<RECORD 1>
Accession number:20182405305854
Title:Simulation and experiment on obstacle-surmounting performance of four swing arms and six tracked robot under unilateral step environment
Authors:Wang, Chuanwei (1); Ma, Kun (1); Yang, Lin (1); Ma, Hongwei (1); Xue, Xusheng (1); Tian, Haibo (1)
Author affiliation:(1) Xi'an University of Science and Technology, Xi'an; 710054, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:46-53
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the agricultural environment, in order to realize the replacement of human by robots and reduce the burden of human labor, the 4-swing-arm6-track robot(4SA-6TR)was designed after studying the structure of tracked robot. The maximum size of the robot is 830 mm ×790 mm ×360 mm, its swing arm is 295 mm, and its weight is about 120 kg. The robot adopts the structure of the sleeve shaft, and the rotation motion of swing arm is independent from that of the tracked wheel, so that the robot's 4 arms can rotate freely, and robots can achieve multi-posture changes. When the robot faces an obstacle, the robot can adjust its posture through changing the rotation angle of the 4 swing arms, so the robot can maintain the higher stability during the obstacle course. Kinematics matrix equations of 4SA-6TR were established. And the center of gravity(CoG) coordinates of the robot were gotten in the global coordinate system with the help of the CoG theorem after analysis of motion attitude of 4SA-6TR robot. The CoG can be used to study the stability of the robot. Sometimes the 2 tracks of the robot don't touch obstacles at the same time. When one side of the robot meets an obstacle, the roll angle, pitch angle and position of the CoG of the robot will change, which will affect the stability of the robot. The obstacle-surmounting mechanism of the robot under the condition of unilateral obstacle was studied. The robot is considered as a connecting rod consisting of a free joint and 4 joints, and the mathematical model was established between the rotation angle of robot's swinging arms and the robot's roll angle. The equation of the rotation angle of robot's swinging arms and the height of the step can be obtained by the derivation of the formula. When robot climbs a unilateral step, its pitch angle and roll angle will change due to its CoG. In the unilateral obstacle environment, when the step height is less than L<inf>1</inf>+r-R(L<inf>1</inf>is the length of the robot's swing arm, r is the radius of the arm wheel, and R is the radius of the driving wheel), the robot can achieve the horizontal posture to overcome the obstacle. The robot will be inclined but it is still able to move steadily without rolling, when the step height meets the conditions of L<inf>1</inf>+r-R≤H≤H<inf>max</inf>(H is the step height, and H<inf>max</inf>is the maximum step height a robot can cross). Therefore, the robot can be balanced by adjusting its swing arm's angle. The 3D (three-dimensional) model of 4SA-6TR robot and terrain was completed by using Solid Works software, then its simplified model was introduced into Adams virtual prototype simulation software, and the virtual prototype simulation environment of the robot and terrain was obtained. A combination of the steps with height of 150 and 100 mm was established in the simulation experiments. The height of the step is less than 247 mm, and the robot can keep its body level during the obstacle course. From the simulation experiment, it can be concluded that, the robot could adjust the posture of its 4 swing arms in real time according to the height and orientation of the obstacle and the speed of the robot in the obstacle-surmounting process. Through indoor test experiments, it can be found that the robot's pitch angular deviation is bigger, and the maximum deviation is 2.4°, but in the end its pitch angle can be stabilized at about 0.1°; the roll angle deviation is small, and finally the roll angle can be stabilized at about 0.3°. The results of the test experiments show that the robot could complete the obstacle-surmounting movement very smoothly, which verified the correctness and feasibility of the control strategy. The attitude control scheme of the unilateral obstacle of the robot can provide the theoretical basis for the automatic obstacle surmounting.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Robots
Controlled terms:Attitude control - Computer software - Experiments - Kinematics - Matrix algebra - Rotation - Software prototyping - Virtual prototyping - Virtual reality - Wheels
Uncontrolled terms:3-D (three-dimensional) - Agricultural environments - Angular deviations - Global coordinate systems - Obstacle-surmounting - Solidworks software - Unilateral step obstacle - Virtual prototype simulation
Classification code:601.2 Machine Components - 723 Computer Software, Data Handling and Applications - 731.3 Specific Variables Control - 731.5 Robotics - 901.3 Engineering Research - 921.1 Algebra - 931.1 Mechanics
Numerical data indexing:Mass 1.20e+02kg, Size 1.00e-01m, Size 1.50e-01m, Size 2.47e-01m, Size 2.95e-01m
DOI:10.11975/j.issn.1002-6819.2018.10.005
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 2>
Accession number:20182405305870
Title:Short-time empirical mode decomposition method of real-time QRS complex identifying for electrocardiography of pig
Authors:Jia, Guifeng (1, 2); Wang, Zichang (1); Xiang, Xingfa (1); Wu, Dun (1); Gao, Yun (1, 2); Li, Xuan (1, 2); Feng, Yaoze (1, 2)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China; (2) Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture, Wuhan; 430070, China
Corresponding author:Feng, Yaoze(yaoze.feng@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:172-177
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pigs' physiological parameters monitoring instantaneously in commercial piggeries is essential for early disease detection and welfare assessment. Heart rate is vital sign of pigs because of its correlation with disease and environment. Usually, the heart rate is calculated by the intervals of QRS complex identified from ECG (electrocardiogram) signal. Due to the low compliance of livestock during monitoring, the pig's ECG signal presents non-stationary characteristics and varieties of noise, which makes it difficult to process instantaneously and correctly. To solve the problem, this study proposed a short-term empirical mode decomposition (ST-EMD) algorithm with the real-time and anti-noise property for ECG data processing based on empirical mode decomposition (EMD). The ST-EMD algorithm comprises 3 procedures including data segmenting, EMD processing and QRS complex feature extracting. In the data segmenting step, the algorithm determines the starting point and terminal point for the next data block according to the latest QRS complex and RRI (RR interval) in current data segment, and then captures the ECG data to meet the predetermined length in real time. After the signal collecting, the new fragment data are decomposed into a series of intrinsic mode functions (IMFs) and residuals by EMD algorithm. Through experiment analysis and comparison, the first IMF contains the most of QRS complex information. In the third procedure, the QRS complex features are extracted based on the first IMF employing energy window transformation and the correctness of the QRS complex identification is checked. After the ST-EMD algorithm was developed in MATLAB, animal experiments were carried out to verify the efficiency. Three piglets born in the same nest were recruited in the experiments. The age of the piglets was 50 d, and the average weight was 18.2 kg. Pig's ECG signal was picked up by 2 electrodes attached on either side of chest and converted by BMD101 analog sensor with 512 Hz sampling frequency. Simultaneously, the software accessed the digital ECG data through Bluetooth communication and computed the heart rate in real time. The collection time of each pig was 120 s, and in total 184320 data were collected. In the signal processing, the mean segmenting length of data block was 0.69 s, while the mean computing time was 0.03 s, which meant that the algorithm could output the heart rate data within 0.72 s after each ECG data block was acquired. Consequently, the ST-EMD algorithm can identify the QRS complex in real time from pig's ECG signal. By comparing the actual QRS complexes, the mean accuracy of QRS complex identified by ST-EMD is 99.6%. The results of animal experiments illustrate that the proposed ST-EMD algorithm is correct and is suitable for the real-time health monitoring of the pig's ECG. Moreover, to ensure the heart rate was correctly extracted by the algorithm, a seven-point moving median filtering was used to eliminate the erroneous values due to baseline drift and interference noise in ECG signal. As a result, the mean heart rates of 3 piglets were (137.47±6.47), (133.01±9.80) and (128±6.51) bmp respectively and all were within normal limits. In summary, the ST-EMD algorithm is efficacious and reliable for real-time processing of pig's ECG signal integrated with moving median filtering.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Biomedical signal processing
Controlled terms:Agriculture - Data handling - Data processing - Electrocardiography - Heart - Identification (control systems) - Image segmentation - Mammals - MATLAB - Median filters - Physiological models - Reaction kinetics - Structures (built objects)
Uncontrolled terms:Bluetooth communications - Early disease detection - Empirical Mode Decomposition - Empirical mode decomposition method - Intrinsic Mode functions - Non stationary characteristics - Physiological parameters - Real-time health monitoring
Classification code:461.2 Biological Materials and Tissue Engineering - 461.6 Medicine and Pharmacology - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 802.2 Chemical Reactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics
Numerical data indexing:Frequency 5.12e+02Hz, Mass 1.82e+01kg, Percentage 9.96e+01%, Time 1.20e+02s, Time 3.00e-02s, Time 6.90e-01s, Time 7.20e-01s
DOI:10.11975/j.issn.1002-6819.2018.10.021
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 3>
Accession number:20182405305868
Title:Real-time recognition of main organs in tomato based on channel wise group convolutional network
Authors:Zhou, Yuncheng (1); Xu, Tongyu (1); Deng, Hanbing (1); Miao, Teng (1)
Author affiliation:(1) College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang; 110866, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:153-162
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The real-time and accurate recognition for the organs in tomato is crucial to achieve automated agricultural production, such as automatic harvesting and targeted drug application. Due to the difference of fruit maturity and flower age, and the color of tomato organs varying frequently during the growth period, it is very difficult for the simultaneous detection of different tomato organs with the traditional image segmentation method based on color space. In the meanwhile, because of the non-real-time nature of filters such as SIFT (scale-invariant feature transform) and Haar-like, they cannot be directly applied to the real-time detection of plant organs. The convolution neural networks (CNNs) can automatically extract the low-level image feature and high-level semantics of image, and they have real-time performance on GPU (graphics processing unit) devices. Therefore, inspired by Faster R-CNN, especially YOLOv2, in this paper, we proposed a real-time recognition method of main organs in tomato based on CNNs, and designed a corresponding recognition network model which can predict the object boundary and type only using feature map. In greenhouse, the images of various forms of tomato flower, fruit and stem organs were collected, and the image data set of tomato organs was constructed according to the influence of illumination of the image which was considered during the acquisition process. For the sake of screening the underlying network structure for recognition network, the performance and applicability of several typical CNN-based classification networks were analyzed based on the criterion of model size, statistical separability, classification performance, and computation speed. Inspired by the advantages of these typical networks, a channel wise group convolutional (CWGC) block and a corresponding classification network (CWGCNet) were designed. A sample extension training method was presented to further improve the feature extraction ability of these classification networks. The CWGCNet, Darknet-19 and Inception v2 were selected as candidate infrastructure for recognition network. Subsequently, a CWGC block with dropout layer and 3 full convolution layers were respectively attached to the infrastructure to form the overall recognition architecture. Based on the Microsoft Cognitive Toolkit (CNTK), all CNN-based classification networks and recognition networks were implemented by using of Python, and the relevant experiment was performed on a computer equipped with a Tesla K40c GPU. The results show that, compared with the typical CNN-based classification networks, CWGCNet combines high feature statistical separability and real-time performance. On tomato organ image dataset, using Caltech256 to perform sample extension training can significantly improve the feature extraction ability of the classification networks. Compared with the exponential function, the nonlinear scaling factor in the Sigmoid form makes the recognition networks easier to train. In contrast to the 3 full convolution layers, using CWGC block with dropout as an additional convolution layer to the recognition network CNN infrastructure can dramatically reduce the size of the model, while significantly improve the network recall rate, recognition speed and average precision (AP). The convolution part of CWGCNet and the CWGC block with dropout are used as the final structure of the recognition network. The final recognition network can identify the different maturity and different forms of tomato organs, which gets the AP of 96.52%, 97.85% and 82.62% respectively for flower, fruit and stem. The growth stage and maturity of tomato organs have a certain influence on the recognition accuracy, and especially the flowering flower, full maturity fruit and lower stem have higher recognition accuracy. The final network can recall different forms of tomato organs, and the recall rates of flower, fruit and stem can reach 77.39%, 69.33% and 64.23% separately. And the recognition speed of the final network is 62 fps. Compared with YOLOv2, the recall rate can be improved by 14.03 percentage points, and AP can be improved by 2.51 percentage points.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Classification (of information)
Controlled terms:Algorithms - Color - Computer graphics - Computer graphics equipment - Convolution - Exponential functions - Extraction - Feature extraction - Fruits - Graphics processing unit - Image enhancement - Image recognition - Image segmentation - Interactive computer systems - Program processors - Real time systems - Semantics
Uncontrolled terms:Agricultural productions - Classification networks - Classification performance - Convolution neural network - Low-level image features - Scale invariant feature transforms - Simultaneous detection - Tomato
Classification code:716.1 Information Theory and Signal Processing - 722.2 Computer Peripheral Equipment - 722.4 Digital Computers and Systems - 723.5 Computer Applications - 741.1 Light/Optics - 802.3 Chemical Operations - 821.4 Agricultural Products - 921 Mathematics
Numerical data indexing:Percentage 6.42e+01%, Percentage 6.93e+01%, Percentage 7.74e+01%, Percentage 8.26e+01%, Percentage 9.65e+01%, Percentage 9.78e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.019
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 4>
Accession number:20182405305880
Title:Object oriented land use classification of Dongjiang River Basin based on GF-1 image
Authors:Li, Hengkai (1); Wu, Jiao (1); Wang, Xiuli (2)
Author affiliation:(1) College of Architecture and Surveying Engineering, Jiangxi University of Science and Technology, Ganzhou; 341000, China; (2) College of Economic Management, Jiangxi University of Science and Technology, Ganzhou; 341000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:245-252
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:We are aimed at the problem of the low classification accuracy of the land surface of the Dongjiang River Basin due to the patch breaking of the Dongjiang River Basin and the numerous lakes and rivers which are found everywhere in the river basin. At present, the data for the Dongjiang River Basin are mostly Landsat TM/ETM images, and the spatial resolution is low, so the multi-view image splicing is needed. The Dongjiang River Basin is in the south China where it is cloudy and rainy. The Landsat TM/ETM image with less cloud is insufficient, and it is difficult to ensure the time consistency, which influences the information extraction effect; and the cost of high spatial resolution image is high, so it is difficult to be applied in the whole basin range. The GF-1 remote sensing image is used as the data source in this paper, and we try our best to use object oriented classification method combined with fuzzy classification and CART(classification and regression trees) decision tree classification method to obtain land use classification information of Dongjiang River Basin by doing the experiments. We spare no effort to attempt a method that can make the classification of Dongjiang River Basin accurately. We read a lot of relevant taxonomy and refer to many experiments, and then launch a classification scheme. We use the software of eCognition 9.0 to complete the process of fuzzy classification and CART decision tree classification, and also we use several kinds of software such as ArcGIS 10.1, ENVI 5.3, SP1, and Qmosaic 6.0 to help do this work. Also we will combine true color remote sensing images of GF-1 to read the classification process visually. First of all, we choose the fuzzy range from 480 to 2200, which is based on the mean of the near-infrared band, and combined with the true color remote sensing images of GF-1. When the mean value of near-infrared band is less than 480 by the experiment, it is identified as water body, and when the mean value of near-infrared band is more than 2200, it is identified as non-water. We choose fuzzy less than membership function to distinguish between water and non-water. Then in water category, the length-width ratio index fuzzy range from 1.53 to 4.32 is used to distinguish the river from the reservoir by using fuzzy greater than function. Similarly, we observe the true color remote sensing images of GF-1. When the index of length-width ratio is less than 1.53, it is identified as a reservoir, and when the index of length-width ratio is more than 4.32, it is identified as a river. In the non-water category, we try to use the fuzzy range of the normalized vegetation index NDVI (normalized difference vegetation index) characteristic value (i.e. from 0.21 to 0.62) to distinguish the vegetation and non-vegetation. When the NDVI index is less than 0.21, it is identified as non-vegetation; when the NDVI index is more than 0.62, it is identified as vegetation. Finally, we use CART decision tree classification method based on samples to distinguish river, reservoir, garden plot, woodland, farmland, grassland, unused land and construction land. Compared with the maximum likelihood classification method and the unsupervised classification method applied in GF-1 remote sensing images, the object oriented CART decision tree classification based on sample method has the best classification effect, whose overall classification accuracy is up to 93.27%, and the Kappa coefficient is up to 0.92. This method can be used as an effective method to obtain higher land use information in Dongjiang River Basin, and it also can provide more accurate data for the study of ecological environment changes in the watershed.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Classification (of information)
Controlled terms:Color - Data mining - Decision trees - Fuzzy systems - Image classification - Image resolution - Information use - Infrared devices - Land use - Maximum likelihood - Membership functions - Object oriented programming - Remote sensing - Reservoirs (water) - Rivers - Vegetation - Watersheds
Uncontrolled terms:Classification and regression tree - Decision tree classification - Dongjiang rivers - GF-1 - High spatial resolution images - Maximum likelihood classifications - Normalized difference vegetation index - Object oriented classification
Classification code:403 Urban and Regional Planning and Development - 441.2 Reservoirs - 444.1 Surface Water - 723.1 Computer Programming - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 903.1 Information Sources and Analysis - 903.3 Information Retrieval and Use - 921 Mathematics - 922.1 Probability Theory - 961 Systems Science
Numerical data indexing:Percentage 9.33e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.031
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 5>
Accession number:20182405305858
Title:Fault-tolerant adaptive sliding mode control method of tractor automatic steering system
Authors:Jia, Quan (1); Zhang, Xiaochao (1); Yuan, Yanwei (1); Fu, Tuo (1); Wei, Liguo (1); Zhao, Bo (1)
Author affiliation:(1) Chinese Academy of Agricultural Mechanization Sciences, Beijing; 100083, China
Corresponding author:Yuan, Yanwei(yyw215@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:76-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Unmanned tractors have become the focus of research in the field of intelligent agricultural machinery in recent years, which can effectively improve the agricultural productivity and the accuracy of operations. Automatic steering control system was a prerequisite for driverless tractors, and the key technologies included steering wheel angle detection method and angle tracking control algorithm. Steering wheel angle measurement results were the direct factors affecting the navigation effect. Encoder measurement and angular rate measurement were 2 commonly used front wheel angle measurement methods. Absolute angle measurement method had higher detection accuracy, but there were too many mechanical connectors using this method, and the calibration work was complex. The angular rate measurement method generally used inertial devices, which were easy to install and had a long working life. However, there was a random drift in the gyroscope and the accumulated error would affect the measurement accuracy. In practical applications, whatever the above-described measuring methods used, the angle measuring device was the most easily damaged component of the entire control system. For example, the angle measuring mechanism was easily damaged during operation by crops when it was installed in the position of the tractor front axle, it would cause signal output failure, and the reliability and safety of the unmanned system would be affected. In addition, the steering control system would be subject to a variety of non-linear factors such as mechanical clearance and hydraulic system lag during the working process, resulting in poor control effects. It was necessary to compensate for the uncertainties to further enhance the effect of angle tracking control. In order to solve the problems above, an RBF adaptive sliding mode control method with the ability of fault-tolerant detection of front wheel angle was proposed. First of all, a discrete state equation of the control system was deduced according to the structure of the tractor steering control system, and then the relationship between the front wheel angle and inertial information of the tractor's steering center including the lateral acceleration and the yaw rate was deduced respectively from the linear two-degree-of-freedom vehicle model. Secondary, in order to obtain a high redundancy value of the front wheel angle, 2 estimated values of the front wheel angle were obtained by Kalman filter, and a fault diagnosis algorithm and a fault-tolerant output algorithm were designed by comparing the residual threshold between the angle encoder value and these 2 estimated values. Thirdly, an adaptive sliding mode control method of the front wheel angle was proposed, which used an RBF neural network to identify the uncertain disturbance in order to ensure that the steering control system could accurately and timely track the expected rotation angle under the uncertainty interference factors. Finally, the fault tolerance test and automatic control test of the front wheel angle were carried out. The experimental results showed that the maximum error of the angular estimation based on the lateral acceleration was 2.94° and the root mean square error was 0.81°, while the maximum error of the angular estimation based on the yaw rate was 1.73° and the root mean square error was 0.12°. The fault-tolerant algorithm could automatically switch to the estimation value when the encoder artificially exerted an interference signal, and it could effectively replace the role of encoder and improve the reliability of the tractor automatic driving system. The experimental results of the angle control system showed that the performance indicators of the adaptive sliding mode control algorithm based on RBF network were better than the traditional PID (proportion, integration, differentiation) control method, and it could track the desired angle quickly with small overshoot, and the maximum error of angle control was 0.21° and the root mean square error was 0.07°. Test results showed that the fault-tolerant adaptive sliding mode control method can improve the reliability and accuracy of the automatic steering control system and help to solve the problem of high failure rate of the front wheel rotation angle measuring device of the tractor autopilot system.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Adaptive control systems
