<RECORD 1>

Accession number:20132916508777
Title:Analysis of handling stability for electric-driven articulated truck
Authors:Shen, Yanhua (1); Li, Yanhong (1); Jin, Chun (1)
Author affiliation:(1) School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China
Corresponding author:Shen, Y.(yanhua_shen@ces.ustb.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:71-78
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Articulated steering trucks have two separate parts that are connected by an articulation joint. The articulated joint will decrease the lateral stability of truck while it drives at higher speeds. The electric-driven articulated truck discussed in this paper is composed of a diesel engine, generator, rectifier, inverter, and in-wheel-motor, among other components. It is driven by a diesel engine and in-wheel-motor with an AC-DC-AC driving mode. Each wheel of the truck is mounted with one in-wheel-motor, which can be driven independently. All-wheel independent drive systems of articulated trucks have some advantages, such as being space-saving, having a fast driving response time, and having accurate control of the driving forces on each wheel. This paper proposes a direct yaw-moment control (DYC) method to enhance the stability behaviors of articulated vehicles for the each wheel to be controlled independently. The modified 3 DOF vehicle dynamics model is built based on the structural features of the articulated steering truck. The feedforward and feedback controller is designed with the mass center slip angle and yaw angular velocity of the front body and the mass center slip angle and yaw angular velocity of rear body set as separate variables. This approach combines the feedforward compensation for the mass center slip angle and yaw angular velocity, and the feedback compensation based on the deflection of real transient output and ideal output of vehicle to control the vehicle movement. The factors of feedforward and feedback compensation are determined by the optimal control strategy based on a linear quadratic regulator (LQR). The two optimal DYC controllers for the yaw stability of articulated vehicles are designed based on the different control variables. The 35 ton electric-driven articulated dump truck was simulated to verify the effectiveness of DYC control strategy for improving the yaw stability of vehicle. The vehicle dynamics simulation model generated by MATLAB/Simulink software is used to perform a transient step response analysis of articulated trucks. The performance of vehicle stability is compared and analyzed from the aspects of response time and accuracy under the two proposed DYC control methods. The values of yaw angular velocity, mass center side slip angle, and lateral acceleration are used to evaluate the lateral dynamics performance of articulated truck. The computer simulation results show that the two control strategies are feasible and correct. Both of them can realize the control target on enhancing articulated truck stability. The controlling effects of these two DYC methods on the articulated truck are compared from the aspects of yaw rate and mass center slip angle simultaneously. The simulation results suggest that the dynamic stability behavior of articulated trucks with the optimal DYC control acting on the front body is better than that of the optimal DYC control on the rear body.
Number of references:22
Main heading:Trucks
Controlled terms:AC generator motors - Angular velocity - Automobile bodies - Automobile steering equipment - Automobiles - Computer simulation - Control - Convergence of numerical methods - Diesel engines - Electric rectifiers  - Optimal control systems - Optimization - Stability - Steering - Vehicles - Wheels
Uncontrolled terms:Articulated dump trucks - Direct yaw moment control - Feed-forward compensation - Linear quadratic regulator - Matlab/Simulink software - Optimal control strategy - Transient step response - Vehicle dynamics simulation
Classification code:961 Systems Science - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 732 Control Devices - 801 Chemistry - 921.5 Optimization Techniques - 921.6 Numerical Methods - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science - 714.2 Semiconductor Devices and Integrated Circuits - 432 Highway Transportation - 601.2 Machine Components - 612.2 Diesel Engines - 705.3.1 AC Motors - 662.1 Automobiles - 663.1 Heavy Duty Motor Vehicles - 663.2 Heavy Duty Motor Vehicle Components - 662.4 Automobile and Smaller Vehicle Components
DOI:10.3969/j.issn.1002-6819.2013.12.010
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 2>

Accession number:20132916508771
Title:Performance test of hand-held electric hole-digger for fertilization in orchard
Authors:Yang, Zhou (1); Chen, Chaohai (1); Duan, Jieli (1); Yan, Guoqi (1); Pan, Xuewen (3); Yan, Liangli (1); Liu, Jialong (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou 510642, China; (2) College of Engineering, South China Agricultural University, Guangzhou 510642, China; (3) Pomology Research Institute, Guangdong Academy of Agricultrural Sciences, Guangzhou 510640, China
Corresponding author:Duan, J.(duanjieli@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:25-31
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to reduce labor intensity and improve efficiency of mechanical hole digger machinery, a portable hand-held electric hole digger was developed to meet the agronomic requirements of watering and fertilization. The operating performance of the developed hand-held electric hole digger was tested, and some main technical parameters of the machine (operational efficiency, noise, vibration acceleration, soil backfilling rate), labor intensity of users, and the economic benefit of usage were selected as the test index. Furthermore, the performance of the electric hole digger was compared with a commonly used hand-held gasoline hole digger. The experimental results showed that: 1) the operational efficiency of the electric hole digger was 76.6 holes/h and the work efficiency of the hand-held gasoline hole digger was 57.3 holes/h, which improved 33.8 percent. 2) The noise of the electric hole digger was 75.45 dB and the noise of the hand-held gasoline hole digger was 100.65 dB under full load working condition, which reduced 25.2dB. 3) The vibration acceleration of left and right hand shanks of the electric hole digger were 34.3 m/s² and 41.8 m/s² and the vibration acceleration of left and right hand shanks of the hand-held gasoline hole digger were 129.4 m/s² and 210.6 m/s² on full load operating condition, which reduced 95.1m/s2 and 168.8 m/s².At the same time, the value of vibration acceleration coefficient variation is bigger for the three identified conditions of the gasoline hole digger, and its vibration is intense. 4) The soil backfilling rate was 7.7% for the electric hole digger and 11.5% for the gasoline hole digger. The performance improvement of the electric hole digger depends on its special features, including portable operation (the machine weighs 15 kg), lower noise (the noise level of full load operating condition was 75.45 dB), smooth operation (the handle vibration acceleration values were 34.3 m/s² in the left handle and 41.8 m/s² in the right handle), and appropriate operating speed (maximum speed 265 r/min); 5). The maximum heart rate of the group operators of the hand-held gasoline hole diggers were 160 bpm, 184 bpm, and 169 bpm, respectively, while the electric hole digger operators were were 157 bpm, 165 bpm, and 143 bpm, respectively. The average heart rate of the group operators of the hand-held gasoline hole digger were 121 bpm, 138 bpm, and 121 bpm, respectively, and the electric hole diggers were 118 bpm, 122 bpm, and 115 bpm, respectively, which reduced 3 bpm, 16 bpm and 6 bpm respectively. 6) The average relative heart rate the operators of the hand-held gasoline hole diggers was 44%, and greater than 40%, the electric hole diggers were 36%. 7) HR<inf>w</inf> 50% level mean that the average heart rate value ratio at the 50% level. If the calculation resulting of HR<inf>w</inf> 50% level value is equal to or greater than 1, it means this work was severe labor intensity; the average value HR<inf>w</inf> 50% level of hand-held gasoline hole diggers was 0.94, the electric hole diggers was 0.88. At the same time, the economic benefit of the two kinds of hole digger was analyzed, and the comprehensive costs were 4645.6 RMB for the electric hole digger and 7888.9 RMB for the gasoline hole digger. These results provide fundamental parameters for the design and development of a new type of hole digger, which will suit the hilly, orchard regions in Southern China.
Number of references:32
Main heading:Gasoline
Controlled terms:Acceleration - Agricultural machinery - Efficiency - Heart - Orchards - Testing
Uncontrolled terms:Design and Development - Electric hole digger - Main technical parameters - Operating performance - Operational efficiencies - Performance improvements - Vibration - Vibration acceleration
Classification code:931.1 Mechanics - 913.1 Production Engineering - 821.3 Agricultural Methods - 821.1 Agricultural Machinery and Equipment - 523 Liquid Fuels - 461.2 Biological Materials and Tissue Engineering - 423.2 Non Mechanical Properties of Building Materials: Test Methods
DOI:10.3969/j.issn.1002-6819.2013.12.004
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 3>

Accession number:20132916508791
Title:Performance testing on warming effect of heat storage-release curtain of back wall in Chinese solar greenhouse
Authors:Liang, Hao (1); Fang, Hui (2); Yang, Qichang (2); Zhang, Yi (2); Sun, Weituo (2)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; (2) Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (3) Key Lab of Energy Conservation and Waster Treatment of Agricultural Structures, Ministry of Agriculture, Beijing 100081, China
Corresponding author:Yang, Q.(yangq@ieda.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:187-193
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The Chinese Solar Greenhouse (CSG), characterized by an east-west orientation, transparent camber south roof, and solid north roof and east and west walls, is utilized primarily in horticulture in northern China. During the day, the CGS stores solar energy through the north wall and soil, and releases it when the inside air temperature is low. Because of limited energy capacity, during cold winter nights, the air temperature can be very low and this considerably decreases crop production. To increase this low nighttime air temperature, a heat collection and storage-release system was studied. This system was installed at Changping District (latitude 39&deg;54' N, longitude 116&deg;24' E), Beijing, China. The CSG was positioned towards the south along a south-north line. The Solar greenhouse was 49 m long, 8 m wide and 3.7 m high. The roof of the greenhouse was covered with polyethylene terephthalate (PET) films. The north wall and sidewalls were made of red brick and polystyrene board (24 cm thickness red brick inner, 10 cm thickness polystyrene board middle and 12 cm thickness red brick outer). During the experimental period from the 15th of November 2012 to the 20th of January 2013, the crop studied was tomato plants, and the covering layer was opened during the daytime (08:30-15:30) and closed during night (15:30-08:30) in sunny days. The results were compared to the nighttime air temperatures in a reference CSG. The system consisted of a solar collector, a heat storage device and a circulation pump. The solar collector was facing south and fixed on the north wall inside the CSG. During daytime, the absorbed solar energy from the system was transferred to the water by the circulation pump. At night, when the greenhouse air temperature dropped below 10&deg;C the system then transferred the low temperature heat from the water to the greenhouse air. The results showed that the average nighttime air temperature in the CSG was 4.6 and 4.5&deg;C higher than that in the reference CSG on cloudy and sunny days, respectively. When the outside air temperature was -12.5&deg;C, the air temperature inside the normal greenhouse was just 5.4&deg;C, while that in the experiment greenhouse was 10.1&deg;C. The average efficiency of the heat storage-release system reached 42.3% and 57.7% on cloudy and sunny days, respectively. Compared with electricity heating equipment, the experiment achieved 51.1% energy savings. The results indicate that the heat storage-release curtain is an effective method to increase the nighttime air temperature in the Chinese Solar Greenhouse.
Number of references:29
Main heading:Greenhouses
Controlled terms:Atmospheric temperature - Brick - Cultivation - Energy conservation - Experiments - Heat storage - Polystyrenes - Roofs - Solar collectors - Solar heating  - Virtual storage
Uncontrolled terms:Average efficiencies - Chinese solar greenhouse - Heat release - Outside-air temperature - Performance testing - Polyethylene terephthalates (PET) - Storage-release system - Walls
Classification code:901.3 Engineering Research - 821.6 Farm Buildings and Other Structures - 821.3 Agricultural Methods - 815.1.1 Organic Polymers - 722.1 Data Storage, Equipment and Techniques - 702.3 Solar Cells - 643.1 Space Heating - 525.7 Energy Storage - 525.2 Energy Conservation - 443.1 Atmospheric Properties - 414.2 Brick Materials - 402.1 Industrial and Agricultural Buildings - 402 Buildings and Towers
DOI:10.3969/j.issn.1002-6819.2013.12.024
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 4>

Accession number:20132916508778
Title:Analysis of liquid flow and axial force calculation in axial clearance for floating impeller of centrifugal pump
Authors:Liu, Zailun (1); Xu, Lizhong (1); Jia, Xiao (1); Wu, Jiao (1); Wang, Dongwei (1)
Author affiliation:(1) College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China; (2) Engineering Institute of Wenzhou Pump and Valve, Lanzhou University of Technology, Wenzhou 325105, China
Corresponding author:Wang, D.(Wangdongweibaby123@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:79-85
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Axial thrust balancing device is an important component for centrifugal pump stable operations. In special, the impeller which arranged in the same direction for segmental type pump and high head submerged (oil) pump is able to bring prodigious axial force. If excessive axial force exist in pump, it will cause safe accident, and influence work, and result in enormous economic expense. The floating impeller which integrated balance holes and the balance disc together is a new technology of balancing axial force automatically in the centrifugal pump. This technology has been applied in individual pumps with a significant and feasible effect, but it is still in its infancy which mainly concentrated on the introduction of principle and structure. In order to investigate the relationship of the fluid leakage, fluid pressure and the axial force on the stainless steel disc under different axial displacement, the flow characteristics in the radial and axial clearance on the back cover plate of floating impeller were analyzed. Fluid flow in radial clearance was simplified as viscous laminar flow of parallel plate model, and the fluid flow in axial clearance was simplified as 2D axisymmetric viscous laminar flow. Due to the equality the fluid leakage in radial and axial clearance, the mathematical expression of the fluid leakage, the fluid pressure and the axial force on the stainless steel disc in the axial clearance were obtained. The curves of the fluid leakage and the axial force on the stainless steel disc with the axial clearance were drawn by the calculation of the design example. The curves showed that the fluid leakage increased and the axial force on the stainless steel disc decreased with the increase of axial clearance, and these curves were relatively flat when the axial clearance was above 0.8 mm. From the perspective of reducing leakage, the smaller the axial clearance, the better. But a small axial clearance would cause the sharp variation of the lubrication and the cooling condition in axial clearance, and sintering phenomenon between the stainless steel plate and graphite disc. Therefore, in order to control the fluid leakage and reduce the axial force, the appropriate axial clearance was from 0.4 to 0.8 mm. When stainless steel disc and graphite disc were uninstalled in the centrifugal pump, the axial force in the balance cavity was calculated. According to the comparative analysis, the floating impeller could obviously reduce the axial force. This research provides a reference for the study of floating impeller in centrifugal pumps.
Number of references:26
Main heading:Axial flow
Controlled terms:Axial loads - Centrifugal pumps - Graphite - Impellers - Laminar flow - Plates (structural components) - Pumps - Sintering
Uncontrolled terms:Axial clearance - Axial displacements - Comparative analysis - Flow charac-teristics - Mathematical expressions - Sintering phenomenon - Stainless steel discs - Stainless steel plate
Classification code:631.1 Fluid Flow, General - 618.2 Pumps - 601.2 Machine Components - 804 Chemical Products Generally - 536.1 Powder Metallurgy Operations - 408.2 Structural Members and Shapes - 408 Structural Design - 421 Strength of Building Materials; Mechanical Properties
DOI:10.3969/j.issn.1002-6819.2013.12.011
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 5>

Accession number:20132916508800
Title:Improving accuracy of prediction model for soluble solids content of watermelon by variable selection based on near-infrared spectroscopy
Authors:Jie, Dengfei (1); Xie, Lijuan (1); Rao, Xiuqin (1); Ying, Yibin (1)
Author affiliation:(1) Land Use and Technology Department, China University of Geosciences (Beijing), Beijing 100083, China; (2) University of Chinese Academy of Sciences, Beijing 100049, China
Corresponding author:Ying, Y.(yingyb@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:264-270
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Fruit internal quality is an important indicator in the fruit grading, preservation and storage stage; rapid non-destructive detection of fruit internal quality can improve the marketable value of watermelon. Near infrared spectroscopy (NIRS) is a powerful technology with the virtue of the convenience and accuracy. This work focused on soluble solids content (SSC) determination of the Qilin watermelon. On basis of the NIRS, we adopted a near-infrared diffuse transmittance technique. We used the home-built measurement system with a fiber optic spectrometer to acquire the spectra. Partial least squares regression (PLSR), multiple linear regression (MLR) and principal component regression (PCR) were used to establish mathematical models. In order to improve the predictive models, firstly, variables were reduced by the interval spectral average method and the interval spectral extraction method, respectively. Further model optimization was carried out by a successive projections algorithm (SPA). The results showed that the PLSR models with 115 variables obtained by an interval of 5 in 574 variables were the best one in first step. Different pretreatments were employed using the 115 variables. By comparison of the results of the PLSR models with different pretreatment, we adopted the normalization pretreatment as the input of SPA algorithm, six optimal wavelengths (702.32, 713.68, 732.58, 770.23, 863.53 and 904.21 nm) were picked out. In a comparison of the predictive results of PLSR, MLR and PCR, the performance of the PLSR model for SSC prediction was better, the correlation coefficient of prediction (rpre) was 0.828, root mean square error of calibration (RMSEC) was 0.589, and root mean square error of prediction (RMSEP) was 0.611.The results revealed that this model took less time for modeling and had reliable predictive ability. This study showed that the home-built measurement system was stable, and provided a theoretical basis for on-line nondestructive detection of the internal quality of watermelon.
Number of references:22
Main heading:Mean square error
Controlled terms:Algorithms - Forecasting - Fruits - Least squares approximations - Linear regression - Mathematical models - Measurements - Models - Near infrared spectroscopy - Optimization  - Principal component analysis
Uncontrolled terms:Diffuse transmittance - Nondestructive determination - Soluble solids content - Variable selection - Watermelon
Classification code:944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 941 Acoustical and Optical Measuring Instruments - 922.2 Mathematical Statistics - 921 Mathematics - 902.1 Engineering Graphics - 821.4 Agricultural Products - 801 Chemistry
DOI:10.3969/j.issn.1002-6819.2013.12.033
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 6>

