<RECORD 1>
Accession number:20194607670301
Title:Crops identification in Kaikong River Basin of Xinjiang based on time series Landsat remote sensing images
Title of translation:基于时序Landsat遥感数据的新疆开孔河流域农作物类型识别
Authors:Wang, Xiaoqin (1, 2, 3); Qiu, Pengxun (1, 2, 3); Li, Yali (1, 2, 3); Cha, Mingxing (1, 2, 3)
Author affiliation:(1) Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education, Fuzhou University, Fuzhou; 350108, China; (2) National & Local Joint Engineering Research Center of Satellite Geospatial Information Technology, Fuzhou; 350108, China; (3) Academy of Digital China (Fujian), Fuzhou; 350108, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:180-188
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The crops information of area and planting distribution has a great influence on the production management and policy making of the agricultural sector. Obtaining this information timely and accurately is not only the main content of agricultural remote sensing, but also the important reference for adjusting planting and estimating crop yield. At present, crop classification based on time series data mainly adopts medium and low spatial resolution images with long time series, while there are a large number of mixed pixels in low and medium spatial resolution images, which limits the classification accuracy of crops. The Normalized vegetation Index (NDVI) is mainly used in the selection of features of crop classification, while the application of other features selection is relatively few. With the rapid development of remote sensing technology, medium and high spatial resolution remote sensing data is becoming more and more abundant. How to make full use of medium and high spatial resolution images for crop classification has great research significance. This paper uses the Landsat7 ETM+ and Landsat8 OLI time series datasets of 2016 to extract crops from Kaikong River agricultural area of Xinjiang based on time-weighted dynamic time warping. It mainly includes pear, wheat, pepper, cotton and so on. According to the sample points collected in the field investigation, the sample database was established, and the NDVI values and PCA1 values of all kinds of samples were extracted at different time phases, that the standard NDVI sequences and PCA1 sequences were generated. In this paper, three classification schemes were designed and compared to explore the effect of DTW method on the recognition ability of different crops by using medium and high spatial resolution time series images, and to evaluate the time weight factor and the influence of NDVI combined with the first principal component (PCA1) on the classification results of crops. The principle of DTW algorithm classification was to calculate the distance value between the pixel sequence to be divided and the standard sequence of each crop. The smaller the distance value is, the higher the similarity between the sequences is. The crop type of the pixel to be divided was determined by comparing the distance value. However, because of its flexibility, the algorithm is prone to abnormal matching, and the introduction of time weight can limit this phenomenon very well. In this paper, DTW and TWDTW algorithms were used to classify crops based on NDVI data, and the classification accuracy of the two methods were 65.69% and 82.68%, respectively. It showed that the addition of time weight factor could effectively avoid the abnormal matching phenomenon of DTW algorithm and improve the ability of the algorithm to identify different crops. With the combination of NDVI and PCA1, the classification accuracy of TWDTW had increased by 2.61 percentage points, and the phenomenon of the misclassification had significantly reduced. It explained that PCA1 could further expand the difference between crops and improve the classification accuracy. The experimental results showed that the TWDTW algorithm could obtain a satisfactory classification result in the case of less high spatial resolution data. It proved that the TWDTW algorithm has great application potential in the time of more and more high- spatial resolution images, and provides a reference for fine identification of crops based on time series data.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Classification (of information)
Controlled terms:Crops - Image resolution - Pixels - Principal component analysis - Remote sensing - Time series - Time series analysis - Vegetation
Uncontrolled terms:Agricultural remote sensing - Classification accuracy - Dynamic time warping - First principal components - High spatial resolution images - Remote sensing technology - Spatial resolution images - Vegetation index
Classification code:716.1 Information Theory and Signal Processing - 821.4 Agricultural Products - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 6.57e+01%, Percentage 8.27e+01%
DOI:10.11975/j.issn.1002-6819.2019.16.020
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 2>
Accession number:20194607667559
Title:Analysis of influencing factors of cultivated land change in Chinese urban agglomerations considering spatially inter-city interactions
Title of translation:空间交互视角下中国城市群耕地变化影响因素分析
Authors:Liu, Dianfeng (1); Zhou, Boyuan (1); He, Jianhua (1); Kong, Xuesong (1); Liu, Yaolin (1)
Author affiliation:(1) School of Resource and Environmental Sciences, Wuhan University, Wuhan; 430079, China
Corresponding author:He, Jianhua(hjianh@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:274-283
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As the basic means of agricultural production, cultivated land plays an irreplaceable role in ensuring food security and promoting social and economic development. With the enhancement of urban interactions in space, the land use conflicts between urban development and agricultural protection have been intensified due to the diversified land demands caused by population agglomeration, industrial restructuring and infrastructure construction. Exploring the impacts of urbanization on cultivated land change has become a hot issue in China at present. Most of current studies have paid increasing attentions to the relationship between the growth of individual cities and cultivated land occupation, and few of them attempted to reveal the driving factors of cultivated land change from the perspective of spatial interaction of cities. Urban agglomeration is the main form of new urbanization in China. It is crucial to identify the distribution of cultivated land change and its driving factors from the perspective of urban agglomeration. In this paper, we measured the spatial connection of urban agglomerations based on the gravity equation and the urban flow intensity model, and then explored influencing factors of cultivated land conversion at the scales of individual cities and urban agglomerations during the period of 2005-2015 using a multilevel linear regression model. The research results show that the area of cultivated land in the major urban agglomerations has dropped sharply by 17 572.8 square kilometers in the decade from 2005 to 2015. The situation of cultivated land protection is grim. Then it shows significant scale effects and regional heterogeneity of cultivated land change in urban agglomerations. At the urban scale, the change of cultivated land is positively correlated with agricultural population, industrial economy and agricultural science & technology development, whereas negatively correlated with the growth of foreign investment and the expansion of construction land. At the scale of urban agglomeration, both indicators of spatial connection have a negative correlation with cultivated land change. Moreover, remarkable regional differences of influencing factors of cultivated land change exist between coastal and inland China. Comparing the regional differentiation of the degree of influence of outward functional forces, it can be found that the spatial interaction of coastal urban agglomerations has a more positive effect on the protection of cultivated land than the inland urban agglomerations with relatively backward development, and the negative impact is also smaller than that of inland urban agglomerations. The comparison with other models verified the effectiveness of the multilevel linear regression approach to reveal the influencing mechanism of cultivated land change on different scales. And the result of null model has proved the necessity and rationality in the research perspective of spatial interactions between cities. As a word, the strengthening of spatial interaction in urban agglomerations under rough development will obstruct the protection of cultivated land. In this case, controlling industrialization and urbanization reasonably, concerning the scale effects and regional heterogeneity, improving laws and regulations, correcting the rough development path, and improving land use efficiency might be the critical roads to relieve conflicts between development of urban agglomerations and protection of cultivated land.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Urban growth
Controlled terms:Agglomeration - Agriculture - Economic and social effects - Food supply - Industrial economics - Investments - Land use - Laws and legislation - Models - Population statistics - Regression analysis
Uncontrolled terms:Agricultural productions - Cultivated lands - Hierarchical linear models - Industrial restructuring - Infrastructure construction - Linear regression models - Social and economic development - Spatial interaction
Classification code:403 Urban and Regional Planning and Development - 403.1 Urban Planning and Development - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 911.2 Industrial Economics - 922.2 Mathematical Statistics - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2019.16.031
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 3>
Accession number:20194607670418
Title:Design and evaluation method of testing bench for spray boom suspension systems
Title of translation:大型喷杆悬架系统测试平台设计与评价方法研究
Authors:Cui, Longfei (1); Xue, Xinyu (1); Le, Feixiang (1); Ding, Suming (1)
Author affiliation:(1) Nanjing Institute of Agricultural Mechanization, Ministry of Agriculture and Rural Affairs, Nanjing; 210014, China
Corresponding author:Xue, Xinyu(735178312@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:23-31
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Boom suspension is an important device that affects the uniformity of droplet deposition distribution on the sprayers, but the field testing and evaluation of the stability of the suspension system are affected by a number of random factors, such as test topography, soil properties, driving proficiency, etc. Therefore, a set of boom stability indoor test platform was designed, including a 6 degrees of freedom chassis motion simulation platform, terrain relief simulation platform and NI PXI-based synchronous trigger measurement and control system, and a test method for quantitative evaluation of suspension stability was proposed. The 6 degrees of freedom platform was designed based on Stewart parallel mechanism, which had special field excitation spectrum reproducing function and excitation spectrum database for the dynamic simulation of the boom, and it could be used to simulate the motion of the chassis in the field of the sprayer. The control system of terrain undulation simulation test rig adopted an upper-lower structure, took NI PXI control computer as the upper computer. The DSP microcomputer was used as the lower computer to receive the position instructions sent by the upper computer, control the rotation of the servo motor, and realize the simulation of ground undulation through the ball screw. In order to accurately simulate the real field working environment, the motion posture signal of the chassis and the terrain elevation data on both sides of the boom were collected at the sprayer work site. During the sprayer working in the field, a dual GPS aided inertial attitude measurement system was used to collect the motion signal of the sprayer chassis, and 2 ultrasonic sensors were installed on both sides of the boom, then the height data of the ground were measured along the direction of the sprayer. Considering the difference between the installation position of the sensor and the ideal operating height of different spray rods, the original Hockley index had been revised to describe the performance of the spray boom suspension system together with standard deviation and coefficient of variation, which made up for their limitations. A 28 m boom was tested under different working conditions such as no suspension, passive suspension, active suspension (including active roll control system and active boom arm control system) by using the developed test system, the coefficient of variation of multiple sets of repeated test results was less than 5.91%. The HI<inf>C</inf> index of the boom was 21.60 when using a rigid connection, 68.37 when using passive suspension, and 89.18 of the boom when using active rolling control system, and the HI<inf>C</inf> index was 92.83 when using active boom arm control system. The results show that the test platform and evaluation index can clearly distinguish the performance of different suspension systems, and have universality for different spray boom. The test platform developed in this study can be considered a potential basis of a standardized protocol for active boom suspension as well as for the definition of performance limits. The research provides important testing and evaluation methods for large booms and balanced suspensions.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Active suspension systems
Controlled terms:Ball screws - Chassis - Computer control systems - Degrees of freedom (mechanics) - Design - Excited states - Hybrid integrated circuits - Landforms - Mechanisms - Mechanization - Simulation platform - Soil surveys - Soil testing - Spraying - Suspensions (components) - Topography
Uncontrolled terms:Active suspension - Boom sprayer - Evaluation method - Passive suspension - Test platforms
Classification code:481.1 Geology - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 662.4 Automobile and Smaller Vehicle Components - 714.2 Semiconductor Devices and Integrated Circuits - 723.5 Computer Applications - 732.1 Control Equipment - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science
Numerical data indexing:Percentage 5.91e+00%, Size 2.80e+01m
DOI:10.11975/j.issn.1002-6819.2019.16.003
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 4>
Accession number:20194607670343
Title:Parameter calibration of wheat flour for discrete element method simulation based on particle scaling
Title of translation:基于颗粒缩放的小麦粉离散元参数标定
Authors:Li, Yongxiang (1); Li, Feixiang (1); Xu, Xuemeng (1); Shen, Changpu (1); Meng, Kunpeng (1); Chen, Jing (1); Chang, Dongtao (2)
Author affiliation:(1) School of Mechanical and Electrical Engineering, Henan University of Technology, Zhengzhou; 450001, China; (2) Henan Jingu Industrial Co., Ltd., Zhengzhou; 450001, China
Corresponding author:Xu, Xuemeng(xuxuemeng7439@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:320-327
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to obtain the precise parameters for the wheat flour discrete element simulation, the actual repose angle of wheat flour was firstly measured by injection method. The experimental material was ordinary wheat flour, which average particle diameter is 0.212 mm and went through a 70-mesh standard sieve. Refer to GB 16913.5-1997, the inner diameter of the used funnel was 5 mm, the taper was 60°, and the cylindrical chassis was 80 mm in diameter. The result indicated the repose angle of the wheat flour was 52.37°, which was average value of five experiments. The irregular wheat flour was simplified into soft spherical particles, and then those particles with the size of 0.212 mm were enlarged to 1.2 mm for simulation thanks to the particle scaling and dimensional analysis, during those analyses, the 3D modeling and simulation were finished by SolidWorks and EDEM software respectively. Considering the bonding characteristics between wheat flour particles, the "Hertz-Mindlin with JKR" contact model was selected to calibrate the contact parameters of wheat flour for discrete element simulation with the repose angle as a reference. Then, through the design-expert software, the parameters that have significant influence on the repose angle of wheat flour by Plackett-Burman test design are surface energy JKR, the rolling friction coefficient for wheat flour-wheat flour, the static friction coefficient for wheat flour-stainless steel. According to the significance parameters designed and screened by the Plackett-Burman test, the steepest ascent test was carried out so that it could be quickly close to the optimal value. The steepest ascent test was stared at the center of the Plackett-Burman test and the step size was determined by the regression coefficients obtained from the test. The Box-Behnken test was then carried out by selecting the low, medium and high levels of the significant parameters according to the results of steepest ascent test and the design principle of response surface, and then the three mediate points were selected to evaluate the errors. At last, the quadratic polynomial model for the repose angle and the significant parameters was successfully established and optimized by the Box-Behnken test. The analysis of variance (ANOVA) of the quadratic polynomial model showed that this model was significant and the lack-of-fit term was non-significant, which means the model can be applied to determine whether the parameters combination is the best. However, some terms in the quadratic polynomial model were non-significant. Therefore, a modified regression model was established by deleting those non-significant terms. The ANOVA of the modified model showed all of the terms were desirable, and the first-order term of those 3 significant parameters, the interactive term of the wheat flour-wheat flour static friction coefficient and JKR surface energy, and the interactive term of the wheat flour-wheat flour rolling friction coefficient and JKR surface energy had a significant effect on the repose angle. The best combination of the significant parameters could be achieved when the JKR value was 0.157, the rolling friction coefficient of wheat flour-wheat flour was 0.25, and the static friction coefficient of wheat flour-stainless steel was 0.58. Finally, the rest simulation test was carried out with the optimal combination of parameters obtained from the experiments, which showed that the repose angle of the simulation test was 52.69°, the error of the repose angle measured by the test was 0.61%, and there was no significant difference between the simulation results and the actual test values. In conclusion, the contact parameters obtained based on the particle scaling calibration can be used for wheat flour discrete element simulation which was shown by the experimental results.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Analysis of variance (ANOVA)
Controlled terms:3D modeling - Agricultural products - Calibration - Finite difference method - Interfacial energy - Particle size - Particle size analysis - Polynomials - Regression analysis - Software testing - Stainless steel - Stiction - Surface testing - Testing
Uncontrolled terms:Bonding characteristics - Discrete element method simulations - Discrete element simulation - Experimental materials - Parameter calibration - Regression coefficient - Repose angles - Static friction coefficient
Classification code:545.3 Steel - 723.5 Computer Applications - 821.4 Agricultural Products - 921.1 Algebra - 921.6 Numerical Methods - 922 Statistical Methods - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 6.10e-01%, Size 1.20e-03m, Size 2.12e-04m, Size 5.00e-03m, Size 8.00e-02m
DOI:10.11975/j.issn.1002-6819.2019.16.035
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 5>
Accession number:20194607670412
Title:Rural landscape classification based on combination of perception elements and sensing data
Title of translation:感知要素与遥感数据结合的乡村景观分类研究
Authors:Zhang, Yibin (1, 2); Hao, Jinmin (1, 2); Huang, An (1, 2); Zu, Jian (1, 2)
Author affiliation:(1) College of Land Science and Technology, China Agricultural University, Beijing; 100193, China; (2) Key Laboratory for Agricultural Land Quality Monitoring and Control, Ministry of Natural Resources, Beijing; 100193, China
Corresponding author:Hao, Jinmin(jmhao@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:297-308
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Landscape classification is the precondition and basis for the description, mapping and evaluation of regional landscape differences. This study took Fourth Tuan Town and Huaiqiao Town, Quzhou County, Hebei Province as the study area. Following the principles and theoretical basis of landscape architecture, landscape ecology and taxonomy, the rural landscape was classified by using the method of combining subjectivity and objectives. Among them, the objective classification method was designed based on high-resolution remote sensing images, topographic data, soil data and other multivariate geographic data, and kernel density analysis method. The subjective classification method was designed based on the cluster analysis method and the visual landscape, which obtained from the field survey in the study area combining the image landscape. The sources of visual landscape were extracted from the artistic conception of the rural landscape description in the famous Chinese pastoral poems. The results showed that: this study constructs a bottom-up rural landscape classification system, which divides the landscape types of the study area into 3 rural landscape groups, 4 rural landscape areas and 55 rural landscape categories, as well as 108 rural landscape elements. The spatial relations among rural landscape groups, landscape area, landscape types and landscape elements be explained. The results could provide theoretical and practical basis for rural landscape planning and design and beautiful rural construction in the development strategy of rural revitalization in the study area, as well as other similar region in China.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Rural areas