Controlled terms:Acceleration - Agriculture - Angle measurement - Automation - Automobile drivers - Automobile steering equipment - Automobile testing - Control systems - Degrees of freedom (mechanics) - Equations of state - Errors - Failure analysis - Fault detection - Fault tolerance - Front axles - Hydraulic equipment - Hydraulic machinery - Mean square error - Navigation - Productivity - Radial basis function networks - Signal encoding - Sliding mode control - Steering - Tractors (agricultural) - Tractors (truck) - Wheels
Uncontrolled terms:Adaptive sliding mode control - Agricultural productivity - Angular rate measurements - Automatic driving system - Automatic steering control - Fault tolerant algorithms - Fault-tolerant detections - Reliability and safeties
Classification code:432 Highway Transportation - 601.2 Machine Components - 632.2 Hydraulic Equipment and Machinery - 662 Automobiles and Smaller Vehicles - 662.4 Automobile and Smaller Vehicle Components - 663.1 Heavy Duty Motor Vehicles - 716.1 Information Theory and Signal Processing - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 931.1 Mechanics - 943.2 Mechanical Variables Measurements
DOI:10.11975/j.issn.1002-6819.2018.10.009
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 6>
Accession number:20182405305857
Title:Influence of outlet edge position of guide vane on performance of well submersible pump
Authors:Cheng, Xiaorui (1, 2); Lü, Boru (1); Zhang, Xuelian (1); Wei, Yanqiang (1); Zhang, Shuyan (1); Wang, Peng (1)
Author affiliation:(1) College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; (2) Key Laboratory of Fluid Machinery and Systems of Gansu Province, Lanzhou; 730050, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:68-75
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The well submersible pumps have a large number of stages and complex structures. The inflow conditions of the secondary impeller are quite different from its first stage. Provided that the inflow conditions of the remaining secondary impeller inlets cannot be guaranteed, the efficiency will be significantly reduced as compared with the first stage impeller, which will result in a decrease of the overall efficiency of entire pump and uncontrollability of the pump design. Therefore, in order to study how the space guide vane ensures the inflow conditions of the secondary impeller, especially the influence of the outlet position of the space guide vane on the inflow conditions of secondary impeller, the 250QJ125 five-stage well submersible pump was studied as a model in this paper. Under the given conditions that other geometric parameters were fixed, the position of the outlet edge of the original guide vanes was changed along axial direction to make it both perfectly perpendicular to the rotation axis and coincide with the radius line, and 6 schemes were designed, including 1 original scheme and 5 improved schemes. Based on Reynolds time-averaged Navier-Stokes equations and RNG(re-normalization group) k-Ε model, the SIMPLE algorithm was used to perform the three-dimensional numerical simulation of the entire flow path. The head and efficiency of the schemes were obtained. It was found that the scheme in which guide vane outlet position extended 30 mm along the axial direction had an increase of hydraulic efficiency of 1.2% compared with the original scheme, and the head increased by 6.8 m, and it was the best scheme. At the same time, according to the calculation results of the external characteristics under the design conditions of each scheme, the impeller data from the first to fifth stage of each scheme were extracted, and it was found that the hydraulic efficiency and head of the first stage impeller were basically the same with the best improved scheme. The remaining secondary impeller efficiency and head were quite different from those of the first stage. The remaining secondary impeller efficiency of the best improved scheme was basically the same as that of the first stage impeller, and the head reduced by 1 m; however, its head was approximately increased by 2.2 m compared with the heads of the other stages of the original scheme. Finally, the internal flow field of each scheme on the outlet section of the vanes was analyzed. The results showed that the vanes' outlet edge position along the axial direction can change the flow state of the water flow at the vanes' outlet, and make it a dispersed rotating flow. The number of dispersed vortices is as same as the number of blades of the guide vane. When the outlet edge of the guide vane extends to an appropriate position, the inlet ring volume and impact loss of the following stage impeller can be reduced. The matching relationship between the guide vanes and the following stage impeller can be improved.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Impellers
Controlled terms:Computer simulation - Efficiency - Flow of water - Navier Stokes equations - Optimization - Pumps - Submersible pumps - Submersibles - Three dimensional computer graphics
Uncontrolled terms:Calculation results - Edge position - External characteristic - Guide vane - Hydraulic efficiency - Internal flow field - Secondary impellers - Three-dimensional numerical simulations
Classification code:601.2 Machine Components - 618.2 Pumps - 631.1.1 Liquid Dynamics - 674.1 Small Marine Craft - 723.5 Computer Applications - 913.1 Production Engineering - 921.2 Calculus - 921.5 Optimization Techniques
Numerical data indexing:Percentage 1.20e+00%, Size 2.20e+00m, Size 3.00e-02m, Size 6.80e+00m
DOI:10.11975/j.issn.1002-6819.2018.10.008
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 7>
Accession number:20182405305875
Title:Benefit on emission reduction of greenhouse gas in biogas digester on scale swine farm based on clean development mechanism
Authors:Chen, Tinggui (1); Zhao, Zicheng (1)
Author affiliation:(1) College of Economics and Management, Shanghai Ocean University, Shanghai; 201306, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:210-215
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Methane digesters in livestock production can serve as a renewable source of electricity, and reduce greenhouse gas emissions from electricity generation. However, most of methane digester systems in China were unprofitable. Newly established China's domestic carbon offset market could provide the possibility to improve the profitability of methane digester systems. To discuss this possibility, three different sizes of pig farms located in Jiangsu province were selected to analyze the carbon emission reduction and the cost-benefit of three methane digester systems. The livestock inventory of farm A was 20000 pigs, 50000 pigs were sold that year. The capacity of its methane digester was 2200 m<sup>3</sup>of manure. The electric generator capacity was 200 kW. The biogas production was 657000 m<sup>3</sup>and the generated electricity was 592000 kWh. The livestock inventory of farm B was 15000 pigs; 35000 pigs were sold that year; The capacity of its methane digester was 2200 m<sup>3</sup>of manure; The electric generator capacity was 280 kW; The biogas production was 321200 m<sup>3</sup>and the generated electricity was 369000 kWh. The inventory of farm C was 5000 pigs; 10000 pigs were sold that year; The capacity of its methane digester was 800 m<sup>3</sup>; The capacity of its generator was 24 kW; The biogas production was 116800 m<sup>3</sup>and the generated electricity was 105120 kWh. This study calculated the carbon emission reduction by Methodology for Small Scale Projects (AMS) III.D, and the net present value (NVP) by cost-benefit analysis with electric sales, carbon credits, and sewage charges savings through several scenarios to give insights into the profitability of the methane digester systems in China. The results showed that the methane digester systems had a significant effect on carbon emissions reduction. The baseline carbon emissions for farms A, B, and C were 9434.37, 7075.77, and 2358.59 t, respectively. The carbon emissions with the methane digester systems are 4197.42, 3058.82, and 1024.66 t in farm A, B and C, respectively. The reduction in carbon emissions was 5236.95, 4016.95 and 1333.93 t, respectively. For all three farms, the reduction rate was above 55%. However, the digester profitability of three pig farms was negative at current situation. If the carbon emission reduction can be traded in the carbon offset markets at a high enough price, for instance at 50 RMB per ton, then the system will be profitable, and thus can be sustainable. So far, except quite a few large-scale pig farms which have made contracts with foreign companies or organizations as CDM (clean development mechanism)programs, most of the pig farms with methane digesters could not access the international carbon offset markets. However, China's newly established domestic carbon offset market can provide that possibility. More government support is needed for the market development. There are obvious scale economies in the methane digesters. The larger pig farms are more profitable methane digesters due to their larger output of methane. Even at the renewable electricity price of 0.67 RMB/kWh and with government subsidy for the methane digester systems, only the NPV of farm A, which is the largest one of the three farms, is positive in the case of the carbon price of 10 RMB/t. For small-scale farms, the construction of centralized digesters (collectively or by a contractor) will be a good option. Farms B and C are comparatively small-scale operations and their methane slurry is used in their own agricultural production.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Pulp digesters
Controlled terms:Agriculture - Biogas - Carbon - Commerce - Cost benefit analysis - Cost reduction - Electric generators - Electric power generation - Emission control - Fertilizers - Gas emissions - Greenhouse gases - Mammals - Manures - Methane - Profitability - Sewage
Uncontrolled terms:Agricultural productions - Carbon emission reductions - Carbon emissions reductions - Clean Development Mechanism - Economy of scale - Electricity generation - Net present value - Small-scale operations
Classification code:451.1 Air Pollution Sources - 451.2 Air Pollution Control - 452.1 Sewage - 705.2 Electric Generators - 804 Chemical Products Generally - 804.1 Organic Compounds - 811.1.2 Papermaking Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 911 Cost and Value Engineering; Industrial Economics - 911.2 Industrial Economics
Numerical data indexing:Percentage 5.50e+01%, Power 2.00e+05W, Volume 1.17e+05m3, Volume 2.20e+03m3, Volume 3.21e+05m3, Volume 6.57e+05m3
DOI:10.11975/j.issn.1002-6819.2018.10.026
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 8>
Accession number:20182405305863
Title:Effects of planting patterns and nitrogen application rates on yield, water and nitrogen use efficiencies of winter oilseed rape (Brassica napus L.)
Authors:Gu, Xiaobo (1); Li, Yuannong (1); Huang, Peng (1); Du, Yadan (1); Fang, Heng (1); Chen, Pengpeng (1)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education, Northwest A&F University, Yangling; 712100, China
Corresponding author:Li, Yuannong(liyuannong@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:113-123
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Poor soil conditions and drought stress are 2 main factors restricting the agriculture production in arid and semiarid areas of northwest China. The ridge film mulching and furrow planting (RFMF) cultivation pattern, which employs ridges mulched with plastic film to serve as the runoff area and furrows used as the planting area, has been shown to have the ability of improving soil water availability, yield and water use efficiency (WUE) of maize, wheat and potato. However, the RFMF planting pattern has rarely been tested in oilseed rape (Brassica napus L.) for yield improvements in areas where soil evaporation is high. A 3-year (2014-2017) field experiment was conducted to determine whether the RFMF cultivation pattern has the potential of improving winter oilseed rape productivity. The optimal nitrogen (N) application rate for the maximum yield of winter oilseed rape under the RFMF cultivation pattern was also determined. Winter oilseed rape was planted in RFMF and flat planting (FP) patterns, both with 6 nitrogen (N) application rates: 0, 60, 120, 180, 240 and 300 kg/hm<sup>2</sup>, named N0, N60, N120, N180, N240 and N300, respectively. The results showed that compared to FP, RFMF significantly increased aboveground dry matter (ADM) by 14.2%-61.5%, nitrogen accumulation amount by 17.4%-61.3%, seed yield by 15.5%-43.5%, water use efficiency (WUE) by 25.5%-69.6%, nitrogen partial factor productivity (NPFP) by 15.4%-43.0%, and significantly reduced evapotranspiration (ET) by 3.3%-9.9%. It was manifested by linear fitting that seed yield and WUE were much higher in RFMF than in FP cultivation condition when the plants of winter rapeseed consumed same amount of water. ADM, nitrogen accumulation amount, seed yield, and WUE of winter oilseed rape were significantly increased with the increase of N application rates (in the range of 0-240 kg/hm<sup>2</sup>) under RFMF cultivation condition. The ADM and nitrogen accumulation amount did not vary significantly, while ET increased significantly, and seed yield and WUE reduced significantly when N application rates exceeded 240 kg/hm<sup>2</sup>. Under both RFMF and FP cultivation conditions, N agronomic efficiency (NAE), N physiological efficiency (NPE) and N recovery efficiency (NRE) of the winter oilseed rape were all firstly increased and then decreased with the increase of N application rates, and reached the maximum at N180; while the NPFP was consistently decreased with the increase of N application rates. No significant differences of NAE, NPE, NRE and NPFP were found between N240 and N180 under RFMF cultivation condition (P>0.05). The highest yield and net benefits of winter oilseed rape under RFMF and FP cultivation conditions were found in N240 and N180, with the average seed yield of 3002 and 2291 kg/hm<sup>2</sup>, and average net benefits of 9538 and 7498 yuan/hm<sup>2</sup>across the 3 years, respectively. The highest yield and net benefit in RFMF was improved by 31.0% and 27.2% in comparison to FP. Present study indicated that RFMF cultivation pattern has the potential of improving winter oilseed rape productivity in arid and semiarid regions of northwest China, with the optimal N application rate of 240 kg/hm<sup>2</sup>.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Cultivation
Controlled terms:Arid regions - Efficiency - Evapotranspiration - Fertilizers - Nitrogen fertilizers - Oilseeds - Productivity - Soil moisture - Water supply
Uncontrolled terms:Nitrogen application rates - Nitrogen-use efficiency - Oil seed rape - Planting pattern - Seed yield
Classification code:443 Meteorology - 444 Water Resources - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.1 Production Engineering
Numerical data indexing:Age 3.00e+00yr, Percentage 1.42e+01% to 6.15e+01%, Percentage 1.54e+01% to 4.30e+01%, Percentage 1.55e+01% to 4.35e+01%, Percentage 1.74e+01% to 6.13e+01%, Percentage 2.55e+01% to 6.96e+01%, Percentage 2.72e+01%, Percentage 3.10e+01%, Percentage 3.30e+00% to 9.90e+00%
DOI:10.11975/j.issn.1002-6819.2018.10.014
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 9>
Accession number:20182405305873
Title:Middle-low temperature drying dynamic characteristics for poultry manure and its parameter optimization
Authors:Li, Xuanyang (1, 2); Li, Baoming (1, 2, 3); Zheng, Weichao (1, 2, 3); Wei, Yongxiang (1, 2); Zhang, Zhi (1, 2)
Author affiliation:(1) College of Water Recourses & Civil Engineering, China Agricultural University, Beijing; 100083, China; (2) Key Lab of Agricultural Engineering in Structure and Environment, Ministry of Agriculture and Rural Affairs, Beijing; 100083, China; (3) Beijing Engineering Research Center for Livestock and Poultry Healthy Environment, Beijing; 100083, China
Corresponding author:Li, Baoming(libm@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:194-199
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The poultry industry in China is developing. The estimated flock in 2017 was over 1.4 billion hens with a yearly manure output of 56 million tons. Such a large amount of poultry manure has a tremendous pressure on environment because of the associated air, water and soil pollution. Environmental and health problems such as odor and pathogens can be eliminated by decreasing the moisture content of poultry manure. Thermal drying has been proven to be an effective method to remove moisture. Drying at middle-low temperature can not only save energy but also reduce the emission of ammonia compared with traditional drying method at high temperature. Middle-low temperature heat sources, such as solar energy and warm weather in-house, can be used to dry poultry manure. Furthermore, dried manure can be utilized as a raw material to produce organic fertilizer. In order to study the drying characteristics of poultry manure at middle-low temperature, drying experiments of poultry manure were carried out in a temperature-controlled drying oven. The effects of drying temperature, manure thickness and air speed on manure moisture ratio and drying rate were examined. After that, common drying models were applied to simulate the drying process. The optimization of the middle-low temperature drying parameters was also performed by orthogonal test. The result showed that the middle-low temperature drying process of poultry manure could be divided into 2 falling rate periods: The first falling rate period and the second falling rate period. The removed water in the first stage was mainly free water, the removed water in the second stage was mainly the capillary water, adsorption water and bound water, and the drying rate in the second stage was lower than that in the first stage. With the increasing of temperature, the decreasing of thickness, and the increasing of air speed, the appearance of inflection point became earlier and the drying time became shorter. Exponential model was more suitable for describing the poultry manure drying process at middle-low temperature and the effective diffusion coefficients were 2.25×10<sup>-7</sup>-2.35×10<sup>-6</sup>m<sup>2</sup>/h. In terms of drying effectiveness, the most efficient technological parameters were presented as follows: Drying temperature of 55℃, manure thickness of 6 cm, and air speed of 1.2 m/s, and the drying effectiveness under this condition was 0.47 h/g. The order of the factors for increasing drying effectiveness was drying temperature > thickness > air speed.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Fertilizers
Controlled terms:Diffusion - Drying - Heating - Low temperature drying - Manures - Models - Moisture - Plants (botany) - Soil pollution - Solar energy - Temperature - Water pollution
Uncontrolled terms:Drying characteristics - Dynamic characteristics - Effective diffusion coefficients - Exponential models - Middle-low temperatures - Organic fertilizers - Parameter optimization - Technological parameters
Classification code:453 Water Pollution - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 802.3 Chemical Operations - 804 Chemical Products Generally - 821.5 Agricultural Wastes
Numerical data indexing:Size 6.00e-02m, Velocity 1.20e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.10.024
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 10>
Accession number:20182405305852
Title:Development of 4JSM-2000A type combined operation machine for cotton stalk chopping and residual plastic film collecting
Authors:Tian, Xinliang (1); Zhao, Yan (2, 3); Chen, Xuegeng (1, 3); Yan, Limin (1, 3); Wen, Haojun (2, 3); Gou, Haixiao (2, 3); Ji, Chao (2, 3)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi; 832000, China; (2) Mechanical Equipment Research Institute, Xinjiang Academy of Land Reclamation Sciences, Shihezi; 832000, China; (3) Key Laboratory of Northwest Agricultural Equipment of Ministry of Agriculture, Shihezi; 832000, China
Corresponding author:Zhao, Yan(xjnkkxy_zy@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:25-35
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plastic film mulching and planting technology has been widely used all over the world, and has made great contribution to the development of agriculture. The film is so thin that it is difficult to recover, resulting in a heavy white pollution problem. Among them, Xinjiang is a heavy disaster area of white pollution. At present, the residual membrane recycling machine widely used in Xinjiang is the vertical rod type cuddle machine. This machine has simple structure, small failure rate and fast moving speed, but has many problems. The recovery rate of residual film is less than 50%, and especially the residual film in narrow rows can't be recovered. Next is the frequent unloading of membrane, and after traveling a distance of about 30 m, membrane needs to be unloaded once, which seriously affects the operation efficiency. The unloading operation is carried out through the up and down jitter of the lifting arm of the machine, and the frequent operation can make a damage to the hydraulic system of the tractor hoist arm. In order to solve the problems that the recovery rate of residual film is not high in the traditional vertical rod encircling machine, the plastic film on the narrow line is basically unrecoverable, and the discharge of the film is frequent, the joint operation machine of 4JSM-2000A cotton stalk crushing and film collecting was designed. The machine is mainly composed of cotton stalk crushing mechanism, screw conveying mechanism, membrane collecting mechanism, membrane unloading mechanism, transmission system and rack. One-time operation can complete 2 steps, i. e. cotton stalk crushing and film wrapping. The side output type cotton stalk crushing device is adopted, and the crushed cotton stalk is output to the ground through a screw auger, so that the separation of the membrane rod can be facilitated. A small narrow row of membrane elastic teeth with floating function are added to the membrane part, so that the residual membrane picking rate is further improved. The residual membrane recovery machine is used to control the hydraulic cylinder by the hydraulic control after the tractor. The automatic membrane unloading is realized, which makes up the deficiency of the existing vertical rod type cuddle machine. According to the design of the main working parts, the arrangement, the speed of the moving knives of the cotton rod device, the screw conveying, the stirring dragon, and the pre-tightening spring of the floating encircling film device are designed and studied, and the structural dimensions are determined. The machine adopts large size spring-tooth, increases the storage space of materials, prolongs the working distance to 50-70 m, reduces the number of film unloading, and improves the working efficiency. After the tractor outputs hydraulic pressure to control hydraulic cylinder expanding and contracting, automatic film unloading is realized. The stress of the spring-tooth is analyzed, and the range of the penetration angle of the spring-tooth is 10°-30°. The depth of the spring-tooth, the number of spring-teeth and the speed of the machine were tested, and the response surface analysis was done. The 3 factors had significant influence on the recovery of residual film, and the optimizing function of Design-Expert software was used for optimization. The test results show that when the depth of the spring-tooth is 20 mm, the number of spring-teeth is 12, and the speed of machine is 1.5 m/s, the recovery rate of residual film is 91%. The experiment shows that the optimization plan is feasible. The parameters of the machine meet the design requirements. The results of the study can provide a reference for the development of residual film recovery machine.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Springs (components)