Accession number:20132916508797
Title:Potential calculation and time-series zoning for rural residential land consolidation at county scale
Authors:Yang, Xilian (1); Yang, Qiqi (3); Zhou, Bingbing (1); L&#252;, Ligang (1); Wang, Shenmin (4); Jin, Xiaobin (1); Zhou, Yinkang (1)
Author affiliation:(1) School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, China; (2) Land Reserve Center of Anhui Provincial Land and Resources Department, Hefei 230022, China; (3) Water Conservancy and Civil Engineering Colleges, Shandong Agricultural University, Taian 271018, China; (4) School of Remote Sensing, Nanjing University of Information Science and Technology, Nanjing 210044, China
Corresponding author:Yang, X.(yxlanhgtchb@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:235-245
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:This paper focused on the time-series arrangements when implementing regional rural residential land readjustment (RRLR) and its relation to regional potential of RRLR. By using a simplified reality-modifying per capita construction land quota method, we estimated the regional RRLR' s realistic potential, on which we proposed the regional important index of RRLR. Afterwards, we further proposed the regional urgent index of RRLR and presented an indicator system to evaluate it. Then, the prioritization matrix was introduced and a prioritization matrix for regional RRLR' s time-series arrangements was established. Finally, we conducted a case study of Rugao city, Jiangsu province. Results showed that RRLR is crucial to support this city' s transformation and sustainable development of its high-growth economy and rapid-changing society. The total realistic potential of RRLR for Rugao was 14859.87 hm², accounting for 46.73 percent of the rural residential land and 56.71 percent of the theoretic potential, and that the 20 towns could be divided into four types which differ in their priority to carry out the RRLR projects. The top priority zone contains four towns that are mostly the city' s growth pools, and the total RRLR' s realistic potential is 3958.04 hm², which accounts for 26.63 percent of the whole city' s total realistic potential. The second priority zone contains two towns that are in urgent need for construction land quotas and increasing regional arable land; their total RRLR' s realistic potential is 926.87 hm², only 6.24 percent. The third priority zone contains five towns that has much realistic potential but is not in urgent need for urban construction and arable land requirements; their realistic potential is 4539.31 hm² that accounts for 30.55 percent of the whole. The last priority zone contain 9 towns that have relatively low potential and less urgent need, their total RRLR' s realistic potential is 5435.64 hm², 36.58 percent of the whole potential. Total realistic potential of the top priority zone and the second priority zone is enough to cover the urban construction land requirements of Rugao city in the coming nine years. To further increase Rugao' s arable land, RRLR in the third priority zone should be paid more attention. To better motivate each stakeholder' s initiative, this paper suggests that we use RRLR-related funds and construction land quotas as the incentives, and that more funds and quotas should be provided for the top priority zone, less funds and enough quotas for the second priority zone, more funds but less quotas for the third priority zone, and provide no active support for the last priority zone. This research presents some guides and policy implications for the regional planning of RRLR projects in Rugao City and similar regions.
Number of references:31
Main heading:Housing
Controlled terms:Consolidation - Economics - Land use - Planning - Public policy - Regional planning - Zoning
Uncontrolled terms:Construction land - Land consolidations - Policy implications - Prioritization - Realistic potentials - Rugao city - Rural residential - Urban construction
Classification code:403 Urban and Regional Planning and Development - 483 Soil Mechanics and Foundations - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2013.12.030
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 7>

Accession number:20132916508792
Title:Load-bearing capacity of films and its effect on structure stability of Chinese solar greenhouse
Authors:Ding, Min (1); Shi, Xudong (1); Li, Mimi (1); Ju, Jinsan (1); Jiang, Xiugen (1)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Jiang, X.(jiangxg@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:194-202
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Besides offering space, appropriate temperature and humidity for animals and plants, greenhouses should also bear all kinds of loads, including the loads induced by improper operation and extreme natural disasters, such as heavy snowfall, high wind and hail. The safety of greenhouses covered with film depends mainly on the film used and greenhouse structure. The mechanical properties of film and their effects on greenhouse structures covered with film are very important to prevent the whole collapse of the greenhouse structure under extreme natural disasters. In order to investigate the effect of plastic film on anti-collapse behaviors of solar greenhouse structures under disaster loads, the numerical simulation on mechanical behavior of single film under wind load, snow load and hail load was carried out by using finite element analysis software ANSYS. The effect of film thickness, film span, film pre-tension and load on load-bearing capacity of the single film was analyzed. At the same time, three computation models of solar greenhouse structures, including single hinged arch structure, whole frame structure without film, and whole frame structure with film, were made. The overall failure process and space coefficient of solar greenhouse structure were obtained. The effect of tensioned film on the solar greenhouse structure stability was discussed with parameters such as film thickness, film elastic modulus and film pre-tension changing. The results showed that film dimension and thickness are the main factors affecting its load-bearing properties, and the ratio of film length to film width should also be considered appropriately. Film at 0.2 mm thick can prevent disaster caused by extra heavy hail. Tension film was used in favor of wind resistance for solar greenhouse structures, but is not effective for snow resistance. The space coefficient of solar greenhouse structures is least effected by film elastic modulus in all analyzed parameters. The ultimate bearing capacity of the whole frame structure without film is higher than that of the single hinged arch structure under wind and snow loads. The reason is that the stiffness out of plane is enhanced by purelines. Film also plays an important role on improving the ultimate load bearing capacity of greenhouse structures. The fruits are useful to the wind, snow and hail resistant design of solar greenhouse structure covered film.
Number of references:30
Main heading:Greenhouses
Controlled terms:Arches - Bearing capacity - Convergence of numerical methods - Disaster prevention - Disasters - Elastic moduli - Film thickness - Films - Finite element method - Loads (forces)  - Snow - Solar heating - Structural dynamics - Structural frames
Uncontrolled terms:Chinese solar greenhouse - Finite element analysis software - Load-bearing properties - Solar greenhouse - Space coefficient - Temperature and humidities - Ultimate bearing capacity - Ultimate load-bearing capacity
Classification code:943 Mechanical and Miscellaneous Measuring Instruments - 933 Solid State Physics - 921.6 Numerical Methods - 914.1 Accidents and Accident Prevention - 643.1 Space Heating - 443.3 Precipitation - 423 Non Mechanical Properties and Tests of Building Materials - 421 Strength of Building Materials; Mechanical Properties - 408.2 Structural Members and Shapes - 408 Structural Design - 402.1 Industrial and Agricultural Buildings
DOI:10.3969/j.issn.1002-6819.2013.12.025
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 8>

Accession number:20132916508799
Title:Hypobaric storage maintains postharvest quality and regulates cell wall metabolism in water bamboo shoot
Authors:Fang, Xiangjun (1); Gao, Haiyan (1); Song, Lili (1); Chen, Hangjun (1); Mao, Jinlin (1); Yang, Qian (1)
Author affiliation:(1) Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
Corresponding author:Gao, H.(spsghy@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:257-263
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Water bamboo shoots (Zizania caduciflora L.), a kind of health-caring vegetable, is becoming more and more popular due to its special flavor and taste in China in recent years. However, water bamboo shoots are very perishable for senescence and deterioration with quality, which results in a short shelf life after being harvested. Hypobaric storage has been shown to inhibit postharvest ripening and senescence and extend shelf life of fruits and vegetables. However, there are no published data on the effects of hypobaric storage on the quality of water bamboo shoots during storage. To study the efficacy of hypobaric storage as a new technique in maintaining the quality of water bamboo shoots (WBS), ambient atmospheric pressure with cold storage was used as a control. The effects of low-pressure storage on quality and cell-wall metabolism of 'Longjiao 2' WBS were investigated. The hypobaric storage maintained the green color of the water bamboo shoot shell, decreased water loss and released fibrosis. The effects of 70-80 kPa treatment were better than 40-50 kPa. After 60 days storage, water-soluble sugar (1.2%, 1.5%), Vc content (2.8, 3.94 mg/100g) and firmness (2.67, 3.47 kg) were kept at a high level in the 40-50 and 70-80 kPa group. There was a significant difference between the control group and the 70-80 kPa group. POD activity in the control treatment and the 40-50 kPa group was 1.90 and 1.54 times than that in the 70-80kPa group. PAL activity was 1.49 and 1.23 times than that in 70-80kPa group. There was also significant difference between the control treatment and the 70-80 kPa group. Mass fraction of water-soluble pectin in the 70-80 kPa group was 1.65 and 1.15 times than that in control and the 40-50 kPa groups. The difference between them was also significant. The mass fraction of lignin was 0.47% in the 70-80 kPa group, which has a significant difference from that in the control group, 1.6 times of its mass fraction. These results indicated that hypobaric storage could delay the degradation of total soluble sugar and Vc, suppress the increasing rate of POD, PAL and CAD activities, inhibit the decrease of water soluble pectin content and the rise of lignin content in postharvest WBS significantly, and delay the process of lignification. Compared with storage under ambient atmospheric pressure or 40-50 kPa, the storage of WBS under 70-80 kPa maintained better appearance quality, higher levels of total soluble sugar and Vc as well as lower enzyme activities of POD, PAL and CAD. After 2 months of storage, hypobaric storage under 70-80 kPa also maintained the characteristic qualities and commercial value of WBS with low degree of lignification.
Number of references:36
Main heading:Bamboo
Controlled terms:Atmospheric pressure - Cold storage - Energy storage - Enzymes - Lignin - Metabolism - Physiology - Quality control - Vegetables - Water quality
Uncontrolled terms:Bamboo shoots - Fibrosis - Hypobaric storage - Protopectin - Water soluble pectins
Classification code:913.3 Quality Assurance and Control - 821.4 Agricultural Products - 815.1.1 Organic Polymers - 702 Electric Batteries and Fuel Cells - 694.4 Storage - 461.9 Biology - 461.2 Biological Materials and Tissue Engineering - 453.2 Water Pollution Control - 443.1 Atmospheric Properties
DOI:10.3969/j.issn.1002-6819.2013.12.032
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 9>

Accession number:20132916508772
Title:Location control of automatic pick-up plug seedlings mechanism based on adaptive Fuzzy-PID
Authors:Wang, Qiao (1); Cao, Weibin (1); Zhang, Zhenguo (1); Zhang, Peng (1); Wang, Peng (1)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi 832003, China
Corresponding author:Cao, W.(cwb_mac@shzu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:32-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:As one of the key components of a fully-automatic field transplanter, an automatic pick-up plug seedlings mechanism has important significance in reducing labor intensity, liberating labor forces, and improving efficiency of transplanting. For a new kind of push-out type automatic pick-up plug seedlings mechanism, this paper systematically studied the method of its location control, which was aimed at enhancing its location accuracy, ensuring its operation efficiency and improving its anti-interference. Through the analysis of mechanical structure characteristics of this new mechanism, it could be concluded that the location control for conveying potted trays is a key factor in ensuring accurate operation of the entire mechanism and finally highlighting its high efficiency. That is, if the accurate location of conveying potted trays is realized when other parts of this mechanism operate with the conventional time, compared with domestic common pick-up plug seedlings manipulators, the operation efficiency of this mechanism will be greatly increased. The location accuracy requirement in conveying potted trays was obtained based on the analysis and calculation in details. At the same time, the control accuracy of the potted trays conveying system under the simple closed loop stepping location control was identified theoretically. This paper then analyzed the limitations of the stepping location control system under a simple closed loop control, fixed parameter PID control or fuzzy control, and the adaptive Fuzzy-PID control algorithm was proposed to be used to achieve the location control. In this paper, the adaptive Fuzzy-PID controller was designed, and the transfer function of the closed loop stepping location control system was constructed, and finally the modeling and simulation analysis in the Matlab were carried on, as well as the system debugging experiment. The simulation analysis showed that the response time of the adaptive Fuzzy-PID control was 0.192s, and that of PID control was 0.359s. In the interference of a disturbance signal, the disturbance overshoot of the adaptive Fuzzy-PID control as a percentage of disturbance signal amplitude was 0.88%, and that of PID control was 10%, so the former was far less than the later. The comparative analysis from above showed that the adaptive Fuzzy-PID control system had a faster response and better anti-interference, so it will have a distinct advantage in working in a complex field operation environment. The system debugging experiment then showed that the maximum relative location error of conveying potted trays under the adaptive Fuzzy-PID control was 0.27%, which was lower than the maximum relative error allowed in conveying potted trays. That is to say, the adaptive Fuzzy-PID controller can satisfy the location accuracy requirement of conveying potted trays. In sum, using an adaptive Fuzzy-PID control algorithm to fulfill the stepping location control of conveying potted trays can enhance the location accuracy, and improve the anti-interference and the system stability, which ensures the efficient operation of this automatic seedling pick-up mechanism and makes it suitable to the complex field transplanting operation environment. This paper provides not only reference and basis for the whole control system's development of this automatic seedling pick-up mechanism but also a new solution for the control system of other seedling pick-up mechanisms or transplanters to adapt the field transplanting operation environment with multiple nonlinear influence factors.
Number of references:26
Main heading:Three term control systems
Controlled terms:Adaptive systems - Agricultural machinery - Algorithms - Closed loop control systems - Computer simulation - Efficiency - Experiments - Fuzzy control - MATLAB - Mechanisms  - Pickups - Position control - Program debugging - System stability
Uncontrolled terms:Analysis and calculations - Comparative analysis - Fuzzy PID controller - Improving efficiency - Maximum relative errors - Mechanical structures - Modeling and simulation - Operation efficiencies
Classification code:961 Systems Science - 921 Mathematics - 913.1 Production Engineering - 901.3 Engineering Research - 821.1 Agricultural Machinery and Equipment - 752.3.1 Sound Reproduction Equipment - 731 Automatic Control Principles and Applications - 723 Computer Software, Data Handling and Applications - 601.3 Mechanisms
DOI:10.3969/j.issn.1002-6819.2013.12.005
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 10>

Accession number:20132916508798
Title:Scenario simulation of land use change in mining city based on CLUE-S model
Authors:Zhang, Dingxuan (1); Fu, Meichen (1); Tao, Jin (1); Hu, Lizhe (1); Yang, Xiaoli (1)
Author affiliation:(1) Land Use and Technology Department, China University of Geosciences (Beijing), Beijing 100083, China; (2) University of Chinese Academy of Sciences, Beijing 100049, China
Corresponding author:Fu, M.(fumeichen@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:246-256
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The LUCC model is an important way to understand the process of land-use change, driving mechanisms, dynamic changes, ecological effects, and environmental impact assessment. Studies of land use models on land use prediction in mining cities are relatively rare. The CLUE-S model, as the representative of experience-based statistical models, has high simulation accuracy and application value in land use change prediction from spatial and temporal aspects. In this paper, the CLUE-S model was applied to land use change simulation in Wu'an, a typical mining city relying on GIS technology. First, selecting the correct driving factors is necessary to the accuracy of prediction map. 15 driving factors of land use were selected from 28 driving factors according to RDA (redundancy analysis) and factor analysis. Using 15 driving factors not only reduces the complexity of the problem, but also preserves simulation accuracy. In consideration of sustainable development, the free market scenario is more suitable compared with the alternatives. The expansion trend of the free-market mode is towards east and southeast, which conforms to the development planning of Wu'an city. Second, we set the corresponding land use quantity change in 2020 under three development modes by a Markov model and GM (1, 1) grey model, and then predicted the land use distribution map under a free market scenario, a cultivated land protection scenario, and an ecological protection scenario. The result showed that forest land and construction land increased under a free market scenario, reflecting the effects of economic development and environmental protection.. In the cultivated land protection scenario, cultivated land distribution restricted the free expansion of construction land. In the ecological security scenario, forestland grows obviously, and mining land reduces sharply influenced by environmental policy. Comprehensive consideration of sustainable development in Wu'an from the perspective of social, economic, ecological development and cultivated land protection, the free market scenario is relatively reasonable, and the other two scenarios can be a supplement for regional land optimal allocation. The results further verify that the CLUE-S model can simulate the future land use change of mining cities under different scenarios. Meanwhile, a new method to predict future land use under different scenario using the CLUE-S model can be applied in the implementation and management of land use planning, which can guide the land use change in the implementation process with reference to different simulation results by adjusting the land use objective and ultimately achieve the purpose of land use optimization.
Number of references:38
Main heading:Land use
Controlled terms:Commerce - Computer simulation - Ecology - Economics - Environmental impact assessments - Environmental protection - Forecasting - Forestry - Geographic information systems - Markov processes  - Mining - Models - Optimization - Planning - Sustainable development
Uncontrolled terms:CLUE-S models - Development planning - Ecological development - Ecological protection - Implementation process - Land-use optimization - Scenario simulations - Wu'an city
Classification code:971 Social Sciences - 922.1 Probability Theory - 921.5 Optimization Techniques - 921 Mathematics - 911.2 Industrial Economics - 902.1 Engineering Graphics - 821.0 Woodlands and Forestry - 723.5 Computer Applications - 723.3 Database Systems - 502.1 Mine and Quarry Operations - 454.3 Ecology and Ecosystems - 454.2 Environmental Impact and Protection - 403 Urban and Regional Planning and Development
DOI:10.3969/j.issn.1002-6819.2013.12.031
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 11>

