<RECORD 1>
Accession number:20161002077962
Title:Numerical simulation of hydraulic performance for portable short-throat flume in field based on FLOW-3D
Authors:Xiao, Yizhou (1); Wang, Wen'e (1); Hu, Xiaotao (1)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
Corresponding author:Wang, Wen'e(wangwene@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:55-61
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Improvement of water management can encourage conservation and make best use of our limited water resources. The measurement of flow rates is an important element of water management. Many devices and structure have been developed for the measuring discharge but measuring flume is one of the most accepted and used structure. According to the practical situation of irrigated areas in northern China, use of portable short-throat flume in field to measure the discharge of water inlet in the field is an emerging technique developed for water discharge measurement of inlet in the field, which contributes to control of irrigation water consumption and water conservation. Based on FLOW-3D software in this study, RNG k-Ε three-dimensional turbulence model, TruVOF technique and FAVOR (fractional area volume obstacle representation) method were employed to simulate three-dimension flow field in portable short-throat flume in field with a 51 mm width throat under 18 working conditions. Experimental results about portable short-throat flume in field were also obtained based on a new test to validate the simulation results. It verified discharge capacity of the flume. The parameter settings and boundary conditions used in the CFD models provided an efficient approach for simulation of the flow through portable short-throat flume in field. Combined with hydraulic experiments, hydraulic performance was obtained from simulation analyses on water surface profiles, Froude number, velocity distribution and head loss. Comparison between experiments and simulations showed that measured and simulated flow capacity, flow field and flow depth have a good consistency, and relative errors were less than 10%, and gave a solid agreement between experimental and numerical simulation results. Hence, it can be used to simulate flow state of portable short-throat flume in field effectively and visually. On the basis of reliable numerical simulated consequents, analyses of hydraulic performances in detail were carried out. The simulation results showed that both Froude number and velocity accelerated along the flume with free flow condition, and in submerged flow condition increased at first and then decreased. The cross-section of critical depth was located at throat section by Froude number analyses. The flow surface profile in throat section of portable short-throat flume in field was highly curvilinear in both free and submerged outflow working conditions as the flow accelerated from the subcritical regime to the supercritical regime. Equations of upstream depth versus discharge under free and submerged outflow working conditions were fitted by regression analyses, respectively. The maximum relative error between measured discharge and calculated discharge by equations was -5.63%, which met the requirements of water measurement for irrigation. Further, maximum head loss of portable short-throat flume with a flat base for the field accounted for 12.10% of total upstream head. Compared with long-throat flume, the head loss of portable short-throat flume in field was less. The three-dimensional turbulence model along with the TruVOF technique allowed one to reproduce the hydraulic characteristics of flow through portable short-throat flume in field. Due to shorter time demand and lower cost of numerical simulations compared to experimental studies in predicting the hydraulic characteristics, simulation of the portable short-throat flume in field flows based on a properly validated model provided the flow characteristics of these flumes for various flow configurations encountered in the field. This study provides a reference for flow-measurement of final stage of canal in irrigation areas in North China. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Computational fluid dynamics
Controlled terms:Buoyancy - Computer simulation - Discharge (fluid mechanics) - Flow fields - Flow measurement - Flow of fluids - Flow rate - Froude number - Irrigation - Numerical models - Regression analysis - Turbulence models - Velocity - Velocity distribution - Water conservation - Water management - Water resources - Water supply - Waterworks
Uncontrolled terms:Flow charac-teristics - Head loss - Hydraulic characteristic - Hydraulic performance - Maximum relative errors - Portable short-throat flume - Three dimension flow fields - Three-dimensional turbulence
Classification code:444 Water ResourcesWater Resources
- 446 WaterworksWaterworks
- 446.1 Water Supply SystemsWater Supply Systems
- 631 Fluid FlowFluid Flow
- 631.1 Fluid Flow, GeneralFluid Flow, General
- 723.5 Computer ApplicationsComputer Applications
- 821.3 Agricultural MethodsAgricultural Methods
- 921 MathematicsMathematics
- 922.2 Mathematical StatisticsMathematical Statistics
- 931.2 Physical Properties of Gases, Liquids and SolidsPhysical Properties of Gases, Liquids and Solids
DOI:10.11975/j.issn.1002-6819.2016.03.009
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 2>
Accession number:20161002077959
Title:Analysis and experimental verification of turbulence models in flow simulation for hydrodynamic coupling under braking condition
Authors:Chai, Bosen (1); Xiang, Yue (2); Ma, Wenxing (1); Yu, Chao (1); Kou, Zunquan (1)
Author affiliation:(1) College of Mechanical Science and Engineering, Jilin University, Changchun, China; (2) Jilin Province Product Quality Supervision Test Institute, Changchun, China
Corresponding author:Ma, Wenxing(mawx@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:34-40
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hydrodynamic coupling is used for power transmission in heavy duty drives, such as power stations, ship propulsion, band conveyers, mills, and larger transport vehicles. Their hydrodynamic principle enables a low-wear torque to convert from a drive to a load. The flow in a hydrodynamic coupling is one of the most complex problems encountered in engineering fluid mechanics. The external performance of hydrodynamic coupling is determined by its internal distribution of flow field. It is very important to make a deep research on the internal distribution of flow field for the performance improvement and structural optimization in the design of hydrodynamic coupling. Numerical simulation is a main way to study the internal flow field of hydrodynamic coupling. The results of numerical simulation that are calculated by different turbulence models are quite different. In order to obtain accurate and reliable results of numerical simulation, it is a key to choose a reasonable turbulence model. The integrated computer engineering and manufacturing (ICEM) software was used to mesh the whole flow channel model of hydrodynamic coupling by hexahedral grids, and the total mesh number was 470 944 and the number of nodes was 521 887. Numerical simulation of three-dimensional unsteady turbulent flows in hydrodynamic coupling was carried out by numerically solving the Navier-Stokes equations in a rotating coordinate system. In order to analyze the applicability of different turbulence models in the calculation of flow field in hydrodynamic coupling, 3 different turbulence models (standard k-Ε model, detached eddy simulation model, large eddy simulation model) were chosen to simulate the internal flow field of square cavity hydrodynamic coupling under braking condition. The quantity and quality of mesh was consistent during the numerical simulation of different turbulence models. The velocity field and vorticity field of radial section in hydrodynamic coupling were simulated and extracted through ANSYS CFX software. In addition, the transparent prototype of hydrodynamic coupling was manufactured and used in the complex flow test experiment, the internal flow field of hydrodynamic coupling under braking condition was tested based on particle image velocimetry (PIV), the characteristics of flow images were extracted by image processing technique, and the velocity field and vorticity field of radial cross-section were calculated by image cross correlation algorithm. Then numerical simulation and PIV experimental results were compared. The PIV test results were used as the evaluation criteria, and the differences of numerical simulation results by 3 kinds of turbulence models were analyzed. Moreover, the applicability of 3 turbulence models was analyzed. The results showed that the simulation results by standard k-Ε model were far different from PIV experimental results, the distribution of flow field in main flow region simulated by the large eddy simulation model was much more real than others, the simulation results could be used to explain the law of multi-scale vortex movement and the mechanism of energy dissipation in the main flow region, and the high-gradient flow field distribution of near-wall area and corner area could be captured more accurately by the detached eddy simulation model. The results of analysis will provide a basis for accurate calculation of flow field and performance prediction of hydrodynamic coupling. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Numerical models
Controlled terms:Automobile manufacture - Channel flow - Computer graphics - Computer integrated manufacturing - Computer simulation - Energy dissipation - Flow fields - Flow separation - Flow velocity - Flow visualization - Fluid dynamics - Fluid mechanics - Hydrodynamics - Image processing - Large eddy simulation - Mesh generation - Models - Navier Stokes equations - Ship propulsion - Structural optimization - Transients - Turbulence models - Turbulent flow - Vehicle transmissions - Velocimeters - Velocity - Velocity measurement - Vortex flow - Vorticity
Uncontrolled terms:Detached eddy simulations - Engineering fluid mechanics - Flow velocity field - Hydrodynamic coupling - Image processing technique - Particle image velocimetries - Rotating coordinate system - Vorticity field
Classification code:525.4 Energy Losses (industrial and residential)Energy Losses (industrial and residential)
- 602.2 Mechanical TransmissionsMechanical Transmissions
- 631 Fluid FlowFluid Flow
- 631.1 Fluid Flow, GeneralFluid Flow, General
- 662.1 AutomobilesAutomobiles
- 675.1 Ship Propulsion (Before 1993, use code 671)Ship Propulsion (Before 1993, use code 671)
- 723.5 Computer ApplicationsComputer Applications
- 921 MathematicsMathematics
- 931.1 MechanicsMechanics
- 943.3 Special Purpose InstrumentsSpecial Purpose Instruments
DOI:10.11975/j.issn.1002-6819.2016.03.006
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 3>
Accession number:20161002077987
Title:Thermokinetics analysis of biomass based on model-free different heating rate method
Authors:Tian, Yishui (1, 2); Wang, Ru (1, 3)
Author affiliation:(1) Rural Energy and Environmental Research Institute, Chinese Academy of Agricultural Engineering, Beijing, China; (2) Key Laboratory of Energy Resource Utilization from Agricultural Residues, Ministry of Agriculture, Beijing, China; (3) College of Engineering of China Agricultural University, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:234-240
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Thermokinetics analysis can test the relationship between physical and chemical properties of material and temperature through controlling heating rate. Through thermokinetics analysis, we can study the combustion, pyrolysis and gasification reaction kinetics of biomass, decide the reaction kinetics model and calculate the reaction kinetics parameters, such as activation energy and pre-exponential factor. In the article, we chose 6 kinds of biomass raw materials, including corn straw, wheat straw, cotton stalk, pine sawdust, peanut shell, and residue of sweet sorghum. The thermal gravity analysis (TG) experiments were carried out, and 8 loss curves were obtained under non-isothermal conditions at linear heating rate of 5, 10, 20 and 30 /min. The 99.99% nitrogen continuously passed and the temperature rose from room temperature to 600. The initial sample weight was always within the range of 3-4 mg. The method of different heating rates was applied to non-isothermal data. The Friedman method and the Flynn-Wall-Ozawa method were used for the estimation of the activation energy, and the Malek method was used for the decision of the reaction kinetics model, which were defined as the sample of the pre-exponential factor and the conversion function, respectively. The results showed that the pyrolysis process of biomass included 3 main stages: drying and preheating stage, volatile matter evaporation stage and carbonization stage. The higher the total moisture in biomass, the greater the mass loss rate for the sample at the first stage. Volatile matter evaporation stage was the most important stage in the pyrolysis process, in which the mass loss rate of the sample increased rapidly with the increase of the temperature. The carbonization stage was mainly the continued pyrolysis of lignin, and carbon and ash were the final products. In the whole range of conversion rate, the activation energy of biomass was not a fixed value, and it would increase gradually with the increase of conversion rate. Due to the influence of the particle size, the buoyancy and the non homogeneous phase, in the range of conversion rate <0.2, and >0.8, the TG curve was difficult to meet the requirements of the temperature at different heating rates under the same conversion rate. In the volatile matter evaporation stage, the activation energies obtained by Friedman method and Flynn-Wall-Ozawa method were almost the same and hardly changed with the conversion rate. The pyrolysis activation energy of the biomass ranged from 144.61 to 167.34 kJ/mol, and the correlation coefficient was almost between 0.99 and 1.00. This shows that the calculation method of the activation energy is reliable in this paper. Among biomass raw materials, corn straw and wheat straw belonged to gramineous crops, whose activation energy was high, 167.34 and 167.20 kJ/mol respectively; lignification degree of cotton stalk, pine sawdust and peanut shell was higher, whose activation energy was lower, 154.06, 147.29 and 146.91 kJ/mol respectively; residue of sweet sorghum was processed by biochemical process, whose activation energy was the lowest, 144.61 kJ/mol. The reaction kinetics models of the biomass conformed the Avrami-Erofeev function. This shows that because the composition and structure of different biomass materials are basically the same, the reaction kinetics models are basically the same. But, there were some differences in the reaction orders. The reaction order of corn stalk and peanut shell was 3; the reaction order of wheat straw, cotton stalk and residue of sweet sorghum was 2; and the reaction order of pine sawdust was 1.5. The pre-exponential factor of the biomass ranged from 26.66 to 33.97 s<sup>-1</sup>. Our results show that biomass pyrolysis is an extremely complex multi-step process, which has different activation energy and reaction kinetics model in different temperature range. This is important theoretical basis for the optimization of process conditions and engineering amplification of biomass pyrolysis process. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Activation energy