Controlled terms:Agricultural machinery - Cotton - Crushing - Cylinders (shapes) - Disasters - Efficiency - Experiments - Failure analysis - Hydraulic equipment - Hydraulic machinery - Mechanical actuators - Membranes - Plastic films - Pollution - Problem solving - Recovery - Screws - Straw - Surface analysis - Tractors (agricultural) - Tractors (truck) - Unloading
Uncontrolled terms:Combined operations - Hydraulic cylinders - Operation efficiencies - Optimizing functions - Plastic film mulching - Response surface analysis - Structural dimensions - Transmission systems
Classification code:601.2 Machine Components - 605 Small Tools and Hardware - 632.2 Hydraulic Equipment and Machinery - 663.1 Heavy Duty Motor Vehicles - 691.2 Materials Handling Methods - 732.1 Control Equipment - 817.1 Polymer Products - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 913.1 Production Engineering - 951 Materials Science
Numerical data indexing:Percentage 5.00e+01%, Percentage 9.10e+01%, Size 2.00e-02m, Size 3.00e+01m, Size 5.00e+01m to 7.00e+01m, Velocity 1.50e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.10.003
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 11>
Accession number:20182405305872
Title:Analysis and application on thermal performance of direct solar drying system
Authors:Hao, Wengang (1); Lu, Yifeng (1); Lai, Yanhua (1, 3); Yu, Hongwen (2, 4); Lü, Mingxin (3)
Author affiliation:(1) School of Energy and Power Engineering, Shandong University, Jinan; 250061, China; (2) College of Materials Science and Engineering, Beijing University of Technology, Beijing; 100124, China; (3) Suzhou Institute, Shandong University, Suzhou; 215028, China; (4) Shandong Sangle Solar Energy Ltd., Jinan; 250014, China
Corresponding author:Lai, Yanhua(laiyh@sdu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:187-193
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The direct solar drying system has the advantages of simple structure, cheapness, and protecting the dried materials from being damaged by dust, rain, dew, and so on; however, there are some disadvantages such as overheating of the dried materials surface, poor quality of the dried material and drying ability limited. In order to solve problems of drying product overheating and drying process uncontrollable in direct solar dryer, a direct solar drying system was designed and built to test system performance by using sweet potatoes as drying material. The system was mainly composed of air inlet, air outlet, dry material tray, transparent glass cover and stainless steel plate. The frame of drying chamber was made of aluminum alloy, and the black endothermic material was uniformly applied to the inner surface of the stainless steel plate of the drying chamber. The tilt angle of the roof glass of the drying chamber was 26.7°. The length, width and height of the drying chamber were 1000, 800 and 800 mm, respectively. The insulation material of the drying chamber was made of 20 mm thick polyurethane insulation cotton to prevent the heat loss, and the transparent surface of drying chamber adopted ordinary glass with transmittance of 90%. The dry material used in this experiment was fresh sweet potato, purchased in Jingdong Mall, with the origin of Yuxi, Yunnan. Before the experiment, the sweet potatoes were cut into pieces of uniform size and thickness, and divided into 2 parts with the same mass by the balance; one part was used for the experimental group of direct solar drying and the other part was used for the comparison group of open sun drying. The experimental test was conducted on May 7, 2017, from 8: 30 to 17: 00. The initial mass of dry materials in the experimental group and the control group was 240 g. In addition, dynamic mathematical models of thermal performance of system were built and calculated with the help of MATLAB 2014a software, outdoor meteorological parameters, the characteristics of drying materials and building systems were given, and the correlations between experimental value and simulation value were analyzed. The results showed that the transmittance of drying chamber ranged from 51.7% to 89.6%. The highest air temperature in the drying chamber appeared half an hour later than the peak of outdoor solar radiation intensity. It indicated that the drying chamber had certain delay and resistance to the change of outdoor environment interference. The average drying rate of the direct solar drying system was 7.7 g/h higher than that of the open solar drying system. Time period with drying air temperature ranging from 50 to 70℃ accounted for 80% of the total drying time, which showed that the direct solar drying system can provide the most suitable drying temperature for most dry materials. The total thermal energy obtained by the drying system was 3.92 kW·h, and the average solar heat utilization efficiency was 21.23%; the correlation coefficient of the experimental value and the simulated value was 0.98, and the root mean square error was 1, which proves that the dynamic model of dynamic thermal performance can accurately predict the surface temperature of the dry materials in the drying chamber.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Drying
Controlled terms:Aluminum alloys - Atmospheric temperature - Efficiency - Energy balance - Energy efficiency - Forecasting - Glass - MATLAB - Mean square error - Plates (structural components) - Solar dryers - Solar energy - Stainless steel
Uncontrolled terms:Correlation coefficient - Drying air temperatures - Dynamic mathematical model - Meteorological parameters - Polyurethane insulation - Root mean square errors - Solar heat utilization - Solar radiation intensity
Classification code:408.2 Structural Members and Shapes - 443.1 Atmospheric Properties - 525.2 Energy Conservation - 541.2 Aluminum Alloys - 545.3 Steel - 657.1 Solar Energy and Phenomena - 812.3 Glass - 913.1 Production Engineering - 921 Mathematics - 922.2 Mathematical Statistics - 931 Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Mass 2.40e-01kg, Mass_Flow_Rate 2.14e-06kg/s, Percentage 5.17e+01% to 8.96e+01%, Percentage 8.00e+01%, Percentage 9.00e+01%, Size 2.00e-02m, Size 8.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.10.023
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 12>
Accession number:20182405305874
Title:Net energy characteristic in biogas plants with slurry waste heat recovery
Authors:Wang, Shuxia (1); Ruan, Yingjun (1); Zhou, Weiguo (1); Wu, Jiazheng (1)
Author affiliation:(1) College of Mechanical and Energy Engineering, Tongji University, Shanghai; 201804, China
Corresponding author:Ruan, Yingjun(ruanyj@tongji.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:200-209
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Anaerobic digestion is a promising technology for the treatment of high strength organic wastes, since it produces renewable energy (biogas) and valuable digestate as fertilizer. The object of this paper is a small-scale anaerobic digestion system treating swine manure, which can operate at two modes. Mode 1 is a base anaerobic digestion unit, mainly including the reactor and biogas boiler, and based on Mode 1, Mode 2 incorporates a slurry waste heat recovery unit. In order to explore the effects of fermentation temperature and volatile solid (VS) concentration on net energy production characteristic of biogas plants, this paper built a numerical energy balance model based on the above system and the two operation modes. An evaluation framework, including energy efficiency ratio and net energy production, was proposed for contrastive analysis between different operation modes. In addition, slurry temperature distribution at ambient conditions without any heating measures and system heat load characteristic at Mode1 were also studied in this paper. It shows that at ambient conditions, the digester could operate normally for 5 months per year with the slurry temperature ranging from 20-35℃, and it could only last 2 hours for temperature 35℃. When heated by biogas boiler, the heat required to raise influent slurry temperature to working temperature (20-60℃) accounted for approximately 69% of the total heat load. For evaluation indicator of energy efficiency ratio, a corresponding maximum digestion temperature to guarantee the benchmark indicator (energy efficiency ratio of 6.4) was determined at Mode 1 with the VS of 6% and digestion temperature of 35℃. From 4% to 10% of VS, the maximum temperature at Mode 1 were 28.9, 35, 39.6 and 39.5℃, respectively, and became more lenient at Mode 2, they were 36.5, 46.4, 54.6 and 58℃, respectively. From 4% to 10% of VS, the digestion temperature for achieving the maximum net energy at Mode 1 were 30, 35, 45 and 60℃, respectively, while at Mode 2, they were 35, 40, 50 and 60℃. Furthermore, heating measures for anaerobic digestion system were beneficial to improve net energy production. At the VS of 6%, biogas production at ambient conditions was only 0.36 times as much as that at mesophilic temperature (35℃). When heated by biogas boiler, the ratio of the maximum net energy was 2.37 times of that at ambient temperatures; While coupled with the recovery of effluent slurry waste heat, it was 2.53 times. The largest increase of the maximum net energy of between Mode 1 and Mode 2 at specific VS was approximately 11.5%, with the corresponding energy efficiency ratio was around 53.1%. Therefore, it is obvious that feeding heating load is a key factor influencing the digestion process. Hence, for the stable fermentation system, it is of great significance to pay more attention to the heating process of the feedstock. Meanwhile, it should consider the digestion temperature, the VS concentration, the energy efficiency ratio, the net energy production, the operation mode and other related factors for optimal operation parameter determination of the anaerobic digestion system. Last but not least, it is necessary to further research the characteristics of the gas production during continuous changes of the influencing factors such as VS concentration and digestion temperature to ensure the accuracy of the optimal parameters.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Anaerobic digestion
Controlled terms:Biogas - Boilers - Digestive system - Effluents - Energy efficiency - Fermentation - Fertilizers - Heating - Slurries - Temperature - Thermal load - Waste heat - Waste heat utilization
Uncontrolled terms:Energy efficiency ratio - Evaluation indicators - Fermentation temperature - Maximum digestion temperature - Mesophilic temperature - Net energy - Waste heat recovery units - Working temperatures
Classification code:452.3 Industrial Wastes - 461.2 Biological Materials and Tissue Engineering - 522 Gas Fuels - 525 Energy Management and Conversion - 614 Steam Power Plants - 641.1 Thermodynamics - 801.3 Colloid Chemistry - 804 Chemical Products Generally
Numerical data indexing:Age 4.17e-01yr, Percentage 1.15e+01%, Percentage 4.00e+00% to 1.00e+01%, Percentage 5.31e+01%, Percentage 6.00e+00%, Percentage 6.90e+01%, Time 7.20e+03s
DOI:10.11975/j.issn.1002-6819.2018.10.025
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 13>
Accession number:20182405305869
Title:Automatic detection of multi-target ruminate cow mouths based on Horn-Schunck optical flow algorithm
Authors:Song, Huaibo (1, 2, 3); Li, Tong (1, 2, 3); Jiang, Bo (1, 2, 3); Wu, Qian (1, 2, 3); He, Dongjian (1, 2, 3)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) Key Laboratory of Agricultural Internet of Things, Ministry of Agriculture, Yangling; 712100, China; (3) Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service, Yangling; 712100, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:163-171
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is of great importance to realize the intelligent monitoring of dairy cow's rumination for improving the modern cultivation and supervision of cows' health. Cow's mouth area is the key to the intelligent monitoring of dairy cows' rumination. A multi-target cow rumination detection method based on Horn-Schunck optical flow method was proposed. The Horn-Schunck optical flow model was carried out to get optical flow field of the time series images for the ruminating video. In each frame of optical flow diagram, vector was used to represent the movement trend of the pixel block, the length of the vector represented the speed of the movement, and the direction of the vector represented the direction of the movement. The most intense part of the movement when cow is ruminating is related to the mouth area, and the region with the densest vectors in each frame of optical flow diagram is the cow's mouth area too. By superimposing each frame of optical flow diagram, the complete optical flow of cow mouth area could be obtained. The data of large optical flow in each frame were superimposed to a new optical flow graph, and the new optical flow graph was divided into binary image by using appropriate threshold segmentation. Disk type structure element was adopted in the mathematical morphological operation to the binary image. Because the most intense part of the movement when cow is ruminating is related to the mouth area, it could be determined that the largest area of the pixel block was the cow's mouth region, and the candidate cows' mouth regions were filtered out. A mathematical model was applied to detect the ruminant cows' mouth area. The main principle of this mathematical model was to determine the size and position of the test box. Setting test box as a square, the side length of the square is equal to the width of cow's mouth. To get the position of the test box, we need to get the coordinate of center point for the test box. Setting the x coordinate of the center point be equal to the rightmost x coordinate of the cow's mouth area minus 50% of cow's mouth width, the y coordinate is equal to the mean value of the y coordinate of each point for cow's mouth area minus 50% of cow's mouth width. In order to verify the effectiveness of the algorithm, 12 video data obtained from different environments including sunny day, cloudy day and strong windy day were verified. The length of each video is 10 seconds, and the number of video frames for each video is between 250 and 280 frames. The results showed that, for the multi-target cows, the proposed method could not detect the area of ruminant cow's mouth in strong wind environment in 2 videos, and could be used for the detection of ruminant cow's mouth in the remaining 10 videos. For 8 videos of the remaining 10 videos the region of ruminant cow's mouth could be detected successfully. According to the percentage of the actual mouth area by the detection box, the true filling rate was defined. According to the percentage of the optical flow algorithm's mouth area by the detection box, the detected filling rate was defined. The highest true filling rate of the 8 videos was 96.76%, the lowest true filling rate of the 8 videos was 25.36%, and the average true filling rate of the 8 videos for which the region of ruminant cow's mouth can be detected was 63.91%. The highest detected filling rate of the 8 videos was 98.51%, the lowest detected filling rate of the 8 videos was 43. 80%, and the average detected filling rate of the 8 videos was 70.06%. The above results indicate that it is feasible to apply the Horn-Schunck optical flow method to detect the area of the multi-target cow's mouth automatically. This study provides the reference for intelligent monitoring of the ruminating behavior of cows.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Flow graphs
Controlled terms:Algorithms - Automatic testing - Binary images - Filling - Flowcharting - Graphic methods - Image processing - Image segmentation - Mathematical morphology - Optical data processing - Optical flows - Pixels - Vectors
Uncontrolled terms:Direction of the movement - Intelligent monitoring - Mathematical morphological operation - Multi-targets - Optical flow algorithm - Strong wind environment - Threshold segmentation - Video analysis
Classification code:691.2 Materials Handling Methods - 723.1 Computer Programming - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 921.1 Algebra - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory
Numerical data indexing:Percentage 2.54e+01%, Percentage 5.00e+01%, Percentage 6.39e+01%, Percentage 7.01e+01%, Percentage 8.00e+01%, Percentage 9.68e+01%, Percentage 9.85e+01%, Time 1.00e+01s
DOI:10.11975/j.issn.1002-6819.2018.10.020
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 14>
Accession number:20182405305877
Title:Simulation of biomembrane degrading organic wastewater by 3D lattice Boltzmann mass transfer model
Authors:Yang, Yanxia (1, 2); Li, Jing (3)
Author affiliation:(1) Department of Thermal Engineering, Taiyuan University of Technology, Taiyuan; 030024, China; (2) Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education of China, Chongqing University, Chongqing; 400044, China; (3) Department of Building Environment and Energy Engineering, Taiyuan University of Technology, Taiyuan; 030024, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:225-230
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biological treatment has been proven as an efficient wastewater treatment technology and widely used in the processes of city sewage and industrial waste. Biomembrane is aggregates of microorganisms suspended in a matrix of extracellular polymeric substances. Especially, photosynthetic bacteria (PSB) have exhibited significant superiorities to degrade the organic compounds in wastewater through utilizing solar energy, and simultaneously generate hydrogen energy, which is considered as a promising candidate due to its advantages of high energy content, high stability of combustion, cleanness and high efficiency. Biofilm is the foundation of biological membrane processing for wastewater treatment systems. In fact, the structure of biofilm has been proven to be a porous membrane, and thereby the degradation process could be considered as bioreaction in a bioreactor with porous media. Recently, numerous bioreactors and experiments have been proposed and implemented with the aim to improve the stability of reactors and performance of hydrogen production. Except experimental study, many theoretical studies have been carried out, and some numerical models have been established to investigate the bioreaction and two-phase flow transport in the bioreactors. Noteworthily, these numerical models are generally based on macro-scale, and require solving the partial difference equations for complex system. Moreover, they are still quite limited to obtain the detail information of fluid flow and mass transport in the biofilm, and also have difficulties in treating complex geometry of biofilm. Therefore, it is necessary to carry out a further numerical study on the flow and mass transport in bioreactor to overcome the limitations. In present study, a lattice Boltzmann method (LBM) was adopted to simulate the biodegradation in the bioreactor. Unlike the conventional numerical methods based on macroscopic continuum equations, the LBM was a mesoscopic approach that incorporates the essential physics of microscopic or mesoscopic process. Lattice Boltzmann models were based on microscopic kinetic equation for the particle distribution function, and the macroscopic quantities were then obtained through moment integrations of the distribution function. The lattice Boltzmann method has the most distinguished advantages, such as the simplicity of algorithm, the flexibility for complex geometries and parallel computing. Therefore, the flow and mass transfer as well as bioreaction were simulated with 3D lattice Boltzmann model. Moreover, the detailed porous structure of biofilm was generated by quartet structure generation set (QSGS) method, which was closely combined with lattice Boltzmann model. In the simulation, the lattice Boltzmann model was coupled with a multi-block scheme to improve the computational efficiency and accuracy, and the non-equilibrium extrapolation method was used for velocity and concentration boundary condition treatment. The effect of porosity and pore structure of biofilm on flow and mass transfer was investigated, and the simulation results were compared with the experimental data, validated the LB model. The simulation results indicated that with the increasing biofilm porosity, the substrate consumption efficiency increased and reached the maximum of 50.97% at porosity of 0.5, then decreased under the condition of the same growth probability on every discrete direction; different growth probabilities would lead to the biofilm with various pore structures and specific surface areas, and thereby affect the performance of membrane bioreactor, and the substrate consumption efficiency was highest, 52.54%, under the condition of biofilm with structure 1 (p<inf>3-4</inf>=0.01, p<inf>1, 2, 5-14</inf>=0.005) at Ε=0.5, indicating that this characteristics of porous biofilm is optimal for bioreaction.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Two phase flow
Controlled terms:Bacteria - Biodegradation - Biofilms - Biological membranes - Biological sewage treatment - Biological water treatment - Bioreactors - Bioremediation - Boltzmann equation - Computational efficiency - Computational fluid dynamics - Cytology - Difference equations - Distribution functions - Electroosmosis - Geometry - Hydrogen production - Industrial waste treatment - Industrial water treatment - Integral equations - Kinetic theory - Mechanical permeability - Models - Numerical methods - Numerical models - Pore structure - Porosity - Porous materials - Reclamation - Sewage - Solar energy - Solar power generation - Superconducting materials - Transport properties - Waste incineration - Wastewater treatment
Uncontrolled terms:Bioreaction - Boundary condition treatments - Extra-cellular polymeric substances - Lattice boltzmann methods (LBM) - Numerical regeneration - Particle distribution functions - Photosynthetic bacteria (PSB) - Wastewater treatment technologies
Classification code:445.1 Water Treatment Techniques - 445.1.2 Water Treatment Techniques for Industrial Use - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 454.2 Environmental Impact and Protection - 461.2 Biological Materials and Tissue Engineering - 461.8 Biotechnology - 462.5 Biomaterials (including synthetics) - 522 Gas Fuels - 615.2 Solar Power - 631.1 Fluid Flow, General - 657.1 Solar Energy and Phenomena - 701.1 Electricity: Basic Concepts and Phenomena - 708.3 Superconducting Materials - 921 Mathematics - 922 Statistical Methods - 922.1 Probability Theory - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 5.10e+01%, Percentage 5.25e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.028
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 15>
Accession number:20182405305851
Title:Design and experiment of precision air-suction type planter for potato
Authors:Lü, Jinqing (1, 2); Yi, Shujuan (1); Tao, Guixiang (1); Mao, Xin (1)
