<RECORD 1>
Accession number:20153601250910
Title:Experiment on cutting characteristics of cotton stalk with double supports
Authors:Song, Zhanhua (1); Song, Hualu (1); Geng, Aijun (1); Li, Yudao (1); Yan, Yinfa (1); Li, Fade (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, China
Corresponding author:Li, Fade
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:37-45
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the effect of the reciprocating cutter's working parameters on cutting characteristics of cotton stalk as well as to optimize the working parameters of the reciprocating cutter, the cutting tests of cotton stalk under the double support condition were performed with a self-developed cutting test bench of cotton stalk. The samples were the ripe cotton stalks with the diameter of 11.7-13.2 mm and the moisture content of 31%-37%. The main test equipment included the self-developed cutting test bench of cotton stalk, a high-speed camera system and a digital camera. The self-developed cutting test bench of cotton stalk consisted of 3 parts: A header, a feeding device and a measurement control system. The cutting tests were grouped into the single factor tests, the response surface tests and the verifying tests. The testing factors were average cutting velocity (ranging from 0.6-1.0 m/s), cutting inclination angle (ranging from 3°-23°) and ratio of cutting velocity to feeding velocity (ranging from 1-2), and 5 levels was set for each factor. The response surface testing scheme designed with the central composite design (CCD) method was a three-factor five-level testing scheme. The response surface analysis method was used to analyze the testing dates and to optimize the working parameters of the cotton stalk reciprocating cutter. The results from the tests showed that the change trends of the objective values (the maximum cutting force per unit diameter and the cutting power per unit cutting area) with the changes of the testing factors were basically consistent with the results of the single factor tests. The effects of the average cutting velocity and the cutting inclination angle on the objective values were significantly different (P<0.01), and the effect of the ratio of cutting velocity to feeding velocity on the objective values was not significantly obvious (P>0.05), but its effect on the morphological structure of the cutting section of the stubble was significantly different. When the ratio of cutting velocity to feeding velocity ranged from 1.25 to 1.5, it was observed that the cotton stalk could be completely cut off by means of the high-speed camera system ant the cutting section was even and smooth, therefore, the quality of the cutting section was the best in the ratio range of from 1.25 to 1.5. It was concluded that the optimal combination of the working parameters of the reciprocating cutter for cutting cotton stalk was as follows: the average cutting velocity of 0.9 m/s, the cutting inclination angle of 12.7°, the ratio of cutting velocity to feeding velocity ranging from 1.25 to 1.5. According to the results from the response surface tests, a regression model was established, which described the cutting characteristics of cotton stalk under the double supports. On the basis of the results of the verifying tests, it was found that the results from the regression model were well consistent with the optimal results obtained from the response surface tests. Therefore, the regression model was fit under the experimental conditions. The results of this research can provide technical support for not only developing a cotton stalk cutter, but also designing the equipment with high efficiency and low energy consumption for harvesting hard stalk. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Cutting equipment
Controlled terms:Cotton - Crops - Cutting - Cutting tools - Energy utilization - Equipment testing - Feeding - High speed cameras - Machinery - Mechanization - Optimization - Regression analysis - Surface analysis - Surface properties - Velocity
Uncontrolled terms:Central composite designs - Cotton stalk - Cutter - Cutting characteristics - High speed camera systems - Measurement control system - Morphological structures - Response surface analysis methods
Classification code:423 Non Mechanical Properties and Tests of Building Materials - 525.3 Energy Utilization - 601 Mechanical Design - 604.1 Metal Cutting - 605 Small Tools and Hardware - 691.2 Materials Handling Methods - 742.2 Photographic Equipment - 821.4 Agricultural Products - 921.5 Optimization Techniques - 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 - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 2>
Accession number:20153601250914
Title:Static contact statuses between conical silos and granular materials and its influential factors
Authors:Wang, Xuewen (1); Qin, Yi (2); Li, Juanli (1); Tian, Yankang (2); Yang, Zhaojian (1)
Author affiliation:(1) Shanxi Key Laboratory of Fully Mechanized Coal Mining Equipment, College of Mechanical Engineering, Taiyuan University of Technology, Taiyuan, China; (2) Department of Design, Manufacture, and Engineering Management, University of Strathclyde, Glasgow; Scotland, United Kingdom
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:65-70
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Finite element models, which employ the Drucker-Prager yield criterion, have been developed to simulate the static contact statuses between conical silos and granular materials in 3 forms: the near contact, the sliding contact and the sticking contact. Contact conditions are established when 2 separated surfaces touch at normal direction while maintaining tangential relative movement. In general physical meaning, the surfaces in contact status have the following characteristics: 1) No penetration between each other; 2) The normal pressure and the tangent friction force may be transferred during contact; 3) Generally the normal pulling force cannot be transferred when surface separation occurs. Due to the symmetric property of conical structures, simplified two-dimensional contacting simulations are carried out in this paper, nonlinear finite element software ANSYS is used and the contacting surfaces between granular materials and conical silos are defined with rigid-to-flexible surface-to-surface contact pair. The target surfaces of conical silos are modeled with TARGE169 element and the contact surfaces of granular materials are modeled with CONTA171 element. During finite element analysis, conical silos and granular materials are meshed with two-dimensional solid element, PLANE42. The static contact statuses are investigated with conical silos containing different granular materials. The silo geometries vary at a dip angle of 20°, 33.7° and 45°. Sunflower seeds, corn, coal, rounded gravel and wheat are selected as the granular materials. Results show that the mechanical properties of granular materials (including bulk density, elastic modulus, Poisson's ratio, dilation angle, internal friction angle, cohesion) and silo designs (especially dip angle) have significant effects on the contact statuses at the interface between conical silos and granular materials: 1) For various granular material, 3 contact statuses, i.e. the form of near contact, sliding contact and sticking contact, can be found between granular materials and conical silo walls; 2) The contact statuses between conical silos and granular materials do not depend on (or not mainly depend on) any mechanical property of granular materials. The contact statuses are a combined effect of all mechanical properties of granular materials. Those granular materials with very small dilation angle may have the near contact statuses. Those granular materials with higher cohesive force usually present a smaller sticking contact area, and those granular materials with higher elastic modulus and bulk density usually present a larger sticking contact area than those with opposite material properties; 3) With the decreasing of conical silo depth, the near contact area disappears, the sliding contact area decreases and the sticking contact area increases. 4) Under the sliding contact status, the friction energy dissipation is mainly due to the relative motion between contact surfaces. Under the sticking contact status, the friction energy dissipation is mainly due to the elastic deformation because of the contact. The greater the sticking contact area, the more difficultly the silo discharges. The greater the sliding contact area, the more seriously the silo internal surfaces could be damaged. Since larger sticking/sliding contact area inevitably causes unloading difficulties or friction damage, contact statuses between granular materials and conical silos should be optimized in the silos design in order to boost storage efficiency. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Materials properties
Controlled terms:Contacts (fluid mechanics) - Density (specific gravity) - Elastic moduli - Electric contacts - Energy dissipation - Finite element method - Friction - Granular materials - Interfaces (materials) - Mechanical properties - Rigid structures - Surface properties - Tribology - Unloading
Uncontrolled terms:Drucker Prager yield criterion - Friction energy dissipation - Influential factors - Internal friction angle - Non-linear finite elements - Sliding contacts - Sticking contacts - Tangent friction force
Classification code:408 Structural Design - 525.4 Energy Losses (industrial and residential) - 674.1 Small Marine Craft - 704.1 Electric Components - 921.6 Numerical Methods - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 3>
Accession number:20153601250943
Title:Optimization of microwave-vacuum drying for detoxified starfish
Authors:Zhang, Guochen (1); Li, Sha (1); Zhang, Qian (1); Li, Xiuchen (1); Mu, Chunfa (1)
Author affiliation:(1) R&D Center of Fisheries Equipment and Engineering of Liaoning Province, College of Mechanical and Power Engineering, Dalian Ocean University, Dalian, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:289-295
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Starfish is widely distributed in inshore aquaculture zones in China and it is the predator for many aquaculture animals such as oyster, scallop and abalone. Since starfish has strong fecundity and regenerative capacity, the number of starfish has been growing in recent years with the development of inshore aquaculture. The annual yield of starfish has reached 50000 tons in Dalian, which seriously imperils the development of aquaculture industry. Starfish is rich in nutrients such as protein and polysaccharide, but it contains some toxic substances (such as saponin) as well. It is accordingly a potential resource for feed processing industries after being detoxified. The drying of detoxified starfish has been paid more attention because the traditional drying methods are inefficient and hardly for product quality controlling. In this paper, microwave-vacuum drying of detoxified starfish was carried out and the drying rate, product quality and energy consumption were evaluated. The influences of microwave power density (3-7 W/g), pulse time (20-60 s) and relative vacuum degree (between -0.070 and -0.090 MPa) on the drying characteristics, energy consumption and protein retention rate were firstly studied by single-variable experiments. Results showed that when the microwave power density increased from 4 to 7 W/g, the drying time reduced from 18 to 11 min, the average drying rate increased from 2.95%/min to 4.87%/min, and the energy consumption decreased from 0.0130 to 0.0054 kW·h/g, but the protein retention rate dropped to 83.06% from 92.77%; meanwhile, when drying under the pulse time of 60 s, the average drying rate, energy consumption and protein retention rate would be respectively 1.17 times, 75.16% and 97.47% of that when drying under 20 s pulse time. Similarly, drying under -0.090 MPa relative vacuum degree, the average drying rate, energy consumption and protein retention rate were 1.19 times, 68.41% and 1.09 times of that drying under -0.070 MPa, respectively. It would be more favorite by controlling the microwave power density, pulse time and relative vacuum degree respectively within 4-7 W/g, 30-60 s and -0.080--0.090 MPa. In addition, the response surface methodology (RSM) was employed for the multi-variable experiments, and the regression model was accordingly established. Results of RSM experiments demonstrated that the drying process of detoxified starfish was significantly influenced by microwave power density, followed by pulse time and relative vacuum degree. The microwave power density and the pulse time had significant effect on the comprehensive score (P<0.01). An interaction worked between the microwave power density and the pulse time on comprehensive score (P<0.05). The average drying rate of starfish, energy consumption, protein retention rate and comprehensive score would be 2.95%/min, 0.0118 kW·h/g, 93.80% and 0.751, respectively, under the drying conditions of 4 W/g microwave power density, 60 s pulse time and -0.090 MPa relative vacuum degree. Under this condition, the energy consumption of 1 kg detoxified starfish dried with microwave vacuum drying method could be saved by 8 kW·h compared to hot air drying and the drying cost of starfish could reduce by 4 RMB. Meanwhile, a higher protein retention rate and good quality of the dried detoxified starfish could be obtained by microwave vacuum drying. Microwave-vacuum drying is an effective method for detoxified starfish processing and it is a promising approach for the industrial utilization of starfish. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Drying
Controlled terms:Aquaculture - Energy utilization - Microwave generation - Microwave heating - Microwaves - Models - Molluscs - Optimization - Proteins - Quality control - Regression analysis - Shellfish
Uncontrolled terms:Detoxified starfish - Drying characteristics - Industrial utilization - Microwave - vacuum drying - Microwave power density - Protein retention - Regenerative capacity - Response surface methodology
Classification code:461.9 Biology - 471 Marine Science and Oceanography - 471.5 Sea as Source of Minerals and Food - 525.3 Energy Utilization - 642.1 Process Heating - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 714.2 Semiconductor Devices and Integrated Circuits - 804.1 Organic Compounds - 902.1 Engineering Graphics - 913.3 Quality Assurance and Control - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2015.16.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 4>
Accession number:20153601250917
Title:Digital closed-loop manufacturing technology of spiral bevel gear based on networked integration
Authors:Li, Jubo (1); Xu, Aijun (1); Xu, Kai (1); Zhang, Hua (1); Li, Tianxing (1); Yang, Jianjun (1)
Author affiliation:(1) School of Mechatronics Engineering, Henan University of Science and Technology, Luoyang, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:86-95
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to break the limitations of information's low inheritance and integration during the process of the spiral bevel gear digital closed-loop manufacturing, as well as achieve the integrated operation of manufacturing process and the integrated management of tooth surface manufacturing information, a networked closed-loop manufacturing model of spiral bevel gears is proposed in this paper based on the analysis of the typical digital closed-loop manufacturing process of spiral bevel gear. In the model, by building a networked integration environment, the following technologies, including design and calculation, computer numerical control machining, tooth surface digital detection and correction, detection of noise and vibration, control management, can be organically combined, which not only forms a networked closed-loop manufacturing model and an information network, but also really realizes the transformation from the traditional closed and independent mode to the more flexible and integrated mode that includes the design, machining, measurement, noise and vibration detection of spiral bevel gear tooth surfaces. On this basis, the operation mechanism of networked closed-loop manufacturing is established. The communication network for spiral bevel gear digital closed-loop manufacturing is built through the distributed integration control mode and the Transmission Control Protocol / Internet Protocol. The integrated control of numerical control equipment with different communication interfaces and communication protocols is realized. For the traditional numerical control equipment with serial communication interfaces, their network communication is realized through the serial port servers and the protocol conversion. Correspondingly, for the advanced numerical control equipment with manufacturing automation protocol interfaces, their network communication is realized directly with the network interfaces. On this basis, the reliable transmission and management of numerical control program is achieved by the developed numerical control integration system. The corresponding function modules such as the modular communication protocol conversion program, machine management, program management, and the communication transmission of numerical control programs are also developed, which realizes the distributed integration control of computer numerical control gear milling equipment. On this basis, the information integration framework model and the implementation mechanism of closed-loop manufacturing process are established with the Web service application integration methodology. The loose coupled integration of different application systems participating in the closed-loop manufacturing process is realized through the Web service interface encapsulation and call mechanism. Thereafter, the closed-loop manufacturing integration system is developed to realize the integrated unified management of manufacturing information based on the idea of hierarchicality and modularization. The functions of the integration system such as system management, gear design management, tooth surface measurement management, numerical control equipment management, and vibration noise detection management are correspondingly developed. Finally, the validity and availability of the proposed model and its implementation technologies are verified through the networked closed-loop manufacturing application test with one kind of hypoid gears. Application results show: the proposed model and its implementation technologies are feasible and practical. It can realize the digitalization and integration operation of tooth surface manufacturing process, as well as obviously improve the tooth surface precision and meshing performance of gear pairs. The hypoid gear pairs scroll detection experiments in this paper show that the radiation noise reduction is around 7%, the vibration acceleration amplitude is reduced by about 15%, and the whole tooth surface quality also meets the requirements of the original gear design. The study can provide a reference for the networked manufacturing and integrated manufacturing of spiral bevel gears. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Bevel gears
Controlled terms:Availability - Closed loop control systems - Computer control systems - Computer integrated manufacturing - Control equipment - Design - Equipment - Gear manufacture - Gears - Information management - Information services - Integral equations - Integrated control - Interfaces (computer) - Internet protocols - Manufacture - Models - Modular construction - Network protocols - Noise abatement - Numerical control systems - Social networking (online) - Surface measurement - Telecommunication networks - Transmission control protocol - Vibrations (mechanical) - Web services - Websites
Uncontrolled terms:Computer numerical control - Computer numerical control machining - Integrated systems - Numerical control equipments - Operation mechanism - Serial communication interfaces - Spiral bevel gears - Vibrations
Classification code:405.2 Construction Methods - 537.1 Heat Treatment Processes - 601.2 Machine Components - 716 Telecommunication; Radar, Radio and Television - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 722.2 Computer Peripheral Equipment - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.1 Control Systems - 732.1 Control Equipment - 751.4 Acoustic Noise - 901 Engineering Profession - 902.1 Engineering Graphics - 903.2 Information Dissemination - 903.4 Information Services - 913.5 Maintenance - 921.2 Calculus - 931.1 Mechanics - 943.2 Mechanical Variables Measurements
DOI:10.11975/j.issn.1002-6819.2015.16.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 5>
Accession number:20153601250928
Title:Characteristics of crop yield and nutrient balance under different long-term fertilization practices in black soil
Authors:Hao, Xiaoyu (1); Zhou, Baoku (1); Ma, Xingzhu (1); Gao, Zhongchao (1)
Author affiliation:(1) Institute of Soil and Fertilizer and Environment Resources, Heilongjiang Academy of Agricultural Sciences, Harbin, China; (2) Heilongjiang Academy of Agricultural Sciences Postdoctoral Programme, Harbin, China
Corresponding author:Zhou, Baoku
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:178-185
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With a cropping area of 7.0 million hm<sup>2</sup>, the black soil (Typic hapludoll) region of Northeast China plays a crucial role in food security to the regional and whole country. In fact, the application of chemical fertilizer is an effective and fast way to increase crop production in a relatively short time. Recently, organic manure application has almost disappeared because its application in cropping system is both labor-demanding and uneconomical. However, there is limited information on crop yields under long-term fertilization of organic and inorganic fertilizers in this rotation system. Nutrient input/output and balance in farmland is critical for nutrient management, scientific distribution and application of fertilizer resources, and improving nutrient use efficiency, etc. The study was conducted to reveal the difference of grain yield and nutrient balance based on the average crop yields, the variation trends of crop yields and apparent balance of soil nutrients under different long-term fertilization conditions in black soil, and to provide scientific references for establishing effective long-term fertilization mode and promoting the sustainable development of crop production. A long-term experiment with various fertilizations was carried out during 1979-2014 in a rotation system with wheat (Triticum Aestivium L.)-soybean (Glycine max Merr.)-maize (Zea mays L.) in black soil area of Northeast China. The experiment consisted of 5 treatments: non-fertilization (CK), conventional chemical fertilizer (wheat: N 150 kg/hm<sup>2</sup>, P<inf>2</inf>O<inf>5</inf> 75 kg/hm<sup>2</sup>, soybean: N 75 kg/hm<sup>2</sup>, P<inf>2</inf>O<inf>5</inf> 150 kg/hm<sup>2</sup>, corn: N 150 kg/hm<sup>2</sup>, P<inf>2</inf>O<inf>5</inf> 75 kg/hm<sup>2</sup>, K<inf>2</inf>O 75 kg/hm<sup>2</sup>, NPK), conventional horse manure (18600 kg/hm<sup>2</sup>, M), conventional horse manure plus chemical fertilizer(the amount of chemical fertilizer was same as NPK, and the amount of horse manure was same as M), and 200% of the MNP (horse manure and chemical fertilizer, the amount was 2 times that of MNP, M<inf>2</inf>N<inf>2</inf>P<inf>2</inf>). The results showed that: 1) Compared with the treatment CK, long-term application of chemical fertilizers (NPK) or long-term application of chemical fertilizers combined with horse manure (MNPK, M<inf>2</inf>N<inf>2</inf>P<inf>2</inf>) increased average crop yield (from 1980 to 2014) by 82.5%-91.6% (wheat) and 35.6%-40.9% (maize), respectively. In respect of average crop yield of 35 years, the treatments displayed an order of M<inf>2</inf>N<inf>2</inf>P<inf>2</inf> >MNPK > NPK >M, but no significant differences were observed between M<inf>2</inf>N<inf>2</inf>P<inf>2</inf>, MNPK and NPK. 2) The yields of wheat and maize in CK decreased by 13.93 and 42.61 kg/(hm<sup>2</sup>·a) respectively, while the yield of soybean in CK increased by 7.409 kg/(hm<sup>2</sup>·a) with the experiment going. It showed the yield trend of wheat, soybean and maize in the treatment with fertilization overall increased with the experiment going. 3) Under the conditions of our experiment, surplus of nitrogen and phosphorus appeared in soil in the treatments of NPK and MNPK, and the increasing amounts were 29.7 and 17.5 kg/hm<sup>2</sup> for nitrogen, and 33.4 and 61.2 kg/hm<sup>2</sup> for phosphorus, respectively. Potassium deficit of 30.4-73.0 kg/hm<sup>2</sup> was observed in all treatments. Compared with NPK, the supplement of nitrogen and potassium could be improved by the combined application of organic manure and inorganic fertilizer (MNPK) by 12.2 and 27.6 kg/hm<sup>2</sup>, respectively. 4) Crop yield was significantly positively correlated with the contents of organic matter, available nitrogen, available phosphorus, accumulated precipitation and daily mean temperature in the growth period (P<0.05). 5) Based on the characteristics of nutrient balance, we proposed the method of fertilizer application, i.e. keeping application amount of nitrogen stable, reducing phosphorus amount and increasing potassium amount under rotation system of wheat, soybean and corn in black soil area. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Fertilizers
Controlled terms:Agriculture - Amino acids - Crops - Cultivation - Food supply - Forestry - Grain (agricultural product) - Manures - Nitrogen - Nitrogen fertilizers - Nitrogen fixation - Nutrients - Phosphorus - Potassium - Soils
Uncontrolled terms:Black soil - Crop yield - Long-term fertilization - Nutrient balance - Organic manure
Classification code:404.2 Civil Defense - 461 Bioengineering and Biology - 461.9 Biology - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.11975/j.issn.1002-6819.2015.16.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 6>
Accession number:20153601250913
Title:Numerical simulation and experimental verification on humidity field for pipeline humidifying device
