent-phase and ascent-phase with position in drying bed; the maximum moisture point moved periodically in the first drying stage, and the minimum one was at the outlet of second drying stage constantly. Coefficient of variation(c.v.) of moisture distribution can be used to measure the uniformity of dried products, statistical results showed the c.v. of moisture distribution changed with time periodically, ranging from 0.006 to 0.059, and was minimum when drying system went through compete cycling time. At different operation conditions, the higher the inlet air temperature and initial moisture content, the higher the average drying rate, however, the effect of grain flow velocity on average drying rate was not significant. The model was validated by performing experiments in a circulation counter-flow rice dryer (5HP-20). The predictions of outlet moisture content and grain temperature vs. drying time were observed to be close to the measured values in the drying experiments, the root mean square error between predicted and measured values of moisture content and grain temperature were 0.99%d.b, and 0.49℃, respectively. The model can be applied to analyze and predict the circulation drying process.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Drying
Controlled terms:Air - Atmospheric temperature - Boiler circulation - Dryers (equipment) - Energy efficiency - Finite difference method - Flow velocity - Forecasting - Grain (agricultural product) - MATLAB - Mean square error - Models - Moisture - Moisture determination - Moisture meters - Plants (botany) - Preheating
Uncontrolled terms:Counter-flows - Distribution - Grain temperature - Rice - Transient model
Classification code:443.1 Atmospheric Properties - 525.2 Energy Conservation - 614.2 Steam Power Plant Equipment and Operation - 631 Fluid Flow - 642.1 Process Heating - 804 Chemical Products Generally - 821.4 Agricultural Products - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 944.1 Moisture Measuring Instruments - 944.2 Moisture Measurements
DOI:10.11975/j.issn.1002-6819.2019.23.035
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 27>
Accession number:20201008270990
Title:Optimization and experiment on key parameters of dehuller for dried mung beans
Title of translation:绿豆干法脱皮设备关键参数优化与试验
Authors:Wang, Jiannan (1, 2); Liu, Minji (1); Hu, Zhichao (1); Wei, Hai (1); Xie, Huanxiong (1)
Author affiliation:(1) Nanjing Institute for Agricultural Mechanization, Ministry of Agriculture and Rural Affairs, Nanjing; 210014, China; (2) Institute of Technology, Nanjing Agricultural University, Nanjing; 210031, China
Corresponding author:Xie, Huanxiong(nfzhongzi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:312-318
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mung bean is one of the widely cultivated crops in China, and its yield and exports account were the first in the world. However dehulling technology and operation quality of mung bean have not been significantly improved over the long term due to insufficient attention. The poor qualified dehulling rate and dehulled mung beans rate restricted the development of mung bean industry. The unreasonable working parameters (speed of dehulling roller, speed of sand drum, operation time) of the dehuller were the main reason of this problem, which had a negative impact on operation quality. In this experiment, quadratic orthogonal rotation and response surface method were used to obtain the best operation quality, and key working parameters were optimized using Design-Expert. The properties of tested mung beans were analyzed, and the results showed that the color of the mung beans was dark green. With the moisture content of the mung bean at 9.2%, the thousand seeds weight was 63.5 g, and the length, width, thickness were about 5.70, 4.18, 4.33 mm respectively, the repose angle of mung beans was 23.71°, the crushing force of 60% mung beans was about 36 N. The data analysis of the dehulling experiment showed that primary and secondary factors for qualified dehulling rate was speed of dehulling roller > operation time > speeds of sand drum. Regarding to the dehulled mung beans rate, the order was: operation time> speed of dehulling roller > speeds of sand drum. The result of interaction analysis showed that the interaction between speed of dehulling roller and operation time had a significant impact on the qualified dehulling rate, while the interactions between other parameters were not significant. The interaction between speed of dehulling roller and operation time had a significant effect on dehulled mung beans rate, and the interaction between the speed of the sand drum and operation time also had a significant effect on dehulled mung beans rate. The optimal working parameters of dehuller for dried mung beans were speed of dehulling roller of 25.20 r/min, speed of sand drum of 1642.61 r/min, and operation time of 108.8 min. With the optimal working parameters, qualified dehulling rate and dehulled mung beans rate of the dehuller were 99.72% and 86.57%, respectively. The results of verification test and optimization result were highly consistent. Production tests were carried out 20 times in the factory according to the optimization results. With the optimal parameters applied by dehuller for dried mung beans, qualified dehulling rate and dehulled mung beans rate were 99.3% and 85.6%, respectively. The results of the production verifications were very close to the results got from the previous model results, and the quality of the dehuller improved greatly. This study is helpful for the improvement of the dehuller for dried mung beans.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Speed
Controlled terms:Crops - Optimization - Physical properties - Rollers (machine components) - Sand
Uncontrolled terms:Dehuller - Interaction analysis - Key components - Mungbeans - Quadratic orthogonal rotation - Response surface method - Technology and Operations - Working parameters
Classification code:483.1 Soils and Soil Mechanics - 601.2 Machine Components - 821.4 Agricultural Products - 921.5 Optimization Techniques - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Force 3.60e+01N, Mass 6.35e-02kg, Percentage 6.00e+01%, Percentage 8.56e+01%, Percentage 8.66e+01%, Percentage 9.20e+00%, Percentage 9.93e+01%, Percentage 9.97e+01%, Rotational_Speed 1.64e+03RPM, Rotational_Speed 2.52e+01RPM, Size 4.33e-03m, Time 6.53e+03s
DOI:10.11975/j.issn.1002-6819.2019.23.038
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 28>
Accession number:20201008270960
Title:Winter environment test and ventilation window location optimization of cascading cage-rearing laying duck house
Title of translation:层叠式笼养肉鸭舍冬季环境测试及通风窗位置优化模拟
Authors:Lin, Yong (1); Bao, Encai (2); Ye, Chengzhi (1); Zhao, Wei (1); Li, Mingyang (1); Yan, Junshu (1); Huan, Hailin (1); Zou, Jibao (3); Ying, Shijia (1); Shi, Zhendan (1)
Author affiliation:(1) Institute of Animal Science, Key Laboratory of Crop and Animal Integrated Farming, Ministry of Agriculture and Rural Affairs, Nanjing; 210014, China; (2) Institute of Agricultural Facilities and Equipment, Jiangsu Academy of Agricultural Sciences, Ministry of Agriculture and Rural Affairs, Nanjing; 210014, China; (3) Ecolovo, Xintai; 271200, China
Corresponding author:Bao, Encai(baoencai1990@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:218-225
