<RECORD 1>
Accession number:20152100877529
Title:Design and engineering structure analysis on paddy-field chassis steering drive axle with standard all-wheel-drive
Authors:Liu, Hongxin (1); Zheng, Lishuang (1); Xu, Gaowei (1); Wang, Chen (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin, China
Corresponding author:Liu, Hongxin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:54-60
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the main grain crop production in China, comprehensive mechanization level for paddy field is the lowest. At the same time, there exists the "bottleneck" problem of "bottleneck" problem such as rice planting mechanization. In the case of transplanter, although we have grasped the core technology of key components, overall machinery can not be popularized and applied due to lack of the support of cost-effective chassis. At present, in Chinese market, most of chassis are imported from Japan and South Korea, which widely use hydraulic transmission and variable speed technology. Because paddy planting operation has the characteristics of stable load and constant speed, using hydraulic transmission and continuous variable device causes low efficiency and has no much practical significance, and meanwhile, the demand for the power increases from 9 to 13 and even 15 kw. Northeast Agricultural University has designed a standard all-wheel drive light paddy self-propelled chassis with diesel-power and mechanical transmission for this situation, whose most prominent shape feature is that four wheels have same size and the front axle is different from any existing paddy field chassis structure. The chassis has the advantages of high transmission efficiency, large torque reserve, anti-sink capacity, dynamic stabilization, and good performance of crossing the earth bank between the paddy fields. As a transmission part, steering drive axle not only is a carrier installed, but also needs to bear the weight of chassis and the effect of impulsive load, and have the function of deflection wheel, and hence its structure is more complex than the traditional shell. The operating environment of paddy field chassis is harsher than general vehicle, which has stricter requirement of sludge, subsidence, bank and over load on axle. So, engineering analysis of structural design process is particularly important, however, conventional theoretical analysis and calculation method can not accurately control the stiffness and strength in the process of structural design. For this situation, the research utilized CATIA finite element analysis module to build the finite element analysis model with connection relationship and force transferring characteristics on the three-dimensional model of axle housing, and according to the working condition features of chassis and mechanics analysis, divided every section of the grids and imposed constraints and load boundary conditions; through the analysis of axle's limit load according to the ground adhesion, it was drawn that the drive force of front axle was 1 143.4 N, and the supporting load was 2 430 N, which met the actual requirement of vehicle application environment and ensured the scientificity and effectiveness of engineering analysis data. The deformation and stress of the axle were respectively 0.218 mm and 121 MPa through theoretical analysis and finite element calculation. The engineering structure of steering drive axle met the design requirements, and the deformation met the relevant standards after the test of experiment and trial installation. The research first makes the standard all-wheel drive paddy chassis, which takes the lightweight and high-passage as the goal, come into the stage of comprehensive performance verification, providing not only the basic technical support for core and special components, but also the reference of technical method for the similar mechanism design with complex structure and complex force. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Structural design
Controlled terms:Agricultural machinery - Agriculture - Airships - Automobile steering equipment - Axles - Chassis - Cost effectiveness - Cultivation - Deformation - Design - Digital storage - Drive axles - Finite element method - Front axles - Hydraulic machinery - Loads (forces) - Machine design - Mechanization - Professional aspects - Research aircraft - Standards - Steering - Structures (built objects) - Three dimensional computer graphics - Transmissions - Wheels
Uncontrolled terms:All-wheel drives - Analysis and calculations - Comprehensive performance - Finite element analysis model - Mechanical transmission - Paddy fields - Structure analysis - Three-dimensional model
Classification code:408 Structural Design - 408.1 Structural Design, General - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 601 Mechanical Design - 601.2 Machine Components - 602.2 Mechanical Transmissions - 632.2 Hydraulic Equipment and Machinery - 652.1 Aircraft, General - 652.5 Balloons and Gliders - 663.2 Heavy Duty Motor Vehicle Components - 682.1.1 Railroad Cars - 722.1 Data Storage, Equipment and Techniques - 723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.1 Engineering Professional Aspects - 901.3 Engineering Research - 902.2 Codes and Standards - 912.3 Operations Research - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.08.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 2>
Accession number:20152100877560
Title:Freshness evaluation of sea bass using multi-sensor information fusion based on olfactory visualization and NIR spectroscopy technique
Authors:Huang, Xingyi (1); Guan, Chao (1); Ding, Ran (1); Lü, Riqin (1)
Author affiliation:(1) School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China
Corresponding author:Huang, Xingyi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:277-282
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Total volatile basic nitrogen (TVB-N) is an important reference index of fish freshness. This study attempted to measure TVB-N content of sea bass using multi-sensor information fusion based on olfactory visualization and near-infrared spectroscopy technique. Sea bass samples were stored under the condition of 4 in refrigerator. The total number of samples was 270, among them 18 random samples every day were firstly detected by olfactory visualization detecting instrument, and then by near-infrared spectrometer. TVB-N content of these samples was measured according to the kjeldahl method. The experiment finished after 15 days because of the serious corruption of samples. Two-thirds of total samples were chosen as calibration set and the remaining samples were taken as prediction set using SPXY (sample set partitioning based on joint x-y distances) algorithm. So the sample sizes of calibration set and prediction set were 180 and 90 respectively. After sample division, a TVB-N prediction model was established based on the fused multi-sensor information. Other two models were also established based on the single-sensor information for comparing. Principal component analysis (PCA) method was used to reduce the dimension of colorimetric sensor array data. The results of PCA showed that the cumulative contribution rate of the first three principal components was 85.441%, which indicated that the first three principal components had been able to explain the vast majority of the overall information about original samples. Based on the first three principal components, a TVB-N prediction model was established by support vector regression (SVR) algorithm. The determination coefficients of calibration set (R2 c) and prediction set (R2 p) of the model were 0.762 and 0.757 respectively, while the root mean square errors of calibration set (RMSEC) and prediction set (RMSEP) were 6.012 and 6.755 mg/100g respectively. Mean centering (MC) method was used to preprocess the raw near-infrared spectrum. After preprocessing, genetic algorithm (GA) combined with partial least squares (PLS) method was carried out on the near-infrared spectrum data to remove irrelevant information as well as simplify the prediction model. The results showed that characteristic variables of near-infrared spectrum reduced from 1557 to 79 after the optimization of GA-PLS. Meanwhile, the root mean square error of cross validation (RMSECV) reduced from 12.763 to 6.585 mg/100 g, which indicated that the remaining variables had higher correlation with TVB-N content than the original variables. Based on the informative near-infrared spectrum data, another TVB-N prediction model was established by SVR algorithm. The R2 c and R2 p of the model were 0.810 and 0.787 respectively, while the RMSEC and RMSEP were 5.385 and 6.186 mg/100 g respectively. Because of the insufficiency in getting freshness information, performance of the two single-sensor models above was unsatisfactory. To improve the predictive accuracy of TVB-N content, the colorimetric sensor array data after dimension reducing and the informative near-infrared spectrum data were fused, and a multi-sensor information fusion model was established based on the fused data. The R2 c and R2 p of the model were 0.893 and 0.882 respectively, while the RMSEC and RMSEP were 4.032 and 4.585 mg/100g respectively. Compared with other two single-sensor models, the R2 p of fusion model increased by 0.095 and the RMSEP reduced by 1.601 mg/100g, which proved the superiority of fusion model. This study shows that multi-sensor information fusion based on olfactory visualization and near-infrared spectroscopy technique can be a feasible method for the evaluation of sea bass freshness. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Sensor data fusion
Controlled terms:Algorithms - Calibration - Colorimetric analysis - Colorimetry - Data reduction - Flow visualization - Forecasting - Genetic algorithms - Information fusion - Information use - Infrared devices - Infrared spectrometers - Least squares approximations - Mean square error - Models - Near infrared spectroscopy - Nitrogen - Principal component analysis - Sampling - Spectrometers - Spectroscopy - Visualization
Uncontrolled terms:Colorimetric sensor arrays - Determination coefficients - Multi-sensor information fusion - Near infrared spectrometer - Partial least square (PLS) - Sea bass - Support vector regression (SVR) - Total volatile basic nitrogens
Classification code:631.1 Fluid Flow, General - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 741.3 Optical Devices and Systems - 801 Chemistry - 804 Chemical Products Generally - 902.1 Engineering Graphics - 903.1 Information Sources and Analysis - 903.3 Information Retrieval and Use - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 941.4 Optical Variables Measurements - 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.1002-6819.2015.08.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 3>
Accession number:20152100877534
Title:Cracking reason for Francis turbine blades based on transient fluid structure interaction
Authors:Wu, Guangkuan (1); Luo, Xingqi (1); Feng, Jianjun (1); Li, Wenfeng (1)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an, China
Corresponding author:Luo, Xingqi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:92-98
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Abstract: With the rapid development of hydroelectric technology, stability problems of hydropower units is gradually drawing people's attention. Especially the crack problem has always existed in various large hydropower stations both at home and abroad, such as the abroad Otani force power station, the domestic Xiaolangdi power station, Yantan Dam, and all runner blades in power stations mentioned above had crack problem of different degrees after putting into operation for some period, which seriously affected the turbine units' hydraulic performance and stable operation. A certain power plant's Francis turbine had blade crack problem of different degrees on the runner blade over the years, and most of the cracks belonged to perfoliate crack. To analyze the causes of the runner blade cracks, this paper adopted fluid dynamics primarily to conduct the numerical simulation on hydraulic turbine units' comprehensive unsteady turbulent flow under four operating conditions with different outputs at the rated head, and then analyzed and compared the changes of the velocity field, pressure field, as well as pressure pulsation situations inside the runner under various conditions. The paper focused on the channel vortex inside the flow passage and the amplitude and frequency resistance of the pressure fluctuation caused by the channel vortex under low load, and the results showed that under the rated condition, the flow field was well-proportioned and there didn't exist the channel vortex, while under the low load condition (45% of the output), there existed the channel vortex, the pressure pulsation amplitude reached its maximum when the output was 30 MW, which was about 4.3% of the head for the units, and the long-term operation under low load condition tended to cause blade fatigue. Next, this paper adopted structure finite element technique to conduct dynamic stress analysis on the units under the above-mentioned four conditions. And what could be concluded was that the stress mainly was concentrated in four areas, namely the blade leading edge and runner crown junction, the tailing edge and runner crown junction, the leading edge and the runner bottom junction and tailing edge and runner bottom junction; the maximum principal stress occurred on the connection of the runner crown and the tailing edge, and the maximum dynamic stress occurred under low load condition, which could reach 164.3 MPa and was close to the blade fatigue strength i.e. 210 MPa. Finally, this paper conducted single-blade modal analysis and calculation on the runner, and obtained the first ten-order natural frequency of the single-blade in the air and in the water separately. Modal calculation results showed that the natural frequency of the runner blade in the water was far away from the unit's rotating frequency and its low-order frequency was doubled, as well as the blade's passing frequency, and thus natural vibration wouldn't occur on the blade surface during the operation process. In short, This paper analyzed reasons for blade crack and put forward homologous crack control countermeasure by means of CFD (computational fluid dynamics) calculation, and can provide a certain reference for the units' stable operation. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Turbomachine blades
Controlled terms:Computational fluid dynamics - Cracks - Finite element method - Fluid dynamics - Fluid structure interaction - Francis turbines - Hydraulic motors - Hydroelectric power - Hydroelectric power plants - Modal analysis - Models - Natural frequencies - Stress analysis - Thermoelectricity - Turbine components - Turbines - Velocity - Vortex flow
Uncontrolled terms:Analysis and calculations - CFD (computational fluid dynamics) - Finite element techniques - Maximum principal stress - Strength - Unsteady - Unsteady turbulent flows - Vibrations
Classification code:421 Strength of Building Materials; Mechanical Properties - 611.1 Hydroelectric Power Plants - 615.4 Thermoelectric Energy - 617 Turbines and Steam Turbines - 617.1 Hydraulic Turbines - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 711.1 Electromagnetic Waves in Different Media - 902.1 Engineering Graphics - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.08.014
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 4>
Accession number:20152100877536
Title:Simulation optimization and test of fire extinguisher funnel based on CFD-DEM coupling method
Authors:Jiang, Meisheng (1); Li, Heng (2); Li, Linshu (3); Peng, Kai (1); Wang, Shunxi (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China; (2) MAE Wellful Industries Co., Ltd, Beijing, China; (3) Zhuhai Entry-Exit Inspection and Quarantine Bureau, Zhuhai, China
Corresponding author:Wang, Shunxi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:104-111
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The mechanic performance of ejecting pneumatic fire extinguisher is determined by the following parameters: air speed at funnel exit, outfire range and ejecting stability; and the second and third parameters depend on the fire extinguishing agent pellet's velocity on funnel exit and the amount of fire extinguishing agent pellets detained in the funnel when extinguisher is working. In this research, the CFD-DEM coupling model was adopted to simulate the working process of ejecting pneumatic fire extinguisher, and the type of 6MF-30 pneumatic extinguisher was used to test the reliability of the coupling model. The funnel throat angle X<inf>1</inf>, the adding position of fire extinguishing agent X<inf>2</inf>, and the funnel length X<inf>3</inf> were selected as the influencing factors, and total 23 experiments were conducted by the simulation model under the quadratic orthogonal rotation design. The virtual tunnel was designed according to the tunnel equipped to 6MF-30 pneumatic extinguisher. The virtual fire extinguishing agent pellets were found on the EDEM interface, coupled to the original CFD by Lagrangian model. The pretest results showed that this model had strong convergence which was proved by its stable airflow performance when running at the time of 0.2-0.25 s, and stable pellet number when running at 0.34 s. The air velocity at exit calculated by the CFD-DEM coupling model was similar to the theoretical value. It could be found that the number of aggregating virtual pellets detained in the region between the air tunnel and the fire extinguishing agent's channel was consistent with the result of research by other scholars. The simulating experiment data were exported for analyzing. The average velocity in axial direction on each point at funnel exit was read by Fluent, and after subtracting the average value 197.550, the deviation data of the 23 experiments were got and selected as the outlet wind velocity (index Y<inf>1</inf>). The max virtual pellet velocities in axial direction monitored by EDEM within 0-0.4 s of all experiments were selected as the spouting velocity (index Y<inf>2</inf>). The vertical coordinates of every virtual pellet at 0.37, 0.38, 0.39, 0.4 s in all experiments were read by EDEM, and 'countif' function was used to calculate the number of virtual pellet located in the tunnel (as assessment index Y<inf>3</inf>) when working. After the significant test and the variance analysis, the regression equation building was done by using SAS9.1. The result showed that the fire extinguishing agent pellet's velocity on funnel exit and the amount of fire extinguishing agent pellets detained in the funnel were significantly correlated to the three factors (P<0.0001, P<0.001 respectively), but the air speed at funnel exit had no correlation with these factors. By using response surface method combined with weighting method, the optimal aggregative index could be obtained under the condition that the funnel throat angle was 20°, the adding position of fire extinguishing agent was 140 mm and the funnel length was 700 mm. Under this condition, the efficiency of ejecting pneumatic fire extinguisher was mostly improved. The virtual test designed by the optimized parameters showed that the fire extinguishing agent pellet's velocity on funnel exit increased to 41.24 m/s, and the number of fire extinguishing agent pellets detained in the funnel decreased to 209. The verify test of the physical prototype indicated that the optimized parameters could improve the working effect of ejecting pneumatic fire extinguisher, which was manifested in extending the outfire range by 2.15 m, reducing the possibility of reburning and shortening the outfire time by 1.7 s. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Fire extinguishers
Controlled terms:Air - Air ejectors - Computer simulation - Fires - Lagrange multipliers - Optimization - Pelletizing - Pneumatics - Testing - Velocity - Virtual reality
Uncontrolled terms:CFD-DEM - Fire extinguishing agents - Funnel - Mechanic performance - Quadratic orthogonal rotation - Response surface method - Simulating experiments - Simulation optimization
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 618.3 Blowers and Fans - 632.3 Pneumatics - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 802.3 Chemical Operations - 804 Chemical Products Generally - 914.2 Fires and Fire Protection - 921 Mathematics - 921.5 Optimization Techniques - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.08.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 5>
Accession number:20152100877552
Title:Establishment of thermo viscoplastic constitutive model for straw biomass briquetting
Authors:Sun, Qixin (1); Chen, Shufa (1); Dong, Yuping (2)
Author affiliation:(1) College of Mechanical Engineering, Huaihai Institute of Technology, Lianyungang, China; (2) Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Shandong University, Jinan, China
Corresponding author:Dong, Yuping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:221-226
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biomass briquetting is one of the key technologies to solve the problem of its collection, transportation and storage. Meanwhile biomass pellet, as a renewable energy, can be used instead of coal for heating, electricity, etc. Study on the mechanism of biomass briquetting is the basic way to develop new forming methods and equipments, and to improve productivity greatly. The research in this paper is about a thermo viscoplastic constitutive model for the biomass briquetting mechanism based on endochronic theory. Straw mainly consisting of cellulose, hemicellulose and lignin, is a typical example of dissipative material. Biomass briquetting process is a mixed process of extrusion flow and interstitial flow. During the process, a large quantity of heat is generated by internal friction. The increase of temperature causes the lignin to soften which provides cohesive force for fiber particles briquetting. To verify the effect of lignin and temperature on the straw plastic deformation, stress-strain test and briquetting temperature test were run on the straw with different lignin mass fractions. Three kinds of biomass raw materials including corn straw, wheat straw and rice straw were the study objects in this paper. Then, these raw materials were added with additional lignin respectively in accordance with the following mass fractions 10%, 20% and 30%. The results show that the increase of lignin mass fraction can reduce stress and temperature obviously. The maximum stress of straw with additional mass fraction of 20% is reduced by about 10 MPa compared with raw materials',and the maximum temperature is reduced by about 10%. Consequently, lignin and temperature have a crucial effect on straw biomass briquetting process which is thermo viscoplasticity process. The constitutive model should reflect the internal characteristics of materials, especially the characteristics of lignin. In order to consider the internal variables of straw, endochronic theory applicable to the dissipative materials was adopted to build the thermo viscoplastic constitutive model. First, endochronic time which replaced Newton time was defined to describe thermo viscoplasticity deformation. Strain, strain rate, temperature and lignin mass fraction were the main internal factors to formulate the briquetting mechanism. Second, the endochronic constitutive equation of straw briquetting was derived according to thermodynamic law and clay rheology. Third, tests were planned to analyze the influence of lignin mass fraction and temperature on straw forming process. The optimal lignin mass fractions of corn straw, wheat straw and rice straw are respectively 29%, 33.5% and 34.3%. The optimal temperature is between 100 and 115. Strengthening function was deducted based on the test data and Johnson-Cook model. Finally, verification test was designed upon GDS consolidation test system. Coefficients of constitutive equation were got by numerical analysis. Compared with test data, the thermo viscoelasticity constitutive model based on endochronic theory has its extensive applicability. When the temperature is between 100 and 115 and the strain rate between 1×10<sup>2</sup> and 1×10<sup>3</sup> s<sup>-1</sup>, corn straw with lignin mass fraction of 29%, wheat straw with lignin mass fraction of 33.5%, and rice straw with lignin mass fraction of 34.3% have the best plastic briquetting performance. This study results provide an operable material model for the finite analysis and an important theoretical basis for equipment structure design. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Lignin
Controlled terms:Biomass - Briquetting - Cellulose - Constitutive equations - Constitutive models - Digital storage - Models - Plasticity - Productivity - Strain - Strain rate - Straw - Temperature - Testing - Viscoplasticity
Uncontrolled terms:Briquetting mechanism - Dissipative materials - Endochronic theory - Internal characteristics - Maximum temperature - Stress-strain tests - Thermo-viscoplasticity - Thermoviscoelasticity
Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 422.2 Strength of Building Materials : Test Methods - 524 Solid Fuels - 641.1 Thermodynamics - 722.1 Data Storage, Equipment and Techniques - 815.1.1 Organic Polymers - 821.5 Agricultural Wastes - 902.1 Engineering Graphics - 913.1 Production Engineering - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.08.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 6>
Accession number:20152100877544
Title:Spatial and temporal variations of rainfall erosivity on Pearl River basin during 1960-2012
Authors:Lai, Chengguang (1); Chen, Xiaohong (1); Wang, Zhaoli (2); Zhao, Shiwei (2); Wu, Xushu (2); Yu, Haixia (1)
Author affiliation:(1) Center for Water Resources and Environment, School of Geography and Planning, Sun Yat-sen University, Guangzhou, China; (2) School of Civil and Transportation Engineering, South China University of Technology, Guangzhou, China; (3) Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education Institute, Guangzhou, China
Corresponding author:Wang, Zhaoli
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:159-167