Authors:Guo, Jiaming (1); Fang, Sizhen (1); Zeng, Zhixiong (1); Lu, Huazhong (1); Lü, Enli (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:Lü, Enli
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:57-64
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Maintaining the humidity in the environment is very important for guaranteeing the qualities and prolonging the shelf-life of fresh products. In order to obtain the distribution characteristics of humidity field when the pipeline humidifying device was working, a transport container for fresh-keeping transportation with a pipeline humidifying device based on differential pressure principle was investigated. In this study, navel orange was used as the test material. A three-dimensional numerical turbulent model of 1/4 ratio of the container was established. The structure of this model was built in PRO/E, and the mesh was generated in ICEMCFD by unstructured mesh method; the maximum size of the cell was 0.05 m and the minimum size was 0.005 m. The humidity distribution in the container with pipeline humidifying device was simulated by adopting Porous Medium Model, Species Transport Model, SIMPLE algorithm and Enhanced Wall Treatment Function method to solve the model in FLUENT. After that, the humidifying rate and the cloud charts of humidity distributions on the longitudinal and cross sections in the container and on the surface of products were obtained. With pipeline humidifying device, the relative humidity in the container could be increased from 75% to 90% in 246 s. The distribution of humidity field in container was uniform and the difference of relative humidity was less than 2%, and the difference of relative humidity on goods surface was no more than 3%. A test in a real container with 75 kg navel oranges was done to verify the accuracy of the model. Experimental validation showed that the test results were in good agreement with the simulation results. The difference between the simulated value and experimental value was less than 1.2%, which proved that such model could be used to study the effects of pipe diameter, number of holes, air velocity of air duct on humidity distribution on products surface. Some comparison and analysis were done for the results, and some conclusions could be drawn. It showed that humidifying rate increased as the velocity of air duct and the diameter of pipe increased; and when the relative humidity at the monitoring point was 90%, the humidifying time was 258, 246, 242 and 236 s, respectively as the velocities of air duct were 2, 4, 6 and 8 m/s, while 255, 252, 246 and 242 s respectively as the diameters of pipe were 12.5, 19.0, 25.4 and 38.1 mm. The effect of the number of holes on the humidifying rate was not significant. The maximum difference of humidity on products surface decreased as the velocity of air duct increased, and the differences were 3.09%, 2.45%, 2.05% and 2.01%, respectively. But it decreased first then increased as the number of holes increased (2, 4, 6 and 8), and the differences were 2.53%, 2.18%, 2.31% and 2.45%, respectively. And it increased first then decreased as the diameter of pipe increased, with the differences being 2.38%, 2.57%, 2.45% and 2.02%, respectively. The results from this study have a certain reference value for the optimization of humidifying device for fresh-keeping transportation containers. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Distribution of goods
Controlled terms:Air - Citrus fruits - Containers - Ducts - Humidity control - Mesh generation - Numerical methods - Pipelines - Porous materials - Transportation - Velocity
Uncontrolled terms:Comparison and analysis - Differential pressures - Distribution characteristics - Experimental validations - Fresh keepings - Humidity distribution - Simulation and experimental verifications - Species transport models
Classification code:402 Buildings and Towers - 431 Air Transportation - 432 Highway Transportation - 433 Railroad Transportation - 434 Waterway Transportation - 619.1 Pipe, Piping and Pipelines - 691 Bulk Handling and Unit Loads - 804 Chemical Products Generally - 821.4 Agricultural Products - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 7>
Accession number:20153601250919
Title:Co-simulation and experiment of wheel loader during operation process
Authors:Yan, Xudong (1); Yang, Jing (1); Quan, Long (1)
Author affiliation:(1) Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan, China
Corresponding author:Quan, Long
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:102-109
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As significant part of the loader, the power of hydraulic system accounts for about 70% of the rated power of the engine. So it is important to improve the efficiency of hydraulic system. Currently, wheel loader's hydraulic system generally uses constant displacement pump, which is supposed to generate large energy consumption. Although some researches have been done to study the energy consumption of loader's hydraulic system, these studies are short of experimental results quantified. In order to analyze the energy consumption of wheel loader during working process, a three-dimensional (3D) model of wheel loader is built by Pro/E software, and then it is imported into the software SimulationX to build the kinetic model of the whole wheel loader. Meanwhile the simulation model of hydraulic system is built by the same software. The research based on hydraulic model is mainly on multi-way valve and priority valve. In multi-way valve case, a 3D model is built firstly and its parameters about throttling grooves are measured by Three-coordinate measuring machine. At last, the flow area of control valve can be obtained by combining corresponding calculation module. By integrating the simulation model of hydraulic system with the kinetic model, the co-simulation model of wheel loader is thus achieved. The precision of co-simulation model of the working device is verified through the comparison between simulation results and test results, and the energy consumption of the hydraulic system driving the working device in the work cycle is analyzed under positive and negative loading condition. The testing results show that, under positive loading condition, the power of working device accounts for about 32% of the total output power of pump, the energy loss in priority valve accounts for about 15% and the energy loss in multi-way valve's export, import and its center position totally accounts for about 49%. Under negative loading condition, the power of working device accounts for about 27% of the total output power of pump, the energy loss in priority valve accounts for about 16% and that in multi-way valve's export, import and its center position totally accounts for about 52%. For the efficiency under negative loading condition is lower than that under positive loading condition, it is better to avoid the operations under unbalance loading condition as much as possible. The important energy loss in loader's working hydraulic system using constant displacement pump is the large throttling loss of multi-way valves when loader's bucket is inserted into materials. The differential pressure drop between the outlet of pump and the inlet of cylinder remains about 2 MPa during a working cycle without considering high pressure relief loss. Additionally, unloading losses can be eliminated if a load-sensitive variable pump is used. The co-simulation model established in this paper can be used to predict and analyze the distribution of energy consumption and the energy-saving potential of working devices. The research methods can be used for further research and comparing the operating characteristics and energy consumption of different hydraulic circuits, and it also can be used to guide the design of the hydraulic system and its practical operation. Moreover, it can provide the basis for designing energy-efficient hydraulic control system of wheel loader. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Electric load loss
Controlled terms:Computer software - Construction equipment - Energy conservation - Energy dissipation - Energy efficiency - Energy utilization - Hydraulic equipment - Hydraulic machinery - Hydraulic models - Hydraulics - Kinetic parameters - Kinetic theory - Loaders - Mining machinery - Models - Pumps - Unloading - Wheels
Uncontrolled terms:Consumption analysis - Cosimulation - Distribution of energy consumption - Hydraulic control systems - Operating characteristics - Three dimensional (3-D) modeling - Three-coordinate measuring machines - Working device
Classification code:405.1 Construction Equipment - 502.2 Mine and Quarry Equipment - 525 Energy Management and Conversion - 601.2 Machine Components - 618.2 Pumps - 632.1 Hydraulics - 632.2 Hydraulic Equipment and Machinery - 674.1 Small Marine Craft - 706.1 Electric Power Systems - 723 Computer Software, Data Handling and Applications - 902.1 Engineering Graphics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2015.16.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 8>
Accession number:20153601250911
Title:Comparision of evaluation method for agricultural mechanization development level
Authors:Lu, Bingfu (1); Han, Weiping (1); Zhu, Ming (2)
Author affiliation:(1) Crops Institute, Heilongjiang University, Harbin, China; (2) Chinese Academy of Agricultural Engineering, Beijing, China
Corresponding author:Zhu, Ming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:46-49
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The development level of agricultural mechanization is an important index to reflect the extent of agricultural mechanization, and also is the foundation to analyze and measure the grade of agricultural mechanization. The evaluating methods were researched for the development level of agricultural mechanization from the 2 aspects of agricultural mechanization operation and farming machines in place of peasants. According to the concept of agricultural mechanization, the basic characteristics of the agricultural mechanization development were scientifically revealed in different stages, which had the certain theoretical and practical significance. Currently the adopted agricultural mechanization operation level was obtained based on the weighted average method of agricultural mechanization degree of "farming", "planting" and "harvesting" in agricultural production process. Agricultural mechanization level was attained by the revision of agricultural mechanization operation level, which was adding the proportion of agricultural labors in total social workers in the evaluation system; agricultural mechanization index indicated the proportion of agricultural mechanization operation cost in total operation costs including mechanized, animal and manual operation costs. Through the comparative analysis among agricultural mechanization operation level, agricultural mechanization level and agricultural mechanization index, the results showed that agricultural mechanization operation level was suitable to evaluate agricultural mechanization operation degree, while could not truly assess the development of agricultural mechanization, because it only considered the mechanization level of the "farming", "planting" and "harvesting" links in agricultural production process, and did not reflect the effect of farming machines in place of farmers. Nevertheless, agricultural mechanization level and agricultural mechanization index could more accurately reflect the real situation of agricultural mechanization development, because they synthetically took account of the agricultural labor decrease and farming machine operation. Although the 2 calculation methods were different, both of the results were consistent to support each other. Therefore, they could more accurately reflect the real development of agricultural mechanization. Relatively speaking, the maneuverability of agricultural mechanization level was stronger than agricultural mechanization index, because it was obtained from the modification of current agricultural mechanization operation level. In a word, the corresponding evaluation index should be chosen according to the needs and the actual situation in the evaluation process of agricultural mechanization development, but each index should be paid attention to its merits and demerits in the concrete operating practice. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Agricultural machinery
Controlled terms:Agriculture - Costs - Mechanization - Operating costs
Uncontrolled terms:Agricultural labors - Agricultural mechanization - Agricultural productions - Basic characteristics - Comparative analysis - Development level - Total operation costs - Weighted average method
Classification code:601 Mechanical Design - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 911 Cost and Value Engineering; Industrial Economics
DOI:10.11975/j.issn.1002-6819.2015.16.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 9>
Accession number:20153601250932
Title:Remediation effects of heavy metals contaminated farmland using fly ash based on bioavailability test
Authors:Li, Nian (1); Li, Ronghua (1); Feng, Jing (1); Zhang, Zengqiang (1); Shen, Feng (1)
Author affiliation:(1) College of Natural Resources and Environment, Northwest A&F University, Yangling, China
Corresponding author:Zhang, Zengqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:213-219
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Fly ash has been used as an immobilization agent over the years to stabilize the heavy metals in the contaminated soils. Fly ash is produced as by-product in coal-based power plants and available in huge quantity. For the assessment of heavy metal remediation in contaminated farmland soil by immobilization with fly ash, a field experiment in Tongguan County, Shaanxi, China was conducted using fly ash as in-situ immobilization agent, and the immobilization efficiencies of metals including cadmium (Cd), mercury (Hg) and lead (Pb) were evaluated through phytoextraction test that planted beneficial local herbaceous plants such as Silphium perfoliatum, sunflower, trilobites ghost needle grass, Amaranthus paniculatus, ryegrass and mandala with poplar in mixed-cultivation pattern. The selected plants for bioavailability test were naturally planted on vast grasslands of Tongguan County. The study site was located in the north of the mining area of farmland. Long-time gold mining activities resulted in the huge quantity of heavy metals waste and tailing dump everywhere in the area, which contaminated local farmland. There were no adequate measures taken by local authorities to get rid of this waste, so 86.3% of the area experienced different levels of soil heavy metals pollution. The area of 1.33 hm<sup>2</sup> flat trapezoidal field was selected as study site to conduct the experiment. Fly ash was collected from coal-fired power plant near Tongguan County, and the pH value of fly ash was 10.58. All the studied plant seeds were collected from Yangling Agricultural Demonstration Zone. In the study site, the arable layer was fully blended with fly ash of 37.5 t/ha using a rotary cultivator. Then soil-fly ash flat land was irrigated with groundwater. The research area were divided into 22 test plots; after one month poplar trees were planted in 2 m×3 m pattern, and then when stable after 3 months, the grass seeds were planted in the spring of next year. Soil samples were collected from 0-20 cm depth and air dried at room temperature. Studied plants were randomly harvested and rinsed with tap water and then distilled water to remove traces of soil. Plants were dried in oven at 105 for 30 minutes. EPA (Environmental Protection Agency) 3050B and TCLP (toxicity characteristic leaching procedure) method were used to detect soil environmentally available and bioavailable heavy metals. Plant samples were digested in mixed acid using HNO<inf>3</inf> - HClO<inf>4</inf> to assess heavy metal contents. The results showed that the concentration of Cd was the highest which ranged from 1.29 to 6.13 mg/kg, followed by Hg and Pb, from 0.53 to 4.14 and from 63.19 to 448.97 mg/kg respectively. The mean values of Cd, Hg and Pb were 6.17, 1.64 and 0.33 times those in the second standard value of Environmental Quality Standards for Soils in China, and the exceeding standard rates were 100%, 64.28% and 7.14%, respectively. And the biological effectiveness of Pb and Cd was positively correlated with the total concentration. Fly ash addition to soil reduced the average bioavailable concentrations of Cd, Hg and Pb, and the concentrations of Hg, Cd and Pb were reduced by 28.57%, 24.36% and 31.83%, respectively. In the phytoextraction experiment, all plants presented the ability of removing Cd, but the content of Cd within plants was less than the standard value of super enriched plants. Datura stramonium was 0.1498 mg/kg per plant for Cd, with the highest absorption capacity of Cd, and Amaranthus paniculatus was 68.04 g/hm<sup>2</sup>, with the highest absorption capacity per unit area. Our results indicate that in the heavy metals contaminated farmland after improved with fly ash, some of the heavy metals still have relatively high bioavailablity. And the planting patterns should be changed, or the crops accumulated with lower heavy metal should be selected in order to prevent heavy metals accumulation in the edible tissue of crops after planting. The findings of our study are providing a new exploration for the remediation of heavy metals contaminated farmland soils in various areas of China. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Soil pollution
Controlled terms:Agriculture - Air quality - Biochemistry - Bioremediation - Cadmium - Coal - Coal ash - Contamination - Crops - Cultivation - Economic geology - Environmental protection - Environmental Protection Agency - Farms - Fly ash - Fossil fuel power plants - Groundwater - Heavy metals - Lead - Mercury (metal) - Plants (botany) - Pollution - Radioactive waste vitrification - Remediation - Soil pollution control - Soil surveys - Soils
Uncontrolled terms:Bioavailable concentrations - Biological effectiveness - Coal based power plants - Environmental quality standards - Heavy metal remediation - Immobilization efficiency - Phytoremediation - Toxicity characteristic leaching procedures
Classification code:443.1 Atmospheric Properties - 444.2 Groundwater - 452.4 Industrial Wastes Treatment and Disposal - 454.2 Environmental Impact and Protection - 461.9 Biology - 481.1 Geology - 483.1 Soils and Soil Mechanics - 524 Solid Fuels - 531 Metallurgy and Metallography - 546.1 Lead and Alloys - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 614 Steam Power Plants - 801.2 Biochemistry - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.11975/j.issn.1002-6819.2015.16.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 10>
Accession number:20153601250905
Title:Stability analysis and gait planning for luffing wheel-legged robot during intelligent obstacle-surmounting process
Authors:Sun, Zhibo (1); Liu, Jinhao (1); Yu, Chunzhan (1); Kan, Jiangming (1)
Author affiliation:(1) School of Technology, Beijing Forestry University, Beijing, China
Corresponding author:Liu, Jinhao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:1-7
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Luffing wheel-leg robot is applied to the operation on uneven surface, because of the characteristics such as high mobility, obstacle-surmounting capability and strong stability. In order to guarantee the smoothness of obstacle surmounting, the paper introduces a novel robot with 6 wheel-legs. This robot is a mobile equipment designed to surmount obstacles actively on forest road. The robot is a combination of 2 frameworks, 2 rear wheel-legs and 2 front wheel-legs. Wheel-legs are attached to the frameworks and distributed on both sides symmetrically. Linear actuators connected between wheel-legs and frameworks can lift the wheel-leg up and down through the obstacle-surmounting process. Front wheel-leg consists of a front straight wheel-leg and a front inverse V-shaped wheel-leg which means the front wheel-leg has 2 degrees of freedom. In order to achieve the intelligent obstacle-surmounting skill, 2 linear actuators are applied to the front wheel-leg on each side of the framework. Through analyzing the simplified model, the intelligent obstacle-surmounting process can be divided into 3 stages: obstacle surmounting of the first wheel in front wheel-leg, obstacle surmounting of the second wheel in front wheel-leg and obstacle surmounting of the rear wheel. The former 2 stages are controlled by the composite motion of the front wheel-legs, and the third one is controlled by the rear wheel-leg motion only, which means intelligent obstacle surmounting of the front wheel-leg is the key factor during the process. The kinematic model is established based on the movement relationship of the system. Through the calculation of the kinematic model, the maximum height of the intelligent obstacle-surmounting process is obtained, which is related to the length of the inverse V-shaped wheel-legs, the angle between the 2 legs in the inverse V-shaped wheel-legs and the swing angle range of the inverse V-shaped wheel-legs. According to the motion differential equation, the Jacobian matrix between the velocities on the wheel center of inverse V-shaped wheel-legs and the linear actuators is achieved. Based on the Lagrange equation, the dynamic model of the wheel-legs during the obstacle-surmounting process is established. According to the dynamic model, the force of the linear actuators can be calculated at the beginning of the progress. In ADAMS, the obstacle with 100 mm height and 180 mm diameter is established for the intelligent obstacle-surmounting simulation. Based on the Jacobian matrix and the initial parameter of the wheel-leg, the velocities of the actuators are fitted by the OLS (method of least squares), which is the input of the simulation. After simulation, the dynamic characteristics of the actuators are obtained. The maximum power is less than the rated power of the actuator, which proves the feasibility of the intelligent obstacle-surmounting process. The test of surmounting the obstacle with 10 cm height is conducted for further validation. With the same structure, velocity and obstacle, the tests are conducted twice using the intelligent obstacle-surmounting method and the passive method respectively. The experimental result shows that the roll angle and trim angle by the intelligent obstacle-surmounting system are heavily decreased respectively from 4.5° and 2.5° to 0.75° and 0.4° compared with the passive method. Simulations and tests prove the validity of theoretical model and the effectiveness of intelligent obstacle-surmounting method. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Wheels
Controlled terms:Actuators - Computer simulation - Convergence of numerical methods - Degrees of freedom (mechanics) - Differential equations - Dynamic models - Dynamics - Equations of motion - Intelligent robots - Inverse problems - Jacobian matrices - Kinematics - Least squares approximations - Linear actuators - Matrix algebra - Models - Robot programming - Robots
Uncontrolled terms:Dynamic characteristics - Intelligent obstacle-surmounting - Method of least squares - Motion differential equation - Movement relationship - Surmount obstacles - Theoretical modeling - Wheel-legged robots
Classification code:601.2 Machine Components - 723.1 Computer Programming - 723.5 Computer Applications - 731.5 Robotics - 731.6 Robot Applications - 732.1 Control Equipment - 902.1 Engineering Graphics - 921 Mathematics - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2015.16.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 11>
Accession number:20153601250915
Title:Effects analysis on rectifying intake flow field for large scale pumping station with combined diversion piers
Authors:Zi, Dan (1); Wang, Fujun (1); Yao, Zhifeng (1); Hou, Yakang (1); Xiao, Ruofu (1); He, Chenglian (2); Yang, Enbao (3)
Author affiliation:(1) Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System in China Agricultural University, Beijing, China; (2) China Water Resources Beifang Investigation Design and Research Co. Ltd, Tianjin, China; (3) Shenzhen Dongjiang Water Resources Project Management Office, Shenzhen, China
Corresponding author:Wang, Fujun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:71-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Surface vortex and submerged vortex originating from intake wall often exist in fore-bay and sump in a large-scale pumping station. These vortices may affect the stability of pump operation. Because of big dimension, single diversion pier cannot effectively improve the intake flow field in large-scale pumping station. The Yonghu pumping station, a large-scale pumping station, which was located in Guangdong Province, was taken as the research object. The numerical simulation and the site test were performed in order to investigate the effects of combined diversion piers on rectifying intake flow pattern in fore-bay and sump. A new type of combined diversion pier composed of double-I type, three-I type and cross vortex baffle were proposed. The flow pattern, the vorticity and the uniformity of axial velocity distribution were compared between the original design and the optimized design. The numerical simulation results showed that the new type of combined diversion pier could effectively improve the intake flow field of the pumping station. For the original design, 2 large-size circulations in the fore-bay and submerged vortices in the sump were observed. The size and strength of vortices increased with the increase of the water depth. Furthermore, spiral vortices existed in the 2 sides of the sump. However, for the optimized design, the double-I type diversion piers in front reduced divergent angle of the fore-bay, and decreased the size and strength of surface vortex. The three-I type piers adjusted the uniformity of flow field, and water flow was well introduced to the corresponding pump sump. Submerged vortices originating from bottom wall were almost completely eliminated by the cross vortex baffle. Flow pattern was uniform and smooth in the inlet of pumps, and the streamlines of axial section of pumps were good, without vortices. The uniformity of axial velocity distribution of pump inlet section was as high as 91.42%, and the axial velocity angle approached 86.01°. Compared to the original design, the uniformity of axial velocity distribution of bell-mouth inlet and pump inlet section for the optimized design was raised by 7.8% and 10.6% respectively. The results of site test showed that the size and the strength of circulations and vortices were decreased observably. The peak-to-peak value of pressure fluctuation at the top of pump volute casing fell from 8.07 to 6.69 m, with a decrease of 17.1%. The vibration velocity RMS (root mean square) values of pumps before optimization almost were completely greater than 2.8 mm/s, namely the vibration level was at level D which was specified in the national standard methods of measuring and evaluating vibration of pumps, and in that level pumps could not normally work. After the combined diversion piers were installed, the vibration velocity RMS values of pumps were less than or equal to 2.8 mm/s, in other words, the vibration level was at level C, and the pumping station could operate normally. By numerical simulation and site test, it can be concluded that the combined diversion piers have many positive effects in rectifying intake flow field of large-scale pumping station. The research results provide a beneficial reference for hydraulic design of this kind of large-scale pumping station. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Vortex flow
