<RECORD 1>

Accession number:20151400700123
Title:Spatio-temporal change analysis of cultivated land in Manas drainage basin during 1962-2010
Authors:Li, Junli (1); Jiang, Liangliang (1); Bao, Anming (1); Chang, Cun (1); Bai, Jie (1); Liu, Hailong (2)
Author affiliation:(1) Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; (2) College of Water Conservancy and Architectural Engineering, Shihezi University, Shihezi, China
Corresponding author:Bao, Anming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:277-285
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Cultivated land is an important indicator of landscape changes driven by human activities. Mapping the spatio-temporal changes of cultivated lands will help us to understand its corresponding environmental and ecological changes in their downstream areas. The Manas drainage basin is the key area of agricultural region in the northern slope of the Tianshan Mountains. However, the drastic farmland reclamation in the last 50 years makes irrigation water increasing rapidly, leading to environmental degradation in the downstream of the Manas River. In this paper, remote sensing and GIS technologies are used to analyze the spatio-temporal characteristics of farmland changes in the Manas drainage basin under the condition of intense soil-water utilization. Firstly, remote sensing images in 1962, 1977, 1989, 2000 and 2010 are applied to map land use changes with the cognition classification software and manual edition. Then the temporal process and spatial pattern of land cover changes are analyzed by geo-statistics and landscape analysis. On the temporal scale, the cultivated land changes and its mutual transition relationships with other land types are analyzed with areal ratio and transition matrix methods; on the spatial scale, GIS spatial analysis tool and landscape class level index are used to describe the characteristics of farmland expansion or shrinking changes in different regions and different land patches. Finally, hydrological data and irrigation construction data are used to explain the impact of climate change and human activities on the farmland landscape. The results show that: (1) The overall land use changes of the Manas drainage basin in the last 50 years are as follows: cultivated land and built-up areas increase continuously, while the unutilized land, wetland and snow/glacier have been decreasing steadily; grassland area is increasing in the former 20 years and then decreasing gradually in the last 30 years; the intensity of land use changes keeps stable after dramatic changes. (2) The overall cultivated land transformations have shifted from outward and inward transformations to single inward transformation; in inward land types, grassland and unutilized land are the main inward land types to farmland, and woodland and wetland take larger percentages in the first 20 years, while less percentages in the later 30 years; in outward land types, built-up land and grassland are the main outward land types, and grassland and unutilized land have larger percentages in the former 20 years due to cultivated land degradation; the total area of inward land types far exceeds than that of the outward land types, and the cultivated land area is steadily increasing in the last 50 years. (3) The focus of cultivated land expansion has shifted from the margins of cities to desert regions, and the newly-increased farmland gradually from the upstream to the downstream; cultivated land expansion firstly begins at the Changji Hutubi and Manas County in the former 20 years, then shifts to Shawan County, the river's surrounding areas and northern deserts; the cultivated landscapes are characterized from discrete and messy pieces into continuous land patches, so the advantage of cultivated landscape is increasing, while the landscape diversity and heterogeneity are decreasing due to land parcel combinations. (4) The increasing precipitation and runoff in the Manas drainage basin provide more water resource for cultivated land reclamation, and reservoir and irrigation channel construction have positive effects on spatial expansion of the cultivated land; when reservoirs and channels are built up, cultivated land will expand correspondingly in a rapid rate in the next decade, and hence the spatio-temporal processes of farmland expansion have high relations with the irrigation facilities. (5) The increasing water resource induced by climate change cannot keep up with the increasing speed of the farmland, and water resource is in the state of over exploitation; measures must be taken to reduce the amount of irrigated water, so as to improve ecological environments in the downstream of the Manas River. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Land reclamation
Controlled terms:Arid regions - Catchments - Climate change - Drainage - Ecology - Farms - Geographic information systems - Image reconstruction - Irrigation - Land use  - Landforms - Remote sensing - Reservoirs (water) - Rivers - Soil moisture - Water management - Water resources - Wetlands
Uncontrolled terms:Cultivated lands - Intensity of land use change - Manas basin - Precipitation and runoff - Spatio-temporal changes - Spatiotemporal characteristics - Transition matrix method - Water conservancy
Classification code:401 Bridges and Tunnels - 406 Highway Engineering - 441.2 Reservoirs - 442 Flood Control; Land Reclamation - 442.2 Land Reclamation - 444 Water Resources - 444.1 Surface Water - 451 Air Pollution - 454.3 Ecology and Ecosystems - 481.1 Geology - 483.1 Soils and Soil Mechanics - 502 Mines and Quarry Equipment and Operations - 723.3 Database Systems - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods
DOI:10.3969/j.issn.1002-6819.2015.04.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 2>

Accession number:20151400700112
Title:Comparison of remote sensing yield estimation methods for winter wheat based on assimilating time-sequence LAI and ET
Authors:Huang, Jianxi (1); Ma, Hongyuan (1); Tian, Liyan (1); Wang, Pengxin (1); Liu, Junming (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China
Corresponding author:Huang, Jianxi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:197-203
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Assimilating biophysical parameters derived from remote sensing into crop growth model is an important approach to improve performance of regional crop yield estimation. Currently, most researches adopt single remote sensing data source and single variable assimilation strategy, which cannot accurately reflect the interactive process among radiation, temperature and water, limiting the performance of data assimilation model. Leaf area index (LAI) and evapotranspiration (ET) are two key biophysical variables related to crop growth and grain yield. The study presents an assimilation framework to assimilate MODIS LAI product (MCD15A3) and MODIS ET product (MOD16A2) into the Soil-Water-Atmosphere-Plant (SWAP) model to improve the estimates of winter wheat yield at the regional scale. The spatial scale is one of the most challenging issues in the field of remote sensing, and the mismatching between remote sensing observations and state variables of crop model has an important impact on the performance of data assimilation model. MODIS LAI and ET products in 1 km scale are severely underestimated compared to the ground-based observations because of the mixed pixel effect and the heterogeneity within pixel, and hence the scale factors of 1 km MODIS products and the crop model's simulated parameters are totally different. So the direct assimilation of 1 km MODIS products would cause abnormal results. At present, there are two types of solutions to mitigate the scale issue; one is to scale down remote sensing parameters or scale up crop model's simulated variables, and the other is to assimilate the time series trend characteristics derived from remote sensing into crop model. In this study, two types of cost functions were constructed through comparing the generalized vector angle or first order difference of the observations and modeled LAI and ET time series trends during the growing season. Two key model parameters (i.e. irrigation water depth and emergence date) were selected as the reinitialized parameters needed to be optimized through minimizing the cost function using the SCE-UA optimization algorithm, and then the optimized parameters were input into the SWAP model for winter wheat yield estimation. Winter wheat yield assimilation estimation accuracy was evaluated for two cost functions (e.g., vector angle and first order difference) at field and regional scales. The results showed that yield estimation accuracy had been greatly improved with assimilation of LAI and ET trends than without assimilation. Furthermore, vector angle strategy (r=0.75, RMSE=494 kg/hm²) had achieved higher accuracy than first order difference (r=0.73, RMSE=667 kg/hm²). In this study, equal weights were given to LAI and ET in the cost function. Giving different weights according to the errors of the LAI and ET data at different crop phenological stages would further improve the performance of data assimilation model. LAI and ET were selected as the assimilation variables in the cost function. Additional important state variables (e.g., soil moisture) that also closely related to grain yield should be incorporated into data assimilation framework to test the impacts to the crop yield. So, a more robust approach needs to be developed to simultaneously assimilate multiple biophysical variables (e.g., LAI, ET/PET, soil moisture), and hybrid approaches, such as combining the use of EnKF and 4DVar, would allow simultaneous estimates and updating of the model parameters and state variables, and would further improve crop yield estimation at field and regional scales. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Remote sensing
Controlled terms:Agriculture - Algorithms - Biophysics - Cost estimating - Cost functions - Costs - Crops - Grain (agricultural product) - Grain growth - Irrigation  - Models - Moisture - Optimization - Parameter estimation - Pixels - Radiometers - Soil moisture - Soils - Time series - Vectors  - Water supply
Uncontrolled terms:Crop yield - Data assimilation - Data assimilation model - First order differences - Ground-based observations - Remote sensing data source - Soil water atmosphere plants - Vector angle
Classification code:446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 701 Electricity and Magnetism - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.1 Control Systems - 801.4 Physical Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 911 Cost and Value Engineering; Industrial Economics - 921 Mathematics - 922.2 Mathematical Statistics - 931 Classical Physics; Quantum Theory; Relativity - 933.1.2 Crystal Growth - 944.7 Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 3>

Accession number:20151400700099
Title:Fracture failure analysis and process improvement of agricultural pump shaft
Authors:Nie, Longwei (1); Sun, Weilian (1); Su, Ke (1); Wang, Rongjun (2); Wang, Huiqiang (1)
Author affiliation:(1) College of Mechanical and Electric Engineering, Agricultural University of Hebei, Baoding, China; (2) Fengfan Co. Ltd., Baoding, China
Corresponding author:Sun, Weilian
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:103-106
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is necessary to possess fine comprehensive mechanical properties because of the severe working conditions of agricultural pump shafts. Therefore, the qualities of the materials, the structural design and the machining methods have strong effects on the using life of the pump shafts. The 40Cr steel, a typical alloy structural steel, shows some advantages such as high strength and toughness. After treated by quenching-tempering process, the 40Cr steel is used to manufacture mechanical parts which bear medium loads and medium speeds, for example, it is machined as the rear axles of cars and the spindles of machine tools. The 40Cr steel can be the best choice of agricultural pumps to manufacture pump shafts. The 40Cr pump shafts, which usually work under the conditions of the twisting moment and impact loads, and the pump shafts also are the important moving parts and load supporting parts which ensure the safe working of pump. The pump shafts need to be strengthened in order to satisfy the requirements of hardness, strength and toughness of the pump. The 40Cr steel uses quenching and high tempering heat treatment processes to obtain sorbitic structures, and its hardness can be ranged from 280 to 320 HBW. For some reasons, the pump can not work normally which is caused by impurities and abnormal microstructures existed in the steel. Parts of agricultural pump shafts present early failure phenomenon in shafts shoulder which is produced by one manufacturing company. It is considered that many impurities and unreasonable structural design should be responsible for the early failure. To find out the reasons of agricultural pump shafts fracturing in the early using life and avoid the appearance of early failure of the pump shafts again, the chemical compositions, the macroscopic fracture figures, the microstructures, the hardness and the impact ductility of the pump shafts were analyzed by using the direct reading spectrometer, scanning electron microscope, optical microscope, the hardness testing machine and impact testing machine. The results showed that the chemical compositions and impact energy of materials met the requirements of the pump. And the main reasons causing the fatigue fracture of pump shafts in the early using life were that the unreasonable structure designs resulted in stress concentration, the oxide film existed in the sample surface decreased the strength, and the inappropriate heat treatment processes produced the ferrites with widmanstatten structure. According to the analytic results, some optimized and improved methods were taken on pump shafts, such as enlarging the fillet sizes of shafts shoulder, using the nitrogen protection during heat treatment process, improving the quenching temperature and changing the cooling medium (replace oil cooling with brine cooling) in heat treatment process. By observing the quenching and tempering organization, the pump shafts reached the requirements after the improvement processes, and fatigue fracture did not appear during the early using life. The long-term durability was improved. The research in this article can provide important reference for improving the control of agricultural mechanical product quality and designing and processing of the key parts of agricultural machinery. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Fracture
Controlled terms:Agricultural machinery - Agriculture - Alloy steel - Automobile manufacture - Building materials - Chemical analysis - Cooling - Design - Failure analysis - Fracture testing  - Hardening - Hardness - Heat treatment - High strength alloys - High strength steel - Impact testing - Machine tools - Manufacture - Materials testing apparatus - Mechanical properties  - Microstructure - Oxide films - Product design - Pumps - Quality control - Quenching - Scanning electron microscopy - Tempering
Uncontrolled terms:Abnormal microstructures - Decarburized layer - Fatigue fracture - Hardness testing machines - High strength and toughness - Impact testing machines - Pump shafts - Widmanstatten structure
Classification code:408 Structural Design - 411 Bituminous Materials - 412 Concrete - 413 Insulating Materials - 414 Masonry Materials - 415 Metals, Plastics, Wood and Other Structural Materials - 421 Strength of Building Materials; Mechanical Properties - 422.1 Strength of Building Materials : Test Equipment - 422.2 Strength of Building Materials : Test Methods - 531.1 Metallurgy - 537.1 Heat Treatment Processes - 545.3 Steel - 603.1 Machine Tools, General - 618.2 Pumps - 641.2 Heat Transfer - 662.1 Automobiles - 712.1.2 Compound Semiconducting Materials - 741.1 Light/Optics - 801 Chemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 913.1 Production Engineering - 913.3 Quality Assurance and Control - 921 Mathematics - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.04.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 4>

Accession number:20151400700090
Title:Design and experiment of stratified seed-filling room on rice pneumatic metering device
Authors:Xing, He (1); Zang, Ying (1); Wang, Zaiman (1); Luo, Xiwen (1); Zhang, Guozhong (2); Cao, Xiaoman (1); Gu, Xiuyan (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China; (2) College of Engineering, Huazhong Agricultural University, Wuhan, China
Corresponding author:Zang, Ying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:42-48
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The technology of rice's mechanical direct seeding can significantly reduce the consumption of manpower and material resources, and meanwhile maintain the production of rice. Super hybrid rice is a kind of hybrid rice and its tillering ability is stronger than the general hybrid rice. Due to the characteristics of high tillering capacity of super hybrid rice, the sowing quantity is required to be 1-3 seeds for each hole when super hybrid rice seeds are directly seeded to the field by the drilling machine, so as to ensure the high precision of seeding and high rate of field seedling emergence. In order to meet the requirement of 1-3 seeds for each hole using the precise hill-drop drilling technique, a seed-filling stratified room was designed, which was between the seed-metering device and the seed box on pneumatic feed mechanism for precision rice hill-drop sowing. It also aimed at improving the liquidity of seeds and raising the seeding precision, the liquidity of rice seed would reduced after accelerating germination. This the reduction of the liquidity of rice seed after accelerating germination had so bad effects on filling process that it limited the improvement of metering performance. Indic hybrid Peizataifeng was taken as the research object, and the impacts of the seed-filling stratified room on the performance of the pneumatic feed mechanism was studied by the single-factor experiment and orthogonal experiment in this paper. These experiments were carried out under different negative pressures for sucking seeds and positive pressures for blowing seeds. The experimental results showed that there existed an optimization condition on the capability of the metering device to meet the needs of the production. The probability about the quantity for each hill was used to evaluate the capability of the pneumatic precise metering device. The seed-filling stratified room consisted of a barrel and two seed-guiding plates. The cross-section of the barrel was the square with 50 mm per side. There were the chutes on the lining of the barrel, which were 1.1 mm wide. Seed-guiding plates were 1 mm thick, which were connected with the barrel by chutes. The two seed-guiding plates formed an angle of 45 degrees. The optimization condition was that the sucking plate's rotation speed was 30 r/min, the negative pressure for sucking seeds was 1.6 kPa and the positive pressure for blowing seeds was 0.1 kPa. With the seed-filling stratified room, the probability of 1-3 seeds per hill for the metering device was 95.4%; in addition, the probability of empty seed was 1.53%, and the probability of greater than or equal to 4 seeds was 3.07%. Under the same condition, the probability of one seed per hill for the metering device was 17.32%; in addition, the two-seed probability was 58.72% and three-seed probability was 19.36%. Compared with the existed researches, the results showed that the seed-filling stratified room between the seed-metering device and the seed box on pneumatic feed device, had a good influence on the precision of the pneumatic seed-metering device, improved the fluidity of the seeds and decreased the friction force and extrusion force among the seeds. This study provides an important reference for the structure optimization and the performance improvement of the pneumatic metering device. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Seed
Controlled terms:Agricultural machinery - Cultivation - Drilling platforms - Drops - Filling - Friction - Plates (structural components) - Pneumatic equipment - Pneumatic materials handling equipment - Pneumatics  - Probability - Structural optimization
Uncontrolled terms:Drilling techniques - Group holes - Optimization conditions - Orthogonal experiment - Seed metering devices - Single-factor experiments - Stratified structure - Structure optimization
Classification code:408.2 Structural Members and Shapes - 511.2 Oil Field Equipment - 632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 691.2 Materials Handling Methods - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.5 Optimization Techniques - 922.1 Probability Theory - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.04.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 5>

Accession number:20151400700124
Title:Layout classification of rural settlement based on combination of multi-dimensional characteristics
Authors:Zhang, Ruijuan (1); Jiang, Guanghui (1); Wang, Mingzhu (1); Ma, Wenqiu (1); He, Xin (1)
Author affiliation:(1) State Key Laboratory of Earth Surface Process and Resource Ecology, Beijing Normal University, Beijing, China; (2) College of Resources Science and Technology, Beijing Normal University, Beijing, China
Corresponding author:Jiang, Guanghui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:286-292
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Under rapid urbanization, analyzing the spatial characteristics and pattern types are fundamental tasks of revealing the mechanism of formation, growth and transition of rural settlements, which are essential to make reasonable decisions for rural settlements consolidation activities. The existing researches mainly considered rural settlements size or configuration characteristics at national or provincial scale, which inevitably hided various problems in small regions and failed to provide explicit characteristics of current size, shape and location required with readjustment of rural settlements. Thus this paper firstly defined rural settlements pattern as the composition of various residential land parcels with number, size, shape, location and organization relationship characteristics. Based on the definition of spatial characteristics of rural settlements pattern and the main compositions, the indicators system and characteristic index model with geometric mean method for evaluating the spatial characteristics of rural settlements pattern were built from size, configuration and location three dimensions. Then a "3-3-2" combination matrix was designed to calculate types of rural settlements spatial pattern by dividing size characteristic index into 3 grades (i.e., small size, medium size and large size), configuration characteristic index into 3 grades (i.e., irregular, moderate irregular, regular), and location characteristic index into 2 grades as advantageous condition and disadvantageous condition. Thus in theoretical rural settlements pattern was concluded 18 types (i.e., 3&times;3&times;2=18) of characteristics discussed above. Finally, the paper took Pinggu district in Beijing as the study area, analyzed the spatial characteristics and types of rural settlements pattern, and recommended optimal directions for rural settlements development in the future.Results showed that rural settlements pattern had multi-dimensional characteristics, and the quantitatively analysis from spatial size, configuration and location reflected the current state of distributation. The combination matrix method effectively overcame the limitations that comprehensive evaluation method hided the variation of pattern's dimensional characteristics. The study showed that rural settlements in Pinggu existed great regional variations, which in size were larger in plain region, came next in semi-mountainous region, and were smaller in mountainous region. Additionally, some rural settlements in configuration confronted irregular and scattered problems, though in location most rural settlements presented the tendency of nearing regions with low altitude, roads, city and towns. Pinggu's rural settlements patterns were divided into 10 types, and mainly included "medium size-moderate regular configuration-advantageous location" and "medium size-regular configuration-advantageous location". The study proved that rural settlements patterns were both influenced by geographical factors and socio-economic factors, but they acted on different characteristics of the pattern. The geomorphic condition basically controlled the size characteristic of rural settlements, while the infrastructures like roads and the adjacent central towns (city) further influenced on their spatial configuration and location. Rural settlements consolidation was a complex program that needed to optimize the hierarchy system from macro perspective, and that also needed to diagnose detail problems about size, configuration and location characteristics at small scale. The study indicated that types of rural settlements pattern indicated by the combination matrix method efficiently reflected multi-dimensional information, which immediately provided guiding directions for rural settlements consolidation and spatial optimization practices. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Spatial variables measurement
Controlled terms:Classification (of information) - Economics - Land use - Macros - Rural areas
Uncontrolled terms:Characteristic indices - Combination matrix - Comprehensive evaluation - Configuration characteristics - Pattern - Pinggu districts - Rural settlement - Spatial characteristics
Classification code:403 Urban and Regional Planning and Development - 716.1 Information Theory and Signal Processing - 723.1 Computer Programming - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 943.2 Mechanical Variables Measurements - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.04.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 6>

