<RECORD 1>

Accession number:201443117747
Title:Kinematic analysis and experiment of dual parallelogram multi-pole planting mechanism
Authors:Xiao, Mingtao (1); Sun, Songlin (1); Luo, Haifeng (1); Wu, Wei (1); Luo, Jianghe (1)
Author affiliation:(1) School of Engineering, Hunan Agricultural University, Changsha, China; (2) Hunan Modern Agricultural Machinery Engineering and Technology Research Center, Changsha, China
Corresponding author:Sun, Songlin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:25-33
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hanging cup type transplanter is widely used because of its good protection to the seedlings, the strong adaptability to the soil and its flexibility of planting depth adjustment. In order to improve the quality of hanging cup type transplanter in transplanting seedlings, static trajectory graft seedlings test, planting perpendicularity comparison test and dynamic trajectory plant seedlings test have been designed according to the agronomic requirements. Through those tests, the relation model between the position of seedling mechanism and the accuracy of graft seedlings, the perpendicularity comparison model before and after plant, and the equations between the qualification rate of the plant perpendicularity and the overlap or deviate width of dynamic trajectory under the plant depth line have been established. The tests showed that the overlap or deviate width of dynamic trajectory under the plant depth line was an important factor to improve the qualification rate of planting. In order to meet those requirements, a double parallel multi-rod planting mechanism was designed. It was mainly composed of a horizontal movement control parallel mechanism and a vertical planting movement control parallel mechanism. Through analyzing and optimizing the structure data, the mathematical model and kinematic equation of this mechanism were built. In addition, based on Matlab-gui, the man-machine interaction program interface was written. According to the simulation results of computer program, a set of data including the length of the rod, the mounting location and the crank initial angle were optimized. Meanwhile, a seedling transplanter prototype was designed and made according to the data.
Number of references:23
Main heading:Seed
Controlled terms:Agricultural machinery - Design - Dynamic models - Dynamics - High speed photography - Human computer interaction - Kinematics - Machine design - MATLAB - Mechanisms  - Models - Optimization - Photography - Software testing - Speed - Trajectories - Transplants
Uncontrolled terms:Dynamic trajectories - Horizontal movements - Man-machine interaction - Maximum intensities - Parallelogram - Seedling - Seedling transplanting - Transplanting mechanisms
Classification code:404.1 Military Engineering - 461.4 Ergonomics and Human Factors Engineering - 462.4 Prosthetics - 601 Mechanical Design - 601.3 Mechanisms - 723.5 Computer Applications - 742.1 Photography - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 902.1 Engineering Graphics - 921 Mathematics - 921.5 Optimization Techniques - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2014.17.004
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 2>

Accession number:201443117781
Title:Drying characteristics and efficacy index evaluation for main root of Yunnan panax notoginseng
Authors:Guo, Hui (1); Yang, Wei (1); Liu, Ying (2)
Author affiliation:(1) Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, China; (2) Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
Corresponding author:Yang, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:305-313
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In foreign countries, the research of drying characteristics about medicinal plants mainly includes ginseng and American ginseng. In China, the study on Yunnan panax notoginseng mainly focuses on the physiological property and effects of ginsenosides on human bodies, but the research on processing technology is superficial. According to the national standard in China, the main efficacy index of panax notoginseng is the panax notoginsenoside(PNS) content. However, there are no reports on the effect of drying methods and drying conditions to PNS content. In order to study the influence of drying process to PNS content of Yunnan panax notoginseng, Yunnan panax notoginsengs and their slices were dried by three different methods (natural drying, oven drying and hot-air drying) in this work. The drying curves and drying rate curves of these methods were obtained. The drying kinetics models of main roots within different temperatures in oven drying were established. Meanwhile, the PNS contents of main roots dried by these methods were tested through High-performance Liquid Chromatography(HPLC), and the regression equation about temperature and time to PNS content was established and optimized. Results showed that oven drying had a shorter drying time and faster drying rate compared with natural drying. The PNS contents of dried products within natural drying, oven drying and hot-air drying were 7.246%, 11.305%, 8.259%, respectively. It showed that the oven drying kept the PNS content of panax notoginseng higher. Through drying curves and drying rate curves of panax notoginseng, it could be found that there was only falling rate period and no constant rate period during the drying process. The parameters of Lewis model, Page model and Henderson-Pabis model were evaluated through R². Page model was found to be more suitable in describing the drying characteristics of panax notoginseng. The drying kinetics equation was MR=exp[-0.0037exp(0.0623T)t^{1.5336exp(-0.0156T)}]. It firstly put forward the relationship among moisture ratio, drying temperature and drying time at the drying process of main roots, and it provided a basis for the control of drying process of panax notoginseng. The effective moisture diffusivity of main roots dried at different temperatures was among 3.073&times;10^-10m²/s-1.291&times;10^-9m²/s. The results of significance analysis showed that the drying temperatures had a highly significant impact on the effective moisture diffusivities. The regression equation about temperature and time to PNS content of main roots was y=-606-61.875T 36.625t 0.7559T²-0.1641Tt-0.1096t². Through response analysis and equation optimization, under the condition of safe moisture content, the better drying temperature (50-60) and time (106-144 h) were obtained. Although main roots' slices had a shorter drying time compared with the whole main roots, the PNS contents of them were lower than the main roots'. To sum up, in order to keep the active ingredients(PNS) of panax notoginseng better, the whole main roots are more fit for the drying process. This result are meaningful to guide the actual production of Yunnan panax notoginseng.
Number of references:24
Main heading:Drying
Controlled terms:High performance liquid chromatography - Liquid chromatography - Models - Moisture - Ovens - Plants (botany) - Temperature
Uncontrolled terms:Drying characteristics - Effective moisture diffusivity - Evaluation - Panax notoginseng - Panax notoginsenosides - Physiological properties - Processing technologies - Significance analysis
Classification code:461.9 Biology - 641.1 Thermodynamics - 642.1 Process Heating - 801 Chemistry - 801.4 Physical Chemistry - 822.1 Food Products Plants and Equipment - 902.1 Engineering Graphics
DOI:10.3969/j.issn.1002-6819.2014.17.038
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 3>

Accession number:201443117771
Title:Optimal regulation model of tomato seedlings' photosynthesis based on genetic algorithm
Authors:Hu, Jin (1); He, Dongjian (1); Ren, Jing (1); Liu, Xiang (1); Liang, Yan (1); Dai, Jianguo (1); Zhang, Haihui (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A and F University, Yangling, China
Corresponding author:He, Dongjian
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:220-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As one of the world's major greenhouse crops, the yield and quality of tomato is significantly affected by photosynthesis. Temperature and photon flux density are important factors affecting photosynthesis; how to effectively evaluate their effects on tomato's photosynthesis, establish optimal model of photosynthetic rate and improve the rate of photosynthesis have become urgent problems in the field of crop cultivation. In view of these requirements, an optimal photosynthesis regulation model of tomato seedlings based on genetic algorithm was proposed in the paper. Firstly, the two-factor nested test of photosynthetic rate was conducted with Li-6400XT under the conditions that the tomato seedling " Wool powder 802" was used as the test sample, the temperature gradients were set at 16, 21, 25, 29, 33, 37, respectively, and the photon flux density gradients were set at 0, 50, 100, 200, 400, 600, 800, 1000, 1200, 1500 &mu;mol/m²&middot;s, respectively. Secondly, a photosynthetic rate model coupling temperature and photon flux density was built by processing multivariate nonlinear regression of the experimental data obtained. Then, the optimization algorithm of photosynthetic rate based on genetic algorithm was designed under different temperature gradients, by which the light saturation points under different temperature conditions were obtained. Furthermore, the optimal regulatory model of tomato seedlings' photosynthesis was established aiming at light saturation points. Finally, the model verification test was conducted by comparing and analyzing the measured data and calculated data by the model under 17 values of light saturation points at different temperatures. The results showed that the correlation coefficient of the values between the measured and the calculated was 0.920, the slope of the fitted line was 1.011, and the ordinate intercept was 0.236, which indicated that these two values had good correlation and similarity. Besides, the maximum of relative error was less than 6%, which proved that the proposed model had a high accuracy and had access to the light saturation points at different temperatures dynamically. The conclusion provides a theoretical basis for the optimal regulation of photosynthetic rate and is of great significance for raising the output of tomato in greenhouse and improving the economic benefits.
Number of references:29
Main heading:Fruits
Controlled terms:Algorithms - Crops - Genetic algorithms - Greenhouses - Optimization - Photons - Photosynthesis - Temperature - Thermal gradients
Uncontrolled terms:Correlation coefficient - Light saturation - Multivariate non-linear regression - Optimization algorithms - Photosynthetic rate - Regulatory model - Temperature conditions - Tomato
Classification code:641.1 Thermodynamics - 723 Computer Software, Data Handling and Applications - 741.1 Light/Optics - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures - 921 Mathematics - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2014.17.028
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 4>

Accession number:201443117748
Title:Design and optimization of operating parameters for potted anthodium transplant manipulator
Authors:Gao, Guohua (1); Feng, Tianxiang (1); Li, Fu (1)
Author affiliation:(1) Mechanical Eng and Application of Electronic Tech Institute of Beijing University of Technology, Beijing, China
Corresponding author:Gao, Guohua
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:34-42
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As potted flower becomes more and more important in people's daily life, its planting area and sales volume have been largely increased in recent years. For saving the space and ensuring the flowering rate, it is a key link to transplant the flower seedlings from small pot to large pot in the growth process of potted flower. However, this task still relies on the manual operation, which is tiring and costly. In order to improve the mechanical transplanting of the potted flower seedling, the transplant manipulator of potted flower was designed which could complete the transplanting task of potted anthurium from the pot of 110 mm &times; 90 mm to the one of 170 mm &times; 150 mm. The manipulator adopted the form that it grasped the stem of flower seedlings from both of the sides, which could provide sufficient grasping force. Due to the large leaves and soft substrates the flower seedlings had in transplanting stage, the gathering gripper was used to protect the leaves, and the steel needles were used to fix the flower seedlings. As the result, it not only improved the success rate of transplanting, but also avoided the injury to the seedlings. Based on the actual situation of potted flower seedling, this paper analyzed the working process of transplant manipulator for potted anthurium. The results showed that the insertion angle and the distance from steel needle's insertion point to the center of flower seedling could be adjusted, and these two major factors would affect the performance of transplant manipulator for potted anthurium. Moreover, lifting cylinder pressure was another major factor. Because the transplanting effects were influenced by multiple parameters, the of combination tests of quadratic orthogonal rotatory regression were conducted to determine the optimal technological parameters of transplant manipulator for potted anthurium, so as to improve the transplanting effect and the success rate of transplanting. According to the transplanting tests, the weighted value of extracting effect was determined as the experimental index, and the breakage rate of leaves, integrity of root and substrate and vertical degree of flower seedlings were selected by the rating condition of weighted value of extracting effect. Three variables were selected as the experimental factors, i.e. lifting cylinder pressure, insertion angle, and the distance from steel needle's insertion point to the center of flower seedling. The regression equation of the model was obtained by the experiment. Based on the regression equation, the influence of single factor and the optimal parameters were obtained. The experiment results showed that as the single factor, the distance from steel needle's insertion point to the center of flower seedling had a significant influence to the weighted value of extracting effect, which changed from 63 to 90 due to the factor. Moreover, when lifting cylinder pressure was 0.36 Mpa, insertion angle of the steel needle was 28 degrees, and the distance from steel needle's insertion point to the center of flower seedling was 38.12 millimeters, the weighted value of extracting effect could achieve 93. The difference between the predicted value and the actual value was 1%, and the result from the model was consistent with that from the experiment. The optimal operating parameters are reliable, stable and can be applied to practical application.
Number of references:26
Main heading:Manipulators
Controlled terms:Agricultural machinery - Cylinders (shapes) - Needles - Optimization - Regression analysis - Substrates - Transplants
Uncontrolled terms:Anthodium - Design and optimization - Experimental factors - Operating parameters - Orthogonal test - Potted flower - Technological parameters - Transplanting stage
Classification code:408.2 Structural Members and Shapes - 461 Bioengineering and Biology - 462.1 Biomedical Equipment, General - 462.4 Prosthetics - 731.5 Robotics - 801 Chemistry - 821.1 Agricultural Machinery and Equipment - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.17.005
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 5>

Accession number:201443117760
Title:Detecting moisture content of soil by transmission-type ground penetrating radar
Authors:Wu, Yanbin (1); Cui, Fan (2); Wang, Lei (2); Chen, Jia (2); Li, Yuanyuan (2)
Author affiliation:(1) College of Management Science and Engineering, Hebei University of Economics and Business, Shijiazhuang, China; (2) State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing, Beijing, China
Corresponding author:Wu, Yanbin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:125-131
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land reclamation requires the monitoring of soil moisture in order to ensure that the soil moisture meets crop growth needs. Traditionally, soil moisture is detected by destructively sampling soils, which is costly and associated with long work periods. Ground penetrating radar (GPR) technique is often used since it is fast, convenient, and nondestructive. GPR launches and receives high-frequency electromagnetic waves via antennae in detection of underground media. By calculating wave velocities, dielectric constants can be obtained. General GPR hardware and detection methods are based on reflector-type antennae. The transmitting antenna and the receiving antenna are both arranged on the surface of the media. Because of this, the reflected waves from different underground layers can mix together, causing errors in the calculation of wave velocity. The computed tomography (CT) transmission-type GPR technique is different from the reflector-type technique. Its transmitting antenna and receiving antenna are located on both sides of the media during the detection. The multiple reflected waves using the reflector-type GPR detection can recede effectively. Thus, the wave velocity can be calculated much more precisely, and thereby, the estimation of moisture content is more accurate. In this study, a 900 kHz transmitting antenna was improved for the CT GPR detection, and a physical model was established to simulate loam and sandy soil with different unsaturated moisture content in order to test the possibility of the CT GPR for soil moisture detection. After the take-off point was selected, the absolute take-off time and apparent take-off time were calculated. The difference of both was considered as actual wave travel time. According to the formula, wave velocity = wave velocity in air / root of dielectric constant, the dielectric constant could be calculated. Different models including the linear regression model, quadratic polynomial model, exponential function model, logarithmic function model, and cube polynomial model were established to describe the relationship between the dielectric constant and volumetric moisture content. Based on the determination coefficient and error, the best model was selected and used for soil moisture detection in a verification experiment. In the verification experiment, the soil samples were taken from Inner Mongolia of China and detected by the TDR and oven-drying method. The results showed that the cube polynomial in the same form as the Topp equation had the best goodness-of-fit. The equation used for sandy soil samples detection yielded closer detection results (R²=0.982) with the oven-drying method than with the TDR method (R²=0.867). The equation used for loam soil samples detection yielded closer detection results (R²=0.987) as well. This indicated that it is possible to use these relation models for accurate estimation of moisture contents of sandy soil and loam soil. For determination of moisture content in sandy soils, the relative error averaged 13.20% using the proposed method here, which was 14.34% lower than that from the TDR method. For determination of moisture content in loam soils, the relative error averaged 9.48% using the proposed method here, 15.79% lower than that from the TDR method. It suggested that the measurement accuracy of the proposed method is higher than that from the TDR method. Therefore, the CT GPR detection for soil moisture content can be an alternative method of TDR under certain conditions of soil moisture.
Number of references:27
Main heading:Moisture determination
Controlled terms:Acoustic wave velocity - Air - Antenna reflectors - Computerized tomography - Electromagnetic waves - Exponential functions - Geological surveys - Ground penetrating radar systems - Land reclamation - Linear regression  - Models - Moisture - Moisture control - Ovens - Permittivity - Polynomials - Radar - Radar antennas - Receiving antennas - Reflection  - Regression analysis - Sand - Soil moisture - Soil surveys - Soils - Takeoff - Velocity - Wave propagation
Uncontrolled terms:Determination coefficients - Estimation of moisture content - Fitting analysis - Ground Penetrating Radar - Ground penetrating radar (GPR) - High frequency electromagnetic waves - Linear regression models - Volumetric moisture content
Classification code:442.2 Land Reclamation - 481.1 Geology - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 652.1 Aircraft, General - 701 Electricity and Magnetism - 711 Electromagnetic Waves - 716 Telecommunication; Radar, Radio and Television - 716.2 Radar Systems and Equipment - 751.1 Acoustic Waves - 801 Chemistry - 801.4 Physical Chemistry - 804 Chemical Products Generally - 822.1 Food Products Plants and Equipment - 902.1 Engineering Graphics - 921 Mathematics - 921.1 Algebra - 922.2 Mathematical Statistics - 931.1 Mechanics - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2014.17.017
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 6>

Accession number:201443117755
Title:Performance analysis of Kaplan turbine with semi-spiral case at large flow conditions
Authors:Liao, Weili (1); Zhao, Yaping (1); Zhao, Qianyun (1); Ruan, Hui (1); Luo, Xingqi (1)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an, China
Corresponding author:Liao, Weili
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:86-92
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The performance of a Kaplan turbine in partial operation conditions is often limited by cavitation and stability, especially at the large flow rate operation conditions. Many problems such as vibration, efficiency dropping, cavitation, and blade cracks caused by unstable flow in each of the flow passage components of the turbine seriously affect the safe operation of the unit, and because of these problems, many power plants are forced to undergo downtime for repairs or renovation. In this paper, a model Kaplan turbine with a semi-spiral case was taken as the research object and the optimal operating point and a large flow rate operating point was chosen as the operating point for research. In order to reveal the reasons that cause the performance deterioration of the turbine at the large flow rate conditions, the comparative analysis of the Kaplan turbine performance at these two operating points was conducted by using the numerical simulation methods. It was found that the following factors caused the poor performance in the large flow rate conditions :1)In the spiral case, the discharge in the non-snail-shaped part was much more than the snail-shaped part relatively, the inertia of water made most of discharge flow into the guide vane at the non-snail-shaped part of the spiral case directly, this led to the axial symmetry of flow field distribution in the semi-spiral case along the circumferential direction deteriorate significantly, and all these imbalance hydraulic factors were passed to the guide vanes and runner, and could not be eliminated. 2) In the guide vane region, the flow distribution along the height direction of the guide vane was uneven, the flow rate increased from the top to the bottom of the guide vane, there were some vortices between the guide vanes located at the snail-shaped part of the spiral case, and these vortices between the guide vanes formed a circumferential unstable source, which not only can lead to the destruction of the guide vane surface, but also have an serious influence on the runner. 3) The destabilizing hydraulic factors generated in the spiral case and guide vanes could be transmitted to the flow passage components behind, lead to the poor axis of symmetry of the hydraulic elements in the runner, and make the blades located in different positions of the runner suffer different hydrodynamic moments. These produced alternating dynamic stress on the blades during rotating, and led to blade cracks and damage. Therefore, at the large flow rate conditions, all these instability hydraulic factors will cause a serious threat for the stability and strength of the unit. This research provides a reference for the Kaplan turbine hydraulic design and actual operating at the large flow rate conditions.
Number of references:24
Main heading:Flow rate
Controlled terms:Animals - Cavitation - Cracks - Flow fields - Hydraulic motors - Kaplan turbines - Models - Molluscs - Numerical methods - Turbomachine blades  - Vortex flow
Uncontrolled terms:Circumferential direction - Comparative analysis - Flow condition - Flow field characteristics - Flow field distribution - Numerical simulation method - Optimal operating point - Performance deterioration
Classification code:421 Strength of Building Materials; Mechanical Properties - 471 Marine Science and Oceanography - 617.1 Hydraulic Turbines - 631 Fluid Flow - 632.2 Hydraulic Equipment and Machinery - 902.1 Engineering Graphics - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2014.17.012
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 7>