Controlled terms:Concrete beams and girders - Design - Flow fields - Flow of water - Flow patterns - Intake systems - Models - Numerical analysis - Numerical models - Piers - Pumping plants - Pumps - Velocity - Velocity distribution
Uncontrolled terms:Axial-velocity distribution - Flow rectification - Fore bays - Peak-to-peak values - Pressure fluctuation - Pumping stations - RMS (root-mean-square) values - Vibration velocity
Classification code:407.1 Maritime Structures - 412 Concrete - 446 Waterworks - 618.2 Pumps - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 902.1 Engineering Graphics - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics - 931.3 Atomic and Molecular Physics
DOI:10.11975/j.issn.1002-6819.2015.16.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 12>
Accession number:20153601250929
Title:Advances in remote sensing derived agricultural drought monitoring indices and adaptability evaluation methods
Authors:Huang, Youxin (1); Liu, Xiuguo (1); Shen, Yonglin (1); Liu, Shishi (2); Sun, Fei (1)
Author affiliation:(1) Faculty of Information Engineering, China University of Geosciences (Wuhan), Wuhan, China; (2) College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
Corresponding author:Shen, Yonglin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:186-195
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Remote sensing technology is a promising means for agricultural drought monitoring in large area, and can continuously obtain long-term time series of crop drought information. Currently, quite a few agricultural drought monitoring indices based on remote sensing technology have been developed from different perspectives. However, different agricultural drought monitoring indices derived from remote sensing have obviously different temporal and spatial adaptability. Selecting the appropriate drought monitoring indices based on different regions and crop growth stages is vital for timely and accurate evaluation of drought impact on crops. It is also important for effective water resource management and drought mitigation. This paper focused on adaptability of the agricultural drought monitoring based on remote sensing, and systematically summarized agricultural drought monitoring indices and their adaptability evaluation methods. Firstly, the satellite data sources and the corresponding sensors that are commonly used for agricultural drought monitoring were summarized. Secondly, the relevant sensitive spectral bands of agricultural drought monitoring parameters were reviewed from 4 aspects, including the atmospheric rainfall, the soil moisture, the change of crop physiology and morphology (such as crop canopy temperature, vegetation water content, and crop morphology and green degree) due to water stress, and the comprehensive parameter information. Thirdly, the adaptations and limitations of various agricultural drought monitoring indices derived from remote sensing were fully discussed which involved 4 aspects: the precipitation monitoring indices based on active and passive radar satellite, such as TRMM (tropical rainfall measuring mission satellite) and SAR (synthetic aperture radar); the soil moisture monitoring indices based on the inversion method of thermal inertia, spectral feature space and microwave remote sensing; the crop water requirement monitoring indices based on the physiological and morphological characteristics of crop mutation; and the comprehensive drought monitoring indices based on integrated reflection of crop drought multiple characteristics. Lastly, the current literature revealed much valuable information about the sensitivity and adaptability evaluation methods for diverse agricultural drought indices derived from remote sensing, which included the spectral feature matching evaluation methods and the multivariate statistical analysis methods considering environmental impact factors of crop growth. Domestic and foreign scholars have achieved great progress on the adaptability of agricultural drought monitoring indices, including the application of multi-source remote sensing data, the sensitive spectral band, the applicability of the indices' own mechanism, and the adaptability evaluation methods. Nevertheless, how to select the most suitable agricultural drought remote sensing monitoring index, according to different regions and crops growth stage, is still a problem. Finally, this paper discussed the highlights, the existing difficulties and the future research trends. 1) The relationship between crop and its growth environment should be considered according to different regions and different crop growth stages; 2) The spectral bands information ought to be increased in order to reduce the ratio of signal to noise in the process of remote sensing data acquisition; 3) The appropriate drought monitoring indices derived from remote sensing should be confirmed, especially in the areas with part of vegetation coverage, because most of the crop growth period is under the condition of partial vegetation fraction; 4) The appropriate spatial and temporal scale for these agricultural drought monitoring indices should be determined according to the research purpose; 5) The study of hyperspectral data and technology in the inversion of precision agriculture drought monitoring indices need to be strengthened; 6) The sensitivity and adaptability of the agricultural drought monitoring indices derived from remote sensing in accordance with its own mechanism is supposed to be further explored. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:71
Main heading:Remote sensing
Controlled terms:Agriculture - Crops - Data acquisition - Drought - Environmental impact - Moisture - Moisture control - Monitoring - Multivariant analysis - Physiology - Precipitation (meteorology) - Radar - Radar measurement - Radar reflection - Rain - Rain gages - Satellites - Signal to noise ratio - Soil moisture - Space optics - Space-based radar - Synthetic aperture radar - Vegetation - Water content - Water management - Water resources
Uncontrolled terms:Adaptability evaluation - Environmental impact factors - Monitoring index - Morphological characteristic - Multivariate statistical analysis - Remote sensing technology - SAR(synthetic aperture radar) - Tropical rainfall measuring mission satellites
Classification code:443 Meteorology - 444 Water Resources - 454.2 Environmental Impact and Protection - 461.9 Biology - 483.1 Soils and Soil Mechanics - 655.2 Satellites - 716.1 Information Theory and Signal Processing - 716.2 Radar Systems and Equipment - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 731.3 Specific Variables Control - 741.1 Light/Optics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 922 Statistical Methods - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 943.3 Special Purpose Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 944.2 Moisture Measurements
DOI:10.11975/j.issn.1002-6819.2015.16.025
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 13>
Accession number:20153601250935
Title:Carbonization temperature optimization experiment of pilot-scale continuous biomass carbonization equipment with internal heating
Authors:Cong, Hongbin (1); Yao, Zonglu (1); Zhao, Lixin (1); Meng, Haibo (1); Dai, Chen (1); Jia, Jixiu (1); Wu, You (1)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture, Beijing, China
Corresponding author:Zhao, Lixin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:235-240
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biochar is a solid product generated by low temperature pyrolysis of biological organic material (biomass) in oxygen or anaerobic environment. Biochar can be used as adsorption material and soil conditioner, and also can be used as reducing agent, slow-release fertilizer carrier and carbondioxide sequestration agent etc., in addition, wood tar and wood vinegar as byproduct of biomass pyrolysis, can be used as the chemical raw materials. In recent years, the biomass pyrolysis carbonization technology has aroused widespread attention at home and abroad. Biomass carbonization technology can be differentiated according to the heating process applied and to the continuity of the biomass production. In China, 3 carbonization techniques are used, viz. external heating, internal heating, and spontaneous combustion. External heating indirectly heats biomass materials by hot air flowing around the carbonization chamber, while internal heating directly heats the biomass material through hot gas that is flooding the furnace from the bottom. In this case, hot gas and biomass materials are moving in opposite directions, increasing the heat transfer efficiency. The spontaneous combustion carbonization technique has the highest thermal utilization efficiency. It heats materials directly by spontaneous combustion of small fractions of the biomass materials. In order to analyze pyrolysis carbonization properties of different materials under internal heating and piecewise continuous pyrolysis technology, and verify the influence of carbonization process parameters on biochar physical and chemical properties, biochar yield rate as well as equipment productivity, this study chooses corn straw, corn cob and peanut shell as raw materials, and carries out the experiment of equipment production process. Test results show: When the draft fan speed is 725 r/min, and the furnace negative pressure remains at around 60 Pa by automatically adjusting the opening of the inlet, the biochar physical and chemical properties, equipment productivity and biochar yield rate are obviously different under different carbonization temperatures, especially the fixed carbon content and ash content of the biochar have significant difference (P<0.05), and corn stalk is the most sensitive to process parameters. Through the comprehensive evaluation analysis, the optimal carbonization temperatures are 550-600, 600-650 and 600-650 respectively for corn straw, corn cob and peanut shell. Application benefit analysis shows that the technology has good economic benefit and outstanding social and ecological benefits, but biochar industrial chain has some bottlenecks, such as biochar application in agriculture being not wide enough, which influences the straw biochar market sales. This study can provide technical support for the application of continuous biomass carbonization equipment. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Spontaneous combustion
Controlled terms:Biological materials - Biomass - Carbon - Carbonization - Chemical analysis - Chemical equipment - Chemical properties - Combustion - Cracking (chemical) - Economic and social effects - Equipment - Heat transfer - Heating - Heating equipment - Ionization of gases - Materials properties - Oilseeds - Optimization - Productivity - Protactinium - Pyrolysis - Soil conditioners - Soil testing - Tar - Temperature
Uncontrolled terms:Bio chars - Carbonization temperatures - Comprehensive evaluation - Heat transfer efficiency - Low-temperature pyrolysis - Physical and chemical properties - Process tests - Thermal utilization efficiency
Classification code:421 Strength of Building Materials; Mechanical Properties - 423 Non Mechanical Properties and Tests of Building Materials - 461.2 Biological Materials and Tissue Engineering - 483.1 Soils and Soil Mechanics - 521.1 Fuel Combustion - 547 Minor, Precious and Rare Earth Metals and Alloys - 641.1 Thermodynamics - 641.2 Heat Transfer - 642.2 Industrial Furnaces and Components - 643.1 Space Heating - 801 Chemistry - 802.1 Chemical Plants and Equipment - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821.4 Agricultural Products - 821.5 Agricultural Wastes - 901 Engineering Profession - 913.1 Production Engineering - 921.5 Optimization Techniques - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2015.16.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 14>
Accession number:20153601250916
Title:Aerodynamic performance of wind turbine under different yaw angles
Authors:Shi, Yali (1); Zuo, Hongmei (1); Yang, Hua (1); Zhou, Hanlong (1); Shen, Wenzhong (2)
Author affiliation:(1) School of Water Conservancy and Energy Power Engineering, Yangzhou University, Yangzhou, China; (2) Department of Wind Energy, Technical University of Denmark, Lyngby, Denmark
Corresponding author:Yang, Hua
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:78-85
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A typical dynamic characteristic of horizontal axis wind turbine shows up under yaw condition. Prediction accuracy is low for momentum-blade element theory and related engineering prediction model. In order to improve the prediction accuracy of dynamic load characteristics, the whole wind turbine models, based on the experiment about MEXICO (model experiments in controlled conditions) rotor in 2006, are established by three-dimensional software called Pro/E. under different yaw conditions, i.e. yaw angle of 0, 15, 30 and 45 degree. ICEM CFD (integrated computer engineering and manufacturing code for computational fluid dynamics) is applied to grid division. The rotating domain containing rotor part is meshed into hexahedral grids, and the static domain containing part of wheel hub, tower and outflow field is meshed into tetrahedral grids. When the grid size of the first layer of blade surface is set as 5×10<sup>-6</sup> m to ensure the first dimensionless size near the wall Y<sup>+</sup><0.5 on the wall, the 2 numbers of grids are determined by the error of axial load on the airfoil in the 60% section of blades, which respectively are 6572451 and 2961385. The aerodynamic performance of models under rated condition is simulated by ANSYS CFX with the turbulence model of SST (shear stress transport), high resolution is chosen as advection scheme, and transient rotor stator as the domain interface method. The results are converted into data, processed and analyzed by MATLAB. Finally the following conclusions are drawn. The distributions of pressure coefficients along the airfoil chord in different blade sections calculated by CFD method are in good agreement with the experimental measurements, and the error on the suction surface of airfoil is mainly caused by stall separation occurring on the pressure surface of airfoil. With the increasing of yaw angle, the pressure coefficients of the suction side are increasing and the location of minimum pressure coefficient moves to airfoil trailing edge slightly. For the pressure side, the pressure coefficients increase at first and then decrease, and the location of maximum pressure coefficient moves to airfoil leading edge slightly. The axial load coefficients and tangential load coefficients of blades first decrease and then increase and then decrease again with the increase of the azimuthal angle. With the increase of the yaw angle, the axial and tangential load coefficients are both reduced. When the yaw angle is within 30°, the relative error of axial load coefficients is in the range of ±5% and the relative error of tangential load coefficients is in the range of ±15%. CFD method is higher than BEM (blade element momentum) method in forecasting accuracy of dynamic load calculation. Under yaw condition, the hysteresis characteristic of airfoil lift and drag in blade root is more remarkable than blade tip, while the variation range of the angle of attack in blade root is much less than that in blade tip. This characteristic must be considered when BEM method is used to predict wind turbine performance. For axial inflow condition, CFD method can well predict the average speed, but restricted by turbulence model and the wake model, CFD calculation did not show the velocity characteristics of rotating vortex shedding from wind turbine impeller under yaw condition. The study provides a data support to build up the forecast model on the engineering and provides the basis for wind turbine design under yaw condition. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Wind turbines
Controlled terms:Advection - Aerodynamic stalling - Aerodynamics - Airfoils - Angle of attack - Axial loads - Boundary element method - Computation theory - Computational fluid dynamics - Computer integrated manufacturing - Dynamic loads - Electric power transmission networks - Errors - Fluid dynamics - Forecasting - MATLAB - Models - Numerical analysis - Shear stress - Turbulence models - Vortex flow
Uncontrolled terms:Aero-dynamic performance - Blade-element momentums - Dynamic characteristics - Dynamic stalls - Horizontal axis wind turbines - Hysteresis characteristics - Shear-stress transport - Yaw angles
Classification code:408.1 Structural Design, General - 421 Strength of Building Materials; Mechanical Properties - 615.8 Wind Power (Before 1993, use code 611 ) - 631.1 Fluid Flow, General - 651.1 Aerodynamics, General - 652.1 Aircraft, General - 703.1 Electric Networks - 731 Automatic Control Principles and Applications - 902.1 Engineering Graphics - 913.4.2 Computer Aided Manufacturing - 921 Mathematics - 921.6 Numerical Methods
DOI:10.11975/j.issn.1002-6819.2015.16.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 15>
Accession number:20153601250920
Title:Effects of rotational tillage on soil water content and crop yield of spring maize system on Weibei dryland
Authors:Li, Juan (1); Wang, Li (1); Li, Jun (3); Shang, Jinxia (1)
Author affiliation:(1) College of Forestry, Northwest A&F University, Yangling, China; (2) Shaanxi Province Land Engineering Construction Group, Xi'an, China; (3) College of Agronomy, Northwest A&F University, Yangling, China; (4) Forest Technology Extend Center of Wuwei City of Gansu Province, Wuwei, China
Corresponding author:Li, Jun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:110-118
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Weibei dryland in Shaanxi Province belongs to the semi-humid drought climate in warm temperate zone, so drought is the biggest limiting factor for crop production in dryland. Shortage of precipitation and its uneven distribution in seasons are the main factors causing the low and unstable yields of winter wheat and spring maize in dryland. The Loess Plateau that is semi-humid and prone-to-drought, is a typical rain-fed agricultural region. Winter wheat and spring maize are main grain crops cultivated in this region. A long-term practice of applying single soil tillage measure in this area causes soil compaction, poor ability of retaining rainwater and improving water use efficiency. Many studies and practices have demonstrated that reasonable soil rotational tillage systems matching different crop rotation systems have played a very important role in maintaining sustainable development of farmland ecosystem, creating suitable environment (soil, nutrients, water, air, temperature) condition for crop growth and promoting crop yields. In order to investigate the effects of different rotational tillage systems on soil production performance in maize fields, the soil water storage, crop yield and water use efficiency as well as economic benefit were determined on the Loess Plateau of China, which would provide a theoretical basis for establishing a reasonable soil tillage system for the crop rotation system with certain fertilizing method on the semi-humid and prone-to-drought Loess Plateau. The aim of this experiment was to study the effects of different rotational tillage patterns on soil water conservation, grain yield and benefit increase in spring maize rotation region in Weibei highland. A six-year field experiment was carried out from 2007 to 2013 in Dryland Agricultural Research Station, Ganjing Town (35°33' N; 110°08' E; 900 m above sea level), Shaanxi Province. Three kinds of different rotational tillage systems in this experiment included continuous no-tillage (NT), no-tillage/subsoiling rotation (NT/ST), and continuous ploughing treatments (CT). The soil moisture during leisure and growth period of spring maize was measured, and the variation regularity of spring maize yield and water use efficiency was analyzed under 3 rotational tillage systems. Results revealed that: 1) Compared to continuous ploughing treatments, average water storage efficiency in 0-200 cm soil layers of no tillage with subsoiling rotation and continuous no tillage in six-year winter fallow periods increased (P<0.05) 64.6% and 46.1%. In normal rainfall years, water storage efficiency of no tillage with subsoiling rotation was little higher than continuous no tillage, but it was no significant difference in drought years. 2) Compared to the CT treatment, the average soil water content in 0-200 cm soil layer for the NT/ST and NT treatment in maize growth period in 6 years increased by 9.7 and 2.1 mm, respectively, and the water storage efficiency in the fallow period increased by 0.7 and 0.5 (P<0.05) percentage point, respectively. 3) Compared to the CT treatment, the corn grain yield for the NT/ST and NT treatment in 6 years increased by 7.6% and 0.3% (P<0.05), respectively, the harvest index increased by 3.6 and 2.3 percentage point, respectively, and the water use efficiency increased by 18.6% and 5.8% (P<0.05), respectively. Among the 3 tillage treatments, the effects of soil water storage capacity, crop yield, harvest index and water use efficiency for the NT/ST and NT treatment were better than those for the CT treatment in the fallow period of winter, and the effects of soil moisture conservation and crop yield increment for the NT/ST treatment were the best, so the NT/ST treatment was the more suitable conservation tillage pattern in spring maize field of Weibei dryland. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Agriculture
Controlled terms:Agricultural machinery - Crops - Cultivation - Drought - Ecosystems - Efficiency - Grain (agricultural product) - Landforms - Moisture - Moisture control - Rain - Rotation - Sea level - Sediments - Soil conservation - Soil mechanics - Soil moisture - Soils - Sustainable development - Water conservation - Water supply
Uncontrolled terms:Conservation tillage - Soil water storage - Water use efficiency - Weibei highlands - Yield
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 444 Water Resources - 446.1 Water Supply Systems - 454.3 Ecology and Ecosystems - 471.1 Oceanography, General - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 601.1 Mechanical Devices - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911.2 Industrial Economics - 913.1 Production Engineering - 944.2 Moisture Measurements
DOI:10.11975/j.issn.1002-6819.2015.16.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 16>
Accession number:20153601250927
Title:Effects of poplar-wheat intercropping system on soil nitrogen loss in Taihu Basin
Authors:Chu, Jun (1); Xue, Jianhui (1); Jin, Meijuan (3); Wu, Yongbo (1); Shi, Hao (4); Xu, Yiqian (1)
Author affiliation:(1) College of Biology and the Environment, Nanjing Forestry University, Jiangsu Key Laboratory of Forestry Ecological Engineering, Nanjing, China; (2) Co-Innovotion Center for the Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China; (3) Suzhou Academy of Agricultural Sciences/Institute of Agricultural Sciences in Taihu Lake District, Suzhou, China; (4) Jiangsu Province Environmental Monitoring Center, Nanjing, China
Corresponding author:Xue, Jianhui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:167-177