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, the meat duck industry in China is mainly dominated by small-scale free rearing. This single-layered flat rearing pattern was characterized by low density, difficulty in feces and sewage management and simple infrastructure, which was weeded out due to the intense pressure for land resources and environment protection. Meanwhile, there was an increasing scale in the development of meat duck industry and an increasing tendency in the spatial aggregation. The cascading cage-rearing laying of meat duck is the rapidly developed stereoscopic breeding pattern. Compared to the traditional duck-rearing pattern, the new meat duck rearing system has an advantage in the improved land use rate, convenient duck feces processing and reduced labor costs. However, there is an accumulation of hazardous gas, particulate matter and airborne microorganism in intensive poultry houses. Poor ventilation not only affects the air quality in poultry houses, but also significantly increases the mirco-environmental humidity, thereby degrading animal’s health and growth. Therefore, the reasonable design and well airflow organization is an important measures for the improvement of environmental quality in houses. Duck house were built at Xintai Ecological Meat Duck Research Base of Shangdong Province (35°30’N, 117°27’E). Length, width and ridge height of the meat duck house were 80.0, 13.0 and 4.0 m. Roof height was 2.6 m. Upper architectural system of the duck house was light steel, while the wall body was a brick-cement structure. 24 ventilation window (length×height= 560 mm×360 mm) were each installed in the south and north walls of duck cages. These ventilation window were evenly distributed at the upper parts of the south and north walls. The ventilation window was controlled by 100 mm-thick color steel polystyrene sandwich boards. Lower parts of the ventilation window were 1.94 m to the floor. Three layers × five columns of cascading individually cages (Length × Width × Height= 69.8 m×1.0 m×2.02 m) were installed inside the duck house. There were 67 duck cages at each layer. Fifteen Cherry Valley meat ducks were reared in an individual cage which size was 1 000 mm×1 000 mm×400 mm (Length × Width × Height). To construct the CFD model of duck house, temperature, humidity, CO<inf>2</inf> and NH<inf>3</inf> concentration in the cascading duck-rearing cages were measured. Temperature field and airflow field of the duck house were simulated and an optimal design for the air conditioning pattern of the present duck house was raised. Results of the study showed that during the test period air temperature in the duck house was 11.35-20.68℃, while the average temperature difference between the inner and outer side of the duck house was 10.86℃. The average relative humidity inside the duck house was 70.27%, slightly higher than that outside the house. Average concentrations of CO<inf>2</inf> and NH<inf>3</inf> in the house were 3 285 and 0.33 mg/m<sup>3</sup>, respectively. The average relative error between the simulated temperature field and airflow field of the original duck house and the measured results was 6.59%-8.87%, suggesting a very good consistence between the digital simulation of the constructed model and the experimental results. Air conditioning was further optimized by lowering the height of ventilation window in either wall. Results of simulation showed that the temperature range of inside the house after model optimization was 11.07-19.71℃. The fluctuation range of temperature was dramatically reduced compared to the original model, which had reduced the temperature-induced stress for ducks. The average air speeds of optimized model W1, W2 and W3 were 0.34, 0.34 and 0.31 m/s, respectively. This was more even than the original model. Results of the present study will supply theoretical evidence to the reasonable design and improvement of the environmental quality for the similar kind of duck house.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Houses
Controlled terms:Air conditioning - Air quality - Ammonia - Carbon dioxide - Computational fluid dynamics - Flow fields - Land use - Meats - Roofs - Sewage - Stereo image processing - Structural design - Temperature - Ventilation - Wages - Walls (structural partitions)
Uncontrolled terms:Airborne microorganisms - Airflow organizations - Architectural systems - Average relative error - Cascading cage-rearing laying - Environment protection - Environmental humidities - Temperature differences
Classification code:402.3 Residences - 403 Urban and Regional Planning and Development - 408.1 Structural Design, General - 408.2 Structural Members and Shapes - 451.2 Air Pollution Control - 452.1 Sewage - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 643.3 Air Conditioning - 643.5 Ventilation - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 804.2 Inorganic Compounds - 822.3 Food Products - 912.4 Personnel
Numerical data indexing:Mass_Density 3.28e-03kg/m3, Mass_Density 3.30e-07kg/m3, Percentage 6.59e+00% to 8.87e+00%, Percentage 7.03e+01%, Size 1.30e+01m, Size 2.60e+00m, Size 4.00e+00m, Velocity 3.10e-01m/s, Velocity 3.40e-01m/s
DOI:10.11975/j.issn.1002-6819.2019.23.027
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 29>
Accession number:20201008270976
Title:Prediction of stress cracks in corn kernels drying based on three-dimensional heat and mass transfer
Title of translation:基于三维湿热传递的玉米籽粒干燥应力裂纹预测
Authors:Wei, Shuo (1); Chen, Pengxiao (1); Xie, Weijun (1); Wang, Fenghe (1); Yang, Deyong (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Yang, Deyong(ydy@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:296-304
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hot air drying is one of the most widely used techniques in large-scale processing of grain. However, the existing problem of grain hot air drying is the high cracking rate, which directly reduces the product grade and storage-transportation performance. It is generally believed that the formation of grain cracks is closely related to the wet stress and thermal stress during hot air drying, since the temperature gradient and moisture gradient often lead to uneven shrinkage, which induces the formation of drying stress. According to von Mises yield criterion, when the von Mises stress is larger than its yield limit, the material will fracture or develop cracks. In this paper, corn kernels were selected as the research object due to their high cracking rate dried by hot air. In order to accurately model the changes of drying stress and predict the formation of stress cracks in corn kernels during hot air drying. Firstly, the edge contour and size parameters of corn kernel were extracted by image processing technology and used to reconstruct its three-dimensional geometric model. Then, the information of temperature, moisture and stress in corn kernels was obtained by the stress mathematical model coupled with the heat-mass transfer. Finally, the stress cracking characteristics of corn grain were predicted by comparing their von Mises stress with yield stress. The results showed that: 1) The moisture content and temperature data determined by the hot air drying experiments were good agreement with the results simulated by the heat and mass transfer mathematical model with the maximum deviation 7.28% and 9.64% respectively, which indicated that the drying model can be used to further explore the changes of temperature and moisture in corn kernels during hot air drying. 2) The simulated results showed that the temperature gradient and moisture gradient in the outer layer of corn kernels were larger than those in the inner layer during drying. The same distribution trend was also found for the wet stress, thermal stress and total stress. The average wet stress and total stress increased first and then decreased, while the thermal stress showed the opposite trend. What’s more, the thermal stress of corn kernels was obviously smaller, so corn kernels were mainly affected by wet stress during drying. 3) The simulated results of corn drying with different drying conditions (hot air temperature 40-80℃, relative humidity 12%-52%) suggested that the maximum stress of corn kernels decreased gradually during drying, which increased with the increase of hot air temperature and decreased with the increase of relative humidity at the same time. The maximum stress of corn kernels was larger than its yield stress in the early stage of drying, the stress cracking of corn kernels could be inhibited by lower hot air temperature and higher relative humidity. Accordingly, it was significant to adopt the subsection drying technology or increase tempering times in the early stage of drying. The result provide a better understanding for the evolution of drying stress and the formation of stress cracks in corn kernels during hot air drying.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Drying