Controlled terms:Activation analysis - Association reactions - Biomass - Carbon - Carbonization - Chemical activation - Chemical analysis - Cotton - Evaporation - Heating - Heating rate - Isotherms - Kinetics - Oilseeds - Particle size - Pyrolysis - Reaction kinetics - Straw - Temperature - Thermoanalysis - Thermodynamics
Uncontrolled terms:Correlation coefficient - Linear heating rates - Non-isothermal condition - Physical and chemical properties - Preexponential factor - Pyrolysis and gasification - Reaction kinetics models - Thermal gravity analysis
Classification code:641.1 ThermodynamicsThermodynamics
- 641.2 Heat TransferHeat Transfer
- 801 ChemistryChemistry
- 802.2 Chemical ReactionsChemical Reactions
- 802.3 Chemical OperationsChemical Operations
- 804 Chemical Products GenerallyChemical Products Generally
- 821.4 Agricultural ProductsAgricultural Products
- 821.5 Agricultural WastesAgricultural Wastes
- 931 Classical Physics; Quantum Theory; RelativityClassical Physics; Quantum Theory; Relativity
DOI:10.11975/j.issn.1002-6819.2016.03.034
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 4>
Accession number:20161002077960
Title:Speed calculation model and simulation of rollover prevention in condition of extreme turn based on lateral force coefficient
Authors:Fan, Li (1, 2); Li, Gangyan (1); Chen, Ran (1); Liang, Haotong (1); Yang, Jian (2); Cao, Linwei (1); Meng, Lihang (1)
Author affiliation:(1) School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan, China; (2) Air Force Airborne Academy, Guilin, China
Corresponding author:Li, Gangyan(gangyanli@whut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:41-47
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The problem of lateral rollover due to excessive speed occurs easily in the process that the vehicle is turning, especially under the condition of vehicle extreme turn. In traditional researches on vehicle roller prevention, rollover threshold is calculated by vehicle tread, height of centroid and other structure parameters. The side acceleration, which is caused when vehicles are turning, is controlled on the basis of rollover thresholds to prevent rollover. However, sometimes the speed calculated by rollover threshold is very high. The lateral load transfer and suspension movement become larger because of sharp turn in actual turning, which can lead to rollover although the speed is under the calculated critical velocity. To solve the problem, the safety speed calculation model of rollover prevention is built, which is under the condition of vehicle extreme turn based on lateral force coefficient. First of all, combined with the expression of lateral force coefficient, and according to the influence of lateral force coefficient on the driving stability in the process of turning, the feasibility of characterizing the safety speed of the vehicle for rollover prevention under vehicle extreme turn condition by lateral force coefficient is analyzed. Secondly, the rigid body dynamic model of vehicle during the turning and the dynamic model with consideration of the suspension of vehicle are established. Through the comparison between the models above, the stress of the vehicle under the condition of extreme turn driving is analyzed. Thirdly, in view of the dynamic models above, the calculation method of traditional lateral force coefficient is optimized. Fourthly, according to the relationship between lateral force coefficient and vehicle speed, the calculation model of the safety speed of the vehicle based on lateral force coefficient is established, which is for rollover prevention under extreme turn driving conditions. Finally, to verify the accuracy and reliability of the model, taking the structure parameters of a truck as the example, through Matlab software, the relationship of turning radius and vehicle safety speed among the model and other 4 representative safety speed calculation models during turning is simulated and compared. It shows that the results from the speed calculation model based on lateral force coefficient are similar to those from other 4 modes, especially approximate with those from Lusetti model. Simultaneously, to verify the reliability of the built mode, the critical safety vehicle speed for rollover prevention in the process of vehicle turning with different turning radius is simulated by using the vehicle dynamics simulation software TruckSim. Comparing the rollover critical vehicle speeds from the simulation software and the speed calculation model based on lateral force coefficient, it shows that the critical safety vehicle speed from the method proposed in the paper is approximately 10% less than that from the TruckSim software. The results in the paper provide a reference for the calculation of safety vehicle speed, the stability evaluation and the active safety control of the vehicle under the condition of extreme turn. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Automobile suspensions
Controlled terms:Computer simulation - Computer software - Dynamic models - Magnetic levitation vehicles - MATLAB - Models - Safety engineering - Software reliability - Speed - Trucks - Vehicles
Uncontrolled terms:Critical velocities - Extreme turn condition - Lateral force - Lateral load transfer - Rigid body dynamic models - Stability evaluation - Structure parameter - Vehicle dynamics simulation
Classification code:662.4 Automobile and Smaller Vehicle ComponentsAutomobile and Smaller Vehicle Components
- 663.1 Heavy Duty Motor VehiclesHeavy Duty Motor Vehicles
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 723.5 Computer ApplicationsComputer Applications
- 914 Safety EngineeringSafety Engineering
- 921 MathematicsMathematics
DOI:10.11975/j.issn.1002-6819.2016.03.007
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 5>
Accession number:20161002077979
Title:Top-view recognition of individual group-housed pig based on Isomap and SVM
Authors:Guo, Yizheng (1, 2); Zhu, Weixing (1); Ma, Changhua (1); Chen, Chen (1)
Author affiliation:(1) School of Electrical and Information Engineering, Jiangsu University, Zhenjiang, China; (2) Taizhou College, Nanjing Normal University, Taizhou, China
Corresponding author:Zhu, Weixing(wxzhu@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:182-187
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Monitoring behavior of pigs in a pen is possible both in group and at individual level. Data analysis at individual level, however, has more advantages. Identification of pigs is a necessary step towards analyzing the different behaviors of pigs individually. Some current computer vision systems that are used for video surveillance of group-housed pigs require that the pigs be marked. In this paper, using a top-view video sequence of group-housed pigs, a machine-vision technology method for recognizing individual pig is proposed. First, to recognize each individual pig, foreground detection and target extraction are conducted on a top-view video sequence of the group-housed pigs. Second, the training samples are established, and the color, texture and shape of the individual pig are extracted; through the combination of these features, a feature vector representing an individual pig is then built. Third, the combined features are fused using the Isomap algorithm, which reduces the feature dimension on the basis of the maximum retention of the effective recognition information. Finally, the features are trained and recognized using a support vector machine (SVM) classifier with an optimal kernel function. The videos used in the present study are collected from pig farms of the Danyang Rongxin Nongmu Development Company, which is the experimental base for the key discipline of Jiangsu University, i.e. agricultural electrification and automation. The pigs are monitored in a reconstructed experimental pigsty. The pigsty is 1 m high, 3.5 m long and 3 m wide. A camera is located above the pigsty with the height of 3 m over the ground. The camera is the FL3-U3-88S2C-C with an image resolution of 1760 × 1840 pixels from the Grey Point Company. The videos are captured from 8 AM to 5 PM. Over 5 days randomly chosen, we collect 6 sections of videos every day at random time, so there are a total of 30 videos randomly chosen in audio video interleaved (AVI) format. The frame frequency of each video is 25 fps with the duration of approximately 120 s. Among the 90 000 frames (5 days × 6 videos × 120 s × 25 fps), 900 frames satisfying the requirement of experimental conditions are selected. The software MATLAB 2012b is adopted. The experimental results show that the proposed method is effective and the highest recognition rate of pigs is 92.88%. In this paper, a method for recognizing group-housed pigs individually from a top-view video sequence is explored based on the machine vision, which differs from traditional radio frequency identification (RFID) of individual pig. This study provides a new idea for the recognition of individual pig without stressing the animals, and lays a foundation for further analysis of the behavior of individual pig. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Mammals
Controlled terms:Agricultural machinery - Animals - Automatic vehicle identification - Cameras - Computer vision - Extraction - Feature extraction - Image resolution - Image retrieval - MATLAB - Radio frequency identification (RFID) - Security systems - Support vector machines - Video recording
Uncontrolled terms:Computer vision system - Experimental conditions - Foreground detection - Group-housed pigs - Individual pig recognition - IsoMap algorithms - Machine vision technologies - Monitoring behaviors
Classification code:406.1 Highway SystemsHighway Systems
- 716.3 Radio Systems and EquipmentRadio Systems and Equipment
- 716.4 Television Systems and EquipmentTelevision Systems and Equipment
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 723.5 Computer ApplicationsComputer Applications
- 742.2 Photographic EquipmentPhotographic Equipment
- 802.3 Chemical OperationsChemical Operations
- 821.1 Agricultural Machinery and EquipmentAgricultural Machinery and Equipment
- 914.1 Accidents and Accident PreventionAccidents and Accident Prevention
- 921 MathematicsMathematics
DOI:10.11975/j.issn.1002-6819.2016.03.026
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 6>
Accession number:20161002077989
Title:High-temperature steam gasification of pine particles for hydrogen-rich gas
Authors:Niu, Yonghong (1); Han, Fengtao (1); Chen, Yisheng (2)
Author affiliation:(1) School of Energy and Environment, Inner Mongolia University of Science and Technology, Baotou, China; (2) Analytical Center, Inner Mongolia University of Science and Technology, Baotou, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:247-252