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil erosion is recognized as one of the most serious, global ecological environmental crises in progress today. A rainfall-runoff erosivity factor, combined with the effects of duration, magnitude and intensity of rainfall event, can be used to measure the rain's potential ability to cause erosion. In this paper, the rainfall erosivity model proposed by the Chinese scholar Zhang Wenbo was used to calculate the rainfall erosivity. Taking the Pearl River basin as the study case, daily rainfall data from 1960 to 2012 in 43 meteorological stations were applied in the model. Methods of linear regression, Mann-Kendall, wavelet analysis and Kriging interpolation were applied to analyze the spatial and temporal variations of rainfall erosivity. The results showed that the range of annual rainfall erosivity in the Pearl River basin was 1858.0-14656.6 MJ·mm/(hm<sup>2</sup>·h) with an average value of 7177.1 MJ·mm/(hm<sup>2</sup>·h). The average annual rainfall erosivity decreased from east to west in general. Larger values mainly appeared in most areas of Pearl River Delta region, Dongjiang River basin and Beijiang River basin, but the values in Nanpanjiang and Beipanjiang River basin which are the upstream regions of the Pearl River basin were smaller. The distribution of average annual rainfall erosivity was similar with the average annual rainfall and there was a strong correlation (R=0.95, P<0.01) between them. Moreover, the average annual rainfall erosivity generally increased with the increasing of longitude (R=0.712, P<0.01), but decreased with the increasing of latitude (R=0.449, P<0.01). Trends of rainfall erosivity were not significant among years, four seasons, flood and non-flood seasons and no significant mutations occurred in these periods. Among them, the rainfall erosivity showed a slight downward trend in spring and autumn, but a slight upward trend in other periods. Among the periods of upward trend, the rainfall erosivity rising in summer was the fastest with a climbing speed of 11.251 MJ·mm/(hm<sup>2</sup>·h·a) and the average summer rainfall erosivity reached up to 5 414.530 MJ•mm/(hm<sup>2</sup>•h). The rainfall erosivity rising in year was the second fastest with a climbing speed of 8.469 MJ•mm/(hm<sup>2</sup>•h) and the average annual rainfall erosivity reached up to 10235.962 MJ·mm/(hm<sup>2</sup>·h). In winter, the rainfall erosivity of 39 meteorological stations accounting for about 90.7% of the total stations showed an upward trend, suggesting that the erosivity in winter rose overall. The mutation analysis of rainfall erosivity in the Pearl River basin indicated that the average annual rainfall erosivity sequences of the 7 sub-regions and the whole basin did not have significant mutations. The annual rainfall erosivity of most areas in the Pearl River basin showed significant upward trends (P<0.05), especially at Shaoguan station. In winter, the annual rainfall erosivity at Zhanyi, Fengshan, Hechi, Baise, Liuzhou, Rong'an and Guilin stations also showed significant upward trends. Evidently, the regions represented by these stations faced great pressure in the water and soil conservation. The rainfall erosivity sequence from 1960 to 2012 had the periods of 2.3, 3.8, 6.9, 12.7 and 23.4 a. Among them, only 2.3 and 3.8 a passed the red noise test at confidence level of 95%. The peak value of wavelet variance in 3.8 a was larger than 2.3 a, which suggested that 3.8 a was the main period. The red noise test also indicated that there was an oscillation period of 2.0-7.0 a in the basin. Generally speaking, the rainfall erosivity in the Pearl River basin showed an exacerbated trend, and therefore water and soil conservation should be well prepared. This study has the potential to provide an important reference for soil and water conservation planning, agricultural protection, ecological protection and disaster control in the Pearl River basin. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Rain
Controlled terms:Conservation - Ecology - Erosion - Floods - Gems - Interpolation - Losses - Meteorology - Precipitation (chemical) - Precipitation (meteorology) - Rivers - Soil conservation - Soils - Water conservation - Water resources - Watersheds - Wavelet analysis
Uncontrolled terms:Agricultural protection - Meteorological station - Pearl River basin - Pearl River Delta region - Soil and water conservation - Spatial and temporal variation - Water and soil conservations - Water and soil loss
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 443 Meteorology - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 454 Environmental Engineering - 454.3 Ecology and Ecosystems - 482.2.1 Gems - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 911.2 Industrial Economics - 914.1 Accidents and Accident Prevention - 921 Mathematics - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.08.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 7>
Accession number:20152100877539
Title:Propagation and closure law of desiccation cracks of loamy clay during cyclic drying-wetting process
Authors:Li, Wenjie (1); Zhang, Zhanyu (1); Wang, Ce (1); Zhu, Wenyuan (1); Chen, Yu (1)
Author affiliation:(1) Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China of Ministry of Education, Hohai University, Nanjing, China
Corresponding author:Zhang, Zhanyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:126-132
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To investigate the propagation and closure law of farmland soil desiccation cracks during cyclic drying-wetting process, laboratory simulation tests were carried out to quantitatively analyze the geometric and morphological characteristics of desiccation crack network of loamy clay with the application of digital image processing techniques. The results showed that the change of gravimetric moisture content during the drying process experienced 3 steps over experiment time, and could be fitted to a linear equation, a quadratic equation and a power equation, respectively, whose determination coefficients were larger than 0.95. During the wetting process, the closure of cracks could be divided into 3 stages and when the moisture content increased to 45%, the cracks were closed completely. When the moisture content was lower than 12%, both crack area ratio and area perimeter ratio decreased slowly with the increasing of the moisture content, and decreased rapidly once the moisture content reached 30%, while keeping stable under the moisture content of between 12% and 30%. Crack length density and connectivity index varied with the increasing of the moisture content in two typical stages, i.e., remaining stable in the initial stage of wetting process and decreasing quickly after the moisture content reached 32% and 35%, respectively. Results suggested that the relationships of crack area ratio with the moisture content in drying and wetting process could be fitted to Logistic function (R<sup>2</sup>=0.9981) and BiDoseResp function (R<sup>2</sup>=0.9972), respectively. The changes of crack length density with the moisture content in drying and wetting process were in line with Logistic function, and their determination coefficients were 0.9962 and 0.9978, respectively. The fitting functions showed that during cyclic drying-wetting process, the change of crack length was partly reversible, but on the whole, the propagation and closure of cracks were two processes that were completely irreversible. The statistical analysis of geometric parameters of cracks at different soil moisture contents during cyclic drying-wetting process indicated that crack area mainly ranged from 0 to 30 mm<sup>2</sup>, and most of the cracks were shorter than 40 mm at different moisture contents. During the drying process from field capacity to wilting coefficient, the frequency distributions of both crack area and crack length significantly changed, and the number of the cracks increased greatly, for example, the number of crack whose area was less than 60 mm<sup>2</sup> increased by 367% and that whose length was less than 40 mm increased by 470%. However, there was no significant change between the frequency distributions of crack area during the wetting process from wilting coefficient to field capacity, neither did the frequency distributions of crack length. The comparison of crack geometric parameters at the same moisture content during the drying and the wetting process showed that the frequency distributions of crack area and length were almost the same when the moisture content was at wilting coefficient. On the contrary, the frequency distributions of crack area and length were quite different at the moisture content of field capacity, and there were a difference of 341% between the numbers of the cracks whose area was less than 60 mm<sup>2</sup> and a difference of 430% between the numbers of the cracks whose length was less than 40 mm during the drying and the wetting process. The research results will contribute to the study on the propagation and closure mechanism of soil desiccation cracks and the crack preferential flow, and provide the theoretical basis for determining precise irrigation system based on the crack network. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Moisture determination
Controlled terms:Crack closure - Cracks - Driers (materials) - Drying - Geometry - Groundwater flow - Image processing - Information dissemination - Moisture - Soil moisture - Soils - Water content - Wetting
Uncontrolled terms:Connectivity indices - Determination coefficients - Different moisture contents - Digital image processing technique - Drying-wetting - Frequency distributions - Laboratory simulation - Morphological characteristic
Classification code:421 Strength of Building Materials; Mechanical Properties - 444 Water Resources - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 642.1 Process Heating - 741 Light, Optics and Optical Devices - 801.4 Physical Chemistry - 803 Chemical Agents and Basic Industrial Chemicals - 903.2 Information Dissemination - 921 Mathematics - 931.2 Physical Properties of Gases, Liquids and Solids - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2015.08.019
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 8>
Accession number:20152100877522
Title:Microhole subsoiling decreasing soil compaction, and improving yield and seed quality of cotton
Authors:Wang, Huijie (1); Hao, Jianping (1); Feng, Ruiyun (3); Nan, Yang (4); Yang, Shuqiao (2); Nan, Jianfu (2)
Author affiliation:(1) Agronomy College, Shanxi Agricultural University, Taigu, China; (2) Cotton Research Institute, Shanxi Academy of Agricultural Sciences, Yuncheng, China; (3) Institute of Crop Sciences, Shanxi Academy of Agricultural Sciences, Taiyuan, China; (4) Institute of Agricultural Resource and Economy, Shanxi Academy of Agricultural Sciences, Taiyuan, China
Corresponding author:Hao, Jianping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:7-14
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:During long-term conventional tillage, frequent use of heavy farm machinery in field operations results in narrow soil effective (plow) layer and thick plow pan. The plow pan resulting from soil compaction is a key constraint on soil quality and crop growth in cultivated land. To address this problem, microhole subsoiling is an alternative to conventional tillage. By reducing the tillage area, microhole subsoiling breaks the plow pan and increases soil permeability, which facilitates root growth into deeper soil, improves uptake of water and nutrients by plant, and reduces surface soil structure damage. Presently, the effects of microhole subsoiling on soil environment, cotton growth and development, and seed quality traits are not well understood. A comparative study of microhole subsoiling and conventional tillage (control) was conducted by one-year field experiment on the Nanhua Farm in Yuncheng, Shanxi Province, China (April 2013 to May 2014). Microhole subsoiling was implemented by vertical drilling using a soil auger with the diameter of 8 cm. Vertical subsoiling was conducted to 80 cm depth in a hole-like pattern at specific intervals. In microhole-subsoiled plots, the actual tillage area was about 239.2 m<sup>2</sup>/hm<sup>2</sup>, i.e., only 2.39 % of total area. At the seedling stage, soil compaction remained almost unchanged and less than 558.8 kPa at 0-40 cm depth in microhole-subsoiled plots, whereas that in control plots was significantly higher and up to 9 069.7 kPa at >20 cm depth. At the boll opening stage, soil compaction increased slowly up to 1 174.2 kPa in microhole-subsoiled plots, while that in control plots reached a maximum of 8 089.7 kPa. Meanwhile, soil bulk density in microhole-subsoiled plots remained lower and decreased from 1.56 to 1.05 g/cm<sup>3</sup> at >35-40 cm depth. Owing to the loosening of deeper soil, microhole subsoiling effectively induced cotton roots to go deeper. The main root reached the depth of over 80 cm depth in microhole-subsoiled plots and <70 cm depth in control plots. At the depth of below 30 cm, microhole subsoiling doubled root biomass (19.77% of total root biomass) and increased lateral roots (32.62% of total lateral root) compared with the control (9.81% of total root biomass and 19.42% of total lateral root). The 5-room boll rate was 15% higher and the number of seeds per cotton pulp was greater by from 1 to 2 in microhole-subsoiled plots than in control plots. At the second and fifth seed positions, cotton seed index, proportion and fiber length were significantly higher in the former than in the latter by 0.03 g, 0.035 g/cm<sup>3</sup> and 2.25 mm, respectively. Similar trends were observed in the emergence and healthy seedling rates, i.e., 1.01% and 2.27% higher in microhole-subsoiled plots than in control plots, respectively. The mortality and weak seedling rates were 0.92% and 1.41% lower in the former than in the latter. Seed protein was significantly higher (P<0.05) while seed fat content was significantly lower (P<0.05) in microhole-subsoiled plots than in control plots. Additionally, the number of bolls per plant, boll weight and lint yield were 6.34%, 5.75% and 10.12% higher in microhole-subsoiled plots than in control plots, respectively. Benefit analysis showed that compared with the control, microhole subsoiling improved the net income of cotton cultivation by 3 338.00 yuan/hm<sup>2</sup>. This benefit was mainly due to cotton yield increased significantly, seed sowing rate reduced effectively and relatively less input of tillage cost. This study revealed that that microhole subsoiling could effectively break local plow pan, thus alleviating soil compaction and reducing soil bulk density. The improvements of soil environment would induce cotton roots to go deeper and increase the number of lateral roots, thus improving seed quality and cotton yield. Microhole subsoiling overcame the environmental problems caused by conventional tillage regarding high energy consumption and severe soil surface damage, and achieved the goal of improving land productivity. The results presented provide the experimental evidence for the application of microhole subsoiling in cotton production. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Quality control
Controlled terms:Agricultural machinery - Agriculture - Biomass - Compaction - Cotton - Ecology - Energy utilization - Machinery - Plants (botany) - Soil mechanics - Soils
Uncontrolled terms:Comparative studies - Conventional tillage - Environmental problems - Experimental evidence - High energy consumption - Land productivities - Micro holes - Soil compaction
Classification code:454.3 Ecology and Ecosystems - 461.9 Biology - 483.1 Soils and Soil Mechanics - 525.1 Energy Resources and Renewable Energy Issues - 525.3 Energy Utilization - 536.1 Powder Metallurgy Operations - 601 Mechanical Design - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2015.08.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 9>
Accession number:20152100877557
Title:Preparation of low-methoxyl pectin by high hydrostatic pressure-assisted with enzyme methods
Authors:Zhao, Wenting (1); Guo, Xingfeng (3); Gao, Lin (1); Hu, Xiaosong (1); Wu, Jihong (1)
Author affiliation:(1) College of Food Science and Nutritional Engineering, China Agriculture University, Beijing, China; (2) National Engineering Research Center for Fruits and Vegetables Processing, Beijing, China; (3) College of Agriculture, Liaocheng University, Liaocheng, China
Corresponding author:Wu, Jihong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:257-263
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Low methoxyl pectin is widely applied as thickener, stabilizer and emulsifier in low calorie or dietetic foods. The main methods reported for the preparation of low methoxyl pectin from high methoxyl pectin have used four types of agents: acids, ammonia in alcohol or concentrated aqueous ammonia, alkali and pectin methyl esterase. The main disadvantage of the first two methods is the slowness of reaction. Alkaline de-esterification is rapid but the removal of methyl ester groups is accompanied by depolymerization of pectin chains. Enzymatic de-esterification represents an attractive alternative to chemical de-esterification, for it is without pollution, but it is time-consuming. Therefore, there is a need to explore new methods to produce pectin with high quality and efficiency. In this study, a novel method of high hydrostatic pressure combined with enzymatic treatment (pectin methyl esterase) was applied in pectin de-esterification. In order to find out the effect of enzymatic treatment assisted with high hydrostatic pressure on the properties of pectin and promote the industrial development of this technology, the physicochemical properties, molecular weight distribution and rheological characteristics of pectins de-esterified by this treatment were investigated and compared with conventional alkaline method. During the de-esterification process of enzymatic treatment assisted with high hydrostatic pressure of 200 and 300 MPa, the degree of de-esterification was reduced from 61.83% to 34.09% and 32.62% in 10 min, respectively. With further de-esterification, the reaction slowed down, while the de-esterification degree of pectin by alkaline method was reduced to 35.54% and decreased continuously when the period was prolonged to 20 min. Based on this experiment, two pairs of pectins with similar degree of de-esterification were prepared by the enzymatic treatment assisted with high hydrostatic pressure and conventional alkaline method, i.e. HHP-1 (200 MPa, 10 min; 34.09?Ddamp;plusmn;1.64%) & AP-1 (pH 11.0, 11 min; 31.96?Ddamp;plusmn;1.92%), HHP-2 (300 MPa, 15 min; 27.69?Ddamp;plusmn;0.51%) & AP-2 (pH 11.0, 16 min; 25.37?Ddamp;plusmn;0.61%). The galacturonic acid content of the pectins had no significant difference (P>0.05), while the apparent viscosity of pectins prepared by enzymatic treatment assisted with high hydrostatic pressure was higher significantly than that by alkaline method (P<0.05). The viscous flow activation energy of HHP-1 was lower than AP-1 prepared by alkaline method, indicating lower temperature dependence and better processability of HHP-1. The molecular weight distribution was determined by size exclusion chromatography. From the profile of molecular weight distribution, two peaks with the molecular weight distribution from 10 kDa to 800 kDa could be observed. The profile showed that the prepared pectins (HHP-pectins) by enzymatic treatment assisted with high hydrostatic pressure were similar to pectin untreated, but the pectins (AP-pectins) produced by alkaline method differed; the signal of Peak I was weaker and Peak was stronger, and Peak 's retention time was delayed as well, indicating that the pectin was depolymerized. The intrinsic viscosity was fitted and calculated using the Kraemer equation. The viscosity average molecular weights were calculated using the Mark-Houwink-Sakurada equation, which of the four pectins (HHP-1, HHP-2, AP-1 and AP-2) were 45 540±5 677, 47 802±3 984, 30 009±2 980 and 29 837±1 374 Da, respectively. The viscosity average molecular weight of HHP-pectins was higher than AP-pectins significantly (P<0.05). The shear stress of HHP-pectins was measured as a function of shear rate and compared with that of AP-pectins. The shear stress of HHP-pectins was much higher than AP-pectins and became strongly dependent upon the shear rate. From these results, it could be concluded that enzymatic treatment assisted with high hydrostatic pressure had no degradation action on pectin molecule and it could be taken as a highly efficient, novel and eco-friendly method for pectin de-esterification, especially for producing pectins with higher viscosity and molecular weight. Low methoxyl pectins with different degrees of esterification could be obtained by enzymatic treatment assisted with high hydrostatic pressure of 200 or 300 MPa in plant production. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Esterification
Controlled terms:Activation energy - Alkalinity - Ammonia - Chemical properties - Chromatography - Emulsification - Enzymes - Esters - Hydraulics - Hydrostatic pressure - Molecular weight - Molecular weight distribution - Physical properties - Shear deformation - Shear stress - Size exclusion chromatography - Temperature distribution - Viscosity
Uncontrolled terms:Conventional alkaline method - Enzymatic treatments - High hydrostatic pressure - Low-methoxyl pectins - Physicochemical property - Rheological characteristics - Viscosity average molecular weight - Viscous flow activation energy
Classification code:421 Strength of Building Materials; Mechanical Properties - 423 Non Mechanical Properties and Tests of Building Materials - 631.1.1 Liquid Dynamics - 632.1 Hydraulics - 641.1 Thermodynamics - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 931.2 Physical Properties of Gases, Liquids and Solids - 931.3 Atomic and Molecular Physics
DOI:10.3969/j.issn.1002-6819.2015.08.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 10>
Accession number:20152100877537
Title:Electro-hydraulic brake control method for hybrid electric vehicle during process of downhill assist control
Authors:Han, Yunwu (1); Luo, Yugong (1); Li, Keqiang (1); Chen, Long (1)
Author affiliation:(1) State Key Laboratory of Automotive Safety & Energy, Tsinghua University, Beijing, China
Corresponding author:Han, Yunwu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:112-118
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve vehicle safety and fuel economy of the whole control system for hybrid electric vehicles (HEV), this paper presents an electro-hydraulic braking control method for the downhill auxiliary braking process. First, through the analysis of the downhill auxiliary braking process and dynamic change of the braking torque, the appropriate time for electro-hydraulic braking and the distribution principle of the braking torque are proposed. Experiment platform and typical control signals are adopted to test the electronic vacuum brake, of which the results illustrate that the braking torque of the electronic vacuum brake is sufficiently large to finish the braking process. However, if the target pressure is low (for example, below 0.15 MPa), the respond of electronic vacuum brake to the pressure is also slow. Increasing target pressure can slove the problem of start-up delay and the response time of the brake. Besides, response errors appearing in the control process of the electronic vacuum brake cannot be eliminated as well. On the contrary, the drive motor has high response speed and high control precision though the maximum driving/braking torque is limited. This provides the possibility of combining the advantages of both devices. Thus, based on the response data of electric vehicle drive motor, the complementarity of braking capacity and response characteristics of the electro-hydraulic system is specifically analyzed and the control inclination of the electro-hydraulic system is obtained. Then, the distribution principle of the downhill auxiliary braking torque is established, which can maximize the breaking torque of the motor in the prerequisite of assuring the total breaking torque. Based on the blending control framework of forward feed and feedback, the hydraulic system response under low pressure is realized using the proposed minimum pressure maintaining method. Meanwhile, by increasing the objective start-up pressure, time delay of the hydraulic system is controlled within the objective minimum range all the time. The response speed is also enhanced by increasing the torque proportion of the hydraulic system when total torque varies. System response errors are also offset by making use of the high response speed and high control precision of the drive motor. The above control strategy can sufficiently take advantage of the electro-hydraulic system and realize the coordinated torque control, achieving the high efficiency of the entire braking system. Finally, based on the slope data of a highway in a certain mountain area (with the slope of between 1% and 13%), the control algorithm model for the electro-hydraulic braking method is built with the software of MATLAB/Simulink using the elementary parameters of a hybrid vehicle with a displacement of 1.6 liters. The effectiveness of this control logic is precisely verified by the simulation results. Furthermore, the control commands related to the hydraulic system are extracted to conduct hardware-in-the-loop test, of which the results greatly coincide with the simulation results. Therefore, the proposed approach can not only reduce the start-up time delay of the hydraulic system effectively, ensuring the overall response accuracy of the downhill auxiliary system, but also provide a new idea for further research of the HEV compound braking. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Process control
Controlled terms:Airships - Algorithms - Blending - Braking - Computer control systems - Computer simulation - Control systems - Delay circuits - Delay control systems - Digital storage - Electric machine control - Electric vehicles - Errors - Fuel economy - Hybrid vehicles - Hydraulic brakes - Hydraulic equipment - MATLAB - Research aircraft - Time delay - Torque - Traction motors - Vehicles
Uncontrolled terms:Coordination control - Electric vehicle drive - Electro-hydraulic brakes - Electro-hydraulic braking - Electro-hydraulic system - Hardware-in-the-loop tests - Motor braking - Response characteristic
Classification code:421 Strength of Building Materials; Mechanical Properties - 432 Highway Transportation - 521 Fuel Combustion and Flame Research - 602 Mechanical Drives and Transmissions - 612.2 Diesel Engines - 632.2 Hydraulic Equipment and Machinery - 652.1 Aircraft, General - 652.5 Balloons and Gliders - 703.1 Electric Networks - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 802.3 Chemical Operations - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.08.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 11>
Accession number:20152100877532
Title:Experiment on stress relaxation characteristics of intact rice straw during rotary compression
Authors:Lei, Junle (1); Wang, Defu (1); Zhang, Quanchao (1); Yang, Xing (1); Li, Liqiao (1); Li, Chao (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin, China; (2) College of Engineering, Heilongjiang Vocational College, Harbin, China; (3) College of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou, China
Corresponding author:Wang, Defu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:76-83
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, rice straw as a kind of renewable material is being used widely in China. The rheologic characteristics of crop straw have great effect on the power consumption, productivity and compression process of compressing equipment, as well as on the bale durability. At present, a lot of researches have been done by many domestic and foreign scholars on the compression rheologic characteristics, but the researches have been aimed at the rectangular baler instead of the steel-roll round baler, and the test materials are mainly concentrated on corn straw, wheat straw and alfalfa, which limit the development and application of the round baler for crop straw in China. Stress relaxation is an important phenomenon in the rheologic characteristics of straw. In order to deeply research stress relaxation phenomenon of intact rice straw during rotary compression under the round baler, a steel-roll round baler was used for rotary compression test in this paper. To timely monitor the force during rotary compression, the force testing device was developed. In experiments, moisture content of rice straw (12%-68%), dry material quantity of bale (15-23 kg), steel roll speed (222-318 r/min) and feeding speed of rice straw (0.4-1.6 kg/s) were chosen as experimental factors, which were at 5 levels. Stress relaxation time and balance elastic modulus were decided as the evaluation indices, and quadratic orthogonal rotatory combination design was used to analyze the effect of different factors. Through analyzing experimental data by Matlab 8.0, the stress relaxation model of intact rice straw during rotary compression could be expressed by three-element equation which was available through the parallel connection of one Maxwell unit and one spring. The regression equations of stress relaxation time and balance elastic modulus had been established respectively by using Design Expert software. Through variance analysis of regression equations for stress relaxation time and balance elastic modulus, the coefficients of determination (R<sup>2</sup>) for the models were 0.96 and 0.97 respectively, which indicated that the proposed model was agreeable with the practical condition, thus the proposed model could be used to predict the change of the stress relaxation time and balance elastic modulus during rotary compression. In addition, the relations between evaluation index and each single factor were shown in response surface. The results showed that: with the increase of moisture content of rice straw, both of stress relaxation time and balance elastic modulus decreased; with the increase of dry material quantity of bale, stress relaxation time decreased and balance elastic modulus increased; with the increase of steel roll speed, stress relaxation time and balance elastic modulus decreased and then increased; and with the increase of feeding speed of rice straw, stress relaxation time decreased and balance elastic modulus increased gradually. The contribution rate of each factor on stress relaxation time was as follows: moisture content of rice straw > dry material quantity of bale > feeding speed of rice straw > steel roll speed. The contribution rate of each factor on balance elastic modulus was as follows: dry material quantity of bale > moisture content of rice straw > feeding speed of rice straw > steel roll speed. When moisture content of rice straw was 65%, dry material quantity of bale was 17 kg, steel roll speed was 257 r/min and feeding speed of rice straw was 1.6 kg/s, stress relaxation time was 17.08 s and the balance elastic modulus was 4.01 kPa, which were the best results. The research provides theoretical and technical support for the process optimization of round baler, as well as the analysis of its compression mechanism. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Stress relaxation