Controlled terms:Atmospheric temperature - Cracks - Digital storage - Grain (agricultural product) - Heat transfer - Image processing - Mass transfer - Models - Moisture - Solar dryers - Stresses - Thermal gradients - Thermal stress - Three dimensional computer graphics - Yield stress
Uncontrolled terms:Corn kernels - Heat and mass transfer mathematical model - Higher relative humidity - Image processing technology - Moisture and heat transfers - Moisture gradient - Stress cracks - Von Mises yield criterion
Classification code:443.1 Atmospheric Properties - 641 Heat and Mass Transfer; Thermodynamics - 657.1 Solar Energy and Phenomena - 722.1 Data Storage, Equipment and Techniques - 723.2 Data Processing and Image Processing - 821.4 Agricultural Products - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 1.20e+01% to 5.20e+01%, Percentage 7.28e+00%, Percentage 9.64e+00%
DOI:10.11975/j.issn.1002-6819.2019.23.036
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 30>
Accession number:20201008270986
Title:Optimization of rotor spacing and energy consumption test for multi-rotor single arm tandem electric UAV
Title of translation:多翼单臂纵列式布局电动无人机旋翼间距优化及能耗试验
Authors:Li, Jiyu (1, 2); Zhan, Yilong (1, 2); Ou, Yangfan (1, 2); Li, Yifan (1, 2); Lan, Yubin (1, 2)
Author affiliation:(1) National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology (NPAAC), Guangzhou; 510642, China; (2) College of Engineering, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Lan, Yubin(ylan@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:87-95
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Along with the continuous development of agricultural aviation application technology, an agricultural unmanned aerial vehicle (UAV) is widely used in modern agricultural production, which is the operation platform for implementing agricultural aviation technology. Due to the characteristics of simple operation, simple structure, easy maintenance and low cost, electric multi-rotor UAV is widely used in the field of agricultural aviation. However, it has the problems of small load capacity, short continuous operation time, low operation efficiency, etc. The multi-rotor single-arm tandem structure can effectively improve the load capacity and operation capacity of the electric UAV, but the structure will lead to the increase of the size and mass of the whole machine and reduce the effective utilization rate of energy, which still needs to be optimized and improved. Rotor spacing affects the overall performance of multi-rotor single-arm tandem electric UAV, but the influence of different rotor spacing on rotor lift of multi-rotor single-arm structure has not been studied. In this paper, by setting up a test platform and taking power consumption (P) and lift (F) as test indexes, the rotors with different spacing were tested, and the optimal spacing ratio between tandem rotors was analyzed and determined. The optimal spacing ratio was verified by theoretical analysis and flight test of solid aircraft. The lift performance and energy consumption of coaxial and tandem twin rotors at different spacing were tested. The results showed that the longitudinal spacing ratio had no effect on the lift performance, while the lateral spacing ratio had an effect on the lift performance. In order to further determine the optimal lateral spacing ratio, the variation law of rotor lift with lateral spacing ratio under the double rotor tandem arrangement was tested. When the lateral spacing ratio was less than 1.8, the lower rotor lift increased with the increase of lateral spacing ratio under the same power consumption. When the lateral spacing ratio was greater than 1.8, the lift of the lower rotor tended to be stable, and the average value of the lower rotor lift relative to the loss percentage of the isolated rotor was stable within 0.70%. When the lateral spacing ratio was equal to 1.8, the average loss percentage of the rotor lift under the tandem layout was 0.66% relative to the isolated rotor lift under different power consumption. At this time, the lower rotor lift is basically the same as the isolated rotor lift, thus determining that the optimal spacing ratio of the tandem double rotor was equal to 1.8. Secondly, by testing the variation of the lift force of two rotors with different sizes and the rotor lift force with the lateral spacing ratio under the tandem layout of multiple rotors, it was concluded that 1.8 was suitable for the tandem layout mechanism with different sizes and number of rotors. In order to validate the optimal effect of the lateral spacing ratio of 1.8 on the rotor spacing of the multi-rotor single-arm tandem electric UAV, this paper compared and analyzed the performance parameters of planar and tandem aircraft of six-axis 12-rotor UAV with multi-rotor single-arm structure. The results showed that compared with the tandem model with lateral spacing ratio 1.8, the fuselage size of the planar model increases by 38.70%, while the lift difference between the two is only 1.52%. Through flight tests, the results showed that under the same load, the hovering power per unit time of the planar model decreased by only 0.06%, while the fuselage mass increased by 6.82% compared with the optimized tandem model, the fuselage size increased by 38.70%. This paper studied the optimal rotor spacing of multi-rotor single-arm electric UAV. On the premise of ensuring the energy efficiency of the UAV, the rotor spacing of the multi-rotor single-arm structure electric UAV is optimized by changing the relative positions between the rotors, so as to optimize the fuselage size and mass, improve the aerodynamic characteristics of the multi-rotor single-arm structure UAV, reduce inertia, enhance payload capacity, and thus improve the overall performance.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Rotors (windings)
Controlled terms:Agricultural machinery - Agriculture - Antennas - Costs - Electric power utilization - Energy efficiency - Energy utilization - Fuselages - Lift - Optimization - Unmanned aerial vehicles (UAV)
Uncontrolled terms:Aerodynamic characteristics - Agricultural productions - Continuous development - Energy performance - Multi-rotor single arm - Operation efficiencies - Performance parameters - Tandem
Classification code:525.2 Energy Conservation - 525.3 Energy Utilization - 651.1 Aerodynamics, General - 652.1 Aircraft, General - 704.1 Electric Components - 706.1 Electric Power Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 911 Cost and Value Engineering; Industrial Economics - 921.5 Optimization Techniques
Numerical data indexing:Percentage 1.52e+00%, Percentage 3.87e+01%, Percentage 6.00e-02%, Percentage 6.60e-01%, Percentage 6.82e+00%, Percentage 7.00e-01%
DOI:10.11975/j.issn.1002-6819.2019.23.011
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 31>
Accession number:20201008270970
Title:Effects of straw application rates on soil aggregates, soil organic carbon content and maize yield
Title of translation:秸秆还田量对土壤团聚体有机碳和玉米产量的影响
Authors:Meng, Qingying (1, 2, 3, 4); Zou, Hongtao (1, 2, 3); Han, Yanyu (1, 2, 3); Zhang, Chunfeng (4)