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agricultural non-point pollution caused by the overuse of fertilizer in farmland has become one of the main factors for water quality deterioration and eutrophication in Taihu Lake. In order to select suitable agroforestry intercropping system to control soil nitrogen loss in Taihu Lake basin, a study was conducted at a distance of 1 km away from the lakeshore to find out how poplar-wheat intercropping system with 2 kinds of densities (AS<inf>1</inf>: poplar spacing 2 m×5 m; and AS<inf>2</inf>: poplar spacing 2 m×15 m) affected the amount of surface runoff, leaching and soil nitrogen loss. The interception of rainfall by the poplar canopy was mainly concentrated from April to October and ranged from 8.6% to 44.5%. The control effects of canopy layer on sprinkle and moderate rain (<1.0 mm/h) were obvious, which were reduced by 47.7% on average. Rainfall interception by canopy was mainly related to the LAI (leaf area index). The volume of rainfall difference between AS<inf>1</inf> and MS (monoculture system) was only 0.8% during the defoliated period while the control effect of AS<inf>1</inf> was raised to 6.4% during the growing period. Compared to AS<inf>2</inf>R (means removing litter) and MSL<inf>0</inf> (monoculture of wheat without litter coverage), the runoff amount of AS<inf>1</inf>R decreased by 9.1% and 11.2%, respectively. There was a significant difference between AS<inf>1</inf>R and AS<inf>2</inf>R/MSL<inf>0</inf> (P<0.05), while the difference between AS<inf>2</inf>R and MSL<inf>0</inf> was not significant (P>0.05). Compared to MS, the volume of surface runoff, leaching and soil nitrogen loss were all effectively controlled by the 2 poplar-wheat intercropping systems. The control effects were more significant under the higher intercropping density. There was no significant difference between the average runoff volume of AS<inf>1</inf>S (means saving litter) and AS<inf>2</inf>S/MSL<inf>0</inf> during the whole growing period (P>0.05), while their average concentration and leaching amount of total nitrogen (TN) and NO<inf>3</inf><sup>-</sup>-N were both significantly lower than MSL<inf>0</inf> (P<0.05). The average leaching water amount of AS<inf>1</inf>S in the depth of 60 cm was significantly different from that of AS<inf>2</inf>S and MSL<inf>0</inf> (P<0.05), while the difference between AS<inf>2</inf>S and MSL<inf>0</inf> was not significant (P>0.05). The difference of average concentration and leaching amount of TN and NO<inf>3</inf><sup>-</sup>-N in 20 cm was not significant among AS<inf>1</inf>S, AS<inf>2</inf>S and MSL<inf>0</inf> (P>0.05) while that in 60 cm was significant (P<0.05). The average runoff amounts of 2 intercropping systems without litter coverage were both higher than those with litter coverage during the poplar defoliated period. It was obvious that the runoff amount, average concentration and leaching amount of TN and NO<inf>3</inf><sup>-</sup>-N with litter coverage were lower than those without litter coverage in AS<inf>1</inf> (P<0.05), while there was no significant difference between AS<inf>2</inf> with litter coverage and without (P>0.05). The litter volume was the major factor to decide whether there was significant difference between the surface runoff and leaching loss. The average surface runoff, concentration and leaching amount of TN and NO<inf>3</inf><sup>-</sup>-N with the litter coverage of 0.4 t/hm<sup>2</sup> were significantly lower than those of 0.2, 0.1 and 0 t/hm<sup>2</sup>. The average leaching water volumes of AS<inf>1</inf>R in 20 and 40 cm soil depth were higher than those of MSL<inf>0</inf> while the result in 60 cm was opposite. The decreasing range of leaching volume of AS<inf>1</inf>R in 60 cm depth was 1.3 times higher than that of MSL<inf>0</inf>, and the leaching volume of AS<inf>1</inf>R were different significantly in 20 and 60 cm (P<0.05), while there was no significant difference among 20, 40 and 60 cm for leaching volume of MSL<inf>0</inf> (P>0.05). There was significant difference between average concentration of TN in 20 and 60 cm for AS<inf>1</inf>R, which were respectively 1.8 and 1.5 times lower than those for MSL<inf>0</inf>. The leaching loss of TN and NO<inf>3</inf><sup>-</sup>-N in 60 cm for AS<inf>1</inf>R was significantly lower than those in 20 cm. Thus it can be concluded that the effects of surface runoff, leaching and nitrogen loss reduction are more significant under the poplar-wheat intercropping system with the spacing of 2 m×5 m. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:51
Main heading:Forestry
Controlled terms:Agriculture - Eutrophication - Lakes - Leaching - Nitrogen - Plants (botany) - Rain - Runoff - Soils - Water pollution - Water quality
Uncontrolled terms:Agricultural non-point pollution - Average concentration - Forest canopies - Intercropping systems - Litter - Rainfall interception - Root - Water quality deterioration
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 443.3 Precipitation - 444.1 Surface Water - 453 Water Pollution - 453.2 Water Pollution Control - 461.9 Biology - 483.1 Soils and Soil Mechanics - 533.1 Ore Treatment - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.0 Woodlands and Forestry
DOI:10.11975/j.issn.1002-6819.2015.16.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 17>
Accession number:20153601250945
Title:Spatiotemporal patterns and evolution characteristics of agricultural production function at county level in Beijing-Tianjin-Hebei Region
Authors:Liu, Yu (1); Tang, Linnan (1); Pan, Yuchun (1); Tang, Xiumei (1); Ren, Yanmin (1)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing, China
Corresponding author:Pan, Yuchun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:305-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Guided by the target of "guaranteeing basic self-sufficiency of grain and other important food", quantitative research on agricultural production functions and their coupling characteristics from internal structure of agricultural products is the important subject that needs to be conducted in depth urgently at present. By building the evaluation indicator system of agricultural production function, and by utilizing the spatial measurement method, the spatial pattern and the evolution trend of agricultural production function including planting production function, forest and fruit production function, livestock production function and aquatic production function in Beijing-Tianjin-Hebei Region at county level during 2000-2013 are analyzed; then the model is applied to analyze the temporal-spatial correlation of planting production function and its coupling characteristics with other production functions, so as to provide reference for agricultural structure adjustment and layout optimization in the process of collaborative development in Beijing-Tianjin-Hebei Region. The research results indicate that: (1) during 2000-2013, under comprehensive influence of resource endowment, location factor, infrastructures, policy inclination and other factors, the agricultural production functions at county level in Beijing-Tianjin-Hebei Region are regularly distributed, and the planting production function is stronger in the plain area; the counties around the municipal district possess stronger function of livestock production; the counties with stronger forest and fruit production function are mainly distributed in the low mountain and hill region; and the counties with stronger aquatic production function are distributed along the eastern coast. Compared with that in 2000, the agricultural production function at county level in Beijing-Tianjin-Hebei Region in 2013 is wholly promoted. However, there are large differences in promotion degree among different functions. (2) From 2000 to 2013, the agglomeration effect of planting production function and livestock production function at county level is slightly weakened, the agglomeration effect of aquatic production function has stayed fairly constant, while that of forest and fruit production function is strengthened, and the homogeneous agglomeration characteristic of the comprehensive production function at county level is significant. (3) It is indicated from bivariate LISA map that there is obvious positive temporal-spatial correlation for planting production function during the research period, and the dualistic structure is significant; there is significant positive coupling between livestock production function and planting production function, forest and fruit production function, and the coupling degree is strengthened. It is suggested to reasonably adjust the agricultural production structure and optimize the layout at county level in combination with the current situation of agricultural production function and the coupling difference among functions, formulate the agricultural development strategy, and promote collaborative development of agricultural production functions in Beijing-Tianjin-Hebei Region. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Agriculture
Controlled terms:Agglomeration - Agricultural products - Couplings - Electromagnetic coupling - Forestry - Fruits - Grain (agricultural product) - Models - Spatial variables measurement
Uncontrolled terms:Agricultural development - Agricultural productions - Beijing-tianjin-hebei regions - Collaborative development - Evaluation indicator system - Evolution characteristics - Exploratory spatial data analysis - Temporal-spatial correlations
Classification code:602 Mechanical Drives and Transmissions - 704 Electric Components and Equipment - 705 Electric Generators and Motors - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 943.2 Mechanical Variables Measurements
DOI:10.11975/j.issn.1002-6819.2015.16.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 18>
Accession number:20153601250925
Title:Numerical simulation and validation test of direct shear test for root-soil composite of Hedysarum scoparium using finite element method
Authors:Tian, Jia (1); Cao, Bing (1); Ji, Jinnan (2); Li, Caihua (1); Guo, Ting (1); Xie, Yanbin (1); Yuan, Bo (1)
Author affiliation:(1) College of Agriculture, Ningxia University, Yinchuan, China; (2) Key Lab of Soil and Water Conservation and Desertification Combating, Ministry of Education, Beijing Forestry University, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:152-158
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plant roots have considerable impact on the shear properties of soil, but to date the underlying mechanisms have been poorly quantified. In order to understand the fundamental mechanisms of soil reinforcement by Hedysarum scoparium roots and reduce the cost of the testing and relieve the destruction of environment due to digging roots, five-year plant specimens were collected from the Gaoshawo forest field (Northwest China) by in-situ excavation in this study. The shear properties of root-soil composite of Hedysarum scoparium were studied by the finite-element numerical simulation software. The influence of the root area ratio (RAR) and the vertical load on the shear strength of root-soil composite of Hedysarum scoparium was discussed in this study. The laboratory direct shear test was used to prove the reliability of the numerical simulation under the condition of the 7% soil moisture content and the RAR of 0.0034. The results showed that the shear strength of roots-soil composite conformed to the Mohr-Coulomb's yield criterion and the roots of Hedysarum scoparium could notably enhance the soil shear strength. It was also found that a strong correlation between the RAR and the root apparent cohesion. The root apparent cohesion increased with the increasing of the RAR according to a linear function (R<sup>2</sup>>0.9). Under the same RAR, the capacity of soil reinforcement by the roots was weakened with the increase of the vertical load, and a logarithmic function (R<sup>2</sup>>0.9) could be used to describe the relationship between the shear strength growth rate of root-soil composite to pure soil and the vertical load. Under the same vertical load, the growth rate of shear strength of root-soil composite to pure soil decreased linearly with the decreasing of the RAR (R<sup>2</sup>>0.9). The roots of Hedysarum scoparium played an obvious role to reinforce soil under the low vertical loads. The results of the study indicated that the peak value of the shear stress of root-soil composite of Hedysarum scoparium appeared later compared with that of pure soil. It implied that the root reinforcement did not occur until the significant plastic deformation appeared. Therefore, the roots seemed to have little influence on soil reinforcement for small strains acting on soil-root composite. The numerical simulation results were consistent with the results of laboratory test (the maximum relative error was only 4.26%). It was found that an increase in the vertical load of root-soil composite of Hedysarum scoparium made the contribution of roots to the shear strength increment of root-soil composite decrease. The differences of the cohesion stress and friction angle of root-soil composite of Hedysarum scoparium were only 0.6179 kPa and 0.0039° respectively based on the fitting equation between the vertical load and the shear strength. The fitting equation was developed from the numerical simulation and the laboratory direct shear test results. This paper presented a numerical simulation model capable of simulating the direct shear of root-soil composite of Hedysarum scoparium. The numerical simulation results could serve as the basis and reference for further studies on shear characteristics of root-soil composite. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soil testing
Controlled terms:Adhesion - Computer simulation - Computer software - Finite element method - Numerical methods - Numerical models - Plastic deformation - Reinforcement - Shear strength - Shear stress - Soil moisture - Soils
Uncontrolled terms:Direct shear test - Finite element numerical simulation - Fundamental mechanisms - Hedysarum scoparium - Logarithmic functions - Maximum relative errors - Shear strength increments - Simulation and validation
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 421 Strength of Building Materials; Mechanical Properties - 483.1 Soils and Soil Mechanics - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 801 Chemistry - 921 Mathematics - 921.6 Numerical Methods - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 19>
Accession number:20153601250908
Title:Analysis on detaching process of detaching device and seedling pot integrity about rape transplanter
Authors:Liao, Qingxi (1); Hu, Xianpeng (1); Zhang, Zhao (1); Liu, Mingfeng (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:22-29
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mechanization transplanting for rapeseed pot seedling can alleviate labor intensity of manpower and shorten reviving time of rapeseed pot seedling. Seedling detaching and transplanting are the 2 main processing operations for transplantation. The stability of detaching has an important influence on the transplanting operation, and the pot seedlings should be stable during transporting and kept integrity for better transplanting quality. However, some detaching devices have complicated structure and easily make damage to seedlings. And therefore, in this paper, a conveyor belt type detaching device of rapeseed transplanter for rapeseed pot seedlings was introduced to solve this problem. The process of detaching was analyzed and the kinematics models in the stage of transmission and detaching were established to explore the stability conditions of transporting pot seedlings. The integrity tests of seedling pot were carried out to evaluate the mechanical properties of rapeseed pot seedlings. The TMS-CONSOLE type texture analyzer produced by American FTC company was used for the integrity tests. Results showed that the stability of transportation was obviously affected by the friction coefficient between seedling pot and materials of key devices in the transmission stage. The dynamic friction coefficient (DFC) between pot and detaching hinge was less than 0.3375, and the DFC between pot and conveyor belt ranged from 0.5 of the DFC between pot and detaching hinge to 0.3375. Accordingly, the rapeseed pot seedlings were transported stationarily. The stability of clamped pots in detaching stage was obviously influenced by the clamping force and clamping height. When the clamping height was lower and the clamping force was larger, the clamped pot seedlings were kept stable more easily. The 3 clamped pots were stable without slippage when the clamping force was more than 0.32 N, and would not flip over when the clamped force was more than 1.2 N. Single flat compression, repeated flat compression and repeated line type compression were included in the integrity tests. The results of single flat compression showed that the fracture resistance force of top edge of seedling pot was more than 6.8 N, and thus the pots maintained certain elasticity and restoring ability. The results of repeated flat compression showed that the number of compression did not influence springiness obviously. The condition of seedling pot damage became worse with the increase of the compression number. The results of repeated line type compression showed that the anti-compression force increased with the increase of clamping height. In order to keep the integrity of seedling pot, the anti-compression force applied was more than 1.99 N, and this requirement was easy to satisfy. To keep the integrity of pot in the detaching process, the clamping force should be proper. Bench test was developed to verify the analyzed results. The results of bench test showed that the detaching ratio of the device was greatly influenced by the transmission ratio and the detaching frequency. The detaching ratio was 90% when the detaching frequency was 40 pots per minute and the transmission ratio was 3 times. The experimental observations showed that the seedling pots were not fractured, and the pot medium were not obviously destructed. The qualified ratio of rapeseed pot seedlings in field test was 88.67%, which basically met transplanting requirements. This research provides a reference for the analysis of seedling separation stability of rapeseed transplanter and also for the research on the synchronization between detaching and planting. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Oilseeds
Controlled terms:Agricultural machinery - Belt conveyors - Clamping devices - Conveyors - Crops - Friction - Materials handling - Stability - Transplants
Uncontrolled terms:Complicated structures - Detaching device - Dynamic friction coefficient - Friction coefficients - Pot integrity - Pot seedlings - Processing operations - Transmission ratios
Classification code:462.4 Prosthetics - 605 Small Tools and Hardware - 691 Bulk Handling and Unit Loads - 692.1 Conveyors - 801 Chemistry - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics - 951 Materials Science - 961 Systems Science
DOI:10.11975/j.issn.1002-6819.2015.16.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 20>
Accession number:20153601250938
Title:Detection method of multi-target recognition of potato based on fusion of hyperspectral imaging and spectral information
Authors:Jin, Rui (1); Li, Xiaoyu (1); Yan, Yiyun (1); Xu, Mengling (1); Ku, Jing (1); Xu, Senmiao (1); Hu, Xuexue (1)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China
Corresponding author:Li, Xiaoyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:258-263
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to conquer the difficulty of simultaneously recognizing the multiple defects of potatoes samples placed randomly, this paper proposed a non-destructive detection method which combined manifold learning dimension reduction algorithm based on hyperspectral information fusion and extreme learning machine (ELM) to simultaneously distinguish the multiple defects of potatoes. In this paper, 367 potatoes were picked which were made up of 111 sprouting potatoes, 90 green rind potatoes, 46 blackheart potatoes and 120 normal potatoes. The hyperspectral image acquisition system contained imaging spectroradiometer (SPECIM, V10E, Finland), data acquisition box, lighting system, electric moving stage and objective table. The reflection hyperspectral information of all those potatoes was acquired by using the hyperspectral image acquisition system, whose spectral wavelength ranged from 390 to 1040 nm. The hyperspectral information included the spectral information from 520 wave bands and the imaging information from 520 gray images. After the correction to hyperspectral data with the standard black and white board, hyperspectral data in the range of 450-990 nm, which had high signal-to-noise ratio (SNR), were selected as original spectrum for subsequent processing. To deal with the spectral information, the average spectrum was abstracted from the region of interests (ROI) on every potato sample by using the environment for visualizing images (ENVI). Comparing several data preprocessing methods, detrend was determined as the optimal spectral preprocessing method. Diffusion maps (DM), locally linear embedding (LLE) and hessian locally linear embedding (HLLE) were respectively utilized for the purpose of cutting down the dimension of spectrum data after the spectral preprocessing named detrend. To deal with the hyperspectral imaging information, every pseudo-color image of potatoes was morphologically processed before extracting 84 image texture characteristics based on gray level co-occurrence matrix (GLCM). By using successive projections algorithm (SPA), 10 texture features were properly selected, which consisted of homogeneity of 45° GLCM in R gray image, energy of 90° GLCM in R gray image, correlation of 90° GLCM in R gray image, contrast of 135° GLCM in R gray image, correlation of 0° GLCM in G gray image, contrast of 0° GLCM in G gray image, correlation of 90° GLCM in G gray image, homogeneity of 45° GLCM in B gray image, correlation of 90° GLCM in B gray image and contrast of 135° GLCM in B gray image. After the fusion of the spectral characteristics and image features, the 367 potato samples were divided into calibration set and test set. The calibration set had 250 potato samples including 74 sprouting potatoes, 59 green rind potatoes, 28 blackheart potatoes and 89 normal potatoes. The whole number of samples in test set was 117 which contained 37 sprouting potatoes, 31 green rind potatoes, 18 blackheart potatoes and 31 normal potatoes. Six models were respectively established based on support vector machine (SVM) and ELM, which were DM-SVM, LLE-SVM, HLLE-SVM, DM-ELM, LLE-ELM and HLLE-ELM. Comparing and analyzing the results of the 6 models and the spending time, we discovered that the DM was the best manifold learning dimension reduction algorithm to deduce the spectral information. We also found that the DM-ELM model was the best model because of the better recognition rate for recognizing the multiple defects of potatoes and spending less time. For the DM-ELM model, the single recognition rate of sprouting potatoes, green rind potatoes, blackheart potatoes and normal potatoes respectively reached 97.30%, 93.55%, 94.44% and 100%, and the mixed recognition rate reached 96.58%. It only cost 0.11 s to build the DM-ELM model. The results indicate that combining hyperspectral information fusion with manifold learning dimension reduction algorithm can simultaneously distinguish the multiple defects of potatoes. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Image texture
Controlled terms:Algorithms - Calibration - Color image processing - Data acquisition - Defects - Image acquisition - Information fusion - Knowledge acquisition - Learning algorithms - Learning systems - Nondestructive examination - Radar target recognition - Signal to noise ratio - Spectroscopy - Support vector machines
Uncontrolled terms:Extreme learning machine - Hyperspectral Imaging - Manifold learning - Potato - Texture features
Classification code:421 Strength of Building Materials; Mechanical Properties - 423 Non Mechanical Properties and Tests of Building Materials - 716.1 Information Theory and Signal Processing - 716.2 Radar Systems and Equipment - 723 Computer Software, Data Handling and Applications - 741.1 Light/Optics - 801 Chemistry - 903.1 Information Sources and Analysis - 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 - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 21>
Accession number:20153601250909
Title:Reverse design and analysis of automatic seedling pick-up mechanism with non-circular gear planetary train
Authors:Zhao, Xiong (1); Wang, Chuan (1); Yang, Maoxiang (1); Sun, Liang (1); Chen, Jianneng (1)
Author affiliation:(1) Faculty of Mechanical Engineering & Automation, Zhejiang Sci-Tech University, Hangzhou, China; (2) Key Laboratory of Transplanting Equipment and Technology of Zhejiang Province, Hangzhou, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:30-36
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Seedling pick-up mechanism is the core mechanism of dry land automatic transplanting machine, and it replaces the traditional manual labor, which picks up seedlings from seedling box folder and sends the single seedling to the planting machine. The dry land automatic transplanting machines in Japan, South Korea and other countries adopt to bar and slider mechanism scheme or adopt chute in combination mechanism scheme, but they lack efficiency. China scholars do a lot of researches on making use of non-circular planetary gear train to achieve special non-circular trajectory, and this kind of transmission is a potential type of effective seedling pick-up mechanism, but it's very difficult to design non-circular planetary gear train mechanism when it is oriented to complex trajectory and needs to meet the attitude requirements, and the corresponding research is still not sufficient. Reverse solution is an effective way when oriented to mechanism design of complex work requirements, and the reverse design on how to plan the expected trajectory to meet the work requirements as well as the transmission ratio requirements, is the difficult points. Authors have conducted reverse design research on plug seedlings picking-up mechanism and proposed reproduced trajectory judgment criterion based on the monotonic mechanism of output member's relative angle. As to the expected trajectory, the applicability of the non-circular planetary gear system transmission can be judged by the monotonicity of relative angle curve. In this paper, the setting method of the key point in planning the expected trajectory is researched so as to facilitate the design of transmission ratio of non-circular gear, and the determination process of data point is given, which satisfies the requirement of working trajectory and attitude; through compiling mechanism's design software, a set of mechanism parameters are determined, and the simulation is carried out by ADAMS and the result is compared with that of the original design. The results achieved by this article are: the minimum distance between trace and seedling transport box is 21 mm, the minimum width of beak dimension is 2.07 mm, the inclined angle of beak shape is 136.4°, the winging angle of picking-up seedling arm is 24.3° in the feeding periods and is 3.6° in the periods of leaving seedling box, the angle of pushing seedling is 76°, the module of gear is 2.53 mm, height of trace is 285 mm, and the maximum transmission ratio of non-circular gears is 1.81. There are some improvements in the results of new design: the minimum width decreases by 3.88 mm in the seedling period; the winging angle of picking-up seedling arm decreases by 2.43° in the feeding period, which is thus useful to picking-up seedling and transplanting seedling; the distance between the trajectory and the delivering plate increases by 8.75 mm in the return period, which improves safety margin between taking seedling mechanism and delivering device; the highest point of trajectory drops by 42.67 mm, the lowest point of trajectory drops by 3.89 mm, the largest angle of picking-up arm drops from 62.21° to 55.47°, and the maximum transmission ratio of non-circular gears decreases from 1.92 to 1.81. The research in article provides a better choice for the picking-up seedling mechanism, and the reproduced trajectory judgment criterion and the trajectory planning method can give a reference for the design of non-circular gear planetary system. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Machine design