Controlled terms:Compression testing - Crops - Elastic moduli - Electric connectors - Feeding - MATLAB - Maxwell equations - Moisture - Moisture determination - Optimization - Relaxation time - Rheology - Rolls (machine components) - Speed
Uncontrolled terms:Compression mechanism - Compression process - Development and applications - Experimental factors - Parallel connections - Relaxation phenomena - Rice straws - Round baler
Classification code:421 Strength of Building Materials; Mechanical Properties - 601.2 Machine Components - 691.2 Materials Handling Methods - 706.2 Electric Power Lines and Equipment - 801.4 Physical Chemistry - 821.4 Agricultural Products - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics - 933 Solid State Physics - 943 Mechanical and Miscellaneous Measuring Instruments - 944.2 Moisture Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 12>
Accession number:20152100877562
Title:Design and test of high accurately measuring equipment for NaCl water solution utilizing ultrasonic velocity with temperature correction
Authors:Meng, Ruifeng (1); Ma, Xiaokang (1); Wang, Zhoubo (1); Dong, Longmei (2); Yang, Tao (1); Liu, Donghong (3)
Author affiliation:(1) College of Mechanical Engineering, Inner Mongolia University of Technology, Hohhot, China; (2) Hangzhou Advance Gearbox Group Co., Ltd., Hangzhou, China; (3) School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China
Corresponding author:Liu, Donghong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:290-295
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In food, chemicals and pharmaceuticals industries, the concentration is a very important parameter for quality control. Continuous process monitoring is a fundamental requirement for the process control in these industries. Besides process parameters, such as temperature, pressure, liquid level, flow rate, concentration measurement is also of special interest. More qualified information obtained from new or better sensors can significantly enhance the process quality and thereby product properties. Low-intensity ultrasonic sensor system can contribute to this development, and it has been widely used in many fields for its characteristics are non-destructive, non-invasive and rapid. In this study, a method based on ultrasound for determining the concentration of NaCl water solution with high accuracy was presented. The ultrasound velocity in different temperatures and in solutions with different concentrations was measured using an emitter-receiver method. The experimental set-up was composed of two matched piezoelectric transducers with the center frequency of around 5 MHz (one used as emitter and the other as receiver), a thermostatic tank, a CTS-80787PR pulse emitter-receiver (used to excite and receive electric signals) and a data acquisition card. The electric pulse at the emitting voltage of -25 V, the width of 100 ns and the repeated frequency of 100 Hz was sent from the CTS-80787PR to the emitter transducer and then transformed to ultrasound wave. This wave traveled through a liquid sample cell with 5 mm wide to reach the receiving transducer, and was transformed back to electric pulse signal. The signal was acquired by the CTS-80787PR and sent to a computer equipped with the LABVIEW via a 16-bit data acquisition card of PCI (peripheral component interconnect) bus with the sampling rate of 40 MS/s. A Labview interface was developed to collect signals, analyze signals, build models and validate models. Through analysis, the measurement accuracy of ultrasound velocity was 1 m/s for this equipment, which ensured the accuracy of concentration measurement. At 2.5°C gradient in the temperature range of 10-30°C, and at a gradient of 0.5 g/100 g in the concentration range of 0-10 g/100 g, NaCl water solutions were prepared. Some were regarded as calibration samples and others as validation samples. In order to predict the concentrations of NaCl water solution, a calibration model was established using a quadratic polynomial approach based on the experimental results. The coefficients of this polynomial were obtained based on ordinary multiple linear regression (OMLR) method by inserting the measurement points, analyzing the residual to eliminate abnormal sample points and checking out the regression coefficient of the model by t-test. The developed model had high prediction accuracy and stability with the maximum prediction error of 0.25 g/100 g, the determination coefficient of calibration (R<inf>cal</inf><sup>2</sup>) of 0.9992, the determination coefficient of validation (R<inf>val</inf><sup>2</sup>) of 0.9988, the root mean square error of calibration (RMSEC) of 0.0894 g/100 g, the root mean square error of prediction (RMSEP) of 0.1015 g/100 g and the ratio performance deviation (RPD) of 28.57, which indicated that the model could be used for practical detection accurately and steadily, and was helpful for on-line measuring. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Process control
Controlled terms:Calibration - Chemical contamination - Computer peripheral equipment - Data acquisition - Flow rate - Forecasting - Linear regression - Liquids - Mean square error - Polynomials - Process monitoring - Quality control - Regression analysis - Solutions - Temperature - Transducers - Ultrasonic applications - Ultrasonic testing - Ultrasonic velocity - Ultrasonic waves - Velocity
Uncontrolled terms:Concentration determination - Concentration Measurement - Determination coefficients - Multi-linear regression - Multiple linear regressions - PCI (peripheral component interconnect) bus - Root mean square error of calibrations - Root-mean-square error of predictions
Classification code:631 Fluid Flow - 641.1 Thermodynamics - 704 Electric Components and Equipment - 715 Electronic Equipment, General Purpose and Industrial - 722.2 Computer Peripheral Equipment - 723.2 Data Processing and Image Processing - 731 Automatic Control Principles and Applications - 753.1 Ultrasonic Waves - 753.3 Ultrasonic Applications - 801 Chemistry - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 822.3 Food Products - 913.3 Quality Assurance and Control - 921.1 Algebra - 922.2 Mathematical Statistics - 931.1 Mechanics - 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.1002-6819.2015.08.042
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 13>
Accession number:20152100877549
Title:Design and development of near field communication intelligent data acquisition terminal system in fresh agricultural product supply chain
Authors:Sun, Xu (1); Yang, Yinsheng (1); Liu, Chunxia (1); Guo, Hongpeng (1)
Author affiliation:(1) College of Biological and Agricultural Engineering, Jilin University, Changchun, China; (2) Jilin Technology College of Electronic Information, Jilin, China
Corresponding author:Yang, Yinsheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:200-206
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the issue that the information transfer of fresh produce supply chain is not continuous, incomplete and untrue, and to prevent agricultural health threat to people's lives, this study has developed a data collection terminal based on near-field communication technology. At present, China fresh produce market for primary agricultural products, food processing and consumer demand increases year by year, but the infrastructure and information technology applications of fresh produce supply chain are behind, resulting in high loss of fresh produce throughout the supply chain in the circulation process, as well as low efficiency and poor reliability of the information, and therefore it is difficult to meet the needs of the modern market of fresh produce. In recent years, the consumption of fresh agriculture products has been continuing to rise with the development of society and the growth in people' s living standard. However, an increasing number of safety problems like poisoning and polluting have been triggered because of the quality problem of fresh agriculture products, which directly influences consumers' health and environmental security. Eventually, it has aroused widespread concern in the whole society. The discontinuity of fresh agriculture product supply chain information is one of the important reasons for the emergence of faulty products. The backwardness of data acquisition equipment and means in each link of fresh agriculture product supply chain, and the data in key link being not able to be collected due to environmental factors, are the main reasons for discontinuous information of fresh agriculture product supply chain. The paper first analyzes data collecting equipments of fresh agriculture product supply chain and its corresponding working conditions. Then, based on near field communication (NFC), bei dou system (BDS) and global system for mobile communications (GSM), it develops the integration technology data collection terminal of fresh agriculture product supply chain. The integration applications of NFC technology and Internet of things have become a focus research issue at home and abroad. In this paper, authors review the research progress of supply chain information systems of domestic agricultural products; summarize the key function of information technology in the agricultural supply chain and information system platform; and analyze the application feasibility of NFC technology in the agricultural supply chain information systems. The data collection terminal mainly includes four modules, namely NFC module, CPU (central processing unit) module, Bei Dou module, GSM module as well as its electrical system. When the data terminal writes data, it simultaneously writes BDS encrypted data to NFC label through NFC chip PN532, and then through GSM module, it transmits the encrypted data to the backend database in text message; finally, it transmits the data information to node enterprises platform by RS232, thus achieving three copies of the backup on fresh agriculture product data information. By means of the advantages of Internet of things and sensor networks, the data terminal implements automatic and intelligent data acquisition and encryption in every link of fresh agriculture product supply chain. And on this basis, it meets the changing needs of data acquisition and storage during the production process, reduces the degree of information asymmetry among node enterprises and enhances the productivity of node enterprises. In short, the data terminal lays the foundation for the fresh agriculture product traceability and has practical value. Compared with other acquisition systems, the biggest difference the terminal system has is that the system not only has the function to read the data, but also has a tag write capability, and can read the offline data stored inside the NFC memory chip carried by the system itself. The terminal reads in extreme environments. Although the speed is reduced by from 10% to 25%, the saving rate is still at 100%, fully meeting the needs of data acquisition. The terminal can achieve the information continuousness between the nodes of the enterprise, and provide the reference for the realization of fresh produce traceability. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Data acquisition
Controlled terms:Agricultural products - Agriculture - Chains - Commerce - Cryptography - Digital storage - Food processing - Global system for mobile communications - Health risks - Information systems - Internet - Internet of things - Mobile telecommunication systems - Near field communication - Product design - Program processors - Security of data - Sensor networks - Supply chains - Wireless telecommunication systems
Uncontrolled terms:Agricultural produces - BDS(bei dou system) - Global system for mobile communications (GSM) - Information technology application - NFC(near field communication) - Supply chain information systems - The near field communication (NFC) - Wireless communications
Classification code:602.1 Mechanical Drives - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 732 Control Devices - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 822.2 Food Processing Operations - 903.2 Information Dissemination - 911.2 Industrial Economics - 912 Industrial Engineering and Management - 912.4 Personnel - 913 Production Planning and Control; Manufacturing - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2015.08.029
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 14>
Accession number:20152100877543
Title:Analysis on characteristics of temporal-spatial potential evapotranspiration distribution in Gansu based on cloud mode
Authors:Yin, Changchen (1); Qi, Guangping (1); Kang, Yanxia (1)
Author affiliation:(1) Engineering College of Gansu Agricultural University, Lanzhou, China; (2) College of Hydrology and Water Resources, Hohai University, Nanjing, China
Corresponding author:Qi, Guangping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:152-158
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Characteristics of temporal-spatial potential evapotranspiration (ET<inf>0</inf>) distribution in Gansu Province were studied based on the Cloud model, which is a mathematical representation of qualitative concepts including expected value Ex, entropy En and hyper entropy He, integrates the fuzziness and randomness of qualitative concept in a unified way, and is a new method for the transformation between the qualitative and the quantitative. The values of ET<inf>0</inf> were calculated by Penman-Monteith. The changes of ET<inf>0</inf> in time were analyzed at monthly, seasonal and yearly intervals, respectively, and spatial changes were mainly divided into 4 parts: Hexi area, the middle, east and south area of Gansu. All data of 63 years (1951-2013) were collected at 29 meteorological stations involving the above districts in Gansu. All ET<inf>0</inf> data were achieved by the soft Interactive data language. The indices of homogeneity and stability were used for reflecting characteristics of temporal-spatial distribution of ET<inf>0</inf>, which were achieved by Cloud mode, solving the uncertain conversion of qualitative concept and quantitative description. And the changes of ET<inf>0</inf> in time (monthly, seaonal and annual) and space were analyzed by the linear change and the contour image. The results showed annual variation in ET<inf>0</inf> had a fluctuation and increasing tendency, and the tendency rate was 2.11 mm/(10a) in all study area (P<0.05). The monthly change curve of ET<inf>0</inf> for 63 years was single apex type, which was: ET<inf>0</inf> in June and July was higher than that in other months. In homogeneity and stability aspects of ET<inf>0</inf>, from November to March of the next year was better than from April to August in the same year. At the same time, there was significant difference on the distribution of ET<inf>0</inf> among seasons, and the maximum was summer, followed by spring, and the least was autumn and winter. The further analysis found that both homogeneity and stability of temporal-spatial distribution of ET<inf>0</inf> had no consistency among seasons. The homogeneity of ET<inf>0</inf> in autumn and winter was higher than that in spring and summer, but the stability in summer and autumn was better than that in spring and winter. Seen from the difference characteristics of the space, ET<inf>0</inf> in the northwest area of Gansu Province were larger than that in the southeast, however, the annual changes of ET<inf>0</inf> among areas were different for 63 years. Concretely speaking, the value of annual ET<inf>0</inf> in Hexi area was keeping the highest from 1951 to 2013. Seeing the changes of ET<inf>0</inf> in the space using the homogeneity and stability, we found ET<inf>0</inf> of Hexi area was most discrete and instable, the east area of Gansu had the best homogeneity and stability, and the middle and south were between them. The homogeneity and stability of ET<inf>0</inf> in the space was worse than that in the time. Generally, the homogeneity of the distribution of ET<inf>0</inf> was increasing since 1981, namely, the homogeneity from 1981 to 2013 was better than that from 1951 to 1981, and at the same time, the stability was also increasing for 63 years. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Spatial distribution
Controlled terms:Entropy - Evapotranspiration - Mathematical transformations - Meteorology - Models - Stability
Uncontrolled terms:Annual variations - Gansu province - Interactive data languages - Mathematical representations - Meteorological station - Potential evapotranspiration - Quantitative description - Temporal spatial distribution
Classification code:443 Meteorology - 444.1 Surface Water - 641.1 Thermodynamics - 801 Chemistry - 902.1 Engineering Graphics - 921.3 Mathematical Transformations - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.08.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 15>
Accession number:20152100877523
Title:Design and experiment on auto leveling control system of agricultural implements
Authors:Hu, Lian (1); Lin, Chaoxing (1); Luo, Xiwen (1); Yang, Weiwei (1); Xu, Yi (1); Zhou, Hao (1); Zhang, Zhigang (1)
Author affiliation:(1) 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:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:15-20
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To ensure agricultural implement level can improve the quality of work in agricultural machinery operation process. In order to maintain the level of agricultural implements in the field working, an agricultural implement auto leveling control system was developed. Real-time roll angle of tractor was obtained from tractor roll angle sensing system. The core algorithm of tractor roll angle sensing system was the Kalman filtering algorithm of tractor roll angle, which fused an accelerometer and gyroscope data to obtain the real-time roll angle of tractor. The leveling hydraulic cylinder elongation was measured using a straight-line displacement sensor. And the relative roll angle conversion function between agricultural implements and tractor was established. Then by controlling the electromagnetic directional valve, the agricultural implement was kept leveling. This article introduced the principle and structure of agricultural implement auto leveling control system, and the Kalman filtering algorithm of tractor roll angle and the relative roll angle conversion function were analyzed in detail. The tractor roll angle's Kalman fusion algorithm was tested in SGT320E three-axis turntable platform, and the experiment of agricultural implement auto leveling control system was carried out in the paddy field based on a matching 1PJ-3.0 laser leveler for paddy field. The leveler featured a specially designed leveling plow connected to an ISEKI PG6 transplanter by means of a hydraulically driven three-point linkage. The auto leveling controller used the Proportional-Derivative (PD) control algorithm to calculate pulse width, modulating for driving two ordinary hydraulic solenoid valves as actuators to regulate the plow's leveling. In order to evaluate the precision of tractor roll angle sensing system and auto leveling control system, 2 inertial reference systems (MTi-300) were installed in the transplanter and plow, respectively. Results showed that, the tractor roll angle sensing system could accurately measure the real-time tractor roll angle; the mean absolute error, the root mean square error and the maximum error were less than or equal to 0.15°, 0.18° and 0.33° respectively in SGT320E three-axis turntable platform; and during the working process in a paddy field, the mean absolute error, the root mean square error and the maximum error were less than or equal to 0.40°, 0.46° and 1.27°, respectively. The agricultural implement auto leveling control system could better realize the scraper's leveling control of laser leveler. The mean absolute error, the mean square error and the maximum error of the scraper's tilt angle were 0.52°, 0.24° and 1.15°, respectively, and in more than 80% of the time, the scraper's tilt angle of laser leveler was less than 0.5°, which was improved by 0.5° compared with the control precision of original leveling control system of laser-controlled land leveler for paddy field. The study provides a method for auto leveling controlling of agricultural implement, which can improve the work quality of agricultural machinery. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Leveling (machinery)
Controlled terms:Agricultural implements - Agricultural machinery - Agriculture - Algorithms - Codes (symbols) - Control systems - Design - Hydraulic actuators - Hydraulic machinery - Kalman filters - Machine design - Mean square error - Quality control - Signal filtering and prediction - Solenoid valves - Tools - Tractors (agricultural) - Tractors (truck)
Uncontrolled terms:Inertial reference systems - Kalman filtering algorithms - Leveling control systems - Mean absolute error - Proportional-derivative control - Root mean square errors - Three-axis turntable - Tilt measurement
Classification code:408 Structural Design - 601 Mechanical Design - 603 Machine Tools - 603.1 Machine Tools, General - 605 Small Tools and Hardware - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 632.2 Hydraulic Equipment and Machinery - 663.1 Heavy Duty Motor Vehicles - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 732.1 Control Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 913.3 Quality Assurance and Control - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.08.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 16>
Accession number:20152100877559
Title:Electric field treatment improving physicochemical properties of zein film produced by casting
Authors:Xu, Hui (1); Chen, Ye (1)
Author affiliation:(1) College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Key Laboratory of Food Nutrition and Safety, Tianjin, China
Corresponding author:Chen, Ye
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:272-276
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Zein is the major storage protein of corn and comprises 45%-50% of total protein in corn, and possesses good property of forming film in virtue of abundant sulphur amino acids. High content of hydrophobic amino acid grants hydrophobicity to zein film, but film made of natural casting retains its crispness. In order to improve the flexibility of zein film, plasticizers are added into the film solution. Though plasticizers can significantly enhance mechanical properties of zein film, they affect their security and edibility. Equipments such as pulsed electric field used in processing of casting can improve the properties of zein film by taking appropriate measures, without affecting the security and edibility of zein film. But the popularization of these equipments is hindered for their high price. In this paper, the combination of DC power (DYY-8C, Beijing) and conducting glass coated with indium tin oxide was used to set up paralleled uniform electric field, and then the electric field was introduced into the processing of zein film. This method was of simple equipment, easy operation and good selectivity. Coupled with the paralleled uniform electric field (1-5 A/m<sup>2</sup>), the soft zein films with complete shape were obtained by casting. The properties of zein film such as tensile strength, elongation at break, water vapor permeability and water absorption were measured and analyzed to evaluate the influence of the paralleled uniform electric field on zein film. Meanwhile, thermostability difference between films before and after treatment was studied by differential scanning calorimetry. By analyzing the data, tensile strength and elongation at break increased with the increase of electric current density while water vapor permeability and water absorption decreased. When electric current density was at 4 A/m<sup>2</sup>, properties of zein film were optimal. Tensile strength and elongation at break reached the maximum value (73.09 MPa and 9.68%, respectively); water absorption and water vapor permeability reached the minimum value (14.87% and 2.54×10<sup>-8</sup> g·m/(m<sup>2</sup>·h·Pa), respectively). Contact angle declined slightly (within 5°), and tended towards stability when electric current density was above 2 A/m<sup>2</sup>. Experiments indicated that the presence of electric field force facilitated interaction between zein molecules, and these molecules were organized in a network pattern contributing to the improvement of mechanical properties. Meanwhile, polar amino acid residues tended to move forward to the topside of the network, resulting in the slight decline of contact angle. There existed significant difference among the data obtained from the experiments by Duncan analysis (P<0.01). During the processing of zein film, no hazardous substance was added into the film solution. By adjusting the electric current density, film or edible packing material with flexibility, fixed shape, mechanical strength, certain mechanical properties or contact angle can be obtained, which are biodegradable, edible and non-toxic toward humans and environment. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Current density
Controlled terms:Amino acids - Biomaterials - Casting - Contact angle - Density (specific gravity) - Differential scanning calorimetry - Digital storage - Electric currents - Electric fields - Elongation - Equipment - Films - Hydrophobicity - Indium - ITO glass - Mechanical properties - Mobile security - Molecules - Plastic films - Plasticizers - Proteins - Reinforced plastics - Solvents - Strength of materials - Tensile strength - Tin oxides - Water absorption - Water vapor - Zein
Uncontrolled terms:Electric field force - Electric field treatment - Hydrophobic amino acids - Physicochemical property - Pulsed electric field - Strength and elongations - Uniform electric fields - Water vapor permeability
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 462.5 Biomaterials (including synthetics) - 534.2 Foundry Practice - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 641 Heat and Mass Transfer; Thermodynamics - 701.1 Electricity: Basic Concepts and Phenomena - 722.1 Data Storage, Equipment and Techniques - 801 Chemistry - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 812.3 Glass - 817.1 Polymer Products - 901 Engineering Profession - 931.2 Physical Properties of Gases, Liquids and Solids - 931.3 Atomic and Molecular Physics - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 17>
Accession number:20152100877546