Controlled terms:Cluster analysis - Ecology - Image analysis - Remote sensing
Uncontrolled terms:Classification methods - Classification technique - Cluster analysis methods - High resolution remote sensing images - Landscape architecture - Objectives - Rural landscapes - Subjectivity
Classification code:454.3 Ecology and Ecosystems - 723 Computer Software, Data Handling and Applications
DOI:10.11975/j.issn.1002-6819.2019.16.033
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 6>
Accession number:20194607667580
Title:Evaluation research of physical characteristics of hybrid rice buds based on principal component analysis
Title of translation:基于主成分分析的杂交稻芽种物理特性评价研究
Authors:Chen, Lintao (1, 2); Ma, Xu (1, 2); Cao, Xiulong (1); Wen, Zhicheng (1); Ji, Chuandong (1); Li, Hongwei (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou; 510642, China; (2) Engineering Research Center of Guangdong for Rice Transplanting Technology and Equipment, Guangzhou; 510642, China
Corresponding author:Ma, Xu(maxu1959@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:334-342
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China possesses a wide area of rice cultivation. The rice planting system is complex and differential from different area, such as single season, double season. The kinds of planting rice are various, mainly consisting of indica and japonica rice, and which also are divided into conventional rice, hybrid rice and super hybrid rice, and the physical characteristic between different planting rice is significant or non-significant. In recent years, the research on hybrid rice seeds mainly focuses on variety selection, identification and promotion, nutritional value and processing quality evaluation, physical property measurement, key parameter calibration of bud seed discrete elements and rapid non-destructive classification among rice varieties. The research on the physical property evaluation of rice seeds currently lacks a kind of objective, scientific, effective and practical evaluation methods. The physical properties of hybrid rice generally have many parameters, such as 1 000-grain weight, density, water content, geometric size, porosity, tribological properties, rheological properties, thermal properties, optical properties, electrical properties and pulverization properties. The research and evaluation of the physical characteristics of hybrid rice buds are closely related to the mechanized production of rice. In order to systematically study and quantitatively evaluate the physical characteristics of hybrid rice buds, 9 kinds of hybrid rice produced in south China area were selected as raw materials to determine eight physical indexes, including moisture content, 1 000-grain weight, sliding friction angle, angle of repose α, angle of repose β, the bud length, the three-axis arithmetic mean particle size and the hardness. The principal component analysis method was employed to simplify the physical property index and establish the scientific evaluation system, and the comprehensive score of each sample was obtained. The results showed that the physical index of different samples was significantly different, and the correlation between the different physical properties of the samples was also represented. The 1 000-grain weight was significantly positive correlated with the angle of repose α and the angle of repose β; the triaxial arithmetic mean particle size was positive correlated between the angle of repose α and the angle of repose β remarkably; the angle of repose α is also obviously positive correlated with the angle of repose β. 1 000-grain weight was positively correlated with water content, triaxial arithmetic mean particle size and sliding friction angle; water content was positively correlated with bud length; bud length was positively correlated with resting angle α, resting angle β and triaxial arithmetic mean particle size. Principal component analysis method was utilized to extract the first three principal component factors, and the cumulative contribution rate reached 80%. The first three principal component factors could represent most of the original eight physical indexes with well representativeness and objectivity, and obtained the evaluation formula Z=0.422Z<inf>1</inf>+0.205Z<inf>2</inf>+0.178Z<inf>3</inf> to calculate the comprehensive score of the physical characteristics of hybrid rice buds. In this study, the physical characteristics of hybrid rice buds were comprehensively evaluated based on principal component analysis method, which provided a new method for the scientific evaluation of the physical characteristics of hybrid rice buds, and also provided theoretical data basis for the design and optimization of operating parameters of precision rice seeder in the future.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Quality control
Controlled terms:Agricultural products - Correlation methods - Cultivation - Friction - Hybrid materials - Optical properties - Parameter estimation - Particle size - Particle size analysis - Petroleum reservoir evaluation - Physical properties - Principal component analysis
Uncontrolled terms:Contribution rate - Design and optimization - Hybrid rice - Physical characteristics - Principal component analysis method - Research and evaluation - Scientific evaluations - Tribological properties
Classification code:512.1.2 Petroleum Deposits : Development Operations - 741.1 Light/Optics - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 8.00e+01%
DOI:10.11975/j.issn.1002-6819.2019.16.037
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 7>
Accession number:20194607667578
Title:Effects of ice temperature or chilled storage on quality and moisture migration of yak meat
Title of translation:冰温或冷藏对牦牛肉贮藏品质及水分迁移的影响
Authors:Gu, Xuedong (1); Sun, Shuguo (1, 2); Yang, Feiyan (2); Li, Beiping (2); Yang, Lin (1); Luo, Zhang (1)
Author affiliation:(1) Food Science College, Tibet Agriculture & Animal Husbandry University, Nyingchi; 860000, China; (2) Faculty of Food Science and Engineering, Center South University of Forestry and Technology, Changsha; 410004, China
Corresponding author:Luo, Zhang(luozhang1759@sohu.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:343-350
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the storage quality of yak meat from the molecular level, this study evaluated the effects of ice temperature (-2℃) and chilled (0℃) storage on the change of sensory quality, malondialdehyde content, the total bacterial number, and color value of fresh yak meat. Low-field nuclear magnetic resonance (LF-NMR) was used to study the moisture migration in yak meat during storage. Fourier transform infrared spectroscopy (FTIR) was applied to investigate the structural protein changes in yak meat during storage. The results showed that the sensory quality of fresh yak meat after 24 days of storage at -2℃ was still kept the secondary freshness according to Chinese national standard, the total bacterial number was 5.12 lg(CFU/g). But the sensory quality of fresh yak meat after 18 days of storage at 0°C reached the secondary freshness with the total bacterial number of 5.25 lg(CFU/g).The quality deterioration was found in yak meat after 24 days of storage at 0℃, the total bacterial number reached 6.28 lg(CFU/g). The color value (a* value) of fresh yak meat firstly rose and then decreased, but the color value of yak meat stored at -2℃ exhibited fewer changes than test samples stored at 0℃. The results showed that the content of malondialdehyde in fresh yak beef increased significantly with the prolongation of storage time. The malondialdehyde content in yak meat stored at 0℃ increased faster than that stored at -2℃. Those data indicated that the ice temperature (-2℃) has a better efficacy of storage and preservation for fresh yak meat. At the same time, the combined water pT<inf>21</inf> in chilled fresh yak meat was similar to that of pT<inf>22</inf> under the different storage conditions, and the difference was not significant (P>0.05). The non-flowing water pT<inf>23</inf> in fresh yak meat stored at -2℃ fluctuated less than that stored at 0℃. The change of free water pT<inf>24</inf> was opposite to that of non-flowing water. Under different storage conditions, the relaxation times of yak meat T<inf>21</inf>, T<inf>22</inf>, and T<inf>24</inf> were corresponded to the combined water and free water, respectively. The combined water in yak meat stored at -2℃showed fewer changes than that of samples at 0℃. This indicated that ice temperature (-2℃) storage were more conducive to maintaining the interaction of water molecules with other biological macromolecules. These data indirectly revealed that the ice temperature (-2℃) storage has a greater storage and preservation effect on the fresh yak meat. The comprehensive analysis showed that compared with refrigeration conditions, the combination of water and protein molecular of the yak beef was more stable than that of samples under ice temperature conditions, which was more favorable for maintaining physiological and biochemical parameters for meat quality determination. Therefore, the ice temperature storage used for meat preservation was better than the chilled storage. The experiment provided a new reference method in the research of the storage and preservation of meat.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Meats
Controlled terms:Aldehydes - Color - Deterioration - Digital storage - Energy storage - Fourier transform infrared spectroscopy - Ice - Magnetic storage - Moisture - Molecules - Nuclear magnetic resonance - Physiological models - Plants (botany) - Proteins - Quality control
Uncontrolled terms:Biological macromolecule - Chinese national standard - Comprehensive analysis - Lipid oxidation - Low field nuclear magnetic resonance (LF NMR) - Protein secondary structure - Quality deteriorations - Temperature conditions
Classification code:525.7 Energy Storage - 722.1 Data Storage, Equipment and Techniques - 741.1 Light/Optics - 801 Chemistry - 804.1 Organic Compounds - 822.3 Food Products - 913.3 Quality Assurance and Control - 931.3 Atomic and Molecular Physics - 951 Materials Science
Numerical data indexing:Age 4.93e-02yr, Age 6.58e-02yr, Temperature 2.73e+02K
DOI:10.11975/j.issn.1002-6819.2019.16.038
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 8>
Accession number:20194607668043
Title:Analysis of surface water changes and driving force in Yellow River Delta from 1986 to 2016
Title of translation:1986-2016年黄河三角洲地表水体变化及其驱动力分析
Authors:Li, Yunlong (1, 2); Kong, Xianglun (1); Han, Mei (1); Wang, Min (1, 2); Pan, Bin (1); Wei, Fan (1); Huang, Shuping (2)
Author affiliation:(1) College of Geography and Environment, Shandong Normal University, Jinan; 250014, China; (2) School of History and Social Development, Qilu Normal University, Jinan; 250020, China
Corresponding author:Han, Mei(hanmei568568@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:105-113
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Surface water played an extremely important role in the formation of Yellow River Delta, ecosystem evolution and social and economic development. In this paper, the combination of threshold method and manual vectorization are used to obtain the distribution of surface water of Yellow River Delta in 1986, 2001 and 2016. The trajectory analysis method is used to construct the transformation trajectory of surface water and analyze the evolution trend of the trajectories. The driving factor index system for the evolution of surface water in Yellow River Delta is constructed, from three aspects of natural environment socio-economic and geographical location. According to the trajectory of surface water transformation, the multi-class logistic regression model was used to analyze the genesis and analyze the driving mechanism of surface water evolution within 30 years. The results show that: 1) From 1986 to 2016, the surface water area of the Yellow River Delta increased by 1 161.53 km<sup>2</sup>, except for river showing a decrease, which was transferred to 63.32 km<sup>2</sup>, and decreased by 33.49 km<sup>2</sup>. Reservoir, pond and salt and aquaculture pond all showed an increasing trend and increased by 84.88, 63.82 and 1 046.33 km<sup>2</sup>, respectively. Unused land to the salt pond culture pond is the largest type of change in the study area. Construction land and pond are the main source of reservoir increase, and the abandonment of small reservoirs is the main way to reservoir reduce. The mutual transformation between cultivated land and pond is the most important form of trajectory transformation in the study area. Unutilized land is the main source of expansion of the salt and aquaculture pond, and farm land is the main flow of its reduction. 2) Logistic regression analysis found that the driving forces of different types evolved differently. Geographical location is the main factor affecting reservoir evolution. Distance from coastline and Distance from township are the leading driving factors for transforming into reservoir. Distance from township is the leading driving force for transforming from reservoir. The evolution of salt pond culture ponds is influenced by socio-economic and location. Aquatic production, population density, distance from city center, distance from Yellow River and gross national product are the main drivers of the transforming into salt and aquaculture pond. Distance from city center has become the dominant factor in controlling the transforming from salt and aquaculture pond in the study area. The conversion of pit pond is affected by location and socio-economic. Distance from townships, population density, and distance from coastline are the main driving factors. In general, the surface water in Yellow River Delta showed an increasing trend from 1986 to 2016, and due to the different types and effects of surface water, the evolution characteristics and driving forces of surface water show significant differences. Natural factors have little impact on the surface water bodies of the Yellow River Delta. Location factors and socio-economic factors are the main influencing factors for surface water changes in Yellow River Delta.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Reservoirs (water)
Controlled terms:Agriculture - Aquaculture - Ecology - Economic and social effects - Economics - Lakes - Location - Population distribution - Population dynamics - Population statistics - Regression analysis - Rivers - Surface waters - Trajectories
Uncontrolled terms:Analysis of surface waters - Ecological evaluation - Evolution characteristics - Logistic regression analysis - Multi-class logistic regressions - Social and economic development - Surface water transformation - Yellow River delta
Classification code:405.3 Surveying - 441.2 Reservoirs - 444.1 Surface Water - 454.3 Ecology and Ecosystems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 922.2 Mathematical Statistics - 971 Social Sciences
Numerical data indexing:Age 3.00e+01yr, Area 1.62e+08m2, Area 3.35e+07m2, Area 4.63e+07m2, Area 6.33e+07m2
DOI:10.11975/j.issn.1002-6819.2019.16.012
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 9>
Accession number:20194607670297
Title:Design of ordered fertilizer device for bagged slow-release fertilizer
Title of translation:袋装缓控释肥有序排肥装置设计
Authors:Xie, Fangping (1, 2, 3); Liu, Minzhang (1); Yang, Mimi (1); Liu, Dawei (1, 2, 3); Wang, Xiushan (1, 3); Ren, Shuguang (1, 2, 3)
Author affiliation:(1) College of Engineering, Hunan Agriculture University, Changsha; 410128, China; (2) Collaborative Innovation Center of Southern Chinese Grain and Oilseed, Changsha; 410128, China; (3) Hunan Key Laboratory of Intelligent Agricultural Machinery and Equipment, Changsha; 410128, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:40-49
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:By controlling the release rate of fertilizer nutrients, bagged slow-release fertilizer can reduce the amount of fertilizer application. In the past, the fertilization method of bagged slow-release controlled release fertilizer was mainly manual, high cost and low efficiency. In order to realize the mechanized application of bagged slow-release fertilizer, we measured its basic physical parameters and mechanical properties, based on the measured data, we had studied the ordered queuing mechanism, residual material cleaning and quantitative application of bagged slow-release fertilizer, designed a bagged slow-release fertilizer ordered fertilizer device, which was composed of an eccentric separating mechanism, a cleaning mechanism, a fertilizer discharging mechanism and a power transmission mechanism. We performed kinematic analysis on the eccentric separation mechanism, calculated the motion parameters of the vibrating plate by vibration principle, found out the factors affecting the movement of the bagged fertilizer, and verified the synonym of the motion parameters. Theoretical analysis showed that the eccentric speed should be in the range of 493.69-618.79 r/min. For the pre-test surface, the flexural strength of the fertilizer was suitable for mechanized discharge in the range of 198-318.34 mN•cm, took the eccentric wheel speed, the brush wheel speed and the distance between the brush wheel and the scraper conveyor belt as the influencing factors. The orthogonal index test was carried out with qualified rate, miss rate and repeat rate as the evaluation indicators. It established a mathematical model of influencing factors and evaluation indicators. We analyzed the response surface map, drove the relationship between influencing factors affecting the trend of the qualification index and the interaction of influencing factors. We used the Design-Expert software, and the optimal combination of parameters was obtained: the eccentric wheel speed was 600 r/min, the brush wheel speed was 95 r/min, and the distance between the brush wheel and the squeegee conveyor belt was 18 mm. Through the verification test, the average value of the qualified rate of was 82%, the average value of the miss rate was 9.33%, and the average value of the repeat rate was 8.67%. Main reason for fertilizer miss was that the fertilizer was oscillated by the eccentric separation mechanism, and its surface was not completely attached to the conveyor belt. When the brush wheel rotated, it was going to "returned" by friction. The main reason for fertilizer repeat was that the rate of vibration of the fertilizer was slightly larger than that of the conveyor belt, and the contusion between the brush wheel and the conveyor belt was prone to occurr, led to the discharge of fertilizers. The faster the eccentric wheel speed, the better the flow performance of the bagged fertilizer on the vibrating plate surface, which could effectively reduce the miss rate. At the same time, it was easy to cause congestion between the brush wheel and the conveyor belt, resulting in an increase in the repeat rate. This study provides a reference for the development of bagged slow-release fertilizers for the ordered application of fertilizers, however, the effect of brush length on cleaning effect is worth further study.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Fertilizers
Controlled terms:Belt conveyors - Cleaning - Design - Mechanisms - Mechanization - Optimization - Speed - Vibration analysis - Wheels
Uncontrolled terms:Application of fertilizers - Controlled-release fertilizers - Degradable packaging bag - Evaluation indicators - Fertilizer applications - Ordered - Separation mechanism - Slow release fertilizers
Classification code:601 Mechanical Design - 692.1 Conveyors - 802.3 Chemical Operations - 804 Chemical Products Generally - 921.5 Optimization Techniques
Numerical data indexing:Percentage 8.20e+01%, Percentage 8.67e+00%, Percentage 9.33e+00%, Rotational_Speed 4.94e+02RPM to 6.19e+02RPM, Rotational_Speed 6.00e+02RPM, Rotational_Speed 9.50e+01RPM, Size 1.80e-02m, Torque 1.98e-03N*m to 3.18e-03N*m
DOI:10.11975/j.issn.1002-6819.2019.16.005
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 10>
Accession number:20194607670261
Title:Mathematical model of fruit's aerial movement in vibration response
Title of translation:果实振动响应时的空中运动数学模型
Authors:Xu, Linyun (1); Liu, Guanhua (1); Xuan, Yan (1); Zhou, Jie (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:206-213