Author affiliation:(1) College of Land and Environment, Shenyang Agricultural University, Shenyang; 110866, China; (2) Northeast Key Laboratory of Conservation and Improvement of Cultivated Land, Ministry of Agriculture, Shenyang; 110866, China; (3) National Engineering Laboratory for Efficient Utilization of Soil Fertilizer Resources, Shenyang; 110866, China; (4) Jiamusi Branch of Heilongjiang Academy of Agricultural Sciences, Jiamusi; 154000, China
Corresponding author:Zou, Hongtao(zouhongtao2001@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:119-125
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Northeast China is an important crop production area, so the amount of crop straw in northeast China is large. Among of main utilization approaches for straw, the straw returned to soil is the most widely adopted approach in China. Returning straw to the soil is beneficial for optimizing the soil environment, preventing and controlling soil degradation, and reducing air pollution that results from burning straw. Currently, straw is returned to the soil in the following three ways: mechanical crushing with backward pressure return, direct mulching and returning straw to deep soil layers. There are many problems with the first two approaches, straw decays slowly because it has a relatively high carbon-to-nitrogen (C/N) ratio, which is not beneficial for the next crop and can decrease the rate of crop emergence. Returning straw to deep soil layers, the bottom of the soil plow layer is broken, the soil bulk density is reduced, and the soil structure is improved. Meanwhile, as straw was buried in the furrow. Crops were planted on the ridge in next season. Thus, crop roots do not directly contact the straw, which could reduce the incidence of disease caused by the harmful substances produced during straw degradation. However, the optimal amount of straw return has not been determined yet. To determine the effects of straw application rates on the soil aggregate,soil organic carbon content and maize yield under the condition of returning straw to deep soil layers,, The experiments were conducted in the experimental field of the agricultural technology popularization center of Lingyuan city, Liaoning province from 2011 to 2016. After corn harvest in October 2011, five treatments were tested: no straw application. The application of maize straw was at a rate of 6 000, 12 000, 18 000, 24 000 kg/hm<sup>2</sup>. The straw was incorporation into the subsurface of soil (>20-40 cm). Apply additional nitrogen fertilizer according to C:N=25.1. The experimental plots were arranged using a random design with three replicates, and the area of each plot was 24 m<sup>2</sup>. The aggregates amount was examined by dry and wet sieving methods. After straw application for six years, compare with CK, all treatments significantly reduced soil bulk density. The size of dry-stable aggregate and water-stable aggregate were mainly >0.25 mm, <0.25 mm, respectively. Compared with CK, the straw application treatments increased mean weight diameter (MWD) and soil organic carbon content. With the increase of straw application rate, MWD increased. The effect on aggregate SOC of surface soil (0-20 cm) was greater than that of the subsurface soil (>20-40 cm). Compared with CK, the straw application treatments increased the maize yield during 2012-2016. In general, the maize yield increased the most was the straw application amount of 12 000 kg/hm<sup>2</sup> among all treatments, so it is the recommended treatment. In conclusion, returning straw to deep soil layers can significantly improve aggregate SOC, soil structure, stability and maize yield and is a suitable agricultural practice to improve soil quality in Northeast China.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Soil quality
Controlled terms:Aggregates - Crops - Cultivation - Nitrogen fertilizers - Organic carbon
Uncontrolled terms:Agricultural practices - Agricultural technologies - Experimental plots - Maize - Mean weight diameter - Mechanical crushing - Soil organic carbon content - Water stable aggregates
Classification code:406 Highway Engineering - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.3 Agricultural Methods - 821.4 Agricultural Products
Numerical data indexing:Area 2.40e+01m2, Size 0.00e+00m to 2.00e-01m
DOI:10.11975/j.issn.1002-6819.2019.23.015
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 32>
Accession number:20201008270998
Title:Spatiotemporal variation of fertilizer utilization and its eco-economic rationality in major grain production areas of China
Title of translation:中国粮食主产区化肥施用时空特征及生态经济合理性分析
Authors:Liu, Qinpu (1); Pu, Lijie (2)
Author affiliation:(1) Research Group of Environmental Science and Engineering, Nanjing Xiaozhuang University, Nanjing; 211171, China; (2) School of Geography and Ocean Science, Nanjing University, Nanjing; 210093, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:142-150
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Studies on the spatial-temporal dynamic changes of fertilizer use and its eco-economic rationality in major grain production areas of China were made in order to provide some references for dealing with fertilizer’s non-point pollution, reduction of fertilizers and grain production safety. Based on the data of fertilizers consumption, crops sowing areas and grain yields during 1993-2017, fertilization eco-economic appropriate amount (FEAA) model and fertilization environmental safety coefficient (FESC) model were established to form the method to assess the rationalities of fertilizer use in major grain production areas of China. The results showed that the fertilization intensities in major grain areas of China increased from 205.5 kg/hm<sup>2</sup> in 1993 to 319.9 kg/hm<sup>2</sup> in 2017 and the fertilization intensities of nitrogen (N), phosphorus (P) and potassium (K) increased from 133.8, 48.0, 23.7 kg/hm<sup>2</sup> in 1993 to 162.6, 84.2, 73.2 kg/hm<sup>2</sup> in 2017, respectively. Proportion of N:P:K was from 1:0.4:0.17 in 1993 to 1:0.52:0.45 in 2017. FEAAs increased from 217.4 kg/hm<sup>2</sup> in 1993 to 300.6 kg/hm<sup>2</sup> in 2017. The fertilization intensities of N had been above the FEAA in 1993, P was above the FEAA from 2001, and K was close to its FEAA from 2009. So the higher risks of non-point pollution of N and P obviously existed. Shandong, Jiangsu and Henan Province were the highest fertilization intensity center during 1993-2017, with other sub-intensity provinces around. In 2017, Henan Provine had the highest fertilization intensity with 462 kg/hm<sup>2</sup>, while Helongjiang Province had the lowest fertilization intensity with 170 kg/hm<sup>2</sup>. Among the 13 provinces of grain production areas, 7 areas, Henan, Jiangsu, Shandong, Hubei, Hebei, Anhui and Inner Mongolia, were all individually beyond their own FEAAs with their fertilization efficiencies lower than the average in 2017, while the other 6 areas were close to or less than their FEAAs with their fertilization efficiencies higher than the average, especially Jilin and Hunan Province was with win-win development of grain production and environmental safety. In 2017, Henan belonged to eco-economic irrationality area due to overuse of fertilizers; Hebei, Jiangsu, Anhui, Shandong and Hubei Province belonged to economic rational and ecological irrational areas of fertilization; Hunan, Jilin, Liaoning and Inner Mongolia belonged to eco-economic rational areas of fertilization. Heilongjiang, Sichuan and Jiangxi Province were ecological rational and economic irrational fertilization areas because of insufficient fertilizer use. So there were great differences of fertilization intensities and rationalities in major grain production areas of China. Overall, the fertilizers were overused in China, but some areas were underused. Governments at all levels should classify the major grain production areas into different sorts of fertilization, and determine the categories of overused, rational used or insufficient used in fertilization. Guidance should be given to farmers to upgrade the grain yield and prevent fertilizer’s non-point pollution, and organic fertilizers should be encouraged to use, and the construction of fertilization standards and information services should be reinforced.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Fertilizers