Title:Application of variable fuzzy pattern recognition method on landslide stability assessment
Authors:Guo, Wenzhao (1); Liu, Yakun (1); Xu, Xiangzhou (1); Li, Min (1)
Author affiliation:(1) School of Hydraulic Engineering, Dalian University of Technology, Dalian, China
Corresponding author:Xu, Xiangzhou
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:176-182
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Landslides occur frequently and lose greatly, especially in China, and always have the characteristics of large scale, complex mechanism as well as serious destruction. It is important to assess landslide stability for understanding the evolution process of the landslide. In this paper, the recognition method of variable fuzzy pattern was applied to evaluate landslide stability. The method was based on the theory of variable fuzzy set, relative membership degree function and multi-level and multi-index evaluation unit system on landslide stability which included both the qualitative and quantitative factors. In order to overcome the limitations of the fuzzy comprehensive evaluation method which had a maximum membership degree, the relative membership degree function and the grade eigenvalue were used in the recognition method of variable fuzzy pattern. For the complexity and fuzziness of landslide system, the multi-level and multi-index evaluation unit system was set up by selecting 4 levels and 17 factors. In the purpose of confirming the fuzzy weights, the comprehensive evaluation of the three-level weights was adopted and the method of dualistic factor contrast combined with fuzzy mood operator was also used. The recognition method of variable fuzzy pattern was adopted to appraise the stability of Danba Landslide, Laojinshan Landslide and Yankou Landslide, and the results of the evaluation were consistent with the investigation. Depending on the different evaluation results of the Danba Landslide in 4 periods, the impact of the stability of Danba Landslide was semi-quantitatively evaluated. The stability declined at first and later improved from 1980s to 2007, and was in the most unstable state from March 2004 to March 2005. By comparing the stabilities of Danba Landslide during 1999-2004 and from March 2004 to March 2005 with that during 1980s-1998, the stabilities declined by 6.4% and 10.1%, respectively. And the stability of the landslide in period d (from March 2005 to 2007) improved by 4.7% compared with period c (from March 2004 to March 2005), and decreased by 5.2% compared with period a (from 1980s to 1998). In order to compare present method with fuzzy comprehensive evaluation method, two cases of Danba Landslide were studied in period a (from 1980s to 1998) and d (from March 2005 to 2007). The results evaluated by variable fuzzy evaluation method and fuzzy comprehensive evaluation method were both in Level three. The stability eigenvalues of Danba Landslide in period a and d were evaluated by variable fuzzy evaluation method, and the two eigenvalues were 3.27 and 3.44, respectively. Stability of Danba Landslide in period d was worse than in period a, although they belonged to the same grade. In this study, the average eigenvalue which could make the error smaller was obtained. Actually, the eigenvalue was obtained by a series of different parameters. Therefore, the recognition method of variable fuzzy pattern is more feasible and reliable, and it is much stricter in the superior grade. Just as any other traditional evaluations, the recognition method of variable fuzzy pattern has a difficult problem that the qualitative factors cannot be completely quantified. But the qualitative indices can be converted into semi-quantitative indices by the recognition method of variable fuzzy pattern. Besides, the reliability of evaluation results can be guaranteed because of reasonable selection of evaluation indices and the accuracy of specific numerical indicators. The recognition method of variable fuzzy pattern is a promising evaluation approach in Landslide stability assessment, and it can provide scientific basis for landslide disaster prevention and control. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Fuzzy set theory
Controlled terms:Convergence of numerical methods - Disaster prevention - Eigenvalues and eigenfunctions - Function evaluation - Landforms - Landslides - Membership functions - Models - Pattern recognition - Slope stability - Stability - System stability
Uncontrolled terms:Comprehensive evaluation - Fuzzy comprehensive evaluation method - Fuzzy evaluation method - Fuzzy pattern - Fuzzy pattern recognition - Prevention and controls - Quantitative factors - Relative membership degrees
Classification code:406.2 Roads and Streets - 481.1 Geology - 484.1 Earthquake Measurements and Analysis - 716 Telecommunication; Radar, Radio and Television - 801 Chemistry - 902.1 Engineering Graphics - 914.1 Accidents and Accident Prevention - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.08.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 18>
Accession number:20152100877528
Title:Evaluation indexes of shifting quality for dual clutch transmission for tractor
Authors:Xu, Liyou (1); Liu, Hailiang (1); Zhou, Zhili (1); Wang, Xinbin (1)
Author affiliation:(1) School of Vehicle and Traffic Engineering, Henan University of Science and Technology, Luoyang, China
Corresponding author:Zhou, Zhili
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:48-53
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:When the tractor assembled with dual-clutch automatic transmission shifts under the condition of working with heavy load in the field, the original shifting quality evaluation indices can't fully investigate their impacts on the performance, so 2 evaluation indices, which are transfer coefficient of transmission's output torque and transmission's output torque, are proposed. The transfer coefficient of transmission's output torque is used to evaluate dynamic load which is produced in shifting process of the tractor assembled with dual-clutch automatic transmission; and the transmission's output torque is used to evaluate power in shifting process of the tractor assembled with dual-clutch automatic transmission. The pattern has been concluded that the superposition degree of 2 groups of clutches (one group is connected with odd gear input shaft, and the other is connected with even gear input shaft) has an effect on shifting quality. In the shifting process of the tractor with dual-clutch automatic transmission, in order to ensure ride comfort, power performance and durability of the transmission system, 2 groups of the clutches should have appropriate superposition in the separation and combination processes. If the superposition degree of 2 groups of clutches is insufficient, it could cause transfer coefficient of transmission's output torque and transmission output torque to decrease and even make power performance and durability of the transmission system enter a poor condition; if the superposition degree of 2 groups of clutches is excessive, it could cause jerk degree and sliding-friction work to increase, even make ride comfort enter a poor condition and shorten the service life of clutch. The dynamic equations of the shifting process of the tractor assembled with dual-clutch automatic transmission have been built and the shifting process has been analyzed. The shifting process is divided into 5 stages. The change trend of the speed and torque of the clutch and engine in each stage is analyzed. Based on the Matlab/Simulink/Stateflow software platform, the simulation model of the whole shifting process has been built. Dongfanghong-1804 tractor is selected as the reference object, and its shifting process has been simulated in plowing conditions. Relevant simulation results indicate that when the lag time of clutch's oil pressure rising is 0, 0.1 and 0.2 s, the corresponding minimum transfer coefficients of transmission's output torque are 0.42, 0.36 and 0.12, respectively, and the corresponding minimum torques output by transmission are 2 257, 1 932 and 725 N·m, respectively. According to the analysis of simulation data, as the lag time of clutch's oil pressure rising extends, the decline degree of transfer coefficient of transmission's output torque becomes larger to cause dynamic load to increase gradually, and the transmission's output torque becomes smaller to make tractor's power performance worse. The 2 new shifting quality evaluation indices can fully evaluate tractor dynamic and dynamic load which is generated in the process of shifting; they are good compliments to original shifting quality evaluation indices and improve the shifting quality evaluation system of the tractor assembled with dual-clutch automatic transmission. Above all, the results of this paper provide some theoretical basis for formulating shifting control strategy of the tractor with dual-clutch automatic transmission. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Quality control
Controlled terms:Clutches - Computer simulation - Computer software - Durability - Dynamic loads - Electric power transmission - MATLAB - Oil shale - Torque - Tractors (agricultural) - Tractors (truck)
Uncontrolled terms:Analysis of simulations - Dual clutch automatic transmission - Dual clutch transmission - Evaluation index - Quality evaluation indices - Quality evaluation system - Sliding friction works - Transmission systems
Classification code:408.1 Structural Design, General - 421 Strength of Building Materials; Mechanical Properties - 512.1 Petroleum Deposits - 602.2 Mechanical Transmissions - 663.1 Heavy Duty Motor Vehicles - 706.1.1 Electric Power Transmission - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2015.08.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 19>
Accession number:20152100877564
Title:Optimization of bacterial cellulose fermentation technology with distiller's grains
Authors:Ma, Xia (1); Dong, Yanyan (1); Yu, Haiyan (1)
Author affiliation:(1) School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai, China
Corresponding author:Yu, Haiyan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:302-307
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China is one of the biggest agriculture countries and brewing countries in the world. Distillers' grains are the wastes produced along with brewing, they are full of nutrients but they are thrown away, which brings pollution to the environment. Bacterial cellulose (BC) is a new biomaterial and has special properties such as higher water content, higher mechanical properties. BC has broad applications in food, medicine, environmental industries. But lower productivity with higher price limits the broad application of BC. So this work considered to utilize distillers' grains as fermentation materials of bacterial cellulose to optimize the production of BC from Acetobacter xylinum M12 by using response surface methodology. The ratio of water to distillers' grains was 4:1 (g/g); and filtered by eight-layer gauzes, the vinasse leaching solution was got. The composition of vinasse leaching solution was evaluated by double nitro salicylic acid (DNS) method, bradford method and high performance liquid chromatography (HPLC) method. Eight parameters including glucose, peptone, yeast powder, citric acid, Na<inf>2</inf>HPO<inf>4</inf>·12H<inf>2</inf>O, KH<inf>2</inf>PO<inf>4</inf>·3H<inf>2</inf>O, MgSO<inf>4</inf>·7H<inf>2</inf>O and size of inoculum were screened by Plackett-Burman design and 3 factors with significance level of above 95% were optimized by the response surface method using a three-level, three-factor Box-Behnken design. The data were analyzed by the software Design-Expert 8.0, and the R<sup>2</sup> for mathematical model for BC fermentation was 0.9734. The regression equation was optimized and evaluated when the optimum conditions and interactive effects were imposed. The microstructure of BC was analyzed by fourier transform-infrared spectrum (FTIR). The results showed that the vinasse leaching solution was full of nutrients, which contained reducing sugar 1 990 mg/L, protein 3 400 mg/L, citric acid 2 060 mg/L and succinic acid 5 638 mg/L. The order of the influence of 3 factors on BC fermentation of distillers' grains from high to low was: glucose, size of inoculum and citric acid, the experimental data were fitted to a second-order polynomial equation using multiple regression analysis. The quadratic regression model was fitted well, as shown by the significance level of 'total regress' (P=0.0001), 'lack of fit' being not significant (P=0.6729) and the high values of determination coefficients before and after adjusting i.e. R<sup>2</sup>=0.9734 and R<inf>adj</inf><sup>2</sup>=0.9392. The best conditions were as follows: to per 1 L vinasse leaching solution, add 23 g glucose, 25 g peptone, 25 g yeast powder, 4.5 g citric acid, 2 g Na<inf>2</inf>HPO<inf>4</inf>·12H<inf>2</inf>O, 1 g KH<inf>2</inf>PO<inf>4</inf>·3H<inf>2</inf>O and 0.2 g MgSO<inf>4</inf>·7H<inf>2</inf>O, with inoculation amount of 8%, fermentation temperature of 30 and fermentation time of 7 d. Under these conditions the result of confirmatory experiment (14.44 g/L) was in good agreement with the predicted value (14.42 g/L), and the production increased by 140.6% compared with 6.00 g/L before optimization. The results of analysis conrmed that the response model was suitable for reecting the expected optimization, and the model was accurate and satisfactory. The FTIR analysis of BC verified the product. This study provides the reference for the resourceful use of distillers' grains. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Fermentation
Controlled terms:Biological materials - Cellulose - Characterization - Citric acid - Fourier transform infrared spectroscopy - Glucose - Grain (agricultural product) - High performance liquid chromatography - Leaching - Liquid chromatography - Mechanical properties - Nutrients - Optimization - Polynomials - Regression analysis - Salicylic acid - Sodium - Software design - Surface properties - Yeast
Uncontrolled terms:Bacterial - Determination coefficients - Distiller's grains - Fermentation technologies - Fourier transform infrared spectrum(FTIR) - Multiple regression analysis - Response surface methodology - Second-order polynomial equations
Classification code:461 Bioengineering and Biology - 533.1 Ore Treatment - 549.1 Alkali Metals - 723.1 Computer Programming - 801 Chemistry - 801.2 Biochemistry - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 821.2 Agricultural Chemicals - 821.4 Agricultural Products - 921.1 Algebra - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.044
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 20>
Accession number:20152100877556
Title:Effect of high intensity pulsed electric fields on physical changes of fishbone liquid
Authors:He, Guidan (1); Yin, Yongguang (1); Yan, Xiaoxia (1); Yu, Qingyu (1)
Author affiliation:(1) College of Biological and Agricultural Engineering, Jilin University, Changchun, China
Corresponding author:Yin, Yongguang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:251-256
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:High-intensity pulsed electric field (PEF) is characterized by transfer uniformity, nonthermal performance, high efficiency, short processing time and low component pollution. PEF shows unique advantages in the processing of liquid foods and thus can be widely applied to sterilization, extraction and enzyme inactivation of foods. PEF is a key processing technique that is most promising for industrial application in the past decade. Nevertheless, the effects of PEF on the physical state changes of foods have never been reported. With the rapid development of fishery worldwide, the fishbone from the majority of fish products is treated as tailing, which is restricted by low price, low processing capacity, low technical content, few high-value-added products, and low level of comprehensive processing and utilization. Higher requirements have been raised for the effective utilization of fish resources along with the development of modern food science and technology, especially the aquatic product processing industry. In this study, a texture analyzer was used to clarify the rheological properties of fishbone liquid and investigate the effects of PEF on the physical state changes of fishbone liquid. The indices used included the first and second compression work, elasticity, cohesiveness and gumminess. The principal component analysis was used to comprehensively assess the physical states of fishbone liquid. This analytical process was simplified into a comprehensive index equation. Single-factor tests were used to clarify the effects of PEF parameters on the physical state changes. The Box-Behnken design and response surface methodology (RSM) were used to investigate the effects of PEF on the electric field intensity, pulse number, and liquid-material ratio of fishbone liquid. Taking comprehensive index as the response value, we finished a 3-factor 3-level central composite design and acquired the optimal parameters of PEF: liquid-material ratio was 9.81 mL/g, field intensity was 23.10 kV/cm and pulse number was 10, and in such conditions, comprehensive index reached 2.3312. Correspondingly, the physical indices of the fishbone liquid were: first compression work was 1.2 N, second compression work was 1.3 N, cohesiveness was 1.21, elasticity was 9.25 mm and gumminess was 0.11 N. On the contrary, the rheological indices of the unprocessed fishbone liquid were: first compression work was 0.1 N, second compression work was 0, cohesiveness was 1.84, elasticity was 8.0 mm and gumminess was 0.18 N. These results indicated that after processing with PEF, the physical state indices of the fishbone liquid were changed during the first and second cycles, including higher energy needed for specified deformation, higher elasticity, lower internal bond strength of structural composition, and lower energy needed before swallowing. Moreover, PEF could significantly improve the physical states of fishbone liquid. PEF brought economic benefits for processing and utilization of fishbone. Therefore, PEF could be used to the processing of fishbone liquid. This study provides a theoretical basis for the application and promotion of PEF. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Liquids
Controlled terms:Elasticity - Electric fields - Fish - Optimization - Principal component analysis
Uncontrolled terms:Box-Behnken design - Central composite designs - Electric field intensities - Fishbone - Food science and technology - High-intensity pulsed electric fields - Physical performance - Response surface methodology
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 461 Bioengineering and Biology - 471 Marine Science and Oceanography - 701.1 Electricity: Basic Concepts and Phenomena - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822 Food Technology - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.08.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 21>
Accession number:20152100877550
Title:Prediction model of phosphorus content for citrus leaves during different growth periods based on hyperspectrum
Authors:Yue, Xuejun (1); Quan, Dongping (1); Hong, Tiansheng (1); Wei, Xiang (2); Liu, Yongxin (1); Wang, Jian (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou, China; (2) Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, Australia
Corresponding author:Hong, Tiansheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:207-213
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Traditional methods of obtaining phosphorus content of citrus leaves are time-consuming procedures with complex operations which can be harmful to citrus trees. More over, traditional methods can not meet the demand of rapid and non-destructive monitoring of phosphorus content in large-scale citrus orchards. In this paper, we presented several models suitable for phosphorus content prediction in 4 growth periods using hyperspectral information. The experiments were conducted in the Crab Village of Luogang District, Guangzhou City, Guangdong Province, and the samples were 195 citrus trees planted. During 4 growth periods, i.e. germination, stability, bloom and picking period, hyperspectral reflectance of citrus leaves was respectively measured by spectrometer (ASD FieldSpec 3), and at the same time, phosphorus content of citrus leaves was obtained by using traditional chemical method. Owing to the high dimensionality and redundancy of raw data, an enhanced algorithm was provided based on manifold learning to deal with the high-dimensional spectral vectors for dimension reduction and feature extraction. First of all, the parameters of wavelet de-noising, which was applied to reduce the high-frequency noise, was determined through orthogonal test, and then 5 manifold learning algorithms, i.e. laplacian eigenmaps (LE), locally-linear embedding (LLE), local tangent space alignment (LTSA), isometric mapping (Isomap) and maximum variance unfolding (MVU) were applied to reduce dimension and extract features for de-noising spectrum. The 5 corresponding prediction models of support vector regression (SVR) for phosphorus content of citrus leaves were established based on their features. Besides, we compared the modeling results of different spectral forms. Some critical conclusions were obtained. First, the optimized parameter combination of wavelet de-noising through orthogonal test was: "coif2" as wavelet basis function, the number of decomposition layer being 7 and "heursure" as the threshold, respectively. Second, the experimental results revealed that these 5 manifold learning algorithms were effective for phosphorus content estimation of citrus leaves. When the raw spectrum was used as the input vector, the Isomap-SVR model achieved better performance than other models; the coefficients of determination for the calibration set were 0.9383, 0.9614, 0.9611, 0.9516 and 0.9430, and the corresponding values of root mean square error (RMSE) were 0.0548, 0.0503, 0.0456, 0.0534 and 0.527 at germination, stability, bloom, picking period and whole growth period, respectively; for the validation set, the coefficients of determination were 0.8866, 0.8923, 0.9236, 0.9005 and 0.8870, and the values of RMSE were 0.0710, 0.0688, 0.0583, 0.0667 and 0.0704, respectively, which meant high usability for the industry. Third, when first derivative spectrum was used as the input vector of the samples with wavelet de-noising, in our research, the Isomap-SVR model achieved the best result and the coefficients of determination for calibration set were 0.9383, 0.9614, 0.9611, 0.9516 and 0.9430 respectively, and the corresponding values of RMSE were 0.0518, 0.0405, 0.0408, 0.0458 and 0.0499 respectively at germination, stability, bloom, picking period and whole growth period; and for the validation set, the coefficients of determination were 0.8913, 0.9107, 0.9373, 0.9135 and 0.8949, and the corresponding values of RMSE were 0.0703, 0.0645, 0.0522, 0.0634 and 0.0659 respectively. Finally, our research proves the feasibility of monitoring phosphorus content of citrus leaves, and may provide a theoretical basis for growth monitoring and nutritional diagnosis of citrus trees. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Learning algorithms
Controlled terms:Algorithms - Blooms (metal) - Calibration - Chemical stability - Cultivation - Feature extraction - Forecasting - Forestry - Mean square error - Models - Monitoring - Orthogonal functions - Phosphorus - Spectrum analysis - Vectors - Wavelet decomposition
Uncontrolled terms:Citrus leaves - First derivative spectrums - Hyper spectra - Local tangent space alignment - Manifold learning algorithm - Non-destructive monitoring - Phosphorus contents - Support vector regression (SVR)
Classification code:535.1.2 Rolling Mill Practice - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 804 Chemical Products Generally - 821.0 Woodlands and Forestry - 821.3 Agricultural Methods - 902.1 Engineering Graphics - 921 Mathematics - 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.1002-6819.2015.08.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 22>
Accession number:20152100877524
Title:Parameter optimization and test on soil-covering mechanism of 2BF-1400 rice mulching film seeder machine
Authors:Zhao, Lijun (1); He, Di (1); Zhou, Fujun (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin, China
Corresponding author:He, Di
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:21-26
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, the advantages of rice dry land direct seeding mulching technique have been widely approved in accumulation of effective temperature and increase of rice yield. However, the performance of the machine matched with the novel planting technology need to be further studied. A soil covering mechanism, as the key part of rice film-mulching seeder, was developed to complete the working steps of mulching plastic film, punching holes through film, seeding and covering soil. The soil coving mechanism consists of rack, screw blade, outer wall of roller, supporting shaft, curve surface soil-sampling disk and knuckle mechanic. In order to improve the mulching quality of covering soil on the film in rice dry land direct seeding, a rice field experiment (1 400 m<sup>2</sup>) was performed to investigate the effect of performance parameters of soil cover mechanism of a rice film-mulching seeder on the indices of the soil-covering at agricultural technology extension center of Raohe County, Heilongjiang Province, China. In the experiment, the working parameters and ranges were determined as follows: the tractor power in range of 24-34 kW, the working speed in range of 3-6 km/h, the diameter and the drift angle of the soil-covering disc of 336 mm and 25°-45°, respectively, the length, diameter and revolving speed of the roller of 1400 mm, 318 mm and 1.1-1.7 r/s, respectively, the soil-discharging hole dimension of 110 mm × 100 mm, the lead angle of 31°, and the hole spacing and hill spacing of 300 and 110 mm, respectively. The forward velocity of the seeder, the diameter and the drift angle of the soil-covering disc were selected as influencing factors, and the soil-covering qualification rate of seeder was selected as the objective index. Box-Behnken central composite design method was employed to establish a model to present the effects of influencing factors on the objective index. In the forward speed of 3-6 km/h, the diameter of the soil-covering disc of 300-350 mm and the dip lead angle of 25°-45°, the qualification rate of soil-covering tended to first increase and then decrease with the increase of the affecting factors, and the forward speed had the most significant effect on the qualification rate of soil-covering, followed by the drift angle of the soil-covering disc, and the diameter of the soil-covering disc was the least. The highest qualified rate was 97%, which was obtained under the optimal working condition with the forward velocity of 5.3 km/h, the soil-covering disk diameter of 336 mm and the drift angle of the soil-covering disc of 34°, with the average soil-covering thickness of 22.44 mm and the soil-covering rate of 100%. According to the requirement of 4-5 grains per hill for dry land direct seeding technology, the qualification rate of dibbling seeding achieved 93% with the seed germination rate of 99.6% and the average germination qualification rate of 87%, and the amplitude of emergence rate affected by soil-covering may be kept below 6%. Therefore, these results verified that the optimal parameters obtained by the test were reliable. This research provides technical basis for the application and promotion of rice film-mulching seeder, which greatly reduces the labor intensity of farmers and improves the working efficiency, and gives the solution for the problems of the inaccurateness of manual operation, poor evenness of soil covering, thickness being not easy to control and unsatisfactory working quality. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Soils
