<RECORD 1>
Accession number:20181104889864
Title:Design on mobile fermenting device of agaricus bisporus cultivating material and experiment of cultivation effects
Authors:Xin, Longzuo (1); Jin, Yazheng (1); Liang, Changming (2); Yang, Xin (3); Huo, Xiaojing (3); Hao, Jianjun (3)
Author affiliation:(1) Department of Horticulture, Hebei North University, Zhangjiakou; 075400, China; (2) School of Foreign Languages, Hebei North University, Zhangjiakou; 075400, China; (3) School of Mechanical and Electrical Engineering, Agricultural University of Hebei, Baoding; 071000, China
Corresponding author:Jin, Yazheng(jyzheng_2@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:241-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nutritious Agaricus bisporus is one of the most extensively cultivated, most productive in total and largest consumed edible fungi in the world. In many parts of China, it is mainly planted in small-scale family cultivation. Due to the inadequate fermentation of cultivating material, it is of low yield and unstable benefit, which has been one of the main reasons resulting in not extensively being planted since it was introduced to China. With its movability, adjustable size, low investment, short, effective and homogeneous fermentation and low labor intensity, new mobile fermenting device was designed for cultivators of medium or small-scale Agaricus bisporus planting. It is mainly made up of ventilation pedestal, fermenting room, compressor fan, controlling system, ventilation pipe, controlling valve and heat exchanger (often used in extremely cold winter outside of Northern China). The key to the fermentation of cultivating material by this device is to homogeneously heat every part of cultivating material in fermenting room to achieve the homogeneity of the effective accumulative temperature. By the flow of heat through air circulation, air pressure and air volume can homogeneously reach each part of the fermenting room through the arrangement of air outlet and duct. The effective fermenting temperature and the need of fresh air for fermentation can be adjusted by the volume of air in and out, and the temperature difference in the fermenting room can be controlled within acceptable range for fermentation by air circulation in it. The experiment formula of ferment effects is about 30% corn stalk, 50% cow manure, 20% cotton seed hull, 1% plaster, 1% superphosphate, and 1% lime on mobile fermenting device. Material temperature changes are observed during 5 temperature phases including temperature increasing, pasteurizing, temperature decreasing, constant-temperature sustaining, and fermentation ceasing. Material temperature in temperature increasing phase has been controlled not more than 65℃, 60-65℃ in pasteurizing phase for 8 h, and 48-52℃ in temperature decreasing and sustaining phase for 24 h. And during fermenting, carbon dioxide in fermenting room has been kept 0.3%-5.0% and ammonia concentration has been not more than 3 mg/L by ventilation. Fermenting results show that according to the characteristics of cultivating material, it takes 15-20 days to have it fermented, which can greatly reduce the fermenting time, labor intensity and production cost of raw material because of no turning of the material and secondary fermentation. And the temperature range of the up, middle and low fermentation material in the room can be managed between 0.1 and 3.9℃, which can achieve the fermentation material more homogeneous. And after fermentation, pH values of the upper, the middle and the lower layer material are respectively 7.5, 7.6 and 7.5, which are fit for the development of Agaricus bisporus. And before fermentation, the moisture content is 68%, but after it, the moisture contents of the upper, the middle and the lower layer material are 63%, 63% and 61%, respectively, which decrease by only 5%-7%. And the nitrogen content is 2.8%-2.9%, and the ratio of carbon to nitrogen is 15.8-16.0. In all, after its fermentation, the physical and chemical properties of the material, such as color, feeling, smell and leachate accord with the standards of compost maturity. Yield of Agaricus bisporus is very important, the average yield of Agaricus bisporus cultivated through the fermentation material can reach 18 kg/m<sup>2</sup>, and it is not different significantly from the contrast (P<0.05).<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Fermentation
Controlled terms:Agricultural implements - Air - Carbon dioxide - Composting - Design - Fertilizers - Fungi - Investments - Lime - Moisture - Moisture determination - Nitrogen - Pasteurization - Temperature - Ventilation
Uncontrolled terms:Agaricus bisporus - Ammonia concentrations - Constant temperature - Material temperature - Mobile fermenting device - Physical and chemical properties - Temperature differences - Yield
Classification code:641.1 Thermodynamics - 643.5 Ventilation - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821.1 Agricultural Machinery and Equipment - 822.2 Food Processing Operations - 944.2 Moisture Measurements
Numerical data indexing:Age 4.11e-02yr to 5.48e-02yr, Mass_Density 3.00e-03kg/m3, Percentage 1.00e+00%, Percentage 2.00e+01%, Percentage 2.80e+00% to 2.90e+00%, Percentage 3.00e+01%, Percentage 3.00e-01% to 5.00e+00%, Percentage 5.00e+00% to 7.00e+00%, Percentage 5.00e+01%, Percentage 6.10e+01%, Percentage 6.30e+01%, Percentage 6.80e+01%, Surface_Density 1.80e+01kg/m2, Time 2.88e+04s, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2017.22.031
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 2>
Accession number:20181104889870
Title:Energy efficiency evaluation and experiment on grain counter-flow drying system based on exergy analysis
Authors:Ma, Xingzao (1, 2); Fang, Zhuangdong (2); Li, Changyou (2)
Author affiliation:(1) College of Electro-mechanical and Engineering, Lingnan Normal University, Zhanjiang; 524048, China; (2) College of Engineering, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Li, Changyou(lichyx@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:285-291
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Grain drying is not only restrained by human operation behavior, but also influenced by a lot of objective factors, such as environmental factors, grain physical properties, and grain flow characteristics, as well as the processing technology and geometry of the dryer. In order to objectively and rationally evaluate the energy efficiency of the drying system, and realize the high efficiency and energy saving of grain drying, based on the heat and mass balance calculation of drying system, as well as the evaluation method of thermal efficiency and exergy efficiency, the energy utilization degree of counter-flow continuous drying process system was investigated under the change of airflow condition. The test results showed that the energy utilization effect of each drying segment in the dryer was better under the experimental condition. In high temperature drying segment, the exhaust gas heat loss and heat loss of drying chamber were not higher than 6.68% and 11.09%, respectively, and the thermal efficiency and exergy efficiency were not less than 83.02% and 68.1%, respectively. In low temperature drying segment, the exhaust gas heat loss and heat loss of drying chamber were not higher than 21.26% and 9.37%, respectively, and the thermal efficiency and exergy efficiency were not less than 69.37% and 56.22%, respectively. In cooling segment, due to that the grain temperature was higher than air temperature, which meant that the air had obvious cooling and dehydration effect on the grain. The average thermal efficiency and exergy efficiency of drying system were 80.24% and 64.52% respectively, which showed that the energy matching effect during grain drying process was good. The heat loss of drying chamber initially was 1.86% while 21.26% in later stage. The corresponding thermal efficiency of drying chamber reduced from 89.09% to 69.37%. The exergy efficiency of drying chamber reduced from 72.55% to 56.22%, which indicated that the energy consumption of grain drying not only had subjective exergy, but also contained objective exergy, and the evaluation of drying process and dryer energy utilization efficiency could not just stay on the subjective thermal efficiency, and should consider the effect of objective energy. Test showed that the average unit heat consumption of grain was 2 944.6 kJ/kg, and compared with the national standard, which was less than 7 400 kJ/kg, the highest energy saving could reached 60.2%. At the same time, the grain temperature was raised slowly with the moisture content decreasing during grain drying, and the highest temperature did not exceed 38.0℃, close to or below the glass transition temperature of grain, which showed that with the reasonable design of the grain drying process, the drying quality of grain could be better ensured. The results provide an analytical reference to improve grain drying efficiency and explore the ways of energy saving drying, as well as provide reference to design the grain drying process system and establish energy efficiency evaluation standard for grain drying.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Drying
Controlled terms:Behavioral research - Dryers (equipment) - Energy conservation - Energy efficiency - Energy utilization - Environmental technology - Exergy - Gases - Glass transition - Grain (agricultural product) - Heat losses - Low temperature drying - Systems analysis - Temperature
Uncontrolled terms:Energy efficiency evaluation - Energy utilization degree - Energy utilization efficiency - Exergy Analysis - Experimental conditions - High temperature drying - Mass-balance calculations - Processing technologies
Classification code:454 Environmental Engineering - 525.2 Energy Conservation - 525.3 Energy Utilization - 641.1 Thermodynamics - 641.2 Heat Transfer - 802.3 Chemical Operations - 821.4 Agricultural Products - 961 Systems Science - 971 Social Sciences
Numerical data indexing:Percentage 1.11e+01%, Percentage 1.86e+00%, Percentage 2.13e+01%, Percentage 5.62e+01%, Percentage 6.02e+01%, Percentage 6.45e+01%, Percentage 6.68e+00%, Percentage 6.81e+01%, Percentage 6.94e+01%, Percentage 7.25e+01% to 5.62e+01%, Percentage 8.02e+01%, Percentage 8.30e+01%, Percentage 8.91e+01% to 6.94e+01%, Percentage 9.37e+00%, Specific_Energy 7.40e+06J/kg, Specific_Energy 9.45e+05J/kg
DOI:10.11975/j.issn.1002-6819.2017.22.037
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 3>
Accession number:20181104889840
Title:Quantitative analysis method and verification of cavitation characteristic signal of hydraulic retarder
Authors:Dong, Liang (1); Liu, Jiawei (1); Liu, Houlin (1); Xiao, Jiawei (1); Zhao, Yuqi (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:53-60
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For accurately quantitatively analyzing characteristics threshold of hydraulic retarder cavitation signal and providing a theoretical basis for the structural optimization of hydraulic retarder and avoiding cavitation resulting in the decrease of braking capacity, a test rig is set, which can collect vibration, noise and pressure pulsation signal synchronously. In the test system, different from the original medium, the medium is clear water which does not change the initial conditions of cavitation and is more conducive to observe the development process of cavitation. In addition, clear water is easy to be replaced, so that the test difficulty is reduced. First, we test the external characteristics and conduct the signal acquisition. The pressure in reducer casing is maintained at 0.1 MPa by booster pump, and the drive motor runs at 800, 900, 1 000, 1 100 and 1 200 r/min respectively. Then the high-speed photography is carried out, and the acquisition of rotation rate, torque, temperature, pressure, noise and vibration acceleration signals is performed, followed by a cavitation performance test and its relevant signal acquisition. Next, pressure inside the chamber is reduced to 0.08, 0.06, 0.04, 0.03, 0.02 and 0.01 MPa respectively. Under these 6 different pressure conditions, the experiment steps were the same as those in 0.1 MPa condition. On the base of broadband vibration acceleration and broadband noise level, the principle of calculating the mean sequence of each working condition is used to analyze vibration and noise of hydraulic retarder of 0° blade dip angle quantitatively, as well as the cavitation characteristics signals of pressure fluctuation. Accordingly, the vibration, noise and pressure pulsation signal and the cavitation threshold in characteristic frequency band are determined. In order to facilitate the study of cavitation development degree under the working conditions, this paper introduces the concept of "relative torque" and "change rate" which can ease the difficult of quantification of the test data. The different cavitation stages are divided into 3 types: the non-cavitation stage, the nascent stage and the serious stage. The non-cavitation stage is the stage in which the hydraulic retarder unit is in normal operation and the relative torque change rate is less than 2.0%. The lower rotation rate and the higher pressure allow the cavitation to be suppressed so that the high-speed camera does not capture the obvious empty bubble. At nascent stage, the relative torque change rate is between 2.0% and 5%. As the rotation rate increases and the pressure in the cavity of the hydraulic reducer decreases, the local pressure of the flow field decreases below the saturated vapor pressure. As a result, bubble begins to generate and initial cavitation occurs, and the volume of vacuoles is small and the vacuoles are destroyed immediately. The relative torque change rate at serious stage is greater than 5%. At this stage, the pressure in most areas of the reducer cavity is less than the saturated vapor pressure. As most of the flow path is occupied by the bubbles, the cavities generate at the outer edge. The flow of liquid spreads to the roots of the blades and cavitation fully develops. In order to verify the effectiveness of the quantitative analysis method proposed in this paper, hydraulic retarder of 15° blade dip angle is selected. And through high-speed photography test, the results show that the proposed method of determining the threshold is able to distinguish cavitation state of hydraulic retarder. The cavitation threshold method is universal for this series of hydraulic reducers. The research provides a theoretical basis for the optimization of the structure of the hydraulic reducer.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Cavitation
Controlled terms:Digital storage - Frequency bands - High speed cameras - High speed photography - Hydrostatic pressure - Photography - Signal analysis - Signal processing - Structural optimization - Testing - Torque - Vapor pressure - Vibration analysis
Uncontrolled terms:Cavitation characteristics - Characteristic frequencies - External characteristic - Hydraulic retarder - Noises - Pressure fluctuation - Saturated vapor pressure - Vibrations
Classification code:631.1.1 Liquid Dynamics - 641.1 Thermodynamics - 716.1 Information Theory and Signal Processing - 722.1 Data Storage, Equipment and Techniques - 742.1 Photography - 742.2 Photographic Equipment - 746 Imaging Techniques - 921.5 Optimization Techniques - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 2.00e+00%, Percentage 2.00e+00% to 5.00e+00%, Percentage 5.00e+00%, Pressure 1.00e+04Pa, Pressure 1.00e+05Pa, Pressure 2.00e+04Pa, Rotational_Speed 1.10e+03RPM, Rotational_Speed 1.20e+03RPM
DOI:10.11975/j.issn.1002-6819.2017.22.007
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 4>
Accession number:20181104889853
Title:Effects of rainfall erosion factor, vegetation type and coverage on soil erosion of sloping farmland
Authors:Xiao, Jibing (1); Sun, Zhanxiang (2); Liu, Zhi (1); Zheng, Jiaming (2); Liu, Yang (2); Feng, Liangshan (2); Yang, Ning (2); Bai, Wei (2)
Author affiliation:(1) Institute of Water and Soil Conservation in Liaoning, Chaoyang; Liaoning; 122000, China; (2) Liaoning Academy of Agricultural Sciences, Shenyang; Liaoning; 110161, China
Corresponding author:Sun, Zhanxiang(sunzhanxiang@sohu.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:159-166
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to discuss the effect of rainfall and vegetion on soil erosion of sloping farmland in cinnamon soil region in western Liaoning, the experiment was carried out under natural rainfall on artificial slope runoff plots from 2006 to 2010. The runoff plots with an interval of 1 m were designed according to the 20-year standard and each area was 60 m<sup>2</sup>. Slope factor was set as 5° and 10° respectively. Among 3 runoff plots built under the same slope, 2 plots were practiced by millet - sweet potato rotation, and another runoff plot was set as the control, which was the natural hillside field in 2006-2007 and bare slope (coverage <5%) in 2008-2010. Millet and sweet potato were planted as test crops by contour tillage and row spacing was 50 cm. The result showed that soil erosion in the sloping farmland mainly occurred between June and August, particularly in July. The surface runoff and erosion amount increased in accordance with the increasing of gradient and the effect of slope on erosion amount was greater than runoff with the slope increasing. When rainfall reached a certain intensity, soil erosion would occur. The experiment also showed that the surface runoff and erosion amount on sweet potato field had significantly positive relations with the rainfall (P<0.01 for runoff, P<0.05 for erosion amount), the maximum 30-minute rainfall intensity (P<0.01), the rainfall erosivity (which was the product of the former 2 factors) (P<0.01), and the product of rainfall and average rainfall intensity (P<0.01); the runoff on bare soil field had significantly positive relations with the rainfall (P<0.01 and P<0.05 on 5° and 10° bare soil field, respectively), and the rainfall erosivity (P<0.01); the erosion amount had significantly positive relations with the maximum 30-minute rainfall intensity (P<0.05 and P<0.01 on 5° and 10° bare soil field, respectively), and the rainfall erosivity (P<0.01), but had not positively significant relation with rainfall. The surface runoff and erosion amount were mostly affected by the precipitation and the maximum 30-minute rainfall intensity respectively through regression analysis and the both had not positively significant relation with average rainfall intensity on sweet potato and bare soil field. Erosion amount had a relation of power function and a significantly positive correlation with surface runoff under medium and higher rainfall intensity (P<0.01). The surface runoff and erosion amount on sweet potato field had a significantly negative exponential function relation (P<0.05). The amount of soil erosion on sweet potato field was the largest, the following was millet field and that of wild grass ground was the least. Multi variance regression analysis revealed that the factors impacting the amount of soil erosion from high to low were surface runoff, rainfall erosivity, and vegetation coverage, and the effects of rainfall erosivity and vegetation coverage on soil erosion increased with the slope increasing. Vegetation cover was especially important to protect against soil erosion on sloping farmland in western Liaoning, and crop management would be paid more attention with the increasing of gradient. The effects of different factors such as rainfall and crop varieties on soil erosion on sloping farmland were preliminarily known after the 5-year experiment in this paper. The research provides theoretical basis and technical support for the effective prevention and treatment of soil erosion in the region.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Agricultural runoff
Controlled terms:Crops - Erosion - Exponential functions - Farms - Precipitation (meteorology) - Rain - Regression analysis - Runoff - Soils - Vegetation
Uncontrolled terms:Cinnamon soil - Effects of rainfalls - Negative exponential functions - Positive correlations - Rainfall erosivity - Rainfall intensity - Sloping farmlands - Vegetation coverage
Classification code:442.1 Flood Control - 443.3 Precipitation - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 922.2 Mathematical Statistics
Numerical data indexing:Age 2.00e+01yr, Age 5.00e+00yr, Area 6.00e+01m2, Size 1.00e+00m, Size 5.00e-01m, Time 1.80e+03s
DOI:10.11975/j.issn.1002-6819.2017.22.020
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 5>
Accession number:20181104889857
Title:Identification of hybrid rice strain based on near-infrared hyperspectral imaging technology
Authors:Liu, Xiaodan (1); Feng, Xuping (1); Liu, Fei (1); He, Yong (1)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou; 310058, China
Corresponding author:He, Yong(yhe@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:189-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The selection and identification of seeds are a key link in the process of agricultural breeding. In this study, near infrared (874-1 734 nm) hyperspectral imaging technology combined with chemometrics and image processing technology was successfully performed to identify and visualize strains of hybrid rice seeds. A total of 2 700 samples of 3 different strains of rice seeds were collected, and all samples were divided into the calibration set and the prediction set according to the ratio of 2:1 using the SPXY algorithm. PCA (principle component analysis) was applied to explore the separability of different rice seeds based on the spectral characteristics of rice samples, and the preliminary results demonstrated that hybrid rice seeds of 3 different strains showed a trend of classification. The full spectrum has a large data volume, and contains a large amount of redundant and collinear information, which would affect the accuracy and calculation speed of the model. Since the optimal wavelength selection can help to extract important information from the whole data to improve the performance of the model while simplifying it, we adopted SPA (successive projections algorithm) to select sensitive wavelengths. Seven sensitive wavelengths (985.08, 1 106, 1 203.55, 1 399.04, 1 463.19, 1 601.81, 1 645.82 nm) were determined from the range of 975-1 646 nm, and these wavelengths were related to functional groups in molecules (N-H, C-H, NH<inf>3</inf><sup>+</sup>), which indicated the reliability of the selected wavelength for modeling. Partial least squares-discriminant analysis (PLS-DA) and support vector machine (SVM) were applied to build the classification models based on the full spectra and optimal wavelengths, and an excellent classification was achieved, with the classification accuracy of over 90% for all models. The SVM model performed better than PLS-DA, and especially the full spectrum-based SVM model achieved outstanding identification results, with 99.67% classification accuracy for calibration set and 97.11% for prediction set. Compared with full spectrum-based models, optimal wavelengths-based models performed relatively worse, but still offered correct discrimination rates of over 90.22%. This results revealed that the selected wavelength is effective and reliable, which can provide a reference for on-line discrimination of different strains of hybrid rice seeds. Combined with image processing technology, the visual prediction map could be generated by inputting the average spectra of each rice seed into the SPA-SVM model, and different colors would be employed to represent different kinds of seeds. It showed that the visual analysis of the sample could intuitively identify rice seeds of different strains by these methods. The overall results indicated that near infrared hyperspectral imaging technology can be used to identify and visually predict hybrid rice seeds. This research provides a new way for rapid screening and identification of seeds in the process of agricultural breeding.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Image processing
Controlled terms:Agricultural machinery - Agriculture - Calibration - Discriminant analysis - Forecasting - Hyperspectral imaging - Infrared devices - Least squares approximations - Principal component analysis - Spectroscopy - Spectrum analysis - Strain - Support vector machines
Uncontrolled terms:Hyperspectral imaging technologies - Image processing technology - Near-infrared hyperspectral imaging - Nondestructive detection - Partial least squares discriminant analyses (PLSDA) - Principle component analysis - Rice seed - Successive projections algorithm
Classification code:723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 921.6 Numerical Methods - 922 Statistical Methods - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 9.00e+01%, Percentage 9.02e+01%, Percentage 9.71e+01%, Percentage 9.97e+01%, Size 6.46e-07m, Size 8.74e-07m to 1.73e-06m, Size 9.75e-07m to 1.65e-06m
DOI:10.11975/j.issn.1002-6819.2017.22.024
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 6>
Accession number:20181104889847
Title:Plot layout method of wheat drip irrigation experiment based on soil water heterogeneity
Authors:Wang, Pengxiang (1, 2); Song, Ni (1); Chen, Zhifang (1); Wang, Feng (1); Shen, Xiaojun (1); Wang, Jinglei (1)