Author affiliation:(1) College of Engineering, Heilongjiang Bayi Land Reclamation University, Daqing; 163319, China; (2) Department of Engineering, Northeast Agricultural university, Harbin; 150030, China
Corresponding author:Yi, Shujuan(yishujuan_2005@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:16-24
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problems such as the lower operation speed, lower precision at the present stage of China's potato planting machine, the potato air-powered precision planter was developed in this paper. This planting machine contains fertilizer shovel, seed-metering device, wind blowing fan, potato seed box, wind suction fan, soil coverer, transmission device and land wheel. The whole machine is tracked by tractor with the power of 88.6 kW, and the power of fan rotary dynamic device is provided by tractor. The air-powered precision seed-metering device for potato is different from the traditional air suction device, and it has the distributed multi suction arms and at the end of each arm is installed with suction nozzles. With the rotation of seed-metering device and the working of suction fan and blowing fan, the potato can be sucked on the suction nozzles and cast into furrow in special position. As the most important structure of the seed-metering device, the sealing property of the device is very significant, and the air distribution valve of this seed-metering device is made of alumina alloy covered with porcelain. The static value cooperates with rotary value. The areas of positive pressure and negative pressure zone in static value are independent, and the negative pressure zone and the positive pressure area account for 300° and 13°, respectively. The suction nozzle contains miniature potato nozzle and conventional potato nozzle. The soil particles are cut and crashed by the edge of the shovel at the front side of the sliding-knife opener, and move along the side of opener. Some of the soil particles fall into the furrow first to create a soft furrow, and the rest of soil particles move backwards along the opener, and then cover the potato when it falls into furrow. The lower soil particles can firstly provide a better furrow situation for potato to grow. Besides, the seed-supplying device is designed to meet the needs of the transfer of potato. This potato level switch is the key part of this device. The electrical signal can be transferred from switch to motor to transfer potato seed. Fan blade is designed to meet the requirements of suction pressure. The centrifugal fan is used due to the higher efficiency. The test was implemented in Heilongjiang Academy of Agricultural Sciences and Keshan Farm in 2016 and 2017. Potato in this test was prepared by Northeast Agricultural University. Field experiments showed that the potato air-suction planter's operating speed reached 10.2 km/h, emergence of seedling was 2-3 days earlier than potato planted by traditional planter, and the seedling rate reached 96%, indicating that the production practice of the seedlings of this device is strong. The field production test area was 200 hm<sup>2</sup>, the replay rate of the potato air-powered planter was below 1%, the missing rate was below 1%, and the coefficient of variation for row spacing was less than 10%, exceeding the national standard and meeting the requirements of potato planting agronomy; the mean absolute deviation of sowing width was less than the traditional potato planter due to the use of sliding-knife opener. This air-powered planter can provide a new technology for high speed precision potato sowing and promote the potato production mechanization process in China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Seed
Controlled terms:Agricultural machinery - Alumina - Aluminum oxide - Design - Fans - Machine design - Nozzles - Pneumatic materials handling equipment - Shovels - Soil testing - Soils - Tractors (truck)
Uncontrolled terms:Agricultural science - Coefficient of variation - Mean absolute deviations - Planter - Potato - Precision seed-metering devices - Seed metering devices - Transmission devices
Classification code:483.1 Soils and Soil Mechanics - 601 Mechanical Design - 618.3 Blowers and Fans - 632.4 Pneumatic Equipment and Machinery - 663.1 Heavy Duty Motor Vehicles - 804.2 Inorganic Compounds - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products
Numerical data indexing:Age 5.48e-03yr to 8.22e-03yr, Percentage 1.00e+00%, Percentage 1.00e+01%, Percentage 9.60e+01%, Power 8.86e+04W, Velocity 2.83e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.10.002
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 16>
Accession number:20182405305871
Title:Thermal performance analysis of assembled active heat storage wall in Chinese solar greenhouse
Authors:Bao, Encai (1, 2); Shen, Tingting (1); Zhang, Yong (1); Cao, Kai (1, 2); Cao, Yanfei (1); Chen, Danyan (1); He, Bin (3); Zou, Zhirong (1, 2)
Author affiliation:(1) College of Horticulture, Northwest A&F University, Key Laboratory of Protected Horticultural Engineering in Northwest, Yangling; 712100, China; (2) Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture, Nanjing; 210014, China; (3) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; 712100, China
Corresponding author:Zou, Zhirong(zouzhirong2005@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:178-186
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solar greenhouse is efficient energy-saving greenhouse which plays an important role in the development of protected horticulture in China. The biggest differences between solar greenhouse and other types of greenhouse are the walls, which act as load-bearing, heat storage and heat preservation. At present, a lot of research has been done on the material and structure of solar greenhouse. In terms of material research, it is generally believed that the performance of composite heterogeneous wall is better than that of single material wall. In terms of structure, many scholars have studied the reasonable thickness of the wall and developed an efficient active heat storage wall structure. Active heat storage wall solar greenhouse has a good heat storage capacity, which is the development trend of solar greenhouse. However, there are some disadvantages such as slow construction speed and high cost. In order to solve these problems, in our research, we simplified the construction techniques of active heat storage wall., The Chinese solar greenhouses with traditional active heat storage wall (G1), backfill-assembled active heat storage wall (G2) and modular assembled active heat storage wall(G3) were constructed, the indoor environments were tested and the thermal performances were analysed. The results showed that under continuous sunny conditions (from 2017-12-30 09: 00 to 2018-01-02 09: 00), the average temperatures in G1, G2 and G3 were 19.9, 20.1, 20.8℃; the night average temperature were 15.2, 16.0, 17.3℃ respectively; the night average temperature in G2 and G3 were 0.8 and 2.1℃ higher than that in G1; the night minimum average temperatures in G1, G2, G3 were 13.4, 14.7, 15.6℃; night minimum average temperature in G2 and G3 were 1.3 and 2.2℃ higher than that in G1. Under continuous cloudy conditions (from 2018-01-13 09: 00 to 2018-01-16 09: 00), the average temperature in G1, G2 and G3 were 12.9, 14.4, 14.3℃; the night average temperatures in G1, G2, G3 were 11.3, 12.9, 13.0℃, the night minimum average temperatures in G1, G2, G3 were 9.8, 11.5, 11.7℃. Therefore, under continuous cloudy conditions, the temperature in G2 and G3 were almost at the same level but were better than that in G1. The temperature analysis results of the coldest month (from 2017-12-22 to 2018-01-21) showed that the average temperature and night minimum temperature in G2 and G3 were higher than that in G1; and the lowest temperature not higher than 8℃ were 2 and 1 days in G2 and G3. Therefore, G2 and G3 had stronger ability to resist continuous low temperature than G1 which could meet the heat demand of greenhouse vegetables without extra heating. The overall performance of G3 was better than that of G2, and the overall performance of G2 better than that of G1. Under typical sunny conditions (from 2017-12-31 09: 00 to 2018-1-1 09: 00), the heat storage thickness of the wall of G1, G2, G3 were 700-800, 800-900 and 700-800 mm; under typical cloudy conditions (from 2018-01-14 09: 00 to 2018-01-15 09: 00), the heat storage thickness of G1, G2, G3 were 300-400, 500-600, 500-600 mm. The cost of the wall of G1 was 461.1 yuan/m<sup>2</sup>, however, the costs of the walls of G2, G3 were significantly reduced to 389.9 and 299.0 yuan/m<sup>2</sup>respectively. In summary, the thermal properties of G2 and G3 were not significantly different, but were both better than that of G1, which could meet the production needs of thermophilic crops in greenhouse. The assembled active heat storage wall was feasible, and the cost was reduced, and had a certain popularization value in some area suitable for constructing greenhouse.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Greenhouses
Controlled terms:Cost reduction - Energy conservation - Heat storage - Solar heating - Storage (materials) - Temperature - Thermal processing (foods)
Uncontrolled terms:Assembled - Chinese solar greenhouse - Construction technique - Greenhouse vegetables - Heat storage capacity - Solar greenhouse - Thermal performance analysis - Wall
Classification code:525.2 Energy Conservation - 641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 694.4 Storage - 821.6 Farm Buildings and Other Structures - 822.2 Food Processing Operations
Numerical data indexing:Age 2.74e-03yr, Age 5.48e-03yr, Size 5.00e-01m to 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.10.022
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 17>
Accession number:20182405305866
Title:Spatio-temporal evolution analysis of soil erosion based on USLE model in Dianchi Basin
Authors:Peng, Shuangyun (1, 3); Yang, Kun (2, 3); Hong, Liang (1, 3); Xu, Quanli (1, 3); Huang, Yajun (1, 3)
Author affiliation:(1) School of Tourism and Geography, Yunnan Normal University, Kunming; 650500, China; (2) School of Information Science and Technology, Yunnan Normal University, Kunming; 650500, China; (3) GIS Technology Research Center of Resource and Environment in Western China of Ministry of Education, Kunming; 650500, China
Corresponding author:Yang, Kun(kmdcynu@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:138-146
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is of great importance to control the spatial distribution pattern and evolution tendency of soil erosion in the Dianchi Basin for optimizing soil and water conservation measures, conducting water pollution control of Dianchi Lake and ensuring the basin's sustainable development. In this study, the amount of soil erosion in the Dianchi Lake basin between 1999 and 2014 has been calculated every 3 years by applying RS and GIS techniques in combination with a soil erosion model (USLE) based on the data source of precipitation, soil, DEM and remote sensing images, for the purpose of analyzing the spatial-temporal evolution characteristics of the basin's soil erosion intensity. The results indicated that: 1) The USLE model showed a high simulation accuracy for the erosion amount with the relative error was ≥18.16% and R<sup>2</sup>≥0.996; 2) The area with no apparent erosion increased from 70% in1999 to 82% in 2014, while there was a year-by-year downtrend for the soil erosion area, with the erosion area in 1999 was 776 km<sup>2</sup>and decreased to 468 km<sup>2</sup>in 2014, which showed that soil erosion in the Dianchi Basin has been effectively controlled; 3) There were remarkable characteristics for the spatial evolution trend of basin's erosion intensity: the erosion intensity in 75% or so of the basin did not change, and was spatially concentrated in the main urban area of Kunming City, the downtown of Jinning County and the area of Xinjie Town; 18.23% of the basin showed a decline in the level of erosion intensity, mainly concentrated in the streams around Dianchi lake and flowing into the lake; 8.36% of the basin showed a rise in the level of erosion intensity, mostly distributed in the mountainous terrains at the east, north and south ends of the Dianchi Basin; 4) The erosion intensity level diverting matrix showed that a relatively small change rate and a relatively high preservation rate in tiny erosion; the rate of high erosion levels shifting to low erosion levels was higher than that of low erosion levels shifting to high erosion levels, illustrated that the erosion areas were well managed with significant effects; the rate of tiny erosion and slight erosion shifting to moderate and intensive erosion was very low, lower than 0.94% in all periods, which meant that the policy of converting farmland into forests launched since 1998 obtained quite good effects. In sum, the production of series of graphs for erosion changes by integrating RS, GIS techniques and the soil erosion model can help to discover vulnerable areas for soil erosion from a spatial-temporal change perspective, which could be helpful to analyze the evolution of regional soil erosion from emergence, development to disappearance, providing the bases for making decisions for further accurate erosion prevention/control measures and as a reference for the basin's eco-environmental protection.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Soil conservation
Controlled terms:Environmental protection - Erosion - Geographic information systems - Lakes - Models - Remote sensing - Soil pollution control - Soils - Sustainable development - Water conservation - Water pollution - Water pollution control
Uncontrolled terms:Dianchi Basin - Soil and water conservation measures - Soil erosion modeling - Spatial distribution patterns - Spatial-temporal changes - Spatial-temporal evolution - Spatiotemporal evolution - USLE
Classification code:444 Water Resources - 453 Water Pollution - 453.2 Water Pollution Control - 454.2 Environmental Impact and Protection - 483.1 Soils and Soil Mechanics - 903.3 Information Retrieval and Use
Numerical data indexing:Age 3.00e+00yr, Area 4.68e+08m2, Area 7.76e+08m2, Percentage 1.82e+01%, Percentage 7.50e+01%, Percentage 8.20e+01%, Percentage 8.36e+00%, Percentage 9.40e-01%
DOI:10.11975/j.issn.1002-6819.2018.10.017
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 18>
Accession number:20182405305883
Title:Comparison and verification of respiratory rate models of Litchi under different storage temperatures
Authors:Xia, Jingjing (1); Yu, Xinxin (2); Lü, Enli (2, 3); Lu, Huazhong (2, 3); Huang, Hao (2); Chen, Minglin (2)
Author affiliation:(1) Guangdong Mechanical & Electrical Polytechnic, Guangzhou; 510550, China; (2) College of Engineering, South China Agricultural University, Guangzhou; 510642, China; (3) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, Guangzhou; 510642, China
Corresponding author:Lü, Enli(enlilv@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:267-273
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Litchi is delicious, which is loved by consumers, But litchi is a fruit which is extremely not resistant storage. After a period of normal temperature, litchi is easy to browning and flavour. Litchi belongs to the respiratory strong fruit, Litchi can consume certain oxygen to produce carbon dioxide during respiration. Therefore, during storage, the concentration of carbon dioxide and oxygen directly affects the respiratory intensity of litchi. For the study of litchi respiration rate prediction model in this paper, "Guiwei" litchi fruit was chosen as the experimental material, at different temperatures (5, 10, 15, 20, 25℃) using a closed space system method to carry out the research on the respiration rate of Litchi, The nonlinear model, Michaelis-Menten model based on the principle of enzyme dynamics and multiple regression model for the prediction of the respiration rate of Litchi. The results show that among the three models, the multivariate regression model has the highest degree of fitting, providing a reference for the calculation of the respiration rate of litchi. The temperature has a certain influence on litchi respiration rate, the temperature rise will accelerate the respiration of litchi, low temperature contribute to the inhibition of respiration, Litchi during respiration rate decreased with time increasing, tends to a stable value, in the long run during the cold storage of litchi to keep low respiratory rate can effectively prolong the quality of litchi shelf life. Based on multiple regression analysis of litchi respiration rate, this paper fitted several respiratory rate models, and the fitting degree is high. The expression can provide reference for the calculation of litchi respiration rate. In order to compare the differences between different models, this paper verified the litchi each respiration model under 15℃, The fitting degree of the three models was greater than 0.92, which indicated that all the three models were suitable for calculating the respiration rate of litchi. There is a certain deviation between the predicted value of different respiration rate models and the actual calculated value. The relative error of Non-linear model P1 prediction value is -10%-28%, The relative error of Michaelis-menten model P2 prediction value is -14%-14% and the relative error of Multiple regression model P3 prediction value is -10%~10%. The three models can to a certain extent show the relationship between respiration rate with time, the respiration rate decreased with time increasing, and finally tends to be stable, confirmatory experiments show that the relative errors of the models prediction values are small, The results showed that the multiple regression model could better characterize the litchi respiration rate model to a certain extent. The selection of the multiple regression model can more accurately reflect the actual respiration rate of Litchi and provide a theoretical basis for gas storage. The results show that the multiple regression model not only has a high degree of fitting, a small relative error, but also a more rigorous prediction trend, and the multiple regression model is suitable for the calculation of respiratory intensity of litchi.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Regression analysis
Controlled terms:Carbon dioxide - Cold storage - Energy storage - Enzyme kinetics - Errors - Forecasting - Fruits - Models - Nonlinear systems - Temperature
Uncontrolled terms:Experimental materials - Gas component - Litchi - Michaelis-Menten model - Multiple regression analysis - Multiple regression model - Multivariate regression models - Respiratory intensity
Classification code:525.7 Energy Storage - 641.1 Thermodynamics - 644.3 Refrigeration Equipment and Components - 804.2 Inorganic Compounds - 821.4 Agricultural Products - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Percentage -1.00e+01% to 2.80e+01%, Percentage -1.40e+01% to 1.40e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.034
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 19>
Accession number:20182405305886
Title:Isolation and purification of flavonoids from Ginkgo biloba pollen and their DPPH scavenging activities
Authors:Qiu, Jiying (1); Chen, Xiangyan (1); Yan, Huijiao (2); Wang, Daijie (2); Chen, Leilei (1)
Author affiliation:(1) Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing Technology of Shandong Province, Jinan; 250100, China; (2) Shandong Analysis and Test Center, Key Laboratory of TMC Quality Control Technology, Jinan; 250014, China
Corresponding author:Chen, Leilei(chenleilei8210@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:289-295
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ginkgo biloba pollens are pollens from the male Ginkgo biloba trees, and contain many active components represented by flavonoids, terpene lactones, and polysaccharides. The total flavonoid content of Ginkgo biloba pollens was approximately 21.4 mg/g, much higher than that of Ginkgo biloba leaves. Previous analyses of flavonoids in Ginkgo biloba pollens were based on the results from Ginkgo biloba leaves, and the flavonoids of pollens and leaves were found to be very different in type and content. For example, rutin was reported to be abundant in Ginkgo biloba leaves, while the rutin content in Ginkgo biloba pollens was less than 6% of that in Ginkgo biloba leaves. Now the research on chemical constituents of Ginkgo biloba pollens was still in its infancy. Thus, studying the chemical composition of Ginkgo biloba pollens by indirectly measuring the flavonoids in Ginkgo biloba leaves was meaningless, and it was necessary to systematically analyze and purify the flavonoids from Ginkgo biloba pollens. In this study, crude extract of total flavonoids from Ginkgo biloba pollens was obtained by microwave-assisted extraction, and was separated into 4 fractions, petroleum ether, ethyl acetate, n-butanol and water by a fractional extraction method. The extract fraction used for further isolation and purification was selected through an assay of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activities and an analysis of flavonoid components. The target flavonoids with DPPH scavenging activities in the selected fraction were screened by a 1, 1-diphenyl-2-picrylhydrazyl -high performance liquid chromatography -photodiode array detection (DPPH-HPLC-PAD) method, then were isolated and purified by a preparative liquid chromatography (preparative LC), and their chemical structures were identified using ultraviolet-visible spectroscopy, mass spectrometry, hydrogen-1 nuclear magnetic resonance (<sup>1</sup>H NMR) spectroscopy and carbon-13 nuclear magnetic resonance (<sup>13</sup>C NMR) spectroscopy. In addition, the DPPH scavenging activities of these components were preliminarily determined. The DPPH scavenging activities of the crude extract as well as the petroleum ether, ethyl acetate, n-butanol and water fractions analyzed by IC<inf>50</inf>values were significantly different (P<0.01). The components with DPPH scavenging activities were efficiently enriched in the ethyl acetate and n-butanol fractions. All in all, the ethyl acetate fraction demonstrated the highest DPPH scavenging activity and accumulated most of the target components for purification, so the ethyl acetate fraction was selected for further screening, isolation and purification of the DPPH-scavenging flavonoids. Finally, 6 flavonoid components with DPPH scavenging activities were respectively purified and identified as kaempferol-3, 4'-di-O-β-D-glucopyranoside (Compound 1), kaempferol-3-O-β-D-glucopyranoside-7-O-α-L-rhamnoside (Compound 2), kaempferol-3-O-β-D-glucopyranoside (Compound 3), kaempferol-3-O-α-L-rhamnopyranoside (Compound 4), naringenin (Compound 5) and kaempferol (Compound 6), of which Compounds 1 and 2 had not been previously purified from Ginkgo biloba L.. The IC<inf>50</inf>values of the 6 compounds from low to high were as follows: Compound 6 < Compound 2 < Compound 3 < Compound 4 < Compound 1 < Compound 5. It meant that the DPPH scavenging ability of kaempferol is the highest among the 6 compounds, followed by kaempferol-3-O-β-D-glucopyranoside-7-O-α-L-rhamnoside, and no significant differences (P>0.05) were identified between Compound 6, L-ascorbic acid and rutin. This research lays a solid foundation for further study of the functional components of Ginkgo biloba pollens and their biological activities.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Flavonoids
Controlled terms:Agricultural products - Alcohols - Ascorbic acid - Chemical detection - Crude oil - Drug products - Ethers - Extraction - High performance liquid chromatography - Mass spectrometry - Nuclear magnetic resonance - Nuclear magnetic resonance spectroscopy - Processing - Purification - Ultraviolet visible spectroscopy
Uncontrolled terms:1 ,1-diphenyl-2-picrylhydrazyl - Anti-oxidation - Dpph radicals - Ginkgo biloba - Isolation and purification - Microwave-assisted extraction - Photodiode array detections - Preparative liquid chromatography
Classification code:512.1 Petroleum Deposits - 801 Chemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 821.4 Agricultural Products - 913.4 Manufacturing
Numerical data indexing:Percentage 6.00e+00%
DOI:10.11975/j.issn.1002-6819.2018.10.037
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 20>
Accession number:20182405305853