Controlled terms:Agricultural machinery - Agriculture - Cultivation - Disks (machine components) - Models - Optimization - Seed
Uncontrolled terms:Agricultural technologies - Central composite designs - Effective temperature - Parameter optimization - Performance parameters - Rice covering direct seeder - Soil coverings - Working parameters
Classification code:483.1 Soils and Soil Mechanics - 601.2 Machine Components - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.08.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 23>
Accession number:20152100877551
Title:Disturbance compensation controller algorithm and implementation for buck converters
Authors:Ding, Shihong (1); Wang, Jiadian (1); Huang, Zhenyue (1); Zhao, Dean (1)
Author affiliation:(1) School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, China
Corresponding author:Ding, Shihong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:214-220
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are a variety of disturbances wide existing in the agricultural devices, including uncertain parameters, input voltage variations and load changes and these perturbations heavily affect the output voltage of the Buck converter. The traditional proportional integral (PI) control methods are difficult to obtain satisfactory performance. To solve this problem, many nonlinear theories have been applied to the Buck converter for obtaining better control performance. However, the implementation of these nonlinear controllers, such as adaptive controller and fuzzy-neural controller, generally requires complex hardware circuit or advanced processor, which increases the cost of the production and reduces the reliability of the control circuit. In this paper, based on the disturbance observation theory, a new control method for disturbance attenuation is proposed. First of all, the conventional PI controller is replaced with the variable-parameter PI (VAPI) controller, which not only possesses the easy-implementation characteristic the conventional PI holds, but also guarantees that the closed loop system will have a better performance in different control stages by online tuning the PI parameters. Then, a linear disturbance observer (DOB) is constructed to estimate the exact value of the disturbance which is caused by input voltage variations and load changes. The disturbance is estimated through the information of output voltage and the structure of control system, and the estimated value is used to compensate the disturbance in forward channel, which will significantly improve the convergence and disturbance rejection property of the closed loop system. With the above improvements, a new composite controller can thus be obtained. The composite controller in the paper is implemented by using a semi-physical experimental platform. The platform is mainly based on a data acquisition card and a buck circuit. When the system of the Buck converter is running, the output voltage can be collected by the data acquisition card. By calculating these voltage data, the control output signal can be obtained directly. Later, the data acquisition card will transmit the obtained control signal to the buck converter circuit. The advantages of this semi-physical experimental platform are making the implementation of the algorithm more flexibly and the modification of controller parameters more conveniently. Based on the experiment platform, the implementation of the composite controller can be summarized as three steps. Firstly, the continuous composite controller is constructed in frequency domain. Secondly, the continuous composite control strategy is discretized so that the data can be processed by computer. Finally, the discrete controller is implemented directly by using the LabVIEW program. Experimental results obtained from the semi-physical experiment platform show that after replacing PI controller with the composite controller, when the load varies, the recovery time of the Buck converter can be shortened by 71.4% and the output voltage error can be reduced by 20.8%. When the input voltage varies, the recovery time can be shortened by 58.3% and the output voltage error can be reduced by 30.0%. According to these comparative results, it is obvious that the proposed new composite controller can effectively improve the convergence and anti-disturbance performance of the Buck converter. Meanwhile, considering the property of easy-implementation, the composite control method has potential applications in engineering area. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Controllers
Controlled terms:Algorithms - Closed loop control systems - Closed loop systems - Control systems - Control theory - Data acquisition - DC-DC converters - Disturbance rejection - Frequency domain analysis - Optimization - Parameter estimation - Two term control systems - Uncertainty analysis
Uncontrolled terms:Buck converters - Composite control strategy - Conventional-PI controller - Disturbance compensation - Disturbance observer - PI control - Proportional-integral control - Semi-physical experiments
Classification code:704.1 Electric Components - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 732 Control Devices - 732.1 Control Equipment - 921 Mathematics - 921.5 Optimization Techniques - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.08.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 24>
Accession number:20152100877555
Title:Agro-ecosystem value connotation based on watershed land use
Authors:Fu, Yicheng (1); Du, Xia (1); Peng, Wenqi (1); Dong, Fei (1)
Author affiliation:(1) The Department of Water Environment, China Institute of Water Resources and Hydropower Research, Beijing, China
Corresponding author:Du, Xia
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:243-250
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The service value of agro-ecosystem is closely related with other product production. The ecosystem can provide service value, which is usually considered as the substitute of purchasing input, in order to benefit the cost reduction. There is dynamic equilibrium between agricultural ecosystem protection and grain output increase, and they have the "falling" relation. In order to maximize profits at the level of land utilization, higher dependence of agricultural producers on ecosystem service will reduce farmland output. In this paper, the production function model of agricultural ecosystem is built so as to reasonably determine the alternative conditions and output results, and quantitative research of allocation proportion between the land reserved and the land providing ecosystem service is conducted. Taking the upstream of Yongding River basin as the study region, the calculation is conducted by means of the elasticity in land yield for production. If the land providing the ecosystem service in the river basin is increased by 1%, the corresponding crop output will be reduced by 2.7%. The quantitative analysis model is given from the micro-level perspective of the "falling" influence of agricultural ecological value, but the research in the influence on environmental protection policies in production shall be strengthened. While there are certainly instances that the interests of agro-ecosystem production and conservation may be aligned, such "win-win" outcomes are typically limited to a certain range of the production vs. conservation space. As literature analysis, some other authors have noted that the characteristic of the interaction between natural and purchased inputs may have important implications for agro-ecosystem conservation policy. The ecosystem services' value often rests on "natural" inputs; when the price of purchased inputs goes up, more land will be conserved to provide ecosystem services. In agro-ecosystems, the changes in the land for planting may also have a dynamic feedback effect on the incentive prices, and the agriculture incentives influence the ecosystem services through motivating the changes in land use and management. Co-benefits and trade-offs can occur over multiple spatial and temporal scales. A typical "falling" in agro-ecosystems is the function of supporting, regulating, habitat and cultural services provided by natural ecosystems, which are substituted for food, fiber and livestock products. This reduction in output will be translated into an increase in agricultural products' prices, as well as greater pressure to produce in other places, as a result, reducing the incentives for other producers to rely more heavily on the ecosystem services in production. At present, the incentives such as payments for ecosystem services are increasingly used to rebalance the supply of non-marketed services. Agro-ecological compensation can eliminate the negative impact of current agricultural production and guarantee the smooth environment-friendly agricultural production. Ecological values are largely influenced by the spatial and temporal dynamic variations and the accurate calculation of input costs and agricultural output remains a challenge. Competitive land utilization and the wide application of pesticides and chemical fertilizers can affect stable and efficient agricultural production, reduce the protein content of crops, and increase the probability of food pollution. Therefore, these magnitudes are so important argues for giving agro-ecosystem protection policy when considering the implications of an ecosystem service approach in future. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Ecosystems
Controlled terms:Agricultural products - Agriculture - Chemical contamination - Commerce - Cost reduction - Costs - Crops - Ecology - Economic and social effects - Economics - Fertilizers - Land use - River pollution - Sales - Watersheds
Uncontrolled terms:Agricultural productions - Falling - Function modeling - Land use and managements - Payments for ecosystem services - Quantitative analysis model - Spatial and temporal scale - Value
Classification code:403 Urban and Regional Planning and Development - 444.1 Surface Water - 453 Water Pollution - 454.3 Ecology and Ecosystems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 822.3 Food Products - 911 Cost and Value Engineering; Industrial Economics - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.08.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 25>
Accession number:20152100877561
Title:Pilot-plant test of soybean oil from enzyme-assisted aqueous extraction processing
Authors:Han, Zongyuan (1); Li, Xiaojing (1); Jiang, Lianzhou (2)
Author affiliation:(1) College of Life and Engineering, Shenyang Institute of Technology, Fushun, China; (2) College of Food Science and Engineering, Northeast Agricultural University, Harbin, China
Corresponding author:Jiang, Lianzhou
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:283-289
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the pilot-plant and continuous enzyme-assisted aqueous extraction processing, soybeans were used as raw materials in order to improve oil extraction efficiency. The lab and scale-up experiments of enzyme-assisted aqueous extraction processing were completed and the mechanism of oil release was determined. Protease was adopted to remove the net structure of protein that wrapped oil, and in addition protein structure in the cream was completely destroyed by the isoelectric point method, aiming to make oil gather and release. After the mechanism was analysed, experimental parameters were optimized in the lab and scale-up experiments. The results indicated: pretreatment conditions were barrel temperature 110, screw speed 100 r/min and sieve mesh 40; enzymolysis parameters were enzyme amount 1.92%, enzymatic temperature 56, enzymatic time 4 h, solid-to-liquid ratio 1:5.04 and pH value 9.15; demulsification conditions were demulsification temperature 63, demulsification time 34 min and demulsification trial 2. The pilot-plant experiments showed that it was more efficient for dehulled soybeans to improve oil extraction efficiency and demulsification efficiency, so soybean dehulling processing was necessary. To determine the effects of different kinds of compositions on extraction yield from enzyme-assisted aqueous extraction processing, through principal component analysis, ten indicators were reduced into 3 independent indicators that could reflect 95% of dehulled soy, which showed that the content of soy oil, free oil+cream after centrifugation, protein and moisture of cream were the key to extracting soy oil. Pilot-plant processing One was adopted to conduct the continuous pilot-plant experiments, and as the trial time increased, oil extraction rate gradually increased, reached the maximum value (66.46?Ddamp;plusmn;0.28%) in the fourth and then remained stable. In addition, in the first the water and enzyme were added according to what was said above, and after that the water and enzyme were reduced by at least 39% and 48%, respectively. Finally, by detecting the characteristic value of soybean oil, the experiment came to a conclusion: acid value, peroxide value and phosphorus content of soybean oil from enzyme-assisted aqueous extraction processing were significantly lower than those of solvent extraction (P<0.05); what was more, the lower the content of free fatty acids, the lower fat oxidation degree, which could help prevent oil rancidity and oxidation; in a word, soybean oil quality of enzyme-assisted aqueous extraction processing was higher than that of solvent extraction method and basically met the demands of national three-level standard. In the pilot-plant experiments, the disc centrifuge was hard for free oil, cream and skim, and the separation effect needed to be improved. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Extraction
Controlled terms:Demulsification - Drying oils - Efficiency - Enzymes - Fatty acids - Oil shale - Pilot plants - Principal component analysis - Proteins - Quality control - Sieves - Solvent extraction - Soybean oil
Uncontrolled terms:Continuous pilot plants - Demulsification efficiency - Enzyme-assisted aqueous extractions - Experimental parameters - Extraction efficiencies - Oil and fats - Pilot plant experiments - Solvent extraction methods
Classification code:402.1 Industrial and Agricultural Buildings - 512.1 Petroleum Deposits - 605 Small Tools and Hardware - 802.3 Chemical Operations - 804.1 Organic Compounds - 813.2 Coating Materials - 913.1 Production Engineering - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.08.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 26>
Accession number:20152100877530
Title:Flow characteristic analysis of intake and end of compression for free piston engine
Authors:Yin, Ningxia (1); Chang, Siqin (2)
Author affiliation:(1) Engineering College of Guangdong Ocean University, Zhanjiang, China; (2) School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing, China
Corresponding author:Yin, Ningxia
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:61-67
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Compared with the conventional four-stroke engine, the four-stroke free piston engine has benefits in terms of high efficiency, weight reduction, and variable compression ratio and expansion ratio. At the same time, both the freedom and convenience control of the movement of the four-stroke free piston are improved. Without the restriction of the crankshaft, the movement of the piston that is determined by the interaction of a number of forces acting on the mover, makes it possible to further improve the performance through design optimization and technology innovation. Based on the dynamics principle of the free piston engine, the dynamic model of the free piston is built. The dynamics of the free piston assembly obeys Newton's second law. On the basis of the movement of the free piston, the geometrical model and the simulation model of the compressed natural gas (CNG) free piston engine are established. With the help of the general fluid computing platform, the module of the free piston movement that can be solved step by step is developed. Moreover, the multi-dimensional transient numerical simulation model of the free piston engine's working process is also established. The effects of the piston movement on the cylinder flow field are also explored. The results show that the fast moving of the piston can get high in-cylinder unit mass kinetic energy and turbulent kinetic energy. When the time of the intake stroke is only 45 percent of the sum time of the intake and compress stroke, the maximum of the in-cylinder unit mass kinetic energy and the turbulent kinetic energy can be 208.8 J/kg and 25.11 m<sup>2</sup>/(s<sup>2</sup>·kg) respectively. But the fast moving piston in intake stroke has little impact on the in-cylinder unit mass kinetic energy and turbulent kinetic energy for the intake end. When the time of the intake stroke is only 45 percent of the sum time of the intake and compress stroke, the in-cylinder unit mass turbulent kinetic energy is only 3 percent higher than that of the intake stroke whose time is 55 percent of the sum time of the intake and compress stroke. Under the conditions of the same compression time, the mid-range acceleration is superior to the acceleration of late course during the compression stroke. This is due to that this movement of the mid-range acceleration during the compression stroke can also enhance the turbulent kinetic energy of the compression end. So the mid-range acceleration is adopted in the compression stroke. The fast moving piston in compression stroke can increase the turbulent kinetic energy of the compression end. When the compression time is equal to 45% of the sum of the intake and the compression time, the turbulent kinetic energy of the compress end can be 4.883 m<sup>2</sup>/(s<sup>2</sup>·kg), and it is 40% higher than that of the compression time equal to 55% of the sum of the intake and the compression time. So the piston movement with slow intake and fast compression is adopted, which can increase the gas movement intensity of the compression end and accelerate the flame propagation. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Engine pistons
Controlled terms:Compressed natural gas - Compression ratio (machinery) - Computational fluid dynamics - Crankshafts - Engines - Flow fields - Free piston engines - Kinetic energy - Kinetics - Models - Numerical analysis - Pistons
Uncontrolled terms:Compressed natural gasses (CNG) - Flow charac-teristics - Flow field analysis - Piston motion - Technology innovation - Transient numerical simulation - Turbulent kinetic energy - Variable compression ratio
Classification code:522 Gas Fuels - 601.2 Machine Components - 612 Engines - 631.1 Fluid Flow, General - 902.1 Engineering Graphics - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.08.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 27>
Accession number:20152100877541
Title:Changes of soil respiration of paddy fields with water-saving irrigation and its influencing factors analysis
Authors:Yang, Shihong (1); Wang, Yijiang (3); Xu, Junzeng (1); Liu, Xiaoyin (2)
Author affiliation:(1) State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China; (2) College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China; (3) Kunshan Water Conservancy Engineering Quality and Safety Supervision and Water Technology Popularization Station, Kunshan, China
Corresponding author:Yang, Shihong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:140-146
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The temporal and spatial variation of soil respiration of farmland has great influence on regional and global carbon cycle. Irrigation is an important factor to soil respiration in farmland. Existing study on the effect of irrigation on farmland soil respiration mainly focused on the dry farmland, but less research focused on paddy fields. Relationships between soil respiration and water depth and short-term drying of paddy fields with flooding irrigation were analyzed in existing studies. In order to reveal the difference of soil respiration in paddy fields with water-saving irrigation and traditional irrigation, the diurnal variation of soil respiration, the impact of alternation of wetting and drying on soil respiration, and the influencing factors of soil respiration for paddy fields were analyzed based on lysimeter experiment. The results showed that diurnal variations of soil respiration of paddy fields with water-saving irrigation and normal irrigation were similar at the period when the status difference of soil moisture was small between the two irrigation modes. Diurnal variations of soil respiration of paddy field with water-saving irrigation showed wider range, and the fluxes and rangeability of soil respiration of paddy field with water-saving irrigation were larger than those for traditional irrigation when the status difference of soil moisture was large. The mean value of soil respiration of diurnal variation during the whole growth period for water-saving irrigation was 1.47 times that for traditional irrigation. But during early tillering stage, jointing-booting stage and milk stage in which water managements were obviously different, the mean values of soil respiration diurnal variations for water-saving irrigation were 3.85, 1.42 and 3.74 times those for traditional irrigation. This results could contribute to frequent alternation of wetting and drying of paddy fields with controlled irrigation. The processes of soil rewatering and soil moisture depletion both had a certain effect on soil respiration of paddy fields. Peaks of soil respiration appeared at the critical point of soil moisture depletion. In the critical point of soil rewatering, the increase of soil respiration rate was not obvious if the rewatering depth was thicker, and the increase was significant if the rewatering depth was thinner. And small peaks of soil respiration appeared when soil water content decreased close to the lower limit of soil water content of paddy field with controlled irrigation during the irrigation interval. Soil temperature and soil moisture had great impact on soil respiration of paddy field with water-saving irrigation. Good exponential dependence was showed between soil respiration flux and soil temperature in the depth of 5 cm in paddy fields, and the correlation reached significant level for paddy field with water-saving irrigation (P<0.05). Management mode without water layer for controlled irrigation led the soil moisture conditions to be similar to dry farmland, so the relationship between soil respiration and soil temperature of paddy fields with controlled irrigation was more consistent with the existing results in dry farmland and forest. Water layer was kept in field surface for a long time under traditional irrigation, which led the soil into strict anaerobic conditions, and the effects of soil temperature on soil respiration was relatively weaken. The soil volumetric moisture content of 43% was the critical point for soil respiration of paddy field with water-saving irrigation when the soil volumetric moisture content ranged from 35% to 55%. Soil respiration flux in paddy field with water-saving irrigation increased with the enhancement of soil moisture content when the soil volumetric water content was lower than the critical value (P<0.05). And soil respiration flux in paddy field with water-saving irrigation decreased with the increase of soil moisture content when the soil volumetric water content was larger than the critical value (P<0.05). This conclusion was consistent with the existing research results. The appropriate soil volumetric moisture content was about 43%, which could create a suitable environment for respirations of rice roots, soil microbes and so on, and increase soil respiration rate. The results of this paper can support for more comprehensively evaluating the ecological environment effect of rice water-saving irrigation. At the same time, it can be helpful to accurately evaluate the carbon source/sink features of paddy field ecosystem. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Soils
Controlled terms:Carbon - Drying - Ecology - Farms - Forestry - Irrigation - Moisture - Moisture determination - Soil moisture - Soil surveys - Temperature - Water conservation - Water content - Water management - Wetting
Uncontrolled terms:Diurnal variation - Paddy fields - Soil respiration - Water-saving irrigation - WETTING AND DRYING
Classification code:444 Water Resources - 454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 642.1 Process Heating - 801.4 Physical Chemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2015.08.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 28>
Accession number:20152100877527
Title:Design and experiment on electrostatic spraying system for unmanned aerial vehicle
Authors:Ru, Yu (1); Jin, Lan (1); Jia, Zhicheng (1); Bao, Rui (1); Qian, Xiaodong (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, China
Corresponding author:Ru, Yu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:42-47
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Unmanned aerial vehicle (UAV) has the advantages of flexible operation and good adaptability to the terrain. Low-speed operating conditions and downward airflow generated by rotor wing of UAV can be very suitable for the application in agricultural pest control. Electrostatic spray has the advantages of uniformity in droplet size and good property of deposition, maturely applied in aerial spray system driven by people. The droplet of electrostatic spray is most likely to be charged when its size ranges from 80 to 200 μm. Taking advantages of such the characteristics as low-speed and low-height flight, and downdraft airflow from rotor, the electrostatic spray technology based on UAV can achieve ultra-low spray volume and hence improve spray quality. The electrostatic spray system is designed for the XY8D UAV, especially electrostatic nozzle structure with conical electrode adapted to the spray angle. The ring-shaped support makes the air flow through the electrodes, which can not only improve the penetrating capability of the droplets, but also guarantee the electrodes to be dry and the voltage to be stable. The power supply of high-voltage electrostatic uses bipolar charge mode, making both sides of the electrodes charged with opposite polarity and keeping the current balance for the UAV. The electrostatic spray test system is established. Under the condition of simulated UAV static electrostatic spray, the atomization and charging property of electrostatic nozzle has been tested by the laser particle size analyzer and Faraday tube test method. The results show high charge-mass ratio of 2.08 mC/kg can be obtained with nozzle tip of 0.4 mm, spray pressure of 0.3 MPa and charging voltage of 8 kV. So 0.4 L/min flow, 0.3 MPa spray pressure and 8 kV charging voltage are successfully identified as the UAV field operating parameters. The XY8D UAV electrostatic spray system is tested at different altitudes with electrostatic or non-electrostatic spray. Results show that the flying altitude is greater, the spray swath becomes wider; and the maximum spray swath is 6.8 m. Compared with non-electrostatic spray, the spray swath under electrostatic condition reduces slightly. Droplet sedimentation and drift experiments are conducted using the UAV electro-spray system over a 50 m × 30 m rice field, with the methods of water-sensitive paper and polyester card collection, respectively. Test results show that for non-electrostatic spray, droplet deposition effect is better when flight altitude is 2 m compared with the flight heights of 1 and 3 m, and the number of droplet deposited on water-sensitive paper reaches 56 per square centimeter; electrostatic spray make droplet deposition increase, and droplet coverages averagely increased by 35.4, 26 and 9 per square centimeter in the target canopy, middle and lower layer respectively. When the flying attitudes are 1, 2 and 3 m, the drift results of electrostatic and non- electrostatic spray are similar, the average droplet drift distances are 12.1, 15.8 and 18.6 m respectively; the average drift amounts are 5.88, 10.31 and 14.98 μg/cm<sup>2</sup> respectively. It indicates that the flying altitude has greater influence on droplet drift, and the electrostatic spray method has little effect on inhibiting spray drift. While comparing with non-electrostatic spray, the deposition concentration of the droplets on polyester cards with electrostatic spray under 3 flying attitudes increases by 2.36, 2.91 and 1.56 μg/cm<sup>2</sup> respectively. Test results provide the reference for the research on electrostatic spraying technologies based on UAV. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Spray nozzles