Author affiliation:(1) Ministry of Agriculture Key Laboratory of Crop Water Requirement and Regulation, Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang; 453002, China; (2) Graduate School of Chinese Academy of Agricultural Sciences, Beijing; 100081, China
Corresponding author:Wang, Jinglei(firiwjl@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:112-118
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The objective of this research was to improve the accuracy and representativeness of the experimental plot date by determining the optimum plot area and the replication number for the wheat drip irrigation. The heterogeneity of soil moisture in experimental plots was provided by Smith heterogeneity index. The relationship between the plot area and the repetition number of the wheat drip experimental plot was measured by Hatheway method. The effect of shape on the accuracy of experimental data was determined by studying the soil moisture heterogeneity index in the horizontal direction of drip tape and the vertical direction of drip tape in experimental plot. The results showed, when the plot area was increased, the variance of soil water in the field was reduced and the relationship between them was in power function. For the plot form 1 m<sup>2</sup>to 50-100 m<sup>2</sup>, the variance decreased significantly. The full irrigation treatment variance was decreased by 0.79-0.84, and the deficit irrigation treatment variance was reduced by 0.79-0.84. For the plot more than 100m<sup>2</sup>, the increase of plot area had a limited effect on the variance reduction. To determine the optimum size of the experimental plot you need take the factors as below into consideration, as the number of treatments increased, the real difference between treatments decreased, and the required size for the experimental increased. When the size of the plot increased to a certain value, improving the identification ability of test difference by increasing the area of experimental plot was limited and adding the repetition number to improve the distinguishing ability of the difference between treatments was necessary. For 50-100 m<sup>2</sup>of experimental plots, when the repetition was increased, the experimental accuracy could be improved with the same area to distinguish the smaller real difference between treatments. By increasing the number of repeats from 2 to 3, the differences of soil moisture between the treatments could be detected which increased from 23.2%-26.5% to 13.1%-15.0%. The recognition ability of the real difference among the treatments could be significantly improved. Hatheway method was used to calculate the optimal experimental plot of the full and deficit irrigation treatment. Due to its larger coefficient variation of soil moisture and heterogeneity index, the deficit irrigation treatment required larger testing area. In order to facilitate the layout of the field experiment, the unified standard of the plot was set up with the optimum specification of deficit irrigation treatment. When the experiment was divided into full and deficit irrigation treatment, the testing plot should be 3 replicates, and the size of each repeat plot should be 50 m<sup>2</sup>.When the irrigation experiment was divided into three treatments, the experiment layout should be 3 replicates, and the size of each replicate plot was 100 m<sup>2</sup>. For the experimental plot shape, according to the relationship between the variance of field block and the size of experimental plot, the Power function was fitted by whether the length is greater than the width to calculate the soil moisture heterogeneity index in horizontal the direction of drip tape and the vertical direction of drip tape. About the difference between two directions, the heterogeneity index of deficit irrigation treatment was greater than that of full irrigation treatment. The heterogeneity index in the horizontal direction of drip tape was greater than that in the vertical direction of drop tape. Therefore, the result of rectangular area arranged along the direction of the drip tape was more accurate (smaller deviation) than other shapes. The rectangular experimental plot with aspect ratio between 1:1 and 5:1 could balance the variability of both directions and made the experimental plot more representative. This paper provided a scientific basis for determining the specifications of drip irrigation experimental plot and the theoretical support for the standardization of irrigation experimental layout.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Irrigation
Controlled terms:Aspect ratio - Moisture - Soil moisture - Soil surveys - Soil testing - Soils - Specifications
Uncontrolled terms:Drip irrigation - Heterogeneity - Layout - Number of replications - Optimum plot area and shapes - Wheat
Classification code:483.1 Soils and Soil Mechanics - 821.3 Agricultural Methods - 902.2 Codes and Standards
Numerical data indexing:Area 1.00e+02m2, Area 5.00e+01m2 to 1.00e+02m2, Area 5.00e+01m2, Percentage 1.31e+01% to 1.50e+01%, Percentage 2.32e+01% to 2.65e+01%
DOI:10.11975/j.issn.1002-6819.2017.22.014
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 7>
Accession number:20181104889851
Title:Subsurface gravel blind ditch increasing improved effects of takyric solonetz by desulfurized gypsum and yield of oil sunflower
Authors:Wang, Xu (1); Sun, Zhaojun (1, 2, 3); Han, Lei (4); Ma, Fei (4); Wang, Fang (2); He, Jun (4)
Author affiliation:(1) School of Civil Engineering and Hydraulic Engineering, Ningxia University, Yinchuan; 750021, China; (2) College of Resources and Environmental Science, Ningxia University, Yinchuan; 750021, China; (3) Ningxia (China-Arab) Key Laboratory of Resources Assessment and Environmental Regulation in Arid Regions, Yinchuan; 750021, China; (4) Institute of Environmental Engineering, Ningxia University, Yinchuan; 750021, China
Corresponding author:Sun, Zhaojun(sunzhaojunyx@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:143-151
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Takyric solonetz, is a kind of alkaline soil, which is quite unique in China and even in the world. In Northern Ningxia, China, this soil belongs to a kind of clay with a big soil bulk density and a badly structured physical property. So, after irrigation, dispersed soil particles in clay lead to low soil porosity, and poor permeability and salt is difficult to be quickly washed away. In order to explore the effect of different blind ditch spacing and gravel cushion thickness on the physical-chemical properties of takyric solonetz, salt ion concentration and oil sunflower yield, a field experiment was carried out in Pingluo County of Ningxia. A total of 3 kind of blind ditch spacing (3, 6, 9 m) and 3 gravel cushion thicknesses (25, 30, and 35 cm) were designed. Besides, the desulfurized gypsum (22.5 t/hm<sup>2</sup>) and leaching amount (4500 m<sup>3</sup>/hm<sup>2</sup>) were applied. Then, the soil physical and chemical properties, soil salt ion concentration and yield of oil sunflower of different treatments were measured to determine the amelioration effect of gravel blind ditch. The test items were permeability of soil, soil pH value, exchangeable sodium percentage (ESP), total salinity and salt ion concentration. The results showed that the gravel blind ditch could improve water permeability of soil and keep desalination by leaching. The desalination effect was closely related to blind ditch spacing and gravel cushion thickness. The smaller the blind ditch spacing and the gravel cushion thickness, the more significant the effect. In the soil layer of 0-40 cm under the gravel blind ditch treatment, the concentration of 4 ions (Na<sup>+</sup>, CO<inf>3</inf><sup>2-</sup>, HCO<inf>3</inf><sup>-</sup>, Cl<sup>-</sup>) significantly decreased and the Ca<sup>2+</sup>and SO<inf>4</inf><sup>2-</sup>concentration increased compared with those under CK. In addition, there was little variation for the concentration of Mg<sup>2+</sup>and K<sup>+</sup>. The result of Person analysis showed that Na<sup>+</sup>was greatly related to Cl<sup>-</sup>and SO<inf>4</inf><sup>2-</sup>and it was an important cation of takyric solonetz. The blind ditch spacing of 3 m and gravel cushion thickness of 35 cm decreased soil pH value, ESP, and total salinity in 0-40 cm by 11.7%, 32.3% compared to CK treatment in the first year. In the second year, the values of pH, ESP and total salinity decreased by 12.5%, 39.6%. Furthermore, the yield of oil sunflower was 2.87 and 3.44 times that of CK respectively in the first and second year. The hydrodynamic force was higher in the blind ditch nearby, where the water moved fast. In the upper soil of blind ditch, the soil salinity infiltrated into the blind ditch along with water. Furthermore, the blind ditch density and gavel straw bed could shorten migration distance of soil salinity so that the soil salinity could be more easily discharged by blind ditch. This could reduce the soil salinity effectively and accelerate the process of salt leaching. Thus we conclude that the subsurface gravel blind ditch is able to improve the newly reclaimed takyric solonetz land most effectively and increase the yield of oil sunflower. These results will also provide a technical support for the salt-water management of the newly reclaimed takyric solonetz farmlands, and a guide for the sustainable development and utilization of waste takyric solonetz land.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Soil testing
Controlled terms:Alkalinity - Chemical properties - Concentration (process) - Desalination - Gravel - Gypsum - Ions - Irrigation - Leaching - pH - Porosity - Soils - Sunflower oil - Waste management - Water management
Uncontrolled terms:Crop yield - Desulfurized gypsums - Development and utilizations - Exchangeable sodium percentages - Physical chemical property - Soil physical and chemical properties - Soil salinity - Takyric solonetz
Classification code:445.1 Water Treatment Techniques - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 801 Chemistry - 801.1 Chemistry, General - 802.3 Chemical Operations - 804.1 Organic Compounds - 821.3 Agricultural Methods - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 1.17e+01%, Percentage 1.25e+01%, Percentage 3.23e+01%, Percentage 3.96e+01%, Size 0.00e+00m to 4.00e-01m, Size 3.00e+00m, Size 3.50e-01m, Size 9.00e+00m
DOI:10.11975/j.issn.1002-6819.2017.22.018
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 8>
Accession number:20181104889835
Title:Design and test of tilt angle measurement system for agricultural implements
Authors:Huang, Peikui (1, 2); Zhang, Zhigang (1, 2); Luo, Xiwen (1, 2); Liu, Zhaopeng (1, 2); Wang, Hui (1, 2); Lin, Zhijian (1, 2); Gao, Weiwei (1, 2)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China; (2) College of Engineering, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Zhang, Zhigang(zzg208@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:9-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agricultural implements tilt angle measurement is one of the key technologies to achieve agricultural implements and equipment precision operations. For example, the precision navigation control and the leveling control of agricultural implements are all dependent on the accurate measurement of tilt angle. What's more, agricultural implements of tilt angle are one of the key parameters of agricultural mechanics modeling and agricultural implements safety warning learning. In order to further improve the quality of agricultural implements operation, we developed a new agricultural implement tilt angle measurement system in this paper and verified by tests on triaxial turntable platform and field. Modern micro-electromechanical systems (MEMS) technologies provide the moderate-cost and miniaturized solutions for the development of attitude reference system. Using highly-integrated inertial measurement units (IMUs) ADIS16445 provided by ADI company and micro ARM processor STM32F446 provided by ST company, we built the hardware platform. ADIS16445 ISensor® includes tri-axial gyroscopes and tri-axial accelerometers, the raw sensors data was sampled by STM32F446RC processor through SPI interface. The attitude calculation was carried out based on the Euler angle algorithm. The Kalman filter model with four state vectors and two observations was established to fuse the accelerometer and gyroscope information to achieve the accurate measurement of the tilt angle of agricultural implements. Considering the zero bias and drift characteristics of the gyroscope and the motion characteristics of the MEMS micro sensor, adaptive error covariance matrix Q and R rules were established to achieve precise tilt angle measurement of agricultural implements under different working conditions. Tests were conducted on SGT320E triaxial turntable platform and ZP9500 high level sprayer provided by LOVOL company dual in the field with the assistance of antenna positioning and attitude module BD982 provided by Trimble company. The SGT320E triaxial turntable platform was the standard equipment for testing the angular motion parameters and inertial systems. By setting the triaxial motion parameters to simulate a variety of motion states, it had speed, position and sine swing modes on all triaxial with a rate resolution of 0.0001°/s. In this paper, we used six position accelerometer calibration method and gyroscope error model to verify the performance of accelerometers and gyroscopes. Three-axis multi-function turntable test results showed that ADIS16445 built-in gyroscopes' and accelerometers' zero bias were under 0.15°/s and 0.075 mg, qualified to meet the system design hardware requirements. Kalman fusion algorithm were more accuracy and effective compare to simple integral by gyroscope and can solve the problem of zero bias and drift characteristics of the gyroscope with tilt static measurement error accuracy was 0.15°, typical dynamic measurement accuracy was 0.3°, maximum measurement error was less than 0.5°. The BD982 supports high precision positioning, attitude and heading output with high stability and fast dynamic response, which is widely used in construction implements, automobiles, agricultural implements and other fields, making it to be the leader of the industry. In this paper, the baseline length was 1.4 m with the measurement accuracy of 0.1°. Test results from high level sprayer showed that the average error of the attitude inclination was less than 0.55°, maximum measurement error was less than 0.91°, which satisfied the precise operation requirement of the agricultural equipment. Test results also verified that self-adaptive Kalman filter algorithm was more accuracy and stable than normal Kalman filter algorithm, which made the system development by this paper have more applicability. The agricultural implements tilt angle measurement system developed in this paper not only can reducing costs but also can improving the quality of agricultural implements operations.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Agricultural implements
Controlled terms:Accelerometers - Adaptive filtering - Adaptive filters - Agriculture - Algorithms - Angle measurement - Antennas - Covariance matrix - Design - Errors - Gyroscopes - Hardware - Integrated circuit design - Kalman filters - Machinery - Measurement errors - Mechanization - MEMS - Microsensors - Tools - Units of measurement
Uncontrolled terms:Adaptive kalman filter - Attitude reference system - Dynamic measurement accuracy - Euler angles - High precision positioning - Micro electromechanical system (MEMS) - Multi-sensory fusion - Tilt angle measurement
Classification code:601 Mechanical Design - 605 Small Tools and Hardware - 704.2 Electric Equipment - 714.2 Semiconductor Devices and Integrated Circuits - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 902.2 Codes and Standards - 921 Mathematics - 943.1 Mechanical Instruments - 943.2 Mechanical Variables Measurements
Numerical data indexing:Angular_Velocity 1.75e-06rad/s, Angular_Velocity 2.62e-03rad/s, Mass 7.50e-08kg, Size 1.40e+00m
DOI:10.11975/j.issn.1002-6819.2017.22.002
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 9>
Accession number:20181104889842
Title:Effects of DOC+POC on characteristics of particulate matter from diesel engine fueled with biodiesel blends
Authors:Du, Jiayi (1); Wei, Song (1); Zhang, Dengpan (1); Yuan, Yinnan (2); Pang, Daqing (3)
Author affiliation:(1) School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) School of Energy, Soochow University, Suzhou; 215006, China; (3) Changchai Company Limited, Changzhou; 213001, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:69-74
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Particulate matter (PM) emissions from diesel engines are being recognized as the pollutants having adverse effects on the environment as well as on human health. Therefore, the combination of using clean alternative fuels and particulate matter after-treatment devices is one of the effective ways to reduce particulate emissions. Biodiesel as an alternative fuel can significantly reduce particulate emissions. The diesel oxidation catalysts (DOC) are commonly used to oxidize carbon monoxide (CO) and hydrocarbon (HC) emissions as well as partial particles. The particulate oxidation catalyst (POC) is considered as an alternative PM reduction aftertreatment technology to the wall-flow diesel particulate filter (DPF). The combination of DOC and POC is a commonly and widely used to reduce PM. In order to analyze the influence of biodiesel blending ratio, DOC+POC on PM emissions and components of soluble organic fractions (SOF), bench test was carried out on a high pressure common rail diesel engine fueled with diesel-biodiesel dual fuels (B0, B10 and B20). Particles were collected at rated condition. Particle samples with different size grades were achieved from micro-orifice uniform deposition impactor (MOUDI) and mass concentration was obtained by weighting the particle samples. Using the Soxhlet extraction method to extract SOF component from particulates. The effects of biodiesel blending ratio and DOC+POC on SOF content were studied by gas chromatography-mass spectrometer (GC-MS) analysis. The distribution of carbon atoms of B0 and B20 were obtained by analyzing the GC-MS data. The results showed that when the content of biodiesel percentage was increased, DOC + POC conversion rate of particulate matter was increased, the conversion of total mass concentration of B0, B10 and B20 were 42.57%, 48.91% and 52.25% respectively. The mass concentration within each size grade was decreased. The mass concentration peak value of particulate matter emitted from three fuels all ranged from 0.18 to 0.32 μm. The mass fraction of lipids and acids components in SOF were increased and alkanes, aromatic hydrocarbons and phenols compounds were decreased. Moreover, the increase of biodiesel percentage promotes the oxidation of high-carbon atoms into low-carbon atoms. the mass fraction of carbon atoms in SOF of B0 and B20 showed a normal distribution with a peak at C16. After the installation of DOC+POC, the mass concentration of particulate matter was decreased and the convert efficiency of accumulation state particles was higher than that of coarse particles. Meanwhile, the convert efficiency of accumulation state particles with B20 reached 58.36%. With the increase of biodiesel percentage, the convert efficiency of SOF was increased, and the convert efficiency of SOF reached 65.15% when B20 fuel was used. DOC+POC had a significant effect on the conversion of lipid and acid substances. The mass fraction of lipid and acid substances changed from 15.4% to 6.86% and 9.43% to 5.35% respectively. Moreover, DOC+POC had obvious effect on the oxidation of C12-C18 in SOF of B20.These results could provide a theoretical basis for the aftertreatment of biodiesel combustion particulates, and it is helpful to improve and optimize of diesel oxidation catalysts and particulate oxidation catalyst, according to the biodiesel emission characteristics.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Particles (particulate matter)
Controlled terms:Alternative fuels - Aromatic hydrocarbons - Atoms - Biodiesel - Blending - Carbon monoxide - Catalysts - Diesel engines - Efficiency - Engines - Fuels - Gas chromatography - High pressure effects - Hydrocarbons - Normal distribution - Oxidation - Particulate emissions - Wall flow
Uncontrolled terms:Diesel oxidation catalyst - Emission characteristics - Gas chromatography-mass spectrometers - High pressure common rail diesel engine - Oxidation catalysts - Particulate Matter - Particulate oxidation catalysts - Wall flow diesel particulate filters
Classification code:451.1 Air Pollution Sources - 523 Liquid Fuels - 612.2 Diesel Engines - 631.1 Fluid Flow, General - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 913.1 Production Engineering - 922.1 Probability Theory - 931.3 Atomic and Molecular Physics - 951 Materials Science
Numerical data indexing:Percentage 1.54e+01% to 6.86e+00%, Percentage 4.26e+01%, Percentage 4.89e+01%, Percentage 5.22e+01%, Percentage 5.84e+01%, Percentage 6.52e+01%, Percentage 9.43e+00% to 5.35e+00%, Size 1.80e-07m to 3.20e-07m
DOI:10.11975/j.issn.1002-6819.2017.22.009
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 10>
Accession number:20181104889869
Title:Extracting irrigated cropland spatial distribution in China based on time-series NDVI
Authors:Liu, Yizhu (1); Wu, Wenbin (1); Li, Zhaoliang (1); Zhou, Qingbo (1)
Author affiliation:(1) Key Laboratory of Agricultural Remote Sensing, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing; 100081, China
Corresponding author:Zhou, Qingbo(zhouqingbo@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:276-284
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Geospatial information of irrigated cropland is necessary for the formulation of food policy, water management and climate change studies. In addition to those methods based on pure image classification or non-remote sensing data, spatial reconstruction of statistics by using remote sensing features, a branch of multi-data fusion, with the advantages of less relying on the sampling points with a good consistency with the statistical data, has played an important role in land cover mapping. However, it gains less attention in regional irrigated cropland extraction, which makes it unclear about its applicability in different regions. In this paper, we firstly tested a fusion method based on NDVI data and statistical data of spatial distribution of irrigated cropland in China. Then, quantitative and spatial accuracy assessment and comparisons with other datasets were also carried out for the sake of discussing the availability of the map. Finally, the possible factors reducing the accuracy of classification were discussed. The results showed that the ratio of irrigation farming decreased and the fragmentation of irrigated croplands increased gradually from east to west. Huang-Huai-Hai and Yangtze River plant regions were the places with the most concentrated irrigation. While in the locations with low precipitation such as northeastern and northwestern areas, irrigation farming was distributed along local water resources. Those irrigation areas were all consistent with the recognized irrigation areas. Quantitatively, the relative errors of more than 90% counties were within 5%, and most of the counties with high relative error (>30%) belonged to Shanxi while the rest were shared by several other provinces. From the view of absolute error, the number of negative ones was much less than positive ones, and this rule was also appropriate on province scale. The total spatial accuracy of the new map was 64.20%, but the values ranged from 31.21% to 90.64% on province scale. Provinces with the accuracies higher than average level were mostly distributed in the eastern areas of the country, and the precision level went lower from north to south. Meanwhile, there was no apparent geographical rule in west. Referring to the comparisons with similar datasets, this fusion method of statistic and remote sensing data could not only perform better quantitatively, but also provide more spatial details than data fusion method without satellite images. In addition, it maintained a same spatial accuracy level with the image classification but accelerated the operating process. These indicated that, the output of the method was both quantitatively and qualitatively comparable to that of similar method in China, yet there was a certain distance with its first application in America. Analysis suggested that, the cropland mask, the method hypothesis and the selected features are the major factors which largely influence the mapping accuracy, so the improvement of the method relies on better cropland maps, and optimization of geographical and spectral features.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:54
Main heading:Mapping
Controlled terms:Climate change - Data fusion - Errors - Forestry - Image classification - Image fusion - Image processing - Importance sampling - Irrigation - Photomapping - Remote sensing - Sampling - Spatial distribution - Statistics - Water management - Water resources
Uncontrolled terms:Accuracy of classifications - Data fusion methods - Geo-spatial informations - Irrigated cropland - Land cover mapping - NDVI - Remote sensing data - Spatial reconstruction