Accession number:201443117757
Title:Numerical value analysis on aerodynamic performance of DU series airfoils with thickened trailing edge
Authors:Xu, Haoran (1); Yang, Hua (1); Liu, Chao (1)
Author affiliation:(1) College of Water Resources and Energy Power Engineering, Yangzhou University, Yangzhou, China
Corresponding author:Yang, Hua
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:101-108
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to analyze the aerodynamic performance of blunt trailing edge airfoils with different thicknesses of trailing edge and maximum thicknesses to chord, in this paper, a method called blending function of exponential was used to enlarge the trailing edge of airfoil. The aerodynamic performance of blunt trailing edge airfoils generated from the DU91-W2-250, DU97-W-300 and DU96-W-350 airfoils by enlarging the thickness of trailing edge symmetrically from the location of maximum thickness to the chord to the trailing edge to 5%c and 10%c were analyzed by using CFD method at a chord Reynolds number of 3&times;10⁶. c denotes the length of the chord line. The calculation domain is a circular domain with a radius of 50c. The airfoil surface was set as an adiabatic no-slip wall boundary condition. A velocity-inlet boundary condition was applied at the inflow boundary and the pressure-outlet boundary condition was applied at the outflow boundary. The transition SST model can accurately predict the aerodynamic performance of conventional and blunt trailing edge airfoils with clean surfaces. The results calculated by the SST turbulence model can represent the aerodynamic performance of airfoils with rough surfaces. The steady calculated results show that the lift of clean airfoil can be predicted accurately by two dimensional CFD calculation while the drag of blunt trailing edge airfoils with larger trailing edge thickness cannot be calculated precisely even at low angles of attack. The aerodynamic performance of blunt trailing edge airfoils with larger trailing edge thickness should be predicted by more accurate three dimensional CFD method further. With the increase of the thickness of trailing edge, the increase rate and amount of lift becomes limited gradually at low angles of attack, while the drag increases dramatically. The larger the thickness of the trailing edge is, the higher the maximum lift is, but too large lift can cause abrupt stall. So the thickness of the trailing edge should be constrained in a certain rage. For example, 5%c is a better choice for blunt trailing edge airfoils, the lift of these airfoils has been increased but with no abrupt stall. In this paper, pressure distributions on original airfoils and trailing edge enlarged airfoils under ten degrees angles of attack calculated by both fully turbulent k-&omega; SST model and transition k-&omega; SST model were analyzed. On the one hand, by enlarging the trailing edge of the airfoil symmetrically, the adverse pressure gradient near trailing edge on suction side can be reduced, the reduced pressure gradient can suppress the reduction of flow velocity in boundary layer due to viscosity and the separation of boundary layer can be delayed consequently. On the other hand, the pressure differential between the pressure side and suction side can be increased. The increase of thicker airfoil's pressure differential is larger than other thinner airfoils. Besides, the increase amount of lift of trailing edge enlarged airfoils calculated by fully turbulent model is larger than that calculated by free transition turbulence model. Compared with free transition condition, the fully turbulent boundary layer are more sensitive to the enlargement of trailing edge thickness.
Number of references:30
Main heading:Airfoils
Controlled terms:Aerodynamics - Angle of attack - Atmospheric thermodynamics - Blending - Boundary conditions - Boundary layer flow - Boundary layers - Computational fluid dynamics - Drag - Lift  - Numerical analysis - Pressure gradient - Reynolds number - Turbomachine blades - Turbulence models - Turbulent flow - Wind turbines
Uncontrolled terms:Adverse pressure gradient - Aero-dynamic performance - Blade - Blunt trailing edge airfoils - Numerical value analysis - Separation of boundary layer - Trailing edges - Turbulent boundary layers
Classification code:421 Strength of Building Materials; Mechanical Properties - 443.1 Atmospheric Properties - 615.8 Wind Power (Before 1993, use code 611 ) - 631.1 Fluid Flow, General - 651.1 Aerodynamics, General - 652.1 Aircraft, General - 802.3 Chemical Operations - 921 Mathematics - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2014.17.014
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 8>

Accession number:201443117750
Title:Evaluation and dynamic forecast of reliability on vehicle brake system based on time-dependent theory
Authors:Shi, Boqiang (1); Tang, Geteng (2)
Author affiliation:(1) College of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China; (2) Key Laboratory of Operation Safety Technology on Transport Vehicles Ministry of Communication, Research Institute of Highway Ministry of Transport, Beijing, China
Corresponding author:Shi, Boqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:50-55
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As one of the most important sub-systems ensuring vehicle's driving safety, the brake system, whose work reliability greatly determines the safety of car running in a large extent, is usually taken as an important object in studies of vehicle's braking reliability. While for brake system, the use reliability is related to the allowable braking distance, braking deceleration and other relevant parameters prescribed by travel safety regulations. The intention of this paper is to establish a model of evaluation and dynamic forecast on brake system's reliability based on time-dependent theory. Therefore the vehicle's braking performance was studied to analyze the use reliability of brake system and the uncertain factors (such as temperature, speed and wear) which can cause the fluctuation of braking performance and exist in brake system's whole lifetime were also analyzed. In addition, the impact extent of uncertain factors was quantified by fuzzy comprehensive evaluation method in this paper as well. Combined with the study of vehicle braking distances under different conditions, the model can not only assess the reliability of brake system in current time, but also dynamically predict that in future time.
Number of references:20
Main heading:Braking performance
Controlled terms:Brakes - Braking - Dynamic models - Forecasting - Fuzzy set theory - Laws and legislation - MATLAB - Numerical methods - Off road vehicles - Reliability  - Reliability theory - Vehicles
Uncontrolled terms:Application examples - Application prospect - Dynamic forecast - Fluctuation coefficient - Fuzzy comprehensive evaluation - Fuzzy comprehensive evaluation method - Theoretical values - Time-dependent theory
Classification code:432 Highway Transportation - 602 Mechanical Drives and Transmissions - 662 Automobiles and Smaller Vehicles - 662.1 Automobiles - 663 Buses, Tractors and Trucks - 663.1 Heavy Duty Motor Vehicles - 921 Mathematics - 922.2 Mathematical Statistics - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2014.17.007
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 9>

Accession number:201443117761
Title:Comprehensive assessment on water-saving renovation of large-scale irrigation districts in Inner Mongolia based on hierarchical analysis- ant colony algorithm
Authors:Huo, Xing (1); Shi, Haibin (1); Yang, Songyi (1); Li, Zeming (1); Gong, Xuewen (1); Yang, Xiao (1)
Author affiliation:(1) College of Water Conservation and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, China
Corresponding author:Shi, Haibin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:132-140
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Inner Mongolia Autonomous Region is located in northern China and it is characterized by dry, little rainfall, and shortage of water resource. Most farmlands in this region are distributed in arid and semiarid areas, and thus agricultural production is highly dependent on irrigation. There are 14 large-scale irrigation districts in 7 municipalities (leagues) or around 3 river basins. Most of the irrigation districts obtain irrigation water from surface water. The irrigation districts as important agricultural bases of China for spring wheat, maize and sunflower production are constructed in 50 s-70 s of 20th century. The old irrigation districts are found with problems such as disrepair, poor auxiliary works, sever canal seepage and low water use efficiency. The increased population and socio-economic development have greatly aggravated the competition for water among agriculture, industry and domestic users in these irrigation districts. In order to deal with such problems and maintain agricultural production, a project of renewed construction and water saving renovation for irrigation districts was implemented in Inner Mongolia Autonomous Region since 1998. It is necessary to evaluate the effects of the project for better managing and developing future projects of water saving renovation. However, since there is large difference in physical conditions, hydrogeology and climate among irrigation districts, the effect of water saving renovation may vary greatly in different irrigation districts, causing the difficulty in selecting indicators for evaluation. In this study, 10 typical irrigation districts (water diversion from the Yellow River, water diversion from reservoirs, water diversion from other rivers, water lifting from rivers and water lifting from wells) were selected and used for the evaluation of water saving renovation using Hierarchical Analysis-Ant Colony method. From the perspective of plant species, irrigation methods, operating management level and economic benefits of different environment, the evaluation indicator system was constructed with 4 parameters for crop cultivation, operation, management and benefit. The Hierarchical Analysis was used to assign the weights to each indicator for each irrigation district and the Ant Colony Algorithm was used to determine the optimal degrees indicating goodness of the water saving renovation in each district. The results showed that the 10 irrigation districts were ranked by optimal degree as Mountain bay (0.91), Dengkou (0.95), Hetao (0.97), the South Bank of Yellow River (0.98), Dian Zi (1.005), Chaer Sen (1.01), Yingjin River (1.115), West Liaohe River (1.14), Madi Hao (1.165), and Moli Temple (1.185) irrigation area. It indicated that of the 10 typical irrigation districts, the water-saving renovation effect of San Wanzi Irrigation District and Dengkou Irrigation District were remarkable but that of Mo Limiao Irrigation District was not desirable. The evaluation was in agreement with the real situations of these irrigation districts, suggesting that the assessment based on the Hierarchical Analysis-Ant Colony method was reliable. The Hierarchical Analysis-Ant Colony method was simple and easy to operate and reliable for evaluation of large-scale irrigation districts. The study introduced a new method for assessment of water-saving renovation effects of large-scale irrigation districts.
Number of references:29
Main heading:Water resources
Controlled terms:Agriculture - Algorithms - Analytic hierarchy process - Ant colony optimization - Competition - Cultivation - Economic and social effects - Economics - Flood control - Groundwater  - Hydrogeology - Irrigation - Models - Reservoirs (water) - River diversion - Rivers - Water conservation - Water management - Water supply
Uncontrolled terms:Ant colony algorithms - Arid and semi-arid areas - Benefit assessments - Evaluation indicator system - Inner Mongolia autonomous regions - Irrigation area - Socio-economic development - Water-saving
Classification code:441 Dams and Reservoirs; Hydro Development - 441.2 Reservoirs - 444 Water Resources - 446.1 Water Supply Systems - 454.1 Environmental Engineering, General - 481.1 Geology - 723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 902.1 Engineering Graphics - 911.2 Industrial Economics - 921 Mathematics - 921.5 Optimization Techniques - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.17.018
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 10>

Accession number:201443117780
Title:Improving quality of tilapia fillets freeze-thaw combined with heat pump drying using suitable additive pretreatment
Authors:Li, Min (1); Wu, Baochuan (1); Guan, Zhiqiang (1); Du, Hui (2); Wu, Yangyang (1)
Author affiliation:(1) Guangdong Ocean University College of Engineering, Zhanjiang, China; (2) Guangdong Ocean University Biochemical Center, Zhanjiang, China
Corresponding author:Li, Min
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:295-304
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to obtain the combined effects of additive pretreatment on the quality of freezing-thawing and heat pump drying of tilapia fillets, and to provide an atmospheric cryogenic drying method which can substitute vacuum frozen drying method, a series of tests of freezing-thawing process combined with heat pump drying for tilapia fillets were conducted in the laboratory, and the best experiment processes obtained were as followed: freezing-thawing pretreatment (conditions: freezing at -32 for 1.0 h, melting at 20 for 1.5 h), hot pump drying (conditions:Temperature 45, wind speed 2.5 m/s for 4 h), freeze and thaw imbedding (conditions: freezing at -40 for 1.5 h, melting at 25 for 1.0 h), hot pump drying (conditions:Temperature 45, wind speed 2.5m/s for 3 h), freeze and thaw imbedding (conditions: freezing at -30 for 1.5 h, melting at 25 for 0.5 h), heat pump drying (conditions:Temperature 45, wind speed 2.5 m/s) to dry basis moisture content 0.30&plusmn;0.02 g/g. In order to further shorten the drying time and improve the quality of the dried products, on the basis of the previous studies, this paper chose three different types of additives including trehalose, sorbitol and maltodextrin to be used on tilapia fillets under the condition of ice-water bath for 1 h before freezing-thawing process combined with heat pump drying. Drying curves and quality indexes variation of different types and concentrations of additive treatments were obtained by the experiments, and the best additive impregnation conditions were obtained through the comprehensive score of dried product's quality index. Contrast tests were carried out using three methods including hot air drying, heat pump drying and vacuum freeze drying under the condition of trehalose solution (mass fraction of 15%) impregnation. The results showed that suitable pretreatment additive and its mass fraction was beneficial to the method of freezing-thawing combined with heat pump drying, and could shorten the drying time and effectively improve the comprehensive quality of tilapia fillets after the process of freezing-thawing and heat pump drying. Within the scope of this study, trehalose solution (mass fraction of 15%) immersion treatment obtained the best results. The comprehensive score of tilapia products' drying quality under the optimum processing conditions increased by 25.41% than that without additive processed, increased by 40.18% and 33.57% respectively compared with hot air drying and conventional heat pump drying, yet was 4.39% lower than vacuum freeze drying, but its drying condition had a greater degree of improvement because of its atmospheric condition compared with vacuum freeze drying. The results can provide a reference for the atmospheric pressure low temperature drying of aquatic products.
Number of references:34
Main heading:Drying
Controlled terms:Additives - Atmospheric pressure - Atmospheric temperature - Freezing - Heat pump systems - Impregnation - Melting - Pumps - Quality assurance - Quality control  - Thawing - Wind
Uncontrolled terms:Atmospheric conditions - Comprehensive qualities - Freezing-thawing - Impregnation conditions - Optimum processing conditions - Tilapia fillets - Trehalose solution - Vacuum-freeze drying
Classification code:443.1 Atmospheric Properties - 531.1 Metallurgy - 618.2 Pumps - 641.2 Heat Transfer - 642.1 Process Heating - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 811.2 Wood and Wood Products - 822.2 Food Processing Operations - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2014.17.037
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 11>

Accession number:201443117776
Title:Analysis on land use change based on decision-tree model with comprehensive multi-scale characteristics
Authors:Liang, Ming (1); Sun, Yizhong (1); Luo, Rong (2); Hu, Zui (1); Chen, Zhao (3)
Author affiliation:(1) Key Laboratory of Virtual Geographic Environment Ministry of Education, Nanjing Normal University, Nanjing, China; (2) School of Urban and Environmental Science, Central China Normal University, Wuhan, China; (3) Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, China
Corresponding author:Sun, Yizhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:259-267
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In present model on land use and land cover change (LUCC) research, the fusion of multiple scales has been less considered. To solve this problem, a decision tree model (DTM) synthesizing multi-scale features was proposed in this paper; additionally, the simulation result was compared to those from the typical data mining methods. Firstly, the space was subdivided to land use unit with appropriate grid cell size of 9.5 km², which was used as simulation unit, and land use intensity (LUI), landscape shape index (LSI), and dominant land use type (DLT) were selected as inner indices, proportion of construction land (POC) and neighborhood average intensity of land use (NAI) were selected as neighborhood index, and the city-suburb index (CSI) was selected as global index. All the indicators of three scales were used as the property terms of the DTM. Then, taking the multi-scale evaluation indices of land use in Nanjing City, Jiangsu Province in 1995 as the test properties of the space instance, in accordance with the method of natural split point, land use intensity was classified into 4 levels, i.e. highest, higher, lower, lowest; and taking the actual levels of land use intensity in 2000 as the prediction of land-use-intensity type (PLT), the DTM was generated based on the sample sets of 816 space instances by using 10-fold iterative method. And the obtained model after the training was expressed to a tree structure. Thirdly, by using spatial and statistical analysis of GIS, the corresponding index values of feature attributes at different scales and conceptual levels were extracted and calculated from land use data. Further, the semantic information at a high abstraction level in different scales was constructed, and the law restraints to the model with the features of different scales were expressed. Based on the land use data in 2000, the simulated classification of land use intensity in 2005 was conducted by using the previous generated DTM. And then, by performing 10-fold cross-training for the 1995 and 2000 sample sets of land use change, the simulated land use intensity in 2005 was obtained and compared with the actual land use intensity in 2005. Finally, the simulated result was compared to those from the Naive Bayes (NB) method, the back propagation neural network (BPNN) method and the support vector machine (SVM) method in model simulation accuracy. The comparative experiments showed that the simulation accuracy of the DTM proposed in this paper was 88.97%, which was higher than the NB, BPNN and SVM methods whose simulation accuracies were respectively 84.44%, 87.13% and 83.46%. Since the simulation results from the DTM could be expressed as a tree structure with semantic clarity, when compared to the NB and SVM models, the DTM had better explanation; on the other hand, the DTM was easy to be constructed and expanded. In conclusion, the proposed DTM with synthesized multi-scale features in this study has similar or better accuracy compared with typical data mining methods, has the advantage of high computing efficiency, is easy to be extended and explained and can be reused at other places, and hence can contribute to support decision in LUCC management.
Number of references:25
Main heading:Land use
Controlled terms:Data mining - Decision trees - Geographic information systems - Iterative methods - Models - Neural networks - Semantics - Support vector machines - Temperature control - Trees (mathematics)
Uncontrolled terms:Back-propagation neural networks - Comparative experiments - Computing efficiency - Decision tree modeling - Land use and land cover change - Multi-scale - Multi-scale features - Spatial data mining
Classification code:403 Urban and Regional Planning and Development - 723 Computer Software, Data Handling and Applications - 731.3 Specific Variables Control - 902.1 Engineering Graphics - 903.2 Information Dissemination - 903.3 Information Retrieval and Use - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2014.17.033
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 12>