Accession number:20151400700096
Title:Active front wheel steering control based on ideal transmission ratio
Authors:Wang, Chunyan (1); Cui, Taowen (1); Zhao, Wanzhong (1); Chen, Junfei (1)
Author affiliation:(1) Department of Automotive Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
Corresponding author:Zhao, Wanzhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:85-90
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Active front steering system with variable transmission ratio control can solve the contradiction of steering portability at low speed and steering stability at high speed, and coordinate the vehicle handling stability and road feeling of the driver. The study of the active front steering system usually assumes that the steering system is able to generate the needed additional angle of front wheel ideally, and it is used for vehicle motion control. However, this method is lack of the study of the ideal transmission ratio law that the additional angle should follow, and the corresponding control strategy of the additional angle. In order to solve these problems, the linear vehicle model with two degrees of freedom, tire model, and active front steering system model involving steering wheel, steering shaft and double row planetary gear mechanism, the lower planetary gear sun wheel mechanism, rotation angle motor and gear rack mechanism are established. Then, the ideal transmission ratio law with fixed yaw rate gain is designed for active front steering system, based on which the additional angle control strategy of active front wheel steering is studied. According to these, the simulation model with Matlab/Simulink software is established. Selecting the speed at 20 and 100 km/h, simulation analyses of angle step input and sinusoidal input for the proposed control strategy are conducted. The simulation shows that at the speed of 20 km/h, the amplitude of yaw rate with the ideal transmission ratio for active front steering becomes larger, compared with the fixed transmission ratio. At the same time, the vehicle has better steering sensitivity, which is conducive to achieve good steering performance at low speed. At the speed of 100 km/h, the amplitude of yaw rate and sideslip angle becomes smaller with the ideal transmission ratio, in contrast to the fixed transmission ratio. Thus, the vehicle has better steering stability, which is conducive to the stability of vehicle at high speed. In order to verify the force characteristics improvement of the active front steering system based on the designed power assisted controller with the proposed control strategy, the original position and low-speed steering test and the middle position test of steering wheel are carried out. In original position and low-speed steering test, the steering wheel torque of the vehicle is small under the designed assisted controller, whose maximum torque is only 4 N&middot;m. The operating torque of the driver is small, which realizes the steering portability at low speed. The results of simulation analysis and experimental verification show that, the designed control strategy can ensure the vehicle has good sensitivity at low speed and good stability at high speed, which can achieve perfect steering quality. The results of this study can provide the theoretical basis for the design and development of active front steering system. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Steering
Controlled terms:Airships - Automobile steering equipment - Computer software - Control - Controllers - Degrees of freedom (mechanics) - MATLAB - Quality control - Speed - Stability  - Vehicle transmissions - Vehicle wheels - Vehicles - Wheels
Uncontrolled terms:Active front wheel steering - Additional angle - Experimental verification - Fixed transmission ratios - Matlab/Simulink software - Planetary gear mechanism - Transmission ratios - Variable transmission ratio
Classification code:432 Highway Transportation - 601.2 Machine Components - 602.2 Mechanical Transmissions - 652.5 Balloons and Gliders - 663.2 Heavy Duty Motor Vehicle Components - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 732 Control Devices - 732.1 Control Equipment - 801 Chemistry - 913.3 Quality Assurance and Control - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics - 951 Materials Science - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.04.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 7>

Accession number:20151400700110
Title:Information collection system for diseases and pests in cotton field based on mobile GIS
Authors:Zhao, Qingzhan (1); Jin, Guangcai (1); Zhou, Wenjie (1); Wang, Chuanjian (1); Dai, Jianguo (1)
Author affiliation:(1) College of Information Science and Technology, Shihezi University, Shihezi, China; (2) Geospatial Information Engineering Research Center, Xinjiang Production and Construction Corps, Shihezi, China; (3) Geospatial Information Engineering Laboratory, Xinjiang Production and Construction Corps, Shihezi, China
Corresponding author:Zhao, Qingzhan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:183-190
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to reduce the losses caused by cotton pests and diseases, the prevention and control of cotton pests and diseases has become an important link in the process of cotton planting. Therefore, a timely and effective collection of information about cotton pests and diseases naturally becomes the premise and basis of monitoring and further forecasting. However, traditional way of collecting data by filling in paper manually presents several defects, such as the error caused in space and time, the cumbersome statistics and its time-consuming characteristic. Moreover, temporal resolution and spatial resolution of remote sensing monitoring can hardly reach the standard of monitoring, and the inversion model usually fails in achieving the ideal monitoring effect in terms of different cotton varieties and different growth stages. In comparison, information collection based on Mobile GIS has such advantages as its portability, public participation, instantaneity and accuracy in space and time. Focusing on the process of data collection, transmission, storage, analysis and service provision of cotton pests and diseases, this paper proposes a business solution of cotton pests and diseases information service based on Mobile GIS. The method tries to combine GPS positioning with off-line map loading in the mobile terminals to help acquire the precise location data. Users can mark the location where cotton pests and diseases occur by plotting points or polygon graphics on the map, the deviation of which is within 15 meters. Through the development of Android/IOS mobile terminal, collection time and grade of cotton pests and diseases are offered, which thus help gather the attribute information. By defining JSON data collection module, the unity of different platforms' data collection is achieved. And through network, the data are further sent to the spatial-temporal database in the service terminal. Since the database of this system is Oracle Spatial database, when the server side receives data, the system automatically writes them to the database by using JDBC technology through Oracle API (application programming interface). Then the integrating and storing of spatial data and attribute data are realized. The whole process can be finished in 5 seconds. By using spatial interpolation based on inverse distance weighted method, the information of cotton pests and diseases is visualized, with the accuracy of 70%. Meanwhile, monitoring and forecasting services are provided to the mobile terminal through the server side by using ArcGIS Server. Users can browse thematic map of cotton pests and diseases released by administrator timely, which simplifies the process of information transmission. Through application and practice, it shows that this system has characteristics of instantaneity, accurate positioning, and public participation. The fact that users play the roles of both data collectors and service receivers propels the forming of new mode of geographical information service. In addition, the system also provides effective reference for information collection and agricultural condition monitoring. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Data acquisition
Controlled terms:Application programming interfaces (API) - Computer systems programming - Computer terminals - Condition monitoring - Cotton - Database systems - Digital storage - Disease control - Diseases - Error statistics  - Geographic information systems - Information services - Intelligent systems - Loading - Maps - Mobile phones - Mobile telecommunication systems - Monitoring - Remote sensing
Uncontrolled terms:Data collection modules - Geographical information service - Information collections - Information transmission - Inverse distance weighted - Prevention and controls - Remote sensing monitoring - Spatio-temporal database
Classification code:461.7 Health Care - 603 Machine Tools - 672 Naval Vessels - 706 Electric Transmission and Distribution - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 718.1 Telephone Systems and Equipment - 722.1 Data Storage, Equipment and Techniques - 722.2 Computer Peripheral Equipment - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 819.1 Natural Fibers - 902.1 Engineering Graphics - 903.4 Information Services - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 8>

Accession number:20151400700102
Title:Variation trends in water requirement of cotton and sugar beet in Xinjiang under climate change scenarios
Authors:Li, Yi (1); Zhou, Mudan (1)
Author affiliation:(1) College of Water Resources and Architecture Engineering, Northwest A&amp;F University, Yangling, China; (2) Water Saving Agriculture Academy in China Arid, Zone, Northwest A&amp;F University, Yangling, China
Corresponding author:Li, Yi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:121-128
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mann-Kendall (MK) trend test is a nonparametric statistical test. When the modified MK (MMK) test was used for serial trend test, it was considered to be stricter than the MK test considering the influence of self-correlation of time series. In this article, the MK method and the MMK method were combined for trend tests of water requirements (ET<inf>c</inf>) for two main economic crops, i.e., cotton and sugar beet, at 41 stations in Xinjiang over two periods of 1961-1961 and 2015-2099. The influences of serial self-correlation of ET<inf>c</inf>on trend test results were investigated, and the spatial distribution of trends in ET<inf>c</inf>of each site and the whole Xinjiang were presented. The results showed that: (1) When the order of self-correlation j was greater than 0, the statistics obtained from the MMK test should be adopted. (2) Over 1961-2010, ET<inf>c</inf>of both cotton and sugar beet had certain temporal-dependent structures. Over 2015-2099, ET<inf>c</inf>of cotton had very significant long-range correlation, but ET<inf>c</inf>of sugar beet hadn't any temporal dependence. (3) Over 1961-2010, which the trends in ET<inf>c</inf>of cotton at 37 sites decreased, of which the trends in ET<inf>c</inf>of cotton at 8 sites were significant. Over 2015-2099 for A2 scenario, trends in ET<inf>c</inf>of cotton at all of the sites in Xinjiang decreased, of which trends in ET<inf>c</inf>of cotton at 13 sites were significant, while trends in ET<inf>c</inf>at 28 sites were not significant. For B2 scenarios, only at Luntai the trend in ET<inf>c</inf>of cotton increased insignificantly, trends in ET<inf>c</inf>of cotton at the remaining 40 sites decreased. Over 2015-2099 for A2 scenario, trends in ET<inf>c</inf>of sugar beet at 13 sites increased, of which trends at 3 and 10 sites were significant and insignificant, respectively; trends in ET<inf>c</inf>of sugar beet at the remaining 28 sites decreased, of which the trends were significantly and insignificant at half of the 28 sites. For B2 scenario, trends in ET<inf>c</inf>of sugar beet at 9 sites increased. (4) Over 1961-2010, trends in ET<inf>c</inf>of cotton and sugar beet in the whole Xinjiang decreased significant and insignificant, respectively. Over 2015-2099 for A2 and B2 scenarios, both trends in ET<inf>c</inf>of cotton decreased significantly; trends in ET<inf>c</inf>of sugar beet also decreased insignificantly for A2 scenario but significantly for B2 scenario. (5) For both cotton and sugar beet, Sen's slope b were related to the linear slope S<inf>L</inf>with high coefficients of determination with linear function, which reflected the high consistency of the two variables when describing the trend amplitudes (6) It is necessary to consider the effects of self-correlation for ET<inf>c</inf>series when using MK test. (7) The synthetic effects of decreases in wind speed and solar radiation as well as the increases in precipitation and relative humidity on the restraining of ET<inf>c</inf>surpassed the effects of increases in air temperatures in Xinjiang. In conclusion, decreases in the trends of ET<inf>c</inf>series showed that there were reduced water demands of cotton and sugar beet in the future in Xinjiang, and the risk of drought also reduced. Trend variations in ET<inf>c</inf>for cotton and sugar beet had important reference value for making the crop irrigation planning and drought disaster prevention under the background of climate change in the arid and semi-arid areas. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Climate change
Controlled terms:Arid regions - Cotton - Crops - Disaster prevention - Drought - Evapotranspiration - Hydrology - Radiation effects - Sugar beets - Sun  - Testing - Wind
Uncontrolled terms:Arid and semi-arid areas - Climate change scenarios - Crop water requirements - Long range correlations - Mann-Kendall - Non-parametric statistical tests - Trend tests - Xinjiang
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 444.1 Surface Water - 471 Marine Science and Oceanography - 657.2 Extraterrestrial Physics and Stellar Phenomena - 711 Electromagnetic Waves - 744 Lasers - 821.4 Agricultural Products - 914.1 Accidents and Accident Prevention
DOI:10.3969/j.issn.1002-6819.2015.04.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 9>

Accession number:20151400700091
Title:Design and experiment of emasculation control system of corn detasseling machine
Authors:Xue, Tao (1); Xie, Bin (1); Mao, Enrong (1); Du, Yuefeng (1)
Author affiliation:(1) Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment, College of Engineering, China Agricultural University, Beijing, China
Corresponding author:Xie, Bin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:49-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Emasculation is closely associated with corn seed production, which directly affects the quality of corn seed. Mechanical emasculation with high efficiency and quality is taking the place of artificial emasculation, which is of low efficiency and poor quality. In China, mechanical emasculation is far behind developed countries, and the emasculation control system is just at the beginning stage, which restricts the development of the emasculation machines. In view of the above problems, this paper designed a set of emasculation control system, which completed adjustment of emasculation mechanism through the parallel four connecting rods driven by cylinder. In order to ensure the accuracy of the parameters, movement of four parallel connecting rods were analyzed. The hardware of the system mainly comprised a display screen, a control board and a control panel. The control board used ATmega128 chip as the control chip, used the 42GRU-9200TTL models (NPN type) photoelectric sensor to collect corn ear height, used MAX4372T chip to collect drive voltage and current, used Power MOSFET IRF4905 to drive proportional valve and used MAX232 chip to complete serial communication. The screen was used to display and set the system parameters. The control panel was used to complete the switch between manual mode and automatic mode and control the height of emasculation mechanism manually by button operation in the manual mode. In automatic mode, the system got the height of ear of corn by photoelectric sensors. The system's control algorithm was that repeatedly reading all the photoelectric sensor signals at a certain time interval, and then storing the number of occluded of up and down photoelectric sensor for the x set of data, and then making the lifting decision of emasculation mechanism according to the first set of data stored previously, and rising the emasculation mechanism only when continuous Z times lifting decision results is rising. Cylinder's movement speed was determined by the opening of proportional valve, and the PWM duty which is directly proportional to proportional electromagnet finally decides the velocity of cylinder. The system controlled the velocity of cylinder by exporting a certain duty PWM signal to control the opening of proportional valve. The system controlled the movement time of cylinder by outputting PWM signal or not, to control the closing and opening of proportional valve. The final purpose of the system is to control the movement of the emasculation mechanism. After analyzing the movement of four parallel connecting rods, combined with the vehicle operation speed and the characteristics of the hydraulic system, the parameters of the system can be obtained by calculating, and were displayed on screen. Through field tests, we found that when the emasculation machine with the emasculation control system designed in this paper rose, the motion time, displacement and maximum speed of cylinder was 150 ms, 0.007 m, and 0.1 m/s, respectively. When the emasculation mechanism went down, the motion time, displacement and maximum speed of cylinder was 180 ms, 0.007 m, and 0.15 m/s, respectively. The testing results showed that the actual movement of the hydraulic cylinder can meet the design requirements and the parameters were reasonably set, and the efficiency and accuracy can meet the castration emasculation operation requirements. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Control rods
Controlled terms:Agricultural machinery - Algorithms - Connecting rods - Control systems - Counting circuits - Crops - Cylinders (shapes) - Digital storage - Efficiency - Hydraulic equipment  - Hydraulic machinery - Photoelectricity - Pulse width modulation - Voltage control
Uncontrolled terms:Developed countries - Emasculation - Hydraulic cylinders - Photoelectric sensors - Photoelectric signals - Proportional electromagnets - Proportional valves - Serial communications
Classification code:408.2 Structural Members and Shapes - 601 Mechanical Design - 602 Mechanical Drives and Transmissions - 621 Nuclear Reactors - 632.2 Hydraulic Equipment and Machinery - 713.4 Pulse Circuits - 716 Telecommunication; Radar, Radio and Television - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 731.3 Specific Variables Control - 741.1 Light/Optics - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 913.1 Production Engineering - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.01.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 10>