Classification code:405.3 Surveying - 443.1 Atmospheric Properties - 444 Water Resources - 723.2 Data Processing and Image Processing - 821.3 Agricultural Methods - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 3.12e+01% to 9.06e+01%, Percentage 5.00e+00%, Percentage 6.42e+01%, Percentage 9.00e+01%
DOI:10.11975/j.issn.1002-6819.2017.22.036
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 11>
Accession number:20181104889834
Title:Spatial-temporal variations of cultivated land and grain production in China based on GlobeLand30
Authors:Wang, Jiayue (1, 2); Xin, Liangjie (1)
Author affiliation:(1) Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing; 100101, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Xin, Liangjie(xinlj@igsnrr.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To understand the spatial-temporal variations of cultivated land and grain production and the sensitivity of grain production in counties to cultivated land variation in China during 2000-2010, this paper analyzed the distribution, variation and the shifting of barycenter of cultivated land and grain production, and the response of grain production to the change of cultivated land by means of statistical analysis using the 30 m resolution global land cover data (GlobeLand30) in the year of 2000 and 2010. The results showed that: 1) Cultivated land was mainly distributed in the eastern region of China, and the variation of cultivated land was characterized by the increase in the west, the decrease in the east and the decline of total amount of cultivated land. And the net decreased area of cultivated land was 1 040 300 hm<sup>2</sup>, and the average annual decrease area was 104 000 hm<sup>2</sup>. In the conversion of other land types to cultivated land, the conversion of forest land, grassland and artificial surface to cultivated land was the most. The conversion between cultivated land and forest land was mainly concentrated in the southern region; the conversion between cultivated land and grassland was mainly distributed in the northeast, Inner Mongolia, Qinghai-Tibet area and the area along the Great Wall, and the ecological construction projects in these areas have achieved remarkable results; the conversion between cultivated land and construction land was mainly distributed in the North China Plain; and the reserve cultivated land resources in Xinjiang were rich, and the conversion between cultivated land and bare land was the most. 2) Grain production was mainly concentrated in Northeast, North China and South China, and the variation of grain yield was characterized by the reduction in the south, the increase in the north and the increase of the total grain output. 3) From the concentration degree of cultivated land and grain production, the concentration degree of cultivated land distribution affected the concentration degree of grain production distribution, and the concentration degree of grain production was generally higher than that of cultivated land. With the opposition of the direction that the barycenter of cultivated land moved, the barycenter of grain production moved toward the north and the east. The contradiction between grain supply and demand in China has increased, and the pattern of grain production in China has changed to "north-to-south grain diversion". 4) The grain production of 32.24% of counties showed the dependence on the quantity of cultivated land, which was mainly distributed in the northeast, North China, western region, the area along the Great Wall, southwest area and southeast coastal area. Grain output is not only affected by the quantity of cultivated land, but also affected by the sown area and the intensity of grain planting. In the areas with high sensitivity of grain production to cultivated land variation, we should strengthen the protection of the quantity and the quality of cultivated land and improve farmers' enthusiasm of grain planting, and in the areas with less sensitivity, more attention should be paid to the protection of cultivated land fertility and the improvement of grain yield per unit area, so as to ensure food security in China. At the same time, the rotation and fallow can be implemented in less sensitive areas, to recover the land fertility without losing the grain production. This study also did the exploring work for the selection and allocation of rotation and fallow areas in China.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Land use
Controlled terms:Cultivation - Economics - Food supply - Forestry - Remote sensing - Sensitivity analysis
Uncontrolled terms:Cultivated lands - Food security - GlobeLand30 dataset - Grain production - Spatial temporals
Classification code:403 Urban and Regional Planning and Development - 821.3 Agricultural Methods - 822.3 Food Products - 921 Mathematics - 971 Social Sciences
Numerical data indexing:Percentage 3.22e+01%, Size 3.00e+01m
DOI:10.11975/j.issn.1002-6819.2017.22.001
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 12>
Accession number:20181104889837
Title:Improved design and experiment of profiling and recycling plastic film mechanism for clamping finger-chain type device of recycling residual plastic film
Authors:Luo, Wei (1); Wang, Jikui (1, 2); Luo, Xinyu (1); Niu, Hailong (1); Duan, Wenxian (1); Li, Yang (1); Halembek, Burlen (1); Bi, Xinsheng (1, 2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi; 832000, China; (2) Key Laboratory of Northwest Agricultural Equipment of Ministry of Agriculture, Shihezi; 832000, China
Corresponding author:Wang, Jikui(shzwjk@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:27-35
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The existing clamping finger-chain type device of recycling plastic film has the problem of poor profiling quality of film collecting operation and instable work performance, so the profiling and recycling plastic film mechanism with single hinge has been designed. The designed device is mainly composed of 2 parts which are profiling mechanism and film collecting mechanism. Whole film collecting device consists of multiple mechanisms of profiling and recycling plastic film mechanism with single hinge. And profiling can be separately performed when each profiling and recycling plastic film mechanism with single hinge is operating. The profiling mechanism is mainly composed of the profiling frame, the film cutting disc, the profiling wheel, compression mechanism and scraping plate, and so on. The role of the scraping plate is to scrape the soil on the profiling wheel, in order to avoid too much clay on the profiling wheel and the increase in size, which result in insufficient finger insertion depth. The mechanism for collecting residual plastic film is mainly composed of film collecting frame, upper film-collecting sprocket, lower film-collecting sprocket, film collecting chain, clamping finger, supporting wheel and tension mechanism. The front part of the profiling frame is hinged on the frame, and the rear part is hinged on the lower film-collecting sprocket shaft. In addition, the profiling wheel is arranged at the shaft end of the lower film-collecting sprocket. The film cutting disc is fixedly connected to the side of the profiling wheel. Under the effect of compression mechanism and the gravity, the film cutting disc and the profiling wheel roll close to the ground. Because the lower film-collecting sprocket is coaxial with the profiling wheel, the lower film-collecting sprocket is undulating along with the profiling wheel. At the same time, the film collecting frame can move up and down on the supporting wheel. When the clamping finger chain turns around the lower chain sprocket, it has a stabilized distance between the clamping finger and the ground. Then the surface profiling can be completed when the residual film is clamped by the clamping finger. When the profiling wheel and finger chain roll forward, the mechanism for collecting residual plastic film will not be blocked, because there is suitable reserved space between mechanisms for collecting residual plastic film. After the upper and lower profiling operation of the device are analyzed and discussed, the structure size parameters of profiling mechanism are determined. By analyzing the movement of the device, it is concluded that the jump distance from the highest point to the landing point is negatively correlated with the stiffness coefficient of the compression spring, and is positively related to the operation speed of the machine. The experiment was conducted on a test ground with complex field environment, uneven ground and large surface firmness. When the traction speed of tractor was 5-5.5 km/h, the diameter of film cutting disc was 280 mm and the diameter of profiling wheel was 220 mm, the recovery rate of residual plastic film was 93.1%, and the profiling wheel had obvious up and down movement relative to the frame. After the operation of the device, there were regular scratches under the effect of fingers on the surface ground, which indicated that the reliability of finger entering into the soil has been increased. There were no obvious bounce and impresses when the profiling wheel passed the convex and concave on the ground. The profiling hysteresis and profiling hypersensitivity did not occur in the experiment, which indicated that profiling and recycling plastic film mechanism with single hinge can meet the technical requirements of residual film collecting. The research results can be helpful to solve the problem of pollution of residual plastic film.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Plastic recycling
Controlled terms:Agricultural machinery - Chains - Depth profiling - Design - Disks (machine components) - Films - Machine design - Plastic films - Plates (structural components) - Recycling - Sprockets - Wheels
Uncontrolled terms:Compression mechanism - Compression springs - Profiling - Residual films - Single hinged - Stiffness coefficients - Surface profiling - Technical requirement
Classification code:408.2 Structural Members and Shapes - 452.3 Industrial Wastes - 601 Mechanical Design - 601.2 Machine Components - 602.1 Mechanical Drives - 801 Chemistry - 817.1 Polymer Products - 821.1 Agricultural Machinery and Equipment
Numerical data indexing:Percentage 9.31e+01%, Size 2.20e-01m, Size 2.80e-01m, Velocity 1.39e+00m/s to 1.53e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.22.004
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 13>
Accession number:20181104889841
Title:Modeling and validation on longitudinal vibration characteristics of electric wheel system considering electromechanical coupling
Authors:Zuo, Shuguang (1); Li, Duoqiang (1); Mao, Yu (1); Deng, Wenzhe (1); Wu, Xudong (1)
Author affiliation:(1) Clean Energy Automotive Engineering Center, Tongji University, Shanghai; 201804, China
Corresponding author:Wu, Xudong(wuxudong@tongji.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:61-68
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Recently, distributed-drive electric vehicle has become one of the development directions of future vehicle with the advantage of miniaturization and high performance. The electric wheel system is a key component of distributed-drive electric vehicle. The longitudinal dynamics of electric wheel system caused by torque ripple of the in-wheel motor is more significant than vertical. The existing studies on longitudinal vibration analysis of electric wheel system are always taking stator and rotor as a whole. Actually, the electric wheel is a complicated electromechanical coupling system. The longitudinal vibration of electric wheel system causes the relative displacement of rotor and stator, resulting in unbalanced magnetic pull (UMP) that acts on the surface of rotor and stator. The induced UMP by electromechanical coupling changes the characteristics of the longitudinal vibration and deteriorates the performance of the electric wheel system further. Therefore, it is important to consider the effects of UMP caused by electromechanical coupling on the longitudinal vibration of the electric wheel system. Longitudinal vibration characteristics of an electric wheel system considering electromechanical coupling was studied in this paper. Firstly, the electric wheel longitudinal-tensional coupling dynamic model was established, and the variation of the modal characteristics for the electric wheel system with and without electromechanical coupling was analyzed. It needs to indicate that the modal shapes of the electric wheel system are identical considering the UMP, but the fifth order modal frequency is decreased obviously. This mode was characterized as the longitudinal translation of the stator. The accuracy of the analytical dynamic model was verified through vibration test of a one-quarter electric wheel system. The electric wheel system adopted a double-wishbone suspension and was installed on the experiment bench developed by the research group. During the test, the tire was driven by the in-wheel motor and directly contacted with the drum. The load on the tire was exerted by the drum to simulate the resistance in the course of vehicle running. The longitudinal acceleration of tire was measured by an acceleration sensor. Time frequency map of the tire longitudinal vibration was then extracted. Three main resonance regions could be found near 48, 94 and 141 Hz, which were consistent with the modal frequencies obtained by the established analytical model. This verified the accuracy of the analytical model on longitudinal dynamics of electric wheel system. When longitudinal vibration frequency of the vehicle driven by in-wheel motor was near 2-3 Hz, it significantly affected the riding comfort as people are sensitive to low-frequency longitudinal vibration. While the high frequency longitudinal vibration is not favorable to the motor. Finally, the longitudinal vibration characteristic of the electric wheel system considering electromechanical coupling was studied. The time and frequency domain acceleration of vehicle body, stator, rotor and tire were obtained by simulation. It inferred from the quantitative analysis that torque ripple caused the relative displacement of stator and rotor, resulting in eccentric of the motor and UMP. The UMP is regarded as external force for the stator and rotor of the motor, while it is regarded as internal force for the vehicle body and tire. As a result, the unbalanced magnetic pull had little influence on the longitudinal vibration characteristic of sprung mass. However, it deteriorated the longitudinal vibration characteristic of unsprung mass sharply, which was harmful to the service life and structure safety. Therefore, it is necessary to consider the unbalanced magnetic pull caused by electromechanical coupling in the development of electric vehicle. This study provides guidance for the design of electric vehicles driven by in-wheel motor.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Vibrations (mechanical)
Controlled terms:Analytical models - Automobile bodies - Dynamic models - Electric vehicles - Electromechanical coupling - Frequency domain analysis - Magnetic levitation vehicles - Magnetism - Models - Stators - Tires - Traction motors - Vehicle wheels - Vehicles - Vibration analysis - Wheels
Uncontrolled terms:Electric wheels - Electromechanical coupling system - Longitudinal acceleration - Longitudinal vibrations - Time and frequency domains - Torque ripples - Unbalanced magnetic pull - Vibrations
Classification code:601.2 Machine Components - 662.4 Automobile and Smaller Vehicle Components - 701.2 Magnetism: Basic Concepts and Phenomena - 705.1 Electric Machinery, General - 818.5 Rubber Products - 921 Mathematics - 921.3 Mathematical Transformations - 931.1 Mechanics
Numerical data indexing:Frequency 1.41e+02Hz, Frequency 2.00e+00Hz to 3.00e+00Hz, Frequency 9.40e+01Hz
DOI:10.11975/j.issn.1002-6819.2017.22.008
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 14>
Accession number:20181104889850
Title:Sediments particle size changes and its sand fixation ability for different shrub dunes
Authors:Gao, Yong (1, 2); Ding, Yanlong (1); Wang, Ji (1, 3); Meng, Zhongju (1, 2); Sun, Xiaorui (1); Zhang, Chao (1); Wei, Yajuan (1)
Author affiliation:(1) College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot; 010018, China; (2) Wind Erosion Key Laboratory of Central and Local Government, Hohhot; 010018, China; (3) Inner Mongolia Hangjin Desert Ecosystem, National Positioning Observation Research Station, Ordos; 017400, China
Corresponding author:Wang, Ji(wangji1957@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:135-142
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land desertification is a major global ecological problem that affects sustainable development of human society. Flow sand dunes are the main source of aeolian sand-dust transport in the surface layer, which causes enormous losses in many arid and semi-arid regions of the world. Aeolian dust transport processes are closely related to the variation of the surface vegetation cover. Therefore, it is necessary to screen plants with strong sand fixability to control the expansion of desert. The Ulan Buh Desert is one of the fastest developing areas of desertification in China. In this study, we aimed to investigate the changes of environmental sensitive particle components and factors affecting vegetation coverage, which would help to describe the process of surface sand movement accurately, and to compare abilities of different plant species to stabilize sand and provide reference for vegetation restoration in the area. The surface (0-2 cm) sediment particle size of five kinds of desert shrub dunes in desert-oasis ecotone at the northeast rim of the Ulan Buh Desert was measured by the laser diffraction method. The eolian environment sensitive grain size components were extracted by grain size class-standard deviation method. Then the sand stability capacity of plants was evaluated according to the changes of sensitive components. And the response of sensitive components to the changes of plant morphological indexes was fitted by multiple linear regression method. The results indicated that the frequency distribution curves of surface sediment under Psammochloa villosa, Agriophyllum squarrosum, Phragmites australis coverage and flow sand dune were single peak type, while under Artemisia blepharolepis and Nitraria tangutorum coverage, they were double-peak type. When the surface was covered by vegetation, the content of fine sand and middle sand reduced, while very fine sand and silt increased, the sorting became worse, the skewness deviated from normal distribution and turned to partially positive, and the kurtosis were decreased. The vegetation under which particle composition ranged from fine to coarse was as follows: Nitraria tangutorum> Artemisia blepharolepis > Phragmites australis > Agriophyllum squarrosum > Psammochloa villosa > flow sand dune. There were two sensitive grain size components of 1.45-76 and 76-456 μm in Ulan Buh Desert, named as fine sensitive components and coarse sensitive components, while the median diameter of two kinds of environment-sensitive particle size components were 57.3 and 193.6 μm, respectively. The fine sensitive components correspond to the suspended load in the sand drift activity, while the coarse sensitive components correspond to the saltation load. The contents of sensitive components were significantly (P<0.05) different under the coverage of each desert shrub. The content of fine components of different shrub dunes were as follows: Nitraria tangutorum> Artemisia blepharolepis > Agriophyllum squarrosum >Phragmites australis > Psammochloa villosa > flow sand dune. At the same time, the content of coarse grain size components showed the opposite law, which meant the ability of five kinds of desert plants to weaken wind erosion was correspondingly reduced. Multiple linear regression analysis showed that the content of fine components was positively correlated with plant height, crown width and branch number, and negatively correlated with porosity of what?(sand dune or plant cover?). With the increasing of the content of fine components in surface sediments, the cause also became complicated.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Particle size
Controlled terms:Climatology - Dust - Grain size and shape - Higher order statistics - Landforms - Linear regression - Normal distribution - Regression analysis - Sand - Sedimentation - Sediments - Soils - Statistical methods - Statistics - Surficial sediments - Sustainable development - Vegetation
Uncontrolled terms:Grain-size components - Sand fixation - Shurb dunes - Standard deviation method - Ulan Buh desert
Classification code:443 Meteorology - 451.1 Air Pollution Sources - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 922.1 Probability Theory - 922.2 Mathematical Statistics
Numerical data indexing:Size 0.00e+00m to 2.00e-02m, Size 1.94e-04m, Size 5.73e-05m, Size 7.60e-05m to 4.56e-04m
DOI:10.11975/j.issn.1002-6819.2017.22.017
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 15>
Accession number:20181104889846
Title:Space-time characteristics of drought and flood in main growing periods of winter wheat in Huaihe River Basin and its impact on yield
Authors:Gao, Chao (1); Yin, Zhouxiang (2); Xu, Ying (3)
Author affiliation:(1) Department of Geography & Spatial Information Techniques, Ningbo University, Ningbo; 315211, China; (2) College of Territorial Resources and Tourism, Anhui Normal University, Wuhu; 241000, China; (3) Anhui Agricultural Meteorological Center, Hefei; 230031, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:103-111
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Droughts and floods occur frequently in Huaihe River Basin, which has a great impact on crop yield. Based on daily mean temperature and precipitation data of 140 meteorological stations from 1961 to 2014, the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI) in each growth period of winter wheat were calculated, and quantitative analysis of climatic characteristics of winter wheat at different growth stages was carried out. Meanwhile, the standardized yield residual (SYR) was calculated to investigate the effects of dry and wet conditions on yield at different growth stages based on the winter wheat unit yield data of 20 sites from 1961 to 2012. Firstly, the variation tendency of mean temperature and precipitation in each growing period of winter wheat was analyzed according to the linear regression. The mean temperature rose significantly and the mean rainfall mainly showed a downward trend in each growing period. According to the Mann-Kendall trend method, the trend values of mean temperature and precipitation in winter wheat growth period were calculated and the spatial characteristics were analyzed. The mean temperature in the south was higher than that in the north and had an increasing pattern from east to west, the trend in the east was higher than that in the west and most of the sites had the highest level of trend in turning green and heading stage. However, the precipitation increased with the decrease of latitude, and the trend was consistent with the temperature in latitude. Secondly, according to the Mann-Kendall trend method, the trend values of SPI and SPEI in winter wheat growth period were calculated, and the increase trend of drought was the biggest in turning green and heading stage at the significant level of 0.05. Comparing the spatial features of SPI and SPEI changing trends, it was found that the drought-flood disaster was affected by temperature in whole growth period, turning green and heading stage and milking ripening period of winter wheat, and was affected by precipitation in growth period before winter and over-wintering stage of winter wheat. And the trend of drought indicated by SPEI was greater than that by SPI. Finally, the correlation between SYR and SPI/SPEI was analyzed using Pearson correlation method to determine the most relevant stage of winter wheat, and then the drought and flood situation of winter wheat was analyzed. There was negative correlation between SYR and SPI/SPEI except growth period before winter, with the highest correlation in turning green and heading stage. When moderate drought or humidity occurred, the yield of winter wheat began to decrease. This research is of guiding implications to the prevention of disaster and yield reduction of winter wheat in Huaihe River Basin.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Crops
Controlled terms:Climate change - Correlation methods - Disaster prevention - Disasters - Drought - Evapotranspiration - Floods - Precipitation (chemical) - Precipitation (meteorology) - Rivers - Watersheds
Uncontrolled terms:Drought and flood disasters - Huaihe river basins - Standardized precipitation evapotranspiration index - Standardized yield residuals - Winter wheat yields
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 444.1 Surface Water - 802.3 Chemical Operations - 821.4 Agricultural Products - 914.1 Accidents and Accident Prevention - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2017.22.013
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 16>
Accession number:20181104889860
Title:Estimation of spring wheat chlorophyll content based on hyperspectral features and PLSR model
Authors:Kasim, Nijat (1, 2); Shi, Qingdong (1, 2); Wang, Jingzhe (1, 2); Sawut, Rukeya (1, 2); Nurmemet, Ilyas (1, 2); Isak, Gulnur (1, 2)