Controlled terms:Agriculture - Efficiency - Grain (agricultural product) - Information services - Pollution
Uncontrolled terms:Eco-economic - Environmental safety - Grain production - Nonpoint pollutions - Organic fertilizers - Spatial temporals - Spatial-temporal changes - Spatio-temporal variation
Classification code:804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 903.4 Information Services - 913.1 Production Engineering
DOI:10.11975/j.issn.1002-6819.2019.23.018
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 33>
Accession number:20201008271049
Title:Recognition method for aggressive behavior of group pigs based on deep learning
Title of translation:群养猪侵略性行为的深度学习识别方法
Authors:Gao, Yun (1, 2); Chen, Bin (1); Liao, Huimin (1); Lei, Minggang (2, 3); Li, Xuan (1, 2); Li, Jing (1); Luo, Junjie (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China; (2) Cooperative Innovation Center for Sustainable Pig Production, Wuhan; 430070, China; (3) College of Animal Science and Technology, College of Animal Medicine, Huazhong Agricultural University, Wuhan; 430070, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:192-200
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pigs like to fight with each other to form a hierarchy relationship in groups. Aggressive behaviors, mostly fighting, are frequently found in intensive pig raising facilities. Strong aggressive behaviors can cause other pigs lack of food and water, growing slowly, wounds, sick and even dead in serious situation. This considerably reduces health and welfare of pigs and further decreases economic benefits of pig industries. Monitoring and recognizing aggressive behaviors among pig group is the first step to manage the aggressive behaviors in group pigs effectively. Traditional human recording method is time-consuming and labor-intensive. This method can’t be used 24 hours a day, 7 days a week. Machine vision technique brings an automatic monitoring method to solve this problem. In this paper, we introduced a new method for aggressive behaviors monitoring based on deep learning. The experiments were held under controlled environments, which were achieved in an environment-controlled chamber designed previously. The details of the chamber were depicted in a published paper written by our research group. Nursery pigs were fed under three different concentration levels of NH<inf>3</inf> gas, which were <3.80, 15.18, 37.95 mg/m<sup>3</sup>, with a suitable temperature of around 27℃ and the comfortable humidity between 50%-70%. Each nursery group had six pigs and were weight around 9.6 kg. During each 28 days’ experiment of three concentration levels of NH<inf>3</inf>, videos were taken from the top of the chamber. An end-to-end network, named 3D CONVNet, was proposed for aggressive behavior recognition of group pigs in this paper, which based on a C3D network and built with 3D convolution kernels. The network structure of the 3D CONVNet was improved in both width and depth dimensions. The number of main convolutional layers was increased to 19, extra batch normalization and dropout layers were added to deepen the network. Furthermore, the multi-scale feature fusion method was introduced to widen the network. This improvement had bettered the performance of the algorithm considerably. To train the 3D CONVNet, 380 aggressive (14 074 frames) and 360 none-aggressive videos (13 040 frames) were chosen from experimental videos recording in experiments of two concertation levels. These videos were randomly divided into training set and validation set, and the ratio of each set is 3:1. Another 556 aggressive videos and 510 none-aggressive videos from the three experimental batches were chosen to build the testing set. There was no overlap among training set, validation set, and testing set. Results showed a total of 981 videos, including aggressive and non-aggressive behaviors, was correctly recognized from the whole 1066 testing videos. The precision of the 3D CONVNet was proved to be 92.03% on testing set. Among them, the precision, recall rate and F1-Score for aggressive behaviors were 94.86%, 89.57%, and 92.14%, respectively. The precision for different NH<inf>3</inf> concentration experimental levels were 94.29%, 89.44%, and 85.91%, respectively, which showed the generalization performance of the 3D CONVNet. With the similar heat environments, the 3D CONVNet also showed the good performances under different illumination condition. The comparison with C3D, C3D_1 (19 layers) and C3D_2 (BN) networks resulted in 95.7% on validation set, 43.47 percent point higher than the C3D network. The recognition on single image using the 3D CONVNet was only 0.5 s, which was much faster than the other three networks. Therefore, the 3D CONVNet was effective and robust in aggressive behavior recognition among group pigs. The algorithm provides a new method and technique for aggressive behavior auto-monitoring of group pigs and helps improve establishment of auto-monitoring system in pig farms and manage level of pig industry.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Deep learning
Controlled terms:Ammonia - Behavioral research - Computer vision - Convolution - Convolutional neural networks - Deep neural networks - Learning systems - Mammals - Models - Monitoring
Uncontrolled terms:Aggressive behavior - Automatic monitoring - Behavior recognition - Controlled environment - Generalization performance - Group pigs - Illumination conditions - Method and technique
Classification code:716.1 Information Theory and Signal Processing - 723.5 Computer Applications - 804.2 Inorganic Compounds - 971 Social Sciences
Numerical data indexing:Percentage 9.20e+01%, Percentage 9.21e+01%, Percentage 9.43e+01%, Percentage 9.49e+01%, Percentage 9.57e+01%, Time 5.00e-01s, Mass 9.60e+00kg, Mass_Density 3.80e-05kg/m3, Percentage 4.35e+01%, Percentage 5.00e+01% to 7.00e+01%, Percentage 8.59e+01%, Percentage 8.94e+01%, Percentage 8.96e+01%
DOI:10.11975/j.issn.1002-6819.2019.23.024
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 34>
Accession number:20201008271001
Title:Correlation of wheat biomass and yield with UAV image characteristic parameters
Title of translation:小麦生物量及产量与无人机图像特征参数的相关性
Authors:Yang, Jun (1, 2); Ding, Feng (3); Chen, Chen (1, 2); Liu, Tao (1, 2); Sun, Chengming (1, 2); Ding, Dawei (3); Huo, Zhongyang (1, 2)
Author affiliation:(1) Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College of Yangzhou University, Yangzhou; 225009, China; (2) Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou; 225009, China; (3) Zhangjiagang Agricultural Experimental Station, Zhangjiagang; 215636, China
Corresponding author:Sun, Chengming(cmsun@yzu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:104-110