Accession number:201443117772
Title:Design and experiment of semi-automatic double-heat source forcing cultivation of temperature control for sweet cherry
Authors:Zhang, Daohui (1); Zhu, Dongzi (1); Wang, Jiawei (1); Wei, Hairong (1); Zong, Xiaojuan (1); Tan, Yue (1); Liu, Qingzhong (1)
Author affiliation:(1) Key Laboratory for Fruit Biotechnology Breeding of Shandong, Shandong Institute of Pomology, Tai'an, China
Corresponding author:Liu, Qingzhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:228-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the rapid development of sweet cherry forcing cultivation, low yield and poor quality issues have become increasingly prominent. For this reason, the semi-automatic double-heat source forcing cultivation system of temperature control was developed for sweet cherry forcing cultivation. The key improvement in this greenhouse is based on the best environment factors for sweet cherry growth and development. This system is composed of automatic monitor and recorder for chilling requirement, high plastic greenhouse, double-heat sources appliance, automatic monitor and recorder for temperature and humidity, alarm system for environmental factors and some temperature adjustment devices six parts. Compared with traditional plastic greenhouse for sweet cherry forcing culture, the semi-automatic double-heat source forcing cultivation system has three improvements: 1) chilling requirement selection and recording changed from manual to automatic method, which overcomes the difficult to accurately record chilling requirement in a short time and accurately monitor and calculate time of chilling requirement; 2) heat sources changed from sole solar energy to the coal-wood and solar complementary appliance in the automatic control system, making it easy to effectively and accurately control the internal temperature and humidity of the greenhouse, especially in successive cloudy weather or low temperature days; and 3) the semi-automatic double-heat source forcing cultivation system uses semi-automatic control system, automated detection and alarm environmental factors, avoiding the frequent access to greenhouses and errors caused by manual recording, and greatly reducing the labor intensity and improving the accuracy of environment in greenhouse. When the chilling requirement was higher than 1200 hours, the semi-automatic double-heat source forcing cultivation greenhouse would be covered with plastic film, enhancing its resistance against cold weather. In this way, the greenhouse with the improved system could effectively control environmental factors within it. This study confirmed that the greenhouse with the system of the improvements above could achieve good results for cherry cultivation and environment adjustment. The results showed that the yield of sweet cherry using the semi-automatic double-heat source forcing cultivation system increased to 11 550 kg/hm² and above 80% the sweet cherries were high-quality fruits in continuous two years (in the year of 2012 and 2013). Flavor and external appearance of sweet cherries were also better than those from the conventional greenhouse. The proportion of cherry with cold injury and cracking fruits was decreased in the improved greenhouse compared with the conventional greenhouse. Application of this technology in facility cultivation for sweet cherry can remarkably increase economic and social benefits of farmers. Furthermore, because the ground heating furnace body and heating furnace funnel are connected with the soil in greenhouse with the improved system, the thermal storage characteristics was improved and thus it is easy to control temperature in the greenhouse. Therefore, the semi-automatic double-heat source forcing cultivation system is suitable for cherry cultivation and can be used widely for facility cultivation.
Number of references:23
Main heading:Quality control
Controlled terms:Alarm systems - Automation - Control systems - Cultivation - Fruits - Greenhouses - Heat resistance - Heat storage - Heating furnaces - Humidity control  - Process control - Solar energy - Temperature control
Uncontrolled terms:Chilling requirement - Double-heat source - Economic and social benefits - Growth and development - Semi-automatic control - Stable yield - Sweet cherries - Temperature and humidities
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 532 Metallurgical Furnaces - 615.2 Solar Power - 641.2 Heat Transfer - 731 Automatic Control Principles and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3 Quality Assurance and Control - 914.2 Fires and Fire Protection - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2014.17.029
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 13>

Accession number:201443117774
Title:Optimization on influencing factors of rice chopped straw anaerobic digestion
Authors:Luo, Tao (1); Shi, Guozhong (2); Mei, Zili (2); Shen, Lukun (2); Xiong, Xia (2); Long, Enshen (1)
Author affiliation:(1) College of Architecture and Environment, Sichuan University, Chengdu, China; (2) Biogas Research Institute of the Ministry of Agriculture, Chengdu, China
Corresponding author:Long, Enshen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:243-249
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mechanical size reduction of the straw ruptures the cell walls and makes the organic matter more readily available for the microorganisms to decompose. However, crushing equipment and energy are demanded to change the particle size. Fermentation process of chopped straw with larger length and higher biogas yield can reduce the energy demand and improve the operating profit of biogas plant. In the study, chopped rice straw was investigated on the main factors affecting digestion process, including temperature (30, 35, 40), TS( total solid)(6%, 8%, 10%), particle size (1cm, 2 cm, 3 cm) and retting period (1 d, 2 d, 3 d). The solid ratio of inoculum to substrate was kept at 3:7 for all the experimental setups. The main response selected for analysis was biogas yield. The study was a two-part test. In test 1, the optimum combination was determined by four-factor and three-level orthogonal test; each reactor had a capacity of 1000 ml and contained 500 ml liquid, and batch experiments were carried in water bath for 40 days. In test 2, after determination of the optimum combination, the verification experiments were carried in a constant incubator, the reactors were replaced by vacuum flasks with a capacity of 2 500 mL and contained total liquid of 1500 ml, and parallel reactor of TS=2% (temperature of 40, 2-day retting and particle length of 1 cm) was also run to verify the phenomenon of self-heating during the rice anaerobic digestion. The results showed that temperature was the leading factor to biogas production potential, and the two had a significant relation(P&lt;0.01). Optimal digestion conditions were defined, that was, temperature of 40, 2-day retting, TS of 8% and particle length of 1 cm. Maximum biogas yield of volatile solid was 385.9 mL/g, achieved by test 2. It has reached a high biogas production potential according to the current fermentation research knowledge. During the tests, biogas yields of reactors at 40 were higher than those at 30 and 35, and all of the cumulative biogas productions in early 20 days were above 73% of total. In test 1, liquid temperature in reactors was observed higher than water temperature in water bath in several days of testing; in test 2, liquid temperature in the reactor of TS=8% was higher than those in the reactors of the comparisons throughout the test. It indicated that the phenomenon of self-heating in anaerobic reactors occurred in rice anaerobic digestion. The result is coincident to the thermodynamic knowledge that a little heat can be produced by anaerobic digestion. The self-produced heat is helpful to raise the digestion liquid temperature and reduce energy input to meet the demand of digestion. What's more, it means that the chopped straw biogas production is profitable when the biogas yield is above 299.3 m³/t, the local biogas price is 1.5 RMB/m³, and rice straw price is 226 RMB/t. The collection and treatment of chopped rice straw through anaerobic digestion is a viable option for producing clean, renewable energy with less equipment input and a high biogas yield. Research on feeding and discharging technology still needs to be conducted before this concept becomes a preferred treatment option.
Number of references:27
Main heading:Anaerobic digestion
Controlled terms:Biogas - Fermentation - Liquids - Particle size - Profitability - Straw - Temperature - Testing
Uncontrolled terms:Biogas plants - Crushing equipments - Fermentation process - Heat production - Liquid temperature - Optimum combination - Renewable energies - Water temperatures
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 452.4 Industrial Wastes Treatment and Disposal - 641.1 Thermodynamics - 802.2 Chemical Reactions - 821.5 Agricultural Wastes - 911.2 Industrial Economics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2014.17.031
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 14>

Accession number:201443117782
Title:Synthesis of soybean oil based polyester plasticizer and its property mixing with polyvinyl chloride
Authors:Jia, Puyou (1); Bo, Caiying (1); Zhang, Meng (1); Hu, Lihong (1); Zhou, Yonghong (1)
Author affiliation:(1) Institute of Chemical Industry of Forest Products, Chinese Academy of Forest (CAF), Nanjing, China; (2) Institute of New Technology of Forestry, Chinese Academy of Forest (CAF), Beijing, China
Corresponding author:Zhou, Yonghong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:314-320
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The utilization of renewable resources in material application attracts increasing attentions in chemical industry, due to the concern regarding environmental sustainability. Nowadays, most commercially available materials are derived from non-renewable resources. With rapid consumption of fossil oils and dramatic fluctuations in the oil price, there is an urgent need to develop chemical materials from renewable resources. Vegetable oils are considered to be important renewable sources due to the rich varieties suitable for chemical transformation, universal availability and low price, and they are the preferred alternatives by chemical industry. In this study, soybean oil monoglycerides were prepared by the transesterification between soybean oil and glycerol at 220~240, then polyester plasticizer based on soybean oil was synthesized from soybean oil monoglycerides and maleic anhydride via direct esterification and polycondensation route. The soybean oil polyester plasticizer was characterized by Gel Permeation Chromatography, FT-IR spectrum and HNMR Spectroscopy. The results showed that the molar mass increased obviously with the extension of reaction time. The molar mass of Mn increased from 3027 g/mol to 3030 g/mol when reaction time was 10 h. And the distribution index was about 1.79-2.10. The blends of soybean oil polyester and polyvinyl chloride (PVC) underwent a melting process. The compatibility, mechanical properties and thermodynamic properties of the blends were characterized by torque rheometer, universal testing machine, thermogravimetric analysis (TGA) and dynamic thermo mechanical analysis (DMA). The results showed that with polyester content increasing from 10 g to 30 g in PVC blends, the TG curves showed a three-stage thermal degradation process above 80. PVC blends were thermally stable in N<inf>2</inf> atmosphere. The first-stage degradation at around 80-280 could be attributed to the evaporation of water and small molecules. The degradation in the second stage at around 280-470 was the fastest and corresponding to the formation and stoichiometric elimination of HCl. The last-stage degradation at above 470 was attributed to cross linking containing C=C bonds and the degradation of inert filler such as thermal stabilizers. The glass-transition temperature (Tg) decreased from 55 to 42, and the change of the Tg of PVC blends was in agreement with the common rule the plasticizer can decrease the Tg of PVC. The reason was that the polyester based on soybean oil could interact with PVC molecular and increase the mobility of PVC chain segment. The scanning electron microscope images of the surface of sample-1 plasticized with polyester plasticizer based on soybean oil presented many particles and fractures on the external surface, the particle appearing on the surface was properly the result of some plasticizer excess that was scattered outside the PVC matrix. It caused the eventual migration of plasticizer out of PVC in the processing and using. The SEM images of the surface of sample-3 showed homogeneous and smooth surface. It indicated that the plasticizer was uniformly dispersed in the PVC matrix and surrounded intimately by PVC continuous phase, and there was not a clear boundary between them to be observed. So there was good compatibility between polyester plasticizer based on soybean oil and PVC. The torque of PVC blends decreased from 13.4 N&middot;m to 10.1 N&middot;m, which corresponded to a decrement of 24.6%. The torque decrement could decrease the melt viscosity and would be conductive to thermoplastic processing of PVC blends. The enhancement in plasticization will expand the application range of PVC plasticized with polyester plasticizer materials. This study may lead to the development of new type of PVC plasticizer based on vegetable oil.
Number of references:14
Main heading:Soybean oil
Controlled terms:Blending - Chemical industry - Chromatography - Convergence of numerical methods - Degradation - Dynamic mechanical analysis - Gel permeation chromatography - Glass transition - Mechanical properties - Oil shale  - Plasticizers - Polyesters - Polyvinyl chlorides - Reinforced plastics - Scanning electron microscopy - Sustainable development - Synthesis (chemical) - Thermodynamic properties - Thermogravimetric analysis - Vegetable oils
Uncontrolled terms:Chemical transformations - Environmental sustainability - Non-renewable resource - Polyester plasticizers - Polyvinyl chloride (PVC) - Thermo-mechanical analysis - Thermoplastic processing - Universal testing machines
Classification code:421 Strength of Building Materials; Mechanical Properties - 512.1 Petroleum Deposits - 641.1 Thermodynamics - 741.1 Light/Optics - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 805 Chemical Engineering, General - 815.1.1 Organic Polymers - 817.1 Polymer Products - 911.2 Industrial Economics - 921.6 Numerical Methods - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.17.039
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 15>

Accession number:201443117764
Title:Changes of daily potential evapotranspiration and analysis of its sensitivity coefficients to key climatic variables in Yellow River basin
Authors:Liu, Qin (1); Yan, Changrong (1); Zhao, Caixia (3); Yang, Jianying (1); Zhen, Wenchao (3)
Author affiliation:(1) Institute of Environment and Sustainable Development in Agriculture, CAAS, Beijing, China; (2) Key Laboratory of Dryland Agriculture, MOA, Beijing, China; (3) College of Plant Protection, Agricultural University of Hebei, Baoding, China
Corresponding author:Zhao, Caixia
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:157-166
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Potential evapotranspiration (ET<inf>0</inf>) is generally accepted to be an important element of the hydrological cycle, and changes in sensitivity coefficients of ET<inf>0</inf> to climate variables are of great significance for agricultural water use planning, irrigation system design and management, especially under the condition when climate change may have important influence on water-shortage regions, such as Yellow River basin (YRB), where warmer and drier conditions might augment water demand by crop. However, little reports have focused on the related issues in the upper, middle, and lower regions of YRB. Therefore, this study aimed to investigate the variation of ET<inf>0</inf> and its response to climate variables in the upper, middle, and lower regions of YRB. Based on data for 109 meteorological stations in and around YRB from the Chinese Meteorological Administration (CMA) in years of 1961-2012, ET<inf>0</inf> was estimated using the Penman-Monteith equation recommended by Food and Agricultural Organization (FAO-56) and its sensitivity coefficient to climate variables (solar radiation, relative humidity, daily air temperature, and wind speed) was calculated. The results showed that the average daily ET<inf>0</inf> value in upper region was higher than in the middle and lower region of YRB and a significantly decreasing trend of ET<inf>0</inf> was detected with the magnitude of 0.043 mm per decade in lower region. The diurnal variation curve of solar radiation, air temperature and their sensitivity coefficients was in a single apex type in the upper, middle and lower regions of YRB, and that the sensitivity coefficients of wind speed changed following a single trough type curve. However, the curves fluctuated largely for relative humidity, wind speed along with sensitivity coefficient for relative humidity and air temperature. Furthermore, the maximum value of sensitivity coefficient for relative humidity was found in December, similarly for air temperature and solar radiation in July and August, respectively. A decreasing trend was observed for solar radiation, relative humidity, wind speed and sensitivity coefficient of solar radiation and air temperature. But, an increasing trend was detected for air temperature, sensitivity coefficient of relative humidity and wind speed in recent 52 years. Relative humidity is considered to be the most sensitive variable, while solar radiation is recognized as primarily controlling variable for ET<inf>0</inf> in the whole year and recent 52 years. Moreover, the high value of sensitivity coefficients to solar radiation, relative humidity and air temperature was found in the southwest study area, while the high value of sensitivity coefficients to wind speed was in the north region. Therefore, the southwest region was recognized as the most sensitive region for response of ET<inf>0</inf> to climate change. The findings from this research provide important information for crop planting adjustment, ecological engineering planning and water-soil resource management in YRB in an attempt to improving the healthy development of agriculture and ecological environment.
Number of references:31
Main heading:Climate change
Controlled terms:Agriculture - Atmospheric temperature - Crops - Ecology - Environmental management - Evapotranspiration - Humidity control - Information management - Radiation - Research and development management  - Rivers - Sensitivity analysis - Solar radiation - Speed - Sun - Water resources - Water supply - Watersheds - Wind
Uncontrolled terms:Annual variations - Driving factors - Food and agricultural organizations - Irrigation system design - Penman-Monteith equations - Potential evapotranspiration - Sensitivity coefficient - Yellow River basin
Classification code:402 Buildings and Towers - 443.1 Atmospheric Properties - 444 Water Resources - 444.1 Surface Water - 446.1 Water Supply Systems - 454 Environmental Engineering - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 901.3 Engineering Research - 903.2 Information Dissemination - 921 Mathematics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2014.17.021
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 16>

Accession number:201443117763
Title:Time scale effect on main factors that influence jujube transpiration in hillside jujube orchard
Authors:Wei, Xinguang (1); Chen, Dianyu (1); Wang, Xing (1); Wang, Youke (1); Wei, Xindong (1)
Author affiliation:(1) College of Water Resources and Architecture Engineering, Northwest A and F University, Yangling, China; (2) Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China; (3) School of Earth Science and Resources, Chang'an University, Xi'an, China
Corresponding author:Wang, Youke
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:149-156
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Jujube is widely cultivated in the Loess Plateau region with limited water resources because of its adaptation and high economic benefits. It is necessary to understand the jujube transpiration in order to provide a sustainable cultivation strategy with high water use efficiency. However, the results from the related studies vary partly because of the time-scale difference in different studies. This study aimed to investigate the influence of time scale effect on transpiration. Monthly and annual transpiration and its driving factors were monitored in the year of 2012-2013 in jujube plantations of the Loess Plateau. The relationship between transpiration and factors was analyzed. The results showed that: 1) With the ascension of time scale, the influence of meteorological factors on transpiration decreased, but the influence of crop growth status on transpiration increased, for both monthly transpiration and annual transpiration; however, the main impact factors of monthly transpiration were different from that of annual transpiration under the same time scale; 2) For monthly transpiration, the determination coefficient R² of its main impact factors varied with the time: during the growth period (May to October), the R² was higher than the dormant period, and the main impact factors at hourly, daily, and a period of ten days transpiration were photosynthetically active radiation (PAR), relative humidity (RH) and wind speed (WS), leaf area index (LAI) and leaf area (LA), respectively; 3) For annual transpiration, as the ascension of dimensions, the changing trends of R² of its impact factors were classified into three types: increase first and then decrease (temperature TA), PAR, vapor pressure deficit VPD), increase (soil water content SW, LA, LAI), and decrease first and then increase (RH, WS). Transpiration on smaller time scales (hourly and daily) had significant (p&lt;0.01) correlations with meteorological factors (except for wind speed that had a complicated influence), but with LAI, LA and SW only on larger time scales (ten daily and monthly). By the correlation analysis and comparison of transpiration and its impact factors under different time scales, we found that time scale was one of the important factors affecting their relationships. This conclusion is very important not only for revealing the impact mechanism of relevant factors on transpiration, but also for optimizing the management of jujube plantations in mountainous regions and guiding development of new type water-saving agricultural technology for dry land. Moreover, it has great value to improve the economic and ecological benefits of jujube plantations in mountainous regions, as well as to promote the sustainable development.
Number of references:21
Main heading:Economic and social effects
Controlled terms:Cultivation - Factor analysis - Landforms - Plants (botany) - Rain - Sediments - Soil moisture - Time measurement - Transpiration - Water conservation  - Water content - Water resources - Wind
Uncontrolled terms:Agricultural technologies - Determination coefficients - Leaf Area Index - Meteorological factors - Photosynthetically active radiation - Scale effects - Statistic analysis - Vapor pressure deficit
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 444 Water Resources - 461.9 Biology - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821.3 Agricultural Methods - 922.2 Mathematical Statistics - 943.3 Special Purpose Instruments - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2014.17.020
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 17>