Accession number:20151400700100
Title:Effects of biochar application on tilth soil hydraulic properties of slope cropland of purple soil
Authors:Wang, Honglan (1); Tang, Xiangyu (1); Zhang, Wei (1); Liu, Chen (1); Guan, Zhuo (1); Xiao, Liang (1)
Author affiliation:(1) Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China; (2) University of Chinese Academy of Sciences, Beijing, China
Corresponding author:Tang, Xiangyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:107-112
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biochar is a kind of solid residual produced by thermal decomposition of orgnic material under limited or absent supply of oxygen, and relatively low temperatures, biochar has the properties of high internal surface area and microporosity, furthmore, non-biological and biological stability. It used as a soil amendment could greatly improve soil physical and chemical properties, reduce the biological effectiveness of soil pollutant and greatly reduce the emission of carbon dioxide and other greenhouse gases and sequestrated soil carbon in recent years. In this study, a one-year field trail of biochar application in the hilly area of central Sichuan Basin, was carried out in sloping farmland plots, which was located at Yanting Agro-ecological Experimental Station of Purple Soil (105&deg;27'E, 31&deg;16'N), Sichuan, Southwest China, to investigate the effects on hydraulic properties of cultivated purple soil (an entisol). Two treatments were set up: control (NPK) and biochar amended (NPK-BC), with each being replicated three times. Comparison between biochar amended and control plots was made by determining soil hydraulic parameters, soil pore size distribution and the contribution of each pore size to flow at two depths (2-7 and &gt;7-12 cm) of the plough layer. Results showed that: 1) due to biochar application, the soil contact angle was increased by 6.7&deg;and 0.5&deg;at the 2-7 and &gt;7-12 cm depth, respectively. This implies that soil water absorption ability was increased and nutrients will be more easily dissolved in the soil.2) After one year of biochar application, the residual water content (&theta;<inf>r</inf>), which is unavailable to plants and water content in structure pores (&theta;<inf>str</inf>), which is easy to be drained out, was decreased, respectively. But the water content in soil matrix pores (&theta;<inf>txt</inf>), which is available to plants, increased significantly (P&lt;0.05) from 0.058&plusmn;0.003 cm³.cm^-3to 0.085&plusmn;0.002 cm³/cm³. This implies its stronger ability to retain plant-available water after biochar amended,; 3) due to biochar application, The effective porosity of r&gt;125 &mu;m pores increased by 54% and 8% at the 2-7 and &gt;7-12 cm depth, respectively. Particularly, the effective porosity of r&gt;500 &mu;m pores increased most markedly, reaching 110% and 355% for the two depths, respectively. This shows that biochar application reduces the 250&lt; r &lt; 500 &mu;m pores volume in the soil, but increased the volume of smaller pore (125&lt; r &lt;250 &mu;m) and larger pore (r&gt;500 &mu;m); 4) the saturated hydraulic conductivity at the two depths (2-7 and &gt;7-12 cm) increased by 45% and 35%, respectively, after a year of biochar application. Tension infiltration data show that soil macropores (r&gt;125 &mu;m) were the main contributing (accounting for 92-94%) pores to the fast drainage at the 2-7 and &gt;7-12 cm depth, under control and biochar amended r, in spite of their very low percentage (3-4%) of total porosity. 5)Therefore, it can be inferred that, on one hand, the application of biochar could increase the soil's capacity to hold plant-available water and thus enhance resistance to drought; on the other hand, it can also enhance water permeability of soil, which can reduce surface runoff and potential soil erosion. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Soil pollution
Controlled terms:Biological materials - Carbon - Carbon dioxide - Decomposition - Greenhouse gases - Hydraulic conductivity - Moisture - Oxygen supply - Pore size - Porosity  - Soil moisture - Soils - Water absorption
Uncontrolled terms:Bio chars - Biological effectiveness - Saturated hydraulic conductivity - Soil hydraulic parameters - Soil hydraulic properties - Soil physical and chemical properties - Soil Porosity - Soil water retention curves
Classification code:461.2 Biological Materials and Tissue Engineering - 483.1 Soils and Soil Mechanics - 632.1 Hydraulics - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.04.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 11>

Accession number:20151400700094
Title:Magnetic nanofluid cooling liquid strengthens local cooling of diesel engine cylinder head under alternative magnetic field
Authors:Zheng, Wei (1); Lin, Yuzi (2); Su, Zhonggen (3)
Author affiliation:(1) Kah Kee College, Xiamen University, Zhangzhou, China; (2) Xiamen University, Xiamen, China; (3) Oujiang College, Wenzhou University, Wenzhou, China
Corresponding author:Zheng, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:69-75
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Using some different ways to strength the local heat transfer ability of diesel cylinder head has some research productions, such as optimization of cooling fluid flow path, using more efficient cooling liquid, and using split cooling systems to meet demands of different positions of diesel engine. However, the effect of the first method seems limited, the results of the second method have been notoriously divergent, and the original intention of the third method is to increase intake flow. Some researchers put forward an idea that uses the nanofluids with jet impingement technology to improve the performance of heat transfer of diesel engine cylinder head, but this method has high energy consumption and cylinder head has been changed big too much. This paper attempts to use magnetic nanofluids with external alternation magnetic field to improve the heat transfer performance of diesel cylinder head at nose bridge area, based on two main reasons, one is nanofluid coolant has good heat transfer characteristics and the other is magnetic field changing enhances the nanometer particle moving trend. Based above reasons, this paper made some basic researches aiming to find out whether external alternative magnetic field can better improve moving trend of magnetic nanometer particles or not, furthermore, applying the above basic research results to a diesel with split-type cooling system to explore whether external alternative magnetic field can improve the heat transfer performance of diesel engine cylinder head or not, using traditional glycol, Cu-glycol nanofluid coolant and magnetic Fe<inf>3</inf>O<inf>4</inf>nanofluid coolant, respectively. The results of this study showed, with the effect of external alternation at 0.17 Hz frequency, the eddy number of magnetic nanofluid coolant was increasing obviously and the heat transfer performance of nanofluid coolant was improved, and the biggest incline range of temperature value of heating rod was caused, which was 17.2%. The temperature test of cylinder head bottom showed that, compared with traditional glycol coolant, under steady operating condition, the maximum declines of the temperature values in the maximum torque point and the calibration operation point were 11.6% and 14.4%, respectively, and the average temperature decline of external characteristics operating point was 23.7 , around 9.4%. The test results of transient condition showed that, compared with traditional glycol coolant or Cu-glycol nanofluid coolant, using magnetic nanofluid coolant with external alternative magnetic field at 0.17 Hz frequency, the tested diesel engine preheating time were reduced by 9.8% and 8.2%, respectively, and the coolant temperature fluctuation was relatively small. Of course, the above research results were obtained in the appropriate measures for test diesel engine. The energy consumption calculation results showed that, at the same cooling effect of test diesel engine cylinder head tiny area, compared with using traditional glycol coolant, the energy-saving rate was 7.2% when using magnetic nanofluid coolant with external alternative magnetic field at 0.17 Hz frequency. The purpose of this study is to explore the basic application method to strengthen local cooling ability on high temperature area such as diesel engine, and to provide a scientific reference of energy saving and less change for cylinder head structure. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Cylinder heads
Controlled terms:Coolants - Cooling - Cooling systems - Diesel engines - Energy conservation - Energy utilization - Engine cylinders - Engines - Flow of fluids - Glycols  - Heat engines - Heat transfer - Liquids - Magnetic fields - Magnetism - Nanofluidics - Nanoparticles - Thermoelectric equipment
Uncontrolled terms:Experimental - External characteristic - Heat transfer characteristics - Heat transfer performance - High energy consumption - Local cooling - Nanofluids - Steady operating conditions
Classification code:525.2 Energy Conservation - 525.3 Energy Utilization - 612 Engines - 615.4 Thermoelectric Energy - 621 Nuclear Reactors - 641.2 Heat Transfer - 701.2 Magnetism: Basic Concepts and Phenomena - 708 Electric and Magnetic Materials - 761 Nanotechnology - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2015.04.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 12>

Accession number:20151400700121
Title:Effects of pyrolysis temperature on carbon retention and stability of biochar
Authors:Li, Feiyue (1); Wang, Jianfei (1); Xie, Yue (1); Li, He (1); Li, Xiaoliang (1); Li, Fenru (1)
Author affiliation:(1) College of Urban Construction and Environment Science, Anhui Science and Technology University, Fengyang, China; (2) School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China
Corresponding author:Li, Feiyue
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:266-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Turning biomass wastes into biochar under the conditions of low temperature and limited oxygen has recently proven to be a promising approach for long-term carbon sequestration. However, the ultimate carbon sequestration efficiency of biochar depends not only on the feedstock type and production condition, but also on the environmental conditions of soil. In order to reveal the effects of pyrolysis temperature which is main parameter of biochar production condition on carbon retention and biochar stability, and provide more information for further improvement of carbon sequestration potential by turning biomass into biochar, the characteristics of biochar derived from walnut shell under lab condition were analyzed. During a typical slow pyrolysis process, the biochar was heated at a speed of approximately 20/min in a Muffle Furnace under limited oxygen and held at 200-700 for 2 h; then, biochar yield, elemental composition, functional groups distribution using Fourier transform infrared spectroscopy (FTIR) analysis and its chemical stability determined by potassium dichromate (K<inf>2</inf>Cr<inf>2</inf>O<inf>7</inf>) and potassium permanganate (KMnO<inf>4</inf>) oxidation methods, were all analyzed. The results showed that the carbon (C) content of biochar increased with the rise of the pyrolysis temperature from 54.0% at 200 to 83.7% at 700, on the contrary, the hydrogen (H) and oxygen (O) contents decreased with the rise of the temperature from 6.31% to 2.22% for H content and 45.1% to 10.6% for O content, respectively. Moreover, the H/C and O/C, usually used as two indexes to estimate carbon aromaticity for biochar, also decreased with the rise of the pyrolysis temperature from 1.25 to 0.32 for H/C and 0.54 to 0.09 for O/C, respectively, which indicated the carbon aromaticity of biochar was strengthened with the rise of the pyrolysis temperature, which is beneficial for the improvement of biochar stability. After the pyrolysis of walnut shell, especially when pyrolysis temperature was above 200, compared to the feedstock, the-C-O and O-CH<inf>3</inf>groups did not exist and the aliphatic-CH gradually disappeared while more aromatization were shown by new aromatic compounds with the increasing of pyrolysis temperature based on FTIR analysis. Biochar yield decreased with the rise of the pyrolysis temperature from 79.1% at 200 to 19.4% at 700. The carbon retention, defined as the proportion of the original carbon, which was from plant photosynthesis and sequestrated the CO<inf>2</inf>in feedstock from atmosphere, was retained in the biochar after the pyrolysis, and also decreased with the rise of the pyrolysis temperature from 69.4% to 11.0%, all of which indicated that high pyrolysis temperature aggravated carbon loss. However, high pyrolysis temperature strengthened the carbon stability, and especially for biochar derived from 500, the carbon loss of biochar oxidated by K<inf>2</inf>Cr<inf>2</inf>O<inf>7</inf>and KMnO<inf>4</inf>were 10.4% and 1.66%, respectively, which were smaller than the other biochars derived from other pyrolysis temperatures. There was significant negative correlation between pyrolysis temperature and the yield and carbon retention of biochar, while there was significant positive correlation between pyrolysis temperature and biochar stability. The stability of biochar in real soil and the optimal temperature of biochar for maximizing its carbon sequestration capacity need to be researched in the future. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Atmospheric temperature
Controlled terms:Aromatization - Carbon - Carbon dioxide - Chemical analysis - Chemical stability - Cracking (chemical) - Feedstocks - Fourier transform infrared spectroscopy - Functional groups - Oxygen  - Potassium - Pyrolysis - Stability - Temperature
Uncontrolled terms:Bio chars - Carbon sequestration - Carbon sequestration potential - Chemical oxidation - Elemental compositions - Environmental conditions - Potassium permanganate - Pyrolysis temperature
Classification code:443.1 Atmospheric Properties - 549.1 Alkali Metals - 641.1 Thermodynamics - 801 Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.04.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 13>

Accession number:20151400700086
Title:Online diagnosis system of threshing cylinder welding quality of combine harvester
Authors:Yuan, Yanwei (1); Fang, Xianfa (1); Rong, Yao (1); Fan, Hongxing (1); Dong, Xin (1); Li, Li (1)
Author affiliation:(1) State Key Lab. of Soil Plant Machinery System Technology, CAAMS, Beijing, China
Corresponding author:Fang, Xianfa
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:11-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As key parts of a corn and wheat combine harvester, the threshing cylinder is mainly processed with the method of welding. The processing quality of threshing cylinders, including cylindricity and verticality of outer radial discs fixed outside of threshing cylinders, is hard to guarantee. The major problems that the threshing cylinder end faces are radial run-out, which have seriously restricted the effect of threshing and selecting corn or wheat from millet straw. Thus, without online diagnosis method and system, the threshing cylinder of corn and wheat combine harvester will get poor quality. In this paper, the welding quality online detection method based on laser sensors was studied, and the online detection system of cylinder roundness and outer radial disc verticality during the welding was developed, including the threshing cylinder rotation driving system, laser sensor distance detection system, sliding guide rail system and data acquisition and display system. As to cylindricity detection, sliding guide rail that was parallel to the threshing cylinder axis was fixed on the welding platform, a laser distance detection sensor was fixed on the sliding guide rail, and a servo motor was connected to the threshing cylinder axis. While detecting, the threshing cylinder was driven to rotate, and at the same time, the laser sensor was driven to move along the sliding guide rail; and the vertical distance from the sensor to the threshing cylinder was detected, which was collected in real time by the computer. According to the threshing cylinder rotation data and laser sensor sliding track data, the threshing cylinder shape and cylindricity were calculated. As to the inspection of outer radial disc verticality, vertical sliding guide was fixed to the parallel sliding guide rail that was perpendicular to the sliding rail. Install laser sensor on the vertical sliding guide rail and keep the laser beam parallel to threshing cylinder axis. When the threshing cylinder was driven by the motor to rotate, the distance from the laser sensor to the outer radial disc was measured by the laser sensor, and the verticality of the outer radial disc was calculated by the computer. According to the method mentioned above, the online test platform was designed, and online detection was realized through data processing. Experiments were done and data was analyzed, including comparing the accuracy of the online detection system in this article and Cylindricity Measuring Instrument Talyrond130 (Taylor Hobson, England) and Laser verticality measuring instrument YHL-800 (ACROBEAM Co. Ltd, Xi'an, China), and the relative errors of duplicate tests were done by the online detection system. Results showed that, compared with Cylindricity Measuring Instrument Talyrond130, whose taper error was 0.00025 &mu;m/mm, the absolute error of cylinder roundness detection was 0.059 mm; and compared with Laser verticality measuring instrument YHL-800, whose accuracy was 1/20000 mm, the absolute error of outer radial disc perpendicularity detection was 0.123 mm. After 6 duplicate tests, the maximum relative error of cylindricity testing was 2.17%, the standard deviation was 0.021 mm, and the maximum relative error of perpendicularity detection was 1.93%, and the standard deviation was 0.011 mm, which met the needs of the online detection of the threshing cylinder welding quality, and the efficiency of online detection system was 20 times that of traditional method. The development of the system can ensure the welding quality of large-scale harvester threshing cylinder. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Cylinders (shapes)
Controlled terms:Agricultural machinery - Agriculture - Combines - Data acquisition - Data handling - Disks (machine components) - Display devices - Error detection - Fixed platforms - Harvesters  - Instrument errors - Laser beams - Measurements - Social networking (online) - Spot welding - Statistics - Welding
Uncontrolled terms:Cylindricity - Maximum relative errors - Measuring instruments - On-line detection method - On-line detection system - Perpendicularity - Roundness detection - Wheat combine harvesters
Classification code:408.2 Structural Members and Shapes - 511.2 Oil Field Equipment - 538.2 Welding - 538.2.1 Welding Processes - 601.2 Machine Components - 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 722.2 Computer Peripheral Equipment - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 744.8 Laser Beam Interactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 14>

Accession number:20151400700087
Title:Analysis on vibration characteristics of throwing impeller of stalk impeller blower
Authors:Zhai, Zhiping (1); Zhou, Lei (1); Yang, Zhongyi (2); Zhao, Yanqiong (1); Gan, Shiming (1)
Author affiliation:(1) College of Mechanical Engineering, Inner Mongolia University of Technology, Huhhot, China; (2) Teaching Affairs Office, Inner Mongolia University of Technology, Huhhot, China
Corresponding author:Yang, Zhongyi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:17-25
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:An impeller blower mainly consists of throwing impeller, shell, discharge tube, etc. When the impeller blower is working, the material is transported by mechanical centrifugal force and airflow which are generated by a high-speed rotating impeller. As the core component of the impeller blower, the impeller have to bear the comprehensive effect of the centrifugal force, the pressure of high-speed air flow inside the impeller blower and impeller gravity, which may produce violent vibration. The vibration will not only accelerate the throwing blade's fatigue fracture and affect its service lifetime but also produce environmental noise. In the meantime, if the excitation frequency is closed to some-order natural frequency of the throwing impeller, the whole device would produce resonance which seriously affects the work performance, the service life and reliability of the impeller blower. Therefore, in order to improve the working performance of impeller blower and avoid the resonance, it is quite important to analyze the vibration characteristics of the throwing impeller. In this paper, the modal frequency and vibration types of the first 12-order free modal and constraint modal were calculated using the finite element analysis software ABAQUS. In order to verify the accuracy of numerical calculation, a modal test of the impeller was carried out using the PSV-500-3D Scanning Vibrometer, which showed the maximum error of numerical modal frequencies and experimental modal frequencies was 8.5%, the vibration types were basically the same, and the numerical calculation results were reliable. Based on analyzing the characteristics of external excitation frequency, the structural parameters such as blade number, blade thickness, whether reinforcement were simulated and compared. The results show that: 1) Prestress increased each order natural frequency of the impeller, and only the first and the second order frequency increased largely while other frequencies increased a little. Prestress has no impact on the vibration type of the impeller. 2) When the speed of impeller was 1500 r/min, the deviation of excitation frequency and the first order natural frequency of the impeller with 3 blades was 57% and the resonance of impeller most unlikely took place. The deviation of excitation frequency and the first order natural frequency of the impeller with 4 blades was 15.9% and the resonance of impeller also couldn't take place. The excitation frequency deviated from the first order and second order natural frequency of the impeller with 5 blades by 13%, which most likely caused the resonance of impeller. 3) The lower natural frequencies of the impeller decreased and the higher natural frequencies increased with the blade thickness increasing. The natural frequency of the impeller with 4 mm thick blade deviated from the excitation frequency by 23% and the resonance of impeller most unlikely took place, while the natural frequency of the impeller with 5 mm thick blade deviated from the excitation frequency by 15.9% and the resonance of impeller also unlikely took place. But the impeller with 6 mm thick blade had low first order natural frequency and deviated from the high excitation frequency by 13%, which most likely caused the resonance of impeller. 4) The impeller with stiffeners could effectively avoid the vibration frequency, improve the dynamic performance and avoid the resonance. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Impellers
Controlled terms:ABAQUS - Agricultural machinery - Blowers - Finite element method - Modal analysis - Natural frequencies - Resonance - Vibration analysis
Uncontrolled terms:External excitation frequency - Finite element analysis software - First order natural frequency - High excitation frequency - Modal test - Numerical calculation - Vibration characteristics - Vibrations
Classification code:601.2 Machine Components - 618.3 Blowers and Fans - 701 Electricity and Magnetism - 711.1 Electromagnetic Waves in Different Media - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 921.6 Numerical Methods - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.04.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 15>