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to determine the correlation between UAV image information and wheat biomass and yield, based on the field experiments of different planting densities, different nitrogen fertilizer levels and different varieties, the RGB images of field wheat at main growth stages were obtained by using UAV aerial photography in this study. The color and texture characteristic parameter values of the wheat images were obtained by image processing, and the wheat biomass and final yield were obtained by field sampling, and then the relationship between the wheat biomass, yield and different index of color and texture feature parameters was analyzed. The results showed that the 8 color indexes such as normalized difference index (NDI), Extra green vegetation index (ExG), visible light atmospherical resistant vegetation index (VARI), extra red vegetation index (ExR), green leaf vegetation index (GLI), extra green-red difference index (ExGR), modified green-red vegetation index (MGRVI), red, green and blue vegetation index (RGBVI) and 4 texture feature parameters such as angular second moment (ASM), gontrast (CON), correlation (COR) and entropy (ENT) could be extracted from UAV images. The correlation between the biomass, yield and various color index at wheat jointing stage and booting stage was high. The correlation between all color indexes and biomass at the jointing stage reached an extremely significant level, and the correlation coefficient between ExGR and biomass was the highest, the correlation coefficient was 0.911. Except for RGBVI, all the other indexes reached a significant or extremely significant correlation at booting stage, among which MGRVI had the highest correlation and the correlation coefficient was 0.817. The correlation trend between color indexes and yield were consistent with that of biomass. The correlation between the color index and biomass and yield at early wintering stage and flowering stage were slightly lower than that at jointing stage and booting stage. Among the wheat texture parameters, only ASM and ENT at early wintering stage and CON and COR at jointing stage and CON at booting stage had a significant or extremely significant correlation with biomass, among which COR had the highest correlation (negative correlation) and the correlation coefficient was -0.574. CON and COR at jointing stage and CON, COR and ENT at booting stage had a significant or extremely significant correlation with yield, among which COR at jointing stage had the highest correlation (negative correlation) with the correlation coefficient of -0.530. After combining color index and the texture feature parameters, the correlation of these parameters with wheat biomass and yield were all improved. Among them, the biomass correlation increased by 0.27%, 0.11%, 8.81% and 2.65% respectively in the 4 stages, and the yield correlation increased by 7.05%, 0.12%, 0.58% and 0.12% respectively in the 4 stages. Therefore, combining the color index of UAV image with the texture feature parameters can improve the estimation accuracy of wheat biomass and yield.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Color image processing
Controlled terms:Aerial photography - Antennas - Biomass - Color - Image enhancement - Image texture - Nitrogen fertilizers - Textures - Unmanned aerial vehicles (UAV) - Vegetation
Uncontrolled terms:Color index - Digital image - Textural feature - Wheat - Yield
Classification code:652.1 Aircraft, General - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 742.1 Photography - 804 Chemical Products Generally
Numerical data indexing:Percentage 2.65e+00%, Percentage 2.70e-01%, Percentage 5.80e-01%, Percentage 7.05e+00%, Percentage 8.81e+00%, Percentage 1.10e-01%, Percentage 1.20e-01%
DOI:10.11975/j.issn.1002-6819.2019.23.013
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 35>
Accession number:20201008271014
Title:Coupling control strategy and test for off-centered shaft steering mechanisms of agricultural flexible chassis
Title of translation:农用柔性底盘偏置轴转向机构联动耦合控制策略及试验
Authors:Qu, Jiwei (1); Guo, Kangquan (1, 2); Song, Shujie (3); Van-Cuong, Tran (4); Li, Yining (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) Shaanxi Engineering Research Centre for Agriculture Equipment, Yangling; 712100, China; (3) College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an; 710119, China; (4) College of Electronic Engineering, Vietnam Russia Vocational Training College No 1, Phuc Yen City; 15910, Viet Nam
Corresponding author:Guo, Kangquan(jdgkq@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:55-65
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agricultural flexible chassis (FC) is a kind of in-wheel motor driving electric vehicle applied for greenhouse. The FC is composed of 4 identical off-centered shaft mechanisms, which can be controlled independently. Through this kind of mechanism, the FC can achieve various motion types. However, it is difficult to maintain the linkage relationship between the 2 front off-centered shaft mechanisms when the FC is in front wheel steering motion, and hard to accomplish smoothly turning. In order to solve this problem, a coupling control strategy for linkage motion was proposed in this study. Firstly, the contour error of the 2 wheel steering angle was deduced based on the Ackermann steering geometry and the cross-coupling control principle. To reduce the contour error during steering, a fuzzy PID control algorithm was designed, which could realize parameters self-tuning. As the electromagnetic friction lock was controlled by pulse width modulation (PWM) signal, the duty cycle of the PWM signal had to be adjusted according to turning situation. Thus, a fuzzy logic method was then introduced to regulate the duty cycle. Namely, the PWM signal duty cycle can be in line with the steering wheel signal size and its change rate, and the motion of the electromagnetic friction lock can match the steering speed of the off-center shaft mechanism. In this way, the coupling control of the 2 front off-centered shaft mechanisms can be achieved. The control strategy was then verified through simulation based on MATLAB/Simulink. To further verify the effectiveness of the control strategy, the control program was loaded into the steering system hardware, and tests were carried out on hard surface road. According to the traditional vehicle steering test methods, step steering test, snake steering test and random steering test were conducted. The effects of front wheel steering under the steering angle allocation control method were compared with coupling control strategy. The simulation results demonstrated that the proposed control strategy was effective and feasible. The test results on hard surface road showed that the FC had a fast steering response in step steering test. The response time of step steering was 0.8s and overshoot was 1.3° under coupling control method during front wheel steering of the FC. The overshoot under allocation control was larger than coupling control and its fluctuation was notable. From the results of the snake steering and random steering, it was obviously that the steering angles of the left and the right front wheels had good tracking performance for their target angles, respectively. The opening and closing of electromagnetic friction lock can match the steering motion of the electric wheel well. The maximum and average following errors of 3 steering modes were less than those under the allocation control method. The maximum and average contour errors of the linkage motion were 1.2° and 0.6° for step steering, 1.1° and 0.6° for snake steering, as well as 1.0° and 0.5° for random steering, respectively. All these errors were also smaller than the allocation control. Under the coupling control, the maximum steering error between simulation and test was 2.2°, and the contour error trend of them was consistent. The simulation model was reasonable and effective. The contour errors of the allocation control in these 3 kinds of tests had more fluctuations and larger range of fluctuations than coupling control. The steering performance under coupling control strategy was obviously better than the allocation control method. The steering angles of the 2 front wheels had maintained Ackerman steering geometry well. The coupling linkage control strategy proposed in this paper has good effectiveness and feasibility. This research can provide references for steering control or other applications of the FC.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Automobile steering equipment
Controlled terms:Agricultural machinery - Agriculture - Algorithms - Chassis - Control engineering - Friction - Fuzzy logic - Locks (fasteners) - MATLAB - Pulse width modulation - Random errors - Roads and streets - Software testing - Steering - Surface testing - Testing - Three term control systems - Tuning - Voltage control - Wheels