Controlled terms:Agricultural machinery - Computer software - Crops - Design - Drops - Epicyclic gears - Gears - Pickups - Seed - Trajectories
Uncontrolled terms:Attitude requirements - Combination mechanisms - Non-circular gears - Planetary gear systems - Plug seedling - Reverse designs - Trajectory planning method - Transplanting machine
Classification code:404.1 Military Engineering - 408 Structural Design - 443.1 Atmospheric Properties - 601 Mechanical Design - 601.2 Machine Components - 723 Computer Software, Data Handling and Applications - 752.3.1 Sound Reproduction Equipment - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products
DOI:10.11975/j.issn.1002-6819.2015.16.005
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 22>
Accession number:20153601250937
Title:Character analysis of mining disturbance and reclamation trajectory in surface coal-mine area by time-series NDVI
Authors:Li, Jing (1); Zipper, Carl E. (2); Li, Song (2); Donovan, Patricia F. (2); Wynne, Randolph H. (3); Oliphant, Adam J. (3); Xia, Qing (1)
Author affiliation:(1) College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, China; (2) College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, Blacksburg, United States; (3) College of Natural Resources and Environment, Virginia Polytechnic Institute and State University, Blacksburg, United States
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:251-257
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Open-pit coal mines are among the most drastic anthropogenic land disturbances. Using Wise County in the USA's Appalachian coal field as the study area, this paper evaluates the mine land disturbance and reclamation process over a 27-year period by conducting time-series analysis of multispectral remote-sensing data at the pixel scale. Twenty TM/ETM images obtained by the Landsat satellites, with 30 m spatial resolution, are treated as a multiple-year chronosequence. Polygonal vector files defining mining permitted areas and 6 high-resolution aerial images are used as auxiliary data; and the normalized difference vegetation index (NDVI) is used as a vegetative cover indicator. The methodology and study process include 3 steps. First, training data are prepared and multispectral image data are preprocessed. Data preprocessing includes band stacking, extracting the study area as image subsets, masking of cloud, cloud shadow and water, and computing NDVI based on each study-area pixel in each image. After the training data are generated, they are used to identify the NDVI thresholds for separating bare-ground from vegetated pixels, and ever-mined pixels from those un-mined. These separations are performed by visually inspecting each individual TM/ETM image displayed through a combination of the band of 2, 3 and 4 while referencing all available high-resolution aerial images and polygon vector files defining mining permitted area. Second, each pixel's time-series NDVI trajectory is constructed and analyzed. Based on individual inspection of training points' NDVI trajectory and qualitative trajectory classification, the characteristic parameters, including the NDVI maximum, the NDVI minimum, the difference of NDVI maxima before and after mining, the bare-ground threshold and ever-mined threshold, are designed, computed and used to identify whether the pixel is ever mined, revegetated or revegetated to the land cover level before mining. The relationship between NDVI minimal values and ever-mined thresholds for each study-area pixel over the full time series is computed and analyzed to determine if the pixel has been mined and, if so, the date of initial disturbance. For mined areas, the relationship between NDVI trajectory and bare-ground threshold for each point in time series after mining is analyzed to determinate if excavated land has been revegetated. For those revegetated pixels, the difference of NDVI maxima before and after mining is computed in order to find if it has been fully revegetated. Thirdly, by the data analysis function of database software and the spatial analysis function of ArcGIS software, the distribution of different mining-reclamation types is analyzed. Except for un-disturbed pixel, each mined pixel was classified for each year; such classes include the mined and un-vegetated during the whole observation period; the mined and un-revegetated after mining; the mined and revegetated without fully restored to the level before mining; and the mined and revegetated with vegetative cover fully restored to the level before mining. Time durations of non-vegetated status and revegetation after initial mining disturbance are also computed for fully reclaimed pixels. The conclusions are as follows: 1) During 1984-2010, the mining disturbs 45.80% mining permitted areas; 66.45% mined land is re-vegetated, which includes 38.42% mined land with fully restored vegetative cover and 28.03% mined land revegetated but without fully restored vegetative cover; 2) The fraction of mined lands with fully restored vegetative cover varies positively with mining-site age, which is found to be 85.54%, 13.92%, and 0.52% lands during the periods of 1984-1993, 1994-2003 and 2004-2010, respectively; 3) The average time for non-vegetated status and vegetated status prior to full cover restoration on the mined lands is 6 and 12 years, respectively; while the 25<sup>th</sup>, 50<sup>th</sup>, 75<sup>th</sup> and 90<sup>th</sup> percentiles for non-vegetated status are 4, 6, 10 and 16 years, respectively; 4) For full restoration of NDVI-derived vegetative cover to the level before mining, the time is 12 years on average. Study results demonstrate that the analysis of pixel-scale NDVI trajectories can reconstruct mining disturbance and land reclamation history, and can disclose its spatial heterogeneity over the broad expanse of space and time. Hence, such analyses can provide a scientific basis for land reclamation management and policy decisions. We note, however, that restoration of the NDVI to the level before mining is not a reliable indicator of reclamation success when viewed alone, although it is easily measured with satellite remote-sensing data. In order to interpret NDVI-derived vegetative cover data as indicators of reclamation success, other factors such as vegetation type and land productivity should be also considered. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Land reclamation
Controlled terms:Coal - Coal deposits - Coal mines - Coal reclamation - Decision making - Geographic information systems - Harmonic analysis - Image processing - Land use - Open pit mining - Pixels - Reclamation - Remote sensing - Restoration - Revegetation - Soil conservation - Space optics - Time series analysis - Trajectories - Vegetation
Uncontrolled terms:High-resolution aerial images - Multi-spectral image data - Multispectral remote sensing - Normalized difference vegetation index - Satellite remote sensing data - Spatial heterogeneity - Surface coal mines - Trajectory classification
Classification code:402 Buildings and Towers - 404.1 Military Engineering - 409 Civil Engineering, General - 442.2 Land Reclamation - 452.4 Industrial Wastes Treatment and Disposal - 482 Mineralogy - 502.1 Mine and Quarry Operations - 503 Mines and Mining, Coal - 503.1 Coal Mines - 524 Solid Fuels - 723.3 Database Systems - 723.5 Computer Applications - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 912.2 Management - 921.6 Numerical Methods - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2015.16.033
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 23>
Accession number:20153601250940
Title:Optimization of technical parameters of breaking Macadamia nut shell and finite element analysis of compression characteristics
Authors:Tu, Can (1); Yang, Wei (1); Yin, Qingjian (1); Lü, Junlong (1)
Author affiliation:(1) Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, China
Corresponding author:Yang, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:272-277
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Macadamia nuts have been successfully cultivated as crops in Australia and the USA and were introduced to China for experimental planting since 1980s. It is rich in fat and protein. The current production is over 700000 tons annually in China, but processing technology for macadamia nuts is undeveloped, especially breaking shell. So it has important significance to optimize technical parameters of breaking macadamia nut shell. Orthogonal design was carried out for optimizing technical parameters of breaking macadamia nut shell. The loading rate, the loading direction and the moisture content of macadamia nut shell were selected as factors and the integrated kernel rate of macadamia nuts was selected as evaluation index in this experiment. Macadamia nuts with different moisture content were selected as test samples, the moisture content of which was obtained by hot air drying at 55. Experiment of breaking macadamia nut was carried out in electronic tensile testing machine. The results indicated that the moisture content of macadamia nut shell and the loading direction had more significant effect on the integrated kernel rate than the loading rate. The most optimal combination of technics parameters was that loading rate, loading direction and moisture content of macadamia nut shell were 45 mm/min, horizontal, and 6%-9%, respectively. In this case, the highest integrated kernel rate of macadamia nut was 93%. The compression test was carried out in the macadamia nut shell moisture content of 6%-9% and the loading rate of 45 mm/min. Average shelled forces were 1018, 2274 and 1173 N in hilum, width and horizontal, respectively. The elastic moduli of macadamia nut shell calculated by the Hertz contact stress theory were 32.24, 68.63 and 39.65 MPa in hilum, width and horizontal, respectively. The results indicated that macadamia nut was anisotropic. Compression capability was the strongest in width and the weakest in horizontal. The shape of macadamia nut was close to sphere. The width diameter was near to average diameter of macadamia nut. The thickness was 4.03-4.36 mm at top of macadamia nut and 2.22-2.48 mm at the middle. That showed that the shell thickness of macadamia nut was nonuniform. The shell's material was similar to wood, so poisson's ratio was near to 0.3. Material properties and geometric model of macadamia nut were imported into ANSYS workbench. The distribution of stress and strain of breaking shell of macadamia nut was obtained by finite element analysis of macadamia nut. According to the finite element analysis diagram of macadamia nuts in the 3 loading directions, it could be known that cracks were easy to emerge and expand in horizontal. It was also horizontal which was the most appropriate for breaking macadamia nut shell. The simulation results were consistent with the results of experiment. The biggest shelled force was 2016 N in horizontal, and therefore the shelled force should not be less than 2500 N for ensuring that all nuts would be cracked. The loaded force should be in horizontal when macadamia nut shell was crushed. It provides the design basis for the macadamia nut shell-breaking machine. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Finite element method
Controlled terms:Compression testing - Cracks - Data compression - Elastic moduli - Loads (forces) - Materials testing apparatus - Mechanical properties - Moisture - Moisture determination - Optimization - Polypropylenes - Shells (structures) - Tensile testing
Uncontrolled terms:Compression characteristics - Different moisture contents - Geometric modeling - Macadamia nut - Optimal combination - Processing technologies - Shell breaking - Tensile testing machines
Classification code:408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 422.1 Strength of Building Materials : Test Equipment - 422.2 Strength of Building Materials : Test Methods - 716.1 Information Theory and Signal Processing - 801.4 Physical Chemistry - 815.1.1 Organic Polymers - 921.5 Optimization Techniques - 921.6 Numerical Methods - 944.2 Moisture Measurements - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 24>
Accession number:20153601250934
Title:Computational study on pyrolysis mechanism of an α, β-diether-type lignin trimer model compound
Authors:Jiang, Xiaoyan (1); Chen, Chen (1); Dong, Xiaochen (1); Lu, Qiang (1); Dong, Changqing (1)
Author affiliation:(1) National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, Beijing, China
Corresponding author:Lu, Qiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:229-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to understand the pyrolysis mechanism of lignin trimer, 4-(1, 2-diphenoxy)-propylphenol was selected as lignin trimer model compound containing both β-O-4 and α-O-4 linkages, and its pyrolysis processes were theoretically investigated by employing density functional theory method at M06-2X level with 6-31++G(d, p) basis set. The equilibrium geometries of the reactant, intermediates, transition states and products in the pyrolysis processes were fully optimized. The activation energy in each pyrolysis pathway was calculated. Analyses were performed to reveal the interaction of the β-O-4 and α-O-4 linkages in their cleavages, as well as the overall pyrolytic mechanisms and the pathways of product formation. The calculation results indicated for the 6 primary homolytic ways of the lignin trimer model compound, and the bond dissociation energies were in the order of C<inf>α</inf>-O < C<inf>β</inf>-O < C<inf>α</inf>-C<inf>β</inf> < C<inf>α</inf>-C<inf>4</inf> < C<inf>4″</inf>-O < C<inf>4'</inf>-O, with the lowest energy of C<inf>α</inf>-O (250.6 kJ/mol) and the second lowest energy of C<inf>β</inf>-O (286.9 kJ/mol), followed by that of C<inf>α</inf>-C<inf>β</inf> (300.5 kJ/mol). Hence, the homolytic cleavage of C<inf>α</inf>-O bond should be the major reaction of primary pyrolysis for the trimer model compound, while the homolytic cleavages of C<inf>β</inf>-O and C<inf>α</inf>-C<inf>β</inf> bonds were competitive pyrolysis reactions. The β-O-4 and α-O-4 linkages had little interaction effects in their primary cleavage reactions, because the bond dissociation energies of C<inf>α</inf>-O and C<inf>β</inf>-O in the lignin trimer model compound were similar to those of the corresponding lignin dimer model compounds. However, after the initial cleavage of the α-O-4 (β-O-4) linkage, the formed intermediate had significantly reduced bond dissociation energy for the further cleavage of the β-O-4 (α-O-4) linkage. Based on the energy barrier of each reaction pathway for the primary homolytic cleavage of C<inf>α</inf>-O bond, the major pyrolytic products of the model compound included phenol, 4-propenylphenol, 4-allyphenol, and dimer compound with double bonds (the precursor of large molecular products). Based on the primary homolysis of C<inf>β</inf>-O bond, the major pyrolytic products included phenol, 4-propenylphenol and 4-propylphenol. From the primary homolysis of C<inf>α</inf>-C<inf>β</inf> bond, the major pyrolytic products included phenetole, 4-hydroxy benzaldehyde, benzene, p-cresol and phenol. In conclusion, based on the 3 homolytic mechanisms, the pyrolysis of the lignin trimer model compound will produce phenol, 4-propenylphenol, 4-allyphenol, and dimer compound with double bonds as the major products, as well as 4-propylphenol, phenetole, 4-hydroxy benzaldehyde, benzene and p-cresol as the competitive products. The research results will provide theoretical basis for the deep understanding of the pyrolysis mechanism of lignin. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Pyrolysis
Controlled terms:Activation energy - Benzene - Biomass - Bond strength (chemical) - Chemical bonds - Computation theory - Density functional theory - Dimers - Dissociation - Lignin - Oligomers - Phenols
Uncontrolled terms:Bond dissociation energies - Calculation results - Computational studies - Density functional theory methods - Equilibrium geometries - Pyrolysis mechanism - Pyrolysis reaction - Pyrolytic products
Classification code:525.1 Energy Resources and Renewable Energy Issues - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 921 Mathematics - 922.1 Probability Theory
DOI:10.11975/j.issn.1002-6819.2015.16.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 25>
Accession number:20153601250922
Title:Effects of biochar on water infiltration, evaporation and nitrate leaching in semi-arid loess area
Authors:Xiao, Qian (1); Zhang, Hongpei (1); Shen, Yufang (1); Li, Shiqing (1)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling, China; (2) College of Forestry, Northwest A&F University, Yangling, China; (3) College of Resources and Environment, Northwest A&F University, Yangling, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:128-134
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Water scarcity and low use efficiency of nitrogen are the major limiting factors for agriculture sustainable development in dryland areas of the Loess Plateau. Biochar has been widely proposed as a promising novel alternative of soil amendment to improve soil quality and increase crop productivity, but limited quantitative work has been addressed on the soil water infiltration process, evaporation characteristics and nitrate leaching. A better understanding of these characteristics can provide the solid basis for the evaluation of the effect of biochar amendment on soil hydrology and nitrogen retention in arid and semi-arid regions. In the present study, by using the soil column simulation investigation, biochar derived from maize stover (pyrolysis temperature of 400) was applied to 3 different types of soil samples (aeolian soil, cultivated loessial soil and dark loessial soil) collected from the Loess Plateau at 6 rates of 0, 0.5%, 1%, 2%, 3% and 5% (w/w) with triplicate. The wetting process, the cumulative infiltration amount, the permeability and the stable infiltration rate were determined. The water infiltration analysis showed that the advancement of wetting front and the cumulative infiltration amount changed with the biochar addition amount and soil texture. The migration rate of water was the fastest in aeolian soil and the slowest in cultivated loessial soil due to the soil texture and structure. The migration rate of wetting front in aeolian soil and dark loessial soil was decreased after the biochar addition. As the rate of biochar addition increased, the cumulative infiltration amount of aeolian soil and dark loessial soil gradually declined. For cultivated loessial soil, the higher biochar addition rates (3% and 5%) increased the time of the wetting front to the bottom of the column, while the lower rates (0.5%, 1% and 2%) increased the wetting front migration rate; the cumulative infiltration amount was not decreased at the rate of 0.5%, 1% and 2%, but reduced significantly at the rates of 3% and 5%. Overall, biochar addition reduced the water infiltration capacity and increased the water holding capacity for aeolian soil and dark loessial soil; the lower rates of biochar addition in cultivated loessial soil were not conducive to the water retention, while the higher rates of biochar addition favored. There were extremely significant power function relationships between wetting front distance and infiltration time under different rates of biochar treatments with the determination coefficient of greater than 0.99. Philip infiltration model was suitable for the simulation of soil water infiltration process under biochar treatments with the determination coefficient ranging from 0.991 to 0.999. During the successive evaporation of 30 days, biochar addition had no significant effects on the cumulative evaporation in cultivated loessial soil and dark loessial soil. However, biochar amendment changed the evaporation characteristics of aeolian soil: the evaporation was inhibited in the early stage; due to the continuous supply of water, the evaporation gradually increased in the later stage, but not significantly. The nitrate leaching was determined by the volume and the concentration of the leaching solution. The 2% addition rate of biochar in aeolian soil and the 1% addition rate of biochar in loessial soil had no significant effects on the total amount of nitrate leaching (P>0.05), when compared with the levels of the control (0%). Biochar addition reduced nitrate leaching by 18.1%-37.2% in aeolian soil, 33.8%-87.7% in cultivated loessial soil and 13.8%-80.8% in dark loessial soil, which may lead to increase the capacity of nitrogen holding in soil, reduce the nitrogen leaching risk in environment. Our results suggest that the use of biochar as soil amendment in agricultural soils plays an important role in increasing soil water holding capacity, improving available nitrogen and helping crop development in dryland areas of the Loess Plateau. However, more studies are needed to understand the mechanisms through which these benefits are achieved. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Infiltration
Controlled terms:Agriculture - Arid regions - Crops - Evaporation - Landforms - Leaching - Moisture - Nitrates - Nitrogen - Sediments - Soil moisture - Soils - Sustainable development - Wetting
Uncontrolled terms:Arid and semi-arid regions - Bio chars - Cumulative infiltrations - Determination coefficients - Infiltration modeling - Nitrate leaching - Soil textures - Water holding capacity
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 911.2 Industrial Economics
DOI:10.11975/j.issn.1002-6819.2015.16.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 26>
Accession number:20153601250933
Title:Comprehensive evaluation model for revegetation potentiality on moving sandy land in alpine valley of Tibet, China
Authors:Li, Haidong (1); Qin, Weihua (1); Zhang, Tao (1); Shen, Weishou (1)
Author affiliation:(1) Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Nanjing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:220-228
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The large area and fast development of aeolian sandy lands in the Yarlung Zangbo River basin of Tibet, China has caused immense damages to local social and economic development, and thus, it is necessary to carry out a series of ecological engineering to recover vegetation on moving sand dunes. However, revegetation potentiality of moving sandy land has rarely been reported with integrated studies, and under the harsh conditions of habitat stress, revegetation potentiality of different types of moving sandy lands is still unclear, which is one of most important technical bottlenecks and critical basis for policy making as well as for ecological restoration. In this paper, three types of moving sandy lands (on flood plain, on river bank, on mountain slope, respectively) in alpine valley in the middle reaches of the Yarlung Zangbo River basin were first chosen as the study objects, and then evaluation indicators and criterion systems of revegetation potentiality were established on the ground of the division of vegetation succession stages and the analysis of their habitat characteristics on different moving sandy lands. Thereafter, a comprehensive evaluation model for revegetation potentiality (CEMRP) on moving sandy land in the alpine valley was built using the analytic hierarchy process (AHP) and the fuzzy comprehensive evaluation method. The results showed that the potentiality of moving sandy land on mountain slope was the strongest at Level I and with the biggest membership degree value (0.2884), versus little strong to moving sandy land on flood plain at Level II and with the biggest membership degree value (0.2869), little poor to moving sandy land on river bank at Level IV and with the biggest membership degree value (0.3296). The congenital conditions which affected the habitat of vegetation growth, such as climate (precipitation, temperature, sunshine duration), topographic (elevation, slope, aspect) and soil conditions (moisture, pH value, organic matter, total nitrogen, texture, temperature of sand dune), may determine what the status of vegetation recovery would be. However, vegetation recovery measures which could be treated as acquired conditions, could be used to adjust revegetation potentiality. In addition, by adopting suitable countermeasures (suitable species, fencing, sand-protecting barrier) for artificial revegetation on different types of moving sandy lands, vegetation potentiality could be promoted directly, while the status of vegetation recovery also could be improved through altering soil conditions indirectly. There were three experimental plots established in 2008 for the observation of vegetation recovery. We integrated the vegetation recovery status of different types of moving sandy lands in 2014, and the accuracy and applicability of CEMRP was validated and discussed. The result indicated that CEMRP fitted very well with vegetation growth on different types of moving sandy lands, and could be used as a decision support system for policy makers to identify the difficulties and the priority of ecological rehabilitation for different types of moving sandy lands, even for different regions under different climatic zones in the Tibetan Plateau. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Landforms