Accession number:201443117752
Title:Turbocharger matching for non-road diesel engine based on parametric sweeping
Authors:Wang, Jun (1); Shen, Lizhong (1); Wang, Guiyong (1); Wan, Mingding (1)
Author affiliation:(1) Yunnan Province Key Laboratory of Internal Combustion Engines, Kunming University of Science and Technology, Kunming, China
Corresponding author:Shen, Lizhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:63-70
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A certain number of turbochargers are usually selected according to calculation parameters to conduct the bench test with diesel engine and the best one among the several turbochargers will be chosen with the traditional turbocharger matching method. However, this method can't guarantee that the selected turbocharger is the best choice. Because the internal combustion engine is a highly nonlinear system, it is difficult to use specific mathematical formula to represent a certain relationship between a parameter and other ones. Parametric sweeping to calculate objective functions to find optima is an optimization. It computes the objective function by directly sweeping the factors and then finds the optima by checking the sweeping results against the constraints. The parameter sweeping method is usually restricted to only one or two deign factors, because it is difficult to plot the parametric data of more than three factors. Meanwhile, the turbocharger matching just has two factors, i.e., compressor and turbine. Therefore, based on the design and development demand of a non-road diesel engine, a turbocharger matching method conducted by parametric sweeping was put forward, the corresponding turbocharged diesel engine model was developed according to the primarily selected turbocharger with GT-Power software as a carrier. In order to choose the best compressor and turbine, parametric sweeping study of normalized compressor mass multiplier and normalized turbine mass multiplier was conducted. The effects of compressors and turbines of different sizes on air-fuel ratio, brake specific fuel consumption, peak cylinder pressure and exhaust manifold temperature were analyzed. The final turbocharger having a good matching with diesel engine was selected under the conditions of the diesel engine design objective and durability constraints. However, the cylinder pressure and temperature will significantly increase when the internal combustion engine is equipped with a turbocharger, and both of the mechanical loading and thermal loading will increase, too. In order to weigh peak cylinder pressure (an indicator of mechanical loading) and exhaust manifold gas temperature (an indicator of thermal loading) after turbocharged, the parametric sweeping simulations of the boost pressure and start of combustion were also conducted. The two appropriate parameters were determined based on the simulation results under the durability constraints. The bench test showed that the selected turbocharger matched well with diesel engine, and the power capability, fuel economy, low-end torque and emissions targets have all reached the design requirements. The diesel engine durability constraints were also within the scope of the limit. Parametric sweeping study displayed the effects of compressors and turbines of different sizes, boost pressure and start of combustion on the diesel engine performance visually. It also can replace the complicated adjustment process of the real turbocharger matching and provide a reference guide for the actual calibration work. In addition, it can effectively balance the contradiction between the peak cylinder pressure and the exhaust manifold gas temperature by the calibration of the boost pressure and start of combustion reasonably.
Number of references:29
Main heading:Diesel engines
Controlled terms:Automobile engine manifolds - Calibration - Combustion - Compressors - Design - Durability - Engine cylinders - Engines - Exhaust manifolds - Fuel consumption  - Fuel economy - Fuels - Internal combustion engines - Machine design - Superchargers - Thermal load - Turbines - Turbomachinery
Uncontrolled terms:Brake specific fuel consumption - Design and Development - Diesel engine performance - Non-road - Parametric sweeping study - Peak cylinder pressures - Turbocharged diesel engine - Turbocharger matching
Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 521 Fuel Combustion and Flame Research - 521.1 Fuel Combustion - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 601 Mechanical Design - 612 Engines - 618 Compressors and Pumps - 618.1 Compressors - 643.1 Space Heating - 661.2 Automotive Engine Components - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.17.009
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 18>

Accession number:201443117759
Title:Optimal design and experiment for divided-flow emitter in drip irrigation
Authors:Yuan, Weijing (1); Wei, Zhengying (1); Chu, Huali (1); Ma, Shengli (1)
Author affiliation:(1) State Key Lab for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, China
Corresponding author:Wei, Zhengying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:117-124
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hydraulic and anti-clogging performances are two important evaluation indicators for drip irrigation emitters. But the two indicators are in conflict when the two design requirements for emitter channel should be satisfied simultaneously. On one hand the channel should be long, narrow and meandering to have good hydraulic performance, but on the other hand it should be short, wide and smooth to obtain good anti-clogging performance. Multi-objective optimization for the emitter channel was reported by Zhang Jun in 2009. The main difficulty lies in the lack of quantitative indicator for the anti-clogging performance of emitters. This paper applied several ways including gradual reduction, gradual divergence and dividing flow to increase local pressure loss in emitter channel design and proposed a multi-objective optimization method for the channel of drip irrigation emitter based on grey target theory. This method combined orthogonal experimental design with grey target theory which is powerful to solve the problems with the uncertainty due to less data, little sample and incomplete information to optimize the emitter channel, with the goal of obtaining reasonable hydraulic and anti-clogging performances. As Computational Fluid Dynamics (CFD) analysis has been widely used in the research on drip irrigation emitters and proved to be effective by many experts, it was adopted to get the orthogonal experimental results in this paper. First, two quantitative indicators for the emitter's hydraulic and anti-clogging performances were defined respectively. The quantitative indicator for the hydraulic performance was flow state exponent. And the quantitative indicator for the anti-clogging performance was particle passing rate which was the ratio between the number of outgoing particles and total particles into the channel. Second, CFD analyses were carried out under different boundary conditions. Third, the results of the orthogonal design were obtained and analyzed with intuitive comparative analysis, variance analysis and linear regression analysis. And then the relationships between the two quantitative indicators and channel parameters were obtained. Fourth, the relationships were used to get more information in this problem, and the data group was extended from 16 to 256. Fifth, grey target theory was employed to analyze the data obtained. The results showed that the preferential sequence could be obtained according to the target heart rate which was an important concept in grey target theory. When the weights of hydraulic and anti-clogging performances were both 0.5, the best combination of factor levels for the emitter channel was A<inf>3</inf>B<inf>4</inf>C<inf>2</inf>D<inf>4</inf>, and the largest target heart rate was 0.795. The optimal channel had a flow state exponent of 0.5150 and a particle passing rate of 88.504%. When the channel was optimized aiming at single objective, the smallest flow state exponent was 0.5136 and the highest particle passing rate was 95.642%. Of course, seen from the comparison of the results between the multi-objective optimization and single-objective optimization, it is difficult to simultaneously get the best result for each target in multi-objective optimization. It is worth noting that when different performance combinations are needed, different weights should be given to the two quantitative indicators. This method provides a quantitative approach to guide the design of emitter channels.
Number of references:27
Main heading:Multiobjective optimization
Controlled terms:Algorithms - Computational fluid dynamics - Design - Design of experiments - Flow visualization - Heart - Irrigation - Optimization - Regression analysis
Uncontrolled terms:Anti-clogging - Computational fluid dynamics analysis - Different boundary condition - Drip irrigation - Grey target theory - Hydraulic performance - Orthogonal experimental design - Single objective optimization
Classification code:408 Structural Design - 461.2 Biological Materials and Tissue Engineering - 631 Fluid Flow - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 821.3 Agricultural Methods - 901.3 Engineering Research - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.17.016
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 19>

Accession number:201443117785
Title:Implementation and achievements of project for high quality scientific journals by China Association for Science and Technology (CAST): a case study of Transactions of the Chinese Society of Agricultural Engineering
Authors:Wei, Xiuju (0); Wang, Liu (0); Cong, Hongbin (0); Zeng, Xieting (0); Liu, Liying (0); Zhu, Ming (0); Zhang, Junfang (0); Qin, Xuemin (0)
Corresponding author:Zhu, Ming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:336-340
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Transactions of the Chinese Society of Agricultural Engineering(TCSAE)was selected in Project High-quality Journals by China Association for Science &amp; Technology (CAST) from 2009-2011. According to the requirements of the project, editorial department of TCSAE carried out a series of work such as improving the editing and publishing processing under network; shortening the publishing period; preventing from academic plagiarized papers; propagandizing the academic papers by mass media. Results of the project showed that quality of TCSAE was greatly improved, influence of TCSAE was expanded, and the virtuous circle of development of TCSAE was formed. This paper summarizes the works, experiences and achievements of TCSAE since implementation of the project, and proposed the development direction of academic journals.
Number of references:3
Main heading:Publishing
Controlled terms:Agricultural engineering - Agriculture - Education
Uncontrolled terms:Academic journal - High quality - Journal development - Journal quality - Scientific journals
Classification code:821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.2 Education - 903.2 Information Dissemination
DOI:10.3969/j.issn.1002-6819.2014.17.042
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 20>

Accession number:201443117746
Title:Resistance changes and effectiveness experiment of increasing yield of rice with mixed planting under mechanical transplanting
Authors:Teng, Fei (1); Chen, Huizhe (1); Xiang, Jing (1); Cai, Xueqing (1); Xu, Yicheng (1); Zeng, Yanhua (1); Zhu, Defeng (1)
Author affiliation:(1) China National Rice Research Institute, Hangzhou, China
Corresponding author:Zhu, Defeng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:17-24
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, growing crops in mixtures has become an important element of sustainable agriculture and organic farming. Mixed cropping is especially popular in parts of Asia. Rice is one of the most important crops in China. Rice is cultivated in a quarter of the arable land in China and supports more than half of its population. Pests and diseases are the main limitations in rice production. It was reported that the rice yield loss due to pests and diseases exceeds 20%. Available insecticides are currently used for the control of rice pest. Mixed planting of different rice varieties is an effective strategy to control weeds, diseases and pests, but it is difficult to extend at large scale because of the complicated operating. Until now, a lot of researches focus on intercropping, but few studies about completely mixed planting have been reported. Meanwhile, along with the development of the agricultural industrialization and modernization, rice mechanized transplanting will replace the traditional transplanting by hand in our country, and the economy and technology conditions for developing rice mechanized transplanting are also maturing day after day. The mixed planting becomes easy to carry out using mechanical transplanting model. The experiment was conducted in China National Rice Research Institute experiment station in 2013, and two rice varieties, i.e. Shenliangyou 5814 and Zhongzheyou 8, which had similar plant height and growth period and different resistance, were used in this experiment. Five patterns including 100:0, 70:30, 50:50, 30:70, and 0:100 mixtures (by plant number) of Shenliangyou 5814 and Zhongzheyou 8 were adopted to evaluate the effects of mixed planting on rice growth and yield. The experiments were laid out in a split-plot design: contrast test of five mixture patterns was in the main plot, and that of non-pesticide and pesticide was in the sub-plot. The results showed that: the mixed planting significantly improved rice yield and the resistance to weeds, disease and pests. In all mixed planting patterns, mixed pattern of 50:50 had the best resistance to weeds, disease and pests, and the weeds biomass decreased by 13.1% and 54.1%, and sheath blight index decreased by 79.5% and 27.1% compared with planting patterns of 100:0 and 0:100, respectively. The lodging rate of rice decreased with the increasing of Zhongzheyou 8 mixture rate. The yields of rice in five mixture patterns without pesticide application decreased by 32.6%, 31.3%, 26.9%, 27.4% and 28.8%, respectively, compared with those of corresponding treatments with pesticide application. So the rice mixed planting was an effective management to improve rice's resistance to weeds, pest and disease, and it could reduce the input of pesticide. The mixed planting pattern can improve rice tiller development and leaf area index, especially at tillering stage. Mixed planting could promote nutrient transformation, and promote nutrient accumulation in the grains. Compared to the monoculture planting patterns (i.e. 100:0 and 0:100), the yield of rice in mixture pattern (50:50) increased by 12.8% and 7.0%, respectively, and the grain filling percentage increased significantly. This study indicated that the fitting rice mixture pattern combined with mechanized transplanting could reduce production input and improve rice yield and quality. More research is needed to do, such as the fitting variety for mixed planting, the production technology for getting high yield.
Number of references:31
Main heading:Grain (agricultural product)
Controlled terms:Agricultural machinery - Agriculture - Crops - Cultivation - Disease control - Diseases - Forestry - Growth (materials) - Mixtures - Modernization  - Nutrients - Pesticides - Plants (botany)
Uncontrolled terms:Machine-transplanted - Mixed planting - Resistant - Rice - Yield
Classification code:461 Bioengineering and Biology - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession
DOI:10.3969/j.issn.1002-6819.2014.17.003
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 21>

Accession number:201443117766
Title:Design of county-level soil information system based on Web-GIS
Authors:Liu, Zhong (1); Li, Baoguo (1); Xu, Min (1); Gao, Qiang (2)
Author affiliation:(1) Key Laboratory of Arable Land Conservation (North China) of Ministry of Agriculture, College of Resource and Environment, China Agriculture University, Beijing, China; (2) College of Resources and Environment, Jilin Agricultural University, Changchun, China
Corresponding author:Li, Baoguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:175-182
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Science research and production practice have accumulated a large number of soil data, which is the valuable essential data for practice and research. It is significant for sustainable land use to enhance soil information management and sharing. But currently the construction of county level soil information system is facing many issues such as the high cost, difficult to maintain, and performance bottlenecks, etc. In this paper, a low-cost open-source Web GIS platform (MapGuide Open Source) was adopted to design and develop a county-level soil information system (CLSIS) for Lishu county based on the second soil survey database and other soil data in Visual Studio.Net. The system development was divided into four stages: system requirement analysis, system design, system implementation and system testing. The system was designed as a three-tier Server/Brower open application system. Client tier may be a browser terminal or a management terminal. Web tier, deployed on the internet information server, was responsible for receiving requests from browsers, passing the requests to the application server and returning the response to browsers. Application tier was composed of a GIS server (MapGuide Open Source 2.1), a database server and a remote Web Map Service (WMS) component. The database was organized as the attribute database and spatial database, respectively. The attribute database includes the soil basic information table, soil physical properties table, soil chemical properties table, geomorphology table, and land use and administrative table. Among all spatial data, the soil, topography, land use and administrative maps are vector layers, but the precipitation and temperature are stored as raster format. The server-side of CLSIS provided map services, feature services, render services and image services. The functions of server-side were implemented by C# and MapGuide Server API in Visual Studio.Net. The browser-side programming is applied with fusion flexible page layout solution, which has better flexibility, scalability and response speed. Fusion framework is an expanded JavaScript library derived from OpenLayers and JXLib. The system built up a dynamic contact with Google WMS, facilitating the switch of base map among the standard, satellite, hybrid and terrain. Google WMS enhanced the visual effect and intuitive feelings of CLSIS. The system maintenance and management is mainly done by MapGuide Maestro, which is a client software based on Client/Server structure. The centralized management makes system maintenance and upgrades more convenient. CLSIS realizes the map navigation, map services, feature services and thematic mapping functions. By utilizing these functions mentioned above, users can conveniently query and browse soil resources and other relevant geographic background informations for Lishu county. The available soil data include soil type, soil texture, soil parent materials, soil organic matter, the thickness of humus, pH value, total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium, trace elements and soil water retention, etc. The operation result shows that the system reaches a good balance between cost of development/maintenance and performance. This system will be a basic county level soil information platform for further expansion in the application of multiple fields.
Number of references:30
Main heading:Soils
Controlled terms:Costs - Database systems - Design - Forestry - Geographic information systems - Information management - Information systems - Java programming language - Land use - Maintenance  - Nitrogen - Open source software - Open systems - Phosphorus - Potassium - Query processing - Rasterization - Social networking (online) - Soil moisture - Soil surveys  - Trace elements - Web browsers
Uncontrolled terms:Basic information tables - Centralized management - Internet information servers - MapGuide - Open sources - Performance bottlenecks - Soil chemical property - Soil information system
Classification code:403 Urban and Regional Planning and Development - 408 Structural Design - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 723 Computer Software, Data Handling and Applications - 804 Chemical Products Generally - 821.0 Woodlands and Forestry - 903.2 Information Dissemination - 911 Cost and Value Engineering; Industrial Economics - 913.5 Maintenance
DOI:10.3969/j.issn.1002-6819.2014.17.023
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 22>

Accession number:201443117753
Title:Shear strength calculation of claw tip in attachment system of plague locust Locusta migratoria manilensis
Authors:Wang, Lixin (1); Cui, Yanping (1); Zhou, Qiang (2)
Author affiliation:(1) School of Mechanical Engineering, Hebei University of Science and Technology, Shijiazhuang, China; (2) College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Wang, Lixin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:71-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plague locusts control is an important aspect in agricultural production, and the conventional method generally used for controlling locust plague is spraying pesticide. This method can quickly and effectively kill the plague locusts to prohibit the agricultural plants from being destroyed, but will result in serious environmental pollution ascribing to the pesticide residues. Many researchers have exerted their efforts to explore innovative methods to not only control the plague locusts, but also avoid the pesticide pollution. The photoelectric technology, i.e. inducing slippery trapping plague locust based on the phototaxis property of locust has been put forward. This technology relies on the spectrum light source to induce plague locusts, as well as depends on the slippery trapping plate and its related mechanical structure to make the trapped locusts in light source district effectively slide to corresponding equipment. In this technology, one of the most important aspects is developing slippery trapping plate with excellent slip function, which can greatly improve the trapping efficiency of photoelectric inducing machine for trapping plague locust. To acquire material strength properties of claw tip of plague locust used for guiding the selection of trapping plate materials, the shear forces of foreleg, mid-leg and hind-leg claws of the locust (Locusta migratoria manilensis) were measured with insect micro-force measurement system designed in this paper. Utilizing scanning electron microscopy (SEM), microstructures and geometrical properties of the claw tips and their fracture sections were observed and analyzed, and sectional areas of the fracture sections were calculated with obtained SEM images and CAD (Computer-aided Design) software. Based on the acquired values of shear force and sectional area, the shear strength of locust claw tip was calculated. The results presented that the shear forces of locust claw tips were between 197.4 mN and 243.6 mN, and claw tips in forelegs exhibited the greatest value (243.6 &plusmn; 8.5 mN), whereas claw tips in mid-legs presented the smallest value (197.4 &plusmn; 8.9 mN), and the shear force of claw tips of hind-legs possess moderate value (215.3 &plusmn; 19.7 mN). The claw tips of forelegs, mid-legs and hind-legs of locust attachment system presented rather smooth surface and resembled a hemisphere at high magnifications, and these claw tips exhibited similar morphologies and structures but differed in geometrical dimensions. SEM images involving the fracture sections of locust claw tips indicated that the interior of the claw tips possessed composite multilayer structure which consisted of exocuticle and endocuticle. Section areas of the fractured claws had different values, and section area of the fractured claws in forelegs exhibited the smallest value (1 0847.6 &plusmn; 770.6 &micro;m²), whereas the section areas of the fractured claws in mid-legs and hind-legs presented the greatest value (13 908.5 &plusmn; 825.7 &micro;m²) and moderate value (12 664.5 &plusmn; 986.8 &micro;m²), respectively. This obvious discrepancy of sectional areas presumably resulted from the difference of fracture positions. Based on the obtained shear force and section area, the shear strength of the claw tips was calculated, and the results demonstrated that the shear strength of claw tips in locust forelegs exhibited the value of (22.5 &plusmn; 1.5 )MPa, whereas the shear strengths of claw tips in locust mid-legs and hind-legs were( 14.2 &plusmn; 1.6 )MPa and (17.1 &plusmn; 2.1) MPa, respectively. The results here provide valuable information for developing locust trapping plate possessing excellent slip function, and probably promote the development of photoelectric technology of inducing slippery trapping plague locust.
Number of references:30
Main heading:Strength of materials
Controlled terms:Agricultural machinery - Agriculture - Computer aided design - Experiments - Force measurement - Light sources - Micromanipulators - Morphology - Pest control - Pesticides  - Photoelectricity - Plates (structural components) - Pollution - Pollution control - Scanning electron microscopy - Shear strength
Uncontrolled terms:Agricultural productions - Claw tip - Environmental pollutions - Geometrical dimensions - Locust - Mechanical structures - Microforces - Morphology structures
Classification code:408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 454.2 Environmental Impact and Protection - 723.5 Computer Applications - 731.5 Robotics - 741.1 Light/Optics - 744 Lasers - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 901.3 Engineering Research - 943.2 Mechanical Variables Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.17.010
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 23>