Uncontrolled terms:Coupling controls - Cross-coupling control - Front-wheel steering - Fuzzy - pid controls - Linkage motion - Parameters self-tuning - Steering performance - Wheel steering angle
Classification code:406.2 Roads and Streets - 601.2 Machine Components - 662.4 Automobile and Smaller Vehicle Components - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723.5 Computer Applications - 731.1 Control Systems - 731.3 Specific Variables Control - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment
Numerical data indexing:Time 8.00e-01s
DOI:10.11975/j.issn.1002-6819.2019.23.007
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 36>
Accession number:20201008270987
Title:Evolution on trade-offs and synergy of multifunction of rural landscape in metropolitan suburbs
Title of translation:都市郊区乡村景观多功能权衡-协同关系演变
Authors:Ren, Guoping (1, 2); Liu, Liming (2); Li, Hongqing (3); Yuan, Chengcheng (2)
Author affiliation:(1) College of Urban Management, Hunan City University, Yiyang; 413000, China; (2) College of Land Science and Technology, China Agricultural University, Beijing; 100193, China; (3) School of Public Administration, Hohai University, Nanjing; 211100, China
Corresponding author:Liu, Liming(liulm@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:273-285
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The rural landscape function has obvious temporal and spatial heterogeneity, and exploring the relationship between landscape functions has become the focus of landscape ecology research. Aiming at the scientific representation of landscape function and the quantification of landscape multifunctional relationship, taking Qingpu district of Shanghai as an example, 6 kinds of landscape functions were constructed according to the functional framework of "production, life and ecology". Based on the data from 1980 to 2015, the variation characteristics of multi-functional trade-off and synergy relationships of rural landscape in 184 administrative villages in this area were studied by using the method of Spearman rank correlation coefficient analysis and bivariate spatial autocorrelation. The following results are obtained: 1) the agricultural production function of urban suburbs cannot replace the function of economic development. The economic development function of Qingpu district has become the leading functional. 2) The spatial and temporal differences of the multi-functional trade-off and synergy relationships of rural landscape in Qingpu district from 1980 to 2015 were significant. The production function- living function is led by the cooperative relationship, the space was spread along the central axis, the production function- ecological function was dominated by the trade-off relationship, the space was spread from the middle to the east, and the living function -ecological function trade-off the cooperative relationship was more balanced, The trade-off relationship was spread from the middle to the east and the synergy was spread from the west to the north and south. The contradiction between agricultural production function - economic development function (EDF), economic development function- ecological regulation function (ERF)/ environmental maintain function (EMF) was the inevitable contradiction in this area, and the economic development of this area was realized at the expense of ecological environment. There was a significant trade-off relationship between the EDF and landscape aesthetic function (LAF), and the pattern of the relationship between the two was the synergy of the eastern trade-off west, and the number of weighing areas was increasing. The relationship between EDF and spatial bearing function presents the pattern of eastern trade-off and western coordination, and the cooperative relationship area showed an increasing trend. The trade-off area between LAF-ERF/EMF was concentrated in Qingdong area, and the cooperative area was distributed in Qingxi area, and the number of weighing area increases at first and then decreases. The synergy area decreases at first and then increases. 3) The analysis method of temporal and spatial combination can accurately and comprehensively reflect the evolution characteristics of multi-functional trade-offs & synergies relationships of multifunctional rural landscape. The correlation analysis of multi-function and single time dimension of rural landscape cannot fully and accurately represent the change of multi-functional relationship, and there are differences in the pattern of space-time relationship. The relationship between spatial carrying function and ecological regulation function/environmental balance function was found to be compatible in time and tradeoff in space. And the results of time synergy and spatial tradeoff between agricultural production function and ecological regulation function/environmental balance function verify the scientific nature of using space-time model to analyze the multi-function tradeoff-synergy relationship of rural landscape.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Economic and social effects
Controlled terms:Agriculture - Ecology - Economics - Environmental regulations - Rural areas - Weighing
Uncontrolled terms:Evolution - Landscape - Multifunction - Qingpu district - Trade off
Classification code:454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 943.3 Special Purpose Instruments - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2019.23.034
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 37>
Accession number:20201008271048
Title:Grasping model and pose calculation of parallel robot for fruit cluster
Title of translation:并联机器人串类水果抓取模型及抓取位姿计算
Authors:Zhang, Qian (1); Gao, Guoqin (1)
Author affiliation:(1) School of Electrical & Information Engineering, Jiangsu University, Zhenjiang; 212013, China
Corresponding author:Gao, Guoqin(gqgao@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:37-47
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Grasping pose calculation with high accuracy and efficiency is precondition to realize the accurate, fast and nondestructive automatic sorting based on machine vision for a robot. Due to the unconstraint shape and location of stalk, the variability of cluster morphology, and unobvious difference between the stalk region and non-stalk region in the image of randomly placed fruit cluster, it is difficult to acquire the grasping pose parameters of robot for fruit cluster sorting based on machine vision accurately. Therefore, in this paper, a grasping pose calculation method of parallel robot for fruit cluster based on 3D grasping model is proposed by fitting stalk skeleton of fruit cluster and constructing 3D grasping model for the machine vision automatic sorting system for fruit cluster based on 4-R(2-SS) parallel robot. Firstly, according to the stalk node, the relationship between the finger length of robot clamping mechanism and centerline of stalk, the stalk of fruit cluster is divided into four categories: the long stalk without node, the short stalk without node, the long stalk with node and the short stalk with node. Four 3D grasping models of randomly placed fruit cluster based on the stalk skeleton are constructed according to the 3D pose of stalk and the features of robot clamping mechanism. The models does not need to calculate the contour parameters of stalk without constraint shape and location, and solve the problem that it is difficult to grasp randomly placed fruit cluster stably and effectively adopting the 2D grasping pose based on plane contour parameters. Secondly, a morphological image segmentation method for extracting stem region of fruit cluster is designed based on the distance between the contours of stem region and