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The objective of the research was to use pine particles as raw material with self-made downdraft gasifier system platform for gasification test. The test was carried out under different conditions of steam flow rate and gasification temperature. Analysis of biomass gasification reaction mechanism was done by using equilibrium theory and chemical reaction kinetics of chemical reaction. Our results showed that method of granulation of biomass wastes can effectively improve stacking density of biomass. By using this method, pine wastes stacking density can be as high as 520 kg/m<sup>3</sup>. Also, by using pine particles for gasification, the bridging phenomenon of material accumulation in the furnace was decreased, thus making the test in a continuous and stable condition, and improving the biomass gasification effect. With the increase of gasification temperature, the degree of gasification reactions was increased as well as the steam reforming which helped the participation of hydrocarbon and coke As such hydrogen content increased, and the volume fraction of H<inf>2</inf>increased from 23.38% at 700 to 44.79% at 950 which nearly doubled that in 700 Moreover, the volume fraction of C<inf>n</inf>H<inf>m</inf>decreased with the gasification temperature increase. However, due to the conversion of carbon monoxide and steam after 900, the volume fractions for H<inf>2</inf>, CO, and CO<inf>2</inf>decreased with the increase of temperature. Besides, high-temperature steam had higher specific enthalpy, which might promote the reforming reaction of steam towards the generation of H<inf>2</inf>The high temperature steam is also a gasification agent and heat carrier in the gasification process. It provides partial energy of biomass gasification reactions. Steam flow is another important indicator of high temperature steam gasification technology. In the range of temperature of 850-950 , the increase of steam flow increased the steam reforming which was in the participation of hydrocarbon and coke. With steam flow increased from 0.3 to 0.9 kg/h, the volume fraction of H<inf>2</inf>increased from 37.06% to 47.67%, the change of the volume fraction of CO was stable. The volume fraction of CO<inf>2</inf>increased, but the volume fraction of C<inf>n</inf>H<inf>m</inf>decreased. Because of the sequentially increase of steam flow, the residence time of steam in the furnace reduced, and that made reaction not sufficient. Therefore, the gas yield and hydrogen production rate increased with the increase of the steam flow. The gas yield and hydrogen yield increased with the increase of the steam flow rate, and then decreased. Especially, with regard to gas quality, when the steam flow rate was 0.6 kg/h with a gasification temperature of 900 , gas yield and hydrogen yield were 2.69 m<sup>3</sup>/kg and 101.8 g/kg respectively. At this time, the ratio of the steam flow rate and biomass in the reaction was about 0.95, the ratio of the steam quantity and the reaction of the reaction was about 0.95, and it was the best condition for the tests. This study provides the necessary basis for the promotion of the technology in the commercial industry. It is capable of providing partial energy of biomass gasification reactions. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:19
Main heading:Steam reforming
Controlled terms:Biomass - Carbon - Carbon dioxide - Carbon monoxide - Chemical analysis - Chemical reactions - Flow rate - Gases - Gasification - Hydrocarbons - Hydrogen production - Reaction kinetics - Reforming reactions - Steam - Volume fraction
Uncontrolled terms:Biomass Gasification - Downdraft gasifier - Gasification process - Gasification reaction - Gasification temperatures - High temperature steam gasifications - Hydrogen production rate - Hydrogen-rich gas
Classification code:522 Gas FuelsGas Fuels
- 631 Fluid FlowFluid Flow
- 641.1 ThermodynamicsThermodynamics
- 802.2 Chemical ReactionsChemical Reactions
- 802.3 Chemical OperationsChemical Operations
- 804 Chemical Products GenerallyChemical Products Generally
DOI:10.11975/j.issn.1002-6819.2016.03.036
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 7>
Accession number:20161002077980
Title:Bio-bedding with automatically running plough system under slatted floor improving air quality of duck house and duck production performances
Authors:Ying, Shijia (1); Yang, Zhiqing (2); Zhu, Bing (3); Dai, Zichun (1); Li, Yinian (3); Zhao, Wei (1); Lin, Yong (1); Ding, Weimin (3); Shi, Zhendan (1)
Author affiliation:(1) Institute of Animal Science, Laboratory of Animal Improvement and Reproduction, Jiangsu Academy of Agricultural Scineces, Nanjing, China; (2) Jiangsu Coastal Region Institute of Agricultural Science, Yancheng, China; (3) College of Engineering, Nanjing Agricultural University, Nanjing, China
Corresponding author:Shi, Zhendan(zdshi@jaas.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:188-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the development of intensive and scalable breeding of meat-type duck in China, a lot of duck manures have not been processed timely because of traditional extensive duck production system, and become the source of environmental pollution influencing duck health. To mitigate the detrimental effects of feces and fecal pathogenic bacteria on duck health and production performance, a novel duck production system of incorporating bio-bedding under slatted floor (BBSF) was developed. Successful operation of the BBSF system was aided by an automatically running plough system (ARPS) that covered duck feces into the bio-bedding. ARPS was composed of sliding touch wire, limit switches, movement orbit, plowing and harrowing device, connection orbit, transfer vehicle, electric brush, power switches, and transfer orbit. The plowing and harrowing device could run among different duck houses to plow bio-bed by cooperating with connection orbit, transfer orbit, and transfer vehicle. The effects of BBSF on airborne pathogenic bacteria and duck production performances in duck house were investigated, which were in comparison with those by conventional floor bio-bedding (CFBB). A total of 2400 8-day-old ducks were randomly and equally allocated into 2 duck production systems, i.e. BBSF and CFBB. Each production system was divided into 6 pens where the ducks were pre-fed for 7 d. Before the age of 26 days, the bio-bedding was not plowed. During the age of 27-34 and 35-39 days, the bio-bedding was plowed once every 4 days and a day, respectively. The counts of total airborne bacteria, Escherichia coli, Staphylococcus aureu and "Salmonella + Shigella" were tested on the age of 26, 34 and 39 days, respectively. Live weight, ratio of feed to meat, total mortality, and stage mortality were analyzed during experiment period, and market elimination rate was counted at the time of live duck slaughter. The results demonstrated that: 1) The sharing of the plowing and harrowing device by different bio-beddings could be achieved through the ARPS. 2) BBSF significantly increased the amounts of total airborne aerobe (1.531×10<sup>5</sup>CFU/m<sup>3</sup>) and Escherichia coli (1.298×10<sup>4</sup>CFU/m<sup>3</sup>) at the age of 26 days in duck house (P<0.05), significantly decreased the amounts of total airborne aerobe (2.304×10<sup>5</sup>CFU/m<sup>3</sup>) and Staphylococcus aureu (1.353×10<sup>5</sup>CFU/m<sup>3</sup>) at the age of 34-days (P<0.05), and significantly decreased the amounts of total airborne aerobe (1.255×10<sup>5</sup>CFU/m<sup>3</sup>) and "Salmonella + Shigella" (14.13 CFU/m<sup>3</sup>) at the age of 39 days (P<0.05). 3) Compared with plowing the bio-bedding once every 4 days, plowing of CFBB once every day decreased the amounts (P<0.05) of total airborne bacteria (2.688×10<sup>5</sup>CFU/m<sup>3</sup>), Escherichia coli (2.038×10<sup>4</sup>CFU/m<sup>3</sup>), Staphylococcus aureu (8.900×10<sup>4</sup>CFU/m<sup>3</sup>) and "Salmonella + Shigella" (47.11 CFU/m<sup>3</sup>), however, the amounts of total airborne aerobe (1.255×10<sup>5</sup>CFU/m<sup>3</sup>) and "Salmonella + Shigella" (14.13 CFU/m<sup>3</sup>) in BBSF were decreased (P<0.05). 4) Compared with CFBB, BBSF significantly (P<0.05) increased live weight, and decreased mortality (0.26%-0.87% vs 0.72%-2.47%), ratio of feed to meat (1.10-2.29 vs 1.17-2.46), and market elimination rate (0.87% vs 1.90%). Our results indicate that BBSF has better effects on controlling airborne microbial environment and improving duck production performances compared with CFBB. This study provides theoretical and technological supports for application of the novel BBSF system in the modern duck industry. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Bacteria
Controlled terms:Air quality - Animals - Commerce - Electric switches - Escherichia coli - Fertilizers - Floors - Growth (materials) - Houses - Meats - Orbits - Population statistics - Salmonella
Uncontrolled terms:Bio-bedding plowing system - Duck - Environmental pollutions - Pathogenic bacterium - Production performance - Slatted floor - Technological supports - Total airborne aerobe
Classification code:402 Buildings and TowersBuildings and Towers
- 402.3 ResidencesResidences
- 451.2 Air Pollution ControlAir Pollution Control
- 461.9 BiologyBiology
- 804 Chemical Products GenerallyChemical Products Generally
- 822.3 Food ProductsFood Products
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.027
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 8>
Accession number:20161002077965
Title:Parameter optimization and sensitivity analysis of soil-crop system model using PEST
Authors:Liang, Hao (1); Hu, Kelin (1); Li, Baoguo (1)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Key Laboratory of Arable Land Conservation in North China, Beijing, China
Corresponding author:Hu, Kelin(hukel@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:78-85
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agricultural production management system models usually require numerous input parameters and the calibration and validation of the parameters are time-consuming, which significantly limit the use of models. This study aimed at improving the efficiency and accuracy of a soil-crop system model (soil water heat carbon and nitrogen simulator, WHCNS) using a model-independent optimization tools (parameter estimation, PEST) and data from field experiments. A two-year field experiment was conducted from October 2009 to October 2011 in Tai'an City, Shandong Province in North China Plain. The crop rotation was winter wheat-summer maize, and three fields with high, middle and low productivity levels based on the wheat yields (named T1, T2 and T3 treatments, respectively) were selected to test the WHCNS model. The dynamics of soil water content and soil nitrate concentration in different soil depths were monitored, crop dry matter and leaf area index at the key crop growth stages and yield data were measured. PEST was used to optimize model parameters and to calculate the relative composite sensitivity (RCS) of each input parameter for WHCNS model. The optimization parameters involved the majority modules of the model, such as soil water dynamic, nitrogen transformation and crop growth. The objective function of the optimization model were consist of four different groups of field data, including soil water content, soil nitrate concentration, crop yield and leaf area index. And the inverse solution was obtained through minimizing the object function using PEST program base on Gauss-Marquardt-Levevberg algorithm. The results of PEST were then compared with the simulations based on measured soil hydraulic parameters and the trial-and-error method. The statistical analysis (root mean square error, model efficiency, and agreement index) indicated that the PEST optimization method provided better accuracy and efficiency than the other two methods. For example, PEST method significantly decreased RMSE of soil water content, nitrate concentration, crop yield and leaf area index by 61.8%, 23.5%, 73.6% and 23.3%, respectively. Furthermore, the accuracy of simulated water content, nitrate concentration and crop yields were significantly improved by using PEST method. However, there were no significant improvements for the soil nitrogen concentrations and leaf area index, compared to the trial-and-error method. With sensitivity analysis, we identified 18 key parameters that had relatively higher sensitivity. Among these 18 parameters, soil water hydraulic parameters and crop genetic parameters had higher sensitivity than soil nitrogen transformation parameters. Among soil water hydraulic parameters, the soil saturated water content had the highest sensitivity; among crop parameters, the total cumulative available temperature and maximum specific leaf area showed the highest sensitivity; and among soil nitrogen transformation parameters, the maximum soil nitrification rate showed the highest sensitivity. Overall, the sensitivity of nitrogen transformation parameters was generally lower compared with those of soil hydraulic parameters and crop parameters. The sensitivity of crop parameters was significantly different between wheat (C3 crop) and maize (C4 crop), e.g., the maximum root depth and the maximum assimilation rate for maize showed a higher sensitivity than those of wheat, suggesting that model calibration and validation should be crop specific. The PEST method not only greatly saved time for model calibration, but also achieved significant higher simulation accuracy than that by trial-and-error method. In conclusion, the PEST parameter optimization program is a useful tool and should be adopted in calibration and application of soil-crop models. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Soil surveys
Controlled terms:Agriculture - Application programs - Calibration - Carbon - Crops - Efficiency - Errors - Forestry - Inverse problems - Mean square error - Models - Nitrates - Nitrogen - Optimization - Plants (botany) - Sensitivity analysis - Soil moisture - Soils - Water content
Uncontrolled terms:Agricultural production management - Model calibration and validation - Nitrogen cycles - Parameter optimization - PEST - Soil nitrogen transformations - Soil saturated water contents - WHCNS
Classification code:483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 804 Chemical Products GenerallyChemical Products Generally
- 804.2 Inorganic CompoundsInorganic Compounds
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 821.4 Agricultural ProductsAgricultural Products
- 913.1 Production EngineeringProduction Engineering
- 921 MathematicsMathematics
- 921.5 Optimization TechniquesOptimization Techniques
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.012
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 9>
Accession number:20161002077983
Title:Greenhouse gas emissions of Megalobrama amblycephala culture pond ecosystems during sun drying of pond
Authors:Zhu, Lin (1); Che, Xuan (1); Liu, Huang (1); Liu, Xingguo (1); Shi, Xu (1); Yang, Jiapeng (1); Wang, Xiaodong (1); Gu, Zhaojun (1); Cheng, Guofeng (1); Zhu, Hao (1)
Author affiliation:(1) Key Laboratory of Fisher Equipment and Engineering, Fisher Machinery and Instrument Research Institute, Chinese Academy of Fishery Sciences, Shanghai, China
Corresponding author:Che, Xuan(chexuan@fmiri.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:210-215