Accession number:20151400700088
Title:Operation mechanism of double support vibration separation device for wine grape berry
Authors:Li, Chengsong (1); Gao, Zhenjiang (1); Kan, Za (2); Wang, Lihong (2); Zhu, Xingliang (2); Yang, Lantao (2)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China; (2) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, China
Corresponding author:Gao, Zhenjiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:26-32
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In rencent years, wine grape planting area expands rapidly in Xinjiang, but the wine grape still harvested by man. Fruit-pedicle separation is a key link in the mechanized harvesting, further a wine grape vibration separation experiment device of 4P-12 type double support was designed to study the operation mechanism of double support wine grape separation device based on vibration, and the device was manufactured by Shihezi Development Zone Shida Ruituo mechanical equipment Co. ltd. The Double Support Wine Grape Separation Experiment Device based on Vibration consisted of driving parts, RSSR mechanism, and working parts, flat double rocker mechanism. The rotation of driving shaft was switched to the rotation of axle vibration rocker shaft by RSSR mechanism, and the rotation of axle vibration rocker shaft was switched to the swing of rib componet. When the vibration device was working, the driving shaft of driving part was drived by motor. The motion drived the eccentric sleeve and was transfered to the axle vibration rock by adjusting linkage, spherical plain rod ends bearing and vibration rocker, and then was transferred to axle driven rocker through active rocker and connecting rod to make the grapevine vibrate, and the grape was separated by the force of inertia. Equivalent plane institutions act and the complex vector method were used to analyze the theories of RSSR mechanism and flat double rocker mechanism, and the models of kinematics and dynamics of working parts were established. At the same time, the main influence factors of separation, motor speed, position and vibration rocker length were determined through the analysis of the models. The Cabernet Sauvignon were selected as samples planted in Xinjiang infantry regiment of the eighth division (Shihezi city) 152 group. The level of each factor was determined by single factor experiment, and L9(3⁴) orthogonal test plan was designed. The wine grape branches with good growth, fruiting of uniform, 0.8~1 m length, were pruned as sample which were refrigerated rapidly to retain freshness. An experiment was conducted according to the orthogonal experiment table and initial mass. Mass of after-separation and Branch mass were recorded to calculate separation rate with the foumula. Visual and variance analysis methods were uesd to analyze the data. The results of visual analysis method indicated that the separation rate of optimal scheme was that the motor speed was 750 r/min, vibration position was 550 mm and vibration rocker length was 125 mm. Analysis of variance showed that motor speed and position influenced separation effect significantly, while the vibration rocker length was affected insignificantly. In addition, the device was simulated in Solidworks and experimented under the high speed-camera after adjusting to the optimal of the optimal scheme, and the working parts were analysised by the high speed-camera Analysis Software. The optimal vibration curves of separation angular velocity and angular acceleration were achieved by Solidworks simulation and high-speed camera, and were fitting each other well, and the correctness of the device's operation mechanism was verified. The study could provide a reference to the design and optimization of wine grape harvester. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Vibration analysis
Controlled terms:Agricultural machinery - Axles - Cameras - Curve fitting - Drive axles - Fruits - High speed cameras - Mechanisms - Models - Separation  - Speed - Vibrations (mechanical) - Wine
Uncontrolled terms:Design and optimization - Double-rocker mechanisms - Kinematics and dynamics - Separation mechanism - Single-factor experiments - Variance analysis methods - Vibrations - Wine grapes
Classification code:601.3 Mechanisms - 663.2 Heavy Duty Motor Vehicle Components - 682.1.1 Railroad Cars - 742.2 Photographic Equipment - 802.3 Chemical Operations - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 822.3 Food Products - 902.1 Engineering Graphics - 921.6 Numerical Methods - 931.1 Mechanics - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.04.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 16>

Accession number:20151400700115
Title:Visual and real-time simulation of dynamic cutting of earthmoving work
Authors:Yu, Changzhi (1); Ni, Tao (2); Lin, Jie (1); Zhou, Danchen (1); Shang, Jun (1)
Author affiliation:(1) Institute of Machinery Manufacturing Technology, China Academy of Engineering Physics, Mianyang, China; (2) College of Mechanical Science and Engineering, Jilin University, Changchun, China
Corresponding author:Ni, Tao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:217-223
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The surface objects of terrain are the main operation objects of earthmoving machinery, and soil cutting resistance from the process is a basic source of all vehicle dynamic phenomenons. The soil cutting resistance is the basis of mathematical model of excavator-terrain dynamic interaction, which has an important influence on hydraulic system, working device, motion mechanism and vehicle performances. Hydraulic excavator as a representative model of engineering machinery, is widely used in construction, mining, forestry, municipal engineering and other fields. The most common working condition of excavator is earthmoving work. However, because of the complexity of working environments, even if the skilled operator couldn't completely understand the status of operation terrain areas, soil parameters, soil-cutting resistance, etc. Especially the soil-cutting resistance has a great significance for the phase of product design and development and path planning. Due to unpredictability of operational terrain areas, improper operation often causes safety accidents, and even machine apart. At present, most construction machinery driving simulators are typically limited to the modeling and simulation of the kinematics and dynamics of the working device under no-loading or steady loading condition. This neglects the influence of the soil excavation resistance on the system under operating conditions. Therefore, it is difficult for these simulators to realistically capture the dynamic interaction between the device and environment, and impossible to make a proper evaluation of the closed-loop human-machine-environment system, which caused the physics behavior of vehicle was not accurate enough. This caused the sense of reality is very low and couldn't provide drivers enough immersion, forming the situation that demonstration effect is greater than engineering application. On the basis of geometric entity modeling in visual simulation engine, Delta3D, real-time multi-body dynamics simulation platform, Vortex, are adopted to build the software framework and simulate dynamic characteristics of excavator, which also has complex collision detection function. A simulation platform for hydraulic excavator driving simulator was established, and carried on typical driving conditions tests of the excavator in the virtual environment, such as excavation, outward transport, pouring soil. It assumed that soil particles are mainly destroyed by shear fracture during digging operations, according to theory of passive soil pressure presented by Terzaghi, cutting resistance model of the soil in working condition is established, which assumed the soil as rigid-plastic material and use the static equilibrium to solve the soil particles resistance acting on excavator bucket..According to the actual operation situations of digging bucket, terrain inclination, acceleration, and side friction from soil to bucket parameters are applied to revise FEE put forward by Reece. The cutting resistance forces from soil to bucket in three interaction operations are obtained, and the factors affecting the cutting resistance were analyzed. By changing the soil cutting parameters, the system can realize the simulation of soil cutting resistance under different working condition. The visualization and real-time simulation of dynamic cutting of earthmoving work platform established provides highly accurate and real-time simulation of the kinetics of hydraulic excavators under a virtual environment. The system has characteristics of high fidelity, well real-time performance and strong immersive, and can be not only used for auxiliary training, guaranteeing the stability in interaction process and improving work efficiency, but also used in the engineering application, providing intuitive measurement method of product design and development, evaluating performance, operating characteristics, control strategy, human-machine safety, etc. With the interaction simulation platform, operators can make correct evaluation of a closed loop system for human-machine-environment. Furthermore, the visualization and real-time simulation of dynamic cutting of earthmoving work platform can provide the multi-repeated data for evaluation of the vehicle manipulation performance for hydraulic excavator. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Excavators
Controlled terms:Airships - Automobile bodies - Automobile simulators - Closed loop systems - Computer programming - Computer software - Construction equipment - Data visualization - Dynamics - Earthmoving machinery  - Excavation - Flow visualization - Hydraulic equipment - Hydraulic machinery - Landforms - Machinery - Mechanics - Motion planning - Municipal engineering - Personnel training  - Product design - Safety engineering - Simulators - Soil testing - Soils - Transients - Vehicle performance - Vehicles - Virtual reality - Visualization
Uncontrolled terms:Dynamic interaction - Earthmoving - Multi-body dynamic - Real time simulations - Soil cuttings
Classification code:403.1 Urban Planning and Development - 405.1 Construction Equipment - 405.2 Construction Methods - 432 Highway Transportation - 481.1 Geology - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 621 Nuclear Reactors - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 652.5 Balloons and Gliders - 662 Automobiles and Smaller Vehicles - 663 Buses, Tractors and Trucks - 671 Naval Architecture - 723 Computer Software, Data Handling and Applications - 901.2 Education - 902.1 Engineering Graphics - 913.1 Production Engineering - 914 Safety Engineering - 931.1 Mechanics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.01.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 17>

Accession number:20151400700114
Title:Detection of soil thickness in forest land based on electrical resistivity tomographic scanning technology
Authors:Xie, Yingge (1); Li, Xia (1); Zhang, Fengbao (2); Wang, Yongji (2)
Author affiliation:(1) College of Science, Northwest A&amp;F University, Yangling, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Yangling, China
Corresponding author:Li, Xia
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:212-216
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil thickness is the key index for the soil quality evaluation and has great effect on the productivity and properties of the forested soils. Soil thickness is commonly defined as the distance from the soil surface to the bedrock. The direct estimates of bedrock depth through drilling steel or from destructive boreholes and pits are too expensive and laborious in large areas, for the study area is often far away from the road and large tools are not accessible. Geophysical method seems to be a possible non-invasive and efficient alternative. Among available techniques, ground penetrating radar, seismic waves or sound waves often provide confusing or even wrong information, which prohibits the signal to go deeper from the shallower rocks. However, electrical resistivity tomography (ERT) offers interesting assets. The electrical resistivity depends on a number of soil textural and structural characteristics and can be regarded as a proxy of many soil properties. The electrical resistivity of the soil is found to be sensitive to the soil inclusion such as the tunnel or rocks. The ERT provides the electrical image of subsurface soil, and the result provided is easy to be explained and straightforward. It has been proved that the approach is suitable to investigate heterogeneous soils having components with contrasted electrical resistivity. This is often the case in soil between the soil matrix and the bedrock. In this research, the ERT was applied to the stony forested soils to study the soil thickness, and the applicability of the ERT was evaluated. Electrical resistivity of the soil samples overlying the bedrock was measured in the lab with four-electrode method and characterized as 48-640 &Omega;m. Electrical resistivity of the bedrock was obtained by data extraction from the ERT surveys and measured on site using four-electrode method, and the results showed that the electrical resistivity of the bedrock could be characterized as 1200-1600 &Omega;m. The two-dimensional ERT was carried on site with gradient electrode array and the results were inversed by RES2DINV; finally the inversed resistivity section were combined with the characteristic electrical resistivity of the bedrock and its overlying soils to estimate the soil thickness. The estimated results by the ERT were compared to the real soil thickness obtained by digging pits. The results indicated that the soil thickness varied between 0 and 2 m in the Mt-ventoux hilly area located in the south of France. The estimated results fitted well with the real soil thickness measured by digging pits with root mean square error (RMSE) of 0.2678 and R²of 0.8223. Thus the excellent applicability of the ERT to the soil thickness evaluation was proved on the forested soils. In this research, the transition between the bedrock and soil surface was found in the field, and the electrical properties of the transition were studied. And still, the applicability of the ERT was verified on account of the transition between the bedrock and soil surface, which is not common in the literature available. The method proposed showed higher accuracy and indicated that the applicability of the ERT for soil thickness distribution evaluation. In the future research, the method will be tried to apply to the soil dry layer which is popular in the Loess plateau and to evaluate the applicability. Soil moisture and temperature has great effect on the soil electrical resistivity, so the soil moisture and temperature is suggested to be measured in the field in order that the results more fit the reality. The research will provide an important tool for the problems related to soil and will be an important aid for the soil quality evaluation and land utilization. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Soils
Controlled terms:Electric conductivity - Electrodes - Forestry - Geological surveys - Geophysics - Ground penetrating radar systems - Mean square error - Moisture - Quality control - Soil moisture  - Tomography
Uncontrolled terms:Bedrock - Electrical resistivity tomography - Ground Penetrating Radar - Root mean square errors - Soil electrical resistivities - Soil quality evaluation - Soil thickness - Structural characteristics
Classification code:481.1 Geology - 481.3 Geophysics - 483.1 Soils and Soil Mechanics - 701.1 Electricity: Basic Concepts and Phenomena - 704.1 Electric Components - 716.2 Radar Systems and Equipment - 731.1 Control Systems - 746 Imaging Techniques - 801.4 Physical Chemistry - 821.0 Woodlands and Forestry - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2015.04.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 18>

Accession number:20151400700118
Title:Effect of no tillage on carbon sequestration and carbon balance in farming ecosystem in dryland area of northern China
Authors:Zhang, Hengheng (1); Yan, Changrong (1); Zhang, Yanqing (1); Wang, Jianbo (1); He, Wenqing (1); Chen, Baoqing (1); Liu, Enke (1)
Author affiliation:(1) Institute of Environment and Sustainable Development in Agriculture, CAAS/Key Laboratory of Dry Land Agriculture, MOA, Beijing, China
Corresponding author:Liu, Enke
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:240-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil conservation tillage practices such as no-tillage and straw mulching are of great significance for saving energy input in farmland, mitigating greenhouse gas emission to the atmosphere, and increasing carbon sequestration potential in soils. Despite of great interest in the effect of no-tillage (NT) management practice on carbon sequestration and GHG emissions in northern China, long-term effects of different tillage practices in that region on farmland system carbon footprints remain unclear. Based on a 20-year conservation tillage experiment in a winter wheat system at Linfen City in Shanxi province, we evaluated long-term (20-year) effects of NT and conventional tillage (CT) practices on the carbon balance. During the experiment, we measured soil respiration and soil carbon concentration in the field. A random block design with three replications was used to assess both the tillage and its effects on soil carbon sequestration and yield of winter wheat (Triticum aestivum L.). Production, formulation, storage, and distribution of these inputs such as seed, chemical fertilizer and application with tractor equipment cause the combustion of fossil fuel and use of energy from other sources, which also emits CO<inf>2</inf>and other GHGs into the atmosphere. Thus, it is essential to understand emissions in kilograms carbon equivalent (kg CE) of various tillage operations, fertilizers, pesticides, harvesting and residue management. The index of carbon emission of different agricultural inputs were taken from literatures. In our study, carbon emission produced by chemical fertilizer with NT and CT practices accounted for 73.3%-77.1% of total carbon emission from agricultural inputs, and has become the main carbon source. Compared with other countries, fertilizer input in China accounts for a greater portion within agricultural production, and fertilizer costs made up about 50% of total costs in china. Reducing fertilizer use is an effective means to decrease indirect carbon emission. Because NT reduced moldboard ploughing, chisel ploughing and stover removal, carbon emission from agricultural inputs under NT was 5.1% less than that under CT. Moreover, T. aestivum L. yield with NT treatment increased by 28.9% over CT treatment. Carbon productivity in the NT system was greater than that in CT. After 20 years, SOC concentration in NT soil was greater than that in the CT soil, but only in the layer between 0 and 10 cm. There was significant SOC accumulation (0-60 cm) in the NT soil (50.86 Mg/hm²) compared with that in the CT soil (46.00 Mg/hm²). The total CO<inf>2</inf>flux of soil respiration under NT was greater than that under CT. However, according to a carbon balance analysis, NT acted as a carbon sink compared to CT as a carbon source. This favored carbon sequestration in the farmland system. Therefore, long-term NT practice can increase soil carbon sequestration and reduce GHG emissions. The carbon emission coefficients are from literatures and N<inf>2</inf>O emission is not considered in the study. These may affect the results, but the trend among the different tillage system remains unchanged. With the improvement of the parameters, the accuracy of the assessment can be further improved. NT can be a significant innovation for carbon-friendly agricultural production technology in Northern China, because of its savings of energy/labor/time, reduction of GHG emissions, and benefits of SOC sequestration. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:48
Main heading:Soil pollution
Controlled terms:Agricultural machinery - Agriculture - Carbon - Carbon dioxide - Carbon footprint - Chemical equipment - Conservation - Crops - Cultivation - Ecology  - Ecosystems - Environmental impact - Farms - Fertilizers - Fuel storage - Greenhouse gases - Organic carbon - Plants (botany) - Soil conservation - Soils
Uncontrolled terms:Carbon balance - Carbon sequestration potential - Conventional tillage - Indirect carbon emissions - No tillage - Soil carbon concentrations - Soil organic carbon - Winter wheat (Triticum aestivum L.)
Classification code:454 Environmental Engineering - 461.9 Biology - 483.1 Soils and Soil Mechanics - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 802.1 Chemical Plants and Equipment - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.04.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 19>

Accession number:20151400700125
Title:Process parameter optimization of dual-roller peeling device for satsuma mandarin peeling machine
Authors:Chen, Hong (1); Yu, Bao (1); Wang, Zhenya (1); Pan, Haibing (1); Zuo, Ting (1); Dong, Wulin (2)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China; (2) Shanghai Triowin Automatic Equipment Co. Ltd., Shanghai, China
Corresponding author:Chen, Hong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:293-298
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Orange petal can is the traditional citrus processing product in China, and is also the most competitive product from China on the citrus processing product market in the international. The annual output of orange petal can in China is more than 0.6 million tons, accounting for more than 75% of the world canned orange production, and the annual export volume reaches 0.3 million tons, accounting for more than 70% of the world canned orange trade volume. China has replaced Japan and Spain and become the world center of the canned orange product; and Satsuma Mandarin is the main material of orange petal can. Currently, the peeling of citrus fruit mainly relies on the manpower, which not only has inefficient production, high labor intensity, but also is not conducive to product safety and healthy. With the rising of labor cost and the more and more strict hygiene requirement of the food market, replacing the manual operation mode and realizing the automatic peeling of citrus is the key problem to be solved for citrus processing industry. Huazhong Agricultural University has designed a kind of citrus stripping unit which includes ring cutting, pericarp opening, peeling and other processes, and the peeling process is realized by roller peeling device. In order to improve the peeling rate of citrus and decrease the damage rate of sarcocarp in the mechanical peeling process, this paper takes Satsuma Mandarin which is the main raw material of orange petal can as the test object, takes peeling rate, damage ratio and the sensory evaluation of citrus flavor as the main indexes, and conducts an experimental investigation of the process parameters and the effect of citrus peeling, so as to provide the basis for the design of Satsuma Mandarin peeling equipment. In the experiment, pretreatment method, roll rotation rate and plate translational speed are the main influence factors. And on the basis of the single factor test of the main affecting factors, an orthogonal test is conducted to study the influence of peeling effect for each factor on the roller peeling device using the self-designed peeling machine. Results show that the pretreatment method, roll rotation rate and plate translational speed have significant effect on peeling rate, while less effect on damage ratio. With the integrated balance method, the optimal parameters are selected, which are 3 min for hot steam heating, 60 r/min for roll rotation rate, and 12.98 mm/s for plate translational speed. Under the conditions, peeling rate is 100%, and damage ratio is 1.96%. The results provide the technical basis for the operation and optimization of the roll citrus peeling equipment. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Citrus fruits
Controlled terms:Agricultural machinery - Commerce - Compensation (personnel) - Optimization - Processing - Rollers (machine components) - Testing - Wages
Uncontrolled terms:Citrus reticulate - Damage ratio - Experimental investigations - Mechanical peeling - Pretreatment methods - Process parameter optimization - Process parameters - Sensory evaluation
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 601.2 Machine Components - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 911.2 Industrial Economics - 912.4 Personnel - 913.4 Manufacturing - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.04.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 20>