Accession number:201443117784
Title:Improve alfalfa silage quality by adding alhagi sparsifolia shap in initial bloom stage
Authors:Jiang, Hui (1); Fang, Lei (1); Zhou, Xiaoling (1); Li, Shengli (2)
Author affiliation:(1) College of Animal Science, Tarim University, Alaer, China; (2) College of Animal Science and Technology, China Agricultural University, Beijing, China
Corresponding author:Jiang, Hui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:328-335
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The objectives of this work were to evaluate the effects of mixed silage of Alhagi sparsifolia Shap in initial bloom stage and alfalfa on silage quality, investigate a way of the silage of juicy alfalfa without additive, and provide a theoretical basis for the development and utilization of A. sparsifolia Shap. 100% of alfalfa (I, as a control group), 100% of A. sparsifolia Shap in initial bloom stage (II), or mixtures of their different percentages (III: 30% of A. sparsifolia Shap 70% of alfalfa, IV: 50% of A. sparsifolia Shap 50% of alfalfa, V: 70% of A. sparsifolia Shap 30% of alfalfa) were used in this experiment and each treatment had three replicates. After 90 d of ensiling, silages were sampled, and sensory quality and fermented products (pH, lactic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, isovaleric, methanol, ethanol, propanol and ammonia nitrogen) were evaluated. Chemical components (dry matter, crude protein, water soluble carbohydrate, neutral detergent fiber, acid detergent fiber), lactobacillus and yeast living cells were determinated for both fresh forages and silages.
Number of references:31
Main heading:Quality control
Controlled terms:Ammonia - Blooms (metal) - Butyric acid - Carbohydrates - Cells - Cytology - Ethanol - Experiments - Fermentation - Lactic acid  - Methanol - Nitrogen - pH - Propanol - Propionic acid - Saturated fatty acids - Yeast
Uncontrolled terms:Acid detergent fiber - Alfalfa - Alhagi sparsifolia shap - Development and utilizations - Different treatments - Lactic acid bacteria - Neutral detergent fiber - Water-soluble carbohydrates
Classification code:461.2 Biological Materials and Tissue Engineering - 461.8 Biotechnology - 535.1.2 Rolling Mill Practice - 801.1 Chemistry, General - 801.2 Biochemistry - 804 Chemical Products Generally - 901.3 Engineering Research - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2014.17.041
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 24>

Accession number:201443117769
Title:Balance between actual number of livestock and livestock carrying capacity of grassland after added forage of straw based on remote sensing in Tibetan Plateau
Authors:Li, Gang (1); Sun, Weilin (2); Zhang, Hua (1); Gao, Chunyu (1)
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy Agricultural Science, Beijing, China; (2) Institute of Agricultural Economics and Development, Chinese Academy Agricultural Science, Beijing, China
Corresponding author:Gao, Chunyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:200-211
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to quickly and accurately know grassland productivity and the balance between the actual livestock and carrying capacity of the grassland, to promote the rational use of grassland and ensure the sustainable development of ecological environment and animal husbandry on the Tibetan Plateau, it is necessary to estimate the stock capacity of natural grassland and grassland after supplementing feed, as well as understand grassland balance situation supplementing feed before and after among different administrative regions in the Tibetan Plateau. The study estimated the grass yield on the Tibetan Plateau and analyzed the yield's spatial distribution of natural grassland using an improved model of CASA combined with the data of NDVI from MODIS, grassland type maps, meteorological data, soil texture on the Tibetan Plateau. The paper adopt the method of straw-to-grain ratio to estimate the volume of straw forage among different administrative regions in the Tibetan Plateau and then to calculate the carrying capacity of the available straw resources of each county. According to the grass yield, carrying capacity of straw resource and the real number of livestock, the paper identified the overgrazing of all counties and cities with grass build balance model. The results showed that the annual grass yield of different regions in the Tibetan Plateau varied a lot in 2010, and the maximum was in Tibet with the largest grass yield of 26 428 890 tons, followed by Qinghai Province with the yield of 23.08 million tons, and Yunnan was the lowest, only 373 600 tons. The total livestock carrying capacity of natural grassland in the Tibetan Plateau was 83 630 365 (standard sheep unit, the same below), in which, the livestock carrying capacities of Qinghai, Tibet, Sichuan, Gansu and Yunnan were 28 890 963, 27 893 522, 18 540 968, 7 964 236 and 340 946, respectively. The overgrazing among each county and city in the Tibetan Plateau was very common. Without adding feed by straw forage, the quantities of the county and city with the overgrazing rate more than 5 times, between 2 and 5 times, less than 1 time accounted for 7.69%, 28.84% and 38.82% of total county and city, respectively. And the counties in which the actual number of livestock did not exceed the local maximum carrying capacity only accounted for 11.19%. In case of adding straw forage, the proportion of the counties without overgrazing remained the same, however the situation of overgrazing county improved. The proportions of the county with overgrazing rates more than 5 times, between 2 and 5 times, between 1 and 2 times decreased by 3.2%, 4.49%, 5.49%, respectively, and the proportion of the county with overgrazing rate less than 1 time increased by 2.2%. Therefore, it is necessary to strictly control the volume of cattle and sheep to match the carrying capacity of natural grassland and feeding straw resources, and to achieve sustainable development of ecological environment and animal husbandry.
Number of references:43
Main heading:Agriculture
Controlled terms:Animals - Ecology - Meteorology - Models - Planning - Remote sensing - Straw - Sustainable development
Uncontrolled terms:Casa models - Ecological environments - Grassland productivity - Grassland yields - Meteorological data - Method of straw-to-grain ratio - Natural grassland - Tibetan Plateau
Classification code:403 Urban and Regional Planning and Development - 443 Meteorology - 454.3 Ecology and Ecosystems - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 902.1 Engineering Graphics - 911.2 Industrial Economics
DOI:10.3969/j.issn.1002-6819.2014.17.026
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 25>

Accession number:201443117756
Title:Collaborative optimization algorithm on axial-flow pump blade design
Authors:Shi, Lijian (1); Tang, Fangping (1); Lei, Cuicui (2); Yang, Hua (1); Yang, Fan (1)
Author affiliation:(1) School of Hydraulic Energy and Power Engineering, Yangzhou University, Yangzhou, China; (2) Shanghai Urban Construction Design and Research Institute, Shanghai, China
Corresponding author:Tang, Fangping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:93-100
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this thesis, collaborative optimization algorithm is applied to the multidisciplinary design optimization of axial-flow pump blades. Collaborative optimization algorithm being a kind of multidisciplinary design optimization has developed rapidly in recent years, and is popular among experts at home and abroad because of its special advantages. First, the main design variables which influence the hydraulic performance and structural strength simultaneously were referred to. Besides, the thesis described collaborative optimization algorithm that is used for complex engineering systems to optimize the design. The computing framework of collaborative optimization algorithm could also be found in this thesis. Moreover, the advantages and disadvantages of the collaborative optimization algorithm were also analyzed. In the part of the system-level mathematical model of collaborative optimization, the surface response method and constraint relaxing method were introduced, which changed equality constraint into inequality constraints. Because the constraint relaxing method needs less calculation and leads to higher rate of convergence, the thesis adopted the collaborative optimization algorithm. Then, the mathematical model for the axial-flow pump blades was set up with collaborative optimization algorithm. The system-level optimization model adopted multidisciplinary and multi-objective optimization method, i.e. the two disciplines-the hydraulic performance and structure-were expressed as an objective function of the system in the form of a linear combination. The subsystem optimization model should suffice the requirements of cavitations performance, cascade diffusion coefficient, and blades stresses. In the end, based on the iSIGHT optimization platform, hydraulic performance and structure were coordinated and optimized collaboratively. By a series of computational analyses, the model of axial-flow pump blades were exported and then tested. The experimental results show that axial-flow pump blades which are designed by this algorithm have a good comprehensive performance. In consequence, the case of the design optimization of axial-flow pump blades indicates that the convergence of the collaborative optimization algorithm based on constraint relaxing method is reliable, and solved the problem that coupling multiple disciplines would have large volumes and complex data. At the same time, it verified the feasibility of a multi-disciplinary design optimization in the pump blade design optimization field. As to an axial-flow pump, collaborative optimization algorithm does produce a better-optimized design scheme, improve the overall performance of axial-flow pump blades, and extend the range of application of the axial-flow pump blades. Meanwhile, this algorithm avoids controlling the related indexes by virtue of mere experience when the design optimization is considered in a single discipline. Therefore, the collaborative optimization algorithm for axial flow-pump blades of multidisciplinary design optimization is efficient and feasible.
Number of references:31
Main heading:Algorithms
Controlled terms:Axial flow - Axial flow turbomachinery - Constraint theory - Design - Design aids - Diffusion - Distributed computer systems - Machine design - Multiobjective optimization - Optimization  - Pumps - Structural design - Turbomachine blades
Uncontrolled terms:Blade design optimizations - Collaborative optimization - Complex engineering system - Comprehensive performance - Constraint relaxation - Multi-disciplinary designs - Multidisciplinary design optimization - System level optimization
Classification code:408.1 Structural Design, General - 601 Mechanical Design - 618.2 Pumps - 631.1 Fluid Flow, General - 722.4 Digital Computers and Systems - 723 Computer Software, Data Handling and Applications - 902.1 Engineering Graphics - 921 Mathematics - 921.5 Optimization Techniques - 931.1 Mechanics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.17.013
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 26>

Accession number:201443117773
Title:Determination of odour emission at compost plant based on electronic nose and GIS
Authors:Lu, Peng (1); Wu, Shixin (2); Dai, Zhifeng (3); Su, Zhaohui (2); Zhang, Xiaohui (1); Fu, Xiao (1); Zhou, Xiaofei (4); Yang, Yongjie (5); Dai, Zhanguo (4); Lu, Xufei (4); Zheng, Bin (4); Shen, Kai (4)
Author affiliation:(1) Bioengineering Faculty of Beijing Electronic Science and Technology Vocational College, Beijing, China; (2) Beijing Environmental Sanitation Engineering Research Institute, Beijing, China; (3) Beijing Municipal Commission of City Administration and Environment, Beijing, China; (4) Beijing Environment Sanitation Engineering Group Co. LTD Siqing Branch, Beijing, China; (5) Sound Environment Group Co. LTD, Beijing, China
Corresponding author:Su, Zhaohui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:235-242
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Three main styles of treatments used in the municipal solid wastes treatment process are compost, landfill and incineration. Composting is an effective treatment for organic solid waste to produce fertilizer. But it always produces a certain amount of leachate and gaseous pollutants during the process, which induces odorous nuisance problems. The malodorous gas produced during composting is an important factor affecting the environment, which often lead to complaints by residents from surrounding area and has negative effect on application of composting technology in municipal solid waste disposal. The odour emission problem from composting plant must be considered carefully.
Number of references:34
Main heading:Waste treatment
Controlled terms:Air quality - Biofilters - Composting - Fermentation - Fog - Geographic information systems - Incineration - Interpolation - Leachate treatment - Municipal solid waste  - Odors - Pollution - Solid wastes - Waste disposal - Waste incineration
Uncontrolled terms:Boundary concentrations - Compositing - Composting technologies - Concentration gradients - Electronic NOSE - Global position systems - Source - Surrounding environment
Classification code:443.1 Atmospheric Properties - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 454.2 Environmental Impact and Protection - 723.3 Database Systems - 802.2 Chemical Reactions - 811 Cellulose, Paper and Wood Products - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2014.17.030
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 27>

Accession number:201443117777
Title:Feasibility of evaluation method for spinach leaf senescence based on biological ultraweak photon emission
Authors:Xi, Gang (1); He, Ruirui (1); Liu, Kai (1); Zhao, Yanyan (1)
Author affiliation:(1) Department of Applied Physics, Institute of Science, Xian University of Technology, Xi'an, China
Corresponding author:Xi, Gang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:268-275
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Evaluation of plant leaf senescence is one of the core issues of life science research, which is generally based on the physiological indicators such as chlorophyll content, malondialdehyde (MDA) content. This evaluation method requires to destroy plant cells, resulting in inaccurate measurements and many other issues. Non-destructive testing and evaluation of leaf senescence has not been resolved. Plant cells in life activity will produce ultraweak photon emissions which include spontaneous photon emission and delayed photon emission induced by external light. The ultraweak photon emission of living cells is closely related with many processes such as physiological metabolism, photosynthesis, and cell division. Through analysis and interpretation to the ultraweak photon emission of plant cells, a new method for non-destructive testing of plant leaf senescence could be proposed. For this purpose, spinach leaves in vitro were treated with H<inf>2</inf>O<inf>2</inf>. Spinach leaf senescence caused by H<inf>2</inf>O<inf>2</inf> stress and the ultraweak photon emission of spinach leaf under H<inf>2</inf>O<inf>2</inf> stress were studied in this paper. The results showed that the spontaneous photon emission of spinach leaves increased with the extension of H<inf>2</inf>O<inf>2</inf> stress time and was positively correlated with changes of MDA content in leaf, with a correlation coefficient of 0.90415, and the changes of spontaneous photon emission in leaves reflected the changes of membrane lipid peroxidation degree in plant leaves. The study also found that the change of delayed photon emission induced by external light also occurred in the process of H<inf>2</inf>O<inf>2</inf> stress. Compared with the control group, the delayed photon emission of spinach leaves decreased rapidly. According to the biological significance of spontaneous photon emission and the delayed photon emission of plant cells induced by external light, using the ratio of integrated intensity of the delayed photon emission to the spontaneous photon emission as a state parameter to describe the overall state of cells, it was found that the changes of cell state parameter based on ultraweak photon emission of cells were positively related to the changes of chlorophyll content in cells in the process of leaf senescence under H<inf>2</inf>O<inf>2</inf> stress, with a correlation coefficient of 0.91437. This result suggested that the degree of cells senescence in leaf could be speculated through the change of cell state parameter based on ultraweak photon emission of cell, so as to realize non-destructive testing and evaluation about the degree of cells senescence of plant leaves. The photonics method of leaf senescence evaluation proposed in this paper needs to be verified in more experiments in different plant leaves.
Number of references:29
Main heading:Photons
Controlled terms:Cell proliferation - Cells - Chlorophyll - Cytology - Heat radiation - Lipids - Nondestructive examination - Parameter estimation - Photonics - Physiological models  - Physiology - Plant cell culture - Plants (botany) - Slip forming
Uncontrolled terms:Biological significance - Cell state - Membrane lipid peroxidation - Non-destructive testing and evaluations - Physiological indicators - Plant leaf - Spontaneous photon emission - Ultra-weak photon emissions
Classification code:412 Concrete - 421 Strength of Building Materials; Mechanical Properties - 461 Bioengineering and Biology - 641.2 Heat Transfer - 712 Electronic and Thermionic Materials - 717 Optical Communication - 731.1 Control Systems - 741.1 Light/Optics - 744 Lasers - 804.1 Organic Compounds
DOI:10.3969/j.issn.1002-6819.2014.17.034
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 28>

Accession number:201443117758
Title:Calculation of sprinkler drive vane positional parameters and its influence on sprinkler performance
Authors:Li, Hong (1); Tang, Pan (1); Liu, Zhenchao (1); Tu, Qin (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China
Corresponding author:Li, Hong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:109-116
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As the water shortage is becoming more and more serious, water-saving irrigation has become an important part of agriculture modernization. Raising the level of agricultural mechanization and improving the utility ratio of water are necessary ways to access agriculture modernization. As the most important parts in sprinkler irrigation system, sprinklers can spray water into the air, turning into small water droplets and then landing on those crops that need irrigation, their performances directly affect the sprinkler irrigation system and engineering quality. At present, the most representative and most widely used sprinkler of the high pressure sprinklers is vertical impact drive sprinkler. The content of this article contains the following aspects. The motion process of sprinkler drive vane for a vertical impact sprinkler in the water jet was analyzed. In order to accurately adjust the position of the drive vane, the respective regression equations of three parameters were calculated, which are the distance between the drive vane and rocker arm shaft (Factor A), the angle between the centerline of drive vane and that of the jet (Factor B), and the angle between straight vane and the centerline of jet (Factor C). Using quadratic regression orthogonal test, the influences of positional factors of drive vane on the shifting frequency, the angle of step-by-step operation and the Christiansen coefficient of irrigation uniformity were investigated. The impact factors in order for the shifting frequency of drive vane are Factor B, Factor C and Factor A; The angle of step-by-step operation is most affected by Factor B, then by Factor A, last by Factor C; In comparison, the influence of three factors on the Christiansen coefficient of irrigation uniformity is not significant. More exactly, the shifting frequency of drive vane diminishes as the distance between the drive vane and rocker arm shaft increases and it rises with the other two factors. However, the angle of step-by-step operation decreases with the increases of these three parameters. The regression equations were derived by Excel through the optimal combination of factors for the highest irrigation uniformity that figured out: Factor A is supposed to be 273 mm, Factor B is 4&deg; and Factor C is 13&deg;. After the optimization of positional parameters for the drive vane, the water in the near range of sprinkler is supplemented better by the jet compared to that before optimization, thus the water distribution is more reasonable. Further, the Christiansen coefficient of irrigation uniformity under larger sprinkler spacing after optimization is far higher than that before optimization. Therefore, the sprinkler with drive vane in optimized positional parameters is more suitable for the overlapping irrigation. The results can provide a basis for designing and optimal layout of vertical impact sprinklers.
Number of references:21
Main heading:Sprinkler systems (irrigation)
Controlled terms:Agriculture - Experiments - Hose - Irrigation - Machinery - Parameterization - Regression analysis - Water conservation - Water supply systems
Uncontrolled terms:Agricultural mechanization - Irrigation uniformity - Optimal combination - Orthogonal test - Quadratic regression - Regression equation - Sprinkler irrigation - Water-saving irrigation
Classification code:444 Water Resources - 446.1 Water Supply Systems - 601 Mechanical Design - 619.1 Pipe, Piping and Pipelines - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.17.015
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 29>