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:High-speed photography which can take a lot of pictures catching the movement state of the fruit in rapid motionin during a very short time has become the mainstream method to study fruit motion. The mean limitation of the existing researchs is that tracking movement of one feature point on fruit surface can not reflect the exact movement of the fruit,especially swing and rotation. In this paper, We divided the spatial motion of the fruit into the translation, swing and rotation of the instantaneous attitude corresponding fruit spatial motion and proposed a method to calculate 3 kinds of spatial motion of fruit by 3 feature points on fruit surface. First, we constructed a coordinate system called characteristic point coordinates with 2 space vectors from 3 surface feature points. Second, we assumed that the fruit was a rotating body. Then, the coordinate system which we called the conjoined base coordinate system was established with the origin of the joint of the fruit stalk, in which the Z-axis coincides with the rotation axis of the fruit. The movement of the fruit was represented by the movement of the conjoined base coordinate origin. The swing of the fruit was represented by the swing of the Z-axis of the conjoined base coordinate system. The rotation of the fruit was represented by the rotating around Z-axis of the Y-axis or X-axis in the conjoined base coordinate system. The third, we got the transformation relationship between 2 coordinate systems through the space vector relationship. Final, we used the spatial coordinates of the feature points and coordinate relationship gotten above to calculate the position and attitude of conjoined base coordinate frame by frame. Conjoined base coordinate of 2 adjacent time could calculate the instantaneous dynamic displacement, speed and acceleration of the fruit, as well as the motion parameters such as instantaneous angle, angular speed and angular acceleration for fruit swing and rotation. The ADAMS computing software was used to simulate the motion by setting a specific complex motion relationship of translation, swing and rotation. The calculation formula constructed in this paper was used for calculation and the calculation results were compared with the theoretical simulation values to determine the calculation accuracy of the calculation formula. The maximum one-way average absolute error of displacement was only 5.9×10<sup>-8</sup> mm, and the absolute errors of displacement, speed and acceleration were enlarged gradually by the order of magnitude of 10<sup>3</sup>. The relative errors of displacement and speed were identical, while the relative error of acceleration was larger than that of displacement and speed. The average absolute error and average relative error of maximum acceleration were 6.5×10<sup>-2</sup> mm/s<sup>2</sup> and 4.13×10<sup>-2</sup>%, respectively. The maximum average absolute errors of swing and rotation were 5.43×10<sup>-2</sup> and 9.51×10<sup>-2</sup> °/s<sup>2</sup>, respectively. The results show that the method constructed in this paper is feasible to solve the instantaneous motion attitude of the fruit.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Fruits
Controlled terms:Acceleration - Antennas - Errors - Harvesting - High speed photography - Kinematics - Rotation - Speed - Vector spaces
Uncontrolled terms:Calculation accuracy - Co-ordinate transformation - Motion attitudes - Motion parameters - Vibration
Classification code:742.1 Photography - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921 Mathematics - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2019.16.023
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 11>
Accession number:20194607670450
Title:Influence of different corn ear position and orientation and water content on fracture mechanics of corn peduncle
Title of translation:不同玉米果穗位姿与含水率对穗柄断裂特性的影响
Authors:Fu, Qiankun (1, 2); Fu, Jun (1, 2, 3); Chen, Zhi (2, 3); Zhang, Libo (4); Ren, Luquan (1, 2)
Author affiliation:(1) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun; 130022, China; (2) College of Biological and Agricultural Engineering, Jilin University, Changchun; 130022, China; (3) Chinese Academy of Agricultural Mechanization Scienceses, Beijing; 100083, China; (4) Hebei Zhongnong Boyuan Agricultural Equipment Co. LTD, Shijiazhuang; 050000, China
Corresponding author:Fu, Jun(fu_jun@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:60-69
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are many problems exsist in the harvesting process of corn head. Firstly, kernels are likely to shed and broken because of the collision and friction between corn head and corn ears. Secondly, the working principle of the existing corn head is to snap corn ears by stretching, which needs a large amount of power consumption. Thirdly, most husks are remained around the corn ears, as the fracture point are mostly located at the growing point of the peduncle, which aggravates the difficulty of dehusking of corn ears and cleaning of corn kernels. However, the mentioned problems above could be avoided effectively when people picking corn ears with their two hands. People apply bending moment with the loading hand and hold peduncle and stalk together tightly with the supporting hand at the same time. Corn peduncles are subjected to tensile forces by the corn ear and tensile force by the stalk. Besides, a bending moment is applied on the peduncle by corn ear, as corn ear are subjected to lever action by people's hand. A fracture model of corn peduncle was refined in the progress of picking corn ear by people's hands in this research. The fracture behavior of corn peduncle could be altered by changing the position and orientation of corn ears. Through the fracture model, a design idea for corn ear snapping was proposed based on the existing corn heads. It worked with the principle of applying lateral force to corn ear when it got in collision with the deck plates. Researches were made to explore the fracture behavior of peduncle at different position and orientation under a range of moisture content and deflection angle. The test material were corn ears with the kernels moisture contents of 34.8%, 30.2%, 25.1% and 20.3%. The fracture force of peduncles, the stretching amount when peduncle fracture and the removal rate of husks were taken as the test indices. The first series of randomized block experiments were carried out on corn ears fixed with a deflection angle relative to the corn stalk. The deflection angle included six treatment from 0° to 75° with an incremental interval of 15°. The sceond series of randomized block experiments were conducted with the deflection angle of 50° and 55° as data jumped greatly between 45°and 60 °. The results showed that there were critical angles of peduncles with the kernels moisture of 34.8%, 30.2%, 25.1% and 20.3%. The critical angles were 50° to 55°, 50° to 55°, 45° to 50° and 45° to 50° corresponding to the moisture contents above. As the deflection angle of corn ears increased to the critical angle, the average fracture force of peduncles decreased from 717.18, 676.49, 611.23 and 462.86 N to 139.98, 94.70, 97.72 and 90.54 N, with the decreasing ratio of 80%, 86%, 84%, and 80%, corresponding to kernels moisture of 34.8%, 30.2%, 25.1% and 20.3%. Also, the stretching amount when peduncle fracture increased with the ratio of 72%, 70%, 93% and 84%, while the removal rate of husks increased by 41%, 34%, 32% and 36%. The Logistic function was the optimal approximation function for the fitting of fracture force of peduncles and the stretching amount when peduncle fracture, while a cubic functions of one variable was optimal for the removal rate of husks. By analysing the "load-displacement" curves of corn peduncles with the deflection angle of 45° and 60° at the moisture content of 25.1%, it showed that the acute change of data was attributed to the change of peduncle fracture mechanism. When the deflection angle was less than the critical angle, the peduncle fractured instantly after crack formation on the surface. The reason for the formation of crack was tensile stress getting higher than the stress limit. Otherwise, the peduncle fractured slowly after crack formation, with the formation reason of crack was bending normal stress getting higher than the stress limit. As an instructive conclusion, the bionic corn ear snapping device could be implemented by applying lateral force on corn ears to change their position and orientation. This study provides not only theory basis but also support data for the design and improvement of bionic corn snapping mechanism.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Cracks
Controlled terms:Agricultural machinery - Bending moments - Bionics - Deflection (structures) - Experiments - Fracture - Fracture mechanics - Mechanics - Moisture - Moisture determination
Uncontrolled terms:Corn - Ear snapping - Fracture behavior - Fracture mechanisms - Load displacements - Logistic functions - Optimal approximation - Position and orientations
Classification code:408.2 Structural Members and Shapes - 461.1 Biomedical Engineering - 821.1 Agricultural Machinery and Equipment - 901.3 Engineering Research - 931.1 Mechanics - 944.2 Moisture Measurements - 951 Materials Science
Numerical data indexing:Force 4.63e+02N, Force 6.11e+02N, Force 9.05e+01N, Force 9.77e+01N, Percentage 2.03e+01%, Percentage 2.51e+01%, Percentage 3.02e+01%, Percentage 3.20e+01%, Percentage 3.40e+01%, Percentage 3.48e+01%, Percentage 3.60e+01%, Percentage 4.10e+01%, Percentage 7.00e+01%, Percentage 7.20e+01%, Percentage 8.00e+01%, Percentage 8.40e+01%, Percentage 8.60e+01%, Percentage 9.30e+01%
DOI:10.11975/j.issn.1002-6819.2019.16.007
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 12>
Accession number:20194607670406
Title:CFD simulation of flow field and temperature field of different air flow circulation modes in vegetable aeroponics cultivation box
Title of translation:蔬菜气雾栽培箱不同气流循环方式的流场和温度场CFD模拟
Authors:Jiang, Pin (1, 2); Yang, Xiwen (1); Luo, Yahui (1, 2); Long, Lixia (1); Shi, Yixin (1, 2); Hu, Wenwu (1, 2)
Author affiliation:(1) College of Engineering, Hunan Agricultural University, Changsha; 410128, China; (2) Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha; 410128, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:233-241
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The air flow and temperature in the vegetable aeroponics cultivation box play an important role in the internal environment regulation and crop growth. The uniform air flow around crops can promote the growth rate of the crop. In order to study the distribution of flow field and temperature field in vegetable aeroponics cultivation box, CFD models of vegetable aeroponics cultivation box under different air flow circulation modes were established based on computational fluid dynamic (CFD) method, FLUENT software, standard turbulence model, porous medium model, crop canopy heat exchange model. The environment in the aeroponics cultivation box was optimized, and three air flow circulation schemes were designed(air flows from top to side, side to top and side to side). The layout of the different positions of the return air outlets was studied, and the numerical simulations of the three air flow circulation schemes were carried out. The simulation results showed that in the scheme of air flow entering from the top and exiting from the side, the suitable wind speed value area of lettuce accounts for 58.1%, the suitable temperature value area accounts for 93.6%, and the ventilation dead zone area accounts for 0.844%. In the scheme of air flow side entering and exiting the top surface, the suitable wind speed value area of lettuce accounts for 59.6%, the suitable temperature value area accounts for 99.98%, and the ventilation dead zone area accounts for 0.069%. In the scheme of air flow side entering side exit, the suitable wind speed value area for lettuce growth accounts for 54.3%, the suitable temperature value area accounts for 92.4%, and the ventilation dead zone area accounts for 16.7%. After comparison, the side entering the top surface was obtained as the optimal air circulation scheme. The temperature and wind speed simulation values and measured values in the aeroponics cultivation box were compared. The results showed that the average temperature relative error was 3.9% and the root mean square error was 0.86 ℃. The average relative error of wind speed was 3.5%, and the root mean square error was 0.26 m/s. The error between simulated and measured values was small, and the simulation effect was good. The accuracy of the CFD model was verified. In crop cultivation, aeroponics was a new cultivation method in the field of soilless cultivation, which could be applied to greenhouses, plant factories, family balconies and other places through microclimate control technology. In this paper, by regulating the wind speed in the aeroponics box, the climate growth environment and temperature uniformity of the crops can be ensured, and the problems of the roots and canopies of the crops can be effectively solved, and the crop yield and quality can be improved. Airflow velocity and temperature are important factors for crop growth in aeroponics boxes, which affect the transpiration and photosynthesis of crops. Therefore, it is of great significance to study the changes of air velocity and temperature to promote air aeroponics technology. This study provides a reference for the flow field and temperature change law in vegetable aeroponics cultivation box, internal environment adjustment and device optimization design.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Air
Controlled terms:Computational fluid dynamics - Crops - Environmental regulations - Errors - Flow fields - Mean square error - Porous materials - Speed - Temperature - Turbulence models - Vegetables - Ventilation - Wind
Uncontrolled terms:Aeroponics - Average relative error - Environment regulations - Optimization design - Root mean square errors - Soil-less cultivation - Temperature uniformity - Wind speed
Classification code:443.1 Atmospheric Properties - 454.2 Environmental Impact and Protection - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 643.5 Ventilation - 723.5 Computer Applications - 804 Chemical Products Generally - 821.4 Agricultural Products - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 1.00e+02%, Percentage 1.67e+01%, Percentage 3.50e+00%, Percentage 3.90e+00%, Percentage 5.43e+01%, Percentage 5.81e+01%, Percentage 5.96e+01%, Percentage 6.90e-02%, Percentage 8.44e-01%, Percentage 9.24e+01%, Percentage 9.36e+01%, Velocity 2.60e-01m/s
DOI:10.11975/j.issn.1002-6819.2019.16.026
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 13>
Accession number:20194607670337
Title:Simulation of reference crop evapotranspiration in hilly area of central Sichuan based on MARS
Title of translation:多元自适应回归样条算法模拟川中丘陵区参考作物蒸散量
Authors:Chen, Xuanquan (1); Cui, Ningbo (1, 2, 3); Li, Jiping (1); Xu, Haoruo (1); Liu, Shuangmei (4); Ma, Zelong (4); Le, Jinhua (5); Wang, Jun (5)
Author affiliation:(1) State Key Laboratory of Hydraulics and Mountain River Development and Protection, College of Water Resources and Hydropower, Sichuan University, Chengdu; 610065, China; (2) Key Laboratory of Water-saving Agriculture for Hilly Areas of Southern China in Sichuan Province, Chengdu; 610066, China; (3) Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Northwest A&F University, Yangling; 712100, China; (4) Sichuan Institute of Hydraulic Research, Chengdu; 610072, China; (5) Beijing Oriental Runze Ecological Technology Co., Ltd., Beijing; 100083, China
Corresponding author:Cui, Ningbo(cuiningbo@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:152-160
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The reference crop evapotranspiration (ET<inf>0</inf>) is a kernel parameter for precise irrigation management of crops and agriculture efficient water use. In order to improve the accuracy of the ET<inf>0</inf> prediction in the hilly area of central Sichuan with missing meteorological data in some area, 15 different prediction models based on multivariate adaptive regression splines (MARS) were established by using different meteorological factors. The daily meteorological data of 11 representative meteorological stations from 1961 to 2016 were analyzed by the MARS models. These data were divided into training set and test set in a ratio of 7:3, and the simulation results of the MARS models were statistically evaluated using the calculation results of the FAO 56 Penman-Monteith model as a standard. In the statistical evaluation, 4 statistical parameters were obtained by the prediction sequence and the calculation result of the FAO 56 P-M model. They were root mean square error (RMSE), mean relative error (MRE), Nash efficiency coefficient (NSE), and R<sup>2</sup>. The value of the index above were used to calculate a score for evaluating the prediction accuracy of the models, and rank the models based on the scores. Then the results were compared with other ET<inf>0</inf> prediction models and the applicability of the models in the hilly area of central Sichuan was evaluated by the portability analysis. The results showed that the full MARS model with 6 input parameters had the highest accuracy. Decreasing 1 input of relative humidity, the model still had the higher accuracy, ranking No 1 based on comprehensive performance indicator (CPI), which was same with the full model ranking. Reducing continually 1 input of sunshine duration still yielded the high simulation accuracy with NSE and R<sup>2</sup> higher than 0.985. Further decreasing 1-2 input, the model NSE and R<sup>2</sup> still were higher than 0.9. Among these models, the model with 2 inputs of radiation and wind speed was the most easy to use since the radiation could be calculated and only wind speed was required to measure. Radiation and wind speed were the keys to determine the regional adaptability of machine learning models. Radiation contained the geographic and temporal information of the site, which made it a key factor in the MARS models to distinguish the differences in geographical environment. On the other hand, radiation could compensate for the negative impact caused by the lack of sunshine duration on the prediction accuracy of the MARS models. The wind speed was more important than the other meteorological factors because the response of MARS models were more sensitive to it. Compared with the Irmak-Allen Model, the Irmak Model, and the Hargreaves-M4 Model, the MARS<inf>6</inf>, MARS<inf>7</inf>, and MARS<inf>8</inf> improve the accuracy. Under the same meteorological factors input, the MARS models had a stronger simulation ability for ET<inf>0</inf> than the existing empirical models; Through the portability analysis, the MARS model with 4 input parameters of radiation, maximum and minimum temperature and wind speed maintained high precision with NSE and R<sup>2</sup> both higher than 0.985, RMSE 0.121-0.193 mm/d and MRE 2.7%-4.1%. In sum, the MARS model realized the deletion and replacement of meteorological factors, reduced dependence of ET<inf>0</inf> forecasting on meteorological data, and maintained a relatively high forecasting accuracy and wide applicability. The MARS was recommended as a reliable ET<inf>0</inf> prediction model in the hilly area of central Sichuan.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Weather forecasting
Controlled terms:Algorithms - Computer software portability - Crops - Evapotranspiration - Mean square error - Meteorology - Models - Radiation - Speed - Splines - Water supply - Wind
Uncontrolled terms:Comprehensive performance indicators - Geographical environment - Machine learning models - Maximum and minimum temperatures - Multivariate adaptive regression splines - Reference crop evapotranspirations - Root mean square errors - Sichuan
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 446.1 Water Supply Systems - 601.2 Machine Components - 723 Computer Software, Data Handling and Applications - 821.4 Agricultural Products - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 2.70e+00% to 4.10e+00%
DOI:10.11975/j.issn.1002-6819.2019.16.017
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 14>
Accession number:20194607667586
Title:Simulation of effects of agricultural water price policy based on positive mathematical programming
Title of translation:基于实证数学规划模型的农业水价政策效应模拟
Authors:Tan, Qian (1); Wang, Shuping (1); Zhang, Tianyuan (1)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing; 100083, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:161-171
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rational water price policy is of great significance for the efficient use of water resources. However, development processes of water price policy are mostly subjective and few methods are suitable to quantify policy effects. In this study, we focused on irrigation areas with multiple water sources and irrigation techniques. A method based on positive mathematical programming (PMP) was proposed to simulate the impacts of agricultural water price policy on economic benefits of water use, irrigation water consumption, planting land occupation and water-saving irrigation area. This method was applied to address a case in Minqin County, Gansu Province. Under the current water price policy of the study area, the model was calibrated with the actual data in 2015, the absolute value of the difference between the optimal solution of the calibrated model and the actual planting area in the base year didn't exceed 1.3×10<sup>-3</sup> hm<sup>2</sup>, indicating that the model was reliable to simulate the effect of water price policy. Subsequently, the model was used to simulate the change trend of index with the rise of water price under the volumetric water price policy, the 2-part water price policy and the differential water price policy. The simulation results showed that, with the rise of water price, the change trend of index under 3 water price policy was similar: the farmer income reduced, the irrigation water consumption and planting area reduced first and then stabilized, the water-saving irrigation area increased, and the benefit per cubic meter of water increased first and then decreased. Simultaneously, in response to rising water price, farmers tended to reduce the planting area of food crops first and then the area of cash crops to alleviate the loss of income. Based on the simulation results, the water price threshold under different policies and the scope of application of various policies were further analyzed, and the following conclusions were drawn. Under the volumetric water price and the 2-part water price policy, the water price should be between 0.24 yuan/m<sup>3</sup>-2.10 yuan/m<sup>3</sup>; under the differential water price policy, the water price should be between 0.24-1.50 yuan/m<sup>3</sup>; when the metering part of the water price was lower than 2.10 yuan/m<sup>3</sup> or higher than 6 yuan/m<sup>3</sup>, the comprehensive benefit of the differential water price policy was the highest; when the metering part of the water price was between 2.10 yuan/m<sup>3</sup> and 6 yuan/m<sup>3</sup>, the volumetric water price policy was the most ideal; when the differential water price policy was implemented and the metering part of the water price was 1.50 yuan/m<sup>3</sup>, the benefit per cubic meter of water was the highest. This paper confirmed that the steady increase of water price would not reduce the comprehensive benefits of water use, but increase the benefit per cubic meter of water. The differential water price policy currently implemented in Minqin County was appropriate. In the future, in Minqin County, the water price under the differential water price policy should be increased within the range of 0.24-1.50 yuan/m<sup>3</sup>. Moreover, during the course of water price rising in the study area, special attentions should be paid to increase investment in water-saving irrigation projects and farmer income subsidy policies should be established under local contexts. Based on the conclusions of this study, various local factors and evaluation indexes such as current water price, farmers' willingness to pay, government financial subsidies, and income from water supply projects, could be comprehensively considered to obtain detailed implementation plan of water price policy. The method established in this paper was also applicable to other areas with similar problems.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Economic and social effects