Accession number:20132916508785
Title:Removing effects of grass filter strips on sediment and herbicide from runoff in simulated experiment
Authors:Xiao, Bo (1); Sa, Renna (2); Tao, Mei (2); Wang, Qinghai (1)
Author affiliation:(1) Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China; (2) College of Resource and Environment Engineering, Liaoning Technical University, Fuxin 123000, China; (3) State Key Laboratory of Soil Erosion and Dry and Farming on the Loess Plateau, Institute of Water and Soil Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China
Corresponding author:Xiao, B.(xiaoboxb@gmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:136-144
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Atrazine, an herbicide to kill broadleaf weeds affecting many different types of crops such as corn, sorghum, and sugarcane, is extensively used in agricultural production around the world in recent years. The worldwide use of atrazine did not only significantly increase crop yields but also result in serious aboveground- and belowground water pollutions. Grass filter strips, planted along streams, ponds, and lakes, were designed to remove sediments, organic materials, nutrients, and chemicals carried in runoff or waste water, and which were regarded as one of the best management practices in the controlling of agricultural non-point source pollution in many countries. However, the efficiency of grass filter strips in the removing of atrazine has not been adequately tested, especially on the Northern China. This study was conducted to evaluate the effects of herbaceous grass filter strips established by Pennisetum (Pennisetum alopecuroides (Linn.) Spreng and Arundinella (Arundinella hirta (Thunb.) C. Tanaka) on the removing of runoff, sediment, and atrazine in a simulated experiment on the soil boxes with runoff generator (water flow rate and speed were 0.22 L/s and 1.3 m/s, respectively). Three treatments, including T1 (inflow sediment content=20 g/L, inflow atrazine concentration=0.3 mg/L), T2 (inflow sediment content=40 g/L, inflow atrazine concentration=0.6 mg/L), and T3 (inflow sediment content=60 g/L, inflow atrazine concentration=0.9 mg/L), were set and each of them had three replications in this study. The differences between the inflow and outflow of runoff, sediment, and atrazine through the grass filter strips were examined to determine the efficiency of the grass filter strips in the decreasing of studied pollutants. The results showed that the grass filter strips significantly reduced runoff by up to 88%. The grass filter strips was also very efficient in reducing sediment and atrazine, but their effects were significantly influenced by sediment content and atrazine concentration in the inflow water through the grass filter strips. The outflow sediment was decreased by 95%, 93%, and 85% by the grass filter strips when the inflow sediment content was 20, 40 and 60 g/L, respectively. Similarly, the outflow atrazine was decreased by 95%, 92%, and 81% by the grass filter strips when the inflow atrazine concentration was 0.3, 0.6 and 0.9 mg/L, respectively. Additionally, the decreasing percentage of the sediment and atrazine was gradually decreased with the increasing time. The sediment was decreased by 97%, 95%, 93%, 91%, and 87% at the 1st, 10th, 20th, 40th, and 60th min, respectively; while the atrazine was decreased by 97%, 93%, 90%, 86%, and 84% at the 1st, 10th, 20th, 40th, and 60th min, respectively. At last, the result of the correlation analysis showed that the outflow concentration of atrazine was significantly correlated with the volume of outflow water (r<inf>1</inf>=0.88, r<inf>2</inf>=0.93, r<inf>3</inf>=0.94), which indicated that the outflow atrazine was mainly determined by the volume of outflow water. From these results we concluded that the herbaceous grass filter strips were very efficient in reducing the sediment and atrazine. This conclusion may be helpful for preventing atrazine and other agricultural non-point source pollution in the Northern China.
Number of references:34
Main heading:Herbicides
Controlled terms:Agricultural runoff - Agriculture - Lakes - Runoff - Sediments - Steel beams and girders - Vegetation - Water pollution - Weed control
Uncontrolled terms:Agricultural non-point source pollutions - Agricultural productions - Atrazine concentrations - Best management practices - Correlation analysis - Outflow concentrations - Simulated experiments - Vegetative filter strips
Classification code:821.5 Agricultural Wastes - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 803 Chemical Agents and Basic Industrial Chemicals - 545.3 Steel - 483 Soil Mechanics and Foundations - 453.1 Water Pollution Sources - 453 Water Pollution - 444.1 Surface Water - 407 Maritime and Port Structures; Rivers and Other Waterways
DOI:10.3969/j.issn.1002-6819.2013.12.018
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 12>

Accession number:20132916508794
Title:Favorable conditions of cotton straw composting using as soilless culture substrate
Authors:Zhang, Ye (1); Yu, Hongjun (1); Yang, Xueyong (1); Jiang, Weijie (1)
Author affiliation:(1) Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Corresponding author:Jiang, W.(jiangweijie@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:210-217
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The aim of this study was to find the optimal conditions for cotton straw composting as a Soilless Culture Substrate. Cotton straw size, carbon-nitrogen ratio, and nitrogen source were investigated to determine their effects on the process of cotton straw composting by using an orthogonal design method. Each factor was set at three levels: C/N ratios were 25:1, 30:1, 35:1, cotton straw sizes were 1, 2, and 3 cm, and nitrogen sources were chicken manure, urea, and a mixture of chicken manure and urea. Cotton straw applied in this trial was bought from the famers in a Beijing suburb and was broken into 1-3 cm particles by machine. The C/N ratio of cotton straw was 38:1. The dry chicken manure and urea as the nitrogen resource were used to adjust the C/N ratio. The cotton straw weight of each treatment was 5 kg, and the water content of each treatment was adjusted to 60%-70%. Plastic weaving bags of 70-liter capacity were used as composting containers and were placed in three layers with a randomized design. Each treatment had one bag and three replications. The bags were turned over every 10 days during the maturation phase in order to improve the O<inf>2</inf> level inside the bags. The trial lasted 30 days. The parameters included composting temperature, C/N ratio, bulk density, pH, EC, accumulated temperature, water holding capacity, and air filled porosity. A temperature meter recorded the temperature in each bag every day. Bulk density and porosity were determined following the Byrne method and conventional method, respectively. The pH and electrical conductivity (EC) were determined by IQ150 Portable pH/mV/thermometer measurement. The results from the study indicated that during the composting period, C/N ratio of 25:1, 1 cm straw particle size, the mixture of chicken manure and urea as an added nitrogen source were the optimal conditions to sustain high temperature (&le50&deg;C) in the composting pile of cotton straw, and the days keeping high temperature in the three conditons was 9, 10, 8 days respectively. The C/N ratio had a significant influence on total porosity reduction, with the highest value (66.0%) in a C/N of 25:1, and that in pre-composting decreased by 24.8% compared with after composting. Cotton straw size had a significant influence on water-holding capacity, accumulated temperature and bulk density increase, and the highest values (59.2%, 1315.75&deg;C, 0.30 g/cm³) occurred with a cotton straw size of 1cm. Compared with pre-composting, the water holding capacity after composting increased by 111.1%, and the bulk density increased by 76.4%. Nitrogen source (chicken manure and urea) had a significant influence on accumulated temperature, and the highest measured value (1354.41&deg;C) occurred with the mixture of chicken manure and urea as the nitrogen source. Recommended values are a C/N ratio of 25:1, 1cm cotton straw particle size, and a mixture of chicken manure and urea as an added nitrogen source for cotton straw composting.
Number of references:23
Main heading:Cotton
Controlled terms:Animals - Composting - Design - Manures - Metabolism - Mixtures - Nitrogen - Optimization - Particle size - Piles  - Porosity - Straw - Urea
Uncontrolled terms:Accumulated temperatures - Carbon-nitrogen ratio - Composting temperature - Electrical conductivity - Maturity indices - Orthogonal design method - Soil-less culture - Water holding capacity
Classification code:931.2 Physical Properties of Gases, Liquids and Solids - 921.5 Optimization Techniques - 822 Food Technology - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 814 Leather and Tanning - 804.1 Organic Compounds - 804 Chemical Products Generally - 802.3 Chemical Operations - 471 Marine Science and Oceanography - 461.9 Biology - 461 Bioengineering and Biology - 408.2 Structural Members and Shapes - 408 Structural Design
DOI:10.3969/j.issn.1002-6819.2013.12.027
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 13>

Accession number:20132916508790
Title:Three-phase parallel inverter synchronous control method based on CAN bus in power supply system
Authors:Wang, Jiangbo (1); Yang, Rengang (1); Gao, Chunfeng (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing 100083, China; (2) College of Electromechanical Engineering, Qingdao Agricultural University, Qingdao 266109, China
Corresponding author:Yang, R.(yrg@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:179-186
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Three phase grid-connected inverters are the key parts for the transfer of dispersed power generation, such as photovoltaic, wind generation, and energy storage systems, and so on. The three-phase system could be replaced with three single phase inverters. In this way, it could enlarge the current capacity easily without using high isolated voltage and large current devices, and it will be more cheap and flexible. However, there would be a significant frequency offset. With the help of a CAN (Controller Area Network) bus, all the parallel inverters could be the master in the given rules. The master inverter sends the frequency of itself with a synchronization-triggered frame on its clock period, and then all the other inverters determine the frequency of the interval between the two frames. For the other inverters, the frame is also taken as the reference phase, which can correct the phase error of the sine signal. However, the communication data exchange speed and quality fall as the CAN busloads increase. The phase synchronization method will cause frequency offset and voltage distortion. Therefore, a PWM carrier period based parallel inverter synchronization control method based on a CAN bus was proposed in the paper. The method works in dynamic master/slave mode. In the CAN protocol, the pulse width modulation period is selected as the basic communication period. The period is divided into 3 ranges, according to the zero point of ABC phase voltage. Each range is divided into 3 time periods, exclusive, arbitration, and free. In the exclusive time period, the most important message is delivered. In the design of the CAN application layer, the master dynamic setting was implemented on the ID allocation, in which the address is allocated dynamically, and the master is determined. When the system is powered on, or the new one is connected, all the inverters will get this information, and then send the serial numbers and connected phase name to the bus. They can receive the serial numbers and connected phase name of the others later. The master inverters will be decided on the given rule of the serials number. If the master stops sending synchronization signals, the dynamic setting will be repeated again to make the new one. The simulation and experiment of parallel inverters were finished in the carrier period based phase synchronization method. In simulation, the phase change and frequency change methods were adopted to compare with the proposed methods. The reference voltage was set to 220 volts, 50 Hertz, and zero initial phase angles. In the result, the proposed method reduces the voltage distortion from 26.7% to 8.8%, compared to the phase change method, while reducing the frequency offset from 16.67 Hertz to 0, compared to the frequency change method. It can be proved from the simulation in Matlab that the method can achieve low distortion and little frequency offset, compared to the other methods. Four inverters were engaged in the experiment, and that is enough to show all the possible capacity enlarging cases with no extra expense. The controller of the inverters was developed on the popular digital processor, which is TMS320F28335 from Texas Instrument. The results show the phase synchronization errors keep within 1&deg; between the inverters in the same phase, or different phases.
Number of references:29
Main heading:Synchronization
Controlled terms:Algorithms - Communication - Control system synthesis - Distributed power generation - Electric distortion - Electric inverters - Electric power systems - Electronic data interchange - Experiments - Frequency allocation  - MATLAB - Pulse width modulation - Signal encoding
Uncontrolled terms:CAN bus - Cans (controller area network) - Grid connected inverters - Parallel inverter - Phase synchronization errors - Single-phase inverters - Synchronization control - Synchronization signals
Classification code:921 Mathematics - 901.3 Engineering Research - 731.1 Control Systems - 723.2 Data Processing and Image Processing - 723 Computer Software, Data Handling and Applications - 716 Telecommunication; Radar, Radio and Television - 711.1 Electromagnetic Waves in Different Media - 706.1 Electric Power Systems - 704.2 Electric Equipment - 702 Electric Batteries and Fuel Cells - 615 Thermoelectric, Magnetohydrodynamic and Other Power Generators
DOI:10.3969/j.issn.1002-6819.2013.12.023
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 14>

Accession number:20132916508802
Title:Preparation technology optimization and characteristic analysis of rice resistance starch
Authors:Zhao, Lichao (1); Yu, Rong (1); Liu, Xin (1); Zhou, Aimei (1); Cao, Yong (1)
Author affiliation:(1) College of Food Science, South China Agricultural University, Guangzhou 510642, China
Corresponding author:Cao, Y.(caoyong2181@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:277-285
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Yitang is a new type rice with high amylose content, which was bred by spaceflight mutation and physical mutation. It has great potential for developing high resistant starch (RS) products. Until recently, most of the studies on the RS preparation have focused on high-amylose corn starch or root vegetables starch. In addition, there is a greater difference between rice starch and other kinds of starch in particle characteristics, composition, etc. The production processes of RS cannot simply be deduced from previous reports. In order to make use of Yitang rice rationally, this article focuses on the production processes of RS as a functional food ingredient. The production processes of Yitang Rice RS were optimized through a Box-Benhnken center-united experiment design and Response Surface Methodology (RSM), based on single-factor experiments of moisture content (starch concentration), pH value, autoclaving treatment temperature, cooling method, cold storage time, drying temperature, and the number of autoclaving treatments. RS characteristics analysis was discussed by assistant analyses of absorption curves of starch and I2-KI compound, infrared spectroscopy, average polymerization degree, scanning electron microscopy, solubility, and water-holding capacity. The results showed that the most influential process factors were moisture content (starch concentration), pH, autoclaving treatment time, and cold storage time. The optimum conditions were a starch concentration of 31%, pH value 5.8, heating time 50 min (under 0.1 MPa, 120&deg;C), natural cooling and cold storage time 15 h, drying temperature 80&deg;C, three autoclaving treatment times, together yielding an RS fraction of 20.1%. The characteristics analysis showed that the "Yitang Rice" RS has ordered crystalline structure which was formed by recrystallizing during starch retrogradation, and the major component of it is short amylose (polymerization degree is 21.43). The characteristics of RS crystal structure which has a narrow molecular-weight distribution and more hydro-keys than native starch are compact and solid. Therefore, its solubility decreased 85.9% as compared to native Yitang rice. However, the RS surface exhibits a multi-pore structure that makes its water-holding capacity higher than other common RS and dietary fiber products such as potatoes RS and corn RS. This research can provide a method for improving the yield of RS from "Yitang Rice" and an explanation of the mechanisms of RS formation, which can promote the wide development and utilization of "Yitang Rice" resources.
Number of references:23
Main heading:Starch
Controlled terms:Cold storage - Cyclodextrins - Drying - Experiments - Infrared spectroscopy - Moisture determination - Molecular weight distribution - Optimization - pH - Polymerization  - Processing - Production engineering - Scanning electron microscopy - Solubility
Uncontrolled terms:Characteristic analysis - Characteristics analysis - Development and utilizations - Formation mechanism - Particle characteristics - Response surface methodology - Single-factor experiments - Yitang rice
Classification code:944.2 Moisture Measurements - 921.5 Optimization Techniques - 913.4 Manufacturing - 913.1 Production Engineering - 901.3 Engineering Research - 815.2 Polymerization - 804.1 Organic Compounds - 801 Chemistry - 741.1 Light/Optics - 694.4 Storage - 642.1 Process Heating
DOI:10.3969/j.issn.1002-6819.2013.12.035
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 15>