Controlled terms:Aircraft control - Airships - Deposition - Design - Drops - Electrodes - Electrostatics - Nozzle design - Nozzles - Particle size - Particle size analysis - Research aircraft - Spraying - Testing - Unmanned aerial vehicles (UAV) - Unmanned vehicles - Vehicles
Uncontrolled terms:Charge-to-mass ratios - Drift - Electrostatic conditions - Electrostatic nozzles - Electrostatic spraying - Laser particle size analyzer - Operating parameters - Water sensitive paper
Classification code:408 Structural Design - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 432 Highway Transportation - 443.1 Atmospheric Properties - 631.1 Fluid Flow, General - 652 Aircraft and Avionics - 701.1 Electricity: Basic Concepts and Phenomena - 704.1 Electric Components - 813.1 Coating Techniques - 943.2 Mechanical Variables Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 29>
Accession number:20152100877558
Title:Drying characteristics of corn in high voltage electric field
Authors:Ji, Xu (1); Leng, Congbin (1); Li, Haili (1); Li, Ming (1); Zhang, Yue (1); Bi, Guanghong (1)
Author affiliation:(1) Solar Energy Research Institute, Yunnan Normal University, Kunming, China
Corresponding author:Ji, Xu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:264-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The internal moisture in corn exists in the states of free water and bound water. It is generally beyond 18% (Wet basis) in the new corn harvested, however, in order to storage safely, the moisture content of corn should be kept below 14%. Therefore, drying becomes an indispensable process in corn's production and processing. The aim of this study was to investigate the dehydration rate of corn by changing the stacking thickness of corn, the density of needle electrode and the electric field intensity in a high voltage needle-disk electric field drying system, as well as to analyze the difference between the traditional natural air drying and hot air drying methods. The results indicated that the dehydration rate increased and then decreased with the increase of the density of needle electrode. When the voltage between the needle and the disk was 40 kV and the separation distance between them was 6.2 cm, the optimum needle electrode density was 170 pieces/m<sup>2</sup>, but its increasing was not significant. Perhaps the reason was that when the density of the electrode was small, effective electric field intensity was not able to cover all the material. However, when the density of the electrode became larger, the charge distributed on the needlepoint was reduced and the electric field intensity was weakened, and the interference increased between two adjacent needles, which led to the decrease of the dehydration rate. Furthermore, the corn stacking thickness had little effect on the dehydration rate under high voltage electric field. There was no obvious effect on the dehydration rate when the thickness was less than 4.6 cm, but the dehydration rate slightly slowed down with the increasing of the stacking thickness, due to the natural evaporation of moisture in corn. The natural evaporation of moisture occurs mainly in the surface layer of material and the thinner stacking thickness leads to the more natural evaporation and the relative faster dehydration rate. When the stacking thickness was thinner than 1 cm, the dehydration rate under the electric field was double to that by natural drying and the drying time reduced by 50%. On the other hand, when the thickness was equal to 1.9 cm, the electric dehydration rate was 6.5 times higher than the natural drying and the drying time reduced by 85%. Subsequently, when the thickness increased from 1.9 to 4.6 cm, the dehydration rate increased only by 28%. On the contrary, the drying time extended with the increase of the thickness in the natural drying, because the natural drying occurred mainly in the surface layer. However, in the high voltage electric field drying system, electric field was evenly distributed in corn material and drying happened in the interior and surface area of the material at the same time, therefore, the stacking thickness of corn showed a less effect in the high voltage electric field drying system. In conclusion, the high voltage electric field drying is suitable for drying the thicker materials which can effectively reduce the drying space and workload, as well as improve the efficiency of drying. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Drying
Controlled terms:Crops - Dehydration - Electric fields - Electrodes - Evaporation - Interference suppression - Moisture - Needles - Solar dryers
Uncontrolled terms:Drying characteristics - Electric field intensities - High voltage electric field - High-voltage needle - Material thickness - Natural evaporation - Needle electrodes - Separation distances
Classification code:701.1 Electricity: Basic Concepts and Phenomena - 704.1 Electric Components - 711 Electromagnetic Waves - 801.4 Physical Chemistry - 802 Chemical Apparatus and Plants; Unit Operations; Unit Processes - 819.6 Textile Mills, Machinery and Equipment - 821.4 Agricultural Products
DOI:10.3969/j.issn.1002-6819.2015.08.038
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 30>
Accession number:20152100877525
Title:Parameter optimization and test on auto guide device for disc type sugar beet harvester
Authors:Wang, Fangyan (1); Zhang, Dongxing (2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Qingdao Agricultural University, Qingdao, China; (2) College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Wang, Fangyan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:27-33
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Sugar beet is one of the most important sugar crops in China, which ranked second in terms of acreage, only after sugarcane. As a kind of seasonal operation, sugar beet harvesting in China is still mainly manual work, which constrains the further development of the sugar beet industry. Mechanized combine harvesting is the inevitable development trend of sugar beet harvesting. Guidance system is the major part of harvest machine, which can reduce the driver's labor intensity and beet's harvest damage in the harvest process. With the development of the technology of electronics, sensor and GPS guidance, the guide technology has been commercialized and applied to the field of agricultural equipment widely in the developed countries. The combine harvesting with the guide device is characterized by high automation and intelligence and advanced performance. However, the guide device is still in the stage of prototype development in China, and there is a great gap between domestic and advanced foreign technology. The research on beet's guiding harvest is scarce, and this restricts the quality of beet digging and mechanization. To solve the problem of the guide on-row harvest of disc type sugar beet harvester, the structure and working mechanism of the guiding system were determined on the basis of analyzing the existing technology and the structure. And the key parameters relating to the performance of guide mechanism were obtained based on its operating conditions and mechanical structure. Combined with the disc type digging method, a guiding system integrating mechanical and hydraulic guide technology was designed to realize the digging along planting row, which mainly consisted of hydraulic steering and direction detection parts. In the process of automatic guide on-row harvest, beet profile was taken as orientation marker, and the information was obtained by guiding detect pole. The real-time direction adjustment was conducted by cylinder's telescopic movement installed on traction frame, which made beet located in the digging scope all the time. Combined with the structure and working characteristics of the guide device, the load and movement characteristics of the guide mechanism were analyzed, the acceleration equation of the guide mechanism was obtained, and the key parameters relating to the performance of guide mechanism were summarized. Based on field experiment and response surface optimization method, the mathematical models of the key parameters and guide effect indices were established, the influence rule of parameters on the test index was studied, and the value range and the optimal combination of the parameters were determined. By field test of harvest performance, the working efficiency, suitability, reliability and other performances of the prototype were improved and the imperfection was perfected. The guide device had an ideal work effect when the bending angle was 145°, install angle was 8° and horizontal length was 240 mm. Conclusion was drawn according to field test: the system implemented the automatic guiding in the harvest process, and the loss rate was 5.12%, which met the harvest quality standard (NY/T 1412-2007). So the prototype has met the performance requirement of harvesting sugar beet. The results can provide the reference for similar harvester design and guiding harvest for other single root crop. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Harvesting
Controlled terms:Agricultural machinery - Agriculture - Combines - Crops - Disks (machine components) - Electronic guidance systems - Harvesters - Hydraulic machinery - Mechanisms - Mechanization - Optimization - Structural design - Sugar beets - Sugar industry
Uncontrolled terms:Acceleration equations - Agricultural equipment - Automatic guide - Mechanical structures - Movement characteristics - Parameter optimization - Performance requirements - Response surface optimization
Classification code:408.1 Structural Design, General - 601 Mechanical Design - 632.2 Hydraulic Equipment and Machinery - 715.1 Electronic Equipment, non-communication - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822 Food Technology - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.08.005
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 31>
Accession number:20152100877531
Title:Parameter optimization and experiment of air-assisted pollination device
Authors:Ding, Suming (1); Xue, Xinyu (1); Fang, Jinbao (2); Sun, Zhu (1); Cai, Chen (1); Zhou, Liangfu (1); Qin, Weicai (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing, China; (2) Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
Corresponding author:Xue, Xinyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:68-75
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The planting area of orchard and fruit production in China is at the top in the world, but there are the disadvantages of the late development of orchard pollination device and the relatively low level of mechanization, so poor pollination has become the main factor influencing the improvement of orchard yield and quality, and seriously hampered the development of Chinese fruit industry. Pollination is the key process in the fruit production, and sufficient and well-distributed pollination can be helpful to increase the outputs and improve the quality. Artificial pollination is widely used in fruit production in recent years, which is labor intensive and with low productivity and process restricted, and cannot adapt to large-scale production. Thus, in order to make full use of the pollen, the technique and machine used for the pollination are needed. Pollination technique, particularly air-assisted pollination technique, is an inevitable trend for fruit production. In order to further study the pollination technique, the pollination testbed was designed. The testbed consisted of a pollination device, direct current stabilized power supply, definite time relay and glassslid. The nozzle diameter, shrinkage pipe diameter and motor voltage were taken as the influencing factors. The dusting rate, solid mass concentration and pollen coverage were used as test indices in the experimental study. Orthogonal rotational quadratic combination test with three factors and three levels was made to evaluate the combined influence of the factors on the test index value, and then regression equations to describe the relationships between the factors and each assessment index were established by using the regression analysis and response surface analysis with the software Design-Expert 8.0.6. The optimum combination of input parameters was obtained and verified, and the experimental verification of the mathematical model was also conducted. The results showed that trial factors had great effects. The significant effects of nozzle diameter, motor voltage and shrinkage pipe diameter on reducing the dusting rate were in a decreasing order. The significant effects of nozzle diameter, motor voltage and shrinkage pipe diameter on reducing solid mass concentration were in a decreasing order. The significant effects of motor voltage, shrinkage pipe diameter and nozzle diameter on increasing pollen coverage were in a decreasing order. The best model of the integrated pollination parameters was as follows: when the nozzle diameter was 5 mm, the shrinkage pipe diameter was 7.5 mm and motor voltage was 8.0 V, dusting rate was 1.70 g/min, solid mass concentration was 17.28 g/m<sup>3</sup>, and pollen coverage was 77.71%. Through comparing the mathematical model and the experimental result, it turned out that the relative errors of all the property indices between the two were less than 6%, which meant that the model established was useful and could be used for predicting and optimizing. The field experiment was conducted in a kiwi grove where "Hongyang" kiwi trees were grown, and the results showed that pollen coverage was 67.11%. Compared with the field result, the laboratory experiment turned out that the error range was less than 16%. It can provide theoretical and experimental basis for further study of pollination mechanism and developing pollination machinery, and also greatly promote the progress of industrialization and large-scale manufacture. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Fruits
Controlled terms:Agricultural machinery - Birds - Farms - Manufacture - Mathematical models - Mechanization - Nozzles - Optimization - Orchards - Piping systems - Regression analysis - Shrinkage - Software design - Software testing - Surface analysis - Surface properties - Testbeds
Uncontrolled terms:Artificial pollinations - Experimental verification - Kiwi - Large scale manufacture - Large scale productions - Pollination - Response surface analysis - Response surface methodology
Classification code:402 Buildings and Towers - 423 Non Mechanical Properties and Tests of Building Materials - 537.1 Heat Treatment Processes - 601 Mechanical Design - 631.1 Fluid Flow, General - 723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 32>
Accession number:20152100877553
Title:Effects of ash forming temperature on water-soluble fraction of biomass ash and it's elements
Authors:He, Fang (1); Yu, Rujun (1); Zhang, Yi (1); Zhu, Jiying (1); Gao, Zhenqiang (1); Sun, Peng (1)
Author affiliation:(1) School of Transportation and Vehicle Engineering, Shandong University of Technology, Zibo, China
Corresponding author:He, Fang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:227-232
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The implementation of biomass ash as a fertilizer is beneficial to the sustainable development of agriculture because it can return the elements taken by the plants from soil during the growth. Water solubility of biomass ash together with its elements is a vital property for the fertilizer's utilization. In this paper, the effects of ash forming temperature on the water solubility of biomass ash and its elements were investigated experimentally. Three typical types of agro-residues in China, i.e. wheat straw, corn stover and rice husk, were chosen for investigation. Materials were collected and the corresponding proximate and elemental analyses were performed. In preparation process, wheat straw and corn stover were milled into powder with the particle size of less than 1 mm. Ashes were prepared in a muffle furnace at different ash forming temperatures in the scope from 400 to 800 with the temperature interval of 50. About 4-5 g of each sample powder and rice husk were put in the crucibles, heated from ambient temperature to ash forming temperature, and then kept at the ash forming temperature for 4 hours in the muffle furnace. After the temperature of the furnace dropped to less than 200, the ashes were taken out to the cabinet dryer, cooled to the ambient temperature, and then weighted and sealed in the sample bag for further measurements. It showed that ash contents of wheat straw, corn stover and rice husk decreased significantly with the increase of ash forming temperature. They decreased from 9.8%, 10.9% and 18.4% at 400 to 6.9%, 8.7% and 16.8% at 800respectively. After the preparation of all the ash, two types of measurements were performed. The first was the water solubility measurement of the ashes according to the standard of GB8307-2002. Total ash of about 0.2-0.3 g was put in a beaker of 50 ml and about 25 ml distilled water was added in it. The mixture was heated and boiled for 2 min and then the solution was filtered through a quantitative filter paper. The filter residue was washed for several times using another 25 ml distilled water. After the burning of the filter residue, the insoluble ash was weighed and sealed in a sample bag. Results showed that the ash's water solubility of corn stover and wheat straw was much higher than that of rice husk. All of them were significantly affected by the ash forming temperature. They decreased from 48%, 35% and 12% to 12%, 8% and 0, respectively. The second was the water solubility measurement of the elements. This was based on the X-ray Fluorescence Spectrometer (XRF) tests of the original ash and water-insoluble ash using ZSX100e. The sample ash was pressed into a thin disc with the diameter of 30 mm. Then it was measured in vacuum with full scan mode by XRF. The data of measurement was processed using SQX (semi-quantitative nonstandard analysis program) and the mass concentrations of the elements were obtained. Result showed that there were respectively 11, 10 and 4 elements whose concentrations were more than 1% in the ash of wheat straw, corn stover and rice husk. And oxygen (O), silicon (Si), potassium (K), and calcium (Ca) were the major elements in all ashes, while chloride (Cl) was rich in stalks. The Cl concentration in the original ash decreased significantly with the increase of ash forming temperature. The water solubility of the elements in ash was calculated via two methods, i.e. mass conservation method and silicon trace method. Result showed that the major dissolved elements in ash were K, Cl and S (sulfur). The solubility of K and Cl decreased with the increases of ash forming temperature and the solubility of S was almost not affected by temperature. The experimental results can be used as the reference for environmental assessment and optimization of thermo-chemical process of biomass. And the method can be expanded to determine the recycling characteristics of other types of biomass ash. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Trace elements
Controlled terms:Biomass - Calcium - Chlorine compounds - Fertilizers - Furnaces - Particle size - Soil testing - Solubility - Straw - Sustainable development - Temperature - X ray spectrometers
Uncontrolled terms:Biomass ashes - Element - Environmental assessment - Temperature intervals - Thermo chemical process - Water solubilities - Water soluble fraction - X-ray fluorescence spectrometer
Classification code:483.1 Soils and Soil Mechanics - 532 Metallurgical Furnaces - 549.2 Alkaline Earth Metals - 641.1 Thermodynamics - 801 Chemistry - 801.4 Physical Chemistry - 804 Chemical Products Generally - 821.5 Agricultural Wastes - 911.2 Industrial Economics - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.08.033
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 33>
Accession number:20152100877533
Title:Design and numerical simulation of cooling circuit in magnetic pumps
Authors:Tan, Linwei (1); Shi, Weidong (1); Kong, Fanyu (1); Zhang, Desheng (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China
Corresponding author:Shi, Weidong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:84-91
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to avoid excessive temperature rise which leads to permanent magnet demagnetization and damage of containment shell, the design of cooling circuit of magnetic pumps was discussed. Theory analysis showed that the cooling circuit had a great influence on magnetic pumps' efficiency and reliability. Analysis and calculation showed that the main heat source of magnetic pumps was the eddy current heat of containment shell. ANSYS-APDL was adopted to calculate the eddy current heat, which simplified the distribution of the magnetic field to two-dimensional. The total heat was obtained through the eddy current heat multiplied by an amplification coefficient k. The cooling flow rate was calculated according to the heat balance and the cooling circuit was designed. The flow field model of the cooling circuit was established by Pro/e software, the structured grid was adopted to mesh the model and the near wall boundary layer was refined to ensure the grid quality. The SIMPLEC algorithm and the k-Ε turbulence model were adopted to solve the N-S equations and energy equation by CFX code. The flow velocity, pressure and temperature distribution were obtained by CFX software post. As could be seen from the numerical simulation, the internal flow of the cooling circuit was spiral motion combining circular motion and linear motion. Through the comparison between internal and external cooling circulations with the same main geometric parameters, it showed that the temperature rise was the highest, and the pressure was low in the internal circulation located in the bottom of containment shell, which maybe caused cavitation. On the other hand, the temperature distribution was uniform and the pressure gradually reduced from shaft hole to external pipeline (the pressure of containment shell bottom was higher) in external cooling circulation, which met the design requirements. Based on the same cooling flow rate, the influence of the shaft bore diameter in external cooling circulation was analyzed. It showed that the spiral movement velocity of cooling circuit was mainly decided by the circular velocity, the axial velocity had a little effect on the system, and a certain level of fluctuations of shaft bore diameter designed had little influence on the cooling result when the cooling flow rate was fixed. Without considering the friction changes at different rotational speeds, the influence of rotational speed was also discussed in external cooling circulation. It showed that the rotational speed powerfully affected the heat transfer. The highest temperature reached 386 K when the internal magnetic rotor didn't rotate, which was far exceeding the safety range, but the highest temperature was basically stabilized at a reasonable range with the internal magnetic rotating. The wall heat transfer coefficient increased significantly with the increase of rotational speed. So the increase of pump's rotational speed can promote heat exchange between the different fluid layers and improve the cooling effect. The research is helpful for the design of cooling circuit in magnetic pumps. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Cooling
Controlled terms:Boundary layers - Computer simulation - Design - Eddy current testing - Flow rate - Flow velocity - Heat transfer - Magnetic fields - Magnetism - Models - Navier Stokes equations - Numerical models - Permanent magnets - Pumps - Reliability analysis - Reliability theory - Shells (structures) - Speed - Temperature distribution - Turbulence models - Velocity
Uncontrolled terms:Amplification coefficient - Analysis and calculations - Cooling circuits - Cooling flows - Eddy current-loss - Efficiency and reliability - Pressure and temperature - Wall heat transfer coefficients
Classification code:408.2 Structural Members and Shapes - 618.2 Pumps - 631 Fluid Flow - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 701.1 Electricity: Basic Concepts and Phenomena - 701.2 Magnetism: Basic Concepts and Phenomena - 704.1 Electric Components - 723.5 Computer Applications - 902.1 Engineering Graphics - 913 Production Planning and Control; Manufacturing - 921 Mathematics - 922.2 Mathematical Statistics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.07.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 34>
Accession number:20152100877542
Title:Scale transformation of utilization coefficient of irrigation water in riverine irrigation district
Authors:Yu, Shuang'en (1); Yu, Zhiheng (1); Guo, Jie (3); Gu, Jing (4); Li, Yuwei (1); She, Dongli (1)
Author affiliation:(1) Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China, Ministry of Education, Hohai University, Nanjing, China; (2) College of Water Conservancy and Hydropower, Hohai University, Nanjing, China; (3) Bureau of Soil and Water Conservation, Changjiang Water Resources Commission, Ministry of Water Resources, Wuhan, China; (4) Yancheng Water Resources Bureau, Yancheng, China
Corresponding author:Yu, Shuang'en
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:147-151
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Utilization coefficient of irrigation water is a key indicator to measure agricultural water-saving efficiency, and it reflects comprehensively the level of water management and irrigation technology and so on. Obtaining reliable data of the utilization coefficient of irrigation water by direct in situ determination methods is difficult in large irrigation districts, but it can be determined by field experiments in the small-scale area. Hence, one of the challenges is to conduct researches on scale transformation in order to predict the utilization coefficient of irrigation water at large-scale irrigation district by the measured utilization coefficient of irrigation water at small irrigation district. The main characteristic of irrigation districts in riverine area is that there is no unified water diversion, and several small irrigation districts usually merge into a larger one. The area is a typical self-similar system. The existence and reusing of the agricultural returning water have induced much debates about the real water-saving potential of the irrigation districts in riverine area, and also the scale effect of utilization coefficient of irrigation water. The paper selected the rice irrigation districts of Yancheng City in Lixiahe riverine region as the experimental object. The study area is flat, where the river and ditch network are densely distributed. Totally, 4 large-scale irrigation districts, 11 medium-scale and 32 small-scale irrigation districts were selected to measure and calculate the utilization coefficient of irrigation water by inclusive method. The utilization coefficients of irrigation water in sampling irrigation districts with different scales were measured in 9 counties in 2012-2013. Fractal characteristics of these riverine irrigation districts were analyzed based on fractal theory. In addition, box dimensions of the Yancheng riverine area and the irrigation districts with different scales were respectively calculated by box-counting method. The box dimension ranged from 1.703 to 1.966, and increased with the increasing of irrigation district area scale. The scale transformation model of utilization coefficient of irrigation water was established based on the relationships among utilization coefficient of irrigation water, irrigation area and box dimension. The calibration results verified that the scale transformation model could predict the utilization coefficient of irrigation water in the riverine irrigation district with high prediction accuracy. With the developed model, the scale transformation of utilization coefficient of irrigation water was performed successfully. This study provides a new way to analyze the utilization coefficients of irrigation water and their transformation in different scales in riverine irrigation districts. In the future, if the means of geographic information system (GIS) is used in calculating the box dimensions, the accuracy of the research will be further improved. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Irrigation