Author affiliation:(1) Collage of Resources and Environmental Sciences, Xinjiang University, Urumqi; 830046, China; (2) Key Laboratory of Oasis Ecology under Ministry of Education, Xinjiang University, Urumqi; 830046, China
Corresponding author:Shi, Qingdong(shiqingdong@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:208-216
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Chlorophyll content is one of the major factors that affect crop growth and crop output, and an important parameter to monitor the stresses and health status of vegetation. Currently the spectral feature parameter is one of the methods that have been widely applied to estimate the chlorophyll content of wheat. In order to provide scientific basis for wheat growth monitoring and agronomic decision-making, the spring wheat canopy chlorophyll content was estimated by using hyper-spectral technology (spectral feature parameters) in this paper. The correlation between hyper-spectral characteristic parameters and chlorophyll content of spring wheat (heading date) was analyzed, and the models for estimating chlorophyll content were established based on spectral feature parameters using partial least squares regression (PLSR) method. Data of chlorophyll content and spectral reflectance of spring wheat were obtained from the experimental plots at Ziniquanzi Town, Fukang City, Xinjiang Uighur Autonomous Region, China in June, 2017. The canopy spectral reflectance and chlorophyll content of spring wheat were measured in the experimental plots. After removing the marginal bands (350-400 and 2 401-2 500 nm) and being smoothed by Savitzky-Golay filter, 16 types of hyper-spectral characteristic parameters (such as red edge, blue edge, green edge, total reflectivity, absorption depth, and normalized absorption depth) were derived from the raw hyper-spectral reflectance data. Thereafter, PLSR was employed to build the hyper-spectral estimation models of chlorophyll content. Next, root mean square error (RMSE<inf>C</inf>and RMSE<inf>P</inf>) and determination coefficient (R<sup>2</sup><inf>C</inf>and R<sup>2</sup><inf>P</inf>) for calibration set and prediction set and relative prediction deviation (RPD) were used for accuracy assessment. The results showed that: 1) Among the selected spectral feature parameters, correlation coefficient between the maximum reflectivity of green edge and chlorophyll content of spring wheat is lower than 0.5. Spectral characteristic parameters that have the higher correlation coefficient (R<sup>2</sup>≥0.5) include maximum reflectivity of blue edge, total reflectivity of blue edge (436-495 nm), maximum reflectivity of yellow edge, total reflectivity of yellow edge (566-589 nm), maximum reflectivity of red edge, total reflectivity of red edge (627-780 nm), total reflectivity of green edge (495-566 nm), maximum reflectivity and total reflectivity within 820-940 nm, normalized absorption depth in 560-670 nm and 560-760 nm. The spectral feature parameters which have the highest correlation coefficient with the chlorophyll content are maximum reflectivity and total reflectivity within 820-940 nm, which reach 0.6 and 0.8, respectively. 2) On the 16 characteristic parameters of PLSR regression, the characteristic parameters (the maximum and sum of reflectance in 820-940 nm) have made a great contribution to the PLSR model, reduce the influence of other parameters on the accuracy of the model, have better performance in predicting chlorophyll content in the study area (R<sup>2</sup><inf>p</inf>=0.8, RMSEp=2.3, RPD=3.0), and provide scientific support and reference for other related local research and precision agriculture. To achieve more universal and stable inversion model, the next step is to enlarge the sampling area and the number of samples as much as possible to improve and perfect the spring wheat hyper-spectral database.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:45
Main heading:Parameter estimation
Controlled terms:Calibration - Chlorophyll - Crops - Decision making - Forecasting - Least squares approximations - Mean square error - Models - Precision agriculture - Reflection - Spectrum analysis
Uncontrolled terms:Canopy spectral reflectance - Determination coefficients - Hyper-spectral characteristics - HyperSpectral - Partial least squares regressions (PLSR) - PLSR - Spectral characteristics - Spectral feature
Classification code:804.1 Organic Compounds - 821.4 Agricultural Products - 912.2 Management - 921.6 Numerical Methods - 922.2 Mathematical Statistics
Numerical data indexing:Size 2.40e-06m to 2.50e-06m, Size 4.36e-07m to 4.95e-07m, Size 4.95e-07m to 5.66e-07m, Size 5.60e-07m to 6.70e-07m, Size 5.60e-07m to 7.60e-07m, Size 5.66e-07m to 5.89e-07m, Size 6.27e-07m to 7.80e-07m, Size 8.20e-07m to 9.40e-07m
DOI:10.11975/j.issn.1002-6819.2017.22.027
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 17>
Accession number:20181104889871
Title:Effects of different harvesting dates and drying methods on peanut quality
Authors:Wang, Haiou (1, 2); Hu, Zhichao (1, 3); Chen, Shoujiang (2); Fu, Qingquan (2); Zhang, Wei (2); Wang, Rongrong (2); Xie, Huanxiong (1, 3)
Author affiliation:(1) Key Laboratory of Modern Agricultural Equipment, Ministry of Agriculture, Nanjing; 210014, China; (2) School of Food Science, Nanjing Xiaozhuang University, Nanjing; 211171, China; (3) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture, Nanjing; 210014, China
Corresponding author:Xie, Huanxiong(who1978@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:292-300
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Peanut is viewed as one of the most important oil crops and food protein resources in China. Its production and planting area have been ranked the first and second in the world, respectively. The post-harvest drying of peanut is an indispensable process in its produce system. It is an important task to determine when to harvest and how to dry peanuts in practice, which will affect the final quality of peanut products. In order to investigate the effects of different harvesting dates and post-ripening drying methods on the quality of peanut, 3 drying modes including sun-drying of pods on plants, sun-drying of picked pods and air-drying of picked pods were adopted for Taihua-5 peanuts which were harvested on the original harvesting date, 1 week earlier and 2 weeks earlier, respectively, and the peanut qualities were analyzed. The results showed that hundred-pod weight and hundred-kernel weight of dried peanuts with the method of sun-drying of picked pods on plants were both higher than the other 2 methods, and the weight-increasing effect was more obvious for earlier harvesting date (P<0.05). As far as the same post-ripening drying method was concerned, hundred-pod weight and hundred-kernel weight of dried peanuts harvested 2 weeks earlier were significantly lower than the one week earlier and the original harvesting date (P<0.05). During the sun-drying period, the water content of peanut shells and kernels with the method of sun-drying of pods on plants were significantly higher than that with the method of sun-drying of picked pods. The difference in water content between the 2 methods was increased in the early stage of drying, and then gradually decreased until almost the same final moisture content was reached (P<0.05). No significant difference was observed for both crude protein content and crude fat content of dried kernels between the 2 methods of sun-drying of picked pods and air-drying of picked pods (P>0.05). However, the 2 indicators under the method of sun-drying of pods on plants were increased by 3% and 2%, respectively. The earlier the harvest date, the lower the crude protein and crude fat content. There was no significant difference in the total relative content of unsaturated fatty acids in the fresh-harvested kernels, dried kernels with sun-drying of pods on plants and dried kernels with sun-drying of picked pods (P>0.05), however, that indicator with the method of air-drying of picked pods was significantly higher than the fresh-harvested kernels (P<0.05). The contents of 8 major amino acids and the total amino acids content in peanut kernels with 3 post-ripening drying methods were ranked in descending order as sun-drying of pods on plants, sun-drying of picked pods and air-drying of picked pods (P<0.05). Electron microscopy photos of cross section of peanut pedicel with the method of sun-drying of pods on plants indicated that the peanut pedicel remained the channel space for the transportation and storage of water and nutrients in the early stage of drying, which provided the necessary conditions for the metabolism and accumulation of peanut pods. The results of the study can provide reference for peanut production practice.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Drying
Controlled terms:Amino acids - Fatty acids - Harvesting - Oils and fats - Oilseeds - Proteins - Quality control - Solar dryers - Sugar beets - Unsaturated fatty acids - Water content
Uncontrolled terms:Crude proteins - Final moisture content - Harvesting dates - Increasing effect - Peanut - Production practice - Ripening - Total amino acids
Classification code:657.1 Solar Energy and Phenomena - 804.1 Organic Compounds - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.3 Quality Assurance and Control
Numerical data indexing:Age 3.84e-02yr, Percentage 2.00e+00%, Percentage 3.00e+00%
DOI:10.11975/j.issn.1002-6819.2017.22.038
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 18>
Accession number:20181104889839
Title:Closure characteristics simulation and experiment of eddy current device with different imported height in drainage pipeline
Authors:Ma, Guangfei (1, 2); Fang, Yong (1, 2); Wu, Yanming (1, 2); Cheng, Wentao (1, 2); Li, Tao (1, 2); Li, Chao (1, 2)
Author affiliation:(1) Hangzhou Mechanical Design Research Institute, Ministry of Water Resource and Standard & Quality Control Research Institute, Ministry of Water Resource, Hangzhou; 310024, China; (2) Water Machinery and Remanufacturing Technology Engineering Laboratory of Zhejiang Province, Hangzhou; 310024, China
Corresponding author:Fang, Yong(fangyongshuilibu@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:46-52
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to provide a new alternative design scheme for the interception treatment of urban sewerage, and reduce the effluent overflow in the catchment or the incidence of water logging in the pipe network, the closure characteristics of the eddy current closure device, the static pressure field distribution, the velocity field distribution and the velocity streamline distribution of the internal flow field at different inlet height are investigated. In this article, the transient N-S equations of incompressible flow, the renormalization group RNG k-Ε turbulence model and the VOF (volume of fluid) method of Euler model are selected to carry out three-dimensional numerical simulation on the eddy closure device. Under the change of inlet height, the influences of the eddy current on the closure properties and closure efficiency of closure device are analyzed, as well as the internal flow characteristics of device. At the same time, the closure characteristics of the eddy current interception device have been experimentally verified. The experimental results are in good agreement with that of the numerical simulation. Based on the analysis of the riveting characteristics and the internal flow field characteristics of the eddy current device, the results show that under all the inlet height, the eddy current closure device produces the S-type turning and plays the role of closure. The smaller the inlet height, the stronger the intercepting capacity of the eddy current closure device; but the possibility of overflow and blockage is also bigger. At the different the inlet height, when the S-type turning occurs, the water level in the catchment is not the same, indicating that the cutoff characteristics of the eddy current closure device not only are related to the water level in the water collecting well, but also may be related to the water level inside the eddy current closure device. When the inlet height is small, the area of the inlet cross section of the eddy current closure device is smaller than that of the outlet cross section, and the inlet function is the effect of the orifice interception. The cutoff is the superposition of the interception of the orifice and the cutoff of the device. With the increase of the inlet height, the cutoff efficiency of the eddy current closure device decreases at first and then increases, and the increase range is between 4/5 and 5/5 of the inlet height, indicating that to ensure no overflow or clogging and achieve good closure, the inlet area of eddy current closure device should be greater than the export cross-sectional area. In the whole flow field, there are different vortices of different sizes, which are mainly present in the bottom of the trap, the gas-liquid interface, and the upper part of the internal and external eddy current closure device, and the existence of the eddy current closure device makes the fluid obtain dynamic pressure, resulting in obstacles obstruction. In the eddy current closure device, the high-speed swirl forms. The eddy closure device has S-type shutoff characteristics because of the low pressure or even negative pressure inside the eddy current closure device. With the decrease of the static pressure, the dynamic pressure increases, and the fluid flow rate increases; on the transverse cross section of the eddy current closure device, a high-speed swirl is produced around the low pressure zone, so the fluid flows out rotationally from the swirl device, resulting in the closure of cyclone flow. Through the experimental verification, it can be explained that the high speed vortex generated by fluid is a spiral gas column, and has a performance of long extension, which is beneficial to realize cyclone cleaning.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Eddy current testing
Controlled terms:Catchments - Eddy currents - Efficiency - Effluent treatment - Effluents - Flow fields - Flow of fluids - Fluid dynamics - Incompressible flow - Navier Stokes equations - Numerical methods - Numerical models - Orifices - Phase interfaces - Runoff - Statistical mechanics - Storms - Turbulence models - Velocity - Vortex flow - Water levels - Water management
Uncontrolled terms:Closure characteristics - Experimental verification - Inlet height - Internal flow characteristics - Transient numerical simulation - Water conservancy
Classification code:442.1 Flood Control - 443.3 Precipitation - 452.3 Industrial Wastes - 452.4 Industrial Wastes Treatment and Disposal - 631.1 Fluid Flow, General - 701.1 Electricity: Basic Concepts and Phenomena - 801.4 Physical Chemistry - 913.1 Production Engineering - 921 Mathematics - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2017.22.006
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 19>
Accession number:20181104889852
Title:Effect on improving mollisol paddy soil and saline meadow soil by continuous deep ploughing
Authors:Wang, Qiuju (1); Liu, Feng (2); Jiao, Feng (3); Sun, Bing (4); Guo, Zhongyuan (5); Chang, Benchao (1); Zhang, Jinsong (1); Gao, Zhongchao (1); Jiang, Hui (2)
Author affiliation:(1) Institute of Soil Fertilizer and Environment Resources, Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China; (2) Management Department of Scientific Research of Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China; (3) Heilongjiang Bayi Agricultural University, Daqing; 163319, China; (4) Institute of Tillage and Cultivation, Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China; (5) Irrigation Experimental Establishment of Heilongjiang, Qingan; 152400, China
Corresponding author:Liu, Feng(liufengjms@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:152-158
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Heilongjiang province is the main production area of Japonica Rice in China. In Heilongjiang Province, rice growing areas are mainly distributed along Rivers and low plains. Due to the short time of planting rice, the development of paddy soil, which still keeps the original soil characteristics, is not completed. Rotary tillage is the main way of soil preparation in spring. Tillage depth is persistently maintained at 8-12 cm in paddy soil, which results in thin tillage layer, shallow plough bottom, and restricts rice root extension. With the decrease of soil holding capacity, rice plants prone to lodging at the later stage of growth, and rice yield and quality are affected. When the tillage layer is thin, the soil nutrient capacity is low, and the natural fertility is restricted, it is often used to increase the yield of rice by adding chemical fertilizer. The increase in the amount of fertilizer is not only a waste of fertilizer, but also pollutes the environment. The experimental results of the Honghe farm in the Sanjiang plain showed that, with the increase of paddy field tillage depth from 10 cm to 15 cm, the yield increased by about 10%. Japanese statistics showed that the thickness of the plough layer was more than 16-18 cm, some of which were more than 20 cm. The yield of rice was closely related to the thickness of topsoil. At present, there is no clear conclusion about the suitable depth of soil in different types of paddy soils in Heilongjiang Province.In order to clarify the effect of deep tillage on different types of paddy soils, the experiment, using the self-developed paddy deep plough, was carried out to study the effects of deep ploughing, shallow ploughing and rotary tillage in black soil and salinized meadow soil. Results showed that the effects of deep tillage on rice yield and soil physical and chemical properties were different. First, black soil deep ploughing treatment increased yield by 7.28%-8.37%. there was no significant difference in grain yield between the deep ploughing and rotary tillage treatment of salinized meadow soil in first years, but in the second year rice yield decreased by 9.96%-11.03%. Second, plowing promoted the homogenization of soil nutrients in black soil, and the soil nutrient content was not significantly reduced, and the difference of nutrient content between soil layers became smaller. Deep tillage caused the decrease of nutrient concentration in salinized meadow soil. The soil organic matter content of the shallow and deep ploughing treatments respectively decreased by 4.57 and 6.68 mg/kg compared with the control in 0-20 cm layer of salinized meadow soil, and total nitrogen decreased by 0.24 and 0.29 g/kg. The alkali hydrolyzable nitrogen in 0-10 cm soil layer of the kind of soil respectively decreased by 2.31 and 11.52 mg/kg, and pH value increased significantly, and the exchangeable Na<sup>+</sup>concentration increased in the 0-30 cm soil layer. Third, compared with the control, the shallow and deep ploughing decreased the solid ratio and bulk density of black soil, and increased soil aeration and water permeability. The soil solid ratio of 10-20 cm soil layer was decreased by 4.23% and 3.23%, respectively. The soil bulk density was decreased by 0.09 and 0.08 g/cm<sup>3</sup>, and the ventilation coefficient increased by 3.04 times and 3.42 times, and the permeability coefficient increased by 1.71 times and 1.14 times, respectively. The soil solid phase ratio of deep ploughing treatment in the 10-20 cm soil layer of black soil was reduced by 1.86%, and the ventilation coefficient and saturated permeability coefficient increased by 0.86 times and 1.87 times. Fourth, there was a tendency to increase the subsoil solid and bulk density and reduce the ventilation and permeability of salinized meadow soil in the shallow and deep ploughing areas. Deep tillage is not suitable for salinized meadow soil, the effect is obvious in black soil, deep tillage can improve soil physical and chemical characteristics and increasing yield.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Soils
Controlled terms:Agricultural machinery - Agriculture - Crops - Cultivation - Fertilizers - Nitrogen - Nutrients - Physical properties - Ventilation - Water aeration
Uncontrolled terms:Chemical characteristic - Deep ploughing - Nutrient concentrations - Paddy soils - Physical and chemical characteristics - Soil organic matter contents - Soil physical and chemical properties - Yield
Classification code:445.1 Water Treatment Techniques - 483.1 Soils and Soil Mechanics - 643.5 Ventilation - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Mass_Density 8.00e+01kg/m3, Mass_Density 9.00e+01kg/m3, Percentage 1.00e+01%, Percentage 1.86e+00%, Percentage 3.23e+00%, Percentage 4.23e+00%, Percentage 7.28e+00% to 8.37e+00%, Percentage 9.96e+00% to 1.10e+01%, Size 0.00e+00m to 1.00e-01m, Size 0.00e+00m to 2.00e-01m, Size 0.00e+00m to 3.00e-01m, Size 1.00e-01m to 1.50e-01m, Size 1.00e-01m to 2.00e-01m, Size 1.60e-01m to 1.80e-01m, Size 2.00e-01m, Size 8.00e-02m to 1.20e-01m
DOI:10.11975/j.issn.1002-6819.2017.22.019
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 20>
Accession number:20181104889868
Title:Influence of blade leading edge erosion features on aerodynamic characteristics of wind turbine airfoil
Authors:Li, Deshun (1, 2, 3); Wang, Chengze (1, 4); Li, Yinran (1, 2, 3); Li, Rennian (1, 2, 3); Zhao, Zhenxi (1); Chen, Xia (1)
Author affiliation:(1) College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; (2) Gansu Provincial Technology Centre for Wind Turbines, Lanzhou; 730050, China; (3) Key Laboratory of Fluid Machinery and Systems, Lanzhou; 730050, China; (4) XEMC Windpower Co. Ltd., Xiangtan; 411101, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:269-275
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Because wind turbine blades are exposed to complex natural environment for a long time, as time goes on, rain, snow, dust and other particles will gradually erode the surface of blade, then causing the erosion on the blade surface, especially at the leading edge of the blades, which is the area with the most serious wear. With wind turbine running time increasing, under the impact of various complex particles, the erosion process on wind turbine blades typically starts with the formation of small pits at the leading edge, which quickly develop into gouges with larger size and deeper depth, and then the increasing pits and gouges eventually lead to the fact that material of the leading edge falls off largely, forming delamination. In order to simulate the leading edge erosion of wind turbine as accurately as possible, a geometric model which is close to the actual wear profile was established and a mathematical model which is suitable for airfoil calculation was selected. According to the erosion features on leading edge of wind turbine blade operating in actual wind farm, the leading edge of DU96-W-180 airfoil profile was modified to study the effects of aerodynamic characteristics caused by leading edge erosion on wind turbine blades. At the same time, a geometric model was built and numerical simulations were performed to solve the RANS equation based on SST k-ω turbulence model. Lift force, drag force and flow field characteristics of the erosion airfoil were analyzed. And then the conclusions were drawn. In the situation that leading edge erosion is characterized by pits and gouges, the coefficients of lift and drag have a small change, and as the attack angle increases, the lift coefficient and lift-drag ratio decrease slightly, and the drag coefficient increases slightly. The influence of leading edge delamination is notable, especially under the situation of high attack angle, and the lift coefficient and lift-drag ratio are significantly reduced and the drag coefficient is sharply enlarged with the increase of the attack angle, and this change becomes more notable with the increase of erosion. The leading edge erosion intensifies the flow separation near the trailing edge of the airfoil suction surface, and makes the separation point move forward. The phenomenon of separation is more and more obvious as the degree of wear and tearing is gradually deepening, and the eddy forms after separation gradually becomes larger, resulting in the fact that lift reduces and resistance increases. Pits and gouges have small influence on the flow near the airfoil leading edge. On the contrary, delamination leads to the step-flow around the airfoil surface, and air bypasses the step with separating flow, and then adheres to the airfoil surface again, so the delamination has a significant impact on the flow near the leading edge, which leads to the deterioration of airfoil aerodynamic performance.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Turbine components
Controlled terms:Aerodynamics - Airfoils - Computational fluid dynamics - Computer simulation - Delamination - Drag - Drag coefficient - Erosion - Flow separation - Geometry - Lift - Lift drag ratio - Numerical models - Turbomachine blades - Turbulence models - Wind power - Wind turbines
Uncontrolled terms:Aerodynamic characteristics - Airfoil aerodynamics - Flow field characteristics - K-Omega turbulence model - Leading edge erosion feature - Natural environments - Wind turbine airfoils - Wind turbine blades
Classification code:615.8 Wind Power (Before 1993, use code 611 ) - 617 Turbines and Steam Turbines - 631 Fluid Flow - 651.1 Aerodynamics, General - 652.1 Aircraft, General - 723.5 Computer Applications - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2017.22.035