Accession number:20132916508776
Title:Comparison of engine body NVH predicted by different bearing calculation model
Authors:Zhang, Huanyu (1); Hao, Zhiyong (1); Zheng, Xu (1)
Author affiliation:(1) Department of Energy Engineering, Zhejiang University, Hangzhou 310027, China
Corresponding author:Hao, Z.(haozy@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:64-70
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:highly strengthened engine is the mainstream of the engine industr' s future development; however, with increasing performance enhancements of the engine, the engine NVH issues will become increasingly more serious. Engine NVH problems will seriously affect the durability and comfort of the vehicle, therefore the noise and vibration reduction work of strengthening the engines is receiving more and more attention. How to solve these problems has become an important responsibility of internal combustion engine workers. As we know, reasonable analysis and diagnosis becomes the key to controlling the engine vibration and noise, so numerical analysis methods become an important means. Since current analysis models cannot meet the design requirements for high reinforcing Engine, it is necessary to improve the current method to find more accurate engine harshness (NVH) performance prediction model. According to previous research, the dynamic characteristic of bearing became crucial to predict the engine NVH performance. In order to study the effects of different bearing calculation models on engine vibration and acoustic prediction, and taking a four cylinder diesel engine as an example, the engine multi-body dynamics models coupling with HD (hydro-dynamic, HD) bearing model, EHD (elastic hydro-dynamic, EHD) bearing model, and TEHD (thermal elastic hydro-dynamic, TEHD) bearing model were respectively proposed in this paper. The maximum oil film pressure and minimum film thickness of different calculation models were analyzed at the engine rated operating conditions, and the results showed that, relative to the TEHD bearing model, the deviations of minimum film thickness and the maximum oil film pressure of the HD bearing model were -68% and 130%, respectively, and the deviations of minimum film thickness and the maximum oil film pressure of the EHD bearing model were 84% and -9%, respectively. These results revealed that bearing thermodynamic properties could significantly affect the bearing lubrication performance, which could not be ignored in the bearing lubrication analysis. With multi-body dynamics calculation results as the boundary condition, the engine body NVH performance was predicted. In the meantime, the surface of the engine body vibration acceleration was measured on the bench test, and the engine body radiated noise was calculated by vibration velocity method. Following this, the experimental and calculated values of the engine noise and vibration were compared to validate the calculation models. The comparison showed that the maximum vibration errors of the HD model, EHD model, and TEHD model are 7 dB, 4.5 dB, and 4.2 dB, respectively, and the maximum acoustic errors of the HD model, EHD model, and TEHD model are 13 dB, 6.1 dB, and 3.8 dBA, respectively. The results of this study showed that the bearing thermodynamic properties will not only affect the lubrication performance results, but also significantly affect the engine NVH performance prediction. After considering the elastic deformation and thermal deformation of bearing, the engine dynamics calculation model has high calculation precision in the engine vibration and noise predictions. Although the method requires more computation time, it is one of the most accurate calculation models in the main bearing force and engine noise analysis field.
Number of references:24
Main heading:Engines
Controlled terms:Acoustic noise - Acoustic noise measurement - Automobile bodies - Bearings (structural) - Boundary element method - Diesel engines - Dynamics - Engine cylinders - Errors - Film thickness  - Fluid dynamics - Forecasting - Lubricating oils - Lubrication - Mechanics - Thermodynamic properties - Vibrations (mechanical)
Uncontrolled terms:Dynamic characteristics - Lubrication performance - Multibody dynamics model - Noise - Noise and vibration reductions - Performance enhancements - Performance prediction models - Vibration velocity method
Classification code:943 Mechanical and Miscellaneous Measuring Instruments - 931.1 Mechanics - 921.6 Numerical Methods - 921 Mathematics - 751.4 Acoustic Noise - 731 Automatic Control Principles and Applications - 663.2 Heavy Duty Motor Vehicle Components - 641.1 Thermodynamics - 612 Engines - 607.2 Lubrication - 607.1 Lubricants - 423 Non Mechanical Properties and Tests of Building Materials - 408.2 Structural Members and Shapes
DOI:10.3969/j.issn.1002-6819.2013.12.009
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 16>

Accession number:20132916508789
Title:Recognition of ripe litchi in different illumination conditions based on Retinex image enhancement
Authors:Xiong, Juntao (1); Zou, Xiangjun (1); Wang, Hongjun (1); Peng, Hongxing (1); Zhu, Mengsi (1); Lin, Guichao (1)
Author affiliation:(1) College of Informatics, South China Agricultural University, Guangzhou 510642, China; (2) Key Lab of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
Corresponding author:Zou, X.(xjzou1@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:170-178
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:To realize the goal of precise positioning of a picking robot in a natural environment of fruit and vegetables, some problems remain to be solved. The variability of illumination in natural environment is one of the main factors and causes low recognition accuracy and long recognition algorithm running time. In order to meet the effectiveness and real-time requirements of the litchi picking robot visual positioning system in a natural environment, the recognition of ripe litchi in a natural environment was studied. According to the litchi color images in different illumination conditions, to analyze the color features of litchi images a bilateral filtering Retinex image enhancement algorithm was used to highlight the litchi fruit and stem, which was needed to reduce the influence of illumination on litchi image processing and to highlight the recognized target. The color component characteristics in different color spaces of litchi images under different illumination conditions were analyzed to determine the H component rotation in HSI color space to the litchi image after image enhancement processing, which can reduce the influence of uneven illumination under the foundation of maintaining a relative relationship between colors of the original image. According to the bimodal characteristics of the H component grayscale histogram after rotation processing, the Otsu automatic threshold segmentation method for H component image threshold segmentation was chosen to remove the complex background except for the litchi fruit and stem. The fuzzy c-means (FCM) clustering algorithm was then selected to segment the fruit and stem of the litchi image, and due to the characteristics of the artificially given clustering number and low arithmetic speed of the traditional fuzzy c-means clustering algorithm, the fuzzy clustering algorithm was improved. Through the fusion of the bicubic interpolation algorithm and the FCM algorithm, the improved fuzzy c-means clustering algorithm was used in the fuzzy cluster segment of the Cr component in YCbCr color space, in which the recognition of the litchi fruit and stem was realized. One Hundred ten litchi images in different illumination conditions were randomly selected and used for the litchi fruit and stem segmentation experiments based on the research algorithm. The experimental results are that 100 mature litchi images were segmented correctly to fruit and stem, and in the other segmentation results, interference noise such as branches, the sky, and land existed. The recognition accuracy rate of ripe litchi can reach 90.9%. The experiment results show that this algorithm has good stability for litchi image segmentation in different illumination conditions, such as sunshine and front lighting, shade, backlighting, and clouds, mainly for the litchi recognition under the condition of weak light in cloudy days and the shaded fruit, which can well maintain the integrity of the litchi fruit and stem. The research results can provide the theoretical basis and technical support to the effectiveness and real-time for fruit and vegetable picking robot vision positioning systems, and lay the foundation for visual precise positioning.
Number of references:32
Main heading:Image segmentation
Controlled terms:Clustering algorithms - Color - Color image processing - Computer vision - Experiments - Fruits - Fuzzy clustering - Image enhancement - Lighting - Robots  - Vegetables
Uncontrolled terms:Bicubic interpolation - Fuzzy c-means clustering algorithms - Illumination conditions - Image enhancemen - Image enhancement algorithm - Improved fuzzy c-means clustering - Lichi image - Otsu automatic thresholds
Classification code:821.4 Agricultural Products - 741 Light, Optics and Optical Devices - 731.5 Robotics - 901.3 Engineering Research - 723.5 Computer Applications - 721 Computer Circuits and Logic Elements - 707 Illuminating Engineering - 723 Computer Software, Data Handling and Applications
DOI:10.3969/j.issn.1002-6819.2013.12.022
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 17>

Accession number:20132916508782
Title:Water balance in red soil hilly regions of Southern China under drought climate situations
Authors:Yang, Yanzhao (1); Zhang, Weike (1); Feng, Zhiming (1); Yang, Gege (1); Yang, Ling (1)
Author affiliation:(1) Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; (2) Department of Geography and Tourism, Handan College, Handan 056005, China; (3) University of Chinese Academy of Sciences, Beijing 100049, China
Corresponding author:Yang, Y.(yangyz@igsnrr.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:110-119
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The water and land resources matching situation is not optimistic, by that the arid climate events occur frequently in Southern China under the background of global warming in recent years. Taking Jitai Basin as an example, we systematically diagnosed drought situation of the past 50 years and identified the type and intensity of the drought by using standardized precipitation index. Moreover, we built a water balance model to analyze the water balance on cultivated land, forest land in red soil hilly regions of Southern China under the drought climate conditions. The results showed that drought events occurred with a higher frequency in nearly 30% during 1960 to 2010 in Jitai Basin, in which the light drought occurred frequency was the most, followed by the special drought, the middle drought and heavy drought. Drought events occurred mostly in autumn, and the spring and winter drought have occurred occasionally. The water balance of early rice, rape, forest land and shrub land in the water surplus in Jitai Basin mainly characterized by moisture surplus, and the rice water deficit rate was at 30% level under no-arid climatic conditions. The volume of water balance in Jitai Basin was about 448 mm under no-arid climatic conditions, which indicated that the natural precipitation could meet the water demands of the major land type on the whole, including forest and cultivated land etc. Water surplus was the basic characteristic, and the distribution of water surplus in valley and plain was lower than in hilly and mountain. Under the different drought climate conditions, the water balance volume of cultivated land was -87, -104, -356 and -553mm, and the water balance of cultivated land in Jitai Basin turned to deficit, with the drought degree aggravating, the water deficit of cultivated land was significantly enhanced, the effects of drought on the water balance of cultivated land were obvious. From the changes of the spatial pattern, the deficit situation of cultivated land was gradually expanded from the central basin valley plains to the hilly areas. The water balance volume of forest land was 376, 271, 200 and 144 mm, while the water surplus of forest land fell in the range of 37.87%-77.80%, With the drought degree aggravating, the water surplus of forest land was overall decreased. From the spatial variations, the water surplus of forest land was decreased from valley plain area to hilly and mountain area. When the light, middle and heavy drought happened, the volume of water balance in Jitai Basin was 215, 142 and19 mm, declined respectively by 55.07%, 70.28% and 96.08%. When the special drought events occurred, water shortage amounted to 72 mm. In a word, water surplus was deceased and water deficit was increased in Jitai Basin as its drought degree intensifying.
Number of references:31
Main heading:Drought
Controlled terms:Forestry - Global warming - Land use - Landforms - Rain - Soils - Water - Water supply
Uncontrolled terms:Basic characteristics - Climatic conditions - Distribution of water - Jitai Basin - Red soil hilly region - Standardized precipitation index - Water balance - Water balance models
Classification code:483.1 Soils and Soil Mechanics - 481.1 Geology - 451 Air Pollution - 821.0 Woodlands and Forestry - 446.1 Water Supply Systems - 443.3 Precipitation - 403 Urban and Regional Planning and Development - 444 Water Resources
DOI:10.3969/j.issn.1002-6819.2013.12.015
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 18>

Accession number:20132916508774
Title:Establishment and application of MAP for regeneration back-pressure threshold value of diesel particulate filter
Authors:Fu, Jun (1); Gong, Jinke (2); Yuan, Wenhua (1); Wang, Benliang (1); Chen, Wei (1)
Author affiliation:(1) Department of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422004, China; (2) State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China
Corresponding author:Fu, J.(huabeifujun@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:47-56
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to obtain the regeneration back-pressure threshold value of a diesel particulate filter (DPF) to provide the estimated criterion of regeneration time, the working principle of a burner-type DPF was introduced, and the estimated method of DPF exhaust back-pressure was put forward based on the total fuel consumption rate. A simulation model of a diesel engine with DPF was built by AVL-BOOST software. Through reasonable simplification, setting its parameters, and defining the boundary conditions, the working performances were simulated and DPF's back-pressure under the allowed total fuel consumption rate of different working conditions was calculated, then verified the simulation values of fuel consumption rate, power, torque, exhaust gas temperature and DPF's back-pressure on the DPF regeneration test bench. It shows that the results of the simulation are in close agreement with the experiments. Under diesel engine's full load working condition, the maximum error and the relative error of power was 3.9 kW and 7.83%, respectively, and that of fuel consumption rate was 12.3g/(kW&middoth) and 4.82%, and the error of DPF's back-pressure between the simulations and the experiments was less than 2.5kPa. Under the diesel engine's partial load working conditions, changes of power, fuel consumption rate, torque, exhaust gas temperature and DPF's back-pressure were consistent with those of full load working conditions, and likewise the simulation value agreed with the experimental data. It showed that the simulation model was valid and able to supply high density and precision measure values instead of the test bench. Based on the multivariate linear regression analysis theory, with the least square fitting method and piecewise linear interpolation technology along the vertical and horizontal direction distribution of the engine's working conditions, respectively, the values of fuel consumption rate were obtained under the diesel engine's all working conditions, and with the help of MATLAB software's powerful mathematics function and graph disposal capability, the curve surface of equal fuel consumption rate was simulated for the diesel engine with clean DPF. To set up the soot layer thickness with 0.0025mm increments in the DPF module of simulation and to record the fuel consumption rate of each working condition, the back-pressure was taken as the threshold value with the fuel consumption rate at 5% more than that of the diesel engine with clean DPF; further, the threshold value MAP of DPF regeneration back-pressure was built. From test results of the MAP application, it shows that DPF regeneration can be completed in 5-10 minutes. Through embedding three temperature measure probes in equal intervals along the axis of DPF's central inlet channels, real-time monitoring on temperature and its gradient were carried out on each measuring point. From the selected four regeneration cases, the peak value and maximum gradient of temperature was 1230, 1180, 1085, 1047K and 26.3, 24.6, 21.5, and 20 K/cm, respectively, which was below the safe threshold value. It indicated that the back-pressure threshold value MAP is very practical. It provides technology references on fast and safe regeneration for DPF.
Number of references:29
Main heading:Diesel engines
Controlled terms:Air filters - Computer simulation - Elementary particles - Experiments - Filters (for fluids) - Fuel filters - Functions - MATLAB - Piecewise linear techniques - Regression analysis
Uncontrolled terms:Arterial pressures - Back pressures - Diesel particulate filters - Exhaust gas temperatures - Least square fitting method - Multivariate linear regression analysis - Piecewise linear interpolations - Regeneration
Classification code:931.3 Atomic and Molecular Physics - 922.2 Mathematical Statistics - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 921 Mathematics - 901.3 Engineering Research - 802.1 Chemical Plants and Equipment - 723.5 Computer Applications - 612.2 Diesel Engines - 523 Liquid Fuels - 522 Gas Fuels - 445.1 Water Treatment Techniques
DOI:10.3969/j.issn.1002-6819.2013.12.007
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 19>

Accession number:20132916508796
Title:Frame construction of national classification system for contaminated sites in China
Authors:Yu, Qinfei (1); Hou, Hong (1); Bai, Zhongke (2); Li, Fasheng (1)
Author affiliation:(1) State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (2) School of Land Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China; (3) Key Laboratory of Land Consolidation and Rehabilitation, The Ministry of Land and Resources, Beijing 100035, China
Corresponding author:Hou, H.(houhong@creas.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:228-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Contaminated sites, which are caused by the industrialization of society, have gradually become a worldwide environmental problem. This problem has brought serious threats to human health and environmental safety. Implementation of scientific management is needed to solve the contamination problem of the sites. Effective category management is the key to achieving contaminated site management nationwide, while the core of classification management for contaminated sites is national classification. Classification management of contaminated sites at the national level can be achieved through national classification of contaminated sites, so that the limited resources will be distributed among the contaminated sites that are badly in need of treatment. During the sustainable development of industrialization and urbanization in the past 30 years in China, socio-economic and people's living have been hugely improved, but many environmental problems have been brought to light by an industrial development pattern of "high input, high consumption, high pollution". The contaminate sites are one of the major environmental problems. On the one hand, there are many contaminated sites with different types distributed widely in China; on the other hand, the costs of remediation for these contaminated sites are very expensive, making it impossible for the government to remediate all of the contaminated sites. It is proposed for the government to construct a national classification of contaminated sites. In addition to the analytic hierarchy process and numerical addition method, researchers also completed a literature analysis method, qualitative and quantitative research methods, environmental risk assessment method and system analysis method for this paper. The construction of a national classification system for contaminated sites mainly includes: (1) Three kinds of assessment factors which include pollution characteristics, migration pathway and pollution receptor as determined by the analysis of the produce and diffusion for soil pollution. (2) The national classification framework is constructed using the site evaluation factors structured by the method of analytic hierarchy process and with the corresponding weights of an orderly restructuring in accordance. (3) By combining the reorganization of the factor with numerical parameters with risk, the qualitative judgment is transformed into quantitative operational numerical. (4) According to the score summary results of the site evaluation factors, the contaminated sites are divided into five types: national priority site for remediation (75&lt;S&lt;100), the sites need to take action (60&lt;S&lt;75), the sites limited to use (45&lt;S&lt;60), the site that needs no action (S&lt;45), and insufficient information site (deterministic percentage for the data of site&lt;85%). The purpose of the study on national classification for contaminated sites identified: (1) The research results can provide technical support and basis for national priority site of remediation and classification management, thus the limited human, material and financial resources will be used for the sites of urgent need for risk management and remediation. (2) The government can take targeted measures according to different risk levels of contaminated sites in order to achieve the unified and standardized management of contaminated sites all over the country. (3) It can provide foundation for the construction of a national contaminated sites database and management for contaminated sites, which helps to promote the management of contaminated sites to develop in the direction of the institutionalization and standardization in China.
Number of references:33
Main heading:Numerical methods
Controlled terms:Analytic hierarchy process - Classification (of information) - Health risks - Industry - Management - Remediation - Research - Risk assessment - Risk management - Soil pollution
Uncontrolled terms:Classification framework - Classification managements - Classification system - Contaminated site management - Contaminated sites - Environmental risk assessment - Literature analysis method - Quantitative research methods
Classification code:922.1 Probability Theory - 921.6 Numerical Methods - 921 Mathematics - 913 Production Planning and Control; Manufacturing - 961 Systems Science - 912 Industrial Engineering and Management - 901.3 Engineering Research - 716.1 Information Theory and Signal Processing - 454.2 Environmental Impact and Protection - 911 Cost and Value Engineering; Industrial Economics
DOI:10.3969/j.issn.1002-6819.2013.12.029
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 20>