Accession number:20151400700105
Title:Effects of two nitrification inhibitors on transformations of nitrogen in soil
Authors:Ning, Jianfeng (1); Cui, Lihua (2); Ai, Shaoying (1); Wang, Ronghui (1); Yao, Jianwu (1); Li, Mengjun (1); Zeng, Zhaobing (1); Wang, Siyuan (1)
Author affiliation:(1) Key Laboratory of Plant Nutrition and Fertilizer in South Region, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, China; (2) College of Resource and Environment, South China Agricultural University, Guangzhou, China
Corresponding author:Ai, Shaoying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:144-151
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nitrification inhibitor has been proved to be effective in retarding nitrification process of nitrogen in the soil. Application of nitrification inhibitors to the field is considered to be a major method in controlling nonpoint pollution induced by nitrogen fertilizer in agricultural production. Dicyandiamide and thiosulfate are two types of nitrification inhibitors widely used throughout the world. A large number of studies have been carried out on dicyandiamide and thiosulfate focusing on their inhibitory effects. Till now, very limited information is available on the comparative effects of dicyandiamide and thiosulfate on transformations of nitrogen in the soil. The aim of this experiment was to investigate the effects of nitrification inhibitor dicyandiamide, potassium thiosulfate and their combination on the changes of mineral nitrogen, nitrification process and nitrogen recovery in the soil. A forty-day incubation experiment was conducted under the laboratory conditions (20 ). The experiment included unfertilized control, soil appended with urea nitrogen of 200 mg/kg alone, soil appended with urea nitrogen and dicyandiamide of 40 mg/kg, soil appended with urea nitrogen and potassium thiosulfate of 64 mg/kg, and soil appended with urea nitrogen and two inhibitors. Soil moisture in different treatments remained 60 percent of field water capacity. During the experimental period, soil samples were collected dynamically and the contents of mineral nitrogen such as nitrate nitrogen, ammonium nitrogen and nitrite nitrogen were analyzed. The result showed that an active nitrification process was found in the soil appended with nitrogen without nitrification inhibitors, where 77.7 percent of NH<inf>4</inf>⁺-N in applied nitrogen disappeared from the mineral nitrogen pool during the whole incubation period of 40 d. It was estimated that 56.6 percent of applied nitrogen was accumulated as NO<inf>3</inf>^--N. Addition of nitrification inhibitors dicyandiamide and potassium thiosulfate resulted in a decrease in the extent of NH<inf>4</inf>⁺-N disappearance by 74.1 percent and 16.6 percent, respectively. However, addition of dicyandiamide and potassium thiosulfate caused the increase in soil NH<inf>4</inf>⁺-N concentration. The nitrification process of nitrogen was inhibited in the soil appended with dicyandiamide and dicyandiamide combined with potassium thiosulfate, and the inhibition rates from 35.5 percent to 98.7 percent and from 82.2 percent to 103.5 percent were recorded, respectively. The delay of nitrification process was more than 20 days in two treatments. The nitrification rate in the soil appended with potassium thiosulfate was from 1.6 percent to 62.6 percent and the delay of nitrification process was 10 days. It was indicated that dicyandiamide induced a more pronounced inhibition on nitrogen nitrification as compared to potassium thiosulfate. Furthermore, a more efficient inhibition was observed for addition of dicyandiamide combined with potassium thiosulfate than that of dicyandiamide or potassium thiosulfate alone. It was also observed that potassium thiosulfate increased the accumulation of NO<inf>2</inf>^--N in the soil while dicyandiamide suppressed the production of NO<inf>2</inf>^--N. Nitrification inhibitor dicyandiamide or dicyandiamide combined with potassium thiosulfate increased the concentration of mineral nitrogen significantly while decreased the concentration of nitrogen unaccounted. Application of dicyandiamide, dicyandiamide combined with potassium thiosulfate increased the nitrogen recovery by 14.7 percent and 12 percent, respectively, compared with that in the treatment receiving nitrogen fertilizer alone. In summary, dicyandiamide proved superior to potassium thiosulfate in maintaining NH<inf>4</inf>⁺-N, inhibiting nitrification process and enhancing nitrogen recovery. A synergistic effect was also observed for the combined application of dicyandiamide and potassium thiosulfate. Results in this study are expected to provide scientific basis for practical application of two nitrification inhibitors. The inhibitory effect of dicyandiamide and potassium thiosulfate depends on soil temperature, moisture, microbial activity and other factors, and field experiment needs to be conducted to test the inhibitive characteristics of dicyandiamide and potassium thiosulfate on the nitrification. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Soil pollution
Controlled terms:Agriculture - Fertilizers - Metabolism - Minerals - Moisture - Nitrification - Nitrogen - Nitrogen fertilizers - Nitrogen oxides - Potassium  - Recovery - Soil moisture - Soil surveys - Soils - Urea
Uncontrolled terms:Agricultural productions - Dicyandiamide - Laboratory conditions - Microbial activities - Nitrification inhibitor - Nitrification process - Nitrogen transformations - Thiosulfates
Classification code:461.9 Biology - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 549.1 Alkali Metals - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.04.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 21>

Accession number:20151400700116
Title:Analysis of propagation and diffraction rule of radiofrequency signal in man-made forest
Authors:Xu, Yunjie (1); Li, Wenbin (2); Xiu, Shudong (1)
Author affiliation:(1) Jiyang College of Zhejiang Agricultural &amp; Forestry University, Zhuji, China; (2) School of Technology, Beijing Forestry University, Beijing, China
Corresponding author:Xu, Yunjie
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:224-231
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The ability of 2.4 GHz signal diffraction which is adopted by WSN (wireless sensor networks) is worse in forests, because the range behind standing tree in forests has blind signal area. Diffraction law of transmission attenuation and clinging trunk of 2.4 GHz radio-frequency signal in forests has been studied. To describe the diffraction effects of the edges of surfaces using a relatively simple mathematical method, the Kirchhoff-Huygens approximation is employed. Based on the uniform geometrical theory of diffraction (UTD), the region of transition is uniform. To account for the disposal of the sensor, only the illuminated region and the shadow are considered. According to the Kirchhoff approximation, the substitution is used to perform integral transform and the model of wedge diffraction gets simplification. Accounting for the influence of the diffusion factor and according to UDT, the aforementioned approach can also be used to derive the field at the receiver point. The research object is wireless radio-frequency signal transmission in man-made forests. The main contents and conclusions are as follows: 1) The signal transmission characteristics in plantation were studied. Tree trunks are replaced by absorbing screens. The leaves and branches are replaced by partial attenuation screens. The phase and attenuation screen is located directly above the absorbing screen for simplicity. The wireless sensor placed at a breast height of 1.3 m can be further lowered to the basal area in the current paper, so only the effects of the basal area of breast height are considered. Circular area expressions are used for the measurements of the basal area of breast height and standing wood volume, with an average error of &plusmn;3%. The configuration characteristics of plantation are combined. Through the modeling methods of hierarchical independent analysis using four-storey independent dielectric layer, the overall propagation model of RF signal in plantation is simplified. The concepts of crown attenuation screen and truck absorbing screen are put forward. And the formula of loss was given equation, when electromagnetic wave was mathematically spreading in plantation medium. 2) The diffraction fields and the shadow of standing tree diffraction are solved using polygons as approximate substitutes for the circle. When shadow results from a single object, such as a standing tree, the attenuation attributable to diffraction can be estimated by considering the obstruction of a diffracting wedge-edge. According to the Kirchhoff approximation, the receiver point can be written as an integral for the complex amplitude over the plane. 3) Taking man-made birch as the example: the frequency of the source point in the base station is 2.4 GHz, the circumference of the standing tree is 800 mm, the radius of standing tree is l/2&pi;, and source and receiver are equal in height, that is, their diameters are both at breast height of 1.3 m. It shows that the propagation loss of the receiver power, transmission height and distance increase with an increase in the distance of the source, i.e., if the propagation loss increases, the free space propagation loss also increases. Application of t-test to test, takes the significance level of 0.05, below which the results are not significantly different, got fired from the receiving point near models more reliable results. In this article, the research result provides a new thread for network optimization decoration strategy of WSN. Meanwhile it can provide theoretical support for communication technology development of other radio-frequency signal. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Forestry
Controlled terms:Complex networks - Data transfer - Diffraction - Electromagnetic field measurement - Electromagnetic wave scattering - Electromagnetic waves - Integral equations - Models - Radio transmission - Radio waves  - Signaling - Wireless sensor networks
Uncontrolled terms:Communication technologies - Configuration characteristics - Kirchhoff approximations - Man-made forests - Transmission attenuations - Uniform geometrical theory of diffraction - Wireless radio-frequency - WSN (wireless sensor networks)
Classification code:404 Civil Defense and Military Engineering - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 716.3 Radio Systems and Equipment - 722 Computer Systems and Equipment - 723.2 Data Processing and Image Processing - 821.0 Woodlands and Forestry - 902.1 Engineering Graphics - 921.2 Calculus - 942.4 Magnetic Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.04.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 22>

Accession number:20151400700093
Title:Effects of piston elastic deformation on piston secondary motion and skirt lubrication characteristics
Authors:Ruan, Dengfang (1); Xu, Jinxia (1); Gao, Xin (1)
Author affiliation:(1) State Key Laboratory of Mechanical Transmission, Chongqing University, Chongqing, China
Corresponding author:Ruan, Dengfang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:63-68
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Piston skirt-liner is one of the primary friction pairs influencing the friction power loss of an internal combustion engine, so it is feasible to improve the fuel economy of engines by studying the lubrication characteristics of the piston skirt-liner to reduce the friction power loss. The piston skirt lubrication is related to the piston secondary motion and the elastic deformation of the piston and liner, and there exists a strong coupled relationship between them. Therefore, it may be more reasonable to couple the elastic deformation equation of piston and liner than ignore the deformation of piston and liner, when the piston skirt lubrication and the piston secondary motion equations are solved. In order to reveal the effects of the piston elastic deformation on the piston secondary motion and skirt lubrication characteristics, the structural dynamics equations of the piston and liner were established based on the finite element modal reduction method, the piston secondary motion equation, the average Reynolds equation and the possible solid-to-solid contact equation in mixed lubrication were solved iteratively based on the parameters of a single-cylinder diesel engine, and the difference between the skirt lubrication performances with or without considering the elastic deformations of piston was analyzed. The results showed that the elastic deformation configurations of the piston skirt thrust and anti-thrust sides experienced different variations with crank angles and the deformation was significant at work stroke. Besides, the maximum deformation region of the piston skirt side was variable at different crank angles, sometimes in the middle of the piston skirt side, and sometimes at the bottom edges of the piston skirt side. It could be found that the piston secondary motion quantities including the piston deformation became bigger, when compared with those excluding the deformation of piston, especially at compress and work strokes. The eccentricity of piston at the bottom of the skirt including the piston deformation was about 1.3 times as big as those excluding the piston deformation in the region from 370 to 500&deg;CA at work stroke. The minimum film thickness was increased at intake, compress and work strokes, with fluctuating at exhaust stroke and significant changes at work stroke. Furthermore, the minimum film thickness considering the deformation of piston were about 2 times as big as those excluding the deformation of piston at work stroke. While the total friction power loss was reduced significantly and was about 0.4 times as big as those excluding the deformation of piston at work stroke, and varied slightly at other strokes. Also, the configurations of the oil film pressure field experienced different variations with crank angles, from parabolic to saddle-shaped ones, when the deformation of piston was not considered and considered. The peak values of oil film pressure field became smaller and were about 0.5 times as big as those excluding the deformation of piston at intake, compress and work strokes. It is necessary to consider the effect of the piston deformation in order to obtain reliable solutions when the piston skirt lubrication is investigated. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Engine pistons
Controlled terms:Diesel engines - Elastic deformation - Engine cylinders - Engines - Equations of motion - Film thickness - Finite element method - Friction - Fuel economy - Internal combustion engines  - Iterative methods - Lubricating oils - Lubrication - Oil shale - Pistons - Structural dynamics - Tribology
Uncontrolled terms:Deformation equations - Finite element modal reduction method - Friction power - Lubrication characteristics - Lubrication performance - Piston secondary motion - Piston skirts - Single-cylinder diesel engine
Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 423 Non Mechanical Properties and Tests of Building Materials - 512.1 Petroleum Deposits - 521 Fuel Combustion and Flame Research - 607.1 Lubricants - 607.2 Lubrication - 612 Engines - 818 Rubber and Elastomers - 921.6 Numerical Methods - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics - 943 Mechanical and Miscellaneous Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 23>

Accession number:20151400700108
Title:Detection of winding orchard path through improving random sample consensus algorithm
Authors:Lin, Guichao (1); Zou, Xiangjun (1); Luo, Lufeng (1); Mo, Yuda (1)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China
Corresponding author:Zou, Xiangjun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:168-174
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agricultural mobile robot and sightseeing agriculture is a direction of agricultural development in recent years. Agricultural mobile robot, a kind of efficient transportation equipment and means of transport, was of great significance in the orchard sightseeing agriculture. Road detection is the key technology and an important prerequisite for mobile agricultural robot to achieve autonomous navigation. In practical applications, the complexity of the orchard environment, e.g., the impact of illumination changes, shadows and occlusion, has resulted in poor robustness of vision detection algorithm. Therefore, the orchard road detection algorithm is required to be improved. So a method fusing edge detection and improved random sample consensus for winding orchard path detection was proposed. The proposed algorithm was consisted of orchard road edge detection algorithm (REE) and improved RANSAC algorithm (IRANSAC). Because the orchard road image contained a lot of noise, such as shadows and occlusion, the REE was aimed at extracting road edge as well as removing noise according to the color distribution and geometry characteristics of the orchard road. First, using the finite difference operator to extract image edge may contain noises. Then a basic assumption that road edges had striking gray contrast among their neighborhood was proposed, so we used the constraint of contrast of gray values to removed noises. However, some noises satisfied the constraint condition, hence another assumption that a curved road could be seen as straight road in a certain scale was proposed, therefore, the image was divided into n regions, if n was large enough, a linear curve could approximate to curve in sub-image. On this basis, an improved hough line detection algorithm was executed to remove noises which were not lying on the lines. The REE could dramatically remove noises and keep the road edge points. However the REE could not remove all the noises, so the linear segments in the image could not represent curve. The spline curve model was proposed to describe the line or curve road, so the remaining problem was how to find the true spline among the edge points. IRANSAC was aimed at fitting the spline curve. The IRANSAC combining the advantages of linear least square method and RANSAC could correctly estimate model parameters of the spline curve, and achieve detecting orchard road. In order to test the proposed algorithm, we collected 240 Orchard Road images as test objects, including straight roads, curved roads, roads disturbed by illumination change and blocked roads in the South China Agricultural University. The result showed that: under the influence of illumination change and occlusion, the REE algorithm can effectively extract the edge of orchard image, and reduce 96.5% residual noises effectively, with the average computation time of 0.1658 s; The IRANSAC can correctly fit the road edge, and the correct fitting rate of the four roads are 93.3%, 86.7%, 85.0% and 91.7% higher than RANSAC respectively, with the average correct rate of 89.1% and the average detection time of 0.1834 s; Sometimes the IRANSAC failed to fit the right spline curve because the complex environment may cause road edge points missing, or the REE algorithm failed to get sufficient edge points. In brief, the proposed algorithm can satisfy the robustness of navigation system and real-time requirements, and ensure the effectiveness of the visual navigation system to achieve orchard road detection. In order to further improve the algorithm robustness under the clutter background, the key point is to improve robustness of REE. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Edge detection
Controlled terms:Agriculture - Algorithms - Curve fitting - Curves (road) - Extraction - Farms - Hough transforms - Image enhancement - Image processing - Iterative methods  - Least squares approximations - Measurements - Mobile robots - Navigation systems - Orchards - Roads and streets - Robots - Signal detection - Transportation - Winding
Uncontrolled terms:Agricultural development - Finite difference operators - Linear least square methods - Polyfit - Random sample consensus - Road detection - Transportation equipments - Visual navigation systems
Classification code:406.2 Roads and Streets - 431 Air Transportation - 431.5 Air Navigation and Traffic Control - 432 Highway Transportation - 433 Railroad Transportation - 434 Waterway Transportation - 434.4 Waterway Navigation - 716 Telecommunication; Radar, Radio and Television - 716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 731.5 Robotics - 741 Light, Optics and Optical Devices - 802.3 Chemical Operations - 816.1 Processing of Plastics and Other Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 921 Mathematics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 24>