Title:Development of on-line monitoring device of grain moisture content in combine harvester with high frequency capacitance
Authors:Chen, Jin (1); Wang, Yuehong (1); Lian, Yi (1); Wang, Shuqing (1); Liu, Xinyi (1)
Author affiliation:(1) School of Mechanical Engineering, Jiangsu university, Zhenjiang; 212013, China
Corresponding author:Chen, Jin(chenjinjd126@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:36-45
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Moisture content of grain is one of the greatest significant factors affecting the quality of food, which still plays an important role as an indicator in food storage, acquisition, processing, transportation, and so on. Recently, as the rapid development of the intelligent combine harvester, intelligent harvest and yield measurement have become possible. It is necessary to monitor the moisture content of grain in real time in automatic harvest. In addition, only when the weight of the harvested grain is converted to the weight of the grain with a fixed moisture content, the yield information can be measured more accurately, and the cause of loss rate can be analyzed more comprehensively. Comparing the domestic machine with that in other countries, the fact is that some latest combine harvesters designed in other nations have installed the real-time grain moisture content monitoring system, while the majority of the domestic combine harvesters have not yet used this technology in practice. By virtue of the huge cost of introducing the measurement systems from other nations, the import of this machine has not been applied in agriculture industry universally. Therefore, in the light of this situation, the research on the on-line monitoring of the grain moisture content for the combine harvester will be of great value in the domestic area to some extent. In order to analyze the influence of edge effect on the capacitive plate, a finite element analysis software COMSOL Multiphysics was adopted to establish the capacitive plate and its working environment model. The influences of the thickness of the capacitive plate, the plate spacing and the relative area on the edge effect have been evaluated. The three-factor and three-levelorthogonal experiment optimization simulation was carried out, using capacitance ratio and sensitivity as the evaluation indicator. According to the simulation results, a copper plate with a plate thickness of 0.15 mm, a plate spacing of 20 mm and a relative area of 3000 mm<sup>2</sup>between the plates was selected. Based on the STM32F103 series microprocessor chip, an on-line monitoring system of grain moisture has been constructed. This system included the power supply module, high frequency excitation signal module, AC (alternating current) small signal amplification circuit, capacitor plate, signal conditioning circuit, mean response power detector, and other designed sensor detection circuits. For the aim of the more accurate consequence of the monitor with respect to the moisture content of cereals, simplifying the circuit structure and reducing the cost, Multisim simulation and experimental verification were carried out on various frequency sources respectively. Then, the high frequency signal with the frequency of 10 MHz was selected as the excitation signal of the monitoring device. Finally, in order to get the changing relationship between the moisture content and the voltage, the output signal of the circuit was converted from a non-sinusoidal wave caused by the capacitor charge and discharge to a DC (direct current) voltage by a mean response power detector taking the AD8361 as a core. Moreover, the device could monitor the grain moisture content on-line, and real-time display and store information The indoor static monitoring and on-field monitoring test were conducted withthe on-line monitoring device of grain moisture content. As a result, the maximum relative error of indoor static monitoring test was 1. 57% and the maximum relative error of field monitoring test was 2.07%.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Monitoring
Controlled terms:Capacitance - Carrier mobility - Display devices - Food storage - Grain (agricultural product) - Harvesters - Harvesting - Low temperature drying - Moisture - Moisture control - Moisture determination - Plates (structural components) - Signal conditioning circuits - Structural optimization - Voltage measurement
Uncontrolled terms:Finite element analysis software - High frequency capacitance - High-frequency excitation - Monitoring device - On-line monitoring device - On-line monitoring system - Simulation and experimental verifications - Structure optimization
Classification code:408.2 Structural Members and Shapes - 694.4 Storage - 701.1 Electricity: Basic Concepts and Phenomena - 712.1 Semiconducting Materials - 722.2 Computer Peripheral Equipment - 722.4 Digital Computers and Systems - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.5 Optimization Techniques - 942.2 Electric Variables Measurements - 944.2 Moisture Measurements
Numerical data indexing:Area 3.00e-03m2, Frequency 1.00e+07Hz, Percentage 2.07e+00%, Percentage 5.70e+01%, Size 1.50e-04m, Size 2.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.10.004
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 21>
Accession number:20182405305882
Title:Analysis of wheat bulk mould and temperature-humidity coupling based on temperature and humidity field cloud map
Authors:Wang, Xiaomeng (1, 2); Wu, Wenfu (1); Yin, Jun (2); Zhang, Zhongjie (2); Wu, Zidan (1); Zhang, Hongqing (2)
Author affiliation:(1) College of Biological and Agricultural Engineering, Jilin University, Changchun; 130022, China; (2) Academy of State Administration of Grain, Beijing; 100037, China
Corresponding author:Wu, Zidan(wuzidan@263.net)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:260-266
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Grain storage has very important effect on national food security and has been given increasing attentions in recent several decades. During long term storage, when grain moisture and temperature exceed critical limits of safe storage, sometimes in limited rehumidified zones of the bulk, the ever-present mould inoculum will start to develop and the deterioration process will be initiated. The mould growth may result in several kinds of food-spoilage: off-flavours, toxins, discolouration, rotting and formation of pathogenic or allergenic propagules. A lot of domestic and overseas research has been carried out on the temperature field, relative humidity field and mould in grain bulk. But grain storage system is complex, and the impact factors are both independent and coupled with each other. Therefore, it is necessary to study the multi-field coupling effect in grain bulk. To explore the coupling relationship among temperature and relative humidity fields and mould in space and time in grain bulk, wheat with different moistures (11% and 20.1%, w.b.) was stored in a self-made simulated silo at 18 ℃ for 800 h non-airtight. The internal diameter, height and thickness of the cylindrical iron simulated silo were 0.54, 0.70 and 0.01 m, respectively. The simulated silo inside was insulated with rubber (0.02 m thickness). And on the top of the silo, the air pipes (0.08 m internal diameter) were applied to exchange the gas inside and outside the silo. In the experiment, the high moisture wheat (cylinder, diameter, 0.30 m; height, 0.30 m; 20.1%, w.b.) in the silo was surrounded by low moisture wheat (11%, w. b.). A 30 ℃ heater was inserted into the center of wet wheat as the artificial hot spot to cause heat and moisture transfer. After 232 h, the heater was stopped. During the storage, changes of CO<inf>2</inf>concentration, temperature, relative humidity and number of fungal spores were measured. And the temperature and relative humidity cloud images of the min-vertical plane were determined. In the process, changes of CO<inf>2</inf>concentration were monitored to detect if there was mould and its degree in wheat bulk. The temperature and relative humidity cloud images indicate that under the action of micro-air flow and diffusion, water vapor from wet wheat zone gradually moves to the top layer. Then the higher relative humidity fossa district above the hot spot is formed. During the experiment, there is almost no mould in the high temperature center of the wheat bulk because of the low relative humidity. Mould is mainly located at higher relative humidity position around the center of high temperature. Under similar temperature conditions, the severe mould area coincides with the highest humidity zone. This experiment shows that in the process of temperature and relative humidity change and coupling, the grain mould is not only a function of time, but also a function of space. The study also states clearly that if the temperature is low, even if the local moisture is relatively high, the growth of the microorganism is relatively slow. At this time, the temperature and relative humidity fields coupling is not enough for the growth of microorganism, so the time needed to cause the explosive growth of microorganism is increased. Even, there is no obvious hot spot, but it will still cause the slow development of mould of the stored grain. As the heat is lost rapidly, no spontaneous hot spots are observed during the experiment. This study provides the reference for the further establishment of multi-field coupling laws and the monitoring and prediction of mould in grain storage.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Food storage
Controlled terms:Atmospheric humidity - Carbon dioxide - Food supply - Grain (agricultural product) - Microorganisms - Moisture control - Molds - Spoilage - Temperature
Uncontrolled terms:CO2 concentration - Grain storage - Heat and moisture transfer - Higher relative humidity - Low relative humidities - Temperature and humidities - Temperature and relative humidity - Temperature conditions
Classification code:443.1 Atmospheric Properties - 461.9 Biology - 641.1 Thermodynamics - 731.3 Specific Variables Control - 804.2 Inorganic Compounds - 821.4 Agricultural Products - 822.1 Food Products Plants and Equipment - 822.3 Food Products
Numerical data indexing:Percentage 1.10e+01%, Percentage 2.01e+01%, Size 1.00e-02m, Size 2.00e-02m, Size 7.00e-01m, Size 8.00e-02m, Time 2.88e+06s, Time 8.35e+05s
DOI:10.11975/j.issn.1002-6819.2018.10.033
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 22>
Accession number:20182405305856
Title:Numerical analysis and verification of flow characteristics of rotor cavity of spiral rotary lobe pump
Authors:Li, Yibin (1, 2); Zhang, Xiaoze (1); Guo, Dongsheng (1); Wang, Xiaofei (1)
Author affiliation:(1) College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; (2) Key Laboratory of Fluid machinery and Systems, Lanzhou; Gansu Province; 730050, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:62-67
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the wide application of the rotary lobe pump, the rotary lobe pump rotor presents the development trend of being multi-leaf and spiral. In order to elucidate the influence of rotor spiral angle on the flow characteristics in the rotor cavity of rotary lobe pump, and reveal the quantitative relationship between the spiral angle and the characteristic curve of the lobe pump, based on FLUENT dynamic mesh and Renormalization Group k-Ε turbulence model, the numerical calculation of 3D (three-dimensional) transient flow in the rotor cavity of rotary lobe pump is carried out. The internal flow characteristics in the rotor cavity of rotary lobe pump with 9 kinds of spiral angles are compared, and the mechanism of the influence of the spiral angle on the transient flow structure in the rotor cavity is revealed. Meanwhile, through theoretical calculation, numerical simulation and experimental verification, the comparative analysis of numerical prediction shows that the relative error is in the range of 2.5%-5.7%, and the numerical simulation has higher accuracy. Research results prove that the periodic changes of the volume of the pump cavity at the high pressure side and the low pressure side make the velocity of the fluid in the gap region suddenly rise or fall, which is accompanied by the wall jet effect of the fluid in the clearance area. During the rotation of the rotor of the straight blade rotary lobe pump, the end wall secondary flow and the periodic flow pulsation appear at the outlet of the pump, the velocity increases abnormally at the rotor edge, and the local vortex structure appears in the rotor cavity. Compared with the rotor with straight blade, the spiral rotor can effectively suppress the secondary flow in the rotor cavity, the sudden change of the occurrence of the vortex structure and the velocity in the rotor clearance region. When the spiral angle is 45°-60°, the above flow phenomenon is obviously improved. The spiral angle has a significant effect on the flow pulsation at the outlet of the rotary lobe pump. Compared with the rotor with straight blades, the outlet flow rate of the spiral rotor decreases, and the amplitude of the outlet flow pulsation of the spiral rotor is also obviously decreased. When the spiral angle is 45°-60°, the flow pulsation amplitude at the outlet of the rotor cavity is only 60% of that of the rotor with straight blade, and the outlet flow rate of the pump reaches the maximum value, which is 97% of the outlet flow rate of the rotor, indicating that the optimum spiral angle of the rotor cavity of the rotary lobe pump is 45°-60°. Under the condition of variable rotational speed and variable outlet pressure, the performance tests of straight blade and rotary lobe pump with spiral angles of 45° and 60° are carried out because the axial leakage amount inside the rotor cavity is not taken into account in the numerical calculation. The numerical simulation and the experimental results are in good agreement with each other. At the same time, by using the theoretical calculation and the numerical calculation, the experiments are compared. The result shows that: because of the inlet and outlet pressure and the axial leakage are not considered in the theoretical calculation, there are some errors between them. But there is still a good degree of agreement. To sum up, through theoretical calculation, numerical simulation and mutual verification of experiments, it is shown that the rotary lobe pump has good performance when the spiral angle is 45°-60°, which provides a certain reference for the optimization design of rotary lobe pump rotor.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Rotors
Controlled terms:Computer simulation - Fighter aircraft - High pressure effects - Models - Numerical models - Periodic structures - Pumps - Secondary flow - Statistical mechanics - Transition flow - Turbulence models - Vortex flow
Uncontrolled terms:Analysis and verifications - Flow pulsation - Internal flow characteristics - K-epsilon turbulence model - Performance tests - Rotary lobe pumps - Simulation and experimental verifications - Spiral angle
Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 652.1.2 Military Aircraft - 723.5 Computer Applications - 921 Mathematics - 931.1 Mechanics - 931.3 Atomic and Molecular Physics
Numerical data indexing:Percentage 2.50e+00% to 5.70e+00%, Percentage 6.00e+01%, Percentage 9.70e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.007
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 23>
Accession number:20182405305879
Title:Spatial distribution optimization of rural residential areas based on town planning regulation
Authors:Zou, Yafeng (1, 2); Li, Yajing (1); Ma, Tianjun (1); Yuan, Zhihong (1); Liu, Juan (1)
Author affiliation:(1) School of Public Management, Inner Mongolia University, Hohhot; 010021, China; (2) nstitute of Geographic Sciences and Natural Resources Research, CAS, Beijing; 100101, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:238-244
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The spatial layout optimization of rural settlements is the main content of new rural construction, and also one of the key contents of the overall land use planning. The rational spatial layout optimization of rural settlements can not only promote the intensive use of land resources and improve rural production and living environment, but also accelerate the transfer of rural labor force and further narrow the gap between urban and rural development. In order to determine the type of spatial layout optimization of rural settlements scientifically and guide the optimization of spatial distribution of rural settlements and the practice of new rural construction effectively, this paper put forward a spatial distribution optimization method of rural residential areas based on town planning regulation, which was applied to Kekeyiligeng Town in Wuchuan County, Inner Mongolia Autonomous Region. Under the regulation of land use planning at town level, the following steps were in process: First of all, the rural residential areas were divided into 2 different evolution directions based on the location within or outside the boundaries of urban construction land expansion: urbanization and non-urbanization. Specifically, the rural residential areas located within the boundaries of urban construction land extension were identified as urbanization type; conversely the rural residential areas outside the extended boundary range were defined as non-urbanization type. Secondly, the spatial layout optimization type of the urbanization type residential areas was determined as the community-based management mode due to that the rural residential areas as urbanization type were likely to be included in urban construction in their future development. Thirdly, for non-urbanization rural settlements, the evaluation index system for the comprehensive influence of rural residential patches was constructed from 3 aspects: the coordination of town planning, the convenience of production and living, and the activeness of residential areas. Based on comprehensive evaluation scores, the spatial layout optimization types of non-urbanization type were accordingly divided into 3 categories: comprehensive development, in-situ renovation, and combined migration. Finally, the rural settlements optimal layout scheme with 4 optimization types was formulated. The results showed that there were 6 rural residential areas identified as community-based management areas in the study area, with an area of 15.29 hm<sup>2</sup>, accounting for 2.92% of the total area of the town; 46 comprehensive development areas, with an area of 178.28 hm<sup>2</sup>, accounting for 35.04% of the non-urbanized rual residential area; 53 in-situ renovation areas, with an area of 189.20 hm<sup>2</sup>, accounting for 37.20%; 40 combined migration areas, with an area of 141.22 hm<sup>2</sup>, accounting for 27.76%; the paper also put forward a more specific optimization plan for the 4 optimization types of rural residential spatial layout. Under the framework of town planning regulation, and given full consideration to the space-time arrangement of the rural settlements layout optimization in the town planning period, the optimal layout scheme obtained by the method constructed in this paper is more accordant with practical circumstances in China, and the spatial distribution optimization method of rural residential areas based on town planning regulation can provide a new idea for spatial optimization and renovation of rural residential areas and also provide reference for related research.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Rural areas
Controlled terms:Housing - Land use - Optimization - Regional planning - Spatial distribution - Urban planning
Uncontrolled terms:Distribution optimization - Patch comprehensive influence - Rural regions - Rural residential areas - WuChuan
Classification code:403 Urban and Regional Planning and Development - 921 Mathematics - 921.5 Optimization Techniques
Numerical data indexing:Percentage 2.92e+00%, Percentage 3.50e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.030
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 24>
Accession number:20182405305865
Title:Modeling and verification of maize biomass based on linear regression anaysis
Authors:Qiu, Ruicheng (1); Miao, Yanlong (1); Zhang, Man (1); Li, Han (2); Sun, Hong (2)
Author affiliation:(1) Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, China Agricultural University, Beijing; 100083, China; (2) Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, China Agricultural University, Beijing; 100083, China
Corresponding author:Zhang, Man(cauzm@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:131-137
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Maize biomass is an essential parameter for assessing plant vigor, which is also a vital parameter for estimating root growth. Traditionally, maize biomass is obtained by manual investigation, which is time consuming and laborious, and it is tough to acquire large samples. With the development of breeding, breeders are eager to rapidly measure or estimate maize biomass. In order to meet the requirement, many biomass models have been developed. Typically plant height is used to develop models to predict plant biomass; the research introduces stem diameter parameters into the models and develops linear models based on maize height, stem long diameter, and stem short diameter to estimate maize biomass. Spreading-leaf maize named Nongda 84 and upright-leaf maize named Jingnongke 728 were cultivated, and the samples at the small trumpet stage and the large trumpet stage were collected. Plant height was taken by measuring the difference between the soil surface and the top point of leaf. Stem diameters were measured using a digital caliper, and the long diameter and short diameter were taken by measuring the longest and shortest axes of the first stem internode. Maize samples were weighted to get their fresh weights on the same day. Maize dry weight was recorded when its weight was constant. Biomass data of Nongda 84 samples and Jingnongke 728 samples at the small trumpet stage were analyzed (40 groups respectively). With the use of multiple regression method and step regression method, linear regressions were conducted, and several biomass models were built. First, plant height(H), stem long diameter(L), and stem short diameter (S) were treated individually as input parameters of linear regression models, and the regression results indicated that the relationships between maize biomass and stem long diameter, short diameter are more significant than between maize biomass and maize height, and stem diameters are of great importance to estimate maize biomass. Then, plant height, stem long diameter, and stem short diameter were combined and integrated in the multiple regression models and step regression models, and the regression precisions of multiple regression models (H+L+S, L×S) and stepwise regression model are high; for maize fresh weight and dry weight, the coefficients of determination are both higher than 0.87, and the root mean square error (RMSE) values are smaller than 7.37 and 0.81 g, respectively. Although the structures of the multiple regression models are simpler than the step regression models, the one-way analysis of variance proved that there are no significant differences among the aforementioned 3 models. In addition, leave one out cross-validation was conducted to use the biomass samples more adequately and the aforementioned 3 models were tested. The coefficients of determination and RMSE values are similar to original models, which showed that the 3 models have a good performance in stability and prediction. After that, multiple regression models H+L+S and L×S, and stepwise regression model were used to estimate maize biomass at the large trumpet stage, and 40 groups of Nongda 84 samples and 37 groups of Jingnongke 728 samples were verified to test the model precisions. In terms of Nongda 84, the multiple regression model L×S and stepwise regression model are advisable to estimate biomass. For Jingnongke 728, the multiple regression model L×S is a prime candidate for estimating biomass. The results also showed that all the models perform better in estimating Nongda 84 than Jingnongke 728. Among all the models, the stepwise regression model has the best performance in estimating the biomass of Nongda 84, and for maize fresh weight and dry weight, the coefficients of determination are 0.866 and 0.875, the RMSE values are 30.790 and 2.752 g, and the relative root mean square errors are 13.53% and 11.41%, respectively. It indicates that maize height, stem long diameter and stem short diameter can be used to estimate maize biomass, and have good performance in estimating spreading-leaf maize biomass.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Biomass