Accession number:201443117770
Title:Automatic segmentation of plant disease images based on graph cuts fusing multiple features
Authors:Wu, Na (1); Li, Miao (2); Chen, Sheng (1); Yuan, Yuan (2); Zeng, Xinhua (2); Chen, Lei (2); Sun, Xiongwei (2); Bian, Chengfei (1)
Author affiliation:(1) School of Information Science and Technology, University of Science and Technology of China, Hefei, China; (2) Institute of Intelligence Machines, Chinese Academy of Science, Hefei, China
Corresponding author:Li, Miao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:212-219
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Diseases in crops can lead to declines of production and quality, which cause economic losses in agricultural industry worldwide. Therefore, detection of the diseases in plants is extremely critical for sustainable agriculture. Many crop diseases perform on the leaves, and often present in the form of spots, so processing the leaf images is a feasible way for identifying and diagnosing diseases. Spots separation from the leaf is a very important step in the process of disease recognition and diagnosis. And the segmentation accuracy affects the reliability of the subsequent feature extraction and the accurateness of following classification directly. To improve the segmentation performance, an automatic segmentation algorithm based on graph cut which fused multiple features was put forward in this paper. Firstly the background was excluded by threshold method so as to speed up the image segmentation. The experimental comparison results showed that the segmentation effect for color images processed by OTSU algorithm, a simple adaptive threshold image segmentation method, was not very satisfactory. Therefore, a new method of threshold processing was studied here, which could remove most of the background and did not lose the disease spots. In addition, the red component of the original color images was used as the research objects of the new threshold method, since it had the strongest contrast compared with the green component and the blue component. Then three features, texture, gray level and distance were fused to build the boundary term of the energy function, which described the similarity between the pixels. Among them, for the sake of reducing the computational complexity and calculation time, the texture feature was simply defined by the one-dimensional entropy of images, which was the amount of information included by the gathered characteristics of gray level distribution. Moreover, in order to reflect the extent of the pixel belongs to the background or target, the red component difference between pixels in the image region and the region boundary was used to set up the area term of the energy function automatically. Finally the maximum flow algorithm was utilized to solve the established energy function, and the segmentation results were obtained. With the purpose of verifying the validity of the proposed algorithm, the method was applied to divide three kinds of cucumber disease (target spot, downy mildew and powdery mildew) leaf images. Each disease of 50 pictures, a total of 150 pictures were selected randomly as the experimental samples. And the OTSU algorithm and semi-automatic graph cuts algorithm were chosen as the contrast means. The experimental results demonstrate that the disease spots of the leaf images can be separated effectively when using the method proposed in this paper. The average error rate is 1.81%, which is lower than the other two algorithms, and its average segmentation time do not significantly increase. This study can provide a technical reference for the automatic identification and diagnosis of cucumber diseases in the future.
Number of references:30
Main heading:Image segmentation
Controlled terms:Agriculture - Algorithms - Automation - Color image processing - Computational complexity - Crops - Diagnosis - Diseases - Feature extraction - Fungi  - Graphic methods - Image processing - Losses - Pixels - Plants (botany) - Textures
Uncontrolled terms:Agricultural industries - Automatic identification - Automatic segmentations - Cucumber - Experimental comparison - Graph cut - Multiple features - Segmentation performance
Classification code:461.6 Medicine and Pharmacology - 461.9 Biology - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 732 Control Devices - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 911.2 Industrial Economics - 921 Mathematics - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2014.17.027
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 30>

Accession number:201443117754
Title:Experiment on mixing performance of on-line mixing spray system
Authors:Qiu, Baijing (1); Ma, Jing (1); Deng, Bin (1); Ou, Mingxiong (1); Dong, Xiaoya (1)
Author affiliation:(1) Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education and Jiangsu Province, Jiangsu University, Zhenjiang, China
Corresponding author:Qiu, Baijing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:78-85
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The aim of this study was to research the influence of the jet-mixing apparatus (one core component) on working state of the on-line mixing spray system. Due to the need of making the mixing process visible, the pesticide was simulated by carmine solution. The working states of the on-line mixing spray system with 3 types of different flow characteristics produced by 3 kinds of nozzles respectively, i.e. TR80-005c, ST110-01 and F110-015 were examined, as well as the jet-mixing apparatus with 24 different structural parameters made up of 4 types of mixing tube's diameters and 6 types of jet nozzle's outlet diameters. Based on spectrophotometric method, the mixing solution from the on-line mixing spray system was collected and measured by the visible spectrophotometer of UV-2102 PCS type. The absorption wavelength of carmine solution was firstly scanned, and 508 nm was selected as the measuring wavelength. Then a series of carmine standard solutions with different concentrations of 0.01, 0.02, 0.04, 0.06, 0.08 and 0.1 g/L were prepared to establish a mathematical expression of carmine solution concentration and the absorbance under the selected wavelength; finally, the concentrations of the collected samples were calculated according to the mathematical expression. The mixture homogeneity of the on-line mixing spray system operated with the nozzle of F110-015 was analyzed by the above method when jet nozzle's outlet diameter of jet-mixing apparatus, d, was set to 2.00 mm, and the area ratio m was set to 4.00. The results of experiments indicated that the structural parameters of the jet-mixing apparatus had a significant effect on the working condition of the on-line mixing spray system. In the same kind of spray system, when the structural parameters of the jet-mixing apparatus changed, the working state of the on-line mixing spray system also changed. And there are two working states for spray system in different experiments: inhalation and backflow. The inhalation is a state that liquid water provided by hydraulic pump is imported into the jet nozzle through the water inlet A of the jet-mixing apparatus, and forms a pressure small enough to make the pesticide sucked into the sucking chamber through the pesticide inlet B. And when the water is imported into the jet-mixing apparatus and then flows out from the pesticide inlet and diffuses, the pesticide can't be sucked; and this state is called as the backflow. Based on the theoretical analysis and experiments, two methods to solve the problem of liquid backflow were given: change the structural parameters of jet nozzle by increasing inlet diameter or decreasing outlet diameter of jet nozzle, and reduce the drag coefficient of the spraying system. In the spray system operated with the nozzle of F110-015 type, CV ( the space coefficients of variation ) of mixture concentration under 4 types of spray pressures (0.26, 0.30, 0.34 and 0.36 MPa) were 2.983%, 3.599%, 4.287% and 4.647%, respectively, all less than 5%. In conclusion, the jet-mixing apparatus can be well applied to the on-line mixing spray system.
Number of references:29
Main heading:Spray nozzles
Controlled terms:Agricultural machinery - Equipment - Hydraulic machinery - Inlet flow - Liquids - Mixing - Mixtures - Nozzle design - Nozzles - Pesticides  - Social networking (online) - Spectrophotometers - Spectrophotometry - Spraying
Uncontrolled terms:Backflow - Coefficient of variation - Coefficients of variations - Inhalation - Jet-mixing apparatus - Mathematical expressions - Spectro-photometric method - Visible spectrophotometers
Classification code:631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 723 Computer Software, Data Handling and Applications - 801 Chemistry - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 813.1 Coating Techniques - 821.1 Agricultural Machinery and Equipment - 901 Engineering Profession - 931.2 Physical Properties of Gases, Liquids and Solids - 941 Acoustical and Optical Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.17.011
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 31>

Accession number:201443117767
Title:Uncertainty of gully sediment budgets based on laser point cloud data
Authors:Li, Binbing (1); Huang, Lei (3); Feng, Lin (2); Ma, Ding (2)
Author affiliation:(1) Process of Soil Erosion in the Loess Plateau and Control Laboratory of Ministry of Water Resources, Zhengzhou, China; (2) Graduate Management Group, Engineering University of Chinese Armed Police Force, Xi'an, China; (3) Department of Information Engineering, Engineering University of Chinese Armed Police Force, Xi'an, China
Corresponding author:Li, Binbing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:183-191
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Gully erosion has been recognized as one of the important processes in sediment production and land degradation in a wide range of environments. Soil loss rates by gully erosion represent from minimal 10% up to 94% of total sediment yield caused by water erosion. The recent advances in LIDAR provide the rapid acquisition method of topographic data at spatial resolutions. These advances make monitoring gully geomorphic changes and estimating sediment budgets through DEM (digital elevation model) differences, a tractable, affordable approach for monitoring applications in both research and practice.In order to reduce the uncertainty of the estimated gully morphological sediment loading produced by the DEM difference, a new method was presented in this paper, which allowed for more robust estimation of DEM uncertainties and propagated this forward to the estimation of morphological sediment loading. The method allowed for probabilistic representation of uncertainty and thresholding of the sediment loading at a user-specified confidence interval. 1000 times sampling were carried out by Matlab through the Bootstrap method to achieve &delta;z which was the error between the observed and calculated elevations, as the individual error, then the individual errors in DEMs can be propagated into &delta;<inf>cutfill</inf> as a priori probability. On this basis, the difference between the initial detection threshold values of DEM for preliminary screening was determined; then, the new approach modified this estimate on the spatial correlation of erosion and deposition units, which was based on a convolution filter creating a moving window of 5 &times; 5 cell size of DEM for calculating erosion/deposition conditional probability; finally, according to the prior probability, conditional probability and confidence level (95%), the minimum detection threshold value was established for the final corrected morphological sediment loading. Compared with those resulted from DEM difference without correction and from DEM difference corrected by Brasington and Lane method, the variable quantity of erosion and deposition estimated by this new method applied in typical gully in Qiaozigou, Tianshui, Gansu Province, decreased by 13.13% and 7.53% respectively at a 95% confidence interval. Moreover, the estimation value was only about 2% error with the observed sediment loading provided by the Water Conservation Station. Besides, the relations between the gully slope, point cloud density, surface roughness and the uncertainty of erosion/deposition were as followed: the greater the gully bank's slope, the greater the uncertainty of erosion/deposition; when the point density was in the range of 0~140 points/m², the erosion/deposition showed a decreasing trend with the point density increasing, while, when the point density was more than 140 points/m², erosion/deposition density had little change; the greater the gully surface roughness, the greater the erosion/deposition uncertainty, the greater the slope of the gully bank. Tests show that the new method provides a scientific basis for the monitoring of the Loess gully erosion morphological change and accurate estimation of erosion.
Number of references:18
Main heading:Sediments
Controlled terms:Budget control - Deposition - Digital instruments - Erosion - Geomorphology - Landforms - Probability - Surface roughness - Surveying - Uncertainty analysis  - Water conservation
Uncontrolled terms:Conditional probabilities - Digital elevation model - Erosion and deposition - Loess Plateau - Monitoring applications - Point cloud data - Probabilistic representation - Sediment budgets
Classification code:405.3 Surveying - 444 Water Resources - 481.1 Geology - 481.1.1 Geomorphology - 483 Soil Mechanics and Foundations - 813.1 Coating Techniques - 911 Cost and Value Engineering; Industrial Economics - 922.1 Probability Theory - 931.2 Physical Properties of Gases, Liquids and Solids - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.17.024
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 32>

Accession number:201443117751
Title:Analytical model of tire rolling resistance based on elastic hysteresis theory
Authors:Li, Bo (1); Zhao, Youqun (1); Zang, Liguo (1); Wang, Jian (1); Zhang, Mingjie (1)
Author affiliation:(1) College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
Corresponding author:Zhao, Youqun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:56-62
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the situation of the global power shortage and the increasing demand for the fuel, it becomes an important subject for the tire researchers to reduce energy consumption of tire and improve tire's energy efficiency. In the field of the interaction mechanism between the tire and the road, a calculation model of the energy consumption of the tire is very meaningful, and it is restricted by multiple conditions, such as the tire temperature, the material properties and the friction conditions. The tire's friction force develops from the contact region. In the process of tire rolling, the forces generate periodical stress spectrum whose frequency lies on the tire's rolling velocity. The periodical stress causes energy loss according to the size and the material property of the tire. The parameter identification of the proposed model in this paper could be carried out through specific experiments, which possessed the variation characteristics for the vertical loading and velocity of the tire through the horizontal motion of the sine guide rail and the load of the guide rod, and the equipment consisted of guide pulley, guide rod, sine guide rail, tire and supporting structure. The brush model assumes that the slide rate develops from the relative displacement of the tread between the wheel hub and the road. The tread is supposed to be elastic brush adhered to the stiff wheel hub. The wheel hub can neither stretch nor shrink, yet deformations may occur in every small elastic brush. Using the brush model to simplify the interaction relationship between the tires and the ground, the contact patch is divided into two parts: the first is loading part which ranges from the starting contact point to the central of the contact region, and the elastic force fits the loading curve of tire's compound restoring force; the second is unloading part which ranges from the central of the contact region to the end contact point, and the elastic force fits the unloading curve of tire's compound restoring force. The analytical model of tire rolling resistance can be obtained by the integral within the two contact parts for the loading curve function and unloading curve function, which is the main innovation of this paper. In the end, by defining the velocity and the load as the test variables, the effectiveness of the proposed analytical model was verified by the experiments of the rolling resistance measurement in accordance with the standard of ISO 28580. The results showed that the rolling resistance of the tire increased with the increasing of speed (10-120 km/h) and vertical load (6-25 kN); and change trend of the test result was consistent with that of the analytical value under the same condition. The new model of rolling resistance proposed in this paper is helpful to structure optimization of the tire.
Number of references:28
Main heading:Tires
Controlled terms:Analytical models - Curve fitting - Curves (road) - Elasticity - End effectors - Energy dissipation - Energy efficiency - Energy utilization - Friction - Hysteresis  - Identification (control systems) - Loads (forces) - Models - Parameter estimation - Roads and streets - Rolling resistance - Structural optimization - Unloading - Wheels
Uncontrolled terms:Brush model - Elastic hysteresis - Interaction mechanisms - Interaction relationship - Parameters identification - Reduce energy consumption - Resistance measurement - Variation characteristics
Classification code:406.2 Roads and Streets - 408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 525 Energy Management and Conversion - 601.2 Machine Components - 674.1 Small Marine Craft - 731 Automatic Control Principles and Applications - 818.5 Rubber Products - 902.1 Engineering Graphics - 921 Mathematics - 931.1 Mechanics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.17.008
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 33>

Accession number:201443117783
Title:Rapid pickling of tuber mustard by using flowing saline solution under magnetic field
Authors:Jin, Yamei (1); Yang, Na (1); Jiao, Aiquan (2); Wu, Fengfeng (1); Jin, Zhengyu (1); Xu, Xueming (1)
Author affiliation:(1) School of Food Science and Technology, Jiangnan University, Wuxi, China; (2) State Key Lab of Food Science and Technology, Jiangnan University, Wuxi, China; (3) Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, China
Corresponding author:Xu, Xueming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:321-327
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pickling is considered to be the most effective method of preserving food materials and of preventing spoilage. Commercial pickled tuber mustard with special favor is very popular in China. Most agricultural raw materials and food itself is porous to a certain extent, favoring ion diffusion. Salting is time-consuming process; therefore, some techniques in salting process has been applied to reduce salting time, such as vacuum impregnation, ultrasound technique and pulsed pressure treatment. Electrolyte solution contains a large number of charged ions such as Na, Cl^-, H, Ca², Mg² and OH^-. The movement of charged ions can be affected by the Lorentz force in the perpendicular magnetic field which induces large-scale mass transfer and migration in a fixed direction. In this study, the low-cost static magnetic field system has been designed which utilized modern NdFeB permanent magnets as the source for the required magnetic flux. The two blocks of NdFeB magnets(100 mm&times; 100 mm&times;15 mm, B<inf>r</inf>=0.5 T) were arranged in parallel, and placed with iron yokes in a way that a magnetic flux density B was generated by adjusting its distance. The magnetic flux densities between the parallel magnets measured by Teslameter, were 200 Gs, 1000 Gs and 2000 Gs, respectively, which were known to be strong enough to have the magnetic effect on the movement of ions. Simultaneously, these magnet systems provided sufficient free space to place the samples. The sample was placed parallel to the direction of magnetic field lines. Then tuber mustard salting by flowing saline was conducted in magnetic field at different treatment conditions. The flow rates of saline solution were respectively 0.03 m/s (Re=563), 0.06 m/s (Re=1127) and 0.22 m/s (Re=4132) corresponding to laminar flow and turbulence. In the experiment, the sampling period was 10 minutes, and then mass fraction of NaCl in the sample was determined after a 3-hour brining period. The mass transfer kinetic model has been investigated for evaluation of salt content in the samples during pickling. All measurements were performed in the laboratory at average room temperature of 20 . Three replicates of each sample were used for statistical analysis. The results showed that mass fraction of NaCl in the sample reached maximum at the magnetic flux density of 2000 Gs and flowing velocity of 0.06 m/s within the salting period. At this point the salinity diffusion coefficient was highest (k=2.35&middot;10^-2 min^-1). The turbulence in saline solution was not conducive to the diffusion of salt into the sample with the lowest diffusion coefficient (k=0.34&middot;10^-2 min^-1 and 0.31&middot;10^-2 min^-1) at 0.22 m/s. There was no significant increase in mass fraction of NaCl in tuber mustard immersed by the static saline solution under the perpendicular magnetic field. However, saline solution in laminar flow conditions was conducive to the diffusion of free ions into the porous plant materials with the action of the Lorentz force. Analysis of mass transfer in sample demonstrated that using the Logistic kinetics model, the highest correlation coefficient of the equations was 0.989. The technology achieves the rapid salting for agric-products.
Number of references:26
Main heading:Magnetism
Controlled terms:Charged particles - Diffusion - Food preservation - Ions - Laminar flow - Lorentz force - Magnetic fields - Magnetic flux - Magnets - Mass transfer  - Neodymium alloys - Pickling - Spoilage - Superconducting tapes - Turbulence - Ultrasonic applications
Uncontrolled terms:Correlation coefficient - Flowing electrolytes - Laminar flow conditions - Mass-transfer kinetics - NdFeB permanent magnet - Perpendicular magnetic fields - Static magnetic fields - Tuber mustard
Classification code:461.9 Biology - 539 Metals Corrosion and Protection; Metal Plating - 547.2 Rare Earth Metals - 631.1 Fluid Flow, General - 641.3 Mass Transfer - 701 Electricity and Magnetism - 704 Electric Components and Equipment - 708.3 Superconducting Materials - 753.3 Ultrasonic Applications - 801 Chemistry - 822.2 Food Processing Operations - 931.1 Mechanics - 931.3 Atomic and Molecular Physics
DOI:10.3969/j.issn.1002-6819.2014.17.040
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 34>