Accession number:20151400700092
Title:Prediction model for fundamental frequency of low frequency bending vibration piezoelectric vibrator of ultrasonic atomizing nozzle
Authors:Gao, Jianmin (1); Teng, Yue (1)
Author affiliation:(1) Key Laboratory of Modem Agricultural Equipment and Technology, Ministry of Education &amp; Jiangsu Province, Jiangsu University, Zhenjiang, China
Corresponding author:Gao, Jianmin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:55-62
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ultrasonic atomization had been paid so much attention as a new spraying technique recently. With such advantages as small droplets, uniform size distribution, high roundness, large atomization quantity and low liquid delivery pressure, ultrasonic atomization is widely used in aeroponic, agricultural humidifying fields, reagents atomization treatment, semiconductor etching and so on. According to different the working frequency, the current ultrasonic atomizer mainly includes high-frequency (working frequency is greater than 1 MHz) and low-frequency (working frequency is in the range between 20 kHz and 100 kHz). Application of high-frequency ultrasonic atomizer was highly limited for such disadvantages as low reliability, high driving voltage, short continuous working time, high energy consuming, failing in atomizing high viscosity liquids, small and unstable atomization amount. Above all, chemical structures of liquids atomized by high frequency ultrasonic atomizer would be changed, so this kind of atomizer was just suitable for atomizing water. Current actuators of low-frequency ultrasonic nozzles were mainly made of Langevin piezoelectric actuators, which included piezoelectric discs, front covers and rear covers. Such disadvantages as high driving working voltage, low efficiency, severe heat, large volume and uneven distribution of droplets limited this kind of low-frequency ultrasonic nozzles to be spread. In order to develop a low frequency ultrasonic nozzle with such advantages as low driving working voltage, high working efficiency, small feat, fine and uneven distribution of droplets, a novel low frequency ultrasonic nozzle, whose actuator was an axial symmetry bending composite piezoelectric actuator, was proposed and designed in this paper. While the core component of this ultrasonic nozzle, namely, an axial symmetry bending composite piezoelectric actuator was composed of a piezoelectric ceramic ring and a metal disc. At the present, the fundamental vibration frequency of this kind of actuator was mainly applying Rayleigh-Ritz theory based on the minimal energy principle to search an approximate value without considering electronic-mechanical coupling. Because Rayleigh-Ritz theory ignored the effect of t electronic-mechanical, the calculation result error was too bigger. At the same time, this method was so complicated that it's not suitable for engineering calculation. So it's necessary to find a simple calculation formulation for engineering application. In order to find out how key structural parameters of axial symmetry bending composite piezoelectric actuators influence on their fundamental frequencies, a virtual testing system based on finite element method was established. In this virtual testing system, element Solid 98, an tetrahedral coupled-field solid element in ANSYS software was used to mesh the prototype of axial symmetry bending composite piezoelectric actuator. Combined with an orthogonal experimental design method, an orthogonal protocol of four factors and five levels was proposed. Based on virtual test data, a regression model between fundamental frequency and key structural parameters of piezoelectric vibrators (significance level &alpha;=0.05) was established. The regression model indicated that: i) P-values of outer diameters, inner diameters of nozzle's piezoelectric discs and diameters of metal discs were 1.2&times;10^-8, 9.97&times;10^-6, 2.093&times;10^-3respectively. It indicated that fundamental frequencies of axial symmetry bending composite piezoelectric actuator were affected by outer diameters, inner diameters of nozzle's piezoelectric discs and diameters of metal discs highly significantly; ii) P-value of piezoelectric disc thickness was 0.012813. It indicated that fundamental frequencies were influenced by piezoelectric disc thickness significantly; iii) outer diameter, inner diameter, thickness of nozzle's piezoelectric ceramic and diameter of metal disc influence frequencies of those actuators in turn. Tests of the nozzle's acoustic impedance were conducted too by PV 70A, an instrument used for measuring piezoelectric part's acoustic impedance parameters. Compared fitting results with test results, fitting errors are nearly all less than 5%, so the regression model was verified. This regression model made it easier to optimize axial symmetry bending composite piezoelectric actuator design. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Piezoelectric actuators
Controlled terms:Acoustic impedance - Actuator disks - Actuators - Atomization - Atomizers - Ceramic materials - Design - Disks (machine components) - Disks (structural components) - Drop formation  - Drops - Finite element method - Liquids - Mechanical actuators - Metals - Natural frequencies - Nozzle design - Nozzles - Piezoelectric ceramics - Piezoelectric materials  - Piezoelectricity - Polysulfones - Regression analysis - Software testing - Spray nozzles - Spraying - Ultrasonic applications - Vibrations (mechanical) - Vibrators - Virtual reality  - Viscosity of liquids
Uncontrolled terms:Calculation formulation - Engineering applications - Fundamental frequencies - Low frequency ultrasonic - Orthogonal design - Orthogonal experimental design method - Piezoelectric ceramic rings - Ultrasonic nozzle
Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 531 Metallurgy and Metallography - 601.1 Mechanical Devices - 601.2 Machine Components - 602.1 Mechanical Drives - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 708 Electric and Magnetic Materials - 708.1 Dielectric Materials - 715 Electronic Equipment, General Purpose and Industrial - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 732 Control Devices - 732.1 Control Equipment - 751.1 Acoustic Waves - 751.2 Acoustic Properties of Materials - 753.3 Ultrasonic Applications - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 812.1 Ceramics - 813.1 Coating Techniques - 815.1.1 Organic Polymers - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.04.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 25>

Accession number:20151400700097
Title:Flow characteristics of blade tip clearance in semi-open centrifugal pump in variable condition
Authors:Jia, Xiaoqi (1); Nie, Xiaolin (2); Tu, Bicheng (2); Cui, Baoling (3)
Author affiliation:(1) Power Machinery &amp; Vehicle Engineering Institute, Zhejiang University, Hangzhou, China; (2) Ebara Great Pump Co. Ltd., Wenzhou, China; (3) Zhejiang Provincial Key Lab. of Fluid Transmission Technology, Zhejiang Sci-Tech University, Hangzhou, China
Corresponding author:Cui, Baoling
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:91-96
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The centrifugal pumps with semi-open impellers have been widely applied in petrol chemical industry, aerospace industry, power energy, etc. The tip clearance flow is a very complex turbulent flow in which the vortex, secondary flow, and recirculation flow are existent simultaneously, and it plays an important role for internal flow characteristics and external performances. In recent years, lots of numerical and experimental studies have been carried out to investigate the tip clearance flow and improve the performance of the semi-open impeller centrifugal pump. In this paper, numerical simulation and performance test are carried out on the centrifugal pump with a semi-open impeller. Influences of tip clearance on performance and the details of flow in tip clearance layer are studied at four different flow rate conditions. In the numerical simulation, the PRO/E software is used to generate computational geometries. The compatible preprocessor, GAMBIT is used to generate meshes. The commercial CFD software Fluent 6.3 is used to solve the N-S equations. The SIMPLEC algorithm is used to couple pressure and velocity. Second order upwind discretizations have been used for convection terms and the central difference schemes are used for diffusion terms. Three-dimensional viscous incompressible flow field simulations have been performed using multiple reference frame coordinates. The impeller and inducer region is taken as a rotating reference frame with a constant angular speed of 1450 r/min, and the other surfaces are defined as stationary reference frame. And the boundary conditions are velocity condition at inlet and outflow at outlet of the pump. Also, no-slip wall conditions have been used for the rest surfaces of the pump. Also, the experimental studies are carried out on the tested centrifugal pump with tip clearances of 1.0 mm, and the results are compared with the numerical calculations. Seal gaskets are used to adjust the tip clearance. Tungsten wires (the diameter is 3 mm) are placed in three positions of each blade (the blade tops near the leading edge, trailing edge and middle edge). Once impeller and casing are installed, and bolts are tightened, tungsten wires will be squeezed. Finally, a vernier caliper is used to measure the thicknesses of the squeezed tungsten wires. The tip clearance &Delta;c is 0.8 mm without any seal gasket and tip clearances are adjusted by increasing the seal gasket (thickness of 0.1 mm, brass gasket). After increasing the seal gasket, the tip clearances will be measured. The results show that there exists strong leakage vortex in the impeller inlet, impeller passage and impeller outlet. Due to the different pressures between suction surface and press surface of blades, the fluid pass through the tip clearance forming a lower pressure area, which leads to the leakage vortex. There exist large vortexes in the tip clearance layer at small flow rate condition. With the increasing of flow rate, vortexes become smaller and the flow state becomes more stable. The vortexes almost disappear at large flow rate condition, whereas the flow speed becomes much higher. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Computational fluid dynamics
Controlled terms:Aerospace industry - Centrifugal pumps - Chemical industry - Computer simulation - Computer software - Flow rate - Gaskets - Impellers - Incompressible flow - Models  - Navier Stokes equations - Numerical models - Pumps - Tungsten - Unsteady flow - Vortex flow - Wire
Uncontrolled terms:Centrifugal impeller - Internal flow characteristics - Numerical and experimental study - Semi-open - Stationary reference frames - Tip clearance - Variable operating condition - Viscous incompressible flows
Classification code:535.2 Metal Forming - 543.5 Tungsten and Alloys - 601.2 Machine Components - 601.3 Mechanisms - 618.2 Pumps - 631 Fluid Flow - 652 Aircraft and Avionics - 653 Aircraft Engines - 654 Rockets and Rocket Propulsion - 655 Spacecraft - 658 Aerospace Engineering, General - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 805 Chemical Engineering, General - 902.1 Engineering Graphics - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.04.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 26>

Accession number:20151400700085
Title:Evaluation index system construction and empirical analysis on food security in China
Authors:Yao, Chengsheng (1); Teng, Yi (1); Huang, Lin (2)
Author affiliation:(1) College of Economics and Management, Nanchang University, Nanchang, China; (2) Foreign Languages College, Jiangxi Normal University, Nanchang, China
Corresponding author:Yao, Chengsheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:1-10
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Food security is not only one of the most important issues that Chinese government attaches great importance to, but also one of the hot topics that researchers focus on. In order to make a comprehensive analysis on China's food security, this paper, from the perspectives of its four subsystems including food production resources, food availability and stability, food access, and food utilization, constructed an evaluation indexes system on food security, and further made a quantitative assessment about the state of food security in China from 1990 to 2011. The results showed that: in China, during the period of 1990-2011, as to the development of food security system, it could be divided into steady increase stage (1990-1998), rapid decrease stage (1999-2003) and rapid increase stage (2004-2011). As to the four food security subsystems, the development of food production resources subsystem could be divided into slow decrease stage (1990-2002) and rapid increase stage (2003-2011); the development of food availability and stability subsystem could be divided into fluctuating increase stage (1990-1998), rapid decrease stage (1999-2003) and steady increase stages (2004-2011); the development of food access subsystem could be divided into slow increase stage (1990-2004) and rapid increase stage (2005-2011); while the development of food utilization subsystem had only one stage, with its index constantly on the rise. As to the impact of the four subsystems on food security system, food production resources subsystem had the greatest impact, while food availability and stability came next, whose weight were 0.377 and 0.302 respectively. Using pathological diagnosis methods, this paper also analyzed the major factors hindering China's food security system from 1990 to 2010, and listed the first five obstacle factors in descending order of hindrance. It pointed out that, from 1990 to 2000, state financial support for agriculture, total grain production and road density were the key factors that had posed the greatest hindrance to the food security system. The obstacle degree of the three factors in 1990, 1995 and 2000 were 44.48%, 44.05% and 44.29%, respectively. However, from 2000 to 2010, the obstacle degree of the three factors on food security system was on the decrease, while the obstacle degree of per capital cultivated land was on the rise. In 2010, the factor of per capital cultivated land became the greatest obstacle to food security system, whose obstacle degree was 29.79%; the next greatest obstacle factors were net grain importation and domestic food price index, whose obstacle degree were 16.93% and 11.87%, respectively. As to the obstacle degree of the four food security subsystems, food production resources subsystem had the maximum obstacle degree to food security system, food availability and stability subsystem coming next, with their obstacle degrees rising from 31.32% and 26.34% in 1990 to 43.69% and 39.32% in 2010, respectively. Finally, based on the development characteristics of China's food security system, this paper proposed some relevant suggestions and policies to improve the state of China's food security. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Mobile security
Controlled terms:Agriculture - Food supply - Grain (agricultural product) - Land use - Security systems - Stability - System stability
Uncontrolled terms:China - Comprehensive evaluation - Food system - Indexes system - Security
Classification code:403 Urban and Regional Planning and Development - 404.2 Civil Defense - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 914.1 Accidents and Accident Prevention - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.04.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 27>

Accession number:20151400700095
Title:Design and experiment of NJS-1 type open-circuit closed wind tunnel for plant protection
Authors:Ding, Suming (1); Xue, Xinyu (1); Lan, Yubin (2); Cai, Chen (1); Zhang, Ling (1); Qin, Weicai (1); Zhang, Songchao (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing, China; (2) Southern Plains Agricultural Research Center, Department of Agriculture, TX, United States
Corresponding author:Xue, Xinyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:76-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Drift potential is one of the most important factors affecting spraying quality. Plant protection wind tunnel is an important and preferred tool for quantitative study on drift potential, which is an effective, reliable and feasible research tool for the parameter localization of spray model building. Wind tunnel can provide a well controlled environment for drift measurements under a range of wind speeds and spraying conditions. The NJS-1 type of plant protection wind tunnel was designed based on the drift potential theory, principle of wind tunnel design and atmospheric boundary layer similarity theory, which was composed of inlet section, power section, flexible section, transition section, diffusion section, stability section, contraction section and working section. The total length of the wind tunnel was about 20.0 m; the length of the working section (including five subsections) was about 7.5 m, while the cross section the of the working section was 1.2 m wide and 1.8 m high; the contraction section was 3.0 m long and the contraction ratio was 4; the settling chamber was 2.5 m long and the cross section was 2.4 m wide and 3.6 m high; a hexagon honeycomb of stainless steel and two 18-mesh stainless steel screens were embedded inside the settling chamber; the diffusion section was 2.5 m long, and diffusion ratio was 4 and diffusion angle was 40&deg;; the transition section was 2.8 m long and its main function coupled the power section and the diffusion section. The power section was composed of collector device, impeller, nose cowl, guide vane unit, trail hood and air duct, and was produced by an axial fan which was driven by the 25 kW electric machine. The design of the air supply device and main technical parameters of key parts was based on the theories of fluid mechanics. The air volume of the fan was 21.6 m³/s at the fan speed of 960 r/min, which was determined to adopt 8 impellers and 9 guide glades, the impeller diameter was 1.2 m and the guide glade width was 0.18 m. Wind profiles and flow dynamic characteristics were investigated for the NJS-1 type of plant protection wind tunnel. The objective of this research was to determine the suitability of the wind tunnel for the experiment research and provide the basic information for droplet drift and deposit experiments in this wind tunnel. The experiment was conducted under the condition of the empty wind tunnel. And the experiment strictly followed the flow field specification on high-speed wind tunnel and low-speed wind tunnel (GJB1179-1991). Pitot tube, spectrum analyzer and contractive segment were applied under different wind velocities. Some tests were finished, which referred to the main characteristic parameter testing of field aerodynamics flows in the plant protection wind-tunnel such as air velocity, turbulence intensity, flow stability and flow field uniformity. The results showed that the flow stability coefficient was less than 1.5%, the turbulence was about 1% within air velocity scope from 1.0 to 9.0 m/s, and wind field distribution was more uniform with the increase of the air velocity. This study suggests that the NJS-1 type of plant protection wind tunnel meets the design standard and experiment requirement. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Wind tunnels
Controlled terms:Aerodynamic stability - Aerodynamics - Air - Atmospheric boundary layer - Atmospheric thermodynamics - Boundary layer flow - Boundary layers - Design - Diffusion - Drops  - Fans - Flow fields - Fluid mechanics - Impellers - Spectrum analyzers - Spraying - Stainless steel - Tunnels - Turbulence - Velocity
Uncontrolled terms:Controlled environment - Experiment research - Flow quality - High-speed wind tunnel - Low-speed wind tunnel - Main technical parameters - Plant protection - Turbulence intensity
Classification code:401.2 Tunnels and Tunneling - 408 Structural Design - 443.1 Atmospheric Properties - 545.3 Steel - 601.2 Machine Components - 618.3 Blowers and Fans - 631.1 Fluid Flow, General - 651 Aerodynamics - 804 Chemical Products Generally - 813.1 Coating Techniques - 931.1 Mechanics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 28>

Accession number:20151400700101
Title:Effects of alternate partial root-zone drip irrigation on growth of root and shoot of Cabernet Sauvignon grape seedlings
Authors:Yu, Kun (1); Yu, Songlin (1); Liu, Huaifeng (1); Wang, Wenjing (1); Bai, Zechen (1); Sun, Junli (1)
Author affiliation:(1) Key Laboratory of Oasis Eco-Agriculture, Xinjiang Production and Construction Group/College of Agronomy, Shihezi University, Shihezi, China
Corresponding author:Yu, Songlin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:113-120
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:On the basis of its own subsurface drip irrigation with tank system, effects of alternate partial root-zone drip irrigation on grape seedling growth were explored, and the best drip irrigation mode and method was selected that was suitable for wine grape production in arid and semiarid areas of China. The experiment used Vitis vinifera L. 'Cabernet Sauvignon' as materials and used conventional drip irrigation (DI) and subsurface drip irrigation with tank system (SDI) (independent design) as the basis of engineering technology. Under bag control experimental condition, four kinds of partial-root zone alternative controlled drip irrigation methods were designed as follows: SDI-DI (SDI was on the left side, DI was on the right side) SDI-SDI (both sides were SDI), DI-SDI (DI was on the left side, SDI was on the right side), DI-DI (both sides were DI).Effects of alternate partial root-zone drip irrigation on shoot biomass, root distribution, root vigor and leaf physiological function of Cabernet Sauvignon seedling were discussed. The ratio of root to shoot was at optimum level (1-1.3) and shoot biomass accumulation were not significantly affected by SDI-SDI, DI-SDI, DI-SDI under the same irrigation conditions. The ratio of root and shoot was increased, plant experienced drought stress more intense and plant growth was limited by DI-DI. Horizontal root number on the left and right of DI-SDI and SDI-DI had great differences, and root number on the right was 13.3%, 10.5%, 14.0%, 22.1% more than that on the left, while horizontal root number on both sides of DI-DI and SDI-SDI had small differences. Root penetration was promoted and root activity in the depth of soil layer 20-60 cm was improved by SDI-DI and DI-SDI. In the depth of soil layer 0-20 cm, Root average diameter on the left side of SDI-DI and SDI-SDI were significantly higher than that of DI-DI and DI-SDI, and root surface area, root volume on the left side of SDI-DI and SDI-SDI were lower than DI-DI and DI-SDI treatment. In the depth of soil layer 0-10 cm, root average diameter on the right of SDI-SDI was the highest, but there was a little difference with DI-SDI. Ratio of root surface area, root volume on the right side of SDI-SDI and DI-SDI in the depth of soil layer of 20-40 cm were the most, root surface area of the two irrigation methods accounted for 48.8% and 49.2% respectively of the total surface area of the root on the right side, root volume accounted for 47.5% and 46.3% of the total volume of the root on the right side. The two irrigation methods maintained leaf photosynthetic performance stability and the leaf instantaneous water use efficiency (WUE) at a high level. The study on relation between root and shoot of plant showed that net photosynthetic leaf photosynthetic rate and transpiration rate were improved by reducing root biomass of surface and increasing root biomass of deep zone. The root activity significantly affected the photosynthetic characteristics of leaves of above-ground part, which was a key factor influencing on physiological characteristics. Under alternate partial root-zone drip irrigation, effects of SDI-DI and DI-SDI on the growth of root and shoot in Cabernet Sauvignon grape seedlings were better than DI-DI, and were the same as SDI-SDI. Considering the production cost, the field operation and difference on growth of root to shoot, SDI-DI and DI-SDI were the best drip irrigation mode and method under the condition of this experiment. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Irrigation
Controlled terms:Biomass - Crops - Ecology - Forestry - Moisture - Physiology - Plants (botany) - Soils - Subirrigation - Tanks (containers)  - Wine
Uncontrolled terms:Arid and semi-arid areas - Drip irrigation - Grape - Photosynthetic characteristics - Physiological characteristics - Root and shoots - Subsurface drip irrigation - Tank system
Classification code:454.3 Ecology and Ecosystems - 461.9 Biology - 483.1 Soils and Soil Mechanics - 619.2 Tanks - 801.4 Physical Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products
DOI:10.3969/j.issn.1002-6819.2015.04.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 29>