Controlled terms:Agriculture - Calibration - Flood control - Forecasting - Fractal dimension - Fractals - Geographic information systems - Models - Water - Water conservation - Water management - Water resources - Water supply
Uncontrolled terms:Box dimension - Box-counting method - Determination methods - Fractal characteristics - Fractal theory - Irrigation districts - Scale - Scale transformation
Classification code:444 Water Resources - 446.1 Water Supply Systems - 454.1 Environmental Engineering, General - 723.3 Database Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 902.1 Engineering Graphics - 921 Mathematics - 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.1002-6819.2015.08.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 35>
Accession number:20152100877521
Title:Status analysis of biogas plants construction associated with development of live pig industry in China
Authors:Hu, Qichun (1); Tang, Xiaoyu (1); Ning, Ruiting (1); Li, Qian (1)
Author affiliation:(1) Biogas Institute of Ministry of Agriculture, Chengdu, China
Corresponding author:Tang, Xiaoyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:1-6
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The data of live pig industry development scale in China and the corresponding construction status of biogas plants from 2007 to 2012 were analyzed in the study. With the development and adjustment of live pig industry, large-scale standardized pig farms grew very fast. In the year of 2012, the proportion of scale pig-breeding farms by which more than 500 live pigs were sold every year achieved 38.5% in the whole country, while the number of pig farms at those scales was doubled during the 5 years. The increase of scale pig-breeding provided the opportunity for biogas plant construction. Thus, there was a rapid development of biogas plant construction in the 4 dominant pig-breeding areas. By the end of 2012, the number of breeding farms' biogas plants in rural regions of China has reached 91 600, which increased by 3 times that in 2007. Especially, the biogas plant coverage of medium-scale and large-scale pig farms in coastal and southwest areas reached more than 80%. On the other hand, there were a larger number of disabled biogas plants during this period. Due to the influence of regional resources, agricultural structure, climate and technology maturity, both the biogas plant construction status associated with live pig industry development and the quality of construction and operation management were uneven. Among all the factors that affected biogas plant's usage and discarding, live pig industry adjustment and market fluctuation played an important role in the normal operation of biogas plants. For this economic development model of biogas plants in the new era, China has paid more attention to the sustainability, the developing quality, the construction pattern and the development speed of biogas plants, which are served as basic agricultural facilities and are faced with the challenge of model change and upgrade. In order to enhance biogas plant's ability of treating livestock industry pollution, we have the following suggestions: 1) improve the quality of biogas production installation and the level of operation management with the help of leading enterprise in pig industry, and encourage the enterprises to establish their own quality standard of biogas plant construction and operation management, 2) emphasize the financial support on large and super-large scale biogas plants by the government and enhance the entering requirements of enterprises involved in biogas plant construction and operation management, 3) improve the functions of balance development between farm breeding and crop planting that are associated with biogas plants, promote the development of ecological and circulatory agriculture and restrict the usage of aerobic ways for post-treatment of digested slurry in the future. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:11
Main heading:Biogas
Controlled terms:Agriculture - Engineering - Industrial management - Industry - Mammals
Uncontrolled terms:Construction patterns - Construction status - Economic development - Market fluctuations - Operation management - Pig industry - Regional resources - Technology maturity
Classification code:522 Gas Fuels - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 912.2 Management - 913 Production Planning and Control; Manufacturing
DOI:10.3969/j.issn.1002-6819.2015.08.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 36>
Accession number:20152100877565
Title:Aging-resistant performance of flax/basalt fiber fabrics reinforced unsaturated polyester resin hybrid composites
Authors:Yang, Yuefei (1); Xu, Jianfeng (1); Lai, Jiajia (1); Zheng, Feng (1); Song, Jianbin (1); Yang, Wenbin (1)
Author affiliation:(1) Material Engineering College, Fujian Agriculture and Forestry University, Fuzhou, China; (2) National Wood and Forest Product of Chemical Quality Supervision and Inspection Center, Sanming, China
Corresponding author:Yang, Wenbin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:308-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, there has been increasing interest in the use of natural fiber reinforced polymer in many fields due to low density, high specific strength and eco-friendly property. However, the application of composites is faced with difficulties in outdoor environment, such as water absorption, degradation, low mechanic strength and dimensional stability. In order to improve the aging-resistant property of flax fiber fabrics/basalt fiber fabrics reinforced UP (unsaturated polyester resin), the author used the artificial simulating climate box (ultraviolet and condensation) to accelerate ageing process of HCM (hybrid composite materials), which was composed of different sandwich layers and included H1, H2 and H3 representing basalt fiber content of total fibers of 20.3%, 41.5% and 63.7%, respectively. Mechanical properties, DMA (dynamic mechanical analysis) performance and microstructure of HCM were affected by basalt fiber content and aging time. The result showed that both flexural strength and impact strength first increased and then decreased with aging time. The retention of flexural strength was 62.5%, 58.1% and 57.0% for H1, H2 and H3, respectively. With regard to impact strength, the figures were 66.8%, 66.7% and 53.2% for H1, H2 and H3, respectively. The results of ANOVA (analysis of variance) and LSD (least-significant difference) illustrated that ultraviolet aging time had significant effects on flexural strength of H3 (P<0.05) while basalt fiber content had not significant effects on flexural strength retention (P>0.05). As ultraviolet aging time increased, rigidity and frangibility of HCM increased gradually. The poor interfacial adhesion was demonstrated between flax fiber and UP by DMA. The result of SEM (scan electron microscope) indicated a poor interfacial adhesion between flax and UP matrix, such as debonding and more voids. However, basalt fibers and UP matrix were combined closely and matrix fragments around basalt fibers were found. The main reason was that hydrogen bond produced after absorbing water destroyed the interface between flax fibers and UP matrix. So process of water damage in the interface was verified by SEM. In conclusion, mechanical properties of HCM increase slightly owing to further solidified substrate. However, with the extension of aging time, irreversible hardening happens to matrix, followed by micro-crack appearing between fiber and matrix, which leads to a decrease in mechanical properties of HCM. In addition, water has significant effect on flax fiber and the mechanism of water damage is approved by SEM results. The manufacture of HCM by using natural degradable fibers is meaningful to environmental protection; on top of that, it can provide the reference to aging-resistance improvement of inorganic fibers/plant fibers reinforced polymer HCM. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Fibers
Controlled terms:Adhesion - Basalt - Bending strength - Composite materials - Dynamic mechanical analysis - Dynamics - Environmental protection - Fiber reinforced materials - Fiber reinforced plastics - Flax - Hybrid materials - Hydrogen bonds - Impact strength - Interfaces (materials) - Linen - Mechanical properties - Polyester resins - Reinforced plastics - Reinforcement - Unsaturated polymers - Water absorption - Yarn
Uncontrolled terms:Aging resistant performance - ANOVA (analysis of variance) - Flax fiber - High specific strength - Hybrid composite materials - Least significant differences - Natural fiber reinforced - Unsaturated polyester resin
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 415.2 Plastics Structural Materials - 421 Strength of Building Materials; Mechanical Properties - 454.2 Environmental Impact and Protection - 505 Mines and Mining, Nonmetallic - 531 Metallurgy and Metallography - 712 Electronic and Thermionic Materials - 801 Chemistry - 801.4 Physical Chemistry - 802.3 Chemical Operations - 811 Cellulose, Paper and Wood Products - 815.1.1 Organic Polymers - 819 Synthetic and Natural Fibers; Textile Technology - 931.1 Mechanics - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.045
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 37>
Accession number:20152100877547
Title:Effects of typical tree species and abiotic factors on hydrologic characters of forest litter in Beijing
Authors:Niu, Yong (1); Liu, Honglu (2); Zhang, Zhiqiang (1)
Author affiliation:(1) College of Soil and Water Conservation, Beijing Forestry University, Beijing, China; (2) Beijing Water Science and Technology Institute, Beijing, China
Corresponding author:Zhang, Zhiqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:183-189
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Litter layer affects hydrologic cycle of forest ecosystem significantly. This study aimed to determine hydrology characters of litter under different tree species and stand densities, and site conditions, and obtain the water holding capacity of litter forests, and the interception process and influencing factors through soaking experiment and rainfall simulating experiment. In order to estimate virtual interception, the relationships between virtual interception and the maximum water holding capacity were analyzed. Fifteen forest stands with different tree species, stand densities and site situations were chosen, and the fieldwork area was situated in Badaling national forest park,which was located in Beijing's rocky and earthy area of northern China. A rainfall circumstance was generated by an intermittent artificial rainfall simulator. In the rainfall simulating experiment, the parameters of rainfall intensity and rainfall amount were set as 5mm/h and 55mm for the simulator, because the rainfall intensity of 59 percentage of all rainfall events (2001-2012) was light rainfall magnitude (less than 10mm for a rain event), and 93 percentage of all rainfall events was less than 60mm in the study area. By outdoor survey, we found that the litter amounts of Pinus tabuliformis Carrière with different stand densities were not different significantly, except for the forest stands with the highest or lowest forest density. A positive correlation between litter amount and forest density was found in Pinus tabuliformis Carrière stands, no matter on ubac or adret. Litter amount differed with tree species, being less in broad-leaved forest than in coniferous forest, which was mainly caused by the lower decomposition rate of coniferous forest litter. The relationship between the maximum water holding capacity of litter and forest density could be described by a quadratic polynomials equation, the maximum water holding capacity of litter on adret was significantly higher than that on ubac (P<0.05). The maximum water holding capacity of the 5 typical forest stands ranged from 9.72 to 48.92 mm. The result of partial correlation analysis showed that most of influencing factors were positively related to the maximum water holding capacity, except for aspect, and the partial correlation coefficient of stand density was the highest, followed by tree species, decomposing layer percentage, slope, aspect, and litter amount, which indicated that the dominated factors of the maximum water holding capacity were complex and the factors affected each other. Rainfall simulating experiment result showed that the ratios of the interception to the maximum water holding capacity of different tree species increased with the increasing of rainfall, while rainfall reached 35-45 mm, the ratios became constant and ranged from 40% to 91%,which could be used to estimate virtual interception of litter, and this conclusion was different with Lee Richard's (1980). Two possible reasons might contribute to explain the phenomenon, At first, structure and material component of leaf litter of Platycladus orientalis (L.) Franco were quite different from other tree species, such as Pinus tabuliformis Carrière, and these differences made it need more time for the water content of litter to reach their virtual interception. Secondly, the rainfall intensity in this rainfall simulation was 5 mm/h, which was deemed as a typical light rain magnitude in northern China, and therefore the ratios of virtual interception to the maximum water holding capacity of the litter of mixed Platycladus orientalis (L.) Franco and Cotinus coggygria Scop. and Platycladus orientalis (L.) Franco could increase in other areas with the mean rainfall intensity bigger than 5mm/h. The conclusions based on the test data in this paper can provide reasonable information and suggestion for eco-hydrological study. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Forestry
Controlled terms:Correlation methods - Decomposition - Ecosystems - Hydrology - Moisture - Precipitation (meteorology) - Rain - Satellite interception
Uncontrolled terms:Broad-leaved forests - Forest litter - Platycladus orientalis - Positive correlations - Quadratic polynomial - Rainfall simulations - Simulating experiments - Water holding capacity
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 444 Water Resources - 454.3 Ecology and Ecosystems - 471 Marine Science and Oceanography - 655.2 Satellites - 802.2 Chemical Reactions - 821.0 Woodlands and Forestry - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.08.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 38>
Accession number:20152100877554
Title:Well-facilitied capital farmland construction based on cultivated land comprehensive quality
Authors:Zhu, Chuanmin (1); Hao, Jinmin (1); Chen, Li (1); Shuang, Wenyuan (4); Liu, Pinghui (3)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing, China; (2) Key Laboratory of Agricultural Land Quality and Monitoring, The Ministry of Land and Resources, Beijing, China; (3) Faculty of Geosciences, East China Institute of Technology, Nanchang, China; (4) College of Public Administration, Huaqiao University, Quanzhou, China
Corresponding author:Hao, Jinmin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:233-242
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve farmland quality, the basic condition of cultivated land and its social suitability must be taken into account simultaneously for high quality farmland evaluation and construction. Therefore, with these requirements and objectives, the evaluation index system and identification model of cultivated land comprehensive quality were established. The index system was from three impact factors including land fertility level, land leveling project, infrastructure in cropland. Thirteen specific indicators including surface soil texture, profile pattern, degree of salinity, soil organic matter, drainage conditions, et al. were selected and analyzed. The weight of each evaluation indicator was determined by Delphi method. With GIS spatial analysis tools, the comprehensive quality suitability for high quality farmland construction was discussed by using the attribute hierarchical model (AHM) and exploratory spatial data analysis (ESDA). On the platform of study on external environment of high quality farmland construction, the index of rural households' comprehensive willingness consisting of the willingness of farmland quality improvement, adjustment of blocks, and scale of operation was constructed. This paper explored the correction model based on the index of rural households' comprehensive willingness, and the index of cultivated land comprehensive quality was modified in terms of rural households' comprehensive willingness. According to the grades of cultivated land comprehensive quality and the data of rural households' comprehensive willingness, the patterns of "comprehensive quality-comprehensive willingness" of high farmland construction could be obtained. The comprehensive suitability for time sequence and zone partition of high quality farmland construction and the concrete project of construction were discussed by using the diagnosis model and the combination of relative limited types. At last, on the platform of the investigation on rural households' comprehensive willingness, Quzhou county was used as a case study. Conclusions from the study can be drawn as: 1) The global spatial autocorrelation of cultivated land comprehensive quality was significant at 0.05 confidence level. The spatial clustering phenomenon about cultivated land comprehensive quality appeared on the whole. Aimed at cultivated land comprehensive quality, the suitable area of high quality farmland construction was 22472.84 hm<sup>2</sup>, which accounted for 47.87 % of the studied area. There were 1298 construction blocks that were suitable for high quality farmland construction. These blocks were in three towns, Anzhai, Disituan and Baizhai; 2) The study zones were divided into three patterns, high quality-low willingness (HQ - LW), low quality-high willingness (LQ - HW), and medium quality-medium willingness(MQ-MW); 3) The recent construction of high quality farmland should be arranged in zone one and the main directions were land leveling project and land block adjustment. The area of comprehensive suitability zone one was 13714.22 hm<sup>2</sup>, accounted for about 29.22% of the studied area. The comprehensive suitability zone two was mainly located in Nanliyue and Houcun. Land fertility level and organic matter were main limiting factors. The long-term construction should focus on the comprehensive suitability zone three. Leading limitation types were infrastructure in cropland and land fertility level. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Quality control
Controlled terms:Biogeochemistry - Biological materials - Farms - Geographic information systems - Hierarchical systems - Land use - Organic compounds - Rural areas - Spatial variables measurement - Zoning
Uncontrolled terms:Comprehensive qualities - Evaluation index system - Exploratory spatial data analysis - Limited types - Quzhou county - Rural households - Spatial analysis tools - Spatial autocorrelations
Classification code:403 Urban and Regional Planning and Development - 461.2 Biological Materials and Tissue Engineering - 481.2 Geochemistry - 723.3 Database Systems - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3 Quality Assurance and Control - 943.2 Mechanical Variables Measurements - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.08.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 39>
Accession number:20152100877545
Title:Changes in soil surface microrelief of purple soil under different slope gradients and its effects on soil erosion
Authors:Zheng, Zicheng (1); Qin, Feng (1); Li, Tingxuan (1)
Author affiliation:(1) College of Resources, Sichuan Agriculture University, Chengdu, China
Corresponding author:Zheng, Zicheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:168-175
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil surface microrelief is a key parameter which influences many processes of soil erosion and runoff. In order to clarify the effect of soil surface roughness on soil erosion in purple hilly areas of Sichuan, from the perspective of the surface roughness combined with the multifractal theory and method, the indoor artificial rainfall experiments were conducted to study the change of soil surface microrelief under different slope gradients. On that basis, the relationship between soil surface microrelief and soil erosion was explored. The results showed that: 1) Under the rainfall intensity of 1.5 mm/min and rainfall duration of 40 min, the variations of relative elevation were -11.66, -3.52 and -5.61 mm respectively for the slope gradients of 10°, 15° and 20°. After rainfall, there was not remarkable rill under the slope gradients of 10° and 15°, however, the initial low-depression parts of the soil surface formed the rill by runoff scouring under the slope gradient of 20°. After rainfall, soil surface roughness decreased in different slope positions (i.e. upslope, middle slope and downhill) under the slope gradients of 10° and 15°. However, soil surface roughness increased at the bottom of the slope when the slope gradient was 20°. For the whole slope surface, soil surface roughness decreased under different slope gradients after rainfall, and the proper order of the decreasing range was 15°>10°>20°. 2) The singular index span of soil surface microrelief increased by 2.81% and 12.90% respectively under the slope gradients of 10° and 15° in the course of the rainfall, which indicated that the spatial differentiation of soil surface microrelief increased. The singular index span of soil surface microrelief decreased by 3.57% under the slope gradient of 20° in the course of the rainfall, indicating that the spatial differentiation of soil surface microrelief decreased. Soil surface microrelief showed the certain multifractal characteristics. Under the different slope gradients, multifractal singular spectrum function showed a "left hooked" profile. The fractal dimension span, the singular index span and the difference in the numbers of minimum and maximum subsets of probability were sensitive indices to describe the space variation of soil surface microreilief. After rainfall, the multifractal parameters of soil surface microrelief increased, and the difference in space variation of the soil surface microrelief enhanced under the slope gradients of 10° and 15°, for under the two slope gradients, the relative elevation of soil surface was mainly increasing, and soil crust and deposition played a prominent role. Under the slope gradients of 20°, the relative elevation of soil surface was mainly decreasing, and rill was developed. The spatial heterogeneity of soil surface had been strengthened and soil surface became smooth and fruity under the slope gradients of 10°and 15°. However, the changes on the slope gradients of 20° were contrary to the slope gradients of 10°and 15°. 3) The runoff-yielding time under the slope gradient of 20° was the earliest, followed by 10°, and 15° was the latest. The surface runoff amount at first decreased and then increased with the increasing of the slope gradient, and the smaller the amplitude of soil surface roughness, the higher surface runoff volume. However, the sediment yield increased significantly with the increasing of the slope gradient. In the late rainfall, sediment yield rate under the slope gradients of 10° was relatively low but surface runoff rate was higher than those of the other slope gradients. Under different slope gradients, the sediment yield rate increased rapidly and then decreased, and reached a steady state finally. From this, the effect of soil surface microrelief on surface runoff volume was relatively strong, and slope gradient was the main factor of affecting sediment yield. This study provides a reference for revealing the essential characteristics and mechanism of soil surface microrelief in the process of water erosion. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Surface roughness
Controlled terms:Erosion - Fractal dimension - Fractals - Landforms - Rain - Runoff - Sediments - Soils
Uncontrolled terms:Essential characteristic - Microrelief - Multifractal characteristics - Multifractal parameters - Purple soils - Slope gradients - Soil surface roughness - Spatial differentiation
Classification code:443.3 Precipitation - 444.1 Surface Water - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 921 Mathematics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.08.025
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 40>
Accession number:20152100877548
Title:Remote sensing monitoring of changes in winter wheat area in North China Plain from 2001 to 2011
Authors:Wang, Xue (1); Li, Xiubin (1); Tan, Minghong (1); Xin, Liangjie (1)
Author affiliation:(1) Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; (2) University of Chinese Academy of Sciences, Beijing, China
Corresponding author:Li, Xiubin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:190-199
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The North China Plain is the major producing area for winter wheat in China. It is also amongst the global hotspots in terms of severe water scarcity. The monitoring and mapping of winter wheat in an efficient and accurate manner is of great significance for effective policy management on both agriculture and water resources in the North China Plain. Remote sensing technology has been proved to be a practical and feasible method for agricultural crop area extraction in previous researches. In this study, a multi-source remote sensing monitoring system was built, in order to quickly and accurately extract the spatial and temporal information of winter wheat in the North China Plain. Specifically, a spectral curve library for winter wheat was constructed, using MODIS EVI time-series data and two TM images in 2011; and the uniform rules were formulated for the identification of winter wheat, with the combination of phenology calendar in each province in the North China Plain. The spatial and temporal changes of areas planting with winter wheat in 2001-2011 in the North China Plain were extracted using the above uniform rules, and its patterns were analyzed at the grid level, the county level and the province level, respectively. The results showed that: 1) The classification accuracy of winter wheat extracted by the multi-source remote sensing monitoring system was good at the grid scale, and the overall accuracies were stable in 2001-2011, with the values ranging between 74.80% in 2001 and 78.14% in 2011; at the county level, area planting with winter wheat extracted by the multi-source remote sensing monitoring system in 2011 agreed well with the statistics, with the determination coefficient R<sup>2</sup> of 0.89 and the root mean square error RMSE of 1.29×10<sup>4</sup> hm<sup>2</sup>; the error between the above two data sets was 11.31% in 2011. 2) Area planting with winter wheat in the North China Plain continued to increase in 2001-2011, and it was 156.05×10<sup>4</sup> hm<sup>2</sup> (14.96%) more in 2011 than that in 2001; in 2001-2006, areas planting with winter wheat all increased in four provinces including Shandong, Henan, Jiangsu and Anhui, and it continued to increase in Shandong and Henan in 2006-2011, while weak reductions occurred in Jiangsu and Anhui at the same time; in comparison, areas planting with winter wheat all represented significant decline in volatility in 2001-2011 in Beijing, Tianjin and Hebei. 3) There was an obvious "increase in the south and decrease in the north" pattern for spatial and temporal changes of areas planting with winter wheat in 2001-2011 across the North China Plain; the spatial expansions of winter wheat were mainly spotted in the middle and southern part of the North China Plain, including the Southwest Shandong Plain, the Jiaolai Plain, the East Henan Plain and the North Anhui Plain, while shrinkages of winter wheat were mainly found in the northern part of the North China Plain, including the plain areas of Beijing, Tianjin and Hebei. The spatial pattern of changes in areas planting with winter wheat could be attributed to the spatial heterogeneity of water resources, and it was also likely to be associated with the increasing opportunity cost of agricultural labor forces, the benefit changes of winter wheat and the agricultural subsidy policy. However, the major driving forces and their driving mechanisms deserved deep analysis. This study can provide useful information for decision makings on crop planting structure adjustment, food security guarantee and water management optimization, and can also be used as a reference for large-scale and long-time monitoring of spatial and temporal information of crop planting areas with remote sensing data as the main data source. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Monitoring