Controlled terms:Agriculture - Crops - Economics - Investments - Irrigation - Mathematical programming - Models - Water - Water conservation - Water management - Water supply - Water supply systems
Uncontrolled terms:Comprehensive benefit - Efficient use of water - Positive mathematical programming - Scope of application - Water prices - Water supply projects - Water use - Water-saving irrigation
Classification code:444 Water Resources - 446.1 Water Supply Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2019.16.018
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 15>
Accession number:20194607667505
Title:Functional properties of mixed probiotics fermentation broth and its feeding attractant effects
Title of translation:复合益生菌发酵液的功能特性及对对虾诱食效果
Authors:Li, Yan (1); Ma, Qingshan (2)
Author affiliation:(1) Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao; 266003, China; (2) School of Medicine and Pharmacy, Ocean University of China, Qingdao; 266003, China
Corresponding author:Ma, Qingshan(horsegreenhill@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:242-248
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the rapid development of aquaculture farming industries, high density farming techniques are now widely adopted in China, facilitated by a raft of approaches including oxygenation enhancement, intensive feeding and the frequent addition of antibiotics for disease control. Such intensive industrialized farming methods have improved yields from aquatic farming of animals. As repeatedly noted, they may also lead to the buildup of unused feed, excreta and other biological residues, as well as the accumulation of harmful chemicals such as nitrite, and the application of chemical drugs and antibiotics has led to the proliferation of harmful and resistant bacteria and harmful algae, meanwhile, drug residues also affect the products quality and aquatic animals safety. Probiotics, such as Bacillus, lactic acid bacteria and yeast have been widely used in aquaculture and yielded beneficial effects, mainly in improving water quality, growth performance and reducing the mortality rate by degradation nitrite, inhibiting pathogens, regulating intestinal flora and stimulating the immune system. It is well known that different types of probiotics can express different functions, such as denitrification, enzyme production and antibacterial activity. Mixed strain fermentation, giving multiple functions of fermentation broth, which can reduce production cost, simplify the process and broaden the application range. In this study, we explored the feasibility of multi-functional mixed strain fermentation, 3 strains of probiotics included yeast, lactic acid bacteria and Bacillus with excellent performances (Saccharomyces cerevisiae NJ-02: producing exopolysaccharide, vitamin, nucleotide, etc; Enterococcus faecium SC-01: producing acetic acid, lactic acid and other organic acids, inhibition of pathogens; Bacillus subtilis M7-1: degradation of ammonia nitrogen and nitrite nitrogen, producing extracellular enzymes). After 24 h incubations, the number of Saccharomyces cerevisiae NJ-02, Enterococcus faecium SC-01 and Bacillus subtilis M7-1 viable bacteria counts reached 3.88×10<sup>8</sup>, 2.41×10<sup>10</sup>, and 5.38×10<sup>9</sup> CFU/mL, respectively. The results also showed that the biological denitrification and promoted algae (Chlorella vulgaris) growth performance of the mixed fermentation broth were directly related to the number of Bacillus subtilis M7-1 viable bacteria. Further into the process, it was observed that 16 h was the best fermented time for degradation nitrite and algae cultivation. It also showed that the nitrite nitrogen degradation rate reached 89% and the C. vulgaris chlorophyll-a concentration increased by 49.6%. Additionally, mixed strain fermentation broth showed the same enzymatic activity (protease, amylase, cellulase) and antibacterial activity (Vibrio parahaemolyticus) when it was compared to Bacillus subtilis M7-1 and Enterococcus faecium SC-01. Furthermore, the feeding attractant effect was significantly improved than that of the control group and chemical attractant trimethylamine oxide (TMAO) (P<0.05), and was equivalent to that of dimethyl-beta-propiothetin (DMPT) based on the feeding behavior of shrimp. The number of lactic acid bacteria and yeast in shrimp intestinal tract was significantly higher (P<0.05) than that of the control group and the chemical attractant group. In summary, we obtained multi-functional mixed strain fermentation broth such as biological denitrification, promoting algae cultivation, antibacterial activity and biological attractant, this fermentation broth was expected to be used in aquaculture to improve water quality, enhance animal appetite and feed intake and maintain intestinal health. The study provides a microbial resource and technical method for sustainable ecological aquaculture.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Probiotics
Controlled terms:Algae - Ammonia - Antibiotics - Aquaculture - Bacilli - Bacteriology - Biodegradation - Biological filter beds - Chemical contamination - Controlled drug delivery - Degradation - Denitrification - Disease control - Enzyme activity - Enzyme inhibition - Feeding - Fermentation - Indicators (chemical) - Lactic acid - Nitrogen - Shellfish - Water quality - Yeast
Uncontrolled terms:Anti-bacterial activity - Attractant effect - Biological denitrification - Chlorophyll-a concentration - Enzymatic activities - Extracellular enzymes - Functional properties - Vibrio parahaemolyticus
Classification code:445.2 Water Analysis - 461 Bioengineering and Biology - 691.2 Materials Handling Methods - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.3 Agricultural Methods - 822.3 Food Products
Numerical data indexing:Percentage 4.96e+01%, Percentage 8.90e+01%, Time 5.76e+04s, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2019.16.027
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 16>
Accession number:20194607667576
Title:Analysis on energy dissipation effect and influencing factors of modified vertical stilling well
Title of translation:改进型深筒式消力井消能效果及影响因素分析
Authors:Jin, Jin (1); Liu, Huanfang (1); Feng, Bo (2); Liu, Zhenji (1)
Author affiliation:(1) College of Water & Architectural Engineering, Shihezi University, Shihezi; 832000, China; (2) Hunan Provincial Communication Planning Survey & Design Institute, Changsha; 410200, China
Corresponding author:Liu, Huanfang(liuhuanfang@tom.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:87-94
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The vertical stilling well can effectively eliminate excess energy in long distance pipeline project. The energy dissipation mechanism is based on the impact of jet flow on the bottom of the well, the diffusion of water flow in the well and the friction between water jets. In this study, we compared the energy dissipation effect of 3 different forms of vertical stilling well in order to design an optimized structure for vertical stilling well. Theory analysis and experimental observation were combined. The 3 types of vertical stilling well included traditional type, improved I type and improved II type. The model test of vertical stilling well was set up in water conservancy hall of Shihezi University in Xinjiang. The relevant hydraulic parameters such as inlet and outlet pipeline pressure, the flow and pressure on the bottom of the vertical stilling well were measured. The head loss coefficient and the energy dissipation rate were calculated. The relationship between the structural parameters of multi-hole outlet and the head loss coefficient as well as that between the height of overflow plate and the head loss coefficient were analyzed. The results showed that flow regime of the improved type II vertical stilling well was more complex than the other types, and the collision and mixing between water flows were more sufficient because of the existence of multi-hole outlet and additional overflow plate. The improved II type vertical stilling well had more than 30% energy dissipation rate than the traditional type. If the improved type II vertical stilling was adopted, the flow over weir was free outflow when the flow rate was very small. The head loss coefficient would increase with flow rate until submerging and flowing out. When the relative aperture area remained unchanged, the influence of the aperture diameter on the head loss coefficient of the stilling wells was small, and the relative aperture was better controlled at about 12%. When the aperture distance-to-diameter ratio was small, the head loss coefficient was large. But when the distance-to-diameter ratio was not less than 2.5, the head loss coefficient also remained basically unchanged. Considering the practical engineering application, the distance-to-diameter ratio should be 3. The head loss coefficient decreased slightly with the increase of aperture, and the head loss coefficient of the staggered arrangement was obviously larger than that of the parallel arrangement. When submerging and flowing out the height of overflow plate had negative effects, otherwise, the height of overflow plate had no obvious effect on the head loss coefficient. The pressure around the bottom plate of the improved II type vertical stilling well was slightly higher than that of the traditional stilling well, and the pressure at the center of the well was slightly lower than static pressure of the well, but the pressure on the bottom plate was distributed evenly on the whole, which could prevent the scouring damage of the bottom plate caused by the inlet pipeline flow and the cavitation damage caused by the negative pressure, thus the durability of the stilling well would be improved. Results above suggested that the improved type II vertical stilling well did not only improve the energy dissipation effect, but also effectively prevented the flow from scouring and damaging the bottom plate, which had obvious advantages in structure. This study provides valuable information for the engineering design of modified vertical stilling wells and for solving the problem of energy dissipation in long-distance pipeline water delivery.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Plates (structural components)
Controlled terms:Energy dissipation - Flow of water - Flow rate - Hydraulics - Pipelines - Pressure - Structural design - Water management - Water pipelines
Uncontrolled terms:Energy dissipation mechanism - Energy dissipation rate - Head loss coefficient - Long distance pipelines - Practical engineering applications - Pressure on the bottoms - Staggered arrangement - Structure parameter
Classification code:408.1 Structural Design, General - 408.2 Structural Members and Shapes - 525.4 Energy Losses (industrial and residential) - 619.1 Pipe, Piping and Pipelines - 631 Fluid Flow - 631.1.1 Liquid Dynamics - 632.1 Hydraulics - 931.1 Mechanics
Numerical data indexing:Percentage 1.20e+01%, Percentage 3.00e+01%
DOI:10.11975/j.issn.1002-6819.2019.16.010
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 17>
Accession number:20194607670319
Title:Spatio-temporal changes and influencing factors of grain yield based on spatial smoothing method in dryland farming regions
Title of translation:基于空间平滑法的旱作区粮食产量时空变化与影响因素研究
Authors:Wan, Wei (1, 2); Li, Hanwei (1, 2); Wang, Jiaying (1, 2); Liu, Zhong (1, 2); Han, Yiwen (1, 2)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China; (2) Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture, Beijing; 100193, China
Corresponding author:Liu, Zhong(lzh@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:284-296
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As water constraints become increasingly severe in Northern China, it is of great significance to study the grain yield pattern and its driving factors in dryland farming regions. Based on the county-level grain statistics from 1995 to 2015, combined with land use raster data and other materials, we studied the spatial pattern and process of grain yield in dryland farming regions of the Northeast and North China Plain using spatial smoothing methods. In addition, the natural and socio-economic driving factors of grain yield in different agricultural regions were investigated. Our results showed that: (1) In the past 20 years, the grain yield increased steadily and high production area expanded gradually in the dryland farming regions of Northeast and North China Plain, with obvious spatial agglomeration characteristics. And the total grain yield in the plain of North China dryland farming regions was higher than that in dryland farming regions of the Northeast China Plain. (2) The main increase rate of grain yield exhibited a medium speed, followed by slow speed, high speed increase, and absolute reduction in production. And increase rate of the grain yield in the dryland farming regions of the Northeast China Plain was higher than that in the North China Plain. (3) The per unit area yield of grain in the dryland farming regions of Northeast China Plain was higher than that of the North China Plain. And after the spatial smoothing processing, the pixel frequency of per unit area yield of grain generally exhibited a Gaussian distribution, which is consistent with the objective laws. The peak value of histogram pixel gradually moved to the right, and the per unit yield grid showed a gradual decentralization trend over time, indicating that the regional yield gap increases with the overall improvement of cultivated land productivity. (4) The mean annual temperature among the natural factors had the highest correlation with the per unit area yield of grain of the agricultural regions in Yan-Taihang mountain foothill plain. The annual precipitation and confluence capacity exhibited the highest correlation with the per unit area yield of grain of the agricultural regions in Ji-Lu-Yu low-lying plain. The soil type showed the highest correlation with the per unit area yield of grain of the agricultural regions in Songnen-Sanjiang plain. (5) The correlation analysis of per unit area yield of grain with socio-economic factors showed that grain production was gradually shifting from labor-intensive to technology-intensive. And the application of agricultural machinery obviously contributed to the study area, especially to the Northeast dryland farming regions of China. The application of chemical fertilizers had always played a significant role in improving grain production in the study region. And irrigation conditions played a critical role in ensuring grain production in the dryland farming regions of North China Plain. In summary, the results of our study are helpful for the research of spatial-temporal pattern of grain yield, and can provide references for the maintenance of high yield, stable yield and cultivated land conservation in different agricultural areas.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:44
Main heading:Grain (agricultural product)
Controlled terms:Agriculture - Conservation - Economics - Fertilizers - Land use - Landforms - Pixels - Plants (botany)
Uncontrolled terms:Dryland farming - North China - Northeast China - Spatial smoothing - Spatio-temporal changes - Yield
Classification code:403 Urban and Regional Planning and Development - 481.1 Geology - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 971 Social Sciences
Numerical data indexing:Age 2.00e+01yr
DOI:10.11975/j.issn.1002-6819.2019.16.032
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 18>
Accession number:20194607667658
Title:Turbocharger matching in plateau area and adaptability of small agricultural diesel engine
Title of translation:小型农用柴油机高原增压匹配与适应性研究
Authors:Wang, Jun (1); Shen, Lizhong (2); Wen, Yijun (3); Xue, Shuang (3); Zhao, Jie (3)
Author affiliation:(1) School of Mechanical and Transportation, Southwest Forestry University, Kunming; 650224, China; (2) Yunnan Province Key Laboratory of Internal Combustion Engines, Kunming University of Science and Technology, Kunming; 650500, China; (3) Kunming Yunnei Power Co., Ltd., Kunming; 650200, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:70-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The environment pressure and air density experience sharp declines at high altitude, which cause a large drop in the intake air mass flow rate of diesel engines. As a result, many aspects of engine performance are deteriorated, such as power, fuel consumption and emissions. Turbocharging matching provides a good technical solution for recovery diesel engine performance at high altitude. There is a large number of agricultural machinery operating in plateau area of China. In order to ensure that the agricultural machinery used in these areas had a good plateau adaptability, taking a small agricultural diesel engine as the research object, an appropriate compressor and turbine were selected respectively through theoretical calculation according to the design and development goals at altitude of 2 000 m. After that, the matching test of the small agricultural diesel engine and selected turbocharger was conducted at this altitude. Finally, the simulation model of the small agricultural turbocharged diesel engine was built by using GT-Power code based on test data. The change rule of diesel engine key performance parameters were simulated and investigated at altitudes of 0, 2 000 and 4 000 m. The results showed that the selected turbocharger made the small agricultural diesel engine achieve the development requirements at the altitude of 2 000 m. Low-end torque reached 120.1 N•m at 1 000 r/min, the peak torque was 180.2 N•m at 1 600 r/min, the rated power was 37.4 kW at 2 600 r/min, and the torque backup coefficient was 131% at this altitude. At 3 altitudes of 0, 2 000 and 4 000 m, the joint operation lines of the small agricultural diesel engine and the selected compressor were all operating in the relatively high efficiency area, and there were a large surge margin at low engine speeds, and also a certain distance from the choke line at high engine speeds. As the altitude went up, the engine torque and boost pressure decreased, while brake specific fuel consumption and turbine inlet gas temperature increased. What's more, with respect to high engine speed, the change of altitude had a greater impact on engine power and economy performance at low engine speed. With the increase of altitude, decreasing amplitude of torque and percentage gain of fuel consumption was both rose at low engine speed, and these tendency were decline gradually with the increase of engine speed. In addition, the engine speed corresponding to the peak torque showed a tendency of gradually moving towards higher engine speed at high altitude. Compared with plain area, the maximum engine torque decreased by 2.59% and 7.19% respectively when it ran at altitudes of 2 000 and 4 000 m. Meanwhile, compared with the previous literatures conclusion, the decreasing amplitude of peak engine torque was smaller when the small agricultural diesel engine operating at altitudes of 2 000 and 4 000 m, respectively. It can ensure the good operation performance of diesel engine in plateau area, and also is beneficial to improve the plateau adaptability when diesel engine and turbocharger are matched at high altitude.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Speed
Controlled terms:Agricultural machinery - Agriculture - Air intakes - Diesel engines - Fuels - Indium plating - Machine design - Torque - Turbomachinery
Uncontrolled terms:Adaptability - Brake specific fuel consumption - Diesel engine performance - Different altitude - Key performance parameters - Plateau - Turbocharged diesel engine - Turbocharger matching
Classification code:539.3 Metal Plating - 601 Mechanical Design - 612.2 Diesel Engines - 631.1 Fluid Flow, General - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 1.31e+02%, Percentage 2.59e+00%, Percentage 7.19e+00%, Power 3.74e+04W, Rotational_Speed 1.00e+03RPM, Rotational_Speed 1.60e+03RPM, Rotational_Speed 2.60e+03RPM, Size 2.00e+03m, Size 4.00e+03m, Torque 1.20e+02N*m, Torque 1.80e+02N*m
DOI:10.11975/j.issn.1002-6819.2019.16.008
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 19>
Accession number:20194607667506
Title:Operation simulation model for middle route of south-to-north water transfer project during ice period
Title of translation:南水北调中线工程总干渠冰期输水调控仿真研究
Authors:Liu, Mengkai (1)
Author affiliation:(1) Evergrande School of Management, Wuhan University of Science and Technology, Wuhan; 430081, China
Corresponding author:Liu, Mengkai(mengkailiu@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:95-104