Controlled terms:Analytic hierarchy process - Artificial intelligence - Banks (bodies of water) - Decision making - Decision support systems - Ecology - Ecosystems - Environmental management - Floods - Models - Recovery - Revegetation - Rivers - Soil conservation - Vegetation - Watersheds
Uncontrolled terms:Analytic hierarchy process (ahp) - Comprehensive evaluation model - Decision supports - Evaluation method - Fuzzy comprehensive evaluation method - Social and economic development - Tibetan Plateau - Yarlung zangbo river basins
Classification code:442.1 Flood Control - 442.2 Land Reclamation - 444.1 Surface Water - 454 Environmental Engineering - 481.1 Geology - 531 Metallurgy and Metallography - 723.4 Artificial Intelligence - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 902.1 Engineering Graphics - 912.2 Management - 921 Mathematics - 961 Systems Science
DOI:10.11975/j.issn.1002-6819.2015.16.029
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 27>
Accession number:20153601250906
Title:Performance experiment of directional precision seeding device for japonica rice
Authors:Han, Bao (1); Meng, Fanchao (1); Liang, Li'na (1); Ge, Yuxiao (1); Xu, Hongyan (1)
Author affiliation:(1) Engineering College, Northeast Agricultural University, Harbin, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:8-15
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problems that the seeding rate was large, the position of dropping seeds was inaccurate and the distribution of seeds was poorly uniform on seedling trays during northern japonica rice seedlings in greenhouses, a new directional precision seeding device with combined V-shaped groove slide was developed. It could achieve that each rice seed was seriately arrayed in its long axis direction by the positioning conveying plates, which moved along the D-shaped trajectory in the V-shaped slide. This device was mainly composed of test-bed bracket, driving system, combined V-shaped groove slide, cleaning-seed brush roll, seed separating and feeding mechanism, and horizontal conveyer system. The combined V-shaped groove slide and the seed separating and feeding mechanism were key parts of the seed-metering device. The chief function of the former was to arrange the seeds in their long axis direction while the seeds moved along the combined V-shaped groove, and the latter could drive the directed seeds to move towards the exit intermittently. The working process of the device would be as follows: the rice seeds were placed in the hopper above the combined V-shaped groove slide at first, then the positioning conveying plates drove the seeds to move towards the exit intermittently; each seed moving in the V-shaped grooves would constantly readjust its own long axis direction influenced by the action of the positioning conveying plates and the inclined plane of the grooves, which made the seed in the long axis arranged in a row along the V-shaped grooves slide, and realized the automatic orientation of the seeds. Later, the directed seeds were conveyed to the exit and located on the seed tape or seedling trays according to the required number and spacing of seed. To study the influence law of different factors on seeding performance for directional precision seeding device and obtain the optimal combination of parameters, the conveying frequency, the tooth spacing and the slide angle were taken as the main impact factors of the seeding device performance. In the self-made test-bed, the long-grain type japonica rice Dong Nong 419 was selected as experimental material, the effects of the 3 main impact factors on seeding qualified rate (1-3 seeds every turn), ideal seeding rate (2-3 seeds every turn) were studied by single factor experiments and three-factor and three-level orthogonal experimental design, and the relationships between 3 main influencing factors and seeding qualified rate and ideal seeding rate were established respectively by regression analysis. The influence law of the factors and their interaction on seeding qualified rate and ideal seeding rate was analyzed, and the best optimized combination of the parameters was obtained. The results indicated that the order of primary and secondary factors affecting seeding qualified rate was: conveying frequency > tooth spacing > slide angle and that affecting ideal seeding rate was: tooth spacing > conveying frequency > slide angle. The optimal combination parameters were conveying frequency of 2.7 Hz, slide angle of 46.8° and tooth spacing of 9.6 mm. Under the combination condition of the optimal parameters, the seeding qualified rate and the ideal seeding rate were 98.75% and 84.8% respectively. The seeding verification test indicated that the result fitted in well with the optimal experiments. The seeding overall performance test was carried out under the same conditions with 3 varieties of long-grain type japonica rice seeds (Dongnong 419, Longyang 16 and Daohuaxiang) and 2 varieties of short-grain type japonica rice seeds (Kongyu 131 and Longjing 26). As the paper tape moved at the speed of 0.04 m/s, the average qualified rate and the ideal seeding rate were 97.22% and 77.57%, respectively, and all the miss-seeding rates and reseeding rates were less than 2.6% and 0.4%, respectively. Experiment results indicated that when seeding long-grain type and short-grain type japonica rice seeds, the device had a better adaptability for the long-grain type. The seeding performance could meet the requirements of precision seeding for the japonica rice. The research provides a theoretical reference for optimizing the design and improving seeding performance of the directional precision seeding device for northern japonica rice. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Grain (agricultural product)
Controlled terms:Agricultural machinery - Conveying - Design of experiments - Equipment testing - Experiments - Optimization - Regression analysis - Seed
Uncontrolled terms:Experimental materials - Japonica rice - Optimized combinations - Orthogonal experimental design - Performance experiment - Precision seeding - Rice nurturing seedlings - Single-factor experiments
Classification code:505.3 Nonmetallic Mining Equipment - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 901.3 Engineering Research - 921.5 Optimization Techniques - 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:10.11975/j.issn.1002-6819.2015.16.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 28>
Accession number:20153601250924
Title:Test for frost heaving damage mechanism of rigid-soften composite trapezoidal canal in seasonally frozen ground region
Authors:Jiang, Haibo (1); Tian, Yan (1)
Author affiliation:(1) College of Water & Architectural Engineering, Shihezi University, Shihezi, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:145-151
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the area of seasonal frozen soil in North China and Northwest, there exists massive and serious frost-heave damage of concrete lining canal. Frost-heave damage is the main reason for the channels. In this paper, the prototype experiments were conducted in order to explore the frost-heave mechanism of rigid-soften composite canal in the irrigation area of high-cold region. The frost deformation the soil moisture variation of the trapezoidal canal lined with concrete and composite geo-membrane, and especially the rules of frost-heave deformation and the deformation features of composite geo-membrane were further systematically studied. The experiment followed the leading thought of suiting and reducing the frost-heave destruction, chose the trapezoidal canal lined with infiltrating structure and integrated rigidity materials as typical experiment segment, and collected the freeze index of various canal lining frameworks; the experiment referred to the advanced method, and adopted the new material. The experiment section of observation prototype was 50 meters long. The measuring section for ground temperature was 3 meters long, and the temperature was measured by the digital thermometer. The measuring section for freeze depth was 3 meters long, measured by the DTM-2 frozen soil apparatus. The section for frost-heave stress was 4 meters long, measured by the strain sensor. The section for frost deformation was 5 meters long, measured by the electronic level and the electronic theodolite. The section for foundation moisture was 20 meters long, and the foundation moisture was measured by the drying method. Prototype test data were obtained through the observation every day. The observation objects in the test included air temperature, ground temperature, foundation moisture, freeze depth, frost deformation and frost-heave stress. The frost-heave mechanism of trapezoidal canal lined with concrete and composite geo-membrane was studied in the prototype experiment, as well as the soil moisture movement on canal base during seasonal freezing-thawing stage. The variation law of frozen depth and frost-heave deformation was derived from soil moisture movement, freezing temperature and frost depth. Based on the observed data in the prototype experiment of the trapezoidal canal lined with concrete and composite geo-membrane under the condition of freezing-thawing cycle, the ground temperature change, the rules of frost-heave deformation and the distribution of normal and tangential frost-heave force were analyzed. The results showed that, the frost-heave amount had a maximum value of 13.1 and 11.2 cm respectively at the site of one third from the bottom on shady slope and at the bottom of trapezoidal canal, which caused lining structure of the canal to rise. During the freezing period, the soil moisture content in the depth of 0-60 cm increased with the increasing of the depth, while that in 60-120 cm decreased with increasing of the depth. The maximum value of water migration and variation was 13.2%, which occurred in the bottom of the canal. After one freeze-thaw cycle, the strength and deformation quantity of composite geo-membrane were still maintained above 90%, so it could fully utilize the features of frost-heave resistance and adaptive deformation of composite geo-membrane. The study shows that the prototype experiment of the canal can provide the reference and the scientific basis for the engineering design of the lining canal with concrete and composite geo-membrane and the mechanics computation in seasonal frost region. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Irrigation canals
Controlled terms:Canals - Concretes - Deformation - Freezing - Frozen soils - Hydraulic structures - Linings - Membranes - Moisture - Permafrost - Rigid structures - Soil moisture - Soil surveys - Soils - Thawing
Uncontrolled terms:Concrete and composites - Freezing thawing cycles - Frost heave - Frost heave deformation - Frost heaving - Frost-heaving amounts - Moisture migration - Seasonally frozen ground
Classification code:407.2 Waterways - 408 Structural Design - 412 Concrete - 421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 441 Dams and Reservoirs; Hydro Development - 483.1 Soils and Soil Mechanics - 611 Hydroelectric and Tidal Power Plants - 801.4 Physical Chemistry - 821.3 Agricultural Methods - 822.2 Food Processing Operations - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.020
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 29>
Accession number:20153601250931
Title:Fruit bunch measurement method for cherry tomato based on visual servo
Authors:Feng, Qingchun (1); Zhao, Chunjiang (1); Wang, Xiaonan (1); Wang, Xiu (1); Gong, Liang (2); Liu, Chengliang (2)
Author affiliation:(1) National Research Center of Intelligent Equipment for Agriculture/Key Laboratory of Agri-Informatics, Ministry of Agriculture/Beijing Key Laboratory of Intelligent Equipment Technology for Agriculture, Beijing Research Center of Intelligent Equipment for Agriculture, Beijing, China; (2) School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China
Corresponding author:Zhao, Chunjiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:206-212
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As the fresh cherry tomato, largely produced and consumed in China, needed an increasing manual-picking cost these years, the automatic harvesting machine was expected to replace the manual labor to implement the intensive work. Accurately identifying and locating the mature fruit bunches, was a key technique of harvesting robot research. The existing research could be classified into active and passive detecting method, among which the active method was becoming more mainstream. In this paper, a new vision system for cherry tomato's automatic harvesting was designed based on laser ranging and vision servo, and the system included a camera, a laser sensor and a manipulator as the servo unit, among which the camera was fixed coaxially ahead of the laser sensor, and could slid up and down driven by a cylinder. When the camera slid down, the laser sensor was triggered to measure the distance between fruit and camera's view system. Through analyzing the color feature of the image acquired from the camera, the R-G color model was adopted to intensify the difference between target fruit and background. According to the column pixel grey statistics, the candidate area of fruit bunch was selected from the R-G image, with a view of decreasing the whole image processing and improving recognition accuracy. Then the CogPMAlignTool contained in the Cognex VisionPro image processing classlib was used for the fruits' identifying from the bunch, with the single fruit's template scaling range (0.8, 1.2), rotating angle range (-π, π) and acceptable threshold 0.36. According to the image coordinate of the periphery fruits and the coordinate transformation between the camera and the manipulator, the stereo coordinate was estimated based on the camera imaging model, which was considered as the initial position for targeting the fruit based on the vision servo. The transition matrix between the camera and the manipulator was determined through the hand-eye calibration. According to the deviation between the fruit's center and the image center, the base joint and the forearm joint were controlled to change the posture of the camera based on vision servo algorithm, so that the 2 centers in the fruit and the image could coincide approximatively. After aiming the fruit, the laser sensor was triggered to measure the distance between the vision system and the fruit, and the accurate coordinate of the periphery fruits could be obtained on the basis of the distance and the gesture of manipulator. Furthermore, the width and the length of the bunch were calculated after the coordinates of 4 periphery fruits were measured, which would be the necessary parameters to guide the robot's grasper to case the bunch from the bottom up with the fruit bag and cut the stem. The test result showed that the average successful identification rate of single fruit from the bunch was 83.5%, and the rate would be better, if the fruit bunch had more regular shape, or the bunch stem was closer to the view center of vision unit; and through the vision servo control to aim the fruit center, the average deviation between the fruit center and the image center was 8.38 pixels. Finally, the measuring error of bunch length was 8.25 mm, and that of bunch width was 5.25 mm. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Fruits
Controlled terms:Cameras - Computer vision - Harvesters - Harvesting - Image processing - Manipulators - Measurements - Pixels - Robots - Stereo image processing - Stereo vision - Visual servoing
Uncontrolled terms:Cherry tomatoes - Co-ordinate transformation - Hand-eye calibration - Identification rates - Laser ranging - Recognition accuracy - Toward-target measuring - Vision servo control
Classification code:731 Automatic Control Principles and Applications - 732 Control Devices - 741 Light, Optics and Optical Devices - 741.2 Vision - 742.2 Photographic Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 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:10.11975/j.issn.1002-6819.2015.16.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 30>
Accession number:20153601250944
Title:Effect of hot air relative humidity on drying characteristics of carrot slabs
Authors:Ju, Haoyu (1); Xiao, Hongwei (1); Zheng, Xia (2); Guo, Xiuliang (3); Liu, Yanhong (1); Zhang, Weipeng (1); Yuan, Jing (1); Gao, Zhenjiang (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing, China; (2) College of Mechanical and Electric Engineering, Shihezi University, Shihezi, China; (3) Zhejiang Keda Biotechnology Co. Ltd, Lishui, 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:16
Issue date:August 15, 2015
Publication year:2015
Pages:296-304
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Drying is one of the most common processing methods for fruits and vegetables. Enhancing drying rate and dried products' quality as well as energy efficiency is very tempting for drying industry. Recently, a lot of investigations have illustrated that drying temperature, air velocity and sample's thickness have a significant influence on drying process. High drying temperature and velocity can extensively reduce drying time and enhance drying rate. However, few investigations take into account hot air relative humidity (RH) as important drying parameter in drying process. Some literatures showed that decreasing RH would lead to a steeper slope of moisture ratio decreasing. Whereas, some researches pointed out that there was no effect of RH on the drying rate in specified range of RH. In general, high RH can contribute to a rapid increase of product temperature. It is expected that with high RH pretreatment, the temperature and moisture tend to be equivalent and after that the RH can be reduced to enhance drying rate. In this circumstance, the temperature and moisture gradient between sample and drying air become consistent and the high efficient drying process could be achieved. Drying process refers to heat and mass transfer efficiency, energy consuming and products quality. Theoretical models, semi-theoretical and empirical models are widely used to describe drying process. However, those models neglect the fundamentals of the drying process and their parameters have no physical meaning and do not help in the optimization. Recently, Weibull model was used to describe drying process because of its applicability. Based on Weibull model, the relationship between scale parameters as well as shape parameters and drying process could be developed. So in current work, carrot slabs were used to explore the drying characteristics under the drying condition of constant RH and of decreasing RH step by step, together with constant drying temperature and constant air velocity. Result showed that under the condition of constant RH, drying rate would rise up in the initial drying period and then drop afterwards, additionally, drying rate was more rapid under lower RH. Drying time was decreased when reducing RH, and drying time under 20% RH was reduced by 27.6% compared to that under 50% RH. However, material's temperature would be the highest under 50% RH drying condition. Besides, under the drying condition of decreasing the RH step by step, when 50% RH was kept for 30 min and then was changed to 20% RH, the drying time was saved by 18.5% compared to constant 20% RH drying condition. When 50% RH was kept for 30 min or more than 30 min, there were 2 accelerating periods of drying rate. The material's temperature would decrease as the RH decreased because of moisture evaporation. Weibull model could fit the drying curves under different conditions accurately. The scale parameter ranged from 1.864 to 3.635 and the shape parameter ranged from 1.296 to 1.713. So there was a lag period according to the shape parameter value. Based on Weibull model, the moisture effective diffusivity calculated was in the range of 1.17×10<sup>-9</sup>-2.92×10<sup>-9</sup> m<sup>2</sup>/s. Taking rehydration ratio, color value, drying time and energy consuming into account, 50% RH kept for 30 min and then reduced to 20% RH was proposed as the favorable condition for drying carrot slabs. The present work contributes to a better understanding of the effect of relative humidity on drying characteristics of carrot slabs, which is useful for enhancing drying rate and dried products' quality as well as energy efficiency. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:45
Main heading:Drying
Controlled terms:Air - Energy efficiency - Humidity control - Mass transfer - Models - Moisture - Thermal processing (foods)
Uncontrolled terms:Carrot - Drying characteristics - Effective diffusivities - Favorable conditions - Fruits and vegetables - Heat and mass transfer - Shape parameter value - Weibull models
Classification code:402 Buildings and Towers - 525.2 Energy Conservation - 641.3 Mass Transfer - 642.1 Process Heating - 801.4 Physical Chemistry - 804 Chemical Products Generally - 822.2 Food Processing Operations - 902.1 Engineering Graphics
DOI:10.11975/j.issn.1002-6819.2015.16.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 31>
Accession number:20153601250939
Title:Improving milling quality of brown rice with compound enzyme solution humidification
Authors:Jia, Fuguo (1); Shi, Yufei (1); Han, Yanlong (1); Wang, Hui (1); Yao, Li'na (1); Zeng, Yong (1); Jiang, Longwei (1); Zhang, Qiang (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:264-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Generally, lots of broken rice is generated and high energy consumption occurs during the rice milling processing, which bring adverse effect to the economic benefits of rice milling enterprises. Therefore, milling quality improvement is of important significance in practice for rice processing industry. Moisture conditioning treatment for the brown rice, which is an advanced technology, can increase head rice yield and reduce the milling energy consumption to some extent. It reduces the maximum compressive strength and maximum tensile strength with the increase of moisture content and generated moisture gradient within the rice by gradual penetration from the exterior into the interior of kernels. However, it does not fundamentally solve the problem caused by the resistant cortex of brown rice. The brown rice's tough cortex is mainly caused by the coarse fiber structure, whose major components are cellulose and araboxylan. This study proposes a new process with composite enzyme of cellulase and xylanase instead of the conventional humidifying method. This method substantially decreases broken rice in the milling process and reduces the milling energy consumption to improve milling quality. The humidification of compound enzyme solution selectively degrades the cortex of brown rice, which can not only reduce the hardness of brown rice kernel and decrease the whitening pressure, but also facilitate the moisture penetration, which would boost cortex softening and increase the grain's toughness. Moreover, the synergy of compound enzyme can improve the efficiency of the enzymatic hydrolysis. A central composite rotatable orthogonal experimental design of response surface methodology with 4 factors and 5 levels was employed. Taking brown rice in storage with moisture content below 15% as raw material, the influences of the 4 parameters including cellulose-to-xylanase mass ratio, concentration of compound enzyme solution, adding liquid proportion and enzyme treating time on the head rice yield and the milling energy consumption in the humidification process of compound enzyme solution were investigated, as well as the optimal parameters of this process. Mathematical models for the influences of various parameters on the head rice yield and the milling energy consumption were established. The test data were processed with Excel, Matlab and Design Expert. Experiment results showed that the parameters of compound enzyme solution humidification had significant impact on the head rice yield and the milling energy consumption. The optimized pretreatment parameters were as follows: the cellulose-to-xylanase mass ratio was 1.3: 1 g/g, the concentration of composite enzyme solution was 65 mg/mL, the adding liquid proportion was 1.25% and the enzyme treating time was 102 min. Under the optimized parameters, the head rice yield was 80.07% and the milling energy consumption was 90.72 kJ/kg. To verify the optimization results, 3 groups of rice milling tests were made under the optimal combination of parameters, and the experiment results showed that there was no significant difference between predicted values and observed values. Contrast validation experiments indicated that the head rice yield and the milling energy consumption were respectively 3.98% higher and 13.06% lower than the values from the moisture conditioning treatment, and 0.98% higher and 5.48% lower than the values from the cellulase solution humidification. The cortex crude fiber degradation of brown rice proved to be the main reason for the improvement of rice milling quality through the optics electronic microscope analysis. This research can provide a theoretical basis for the new technology of rice milling pretreatment. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Milling (machining)
Controlled terms:Cellulose - Compressive strength - Digital storage - Economic and social effects - Energy utilization - Enzymatic hydrolysis - Enzymes - Grain (agricultural product) - Models - Moisture - Moisture determination - Quality control - Tensile strength
Uncontrolled terms:Brown rice - Cortex characteristic - Enzyme solutions - High energy consumption - Maximum compressive strengths - Milling quality - Orthogonal experimental design - Response surface methodology
Classification code:421 Strength of Building Materials; Mechanical Properties - 525.3 Energy Utilization - 604.2 Machining Operations - 722.1 Data Storage, Equipment and Techniques - 801.4 Physical Chemistry - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 821.4 Agricultural Products - 902.1 Engineering Graphics - 913.3 Quality Assurance and Control - 944.2 Moisture Measurements - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2015.16.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 32>
Accession number:20153601250921