Controlled terms:Agriculture - Classification (of information) - Crops - Decision making - Error statistics - Food supply - Information management - Mean square error - Remote sensing - Water management - Water resources
Uncontrolled terms:Agricultural subsidy policies - Determination coefficients - North China Plain - Remote sensing monitoring - Remote sensing technology - Spatial and temporal changes - Spatial-temporal changes - Spectral curves
Classification code:404.2 Civil Defense - 444 Water Resources - 716.1 Information Theory and Signal Processing - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 912.2 Management - 922.2 Mathematical Statistics - 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.1002-6819.2015.08.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 41>
Accession number:20152100877540
Title:Biological traits on corn straw interlayer in improving saline-alkali soil
Authors:Fan, Fu (1); Zhang, Qingguo (1); Tai, Jicheng (1); Hou, Mihong (1); Sun, Dezhi (1); Wang, Shanshan (1); Zhang, Jianan (1)
Author affiliation:(1) College of Agronomy, Inner Mongolia University for Nationalities, Tongliao, China
Corresponding author:Fan, Fu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:133-139
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Many measures have been adopted to improve saline-alkali soil in recent years, but the effects of different measures have advantages and disadvantages. Water conservancy facilities improve quickly and effectively, but the cost is high. Chemical modifiers are palliatives and not conducive to the sustainable development. It is necessary to explore a better measure to improve saline-alkali soil. It is easy for crop straw to cut off the continuity of the capillaries and partition the phreatic evaporation. The salt accumulation has been prevented in the surface of soil and a good physical and chemical soil environment is created for the crops to the normal growth and development. And burying straw into soil also prevents the salt in the deeper soil to return to the surface layer. Tongliao City is the corn production base in Inner Mongolia Autonomous Region and even the whole nation. The corn planting area is more than 1 100 000 hm<sup>2</sup> every year, and there is wide source and large storage capacity of corn straw. It is necessary to study the effect of corn straw interlayer on improving saline-alkali soil. In the experiment, corn straw interlayer was made in different soil depths (10,15 and 20 cm) and different dosages (30 000, 45 000 and 60 000 kg/hm<sup>2</sup>) using corn stalks in saline-alkali soil. The soil was collected from Huatugula, Tongliao City in 2008 and then the barley was planted in the soil from 2009 to 2011. The paper studied the microorganism number and the enzyme activity in saline-alkali soil, and the impact of corn stalk isolation layer on saline soil's biological traits and barley yield. The results showed that the numbers of bacteria, actinomycetes, fungi, nitrite bacteria and cellulolytic bacteria, and the activities of urease, protease, amylase, cellulase and catalase significantly increased (P<0.01), while polyphenol oxidase activity reduced in alkali soil with corn straw interlayer (P<0.01). With the increasing of corn stalks' quantity, the numbers of microorganisms and the activities of urease, protease, amylase and polyphenol oxidase all increased (P<0.01), while the activities of cellulase and catalase did not change significantly. With the increasing of corn stalks' burying depth, the numbers of microorganisms and the protease activity both reduced (P<0.01), while polyphenol oxidase activity increased (P<0.01) and other enzymes' activities did not change significantly. As the time increased, the numbers of microorganisms and the activities of enzymes in saline-alkali soil increased significantly (P<0.01). The treatment A<inf>3</inf>B<inf>1</inf> (straw dosage of 60 000 kg/hm<sup>2</sup>, burying depth of 10 cm) reached the highest activity for 6 kinds of enzymes and the highest yield of 1914 kg/hm<sup>2</sup>. The treatment A<inf>3</inf>B<inf>1</inf> was the optimum of all treatments. Corn straw as the resource with advantage can be used for improving saline-alkali soil, which is of great significance to the protection of the ecological environment, the expansion of the grain growth and the revitalization of the rural economy in Tongliao City. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Soils
Controlled terms:Amylases - Bacteria - Crops - Enzyme activity - Enzymes - Grain growth - Microbiology - Microorganisms - Straw - Sustainable development - Water management
Uncontrolled terms:Cellulolytic bacterium - Corn stalk - Ecological environments - Inner Mongolia autonomous regions - Interlayer - Protease activities - Saline-alkali soils - Soil enzyme activity
Classification code:444 Water Resources - 446 Waterworks - 461.9 Biology - 461.9.2 Microbiology - 483.1 Soils and Soil Mechanics - 804.1 Organic Compounds - 821.4 Agricultural Products - 821.5 Agricultural Wastes - 911.2 Industrial Economics - 933.1.2 Crystal Growth
DOI:10.3969/j.issn.1002-6819.2015.08.020
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 42>
Accession number:20152100877538
Title:Fuzzy anti-slip control based on optimal slip control
Authors:Feng, Yanbiao (1); Yang, Jue (1); Ji, Zhiyi (1); Zhang, Wenming (1)
Author affiliation:(1) School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
Corresponding author:Yang, Jue
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:119-125
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The slip phenomenon is common for heavy truck which is starting. This paper develops the anti-slip control strategy based on optimal slip rate, and the ASR (anti-slip regulation) is applied to heavy truck. In this paper, the speed is estimated by the acceleration; the wheel rotation speed can be easily got because the alternating current motor speed is easy to monitor; and then the slip rate is known. The fuzzy controller's knowledge bank is designed based on references' theory and engineering experience. At the same time, the SPWM (sinusoidal pulse width modulation) model is built. In the SPWM model's inner ring, the torque is positively related to the current. And the torque can be adjusted, so the current can be modified, and the motor output torque can be rectified. If the motor output torque is adjusted, the torque which is input to the wheel is increasing or decreasing correspondingly. So the driving torque on wheel can be balanced with the resistance torque on wheel, which means the truck can operated at a steady state. The fuzzy control system adjusts the torque distribution of the wheel-motors to maintain the optimal slip rate. The system is modeled with Matlab/Simulink software. Using this model, serial tests are simulated on various terrains including the road with low attachment coefficient, the bisectional road and the joint road. In the road with low attachment coefficient, the slip rate without control is very high that can reach 1, which means the wheel is rotating but truck wouldn't move. After applying the control, the slip rate can stabilize at a given reference value. Meanwhile, the attachment coefficient can be controlled at an optimal level. In the bisectional road, the slip rate is ideal when the truck's wheel is at the side of the road with high attachment coefficient; but when the truck moves into the road with low attachment coefficient, the slip rate sharply increases. At this moment, the truck can't ensure the direction of stability. So the danger coefficient is high. But the slip rate with control is stabilized at a given value. The result shows that the fuzzy control system can raise the utilization attachment coefficient and improve the power, stability and safety. Finally, to verify the controller's feasibility and calculation efficiency, the hardware-in-loop (HIL) simulation system is implemented. The national instrument (NI) embedded system is used. The truck's model that includes the dynamic model and the AC motor's control model is operated in PXI8110. And the control algorithm is running in CompactRIO-9024 which is an excellent controller to simulate the real-time situation. All the simulation operations are run again in the HIL system, and the road with low attachment coefficient, the bisectional road and the joint road are included. In the HIL simulation, the shapes of slip rate curve and attachment coefficient curve are consistent with the simulation results in Matlab/Simulink. The real-time simulation result shows that the slip rate and attachment coefficient can be quickly stabilized at an optimal level. But the response time is really different. For example, the simulation time in Matlab/Simulink is much more than the HIL time. The HIL simulation system's advantage is that not only the simulation time is much less than the Matlab/Simulink but also the response time is much less. On the other hand, the response time is short, which means that the HIL simulation system has a more perfect real-time performance. In short, the real-time performance of the fuzzy control algorithm has been proved. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Electric machine control
Controlled terms:AC motors - Airships - Algorithms - Computer simulation - Control - Control systems - Controllers - Electric machine theory - Fuzzy control - Fuzzy systems - MATLAB - Pulse width modulation - Research aircraft - Response time (computer systems) - Roads and streets - Torque - Traction control - Transportation - Trucks - Vehicles - Voltage control - Wheels
Uncontrolled terms:Alternating current motors - Attachment coefficient - Calculation efficiency - Matlab/Simulink software - Optimal slip - Real time simulations - Sinusoidal pulse width modulation - Wheel motors
Classification code:406.2 Roads and Streets - 421 Strength of Building Materials; Mechanical Properties - 432 Highway Transportation - 601.2 Machine Components - 652.1 Aircraft, General - 652.5 Balloons and Gliders - 663.1 Heavy Duty Motor Vehicles - 705.1 Electric Machinery, General - 705.3.1 AC Motors - 716 Telecommunication; Radar, Radio and Television - 722.4 Digital Computers and Systems - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 732 Control Devices - 732.1 Control Equipment - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.08.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 43>
Accession number:20152100877563
Title:Effect of surface adsorption of microfiltration for magnetized sugarcane mixed juice on model of mass transfer
Authors:Ma, Sen (1); Gao, Junyong (2)
Author affiliation:(1) College of Grain Oil and Food Science, Henan University of Technology, Zhengzhou, China; (2) Guangzhou Sugarcane Industry Research Institute, Guangdong Key Lab of Sugarcane Improvement & Biorefinery, Guangzhou, China
Corresponding author:Ma, Sen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:296-301
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Chemical substances such as lime, phosphate and sulfur dioxide are needed in the sugar refinery process, resulting in high COD (chemical oxygen demand) of factory sewage and high cost. Membrane technology has the advantages of low energy consumption, no phase change and molecular screening, which may improve the clarification effect of mixed sugar juice and reduce the chemical adding quantity. However, the concentration polarization phenomenon causes the decrease of membrane flux, so a more effective method is needed in order to improve the membrane process for the clarification of sugar mixed juice. Magnetic field combined with microfiltration process is a key issue in recent years, but there are few researches about the proper mass transfer phenomenon. So, the mass transfer modeling of microfiltration process for magnetic cane mixed juice was studied in this paper. By analyzing the mechanism of mass transfer process on the membrane surface, the mass transfer model of microfiltration was deduced according to the theory of osmotic pressure and gel layer. However, the sugar cane mixed juice suffered different adsorption effects on the membrane surface and concentration polarization layer. The forming trend of the adsorbed layer on the membrane surface had close relationship with its surface properties. Therefore, adsorption effect was considered in the process of deducing model. The mass transfer modeling of microfiltration process for magnetic cane mixed juice was deduced at two important cases under the optimum magnetic conditions. Without considering the adsorption of membrane surface layer, the mass transfer coefficient of 0.45 µm ceramic microfiltration membrane for separation was -81.406, the regression equation was significant, and the value of R<sup>2</sup> was 0.921. While the mass transfer coefficient of 0.20 µm ceramic microfiltration membrane for separation was -83.130, the regression equation was significant, and the value of R<sup>2</sup> was 0.920. When considering the adsorption of membrane surface layer, the mass transfer coefficient of 0.45 µm ceramic microfiltration membrane for separation was -323 254.006 and the adsorption coefficient was 0.995. Its regression equation was significant, and the value of R<sup>2</sup> was 0.939. The mass transfer coefficient of 0.20 µm ceramic microfiltration membrane for separation was 573281.937 and the adsorption coefficient was 0.994. Its regression equation was significant, and the value of R<sup>2</sup> was 0.999. Both membranes were affected by the concentrations of the main flow and penetrating fluid, and the membrane surface adsorption. Retest results of model showed that the calculation results and error rates of two mass transfer models in which the adsorption process was considered were better than that without considering the adsorption process. The solid particles accumulated on the membrane surface to form the filter cake, and the filtrate moved between the filter cake and the channel of membrane tube through the pressure difference across the membrane and solute concentration difference. When membrane flux was stable, the absorption between solute and solution achieved a balance, which made a higher accuracy and a lower error rate for the models. All results showed that the mass transfer model containing the adsorption of membrane surface was suitable for the separation process of 0.45 and 0.20 µm membrane. This study is helpful for the improvement of membrane separation equipment, and the optimizing of operating conditions. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Mass transfer
Controlled terms:Adsorption - Ceramic materials - Chemical oxygen demand - Clarification - Clarifiers - Energy utilization - Filtration - Magnetism - Membrane technology - Membranes - Microfiltration - Models - Osmosis - Polarization - Regression analysis - Sewage - Sugar cane - Sugar factories - Sulfur dioxide
Uncontrolled terms:Adsorption coefficients - Ceramic micro-filtration membranes - Concentration polarization - Low energy consumption - Magnetized sugarcane mixed juice - Mass transfer modeling - Mass transfer phenomena - Solute concentrations
Classification code:402.1 Industrial and Agricultural Buildings - 453 Water Pollution - 453.1 Water Pollution Sources - 525.3 Energy Utilization - 641.3 Mass Transfer - 701.1 Electricity: Basic Concepts and Phenomena - 701.2 Magnetism: Basic Concepts and Phenomena - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 804.2 Inorganic Compounds - 812.1 Ceramics - 821.4 Agricultural Products - 902.1 Engineering Graphics - 922.2 Mathematical Statistics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.08.043
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 44>
Accession number:20152100877535
Title:Wavelet energy features of acoustic emission signals under centrifugal pump cavitation conditions
Authors:Liu, Zhong (1); Zou, Shuyun (1); Li, Zhipeng (1); Ju, Wei (1)
Author affiliation:(1) School of Energy and Power Engineering, Changsha University of Science and Technology, Changsha, China
Corresponding author:Liu, Zhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:99-103
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the development of Acoustic Emission (AE) techniques, researches on the AE signals emitted during the cavitation process to judge whether the cavitation has occurred or not and its development degrees are getting more and more attentions. However, the frequency distribution features and their variation laws with the cavitation states of centrifugal pumps remain to be further studied. In this paper, the wavelet energy features of the AE signals under the cavitation conditions of a centrifugal pump were extracted with the wavelet analysis method, and the variation laws of these features were also revealed. Firstly, the cavitation processes of the centrifugal pump with constant flows and constant speeds at the 60%, 100% and 120% rated flow respectively were simulated on an open centrifugal pump test bench. Each cavitation process included such different stages as no cavitation, cavitation just appearing and cavitation developed with different degrees. Simultaneously, the corresponding operational parameters of the centrifugal pump and the AE signals emitted near the inlet and outlet casing of the centrifugal pump were collected. Based on the calculation of the heads H and the net positive suction heads NPSH, the cavitation curves with different flows were obtained. Secondly, the AE signal energy feature extraction method based on wavelet analysis was studied, so as to obtain the specific frequency bands' absolute energies and relative ones. Then, taking the 60% rated flow as an example, five typical operating points on the curves were selected and marked as A, B, C, D and E, representing different cavitation stages. The five-layer decomposition and the soft threshold denoising with the mother wavelet db5 were implemented on the AE signals near the inlet and outlet casing of the centrifugal pump corresponding each operating point. These AE signals were divided into six frequency bands, i.e. 0-31.25, >31.25-62.5, >62.5-125, >125-250, >250-500 and >500-1 000 kHz, and the absolute energy and the relative one in each band were calculated. Finally, the relation curves of these energies with NPSH from the operating point A to E were compared and the variation rules were analyzed in details. The results showed that the AE signals' absolute energies in the whole frequency band near the inlet and the outlet casing of the centrifugal pump varied both obviously with the changes of NPSH. With the cavitation developing from nothing to serious degrees, the NPSH values remained unchanged firstly then fell sharply, after that increased gradually and finally closed to the values before the occurrence of cavitations. However, the changes of the AE signals' absolute energies in the six frequency bands were not identical. The absolute energies in 31.25-62.5, >62.5-125 and >125-250 kHz varied obviously with the cavitation stages in the same way to the absolute energy in the whole frequency band, while those in the 0-31.25, >250-500 and >500-1 000 kHz bands changed very little. It can be inferred that the 0-31.25 kHz band corresponded to the background noises due to the fluid motion and the interaction between the fluid and the mechanical components of the centrifugal pump, and the latter two higher frequency bands corresponded to the electromagnetic noises and other random noises in the test field. The components of these three frequency bands were irrelevant to the cavitation states. Therefore, the absolute energy changed in the frequency bands such as 31.25-62.5, >62.5-125 and >125-250 kHz can reflect the cavitation states directly, which should be paid more attentions. Moreover, the relative energies in the 31.25-62.5 kHz band for both AE signals kept unchanged during the cavitation process, while those in the 62.5-125 and >125-250 kHz bands varied obviously. These wavelet energy variation laws can serve as a technical reference for identifying cavitation stages of centrifugal pumps. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:12
Main heading:Cavitation
Controlled terms:Acoustic emissions - Acoustic noise - Centrifugal pumps - Feature extraction - Frequency bands - Pumps - Signal processing - Wavelet analysis - Wavelet decomposition
Uncontrolled terms:Acoustic emission signal - Acoustic emission techniques - Energy feature - Frequency distributions - Net positive suction heads - Operational parameters - Wavelet analysis method - Wavelet energy feature
Classification code:618.2 Pumps - 631.1.1 Liquid Dynamics - 716 Telecommunication; Radar, Radio and Television - 751.2 Acoustic Properties of Materials - 751.4 Acoustic Noise - 921 Mathematics - 921.3 Mathematical Transformations
DOI:10.3969/j.issn.1002-6819.2015.08.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
<RECORD 45>
Accession number:20152100877526
Title:Design and test on 4B-1200 type bulbus fritillariae ussuriensis medicinal material harvester
Authors:Song, Jiang (1); Qiu, Shenglan (2); Wang, Xinzhong (1)
Author affiliation:(1) Heilongjiang Bayi Agricultural University, Daqing, China; (2) Cavaville Energy Services Ltd, Beijing, China
Corresponding author:Song, Jiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:8
Issue date:April 15, 2015
Publication year:2015
Pages:34-41
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Bulbus fritillariae ussuriensis is one of the fritillaria medical drugs. The bulbs of fritillary belong to lilaceous perennial herbaceous plants, and the underground bulbs are the medicinal part with very high medicinal value. Bulbus fritillariae ussuriensis is not only the relatively rare traditional Chinese medicinal material, but also the important Chinese export commodity, so it is quite popular on the market at home and abroad. Bulbus fritillariae ussuriensis mainly grows in the eastern mountain foothills such as Heilongjiang, Jilin, Liaoning Province, and the traditional manual harvesting of bulbus fritillariae ussuriensis is with big labor intensity and low efficiency, which leads to economic loss. Therefore, developing the small medicinal materials harvester of bulbus fritillariae ussuriensis is the priority of bulbus fritillariae ussuriensis production. Herbalists are keen to use mechanization technology to replace the heavy physical labor, reduce labor intensity, increase the harvest productivity and their income, and promote the local economic development. So, aiming at the above problems, the research team has been dedicated to the research on the fritillaria mechanical harvesting, focusing on the two key technologies containing level screening and mining technology of bulbus fritillariae ussuriensis. Sectional terms of mechanized harvesting method had been proposed in the past, and correspondingly level screening machinery and excavator of bulbus fritillariae ussuriensis had been developed, but the efficiency was low and the production cost was relatively high, so in order to solve these problems above, the fritillaria harvester matched with a walking tractor is designed in this study. The machine mainly consists of a scraping mechanism, a digging shovel, a vibration screen, below-sift separate shellfish and soil mechanism, bagging apparatus, transmission system, frame, land wheels and other key components. It is obtained by formula derivation that the width of bulldozing shovel is 1400 mm, the height of bulldozing shovel wing is 500 mm, the shovel wing surface radius is 400 mm, the shovel wing plane width is 120 mm, the shovel wing angle is 120°, the breaking ground angle is 65°, and the forward turning angle is 75°; and the shovel surface width of digging shovel is 1200 mm, the level inclination of shovel surface is 26°, the shovel surface is 140 mm long, the spacing of digging shovel's end grid is 8 mm, and the grid length is 40 mm. By analyzing the four-bar mechanism based on analytical graphic method, it is determined that the speed range of vibration sieve crank is 240-535 rad/min and within this range the mixture of bulbus fritillariae ussuriensis and soil can pass successfully. It is shown by the force analysis of the reverse spiral blade that the spiral blade speed of soil separating part below sieve is less than 4 m/s. By means of UG (Unigraphics NX) software, the three-dimensional model of bulbus fritillariae ussuriensis medicinal materials harvester is programmed to assemble the parts and analyze the feasibility of the structure design, on the basis of which the experiment prototype is produced. The field experiments show that the matching dynamic of bulbus fritillariae ussuriensis is the walking tractor with 13.2 kW, the damage rate is less than 4.1% and the loss rate is less than 4.9%. All the indices are in accord with the industry standard regulations. The below-sieve transportation spiral of shellfish and soil can separate shellfish and soil to two sides of border check surface. The study can provide a technical reference to research bulbus fritillariae ussuriensis medicinal materials harvester at product level. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Shovels
Controlled terms:Design - Diagnosis - Economic and social effects - Graphic methods - Harvesters - Harvesting - Losses - Machine components - Machinery - Mechanisms - Mechanization - Medical applications - Plants (botany) - Separation - Shellfish - Sieves - Soils - Tractors (truck) - Vibration analysis - Vibrations (mechanical)
Uncontrolled terms:Bulbus fritillariae ussuriensis - Digging shovels - Local economic development - Mechanized harvesting - Spiral blades - Three-dimensional model - Transmission systems - Vibration creen
Classification code:408 Structural Design - 461 Bioengineering and Biology - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 605 Small Tools and Hardware - 605.2 Small Tools, Unpowered - 663.1 Heavy Duty Motor Vehicles - 802.3 Chemical Operations - 821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods - 902.1 Engineering Graphics - 911.2 Industrial Economics - 931.1 Mechanics - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.08.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
- 邮编 100125
- 电话 010－59197078/7077/7076
- 邮箱 tcsae@tcsae.org
微信公众号
二维码
友情链接
- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
- 中华人民共和国农业农村部-MARA
- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
- 期刊界
- CNKI
- 万方数据
- 维普