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Global warming and ozone depletion caused by greenhouse gases are currently two major global environmental issues. While China's freshwater aquaculture production has long been ranked first in the world, greenhouse gas emissions from freshwater ponds becomes an important source of China's greenhouse gas emissions. But the research on greenhouse gas emission in freshwater aquaculture ecosystem is limited. In order to investigate greenhouse gas emissions and comprehensive global warming potential of Megalobrama amblycephala culture pond ecosystems during pond basked, we used the static opaque chamber-GC techniques to conduct an in situ determination of greenhouse gas emissions (CO<inf>2</inf>, CH<inf>4</inf>, N<inf>2</inf>O) of Megalobrama amblycephala culture pond ecosystems. The results showed that the CO<inf>2</inf>fluxes measured in every 15 days were (2652.46±325.36), (2313.82±245.14), (1456.42±124.67) and (1373.27±167.39) mg/(m<sup>2</sup>·d) respectively for the air temperature of 8.9, 7.2, 5.8 and 6, at the ponds during sampling. The potential of hydrogen at the ponds during the sampling at each temperature was (7.73±0.26), (8.26±0.35), (7.75±0.37) and (7.68±0.48), respectively. The total organic carbon at the ponds for each sampling was (3.61±0.43), (3.32±0.17), (3.16±0.31) and (3.23±0.27), respectively. The redox potential for each sampling was (206.7±34.9), (216.8±27.6), (56.8±9.3) and (124.8±16.5) mV, respectively. The moisture content of sediment for samples taken at 11.2, 10.3, 9.6 and 9.8 was (55.25%±2.54%), (54.53%±5.61%), (46.62%±4.38%), and (48.35%±3.14%), respectively. Among December 28, January 13, January 28, February 13, 2014, when the pond temperature was the highest on December 28, the CO<inf>2</inf>emission flux peaked (2652.46±325.36) mg/(m<sup>2</sup>·d)). In comparison, on February 13 2015, the smallest CO<inf>2</inf>emission flux (1373.27±167.39) mg/(m<sup>2</sup>·d)) corresponded with the lowest pond temperature, CH<inf>4</inf>is transformed from methane bacteria via an organic carbon source. As culturing activity increased with rising temperatures, phytoplankton dies and the organic artificial diets left over by fish increases, providing a rich carbon source for methane bacteria. In this study, CH<inf>4</inf>emission flux paralleled that of CO<inf>2</inf>, and in general, CH<inf>4</inf>emission flux was positively correlated with temperature. On December 28, 2014, there was a peak of CH<inf>4</inf>emission flux (82.42 ± 6.32) mg/(m<sup>2</sup>·d)) in the freshwater ponds. From December 28, 2014 to February 13 2015, the measured CH<inf>4</inf>emission fluxes were (82.42±6.32), (81.08±7.43), (7.63±1.84) and (7.06±2.93) mg/(m<sup>2</sup>·d), respectively. On February 13 2015, the lowest water temperature was accompanied by the smallest CH<inf>4</inf>emission flux (7.06±2.93) mg/(m<sup>2</sup>·d). From December 28, 2014 to February 13 2015, the N<inf>2</inf>O emission fluxes were (172.34±10.56), (204.57±16.84), (160.36±12.87), and (90.39±10.67) μg/(m<sup>2</sup>·d), respectively. Megalobrama amblycephala culture ponds during pond basked were the source of CO<inf>2</inf>, CH<inf>4</inf>and N<inf>2</inf>O, of which CO<inf>2</inf>emission during pond basked amounted to (86.72.10±12.46) g/m<sup>2</sup>, CH<inf>4</inf>emission of (2.01±0.34) g/m<sup>2</sup>, and N<inf>2</inf>O emission of (7.44±0.98) mg/m<sup>2</sup>. For 20-years Megalobrama amblycephala culture pond ecosystems during pond basked, greenhouse gas warming potential had an increase trend. Comprehensive global warming potential was (157.28±24.31) g/m<sup>2</sup>. Therefore, there was a great potential in greenhouse gas emission reduction in Megalobrama amblycephala culture pond ecosystems. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Gas emissions
Controlled terms:Aquaculture - Bacteria - Carbon - Carbon dioxide - Ecology - Ecosystems - Emission control - Gases - Global warming - Greenhouse effect - Greenhouse gases - Lakes - Methane - Organic carbon - Ozone layer - Ponding - Ponds - Redox reactions - Solar dryers - Water
Uncontrolled terms:Environmental issues - Global warming potential - Greenhouse gas emission reduction - Megalobrama amblycephala - Rising temperatures - Sun drying - Total Organic Carbon - Water temperatures
Classification code:443.1 Atmospheric PropertiesAtmospheric Properties
- 451.1 Air Pollution SourcesAir Pollution Sources
- 451.2 Air Pollution ControlAir Pollution Control
- 454.3 Ecology and EcosystemsEcology and Ecosystems
- 802.1 Chemical Plants and EquipmentChemical Plants and Equipment
- 802.2 Chemical ReactionsChemical Reactions
- 804 Chemical Products GenerallyChemical Products Generally
- 821.3 Agricultural MethodsAgricultural Methods
DOI:10.11975/j.issn.1002-6819.2016.03.030
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 10>
Accession number:20161002077976
Title:Hyperspectral estimation of leaf area index for winter wheat based on Akaike's information criterion
Authors:Yang, Fuqin (1, 2, 3, 4, 5); Feng, Haikuan (2, 3, 4); Li, Zhenhai (2, 3, 4); Gao, Lin (2, 3, 4); Yang, Guijun (2, 3, 4); Dai, Huayang (1)
Author affiliation:(1) College of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing, Beijing, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing, China; (3) Key Laboratory for Information Technologies in Agriculture, The Ministry of Agriculture, Beijing, China; (4) Beijing Engineering Research Center of Agricultural Internet of Things, Beijing, China; (5) College of Civil Engineering, Henan Institute of Engineering, Zhengzhou, China
Corresponding author:Feng, Haikuan(fenghaikuan123@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:163-168
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Winter wheat leaf area index (LAI) is one of important parameters in describing the canopy structure, which is particularly significant in the analysis of winter wheat growth and the yield prediction. The objective of the study was to demonstrate the feasibility of remote sensing monitoring on winter wheat LAI and its expansibility in spatial and temporal scale. Canopy LAI variables from remote sensing data were investigated using empirical statistics inversion model. This study focused on analyzing the correlation between vegetation index and LAI. After sorting the vegetation index using grey relational analysis (GRA), the number of independent variables of different vegetation indices was chosen to participate in the regression using the partial least squares regression (PLS). Based on these LAI models, the Akaike's information criterion (AIC) values were calculated, and the model with the smallest AIC value was chosen as the optimal winter wheat LAI estimation model, i.e. the optimal winter wheat LAI estimation model was established by integrating the methods of GRA, PLS and AIC. Spectral reflectance of leaves and concurrent LAI parameters of samples were acquired in Tongzhou and Shunyi District, Beijing City, China during 2008-2009, which were for model establishment. Fourteen vegetation indices related to LAI were chosen to evaluate the model of LAI. Firstly, the correlation coefficient was analyzed, and it was found that there was significant negative correlation between transformed chlorophyll absorption in reflectance index / optimized soil adjusted vegetation index (TCARI/OSAVI), structure insensitive pigment index (SIPI), photon radiance index (PRI) and LAI, and significant positive correlation between normalized difference vegetation index (NDVI), simple ratio index (SR), OSAVI, normalized difference vegetation index 705 (NDVI705), modified red edge simple ratio index (MSR705), modified red edge normalized difference vegetation index (mNDVI705), Vogelmann index 1 (VOG1), modified chlorophyll absorption in reflectance index (MCARI2), modified soil adjusted vegetation index (MSAVI), modified simple ratio (MSR) and LAI. Secondly, the related degree order between 14 vegetation indices and winter wheat LAI could be drawn as follows: VOG1 > SIPI > MCARI2 > NDVI > MSR > mNDVI705 > OSAVI > NDVI705 > TCARI/OSAVI > TCARI > PRI > MSAVI > MSR705 > SR. Among them, the biggest GRA correlation degree was VOG1, whose value was 0.9211 and the smallest was SR, whose value was 0.6178. Thirdly, in accordance with the arrangement size of GRA, we used the PLS algorithm to increase the number of independent variables in turn to build 9 winter wheat LAI inversion models. Based on the AIC, we filtered and optimized the 9 winter wheat LAI models. Then, the optimal winter wheat LAI model was constructed by 8 independent variables, which were VOG1, SIPI, MCARI2, NDVI, MSR, mNDVI705, OSAVI and NDVI705. The decision coefficient (R<sup>2</sup>) and standard error (SE) of the GRA-PLS-AIC method modeling were respectively 0.76 and 0.009, which had a higher ability to predict winter wheat LAI. Considering the temporal characteristics of winter wheat LAI, we incorporated the relevant data from 2009 to 2010 to the model and evaluated its ability of estimating the winter wheat LAI in different years. The R<sup>2</sup>, relative root mean standard error (RRMSE) and the slope of the fitted line between measured and predicted LAI value in validation set by GRA-PLS-AIC method were respectively 0.63, 0.004 and 0.68. It shows that the model has a higher predictive ability, which lays an important foundation for improving the precision of forecasting winter wheat LAI using remote sensing method. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Vegetation
Controlled terms:Chlorophyll - Crops - Forecasting - Least squares approximations - Models - Plants (botany) - Reflection - Remote sensing
Uncontrolled terms:Akaike's information criterions - Grey relational analyses (GRA) - Grey relational analysis - Leaf Area Index - Normalized difference vegetation index - Partial least square (PLS) - Partial least squares regression - Remote sensing monitoring
Classification code:804.1 Organic CompoundsOrganic Compounds
- 821.4 Agricultural ProductsAgricultural Products
- 921.6 Numerical MethodsNumerical Methods
DOI:10.11975/j.issn.1002-6819.2016.03.023
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 11>
Accession number:20161002077977
Title:Capacitance measurement and parameter estimation method for supercapacitors with variable capacitance
Authors:Yu, Peng (1, 2); Jing, Tianjun (1); Yang, Rengang (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China; (2) College of Engineering, Bohai University, Jinzhou, China
Corresponding author:Jing, Tianjun(jtjy11@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:169-174
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Estimating the parameters of capacitance function is important for supercapacitor manufacture and integration. The estimated parameters are useful for fault monitoring and health state identification. Because the capacitance can't be measured directly, indirect measurement model is needed. The capacitance of supercapacitor has relation with voltage or current. The existing methods of supercapacitor parameters estimation have poor performance on variable capacitance and poor adaptability with signal noise. According to the disadvantages of existing methods, a capacitance measurement and parameter estimation method for variable capacitance of supercapacitors was proposed in this paper. This method included two parts: a measurement model; and parameter estimation. The time variable parameter classic model with variable capacitance was used to simulate the time variance character of supercapacitor. Based on this model, a new method was inferred. In this method, the equations based on charge and energy conservation were used to form measuring equation group. Trapezoid formula was applied to solve discrete integral in the equation group. By solving equation groups, the capacitance in every sampling time was measured indirectly. As result, the time series of capacitance were expressed by stack of voltage and current. After bringing the measured voltage and current into the expression of capacitance, the time series of capacitance were obtained. After the capacitances were measured indirectly, the fixed memory least squares method was applied on the time series of capacitance to estimate the parameters of capacitance function. Two simulation experiments based on Matlab were conducted to verify the capacitance measurement and parameter estimation. In these experiments voltage source and load resistance were used to make the supercapacitor charge and discharge randomly. In the first experiment, we used four different functions of the capacitance to test the adaptability of measurement. Comparisons were made between methods, published one in the literature and the ones proposed in this paper. When the capacitance was constant, the average relative error of measurement was 1.51%. The error of reference group was 8.23%. When the capacitance was linear function, the average relative error of measurement was 3.74%. The error of reference group was 36.15%. When the capacitance was quadratic polynomial function, the average relative error of measurement was 11.04%. The error of reference group was 100%. When the capacitance was exponent function, the average relative error of measurement was 26.85%. The error of reference group was 100%. This result showed that the new method was effect under four situations while the reference method was only effect in the situation of that the capacitance was constant and the capacitance was linear function. The second experiment was done with two types of capacitance functions to verify the method under measurement noise. The white Gaussian noise was added into the measured signal to simulate the practical situation. When the capacitance was linear function of current, the average relative errors of measurement were 0.6% and 7%. When the capacitance was quadratic polynomial function of voltage, the average relative errors of measurement were 10.62%, 19.7% and 11.5%. The result showed that the new method was effective under white Gaussian noise. The reference simulation of capacitance measurement based on an existing method was made. The reference method is a computing capacitance method. The result showed that the proposed method had lower error than the reference method. The experiment result supported that the proposed method in this paper was adaptive for different function of capacitance and the method was effect under additive white Gaussian noise on voltage and current signal. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Capacitance