Accession number:20132916508769
Title:Performance experiment of friction conveying device for maize ears
Authors:Liu, Shiduo (1); Niu, Kang (1); Shi, Qingxiang (1); Wang, Shengsheng (1); Yuan, Qibao (1); Zhang, Kui (1)
Author affiliation:(1) Department of Vehicle and Motive Engineering, Henan University of Science and Technology, Luoyang 471003, China
Corresponding author:Liu, S.(liushiduo@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:9-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:At present, chain-rake grain conveying devices are widely used in corn united harvest machines. They are reliable with stable performance, but their structures are complicated. Screw conveying devices have the advantages of being simple in structure; they are also applied in corn united harvest machines, but since they use a helical blade space to transport corn, the structures are huge and difficult to configure in small corn united harvest machines. Therefore, it is necessary to develop a new conveying device. The blades of the new maize ears helical blade friction conveying devices are lower, so the grains during the course of transmission are on the top of the blades at all times. Thus, the conveyer structure can be smaller in size, with less grain injuries in the conveying process. By using a self-made conveying device for maize ears, the research focused on the laws of effects on maize ears conveying performance caused by the new-type transmission auger's blade height, guide side panel's inclining angle, guide side panel position angle, auger lift-and-convey angle, and the rotational speed of the auger. Performances of maize ear conveying devices mainly displays in three aspects: the damage degree of maize ears, the quantity of shattering, and the transport capacity. In the paper, maize ears were first be divided into four states according to the average length, diameter and differences of moisture content. The first state was chosen in the test. Maize ears of the first state are different from the ones of state two, three, and four, respectively, in diameter, length, and moisture content. The state classification was used to study the adaptability of the conveyor as the single characteristic of the material changes. It helps to compare the test results more directly and clearly. Analysis of variance was used in the test to calculate the test results. The test verified that the maize ear conveying device is adapted to many causes, including different maize ear sizes and moisture content. With a blade height of 20 mm, an auger rotational speed of 300 r/min, side panel position angle of 70&deg; and side panel inclination angle of 75&deg;, the novel conveying device can convey maize ears better and effectively avoid the injury by traditional helical conveying devices.
Number of references:26
Main heading:Conveying
Controlled terms:Augers - Conveyors - Display devices - Efficiency - Friction - Harvesters - Harvesting - Moisture determination - Screws - Testing
Uncontrolled terms:Inclination angles - Injury - Maize ears - Performance experiment - Rotational speed - Stable performance - State classification - Transport capacity
Classification code:931.1 Mechanics - 913.1 Production Engineering - 821.3 Agricultural Methods - 821.1 Agricultural Machinery and Equipment - 944.2 Moisture Measurements - 722.2 Computer Peripheral Equipment - 605 Small Tools and Hardware - 502.2 Mine and Quarry Equipment - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 692.1 Conveyors
DOI:10.3969/j.issn.1002-6819.2013.12.002
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 21>

Accession number:20132916508788
Title:Judgment of CO<inf>2</inf> leaking in underground storage using spectral characteristics of soybean
Authors:Jiang, Jinbao (1); Steven, Michael D (2); He, Ruyan (1); Cai, Qingkong (1); Chen, Yunhao (3); Xu, Jin (1)
Author affiliation:(1) College of Geosciences and Surveying Engineering, China University of Mine and Technology, Beijing 100083, China; (2) School of Geography, University of Nottingham, Nottingham, NG7 2RD, United Kingdom; (3) College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China
Corresponding author:Chen, Y.(cyh@bnu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:163-169
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:To mitigate the global warming caused by the excessive emission of CO<inf>2</inf>, Carbon Capture and Storage (CCS) techniques have been proposed to reduce the concentrations of atmospheric CO<inf>2</inf> and to slow down the change of climate. However, everything has two sides for there is a risk of the CO<inf>2</inf> leakage from the stored sites that may impact the surrounding environment significantly. Therefore, the monitoring of CO<inf>2</inf> leaking spots has become a crucial issue to be solved in applying CCS. It is therefore needed to develop a large-scale, quick and highly efficient method for detecting the CO<inf>2</inf> leakage on the surface of the sequestrating fields. Considering that the hyperspectral remote sensing technique can monitor the slight changes of surface vegetation by spectral feature analysis, this paper is dedicated to studying the impacts of the slight CO<inf>2</inf> leakage stress on the surface vegetation through simulating experiment in the field. The experiment was carried out from May 2008 to August 2008 at the Sutton Bonington Campus(52.8 N, 1.2 W)of the University of Nottingham. Beans (Vicia faba cv Clipper) were sowed by hand on June 4th, 2008. From July 4th on, the controlled CO<inf>2</inf> was injected into the soil at a rate of 1L/min, and the concentrations of CO<inf>2</inf> in the soil were measured every day in the field. Additionally, the chlorophyll contents and spectral data of beans were measured one time every week in the laboratory. The results showed that when the concentrations of soil CO<inf>2</inf> was under 15%, there was no significant difference for chlorophyll contents between the control and stressed beans (P&le0.1). However, when the concentrations of soil CO<inf>2</inf> was above 15%, there was a great significant difference for chlorophyll contents between control and stressed beans(P&lt;0.001). As the time passed by, the experimented beans became premature senescent, experienced fallen leaves, and even died. The spectral data were processed by the continuum removal method and the results indicated that in the green bands the spectral reflectance gradually increased as the CO<inf>2</inf> concentrated in the soil; nevertheless, in other bands there were no apparent and stable rules that could be derived from the spectral analysis for the whole growth stage of beans. According to the spectral feature analysis of beans under the stress of CO<inf>2</inf> leakage, a new index (Area(510-590 nm)) was designed to identify the beans. The experiment results showed that the Area (510-590 nm) index was able to identify the stressed beans when the CO<inf>2</inf> concentrations in the soil were above 15%. However, the index was unable to identify the stressed beans when the CO<inf>2</inf> concentration in the soil was fewer than 15%. It can be concluded that the research is of great importance and has application value for detecting the leakage spots, monitoring and evaluating land-surface ecology under CO<inf>2</inf> leakage stress.
Number of references:32
Main heading:Carbon dioxide
Controlled terms:Carbon capture - Chlorophyll - Digital storage - Experiments - Global warming - Models - Sensors - Soils - Spectrum analysis - Vegetation
Uncontrolled terms:Bean - Carbon capture and storage - Hyperspectral remote sensing - Significant differences - Simulating experiments - Spectral characteristics - Surrounding environment - University of Nottingham
Classification code:901.3 Engineering Research - 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 - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 451 Air Pollution - 454 Environmental Engineering - 483.1 Soils and Soil Mechanics - 722.1 Data Storage, Equipment and Techniques - 801 Chemistry - 801.2 Biochemistry - 804.2 Inorganic Compounds
DOI:10.3969/j.issn.1002-6819.2013.12.021
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 22>

Accession number:20132916508795
Title:Characteristic of Zn²/Cd²/NH⁴ transport in soils with different pH value and ionic strength
Authors:Sun, Yingying (1); Xu, Shaohui (1)
Author affiliation:(1) Department of Environment Science, Qingdao University, Qingdao 266071, China
Corresponding author:Xu, S.(shhxu@qdu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:218-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:In order to make a thorough inquiry of Zn, Cd, NH⁴ transportation in soils, the effect of pH and ionic strength on Zn, Cd, NH⁴ transport in soils were studied, through a stable flow miscible displacement experiment. Breakthrough curves (BTCs) of the tracer bromide (Br) and Zn²/Cd²/NH⁴ were obtained in these soil column experiments. With the software HYDRUS-1D, the local equilibrium assumption (LEA) model was used to simulate the observed BTCs of Br. Then we estimated the porosity &theta; and dispersion coefficient D and got the soil column migration model parameters. Through adjusting the value of Kd, &beta;, &alpha;, f, two-site model (TSM) was used to simulate the BTCs of Zn²/Cd²/NH⁴ with software HYDRUS-1D. Based on the analysis of BTCs observation, it turned out that transport velocity of Zn²/Cd²/NH⁴ is NH⁴ &le Zn² &le Cd² when they coexisted in migration. The higher the pH is, the later the flow time of Zn²/Cd²/NH⁴ is, and the lower peak value of relative concentration is. The flow time of NH⁴ was delayed by 8.08 pv to 9.72 pv and the peak value of the relative concentration dropped from 0.976 to 0.904. The flow time of Zn² was delayed by 12.89 pv to 15.45pv and the peak value of BTCs dropped from 0.548 to 0.448. The flow time of Cd² was delayed by 13.32pv to 16.44pv and the peak value of the relative concentration dropped from 0.315 to 0.235. So the rise of pH can increase the adsorption quantity of Zn²/Cd²/NH⁴ in soil and consequently block their transportation. On the other hand, the bigger the ionic strength is, the earlier the flow time of Zn²/Cd²/NH⁴ is, and the higher the peak value is. The flow time of NH⁴ was advanced from 8.78 pv to 7.68 pv and the peak value of the relative concentration rose from 0.933 to 1.013. The flow time of Zn² was advanced from 14.83 pv to 13.98 pv and the peak value of relative concentration rose from 0.496 to 0.542.The flow time of Cd² was advanced from 15.86 pv to 14.69 pv and the peak value of relative concentration rose from 0.281 to 0.294.Thus, the increase of ionic strength can decrease the adsorption quantity of Zn²/Cd²/NH⁴ in soil and thereby promote their transportation. The non-equilibrium theory which describes a solute transport based two-site model described better transport of Zn²/Cd²/NH⁴ in soils of this experiment. The higher the pH was, the bigger the partition coefficient Kd obtained through simulation was (taking Zn² for example, Kd was advanced from 3.853 to 4.386), the smaller f was (taking Zn² for example, f rose from 0.231 to 0.006), and fractal coefficient &beta; was small and had no obvious change rule. The bigger the ionic strength was, the smaller the partition coefficient Kd obtained through simulation was (taking Zn² for example, Kd rose from 4.023 to 3.381), f and fractal coefficient &beta; was very small and had no obvious change rule. The study has an important significance for heavy metals and the migration behavior of nitrogen in the soil and risk assessment, and pollution repair.
Number of references:33
Main heading:Soil pollution
Controlled terms:Adsorption - Experiments - Heavy metals - Ionic strength - pH - Repair - Risk assessment - Soils - Solute transport - Zinc
Uncontrolled terms:Cd - Flow-time - Ironic strength - NH⁴ - Peak values - pH value - Transport
Classification code:922.1 Probability Theory - 913.5 Maintenance - 901.3 Engineering Research - 802.3 Chemical Operations - 801.4 Physical Chemistry - 801.1 Chemistry, General - 546.3 Zinc and Alloys - 531 Metallurgy and Metallography - 483.1 Soils and Soil Mechanics
DOI:10.3969/j.issn.1002-6819.2013.12.028
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 23>

Accession number:20132916508780
Title:Modeling and analyzing water flow in a thick unsaturated zone during precipitation and infiltration
Authors:Li, Na (1); Ren, Li (2); Tang, Zejun (3)
Author affiliation:(1) School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China; (2) College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; (3) College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100193, China
Corresponding author:Li, N.(lina@cugb.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:94-100
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:With more and more attention being received in water flow through the widely distributed thick unsaturated zone in arid and semiarid region, the influence of thick unsaturated zone on the groundwater recharge is of important study. Quantification of groundwater recharge from precipitation under thick unsaturated zone condition can provide theoretic basis for analyzing the hydrological cycle with human disturbance, and reasonably establish water resources development and utilization. Based on the measured soil properties of a 9.6m-deep vadose zone core drilled by GEOPROBE from Caiyu town located in Xinfeng river basin in Daxing district in Beijing, this study focuses on simulation of one-dimensional water transport under 55-year long precipitation time series conditions, analysis of the spatio-temporal characteristics of the water flux and its response to the precipitation and soil texture, and discussion of the feasibility of estimating deep drainage from the shallow water flux. We aim to provide a simple and practical method for evaluation of the contribution of precipitation to groundwater recharge in bare soils. To achieve this, the mechanistic numerical model HYDRUS-1D based on the Richards' equation is used. First, annual precipitation and simulated evaporation, and deep drainage are calculated for the period 1951-2005, with an average annual precipitation of 597.59 mm, an average annual evaporation of 964.38 mm, and an average annual deep drainage of 131.03 mm. Variability in precipitation, ranging from 261.8 mm to 1406 mm (C<inf>v</inf>=35.72%), was amplified in deep drainage, ranging from 17.54 mm to 699.36 mm (C<inf>v</inf>=88.03%), and was reduced in evaporation (C<inf>v</inf>=4.58%). Then the long-term monthly average water flux of the soil profile is calculated for the period 1951-2005. The average monthly infiltration rate in the top layer of soil exceeds average monthly evaporation between May and September. Subsequently, long-term (1951-2005) monthly average rainfall, evaporation, and deep drainage for an extreme high (a), high (b), medium (c), and low (d) precipitation region are depicted. The average deep drainage is 103.55 mm in the medium precipitation region (575.76 mm/year average rainfall), with the coefficient of recharge from precipitation of 0.1799, which is lower than the 55-year average coefficient of recharge from precipitation of 0.2138. In general, the highest precipitation months are July and August, and average monthly precipitation exceeds average monthly evaporation during these months except for the low precipitation region. The highest evaporation months are from May to July due to high solar radiation and temperatures in these months. Finally, long-term average soil moisture fluxes in the whole soil profile corresponding to four different time periods (1996-2005, 1981-2005, 1966-2005, 1951-2005 respectively) are calculated, which reveals that the average infiltration rate on soil profile below 2 m keep almost unchanged with the variation of depth between 1951 and 2005.
Number of references:22
Main heading:Infiltration
Controlled terms:Arid regions - Evaporation - Flow of water - Hydraulics - Phase transitions - Precipitation (chemical) - Rain - Recharging (underground waters) - Soil moisture - Soil testing  - Sun
Uncontrolled terms:Arid and semi-arid regions - Average annual precipitation - HYDRUS-1D - Monthly average rainfalls - Precipitation time series - Soil water fluxes - Spatiotemporal characteristics - Water resources development
Classification code:801.4 Physical Chemistry - 657.2 Extraterrestrial Physics and Stellar Phenomena - 632.1 Hydraulics - 631.1.1 Liquid Dynamics - 802.3 Chemical Operations - 483.1 Soils and Soil Mechanics - 444 Water Resources - 443.3 Precipitation - 443 Meteorology - 444.2 Groundwater
DOI:10.3969/j.issn.1002-6819.2013.12.013
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 24>