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 21>
Accession number:20181104889838
Title:Variable coupling strength analysis of Francis turbine runner design
Authors:Zhu, Guojun (1); Luo, Xingqi (1); Feng, Jianjun (1); Lu, Jinling (1); Wu, Guangkuan (1)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an; 710048, China
Corresponding author:Luo, Xingqi(luoxq@xaut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:36-45
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hydropower is one of the most reliable source of green energy and is widely used to meet real-time electricity demand. The ever escalating energy demand and iterative development in hydropower have pushed the generation of hydropower towards a low lost-cost and more flexible state which can work in a wider hydrodynamic region without compromising its performance. So the research on multidisciplinary optimization of hydro turbine needs to be carried out. Francis-type turbine is attractive because the efficiency of the unit at its design point exceeds the other types. As mentioned above, with the needs of robust operation in wide region without compromising its performance, the Francis turbine runner has to be optimized under multidisciplinary constraints. Multidisciplinary optimization technology of Francis runners has always been a key point in the field of turbine research. The coupling strength of each variable is the basis for establishing a concise and efficient multidisciplinary optimization strategy. So in the multidisciplinary optimization of Francis runner, it is necessary to analyze the coupling strength of design variables. In this paper, based on the global relative sensitivity of design variables, a coupling strength analysis method of runner design variables has been presented. First, combing three-dimensional (3D) inverse design theory with curve parametric method, a parametric 3D inverse-design method has been developed to control the Francis runner geometry. According to this parametric 3D inverse-design method, the meridional flow passage and geometry of runner blade can be controlled by a set of discrete parameters. These parameters are treated as runner design variables. The hydraulic efficiency of turbine, the minimal pressure coefficient on runner blade and the maximum static stress of blade are selected as objective functions. Then the global relative sensitivity of each objective function to design variables is calculated by an improved Morris OAT method. Compared with the traditional Morris OAT method, an optimal Latin hypercube design technique is adopted in the improved method. The optimal Latin hypercube design technique has a better space filling property than the traditional one. So the sampling only needs to be done once, which reduces the time of global relative sensitivity analysis without compromising its precision. On the basis of the improved Morris OAT method, the speed of global relative sensitivity calculation is improved obviously. Secondly, the set which contains global relative sensitivity of design variables is treated as universe, and the semi-trapezoidal function in fuzzy mathematics is imported to quantify the membership of each variable to objective functions. After obtaining the membership of each variable, a judgment principle of variable's coupling strength is presented in this paper. According to this judgment principle, the coupling strength property of each design variable can be defined as strong coupling, middle coupling and weak coupling. Finally, based on the coupling strength of each design variable, the multidisciplinary optimization strategy of Francis runner is established. And then the multidisciplinary optimization of Francis runner can be carried out. In order to validate the coupling strength analysis method, an application case is presented in the paper. In that case, the design variables of a Francis turbine runner with the head of 200 m are chosen as the analysis object. From the analysis result, it can be found that only the coupling strength property of maximum thickness is weak coupling, and the others are middle coupling. According to the result, a multidisciplinary optimization strategy is established and used in the optimization of Francis turbine runner. After optimization, both the hydraulic performance and strength property of the optimized runner are improved, demonstrating the effectiveness of the coupling strength analysis method. In conclusion, the method proposed in this paper can be adopted to analyze the coupling strength of design variables of Francis runner.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Design
Controlled terms:Computer simulation - Francis turbines - Functions - Hydraulic motors - Hydroelectric power - Inverse problems - Iterative methods - Optimization - Sensitivity analysis - Turbomachine blades
Uncontrolled terms:Coupling strengths - Francis runner - Francis turbine runner - Improved Morris OAT method - Inverse design methods - Multi-disciplinary optimizations - Optimal latin hypercube designs - Relative sensitivity
Classification code:611.1 Hydroelectric Power Plants - 617.1 Hydraulic Turbines - 632.2 Hydraulic Equipment and Machinery - 723.5 Computer Applications - 921 Mathematics
Numerical data indexing:Size 2.00e+02m
DOI:10.11975/j.issn.1002-6819.2017.22.005
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 22>
Accession number:20181104889845
Title:Evaluation on impact of artificial disturbed underlying surfaces on water retention function during urbanization process
Authors:Shi, Dongmei (1); Jiang, Guangyi (2); Peng, Xudong (3); Li, Yexin (4); Jin, Huifang (1); Lin, Zi (1)
Author affiliation:(1) College of Resources and Environment, Southwest University, Chongqing; 400715, China; (2) Chongqing Eco-environment Monitoring Station of Soil and Water Conservation, Chongqing; 401147, China; (3) College of Forestry, Guizhou University, Guiyang; 550025, China; (4) College of Environment Science and Engineering, Liaoning Technical University, Fuxin; 123000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:92-102
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Great decrease in water retention function of various artificial disturbed landform units (DLU) caused by urbanization activities, when compared with original landform units (OLU), is the main reason and factor that not only cause urban water and soil loss but also aggravate urban waterlogging under the certain rainfall and special designed drainage network capability. Field investigations, physical laboratory analyses and analytic hierarchy process composite method were performed comprehensively to analyze the impacts of various DLUs on water retention function of OLU. Results indicated that: 1) >2mm particle content for various DLU was over 45%, and <2 mm particle content of OLU was more than 92%; natural repose angle of soil-sock mixture (34°-38°) in DLU were all higher than OLU; uniformity coefficient and curvature coefficient changed between 11.05-41.30 and 0.32-3.15, in which uniformity coefficient decreased by 4.51%-80.27% than OLU. 2) The soil bulk density of various DLU showed the order as construction road (CR, 1.74 g/cm<sup>3</sup>) >slope greening belt (SGB, 1.54 g/cm<sup>3</sup>) > 1 year disturbed soil accumulation (DSA<inf>1</inf>, 1.48g/cm<sup>3</sup>) > 2 year disturbed soil accumulation (DSA<inf>2</inf>, 1.34 g/cm<sup>3</sup>) >3 year disturbed soil accumulation (DSA<inf>3</inf>, 1.31 g/cm<sup>3</sup>), which increased by 33.85%, 18.46%, 13.85%, 3.08%, 0.77%, respectively, compared with sloping land; and the soil total porosity, field capacity and saturated water content presented the contrary trends. 3) Soil infiltration capacity of various DLU were lower than that of OLU, the soil stable infiltration rate presenting the order as DSA<inf>3</inf>(2.89 mm/min) > SGB (2.65 mm/min) > DSA<inf>2</inf>(1.89 mm/min) > DSA<inf>1</inf>(1.64 mm/min) > CR (0.45 mm/min), at same time, the soil stable infiltration rate of OLU ranged between 2.83 and 6.22 mm/min; the conversion from forest to new-DSA had greatest impact on regulating function for rainfall and urban flood, while conversion to CR was the lowest. 4) The soil total reservoir storage, usable storage and flood control storage in various DLU were lower than that in OLU, soil total reservoir storage showing the order as DSA<inf>3</inf>> DSA<inf>2</inf>> DSA<inf>1</inf>> SGB > CR, which presented decreases of 1.08%, 2.27%, 5.63%, 15.41% and 21.96%, respectively, compared with sloping land (453.70 t/hm<sup>2</sup>); the conversion process from grass to CR caused the greatest damage to storing water and regulating the overland flow. 5) The water retention functions in DLU were all obviously weaker than that in OLU, and CR was weakest (0.421) while NF was strongest (0.651), the water retention function was influenced by factors such as soil depth, particle-size distribution, soil porosity, soil organic matter content, soil bulk density, and soil permeability, so more attentions should be paid to urban surface water, forest and grassland occupied area and its spatial distribution, short-term disturbed soil accumulation should also be conducted by temporary greening measures at the same time during urbanization process. These results could provide scientific basis for the function recovering of urban soil and water conservation ecological services, which also help for constructing urban green belts and alleviating flood waterlogging during the urbanization construction process.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Infiltration
Controlled terms:Flood control - Floods - Forestry - Laboratories - Landforms - Particle size - Particle size analysis - Porosity - Rain - Reservoirs (water) - Size distribution - Soil conservation - Soils - Surface waters - Water - Water conservation
Uncontrolled terms:Construction process - Field investigation - Forest and grassland - Soil organic matter contents - Three gorges reservoir area - Underlying surface - Urban surface waters - Water retention
Classification code:441.2 Reservoirs - 442.1 Flood Control - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 481.1 Geology - 483.1 Soils and Soil Mechanics - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 1.38e+01%, Percentage 1.54e+01%, Percentage 1.85e+01%, Percentage 2.20e+01%, Percentage 2.27e+00%, Percentage 3.08e+00%, Percentage 3.39e+01%, Percentage 4.50e+01%, Percentage 4.51e+00% to 8.03e+01%, Percentage 5.63e+00%, Percentage 7.70e-01%, Age 1.00e+00yr, Age 2.00e+00yr, Mass_Density 1.31e+03kg/m3, Mass_Density 1.34e+03kg/m3, Mass_Density 1.48e+03kg/m3, Mass_Density 1.54e+03kg/m3, Mass_Density 1.74e+03kg/m3, Percentage 1.08e+00%
DOI:10.11975/j.issn.1002-6819.2017.22.012
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 23>
Accession number:20181104889872
Title:Parameter optimization on improving aged cotton seeds vigor by extremely low frequency high voltage pulsed electric field
Authors:Yan, Yinfa (1, 2); Han, Shouqiang (1); Zhou, Shengxiang (3); Song, Zhanhua (1); Li, Fade (1, 2); Zhang, Chunqing (4); Zhang, Xiaohui (1); Wang, Jing (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Shandong Agricultural University, Tai'an; 271018, China; (2) Shandong Provincial Key Laboratory of Horticultural Machineries and Equipments, Tai'an; 271018, China; (3) Zhongtian Technology Group, Nantong; 226009, China; (4) College of Agronomy, Shandong Agricultural University, Tai'an; 271018, China
Corresponding author:Song, Zhanhua(songzh6688@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:301-307
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the effect of extremely low frequency high-voltage pulsed electric field on the aged cotton seed vigor, high voltage pulse power supply and arc electrode were used to treat aged cotton seeds with different voltages and frequencies. The treatment time was 40 s. The experiment environment temperature was set as 25℃, the relative humidity was set as 30%, and the temperature and humidity were remained relatively stable during the experiment. The effect of high voltage and extremely low frequency on germination ability of aged cotton seeds was studied. The voltage of vertically downward electric field was 12-20 kV, the pulse frequency was 5-15 Hz, the electrode was arc, and the distance between electrode plates was 50 mm. The point of 16 kV and 10 Hz was selected as the center point, and the orthogonal test was designed by Design-Expert software. The CK stood for the aged cotton seeds that had not been treated by electric field. The aged cotton seeds treated by electric field were taken into the sealed bag in time, and all the seeds were germinated within 4 h after treatment. The aged cotton seeds in sealed bag were put separately into the HgCl<inf>2</inf>solution with mass fraction of 0.2% for sterilization before seeds germination, and then 50 seeds were selected randomly from each seed sterilization group. Finally, the selected seeds were cleaned and put on the germination bed with sand bed method. The seed germination experiments were carried out at the National Key Laboratory of Crop Biology, Shandong Agricultural University, which were in accordance with the national standard: 25℃ constant temperature, continuous light, and relative humidity of 100%. Four boxes of seeds were treated under each electric field for 40 s, which were 4 repetitions, and then the average of each index was calculated. During the cotton seeds germination, the moldy cotton seeds should be removed timely, in order not to affect other seeds growth. According to the response surface analysis of the pulsed electric field and the arc electrode to the dynamic index of the aged cotton seed, and the single factor analysis of the pulsed electric field and the arc electrode to the cotton vigor index, the effect of increasing the voltage on the aged cotton seed vigor index was similar. At different voltages, the influence of increasing frequency on the cotton seed vigor index was similar. On the whole, the cotton seed vigor index after arc electrode electric field treatment showed a tendency of rising firstly and then falling with the increasing of voltage and frequency. And the influence of pulse frequency on cotton vigor index was obvious. Using the Design-Expert software, the pulse voltage and frequency were optimized, and the optimal condition was that the pulse voltage was 16.25 kV and the pulse frequency was 10.90 Hz. Under the optimal condition, the germination potential was increased by 44.2%, the germination rate was increased by 56.8%, the germination index was increased by 64.3%, and the vigor index was increased by 81.8%, and the indices were all significantly different (P<0.01) from that of the CK.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Seed
Controlled terms:Chlorine compounds - Cotton - Cultivation - Electric fields - Electric power systems - Electrodes - Mercury compounds - Optimization - Software design - Software testing - Sterilization (cleaning) - Surface analysis
Uncontrolled terms:Arc electrodes - Electric field treatment - Environment temperature - Extremely low frequencies - High-voltage pulse power supply - High-voltage pulsed electric field - Response surface analysis - Temperature and humidities
Classification code:701.1 Electricity: Basic Concepts and Phenomena - 706.1 Electric Power Systems - 723.5 Computer Applications - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921.5 Optimization Techniques - 951 Materials Science
Numerical data indexing:Frequency 1.00e+01Hz, Frequency 1.09e+01Hz, Frequency 5.00e+00Hz to 1.50e+01Hz, Percentage 1.00e+02%, Percentage 2.00e-01%, Percentage 3.00e+01%, Percentage 4.42e+01%, Percentage 5.68e+01%, Percentage 6.43e+01%, Percentage 8.18e+01%, Size 5.00e-02m, Time 1.44e+04s, Voltage 1.20e+04V to 2.00e+04V, Voltage 1.60e+04V, Voltage 1.62e+04V
DOI:10.11975/j.issn.1002-6819.2017.22.039
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 24>
Accession number:20181104889859
Title:Recognition of tea disease spot based on hyperspectral image and genetic optimization neural network
Authors:Zhang, Shuaitang (1); Wang, Ziyan (1); Zou, Xiuguo (1); Qian, Yan (1); Yu, Lei (1)
Author affiliation:(1) College of Engineering/Jiangsu Key Laboratory of Intelligent Agricultural Equipment, Nanjing Agricultural University, Nanjing; 210031, China
Corresponding author:Zou, Xiuguo(zouxiuguo@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:200-207
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to achieve fast and efficient identification of tea diseases, the method of identifying tea diseases based on hyperspectral imaging technology was put forward. Four kinds of samples, including anthracnose, brown leaf spot disease, white star disease and healthy leaf, were collected in Pingshan tea plantation of Nanjing. Hyperspectral images of these samples, ranging from 358 to 1 021 nm, were collected by hyperspectral imaging system. Among them, there were 80 samples of anthracnose, 72 samples of brown leaf spot disease, 80 samples of white star disease and 60 samples of healthy leaves. The region of interest (ROI) was an area of 200 pixels × 200 pixels near the tip of the tea leaf. The average spectral reflectance curves of the effective band of ROI were extracted to analyze the spectral characteristics. For the purpose of decreasing the redundancy of hyperspectral data, and reducing the computational complexity, this study used principal component analysis (PCA) to process the original hyperspectral images, and obtained 4 kinds of principal component images for the samples with the maximum weight coefficients, and the wavelengths of 762, 700, 721, 719 nm corresponded were taken as the characteristic wavelengths. The test showed that direct use of 481 bands for the first PCA resulted in low calculation speed and low processing efficiency. Thus, the second principal components with the 4 characteristic wavelengths were employed, and the second principal component image was selected as the feature image through comparing the characteristics of lesion and non lesion regions. To get the accurate extraction of tea leaf spots, OTSU algorithm for image segmentation was adopted, the optimal threshold of 4 kinds of leaf samples was determined, and finally the sample images containing only leaf lesion regions were extracted. After image segmentation, 3 color feature parameters were extracted from the single-channel first moments, second moments and three-order moments of each feature image based on color moments; and 20 texture parameters were calculated from the 4 directions (0, 45, 90 and 135°) of energy, contrast, correlation, stability and entropy based on gray level co-occurrence matrix (GLCM); and 3 spectral characteristic parameters of relative spectral reflectance of sensitive bands, including 560, 640 and 780 nm, were obtained. The color feature, texture feature and spectral feature were optimized into 2 feature vectors, and the training set and test set were tested by BP (back propagation) neural network and support vector machine (SVM) respectively. A total of 188 samples, including 50 anthracnose samples, 48 brown spot disease samples, 50 white star disease samples and 40 healthy leaf samples, were randomly selected as the training set, and the remaining 104 samples were used as the test set. The recognition rates of the test set through the feature vector combination of color features and texture features were generally low by BP neural network and SVM, and the recognition rates of the test set through the feature vector combination of color feature, texture feature and spectral feature were higher, which were 89.59% and 86.67% for BP neural network and SVM respectively. In order to further improve the recognition rate and shorten the modeling time, genetic algorithm was used to reduce the dimensionality of the input feature. Through taking selection, crossover and mutation operations, 26-dimensional input features were optimized to 14 dimensions, and then BP neural network was to recognize the tea spots. Finally, the average recognition rate was raised to 94.17%, and the model setup time was also shortened from 6.6 to 1.7 s. The result shows that it is possible to achieve fast and efficient identification of tea diseases by the fusion of spectral information and image information with pattern recognition technique. The neural network identification model based on genetic algorithm optimization has the advantages of short modeling time and high recognition accuracy.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Principal component analysis
Controlled terms:Algorithms - Backpropagation - Color - Genetic algorithms - Hyperspectral imaging - Image processing - Image retrieval - Image segmentation - Independent component analysis - Neural networks - Optimization - Pattern recognition - Pixels - Reflection - Spectroscopy - Stars - Support vector machines - Testing - Vectors
Uncontrolled terms:BP (back propagation) neural network - Genetic-algorithm optimizations - Gray level co occurrence matrix(GLCM) - Hyperspectral imaging technologies - Neural network identifications - Pattern recognition techniques - Spectral characteristics - The region of interest (ROI)
Classification code:657.2 Extraterrestrial Physics and Stellar Phenomena - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 741.1 Light/Optics - 921.1 Algebra - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 8.67e+01%, Percentage 8.96e+01%, Percentage 9.42e+01%, Size 3.58e-07m to 1.02e-06m, Size 6.40e-07m, Size 7.19e-07m, Size 7.80e-07m, Time 6.60e+00s to 1.70e+00s
DOI:10.11975/j.issn.1002-6819.2017.22.026
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 25>
Accession number:20181104889843
Title:Droplet drift characteristics of aerial spraying of AS350B3e helicopter
Authors:Yao, Weixiang (1); Lan, Yubin (1); Wang, Juan (1, 2); Wen, Sheng (3); Wang, Guobin (1); Chen, Shengde (1)
Author affiliation:(1) College of Engineering, South China Agricultural University/National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology (NPAAC), Guangzhou; 510642, China; (2) Mechanical and Electrical Engineering College, Hainan University, Haikou; 570228, China; (3) Engineering Fundamental Teaching and Training Center, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Lan, Yubin(ylan@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:75-83
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The use of aircraft for aerial spraying is an important aspect of precision agriculture (PA). In China, many scholars are engaged in research on aerial spraying technology with agricultural unmanned aerial vehicle (UAV), but few of them concentrate in the field of agricultural manned helicopter. Up to now the related studies about manned agricultural helicopter in China are mainly focused on pesticides efficacy analysis. It usually lacks practical assessment of actual application parameters, especially the regular patterns of droplet drift after spraying. In order to determine the regular patterns of droplet drift of the AS350B3e helicopter with the AG-NAV Guía system, spray tests were conducted with different operating parameters, and the precision operating parameters (time, velocity, height, trajectory) were obtained by the light airborne BeiDou real-time kinematic (RTK) differential system. There are many factors that affect the characteristics of helicopter spraying drople0t drift, including the effective composition and type of liquid prepared, droplet size, aircraft operating parameters, weather conditions, terrain, the operator's sense of responsibility and skill level. In this paper, the deposition distribution and drift law of droplets in the sampling lines were evaluated for 6 single-pass applications in 4 different ranges of flight velocities, and the effects of adding aerial adjuvant on droplet drift distance and amount were compared. The analysis results showed that the position of the effective spraying area was affected by natural wind velocity and wind direction, and would shift to the downwind direction area from the helicopter route with different degrees. When the helicopter was operated at 70, 90, 100, and 120 km/h, the effective swath width increased slowly and then decreased sharply with the increase of flight velocity. It was found that flight velocity of 100 km/h was the peak inflection point of effective spray width variation. Among the 6 single-pass application tests, when the wind velocity was 1.1-2.3 m/s, the minimum width of the target spray area was in the range of 27.61-48.94 m in the horizontal downwind direction of the spray area, and the measured downwind drift distance was close to or less than the downwind effective swath width. It was also found that droplets with droplet size below 200 μm were more likely to drift, which accounted for more than 70% of the total number of droplets in the drift area. Therefore, when the helicopter was in operation, it should reserve a buffer zone (safety zone) of 50 m at least and the aviation nozzle should be selected reasonably to avoid the hazards of droplet drift. Adjuvant was also a key factor affecting drift. It indicated that the use of aerial adjuvant had a significant effect on the percentage of droplet drift in the total amount of spray, and the addition of aerial adjuvant could reduce the droplet drift by 33.94% under the same operating conditions. The results of this study can provide technical basis for the improvement of the performance of the helicopter spraying system, which is of great significance to the reasonable spraying of pesticides, the reduction of the drift and the improvement of the utilization rate of pesticides.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Spray nozzles