Controlled terms:Capacitance measurement - Capacitors - Errors - Estimation - Functions - Gaussian distribution - Gaussian noise (electronic) - Integral equations - Least squares approximations - MATLAB - Parameter estimation - Time series - Vaporization - White noise
Uncontrolled terms:Additive White Gaussian noise - Average relative error - Least squares methods - Parameter estimation method - Parameters estimation - Quadratic polynomial functions - Super capacitor - Variable capacitances
Classification code:701.1 Electricity: Basic Concepts and PhenomenaElectricity: Basic Concepts and Phenomena
- 704.1 Electric ComponentsElectric Components
- 802.3 Chemical OperationsChemical Operations
- 921 MathematicsMathematics
- 922.2 Mathematical StatisticsMathematical Statistics
- 942.2 Electric Variables MeasurementsElectric Variables Measurements
DOI:10.11975/j.issn.1002-6819.2016.03.024
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 12>
Accession number:20161002077971
Title:Effect of gravel on runoff and erosion characteristics on engineering accumulation slope in windy and sandy area, northern China
Authors:Kang, Hongliang (1); Wang, Wenlong (1, 2); Xue, Zhide (3); Guo, Mingming (1); Li, Jianming (4); Bai, Yun (5); Deng, Liqiang (6); Li, Yanfu (7); Li, Yaolin (8)
Author affiliation:(1) State Key Laboratory of Erosion and Dryland Agriculture on the Loess Plateaus, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China; (2) Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, China; (3) College of Natural Resources and Environment, Northwest A&F University, Yangling, China; (4) Department of Soil and Water Conservation, Changjiang River Scientific Research Institute, Wuhan, China; (5) Life Science College, Yulin University, Yulin, China; (6) Institute of Soil and Water Conservation and Ecology, Water Resources Research Institute of Shandong Province, Ji'nan, China; (7) Nanjing Institute of Water Resources and Hydropower Research, Nanjing, China; (8) Xifeng Experimental Station of Soil and Water Conservation, Yellow River Conservancy Commission, Xifeng, China
Corresponding author:Wang, Wenlong(wlwang@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:125-134
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Different from abandoned field and cropland and natural landscape, engineering accumulation is a special man-made geomorphic unit and has been found much more serious soil erosion. The anthropogenic accelerating erosion poses great threat to ecological environment of construction sites with surrounding regions and seriously hinders local economic growth and improvement of people's living standard. Gravel is always an important composition of depositions and it causes particular erosion characteristics. An indoor artificially simulated rainfall experiment was carried out in the State Key Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, China to investigate runoff hydraulic character and sediment yield process and erosion dynamic mechanism on slope of engineering deposition with different content of gravel. Soil sample, collected from Jingbian, Shanxi (N37°26'08″, E108°54'53″), was evenly mixed with gravel to be used as the main test material. According to preliminary field investigations, the grain diameter≤50mm of gravel was chosen as the gravel for the test and divided into 3 classes with different ranges of diameter: 2-14 mm (small) and 14-25 mm (medium) and 25-50 mm (large). Gravel sample for each test was consisted of 30% small, 50% medium, 20% large gravel. Mass content of gravel designed varied from 0 to 30%. Mobile hydraulic steel tank with the size of 5m×1m×0.6m (length×width×height) was applied for holding test material. Test slope was adjusted to 25° according to construction requirement of standard experimental plot. The results showed that: 1) Flow velocity on soil-rock deposition slope was higher with a maximum amplification of 52.8% during 0-6 min due to the positive effect of gravel on confluence compared to the bare. Whereas it was lower with a maximum damping of 408.5% when rill erosion dominated on the slope because of inhabitation from gravel which was exposed in the rill; 2) In terms of average level in an event, surface roughness increased and runoff, acted as laminar flow, flowed more slowly with smaller velocity on the slope of deposition with gravel. For the accumulation with 30% gravel content, resistance coefficient increased by 88.8%-288.4% and Froude number and flow velocity decreased by 28.9%-41.8% and 0-45.8% respectively compared to the homogeneous; 3)Sediment yield process could fall into 3 stages: quick reduce - smooth transition - fluctuate increase, in the third period, hyper-concentrated flow was easily found on the slope of the bare and the deposition with 10% of gravel, and frequency and degree of gravitational collapse increased with rainfall intensity increasing. The chance of hyper-concentrated flow approximately equaled to 0 for deposition with 20% and 30% of gravel. Relative soil loss ratio decreased exponentially with increasing gravel content; 4) The relationship between soil detachment rate and hydrodynamic parameters could be described with linear function. Unit stream power was the best one of all the hydrodynamic parameters to describe the hydrodynamic process of soil erosion on accumulation with 0 and 10% of gravel contents, whereas stream power tended to be more scientific to study the erosion process on deposition with 20% and 30% gravel contents. The results provide valuble information for the establishment of empirical and process-based model of soil and water loss on engineering accumulation on a national scale. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Soil pollution
Controlled terms:Agricultural runoff - Agriculture - Deposition - Economics - Erosion - Flow velocity - Fluid dynamics - Gravel - Hydrodynamics - Laminar flow - Rain - Runoff - Sediments - Soil conservation - Soils - Surface roughness - Water conservation - Water resources
Uncontrolled terms:Chinese Academy of Sciences - Construction requirements - Ecological environments - Gravel content - Runoff sediments - Soil and water conservation - Soil detachment - Windy and sandy area
Classification code:443.3 PrecipitationPrecipitation
- 444 Water ResourcesWater Resources
- 444.1 Surface WaterSurface Water
- 483 Soil Mechanics and FoundationsSoil Mechanics and Foundations
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 631 Fluid FlowFluid Flow
- 631.1 Fluid Flow, GeneralFluid Flow, General
- 802.3 Chemical OperationsChemical Operations
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 821.5 Agricultural WastesAgricultural Wastes
- 931.1 MechanicsMechanics
- 931.2 Physical Properties of Gases, Liquids and SolidsPhysical Properties of Gases, Liquids and Solids
- 971 Social SciencesSocial Sciences
DOI:10.11975/j.issn.1002-6819.2016.03.018
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 13>
Accession number:20161002077994
Title:Dynamic characteristics of sandy vegetation landscape pattern based on dimidiate pixel model
Authors:Wang, Xinjun (1, 2); Zhao, Chengyi (2); Yang, Ruihong (1, 2, 3); Jia, Hongtao (1)
Author affiliation:(1) Xinjiang Key Laboratory of Soil and Plant Ecological Processes, College of Grassland and Environmental Sciences, Xinjiang Agricultural University, Urumqi, China; (2) Xingjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; (3) Branch of Science Education, Xinjiang Teacher's College, Urumqi, China
Corresponding author:Zhao, Chengyi(zcy@ms.xjb.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:285-294
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The relationship between landscape pattern and process is a hot research topic in southern Gurbantunggut Desert. Desertification in fact is a process of landscape changing. Taken Landsat MSS/TM/ETM+ image as remote sensing data sources in selections of typical meteorological year (1977, 1990, 2001 and 2010) from 1977 to 2010, characteristics of the sandy vegetation landscape pattern were analyzed by using theory of landscape ecology, RS and GIS. Firstly, using remote sensing images based on pre-treatment, vegetation coverage classification map was gained by the dimidiate pixel model; then landscape pattern of desert vegetation coverage was analyzed using Fragstats 4.0 software to compute landscape pattern index or landscape analysis. The desert vegetation area changes and its mutual transition relationships with other types were analyzed with area ratio and transition matrix methods by ENVI software. The migration path of vegetation patch gravity center was analyzed with computing patches gravity center of different coverage of vegetation by ArcGIS software. The results showed that during the periods of 1977-1990 and 2001-2010, medium coverage desert vegetation area and its proportion were increasing, and vary low coverage desert vegetation area and its proportion were decreasing. While during the period of 1990-2001, vary low coverage desert vegetation area and its proportions were increasing, and low, medium and high coverage desert vegetation area and its proportion were decreasing. During the periods of 1977-2010, desert vegetation showed a changing trend of "restoration - degradation - restoration" cycle in southern Gurbantunggut Desert, and the general trend was restorative. In recent 40 years, landscape fragmentation showed a growing trend, and landscape heterogeneity was enhanced at landscape level. Fragmentation of different desert vegetation coverage changed with fluctuating in different trend at class level, from which relatively high coverage of vegetation fragmentation was increased and relatively low degree of coverage of vegetation fragmentation was decreased. During the period of 1977-2010, gravity center of vegetation patch fluctuated alternately with from SW to NE, and the track of gravity center shaped like a Z. Overall, gravity center of vegetation patch moved to NE with precipitation increasing. On the whole, vegetation patches were expanded from southwest margin of the desert to northeast of the desert heartland. Evolutionary direction of desert vegetation coverage, the degree of landscape fragmentation, percentage of different desert vegetation coverage, fragmentation of different desert vegetation coverage and migration direction of vegetation patches had close relationship with precipitation fluctuating. Therefore, evolution of desert vegetation landscape pattern had a strong relevancy with precipitation frequency. Along with the increasing annual precipitation, dominant role changed from bare land to vegetation with higher coverage. The bare land with a 91 mm annual precipitation had very low vegetation coverage vegetation. The area with 129.5 mm precipitation had the low vegetation coverage whereas the medium vegetation coverage area had 184.4 mm, and high vegetation area had a 221.4 mm annual. In last 40 years, both precipitation as a primary factor and topography induced water redistribution on the landscape as a secondary factor affected vegetation distribution pattern evolution on a landscape in southern Gurbantunggut Desert. Landscape pattern of the desert vegetation had an obvious response to change of annual precipitation, indicating that desert vegetation would continue to be in a restoring trend. Landscape fragmentation would continue to be in an increasing trend. Dominant effect and connectivity of medium and high coverage vegetation would have an enhancing trend, and vegetation patches would expand towards to northeast of the desert heartland in the future. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Vegetation
Controlled terms:Computation theory - Ecology - Forestry - Image analysis - Image reconstruction - Landforms - Pixels - Remote sensing - Restoration - Sand
Uncontrolled terms:Dichotomy - Gurbantunggut deserts - Landscape heterogeneities - Landscape pattern - Landscape pattern indices - Remote sensing data source - Transition matrix method - Typical meteorological year
Classification code:454.3 Ecology and EcosystemsEcology and Ecosystems
- 481.1 GeologyGeology
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 721.1 Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming TheoryComputer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory
DOI:10.11975/j.issn.1002-6819.2016.03.041
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 14>
Accession number:20161002077966
Title:Reduction of nitrogen, phosphorous and runoff by coordination controlled drainage with basin and ditch in paddy field
Authors:Zhu, Chengli (1); Guo, Xiangping (1); Liu, Minhao (2); Tang, Shuhai (3)
Author affiliation:(1) Key Laboratory of High-Effective Irrigation and Drainage and Agricultural Water and Soil Environment in Southern China, Ministry of Education, Hohai University, Nanjing, China; (2) Development Center for Science and Technology of Rural Water Resources of Jiangsu Province, Nanjing, China; (3) Lianshui Water Conservancy Research Institute, Lianshui, China
Corresponding author:Guo, Xiangping(xpguo@hhu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:86-91