Accession number:20132916508786
Title:Improvement effects of subsurface pipe with different spacing on sodic-alkali soil
Authors:Tian, Yufu (1); Dou, Sen (2); Zhang, Yuguang (3); Wang, Changyu (3); Wu, Jinsong (5)
Author affiliation:(1) School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; (2) College of Resources and Environment, Jilin Agricultural University, Changchun 130118, China; (3) Land Consolidation and Rehabilitation Center of Jilin Province, Changchun 130042, China; (4) Land Consolidation and Rehabilitation Center, The Ministry of Land and Resources, Beijing 100035, China; (5) Da'an Land and Resources Bureau, Da'an 131300, China
Corresponding author:Dou, S.(dousen@tom.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:145-153
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:According to the worldwide difficult problem of soda meadow alkaline soil improvement, the paper used the technology of subsurface drainage and desalination, and studied the effects of different spacing (L1 with 5 m, L2 with 10 m, L3 with 20 m and L4 with 40 m) on soil permeability, organic matter content and exchangeable sodium percentage (ESP), sodium adsorption ratios(SAR), and other physical-chemical characters of soda meadow alkaline soil. Supplementary measures contained applying farmyard manure (34 m³/hm²) and modifier (15 t/hm²). Pipe spacing was obtained by the below three means of Dacey law, pipe spacing numerical method of experience and the relational expression between pipe buried depth and pipe spacing. The results showed that: 1) compared with CK (no subsurface drainage and no supporting measures), CK1 (no subsurface drainage but having supporting measures) improved the soil permeability significantly; compared with CK1, the soil permeability of L1, L2 and L3 was improved significantly; and the soil permeability coefficient (K10)of L1 treatment is higher than others; 2) compared with CK, the organic matter content, available potassium content and cation exchange capacity (CEC) of CK1 was increased significantly; compared with CK1, the organic matter content of L1, L2 and L3 was increased significantly, and the alkaline nitrogen content, available potassium content and CEC of L1 increased significantly; 3) the treatment of subsurface pipe being densely buried can decrease the soil pH, electrical conductivity (EC), total alkalinity (TA), ESP and SAR of soil. Effects of treatment L1 on the soil pH, EC, TA, ESP and SAR of soil were the most obvious among the treatments, and pH, EC, TA, ESP and SAR of L1 treatment were the minimum with 7.85, 0.15 mS/cm, 2.34 cmol/kg, 39.47% and 2.41 (mmol/L)^1/2 respectively. In general, under the conditions of subsurface drainage with burial depth 0.8 m, and the same rice-planting and supporting measures, subsurface drainage spacing of 5 m had the best improvement effect, and pH value of the surface soil dropped to below 8.0. This research preliminarily solved the problem of soda meadow alkali soil improvement, providing an important theoretical basis and technical support for ameliorating sodic soil, improving land capability and discussing the feasibility of subsurface pipe technology using for amelioration of sodic soil in soda saline-alkali soil region, and promoting the development, popularization and application of the subsurface drainage and desalination soil technology.
Number of references:34
Main heading:Soils
Controlled terms:Alkalinity - Biogeochemistry - Biological materials - Desalination - Drainage - Groundwater flow - Organic compounds - pH - pH effects - Water filtration
Uncontrolled terms:Alkaline soils - Available potassiums - Cation exchange capacities - Electrical conductivity - Exchangeable sodium percentages - Organic matter content - Pipe spacings - Sodium adsorption ratio
Classification code:804.1 Organic Compounds - 801.2 Biochemistry - 801.1 Chemistry, General - 502 Mines and Quarry Equipment and Operations - 483.1 Soils and Soil Mechanics - 461.2 Biological Materials and Tissue Engineering - 445.1 Water Treatment Techniques - 444.2 Groundwater - 442 Flood Control; Land Reclamation - 406 Highway Engineering - 401 Bridges and Tunnels
DOI:10.3969/j.issn.1002-6819.2013.12.019
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 25>

Accession number:20132916508787
Title:Effects of warping dams of different storage capacity configuration proportion on reducing sediment base
Authors:Ran, Dachuan (1); Yao, Wenyi (1); Li, Zhanbin (2); Luo, Quanhua (3)
Author affiliation:(1) Yellow River Institute of Hydraulic Research, Yellow River Conservancy Commission, Zhengzhou 450003, China; (2) Faculty of Water Resources and Hydraulic Power, Xi'an University of Technology, Xi'an 710048, China; (3) Xifeng Soil and Water Conservation Experimental Station, Yellow River Conservancy Commission, Qingyang 745000, China
Corresponding author:Ran, D.(xfrdc@sohu.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:154-162
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:This paper analyzed the effect of warping dams of different configuration ratios on reducing sediment and major factors contribution rate by mathematical statistics method and the investigation data in Dali River basin in middle of Yellow River. The investigation data showed land area of different type dams increased with time in Dali River basin, but presented obviously slow increasing in the near future. Warping dams reduced mean flood amount with 18.4 million m³ and sediment 12.9 million t during 1960-2002 annually, and the ratio of different type dams was 80.1%, 14.6%, 5.3%, respectively. The period of biggest reduction of sediment with 30.2% was 1990 s, and the responding ratio of different type warping dams was 1.84:2.37:5.79.The sediment decrement of large-scale soil-retaining dam was 5.5 times than that of medium dam, and was 15 times than that of small dams. The optimized proportion of distributions of warping dams for achieving continuous sediment reduction in the future in drainage basin was 1:3.0:7.0. The maximum amount of sediment reduction by different types of soil retaining dams correlated closely with flood season rainfall and 1-day maximum rainfall. Within the sediment reduction capability of warping dams, the amount of sediment reduction increased with rainfall intensity, presenting the characteristics of "the more sediment reduction with the more incoming sediment". Reducing sediment of the warping dams had a proportionality relationship with observed flood in different periods. Since 1990s, sediment reduction was about 0.23 t/m³ of unit cubic meter of flood discharge. Sediment reduction amount was about 0.19t/m³ per unit cubic meter of flood discharge during 1970s and 1980s, and the amount was about 0.23 t/m³ since 1990s. The warping dams reduced sediment increased with the value of 3 major factors. The contribution ratio of the factors was in the order: the flood amount &le rain season rainfall &le 1-day maximum rainfall.
Number of references:26
Main heading:Sediments
Controlled terms:Dams - Floods - Rain - Statistics - Watersheds
Uncontrolled terms:Configuration ratio - Contribution rate - Contribution ratios - In-coming sediments - Mathematical statistics methods - Rainfall intensity - Sediment reduction - Storage capacity
Classification code:441.1 Dams - 443.3 Precipitation - 444.1 Surface Water - 483 Soil Mechanics and Foundations - 914.1 Accidents and Accident Prevention - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2013.12.020
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 26>

Accession number:20132916508801
Title:Moisture transport in carrot during hot air drying using magnetic resonance imaging
Authors:Xu, Jianguo (1); Xu, Gang (1); Zhang, Xukun (2); Gu, Zhen (1); Zhang, Senwang (1); Li, Huadong (1)
Author affiliation:(1) Food Engineering Innovation Center of Jiangxi Academy of Sciences, Nanchang 330029, China; (2) Key Laboratory of Non-destructive Testing of Ministry of Education, Nanchang Hangkong University, Nanchang 330063, China
Corresponding author:Xu, J.(chem._food@hotmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:271-276
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The drying process is one of the most important processes in food engineering. Heat and moisture transfer in fruits and vegetables during drying is a complex process, and knowledge of the moisture profile is fundamentally important for industrial processes, because the quality aspects of dried foodstuffs, such as nutrient content, safety and weight, are related to moisture content. A better understanding of the mechanism of moisture transfer should help improve product quality and the efficiency of the drying process. Such information will also help produce realistic computer simulations of drying processes and Fickian and non-Fickian models of moisture transport. Moisture profiles in foodstuffs can be measured using destructive and non-destructive methods. Slicing and freezing is not an accurate method because of low precision and moisture loss during cutting process, although it could give inside moisture distribution. In recent years, the applicability of nuclear magnetic resonance imaging (MRI) to measure mass transport phenomena in porous systems, especially in foodstuffs and biological materials, including drying processes, has been demonstrated. NMR imaging as a non-destructive, non-invasive, promising technique has been used to obtain moisture profiles during drying of vegetables and fruits. In this paper, the moisture transport in a cylindrical carrot sample was visualized and studied using nuclear magnetic resonance images obtained from the drying experiments. The transient moisture profile distributions in carrot were measured during the hot-air drying process with air temperatures of 40 and 70&deg;C, respectively. Experimental results showed that the moisture profiles moved irregularly toward the center of the carrot sample in both the axial and radial directions, indicating a muti-dimensional and unsteady-state mass transfer process that has non-Fickian moisture transport characteristics. In the initial drying stage, a sharp moisture gradient was found indicating significant moisture flux at the surface of the carrot. With the process of drying, the ratio of the MRI diameter declined faster than that of the optical diameter, which indicated that the dried layer appeared at the surface and moisture profile moved inside. The Henderson-Pabis model (MR=1.003e-0.01114t, R²=0.9994) achieved better predictive accuracy than other models and satisfactorily described drying characteristics of the carrot cylinder at 70&deg;C. The maximum relative error of prediction compared with the measured results was 7.69%, with relative errors during the drying process at 70&deg;C commonly remaining less than 4%. The moisture transport of the carrot center layer was simulated by the Henderson-Pabis model (MR=1.005e-0.00286t, R²=0.9978) during the drying process at 40&deg;C. These results could assist in the optimization of drying process and theoretical simulation on moisture transport considering shrinkage caused by drying.
Number of references:28
Main heading:Drying
Controlled terms:Biological materials - Computer simulation - Fruits - Magnetic resonance imaging - Moisture - Moisture control - Nondestructive examination - Shrinkage - Vegetables
Uncontrolled terms:Drying characteristics - Heat and moisture transfer - Maximum relative errors - Moisture distribution - Moisture profiles - Moisture transport - Nondestructive methods - Theoretical simulation
Classification code:951 Materials Science - 944.2 Moisture Measurements - 821.4 Agricultural Products - 801.4 Physical Chemistry - 746 Imaging Techniques - 723.5 Computer Applications - 642.1 Process Heating - 461.2 Biological Materials and Tissue Engineering - 421 Strength of Building Materials; Mechanical Properties
DOI:10.3969/j.issn.1002-6819.2013.12.034
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 27>

Accession number:20132916508781
Title:Estimating land surface evapotranspiration based on trapezoidal relationship between land surface temperature and vegetation index
Authors:Wang, Wen (1); Wang, Xiaogang (1); Huang, Dui (1); Yong Bin (1)
Author affiliation:(1) State Key laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
Corresponding author:Wang, W.(w.wang@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:101-109
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Land surface evapotranspiration (ET) is an important link in the process of regional water cycle. Many methods have been proposed for estimating ET utilizing information from different types of remotely sensed data, often in combination with ancillary surface and atmospheric observations. In particular, Ts-VI (surface temperature/vegetation index) triangle method using optical and thermal infrared satellite data is common for the retrieval of ET. However, Ts-VI triangle method has several major limitations, including the subjectivity of determining the dry and wet edges and the difficulty in defining the ET at the joint of dry edge and wet edge. By modifying the concept of the vegetation index-temperature (VIT) trapezoid proposed by Moran et al. (1994), Wang et al. (2011) developed a method of constructing the trapezoidal relationship between land surface temperature (Ts) and enhanced vegetation index (EVI) using ground-based meteorological observations and satellite remotely sensed surface temperature and vegetation index data jointly based on the energy balance equation. On the basis of that, a land surface actual ET estimating method was developed in the present study by estimating Priestley-Taylor coefficient, and then ET was calculated using the Priestley-Taylor equation for each pixel. The method is composed of three major steps: 1) establish Ts-VI trapezoidal space under extreme conditions, i.e., full vegetation cover and bare soil with extreme dryness and wetness, for each pixel, based on the principle of land-surface energy balance; 2) calculate the Priestley-Taylor coefficient for each pixel according to the position of the observed Ts-VI point in the trapezoid space; 3) finally use the Priestley-Taylor equation to estimate actual ET of the pixel. Compared with the method of VIT trapezoid, the Ts-VI trapezoid method has the advantage of taking into account the interaction of different variables and parameters (such as the net radiation Rn, aerodynamic resistance ra, sensible heat flux density H, stability correction for heat &psi;h, stability correction for momentum &psi;m) in the process of calculating the Ts at four extreme conditions, which better describes the relationship between those parameters. In addition, another major differences between the Ts-VI trapezoid method and the Ts-VI triangle method as well as the VIT trapezoid method is that, we did not assume zero ET at dry edge (except at the dry point at bare soil condition). The method was validated using MODIS data and ground observation data for the semi-arid Walnut Gulch watershed at Arizona, USA. The result of ET estimation was satisfied with mean absolute error of about 35.5%.
Number of references:32
Main heading:Atmospheric temperature
Controlled terms:Energy balance - Estimation - Evapotranspiration - Heat flux - Heat resistance - Pixels - Radiometers - Remote sensing - Surface measurement - Temperature  - Water supply
Uncontrolled terms:Enhanced vegetation index - Land surface temperature - Meteorological observation - MODIS - Priestley-Taylor - Priestley-Taylor equation - Trapezoidal relationship - Vegetation index
Classification code:943.2 Mechanical Variables Measurements - 931.2 Physical Properties of Gases, Liquids and Solids - 931 Classical Physics; Quantum Theory; Relativity - 921 Mathematics - 731.1 Control Systems - 944.7 Radiation Measuring Instruments - 723.5 Computer Applications - 641.1 Thermodynamics - 446.1 Water Supply Systems - 444.1 Surface Water - 443.1 Atmospheric Properties - 641.2 Heat Transfer
DOI:10.3969/j.issn.1002-6819.2013.12.014
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 28>

Accession number:20132916508779
Title:Constant pressure water supply automatic device designed for micro-irrigation system based on solar energy
Authors:Li, Jianian (1); Hong, Tiansheng (2); Ni, Huina (2)
Author affiliation:(1) Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming 650500, China; (2) College of Engineering, South China Agricultural University, Guangzhou 510642, China; (3) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, Guangzhou 510642, China; (4) Division of Citrus Machinery, China Agriculture Research System, Guangzhou 510642, China
Corresponding author:Hong, T.(tshong@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:86-93
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The stability of micro-irrigation system inlet water pressure affects the uniformity of the micro-irrigation and the mixed fertilizer accuracy of automatic fertilizer mixing device. In order to provide a constant inlet water pressure for small and medium-sized irrigation pipe network which adopts gravity drip irrigation, a constant pressure water supply automatic control device was developed, through employing a diaphragm pump DP-60 powered by solar energy to carry water to the reservoir built in high place, and maintaining the reservoir' water level at a fixed height in the drip irrigation process. The water level was detected online by using a level sensor YZ-YO-LAG1, and the controller control DP-60 carrying water to the reservoir according to the water level detected. Due to the certain distance between reservoir water level detection terminal and DP-60 control terminal, two wireless communication modules CC1100 were installed in each terminal respectively to realize wireless data transmission and control between two terminals. To reduce power consumption of wireless communication, a regular communication strategy combining with sleeping mechanism was adopted, and a kind of time synchronization technology was employed to keep time synchronization between the communication parties, and the WOR (wake on radio) mode of CC1100 module was enabled while communicating, the communication success rate was 100% verified by practical test. Photovoltaic capacity of the system had been designed for obtaining an optimal capacity combination of solar cell array and lead-acid battery, and the solar panel power was determined to be 60 W and the battery capacity to be 60 A&middoth, the capacity combination could meet the electricity demand of 500L irrigation norm for each drip irrigation cycle, and ensure that the system operates normally in seven consecutive days without sunshine. In order to maximize the use of solar energy, the relationship between solar panel power and the output frequency of solar radiation sensor TSL230 was calibrated through experiment, and then the controller could select the battery or solar panel as the direct power for DP-60 automatically, based on actual output power (obtained from the output frequency of TSL230) of the solar panel and the stage of charge of battery. To guide the application and installation of DP-60 in actual engineering, the maximum pumping head, maximum suction head, current characteristics and flow characteristics of DP-60 had been determined by experiments, with its inlet and outlet connecting with a PVC pipe of DN15 diameter respectively. To avoid the large peak pulse current, a soft start-up control was applied to control DP-60 by employing PWM (pulse width modulation) technology, and the frequency of PWM was 20 kHz, and the period for accomplishing a soft start or a soft stop was 2s. Practical application experiment for the constant pressure water supply automatic control device had been taken for more than 6 months, and the results showed the device was stable and the error of the reservoir water level was less than 1 cm.
Number of references:19
Main heading:Controllers
Controlled terms:Automation - Communication - Control - Control equipment - Experiments - Fertilizers - Inlet flow - Irrigation - Polyvinyl chlorides - Process control  - Pulse width modulation - Reservoirs (water) - Solar concentrators - Solar energy - Sun - Water levels - Water supply - Wireless telecommunication systems
Uncontrolled terms:Communication strategy - Constant pressures - Current characteristic - Microirrigation systems - Soft start-up controls - Solar radiation sensors - Wireless communications - Wireless data transmission
Classification code:901.3 Engineering Research - 821.3 Agricultural Methods - 815.1.1 Organic Polymers - 804 Chemical Products Generally - 732.1 Control Equipment - 731 Automatic Control Principles and Applications - 716 Telecommunication; Radar, Radio and Television - 657.2 Extraterrestrial Physics and Stellar Phenomena - 657.1 Solar Energy and Phenomena - 631.1 Fluid Flow, General - 614.2 Steam Power Plant Equipment and Operation - 446.1 Water Supply Systems - 441.2 Reservoirs
DOI:10.3969/j.issn.1002-6819.2013.12.012
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 29>