Title:Spatial interpolation of soil moisture and nutrients using BME combined with BNN
Authors:Xu, Ying (1); Xia, Bing (1)
Author affiliation:(1) School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:119-127
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Understanding spatial distribution characteristics of soil moisture and nutrients is an important step for precision agriculture and site-specific soil management. In order to improve the accuracy of soil spatial prediction, it is of great importance to predict and map soil spatial characteristics based on limited data and develop new methods by integrating different spatial analysis theories. By analyzing the advantages and disadvantages of the Bayesian maximum entropy method (BME) and the Bayesian neural networks (BNN), this study proposed a Bayesian maximum entropy method combined with the Bayesian neural networks (BMENN) to predict the spatial distributions of soil moisture and nutrients in farmlands. The BMENN method takes the following steps: first, the BNN is used to quantify the prediction uncertainties of soil moisture and nutrients at all predicted locations; then, the uncertainties expressed by 95% prediction limits are regarded as soft data of BME method to be interpolated in spatial distributions of soil variables. Six soil variables, including moisture content, organic matter, total nitrogen (N), alkali-hydrolyzable N, available phosphorus (P) and available potassium (K), were measured at 161 locations in agricultural field in the north of Yangzhou City, Jiangsu Province. The locations were selected on the basis of 5 m×5 m regular grid. Based on these soil data, the performance of the BMENN method for spatial prediction of soil moisture and nutrients was compared quantitatively with the BNN method and the ordinary Kriging (OK) using Pearson correlation coefficient (r), mean error (ME) and mean squared error (MSE). The sampling data from the 161 locations for each variable were divided into the calibration data set and the validation data set. The calibration data set was used to build prediction models of all 3 methods. The 3 methods were compared by the cross-validation using the validation data set. The MSE was divided further into 3 components revealing different aspects of the discrepancy between the observed and the estimated values of soil moisture and nutrients. The results showed that: 1) Compared to the other 2 approaches, the BMENN reduced MSE by 2.26%-23.54% and had the smallest MSE for all soil variables, indicating that the BMENN predictions had less estimation errors than those of the OK and BNN method because the BMENN incorporated the uncertainty estimated by the BNN into the BME method. 2) The Pearson correlation coefficients were of the same magnitude or close to 1 for the BMENN, which indicated that the linear relationship was stronger between the BMENN estimates and the observed values. 3) Although the BMENN method did not produce the largest unbias (ME was close to zero) for all soil variables compared with the other 2 approaches, the ME values of the BMENN were very small for all soil variables, especially for the alkali-hydrolyzable N and available K, which showed that the BMENN provided the unbiased estimates. 4) The contribution of the bias (ME) to the MSE was almost zero and the lack of positive correlation (LCS) was the factor that contributed the most to the MSE of the 3 interpolation methods for all soil variables. This indicated that the differences between the estimated and the measured values were mainly caused by the differences in the degree of their fluctuations. 5) The MSE decomposition showed that the BMENN method performed better than the other 2 approaches in reproducing the magnitude and degree of fluctuation observed in soil moisture and nutrients. 6) The soil spatial distribution maps generated by the BMENN approach had more continuous changes with a little less fragmentized polygons than those by the BNN and OK methods. The BMENN approach could more accurately express the regionalization characteristics of soil moisture and nutrients. In summary, the BMENN is a better prediction method than the OK and BNN, and the stronger the spatial autocorrelation of soil variable, the higher its prediction accuracy. The BMENN approach has great significance in improving the accuracy of soil spatial mapping based on limited soil data, and may provide the scientific evidence for the application of the soil management, precision agriculture and regional environment planning. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Soil surveys
Controlled terms:Agriculture - Agronomy - Bayesian networks - Calibration - Correlation methods - Errors - Forecasting - Interpolation - Location - Maximum entropy methods - Mean square error - Moisture - Neural networks - Nutrients - Soil moisture - Soils - Spatial distribution - Spatial variables measurement - Uncertainty analysis
Uncontrolled terms:Bayesian maximum entropies - Bayesian maximum entropy methods - Bayesian neural networks - Distribution characteristics - Pearson correlation coefficients - Spatial autocorrelations - Spatial characteristics - Spatial distribution map
Classification code:483.1 Soils and Soil Mechanics - 716.1 Information Theory and Signal Processing - 723.4 Artificial Intelligence - 801.4 Physical Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 921 Mathematics - 922.1 Probability Theory - 922.2 Mathematical Statistics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 943.2 Mechanical Variables Measurements - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.11975/j.issn.1002-6819.2015.16.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 33>
Accession number:20153601250926
Title:Improvement of export coefficient model for N and P based on rainfall intensity and its application
Authors:Xu, Lihong (1); Chen, Chengguang (2); Hu, Baowei (3); Xing, Bo (1); Ye, Lujie (1)
Author affiliation:(1) Shaoxing Environmental Monitoring Center, Shaoxing, China; (2) Department of Life Sciences for Shaoxing University Yuanpei College, Shaoxing, China; (3) Shaoxing University, Shaoxing, China
Corresponding author:Hu, Baowei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:159-166
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the output loads of TN (total nitrogen) and TP (total phosphorus) from agricultural non-point sources in Cao'e River basin in Shaoxing, an improved export coefficient model for TN and TP was firstly established. According to the theory of black box, the TN and TP from rainfall and agricultural pollution sources were respectively integrated to the total amount of pollutant in this model, and the output intensity of TN and TP in the transportation process was taken into account for the pollutant producing coefficient for the basin, which reflected the effects on the output of TN and TP due to the various losses during the process of rainfall runoff and pollutant transport. After that, the total output loads of TN and TP from agricultural non-point sources during 2005-2010 were estimated using this improved export coefficient model, in which the basic data were obtained from Shaoxing Statistical Yearbook. When the values predicated by the model were compared with those measured by the experiments, the authors found that the total output loads of TN and TP from agricultural non-point sources during 2005-2010 were greatly influenced by rainfall. The total output loads of TN and TP had a positive exponential relationship with the annual rainfall intensity, and therefore a new improved export coefficient model for TN and TP based on rainfall intensity was also established. Finally, this new model was applied to estimate the output loads of TN and TP from various agricultural pollution sources in Cao'e River basin. The estimation results showed that the total output loads of TN were annually far greater than that of TP from agricultural non-point sources during 2005-2010, and the maximum was up to 20.67 times, but with the influence of annual rainfall intensity, they presented uneven temporal distribution during 2005-2010, and the annual total output loads of TN ranged from 5456.60 to 12268.38 t and those of TP ranged from 393.19 to 820.65 t. In those years, when the rainfall intensity was small, the total output loads of TN and TP were both relatively low, and the contributions of rainfall to output loads of TN were up to 54.75%-69.67%, indicating that rainfall had become a key pollution source for TN output in Cao'e River basin. In addition, the results also showed that the order for the contributions of various agricultural pollution sources to output loads of TN from high to low was as follows: rural residents, livestock and poultry, and agricultural land. As a result of shortage of environmental infrastructure in rural area, deficiency of life sewage collection pipe, discharging the polluted water into river directly, and letting off waste randomly, rural life became primary agricultural pollution source to the output of TN in Cao'e River basin. However, the contributions of various agricultural pollution sources to output loads of TP decreased in the order of livestock and poultry, rural residents and agricultural land, and the contributions to output loads of TP from livestock and poultry (44.75%-55.74%) were significantly greater than that from rural residents in Cao'e River basin, showing that the problem of fecal pollution should be paid enough attention with the rapid development of livestock and poultry breeding industry. In comparison, the contributions to output loads of TN and TP from agricultural land were smaller, but the output loads of TN and TP from cultivated land were annually greater than that from garden plot and forest land. Therefore, it was necessary to further control the excessive fertilization in agricultural land to reduce the loss of nitrogen and phosphorus. The improved export coefficient model for TN and TP in this paper had certain applicability in Zhejiang area, however, in order to further improve the accuracy of the model, it was still necessary to strengthen the monitoring of regional rainfall runoff and the study on the uncertainty of model parameters in the future. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:River pollution
Controlled terms:Agricultural runoff - Agriculture - Models - Nitrogen - Phosphorus - Pollution - Rain - Rivers - Runoff - Rural areas - Sewage - Water pollution - Watersheds
Uncontrolled terms:Agricultural pollution - Annual rainfall - Export coefficient models - Loss of nitrogen and phosphorus - Pollutant producing coefficient - River basins - Temporal distribution - Transportation process
Classification code:443.3 Precipitation - 444.1 Surface Water - 453 Water Pollution - 453.1 Water Pollution Sources - 454.2 Environmental Impact and Protection - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 902.1 Engineering Graphics
DOI:10.11975/j.issn.1002-6819.2015.16.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 34>
Accession number:20153601250941
Title:Rheological model for swida wilsoniana fruits in process of cold pressing based on stress-relaxation tests
Authors:Liu, Rukuan (1); Xiao, Zhihong (1); Zhang, Aihua (1); Li, Peiwang (1); Zhang, Liangbo (1); Li, Hui (1); Li, Changzhu (1)
Author affiliation:(1) Institute of Bioenergy, Hunan Academy of Forestry, Changsha, China; (2) College of Chemistry & Chemical Engineering, Central South University, Changsha, China; (3) Hunan Engineering Research Centre for Biodiesel, Changsha, China
Corresponding author:Li, Changzhu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:278-283
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Swida wilsoniana is one of the important woody oil plants supported by the State Council, mainly distributed in Hunan, Guizhou and Jiangxi Province, of which the whole fruits contain about 30% oils with high nutritional value. Mechanical pressing and solvent extraction are 2 major ways for fruit oil, and the lack of equipment for Swida wilsoniana fruits with the characteristics of hard core make it imperative to carry out this work. In order to study the rheological property of Swida wilsoniana fruits in cold pressing process, the stress relaxation tests under different loading strain levels were carried out by using the self-made straight cylinder pressing device. Based on the basic model of rock rheology, the relationship between the stress and strain was simulated, and its rheological model was established. The results showed that the relationship of stress and strain in the loading process of Swida wilsoniana fruits was divided into 2 parts which were defined as linear period and nonlinear period, and the critical yield strain was 0.4, meaning that the relationship between stress and strain was linear when the strain level was lower than 0.4 and was nonlinear as strain level was higher than 0.4. The amount of stress relaxation rose with the increase of pressing strain level, especially as the strain level was higher than 0.5, due to the oil bursting out of oilseeds, and the higher strain levels, the greater amount of oil, and the greater amount of stress relaxation. Segmented simulation was used to analyze and determine the parameters of the model. Firstly, the Maxwell model generalized by elastic element and damper mode was used to simulate the linear relaxation process. Then linear mode and the Kawakita's superposition model jointly simulated the process of nonlinear relaxation. Finally the rheological model was established and the parameters were obtained. Error analysis showed the application range and simulation effect. The relative error was large when the strain was 0.5 due to the rupture occurring in the period of loading, and the average relative errors were less than 7% when the strains were larger than 0.55, which could provide basic data of stress and strain parameters for squeezing process and special equipment. However, pressing pressure was only one of the pressing factors which would affect the pressing effect for Swida wilsoniana fruits. Other factors such as form of oilseeds, composition of main contents, pressing speed and temperature were also important factors influencing squeezing effect. Morphological change of Swida wilsoniana fruits was just a reflection for pressing, which had some limitations. The main evaluation index for pressing effect was the oil yield rate or residual oil of cake. So establishing the relationship between stress, strain and residual oil was an important direction of research. Therefore, a comprehensive analysis of the impact of various factors should be considered to establish an appropriate system for oilseed processing conditions, and to realize a cold and effective pressing technique for oil Swida wilsoniana fruits. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Strain
Controlled terms:Elasticity - Errors - Fruits - Models - Nonlinear analysis - Oilseeds - Relaxation processes - Solvent extraction - Stress analysis - Stress relaxation - Stress-strain curves - Testing
Uncontrolled terms:Average relative error - Cold pressing - Comprehensive analysis - Morphological changes - Oil and fats - Rheological modeling - Rheological property - Stress relaxation tests
Classification code:421 Strength of Building Materials; Mechanical Properties - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 731 Automatic Control Principles and Applications - 802.3 Chemical Operations - 821.4 Agricultural Products - 902.1 Engineering Graphics - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 35>
Accession number:20153601250918
Title:Modeling and analysis of electromagnetic force approximate model of high-speed solenoid valve
Authors:Liu, Peng (1); Fan, Liyun (1); Bai, Yun (1); Ma, Xiuzhen (1); Song, Enzhe (1)
Author affiliation:(1) College of Power and Energy Engineering, Harbin Engineering University, Harbin, China
Corresponding author:Fan, Liyun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:96-101
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:High-speed solenoid valve (HSV) is the key component of electronic control fuel injection system for diesel engine. Improving the dynamic response speed of HSV will be able to achieve higher injection precision and more flexible fuel injection law, thus reducing gas emissions of diesel engine and improving its fuel economy. However, HSV is the complex coupling system of electric field, magnetic field, mechanical movement and flow field, and the interactions of multiple parameters exist between the fields for HSV. To improve the dynamic response speed of HSV is a complex optimization problem of multiple physical field and multiple parameters. A zero-dimensional approximation coupling model of HSV can be developed instead of the CAE (computer aided engineering) models or physical experiments, which conduces to achieve the efficient prediction and global optimization of performances. So the approximation model method was employed in this paper. First, the structure and principle of HSV for electronic unit pump of diesel engine were presented. Second, the three-dimensional (3D) finite element model of HSV was developed to calculate the electromagnetic force, and its accuracy was verified by means of the comparison with experimental data. Third, 3 major methods of experimental design, i.e. central composite faced-centered design (CCF), central composite inscribed design (CCI) and optimal latin hypercube design (OLH), and 3 typical approximation methods, i.e. quadratic polynomial response surface model (RSM), Kriging model (KR) and radial basis function model (RBF) were introduced. Fourth, 6 key parameters including 2 field coupling parameters, i.e. working air gap and drive current, and 4 structure parameters, i.e. coil turns, side pole radius, thickness and radius of armature were determined for establishing the approximate models. Next, 6 groups of sample points were designed, whose response values of electromagnetic forces were obtained by the 3D finite element model of HSV. Four of the groups were designed with different sizes by the OLH, and the other 2 groups were designed by the CCF and CCI. Then, 18 groups of electromagnetic force approximation models were developed by combining the 6 groups of experimental design with the 3 typical approximation methods introduced. To compare the accuracy of approximation models, 3 kinds of evaluation indices were introduced. They were multiple correlation coefficient, average absolute error and root mean square error respectively. In the end, the effects of different sample point sizes, experimental design methods and approximate methods on the accuracy of electromagnetic force approximation models were analyzed in detail. It is concluded that the accuracy of approximate model doesn't increase monotonically with the increase of the set size of sample points, and too many sample points maybe leads to the decrease of the accuracy of approximate model; the OLH has good adaptability with the KR and RBF, and can be given priority for developing approximation models. In addition, the best solution for establishing electromagnetic force approximation model of HSV is the combination of the KR and OLH, whose size of sample points is 1.5 times of the minimum sample points required by the quadratic polynomial response surface model. Its multiple correlation coefficient, average absolute error and root mean square error are 0.97, 0.06 and 0.09 respectively. It provides a theoretical guidance for the establishment of the zero-dimensional approximation coupling model and the optimization of HSV. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Structural design
Controlled terms:Approximation theory - Computer aided engineering - Design - Design of experiments - Diesel engines - Digital storage - Dynamic response - Dynamics - Electric fields - Engines - Errors - Exhaust systems (engine) - Finite element method - Fuel economy - Fuel injection - Fuels - Gas emissions - Global optimization - Mean square error - Models - Optimization - Polynomial approximation - Polynomials - Radial basis function networks - Solenoid valves - Solenoids - Speed - Statistics - Surface properties - Valves (mechanical)
Uncontrolled terms:Complex optimization problems - Electromagnetic forces - Experimental design method - High-speed solenoid valve - Multiple correlation coefficients - Optimal latin hypercube designs - Radial basis function models - Three-dimensional (3D) finite element models
Classification code:408.1 Structural Design, General - 451.1 Air Pollution Sources - 521 Fuel Combustion and Flame Research - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 612 Engines - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 701.1 Electricity: Basic Concepts and Phenomena - 704.1 Electric Components - 722.1 Data Storage, Equipment and Techniques - 723.4 Artificial Intelligence - 723.5 Computer Applications - 901.3 Engineering Research - 902.1 Engineering Graphics - 921 Mathematics - 922.2 Mathematical Statistics - 931.1 Mechanics - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2015.16.014
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 36>
Accession number:20153601250942
Title:Effects of transportation time and temperature on pig stresses and pork quality
Authors:Tian, Hanyou (1); Zou, Hao (1); Liu, Fei (1); Wang, Hui (1); Li, Jiapeng (1); Chen, Wenhua (1); Qiao, Xiaoling (1)
Author affiliation:(1) China Meat Research Center, Beijing, China
Corresponding author:Qiao, Xiaoling
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:284-288
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Because of the pig stress, 20 000 tons of PSE (pale soft exudative) and DFD (dark firm dry) meat were engendered in Beijing every year. Transportation time and temperature were studied, since other factors which caused pig stress made no difference in Beijing. In order to investigate the effects of different transportation time (0, 3, 6, 9 h) and temperature (-10-0, 0-10, 10-20, 20-30) on pig stress and pork quality, a total of 84 Duroc × Landrace Large × White barrows were transported to the same abattoir, and the barrows had been raised up to (104±4) kg by the same person. The transportation speed was 60-70 km/h and the transportation density was 2.2 pigs per square meter. The pigs were transported without stops. During loading and unloading, in the farm and at the abattoir the pigs were gently handled, and no whips and electric prods were used. No food was available while the water was continually available during the transportation. The pigs were stunned electrically with 125 V on head and 75 V on heart. The blood constituents were used as the indicators of pig stress, and the pork quality traits including the pH values 45 min and 24 h after slaughter and the pork color grade were measured in this study. The results showed that the alanine aminotransferase (ALT) in blood plasma after 6 h transportation increased significantly (P<0.05) compared to that after zero and 3 h transportation, which meant the pigs presented stress reaction after 6 h transportation, and the ALT, aspartate transaminase (AST), lactate dehydrogenase (LDH), cortisol (COR) after 9 h transportation increased significantly (P<0.05) compared to those after zero, 3 and 6 h transportation, which meant the stress was significantly stronger after 9 h transportation. The pork pH values 45 min after slaughter through 6 and 9 h transportation were significantly lower than those after 3 h transportation (P<0.05). In the same time, the pork color grades (above 4) were significantly higher than those after 3 h transportation (P<0.05) which caused the pork quality to decrease. Pigs presented stress reaction when they were transported at the temperature of under 10 since the AST and alkaline phosphatase (ALP) increased significantly (P<0.05), and the stress was significantly stronger when they were transported at the temperature of under 0 since the creatine kinase (CK), LDH and COR increased significantly (P<0.05) compared to the other conditions. The pork pH values 24 h after slaughter at the transportation temperature of -10-0 and 20-30 were significantly higher (P<0.05) than those at 0-10 and 10-20 which caused the pork quality to decrease. The research identified that the pigs in Beijing should be transported within 6 h and at 10-20 in order to reduce the impact of stress and improve pork quality. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Transportation
Controlled terms:Alkalinity - Amino acids - Blood - Mammals - Meats - pH - Phosphatases - Quality control - Stresses - Unloading
Uncontrolled terms:Alanine aminotransferase - ALkaline phosphatase - Blood parameters - Lactate dehydrogenase - Loading and unloading - Pig - Stress reaction - Transportation time
Classification code:421 Strength of Building Materials; Mechanical Properties - 431 Air Transportation - 432 Highway Transportation - 433 Railroad Transportation - 434 Waterway Transportation - 461 Bioengineering and Biology - 461.2 Biological Materials and Tissue Engineering - 674.1 Small Marine Craft - 801.1 Chemistry, General - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822.3 Food Products - 913.3 Quality Assurance and Control
DOI:10.11975/j.issn.1002-6819.2015.16.038
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 37>
Accession number:20153601250930
Title:Comparison on linear feature real width and interpretation width using Landsat TM8 images and GF-1 images
Authors:Xin, Rui (1); Lu, Zhongjun (1); Liu, Yang (1); Fu, Bin (1); Liu, Kebao (1)
Author affiliation:(1) The Remote Sensing Technology Center of Heilongjiang Academy of Agricultural Sciences, Harbin, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:196-205