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Heavy rains occur frequently in South China during rice growth stages. The large amount of discharge from paddy field combined with high fertilization has caused serious environmental problems. The present controlled drainage methods pay much attention to holding more water in basins and reducing pollutant from basins, however, how to control runoff from field ditches and non-cultivated areas are often ignored. Coordinated Controlled Drainage (CCD) was proposed in the paper to solve the problem above by making most use of the wetland effects of both paddy field and field ditches that were widely distributed in the farmland in South China. The CCD technique tries to store rainwater in basins as much as possible by using rain-catching and controlled irrigation (RCCI) technique that maintains lower irrigation limit and higher water depth after rain depending on the waterlogging-tolerant and drought-tolerant ability of rice so as to reduce runoff from basins. Furthermore, it also impouned runoff from basins and non-cultivation lands such as roads, ditches and canals by a construction at the outlet of the field ditch. Field experiments were conducted in 2013 to verify the feasibility of the model. Controlled and uncontrolled drainages treatments were designed in rice field. Each controlled field of 4.5 hm<sup>2</sup>. Three replicates were designed. During the experiment, the drainage from field and trench were collected for determination of total nitrogen and phosphorus (TN and TP). Rice yield was measured. The results showed that at field scale, CCD could reduce evaportanspiration and water consumption by 18.8% and 15.3%, compared with frequent and shallow irrigation technique (FSI) respectively. Irrigation quote, drainage quote and irrigation frequency declined 28%, 60.6% and 4 times while TN and TP loss reduced 58.6% and 58.8%. At field control scale, surface drainage volume, the TN and TP burden from controlled ditch decreased by 55.9%, 59.7% and 66.7%, respectively under CCD without reduction of grain yield compared with uncontrolled ditch combined with FSI. The investigation also found that TP and TN concentrations were high both in basin water and ditch water at early stage after rainfall and decreased rapidly with time, indicting that holding water in basins and ditches at that time could remove TN and TN more efficiently. Runoff from non-cultivated area accounted for 31.3%-38.7% of the total runoff from ditches, indicating it was an important source of pollutant. The results above suggested CCD was an effective method to reduce water application, cost of labor, and pollutant burden in paddy field in South China. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:12
Main heading:Catchments
Controlled terms:Drainage - Irrigation - Nitrogen - Phosphates - Phosphorus - Pollution - Rain - Runoff - Water pollution
Uncontrolled terms:Controlled drainage - Controlled irrigations - Environmental problems - Field experiment - Irrigation frequency - Paddy fields - Surface drainage - Water consumption
Classification code:442.1 Flood ControlFlood Control
- 443.3 PrecipitationPrecipitation
- 453 Water PollutionWater Pollution
- 804 Chemical Products GenerallyChemical Products Generally
- 821.3 Agricultural MethodsAgricultural Methods
DOI:10.11975/j.issn.1002-6819.2016.03.013
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 15>
Accession number:20161002077984
Title:Method of calibrating ebullition rate based on tension sensor in eutrophic waters
Authors:Zeng, Kai (1, 2); Liu, Xinhong (1); Zhang, Zhenhua (1); Yan, Shaohua (1)
Author affiliation:(1) Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, China; (2) School of Information Engineering, Zhejiang A & F University, Lin'an, China
Corresponding author:Yan, Shaohua(shyan@jaas.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:216-219
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A method based on tension sensor was deployed to calibrate the ebullition rate in the eutrophic waters. The ebullition was collected using sealed glass bottle connected to a transparent collector and the weight of ebullition in the collector was detected in every hour in the day or night. The transparent collector was used under the water because of its transparent did not shield the light and affect the normal ecosystem activity under the light in water. All the ebullition was collected by the transparent collector connected to a sealed glass bottle through the rubber tube. The sealed glass bottle was fitted with two rubber tubes. The one was used to collect ebullition, and the other was used for drainage. The sealed glass bottle was filled with water first. With the ebullition entering into the sealed glass bottle, the weight of the sealed glass bottle was reduced. The change of the weight of the sealed glass bottle reflected the change of the ebullition. The weight of the sealed glass bottle can be detected by the tension sensor in situ. The weight of the sealed glass bottle was related to the ebullition quantity of the eutrophic waters. The rate of weight reduction was related to the ebullition rate of the eutrophic waters. All of the data can be measured and transmitted by a tension sensor, and collected by the monitoring system in a computer. The analysis and statistics about the ebullition quantity and rate can be monitored through the system software. The method can monitor the ebullition in the eutrophic waters in every minute. It had less artifacts compared to the manual monitoring which is inefficiency, low accuracy, higher complexity and labor intense. The method can completely detect the ebullition in the every time node during a day or night. Not only the method can monitor ebullition rule to reflect ecosystem activity in the eutrophic waters during the day, but also during the night. The results indicated that the method could detect the ebullition rates from 57 to 539 g/(m<sup>2</sup>h) in the day with the high temperature, and the ebullition rates from 49 to 280 g/(m<sup>2</sup>h) in the night with the low temperature in the near optical layer. With this method, we determined ebullition quantity change with time and correlated the ebullition rates and temperatures, light intensities in the environment. Through detecting ebullition quantity and rates in the time node and using the gas chromatography instrument to analyze the component about gas which was collected in a time node, it was found that there were many kinds of gases in the ebullition, and ebullition quantity and rates of each kind of the gas in the eutrophic waters at the different time nodes can be determined. So the ebullition rate at the divided-period contributed to assess the N<inf>2</inf>, N<inf>2</inf>O ebullition fluxes in the eutrophic waters. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Bottles
Controlled terms:Ecology - Ecosystems - Eutrophication - Gas chromatography - Gases - Glass - Glass bottles - Rubber - Sensors - Temperature - Water
Uncontrolled terms:Eutrophic - High temperature - Light intensity - Low temperatures - Manual monitoring - Monitoring system - System softwares - Weight reduction
Classification code:454.3 Ecology and EcosystemsEcology and Ecosystems
- 641.1 ThermodynamicsThermodynamics
- 694.2 Packaging MaterialsPackaging Materials
- 802.3 Chemical OperationsChemical Operations
- 812.3 GlassGlass
- 818.1 Natural RubberNatural Rubber
DOI:10.11975/j.issn.1002-6819.2016.03.031
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 16>
Accession number:20161002077970
Title:Effect of soil erosion in slope cultivated land of Longmenshan earthquake zone on lateral movement of soil organism carbon
Authors:Su, Zheng'an (1, 2); Li, Yan (1); Xiong, Donghong (2); Dong, Yifan (2); Zhang, Su (2); Zhang, Baojun (2)
Author affiliation:(1) Ecological Security and Protection Key Laboratory of Sichuan Province, Mianyang Normal University, Mianyang, China; (2) Key Laboratory of Mountain Hazards and Earth Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China
Corresponding author:Li, Yan(leeleehi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:118-124
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil erosion in the sloping farmland has been recognized as a major contributor that affects soil organic carbon (SOC) stocks and dynamics. However, understanding of the influence of accelerated soil erosion (water erosion and tillage erosion) on carbon dynamics is limited. In particular, little is known on the influence of earth quake-induced erosion and deposition on SOC stocks and dynamics in terraced field systems and steep sloping farmland in Longmenshan earthquake zone, China. In this study, we assessed the spatial variation of soil erosion and lateral movement of soil organic carbon (SOC) in toposequence of stone dike terraces as well as a steep sloping farmland of Longmenshan earthquake zone, China using<sup>137</sup>Cs technique and field investigation. In this study area, effective<sup>137</sup>Cs reference value of the yellow brown soil was estimated at 1 473 Bq/m<sup>2</sup>. Soil loss appeared over the upper parts of the slopes and deposition occurred towards the downslope boundary on each terrace, as well as soil loss at upper terraced fields and soil accumulation at lower terraced fields. Those results indicated that water erosion could transport soil from upper terrace to lower terrace due to lacking banks between two adjacent terraces. It should be noted that net soil erosion rate in the toposequence of the terraced fields was very low. Meanwhile, tillage erosion played an important role in transporting soil from upper slope positions to lower positions within a terrace. Soil erosion rates in the steep slope were higher than those in the toposequence of terraced fields. Besides water erosion, collapse of terrace resulting from earthquake and tillage erosion were also important soil erosion processes on the complex slope. In the steep sloping farmland, soil erosion rates were high at the summit and the lower slope with a high slope curvature. Soil accumulation appeared at lower slope with a low slope curvature and toe slope position. Discrete patterns of SOC inventories (mass per unit area) appeared over the whole terraced toposequence, while SOC inventories were low over the upper parts of the slopes but increased towards the downslope boundary on each terrace. For the steep slope farmland, SOC inventories were lower at the top of slope and at lower slope position with a high slope curvature. Soil organic matter inventories in the terraced filed series and steep slope farmland showed a similar pattern as the<sup>137</sup>Cs inventories. Those patterns were consistent with redistribution of SOC with soil as coupling effect of tillage erosion, water erosion and collapse due to earthquake. Those results indicated that terraced fields played an important role in soil conservation and SOC sequestration in the Longmenshan earthquake zone, China. Although different soil erosion processes were observed between the terraced field series and steep sloping farmland, severe erosion due to anthropogenic activity after the Wenchuan Earthquake significantly changed spatial variations in SOC inventories. In other words, tillage erosion was also one of the important soil erosion processes within a sloping farmland. More attention should be paid to prevention of tillage erosion in this area. Our results demonstrated that terrace with stone dike can better conserve soil in this earthquake stricken area. Soil erosion caused by tillage was one of the major soil erosions in this region for the sloped land. Soil conservation practice must be taken into a consideration in agriculture production. Our results also showed that<sup>137</sup>Cs can be used to successfully trace soil erosion and SOC dynamics in sloping farmland in the Longmenshan earthquake zone, China. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Soil conservation
Controlled terms:Agricultural machinery - Agriculture - Cesium - Deposition - Dynamics - Earthquakes - Erosion - Farms - Geophysics - Hydraulic structures - Levees - Organic carbon - Soils - Water
Uncontrolled terms:Agriculture productions - Anthropogenic activity - Conservation practices - Earthquake zones - Erosion and deposition - Slope terrace - Soil organic matters - Tillage
Classification code:442.1 Flood ControlFlood Control
- 481.3 GeophysicsGeophysics
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 484 SeismologySeismology
- 549.1 Alkali MetalsAlkali Metals
- 802.3 Chemical OperationsChemical Operations
- 804.1 Organic CompoundsOrganic Compounds
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 821.1 Agricultural Machinery and EquipmentAgricultural Machinery and Equipment
DOI:10.11975/j.issn.1002-6819.2016.03.017
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 17>
Accession number:20161002077963
Title:Modeling response of cotton yield and water productivity to irrigation amount under mulched drip irrigation in North Xinjiang
Authors:Wang, Jun (1); Li, Jiusheng (1); Guan, Hongjie (1, 2)
Author affiliation:(1) State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China; (2) College of Soil and Water Conservation, Beijing Forestry University, Beijing, China
Corresponding author:Li, Jiusheng(lijs@iwhr.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:62-68