Controlled terms:Agriculture - Antennas - Aviation - Drops - Helicopters - Pesticides - Precision agriculture - Radio navigation - Spraying - Unmanned aerial vehicles (UAV) - Velocity - Wind
Uncontrolled terms:Adjuvant - Aerial application - Agricultural helicopters - Application parameters - Deposition distribution - Differential systems - Drift law - Operating parameters
Classification code:431.1 Air Transportation, General - 443.1 Atmospheric Properties - 631.1 Fluid Flow, General - 652.1 Aircraft, General - 652.4 Helicopters - 716.3 Radio Systems and Equipment - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 3.39e+01%, Percentage 7.00e+01%, Size 2.00e-04m, Size 2.76e+01m to 4.89e+01m, Size 5.00e+01m, Velocity 1.10e+00m/s to 2.30e+00m/s, Velocity 2.78e+01m/s, Velocity 3.33e+01m/s
DOI:10.11975/j.issn.1002-6819.2017.22.010
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 26>
Accession number:20181104889836
Title:Design and experiment of combined tillage machine for subsoiling and rotary burying of straw incorporated into soil
Authors:Zhou, Hua (1); Zhang, Jumin (1); Zhu, Yinghao (1); Zhang, Chunling (1); Tahir, H.M. (1); Xia, Junfang (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China
Corresponding author:Xia, Junfang(xjf@mail.hza.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:17-26
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil compaction become very serious problem due to many years of traditional tillage practices which result in formation of hard plow pan, shallower rooting depth, decreased air and water permeability, and confined root system development. Subsoiling and straw incorporated into soil applied jointly result in good working efficiency, alleviation of plow pan by subsoiling, improved water holding capacity and buried crop residue. This is direct and effective way of improving organic matter contents and it can also effectively alleviate the environmental pollution caused by straw burning. This practice will not only reduce wheel traffic in field, it also will save busy time in farming season and will play an important role in increasing crops yield and farmer's income. Through the study of relevant literature, in order to meet the needs of deep tillage and straw burying at the same time, a multifunctional machine for subsoiling and rotary burying have designed, which was capable of joint operations like subsoiling, stubbles cutting, soil crushing, residue burying and leveling. Subsoiling implement with self-excited vibration and adjustable pre-tightening force were devised in this machine which worked to reduce subsoiling resistance to certain degree and also protected the subsoiler when it encountered obstacles. The principle of sliding cutting was adopted in the design of the deep shovel bar which can cut off straw and weeds effectively and prevented winding and clogging to the subsoiler bar. The stress analysis of the subsoiling implement was carried out and the force formula was determined. Blades of rotary cutter were rearranged and optimized to improve working stability and soil cutting and crushing capacity. Subsoiling provided good condition for rotary burying and the depth of straw embedment was increased. Different field tests such as separate subsoiling, rotary burying after subsoiling, separate rotary burying and subsoiling with rotary burying as combined operation was carried out. The traction resistance and power consumption of implement under different working conditions were analyzed. Results showed that the traction resistance and power consumption of subsoiling operation was greatly affected by the working speed. In the rotary burying operation, the driving force of the positive rotation of the rotary cutter roll was opposite to the working resistance so that the cancel out and the traction power consumption of rotary burying operation were small, and power ratio for rotary burying was more. Under the 1st and 2nd gear speeds of the tractor, the total power respectively for the combined operation of subsoiling and rotary burying was 32.72 and 41.88 kW. They accounted for 85% and 82.2% of the total sum of individual subsoiling and rotary burying operations, respectively. Through consulting relevant documents, compared with the traditional machine for subsoiling and rotary tillage, the power consumption was reduced by 4.4% to 14.8% and 7.9% to 14.0%, respectively in the same working condition. Other parameters of experiment collected after combined operation of subsoiling and rotary burying and statistically analyzed included average depth of subsoiling. The results showed that rotary burying were 28.9 and 17.5 cm, respectively, subsoiling tillage stability was 93.5% and rotary burying tillage stability was 87.4%, the average vegetation cover rate was 92.0%, the surface evenness after tillage was 1.0 cm, and soil resistance of 0-15 and 15-30 cm after tillage were 437.6 and 951.8 kPa, which were 78.4% and 67.4% less than that before tillage, respectively. Soil bulk density of 0-10 and 10-20 cm after tillage were 1.40 and 1.41 g/cm<sup>3</sup>which decreased by 6.7% and 8.4%, respectively compared with that before tillage. The performance evaluation indexes of subsoiling field preparation combine machine were compared, and the measured values of the above parameters for combined operation of subsoiling and rotary burying exceeded the quality evaluation index and meet the agronomic requirements.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Agricultural machinery
Controlled terms:Agricultural wastes - Agriculture - Crops - Crushing - Cultivation - Cutting tools - Design - Electric power utilization - Machine design - Quality control - Soil mechanics - Soils - Stress analysis
Uncontrolled terms:Combination operation - Environmental pollutions - Multifunctional machines - Performance evaluations - Quality evaluation indices - Rotary burying - Self-excited vibrations - Subsoiling
Classification code:483.1 Soils and Soil Mechanics - 601 Mechanical Design - 603.2 Machine Tool Accessories - 706.1 Electric Power Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3 Quality Assurance and Control - 951 Materials Science
Numerical data indexing:Mass_Density 1.40e+03kg/m3, Mass_Density 1.41e+03kg/m3, Percentage 4.40e+00% to 1.48e+01%, Percentage 6.70e+00%, Percentage 6.74e+01%, Percentage 7.84e+01%, Percentage 7.90e+00% to 1.40e+01%, Percentage 8.22e+01%, Percentage 8.40e+00%, Percentage 8.50e+01%, Percentage 8.74e+01%, Percentage 9.20e+01%, Percentage 9.35e+01%, Power 3.27e+04W, Power 4.19e+04W, Pressure 4.38e+05Pa, Pressure 9.52e+05Pa, Size 1.00e-01m to 2.00e-01m, Size 1.00e-02m, Size 1.50e-01m to 3.00e-01m, Size 1.75e-01m, Size 2.89e-01m
DOI:10.11975/j.issn.1002-6819.2017.22.003
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 27>
Accession number:20181104889863
Title:Stability analysis of cable-stiffened single-layer two-way grid reticulated domes of greenhouse
Authors:Zhang, Zhonghao (1, 2); Fu, Qiang (1); Fan, Feng (2)
Author affiliation:(1) School of Water Conservancy & Civil Engineering, Northeast Agricultural University, Harbin; 150030, China; (2) School of Civil Engineering, Harbin Institute of Technology, Harbin; 150090, China
Corresponding author:Fu, Qiang(fuqiang@neau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:233-240
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A single-layer reticulated dome structure is elegant and has reasonable stress distribution and various grid types. It has been widely used in various projects, and its stability problem has become the focus of research work. Single layer two-way grid reticulated domes are superior in aesthetic and material efficiency but have a low rigidity. In recent years, researchers worldwide have conducted a series of studies on the low structural rigidity of a two-way grid dome. In these studies, diagonal cables for the two-way grid are used to strengthen the in-plane rigidity of the structure and to improve the overall stability of the reticulated shell structure; the validity of the cable arrangement method is confirmed via testing and theoretical analysis. But researchers have not proposed arrangement of cables between non-adjacent nodes at the out-of-plane of the reticulated dome to improve the rigidity of out-of-plane of the structure. Therefore, to increase the rigidity of the in-plane and out-of-plane of a single-layer two-way grid reticulated dome, cables are installed in diagonals and at the out-of-plane of the reticulated dome. Hence cable installation pattern is considered to increase the in-plane and out-of-plane rigidity of two-way grid domes with width 30, 40 and 50 m. A new cable-strengthened single-layer reticulated dome system is developed for dome structure design. To further investigate structure stability before and after the cable-strengthened reticulated dome develops instability, in this study, an analysis of the complete non-linearity process was employed to perform large-scale parameterization analysis for a reticulated dome structure under various cable arrangement scenarios. More than 500 examples of reticulated domes were carried out with considering both geometric and material nonlinearity based on commercial finite element software ANSYS and self-compiled pre-post-processing programs. The effects of cables and various structural responses such as critical loads, buckling modes, and plastic development levels were examined by the numerical study. The rise-span ratio, cable pre-stress, initial geometric imperfection and unsymmetrical distribution of loads were collected to investigate the stability of reticulated domes. In the numerical calculations, cable arrangement at interior and exterior surfaces of the two-way grid reticulated dome structure effectively improved the bearing capability of the structure, with an improvement range of 29%-92%. Cable pre-stress was more effective in improving the bearing capability of a large span reticulated dome structure than small span reticulated dome structure. The stability of a cable-strengthened single-layer reticulated dome structure was affected by an asymmetric load distribution and initial geometric imperfection; bearing capacity decreases to various degrees. Through a statistical analysis of elastic and elasto-plastic stability critical loads, a plasticity reduction coefficient for the cable-stiffened single layer two-way grid domes was proposed to reveal the influence of material nonlinearity on critical loads. As a result, the plastic reduced coefficients of cylindrical shells were summarized to be 0.7 - 1.0. The impact of material non-linearity on various types of reticulated dome structures had little influence on the structural stability bearing capacity, and the plastic reduction coefficients were above 0.7 Through the analytical results, the elasto-plastic stability behaviors of cable-stiffened single layer two-way grid domes were concluded, and the results provide a theoretical basis and technical support for the practical engineering in modern greenhouse construction.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Rigid structures
Controlled terms:Bearing capacity - Cables - Convergence of numerical methods - Domes - Elastoplasticity - Engineering research - Finite element method - Geometry - Greenhouses - Loading - Rigidity - Stability - Structural analysis
Uncontrolled terms:Asymmetric load distribution - Critical load - Finite element software - Geometric and material nonlinearities - Initial geometric imperfection - Reticulated shell structure - Two ways - Unsymmetrical distribution
Classification code:408 Structural Design - 691.2 Materials Handling Methods - 821.6 Farm Buildings and Other Structures - 901.3 Engineering Research - 921 Mathematics - 921.6 Numerical Methods - 951 Materials Science
Numerical data indexing:Percentage 2.90e+01% to 9.20e+01%, Size 4.00e+01m, Size 5.00e+01m
DOI:10.11975/j.issn.1002-6819.2017.22.030
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 28>
Accession number:20181104889873
Title:Experimental study on cold retention characteristics of cold storage incubator using Na<inf>2</inf>SO<inf>4</inf>·10H<inf>2</inf>O as PCMs
Authors:Xu, Xiaofeng (1); Zhang, Xuelai (1); Munyalo, Jotham Muthoka (1); Li, Yuyang (1); Chen, Yue (1); Chen, Qiyang (1); Liu, Sheng (2)
Author affiliation:(1) Institute of Cool Storage Technology, Shanghai Maritime University, Shanghai; 201306, China; (2) Vegetable Research Center of Beijing Academy of Agriculture and Forestry Sciences, Beijing; 100097, China
Corresponding author:Zhang, Xuelai(xlzhang@shmtu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:308-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:At present, cold chain in China is developing rapidly, especially in the cold chain market of agricultural products, it has huge market potential. But the cold chain transportation still faces serious constrains for its development. The shortage of cold chain capacity and frequent discontinuity in the process of transportation deteriorate the quality of agricultural products. Thermal storage cold chain transportation equipment currently used includes refrigerated transportation with cold storage technology and adiabatic thermal insulation technology from which thermal storage insulation boxes are mainly used. Thermal storage insulation box is composed of heat preservation box and thermal storage plate. Thermal storage insulation box has no refrigeration function, the temperature is controlled by putting thermal storage plates of different temperature in the box, and the temperature could be maintained for a long time. The temperature of fresh-keeping and cold chain transportation are requested in the range of 2 - 8℃, the thermal storage material (sodium sulfate salt hydrate system) is wrapped in polyethylene thermal storage plate. It is used in polypropylene (EPP) foaming thermal storage boxes and vacuum insulation plate (VIP) boxes, and constitutes the thermal storage cold chain transportation equipment. Good Supply Practice (GSP) was used in this study to verify equipment and built temperature test system of thermal storage insulation boxes. Temperature measuring points were distributed at different sites, as such, the heating curve of each point in the box was obtained. Heat preservation effect was evaluated by the average cooling time in box. The influence of the way of holding thermal storage plates and the insulating properties of the insulation box material were considered. Our study showed that the insulation property of vacuum insulation board was better than foamed PP, the cooling maintain time could be increased by 13.31% and the average cooling maintain time increased 1.24 h. The temperature distribution was more uniform and stable. However, if each wall in the vacuum insulated plate insulation box was arranged with a cooling board, the box capacity would be reduced effectively. So it was necessary to consider the influence of this factor in the practical application. The cooling maintaining time of the refrigerant under the modality of side-sway was extended by 4.7% than top-sway. But the temperature difference between top and bottom of the box was large. The temperature distribution is uneven. Adding of thermal storage board on the top made the temperature declined 3℃. The temperature distribution was more uniform when the modality of top and side were adopted, which was more conducive to the preservation of fruits and vegetables. The temperature of each point when the box was loaded and unloaded was compared, and the cooling maintaining property was analyzed, the cooling maintaining time of load decreased 0.77 h than unload. In the actual application process, all factors which affect the quality of the goods and reasonable selection of the pre-cooling temperature, the amount of refrigerant and pre-cooling temperature of the refrigerant should be considered.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Thermal insulation
Controlled terms:Agricultural products - Agriculture - Chains - Cold storage - Commerce - Cooling - Electron emission - Fruits - Heat storage - Insulation - Materials handling - Phase change materials - Polypropylenes - Refrigerants - Sodium sulfate - Storage (materials) - Sulfur compounds - Temperature distribution
Uncontrolled terms:Cold chain - Cold plates - Fruits and vegetables - Insulation technology - Retention characteristics - Temperature differences - Temperature measuring - Transportation equipments
Classification code:413 Insulating Materials - 413.2 Heat Insulating Materials - 602.1 Mechanical Drives - 641.1 Thermodynamics - 641.2 Heat Transfer - 694.4 Storage - 803 Chemical Agents and Basic Industrial Chemicals - 804.2 Inorganic Compounds - 815.1.1 Organic Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products
Numerical data indexing:Percentage 1.33e+01%, Percentage 4.70e+00%, Time 2.77e+03s, Time 4.46e+03s
DOI:10.11975/j.issn.1002-6819.2017.22.040
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 29>
Accession number:20181104889866
Title:Study of structure optimization of solar hot water storage tank with conical top
Authors:Wang, Ye (1, 2); Bao, Chengke (1); Fu, Yin'an (1); Wang, Leli (1, 2)
Author affiliation:(1) School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou; 730070, China; (2) Key Laboratory of Railway Vehicle Thermal Engineering, Ministry of Education of China, Lanzhou Jiaotong University, Lanzhou; 730070, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:255-261
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solar hot water storage tank is one of the key thermal storage equipment of the solar energy system and it has significant effect on the reliability of thermal energy supply. For the solar hot water storage tank, its optimal structure and reasonable fluid parameters are very important for improving the solar energy system efficiency. Published references indicate that the hot water storage tank with conical top has better performance than the hot water storage tank with plane top. But there is no study about the relationships among the cone vertex angles, fluid parameters and the thermal stratification effect for the hot water storage tank with conical top. This paper mainly aims to obtain the optimal structure of the solar hot water storage tank with conical top and the operating parameters. The standard k-Ε model was adopted to analyze the influence of cone vertex angle and operating parameters on the thermal stratification of the hot water storage tank with conical top. The results show that the studied cone vertex angles have a little effect on thermal stratification and the hot water region slightly expands with the decreasing of cone vertex angle. In terms of the optimal water storage tank with the conical top height of 0.09 m and cone vertex angle of 159.6°, the hot water region is reduced with the increasing of cold water inlet velocity and the decreasing of hot water inlet temperature. However, higher hot water inlet temperature has less effect on the hot water region on condition of higher cold water inlet velocity than that of lower cold water inlet velocity. Thus, in practical engineering operation, to improve hot water inlet temperature under lower cold water inlet velocity can obtain better thermal stratification effect. For given fluid parameters, the difference between the hot water outlet temperature and cold water outlet temperature increases with the increasing of cold water inlet velocity. Increasing hot water inlet temperature under lower cold water inlet velocity makes a slightly larger contribution to improving the difference between the hot water outlet temperature and the cold water outlet temperature. To improve hot water inlet temperature from 333 to 343 K has no effect on the cold water outlet temperature in this study. One case with hot water inlet temperature of 333 K, cold water inlet temperature of 303 K, hot water inlet velocity of 0.05 m/s and cold water inlet velocity of 0.9 m/s and the other case with hot water inlet temperature of 343 K, cold water inlet temperature of 303 K, hot water inlet velocity of 0.05 m/s and cold water inlet velocity of 0.9 m/s are suitable to the running mode of "low flow flux and high temperature difference". One case with hot water inlet temperature of 333 K, cold water inlet temperature of 303 K, hot water inlet velocity of 0.05 m/s and cold water inlet velocity of 0.1 m/s and the other case with hot water inlet temperature of 343 K, cold water inlet temperature of 303 K, hot water inlet velocity of 0.05 m/s and cold water inlet velocity of 0.1 m/s are suitable for the users with large demand for hot water supply. In order to obtain high efficiency of solar energy system in practical engineering, many factors, such as types of solar collectors, local weather conditions, specific requirements of thermal users and operation modes must be considered simultaneously.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Water
Controlled terms:Collector efficiency - Computer simulation - Energy efficiency - Heat pump systems - Heat storage - Hydrophilicity - Inlet flow - Optimization - Solar concentrators - Solar energy - Structural optimization - Tanks (containers) - Temperature - Thermal Engineering - Thermal stratification - Velocity - Water supply
Uncontrolled terms:Hot water storage tanks - Local weather conditions - Operating parameters - Practical engineering - Solar hot water - Structure optimization - Thermal storage equipments - Vertex angle
Classification code:446.1 Water Supply Systems - 525.2 Energy Conservation - 616.1 Heat Exchange Equipment and Components - 619.2 Tanks - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 702.3 Solar Cells - 723.5 Computer Applications - 921.5 Optimization Techniques
Numerical data indexing:Size 9.00e-02m, Temperature 3.03e+02K, Temperature 3.33e+02K, Temperature 3.33e+02K to 3.43e+02K, Temperature 3.43e+02K, Velocity 1.00e-01m/s, Velocity 5.00e-02m/s, Velocity 9.00e-01m/s
DOI:10.11975/j.issn.1002-6819.2017.22.033
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 30>
Accession number:20181104889861
Title:Development of device for semiconductor's freezing and dehumidification and recycled evapotranspiration water for irrigating in closed greenhouse
Authors:Kang, Ningbo (1); He, Jianguo (1, 2); Wu, Longguo (1); Wang, Songlei (1, 2); Liu, Guishan (2); Shang, Mengyu (3)
Author affiliation:(1) School of Construction and Hydraulic Engineering, Ningxia University, Yinchuan; 750021, China; (2) School of Agricultural, Ningxia University, Yinchuan; 750021, China; (3) School of Physics and Electronic-electrical Engineering, Ningxia University, Yinchuan; 750021, China
Corresponding author:He, Jianguo(hejg@nxu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:217-223
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To improve the water use efficiency of artificial light greenhouse, on the basis of the semiconductor refrigeration and the theory of air dew-point, the water transpiration by plants in greenhouse is condensed, which meets the requirement of the indoor dehumidification and recycling for irrigation. The studying object is potted pepper. The experimental period is from May 7 to July 4 including the growth period, the flowering period and the fruiting period. The experimental greenhouse is an airtight greenhouse designed with glass in this paper, whose size is 2 000 mm × 600 mm × 1 200 mm. The red light emitted by LED (light emitting diode) is used as the light source of photosynthesis, with 650 nm wavelength and light intensity of 400 μmol/m<sup>2</sup>·s. The experiment of potted pepper culture was conducted in greenhouse, and outdoor controlled trials were conducted. The cavity with a diameter of 16 cm was opened on the side wall of the greenhouse, and the 250 cm aluminum foil tube is used to connect the condenser box and the cavity. The aluminum foil tube forms a closed loop pipe equipped with a duct fan, which can carry out air circulation. The results show that the working temperature of the semiconductor refrigeration aluminum plate is 5.5℃, which corresponds to the temperature range of 7-18℃ in sealed space. In the closed greenhouse, the semiconductor refrigeration is opened and the natural convection and forced convection are designed. The convection test was carried out in the greenhouse. The average humidity is 76% for the natural convection and 53.8% for the forced convection, which can meet the requirement of dew-point dehumidification. In the growth phase test, the forced convection air inlet is adopted to dehumidification. In different periods, the temperature range of closed greenhouse is from 18.6 to 28.2℃, and the dehumidification effect is significantly improved with the temperature increasing. The amount of irrigation in the development period and the flowering period shows a steady upward trend from 132 to 201 mL, indicating that the plant transpiration is small. The recovery in the same period is also in a steady upward trend from 35 to 101 mL, with an average recovery rate of 26.3%. In the fruiting period, the amount of irrigation increases to 540 mL. With the increasing of the ambient temperature and plant growth demand, transpiration is increased. In the same period, the daily recovery is 375 mL, and the recovery rate is 69.4%. Observing the physiological changes of potted pepper indoor and outdoor, the plant height, stem thickness and singe leaf area of the former are significantly different from the latter. In this paper, the artificial closed greenhouse uses semiconductor refrigeration to condense water evaporated and spread by plants. The effect is remarkable. And the irrigation of the potted pepper can use recycled water to realize the normal growth in closed greenhouse.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Water recycling