Accession number:20151400700120
Title:Evaluation method for application of internet of things for aquaculture
Authors:Yuan, Xiaoqing (1); Kong, Qingxin (2); Li, Qifeng (3); Li, Lin (1); Li, Daoliang (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China; (2) Chinese Academy of Agricultural Engineering, Beijing, China; (3) Beijing Research Center for Information Technology in Agriculture, Beijing, China
Corresponding author:Li, Daoliang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:258-265
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Internet of things for Aquaculture is an integrated modern system based on computing and communications technology like smart sensor technology, reliable telecommunication, intelligent information processing, which can collect data and images, transmit and process data intelligently, forecast future trend and early-warning for decision support. First of all, it is a key issue to establish scientific and rational index system and evaluation method for internet of things for aquaculture to guarantee its effectiveness. With the rapid development of information technology in China, the internet of things for aquaculture has been promoted and applied in Jiangsu, Shandong, Hunan, Hubei, Zhejiang and Guangdong. However, the internet of things for aquaculture in China is at an early stage and there are some problems, which cause negative impact on the promotion and application of the system, for examples, redundant functions, high cost, unstable performances, and so on. Secondly, in order to assess internet of things for aquaculture system, index system to assess internet of things for aquaculture was built in this paper by indicator optimization model to solve randomicity, redundancy, cross-connection and overlap caused subjective selection. Three steps composed of the selection process: 1) first round selection, three categories indices of function indicator, performance indicator and effectiveness indicator, targeted to 40 indicators were selected; 2) second round selection, 40 indicators representing perception layer, transmission layer and application layer, were optimized to 26 by method proposed by Dale and Beyeler, in which the standard conformity degree of each indicator was checked one by one and indicators need to meet at least 5 standards, otherwise they will be eliminated; 3) indicator screening model, by which 26 indicators were reduced to 14, with only 35% of total indicators representing 88.45% of total information, capturing the requirements of completeness and simplicity. Thirdly, fuzzy comprehensive evaluation approach, which comprise of three levels fuzzy comprehensive evaluation, was established to assess the application of internet of things for aquaculture. Most of the 14 indicators got in the first phase are qualitative factors and difficult to be quantified. That is why fuzzy comprehensive evaluation approach was used in this paper. Meanwhile, it is better to adopt multi-level factors as weights are not easy to be assigned reasonably when factors are too many, which leads unreasonable and wrong results. Multi-level fuzzy comprehensive method works well to solve this problem and can be applied to assess function characteristics, performance and effectiveness of the system of internet of things for aquaculture. Multi-level fuzzy comprehensive was built by steps of establishing comment set, membership and got quantitative score A, which can fall into five levels of excellence (A&ge;82.5), good (82.5&gt;A&ge;67.5), satisfactory (67.5&gt;A&ge;52.5), barely adequate (52.5&gt;A&ge;35) and fail (A&lt;35). Finally, case studies were carried out in Yixing of crab cultivation, Jiangsu province and Zhanjiang of white shrimp cultivation, Guangdong province, in which the index system and multi-level fuzzy comprehensive method were tested based on the internet of things for aquaculture system developed independently by China Agricultural University (CAU). Results showed that the score in Yixing was 87.371 indicating application of internet of things for aquaculture system in Yixing is excellent, meanwhile, the score in Zhanjiang is 74.921, which is good. Both of the two results are consistent with the actual situation of two bases, showing that index system and multi-level fuzzy comprehensive method proposed in this paper are feasible and reasonable for evaluation of application of internet of things for aquaculture and can guide its construction and improvement. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Internet of things
Controlled terms:Aquaculture - Cultivation - Decision support systems - Function evaluation - Fuzzy set theory - Indicators (instruments) - Internet - Optimization - Shellfish
Uncontrolled terms:Communications technology - Effectiveness indicators - Function characteristic - Fuzzy comprehensive evaluation - Fuzzy comprehensive methods - Fuzzy evaluation - Intelligent information processing - Smart sensor technology
Classification code:461.9 Biology - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 723 Computer Software, Data Handling and Applications - 821.3 Agricultural Methods - 921 Mathematics - 944.3 Pressure Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 30>

Accession number:20151400700127
Title:Improvement and application of vegetable traceability system with integrated real-time rapid detection of information
Authors:Qian, Jianping (1); Zhang, Baoyan (2); Xing, Bin (1); Yang, Xinting (1); Li, Long (1); Wang, Hongbin (3)
Author affiliation:(1) National Engineering Research Center for Information Technology in Agriculture, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China; (2) Tianjin Agricultural Information Center, Tianjin, China; (3) Tianjin Pollution-free Agri-Products (Crop Planting) Management Center, Tianjin, China
Corresponding author:Yang, Xinting
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:306-311
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The detection information of farm products increases rapidly, and plays an important role in traceability. The existed detection processing method used the mode of testing sample with detection instruments and manual recording data. This mode leads to the hazard of unassociated batches and distorted information, so the direct and credible effects of detection information in the traceability content are needed. In this paper, the reasons why detection information is not able to be integrated in the existed traceability system were analyzed. Modified system framework with detection information extracting and identification was proposed, which combined the rapid real-time detection instrument for vegetable pesticide residues mainly using enzyme inhibition method. In the detection process, information including detection ID, farm product batch and inhibition rate was recorded. In order to implement the automation reading and extracting of detection information, the access flowchart of detection data included the steps of instrument connection, vegetable detection, data extraction and data storing. The correlation between vegetable plant batch, detection identification number and product traceability code was the other important step for detection information tracing. Because one vegetable plant batch may be divided into many package units, the relationship between the batch code of vegetable plants and product traceability code was the type of 'one to many'. Because of the similar characteristics in one plant batch, the same batch of vegetable was detected once and the relationship between vegetable plant batch code and detection identification code was the type of 'one to one'. The batch correlation between product traceability code and detection identification code was established with the link of vegetable plant batch code. Based on.Net platform and the existed vegetable safety production management system, the vegetable production management and traceability system was updated for three functions. The detection instrument linked the vegetable production management and traceability system with serial port, and linking self-checking was implemented in the instrument link function. Then detection data was obtained through special data format. The detection data could be displayed but not modified in the data management function. The updated system was applied in 153 vegetable production bases in Tianjin city. During March 1st to May 30th in 2014, 28038 vegetable samples were detected and data obtain success rate with the updated system was 100%, and the data acquirement efficiency was improved. Furthermore, the detection results of 20 samples were compared between rapid real-time detection by enterprise self-check and casual inspection by supervision departments. The 20 samples were divided into two groups with No.1-8 samples using the manual recording mode of detection data without the updated the system and No.9-20 obtaining the detection data by automatic reading with the updated the system. The application results showed that the data acquisition success rate was 100% and the difference between the enterprise self-check value and the supervision casual inspection value was low with the absolute value of 4.37 after using the updated the system. The detection value with manual recording of No.3 sample was obviously lower than the one by supervision departments, which has the possible of distort data. Furthermore, the traceability results for using and not using the updated system were compared. Through using the system, the traceability results could indicate the precision detection information through the batches' correlation. The study in this paper presents an important step for satisfying the deeper requirement in traceability system. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Vegetables
Controlled terms:Agricultural products - Codes (symbols) - Computer systems - Data acquisition - Enzyme inhibition - Industrial management - Information management - Instrument testing - Measurements - Pesticides  - Signal detection
Uncontrolled terms:Detection identifications - Detection informations - Detection instruments - Management functions - Precision detections - Traceability - Traceability systems - Vegetable productions
Classification code:716.1 Information Theory and Signal Processing - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 801 Chemistry - 803 Chemical Agents and Basic Industrial Chemicals - 821.4 Agricultural Products - 912.2 Management - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.043
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 31>

Accession number:20151400700107
Title:Identification and navigation system of farmland path for high-clearance vehicle based on DM642
Authors:Zhang, Tiemin (1); Zhuang, Xiaolin (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou, China
Corresponding author:Zhang, Tiemin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:160-167
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This article presents a solution to achieve autonomous vehicle navigation and path recognition. The visual inspection system is established by utilizing agricultural four wheels drive vehicle equipped with a high performance digital media processor. This visual inspecting system is capable of collecting and displaying real time image, using an improved algorithm for path detection, which combines a serial of technologies, including 2G-R-B colour identification for identify the greens, central line algorithm for route calculation, and using double polyline algorithm including multi polyline to simulate Hough transform. In this article, the pro and con of each algorithm were compared and also its applicable environment by a series of path recognition and navigation tests. Although TMS320 DM642 has a strong operational ability, Hough transform needs a lot of operation. In order to reduce the delay in the process of image processing, a series of program optimizations had been launched in vehicle including Hough transform to extract path, Hough transform of double polylines fitting to extract path and Hough transform of multi polylines fitting to extract path. For example, the interesting areas were chosen to process, the step length of Hough transform appropriately increased, and interlaced scanning made the program of Hough transform in an easier, faster and more efficient way. The data receiving of the system was in the form of the serial port interrupt. In this agreement, according to the different environments, vehicle control chip could send proper instruction to control image processing chip to pick an optimal image algorithm. Meanwhile, according to the existing rules, the deviation of high-clearance vehicle's direction could be told to vehicle control chip by image processing chip in order to adjust the vehicle's direction appropriately according to the vehicle movement. Generally speaking, image processing chip would send data to vehicle control chip one time every 400 ms to control the vehicle in near real time. The accuracy could satisfy the need of the navigation. Experiment of walking straight showed that the standard deviation of lateral deviation was 7.199, the standard deviation of angular deviation was 6.294, and angular deviation could reach 22.5&deg;. Experiment with velocity influence on navigation precision showed that the average tracking deviation was 0.61 cm and the maximum tracking deviation was 16 cm in small turn at low speed. The average tracking deviation was 5.21 cm and the maximum tracking deviation was 29 cm in small turn at high speed. The average tracking deviation was 0.78 cm and the maximum tracking deviation was 23 cm in large turn at low speed. The average tracking deviation was 6.36 cm and the maximum tracking deviation was 35 cm in large turn at high speed. Therefore, this navigation control system is stable and reliable when the vehicle passes a straight line. Navigation precision decreases under the condition of high speed. The effect of the tracing also decreases when the turning radius is too large. However, this system can meet the demands of agricultural vehicles in navigation. The results of a series of route recognition and navigation tests demonstrates the efficiency of this visual inspection system. The combination of different technologies such as central line algorithm, Hough transform, double polyline algorithm and multi polyline to simulate Hough transform can help the vehicle to achieve self-navigation in all kinds of indoor and outdoor environments. Also in a spiral of path recognition and navigation tests, the vehicle performs great adaptability and strong anti-interference ability, and also reacts quick and is highly stable. The application of such tracing system has full potential in the future. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Navigation systems
Controlled terms:Agriculture - Airships - Algorithms - Control system synthesis - Digital storage - Extraction - Feature extraction - Hough transforms - Identification (control systems) - Image processing  - Indoor positioning systems - Inspection - Inspection equipment - Measurements - Speed - Statistics - Vehicles
Uncontrolled terms:Autonomous vehicle navigation - Colour identifications - Digital media processor - Hough Transformation - Navigation control systems - Path identifications - Tracking controls - Visual inspection systems
Classification code:432 Highway Transportation - 434.4 Waterway Navigation - 652.5 Balloons and Gliders - 716 Telecommunication; Radar, Radio and Television - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3.1 Inspection - 921 Mathematics - 921.3 Mathematical Transformations - 922.2 Mathematical Statistics - 931.1 Mechanics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 32>

Accession number:20151400700111
Title:Analyzing plant characteristics of rice suffering leaf blast in cold area based on Raman spectrum
Authors:Tan, Feng (1); Cai, Qiaoling (1); Sun, Xuecheng (1); Ma, Zhixin (1); Hou, Zhaolong (1)
Author affiliation:(1) Information Technology of Heilongjiang Bayi Agricultural University, Daqing, China
Corresponding author:Tan, Feng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:191-196
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Raman spectroscopy has been widely applied in some areas, such as agricultural products, food, and so on. In chemical molecular structure analysis and appraisal, it has some merits of simple pretreatment, nondestructive, rapid detection, etc. We all know that the Raman spectra of some substances with similar molecular structures may have significant differences. We can take advantage of this characteristic to effectively distinguish some substances with other similar molecular structures. Rice leaf blast is one of the most serious diseases that affect the yield of rice in cold area. In order to reduce the impact caused by the disease and increased early detection methods, Raman spectroscopy was used to collect spectroscopy of normal rice leaves and abnormal rice leaves and identified the characteristic frequency of the rice leaf. Through analysis of the spectral peaks and characteristic frequency offset of normal rice and abnormal rice functional groups, we found that the spectral peaks and the sensitive spectrum lines ranged from 1800 to 2600 cm^-1. The slopes of bimodal lines between 984 and 994 cm^-1, and between 828 and 851cm^-1were increased as the degree of disease increased. In random samples of 20 Raman spectra, the correct recognition ratio reached 75%. Collected Raman spectra have certain fluorescence background, and the process of baseline correction to the background has great influence on the Raman band peak height, but it has little influence on the peak area relatively. Therefore we can divide it by the peak maxima in the calculation of the spectral intensity. Finally, 50 samples of Raman spectra were randomly selected for analysis. We can get 1005, 1527cm^-1in the vicinity of the scattering cross section size and 2000-2300 cm^-1within the scope of the multiple spectral sum of peak scattering cross section size. We can see the change from the first 25 samples which are not very large. But with the aggravation of the rice disease extent, the scattering cross section values increased obviously. It showed that the Raman spectra of the rice leaf without disease were very small in the 2000-2300 cm^-1range. Because in the acquisition process of the Raman spectrum of rice leaf, the total energy of the light source is conserved, the increase in rice blast disease sensitive band scattering intensity of spectral peak intensity will correspondingly weakened other characteristic functional groups. So, the influence of ratio of rice blast sensitive band scattering intensity and scattering peaks characteristic functional groups were more obvious in rice blast disease of Raman spectral lines. The scattering cross section of 2000-2300 cm^-1increased with the increase of the degree of disease through the analysis of 50 randomly selected samples of Raman spectra, which showed a good relationship between the changes of the scattering cross section and the rice blast disease. Raman spectroscopy provides an effective method for the early detection of rice leaf blast. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Spectrum analysis
Controlled terms:Agricultural products - Chemical analysis - Chemical detection - Crops - Diseases - Frequency allocation - Functional groups - Light sources - Molecular structure - Plants (botany)  - Raman scattering - Raman spectroscopy
Uncontrolled terms:Acquisition process - Baseline correction - Characteristic frequencies - Plant characteristics - Raman spectral lines - Rice leaf - Scattering cross section - Scattering intensity
Classification code:461 Bioengineering and Biology - 716.4 Television Systems and Equipment - 741.1 Light/Optics - 801 Chemistry - 801.4 Physical Chemistry - 804.1 Organic Compounds - 821.4 Agricultural Products - 921 Mathematics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.04.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 33>

Accession number:20151400700106
Title:Analysis on drought risk of maize in Southwest China based on natural disaster risk theory and ArcGIS
Authors:Jia, Jianying (1); He, Nan (3); Han, Lanying (1); Zhang, Qiang (1); Zhang, Yufang (5); Hu, Jiamin (6)
Author affiliation:(1) Key Open Laboratory of Arid Climatic Change and Reducing Disaster of China Meteorological Administration, Institute of Arid Meteorology, China Meteorological Administration, Lanzhou, China; (2) Northwest Regional Climate Center, Lanzhou, China; (3) Public Weather Service Center, China Meteorological Administration, Beijing, China; (4) Meteorology Bureau of Gansu, Lanzhou, China; (5) Sichuan Agro-Meteorological Center, Chengdu, China; (6) Guizhou Provincial Climate Center, Guiyang, China
Corresponding author:Jia, Jianying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:152-159
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Southwest China is an important region for maize production, accounting for about 15% of the total maize area and output in China. There were abundant rainfall and humid climate in Southwest China. But in recent years, severe drought events often occurred there, which caused huge damage to local social economy and attracted widespread interest. Agro-drought risk analysis is helpful for improving the ability of regional disaster management and reducing potential drought risk. In this paper, the daily meteorological observations from 60 stations and the data related to maize agricultural production in Southwest China during the period of 1961-2012 were used. Based on natural disaster risk theory, maize drought risk assessment model was established from four factors: hazard, exposure, vulnerability, drought prevention and mitigation, and maize drought risk was zoned and analyzed in Southwest China. It showed that maize spring drought mainly occurred in most of District I, District II and District III, maize summer drought appeared in north of District I, most of District III and District IV, District V and District VI. High and sub high drought hazard zones of maize in whole growth period were mainly located in District III, parts of District I and District II. High and sub high exposure zones were mainly located in District II and District III; high and sub high vulnerable zones mainly were distributed in east of District II, parts of District IV and District V; low and sub low drought prevention and mitigation zones were located in parts of District II and District IV. The results showed that maize drought high risk and sub high zones in Southwest China were mainly located in District III, small parts of District I, District II, District IV and District V, in the majority of which maize drought hazards in whole growth period were high or sub high, maize area ratios were higher than maize average area ratio in Southwest, and maize yield per unit was higher than maize average yield per unit in Southwest. Moderate risk zones were mainly located in District V and District VI, in the majority of which maize drought hazards in whole growth period were moderate, maize area ratios, yield fluctuations and yield levels were comparable to maize average productivity level in Southwest. Low and sub low risk zones were mainly distributed in central of District I, southwest of District II, south and east of District IV, where maize drought hazards in whole growth period were low, and maize productivity levels were different. The study provides a theoretical basis for the maize production risk management and sustainable development in Southwest China. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Risk assessment
Controlled terms:Agriculture - Crops - Disaster prevention - Disasters - Drought - Hazards - Productivity - Risk analysis - Risk management - Risks
Uncontrolled terms:Agricultural productions - ArcGIS - Drought prevention and mitigations - Local social economy - Maize - Meteorological observation - Natural disaster risk - Southwest China
Classification code:444 Water Resources - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 912.2 Management - 913.1 Production Engineering - 914 Safety Engineering - 914.1 Accidents and Accident Prevention - 922 Statistical Methods - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.04.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 34>