Controlled terms:Linear regression - Mean square error - Models - Parameter estimation - Plants (botany)
Uncontrolled terms:Leave-one-out cross validations - Linear regression models - Modeling and verifications - Multiple regression methods - Multiple regression model - Plant height - Root mean square errors - Stem diameter
Classification code:922.2 Mathematical Statistics
Numerical data indexing:Mass 2.75e-03kg, Mass 3.08e-02kg, Mass 7.37e-03kg, Mass 8.10e-04kg, Percentage 1.14e+01%, Percentage 1.35e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.016
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 25>
Accession number:20182405305884
Title:Detection of internal water flow in germinating corn seeds based on low field nuclear magnetic resonance
Authors:Song, Ping (1, 2, 3); Peng, Yufei (1); Wang, Guihong (1); Song, Peng (2, 3); Wang, Kaitian (1); Yang, Tao (1)
Author affiliation:(1) College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang; 110866, China; (2) Beijing Research Center for Information Technology in Agriculture, Beijing; 100097, China; (3) National Research Center of Intelligent Equipment for Agriculture, Beijing; 100097, China
Corresponding author:Yang, Tao(328748306@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:274-281
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the rule of internal water flow in corn seed germination process, the internal physiological metabolism state was analyzed, which changed the traditional research on the germination rate based on quantitative statistics, or considering the change of water from a point of view of time, or to explain the malpractice of the distribution of its internal water by the physiological anatomy of the seed. In this experiment, 3 varieties of corn seeds i.e. Nongda 108, Liaodan 565 and Yuqing 1 were used, which were from the Agricultural College, Shenyang Agricultural University and were the seeds in 2016. The dynamic monitoring of maize seeds at 3 stages of imbibition, germination and sprouting was performed by low field nuclear magnetic resonance (NMR) technique for 60 h, and 160 seeds were selected for each species, every 4 seeds are divided into a group, and 40 parallel test samples were prepared for each species (the sample quality was 1.685 g). The transverse relaxation time (T<inf>2</inf>) signal of NMR was collected for maize seeds in 2 constant-temperature germination environments at 25 and 31 ℃, their germination time was 0, 12, 36 and 60 h, each collection was repeated 4 times, the inversion spectrum of the T<inf>2</inf>was obtained by the inversion. At the same time, the number of germinated seeds in the test sample was counted (taking embryo expansion and skin broken as a criterion), and then the seed germination rate was calculated. Water was replenished for the experimental samples, which were then continually cultivated in the artificial climate box, and the monitoring of the germination process of maize seeds was realized. The experimental results show that: Through the T<inf>2</inf>, the internal moisture of maize seed can be divided into 3 water phase states: bound water (0.1< T<inf>2</inf><10 ms), semi bound water (10 < T<inf>2</inf>< 100 ms) and free water (100 < T<inf>2</inf>< 1000 ms); the combination of water molecules and biological macromolecules is closer, which has low kinetic activity, and the amplitude of the signal is expressed as A<inf>21</inf>; the fluidity of semi bound water is restricted by certain constraints, and the amplitude of the signal is expressed as A<inf>22</inf>; free water molecules have strong mobility, and the amplitude of the signal is expressed as A<inf>23</inf>. With the prolongation of germination time, the water content of 3 varieties of maize seeds increases rapidly and then decreases gradually in 2 germinating environments, and the increase speed is also weakened. The content of free water shows a tendency to decrease firstly and then increase, and its increase speed is also increasing, while semi bound water and total water content are increasing. The corn seeds have the following absorption: rapid water absorption in the stage of suction, steady water absorption at the stage of initiation, water concussive absorption during the germination stage. The result from the low field NMR detection is consistent with that from the traditional drying weighing method. The influence of external temperature on the water content of 3 phase states is not the same, and there is no consistency between the change of water at each phase and the temperature of germination, however, when the external temperature increases, the semi bound water and the total water in the seed are shown to be gradually enhanced at every typical time of germination process. It is suggested that the increase of germination temperature can promote the combination of seed cell and water, improve the overall speed on water absorption and increase the germination rate of corn seeds. The result provides an important theoretical basis for the study of the mechanism of maize seed germination, and has important guiding significance for the determination of the maize growth and development of the later period, the formation of quality and the practice of production.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Water absorption
Controlled terms:Cultivation - Flow of water - Hydraulics - Magnetism - Molecules - Nuclear magnetic resonance - Physiology - Seed - Water
Uncontrolled terms:Biological macromolecule - External temperature - Germination - Germination temperature - Growth and development - Guiding significances - Low field nuclear magnetic resonance - Transverse relaxation time
Classification code:461.9 Biology - 631.1.1 Liquid Dynamics - 632.1 Hydraulics - 701.2 Magnetism: Basic Concepts and Phenomena - 802.3 Chemical Operations - 821.3 Agricultural Methods - 821.4 Agricultural Products - 931.3 Atomic and Molecular Physics
Numerical data indexing:Mass 1.69e-03kg, Time 1.00e+00s, Time 1.00e-01s, Time 1.30e+05s, Time 2.16e+05s
DOI:10.11975/j.issn.1002-6819.2018.10.035
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 26>
Accession number:20182405305860
Title:Monitoring of planted lines for breeding corn using UAV remote sensing image
Authors:Su, Wei (1); Jiang, Kunping (1); Yan, An (2); Liu, Zhe (1); Zhang, Mingzheng (1); Wang, Wei (1)
Author affiliation:(1) College of Land Science and Technology, China Agricultural University, Beijing; 100083, China; (2) Tiangang School of Tengzhou City, Tengzhou; 277519, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:92-98
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The planted line is one of the important phenotypic parameters for breeding corn. And extracting the planted lines of breeding corn quickly and nondestructively is vital to corn breeding trials and research. Unmanned aerial vehicle (UAV) remote sensing technique has advantage in extracting phenotypic parameters of corn canopy, which can be used to extract the phenotyping parameters in large area for breeding corn. This research is aiming at extracting the planted lines for breeding corn using UAV image acquired from DJS1000+UAV platform by calclulating the super-green feature and Hough transform of the UAV images of 3 different growing seasons, i. e. seeding stage, jointing stage, and maturation period. The first step is calculating the super-green features of 3 UAV images, and then binary optimization and morphological open operation are performed so as to separate corn canopy and soil background. In addition, we use 3 different window sizes, i. e. 1×15, 1×25, 1×50, to search and detect the locating middle points for extracting planted line of breeding corn in 3 different growing seasons. Next step, the center point of corn ridge line is identified by projecting the segmented objects. The judging conditions of left border and right border for center points extraction are as follows: The points will be classified as left border points if the pixel mean is greater than pixel of column j-1 and the pixel mean is less than pixel of column j+1; and the points will be classified as right border points if value the pixel mean is less than pixel of column j-1 and the pixel mean is greater than pixel of column j+1; the central location will be labeled as the central point of planted line. Finally, the line of breeding corn is identified by Hough transform of the above center points of corn ridge line. Hough transform is casting all the points in image domain to the points in transforming domain, and one point in image domain is corresponding to one sine curve in transforming domain. Therefore, the sine curves that are corresponding to the points located on the same line will be intersected at one same point, which will establish the line in image domain. We select 3 breeding corn plots in 3 different growing periods i. e. seeding stage, jointing stage, and maturation period. The results indicate that the planted line of breeding corn in jointing stage can be extracted more accurately than that in seeding stage and maturation period. There were 74 lines used in planted line extraction experiment in jointing stage, and our extraction results are 74, 74, and 105 lines using 3 different window sizes respectively. In this growing stage, the corn plants are big enough for planted line extraction and the leaves between different lines do not connect meanwhile. There were 43 lines used in planted line extraction experiment in seeding stage, and our extraction results are 42, 45, and 58 lines using 3 different window sizes respectively. The leaves between different lines have already connected, which affects the planted line extraction. And there were 44 lines used in planted line extraction experiment in maturation stage, and our extraction results are 46, 40, and 49 lines using 3 different window sizes respectively. In this seeding stage, the leaves are too small (1-2 cm) and the planted line extraction is more difficult. So our method can be used to extract the number of breeding corn lines, and the optimal growing stage for planted line extraction is jointing stage and the window size for searching and detecting the locating middle points should be similar to the row spacing of planted corn.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Image processing
Controlled terms:Antennas - Extraction - Feature extraction - Hough transforms - Location - Monitoring - Pixels - Plants (botany) - Remote sensing - Seed - Unmanned aerial vehicles (UAV)
Uncontrolled terms:Binary optimization - Breeding corn - Maturation periods - Planted lines - Remote sensing techniques - Segmented objects - Super-green feature - UAV remote sensing
Classification code:652.1 Aircraft, General - 802.3 Chemical Operations - 821.4 Agricultural Products - 921.3 Mathematical Transformations
Numerical data indexing:Size 1.00e-02m to 2.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.10.011
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 27>
Accession number:20182405305862
Title:Influence of sprinkler height on irrigation performance of center pivot irrigator
Authors:Zhao, Weixia (1); Zhang, Meng (1); Li, Jiusheng (1); Li, Yanfeng (1)
Author affiliation:(1) State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing; 100038, China
Corresponding author:Li, Jiusheng(lijs@iwhr.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:107-112
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In most nozzle configuration software, the irrigation uniformity of center pivot irrigation system is simulated from the water distribution characteristics of single sprinkler at a special height. Influenced by the plant height and topographic slope, the actual installation height of sprinkler is often not equal to the simulated height and is kept constant during the growing season of crop as lack of the regulation apparatus, which resulted in the unknown irrigation uniformity and irrigation depth. To guarantee the irrigation uniformity and irrigation efficiency of center pivot irrigation system, the principle of keeping the sprinklers on the top of the plant height was proposed and a control apparatus was invented by changing the insert length of counterweight steel tube into the sag pipe to adjust the sprinkler height timely. In this study, the performance of the center pivot sprinkler system outfitted with D3000 non rotating nozzles spaced at 2.92 m was tested to verify the stability of irrigation uniformity and irrigation water depth at 5 installation heights of sprinkler (0.5, 1.0, 1.5, 2.0, and 2.6 m) and 3 outflow rates of sprinkler machine (8.8, 16.7, and 24.2 m<sup>3</sup>/h). The height of 1.5 m is the standard value simulated by nozzle configuration software. The outflow rates were obtained by using different sprinkler configuration. Catch cans were arranged in transect to obtain the irrigation water depth along the pivot lateral. The modified Heermann-Hein uniformity coefficient was calculated to evaluate the irrigation uniformity. During each test, the wind speed was smaller than 2 m/s. The results indicated that when the sprinkler was adjusted to the standard height of 1.5 m, the application performance of center pivot irrigation system was basically stable under the 3 outflow rates of sprinkler machine. The irrigation depth changed with zigzag wave along radial direction, and a target irrigation water depth could be obtained accurately through setting a specific rotation speed of the pivot. The modified Heermann-Hein uniformity coefficient along the pivot lateral ranged from 82.5% to 84.0%. When the sprinkler height was smaller than 1.5 m, the irrigation depth changed greatly along radial direction, especially at 0.5 m height, under which the modified Heermann-Hein uniformity coefficient significantly decreased by 23.9%. When the sprinkler height was greater than 1.5 m, the distribution of water irrigated along radial direction was more uniform, and there was no significant difference in uniformity coefficients among the 1.5, 2.0, and 2.6 m installation heights. After the sprinkler height was adjusted, although the irrigation water depth was obviously decreased at the height of 2.6 m because of the greater evaporation resulting from longer flying time, the mean absolute value of relative error for measured water depth was less than 10% compared with that at standard sprinkler height. The experimental results demonstrate that the sprinkler height can be raised timely when the plant height is bigger than 1.5 m to guarantee the uniformity coefficient and irrigation water depth of center pivot irrigation system.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Sprinkler systems (irrigation)
Controlled terms:Agricultural machinery - Crops - Hose - Installation - Irrigation - Nozzles - Tubular steel structures - Water - Water supply systems - Wind
Uncontrolled terms:Application performance - Center pivot irrigation systems - Distribution of water - Installation heights - Irrigation depth - Irrigation efficiency - Irrigation performance - Uniformity coefficient
Classification code:408.2 Structural Members and Shapes - 443.1 Atmospheric Properties - 446.1 Water Supply Systems - 619.1 Pipe, Piping and Pipelines - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.00e+01%, Percentage 2.39e+01%, Percentage 8.25e+01% to 8.40e+01%, Size 1.50e+00m, Size 2.60e+00m, Size 2.92e+00m, Size 5.00e-01m, Velocity 2.00e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.10.013
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 28>
Accession number:20182405305885
Title:Distinction of leisure dried tofu brands by using chemical pattern recognition combined with low field nuclear magnetic resonance
Authors:Xia, Alin (1); Xia, Xiaming (1); Ji, Linlin (1); Zhao, Liangzhong (1)
Author affiliation:(1) School of Food and Chemical Engineering, Shaoyang University, Shaoyang; 422000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:282-288
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:By using low field nuclear magnetic resonance (LF-NMR) spectrometer, the leisure dried tofu samples were measured for obtaining transverse relaxation data. The experimental data were analyzed by pattern recognition methods including principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and Bayesian regularization-back propagation-artificial neural network (BR-BP-ANN). The research purpose is to search for a method which can quickly discriminate the brand of leisure dried tofu. The 4 common dried tofu brands were chosen and the samples of each brand were collected from 5 batches of leisure dried tofu. Sixteen small bags of dried tofu were randomly selected as study samples from each batch. In this way, 320 samples were obtained. These samples were measured with an LF-NMR instrument. Each sample was measured repeatedly 3 times. The average value of them was taken as the result of the measurement. A total of 320 sample spectra were obtained. Then, 60 samples were selected randomly as training set from 80 samples of each brand. A total of 240 training samples were randomly acquired in this manner, and the remaining 60 samples were used as prediction set. These samples of 4 brands were used for rapid distinction by pattern recognition methods. The experimental results showed that each brand was difficult to be picked out with eyes by three-dimensional PCA scoring plot. Further, measurement data of dried tofu were treated by PLS-DA. The results displayed that the recognition rate of Brand 4 was the highest, 93.3%, and the worst was the recognition rate of Brand 3, 76.7%, and the total recognition rate of all brands was 86.3% for the training set. For the prediction set, the recognition rate of Brand 4 was also the highest, and the recognition rate of Brand 2 was the worst, 75%, and the total recognition rate was 81.3% for all brands. However, the BR-BP-ANN method can discriminate 4 bands simultaneously. The predicted value is in good agreement with the actual expected value for training set. In other words, the prediction values were highly consistent with the expected values of 1-0-0-0 for No. 1-60 samples, which met the criteria. So these samples belonged to Brand 1. Similarly, the prediction values were in agreement with the expected values of 0-1-0-0 for No. 61-120 samples. Then these samples were classified into Brand 2. In the same way, No. 121-180 samples were taken into account, and the prediction values were close to the expected values of 0-0-1-0. Consequently, these samples belonged to Brand 3. Similarly, No. 181-240 samples belonged to Brand 4 since the prediction values were similar to the expected values of 0-0-0-1. In the same way, good results were also obtained for prediction set since the predicted values were in perfect agreement with the expected values. It's interesting to note that the correct rate of prediction was 100% for brand discrimination. So the combination of LF-NMR and BR-BP-ANN can provide a fast and accurate method and better technical support for the brand discrimination of the leisure dried tofu.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Nuclear magnetic resonance
Controlled terms:Algorithms - Backpropagation - Chemical analysis - Data flow analysis - Discriminant analysis - Forecasting - Least squares approximations - Magnetic levitation vehicles - Magnetism - Neural networks - Pattern recognition - Principal component analysis
Uncontrolled terms:Back propagation artificial neural network (BPANN) - Bayesian regularization - Chemical pattern recognition - Leisure dried tofu - Low field nuclear magnetic resonance - Low field nuclear magnetic resonance (LF NMR) - Partial least squares discriminant analyses (PLSDA) - Pattern recognition method
Classification code:701.2 Magnetism: Basic Concepts and Phenomena - 723.4 Artificial Intelligence - 921.6 Numerical Methods - 922 Statistical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.00e+02%, Percentage 7.50e+01%, Percentage 7.67e+01%, Percentage 8.13e+01%, Percentage 8.63e+01%, Percentage 9.33e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.036
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 29>
Accession number:20182405305859
Title:Martensitic transformation and abnormal thermal expansion in Ni-Mn-Ga alloy magnetic refrigeration materials
Authors:Wei, Shengxian (1); Li, Hui (2); Li, Zhe (1); He, Xijia (1); Zhang, Yuanlei (1); Shi, Youming (2); Tao, Chang (2)
Author affiliation:(1) Center for Magnetic Materials and Devices, Qujing Normal University, Qujing; 655011, China; (2) College of Physics and Electronic Engineering, Qujing Normal University, Qujing; 655011, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:85-91
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ni-Mn-Ga alloy is a kind of typical magnetic refrigeration material. The thermal expansion coefficient of the alloy is one of the most important parameters in the engineering design. The mismatch of thermal expansion coefficient between the various materials used in magnetic refrigerators can lead to thermal stresses that can trigger complex failure mechanisms like component distortion, stress rupture, and thermomechanical fatigue, and thereby seriously degrade device reliability and lifetime. Therefore, minimizing the mismatch between the materials is desirable if for no other reason than to significantly improve overall device reliability. In this work, the magnetic refrigeration materials Ni<inf>54+x</inf>Mn<inf>19-x</inf>Ga<inf>27</inf>(x=0, 0.2, 0.4, 0.6) with nominal composition were fabricated by conventional arc melting in an argon atmosphere using high purity elements Ni (99.98%), Mn (99.98%) and Ga (99.999%) to reveal the thermal expansion properties of Ni-Mn-Ga alloy. The actual compositions, crystal structures, martensitic transformation temperatures, magnetic transition and zero field thermal strain of the alloys were experimentally investigated by a scanning electron microscope equipped with an energy-dispersive spectrometer (SEM-EDS), an x-ray diffractometer (XRD), a differential scanning calorimetry (DSC), a vibrating sample magnetometer (VSM) and a standard strain-gauge connected with physical properties measurement system (PPMS). The room temperature XRD patterns of Ni<inf>54+x</inf>Mn<inf>19-x</inf>Ga<inf>27</inf>indicate that the alloys (x≤0.4) possess an ordered L2<inf>1</inf>(cubic) austenite structure and the sample (x=0.6) predominately possesses a 7M modulated martensitic structure with small residual traces of non-modulated martensitic structure. The results from DSC and magnetic transition measurements show that the martensitic transformation temperatures gradually increase with the Ni content increasing. Moreover, the peak temperatures of direct and reverse martensitic transformations increase from 257, 266 (x=0.0) to 292, 300 K (x=0.6), respectively, and they have a distinct thermal hysteresis of about 6-11 K. Zero field thermal strain curves illustrate that the Ni-Mn-Ga alloys exhibit an isotropic thermal expansion property. The thermal expansion coefficients range from 8.87×10<sup>-6</sup>to 16.60×10<sup>-6</sup>/K and from 5.21×10<sup>-6</sup>to 6.26×10<sup>-6</sup>/K at martensite phase and austenite phase, respectively, for Ni<inf>54+x</inf>Mn<inf>19-x</inf>Ga<inf>27</inf>alloys. More importantly, the alloys exhibit an obvious and abnormal negative thermal expansion behavior in the vicinity of the martensitic transformation. The negative thermal expansion coefficients are in the range from -147.54×10<sup>-6</sup>to -17.60×10<sup>-6</sup>/K and from-133.30×10<sup>-6</sup>to -88.72×10<sup>-6</sup>/K respectively for heating and cooling the alloys. The amplitude of thermal expansion coefficient near the martensitic transformation is approximately 1.47-16.63 (heating) and 6.63-12.89 (cooling) times those of the martensite phase. This abnormal negative thermal expansion behavior may well be related to the nucleation and orientation of martensitic variants during the martensitic transformation. The mechanism behind the negative thermal expansion phenomenon is not clear and requires a further study with experimental techniques on microscopy. The results in this work are very meaningful for the adjustment and control of thermal expansion coefficient in Ni-Mn-Ga magnetic refrigeration material.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Thermal expansion