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The middle route of south-to-north water transfer project is a canal system. The downstream part from Anyang to Beijing has ice in winter every year. And the water resources requirement of this part is still hard in winter.. Ice condition is important to operation the canal system in winter. Ice evolution simulation is an important method to improve ice hazard threat of the middle route of south-to-north water transfer project by ice prediction and canal system automation operation. In this paper, a one dimensional operation simulation model for the middle route of South-to-North water transfer project has been established, which including unsteady flow simulation, water temperature simulation, ice cover evolution simulation and PI controller. It could describe the ice evolution process, hydraulic responses and gates operation process. And the model had taken the canal system characteristics into consideration including ice cannot flow through downstream gate of each pool and coupling of system hydraulic response. Ice observation is a dangerous work, and the project is so long. So, just limited ice observed data at some canal pools of the project is used to confirm the parameters value for the model. The parameters calibration results showed that the heat exchange coefficient of open channel was 18 W/(m<sup>2</sup>•℃) and heat exchange coefficient under ice sheet conditions was 26 W/(m<sup>2</sup>•℃), and the averaged error of ice cover thickness and water temperature were 0.67 cm and 0.07℃ respectively. So the reliability of the model was confirmed to calibrate water temperature process, ice cover formation process and ice cover thickness process. And then, the model was applied to Beijing-Shijiazhuang part of the south-to-north water transfer project case simulation to study the ice situation evolution, hydraulic response and gate group regulation process in Ianuary-February 2016. The simulated canal system consists of 13 channels separated by 14 control gates. Water transfer flow of Hebei terminal and Tianjin were set as 20 m<sup>3</sup>/s and 10 m<sup>3</sup>/s. Two working conditions were simulated according to the temperature conditions. The results showed that the ice evolution parameters value can worked well to simulate ice evolution for long distance canal system, but the air temperature input conditions of the model must be the local value near each pool. The applied case results show that the canal system hydraulic response processes are complicated caused by ice evolution process, and the PI controller can reduce water level fluctuant amplitude and keep on the downstream water level operation mode well. The prediction of ice evolution process and gates operation processes was helpful to improve safety and economic benefit of the engineering.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Ice
Controlled terms:Computer simulation - Controllers - Heat exchangers - Hydraulic structures - Ice control - Lakes - Models - Open channel flow - Temperature - Water levels
Uncontrolled terms:Heat exchange coefficients - Hydraulic response - Operation control - Operation simulation - Parameters calibrations - South to North Water Transfer Project - Temperature conditions - Water transfers
Classification code:443.3 Precipitation - 616.1 Heat Exchange Equipment and Components - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 723.5 Computer Applications - 732.1 Control Equipment
Numerical data indexing:Size 6.70e-03m
DOI:10.11975/j.issn.1002-6819.2019.16.011
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 20>
Accession number:20194607670390
Title:Effect of incident angle on wheat soil-ripping parameters by pneumatic seeding
Title of translation:入射角度对气力射播小麦种粒入土参数影响的试验研究
Authors:Wang, Chao (1, 2); Li, Hongwen (1, 2); He, Jin (1, 2); Wang, Qingjie (1, 2); Cheng, Xiupei (1, 2); Wei, Zhongcai (1, 2); Liu, Junxiao (1, 2)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) Agricultural Science Observation and Experiment Station of Arable Land Conservation (Northern Hebei Province), Ministry of Agriculture, Beijing; 100083, China
Corresponding author:Li, Hongwen(lhwen@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:32-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rice-wheat rotation area, with heavy clay soil texture, that it is wheat planting area accounts for more than 37% of the total wheat sowing area in China as one of the major grain production bases, and rice-wheat rotation is the main cropping pattern in this region. Meanwhile, because of the shortage crop stubble and more rainfall in autumn, which lead to serious wet damage during the tilling and seeding stage for this field. Currently, most of the existing no-tillage and less-tillage seeding equipment for wheat sowing in rice stubble areas were optimized and developed on the basis of traditional contact-type wheat seeding technology, which lead to adhesion and serious blockage phenomenon, as well as increasing of operating resistance and power consumption during working. Therefore, a innovative technical proposal of non-contact type pneumatic seeding technology that could avoid contacting between sowing parts and soil was introduced in this paper, which in order to solve the problems of soil adhesion, blockage, drag increment as well as poor sowing quality for wheat seeders under the condition of sticky heavy loam clay in rice-wheat rotation areas. Experiment that utilized a self-made platform for wheat pneumatic seeding was conducted, which could rip wheat seed into the soil condition of clean seed bed without straw and stubble mulching by high pressure accelerating airflow. During the pneumatic seeding experiment, keeping a certain pneumatic seeding height and incident angle between the accelerating tube and topsoil surface, high-pressure gas was injected from the upper apex of the air nozzle and ejected from the bottom of it, which a stable high-speed airflow was formed in the accelerator tube (the length of the accelerator tube is 600 mm and the diameter is 10 mm). Then wheat seeds were put into the seed entrance and absorbed at a high speed under the negative air pressure of the ejector, during which the rubber sleeve could protect wheat seeds from damaging. After mixing with airflow, wheat seeds were accelerated by high-speed air flow in the accelerating tube. Finally, the wheat seeds flew out and ripped into the soil at a certain incident angle and high pneumatic seeding velocity. At the same time, high-speed photography technology was used to study the parameters of pneumatic seeding velocity, vertical velocity and pneumatic seeding depth under six levels (15°, 30°, 45°, 60°, 75°, 90°) of incident angles, and pneumatic seeding experiments under five different accelerating air pressures of 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa and 1 MPa for each incident angle were carried out respectively. Pneumatic seeding experimental results showed that: For pneumatic seeding in soil without straw and stubble mulching, when the incident angle increases continuously, wheat seeds can achieve higher vertical component of pneumatic seeding velocity deeper and pneumatic seeding depth at the same accelerating air pressures, the probability of horizontal slip and bounce of wheat seeds after touching soil show an decreasing trend, and pneumatic seeding depth has a positive correlation with pneumatic seeding velocity under each incident angle. Moreover, wheat seeds show various pneumatic seeding depth and soil impact effect without damage after pneumatic seeding. When the incident angles and the vertical component of pneumatic seeding velocity were more than 45° and 25 m/s respectively, wheat seeds can be completely ripped into the soil and the emergence rate is more than 86%. The best pneumatic seeding effect achieved as incident angle is 90°. In order to realize wheat vertical pneumatic seeding in field operation, the horizontal component of pneumatic seeding velocity should be equal to the operating speed of seeder and the vertical component of pneumatic seeding velocity should be greater than 25 m/s, which the seeder operating speed shows positively and negatively correlated with pneumatic seeding velocity and incident angle, respectively. The experimental results can provide basic data and technical support for the development of non-contact wheat seeding equipment in rice-wheat rotation area.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Pneumatics
Controlled terms:Adhesion - Agricultural machinery - Agriculture - Air - Air ejectors - Atmospheric pressure - Clay products - Experiments - High speed photography - Rotation - Textures - Velocity
Uncontrolled terms:Incident angles - Non-contact type - Positive correlations - Rice-wheat rotations - Seeder operating speed - Seeding technology - Technical proposals - Wheat
Classification code:443.1 Atmospheric Properties - 618.3 Blowers and Fans - 632.3 Pneumatics - 742.1 Photography - 804 Chemical Products Generally - 812.1 Ceramics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 901.3 Engineering Research - 931.1 Mechanics - 951 Materials Science
Numerical data indexing:Percentage 3.70e+01%, Percentage 8.60e+01%, Pressure 1.00e+06Pa, Pressure 2.00e+05Pa, Pressure 4.00e+05Pa, Pressure 6.00e+05Pa, Pressure 8.00e+05Pa, Size 1.00e-02m, Size 6.00e-01m, Velocity 2.50e+01m/s
DOI:10.11975/j.issn.1002-6819.2019.16.004
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 21>
Accession number:20194607670376
Title:Optimization of combustion process for non-road heavy-duty diesel engines
Title of translation:非道路用重型柴油机燃烧过程优化
Authors:Ma, Zhihao (1); Liu, Cheng (1); Wang, Xin (1); Liu, Wenbin (2); Ma, Fanhua (3)
Author affiliation:(1) College of Vehicle & Transportation Engineering, Henan University of Science and Technology, Luoyang; 471003, China; (2) Henan Diesel Engine Industry Corporation, Luoyang; 471000, China; (3) State Key Laboratory of Automotive Safety and Energy Conservation, Tsinghua University, Beijing; 100084, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:78-86
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Due to its high thermal efficiency and excellent performance, diesel engine is widely used in non-road mobile machinery, such as engineering and agricultural industry, whose power ranges from a dozen to several hundred kilowatt. However, it also brings amounts of NO<inf>x</inf> and soot emissions. The problems caused by emissions from non-road diesel engine have widely drawn people's attention. In recent years, Chinese government has also launched a series of stringent regulations to limit emissions from non-road engines, which can even be equivalent with the US EPA-IV, the most stringent emissions regulation in the whole world. In order to meet those harsh items of emissions regulation, all the engine manufacturers have to upgrade the products in a short time. At the same time, domestic and foreign internal combustion engine (ICE) experts have also carried out a lot of research related to the upgrading of non-road diesel engines. Small and medium power (< 75 kW) non-road diesel engines have innate advantages and wide applications in agricultural production. With the rapid development of after-treatment technology, such as diesel oxidation catalyst (DOC), diesel particulates filter (DPF), selective catalyst reduction (SCR), et al, the path to meet emissions regulations becomes more diverse. However, to meet the non-road stage IV emissions regulation, in addition to exhaust gas recirculation (EGR) and after-treatment technology, basic measurements (in-cylinder purification) must be used to reduce the raw emissions of engine. For the purpose of reducing raw emissions of the non-road heavy-duty diesel engine, experimental study was carried out on the in-cylinder combustion process of the diesel engine in this paper. CHD234V8 common rail direct injection diesel engine was used as a prototype. Through optimization design and matching of the diesel engine combustion chamber structure with fuel injection strategy, the quality of fuel and gas mixture in the cylinder was improved, the proportion of fuel impacting on the combustion chamber wall was optimized, and the maximum in-cylinder pressure was reduced. After the optimization of the diesel engine, the emission performance was greatly improved. Compared with the original engine, the specific fuel consumption at rated power and maximum torque conditions decreased 2.5% and 6.2%, and the smoke emission decreased 71.4% and 67.9%, respectively. CO, (HC+NO<inf>x</inf>), and particulate matters (PM) decreased 33.9%, 11.8%, and 73%, respectively. Emission performance of CHD234V8 diesel engine met the non-road stage III emissions regulation after optimization.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Engine cylinders
Controlled terms:Agriculture - Air purification - Catalysts - Combustion chambers - Diesel engines - Direct injection - Emission control - Exhaust gas recirculation - Fuels - Gas emissions - Nitrogen oxides - Optimization - Particulate emissions - Roads and streets - Smoke - Thermal Engineering
Uncontrolled terms:After-treatment technology - Diesel engine combustions - Direct injection diesel engines - Exhaust gas recirculation (EGR) - Fuel injection strategies - Heavy-duty diesel engine - Non-road mobile machineries - Selective catalyst reduction
Classification code:406.2 Roads and Streets - 451.1 Air Pollution Sources - 451.2 Air Pollution Control - 521 Fuel Combustion and Flame Research - 612.1.1 Internal Combustion Engine Components - 612.2 Diesel Engines - 654.2 Rocket Engines - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.5 Optimization Techniques
Numerical data indexing:Percentage 1.18e+01%, Percentage 2.50e+00%, Percentage 3.39e+01%, Percentage 6.20e+00%, Percentage 6.79e+01%, Percentage 7.14e+01%, Percentage 7.30e+01%, Power 7.50e+04W
DOI:10.11975/j.issn.1002-6819.2019.16.009
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 22>
Accession number:20194607667561
Title:Effects of sowing date, water and nitrogen coupling management on cane yield and sugar content in sugarcane region of Yunnan
Title of translation:云南蔗区播期与水氮耦合对甘蔗产量和糖分影响
Authors:Mao, Jun (1, 2); Wang, Jing (1); Huang, Mingxia (1); Lu, Xin (2); Dao, Jingmei (2); Zhang, Yuebin (2); Tao, Lianan (3); Yu, Huaxian (3)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China; (2) Sugarcane Research Institute, Yunnan Academy of Agricultural Sciences, Kaiyuan; 661699, China; (3) Ruili Sugarcane Breeding Station of Sugarcane Research Institute, Yunnan Academy of Agricultural Sciences, Ruili; 678600, China
Corresponding author:Wang, Jing(wangj@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:134-144
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Sugarcane is a staple sugar crop with a consistently large planting area in Dehong, a humid sugarcane region in Yunnan province, but data are lacking on the interaction effects of sowing date, water (rainfed and irrigated), and nitrogen management on sugarcane production. In this study, the suitability of APSIM-Sugar model (version 7.8) in a humid sugarcane region in Yunnan province was tested based on sequential sowing date experiments conducted at Ruili experimental station in Dehong. Sowing date experiments of sugarcane planting in winter were used for model calibration while sowing date experiments of sugarcane planting in spring were used for model validation. Genetic parameters for 2 sugarcane varieties YZ0551 and ROC22 were derived with trial-and-error method. Using the validated APSIM-Sugar model long-term simulation experiments were designed to evaluate the impacts of coupled sowing date, water and nitrogen management on sugarcane production in Yunnan. Three typical sowing dates were used for sugarcane planting in spring, summer, autumn and winter, i.e. February 20, March 20 and April 20 for sugarcane planting in spring, May 20, June 20 and July 20 for sugarcane planting in summer, August 20, September 20 and October 20 for sugarcane planting in autumn, November 20, December 20 and January 20 for sugarcane planting in winter. We compared different evaluation indices, such as sugarcane yield, sugar content, water, and nitrogen use efficiency, to determine optimal cultivation management options for rainfed and irrigated sugarcane production. The study results confirmed that the APSIM-Sugar model performed well in simulating sugarcane yield and sugar content with normalized root mean squared error (NRMSE) less than 10% and R<sup>2</sup> more than 0.9. Suitable sowing date and optimal management of water-nitrogen could improve significantly sugarcane yield, sugar content, water use efficiency and nitrogen use efficiency in Yunnan Province. Sufficient base fertilizer and appropriate irrigation were the 2 key factors in ensuring high sugarcane yield. However, nitrogen use efficiency decreased significantly when nitrogen fertilizer was applied excessively. Especially under water limited conditions, increasing nitrogen application rate did not increase sugarcane yield, and even led to the decrease of cane yield and sugar content. Planting sugarcane under the suitable sowing date, the natural precipitation in a humid sugarcane production region could meet the water demand during seedling and maturity stages of sugarcane. Irrigation at tillering stage could improve significantly the yield of autumn and winter planting sugarcane while irrigation at elongation stage could be beneficial on the growth of sugarcane planting in spring, summer and autumn season. Water requirement of sugarcane during the whole growth period was generally 1 000-1 200 mm and therefore supplementary irrigation of 180-720 mm was needed for growth and development of sugarcane. Applying base fertilizer plus additional fertilizer could not improve sugarcane yield compared with applying base fertilizer only. Therefore, applying sufficient base fertilizer at sowing was conducive to cost-saving and efficiency-increasing. In order to ensure higher water-nitrogen use efficiency, the reasonable application amount of nitrogen fertilizer for rainfed sugarcane field was 60-120 kg/hm<sup>2</sup>, and that for irrigated sugarcane field was 120-180 kg/hm<sup>2</sup>. Under rainfed condition, planting in spring or winter would probably ensure stable sugarcane yield with high water use efficiency and agricultural efficiency of nitrogen. Simulations predicted sugarcane yields of about 95-100 t/hm<sup>2</sup> and 19% sugar if planted in late February or late December with 60 kg/hm<sup>2</sup> nitrogen and no irrigation. If irrigation was possible, sugarcane planted in spring or autumn would lead to high yield and high water use efficiency and agricultural efficiency of nitrogen. Simulations predicted sugarcane yields of about 120-170 t/hm<sup>2</sup> and 17%-18% sugar for planting in late February or late October with 120-180 kg/hm<sup>2</sup> nitrogen and 360-720 mm irrigation. These results provide supports for improving sugarcane high efficiency production and manage decision by optimizing sowing date, irrigation, and nitrogen management, especially in a humid sugarcane planting region of Yunnan.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Nitrogen fertilizers
Controlled terms:Cultivation - Efficiency - Fertilizers - Irrigation - Mean square error - Sugar cane - Water management
Uncontrolled terms:Agricultural efficiency - Experimental stations - Growth and development - Nitrogen application rates - Nitrogen-use efficiency - Root mean squared errors - Sowing - Trial-and-error method
Classification code:804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.1 Production Engineering - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.00e+01%, Percentage 1.70e+01% to 1.80e+01%, Percentage 1.90e+01%, Size 1.00e+00m to 1.20e+00m, Size 1.80e-01m to 7.20e-01m, Size 3.60e-01m to 7.20e-01m
DOI:10.11975/j.issn.1002-6819.2019.16.015
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 23>
Accession number:20194607667660
Title:Analysis on spatial-temporal evolution of livestock manure emission and pollution load of cultivated land in Nyingchi
Title of translation:林芝畜禽养殖粪便排放时空演变及耕地污染负荷分析
Authors:Hao, Shouning (1); Pubu, Ciren (2); Dong, Fei (3)
Author affiliation:(1) Tibet Agriculture and Animal Husbandry University, Nyingchi; 860000, China; (2) Tibet Vocational Technical College, Lasa; 850000, China; (3) China Institute of Water Resources and Hydropower Research, Beijing; 100038, China
Corresponding author:Dong, Fei(183554031@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:225-232
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to accurately grasp the regional differences in the development of livestock and poultry breeding in NyingchiCity and the pollution threat of livestock and poultry faeces to the environment, this study demonstrated the regional differences and spatio-temporal changes in the increase rates of livestock and poultry production and nitrogen and phosphorus pollution, and analyzed the livestock and poultry pollution load of the cultivated land by using the methods of annual average growth rate and output coefficient. The results showed that the livestock and poultry breeding industry in NyingchiCity developed rapidly, and the annual average growth rates of cattle, pigs and poultry in all the counties were generally higher. Differed from that of other livestock and poultry, the sheep showed a negative growth rate. The development of livestock and poultry breeding could be divided into three stages, i.e. steady development stage (1986-2000), comprehensive development stage (2000-2010), and modernised development stage (2010-2014). In the temporal and spatial evolution of livestock and poultry pollution load in each county of the study area, Milin County and Gongbo'gyamda County grew the fastest. Motuo County kept the minimum load all the time. Longxian County, Gongbo'gyamda County and Milin County had the greatest annual load risk per unit cultivated land area.By comparison, the amount of livestock and poultry pollution was larger in Gongbo'gyamda County, the annual average growth rates were higher in Nyingchi County and Mainling County, and the pollution loads of nitrogen and phosphorus from the livestock and poultry breeding in the unit cultivated area were the heaviest in Lang County. The average loads of phosphorus and nitrogen from the livestock and poultry breeding in Nyingchi City were 400 and 2 345 kg/hm<sup>2</sup>, respectively. The temporal and spatial evolution of livestock and poultry breeding and TP, TN in the study area were similar, and TP,TN pollutants mainly came from the cattle breeding and excretion. The total amount of TP, TN pollutants in livestock and poultry breeding in each county of the study area was different in the three stages of aquaculture development, and the fastest growth was in Nyingchi County, Milin County and Gongbo'gyamda County as a whole. Among them, the highest risk administrative districts were Gongbo'gyamda County and Longxian County, and the least risk administrative districts were Motuo County. The results showed that the TP, TN pollution load of livestock and poultry breeding per unit cultivated land area in the study area had far exceeded the warning stipulated in the agricultural policy of the European Union. Because of the dense inland river network and sensitive ecosystem in Nyingchi City, it was urgent to take scientific and reasonable measures and meant to effectively control and manage the livestock and poultry breeding industry, and to take effective measures to deal with pollutants such as livestock and poultry faeces, so as to ensure the sustainable development of livestock and poultry breeding in NyingchiCity. These results could provide scientific basis for the development planning of agriculture and animal husbandry and the structural adjustment of livestock and poultry breeding in Nyingchi City.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Agriculture