berry region. Then a multi-dimensional feature vector is constructed based on the descriptors of region. The Gaussian mixture model that can learn the object features independently is adopted to extract the stalk region from the stem region. It can solve the problem that it is difficult to extract and fit the stalk skeleton accurately because of the variability of cluster morphology, unobvious difference between the stalk region and non-stalk region in the image of randomly placed fruit cluster. Thirdly, the grasping pose parameters including spatial position, rotation angle about Z-axis and finger opening width of clamping mechanism under different grasping conditions are calculated based on the stalk skeleton of fruit cluster and 3D grasping model. Then the transformation matrix of clamping mechanism from the current pose to the grasping pose in world coordinate system is calculated based on the closed loop of coordinate transformation chain, which can be directly used to realize the automatic and stable grasping of fruit cluster. Finally, the proposed grasping pose calculation method is verified by experiments with the self-developed machine vision automatic sorting system for fruit cluster based on 4-R(2-SS) parallel robot. The average errors of pose parameters x, y, z, θ and w calculated by the proposed grasping pose calculation method are 1.400 mm, 1.217 mm, 1.837 mm, 3.331° and 0.833 mm respectively. Compared with the existing 2D grasping pose calculation method, the success rates of grasping for the fruit cluster with stalk node and the fruit cluster without stalk node, and the average success rate of grasping based on the proposed method increased by 14, 12 and 13 percentage points respectively. Experimental results demonstrate that the proposed grasping pose calculation method of parallel robot for fruit cluster based on 3D grasping model can effectively improve the grasping accuracy of 4-R(2-SS) parallel robot for randomly placed fruit cluster based on machine vision, and realize accurate and fast automatic sorting of fruit clusters.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Computer vision
Controlled terms:3D modeling - Clamping devices - Contour followers - Fruits - Gaussian distribution - Image segmentation - Linear transformations - Morphology - Musculoskeletal system - Robots
Uncontrolled terms:Automatic sorting systems - Co-ordinate transformation - Gaussian Mixture Model - Grasping pose - Multi-dimensional feature vectors - Segmentation methods - Transformation matrices - World coordinate systems
Classification code:461.3 Biomechanics, Bionics and Biomimetics - 603.1 Machine Tools, General - 723.5 Computer Applications - 731.5 Robotics - 821.4 Agricultural Products - 921.3 Mathematical Transformations - 922.1 Probability Theory - 951 Materials Science
Numerical data indexing:Size 1.22e-03m, Size 1.40e-03m, Size 1.84e-03m, Size 8.33e-04m
DOI:10.11975/j.issn.1002-6819.2019.23.005
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 38>
Accession number:20201008271047
Title:Research status and existing problems in establishing cow heat stress indices
Title of translation:奶牛热应激指数的研究现状及问题分析
Authors:Yan, Geqi (1, 2); Li, Hao (1, 2, 3); Shi, Zhengxiang (1, 2, 3); Wang, Chaoyuan (1, 2, 3)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing; 100083, China; (2) Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture and Rural Affairs, Beijing; 100083, China; (3) Beijing Engineering Research Center on Animal Healthy Environment, Beijing; 100083, China
Corresponding author:Shi, Zhengxiang(shizhx@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:23
Issue date:December 1, 2019
Publication year:2019
Pages:226-233
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Heat stress seriously affects the productivity, fertility and welfare of dairy cows. It is to be expected that, in the course of the next few decades, climate conditions for raising cattle will deteriorate. In order to reduce the risks of heat stress in dairy cows, researchers have been trying to seek a reliable method to predict or evaluate heat stress, and it has been become to a hot topic in this research field to obtain an index model by combining multiple environmental factors. To avoid blindness in selecting these environmental factors, this paper systematically analyzed the temperature-humidity index, and its modified indices based on THI combined with other factors, and compared the differences among these indices in characterizing the heat stress of dairy cows. These differences relate to the thresholds of indices, environmental factors involved and heat exchanging properties, and the relationships between physiological responses of dairy cows and indices. In this paper, the problems of heat stress index of dairy cows are also discussed. The most widely used temperature-humidity index is based on thermal sensation and thermal comfort of human, but had not been actually related to cow’s living environments. Most indices linking environmental parameters to the physiological or behavioral responses of cows were established through the statistical correlation analysis process, but it did not reflect the real physical significance of the effects of environmental parameters on the process of heat exchange between animals and its environmental factors. In addition, the indices could only be well applied to the situation where they were established properly with the sufficient information for their use. We believed that THI had played an important role in the past when environmental parameters, physiology indicators and behavior responses were hard to be obtained, but the problem of THI had been existing in its application, so other direct parameters such as heat tolerance of high-yielding cows, the change of building structure and the linkage of various cooling modes should be considered when a new THI is being designed. Otherwise, the current THI will be not to meet the future production requirements of the dairy farming industry. With the application of digital technology, multi-parameter acquisition technology has been fundamentally changed, so it is necessary to develop a more reliable index of evaluating heat stress for cows to meet the needs of increasing livestock productivity and achieving welfare. Our suggestions to achieve this goal are as follows: 1) The index should be developed to incorporate more environmental parameters reflecting heat transfer mechanism. 2) The index can be applied not only in some specific climatic conditions, but also in other climatic conditions. 3) The index is to have applicable conditions and thresholds, and the thresholds of the index should be able to be dynamically adjusted to extend the scope of its application. 4) The index should be linked to animal physiological parameters and environmental factors, and consideration could be given to constructing a new index by meeting the theory of animal thermal balance.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:48
Main heading:Physiological models
Controlled terms:Agriculture - Animals - Correlation methods - Environmental management - Heat exchangers - Heat transfer - Physiology - Productivity - Technology transfer - Thermal comfort - Thermal stress
Uncontrolled terms:Dairy cow - Environmental control - Environmental parameter - Heat stress - Heat transfer mechanism - Physiological parameters - Production requirements - Temperature humidity index
Classification code:454.1 Environmental Engineering, General - 461.9 Biology - 616.1 Heat Exchange Equipment and Components - 641.2 Heat Transfer - 643 Space Heating, Ventilation and Air Conditioning - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.11975/j.issn.1002-6819.2019.23.028
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
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- 主管单位 中国科学技术协会
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