Accession number:20132916508775
Title:Prediction of failure modes and finite element verification of laser tailor welded blanks for vehicle
Authors:Chen, Shuisheng (1); Lin, Jianping (2); Wang, Yuqing (1)
Author affiliation:(1) School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454000, China; (2) School of Mechanical and Energy Engineering, Tongji University, Shanghai 201804, China
Corresponding author:Lin, J.(jplin58@tongji.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:57-63
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Tailor welded blanks (TWB's) consist of steel sheets with different materials, thickness, and coating welded into a single flat blank prior to forming in order to meet the different needs for various positions of parts. TWB's provide various advantages, namely, reduction of weight, fuel consumption and air pollution, lower manufacturing costs, and improved structural integrity over conventional sheet metal forming methods. However, the degradation of TWB's formability causes current applications to be limited. In order to take advantage of these benefits, we need to understand the characteristics related to TWB's forming, and especially be able to predict the failure modes during the press forming. Some important factors which influence the failure modes of the TWB's are: the thickness ratio, the base materials combination and the weld properties. To simplify calculation, in the current investigation, the TWB's with similar materials and different thicknesses were considered to study the effect of the thickness ratio on the failure modes. We created a biaxial stretching model consisting of the weld region, the thicker and thinner sides, and further assumed that the strain was equal along the weld direction. The North American Deep Drawing Research Group (NADDRG) model was used to evaluate the formability of the base materials and the weld. The deformation coordinate relationship among the weld element and the adjacent thinner side element at the dangerous point was modeled analytically based on the statistical mechanical theory. The Ludwick-Hollomon power law was employed to characterize the strain-hardening behavior of the base material and the weld. During calculations, thickness average of thinner and thicker sheets was assumed as weld zone thickness. Then a so-called model of critical thickness ratio (CTR) was presented by the analytical method to predict the failure mode of tailor welded blanks (TWB's) during forming. The model demonstrates that the rupture occurs simultaneously at the weld and the thinner side when the weld properties, the base material properties, and the initial thickness ratio meet CTR model. Other parameters keep constant in the CTR model, only the effect of the thickness ratio on the failure modes was considered in this study. If the thickness ratio exceeds CTR, the rupture occurs at the thinner side; otherwise, the rupture occurs at the weld. To verify the effectiveness of the developed CTR model, we carried out the limit bulging height tests for the TWB' s with dissimilar thickness combinations by finite element and experimental methods. The laser TWB's with the base material of DC56D Z used in experiments were provided by Baosteel Co., Ltd. Tensile tests according to GB/T 228-2002 standards were used to determine the mechanical properties of the base sheets, while miniature samples were used to acquire the mechanical properties of the weld, of which the width was identified by executing the hardness tests. It can also be seen from the hardness analysis results, micro-hardness is not uniformly distributed along the cross-section of TWB' s, which reflects the difference in material hardening behavior across the weld lines. The hardness of the weld metal is higher than that of the HAZ and the base metal. The weld width was approximately estimated at 1.5 mm. According to the analytical model of the CTR, it is necessary to give the strain state of TWB's before the CTR is calculated. The biaxial tension with equal displacements was considered in the investigation. The deformation of the weld was much less than the base material of TWB's in the direction perpendicular to the weld line. We can exclude the effect of the deformation of the weld on the global deformation. The deformation compatibility relationships between the base sheets were only considered in the direction perpendicular to the weld line. The deformations in the two directions parallel and perpendicular to the weld line were equal based on the hypothesis of the biaxial tension with equal displacements. Then, the strain state of the biaxial tension with equal displacements can be determined. Two approaches, excluding and including the weld properties, was used to model the weld of TWB's in the finite element analysis. The failure always occurs at the thinner side of TWB's when modeling the weld using the former method. It occurs at the thinner side when the thickness ratio is large or at the weld when the thickness ratio is small if modeling the weld using the latter method. Comparing the results from the two methods, we can capture the CTR of TWB's. Given the equiaxial strain state, in the case of two TWB's recommended in the published literatures, the critical thickness ratio was achieved through the analytical and FE method. From the comparison of the two results, there were errors between the analytical and FE results, 7.76% and 6.15% respectively, which attributes to the deviation of the strain state in FE analysis from the equiaxial strain state. The results show the presented CTR analytical model is effective and can predict the failure mode of TWB's in the forming process.
Number of references:21
Main heading:Failure modes
Controlled terms:Analytical models - Deformation - Finite element method - Forecasting - Hardening - Hardness - Heat affected zone - Joints (structural components) - Materials - Models  - Tensile testing - Vehicles - Welding
Uncontrolled terms:Critical thickness - Deformation compatibility - Experimental methods - Finite element verification - North american deep drawing research groups - Prediction of failures - Statistical mechanical theory - Strain-hardening behaviors
Classification code:951 Materials Science - 921.6 Numerical Methods - 921 Mathematics - 902.1 Engineering Graphics - 538.2 Welding - 537.1 Heat Treatment Processes - 432 Highway Transportation - 422.2 Strength of Building Materials : Test Methods - 422 Strength of Building Materials; Test Equipment and Methods - 421 Strength of Building Materials; Mechanical Properties - 408.2 Structural Members and Shapes
DOI:10.3969/j.issn.1002-6819.2013.12.008
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 30>

Accession number:20132916508770
Title:Development of auto-follow row system employed in pull-type beet combine harvester
Authors:Wu, Huichang (1); Hu, Zhichao (1); Peng, Baoliang (1); Gu, Fengwei (1); Wang, Haiou (1); Wang, Bokai (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing 210014, China
Corresponding author:Hu, Z.(nfzhongzi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:17-24
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:The sugar beet is one of the major sugar crops in China, accounting for about 17% of Chinese total sugar production. As a seasonal operation, sugar beet harvesting in China is still mainly manual work, characterized by high labor intensity, low efficiency, great harvest losses, and huge occupation of farming, all of which constraine the further development of the sugar beet industry. Mechanized harvesting is the inevitable development trend of sugar beet harvesting. The current domestic sugar beet harvesters are basically simple sectional operating machinery. Sugar beet combine harvesters are mainly imported from abroad, having high automation and intelligence and advanced performance. The domestic beet combines are still in the prototype development stage, having a great gap with the advanced foreign technology. Auto-follow row technology is one of the key features of beet combine harvesting, having great influence on machinery performance. Although domestic researchers have performed lots of studies on the automatic control of agricultural machinery, research on control systems for auto-follow harvesters is still scarce, which greatly affects the automation level and operation performance of domestic beet combine harvesters. In order to improve the automation level and reduce harvesting loss, a set of auto-follow row system for a pull-type beet combine harvester was designed by adopting hydraulic technology, sensor signal acquisition technology, and microprocessor control technology, which was based on the ridge-planting cultivation of sugar beets. The system includes a row detection mechanism, an adjustment mechanism for traction offset, a hydraulic control system, an electronic control system, and control software. The row detection mechanism detects the position of the ridge top beetroot block, converts the offsets of excavation forward locus to angle quantity, and then sends the information to the offset angle acquisition sensor. The offset angle acquisition sensor converts angle information to a digital signal and sends it to the controller. The controller handles the angle signal and outputs a control signal for the solenoid valve, through the control software, opening the hydraulic cylinder drive oil line. The hydraulic cylinder drives the traction biasing mechanism, adjusting the digging position. The angle feedback sensor installed on the traction-offset mechanism feeds back the adjusted angle signal to the controller. The controller adjusts output control signals in real time, ensuring the excavation forward locus always consistent with the beetroot block position. The entire control system is a closed-loop feedback system. The controller is a single-chip microprocessor &mu;PD78F0525. Control software adopts Keil C language, using a fixed double dead zone control algorithm, because it increases system noise immunity, avoids frequent shocks of control action, and improves control stability. Standard signal tracking tests showed that the system had fast-response characteristics and high stability. The results of comparison experiments showed that the harvesting indexes of the beet combine were improved by employing the control system of auto-follow row, in which the loss rate of un-harvested beets, the root body fracture rate, and the root block damage rate were reduced by 2.03%, 1.48% and 2.64%, respectively. This study can provide effective reference for the development of auto-follow row systems employed in similar harvesting machinery.
Number of references:32
Main heading:Traction control
Controlled terms:Agricultural machinery - Algorithms - Automation - C (programming language) - Control systems - Controllers - Excavation - Harvesters - Harvesting - Hydraulic machinery  - Mechanical actuators - Microprocessor chips - Sensors - Signal detection - Sugar beets - System stability - Technology
Uncontrolled terms:Auto-follow row - Closed-loop feedback system - Combine harvesters - Electronic control systems - Hydraulic control systems - Microprocessor control - Output control signals - Single chip microprocessor
Classification code:732 Control Devices - 732.1 Control Equipment - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession - 921 Mathematics - 961 Systems Science - 731 Automatic Control Principles and Applications - 502.1 Mine and Quarry Operations - 632.2 Hydraulic Equipment and Machinery - 716.1 Information Theory and Signal Processing - 721 Computer Circuits and Logic Elements - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 723.1.1 Computer Programming Languages
DOI:10.3969/j.issn.1002-6819.2013.12.003
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 31>

Accession number:20132916508793
Title:Daily change and math-expression method of outside temperature in winter for greenhouse environmental analysis
Authors:Xu, Fan (1); Ma, Chengwei (1)
Author affiliation:(1) Key Laboratory of Agricultural Engineering in Structure and Environment, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Ma, C.(macwbs@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:203-209
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Hourly, outdoor meteorological data are essential for the accurate dynamic simulation and analysis of the greenhouse thermal environment. Most meteorological stations have only published the four times (six/eight times) observation results, but hourly data have always been considered as classified files and not published. Also not published is the continuous observation temperature data in research or production, which should be included in the change principle and in greenhouse environment analysis. In this paper, we examined the daily change rule of outside air temperature in January for greenhouse environment analysis. According to observation data from 2009 to 2011, measured and recorded by the thermal recorder RS-12, we acquired the temperature data of each 10 min interval from 14 stations in North China. For each station, we adjusted the data to reflect true solar time, and using the hourly temperature at the true solar hourly time, we calculated the hourly temperature changing coefficient &beta;. We then analyzed the hourly change of outside temperature in five provinces of North China for the month of January, and summarized a mathematical method for hourly air temperature by using &beta; when the daily maximum and minimum temperature were known. The results showed: In the same province, although the measured temperature is quite different in various years, &beta; is always on the similar change trend and value at the same hour, so the outside temperature daily change can be described by the same coefficient in each province. By comparing &beta; of the five provinces in North China, we found that &beta; are similar, and R2 reached 0.9704, so we can also show the hourly change of outside temperature by the same &beta;. Based on the results above, we summed the hourly changing coefficient (1-24h) of outside temperature in January in North China. When we contrasted &beta; with heating ventilation and air conditioning (HVAC), the two curves were different in minimum value time and rise/fall speed, which is related to seasons. The values of the outside air temperature hourly were changing coefficient &beta; from 1 to 24h is -0.35, -0.37, -0.40, -0.44, -0.46, -0.48, -0.50, -0.39, -0.09, 0.12, 0.28, 0.39, 0.46, 0.50, 0.49, 0.41, 0.20, 0.02, -0.08, -0.15, -0.19, -0.24, -0.27, -0.31, respectively. The winter coefficient was examined by Xinkaikou Town in Tianjin in January of 2011, and Tongzhou District in Beijing in January of 2012.The simulation results of hourly air temperature outside by this method were similar to the actual measurements, the R2 all reached 0.98, and average error were all 0.3&deg;C. On this basis, using the Fourier series expansion, we stated a mathematical expression for calculating outside temperature at any time. According to the daily maximum and minimum temperature outside, we could determine the outside temperature at any time and provide full outdoor temperature data for greenhouse environment simulations accurately.
Number of references:28
Main heading:Greenhouses
Controlled terms:Air conditioning - Atmospheric temperature - Computer simulation - Fourier series - Meteorology - Temperature
Uncontrolled terms:Air temperature - Environmental analysis - Fourier-series expansion - Heating ventilation and air conditioning - Mathematical expressions - Maximum and minimum temperatures - Outside-air temperature - Simulation and analysis
Classification code:921.3 Mathematical Transformations - 723.5 Computer Applications - 643.3 Air Conditioning - 641.1 Thermodynamics - 443.1 Atmospheric Properties - 443 Meteorology - 402.1 Industrial and Agricultural Buildings
DOI:10.3969/j.issn.1002-6819.2013.12.026
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 32>

Accession number:20132916508803
Title:Oxidation and decrease of gelling properties for meat myofibrillar protein induced by hydroxyl radical
Authors:Li, Yin (1); Li, Xia (1); Zhang, Chunhui (1); Sun, Hongmei (1); Dong, Xianbing (1)
Author affiliation:(1) Comprehensive Key Laboratory of Agro-Products Processing, Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
Corresponding author:Zhang, C.(dr_zch@yahoo.com.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:286-292
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Oxidation and changes of gelling properties of myofibrillar protein (MP) induced by the hydroxyl radical (&middotOH) were studied in this paper. Pork myofibrillar protein was suspended in 15 mmol/L piperazine-N, N-bis(2-ethane sulfonic acid) (PIPES) buffer (pH 6.0), and 0.6 mol/L NaCl, and incubated at 4&deg;C for 24 h with ferric ion (Fe³) and ascorbic acid (Vc) at six concentrations of hydrogen peroxide (0, 0.5, 1.0, 5.0, 10.0, 20.0 mmol/L H<inf>2</inf>O<inf>2</inf>). The indexes including protein carbonyl content and whiteness, water-holding capacity (WHC), and texture profile analysis (TPA) of MP gel were measured. The ability of MP to form a fine gel network was described in terms of shear storage modulus (G'), and it was analyzed by small strain oscillatory rheological testing. The microstructure of MP gel was observed by scanning electric microscopy (SEM). The transverse relaxation time (T2) and water distribution of MP gel were analyzed by low-field nuclear magnetic resonance (low-field NMR). Correlation analysis between indexes of MP gel was also performed to establish possible linkages between concentration of H<inf>2</inf>O<inf>2</inf> and different parameters of MP gel in this study. The results showed that carbonyl content steadily increased with H<inf>2</inf>O<inf>2</inf> concentration, increased from 1.17 nmol/mg protein (non-oxidized MP) to 2.82 nmol/mg protein (20.0 mmol/L H<inf>2</inf>O<inf>2</inf>). With increasing H<inf>2</inf>O<inf>2</inf> concentration, the whiteness and WHC of MP gel decreased significantly (p&lt;0.05) (89.89, 64.17% respectively for non-oxidized MP gel, 87.35, 54.77% respectively for 20.0 mmol/L H<inf>2</inf>O<inf>2</inf>). The texture (hardness, springiness, cohesiveness and chewiness) and shear storage modulus (G') also attenuated with increasing H<inf>2</inf>O<inf>2</inf> concentration. The SEM results demonstrated that oxidation of protein could significantly affect the microstructure of MP gel. The non-oxidized MP gel exhibited a compact and homogeneous fine network microstructure, whereas the oxidation process produced empty spaces and changed the compact and fine gel structure to a coarser network, and the effect increased with higher H<inf>2</inf>O<inf>2</inf> concentration. The low-field NMR relaxation measurement results indicated that the oxidation degree of protein had no effect on the bound water (T<inf>21</inf>) of MP gel but had significant effects on immobile water (T22) and free water (T<inf>23</inf>) of MP gel. T<inf>22</inf> water content (P<inf>22</inf>) decreased with increasing H<inf>2</inf>O<inf>2</inf> concentration (94.03% for non-oxidized MP gel, 91.16% for 5 mmol/L H<inf>2</inf>O<inf>2</inf>, 88.14% for 20 mmol/L H<inf>2</inf>O<inf>2</inf>). T<inf>23</inf> water content (P23) increased with H<inf>2</inf>O<inf>2</inf> concentration (1.37% for non-oxidized MP gel, 4.25% for 5 mmol/L H<inf>2</inf>O<inf>2</inf>, 7.56% for 20 mmol/L H<inf>2</inf>O<inf>2</inf>). Taken together, these results demonstrate that with increasing H<inf>2</inf>O<inf>2</inf> concentration, some part of the immobile water of MP gel shifts to free water, and the free water would become the potential centrifuge drip loss. Correlation analysis results showed that concentration of H<inf>2</inf>O<inf>2</inf> was highly negatively correlated with whiteness, WHC, hardness and chewiness (p&lt;0.05). Based on the synthetic evaluation on the testing results of the MP gel, it can be concluded that the &middotOH will result in oxidation of MP, and have detrimental effects on the gelling property of porcine MP. Therefore, it is imperative to inhibit the oxidation of MP during storage and processing of meat to avoid losing the functional properties of porcine MP.
Number of references:30
Main heading:Oxidation
Controlled terms:Ability testing - Correlation methods - Food processing - Gelation - Hardness - Meats - Microstructure - Nuclear magnetic resonance - Proteins - Textures  - Water supply systems
Uncontrolled terms:Hydroxyl radicals - Myofibrillar proteins - Network microstructures - Nuclear magnetic resonance(NMR) - Protein carbonyl content - Texture profile analysis - Transverse relaxation time - Water holding capacity
Classification code:933 Solid State Physics - 932.2 Nuclear Physics - 922.2 Mathematical Statistics - 912.4 Personnel - 822.3 Food Products - 951 Materials Science - 822.2 Food Processing Operations - 802.3 Chemical Operations - 802.2 Chemical Reactions - 446.1 Water Supply Systems - 421 Strength of Building Materials; Mechanical Properties - 804.1 Organic Compounds
DOI:10.3969/j.issn.1002-6819.2013.12.036
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 33>