Controlled terms:Fertilizers - Land use - Mammals - Nitrogen - Phosphorus - Pollution - River pollution - Sustainable development
Uncontrolled terms:Agricultural policies - Annual average - Livestock and poultry breeding - Nitrogen and phosphorus - Regional differences - Spatial-temporal evolution - Spatio-temporal changes - Temporal and spatial evolutions
Classification code:403 Urban and Regional Planning and Development - 453 Water Pollution - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.11975/j.issn.1002-6819.2019.16.025
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 24>
Accession number:20194607670350
Title:Soil quality evaluation for reclamation of mining area on Loess Plateau based on minimum data set
Title of translation:基于最小数据集的黄土高原矿区复垦土壤质量评价
Authors:Li, Pengfei (1, 2, 3); Zhang, Xingchang (2); Hao, Mingde (2); Zhang, Yanjiang (4); Cui, Yongxing (2, 3); Zhu, Shilei (4)
Author affiliation:(1) Upper and Middle Yellow River Bureau, Yellow River Conservancy Commission of the Ministry of Water Resources, Xi'an; 710021, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling; 712100, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China; (4) College of Resources and Environment, Northwest A&F University, Yangling; 712100, China
Corresponding author:Zhang, Xingchang(zxc@xab.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:265-273
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mineral exploitation affects soil quality especially in the ecologically fragile areas the Loess Plateau. The quality of soil can be improved by vegetation restoration. In order to reveal the changes of soil quality in the process of vegetation restoration in the reclaimed land of mining, we took Heidaigou mining area and the surrounding natural vegetation restoration area as the research area, and selected 21 physicochemical indicators as the total data set (TDS). The minimum data set (MDS) was constructed by using principal component analysis (PCA) and Norm values. Two evaluation methods, non-linear (NL) and Linear (L), were used to evaluate the soil quality in this study area. The results show that the minimum data set include percentage of silt (Silt), organic matter (OM), available phosphorus (AP), sodium adsorption ratio (SAR) and microbial carbon (MBC). It indicates that in addition to conventional nutrients and physical properties, soil quality in this region is restricted by salinization and microbial biomass. The order of weight of MDS was: MBC (0.241) > OM (0.235) > AP (0.193) > Silt (0.174) > SAR (0.157). The applicability of the two evaluation methods is verified and we find that the overall spatial pattern of soil quality obtained by the two methods is similar, but there are still differences in details. According to the analysis results of the two evaluation methods, soil quality index (SQI) were all significantly improved by vegetation restoration (P < 0.05).Under different vegetation restoration types, the average value of the SQI-NL based on the MDS was sorted as follows: natural vegetation restoration land (NL, 0.587) > shrubs reclamation for 20 years (RLS 20, 0.479) > herbs reclamation for 12 years (RLH 12, 0.455) > shrubs reclamation for 10 years (RLS 10, 0.453) > herbs reclamation for 20 years (RLH 20, 0.424) > arbors reclamation for 20 years (RLA 20, 0.364) > and unreclaimed land (UL, 0.262) (P < 0.05), the average value of the SQI-L based on the MDS was sorted as follows: NL (0.522) > RLS 20 (0.444), > RLS 10 (0.412), > RLH 12 (0.401) > RLH 20 (0.400) > RLA 20 (0.326) > UL (0.228) (P < 0.05). In summary, different vegetation restoration years and different vegetation restoration types significantly improved the SQI of reclaimed land of mine areas (P < 0.05); however, the SQI of all reclaimed land has not reached that of natural vegetation restoration land, which indicates that the soil quality restoration of reclaimed land of mine areas is a long process. Since the SQI - NL method has a wider value range of SQI and coefficient of variation, this method has better applicability in this region than SQI-L, this is because 1) in the case of a wide range of soil quality index, the identification and classification accuracy of soil quality can be improved, which is conducive to the accurate evaluation of soil quality status and the timely detection of problems; 2) the coefficient of variation represents the sensitivity of SQI to changes in different environmental conditions, the higher the sensitivity of soil quality index to changes in environmental conditions is, the clearer the influence factors of soil quality change can be reflected, thus more effectively guiding the scientific management of soil quality improvement. Under the SQI-NL and SQI-L methods, the determination coefficients between MDS and TDS are 0.911 and 0.866, respectively, indicating that MDS can accurately replace TDS for soil quality evaluation. This study summarizes the MDS and soil quality evaluation methods suitable for the reclamation soil quality evaluation in the mining areas of the Loess Plateau, and recommends the future research and application in the same area and soil conditions.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Quality control
Controlled terms:Land reclamation - Landforms - Principal component analysis - Quality assurance - Reclamation - Restoration - Sediments - Sensitivity analysis - Silt - Vegetation
Uncontrolled terms:Coefficient of variation - Determination coefficients - Environmental conditions - Loess Plateau - Minimum data set - Mining areas - Research and application - Soil quality evaluation
Classification code:442.2 Land Reclamation - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 913.3 Quality Assurance and Control - 921 Mathematics - 922.2 Mathematical Statistics
Numerical data indexing:Age 1.00e+01yr, Age 1.20e+01yr, Age 2.00e+01yr
DOI:10.11975/j.issn.1002-6819.2019.16.030
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 25>
Accession number:20194607667518
Title:Effect of wind-preventing and sand fixation of belt sand barrier under different degree of sand burial
Title of translation:不同沙埋程度下带状沙障的防风固沙效果研究
Authors:Yuan, Limin (1, 2); Huang, Haiguang (1, 2, 3); Yan, Deren (1, 2); Hu, Xiaolong (1, 2)
Author affiliation:(1) Inner Mongolia Institute of Forestry Research, Hohhot; 010010, China; (2) Inner Mongolia Duolun Hunshandake Sand Ecosystem Research Station, Xilingol; 027300, China; (3) Forestry College of Inner Mongolia Agricultural University, Hohhot; 010018, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:172-179
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Sand barrier is easy to be buried by sand at the beginning of the sand barrier setting and it will lose wind-preventing and sand fixation function when it is buried deeper, but moderate sand bury can improve protect effect while sand burial will help the sand barrier to form a stable protective structure. So it is conducive to understanding the sand burial mechanism and the change law of protective benefits caused by sand burial. In order to study the difference of wind-preventing and sand fixation of different depth sand burial of sand barrier, the research conducted wind tunnel simulation and field experiment. The laws of wind flow field and sediment transport flux in surface layer of the protection zone which was protected by sandbag sand barrier under the condition of bare, shallow and deep sand buried were studied, and the mobile sand dunes without sand barrier was taken as a control. In the wind tunnel test, the variation of the near-surface airflow field, wind speed profile, sediment transport rate and sediment transport height during the sand burial process were analyzed. Sandbag sand barriers were set up in the windward slopes of mobile sand dunes and wind erosion resistance effects of the three sand burial states were tested. The research results showed that with the sand barrier experienced the process of being bare-shallow-deep sand burial, 1) the variation of the airflow field was gradually and steadily in the near-surface layer, and the turbulent flow was reduced significantly, multiple low-speed settlement areas appeared at the right rear when it was bare, and disappeared when it was shallow burial; 2) Both of effective protecting distance and height of transit flow were decreased, that were at least 70 cm and 15 cm of the leeward side of the sand barrier when it was bare, but fell below 50 cm and 7 cm respectively when it was deep burial; 3) The wind speed distribution curve of the near surface layer on the windward and leeward side of the sand barrier did not obey the logarithmic function, and the wind speed profile was volatility change with the height, as the sand barrier was gradually buried by sand, wind speed profile was the same as that of the control and obeyed the law of logarithmic distribution; 4) The height of transporting sediment discharge on protection zone of the sand barriers decreased significantly (P<0.01), height of transporting sediment discharge decreased from 42 cm (bare) to 34 cm (shallow burial) and finally to 28cm (deep burial), and the distribution height of the control was 24 cm; 5) Field experiments of three burial depths showed that wind erosion depth of bare, shallow and deep buried sandbag sand barriers in protection area showed a decreasing trend two years after setting up, the depth of wind erosion decreased by 18.53%, 72.97% and 80.40% respectively compared with the control. The research can provide theoretical support for optimization of sand barrier height and improvement of applied technology.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Sand
Controlled terms:Air - Erosion - Flow fields - Sediment transport - Sedimentation - Soil testing - Soils - Speed - Wind - Wind tunnels
Uncontrolled terms:Sand barriers - Sediment discharge - Wind erosions - Wind profiles - Wind speed
Classification code:443.1 Atmospheric Properties - 483.1 Soils and Soil Mechanics - 631.1 Fluid Flow, General - 651.2 Wind Tunnels - 802.3 Chemical Operations - 804 Chemical Products Generally
Numerical data indexing:Percentage 1.85e+01%, Percentage 7.30e+01%, Percentage 8.04e+01%, Size 1.50e-01m, Size 2.80e-01m, Size 3.40e-01m, Size 4.20e-01m, Size 5.00e-01m, Size 7.00e-01m, Size 7.00e-02m
DOI:10.11975/j.issn.1002-6819.2019.16.019
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 26>
Accession number:20194607667585
Title:Development of spraying device for precise and deep application of liquid fertilizer in sowing period
Title of translation:播种期液态肥精量深施系统喷肥装置研制
Authors:Yu, Changchang (1); Wang, Qingjie (1); He, Jin (1); Li, Hongwen (1); Lu, Caiyu (1); Liu, Zhengdao (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Wang, Qingjie(wangqingjie@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:50-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To satisfy the technical requirements of precise and deep application of liquid fertilizer in sowing period of maize, a toward-target spot application system of liquid fertilizer is proposed in this paper, and a liquid fertilizer spraying device is designed. The device consisted of valve body, pressure regulation spring, valve seat, valve core and nozzle. The initial deformation of pressure regulating spring can be changed by adjusting the length of the nozzle screwed into the valve body, so the contact pressure between valve core and valve seat is changed. The liquid fertilizer spraying device is mainly divided into two states when working, open and closed, which were determined by the liquid fertilizer pressure and the contact pressure (which was the pressure between valve core and valve seat). The liquid fertilizer spraying device closes when liquid fertilizer pressure is less than the contact pressure, and in contrast, the liquid fertilizer spraying device open, thus the operation process of intermittent discharge of the liquid fertilizer was achieved. Nozzle is a key component of the fertilizer application, and the shape and parameters of nozzle are important factors affecting the performance of the liquid fertilizer spraying device. In order to obtain the best nozzle shape and parameters, two-dimensional geometric models of different shaped nozzles, such as conical straight, conical and cylindrical, are established in ANSYS Fluent. The geometric model is meshed and boundary conditions such as entrance boundary, exit boundary and symmetrical boundary are set. In the calculation model, VOF (fluid volume) is used as the multiphase flow model, in which the initial phase is air and the second phase is liquid fertilizer. And RNG k-Ε model is used for viscous model and standard wall function is used for near wall. The non-submerged jet process of the nozzle is simulated by the non-coupled solver SIMPLE (semi-implicit method for pressure linked equation) algorithm. The velocity and total pressure of different nozzles in the direction of the central axis and the radial are analyzed, and obtained the bundle performance of different nozzles. According to the simulation results, the cone shape is determined as the best nozzle shape. In order to evaluate the working performance of the liquid fertilizer spraying device, a conical nozzle is selected to establish a fluid simulation model. And taking the fertilization amount as the evaluation index, the pump pressure and nozzle diameter as the test factors, the two-factor and five-level full factors experiment is designed, and the nalysis of variance (ANOVA) is performed to find the influence of parameters. The simulation results show that the factors of pump pressure and nozzle diameter have significant effects on fertilization amount (P<0.01), and the diameter of the nozzle has a greater influence than the pump pressure. A regression equation between the fertilization amount, the pump pressure and the nozzle diameter is established, and the R<sup>2</sup> of the equation is 0.998. The bench experiments of liquid fertilizer spraying device with the nozzle diameters of 2.5 and 3.0 mm are carried out separately. The results show that the value of the fertilization amount increases gradually as the pump pressure increasing when the pump pressure is within the range of 0.2 to 0.6 MPa. The growth trend of the fertilization amount is basically consistent with the predicted value of the regression equation. The experiment value of fertilization amount average decreases by 1.62% (0.12 mL) than predicted value after the regression equation was corrected. The accuracy of the simulation model and the regression equation is verified. This study can lay a foundation for the further study of the toward-target spot application system of liquid fertilizer.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Fertilizers
Controlled terms:Agricultural machinery - Air - Experiments - Geometry - Liquids - Nozzles - Pumps - Regression analysis - Spray nozzles - Wall function
Uncontrolled terms:Fertilizer applications - Intermittent discharge - Liquid fertilizers - Multi-phase flow models - Regression equation - Semi-implicit method for pressure linked equations - Simulation - Technical requirement
Classification code:618.2 Pumps - 631.1 Fluid Flow, General - 804 Chemical Products Generally - 821.1 Agricultural Machinery and Equipment - 901.3 Engineering Research - 921 Mathematics - 922.2 Mathematical Statistics
Numerical data indexing:Pressure 2.00e+05Pa to 6.00e+05Pa, Size 2.50e-03m, Size 3.00e-03m, Volume 1.20e-07m3
DOI:10.11975/j.issn.1002-6819.2019.16.006
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 27>
Accession number:20194607670453
Title:Effect of water-fertilizer coupling on photosynthetic characteristics, fruit yield, water and fertilizer use of mango
Title of translation:水肥耦合对芒果光合特性和产量及水肥利用的影响
Authors:Liu, Xiaogang (1); Sun, Guangzhao (1); Peng, Youliang (1); Yang, Qiliang (1); He, Hongyan (2)
Author affiliation:(1) Faculty of Agriculture and Food, Kunming University of Science and Technology, Kunming; 650500, China; (2) Tropical and Subtropical Economic Crops Institute, Yunnan Academy of Agricultural Sciences, Baoshan; 678025, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:125-133
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mango (Mangifera indica L.) is one of the most important economic crops in dry and hot regions of southwest China. The yield is unstable due to seasonal drought, no irrigation or flood irrigation, and irrational fertilizer. Given the current situation of water and fertilizer supply as well as future scenarios, it is important to delineate strategies for improving water and fertilizer use efficiency and crop productivity. In this study, the native 4-year-old mango (Mangifera indica L., cv. 'Guifei') was chosen as experiment material. The field experiment was conducted during main growing seasons (from January to July in 2018) in an experimental mango orchard in Yuanjiang Country, Yunnan, China. We investigated the effect of water and fertilizer regulating on canopy structure, photosynthetic characteristics, fruit yield, irrigation water use efficiency (IWUE), and fertilizer partial productivity of mango. The irrigation and fertilizer treatments were designed in orthogonal experiment (L<inf>9</inf> (3<sup>4</sup>)). Four experimental factor were included the supply fertilizer at the three growth stages (flower bud differentiation stage (F<inf>Ⅰ</inf>), flowering stage (F<inf>Ⅱ</inf>) and fruit expansion stage (F<inf>Ⅳ</inf>)) and irrigation level. Three fertilization levels were 75 kg/hm<sup>2</sup> (F<inf>75</inf>), 50 kg/hm<sup>2</sup> (F<inf>50</inf>), and 25 kg/hm<sup>2</sup> (F<inf>25</inf>), and three irrigation levels were full irrigation (FI-100%ET<inf>c</inf>, ET<inf>c</inf> means crop water requirement), mild deficit irrigation (DI<inf>M</inf>-75%ET<inf>c</inf>), and severe deficit irrigation (DI<inf>S</inf>-50%ET<inf>c</inf>), respectively. The results showed that compared with FI, DI<inf>S</inf> reduced significantly LAI, net photosynthetic rate (except for 15:00), transpiration rate, stomatal conductance and carboxylation efficiency (P<0.05). After fertilizer application at fruit expansion stage, T8 treatment (FIF<inf>Ⅰ50</inf>F<inf>Ⅱ25</inf>F<inf>Ⅳ75</inf>) had the largest LAI and transpiration rate, and the net photosynthetic rate, stomatal conductivity and carboxylation efficiency at 11:00 of T6 treatment (DI<inf>M</inf>F<inf>Ⅰ75</inf>F<inf>Ⅱ25</inf>F<inf>Ⅳ50</inf>) were higher than that of other treatments. In addition, the leaf instantaneous water use efficiency (LWUE) at 11:00 of most DI<inf>M</inf> was much higher than FI (P<0.05). Under the condition of quantitative fertilization in the whole growth period, the increase of the proportion of fertilizer distribution in flower bud differentiation and fruit expansion could increase the fruit yield and the fertilizer partial productivity at FI, and could improve IWUE at DI<inf>M</inf>. T8 treatment had the largest fruit yield (14 480.46 kg/hm<sup>2</sup>) and fertilizer partial productivity (96.54 kg/kg), and T6 treatment had the highest IWUE (6.67 kg/m<sup>3</sup>). The order of factors affecting the fruit yield, water and fertilizer use efficiency was obtained by the range analysis as follows: irrigation level> flowering stage fertilization> fruit expansion period fertilization> flower bud differentiation stage fertilization. The comprehensive scoring method evaluation indicated that, the optimal mode of coupling between variable fertilization at different growth stages and irrigation was irrigation level of 75%ET<inf>c</inf>, fertilizer rate of flower bud differentiation stage of 75 kg/hm<sup>2</sup>, flowering stage of 25 kg/hm<sup>2</sup>, and fruit expansion stage of 50 kg/hm<sup>2</sup> (DI<inf>M</inf>F<inf>Ⅰ75</inf>F<inf>Ⅱ25</inf>F<inf>Ⅳ50</inf>). The study results could provide a scientific reference to water and fertilizer managements of mango in dry and hot regions.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Fruits
Controlled terms:Carboxylation - Crops - Efficiency - Fertilizers - Irrigation - Plants (botany) - Productivity - Transpiration - Water supply
Uncontrolled terms:Comprehensive evaluation - Fertilization - Hot regions - Orthogonal design - Yield
Classification code:446.1 Water Supply Systems - 461.9 Biology - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.1 Production Engineering
Numerical data indexing:Age 4.00e+00yr, Mass_Density 6.67e+00kg/m3
DOI:10.11975/j.issn.1002-6819.2019.16.014
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 28>
Accession number:20194607670314
Title:Image segmentation of maize stubble row based on genetic algorithm and threshold filtering noise
Title of translation:基于遗传算法和阈值滤噪的玉米根茬行图像分割
Authors:Wang, Chunlei (1, 2); Lu, Caiyun (1, 2); Chen, Wanzhi (1, 2); Li, Hongwen (1, 2); He, Jin (1, 2); Wang, Qingjie (1, 2)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) Scientific Observing and Experimental Station of Arable Land Conservation (North Hebei), Ministry of Agriculture, Beijing; 100083, China