Accession number:20151400700131
Title:Analysis of process and interface structure of straw geopolymer building material with heat preservation
Authors:Jin, Mantong (1); Zhu, Congying (1); Jin, Zanfang (1)
Author affiliation:(1) College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, China
Corresponding author:Jin, Zanfang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:332-338
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to develop a new insulation building material with high strength and better corrosion resistance, straws were added into geopolymer to synthesis straw-reinforced geopolymer composites, which can save building energy consumption and broaden industrial utilization way of straw because of its good thermal insulation and light weight properties. The composites also overcome the defects of low strength in traditional straw building materials. In this paper, modulus of the sodium silicate mixed with NaOH as alkaline activator was 3, and straws were cut to specific lengths after drying. After a certain amount of distilled water and alkaline activator added, the reaction was carried out in a cement paste mixer with constant stirring. When the geopolymer turned to be slurry, it was moulded into 20 mm&times;20 mm&times;20 mm cubes for 24 hours. Then the demolded straw-geopolymer would be placed into a humidity chamber and tested for compressive strength using TYE-300B Pressure Testing Machine when the schedule maintenance completed. The experiments which aimed to study the effect of A (molar ratio of SiO<inf>2</inf>and Al<inf>2</inf>O<inf>3</inf>in the reaction system), B (molar ratio of Na<inf>2</inf>O and SiO<inf>2</inf>in the reaction system) value on the compressive strength of straw-geopolymer were carried out by adopting the matrix design. Besides, the effects of straw length (1-10 mm), straw content (1%-10%), water-metakaolin ratio (0.09, 0.10, 0.11, 0.12) and relative humidity (50%-90%) were studied under the best values of A and B. Process of straw-reinforced geopolymer was optimized based on compressive strength. The thermal conductivity was also measured to ensure the thermal insulation property. The eutectic phase, chemical bonding and microstructure were analyzed by XRD, SEM and FT-IR. Results showed that the better formula of straw-geopolymer was that molar ratios of S<inf>i</inf>O<inf>2</inf>and Al<inf>2</inf>O<inf>3</inf>, and of Na<inf>2</inf>O and S<inf>i</inf>O<inf>2</inf>were 3.9 and 0.30, respectively. The mixed straw accounted for 4% with the length of 1 mm, and the ratio of water and metakaolin was 0.10. The samples should be cured at temperate of (20&plusmn;2)  and relative humidity of 70?Ddamp;plusmn;2% for 7 d. The compressive strength of straw-geopolymer can be up to 54.58 MPa, and the thermal conductivities of straw-geopolymer which were synthesised under the optimal formula with different straw content (0-6%) were also been studied. Thermal conductivity measurement was based on steady-state method. The results showed that the thermal conductivity of straw-geopolymer decreased with the increase of straw content, and the thermal conductivity of straw-geopolymer at 4% straw content was 0.0681 W/(m&middot;K). Comparing the thermal conductivity of straw-geopolymer material with other thermal insulation materials, it can be seen that the thermal conductivity of this material was close to that of cotton stalk insulation board and even smaller than foam concrete. Meanwhile, considering its high temperature resistance, cost saving and environmental contribution, the material synthesized in present work showed potential for building thermal insulation application. As a typical composite material, the interface between geopolymer and reinforcing straw had a significant correlation with the macroscopic properties of straw-reinforced geopolymer. The interface between straw and geopolymer was also studied through XRD, SEM, FT-IR analyses. XRD, SEM and FT-IR analyses results showed that the phases of straw-geopolymer were mainly composed of amorphous phase and crystalline phases of Quartz. The straw-geopolymer was semi-crystal, amorphous phase with Si, O and Al elements. Gaps and cracks were appeared near the straw/geopolymer interface. The cracks were diverged when there were straw, and secondary cracks appeared. The combination interface was week in the geopolymer matrix propagate and grow along the interface between straw and geopolymer. Moreover, new cracks generated approximately perpendicular to the strike direction of the original crack which could absorb plenty of fracture energy during crack propagation process. There was a clear imprint of the surface texture of the straw remaining on the geopolymer after straw pulled out. FT-IR analyses showed that the infrared peaks of straw-geopolymer are consistent with geopolymer. Overall, the bonding between straw and geopolymer mainly included mechanical locking, infiltration and vander waals forces. There was no chemical bonding between straw and geopolymer matrix. The study provided a new way to industrial utilization of straw, and provided guidance for research on green and insulation building material. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Thermal conductivity
Controlled terms:Alkalinity - Aluminum - Amorphous silicon - Building materials - Buildings - Chemical analysis - Chemical bonds - Compressive strength - Corrosion resistance - Cracks  - Energy utilization - Geopolymers - Historic preservation - Industrial research - Inorganic polymers - Insulation - Interfaces (materials) - Locks (fasteners) - Matrix algebra - Processing  - Quartz - Reinforcement - Silicates - Silicon compounds - Sodium - Straw - Strength of materials - Synthesis (chemical) - Testing - Thermal insulation
Uncontrolled terms:Building energy consumption - Environmental contributions - Geopolymer - High temperature resistance - Insulation applications - Thermal conductivity measurements - Thermal insulation materials - Thermal insulation properties
Classification code:402 Buildings and Towers - 413 Insulating Materials - 413.2 Heat Insulating Materials - 414 Masonry Materials - 415 Metals, Plastics, Wood and Other Structural Materials - 421 Strength of Building Materials; Mechanical Properties - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 482.2 Minerals - 525.3 Energy Utilization - 541.1 Aluminum - 549.1 Alkali Metals - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 601.3 Mechanisms - 641.2 Heat Transfer - 801 Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.5 Agricultural Wastes - 901.3 Engineering Research - 913.4 Manufacturing - 921.1 Algebra - 951 Materials Science - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.04.047
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 35>

Accession number:20151400700126
Title:Remote intelligent measurement and control system for granary ventilation based on absolute water potential diagram
Authors:Chen, Long (1); Wu, Wenfu (1); Qin, Xiao (1); Wu, Yuzhu (1); Chen, Siyu (1); Liu, Jingsheng (2); Zhang, Yaqiu (1)
Author affiliation:(1) College of Biological and Agricultural Engineering, Jilin University, Changchun, China; (2) College of Food Science and Engineering, Jilin Agricultural University, Changchun, China
Corresponding author:Zhang, Yaqiu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:299-305
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, a design of 'intelligent remote monitoring and control system of the granary' based on the absolute water potential theory (AWPT) has been proposed, which is used to improve information and intelligence level of the granary, and reduce the granary administrator's work difficulty. "Granary Ventilation Intelligent Decision System" (GVIDS) is the realization of this design. GVIDS's program development relies on the Android and the 'internet of things' technology. Its hardware framework, software framework, the main function modules and operational processes are the main research contents in this paper. The essence of AWPT is "the management and control method of granary's mechanical ventilation using water potential diagram" proposed by Wu Wenfu et al., which is improved on the basis of the Wu model. In the AWPT, there are three ventilation windows: cooling window, precipitation window and quality adjustment window, and each window corresponds to its appropriate operation mode of ventilation. When using AWPT to guide granary ventilation, the position of the air-temperature-point in the 'absolute water potential diagram' is observed to determine the need for ventilation, which means that the administrator makes proper ventilation operation according to the ventilation window area that the air-temperature-point falls. The client APP (application) consists of five parts, which are "Information Profile" module, "Absolute Humidity Diagram" module, "Absolute Water Potential Diagram" module, "Associated Equipment" module and "Managing Log" module. The "Information Profile" module is mainly responsible for displaying the basic information of different granaries; the theoretical basis of "Absolute Humidity Diagram" module is the WU model. First, the client will obtain the latest temperature and humidity data collected from the database. Then, according to the new grain CAE equation and allowing ventilation condition table, calculate and judge whether the current situation needs ventilation. Finally, draw the balanced absolute humidity diagram and balanced relative humidity diagram on the client. Absolute Water Potential Diagram (AWPD) is mainly composed of four curves and one point: absolute potential line of the air, absolute adsorption water potential line of the grains, absolute desorption water potential line of the grains, saturated humidity line of the air, and saturated humidity point of the air (Q). In the AWPD, the area surrounded by the blue lines is the cooling window, the area surrounded by the red line is the precipitation window, and the area surrounded by the green lines is the quality adjustment window. Because the cooling operation and precipitation operation is sometimes performed at the same time, there will be an overlap of the cooling window and precipitation window. "Associated Equipment" module is used to display the current equipments associated with the state of the work, and the user can remotely control these equipments with the switch buttons. "Managing Log" module is used for displaying all of the granary operation logs. The client App has so many advantages, such as friendly interface, simple operation, wide adaptability and intelligent and remote control, and it would solve the problem of limited working place for the granary administrator. In the simulated granary loading experiment, the performance of this system is very good, and it should be promoted. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Ventilation
Controlled terms:Atmospheric temperature - Computer programming - Control systems - Control theory - Cooling - Equipment - Grain elevators - Internet - Internet of things - Moisture  - Moisture control - Monitoring - Remote control - Temperature
Uncontrolled terms:Intelligent decision systems - Intelligent measurement - Management and controls - Mechanical ventilation - Operational process - Remote monitoring and control systems - Temperature and humidities - Water potential
Classification code:402.1 Industrial and Agricultural Buildings - 443.1 Atmospheric Properties - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.5 Ventilation - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 723 Computer Software, Data Handling and Applications - 723.1 Computer Programming - 731.1 Control Systems - 731.3 Specific Variables Control - 901 Engineering Profession - 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 - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2015.04.042
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 36>

Accession number:20151400700119
Title:Analysis of effect mechanism and risk of biochar on soil fertility and environmental quality
Authors:Wang, Xin (1); Yin, Daixia (1); Zhang, Feng (1); Tan, Changyin (1); Peng, Bo (1)
Author affiliation:(1) College of Resources and Environmental Science, Hunan Normal University, Changsha, China
Corresponding author:Wang, Xin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:248-257
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biochar is a solid material that is produced from biomass pyrolysis in oxygen-limited atmosphere at relatively low temperatures. Therefore, the conversion of biosolids (e.g. agricultural waste, invasive species, municipal sewage sludge, etc) into biochar could provide a useful way to achieve resource reuse and environmental management. In China, decreased land resources and soil fertility is of increasing concern presently, which may threat national food security. Therefore, a range of biochars have been tested for their potential in improving farming soil quality considering the high fertility sustained by biochar in Amazonian Dark Earths locally known as Terra Preta de Indio. Some studies have proved that biochar can play a positive role in improving the fertility of agricultural soils and thus increasing crops yield. Moreover, biochar has also been shown to be effective in control and remediation of a range of soil contamination and hence improve soil environmental quality, leading to increased food output and quality. In the present review, the most recent advances in the effect of biochar on agricultural soil fertility and soil environment quality with the underlying mechniasms are reviewed and discussed here in detail. Firstly, most biochars, particularly those produced from wetland plant residues tend to improve water retention capacity of agricultural soil, especially for those with sandy texture. This phenomenon could be caused by the porous structure of biochar, which can increase the water-holding porosity of soils. Secondly, substantial evidence has shown that the bioavailability of key mineral nutrients increase remarkably in response to biochar application, which could be attributed to the sufficient mineral ash in biochar and relatively high caiton exchange capacity (CEC) originated from the rich surface functional groups of biochar. Thirdly, the alkalinity of biochar, which is most likely resulted from the high mineral content, has exhibited potential in mitigation of soil acidity. As a result, the leaching of essential minerals and associated water eutrophication could be controlled to different degrees. However, the long-lasting buffering performance of biochar in the areas of acid rain is still unknown, which needs long-term monitoring with locating tests. Fourthly, with high CEC and mineral content, biochar could be used as fixing agent to sequester heavy metals in agriculture soils through complexation and precipitation, resulting in decreased transfer and accumulation of heavy metals in food chain. On the other hand, a series of negative impacts of biochar on farmland are also highlighted in this review. First of all, biochar may reduce the aggregation of soil particles, and bring ammonia gas gathered in soils which is detrimental to the soil organisms. Simultaneously, the application of biochar into soil could induce the enrichment of polycyclic aromatic hydrocarbon and heavy metals in uncontaminated farmland as well as decreased nitrogen uptake by crops, All of these potential risks can not be ignored. Full realization and systematic investigation on these hazardous effects of biochar is essential to ensure the safe and efficient application of biochar for the improvement of soil fertility and environmental quality. At last, a range of research gaps and future challenges have been characterized and discussed in detail. To achieve better understanding of the effect of biochar on sustainable agriculture with associated mechanisms, long-term experiments in field scales are needed to investigate the persistent output and biogeochemical behaviors of different kinds of biochar. Besides, more field experiments should be carried out to explore the applicability of biochars in differing regions with specific soil types, which could provide more realistic information to improve the local soils. In parallel, ecological and toxicological effects of biochar should be addressed to identify the potential risks. Finally, more efforts should be paid to establish the regulation framework and reference criterion to ensure biochar quality and evaluate its effect on soil fertility and environmental quality. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:94
Main heading:Soil pollution
Controlled terms:Acid rain - Agglomeration - Agricultural wastes - Agriculture - Aromatic hydrocarbons - Biochemistry - Biohazards - Chemical contamination - Crops - Environmental impact  - Environmental management - Environmental regulations - Eutrophication - Farms - Food supply - Heavy metals - Minerals - Polycyclic aromatic hydrocarbons - Porosity - Quality control  - Risk assessment - Sewage sludge - Soils - Waste management
Uncontrolled terms:Agricultural safety - Bio chars - Environmental quality - Long-term experiments - Municipal sewage sludge - Surface functional groups - Sustainable agriculture - Water retention capacity
Classification code:451.1 Air Pollution Sources - 453 Water Pollution - 453.1 Water Pollution Sources - 454.2 Environmental Impact and Protection - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 801.2 Biochemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 913.3 Quality Assurance and Control - 914.1 Accidents and Accident Prevention - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.04.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 37>

Accession number:20151400700109
Title:Frequency domain coherence analysis and relationship recognition between gearbox vibration and input energy signal
Authors:Li, Huaijun (1); Liu, Yueqi (1); Xie, Xiaopeng (2)
Author affiliation:(1) Vehicle Safety Engineering Technology Center, Guangdong Communication Polytechnic, Guangdong, China; (2) Tribology and Fault Diagnosis Institute, South China University of Technology, Guangdong, China
Corresponding author:Liu, Yueqi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:4
Issue date:February 15, 2015
Publication year:2015
Pages:175-182
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:From the perspective of energy, vibration of gearbox and other rotating equipment actually is the energy propagation process. Although vibration signal analysis is the most popular technology to realize fault diagnosis for such equipment, but to broaden the horizons of rotating equipment fault diagnosis technology, the validity of energy signal analysis method was proposed and discussed in this paper. How to shed some further light on the issue through theoretical and experimental study is a prospective research work in this field. Firstly, the relationship between the gearbox transmission energy and vibration signal was analyzed based on the vibration mechanism which revealed that the torque and input power generate gear static transmission error, and then produce the vibration signal. Meanwhile, a general formula was given for calculating the input power of the transmission system, which was used to establish the theory basis for the pre-processing of the original energy data. Secondly, the model of gear transmission energy interact with vibration was proposed to analyze the stable I/O relationship between the input energy and vibration signal response using correlation function based on the probability statistics form. Results showed that the larger of correlation value in the key frequency point, the more obvious of vibration energy dissipation. Finally, the normal and fault gear contrast experiment was carried out in the energy monitoring experimental platform of gear transmission system. Analysis of the experimental power signal spectrum found it is similar to vibration signal that the side band also appeared with the rotating frequency as modulation frequency on the both side of the fault gear's meshing frequency and typical frequency point distribution with larger amplitude accords with the traditional gear fault characteristic spectrum. Thus the spectrum features of power signal was confirmed consistent with traditional gear fault vibration spectrum, which all could reflect rich frequency information. So, condition of gearbox could also be revealed obviously by using power signal spectrum Meanwhile, auto power spectrum and cross power spectrum of vibration and power signal were all analyzed by using coherent analysis method, and the forecast that they correlate highly was verified based on classical control theory. In conclusion, vibration excitation originated from in gear vibration mechanism analysis filed, and energy had a close relationship with vibration signal. The paper lays an effective foundation for the fault diagnosis technology based on energy signal analysis. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Vibration analysis
Controlled terms:Control theory - Electric power transmission - Energy dissipation - Equipment - Fault detection - Frequency domain analysis - Power spectrum - Power transmission - Rotating machinery - Signal analysis  - Spectrum analysis - Vibrations (mechanical)
Uncontrolled terms:Coherence analysis - Cross power spectrum - Fault diagnosis technology - Frequency domain coherence - Input energy - Static transmission errors - Vibration signal analysis - Vibrations
Classification code:422 Strength of Building Materials; Test Equipment and Methods - 525.4 Energy Losses (industrial and residential) - 601.1 Mechanical Devices - 602.2 Mechanical Transmissions - 706.1.1 Electric Power Transmission - 711 Electromagnetic Waves - 716.1 Information