Accession number:201443117779
Title:Inhibition of membrane lipid super oxidization and browning by rapid dehydration technique during drying of grapes
Authors:Liu, Fengjuan (1); Meng, Yang (2); Bai, Yujia (2); Liu, Chunyue (2); Huang, Wenshu (2); Feng, Zuoshan (1)
Author affiliation:(1) College of Forestry and Horticulture, Xinjiang Agricultural University, Urumqi, China; (2) College of Food Science and Pharmacology, Xinjiang Agricultural University, Urumqi, China
Corresponding author:Huang, Wenshu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:285-294
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Xinjiang is abundant in grapes. According to statistics, the production of grape accounted for 28.4% of the whole fruit production in Xinjiang in 2012. Since the mature period of grapes is very short, dehydrated drying after grape harvest is an important method of processing. Thompson seedless grape (Vitis vinifera L. var Wuhebai) is the main species of green raisins. As green raisins produced from traditional dry room are likely to browning, it's well acknowledged as a key issue for the development of Xinjiang raisins. It was reported that the browning of actinidia arguta, longan, litchi and peach was caused by the polyphenol oxidase (PPO) contacting with the phenolic substrates, which resulted in the strengthen of the membrane lipid peroxidation and the increase of cell membrane permeability in fruits. These researches were focused on the relationship between browning caused by dehydration treatment before storage or nature water loss during storage and the membrane lipid peroxidation. But the dehydration was different from dehydration drying process. In order to investigate the mechanism that rapid dehydration inhibited the membrane lipid peroxidation, PPO, browning of Thompson seedless grapes during the drying, the changes of physiological and biochemical properties caused by grape browning in dehydration drying process were investigated in this study, and subsequently obtained the theoretical basis for preventing raisins browning and maintaining the quality of Thompson seedless grapes. Xinjiang Thompson seedless grapes were used as experiment materials. After being operated by the drying agent, two treatments, i.e. rapid dehydration and slow dehydration were conducted. Samples were taken every 10% loss in weight of the samples and stored for further use. The effects of different drying methods on dry basis moisture content, drying rate, browning, membrane permeability (relative conductivity), malonaldehyde (MDA) content, lipoxygenase (LOX) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase (POD) activity, polyphenol oxidase (PPO) activity and total phenol content were studied. The results showed that there were two stages in the drying of Thompson seedless grapes, i.e. constant rate drying and falling rate drying, and the significant browning of Thompson seedless grape during two drying methods both occured in the falling rate drying stage. The browning of Thompson seedless grape in the slow dehydration was in positive correlation with LOX activity, and the browning of Thompson Seedless grape in the rapid and slow dehydrations was in positive correlation with membrane permeability and MDA content, and negatively correlated to SOD activity, CAT activity, PPO activity, and total phenols content. It was found that the browning in the dehydration process of Thompson seedless grapes was closely related to the membrane lipid peroxidation. Rapid dehydration treatment significantly slowed down the development of the browning, as well as MDA content and membrane permeability; besides, LOX activity was also inhibited. The relatively high activity of active oxygen scavenging enzymes including SOD, CAT and POD and the more content of total phenols were maintained, and PPO was kept at a low level of activity. In conclusion, rapid dehydration can effectively inhibit the membrane lipid peroxidation of Thompson seedless grapes from cell membrane damage, maintain the integrity of the cells, and retard the browning of Thompson seedless grapes during drying and heating processes. The results provide a reference for the application of rapid dehydration in the drying of Thompson seedless grapes.
Number of references:32
Main heading:Dehydration
Controlled terms:Biological water treatment - Cell membranes - Cytology - Drying - Fruits - Ionization of gases - Lipids - Membranes - Oxidation - Oxidative stress  - Oxygen - Phenols - Plants (botany) - Quality control - Scavenging
Uncontrolled terms:Biochemical properties - Browning - Cell membrane permeability - Membrane lipid peroxidation - Oxidization - Positive correlations - Superoxide dismutase activities - Thompson seedless
Classification code:445.1 Water Treatment Techniques - 461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 612.1 Internal Combustion Engines, General - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.17.036
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 35>

Accession number:201443117762
Title:Scheduling optimization of drainage pumping stations in urbanization polders
Authors:Liu, Jingsen (1); Cheng, Jilin (1); Gong, Yi (1)
Author affiliation:(1) College of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou, China
Corresponding author:Cheng, Jilin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:141-148
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For guaranteeing flood control security, the drainage pumping stations with large installed capacity were distributed densely at urbanization areas set with embankments. Conducting optimization research on operation scheme under different precipitation conditions lower than drainage standard should effectively decrease energy consumption. The main difficulty of operation scheme optimization of urban drainage pumping stations was that with the increase of pumping station quantity and single station's installed capacity, the combination number of feasible schemes increased too fast to be difficult to calculate. This paper proposed an optimization method which selected the lowest total energy consumption from multiple schemes with orthogonal test and eliminated unqualified schemes with controlling river water level outside the polder. Using this method, pumping stations in the drainage area were divided into different groups according to their actual layout, and a certain quantity of start-up schemes combined with practical experience were established for each group of pumping stations under different precipitation conditions. Then, taking pumping station group as the test factor, start-up scheme as the test level, and the lowest total electric power consumption as the objective function, the orthogonal experiment was carried out. The sequence of influence extent of various test factors and levels as well as the best test lever of each test factor to the target function could be obtained by conducting orthogonal analysis on test results. Thus the sequence of multiple optimized operation schemes including theoretically the best one could be obtained. Using the unsteady flow model to calculate each level of river water for each optimization scheme, and if each level of river water was within the allowable variation amplitude, the scheme was optimal and feasible, otherwise, the scheme could be crossed out. The operation scheme which met the requirement of the lowest total electric power consumption was found out from all of the feasible schemes, and taken as the best optimized scheduling method under the specific precipitation condition. Taking certain area of Shanghai as a study case, the optimized scheduling schemes under four common precipitation conditions lower than the drainage standard were worked out respectively for the two hydrological conditions, i.e. self-draining via the tide outside the river and self-draining that cannot utilize the tide outside the river. On the most unfavorable hydrological condition that could not utilize the tide outside the river for self-draining, the total electrical power consumption of the optimized scheduling scheme could be saved about 12% compared with the current operation scheme. By comparing energy-saving benefit between optimal scheduling schemes and current schemes, the rationality of current scheme had been verified, and the optimization suggestion was proposed in this paper as well. The method proposed in this paper was a beneficial attempt to enrich and improve the method of optimizing operation scheme of pumping stations.
Number of references:25
Main heading:Scheduling
Controlled terms:Drainage - Electric utilities - Energy utilization - Flood control - Optimization - Orthogonal functions - Pumping plants - Rain - Rivers - Water levels  - Water resources
Uncontrolled terms:Energy cost - Orthogonal test - Polder areas - Pumping stations - Storm drainage
Classification code:401 Bridges and Tunnels - 406 Highway Engineering - 442 Flood Control; Land Reclamation - 442.1 Flood Control - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 446 Waterworks - 502 Mines and Quarry Equipment and Operations - 525.3 Energy Utilization - 614.2 Steam Power Plant Equipment and Operation - 706 Electric Transmission and Distribution - 912.2 Management - 921 Mathematics - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2014.17.019
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 36>

Accession number:201443117778
Title:Transfer method among water content detection models for different breeds of pork by hyperspectral imaging technique
Authors:Liu, Jiao (1); Li, Xiaoyu (1); Guo, Xiaoxu (1); Jin, Rui (1); Xu, Senmiao (1); Ku, Jing (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China
Corresponding author:Li, Xiaoyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:276-284
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:At present, most studies on model transfer were based on different spectrometers, and models were established using the near infrared spectroscopy. In this study, a hyperspectral detection model of water content of fresh pork was established by partial least squares regression (PLSR) method. In order to enhance model prediction applicability to different breeds of pork samples, a new model transfer method, piecewise direct standardization combined with linear interpolation (PDS-LI) was processed. In this method, the spectra of slave breed were corrected according to the spectra difference between master breed and slave breed, and then the corrected spectra of slave breed were predicted by master model. A function based on the prediction and reference values of slave breed samples was established. This function would be used to correct the prediction values of unknown test samples of slave breed. The specific steps were as followed: 1) Samples of master breed were divided into the calibration set and the test set, and the master model was built based on the calibration set by PLSR method. 2) Samples of slave breed were partitioned into standard sample selection set C<inf>2</inf>, standard sample set C<inf>2std</inf> and unknown test set T<inf>2un</inf>, and C<inf>2</inf> was used for the selection of C<inf>2std</inf> and T<inf>2un</inf> was used to verify the transferred model. 3) Transfer matrix F was calculated by PDS algorithm according to the spectra difference between calibration set in master breed and C<inf>2std</inf> in slave breed, and then C<inf>2std</inf> and T<inf>2un</inf> were respectively corrected by transfer matrix F. 4) In order to improve the prediction accuracy of master model to the corrected spectrum of slave breed, the prediction value of T<inf>2un</inf> need to be corrected. For sample i in unknown test set T<inf>2un</inf>, symbiosis distance D(i) between sample i and every sample else in standard sample set C<inf>2std</inf> was calculated successively. D(i) was the sum of Euclidean distances between converted spectrum and absolute deviation of the prediction values. Two minimum values of D(i) were selected, so the prediction value of sample i in T<inf>2un</inf> could be corrected by the prediction and reference values of the 2 minimum samples. Three breeds, Duchangda, Maojia and Linghao pork were researched in this paper. As master breed, Duchangda samples were used to build the master model, and Maojia and Linghao were considered to be slave breeds to test the feasibility of model transfer algorithm. Equations with predictive determination coefficient (R²<inf>p</inf>) no less than 0.7 and residual prediction deviation (RPD) no less than 1.9 were considered to be applicable to predict pork quality. Model prediction results showed that for Duchangda samples, the coefficient of determination in cross-validation (R²<inf>cv</inf>) was 0.884, R²<inf>p</inf> was 0.883, root mean squared error of cross validation (RMSECV) was 0.279%, root mean squared error of prediction (RMSEP) was 0.237%, and RPD was 2.911, but for Maojia and Linghao samples, the prediction results were very poor: R²<inf>p</inf> only reached to 0.263 and 0.507, RMSEP, 1.151% and 0.857%, RPD, 1.000 and 1.214, respectively. With PDS-LI transfer method, the model prediction accuracies were substantially increased: R²<inf>p</inf> increased to 0.832 and 0.848, RMSEP decreased to 0.470% and 0.440%, RPD improved to 2.447 and 2.364, respectively, which indicated that PDS-LI transfer algorithm can achieve the model prediction transfer from Duchangda to Maojia and Linghao pork samples.
Number of references:30
Main heading:Forecasting
Controlled terms:Algorithms - Calibration - Imaging techniques - Least squares approximations - Mean square error - Meats - Models - Near infrared spectroscopy - Spectrometers - Spectroscopy  - Standardization - Testing - Transfer matrix method - Water content
Uncontrolled terms:Coefficient of determination - Determination coefficients - HyperSpectral - Hyperspectral imaging techniques - Model transfer - Partial least squares regressions (PLSR) - Piecewise direct standardization - Root mean squared errors
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 444 Water Resources - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 746 Imaging Techniques - 801 Chemistry - 822.3 Food Products - 902.1 Engineering Graphics - 902.2 Codes and Standards - 921 Mathematics - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2014.17.035
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 37>

Accession number:201443117749
Title:Precise control of clamping force for watermelon picking end-effector
Authors:Hu, Zhiyong (1); Zhang, Xuewei (1); Zhang, Wei (2); Wang, Lin (1)
Author affiliation:(1) Mechanical Engineering College, Inner Mongolia University of Technology, Huhhot, China; (2) Qinhuangdao Port Co., Ltd, Qinhuangdao, China
Corresponding author:Hu, Zhiyong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:43-49
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Certain agricultural work requires a very stable robot end-effector to reduce vibration and damage to products. However, the structures of conventional articulated robots tend to be too weak to manipulate heavy objects, such as the watermelon. To achieve mechanized harvesting of the watermelon, we compared the characteristics of different end-effectors with the motor, pneumatic and hydraulic drives. By contrast, the hydraulic drive has many advantages, such as high power-weight ratio, compact structure and convenient layout. Therefore, the end-effector with hydraulic drive is more suitable for heavy fruit harvesting such as the watermelon. The hydraulic drive system based on force perception can output appropriate clamping force according to actual situation. When picking robot crawls and picks, it needs to avoid the damage to fruits and vegetables caused by unstable clamping force and to achieve the precise control of the clamping force for picking robot end-effector. Therefore, how to improve output force's control precision of the valve control cylinder and reduce interference are key to improve the picking performance. Two identical small valve control cylinders were used to establish a load simulation test platform for simulating the loading condition of the clamping force in picking watermelons. There existed the question that position control system interfered the force system on load simulation test platform, which situation would affect the loading accuracy of the end-effector and result in the loading error; and hence in order to reduce the loading error, the control compensation method, which could produce a compensation effect by increasing the compensation algorithm link in the control program, was adopted in this paper. Through this method the loading error was effectively suppressed. Based on the load simulation test platform, the researches of the theory, simulation and experiment on the inhibition of the loading error were carried out. The mathematical relationship between position disturbance and output force was built with mechanism modeling method. Based on the speed synchronization control method, the simplified compensation link of loading error was designed and the co-simulation model of AMESim &amp; Simulink and physical experiment platform were built; in addition, for picking watermelon, the mechanical properties and the situation of actual picking watermelons were taken into consideration in this paper. Researching the compression characteristics of watermelon, it was known that before watermelon reached yield limit, microstructure of watermelon was without damage, so the compression force at this point was considered to be safe. Taking into account the yield limit of loading compression force, the safe loading force in simulation and experiment was set up. In the watermelon's picking process, the position of the disturbance will inevitably produce. Different crawling and moving speeds will produce in various degrees of disturbance. At the same time, picking different qualities of watermelons needs different clamping forces. The accuracies of loading clamping forces at different speeds and different loads during the picking process were studied. By simulation and experiment methods, the loading error can be restrained effectively and the load simulation accuracy of end-effector can be improved greatly, which contributes to the synchronous speed control method. This method provides a powerful guide for the design of end-effector and precise control and real-time tracking of the output force. In this paper, watermelon picking is taken as the example to study the feasibility of control theory, but the study is not limited to the watermelon picking. The results in this paper are generally applicable to the accuracy control of the end-effector driven by hydraulic pressure.
Number of references:28
Main heading:Loads (forces)
Controlled terms:Agricultural machinery - Agriculture - Clamping devices - Control theory - Cylinders (shapes) - Data compression - End effectors - Error compensation - Fruits - Hydraulic drives  - Hydraulic machinery - Interference suppression - Mechanical properties - Robots - Software testing
Uncontrolled terms:Clamping Force - Compression characteristics - Control compensation methods - Load simulation - Mathematical relationship - Precise control - Valve control cylinders - Watermelon picking
Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 605 Small Tools and Hardware - 632.2 Hydraulic Equipment and Machinery - 711 Electromagnetic Waves - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.17.006
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 38>

Accession number:201443117744
Title:Line-churning tooth design and metering accuracy experiment of rice pneumatic precision hill-drop seed metering device on pregnant Japonica rice seed
Authors:Zhang, Guozhong (1); Zang, Ying (2); Luo, Xiwen (2); Wang, Zaiman (2); Li, Zhaodong (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China; (2) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China
Corresponding author:Luo, Xiwen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:1-9
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are two rice varieties in China. One is Japonica rice and another is Indica rice, and there are obvious differences between them. Due to the need to accurately obtain seed quantity for each hill in direct rice seeding, a novel precise pneumatic metering device was designed with a group sucking holes plate in a seed metering device, by which 3-4 seeds can be sucked and dropped at the same time. Existing experiments were conducted to investigate the sucking characteristics of the group holes on the sucking plate under vacuum, the diameter of the hole, and the seed-clearing device. For optimization of the pneumatic precise metering device structure and motion parameters, improving its capability on accurately sucking different rice varieties of seed, a kind of line-churning tooth was designed. A quadratic orthogonal rotation regression experiment was conducted to investigate the sucking characteristics of the precise pneumatic metering device under vacuum, the rotation speed of the plate, the distance between the sucking-hole center, and the line-churning tooth and height of the line-churning tooth. A probability about the quantity for each hill was used to evaluate the capability of the pneumatic precise metering device. The experimental equipment consisted of a pneumatic metering device with group holes, a U-shaped manometer, a positive and negative pressure air pipeline, a cut-off valve, and a vortex pump. In the experiments, the rotating speed of a sucking plate was 15-45 r/min and its diameter was 165 mm. The diameter of the sucking hole was 1.8mm, and the distance between sucking holes were 6.5mm, while the distance was 65 mm between the middle hole and the center of the plate. There were ten group holes on the plate, and every group had three sucking holes on a straight line of radius direction. A fingerlike clearing device was set on the plate while the distance was 123.75 mm between it and the center of the plate, its length was 38 mm, and the installation angle was 25&deg; to vertical axis of the plate. The rice variety was pregnant Japonica rice seed whose name was Yanfeng 47. Its moisture content (wet basis) was 21.30%-21.79%, its 1000-grain was 30.03 g, its sphericity was 0.54, and its overall dimension (length&times;width&times;thickness) was 6.82 mm&times;3.23 mm&times;2.24 mm. Its sliding friction angle was 36.15&deg;, and its natural repose angle was 27.12&deg;. With a probability of (3-4) seeds per hill, a probability of three seeds per hill, a probability of four seeds per hill, and a probability of &ge;5 seeds per hill, four regression equations were established. Every equation's evaluation of fitting was very good, and all equations were significant at the 0.05 level. The experimental results showed that there existed an optimization condition on the capability of the metering device to meet the needs of production. The optimization condition included that the vacuum was 2.4 kPa, the rotation speed was 30r/min, the distance between the churning tooth and sucking hole was 8mm, the seed churning tooth height was 3mm, the sucking hole diameter was 1.8 mm, and the distance between the holes was 6.5 mm. With the cleaning device, the probability of (3-4) seeds per hill of the metering device was 77.28%; in addition the &le;2 seeds probability was 3.04%, and &ge;5 seeds probability was 19.67%, while the experimental results were very close to the regression model calculation results. The study proved that the metering device could accurately obtain seed quantity for each hill of pregnant Japonica seeds, and the regression model could be used to predict probable seed quantity for each hill. This study was an important reference basis for the pneumatic metering device on structure design and motion parameters optimization on seeding pregnant Japonica seeds.
Number of references:22
Main heading:Structural design
Controlled terms:Agricultural machinery - Drops - Plates (structural components) - Pneumatic equipment - Pneumatics - Probability - Regression analysis - Seed
Uncontrolled terms:Experimental equipments - Group holes - Metering devices - Optimization conditions - Precision hill-drop - Quadratic orthogonal rotation - Rice - Seed metering devices
Classification code:408.1 Structural Design, General - 408.2 Structural Members and Shapes - 443.1 Atmospheric Properties - 632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 922.1 Probability Theory - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.17.001
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 39>