Corresponding author:Li, Hongwen(lhwen@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:198-205
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Green crop is generally used as the foreground in image segmentation of agricultural visual navigation system because of its obvious chromaticity difference from the basic image background. However, for the segmentation of maize stubble row, there are many backgrounds in the field harvested by combine harvester, such as naked land surface, maize residues, which has little color difference with the maize stubble row. To achieve accurate and quick segmentation of maize stubble row, an image segmentation approach of maize stubble row based on genetic algorithm and threshold filtering noise was proposed in this paper. Firstly, the RGB color space was selected to accomplish the segmentation, which is a basic color space and widely used in machine vision automatic guidance systems. Secondly, to reduce the difficulty of image segmentation, the region of interest (ROI) was selected by calculating the maximum of column gray value accumulation. Thirdly, the gray-scale image of the maize stubble row was obtained through the optimized gray-scale operator. Besides, the genetic algorithm was often used in global optimization, which was used to optimize the gray-scale operator. Specially, the maize stubble row image's pixel was divided into 3 classes: land surface, residues in rows and stubble tip incision, and the 3 classes were selected as the sample to optimize the gray-scale operator by genetic algorithm. Then, the segmentation of single threshold method was used to segment the gray-scale image. Furthermore, the segmentation of single threshold method is widely used in image segmentation because of its high efficiency and convenience. Lastly, the morphological corrosion treatment (MCT) and threshold noise filtering algorithm (TNFA) were applied to guarantee the integrity of the maize stubble row region and the noise points on both sides of the maize stubble row removal. In order to verify the effect of the method proposed in this paper, 200 test images were captured from Scientific Observing and Experimental Station of Arable Land Conservation (North Hebei), Ministry of Agriculture in Baoding City, China in each October during 2014-2016. The acquisition was often on sunny day, aiming at collecting images under different natural lighting conditions, different positions in maize stubble row field. The results showed that the average relative object area error (ARAE) by our method was only 24.68%, while the AREA of the iteration method and the OTSU method were 90.67% and 86.42%, respectively. The average processing time of a test image based on this paper presented algorithm was 0.16 s, which was much more time-consuming than the OTSU method (0.07 s), while the processing time of our method was less than the iteration method (0.25 s). Therefore, the method presented in this paper achieved better performance than other methods in maize stubble row segmentation, and was effective to segment the maize stubble row in the complicated backgrounds. The presented method can provide precise basis for detection of guidance line in maize straw covering field.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Image segmentation
Controlled terms:Color - Colorimetry - Computer vision - Conservation - Corrosion - Genetic algorithms - Global optimization - Grain (agricultural product) - Iterative methods - Navigation systems - Surface measurement
Uncontrolled terms:Combine harvesters - Corrosion treatment - Experimental stations - Gray-scale images - Maize stubble row - The region of interest (ROI) - Threshold filtering - Visual navigation systems
Classification code:741.1 Light/Optics - 741.2 Vision - 821.4 Agricultural Products - 921.5 Optimization Techniques - 921.6 Numerical Methods - 941.4 Optical Variables Measurements - 943.2 Mechanical Variables Measurements
Numerical data indexing:Percentage 2.47e+01%, Percentage 8.64e+01%, Percentage 9.07e+01%, Time 1.60e-01s, Time 2.50e-01s, Time 7.00e-02s
DOI:10.11975/j.issn.1002-6819.2019.16.022
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 29>
Accession number:20194607670341
Title:Remote estimation of cotton LAI using Sentinel-2 multispectral data
Title of translation:基于Sentinel-2多光谱数据的棉花叶面积指数估算
Authors:Yi, Qiuxiang (1, 2, 3)
Author affiliation:(1) State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi; 830011, China; (2) Key Laboratory of GIS & RS Application Xinjiang Uygur Autonomous Region, Urumqi; 830011, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Yi, Qiuxiang(yiqx@ms.xjb.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:189-197
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rapid and accurate LAI (Leaf Area Index) acquisition is of great significance for remote sensing monitoring of cotton growth, diagnosis of growth stage, extraction of cotton plant area and yield estimation. The present research discussed the characteristics of Sentinel-2 multi-spectral satellite data for remote estimation of cotton LAI. Measured LAI from filed experiments and Sentinel-2 data in 2017 and 2018 were obtained, and LAI estimation model for different and for all growth stages were established basing on single spectral band reflectance on Sentinel-2 and various vegetation index from Sentinel-2 bands. The estimation accuracy of the established LAI models were validated by coefficient of determination (R<sup>2</sup>), RMSE (root mean square error), mean bias, and slope and intercept, using LOOCV (Leave-One-Out-Cross Validation) method and cross validation, respectively. The results showed that: 1) for the single-band reflectance of sentinel-2 multi-spectral satellite data, two red-edge bands of B6 and B7, and two near-infrared bands of B8 and B8a, were all significantly (P<0.001) correlated to LAI at all three tested growth stages, i.e. bud stage (16-Jun-2017), and flowering stage (23-Jun-2018), and boll stage (2-Aug-2017), with correlation coefficient greater than 0.7. And when the correlation between LAI and band reflectance were performed using data consist of three growth stages, the correlation coefficient for all tested bands reach significant level (P<0.001), and the maximum correlation coefficient was 0.943 of near-infrared narrow band B8a, which center at 865 nm with a wave width of 32 nm. The accuracy of LAI estimation at different development stages was optimized using the near-infrared band B8 which with a central wavelength of 842 nm and a wave width of 145 nm, with all RMSE smaller than 0.465. 2) for seventeen LAI related vegetation indices, including EVI (Enhanced Vegetation Index), MSAVI2 (Modified Soil Adjusted Vegetation Index 2), IRECI (Inverted Red-Edge Chlorophyll Index), etc., most of them were significantly (P<0.001) correlated with LAI, especially atmospheric correction index EVI, soil adjusted index MSAVI2, and red-edge index IRECI, and the coefficient of correlation were over 0.8. EVI provided the best result for LAI estimation at bud stage and boll stage, and at flowering stage it consists by MASVI2, with bud stage RMSE=0.352, and boll stage RMSE=0.367 and flowering stage RMSE=0.323, respectively. 3) LAI estimation models for whole growth stages performed better than these for one single growth stage. And the best LAI estimation models for whole growth period using single spectral band reflectance and vegetation index were respectively obtained by near-infrared narrow band B8a and IRECI, with IRECI performed slightly better, which with R<sup>2</sup>=0.908 and RMSE=0.425 for LOOCV, and R<sup>2</sup>=0.951 and RMSE=0.368 for cross validation. Additionally, when apply IRECI-LAI estimation model for whole growth stages on one single growth stage LAI estimation, the accuracy comparison between the IRECI-LAI model and single growth stage LAI models showed that the average cross validation RMSE was only 0.07 greater than the average LOOCV RMSE, indicating the good universality of LAI estimation model for whole growth stages.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:44
Main heading:Infrared devices
Controlled terms:Cotton - Mean square error - Models - Reflection - Remote sensing - Vegetation
Uncontrolled terms:Coefficient of determination - Leaf Area Index - Leave-one-out cross validations - Maximum correlation coefficient - RMSE (root mean square error) - Rops - Sentinel-2 data - Vegetation index
Classification code:821.4 Agricultural Products - 922.2 Mathematical Statistics
Numerical data indexing:Size 1.45e-07m, Size 3.20e-08m, Size 8.42e-07m, Size 8.65e-07m
DOI:10.11975/j.issn.1002-6819.2019.16.021
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 30>
Accession number:20194607670298
Title:Upgrading biomass pyrolysis gas from corn stalk by charcoal catalytic reforming
Title of translation:生物质炭催化玉米秸秆热解气重整提质研究
Authors:Wang, Jingru (1, 2); Yao, Zonglu (1); Cong, Hongbin (1); Zhao, Lixin (1, 2); Ma, Teng (1); Huo, Lili (1); Yuan, Yanwen (1)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture and Rural Affairs, Beijing; 100125, China; (2) School of Engineering, Heilongjiang Bayi Agricultural University, Daqing; 163319, China
Corresponding author:Zhao, Lixin(zhaolixin5092@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:258-264
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biomass pyrolysis technology is a thermochemical conversion technique. Through the pyrolysis technology, straw recycling can be realized, and high value-added energy products such as biochar and pyrolysis gas can be obtained. However, the tar produced in the pyrolysis process contains heavy poisonous components, and the low temperature viscosity is high, which easily causes pipeline blockage. In order to study the effect of biochar as catalyst for reducing tar and improving pyrolysis gas quality, taking corn stalk as raw material, the tar conversion rate, pyrolysis gas yield and pyrolysis gas heat value were selected as index. The effects of reforming temperature (550, 600, 650, 700, 750, 800℃), residence time (0.2, 0.6, 1.0, 1.4, 1.8 s) and biochar characteristics (corn straw charcoal, rice husk, wood charcoal) on pyrolysis gas quality were studied. The changes of specific surface area of biochar catalysts before and after reforming were analyzed. The results showed that at high temperature cracking, the pyrolysis gas yield was 33.8%, and the pyrolysis gas heat value was 18.0 MJ/m<sup>3</sup>, biochar had better catalytic properties than quartz sand (high temperature cracking), and its catalytic properties were: rice husk charcoal > wood charcoal > corn straw charcoal, indicating that the catalytic properties of rice hull carbon were better. The pyrolysis gas yields of rice husk charcoal, wood charcoal and corn straw charcoal were 39.7%, 38.6%, and 37.9%, respectively, and the tar conversion rates were 79.8%, 78.6% and 72.6%, the calorific values were 17.8, 17.7 and 17.6 MJ/m<sup>3</sup>, respectively. When the reforming temperature was increased from 550 to 800℃, the pyrolysis gas yield increased from 21.0% to 37.9%, the tar conversion rate increased from 23.8% to 72.6%, and the pyrolysis gas calorific value increased from 13.0 to 17.6 MJ/m<sup>3</sup>, which was due to the increase of temperature to promote the cracking reaction of tar. The tar heavy components were partially converted into light components and non-condensable gases. As the residence time increased from 0.2 to 1.8 s, the pyrolysis gas yield increased from 37.9% to 54.3%, and the tar conversion rate increased from 72.6% to 79.8%. The pyrolysis gas heat value was reduced from 17.6 to 16.8 MJ/m<sup>3</sup>. It was due to the increase in residence time, which promoted the catalytic conversion of the tar component on the active site of the mineral component on the surface of the biochar, resulting in an increase in the yield of the pyrolysis gas. At 800 ℃, the specific surface area of biochar after catalytic cracking was 79.81 m<sup>2</sup>/g, which was higher than the specific surface area of pyrolysis biochar of 37.96 m<sup>2</sup>/g. In summary, as the reforming temperature and residence time increased, the pyrolysis gas yield and tar conversion rate increased, and the pyrolysis gas heat value increased only as the reforming temperature increased. Although biochar can increase pyrolysis gas yield and tar conversion rate, the calorific value was low. Biochar can not only improve the quality of pyrolysis gas, but also increase the specific surface area of biochar at 800℃, indicating that the interaction between biochar and pyrolysis gas can not only improve the quality of pyrolysis gas, but also increase the specific surface area of biochar.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Catalytic reforming
Controlled terms:Calorific value - Catalysts - Catalytic cracking - Charcoal - Couplings - Gases - Pyrolysis - Specific surface area - Straw - Tar - Temperature
Uncontrolled terms:Bio chars - Catalytic properties - Catalyzation - Gas calorific values - High temperature crackings - Low-temperature viscosity - Reforming temperatures - Thermochemical Conversion
Classification code:524 Solid Fuels - 641.1 Thermodynamics - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.5 Agricultural Wastes
Numerical data indexing:Percentage 2.10e+01% to 3.79e+01%, Percentage 2.38e+01% to 7.26e+01%, Percentage 3.38e+01%, Percentage 3.79e+01%, Percentage 3.79e+01% to 5.43e+01%, Percentage 3.86e+01%, Percentage 3.97e+01%, Percentage 7.26e+01%, Percentage 7.26e+01% to 7.98e+01%, Percentage 7.86e+01%, Percentage 7.98e+01%, Specific_Surface_Area 3.80e+04m2/kg, Specific_Surface_Area 7.98e+04m2/kg, Time 1.80e+00s, Time 2.00e-01s to 1.80e+00s
DOI:10.11975/j.issn.1002-6819.2019.16.029
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 31>
Accession number:20194607667588
Title:One-dimensional isothermal drying model for parenchyma cell tissue of potato tuber
Title of translation:马铃薯薄壁细胞组织一维等温干燥模型
Authors:Xiao, Bo (1, 3); Yun, Hongxiang (2); Yang, Deyong (3); Liu, Qinghua (1); Liu, Xiangdong (3)
Author affiliation:(1) Guangdong Institute of Modern Agricultural Equipment, Guangzhou; 510630, China; (2) Sanjian Branch, Jinan Foreign Language School, Jinan; 250108, China; (3) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Liu, Xiangdong(xdliu@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:309-319
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Drying is a widely used technique in processing plant materials, such as fruits and vegetables. The material structure significantly change before and after drying, an accurate description of this structural change, however, has not yet been seen. From the perspective of whole drying process, the relationship between cell water potential and its water content is no longer an approximate linear relationship; and the water diffusion resistance inside cells is no longer negligible compared with the cell membrane resistance. The known mass transfer models for evaporative water loss, including drying models, with considering the cellular structure, are based on an accurate description of the geometric structure of fresh tissue with positive cell turgor pressure, and are not fully applicable to entire drying process. In order to describe the moisture transport mechanism of entire drying process, it is necessary to propose a cell tissue model suitable for the structure change from the state of positive turgor pressure to the state of turgor pressure lost during drying, and to consider the characteristics of moisture transport at cell scale. Based on tissue physiological structure, micro-parameter measurement technology and cell structure change, a parenchyma cell tissue model for isothermal convection drying under low temperature is proposed. The drying temperature is lower than 50℃, because higher temperature will damage cell membranes. The tissue is made up of cells that are composed of cell walls, cell membranes, and model solutions in the cell cavities. The water in the cell walls is pure water, and the cell walls only deform during drying and do not shrink. Smooth the subcellular structures in the cell cavities. A cell membrane is an ideal semi-permeable membrane, which lumps all the transmembrane effects in the real cell. The diffusion of water in a model solution represents all the diffusion effects inside the real cell. During drying process, the cell membranes always cling to the cell walls, and after turgor lost, the cells collapse and shrinkage. Based on the method of building composite parameter transport model, a one-dimensional mass transfer model was constructed, considering cells and shrinkage. The transfer coefficient is directly derived from cell transport properties by replacing plant tissue with regularly arranged cells. The cell-scale water transport is identified as the cell cavity to cell cavity, the cell wall network and the intercellular air space transports under the assumption of local water potential equilibrium. The diffusion effect in cell cavity and the nonlinear relationship between water potential and cell moisture content is included in the transfer coefficient. The composite parameter model does not depend on a precise description of the cellular structure of tissue, but only its representative parameters, it is expected to be useful in describing the drying process of plant cell tissue. Simulation and experiment results show that the model can predict the drying process of potato tuber tissue accurately when the average moisture content is not less than 1.0 (d.b.). Model analysis reveals that the priority of water transport pathways in the drying process of potato tuber tissue is cell cavity to cell cavity > cell wall network > intercellular air space. However, this model cannot explain the vapor diffusion effect in the intercellular air space in the end period of drying. To solve this problem, the stop of transports from cell cavity to cell cavity and in cell wall network should be studied in the future research. To describe the drying process better, the influences of anisotropic shrinkage on the porosity and tortuosity tensor in drying also should be studied in the future.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:47
Main heading:Cytology
Controlled terms:Cells - Cellular automata - Diffusion - Drying - Isotherms - Membranes - Models - Moisture control - Moisture determination - Physiological models - Shrinkage - Temperature - Tissue - Walls (structural partitions)
Uncontrolled terms:Intercellular air spaces - Mass transfer modeling - Moisture transfer - Non-linear relationships - Physiological structures - Plant parenchyma - Potato - Semi-permeable membranes
Classification code:408.2 Structural Members and Shapes - 461.2 Biological Materials and Tissue Engineering - 641.1 Thermodynamics - 723 Computer Software, Data Handling and Applications - 921 Mathematics - 944.2 Moisture Measurements - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2019.16.034
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 32>
Accession number:20194607667575
Title:Coupling relationship between content of unsaturated fatty acid and drying system of corn grain after variable temperature and humidity drying
Title of translation:玉米籽粒变温变湿干燥后不饱和脂肪酸与干燥系统的耦合关系
Authors:Wu, Wenfu (1); Chen, Junyi (1); Cheng, Rongmin (2); Jin, Yi (1); Wei, Xuesong (1); Xiao, Biliang (3); Xu, Yan (1)
Author affiliation:(1) College of Biology and Agricultural Engineering, Jilin University, Changchun; 130022, China; (2) College of Chemistry, Jilin University, Changchun; 130021, China; (3) Technical Engineering College, Lanzhou University of Technology, Lanzhou; 730050, China
Corresponding author:Xu, Yan(xuyan@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:328-333
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The content of unsaturated fatty acid (UFA) is an important index to evaluate the quality of corn. It is not only the main fatty acid of corn, but also a very important dietary fatty acid and essential nutrient in human body. In order to study the relationship between UFA content and the drying system coupling factor of corn, an orthogonal experiment was designed. This experiment was based on the actual drying parameters of the corn dryer in Harbin grain dryer. First, the drying process was divided into three stages, each stage had different hot air temperature and relative humidity, so as to establish a six factors and three levels of sectional temperature and humidity orthogonal drying experiment. There were a total of 30 groups of experiments. Then, the content of UFA in dry corn was determined by microwave extraction and gas chromatography. Finally, the relationship between drying system coupling factor and UFA content in corn was calculated. On the premise of meeting the drying standard of edible corn, the highest content of UFA was 6.553% under the drying conditions of hot air temperature of 35℃-50℃-50℃ and relative humidity of 30%-45%-30%.After repeated verification, the actual optimal value was 6.547%. It is proved that the actual optimal value was consistent with the predicted value through the verification of the predicted optimal combination. Then the coupling relationship between UFA and coupling factors of the drying system ( including accumulated temperature, the absolute water potential sum of the air, the absolute water potential sum of the grain, the difference between the absolute water potential sum of the air and the absolute water potential sum of the grain, the accumulated of the absolute water potential of the air, the accumulated of the absolute water potential of the grain, the difference between the accumulated of the absolute water potential of the air and the accumulated of the absolute water potential of the grain) were calculated, and the results showed that the order of coupling relationship between UFA content and drying system was as follows: STMMG (0.674 3)> DSTMMGA (0.660 2)> STMMA (0.608 9)> SGT (0.589 3)> DATMMGA (0.477 2)> ATMMA (0.315 7)> ATMMG (0.257 6)> EAT (0.203 8). The coupling relationship between UFA content and absolute water potential of grain was the best. The formula for calculating the absolute water potential of grain can explain the coupling degree between them, and also prove that the theory of water potential can analyze and predict the content of unsaturated fatty acids in corn grains.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Grain (agricultural product)