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Xinjiang Uygur Autonomous Region is the largest cotton-production area of China. As a water saving and high yield irrigation technique, mulched drip irrigation is popular water application method for cotton production in Xinjiang Uygur Autonomous Region. Studying the response of cotton yield to irrigation amount is of great importance. In this study, a two-dimensional soil water transport and crop growth coupled model was calibrated and validated using field data of cotton under mulched drip irrigation, and then used to estimate the cotton yield under different irrigation amount. The field experiment was conducted at the experimental station located in Urumqi, Xinjiang Uygur Autonomous Region, China, during the cotton growing seasons of 2010 and 2011. In this experiment, 3 irrigation levels of 50%, 75% and 100% of full irrigation were adopted. For the full irrigation treatment, irrigation was applied when the averaged soil moisture within the root zone (40 cm for the squaring stage and 60 cm for the bloom stage) was depleted to 60% and 70% of the field capacity for the squaring and bloom stages, respectively. The irrigation was applied until the soil water content reached to 85% and 95% of the field capacity for the squaring and bloom stage, respectively. Soil water content was measured weekly by a Trime-FM probe to 100 cm depth to determine irrigation schedule. Leaf area index and aboveground biomass of cotton plant were observed at squaring, bloom, and boll-forming stages. At the end of each growing season, the seed cotton was harvested by hand. Considering the features of water transport from emitters into soil, a process-based two-dimensional soil water transport and crop growth simulation tools would be preferred to modeling the response of crop yield to irrigation amount under mulched drip irrigation. The coupled model was coded in program subroutines and functions integrated with CHAIN_2D and the crop growth model of EPIC. This model was written in FORTRAN 90 for Windows system. In the coupled model, the root water uptake model of Vrugt was coupled with the root depth growth model in order to consider the interaction between root water uptake and crop growth. To study the response of cotton yield and water productivity to irrigation amount, the two-dimensional soil water transport and crop growth coupled model was calibrated and validated by soil water content dynamic, crop growth indexes and seed cotton yield obtained from the field experiments. The calibration and validation results indicated that the coupled model performed well in predicting the soil moisture, above ground biomass, seed cotton yield and total water use. The values of normalized root mean square error (nRMSE) and index of agreement between observed and simulated soil water contents was 4.6%-23.4%, and 0.677-0.974, respectively. The nRMSE values of leaf area index and aboveground biomass was 6.3%-15.7% and 7.2%-14.1%, respectively. The differences between simulated and measured seed cotton yields and water uses were ranged from 1.1% to 6.7% and from 0.3% to 9.2%, respectively. Furthermore, the calibrated two-dimensional soil water transport and crop growth coupled model was used to simulate seed cotton yield and water productivity under 10 irrigation scenarios, i.e. 40%-130% of full irrigation amount with the increment of 10%. The results showed that the seed cotton yield and water productivity were increased and decreased through quadratic functions as the irrigation amount increased, respectively. Therefore, this study suggested that the appropriate mulched drip irrigation amounts for cotton in the North Xinjiang region ranges from 280 to 307 mm considering the yield and water productivity. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Irrigation
Controlled terms:Biomass - Blooms (metal) - Calibration - Cotton - Couplings - Crops - Cultivation - Ecology - Forestry - Mean square error - Models - Moisture - Productivity - Soil moisture - Soil surveys - Soils - Subirrigation - Subroutines - Water conservation - Water content - Water resources
Uncontrolled terms:Above ground biomass - Calibration and validations - Crop growth model - Experimental stations - Mulched drip irrigations - Root mean square errors - Water productivity - Xinjiang Uygur autonomous region
Classification code:444 Water ResourcesWater Resources
- 454.3 Ecology and EcosystemsEcology and Ecosystems
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 535.1.2 Rolling Mill PracticeRolling Mill Practice
- 723.1 Computer ProgrammingComputer Programming
- 821.3 Agricultural MethodsAgricultural Methods
- 821.4 Agricultural ProductsAgricultural Products
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.010
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 18>
Accession number:20161002077957
Title:Optimization design of non-circular planetary gear trains pricking hole mechanism based on MATLAB
Authors:Wang, Jinwu (1); Zhang, Chunfeng (2); Zhou, Wenqi (1); Pan, Zhenwei (1); Tang, Han (1); Duo, Tianyu (1)
Author affiliation:(1) Engineering College, Northeast Agricultural University, Harbin, China; (2) Beijing Research Center for Intelligent Agricultural Equipment, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:22-28
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, as China government policies in agriculture are focused on improving agriculture machinery, deep-fertilization liquid fertilizer applicator with high efficiency, low price, easy operation and environment protection attracts more and more concerns. Deep fertilization for liquid fertilizer is a technology that liquid fertilizer is application accurately in 120-150 mm depth soil, which decreases fertilizer volatilization, increases crop's nutrient absorbance in fertilizer, decreases environmental pollution brought by fertilizer, and increases crop yield and quality. Deep fertilization for liquid fertilizer is to make the liquid fertilizer into the soil. Northeast Agricultural University developed all elliptic planetary gears for pricking hole mechanism of 1YJ-140 type deep-fertilization liquid fertilizer applicator. Although the mechanism was obtained via using design method for obverse operation, there were a certain blindness in the process of seeking the optimal parameters and a long process of seeking parameters. The transmission part of pricking hole mechanism adopted all elliptic planetary gears so its transmission ratio was fixed. It was difficult to find a perfect path curve. So the non-circular planetary gear trains for pricking hole mechanism was proposed. Several date points on the motion trace of fertilizer-spraying needle tip were selected, and then the curve fitting technique of cubic non-uniform B-spline was applied to control and ascertain the whole trace curve. The inverse kinematics model of the pricking hole mechanism was established on this basis. Then, other parameters could be reversed easily. To meet agronomic requirements of verticality and hole mouth size for deep-fertilization liquid fertilizer machine' fertilizer-spraying needle when it came in and went out of the soil, the simulation software of reverse design and kinematics analysis was compiled, which was for pricking hole mechanism of the non-circular gear planetary system. The software avoided the blindness that the obverse design method tried the wrong parameters. By changing the coordinates for some types of value points on static trajectory to control fertilizer-spraying needle point posture, the reverse process, simulation result and mechanism motion process were showed intuitively and dynamically, and the optimized parameters were that the gears' center distance was 61.5 mm, the distance between planetary gear center and fertilizer-spraying needle point was 161 mm, the cave mouth width was 28 mm, the track height was 252 mm and the width was 182 mm. High-speed photography bench was established and tested. The relative motion trajectory of fertilizer-spraying needle point and the key point posture were inspected in the process of actual operation. The results showed that the fertilizer-spraying needle point trajectory height was 246 mm and the width was 188 mm, and the accuracy and feasibility of reverse design and analysis were validated. This study uses many methods such as theoretical analysis mathematics, computer numerical simulation, high speed camera technology and rack experiments, and provides the reference for improving agricultural machinery quality and fertilizer applicator design level. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Fertilizers
Controlled terms:Agricultural machinery - Agriculture - Applicators - Computer simulation - Computer software - Crops - Curve fitting - Design - Environmental technology - Epicyclic gears - Eye protection - Gears - High speed cameras - High speed photography - Inverse kinematics - Inverse problems - Kinematics - Liquids - Machine design - MATLAB - Mechanization - Needles - Numerical methods - Optimization - Quality control - Soils - Trajectories
Uncontrolled terms:Agriculture machinery - Curve fitting technique - Environment protection - Environmental pollutions - Liquid fertilizer applicators - Liquid fertilizers - Planetary gear train - Reverse designs
Classification code:454 Environmental EngineeringEnvironmental Engineering
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 601 Mechanical DesignMechanical Design
- 601.2 Machine ComponentsMachine Components
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 723.5 Computer ApplicationsComputer Applications
- 742.1 PhotographyPhotography
- 742.2 Photographic EquipmentPhotographic Equipment
- 804 Chemical Products GenerallyChemical Products Generally
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 913.3 Quality Assurance and ControlQuality Assurance and Control
- 914.1 Accidents and Accident PreventionAccidents and Accident Prevention
- 921.5 Optimization TechniquesOptimization Techniques
- 921.6 Numerical MethodsNumerical Methods
- 931.1 MechanicsMechanics
DOI:10.11975/j.issn.1002-6819.2016.03.004
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 19>
Accession number:20161002077956
Title:Design and experiment on air-blast rice side deep precision fertilization device
Authors:Zuo, Xingjian (1, 2, 3, 4); Wu, Guangwei (2, 3, 4); Fu, Weiqiang (2, 3, 4); Li, Liwei (2, 3, 4); Wei, Xueli (2, 3, 4); Zhao, Chunjiang (1, 3)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, China; (2) National Research Center of Intelligent Equipment for Agriculture, Beijing, China; (3) Key Laboratory of Agri-informatics, Ministry of Agriculture, Beijing, China; (4) Beijing Key Laboratory of Intelligent Equipment Technology for Agriculture, Beijing, China
Corresponding author:Zhao, Chunjiang(zhaocj@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:14-21
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rice is the most important crop in China, which has the largest plant area, the highest per unit area yield and the most total output. Fertilization is an important process of rice production, which directly affects the yield of crops, and reasonable and effective use of chemical fertilizer can improve the yield of crops. At present, the mechanization level of rice fertilization is very low in China, and the artificial fertilization with a large amount of fertilizer causes the uneven distribution of fertilizer. The side deep fertilization for rice is an ideal way of fertilization. The fertilization device will apply fertilizer (basal and tiller fertilizer) quantitatively and with one-time positioning based on the agronomic requirements, and it can carry out a uniform fertilization to the rice's side position with a certain depth, which can reduce nitrogen fertilizer amount of 20%-30% compared with the traditional fertilization operation. It is a cultivation technique with high output, stable yield and low cost. In view of the low-level mechanization of rice fertilization in China, the large amount of fertilizer application and the low fertilizer utilization in the traditional manual fertilization, combined with the agronomic characteristics of side deep fertilization, we analyzed the fertilization method of wind delivering and developed the air-blast rice side deep precision fertilization device. This device adopted the modularization design and was combined with riding type rice transplanter for use. In the process of operation, the fertilizer granules fell into the deep trench with a certain amount under the effect of gravity and wind; the trench with 5 cm depth was dug by fertilizer exports at the position 3 cm away from seedling side, and the fertilizers would be covered in the mud by covering plate. The device used the rated voltage of 12 V and the power of 72 W; the blower was used to transport fertilizer based on the Venturi effect, and the inner diameter of fertilizer conveying pipe was 25 mm and the velocity was 21 m/s; the global position system (GPS) was used to measure transplanter speed. The speed of the vehicle was proportional to the speed of the motor by using the precision fertilization control method, which could match the vehicle speed and drive motor speed in real time. The speed measurement closed-loop control was used as the control system. Motor drive used the AQMD2410NS direct current motor drive, and motor hold a stable speed by using the internal drive integration of the proportion-integration-differentiation (PID). The vehicle control terminal was designed under the embedded Visual C++ integrated development environment in the XP Windows operating system, the interface could display the current operating data, and meanwhile, the user could set the working parameters according to the actual operating requirements. When presetting fertilization amount to 300 kg/hm<sup>2</sup>, the motor rotation speed was 10, 20, 30 and 40 r/min, respectively. The fertilizer difference test with 6 fertilizer discharging ports was carried out, and the coefficients of variation of fertilizer application amount were 2.3%, 2.1%, 2.2% and 1.8%, respectively. The experiments were conducted on Heilongjiang Seven-star Farm, and the result showed, planting and fertilization could be done completely and independently in one time when fertilization device and riding type rice transplanter operated. When the preset rate of fertilization was 300 kg/hm<sup>2</sup>and the vehicle speed was 1 m/s, the fertilization device could realize the precision fertilization, and the deviation of fertilization application amount was within 5.82%, which could meet the requirement of the actual production. The research provides reference for the development of the rice variable fertilization control technology and the research and development of the rice side deep fertilization device. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Nitrogen fertilizers
Controlled terms:Agricultural machinery - Agronomy - C++ (programming language) - Control system synthesis - Crops - Cultivation - DC motors - Design - Digital storage - Electric drives - Electric motors - Fertilizers - Machine design - Mechanization - Modular construction - Proportional control systems - Speed - Vehicles - Web services - Windows operating system