Controlled terms:Austenite - Buoyancy - Differential scanning calorimetry - Expansion - Gallium alloys - Magnetic materials - Magnetic refrigeration - Magnetism - Manganese alloys - Martensite - Martensitic transformations - Negative thermal expansion - Nickel alloys - Phase transitions - Refrigeration - Scanning electron microscopy - Spectrometers - Strain gages - Structural properties - Ternary alloys - Thermal Engineering - X ray diffraction
Uncontrolled terms:Magnetic refrigeration materials - Martensitic transformation temperatures - Negative thermal expansion behaviors - Negative thermal expansion coefficients - Ni-Mn-Ga alloys - Physical-properties measurement systems - Thermal expansion properties - Thermo mechanical fatigues (TMF)
Classification code:531.2 Metallography - 543.2 Manganese and Alloys - 548.2 Nickel Alloys - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 644.1 Refrigeration Methods - 701.2 Magnetism: Basic Concepts and Phenomena - 708.4 Magnetic Materials - 741.3 Optical Devices and Systems - 801.4 Physical Chemistry - 931.2 Physical Properties of Gases, Liquids and Solids - 943.1 Mechanical Instruments - 944.6 Temperature Measurements - 951 Materials Science
Numerical data indexing:Percentage 1.00e+02%, Temperature 6.00e+00K to 1.10e+01K
DOI:10.11975/j.issn.1002-6819.2018.10.010
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 30>
Accession number:20182405305876
Title:Resistance evaluation and "source-sink" risk spatial pattern of agricultural non-point source pollution in small catchment
Authors:Wang, Jinliang (1); Chen, Chenglong (1); Ni, Jiupai (1); Xie, Deti (1); Shao, Jing'an (2)
Author affiliation:(1) College of Resource and Environment, Southwest University, Chongqing; 400715, China; (2) College of Geography and Tourism, Chongqing Normal University, Chongqing; 401331, China
Corresponding author:Ni, Jiupai(nijiupai@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:216-224
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It has important practical significance for the prevention and control planning of agricultural non-point source pollution in small catchment by identifying and evaluating "source-sink" risk pattern impacting agricultural non-point source pollution. Therefore, in this paper, a case study was carried out in a small catchment named Wangjiagou, which located in the typical agricultural region of the Three Gorges Reservoir Region, and the minimal cumulative resistance model (MCR) was used to evaluate resistance and identify "source-sink" risk of agricultural non-point source pollution. At first, the source lands were divided into 6 grades by processing and analyzing on the land use data. Secondly, the resistance base surface impacting the agricultural non-point source pollution was constructed based on the selection of main natural influence factors, including topography factors (relative elevation and slope), land use factors (source-sink landscape type and vegetable interception index), hydrological factors (flow length and topographic wetness index), soil factors (soil loss vertical distance index and soil erosion intensity), nitrogen and phosphorus factors (nitrogen input and phosphorus input). Thirdly, MCR model was applied to obtain nitrogen, phosphorus and total resistance surface, respectively, and by which spatial distribution trend of resistance were identified. In the end, according to the resistance threshold, "source-sink" risk pattern was classified. The results showed that: 1) There were obvious difference among the spatial distribution of different resistance factors impacted on agricultural non-point source pollution, which established the foundation for spatial heterogeneity of resistance base surface. Resistance base surface reflected the spatial difference of "source-sink" landscape in the small catchment in the Three Gorges Reservoir Region, with the resistance base surface value of "source" landscape smaller than that of "sink" landscape. The obvious characteristic of resistance surface was that resistance surface changes were mainly influenced by spatial distance, and the value of resistance surface was smallest in the buffers located at the source lands, while the value was bigger and bigger as the distance was far from the source lands. 2) The MCR model was applied to classify "source-sink" risk pattern in the small catchment into 5 grades, including extremely high risk zone (0.2977 km<sup>2</sup>), high risk zone (0.1544 km<sup>2</sup>), medium risk zone (0.1475 km<sup>2</sup>), low risk zone (0.1474 km<sup>2</sup>) and extremely low risk zone (0.0160 km<sup>2</sup>), which indicated that there was a high risk trend of "source-sink" risk pattern, while there were still a certain range of low risk areas in the small catchement, which can ensure the effective interception for nitrogen and phosphorus loss. The results are helpful to evaluate the risk degree and rank of non-point source pollution produced by "source-sink" landscape from the angle of resistance surface, and can provide the policy-making basis for preventing and controlling agriculture non-point source pollution scientifically.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Surface resistance
Controlled terms:Agriculture - Catchments - Land use - Models - Nitrogen - Phosphorus - Pollution - Pollution control - Reservoirs (water) - Runoff - Soils - Spatial distribution
Uncontrolled terms:Agricultural non-point source pollutions - Nitrogen and phosphorus loss - Non-point source pollution - Resistance modeling - Small catchment - Source-sink - Three Gorges Reservoir region - Topographic wetness index
Classification code:403 Urban and Regional Planning and Development - 441.2 Reservoirs - 442.1 Flood Control - 483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 951 Materials Science
Numerical data indexing:Area 1.47e+05m2, Area 1.48e+05m2, Area 1.54e+05m2, Area 1.60e+04m2, Area 2.98e+05m2
DOI:10.11975/j.issn.1002-6819.2018.10.027
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 31>
Accession number:20182405305881
Title:Spatial prediction of soil organic carbon content in coal mining subsidence area based on GIS and partition Kriging
Authors:Xu, Zhanjun (1); Zhang, Yuan (1); Zhang, Shaoliang (2); Li, Lele (1); Yu, Mingcheng (1)
Author affiliation:(1) College of Resources and Environment, Shanxi Agricultural University, Jinzhong; 030801, China; (2) School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou; 221008, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:253-259
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China's coal production accounts for 46.9% of total world coal production, and the annual subsidence area is about 200 km<sup>2</sup>, which greatly disturbs the soil carbon pool of farmland. As the soil organic carbon (SOC) pool of farmland is the most potential factor reducing carbon emissions from terrestrial ecosystems, China and other major coal mining countries in the world must do better in managing the SOC pool in the coal mining area, which is also an important way for low-carbon coal mining. A spatial prediction method with good prediction accuracy of SOC content in subsidence area of coal mining is the prerequisite of scientific management of SOC pool in coal mining subsidence area. In order to determine a prediction method with high accuracy, taking Jiuli mining area in Xuzhou as a case, this paper predicted SOC content in the study area by the ordinary Kriging and the partition Kriging method. The ordinary Kriging directly spatially interpolated the SOC content based on the regionalized variable theory. In the partition Kriging method, the study area was categorized into non-waterlogged subsidence area, seasonally waterlogged subsidence area and wetland according to the subsidence and water-logging condition in the study area. With the method of partition Kriging, the spatial prediction value can be gained by summing up the mean value of SOC content in each separated area and the predictive residuals through spatial interpolation based on the residual data of the SOC content at each sampling point. Lastly this paper compared the prediction accuracy between the 2 methods with the measured values to determine the better method. It is found that the SOC content obtained by ordinary Kriging ranged from 9.34 to 16.252 g/kg, while the result of the partition Kriging was from 9.333 to 18.058 g/kg. The estimated ranges of the 2 methods were approximately same. Through the comparison, the spatial distribution of the SOC content obtained by ordinary Kriging showed no regularity because of neglecting the smooth transition between regions, while the spatial gradient features of SOC could be enhanced by the partition Kriging. The result showed that the correlation coefficient between the predicted and observed values obtained by the partition Kriging method was 0.7564, which was far higher than that by the ordinary Kriging method (0.5086). The root-mean-square error (RMSE), the mean absolute error (MAE) and the mean error (ME) of 2 methods were 0.35 and 0.55, 1.8511 and 1.2878, 0.0202 and 0.018, respectively. The partition Kriging performed much better than ordinary Kriging as it revealed much lower values of ME, MAE, and RMSE and a higher R<sup>2</sup>, indicating that the former has higher prediction accuracy. It is concluded that the partition Kriging interpolation model is a more appropriate spatial prediction model for SOC content in coal mining subsidence area, which provides the scientific basis for low-carbon land reclamation in mining area and even utilization of land resources in the region.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Interpolation
Controlled terms:Carbon - Coal - Coal deposits - Coal mines - Coal reclamation - Cutting machines (mining) - Errors - Farms - Forecasting - Geographic information systems - Lakes - Mean square error - Organic carbon - Soils - Subsidence
Uncontrolled terms:Coal mining subsidences - Correlation coefficient - Kriging interpolation - Ordinary kriging methods - Regionalized variables - Root mean square errors - Soil organic carbon content - Spatial prediction modeling
Classification code:483.1 Soils and Soil Mechanics - 502.2 Mine and Quarry Equipment - 503 Mines and Mining, Coal - 503.1 Coal Mines - 524 Solid Fuels - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 903.3 Information Retrieval and Use - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Area 2.00e+08m2, Percentage 4.69e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.032
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 32>
Accession number:20182405305867
Title:Segmentation algorithm with threshold for wheat lesion based on improved fuzzy edge detection
Authors:Diao, Zhihua (1, 2); Diao, Chunying (1, 2); Yuan, Wanbin (1, 2); Wu, Yuanyuan (1, 2)
Author affiliation:(1) Electric Information & Engineering Department, Zhengzhou University of Light Industry, Zhengzhou; 450002, China; (2) Henan Key Lab of Information Based Electrical Appliances, Zhengzhou; 450002, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:147-152
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wheat is an economic crop correlated with national lifeblood, and its yield has a direct impact on people's living standard and economic development, while the occurrence of disease is an important cause of crop yield decline. There are many kinds of crop diseases. Timely detection of disease types and corresponding prevention and control are urgent requirements to reduce the risk of crop yield decline. The disease segmentation is the priority among priorities of disease detection, and segmentation of lesion information is a prerequisite for disease identification, discrimination of disease degree, and pesticide application decision. The picture of wheat taken under natural conditions is greatly affected by the environment. The main obstacle of image segmentation is to find interesting parts in complex background. At present, the RGB (red, green, blue) sub region component segmentation method is usually used for image segmentation, and then the results are obtained by using some merging methods, but there is a large amount of computation in the segmentation of sub region components. For the wheat lesion segmentation, there exist the problems of noise and lesion edge being not clear. The research on wheat lesion image segmentation algorithm shows that the general image segmentation method has poor adaptability and compatibility, and other methods of mixing is difficult to achieve the desired results. Fuzzy edge detection with strong adaptability is the first algorithm to solve such problems. The traditional fuzzy edge detection method is first-order differentiating the preprocessed images, and edge detection is realized by edge discontinuity. Aiming at the disadvantages of the traditional algorithm such as high error rate, easy to lose the weak edge information, an improved image threshold segmentation algorithm based on fuzzy edge detection is proposed in this paper. In the aspect of image preprocessing, after analyzing the shortcomings of the traditional fuzzy edge detection, 2 improvements have been made to the algorithm. Gradient inverse weighted average filtering method is modified for the removal of noise and lesion of wheat, and numerical hierarchical improvement is made to multi-level fuzzy algorithm to enhance the edge information of the lesion. In the threshold segmentation algorithm, parameters directly influence the efficiency of image segmentation, so the level of detail segmentation on wheat spot shape can rely on the regulation of 2 aspects: One is the threshold, and the threshold value is influenced by relative pixel gray difference control; the other is the data involved in the calculation, and the data are related to the time of calculation. Reducing the participation data is the main method to improve the efficiency of the segmentation algorithm. An improved threshold segmentation method for maximum inter-class variance ratio is proposed. Based on the enhancement of image edge, threshold segmentation is applied to improve the threshold selection method. We use improved new formula to classify 2 kinds of variances and improve the overall performance of threshold segmentation from 2 aspects. The traditional threshold segmentation algorithm is improved, which is used to extract wheat spot shape feature from the wheat spot image. Compared with the traditional threshold segmentation algorithm, the improved algorithm based on fuzzy edge enhancement and threshold segmentation achieves an average accurate segmentation rate of 98.76%. The improved algorithm highlights the lesion edge information, and has the advantages of high segmentation efficiency and low noise. The noise ratio is reduced by 8.36 percentage points, and the time consuming is reduced by 0.331 s, which provides a reference for the improvement of image segmentation method. In the process of image segmentation, the improved algorithm is used to segment the wheat disease images, and the average multiple segmentation results are used as the parameters of final segmentation result. From the comparison results of 3 wheat lesion segmentation pictures, it can be seen that the improved algorithm is more meticulous to reflect the morphological characteristics of wheat disease, while retaining the edge information of wheat disease.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Image segmentation
Controlled terms:Algorithms - Behavioral research - Crops - Data reduction - Disease control - Diseases - Edge detection - Efficiency - Fuzzy sets - Image enhancement - Information filtering - Inverse problems - Numerical methods - Parameter estimation
Uncontrolled terms:Fuzzy enhancement - Morphological characteristic - Multiple segmentation - Pesticide applications - Prevention and controls - Segmentation algorithms - Threshold segmentation - Weak edge information
Classification code:723.2 Data Processing and Image Processing - 821.4 Agricultural Products - 903.1 Information Sources and Analysis - 913.1 Production Engineering - 921.6 Numerical Methods - 971 Social Sciences
Numerical data indexing:Percentage 9.88e+01%, Time 3.31e-01s
DOI:10.11975/j.issn.1002-6819.2018.10.018
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 33>
Accession number:20182405305850
Title:Research progress on precision control methods of air-assisted spraying in orchards
Authors:Zhai, Changyuan (1, 3, 4, 5); Zhao, Chunjiang (2); Wang, Ning (3); Long, John (3); Wang, Xiu (2); Weckler, Paul (3); Zhang, Haihui (1, 4, 5)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) National Engineering Research Centre for Information Technology in Agriculture, Beijing; 100097, China; (3) Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater; OK; 74078, United States; (4) Key Laboratory of Agricultural Internet of Things, Ministry of Agriculture, Yangling; 712100, China; (5) Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service, Yangling; 712100, China
Corresponding author:Zhao, Chunjiang(zhaocj@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:1-15
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Orchard air-assisted spraying technology and equipment are incorporating intelligent technologies to achieve higher precision. Liquid application rate and air supply rate are the two manipulated outputs of an orchard sprayer control system, which should be simultaneously controlled precisely at all times. For a target-oriented precision spraying, which aims to reduce off-target deposition or drift to keep environmental pollution to a tolerable limit, an orchard tree detection is indispensable. In this paper, the research progress analysis focuses on three methodologies: orchard target detection method, spraying dose control method and airflow control method. The orchard target detection method provides characteristic information of a target including tree position, canopy profile, canopy volume, canopy internal structure, canopy density, and canopy pest/disease level. Orchard tree positions are obtained by detecting tree canopies using ultrasonic sensors or optical sensors at different heights, or by sensing tree trunks using photoelectric sensors. Tree canopy profile and internal structure, which are used to estimate the volume and density of the canopy, can be detected based on ultrasonic sensing, LIDAR and machine vision. Spectroscopy, machine vision and electronic nose technologies are applied to evaluate the canopy pest/disease levels. Flow rate control methods through the sprayer plumbing and nozzles were reviewed. The plumbing flow rate can be adjusted by controlling spray pressure with electric regulating valves using hysteresis switch control, PID control, fuzzy control and artificial neural network. Regulating the injecting flow rate is another effective way to control pesticide application rate using an online mixing system in a sprayer. Major breakthroughs were obtained in plumbing design, pesticide mixing methods and strategies for plumbing flow rate control. There are also a large number of achievements in individual nozzle flow rate control based on PWM (pulse-width modulation) technology. Control systems of plumbing and individual nozzle flow rate regulation are commercialized, and some sprayers with these systems are available on the market. The theoretical principle of the air speed and air volume demand, which is the basic information for airflow control in orchard air-assisted spraying, is summarized. Air and droplet field modeling, airflow adjustment methods, and equipments are discussed. CFD (computational fluid dynamics) simulations combined with laboratory/orchard tests using special airflow and droplet deposition measuring systems become a viable way to establish spray spatial dynamic models. To adjust airflow of the air-assisted sprayer, the three key factors, including air direction, air speed and air volume, should be focused on. Air direction control mainly adopts the rotation of sprayer bellows and angle adjustment of air deflectors in the bellows, and the air speed and air volume are controlled mainly by changing the air inlet area, air outlet area and fan speed of an air-assisted sprayer. Finally, the obstacles and challenges in the current research related to the methods of orchard tree detection, spraying dose control and the airflow control are discussed. The obstacles and challenges include precision sensing methods exploration for canopy density and pest/disease level detection, establishment of universal models of orchard target air speed and air volume demand, investigation of airflow modeling and control base on the airflow demand, and integration of orchard precision spraying systems. The future development of precision control methods for air-assisted spraying in orchards was presented: 1) Orchard canopy density and pest/disease level online detection method is becoming a new research topic; 2) The study on the basic theoretical principles of air speed and air volume demand, airflow modeling, and control methods are an urgent need; 3) With the new advanced technology, scientific research institutions and companies will have great opportunities to optimize the design and development of new spraying dose and airflow control systems and integrate it with orchard precision sprayers.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:110
Main heading:Air
Controlled terms:Agricultural machinery - Bellows - Computational fluid dynamics - Computer vision - Deposition - Drops - Electric switches - Electronic nose - Flow rate - Forestry - Fuzzy control - Mixing - Neural networks - Online systems - Optical radar - Orchards - Pesticides - Plumbing - Pulse width modulation - Speed - Spray nozzles - Spraying - Three term control systems - Ultrasonic applications - Voltage control
Uncontrolled terms:CFD (computational fluid dynamics) - Design and Development - Environmental pollutions - Intelligent technology - On-line detection method - Pesticide applications - Scientific researches - Variable rate technology
Classification code:601.2 Machine Components - 619.1 Pipe, Piping and Pipelines - 631 Fluid Flow - 631.1 Fluid Flow, General - 716.2 Radar Systems and Equipment - 722.4 Digital Computers and Systems - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 753.3 Ultrasonic Applications - 801 Chemistry - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods
DOI:10.11975/j.issn.1002-6819.2018.10.001
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 34>
Accession number:20182405305878
Title:Effects of NaCl salinity on wastewater pollutants removal and microorganism in A<sup>2</sup>/O technology process
Authors:Zhang, Lanhe (1); Tian, Rui (1); Chen, Zicheng (1); Guo, Jingbo (2); Jia, Yanping (1)
Author affiliation:(1) School of Chemical Engineering, Northeast Electric Power University, Jilin; 132012, China; (2) School of Civil and Architecture Engineering, Northeast Electric Power University, Jilin; 132012, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:231-237