Controlled terms:Aluminum - Aluminum foil - Atmospheric humidity - Evapotranspiration - Forced convection - Greenhouse effect - Greenhouses - Humidity control - Irrigation - Light sources - Natural convection - Recovery - Recycling - Refrigeration - Temperature - Transpiration - Water supply
Uncontrolled terms:Average recovery rate - Controlled trial - Dehumidification - Plant transpiration - Semiconductor refrigerations - Temperature range - Water use efficiency - Working temperatures
Classification code:443.1 Atmospheric Properties - 446.1 Water Supply Systems - 452.3 Industrial Wastes - 461.9 Biology - 541.1 Aluminum - 641.1 Thermodynamics - 641.2 Heat Transfer - 644.1 Refrigeration Methods - 821.3 Agricultural Methods - 821.6 Farm Buildings and Other Structures
Numerical data indexing:Percentage 2.63e+01%, Percentage 5.38e+01%, Percentage 6.94e+01%, Percentage 7.60e+01%, Size 1.20e+00m, Size 1.60e-01m, Size 2.50e+00m, Size 6.50e-07m, Volume 1.32e-04m3 to 2.01e-04m3, Volume 3.50e-05m3 to 1.01e-04m3, Volume 3.75e-04m3, Volume 5.40e-04m3
DOI:10.11975/j.issn.1002-6819.2017.22.028
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 31>
Accession number:20181104889858
Title:Remote sensing inversion of soil moisture based on laboratory reflectance spectral data
Authors:Yang, Xiguang (1); Yu, Ying (2)
Author affiliation:(1) Key Laboratory of Saline-Alkali Vegetation Ecology Restoration (SAVER), Alkali Soil Natural Environmental Science Center (ASNESC), Northeast Forestry University, Harbin; 150040, China; (2) College of Forestry, Northeast Forestry University, Harbin; 150040, China
Corresponding author:Yu, Ying(yuying4458@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:195-199
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil moisture is one of the important components of soil and plays an important role in the material and vegetative nutrient transport process in the soil system. Soil moisture is also an essential soil physical parameter in the study on water cycle in ecological system, and a key variable of drought monitoring, soil erosion and surface evaporation studying. Therefore, soil moisture monitoring is very important. Remote sensing technology has been applied to soil moisture monitoring with its advantage of high efficiency and rapidness. The soil hyper-spectral ground experiment and the soil hyper-spectral characteristics are the basis for the inversion of soil moisture. In this paper, soil samples collected in field were mixed to achieve the purpose of keeping approximately constant soil properties. Then mixed soil sample was divided into 16 independent samples in order to ensure that the effects of soil properties on reflectance of each soil sample were at the same level, such as soil organic matter, soil texture, and soil salinity. After that, the samples were slowly irrigated with distilled water to get different levels of moisture. And the spectral data of each sample were measured at the same time under laboratory conditions. Based on this dataset, a remote sensing inversion model of soil moisture content based on exponential function was established and the parameters of model were fitted by using the experimental spectrum data. Fitted parameters illustrated the effects of soil moisture on soil reflected energy at each single band from 350 to 2 500 nm. A larger value of the fitted parameter indicated that more energy was absorbed by water and less energy was reflected. Result showed that there were 2 peaks near 1 400 and 1 900 nm after a steady trend less than 1 300 nm. And this fitted result was consistent with the absorption coefficients of pure water. It indicates that the exponential model with physically definable parameters can be used to describe the characteristics of soil reflectance changing with soil moisture conditions. Then this inversion model was used to estimate the soil moisture based on laboratory spectral data. The accuracy varied with soil moisture level, and it was lower for samples with soil moisture larger than 32.75% and lower than 5.52%. When soil moisture was 32.75%, the maximum absolute error and the minimum absolute error were 134.89% and 25.44%, respectively. When soil moisture was equal and lower than 5.52%, the maximum absolute error was larger than 200%. The estimation accuracy was better when the soil moisture was between 5.52% and 32.75%. The mean absolute error was less than 30% and the maximum absolute error was 83.81%. The determination coefficient and RMSE (root mean square error) between estimated and measured soil moisture content at 640 nm were 0.706 2 and 3.49%, respectively. The results indicate that the inversion model based on the exponential function can be used for soil moisture content estimation with good accuracy. This work provides new methods and ideas for monitoring topsoil moisture content by using remote sensing technology.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soil moisture
Controlled terms:Errors - Exponential functions - Mean square error - Microwave measurement - Models - Moisture - Moisture control - Moisture determination - Reflection - Remote sensing - Soil surveys - Soils - Water absorption
Uncontrolled terms:Determination coefficients - Hyper-spectral characteristics - Hyperspectral remote sensing - Inversion models - Remote sensing technology - RMSE (root mean square error) - Soil moisture monitoring - Soil physical parameters
Classification code:483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 921 Mathematics - 922.2 Mathematical Statistics - 942.2 Electric Variables Measurements - 944.2 Moisture Measurements
Numerical data indexing:Percentage 1.35e+02%, Percentage 2.00e+00%, Percentage 2.00e+02%, Percentage 2.54e+01%, Percentage 3.00e+01%, Percentage 3.28e+01%, Percentage 3.49e+00%, Percentage 5.52e+00% to 3.28e+01%, Percentage 5.52e+00%, Percentage 8.38e+01%, Size 1.30e-06m, Size 1.40e-06m, Size 1.90e-06m, Size 3.50e-07m to 2.50e-06m, Size 6.40e-07m
DOI:10.11975/j.issn.1002-6819.2017.22.025
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 32>
Accession number:20181104889848
Title:Aeration irrigation improving grape rhizosphere soil chemical properties and bacterial community structure in arid area
Authors:Zhao, Fengyun (1); Yang, Xiang (1); Dong, Mingming (1); Jiang, Yu (1); Yu, Kun (1); Yu, Songlin (1)
Author affiliation:(1) Agricultural College/Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization of Xinjiang Production and Construction Group, Shihezi University, Shihezi; 832003, China
Corresponding author:Yu, Kun(yukun409@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:119-126
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In traditional agricultural irrigation, uptake of water of plant root and its own respiration are relatively contradictory. When the water content is satisfied, aerobic respiration can not fully carry out due to limited air supply in soil. Good soil aeration is beneficial for maintaining higher soil fertility and crop growth and development. Once air capacity in soil decreases and gas exchange is restricted, the soil physical and chemical properties would become deteriorated, which affects the normal growth of the crops, resulting in reduced production. Aeration irrigation is an improvement of subsurface drip irrigation (SDI), and it involves the delivery of oxygen or oxygenated material to the root zone of the crop through subsurface drip irrigation systems to improve soil aeration, and to meet the needs of root growth and development, thereby promoting growth and development of crops and improving crop yield and quality. Soil microorganisms are the most important and active part of soil ecosystems and reflect changes in soil quality in a sensitive, timely, and accurate manner. However, few reports have described the effects of aeration on soil microbial diversity. In this study, Red Globe grape planted in boxes was used as experimental material, self-designed integrated equipment of SDI with tanks of fertilizer-water-gas was involved as gas injection device, and high-throughput 16S genome sequencing was the key technique to study effect of aeration of rhizosphere under condition of SDI with tanks on the rhizosphere soil and bacterial community structure. The results showed that aeration of rhizosphere under condition of SDI with tanks could raise the pH values of soils, increase the contents of Olsen-P and available K in soil, and promote decomposition of organic matter in the 20-30 cm soil layer. Analysis of bacteria related to nitrogen, phosphorus and potassium metabolism showed that rhizosphere aeration can promote the Nitrosospira associated with nitrification, Pseudomonas and Bacillus associated with phosphorus and potassium metabolism, and inhibited Ralstonia associated with denitrifying bacteria. It showed that absorption of nitrogen, phosphorus and potassium in the plant maybe due to the increase of nitrifying bacteria and bacteria of decomposition of organic phosphorus and potassium. According to the analysis of microbial community structure, we learned that aeration of rhizosphere under condition of SDI with tanks promoted the growth of aerobic bacteria such as Nitrospirae, inhibited the growth of anaerobic bacteria Planctomycetes. Furthermore, Chao1 and Shannon index analyses indicated that aeration of rhizosphere under condition of SDI with tanks could change the abundance of bacterial community effectively. However, it had little effect on bacterial community diversity. In addition, for bacterial phylum, aeration treatment increased the abundance of actinomycetes and Nitrospira, which were 16.7% and 22.7% higher (P<0.01) with aeration treatment than that without aeration in the 40-50 cm soil layer, respectively, and reached extremely significant levels (P<0.01). Canonical correspondence analysis (CCA) and correlation analyses showed that the pH values of soils, Olsen-P and available K contents were important indicators of bacterial community structure when applying aeration of rhizosphere under condition of SDI with tanks. The results of this study showed that the SDI system can be used for aeration without extensive increases cost. This irrigation approach can improve soil aeration quality, optimize soil microbial community structure, and improve fertilizer use efficiency, which has certain application and promotion prospects. However, the frequency and intensity of aeration of rhizosphere under SDI with tanks need to be further optimized.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Bacteria
Controlled terms:Aerobic bacteria - Agriculture - Bacteriology - Chemical analysis - Chemical properties - Crops - Decomposition - Denitrification - Fertilizers - Forestry - Irrigation - Metabolism - Microorganisms - Nitrification - Nitrogen - pH - Phosphorus - Physiology - Potassium - Soils - Subirrigation - Tanks (containers) - Water aeration - Water injection - Water tanks
Uncontrolled terms:Bacterial community structure - Canonical Correspondence Analysis - Crop growth and development - Microbial community structures - Soil microbial community structure - Soil microbial diversity - Soil physical and chemical properties - Subsurface drip irrigation
Classification code:445.1 Water Treatment Techniques - 461 Bioengineering and Biology - 461.9 Biology - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 612.1 Internal Combustion Engines, General - 619.2 Tanks - 801 Chemistry - 801.1 Chemistry, General - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.67e+01%, Percentage 2.27e+01%, Size 2.00e-01m to 3.00e-01m, Size 4.00e-01m to 5.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.22.015
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 33>
Accession number:20181104889856
Title:Modification of tilling depth measurement errors by linear fitting and Kalman prediction method
Authors:Shang, Gaogao (1); Liu, Cunhao (1); Han, Jiangyi (1)
Author affiliation:(1) School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:183-188
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To precisely control the tillage depth and ensure uniform tillage depth, in this study, measured values of the tillage depth are corrected based on the tillage depth measurement methods and the causes of the measurement errors. In indirect measurement of the tillage depth, the tillage depth is calculated by monitoring the angle of the lifting arm based on the geometric relationship between the position of the suspension mechanism and the angle of the lifting arm. The tillage depth can also be measured directly by monitoring the height change of the plow frame relative to the land that has not been tilled. Due to the excellent imitation real-time response of the land wheels and the high measurement accuracy of the pull rope sensor that is less susceptible to the impact of the operating environment, with the system made up by the land wheels and the pull rope sensor as the measuring basis, the angular transducer and ultrasonic transducer as the cases, the principles of the tillage depth measurement, both direct and indirect, are analyzed. Besides, the prototype is rebuilt and the tillage and imitation tests are carried out in the Mahindra Tractor Experimental Field (Nanchang, China). The causes of errors in the indirect and direct measurement of tillage depth are explored based on the collected data. As shown by the experiment results, due to the changed measuring basis that might be caused by the wheel sinkage and the tilted tractor body, the indirectly measured tillage depth is always smaller than the target tillage depth, and the deviation becomes larger as the target tillage depth increases; there is a great fluctuation in the values obtained using the direct measurement method, for the sensor cannot conduct accurate sampling because of the factors like soil unevenness, plant residuals, and unit vibration. Based on the causes of the measurement errors, both the direct and indirect measurement results are corrected by the fitting and the Kalman prediction, respectively. As suggested in the modification results, there is an approximate linear correlation between the tillage depth deviation from the indirect measurements and the actual tillage depth (R<sup>2</sup>=0.986 1), which can effectively reduce the deviation based on the fitting formula (before compensation: 3.20, 4.48, 5.61, 6.90 cm; after compensation: 0.14, 0.19, 0.16, 0.17 cm) and ensure that the standard deviation after compensation remains approximately unchanged (before compensation: 0.042, 0.08, 0.032, 0.07 cm; after compensation: 0.047, 0.06, 0.03, 0.082 cm); Kalman prediction can accurately predict the arrival time of the echo and reduce the noises in the measurements through the state update, which reduces the standard deviation of tillage depth (before: 1.60, 1.83, 1.33, 1.83 cm; later: 0.032, 0.010, 0.042, 0.092 cm) and ensures that the average tillage depth (before: 15.06, 20.05, 25.42, 29.33 cm; later: 15.02, 20.08, 25.07, 30.137 cm) and deviation (before: 0.064, 0.05, 0.42, 0.65 cm; later: 0.02, 0.084, 0.07, 0.17 cm) are approximately the same. Through fitting, the variation patterns of the limited observation data and the tillage depth deviations can be explored, and Kalman prediction can minimize the impact of noises on the identification of the system state. As fitting and Kalman prediction play an effective role in analyzing the influence of different parameters on test results and noise reduction, they are applicable to the correction of tillage measurement errors. The method to correct errors in indirect and direct measurements of the tillage depth proposed in this study provides a new solution for precisely controlling the electronic suspension and ensuring the seeding depth.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Agricultural machinery
Controlled terms:Agriculture - Algorithms - Errors - Forecasting - Measurement errors - Noise abatement - Rope - Sensors - Statistics - Tractors (truck) - Transducers - Ultrasonic transducers - Vibrations (mechanical) - Wheels
Uncontrolled terms:Direct and indirect measurements - Direct measurement method - Geometric relationships - Indirect measurements - Kalman prediction - Kalman prediction methods - Operating environment - Tilling depth modification
Classification code:601.2 Machine Components - 663.1 Heavy Duty Motor Vehicles - 751.4 Acoustic Noise - 753.2 Ultrasonic Devices - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 922.2 Mathematical Statistics - 931.1 Mechanics
Numerical data indexing:Size 1.70e-03m, Size 3.01e-01m, Size 8.20e-04m, Size 9.20e-04m
DOI:10.11975/j.issn.1002-6819.2017.22.023
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 34>
Accession number:20181104889855
Title:Effect of concentration of potassium and calcium cations on soil aggregates stability during fast wetting process
Authors:Hu, Jie (1, 2); Wu, Xinliang (1, 2); Cai, Chongfa (1, 2)
Author affiliation:(1) College of Resources and Environment, Huazhong Agricultural University, Wuhan; 430070, China; (2) Key Laboratory of Arable Land Conservation, Middle and Lower Reaches of Yangtze River of Ministry of Agriculture, Wuhan; 430070, China
Corresponding author:Cai, Chongfa(cfcai@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:175-182
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil aggregates are basic properties of soil structure, and it is of very necessity to investigate soil aggregates stability when it comes to analyze the soil quality. At present, the soil aggregates are measured in medium of pure water, which ignores the existence of salt ions in soil water. Whereas, the soil water contains a variety of chemical substance. In addition, there is plentiful chemical substance in the irrigation water and fertilizer, which inevitably affects the stability of soil aggregates. Precipitation is abundant in Hubei area, and the alternation of rain and drought is also frequent. For investigating the effects of fertilization in droughty soil before irrigation or rainfall on the stability of soil aggregates, in this study, 2 different groups of experiments were carried out. In the first group, the soil aggregates from 3 types of soil (yellow cinnamon soil, yellow brown soil and brown red soil) in 2 kinds of land use types (forest and cultivated land) in Hubei Province were fast wetted under 2 kinds of electrolyte (KNO<inf>3</inf>and Ca(NO<inf>3</inf>)<inf>2</inf>) solutions in different concentrations (0, 0.005, 0.01, 0.02, 0.05, 0.08, 0.10, 0.20 mol/L) and then washed by alcohol. MWD (mean weight diameter) values were calculated after wet sieving. In the second group, these air-dry soil aggregates were immersed under KNO<inf>3</inf>and Ca(NO<inf>3</inf>)<inf>2</inf>solutions with concentrations of 0, 0.05, 0.10 and 0.20 mol/L. The parameter values of the breaking energy of the aggregates at the initial stage) were assessed by double exponential fitting model of AS (percentage of intact aggregates in all the tested aggregates during wetting process) and wetting time. The results indicate that: 1) When the concentration of solution was lower than 0.1 mol/L, as electrolyte concentration increases, MWD value decreased and the aggregates tended to break down into smaller size fractions; 2) AS value exponentially decays as the wetting time. Compared with pure water, the crushing of the brown red soil and the forest yellow cinnamon soil was affected significantly by the electrolyte solution. The aggregates of yellow cinnamon soil and the yellow brown soil of the cultivated land were rapidly broken in the electrolyte solution; 3) The AS of aggregates was negatively correlated with the breaking energy of the aggregates at the initial stage, which is a parameter in the exponential model, and the crushing energy was negatively correlated with the ratio of silt to clay in soil and content of soil organic matter, while positively correlated with the content of oxidative iron and aluminum. In summary, while the concentration increases, the rate of solution penetrating into aggregates increases with the surface tension of solution. As a result, the stability of aggregates decreases when the solution concentration rises. And compared with pure water, aggregates are crushed faster under electrolyte solution. These findings demonstrate that the soil aggregates stability tested by medium of pure water is different from the actual situation in the field, which is helpful to provide practical reference for modern agricultural production. Considering the characteristics of fertilizer application in actual production, K<sup>+</sup>and Ca<sup>2+</sup>are selected as representative research objects. In further study, more kinds of salt cations can be tested to explore the effects of different kinds of cations on soil aggregates stability.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Infiltration
Controlled terms:Aggregates - Agriculture - Calcium - Calcium compounds - Chemical stability - Crushing - Electrolytes - Fertilizers - Forestry - Irrigation - Land use - Positive ions - Potash - Precipitation (meteorology) - Rain - Soil mechanics - Soil moisture - Soils - Stability - Well drilling - Wetting
Uncontrolled terms:Agricultural productions - Concentration of solutions - Electrolyte concentration - Fast wetting - Fertilizer applications - Infiltration rate - Slaking - Solution concentration
Classification code:403 Urban and Regional Planning and Development - 406 Highway Engineering - 443.3 Precipitation - 483.1 Soils and Soil Mechanics - 549.2 Alkaline Earth Metals - 702 Electric Batteries and Fuel Cells - 801 Chemistry - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods
Numerical data indexing:Molar_Concentration 1.00e+02mol/m3, Molar_Concentration 2.00e+02mol/m3
DOI:10.11975/j.issn.1002-6819.2017.22.022
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 35>
Accession number:20181104889862
Title:Warming effect comparison between substrate warming system and air warming system by active heat storage-release in Chinese solar greenhouse
Authors:Ke, Xinglin (1, 2); Yang, Qichang (1, 2); Zhang, Yi (1, 2); Fang, Hui (1, 2); He, Yongkang (1, 2); Zhang, Chen (1, 2)
Author affiliation:(1) Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing; 100081, China; (2) Key Labatory of Energy Conservation and Waste Management of Agricultural Structures, Ministry of Agriculture, Beijing; 100081, China
Corresponding author:Zhang, Yi(xingfu_536@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:224-232
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the utilization efficiency of the heat from active heat storage-release system in Chinese solar greenhouses, the solar energy can be utilized to improve the temperature of the substrate. Based on the active heat storage-release system, we designed the active heat storage-release substrate warming system (AHSSWS) in order to provide theoretical basis for multiple applications of the active heat storage-release system. The AHSSWS was composed of active heat storage-release plates, water tank, heating pipes under substrate bags and submersible pump. In the daytime, when the water circuited in the system, the solar radiation and thermal energy in the air were absorbed. Then the heat would be released to the substrate in the soil through the heating pipes embedded. The experiment was conducted from December 16, 2016 to February 16, 2017. Tomato was used as the model plant in the greenhouse. The AHSSWS was compared with the active heat storage-release air warming system (AHSAWS) in order to find out which was better to lower the heat consumption for unit production. Effects of 2 heating approaches on the substrate temperature, air temperature indoor, plant height and stem diameter of tomato on different dates and tomato yield were contradistinguished. Moreover, collected and released heat, COP (coefficient of performance), power consumption and facility investment of 2 systems under diverse weather conditions were analyzed and compared. The results showed that compared with AHSAWS, AHSSWS designed could increase the substrate temperature by 2.5-5.3℃, but there was not obvious difference on air warming. Compared with air heating, substrate heating treatment could significantly increase the height, fresh weight and dry weight of tomato plant. In the case of continuous sunny days, the COP of AHSSWS was 1.5-1.9 and that of AHSAWS was 3.0-4.0. In the case of continuous cloudy days, the COP of AHSSWS was 0.5-0.9 and that of AHSAWS was 1.0-2.2. The difference between water temperature and substrate temperature in the AHSSWS was smaller than the AHSAWS, and the heat transfer mode was mainly thermal conduction when the heat was released to the substrate, while the heat transfer mode was mainly thermal convection when the AHSAWS was heating air. So compared with the AHSAWS, the AHSSWS had slightly lower heat storage efficiency, heat saving rate and average COP. The average daily electricity consumption of the AHSSWS was 0.031 kW·h/(m<sup>2</sup>) during both sunny days and cloudy days while the average daily electricity consumption of the AHSAWS was 0.026 kW·h/(m<sup>2</sup>). Tomatoes were picked about 5 times and the yield under the treatment of AHSSWS was 6.73 kg/m<sup>2</sup>. At the same time the yield under the treatment of AHSAWS was 3.83 kg/m<sup>2</sup>. Last but not least, the heat consumption for unit production under the AHSSWS was 0.7 kJ/kg, which was 1.0 kJ/kg lower than that of the treatment with AHSAWS. If tomatoes could be sold at the price of 2.7 yuan/kg, there would be favorable for productors using the AHSSWS compared with the AHSAWS. The results of this study provide the basis for the efficient application of active heat from active heat storage-release system and the application of the AHSSWS in tomato cultivation in Chinese solar greenhouses in winter and spring.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Heat convection