Controlled terms:Atmospheric humidity - Atmospheric temperature - Couplings - Dryers (equipment) - Drying - Gas chromatography - Optimal systems - Temperature - Unsaturated fatty acids
Uncontrolled terms:Accumulated temperatures - Corn - Coupling relationships - Microwave extraction - Orthogonal experiment - Temperature and humidities - Variable temperature - Water potential
Classification code:443.1 Atmospheric Properties - 641.1 Thermodynamics - 802.3 Chemical Operations - 804.1 Organic Compounds - 821.4 Agricultural Products - 961 Systems Science
Numerical data indexing:Percentage 6.55e+00%
DOI:10.11975/j.issn.1002-6819.2019.16.036
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 33>
Accession number:20194607670380
Title:Physical and chemical properties and product quality evaluation of biochar from typical agricultural residues
Title of translation:典型农业生物炭理化特性及产品质量评价
Authors:Huo, Lili (1); Yao, Zonglu (2); Zhao, Lixin (1); Meng, Haibo (1); Cong, Hongbin (1); Li, Lijie (1); Yuan, Yanwen (1); Liu, Guanghua (3)
Author affiliation:(1) Chinese Academy of Agricultural Engineering Planning & Design, Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture and Rural Affairs, Beijing; 100125, China; (2) Institute of Environment and Sustainable Development in Agriculture, CAAS, Beijing; 100084, China; (3) Chengde Bente Ecology & Energy Technology Co.Ltd., Chengde; 067000, China
Corresponding author:Yao, Zonglu(yaozonglu@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:249-257
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biochar can repair soil, replace fossil fuels, and adsorb environmental pollutants. Biochar helps to reduce greenhouse gas emissions and prevent environmental pollution. Its application value is very large and its use range is wide. At present, there are problems such as large differences in quality of straw-based biochar products, inconsistencies in characteristics and test methods. This paper systematically studied the quality requirements of biochar at home and abroad. The research put forward the biochar evaluation index system of fertilizer application, energy carbon, activated carbon and other application directions. Focusing on straw biochar, the study analyzed the meanings and influencing factors of physical, chemical, thermochemical, surface chemistry and toxic pollutants. The results showed that the content of C element in straw biochar was generally higher than 40%, and the pH value was alkaline, generally 7.0-10.3. Straw biochar contained a certain amount of nutrients and could be used as a fertilizer supplement, but it was necessary to prevent the risk of heavy metals exceeding the standard. The straw-like biochar had a calorific value of 20-30 MJ/kg, a fixed carbon content of 40%-61%, and a volatile content of <20%, which was close to the medium and low volatile bituminous coal, could be used as an energy carbon application. The straw biochar had high alkali metal and chlorine content, low ash melting point, so it needed to prevent slagging and corrosion problems. The specific surface area of straw biochar was <500 m<sup>2</sup>/g, the pore size distribution was concentrated near mesopores, and the CEC value was <50 cmol/kg. The most important functional group on the surface of biochar was oxygen-containing functional group, and the number of basic functional groups was average, which was greater than the number of acidic functional groups. Biochar had a large specific surface area, a rich surface pore diameter, and a certain adsorption property, which could be used for activated carbon. The contents of toxic pollutants PAHs, PCBs and PCDD/Fs in biochar were below the limits. Biochar had a stable structure, which was conducive to carbon fixation, and it had rich surface pore structure and strong adsorption, and it can prevent environmental pollution and reduce greenhouse gas emissions. The research put forward the biochar quality evaluation index and index range requirements for fertilizer application, energy carbon, activated carbon and other application directions, and recommended the measurement standards of the corresponding indicators. The number of indicators was: fertilizer carbon included 21 items, energy carbon included 19 items, and activated carbon included 7 items. It was recommended to develop biochar quality evaluation and grading standards as soon as possible to provide technical support for promoting the multi-value and high value utilization of biochar products, and further accelerating the industrial application of biochar.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Quality control
Controlled terms:Activated carbon - Agricultural wastes - Alkali metals - Alkalinity - Biomass - Bituminous coal - Chemical analysis - Chemical properties - Corrosion prevention - Fertilizers - Gas emissions - Grading - Greenhouse gases - Heavy metals - Physical properties - Pollution control - Polychlorinated biphenyls - Pore size - Pore structure - Soil testing - Specific surface area - Surface chemistry
Uncontrolled terms:Acidic functional groups - Bio chars - Environmental pollutions - Large specific surface areas - Oxygen-containing functional groups - Physical and chemical properties - Quality evaluation indices - Test method
Classification code:451.1 Air Pollution Sources - 483.1 Soils and Soil Mechanics - 524 Solid Fuels - 531 Metallurgy and Metallography - 539.2 Corrosion Protection - 549.1 Alkali Metals - 801 Chemistry - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.5 Agricultural Wastes - 913.3 Quality Assurance and Control - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 4.00e+01%, Percentage 4.00e+01% to 6.10e+01%, Specific_Energy 2.00e+07J/kg to 3.00e+07J/kg
DOI:10.11975/j.issn.1002-6819.2019.16.028
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 34>
Accession number:20194607670410
Title:Design of mobile phone on-line control device for evaporator with automatic rainproof and early warning push function
Title of translation:自动挡雨预警推送蒸发器手机在线控制装置研制
Authors:Cao, Chunhao (1); Yang, Qiliang (1); Li, Jianian (1); Liu, Xiaogang (1); Yu, Liming (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:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:145-151
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this research, in order to eliminate the adverse effect of rainfall weather on the detection results of evaporator water surface evaporation, a mobile phone on-line control device for evaporator based on automatic rainproof and early warning push function was designed. The device consists of 57BYG250B stepper motor, coupler, limit switch, bearing, touch rod, rotating arm, 20 rain sensors and rain cover. The rotating arm and the touch rod were fixed on the supporting rod, and a bearing was fixed below the touch rod to ensure that the supporting rod would not flutter when it rotated. The clockwise and counterclockwise rotation of the supporting rod were driven by 57BYG250B stepper motor. The drive shaft of the supporting rod passing through the bearing and the 57BYG250B stepper motor were connected and fixed by the coupler. The limit switch was installed in the same plane position and parallel to the touch rod. A rotating arm was fixed on the supporting rod, and the rain cover was installed on the rotating arm. The output shaft of 57BYG250B stepper motor was connected with the supporting rod through the coupler. 20 rain sensors were connected in parallel to automatically detect whether there is rainfall by judging if the rain sensors output low level. The rotation of 57BYG250B stepper motor drove the rain cover to completely shield the evaporator and returned to its initial position. The data transmission format between Internet of Things server and push server, Internet of Things server and mobile app, Internet of Things server and the device developed is JSON. The Internet of Things server was called public API of weather forecast regularly, and the mobile terminal integrated GeTui SDK for rainfall warning, evaporator completely-shielded and backed to initial position. The MCU program uses C language to compile the code of rainproof and removal of rain cover, and encapsulates it. The mobile program sent rainproof instructions or the rain sensor detected rainwater falling on the surface of the sensor, which would call the rainproof function. When the mobile program issued a rain-shield removal instruction or the rain sensor was dried, the rain-cover removal function was produced. The mobile program called the instruction sending function in Objective-C language and passed the corresponding instruction parameters. The stability and reliability of the device were verified by testing the performance of 20 rain sensors and 57BYG250B stepper motor. The results showed that 1) the device was reliable in operation. In 60 tests, the success rate of complete shelter and returning to the initial position of the rain shield was 98.3%; 2) the operation of the device was stable, and the error range of the theoretical angle of the support rod rotation and the measured angle was 1.6°-3.5°, the maximum relative error was 4.1%, and the minimum relative error was 1.9%; 3) In the reliable test of 60 message pushes, the success rate of receiving feedback messages was 98.3% after the rain and the rain cover were removed successfully. Field test results showed that 5 days in 14 days are rainy days. The rain warning message has been received before it rains. The device has strong adaptability and good performance and its maximum error range was 3.4°. The device could not only automatically passes perception of rainfall to rainproof, but also be operated online by mobile phone to give early warning notice for rainy weather. The successful push message of the evaporator completely blocked by the rain cover and returned to the initial position, which improved the intelligent level of the evaporator rainproof operation. This research provided new ideas for the application of intelligent rainproof technology and message push technology in the development of agricultural intelligent equipment.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Rain
Controlled terms:Bearings (machine parts) - C (programming language) - Cellular telephones - Digital storage - Errors - Evaporation - Evaporators - Internet of things - Precipitation (chemical) - Rotation - Sensors - Stepping motors - Weather forecasting
Uncontrolled terms:Counter clockwise rotation - Data transmission formats - Feedback messages - Intelligent equipment - Intelligent rainproof - Maximum relative errors - Stability and reliabilities - Warning push
Classification code:443 Meteorology - 443.3 Precipitation - 601.2 Machine Components - 705.3 Electric Motors - 718.1 Telephone Systems and Equipment - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 723.1.1 Computer Programming Languages - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 931.1 Mechanics
Numerical data indexing:Percentage 9.83e+01%, Age 1.37e-02yr, Age 3.84e-02yr, Percentage 4.10e+00%
DOI:10.11975/j.issn.1002-6819.2019.16.016
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 35>
Accession number:20194607670356
Title:Performance of positive pressure fan-pad cooling system and cooling load model for Chinese solar greenhouse
Title of translation:日光温室正压湿帘冷风降温性能及冷负荷计算模型
Authors:Sun, Weituo (1, 2); Zhou, Bo (1, 2); Xu, Fan (1, 2); Shang, Chao (1, 2); Lu, Chungui (3); Guo, Wenzhong (1, 2)
Author affiliation:(1) Beijing Research Center of Intelligent Equipment for Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing; 100097, China; (2) Key Laboratory of Agri-informatics, Ministry of Agriculture, Beijing; 100097, China; (3) School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottinghamshire; NG250QF, United Kingdom
Corresponding author:Guo, Wenzhong(guowz@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:214-224
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Year-round and efficient production for crop products of high yield, quality and cleanliness is the development trend of the Chinese solar greenhouse (CSG). However, this is limited by unfavorable climate conditions inside the CSG, such as high air temperature in warm seasons. The fan-pad cooling system, normally adopting negative pressure ventilation, has been widely used for greenhouse cultivation. But it generates a large air temperature gradient in greenhouse, limits the greenhouse dimensions. Above deficiencies are more serious in the CSG. Because CSG always has a long distance between the sidewalls, fans and gaskets are installed separately on the sidewalls. In order to overcome the limitations of negative fan-pad cooling system and improve ability of the CSG in coping with high temperature, a positive pressure fan-pad cooling system (PPFPCS) was designed in this study. By using this system, the cold and humid air enters the CSG from bottom of south roof, and then hot air leaves the CSG through roof vents. Performance of the PPFPCS was tested in a CSG without crops in Beijing area during summer. Results showed that in typical summer hot days, the PPFPCS cooperating with external shading net could decrease mean air temperature of the CSG experimental area to 30.7-33.4℃, which was lower than that in the CSG contrast area using natural ventilation combination with external shading net by 5.4-11.1℃. Air temperature of the CSG experimental area was also lower than that outside the CSG with a temperature difference of 2.4-5.4℃. Nevertheless, both natural and mechanical ventilations were tested to have limited cooling capacity to meet climate requirement for CSG cultivation. The PPFPCS could also decrease the CSG air temperature at night, but had a poorer performance in comparison with daytime cooling due to the smaller vapor pressure deficit (VPD). The contrast area of CSG encountered an extreme low air humidity state with mean VPD of 3.4-6.1 kPa. PPFPCS could effectively alleviate low humidity stress: the average relative humidity in CSG experimental area was between 49.8% and 62.3%, which was 13.6% - 21.2% higher than that in CSG control area and 13.6%-24.6% higher than that in outdoor area. Wind velocity inside the CSG experimental area ranged from 0.35 to 1 m/s, which indicated a relative uniform air flow distribution. Cooling efficiency of the PPFPCS was about 91%, which was over 10 percentage points higher than that of the traditional negative pressure fan-pad cooling system. Low temperature of the PPFPCS circling water contributed to the high cooling efficiency. Average water consumption rate of the PPFPCS used for CSG cooling was 0.035-0.079 g/(m<sup>2</sup>•s) during the test. It had a positive linear correlation with VPD of outdoor air, that is drier outdoor air anticipates larger water consumption and better cooling performance. Both cooling load model of the CSG and selection method for fan-pad cooling system were derived. Cooling load model is the basis for capacity calculation of cooling equipment to be installed. Cooling load of the CSG in summer was 299.1 W/m<sup>2</sup>. Contribution ratios of convective heat transfer between north wall and indoor air, convective heat transfer between greenhouse floor with indoor air, hot air infiltration, as well as heat transfer between indoor and outdoor air though south roof, north roof and side walls were 11.0%, 73.3%, 1.3% and 14.4%, respectively. The maximum specific ventilation rate of the PPFPCS used for CSG cooling was recommended to be 0.067 m/s. This study can provide technical support for the application of PPFPCS in CSG cultivation and provide theoretical basis for the climate control of CSG production in summer.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Air
Controlled terms:Air conditioning - Atmospheric temperature - Cooling systems - Crops - Efficiency - Greenhouses - Heat convection - Humidity control - Models - Plants (botany) - Roofs - Solar heating - Thermoelectric equipment - Ventilation
Uncontrolled terms:Chinese solar greenhouse - Convective heat transfer - Indoor and outdoor airs - Mechanical ventilation - Positive pressure ventilation - Temperature differences - Vapor pressure deficit - Water consumption rate
Classification code:443.1 Atmospheric Properties - 615.4 Thermoelectric Energy - 641.2 Heat Transfer - 643.3 Air Conditioning - 643.5 Ventilation - 657.1 Solar Energy and Phenomena - 804 Chemical Products Generally - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures - 913.1 Production Engineering
Numerical data indexing:Velocity 3.50e-01m/s to 1.00e+00m/s, Velocity 6.70e-02m/s, Percentage 1.10e+01%, Percentage 1.30e+00%, Percentage 1.36e+01% to 2.12e+01%, Percentage 1.36e+01% to 2.46e+01%, Percentage 1.44e+01%, Percentage 4.98e+01% to 6.23e+01%, Percentage 7.33e+01%, Percentage 9.10e+01%, Pressure 3.40e+03Pa to 6.10e+03Pa, Surface_Power_Density 2.99e+02W/m2
DOI:10.11975/j.issn.1002-6819.2019.16.024
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
<RECORD 36>
Accession number:20194607670253
Title:Analysis on driving force of runoff change in hill-plain-wetland area of Naoli River Basin
Title of translation:挠力河流域丘陵-平原-湿地区径流变化驱动力分析
Authors:Gong, Xinglong (1); Du, Shuping (1); Fu, Qiang (1); Guan, Yinghong (1); Xing, Zhenxiang (1); Li, Mo (1); Wang, Bin (1)
Author affiliation:(1) College of Water Conservancy and Architecture, Northeast Agricultural University, Harbin; 150030, 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:35
Issue:16
Issue date:August 15, 2019
Publication year:2019
Pages:114-124
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to prevent the increase of evaporation in hilly-plain-wetland area, decrease of runoff and degeneration of wetland, it is necessary to find the driving force of runoff change in hilly-plain-wetland area. In the present study, Naoli River Basin, a typical plain-hilly-wetland area, was selected as the research object. Data were from Baoan, Baoqing, Hongqi mountain and other hydrologic stations. The model of TOPMODEL was used for the study. During model validation, the absolute value of relative error of runoff of secondary flood was 2.73%-8.33%, the absolute value of flood peak flow was 2.49%-10.47%, and the determination coefficient of flood process line was 0.612-0.893, which indicated the rationality of the description of spatial distribution of rainfall, water shortage in unsaturated zone and spatial distribution of flow in soil by using the model. The influencing factors of runoff including hydrometeorology, rainfall-runoff relationship, cover type and dry-land crop species were analyzed. And the scenarios with different combination of influencing factors were assumed. The effects of runoff factors and their changes on hydrological cycle and runoff were analyzed by using hydrological model. The results showed that the change of regional precipitation was the key driving force of runoff change. Rainfall and runoff were generally in a decreasing trend. And the decrease of runoff depth was more obvious than that of precipitation. The other factors also played important roles in the runoff change besides the rainfall, and their influences increased gradually. Climate change was also one of the important driving forces of runoff change. Temperature, vapor pressure, sunlight intensity and wind speed increased significantly in summer and autumn from 1965 to 2014, while temperature and vapor pressure increased significantly in spring, and wind speed decreased during the spring. During the period of May to October in the years of 1965-2014, the basin evaporation did not always increased with temperature, sunlight intensity, vapor pressure and wind speed. During some periods, the basin evaporation decreased as the increase of temperature, sunlight intensity, vapor pressure and wind speed for some special cover types. Furthermore, the change of cover type in catchment area was also one of the important driving forces for runoff change. The transformation of unused land into dry land, dry land into paddy land and the adjustment of agricultural structure accelerated the evapotranspiration in the studied area, and then resulted in the fast deceleration of runoff depth and the abnormal response of runoff depth to precipitation. Based on the analysis above, precipitation, climate factors and land cover types showed complex effects on the temporal and spatial variations of evaporation, root zone water content, unsaturated zone water content and runoff.<br/> © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Climate change
Controlled terms:Agricultural runoff - Catchments - Evaporation - Evapotranspiration - Flood control - Floods - Groundwater - Hydrostatic pressure - Rain - Runoff - Solute transport - Spatial distribution - Vapor pressure - Water supply - Watersheds - Wetlands - Wind
Uncontrolled terms:Determination coefficients - Driving forces - Hydrological modeling - Land-cover change - Rainfall and runoffs - Rainfall-runoff relationship - Temporal and spatial variation - Wetland area
Classification code:442.1 Flood Control - 443.1 Atmospheric Properties - 443.3 Precipitation - 444.1 Surface Water - 444.2 Groundwater - 446.1 Water Supply Systems - 453.1 Water Pollution Sources - 631.1.1 Liquid Dynamics - 641.1 Thermodynamics - 802.3 Chemical Operations - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Percentage 2.49e+00% to 1.05e+01%, Percentage 2.73e+00% to 8.33e+00%
DOI:10.11975/j.issn.1002-6819.2019.16.013
Database:Compendex
Compilation and indexing terms, Copyright 2020 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
- 邮编 100125
- 电话 010－59197078/7077/7076
- 邮箱 tcsae@tcsae.org
微信公众号
二维码
友情链接
- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
- 中华人民共和国农业农村部-MARA
- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
- 期刊界
- CNKI
- 万方数据
- 维普