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A large amount of wastewater containing NaCl was produced in the rapid developed industries such as food processing, leather manufacturing and seawater recycling. The salty wastewater entered the urban sewage treatment plants and contacted with the activated sludge, and would affect the properties of activated sludge and influence the pollutant treatment efficiency. For example, the change of microbial community structure in the sewage treatment plants is known to be closely related to the pollutants' removal efficiency of the biological wastewater treatment process. The A<sup>2</sup>/O technology process is widely applied in the wastewater treatment due to its simple processing flow and ideal denitrification performance. The growth environment for microorganisms is different in anaerobic zone, anoxic zone and oxic zone, which leads to different microbial community structure in different zones of the system. However, few studies have been performed with regard to the effects of salinity on microbial community structure in different zones of A<sup>2</sup>/O technology process, and the distribution of main populations affecting biological denitrification remains unclear. In order to provide concrete information for improving the pollutant removal efficiency, the effects of NaCl salinity variations on the microbial community structure in different zones of A<sup>2</sup>/O technology process were investigated through high-throughput sequencing by analyzing the microbial community structures in anaerobic, anoxic and oxic zones. The results showed that: 1) With the increase of NaCl salinity, COD removal efficiency decreased. For example, when the salinity increased from 0 to 40 g/L, the COD removal efficiency decreased from 52%, 80% and 56% to 30%, 50% and 40% in anaerobic, anoxic and oxic zones, respectively, while the removal efficiency of NH<inf>4</inf><sup>+</sup>-N decreased from 33% and 61% to 11% and 39% in anaerobic zone and oxic zone, respectively, and the removal efficiency of NO<inf>3</inf><sup>-</sup>-N in anoxic zones decreased form 63% to 47%. 2) Compared with wastewater without NaCl, the addition of NaCl resulted in a decrease of microbial diversity; The microbial communities detected under higher salinity (40 g/L) and lower salinity (0 and 10 g/L) showed big difference; The decrease of the relative abundance of Thauera and Paracoccus in anoxic area, Clostridium and Nitrospira in oxic area, attributed to the decrease of nitrogen removal efficiency of the A<sup>2</sup>/O technology process; The relative abundance of some strains in Firmicutes (such as: Lactobacillus, Streptococcus, Tepidibacterium, Veillonella, Lachnoclostridium and Zoogloea) with stronger salinity tolerance increased as the increasing of salinity; The abundance of microorganisms related to denitrification (such as: Proteobacteria, Bacteroidetes and Firmicutes) always maintained at relatively high levels and they were dominant with the increasing salinity all the time in different zones of A<sup>2</sup>/O technology process, which guaranteed the system always having a certain denitrification efficiency.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Wastewater treatment
Controlled terms:Activated sludge process - Biological sewage treatment - Biological water treatment - Denitrification - Efficiency - Food processing - Microorganisms - Nitrogen removal - Pollution - Sewage treatment plants - Sodium chloride - Wastewater - Wastewater reclamation
Uncontrolled terms:Biological nitrogen removal - Biological wastewater treatment process - Denitrification efficiencies - Microbial community structures - Nitrogen removal efficiency - Pollutant removal efficiency - Salinity - Sludge
Classification code:445.1 Water Treatment Techniques - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 461.9 Biology - 802.2 Chemical Reactions - 822.2 Food Processing Operations - 913.1 Production Engineering
Numerical data indexing:Mass_Density 0.00e+00kg/m3, Mass_Density 0.00e+00kg/m3 to 4.00e+01kg/m3, Mass_Density 1.00e+01kg/m3, Mass_Density 4.00e+01kg/m3, Percentage 3.30e+01%, Percentage 3.90e+01%, Percentage 4.00e+01%, Percentage 5.00e+01%, Percentage 5.20e+01%, Percentage 5.60e+01% to 3.00e+01%, Percentage 6.10e+01% to 1.10e+01%, Percentage 6.30e+01% to 4.70e+01%, Percentage 8.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.10.029
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 35>
Accession number:20182405305855
Title:Time-delayed feedback control of vehicle suspension system based on state transformation
Authors:Yan, Gai (1); Fang, Mingxia (1); Dong, Tianfu (1); Ji, Renjie (1)
Author affiliation:(1) School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai; 200092, China
Corresponding author:Fang, Mingxia(mxfang_tj@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:54-61
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Vehicle active/semi-active suspension is added with control force by actuators based on vehicle driving condition to achieve the purpose of improving vehicle ride comfort and safety. However, time delay is inevitable in control system because of the factors such as signal acquisition, transmission, controlling calculation and actuator actuation. It is found that time delay has a great influence on system control and even can lead to the system instability and divergence. In order to improve the ride comfort and stability of the vehicle, and study the effect of time delay compensation control in the suspension system, 2 degrees of freedom vehicle semi-active suspension system is established based on the suspension system of Sail sedan in this paper. And a time-delayed feedback controller is designed. Moreover, the method of combining theory and experiment is used to study the characteristics of the system with time-delayed feedback control. Firstly, a dynamic model of suspension system with time delay is established. The stability of the system is analyzed by the ordinary differential theory and polynomial discrimination method. According to this method, the time delay stable interval (0, 0.0143 s) of the system is got under the feedback gain obtained by the classic quadratic optimal control. The simulation results show that the system remains stable when the inherent time delay is 0.01 s, and when the inherent time delay is 0.0143, 0.05 or 0.065 s, the system is unstable and diverges after control. And the amplitude frequency characteristic curve of the system can also explain this phenomenon. So the results of the theoretical analysis are verified by the simulation calculation. In a word, when the time delay of the system exceeds the critical delay, the qualitative features of the suspension system with time delay may be changed and become unstable and divergent under the classic quadratic optimal control. And the structure of the system will be damaged in this time. In order to ensure the stability of the system, the state transform method and optimal control theory are applied to design the optimal time-delayed feedback controller. The controller can not only guarantee the stability of the system, but also improve the damping characteristics of the system. It can be seen that the most important evaluation index, i. e. the amplitude of the spring mass acceleration, decreases from 2.70 to less than 1.50 m/s<sup>2</sup>when comparing the simulation results under time-delayed feedback control with the uncontrolled results. When the inherent time delay in the system is 0.065 s, the amplitude of the spring mass acceleration is about 1.40 m/s<sup>2</sup>. It is noted that the amplitude of the spring mass acceleration decreases by 48.15% compared with passive control. Therefore, the damping performance of the suspension system is improved effectively with time delayed feedback control, and the time-delayed feedback controller designed through integral transformation is very reasonable and effective. Finally, in order to verify the reliability of the analysis in this paper, a suspension time delay control platform is designed and assembled. Then the experimental results are compared with the simulation results under the same working conditions to verify the effectiveness of the results. In the experiment, the inherent delay of the suspension system is divided into 2 parts. One is the time lag of the signal from the acquisition to the time point before input into magneto rheological damper and it can be identified based on time domain signal. The other is the reaction delay of the actuator. Hence, the inherent time delay of the system measured is approximately equal to 0.065 s. It is found from the experiment that the experimental results and simulation results are stable, and the experimental results are slightly larger than the simulation results, but the error is less than 15%, which meets the engineering requirements. It indicates that the research is highly reliable. It provides an effective control method for suspension damping, and has a great value in engineering application.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Suspensions (components)
Controlled terms:Active suspension systems - Actuators - Automobile suspensions - Control engineering - Control system stability - Control theory - Controllers - Convergence of numerical methods - Damping - Degrees of freedom (mechanics) - Delay control systems - Feedback control - Integral equations - Magnetic levitation vehicles - Quadratic programming - Reliability analysis - Stability - Time delay - Time domain analysis - Vehicles
Uncontrolled terms:Active/semi-active suspensions - Amplitude frequency characteristics - Engineering applications - Magneto- rheological dampers - Quadratic optimal control - Semi-active suspension systems - Time delayed feedback control - Vehicle suspension systems
Classification code:601.2 Machine Components - 662.4 Automobile and Smaller Vehicle Components - 713 Electronic Circuits - 731.1 Control Systems - 731.4 System Stability - 732.1 Control Equipment - 921 Mathematics - 931.1 Mechanics
Numerical data indexing:Acceleration 1.40e+00m/s2, Acceleration 1.50e+00m/s2, Percentage 1.50e+01%, Percentage 4.81e+01%, Time 1.00e-02s, Time 6.50e-02s
DOI:10.11975/j.issn.1002-6819.2018.10.006
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 36>
Accession number:20182405305864
Title:Simulation and verification of photosynthesis-stomatal conductance coupled model under different nitrogen application rates in winter wheat with drip irrigation
Authors:Zhang, Yanqun (1); Wang, Jiandong (1); Zhao, Yuefen (2); Gong, Shihong (1); Sui, Juan (1)
Author affiliation:(1) Department of irrigation and drainage, China Institute of Water Resources and Hydropower Research, Beijing; 100048, China; (2) Beijing IWHR Corporation, China Institute of Water Resources and Hydropower Research, Beijing; 100048, China
Corresponding author:Wang, Jiandong(wangjd@iwhr.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:124-130
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aiming at the phenomenon of excess nitrogen (N) application rate in winter wheat field in North China Plain, measuring and modelling photosynthetic rates under different N rates is helpful to understand the physiological basis of the influence of reducing traditional N application rates on crop yield. This study set up 3 amounts of N rates, i.e. 290, 190 and 110 kg/hm<sup>2</sup>, as high (N3), middle (N2) and low N (N1) treatments, respectively in drip irrigation winter wheat field in 2 consecutive growing seasons (2012-2014). The coupled model of photosynthesis and stomatal conductance was established to model photosynthetic rates. Photosynthetic rates to intercellular CO<inf>2</inf>concentration response curves (A<inf>n</inf>-C<inf>i</inf>curves) were measured in 2014 to determine key parameters of the model from the heading stage to harvest stage. Daily dynamics of photosynthetic rates were measured in 2013 as the verification data of the coupled model. The results showed that the apparent maximum carboxylation rate of Rubisco (V<inf>cmax</inf>) and maximum electron transfer rate (J<inf>max</inf>) was significantly affected by N treatments. The measured V<inf>cmax</inf>varied from 84.5 to 153.3 μmol/(m<sup>2</sup>·s) and J<inf>max</inf>varied from 156.5 to 236.2 μmol/(m<sup>2</sup>·s) during the measurements and among treatments. Differences of V<inf>cmax</inf>and J<inf>max</inf>among treatments were more significant when the measurement dates close to the harvest stage. During the filling stage (May 21st to 23rd), only V<inf>cmax</inf>and J<inf>max</inf>of the low N treatment (N1) was significantly lower than that of high N treatment (N3), the corresponding values of the middle N treatment (N2) were not significant lower than those of N3. During the milking stage (June 2nd to 3rd), however, the V<inf>cmax</inf>and J<inf>max</inf>of both N2 and N1 were significantly lower than those of N3. There was no significant difference in the ratio of J<inf>max</inf>/V<inf>cmax</inf>among treatments during the three measurements. The ratio of J<inf>max</inf>/V<inf>cmax</inf>gradually increased along with the advancing of growing stages and changed from 1.49 to 2.00 during the measurements. The differences of V<inf>cmax</inf>among treatments could be quantified by leaf mass N content. Then the J<inf>max</inf>value can be calculated according to the ratio of J<inf>max</inf>/V<inf>cmax</inf>. The slope (g<inf>1</inf>) and intercept (g<inf>0</inf>) of the stomatal conductance sub-model were changed with different N application. During the filling stage (May 21st to 23rd), it was found that the N3 treatment with the highest g<inf>0</inf>and the smallest g<inf>1</inf>. The analytical solution of the photosynthesis model and the Ball-Berry stomatal conductance model was derived to solve the coupled model. Considering the difference between the key parameters, the simulation results of the coupling model for photosynthetic rate from the daily process was good, with the average absolute error were 2.11 and 2.23 μmol/(m<sup>2</sup>·s) for the 2 measurements in 2013 and the differences between simulated and measured photosynthetic rate were less than 5%. The prediction of the model also showed that different parameters have different effects on the simulation results of photosynthetic rate. For example, although the g<inf>0</inf>of stomatal conductance sub-model is often relatively small, it will cause large error in the simulation of photosynthetic rate under low light intensity, while some researchers may neglect this parameter when running the model. The model can be used to simulate photosynthetic rates under change of single physiological or environmental factor and change of multi factors, so as to better predict the yield changes.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Physiological models
Controlled terms:Carboxylation - Crops - Irrigation - Nitrogen - Photosynthesis - Physiology
Uncontrolled terms:Average absolute error - Coupled modeling - Electron transfer rates - Environmental factors - Nitrogen application rates - Photosynthetic rate - Stomatal conductance - Winter wheat
Classification code:461.9 Biology - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products
Numerical data indexing:Percentage 5.00e+00%
DOI:10.11975/j.issn.1002-6819.2018.10.015
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 37>
Accession number:20182405305861
Title:Calculated model and application of ice-free length of diversion channel for pumping well water to melt ice at high altitude and cold regions
Authors:Zong, Quanli (1); Zheng, Tiegang (2); Wu, Sujie (1); Liu, Zhenji (1); Liu, Huanfang (1)
Author affiliation:(1) College of Water Conservancy and Architectural Engineering, Shihezi University, Shihezi; 832000, China; (2) Sate Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing; 100038, China
Corresponding author:Zheng, Tiegang(zhengtg@iwhr.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:99-106
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pumping well water to melt ice is an effective method to solve the ice problem for diversion channel at high altitude and cold regions, which is widely used in Hongshanzui hydropower station, Jingou river hydropower station, Youth hydropower station of Xinjiang and Xiangjia hydropower station of Qinghai Province. According to the local hydrological and natural conditions and the characteristics of hydropower projects, pumping well water to melt ice is a method to pump high temperature underground well water into the diversion channel to increase water temperature, which makes the ice in the channel melted. In order to solve the calculation problem of ice-free length for pumping well water to melt ice, the calculation formula of ice-free length was proposed theoretically based on water heat balance theory. The influences of hydraulic, thermal and climatic conditions on ice-free length were considered in above formula, which was verified by using the values of ice-free length of diversion channels in Hongshanzui and Jingouhe hydropower station of Manas River, Xinjiang. The results show that calculated results are in agreement with measured values of the ice-free length for the diversion channel of the Hydropower station with the minimum and maximum errors of 6.2% and 29.5%, respectively, which confirmed the reliability of deduced formula. In this study, the second diversion channel of Hongshanzui hydropower station in Manas River of Xinjiang was selected as the study area, and the values of ice-free length were calculated under different hydraulic, thermal and climatic conditions. The calculated results indicate that the ice-free length is proportional to discharges of channel and well water, temperature of well water, atmospheric temperature and daily solar radiation, and it is inversely proportional to wind speed, atmospheric saturation deficiency and daily snowfall. Firstly, the value of ice-free length is increased by only 200 m with the channel discharges being increased from 0 to 20 m<sup>3</sup>/s under the conditions of atmospheric temperature of -20℃ and well water discharge of 0.16 m<sup>3</sup>/s, which indicates that the influence of channel discharge on ice-free length is little. Secondly, the value of ice-free length can be increased by 400 m with well water discharge being increased by 0.02 m<sup>3</sup>/s under the condition of atmospheric temperature of -20℃. In practical engineering, the increase of well water discharge is a direct and effective way to increase the mixed water temperature of channel, and to increase the ice-free length. Thirdly, the values of ice-free length can be decreased by 16.1%-31.3% with atmospheric temperature being decreased by 5℃, which shows that the influence of atmospheric temperature on the ice-free length is also significant. Finally, the values of ice-free length can be decreased by 4.30%-53.0% with wind speed being increased from 0.5 to 6.0 m/s under the condition of atmospheric temperature of -20℃. Above results indicate the influences of well water discharge, atmospheric temperature and wind speed on ice-free length are significant. This study can provide valuable information for preventing ice hazards of diversion channel of diversion power station at high altitude and cold regions.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Ice
Controlled terms:Atmospheric temperature - Atmospheric thermodynamics - Hydroelectric power - Hydroelectric power plants - Ice control - Ice problems - Models - River diversion - Temperature - Well pumps - Wells - Wind
Uncontrolled terms:Atmospheric saturation - Cold regions - Daily solar radiations - Free water - Hydropower stations - Practical engineering - Pumping well - Theoretical analysis
Classification code:441 Dams and Reservoirs; Hydro Development - 443.1 Atmospheric Properties - 443.3 Precipitation - 611.1 Hydroelectric Power Plants - 618.2 Pumps - 641.1 Thermodynamics
Numerical data indexing:Percentage 1.61e+01% to 3.13e+01%, Percentage 2.95e+01%, Percentage 4.30e+00% to 5.30e+01%, Percentage 6.20e+00%, Size 2.00e+02m, Size 4.00e+02m, Velocity 5.00e-01m/s to 6.00e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.10.012
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 38>
Accession number:20182405305887
Title:Corn silage fermentation quality and microbial populations as influenced by adding homo-and hetero-fermentative bacteria after silos opened
Authors:Wang, Xuzhe (1); Zhang, Fanfan (1); Ma, Chunhui (1); Miao, Fang (1); Tang, Kaiting (1); Li, Feifei (1)
Author affiliation:(1) College of Animal Sciences and Technology, Shihezi University, Shihezi; 832003, China
Corresponding author:Ma, Chunhui(chunhuima@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:10
Issue date:2018
Publication year:2018
Pages:296-304
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ensiling has been known as a method to preserve the moist in crops by controlling anaerobic fermentation. If management requirements are not met, to improve silage quality, additives are often used. Inoculation of Lactobacillus in the ensiling process has been recommended in order to make good quality silage. The objective of this study was to investigate the effects of different additives of homo-and hetero-fermentative bacteria on the fermentation characteristics, microorganism content, and aerobic stability of corn (Zea mays L. cv. Xinsiyu 10) silage during aerobic conditions for silage production practice. The corn was ensiled at 4 different treatments: Control (CK) had no added inoculants; the T group (homo-fermentative bacteria) contained Lactobacillus plantarum and Pediococcus acidilactici with a ratio of 1: 1, 1×10<sup>5</sup>cfu/g; the Y group (hetero-fermentative bacteria) contained Lactobacillus buchneri at 1×10<sup>5</sup>cfu/g; and the T+Y group (all of these homo-and hetero-fermentative bacteria) contained Lactobacillus plantarum, Pediococcus acidilactici and Lactobacillus buchneri with a ratio of 1: 1: 1, 1×10<sup>5</sup>cfu/g, and then they were fermented for 60 days. Silage samples were collected when the silos were opened for 0, 48, 96, 144, 192, and 240 h and then analyzed to determine pH value, dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), water soluble carbohydrates (WSC), lactic acid, acetic acid, and NH<inf>3</inf>-N, and the aerobic stability was evaluated by using an online multi-channel data logger temperature recorder. Microbial populations (Lactobacillus, moulds, yeast and aerobic bacteria) in the silage were also determined. The comprehensive assessment was performed for the 4 treatments through the calculation of 12 indices by a membership function analysis. The results showed that aerobic stability time in the Y and TY treatments reached 195.58 and 196.21 h, respectively, 63.87-64.67 h longer than that in the CK and T treatments in air respectively (P<0.05), and acetic acid concentrations were significantly higher than that in the CK and T treatments (P<0.05). T treatment showed the lowest pH value among the treatments, 0.5%-15.2% lower than other treatments (P<0.05), and lactic acid concentrations were significantly higher than that in the CK and Y treatments (2.4%-46.5%, P<0.05). Y treatment had the highest water soluble carbohydrates concentrations and the lowest population of moulds among the treatments (3.5%-24.5%, 4.6%-45.2% respectively; P<0.05). The NH<inf>3</inf>-N concentrations and populations of aerobic bacteria in the CK were 11.1%-43.7% and 1.2%-15.1% respectively greater than that in the T, Y, and TY treatments (P<0.05), and CO<inf>2</inf>concentrations in CK treatment also were the highest among the treatments (P<0.05). Significant linear relationship existed between moulds, aerobic bacteria populations, and silos opening time; the relationships between CO<inf>2</inf>concentrations, lactic acid bacteria, yeast populations and silos opening time were best described by Allometric I, ExpDec I, and Logistic equation respectively. Comprehensive evaluation was as follows: Y > TY>T>CK. Therefore, corn silage with silage addition of hetero-fermentative bacteria was better than adding silage homo-fermentative bacteria or mixed biological inoculant containing homo-and hetero-fermentative bacteria in enhancing silage fermentation quality, reducing the number of harmful microbes, and prolonging aerobic stability during the silos opening time.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:44
Main heading:Aerobic bacteria
Controlled terms:Acetic acid - Bacilli - Bacteria - Carbohydrates - Carbon dioxide - Fermentation - Lactic acid - Membership functions - Molds - pH - Quality control - Stability - Water treatment - Yeast
Uncontrolled terms:Acetic acid concentration - Aerobic stability - Comprehensive assessment - Comprehensive evaluation - Corn silage - Lactic acid bacteria - Microbial populations - Water-soluble carbohydrates
Classification code:445.1 Water Treatment Techniques - 461 Bioengineering and Biology - 461.9 Biology - 801.1 Chemistry, General - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 822.3 Food Products - 913.3 Quality Assurance and Control - 921 Mathematics
Numerical data indexing:Age 1.64e-01yr, Percentage 1.11e+01% to 4.37e+01%, Percentage 1.20e+00% to 1.51e+01%, Percentage 2.40e+00% to 4.65e+01%, Percentage 3.50e+00% to 2.45e+01%, Percentage 5.00e-01% to 1.52e+01%, Time 2.30e+05s to 2.33e+05s, Time 7.04e+05s, Time 7.06e+05s, Time 8.64e+05s
DOI:10.11975/j.issn.1002-6819.2018.10.038
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
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