Controlled terms:Electric power utilization - Fruits - Greenhouse effect - Greenhouses - Heat storage - Heat transfer - Heating - Investments - Solar energy - Solar heating - Substrates - Temperature - Water tanks
Uncontrolled terms:Chinese solar greenhouse - Coefficient of Performance - Electricity-consumption - Heating facilities - Multiple applications - Storage-release system - Tomato - Utilization efficiency
Classification code:446.1 Water Supply Systems - 451 Air Pollution - 641.1 Thermodynamics - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 706.1 Electric Power Systems - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures
Numerical data indexing:Specific_Energy 1.00e+03J/kg, Specific_Energy 7.00e+02J/kg, Surface_Density 3.83e+00kg/m2, Surface_Density 6.73e+00kg/m2
DOI:10.11975/j.issn.1002-6819.2017.22.029
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 36>
Accession number:20181104889867
Title:Aerodynamic performance research and structural parameter optimization of helical vertical axis wind turbine
Authors:Xie, Dian (1); Gu, Yujiong (1); Yang, Hongyu (1); Sun, Wang (1); Geng, Zhi (1); Wang, Bingbing (1)
Author affiliation:(1) School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing; 102206, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:262-268
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Vertical axis wind turbine (VAWT) has the advantages of good adaptability to wind direction, low noise, simple structure, and so on. It has a good application value in the field of small and medium-sized wind turbines. Among all kinds of VAWTs, H type VAWT is used more widely and has better performance. However, it still has some drawbacks, such as poor starting performance, low utilization coefficient of wind energy, large torque fluctuation in the process of rotation, alternating load and fatigue of the wind wheel. In this paper, a scheme for forming a helical VAWT by rotating a straight blade of an H type wind turbine to a certain angle is presented. The performance analysis and parameter optimization of this kind of wind turbine are carried out. First of all, the working principle and force situation of the helical wind turbine are analyzed, and a rough analysis of its performance is carried out based on the flow pipe model through MATLAB programming. In this process, the influence law of blade rotation angle on tangential force coefficient of wind turbine is studied. Hence, a preliminary physical model of helical wind turbine is obtained, which is a rotor consisting of 3 blades with 120° rotation. Then, the helical wind turbine is simulated by Fluent software. In the process of numerical simulation, we choose the torque coefficient as the validation parameter to carry out the grid independent verification analysis at first. Secondly, the influence of wind speed on the aerodynamic performance of wind turbine is studied. Thirdly, the effects of a few key parameters on the wind turbine's aerodynamic performance and starting performance are researched. They are blade number, chord length, and ratio of height to diameter of the wind turbine. With the power coefficient as the evaluation index, the power coefficient of the wind turbine at different tip speed ratio is calculated by changing a parameter value of the wind turbine every time. Consequently, a set of optimized wind turbine structural parameters are obtained: Blade number is 3, chord length is 320 mm, and ratio of height to diameter is 1.6. At last, the wind energy utilization coefficients and torque coefficients of the optimized helical type wind turbine and an H type wind turbine with the same swept area are calculated by Fluent software, and the results are compared and analyzed. The results show that the torque coefficient of the helical wheel fluctuates less than 40% during its one-week rotation, and the torque coefficient is always positive, which is beneficial to start up. The torque coefficient of the H type wind turbine is negative at the azimuthal angle of 0 and 180°, showing poor starting performance. In addition, the overall coefficient of wind energy utilization of the helical wind turbine is also higher 2%-3% than that of the H type wind turbine, and especially in the case of low tip speed ratio, the gap is more obvious. These experimental results support the conclusion that a helical wind turbine has better aerodynamic performance and start-up performance.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Wind turbines
Controlled terms:Aerodynamics - Computer simulation - Energy utilization - MATLAB - Numerical models - Optimization - Rotation - Structural optimization - Torque - Turbine components - Turbomachine blades - Well pumps - Wheels - Wind - Wind power
Uncontrolled terms:Aero-dynamic performance - Comparative analysis - Helical type - Parameter optimization - Tangential force coefficient - Validation parameters - Vertical axis - Vertical axis wind turbines
Classification code:443.1 Atmospheric Properties - 525.3 Energy Utilization - 601.2 Machine Components - 615.8 Wind Power (Before 1993, use code 611 ) - 617 Turbines and Steam Turbines - 618.2 Pumps - 651.1 Aerodynamics, General - 723.5 Computer Applications - 921 Mathematics - 921.5 Optimization Techniques - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 2.00e+00% to 3.00e+00%, Percentage 4.00e+01%, Size 3.20e-01m
DOI:10.11975/j.issn.1002-6819.2017.22.034
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 37>
Accession number:20181104889849
Title:Silicon improving water conservation, yield and quality of tomato under alternate wetting and drying condition
Authors:Cao, Bili (1); Zhang, Zhihuan (1); Xu, Kun (1)
Author affiliation:(1) College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an; 271018, China
Corresponding author:Xu, Kun(xukun@sdau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:127-134
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Silicon plays an important role in improving crop drought resistance. The irrigation of alternate wetting and drying condition is a method that can achieve the goal of saving water resources and increasing production, through the inducement of the drought regulation potential by exposure of the plant roots to drought stress. Signal feedback control in the root zone can be performed adequately under alternate wetting and drying condition, and therefore physiological water conservation can be achieved. However, the conclusions on the effects of water-saving irrigation on the physiological characteristics of crops are different. With regard to the research about applicability of alternative irrigation method on tomato (Solanum lycopersicum L.) cultivation. In order to investigate the impacts of application of exogenous silicon on tomato under alternate wetting and drying condition, the effects of silicon on the silicon mass fraction in plant, plant growth, fruit yield and quality of tomato under alternate wetting and drying condition simulated. The simulation system was achieved by the use of a self-designed ebb-and-flow irrigation system. The results showed that the application of exogenous silicon in culture solution resulted in the increase of silicon mass fraction in tomato plants. The silicon mass fraction of tomato roots, stems, leaves and fruits increased by 494%, 444%, 246% and 631%, respectively. During the period of seedling stage and the period of flowering and fruit bearing stage of tomato, the irrigation of alternate wetting and drying condition can be used to control the growth and nurture strong seedlings. From the period of early fruiting stage to the period of later fruiting stage of tomato, especially fruit flourish stage, it is not appropriate to use the irrigation of alternate wetting and drying condition. Dry and wet alternation resulted in a serious decline in tomato production and a decline in lycopene mass fraction, vitamine C mass fraction, titratable acid mass fraction, but significantly improved other quality indicators of tomato fruit, such as soluble protein mass fraction, free amino acids mass fraction, soluble solid mass fraction, soluble sugar mass fraction, titratable acid mass fraction, fruit rigidity, sugar-acid ratio. Especially, sugar and acid ratio increased by 30%. The application of exogenous silicon can alleviate the adverse effects of alternate wetting and drying condition on fruit yield and quality in the late growth and development period of tomato. To this end, the combination of the irrigation of alternate wetting and drying condition and the application of exogenous silicon, in the promotion of stable production of tomatoes under the premise of high quality, can cause water conservation up to 23%. Based on this study, how exogenous silicon regulated the yield and quality of tomato under the condition of alternate wetting and drying was investigated, and the role of exogenous silicon in mediating changes of some physiological parameters of tomato planted under variable water conditions was made a thorough inquiry. The theoretical contents that refer to how exogenous silicon improved plant drought resistance were expanded. Irrigation method of alternate wetting and drying condition in tomato water-saving cultivation was further optimized. The result of this paper is of great significance to a reasonable water saving and to the improvement of the commodity rate of tomato.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Fruits
Controlled terms:Crops - Drought - Drying - Image quality - Irrigation - Physiological models - Physiology - Plants (botany) - Silicates - Silicon - Water conservation - Water resources - Wetting
Uncontrolled terms:Alternative irrigations - Dry and wet - Furits - Physiological characteristics - Physiological parameters - Water saving cultivations - Water-saving irrigation - Yield
Classification code:444 Water Resources - 461.9 Biology - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 821.3 Agricultural Methods - 821.4 Agricultural Products
Numerical data indexing:Percentage 2.30e+01%, Percentage 2.46e+02%, Percentage 3.00e+01%, Percentage 4.44e+02%, Percentage 4.94e+02%, Percentage 6.31e+02%
DOI:10.11975/j.issn.1002-6819.2017.22.016
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 38>
Accession number:20181104889844
Title:Design and experiment of sprinkler irrigation device with square spray field
Authors:Xing, Haonan (1); Yang, Qiliang (1); Yu, Liming (1); Liu, Xiaogang (1)
Author affiliation:(1) College of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming; 650500, China
Corresponding author:Yang, Qiliang(yangqilianglovena@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:84-91
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this research, the sprinkler irrigation device with square spray field was developed to solve the problem of overlapping irrigation and extraterritorial spraying of the circular spray field sprinkler. The device spray field can completely cover the square area of 30 m×30 m. We used the link mechanism and the cam to controls the elevation angle of the sprinkler in order to change the range to form a square area during the sprinkler irrigation. In the design process, we selected 20PY sprinkler, and expanded the sprinkler diameter to 8 mm. We determined the elevation angle of the sprinkler of 5°-30° by the experiment. The results showed that the rotational speed of the sprinkler was linearly related to the velocity of the elevation. We created solid model with solid works, and use solid works motion software to simulate the motion so that we can draw the outline of the cam. In the terms of the spray uniformity, it resulted in uneven spraying that the sprinkler range was constantly changing and the sprinkler unit time was kept constant during the sprinkler process. The device adjusted the sprinkler rotation speed by changing the resistance coefficient between cam roller and cam contact surface so that when the range was far away, the rotation speed was relatively slow, and when the range was closer, the rotation speed was slightly faster to adjust the sprinkler's shooting time in a variety of range. Thereby the spray uniformity was improved. When we calculated the spray duration, the cam profile was symmetric. As such, we can select a quarter of the cam as the object of study, and divided this part into 18 regions by angle, and the ratio of the sprayed area to the 18 regions was the ratio of these areas' spray duration. The work of the rocker arm fighting once was relatively stable. The work of the corresponding area was the product of the spray time, rocker strike frequency and the work of the rocker arm fighting once in the area. And we can set the equation with the corresponding regional's work and resistance coefficient to solve the resistance coefficient of roller and cam contact surface in this area. We took the 1/4 spray field to verify device performance in the experiment. The experimental results verified that the proximity between the spray field and the spray area, and the proximity was 92.06%. The sprinkler uniformity of the device was well, and the Christiansen uniformity of the sprinkler was 82.07% in the uniformity. In addition, the outside sprinkling irrigation quantity was also an important indicator of the test, and we regarded 15 m×15 m square outside the area of precipitation as the outside sprinkling irrigation quantity. The experiment showed that the ratio of the amount of the outside spray to the total spray was 1.32%. When we irrigated the edge of land, the outside sprinkling irrigation quantity amount from the device was decreased by 13.53% than the circular spray domain. The device avoided the overlapping of the circular spray field sprinklers, and the spray uniformity was high. At the same time, the device can effectively avoided the outside spray in the corner of land, thus improved the water use efficiency significantly. Our research provides a new concept and a method for the research and development of new sprinkler. The combined sprinkler and the spray situation in the impact of wind are still variables affecting effectives of sprinkler that needs to be studied.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Sprinkler systems (irrigation)
Controlled terms:Cams - Design - Hose - Irrigation
Uncontrolled terms:Research and development - Resistance coefficients - Spray area - Sprinkler irrigation - Sprinkling irrigation - Square - Uniformity - Water use efficiency
Classification code:601.3 Mechanisms - 619.1 Pipe, Piping and Pipelines - 821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods
Numerical data indexing:Percentage 1.32e+00%, Percentage 1.35e+01%, Percentage 8.21e+01%, Percentage 9.21e+01%, Size 8.00e-03m
DOI:10.11975/j.issn.1002-6819.2017.22.011
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 39>
Accession number:20181104889854
Title:Quantitative evaluation of macropore flow in purple soil of sloping cropland
Authors:Wang, Honglan (1, 2); Jiang, Shunyuan (2); Cui, Junfang (1); Tang, Xiangyu (1)
Author affiliation:(1) Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu; 610041, China; (2) Sichuan Academy of Chinese Medicine Sciences, Chengdu; 610041, China
Corresponding author:Cui, Junfang(jfcui@imde.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:167-174
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The importance of macropore flow as a preferential flow mechanism for infiltrating water and transport of solutes has been generally recognized during a couple of decades. Macropore flow plays significant roles in the structured soil, such as leading to more infiltration and thus reducing overland flow and rapidly transferring pesticides and other pollutants through the soil macropores into the groundwater. Due to its critical effect on field-scale soil water flow and transport of contaminants in soils, macropore flow is gaining more interest. In this study, soil samples were collected at depths of 0-20 cm and 20-40 cm from sloping cropland of purple soil, which are located at Yanting Agro-ecological Experimental Station of Purple Soil (105°27'E, 31°16'N), hilly central Sichuan, Southwest China. Using Br<sup>-</sup>tracer and simulated rainfall methods, lab-scaled disturbed and undisturbed soil column experiments were conducted to characterize the preferential transport behavior and evaluate the contribution of preferential flow based on simulations with the CXTFIT model. The breakthrough curves (BTCs) for each soil column were also obtained by analyzing the dynamics of Br<sup>-</sup>in the outflow. The integrated parameter, PFSP, defined as the ratio of extended quantity of BTCs due to preferential flow to extended quantity of BTCs caused by hydrodynamic dispersion and two-region effect, was calculated based on BTCs and CXTFIT datasets of the undisturbed soil columns. The BTCs of undistributed soil column showed an early breakthrough of Br<sup>-</sup>and also an upturned tail, indicating the presence of both preferential flow and matrix flow in studied soil. The preferential flow contributed 66.2%-68.5% of water discharge and 62.3%-66.1% of cumulative Br<sup>-</sup>discharge from undisturbed soil columns collected at the 0-20 cm depth, and at the 20-40 cm depth, their contributions was 0.2%-1.7% and 14.5%-20.5%, respectively. These implied that preferential flow made a much greater contribution to cumulative Br<sup>-</sup>discharge for the soils at the 0-20 cm depth compared to the soils at the 20-40 cm depth. Transport parameters of Br<sup>-</sup>were obtained by fitting its BTCs in the soil column with two-region model and CXTFIT software. It was found that the values of pore velocity and hydrodynamic diffusion coefficient for the soil at the depth of 0-20 cm were higher than those at 20-40 cm depth, while the retardation factor, with higher value indicating more preferential flow developed in the soil, showed contrast trend for the 2 depths. This was due to the fact that Br<sup>-</sup>quickly migrates with preferential flow through soil macropores, which may weaken the retardation effect. As for the dynamic watershed scale factor, the value was higher at the depth of 0-20 cm than that of 20-40 cm, indicating the higher percentage of flowing water in the soil column collected at 0-20 cm depth that has better developed preferential flow. The mass transfer coefficient value of the undisturbed soil column taken at 0-20 cm after plowing activity was the lowest, while the values were close among other soil columns. The PFSP value, which can ascertain the contribution of preferential flow out of other mechanisms, revealed that macropore flow made the biggest contribution to the extended quantity of BTCs, two-region effect made the second and hydrodynamic dispersion made the third, indicating PFSP can be a useful index to quantify the contribution extent of macropore flow.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Infiltration
Controlled terms:Flow of water - Fluid dynamics - Groundwater - Groundwater flow - Groundwater pollution - Hydrodynamics - Mass transfer - Rain - Runoff - Soil moisture - Soils
Uncontrolled terms:Experimental stations - Hydrodynamic dispersions - Integrated parameter - Macropore flow - Quantitative evaluation - Slope - Soil-column experiment - Transport parameters
Classification code:443.3 Precipitation - 444.1 Surface Water - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 631.1.1 Liquid Dynamics - 641.3 Mass Transfer - 931.1 Mechanics
Numerical data indexing:Percentage 1.45e+01% to 2.05e+01%, Percentage 2.00e-01% to 1.70e+00%, Percentage 6.23e+01% to 6.61e+01%, Percentage 6.62e+01% to 6.85e+01%, Size 0.00e+00m to 2.00e-01m, Size 2.00e-01m to 4.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.22.021
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
<RECORD 40>
Accession number:20181104889865
Title:Impact of unit width of swine bed and social hierarchy on behavior of pregnant sows
Authors:Li, Wei (1); Liu, Zuohua (1); Wang, Chaoyuan (2, 3); Li, Baoming (2, 3)
Author affiliation:(1) Chongqing Academy of Animal Sciences, Southwest Scientific observation station of Animal Housing Systems, Ministry of Agriculture, Chongqing; 402460, China; (2) Key Laboratory of Agricultural Engineering in Structure and Environment, College of Water Resources and Civil Engineering, China Agricultural University, Beijing; 100083, China; (3) Beijing Engineering Research Center for Animal Health 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:33
Issue:22
Issue date:November 15, 2017
Publication year:2017
Pages:248-254
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Free expression of pig behavior is considered to be an important index of animal welfare. The free beds developed by China Agricultural University, where the sows are freely access to, can act as partitions to reduce the aggression behavior due to feeding competing on one hand, and on other hand provide a better lying environment for the sows. Effects of the free beds on improving the thermal comfort of the sows were confirmed, while the design on the bed width is not specified yet. The objective of this study was to evaluate the impact of unit width of swine bed and social hierarchy on behavior of pregnant sows to provide fundamental information of the bed design. In total, eighteen sows at about four weeks after breeding were randomly allocated into three special stimulation pens, and each pen was assigned with six pregnant sows. Every pen was equipped with six units of water-cooled cover, and the unit widths were 600 mm, 700 mm and 800 mm, respectively. Based on the results of wins and defeats of each sow during the first 48 h after mixing, they were individually labeled as dominant, subordinate, or submissive. The sows ranked 1st to 2nd places were defined as dominant, 3rd to 4th as subordinate and 5th to 6th as submissive. The results showed that lying and feeding behavior of group-housed sows was greatly affected by unit width of the bed and their social hierarchy. Generally, the sows spent more time lying inside the beds as the width increasing, and total lying time of each sow spent in the 600 mm width unit was significantly less compared with the 800 mm unit (P<0.05). The average duration of each lying behavior for subordinate sows in the swine bed were remarkably less than that of submissive sows (P<0.05). No significant difference was found on the duration of lateral lying that the dominant and subordinate sows spent in the 700 mm unit (P>0.05). However, it was significant less than that of submissive sows (P<0.05). Frequency of aggression behavior happened in the 600 mm width unit were significantly less than those of the 700 or 800 mm width unit (P<0.05). The frequency of replacement behavior during feeding increased progressively with increasing the unit width, and significant difference among different width units was observed (P<0.01). Compared with submissive sows, the frequency of attack and replacement behavior initiated by dominant and subordinate sows were significant higher (P<0.05). The occupying percentage of the first feeding unit by dominant sows was 62.5%, 50.0% and 100.0% in the three pens, respectively. The findings suggest that 800 mm unit widths of the bed is helpful for the sows to perform lying behavior but go against the feeding behavior, and the favorable resources of lying and feeding were typically occupied by dominant sows. Based on the finding of this study, it is suggested to appropriately increase the free beds width for better lying behavior of the sows, and meanwhile to design a locking component attaching on the ending part of the bed to reduce the aggressive behavior between the sows during feeding in the future work.<br/> © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Behavioral research
Controlled terms:Animals - Experiments - Feeding - Locks (fasteners)
Uncontrolled terms:Animal welfare - Feeding behavior - Group-housed sows - Locking components - Pregnant sows - Social hierarchy - Swine bed - Unit width
Classification code:691.2 Materials Handling Methods - 901.3 Engineering Research - 971 Social Sciences
Numerical data indexing:Percentage 1.00e+02%, Percentage 5.00e+01%, Percentage 6.25e+01%, Size 6.00e-01m, Size 7.00e-01m, Size 8.00e-01m, Time 1.73e+05s
DOI:10.11975/j.issn.1002-6819.2017.22.032
Database:Compendex
Compilation and indexing terms, Copyright 2018 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
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