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Linear feature general exist in the nature and RS images as a type of land use. Linear feature's image feature is long and narrow object on the RS images, and it is visibility to the human eyes. On the other hand, a large number of linear feature hide in the mixed pixel in the RS images for their relative invisibility. In the surface feature interpretation, linear feature always includes to the surface feature to enlarge the achievement for the limited resolution. So, accurate linear feature interpretation can supply the surface feature result from deduction technology. Landsat TM8 image and GF-1 image have been extensively applied in different trade for their high quality and high resolution in several years, so as to agricultural RS field. In the crop area estimation, the accuracy of linear features extraction in Landsat TM8 image and GF-1 image can impact on the crop area estimation accuracy directly. So, the study of linear feature real width and interpretation width has a great significance for the crop area and yield estimation. GF-1 image has obvious advantage in linear feature interpretation for the higher resolution. Research areas were selected in Heilongjiang province, involving 56 counties and cities. The field investigation time was Sep 22-28, 2013, and 341 linear features were einvestigated. The a certain number of linear features in field investigation was selected in random, then recorded the width with the tape, at the same time, use the Trimbes GPS positioning. Preliminary statistics the result of the Heilongjiang Province linear feature field investigation in 2013, then classification the linear feature with trend, type, real width. There are 3 catalogs and 13 type, including south-north trend, east-west trend, northeast-southwest trend, northwest-southeast trend, highway, field road, forest belt, ditch, 0-10 m, 10-20 m, 20-30 m, 30-40 m, >40 m and so on. 23 Landsat TM8 images and 14 GF-1 images were selected for the linear feature interpretation, imaging time concentrated in Jul 11, 2013-Sep 18, 2013. The primary compression package of the Landsat TM8 image's the fifth band TIFF file, the sixth band TIFF file, the forth band TIFF file were selected for layer stack, and then resampling the layer stack result to Albers conical projection, Krasovsky ellipsoid, Pulkovo 1942 coordinate system file. The.img file's named way is <satellite name and number>_<orbit number>_<imaging time>_<projection>.img. The.img file's band combination is R: 1, G: 2, B: 3. The primary compression package of the GF-1 image's TIFF image was handled to receive the.img file with Albers conical projection, Krasovsky ellipsoid, Pulkovo 1942 coordinate system file. The.img file's named way is < satellite name and number >_<sensor>_<center point longitude>_< center point latitude>_< imaging time >_< projection >.img. The.img file's band combination is R:4, G:3, B:2. The study compared the 341 linear features' real width and interpretation width though statistics method in Heilongjiang province using 23 Landsat TM8 images and 14 GF-1 images. The results showed that all the trends linear feature's real width and interpretation width had a large standard deviation, and coefficient of variation of GF-1 images interpretation width's standard deviation and coefficient of variation were smaller than the Landsat TM8 images interpretation width's. According to the classification of linear feature type, highway and ditch's standard deviation and coefficient of variation had a vary widely to the field way and forest belt's, and GF-1 images interpretation width's standard deviation and coefficient of variation were smaller than the Landsat TM8 images interpretation width's. According to the classification of real width, because all the sample values are in the same interval, all the types had a small standard deviation and coefficient of variation except real width >40 m, and GF-1 images interpretation width's standard deviation and coefficient of variation were smaller than the Landsat TM8 images interpretation width's. It means that RS satellite image's resolution determined the linear feature interpretation precision. 94 linear features had low interpretation precision with Landsat TM8 images interpretation (the absolute value of the exaggeration more than 50%), for 27.5660% of the entire linear feature, and in this part, interpretation width always larger than real width, and the category of 0-10 m had a worst interpretation precision, the category of trend and type had no influence to the linear feature interpretation accuracy. 29 linear features had low interpretation precision with GF-1 images interpretation, for 8.5044% of the entire linear feature, and in this part, interpretation width always much greater than real width. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Classification (of information)
Controlled terms:Crops - Forestry - Image recognition - Land use - Orbits - Remote sensing - Satellites - Statistics - Transportation
Uncontrolled terms:Coefficient of variation - Crop area estimations - Exaggeration - Images interpretation - Interpretation width - Linear feature - Precision - Primary compressions
Classification code:403 Urban and Regional Planning and Development - 431 Air Transportation - 432 Highway Transportation - 433 Railroad Transportation - 434 Waterway Transportation - 655.2 Satellites - 716 Telecommunication; Radar, Radio and Television - 716.1 Information Theory and Signal Processing - 731.1 Control Systems - 821.0 Woodlands and Forestry - 821.4 Agricultural Products - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2015.16.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 38>
Accession number:20153601250912
Title:Optimization design of performance test of cyclone separator sand sampler based on numerical simulation and wind erosion tunnel experiment
Authors:Huang, Yan (1); Zhao, Manquan (1)
Author affiliation:(1) College of Mechanical and Electrical Engineering of Inner Mongolia Agricultural University, Hohhot, China; (2) College of Mechanical Engineering and Applied Electronics Technology of Beijing University of Technology, Beijing, China
Corresponding author:Zhao, Manquan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:50-56
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For the purpose of knowing the motion law of sand erosion and improving the efficiency of cyclone separation sand sampler, the finite element model of cyclone separation sand sampler is built by using the software of Fluent. There is a two-phase movement inside the cyclone separation sand sampler, including air and soil particles. The cyclone separation sand sampler mainly separates the soil particles from the air. Since the concentration of the soil particles is not too high, its movement inside the sand sampler depends largely on the gas phase (air) movement, and a majority of the particles flow with the air. Due to the above-mentioned reasons, it is necessary to make further analysis on the air flow inside the cyclone separation sand sampler. Boundary conditions are of great importance to the simulation of the gas flow inside the cyclone separation sand sampler, and the gas phase has been simplified: the gas in the sand sampler is air, with a density of 1.225 kg/m<sup>3</sup> and a viscosity of 18.1×10<sup>-6</sup>; it is treated as incompressible gas, and its flow is treated as in steady state; the exit is set for free outflow; the wall surface is set as no skidding and no moving surface; the 2 surfaces overlapped by the ascension pipe and the barrel of the sand sampler are set respectively as Interface for data exchange; the upper part of the sand sampler and the sandbox are sealed well, without gas flowing out; the straight pipe connecting the cone-shaped part and the sandbox is 10 mm long; the hydraulic diameter is 0.015 mm, the Reynolds number is 1.02×10<sup>4</sup> and the turbulent intensity is 5.1%. Based on the RNG k-Ε model and the Reynolds stress model, numerical analysis is carried out for the cyclone separation sand sampler. Besides, some wind tunnel tests are made for 3 cyclone separation sand samplers with different structure parameters. The internal motion law of the gas phase is found through the finite element analysis; current field intensity near the gas exit tube of the sand sampler is stronger and the "shunting flow" exist inside. At the same time, by the numerical simulation of 3 cyclone separation sand samplers with different structure parameters, the results show that the sand sampler with cylinder diameter of 50 mm, and cone height of 125 mm has the smaller turbulent kinetic energy 0.99 m<sup>2</sup>/s<sup>2</sup> and the maximum upward axial velocity 1.48 m/s in sandbox bottom. In addition, the wind tunnel test is done with 3 different structural parameters of the cyclone separation sand sampler, and the experimental results show the turbulent kinetic energy of sandbox bottom which has certain impact on the trapping efficiency is changed with cylinder diameter and cone segment height. Compared to cylinder diameter, cone segment height has greater influence on the efficiency of the cyclone separation sand sampler. The cyclone separation sand sampler has better separation performance and higher trapping efficiency when the turbulent kinetic energy and the upward axial velocity of sandbox bottom are lesser. Through numerical simulation and wind tunnel test, the objective function is determined by the turbulent kinetic energy and the upwards axial velocity of the bottom of sandbox. The length of the straight tube of sandbox is optimally designed through the objective function. The efficiency of cyclone separation sand sampler can be improved while the straight pipe of sandbox is 16 mm. The results can provide the basis for further enhancing the performance of cyclone separation sand sampler. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Finite element method
Controlled terms:Air - Computational fluid dynamics - Cyclone separators - Cylinders (shapes) - Efficiency - Electronic data interchange - Energy efficiency - Erosion - Flow of gases - Gases - Importance sampling - Interface states - Ionization of gases - Kinetic energy - Kinetics - Numerical models - Optimization - Phase interfaces - Reynolds equation - Reynolds number - Sand - Separators - Soils - Turbulent flow - Wind stress - Wind tunnels
Uncontrolled terms:Objective functions - Reynolds stress models - Separation performance - Structural parameter - Trapping efficiencies - Turbulent intensities - Turbulent kinetic energy - Wind tunnel tests
Classification code:402 Buildings and Towers - 407 Maritime and Port Structures; Rivers and Other Waterways - 408.2 Structural Members and Shapes - 421 Strength of Building Materials; Mechanical Properties - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 525.2 Energy Conservation - 631.1 Fluid Flow, General - 631.1.2 Gas Dynamics - 651.2 Wind Tunnels - 723.2 Data Processing and Image Processing - 802.1 Chemical Plants and Equipment - 804 Chemical Products Generally - 913.1 Production Engineering - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 932 High Energy Physics; Nuclear Physics; Plasma Physics
DOI:10.11975/j.issn.1002-6819.2015.16.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 39>
Accession number:20153601250936
Title:Effect of land use/landscape changes on diffuse pollution load from watershed based on SWAT model
Authors:Geng, Runzhe (1); Li, Mingtao (1); Wang, Xiaoyan (1); Pang, Shujiang (1)
Author affiliation:(1) College of Resource Environment and Tourism, Capital Normal University, Beijing, China; (2) Policy Research Center for Environment and Economy, Ministry of Environmental Protection, Beijing, China; (3) School of Urban Economics and Tourism Culture, Lanzhou City University, Lanzhou, China
Corresponding author:Wang, Xiaoyan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:241-250
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The loss of nitrogen and phosphorus via non-point source (NPS) pollution in the Chaobai river watershed has become the main pollution sources of river waters in the Miyun reservoir area in the past decades. Climatic conditions and human activities directly affect changes of runoff. In addition, land use types are closely related to NPS pollution. Climate change and human activities can potentially lead to changes in runoff and can significantly impact the regional hydrology and future availability of water resources. Researches showed that NPS pollution has become an important source affecting the quality of the Miyun reservoir water environment. Therefore, exploring the impact of land use change on NPS pollution under different climate scenarios has important practical implications for control non-point source pollution in this area. In this study, Miyun reservoir watershed was used as a study area to determine the response of non-point source pollution to land use change under different climate scenarios. An integrated model system was developed which included three parts, the Soil and Water Assessment Tool (SWAT) as the hydrological and non-point source pollution estimator; the Canonical Correspondence Analysis (CCA), and Path Analysis to explore the relationship between land use change and non-point source pollution loads. The statistical downscaling model was conducted to generate the different climate scenarios for discussing the impact on hydrological process and non-point source pollution losses. The results showed that SWAT model was suitable for the study area. Total nitrogen (TN) and total phosphorus (TP) loads decreased with the rainfall during 1995 to 2005, indicating that the rainfall was an important factor on the temporal variability of pollution loads. The spatial distribution of TN and TP loads were significantly affected by the comprehensive influence of rainfall and land use. The high-risk areas were mainly located in Chicheng, Chongli, and Fengning county. There was a significant correlation (P<0.05) between NPS pollution loads and landscape characteristics in the upper watershed of Miyun reservoir. Correspondence Analysis (CCA) and Path Analysis indicated that landscape variables can explain 56.3% variation of TN and TP loads. For landscape level, the fragmentation metrics, and shape metrics were the main pattern indices effectively affecting the variation of nutrient losses. For patch-class level, landscape metrics that affected the spatial variation of pollution process varied with land use types. The result of path analysis suggested that the proportion of arable land and forest land area, patch density, and shape index were the main pattern indices effectively affecting the nutrient pollution process. The interpretation capacity of proportion of arable land and shape index to TN and TP loads was greater than the other indicators. The relationship was closely associated with the spatial scale. With the spatial scales increased, the interpretation capacity of landscape variables reduced. Cumulative variances of the first grade protection zones are the highest in CCA ordination analysis, which reached 62.9%, indicating that the area around the reservoir area should be highly valued for the prevention and treatment of NPS pollution. As a result of this work, prioritized areas and the relationship between nutrients load and land use pattern can be used as information for implementation of conservation practices in the Miyun reservoir watershed. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:River pollution
Controlled terms:Agriculture - Climate change - Climate models - Forestry - Land use - Nitrogen - Nutrients - Phosphorus - Pollution - Pollution control - Rain - Regression analysis - Reservoirs (water) - Runoff - Water pollution - Water resources - Watersheds
Uncontrolled terms:Canonical Correspondence Analysis - Integrated modeling system - Landscape characteristic - Loss of nitrogen and phosphorus - Miyun Reservoir - Non-point source pollution - Soil and water assessment tool - SWAT model
Classification code:403 Urban and Regional Planning and Development - 441.2 Reservoirs - 443 Meteorology - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 451 Air Pollution - 453 Water Pollution - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2015.16.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 40>
Accession number:20153601250907
Title:Effects of precision rice hill-drop drilling on rice quality
Authors:Wang, Zaiman (1); Luo, Xiwen (1); Chen, Xiongfei (1); Mo, Zhaowen (3)
Author affiliation:(1) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China; (2) Synergistic Innovation Center of Modern Agricultural Equipment and Technology, Jiangsu University, Zhenjiang, China; (3) College of Agriculture, South China Agricultural University, Guangzhou, China
Corresponding author:Luo, Xiwen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:16-21
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Grain qualities including milling, appearance, cooking and nutritional quality, are important traits that have aroused rice researchers' attention worldwide. Head rice rate, an important milling quality together with grain yield affects head rice yield. The head rice yield is directly related to economic value of the grains, and has significant impacts on income of rice producers. Precision rice hill-drop drilling is a simplified technique, which can achieve high yield while is applied at appropriate rice growth regions. The precision rice hill-drop drilling technique has been applied in many rice growth regions in China. Previously, precision rice hill-drop drilling technique has been proven to influence rice yield, agronomic performances and grain qualities in small region only and assessing the effect of precision rice hill-drop drilling technique on grain qualities in national wide is therefore important. In order to investigate the influence of precision rice hill-drop drilling technique on grain qualities in multiple rice growth regions in China, the comparison experiment were carried out. In this study, comparisons of the grain qualities between precision rice hill-drop drilling and machanical transplanting were investigated in the mainly planting areas (viz: Anhui, Shanghai, Guangdong, Sichuan, Xinjiang and Shandong) of precision rice hill-drop drilling in China. Results showed that precision rice hill-drop drilling technique was beneficial to improve head rice yield. Rice by using precision rice hill-drop drilling had higher head rice yield than that by using machanical transplanting in Nanling Anhui, Mianzhu Sichuan, Wensu Xinjiang, and Gaoqing Shandong regions, which increased by 9.11%, 27.02%, 4.08%, and 11.11% significantly. Moreover, the effects of precision rice hill-drop drilling technique on protein content and amylose content in grains from different investigated regions were different because of the difference in cultivars and environmental conditions, and the decrease in protein content and amylose content in grains were detected for some investigated regions. Furthermore, precision rice hill-drop drilling technique significantly decreased chalky rice rate in grains in Gaoqing Shandong, while showed no significant effect on appearance qualities of grains for other investigated regions. This study have investigated the impact of precision rice hill-drop drilling technique on grain quality of the rice varieties planted in large areas of the rice planting regions in China, this work is beneficial to further promotion to the popularization and application of precision rice hill-drop drilling technique in appropriate areas. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Grain (agricultural product)
Controlled terms:Agricultural machinery - Crops - Cyclodextrins - Drilling platforms - Drops - Economic analysis - Grain growth - Mechanization - Milling (machining) - Plants (botany) - Proteins - Thermal processing (foods) - Transplants
Uncontrolled terms:Appearance qualities - Drilling techniques - Environmental conditions - Mechanical transplanting - Nutritional qualities - Protein contents - Rice - Rice qualities
Classification code:443.1 Atmospheric Properties - 461.9 Biology - 462.4 Prosthetics - 511.2 Oil Field Equipment - 601 Mechanical Design - 604.2 Machining Operations - 804.1 Organic Compounds - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 822.2 Food Processing Operations - 911.2 Industrial Economics - 933.1.2 Crystal Growth
DOI:10.11975/j.issn.1002-6819.2015.16.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
<RECORD 41>
Accession number:20153601250923
Title:Evaluation level construction and analysis of risk on rice flood in Southwest China
Authors:Yang, Jianying (1); Huo, Zhiguo (1); Wu, Li (1); Zhang, Guixiang (1); Wang, Tianying (1)
Author affiliation:(1) Chinese Academy of Meteorological Sciences, Beijing, China; (2) Collaborative Innovation Center of Meteorological Disaster Forecast, Early-Warning and Assessment, Nanjing University of Information Science & Technology, Nanjing, China
Corresponding author:Huo, Zhiguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:16
Issue date:August 15, 2015
Publication year:2015
Pages:135-144
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Increasing of extreme precipitation has been witnessed in Southwest China in the past several decades. The frequent occurrence of extreme weather has aggravated the formation of regional flood hazards in this region. As the main crop in Southwest China, rice is generally considered to be seriously threatened by flood. Nowadays, researches on rice flood however cannot be connected with disastrous weather effectively, which has brought great difficulties for rice flood monitoring accurately and timely. Therefore, it is of great importance to establish the evaluation level of rice flood based on the metrological method so as to provide a technical support for rice flood monitoring, prevention and mitigation, and agricultural disasters' insurance management. Given above background, based on a data set of daily precipitation from 1961 to 2012 in 193 meteorological stations, associated with historical disaster and phenophase data of rice in Southwest China (Sichuan, Chongqing, Guizhou and Yunnan), the evaluation of the flood related to single cropping rice based on the metrological method was conducted in this study, and meanwhile, the rice flood risk was consequently estimated according to the rice flood evaluation indicators, in order to gain detailed information of the characteristics of rice flood disaster in Southwest China. Historical rice flood disasters were represented through the coupling with precipitation data. Afterwards, 27 rainfall sets of rice flood samples were built in the context of the combinations of different growth stages (transplanting-tillering, jointing-booting and tasselling-maturity), flood levels (light, moderate and heavy) and precipitation duration days (1 d, 2 d, ≥3 d). Kolmogorov-Smirnov (K-S) method was used in the distribution fitting of the rainfall sets, and 27 normal distribution functions were established. Each indicator of rice flood evaluation level (light, medium and heavy) was built using the statistical analysis, with the lower limit of 95% confidence interval as the critical threshold. The evaluation level of rice flood disaster has been validated by the reserved independent samples of rice flood. According to the rice flood indicators, the risk index of rice flood disaster was calculated based on the data in 193 metrological stations in Southwest China. The results were as follows: rice flood disaster caused by the rainfall was more intense in tasseling-mature stage, followed by the jointing-booting stage and transplanting-tillering stage. The precipitation threshold of rice flood in transplanting-tillering stage was 120, 130 and 150 mm respectively for the flood disaster lasting for 1 d, 2 d and ≥3 d. It became 150, 160 and 180 mm for jointing-booting stage, and 170, 200 and 230 mm for tasselling-maturity stage respectively. The rice flood level indicator could better reflect the actual level of damage caused by flood disaster in rice planting and be used in monitoring and assessing disaster damage in regional scale. The identification results based on rice flood level indicator were detected to be basically consistent with the historical occurrence levels of rice flood disasters, with 66.7% assessment of flood levels being completely consistent with the historical records, and calculation errors of all validation samples being within one level. High flood risk existed in transplanting-tillering stage and furthermore, higher rice flood risk from transplanting to tillering stage was mainly concentrated in southern area of Yunnan Province and Liuzhi Special Zone, Guizhou Province with the rice flood index of more than 1.5. Flood risk decreased in Guizhou and the northeast area of Yunnan, while it increased in mid regions of Sichuan Province in jointing-booting stage, compared to the early growth stage of rice. Southern Yunnan and mid Sichuan were detected with higher rice flood risk in tasselling-maturity stage. Overall, high-risk areas of rice flood in whole rice growth stage included south and northeast areas of Yunnan, southern Guizhou, and Chengdu, Meishan and Deyang in Sichuan Province. The evaluation level of rice flood firstly established in this paper could be used in the future monitoring and evaluation of rice flood in South China. The results of rice flood risk analysis could provide basic evidence for the prevention and mitigation of rice flood. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Floods
Controlled terms:Balloons - Crops - Disaster prevention - Disasters - Distribution functions - Gages - Normal distribution - Precipitation (meteorology) - Rain - Risk analysis - Risk assessment - Risk perception
Uncontrolled terms:Agricultural disasters - Different growth stages - Flood disaster - Meteorological station - Monitoring and evaluations - Precipitation threshold - Single cropping rice - Southwest China
Classification code:443.2 Meteorological Instrumentation - 443.3 Precipitation - 821.4 Agricultural Products - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 914 Safety Engineering - 914.1 Accidents and Accident Prevention - 922 Statistical Methods - 922.1 Probability Theory - 943.3 Special Purpose Instruments
DOI:10.11975/j.issn.1002-6819.2015.16.019
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.Compendex references:YES
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
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- 电话 010－59197078/7077/7076
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- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
- 中华人民共和国农业农村部-MARA
- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
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