Accession number:201443117775
Title:Effect of reactor temperature and residence time on physiochemical performance of cellulose hydrothermal products
Authors:Gao, Ying (1); Chen, Hanping (2); Yuan, Qiaoxia (1); Wang, Xianhua (2); Yang, Haiping (2); Wu, Ke (1); Cao, Hongliang (1)
Author affiliation:(1) Engineering Technology Academy, Huazhong Agriculture University, Wuhan, China; (2) State Key Laboratory of Coal Combustion Huazhong University of Science and Technology, Wuhan, China
Corresponding author:Chen, Hanping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:250-258
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The characteristics of cellulose's products under hydrothermal treatments in an autoclave were investigated at various temperature (200~400) and residence time (5~120 min). With the temperature increasing from 200 to 250, heavy oil yield increased sharply from 5% to 14.75%. The temperature of 250 was suitable for the liquefaction to obtain higher yield of liquid products, with a maximum of 14.75%. With the increase in residence time, heavy oil yield increased in the first 10 minutes, and thereafter decreased with further increase in residence time because of the cracking reaction occurring in the primary hydrothermal product of heavy oil. The hydrochar yield decreased in the first 5 minutes, and then increased. At the same temperature with residence time of 5 min, the hydrochar yield reached a maximum of 50% and heavy oil yield was 16.25%. The yields of light oil and gas increased with the time increasing. The chemical compounds of heavy oil identified at 200, 250, 300, 350, and 400 in residence time of 30 min were mainly furans, phenols, carboxylic acids, aldehydes and ketones, and high molecular compounds were determined by gas chromatography-mass spectrometry (GC-MS). Aldehydes, phenols, ketones, acid groups and sugars in the light oil were determined by GC-MS as well as Fourier transform infrared (FTIR). The hydrochar was analyzed by elemental analyzers, scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analysis, x-ray photoelectron spectroscopy (XPS) and FTIR. The elemental composition of the hydrochar from hydrothermal degradation of cellulose at 200~400 for 30 min showed the relationship between the hydrogen/carbon (H/C) and oxygen/carbon (O/C) ratios of the hydrochar. The ratios of H/C and O/C decreased continuously with increasing temperature, however, after the temperature increased to 250, the ratios became constant at higher temperatures. These results were consistent with the yield of the gases and hydrochars at the same temperature. Through the SEM and TEM, it was found that the hydrochar had a core-shell structure. From the FTIR spectra, the hydrochar from cellulose hydrothermally treated at 250 with residence time of 30 min and 2 h exhibit was completely different from the cellulose FTIR traces. There was no O=C=O adsorption peak under the conditions of 250 and residue time of 2 h. The adsorption peak of the C=O vibration was wider, which indicated the existence of ketones and aldehydes. The results showed that the hydrochar was composed of aromatics and polymeric products, which revealed that aromatization processes took place during hydrothermal treatment. The XPS spectra of cellulose and hydrochar produced from hydrothermal treatment at 250 for 2 h showed that there was a large amount of hydroxyl groups attached to carbon atom in the cellulose, and the hydrochar contained additional aliphatic/aromatic carbon groups (C-C/C=C) and carboxylic groups, esters, or lactones (-COOR). Compared with the results from the FTIR spectra, the basic behavior of the hydrochar's functional groups could be investigated by XPS. The CH, C-O, and C=O groups decreased with the increase in residence time, similar to the results obtained with FTIR. From the chemical point of view, oxygen groups of the hydrochar differed in the core and shell, inferred from the XPS and FTIR measurements. Indeed, the core contained ketone and ether groups and the shell contained carboxylic and carbonyl groups. In conclusion, the formation of the hydrochar is through hydrolysis and dehydration of cellulose, and the hydrochar has a core-shell structure and better physicochemical characterization at lower temperature and longer residence time.
Number of references:31
Main heading:Fourier transform infrared spectroscopy
Controlled terms:Adsorption - Aldehydes - Biomass - Carbon - Cellulose - Chemical compounds - Chromatography - Crude oil - Electron microscopy - Esters  - Functional groups - Gas chromatography - Heavy oil production - Ketones - Mass spectrometry - Oil shale - Oil wells - Phenols - Scanning electron microscopy - Shells (structures)  - Temperature - Transmission electron microscopy - X ray photoelectron spectroscopy
Uncontrolled terms:Carboxylic acids , aldehydes - Fourier transform infrared - Gas chromatography-mass spectrometries (GC-MS) - Heavy oil - Hydrochar - Hydrothermal - Hydrothermal degradation - Physico-chemical characterization
Classification code:408.2 Structural Members and Shapes - 512 Petroleum and Related Deposits - 523 Liquid Fuels - 525.1 Energy Resources and Renewable Energy Issues - 641.1 Thermodynamics - 741.1 Light/Optics - 741.3 Optical Devices and Systems - 801 Chemistry - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2014.17.032
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 40>

Accession number:201443117765
Title:Regional heterogeneity of hyperspectral characteristics of salt-affected soil and salinity inversion
Authors:Peng, Jie (1); Liu, Huanjun (2); Shi, Zhou (3); Xiang, Hongying (1); Chi, Chunming (1)
Author affiliation:(1) College of Plant Science, Tarim University, Alar, China; (2) College of Resources and Environment, Northeast Agricultural University, Haerbin, China; (3) Institute of Agricultural Remote Sensing and Information Technology Application, Zhejiang University, Hangzhou, China
Corresponding author:Shi, Zhou
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:167-174
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The objectives of this study were to analyze regional heterogeneity of hyperspectral characteristics of salt-affected soils from Xinjiang Uygur Autonomous Region, Zhejiang and Jilin provinces and to establish hyperspectral inversion model of salinity for cross-regional salt-affected soils with high precision. One hundred and fifty-nine soil samples at 0-20 cm depth were taken from Xinjiang Uygur Autonomous Region (58 soil samples), Zhejiang (68 soil samples) and Jilin (33 soil samples) provinces, respectively. Electrical conductivity(1:5 soil to water, EC<inf>1:5</inf>) and spectral reflectance (SR) of all the 159 soil samples were determined. Regression models between EC<inf>1:5</inf> and SR were fitted using principal component regression (PCR), multiple linear regression (MLR), and partial least squares regression (PLSR) based on local and global models, respectively. The prediction accuracies of these models were assessed by comparing determination coefficients (R²), relative percent deviation (RPD) and root mean squared error (RMSE) between predicted and measured EC<inf>1:5</inf>. Results showed that there were obvious differences not only in spectral reflectances but also in spectral curve shapes among the salt-affected soils from different regions. After a first derivative data processing, however, these differences were decreased. Values of R², RMSE and RPD between the predicted and measured EC<inf>1:5</inf> for the global model were 0.06, 0.93 and 1.03 for PCR equation, 0.10, 0.91 and 1.04 for MLR equation, 0.71, 0.51 and 1.85 for PCR equation, and 0.71, 0.51, 1.86 for PLSR equation, respectively. Values of R², RMSE and RPD between the predicted and measured EC<inf>1:5</inf> for the local model were 0.45, 0.73 and 1.30 for LR equation, 0.50, 0.69 and 1.38 for MLR equation, 0.76, 0.46 and 2.05 for PCR equation, and 0.78, 0.44, 2.15 for PLSR equation, respectively. The values of R² and RPD between the predicted and measured EC<inf>1:5</inf> were higher for local models than those of global models, but the values of RMSE of local models between the predicted and measured EC<inf>1:5</inf> were lower than that of global models. This indicated that the local models were more accurate than the global models in predicting EC<inf>1:5</inf> from soil spectral reflectances. In order to improve the prediction accuracy of global model, 25 data processing methods were carried out for soil spectral reflectances. It was shown that the sensitive bands of EC<inf>1:5</inf> varied with study regions. Among all of the 25 data processing methods, the prediction accuracy of global model based on Savitzky Golay Second Derivative (SGSD) method decreased drastically compared with that based on the spectral reflectance method. Prediction accuracies of inversion models decreased slightly based on area normalization (AN), mean normalization (MN), unite vector normalization(UVN), maximum normalization (MAN), range normalization(RN), linear baseline correction(LBC), Savitzky Golay Smoothing (SCS) and multiplicative scatter correction (MSC). Six data processing methods including three-point savitzky golay first derivative (SGFD3), five-point cavitzky golay first derivative (SGFD5), seven-point savitzky golay first derivative (SGFD7), LBC SGFD3, SGS SGFD3 and SGS LBC SGFD3 improved inversion accuracies of global models. The values of PRD were greater than 2.0 for inversion equations based on these 6 data processing methods. The inversion accuracy based on SGS SGFD3 data processing method was best with the R², RMSE and RPD of 0.80, 0.43, and 2.23, respectively. The study can provide valuble information for aerospace hyperspectral remote sensing of cross-regional soil salinization.
Number of references:19
Main heading:Soils
Controlled terms:Data handling - Electric conductivity - Forecasting - Least squares approximations - Linear regression - Principal component analysis - Reflection - Regression analysis - Remote sensing - Salts  - Soil surveys
Uncontrolled terms:Electrical conductivity - Hyper-spectral characteristics - HyperSpectral - Inversion accuracy - Multiplicative scatter correction - Partial least squares regressions (PLSR) - Salinization - Xinjiang Uygur autonomous region
Classification code:483.1 Soils and Soil Mechanics - 701.1 Electricity: Basic Concepts and Phenomena - 711 Electromagnetic Waves - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 804.1 Organic Compounds - 921.6 Numerical Methods - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.17.022
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 41>

Accession number:201443117745
Title:Comparation on rape combine harvesting and two-stage harvesting
Authors:Wu, Chongyou (1); Xiao, Shengyuan (2); Jin, Mei (1)
Author affiliation:(1) Nanjing Research Institute for Agricultural Mechanization Ministry of Agriculture, Nanjing, China; (2) Hefei Academy of Agricultural Sciences, Hefei, China
Corresponding author:Wu, Chongyou
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:10-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to find out the differences between two methods of rape harvest, i.e. combine harvesting and two-stage harvesting and to provide a reasoning basis for choosing mechanized harvesting method, the simulation contrast experiments of the two harvesting methods were carried out in this paper, and the economic coefficient, grain water content, stalk moisture content, loss rate and seed quality were tested at different harvesting times. Artificial simulation of combine harvesting means artificial direct harvesting (ADH). First, the rape was cut down from a randomized plot of 5 square meters in the field, moved to a threshing ground, and then threshed and separated by manual labor immediately. The total loss was the sum of those occurred in oilseed rape due to natural shedding, crop disturbance by human being, and threshing and separation losses. The artificial two-stage harvesting (ATH) means cutting down the rapes and picking up them in different periods. The rape should be aired for 4~5 days after cutting down, then threshed and cleaned by manual labor. The artificial simulation experiments showed that the seed loss of ADH got to 3.2%, 50.8% lower than that of ATH, 6.51%, and the oilseed qualities of the two harvesting methods had no obvious difference, however the oil content of ADH was slightly higher than ATH, while its protein content was slightly lower. Besides, the two kinds of mechanized harvesting experiments were carried out. Fifteen types of combine harvesters produced by 12 enterprises were put in use in the two-stage harvesting. The loss rate, broken rate, impurity rate and operation efficiency were measured. Except the impurity rate, the measurements of mechanized two-stage harvesting (MTH) were better than mechanized combine harvesting (MCH). Further more, economic efficiencies of the two harvesting modes were analyzed. The fuel cost, labor cost, workload in life period, depreciation cost, income of yield increase and comprehensive benefit in the lifetime were compared. The results indicated that the economic benefit of MTH was 361 yuan/hm² higher than that of MCH. In addition, the two harvesting methods were comparatively analyzed based on the machinery performance, adaptability and some other aspects. The time of vacating field for the next crop could be about 4.8 days earlier in MTH. And it had widespread adaptability to various rapes and different harvest conditions, also had superiority in seeds storage and straw chopping because of the lower moisture content. However, finishing the swathing and picking up in two operations was one of the imperfections, and another was its relatively poor ability of adapting to cloudy day or continuous rain. MCH was relatively more convenient and had higher efficiency for it could finish harvesting in shorter time, but it didn't well adapt to different crop morphologies, and had high loss rate if the rape of improper breed was not gathered in time. The analyses indicate that the two harvesting methods have their own advantages and disadvantages and adapt to different regions and conditions, so the two methods will have further development in China, and should be chosen and used in accordance with local conditions.
Number of references:28
Main heading:Harvesting
Controlled terms:Agriculture - Combines - Compensation (personnel) - Costs - Crops - Efficiency - Experiments - Grain (agricultural product) - Harvesters - Machinery  - Moisture - Moisture determination - Oilseeds - Wages - Water content
Uncontrolled terms:Agriculture machinery - Artificial simulation - Comparison - Comprehensive benefit - Machinery performance - Mechanized harvesting - Operation efficiencies - Rapeseed
Classification code:444 Water Resources - 601 Mechanical Design - 801.4 Physical Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 911 Cost and Value Engineering; Industrial Economics - 912.4 Personnel - 913.1 Production Engineering - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2014.17.002
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 42>

Accession number:201443117768
Title:Winter wheat growth spatial variability character analysis based on remote sensing image with high resolution
Authors:Song, Xiaoyu (1); Wang, Renhong (1); Yang, Guijun (1); Wang, Jihua (2)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing, China; (2) Beijing Academy of Agriculture and Forestry Science, Beijing, China; (3) Yangzhou University, Yangzhou, China; (4) Beijing Research Center for Agri-food Testing and Farmland Monitoring, Beijing, China
Corresponding author:Song, Xiaoyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:17
Issue date:September 1, 2014
Publication year:2014
Pages:192-199
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Crop growth diagnosis or evaluation mainly relies on field survey, manual sampling and biochemical analysis in the laboratory. It is difficult to master the real spatial variance characteristics for the whole crop field because sample collection is restricted to the manpower and material resources, as well as the time consumption of data analysis in the laboratory. Remote sensing technology provides an opportunity for spatial variance monitoring of crop growth with its rapid development in recently years. In this study, the remote sensing image of the QuickBird with a high spatial resolution acquired on May 2^nd, 2006 was used to analyze the spatial heterogeneity characteristics of winter wheat from different fields. Firstly, the coarse and precise geometric corrections were carried out by ground control points (GCP) and difference global positioning system (DGPS), respectively. Then, atmospheric correction was processed using the 'empirical line method' (ELM) based on ground spectral measurements. After the geometric and atmospheric corrections, a pan-sharpening process was applied to the QuickBird's four multi-spectral bands by using the pan band. Then the normalized difference vegetation index (NDVI) image was calculated based on the QuickBird images in Band 3 and Band 4. Six winter wheat fields were selected for the spatial heterogeneity analysis through the geo-statistics method. The empirical semi-variance function was established based on the NDVI values of the pairs of pixels within the range of 0.6 meter to 27 meters in the directions vertical to ridge and parallel to ridge in all six fields. Then semi-variograms were fitted with Spherical model, Exponential model and Gaussian model, respectively. The optimization model was then selected after evaluated by the SSE (sum of squares due to error) and R² (determination coefficient) through the method of maximum likelihood. Three parameters for semi-variogram model, sill, range and nugget were calculated for all six fields in two directions using the least squares algorithm. Meanwhile, the statistical parameters for winter wheat's NDVI image, including the values of minimum, maximum, mean, standard deviation and coefficient of variance (CV), as well as the image texture parameters, including the data range, data variance and data entropy were calculated for all the fields. The NDVI coverage information with different value range was also used in this study. After that, the relationships between NDVI semi-variogram parameters and NDVI statistical information, texture information, and NDVI coverage information were analyzed, respectively. The results indicated that NDVI's spatial semi-variogram showed an obvious sill pattern for wheat field. The value of sill in the direction vertical to ridge was higher than that in the direction parallel to ridge for the same field. And the range and nugget values in the two directions were also different for the same field. It can be concluded that the wheat growth shows the zonal anisotropy. The results revealed that the sill values in the directions vertical to ridge and parallel to ridge were both related to the NDVI texture range, texture variance and the NDVI coverage value. While the NDVI range was related to the NDVI mean value, CV value and the coverage of pixels with NDVI value less than 0.30 and 0.40 in the field in the direction vertical to ridge. The NDVI nugget was related to the NDVI mean value, CV value and the coverage of pixels with NDVI value less than 0.30 and 0.40 in the field in the direction vertical to ridge. But the range and nugget were irrelevant to any factor in the direction parallel to ridge. This study indicates that remote sensing technique can provide an effective new method for the study on spatial heterogeneity of crop growth.
Number of references:21
Main heading:Image texture
Controlled terms:Crops - Forestry - Growth (materials) - Image coding - Image reconstruction - Maximum likelihood - Optimization - Pixels - Remote sensing - Rock mechanics  - Spatial variables measurement - Textures - Woolen and worsted yarn
Uncontrolled terms:Method of maximum likelihood - Normalized difference vegetation index - Nugget - Precise geometric correction - Range - Semivariograms - Sill - Spatial heterogeneity analysis
Classification code:502.1 Mine and Quarry Operations - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 731.1 Control Systems - 819.1 Natural Fibers - 821.0 Woodlands and Forestry - 821.4 Agricultural Products - 921.5 Optimization Techniques - 922.1 Probability Theory - 933 Solid State Physics - 943.2 Mechanical Variables Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.17.025
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.