Accession number:20132916508783
Title:Analysis on basic soil productivity change of winter wheat in fluvo-aquic soil under long-term fertilization
Authors:Gong, Fufei (1); Zha, Yan (1); Wu, Xueping (1); Huang, Shaomin (2); Xu, Minggang (1); Zhang, Huimin (1); Liu, Hailong (3); Jiang, Zhiwei (1); Wang, Xiaobin (1); Cai, Dianxiong (1)
Author affiliation:(1) Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (2) Soil and Fertilizer Institute, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China; (3) Agricultural Information Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Corresponding author:Wu, X.(xpwu@caas.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:120-129
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Fluvo-aquic soil areas are important grain production areas in China. With the population increasing and the economy developing, China is facing the big challenge to increase grain yield and ensure food security. Because the use of fertilizer has reached a high level, increasing fertilizer application is no longer an effective way to increase production. The results of many long-term soil fertility experiments show that the basic soil productivity (BSP) change was important to reduce fertilizer application rates and increase crop yield. Thus, studying the change characteristics of BSP in fluvo-aquic soil areas has theoretical and practical significance to guide the proper oriented soil fertility cultivation to meet the national demand for the grain increase. This paper analyzed the trends and influencing factors of BSP in winter wheat seasons under different long-term fertilization processes based on National Soil Fertility and Fertilizer Effects Long-term Monitoring Experiments, in order to provide a scientific basis to strengthen the oriented soil fertility cultivation in fluvo-aquic soil areas of China. The research was based on an 18-year field experiment on fluvo-aquic soil in Zhengzhou City, Henan Province. Five fertilization treatments were set up in the experiment, including CK (no fertilizer), NPK (single inorganic fertilizer), NPKM (organic fertilizer and inorganic fertilizer), 1.5 NPKM (organic fertilizer and inorganic fertilizer, the count was 1.5 times of NPKM), and NPKS (straw and inorganic fertilizer). The yields based on BSP were simulated by using the DSSAT (decision support system for agro-technology transfer) model. First, we input the parameters of soil, weather and field management into the DSSAT model, then modified and calibrated the crop variety parameters based on the measured yield; after that, we set up the fertilization opinion in the model to get the BSP yield. The contribution percentage of BSP to yield was calculated by the BSP yield and measured yield. The influencing factor was identified by analyzing the relationship between the contribution of BSP to yield and soil nutrient contents. The yields based on BSP of NPK, NPKM, 1.5NPKM, and NPKS treatments increased gradually with time. The yields based on BSP increased by 721, 1033, 2108 and 1306 kg&middothm^-2 after the 18-year fertilization management, respectively, with increasing rates of 29.6%, 42.4%, 86.6% and 53.7%, and average annual increasing rates of 1.6%, 2.4%, 4.8% and 3.0%, respectively. The average yields based on BSP were 2711.7, 3186.3, 3704.7 and 3053.6kg. hm-2, respectively. The treatment of 1.5 NPKM achieved the highest yield based on BSP, suggesting that it was the most effective measure to increase the BSP of winter wheat. The contribution percentage of BSP to yield ranged from 36.5% to 70.9% during 1991-2008, and the average contribution percentage of BSP to yield was 42.5%, 59.9%, 58.9% and 52.5%, respectively, following the order of NPKM &lt; 1.5NPKM &lt; NPKS &lt; NPK. This indicated that compared with the application of single chemical fertilizer, organic fertilizer or straw residue combined with inorganic fertilizers can increase the yield and more effectively increase the contribution percentage of BSP to yield of winter wheat in fluvo-aquic soil. The contribution percentage of BSP to yield was significantly correlated with soil organic carbon, total nitrogen, available nitrogen, available phosphorus and available potassium contents. However, the correlation between the contribution percentage of BSP to yield and the contents of soil total potassium and total phosphorus did not reach a significant level. Soil organic carbon and total nitrogen contents were the main controls of BSP in the fluvo-aquic soil area.
Number of references:36
Main heading:Fertilizers
Controlled terms:Artificial intelligence - Computer simulation - Crops - Decision support systems - Experiments - Food supply - Models - Potassium - Productivity - Soils  - Technology transfer
Uncontrolled terms:Dssat models - Fertilizer applications - Fluvo-aquic soils - Inorganic fertilizers - Long-term fertilization - Soil productivity - Total nitrogen content - Winter wheat
Classification code:902.1 Engineering Graphics - 901.4 Impact of Technology on Society - 901.3 Engineering Research - 821.4 Agricultural Products - 913.1 Production Engineering - 804 Chemical Products Generally - 549.1 Alkali Metals - 483.1 Soils and Soil Mechanics - 404.2 Civil Defense - 723 Computer Software, Data Handling and Applications
DOI:10.3969/j.issn.1002-6819.2013.12.016
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 34>

Accession number:20132916508773
Title:Mechanism analysis and simulation of blueberry harvest by vibration mode
Authors:Wang, Haibin (1); Guo, Yanling (2); Bao, Yudong (2); Geng, Lei (3)
Author affiliation:(1) College of Engineering and Technology, Northweast Forestry University, Harbin 150040, China; (2) College of Mechtronic Engineering, Northest Forestry University, Harbin 150040, China; (3) College of Mechanical Engineering, Heilongjiang Institute of Science and Technology, Harbin 150027, China
Corresponding author:Guo, Y.(Guo.yl@hotmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:40-46
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Recently, the blueberry was served as the king of fruits, and people have been paying more attention to the health care effect, economic and medicinal value of the blueberry. Planting the blueberry is a new economic growth point in agriculture and forestry. The demand for blueberry exceeds the supply in the international market with high-speed growth demand. However, the blueberries are harvested depending entirely on hand picking in China with serious losses, and the picking cost accounts for 50%-70% of the total blueberry production cost. The old harvesting method restricts the widespread popularization and planting of blueberries. Research on blueberry picking machines and blueberry picking mechanisms is in its infancy in China. The price of blueberry picking machines is high. An experiment was conducted to change the artificial harvesting status of the blueberry, realize the mechanization of a high-bush blueberry-picking tool, and establish the theoretical guidance and design basis for the blueberry-picking machine for Chinese national conditions. We studied the vibration mechanism of the high-bush blueberry in picking and identified the picking frequency by simulation analysis and the experimental verification. First, we analyzed the working principle of the picking machine to get the vibration picking mechanism. The blueberry plants' geometry model was simplified and analyzed to get the blueberry plants physical model and the mathematical model, which was solved by a partial differential equation solution. We then obtained the forced vibration response of the blueberry plants and the forced vibration picking inertia force at steady state of the blueberry fruit. Second, ten strains of blueberry trees were selected as the test samples. We measured the binding force and mechanical parameters of the blueberry plants, such as the diameter, length, density, elastic modulus, fruit, and tree growth parameters. The vibration shape of the fruit branches and the inertia force of the fruit were simulated by using MATLAB software simulation, and the blueberry picking frequency at vibration condition was 14-16 rad/s. Finally, using an experimental self-developed blueberry picking machine at Xinkang blueberry planting area, in Wulongbei, Zhen'an District, Dandong City, Liaoning Province, the vibration shape of the fruit branches was observed and the fruit distribution before and after picking was compared. The results show that: there are fewer errors between the actual vibration response and the simulation results, but the overall vibration shape of blueberry branches, the vibration response, and picking effects are consistent with the simulation results. In addition, the effect of frequency on blueberry picking was analyzed by the experiment. The number of the mature fruit, ripe fruit, damaged fruit and the fruit left on the branch under different picking frequency were recorded. Then, the picking fruit rate, the fruit damage rate and the left fruit rate were calculated. The reasonable picking frequency is 15 rad/s, and the quality evaluation indexes at this frequency are as follows: the picking efficiency is 913 pieces/min, the picking ripe fruit rate is 2.99%, the damage fruit rate was 2.86%, the leaving rate is 3.17%, and the ratio of machine to worker is 10.14.
Number of references:30
Main heading:Fruits
Controlled terms:Agricultural machinery - Angular velocity - Computer software - Costs - Economics - Experiments - Forestry - Harvesting - International trade - Mathematical models  - MATLAB - Mechanization - Partial differential equations - Quality control
Uncontrolled terms:Experimental verification - Forced vibration response - High-bush blueberry - International markets - Mechanical parameters - Vibration condition - Vibration mechanisms - Vibrations
Classification code:971 Social Sciences - 931.1 Mechanics - 921.2 Calculus - 921 Mathematics - 913.3 Quality Assurance and Control - 911.4 Marketing - 911 Cost and Value Engineering; Industrial Economics - 901.3 Engineering Research - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 723 Computer Software, Data Handling and Applications - 601 Mechanical Design
DOI:10.3969/j.issn.1002-6819.2013.12.006
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

<RECORD 35>

Accession number:20132916508768
Title:Design and experiment of oriented seed churning device on pneumatic seed metering device for rice
Authors:Zhang, Guozhong (1); Zang, Ying (2); Luo, Xiwen (2); Wang, Zaiman (2); Zeng, Shan (2); Zhou, Zhiyan (2)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; (2) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
Corresponding author:Luo, X.(xwluo@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Due to high tilling capacity and preventing the risk of low seedling emergence rate in the field, generally 3-4 seeds are required for each hole when hybrid pregnant rice seeds were direct seeded to the field by drilling machine. Even though the seeds sprouted and their bud length were less than 3 mm with high moisture content, they were low in liquidity and had irregular shapes making it quite difficult to meet the requirement. In order to solve the problem, a novel pneumatic metering device was designed with group sucking holes plate in a seed metering device, by which 3-4 seeds can be sucked and dropped at the same time. Existing experiments were conducted to investigate the suck characteristic of the group holes on the sucking plate under vacuum, diameter of the holes, and seed-clearing device. The results showed the optimal parameter combination was vacuum at 3.2 kPa and the diameter of the hole at 1.5 mm. The results: the &lt;2 sucked seeds per hill, the (3-4) sucked seeds per hill, and the &le5 sucked seeds per hill were 8.27%, 81.87%, and 9.86% while the sucking plate rotating speed was 8 rpm. In order to improve the device performance, the group sucking holes on the plate were increased from eight to ten, its circular distribution was replaced by a linear distribution, and a kind of oriented churning device that consisted of two churning teeth was set on the plate. The single factor experiments and combination factor contrast experiments were conducted to investigate the suck characteristics of the sucking plate under vacuum, diameter of the holes, and oriented churning device. The experimental equipment consisted of a pneumatic metering device with group holes, a U-shaped manometer, a positive and negative pressure air pipeline, a cut-off valve, and a vortex pump. In the experiments, the rotating speed of the sucking plate was 30 rpm and its diameter was 165 mm, the distance between 3 sucking holes were 6.5 mm and 11.5 mm while the distance was 65 mm between the middle hole and the center of the plate. A fingerlike clearing device was set on the plate while the distance was 118mm between it and the center of the plate; its length was 38mm and its installation angle was 25&deg;. Rice varieties were Indic hybrid, Peizataifeng, and Y-Liangyou 1 pregnant rice seed. Their moisture content (wet basis) were 11.6%-11.9% and 23.93%, their 1000-grain were 22g and 25.2g, and their overall dimensions (length &times; width &times; thickness) were 8.94mm &times; 2.30 mm &times; 1.94 mm and 9.11 mm &times; 2.30 mm &times; 1.87 mm. The experimental results showed the metering device performance was obviously improved after installing the oriented churning device, by which its rotating speed was significantly increased and its air vacuum requirements were reduced on the same precision. To suck Y-Liangyou 1 pregnant rice seed, the optimal parameter combination was the vacuum with 2.0kPa, the rotating speed of the plate at 30 rpm, the wedge angle of the churning tooth at 60&deg;, the thickness of the churning tooth at 2 mm, the installation angle of the inner-churning tooth at 90&deg;, the installation angle of the outer-churning tooth at 60&deg;, and the diameter of the hole at 6 mm. The (3~4) sucked seeds per hill of the pneumatic seed metering device, &lt;2 sucked seeds per hill, and the &le5 sucked seeds per hill were 59.48%, 15.03%, and 25.49%. The results showed that the seeds were separated, oriented, rubbed, and pushed by churning device that has a good influence to the precision of the pneumatic seed-metering device.
Number of references:31
Main heading:Pneumatics
Controlled terms:Agricultural machinery - Experiments - Moisture determination - Optimization - Pneumatic equipment - Rotating machinery - Seed - Vacuum
Uncontrolled terms:Experimental equipments - Group holes - High moisture contents - Metering devices - Optimal parameter combinations - Precision hill-drop - Rice - Single-factor experiments
Classification code:944.2 Moisture Measurements - 921.5 Optimization Techniques - 901.3 Engineering Research - 821.4 Agricultural Products - 821.1 Agricultural Machinery and Equipment - 633 Vacuum Technology - 632.4 Pneumatic Equipment and Machinery - 632.3 Pneumatics - 601.1 Mechanical Devices
DOI:10.3969/j.issn.1002-6819.2013.12.001
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.

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Accession number:20132916508784
Title:Increasing lodging resistance performance of rice by alternating drought and flooding stress
Authors:Guo, Xiangping (1); Zhen, Bo (1); Wang, Zhenchang (1)
Author affiliation:(1) College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China
Corresponding author:Guo, X.(xpguo@hhu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:29
Issue:12
Issue date:June 15, 2013
Publication year:2013
Pages:130-135
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering, Agricultural Exhibition Road South, Beijing, 100026, China
Abstract:Stem lodging could result in the reduction of rice yield and was easily affected by drought and flooding which were widely used to reduce irrigation water applied by reducing evaportanspiration and catching rainwater. Previous studies found that flooding could decrease the ability of resistance lodging in most cases while drought has the opposite effects. So it seems possible to mitigate the negative effects of flooding by using the advantages induced by drought under rain-catching and controlled irrigation mode. However, how alternate drought and flooding stress affect the ability of resistance lodging, as well as its underlying mechanism for these behaviors has remained elusive. In this study, three field experiments of T1 (slight drought combined with shallow depth of water after rainfall in paddy field), T2 (slight drought combined with deep depth of water after rainfall in paddy field) and CK (conventional irrigation mode for rice which always keep the shallow depth of water in paddy field), were established to investigate the responses of stem anatomical structure, stem growth indexes and lodging resistance capabilities to the alternate drought and flooding stress as well as to illustrate the lodging resistance mechanisms for rice stalks under rain-catching and controlled irrigation mode. The results indicated that compared with CK, T1 could decrease the basal inter-node length and increase the stem diameters and stem cross section areas, even thought the differences were not significant. Compared with CK, T1 significantly increased the bending cross-section modulus and cumulative damage energy of stems by 12.4% and 9.4%, respectively; according to stem mesostructure of different treatments, the increase of stem wall thickness, vascular bundles numbers and vascular areas together with the compact vascular cells finally resulted in the improvement of the fracture resistance and the decrease of lodging resistance indexes. Whereas, because of the extremely higher depth of water levels after drought stress, the capability of lodging resistance for T2 treatment decreased. The rising or decline of fresh weight above ground was the major reason for the increase or decrease of lodging resistance indexes rather than that of fracture resistance. In conclusion, properly drought stress exposed in the late growth stage of rice could compensate the decrease of lodging resistance capability and could be used to improve the lodging resistance capability of rice stalk under alternate drought and flooding stress. It also suggested that further increasing the depth of water levels after heavy rain in paddy field under the current water-saving mode would not increase the risk of lodging for rice plant.
Number of references:19
Main heading:Drought
Controlled terms:Experiments - Floods - Fracture toughness - Growth (materials) - Irrigation - Mechanical properties - Rain - Water conservation - Water levels - Water supply
Uncontrolled terms:Anatomical structures - Controlled irrigations - Different treatments - Flooding stress - Lodging - Mesostructures - Rice - Three-field experiments
Classification code:951 Materials Science - 914.1 Accidents and Accident Prevention - 901.3 Engineering Research - 821.3 Agricultural Methods - 614.2 Steam Power Plant Equipment and Operation - 446.1 Water Supply Systems - 444 Water Resources - 443.3 Precipitation - 421 Strength of Building Materials; Mechanical Properties
DOI:10.3969/j.issn.1002-6819.2013.12.017
Database:Compendex
Compilation and indexing terms, Copyright 2012 Elsevier Inc.