Uncontrolled terms:Coefficients of variations - Fertilizer applications - Integrated development environment - Precision fertilizations - Proportion integration differentiations - Research and development - Side deep fertilization - Variable fertilizations
Classification code:405.2 Construction MethodsConstruction Methods
- 601 Mechanical DesignMechanical Design
- 705.3 Electric MotorsElectric Motors
- 705.3.2 DC MotorsDC Motors
- 722.1 Data Storage, Equipment and TechniquesData Storage, Equipment and Techniques
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 723.1.1 Computer Programming LanguagesComputer Programming Languages
- 731.1 Control SystemsControl Systems
- 804 Chemical Products GenerallyChemical Products Generally
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.11975/j.issn.1002-6819.2016.03.003
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 20>
Accession number:20161002077991
Title:Prediction for relocation scale of rural settlements based on farming radius in reclamation area of open-pit coal mine
Authors:Hu, Xingding (1); Bai, Zhongke (1, 2)
Author affiliation:(1) School of Land Science and Technology, China University of Geosciences, Beijing, China; (2) Key Lab of Land Consolidation and Rehabilitation, The Ministry of Land and Resources, Beijing, China
Corresponding author:Bai, Zhongke(Baizk@cugb.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:259-266
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mine reclamation has become a worldwide problem recently and has similar research directions both in China and abroad, including ecological restoration, mining technology, bioremediation technology, soil reconstruction techniques, soil quality testing, plant species selecting. The key target is to restore the ecological system and improve the environment. One of the main purposes of reclamation is to restore farmland, which is scarce in China. In addition, resettlement of residents and their living environment need to be taken into account. In this paper, the study area is the Pingshuo open-pit mine, which is located in Shuozhou City, Shanxi Province, China, and belongs to super-large open-pit mine with modern production. Mining activities began in 1987, and have lasted for 28 years until now. Fourteen rural settlements have moved, and resettlement population has reached 8400 by 2013. From the perspective of farming radius, buffer analysis of rural settlements was used to contrast the difference of farming radius before and after the open-pit mining by geographic information system (GIS) technology. Considering the impact of topography on farming radius, this paper calculated the terrain correction coefficient of farming radius in the study area using the achievements about relief amplitude, and the mean change-point analysis method was adopted to determine the best statistics grid unit to reflect terrain. Through buffer analysis, the result of spatial farming radius showed that the farming radius had a great change from 1986 to 2013 because of open-pit mining. Therefore, the best farming radius should be determined based on the result in 1986. Using the equation of farming radius, per capita arable land and the number of population were calculated through combining the method of "the ratio of arable land area to settlements land area" Finally, optimal farming radius was determined according to the calculation result about the terrain correction coefficient and the scale of arable land. We predicted the size and number of rural settlements after completing reclamation. The results showed that: 1) Affected by mining, the farming radius has expanded by 1500 m from 1986 to 2013, and the largest farming radius was 4500 m; 2) Determining the optimal statistics grid unit to calculate the value of relief amplitude, the result showed that 550 m × 550 m was the optimal statistics grid unit to reflect terrain in study area; 3) Based on the buffer analysis, digital elevation map neighbourhood analysis and forecasting, the terrain correction coefficient of farming radius was 1.6836, and the optimal actual farming radius was 1500 m, and therefore, the optimal spatial farming radius was 891 m. 4) On the premise of guaranteeing the arable land quantity unchanged, the total area of relocated rural settlements was about 651.24 hm<sup>2</sup>, and there were 67 rural settlements in total. Individual rural settlement area was predicted to be 9.72 hm<sup>2</sup>, and the control area of arable land was about 109.68 hm<sup>2</sup>. 5) The total relocated population would be about 29521 (7380 families). The results of this study can provide the reference for the implementment of relocating rural settlements and the reuse of reclaimed arable land in Pingshuo mining area. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Open pit mining
Controlled terms:Agriculture - Bioremediation - Coal mines - Coal reclamation - Ecology - Geographic information systems - Land reclamation - Land use - Landforms - Mining - Reclamation - Removal - Restoration - Rural areas - Soil testing
Uncontrolled terms:Bioremediation technologies - Digital Elevation Map - Ecological restoration - Farming radius - Large open-pit mines - Placement - Reconstruction techniques - Rural settlement
Classification code:403 Urban and Regional Planning and DevelopmentUrban and Regional Planning and Development
- 442.2 Land ReclamationLand Reclamation
- 454.2 Environmental Impact and ProtectionEnvironmental Impact and Protection
- 454.3 Ecology and EcosystemsEcology and Ecosystems
- 481.1 GeologyGeology
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 502.1 Mine and Quarry OperationsMine and Quarry Operations
- 503.1 Coal MinesCoal Mines
- 524 Solid FuelsSolid Fuels
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 903.3 Information Retrieval and UseInformation Retrieval and Use
DOI:10.11975/j.issn.1002-6819.2016.03.038
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 21>
Accession number:20161002077968
Title:Relationship between multi-scale landscape pattern and salinity in Weigan and Kuqa rivers delta oasis
Authors:Cao, Lei (1, 2); Ding, Jianli (1, 2); Yu, Haiyang (1, 2)
Author affiliation:(1) College of Resources and Environment Sciences, Xinjiang University, Urumqi, China; (2) Key Laboratory of Oasis Ecology under Ministry of Education, Xinjiang University, Urumqi, China
Corresponding author:Ding, Jianli(watarid@xju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:101-110
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Saline soil occupies a large area and is widely distributed in China. Soil salinization poses a great threat to regional agriculture development. Exploring the relationship between landscape pattern and soil salinity will facilitate the monitoring and assessment of soil salinization. In this study, Weigan and Kuqa rivers delta oasis taken as a study area, the effects of soil salinity on regional landscape pattern was investigated through the analysis of multi-scale landscape pattern and soil salinity in different sections with the combination of regional soil salinity variation regularity. GF-1 satellite imagery (taken on July 19, 2014) was used as the main data source, land use/land cover types of the study area were divided into 5 categories using the maximum likelihood supervised classification: arable land, forest and grassland (including the garden, natural forests and grasslands), water, saline land (heavily) and others (including slightly and moderately saline land, desert, mountains, etc.). 11 landscape indices were selected including class area (CA), number of patches, largest patch index(LPI), percentage of landscape(PLAND), patch density(PD), landscape shape index(LSI), fractal dimension (perimeter-area fractal dimension, PAFRAC), aggregation index(AI), interspersion and juxtaposition index(IJI), shannon's diversity index(SHDI), contagion index(CONTAG). Combined with soil salinity data at different depths of 38 samples collected in 22-28 July 2014, to the center of a circle of sampling points, a total of 5 circular buffer gradients with 0.5, 1, 2, 3 and 5 km radius buffer was chosen as the unit of analysis. Pearson correlation analysis and stepwise regression analysis were applied to analyze the relationships between landscape pattern and soil salinity and reveal the spatial distribution pattern of soil salinity. In the end, the typical pattern of oasis, oasis-desert ecotone pattern, desert landscape pattern and Weigan and Kuqa rivers delta oasis overall landscape pattern were analyzed. The results showed that: 1) On the horizontal direction, highly salinized soil was mainly distributed in the eastern desert and western farming-pastoral zone of the oasis; On the vertical direction, soil salinization problem was most serious on soil surface and was less serious in the other soil layers. The degree of soil salinization decreased as the increase of depth; 2) The fragmentation index of oasis was higher than other landscape because of the oasis area easily affected by human activities. Under different gradient, the region landscape types increased, heterogeneity decreased, diversity increased, when buffer distance increased; 3) The amount of cultivated land could indicate soil salinity, but the other indexes including land area, saline land area, water area, LPI, CONTAG and PAFRAC exhibited limited influence on salinity; 4) For the independent variables from soil depth 10-20 to 80-100 cm, the arable land, water area and LPI had negative relationship with soil salinity while it became positive for indexes including salinized land area, CONTAG and other PAFRAC. The best regression model was obtained with R<sup>2</sup>=0.537. The study confirmed that the character of soil salinity distribution and the degree of influence of different level of salinity on oasis landscape pattern. Our results can provide some basic information for soil salinity warning/alarming in arid area in northwest China. Meanwhile, it can serve as a reference to the research on landscape pattern in arid areas. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Soils
Controlled terms:Agriculture - Arid regions - Correlation methods - Forestry - Fractal dimension - Fractals - Land use - Landforms - Maximum likelihood - Regression analysis - Remote sensing - Rivers - Saline water - Salts - Satellite imagery
Uncontrolled terms:GF-1 - Landscape pattern - Maximum likelihood supervised classifications - Monitoring and assessment - Pearson correlation analysis - Spatial distribution patterns - Stepwise regression analysis - Weigan and Kuqa rivers delta oasis
Classification code:403 Urban and Regional Planning and DevelopmentUrban and Regional Planning and Development
- 444 Water ResourcesWater Resources
- 481.1 GeologyGeology
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 655.2 SatellitesSatellites
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 921 MathematicsMathematics
- 922.1 Probability TheoryProbability Theory
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.015
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 22>
Accession number:20161002077974
Title:Inverting wheat leaf area index based on HJ-CCD remote sensing data and random forest algorithm
Authors:Wang, Liai (1); Zhou, Xudong (2); Zhu, Xinkai (1); Guo, Wenshan (1)
Author affiliation:(1) Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou, China; (2) Information Engineering College of Yangzhou University, Yangzhou, China
Corresponding author:Guo, Wenshan(guows@yzu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:149-154
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The leaf area index (LAI) of crops is an important parameter for crop monitoring. With the remote sensing application in agriculture, inverting LAI of crops from remote sensing data has been studied. Among these studies, vegetation indices are widely used because they can reduce effect background noise on the spectral reflectance of plant canopies. In addition to using vegetation indices, modeling algorithm also plays an important role in improving the remote estimation accuracy of crop LAI. Recently, the emerging Random Forest (RF) machine-learning algorithm is regarded as one of the most precise prediction methods for regression. In this paper, we conducted studies on wheat LAI estimations utilizing RF algorithm and vegetation indices. Firstly based on China's environmental satellite charge-coupled device (HJ-CCD) image data of wheat (Triticum aestivum) from test sites in Jiangsu province of China during 2010-2013, fifteen vegetation indices from previously reported results and related LAI were respectively calculated at the jointing, booting, and anthesis stages. Then, through utilizing RF algorithm, the LAI inverting model for each stage was respectively established based on its vegetation indices and corresponding in situ wheat LAI measured during the HJ-CCD data acquisition. For each stage, the pooled data from 2010-2013 were randomly divided into a training dataset and an independent model validation dataset (75% and 25% of the pooled data, respectively). For the training dataset, the number of samples was 174 at jointing, 174 at booting, and 147 at anthesis. For the validation dataset, the number of samples was 58 at jointing, 58 at booting, and 49 at anthesis. The training dataset was used to establish models to predict wheat LAI during each growth stage, and the validation dataset was employed to test the quality of each prediction model. The RF model of each stage for estimating wheat LAI was then established in which the 15 vegetation indices were considered to be the independent variables and wheat LAI was the dependent variable. Additionally for each stage, the model based on artificial neural network (ANN) machine-learning algorithm was employed as a reference model, which had been successfully used to invert LAI of crops in previous studies. In order to evaluate each model's estimation accuracy and to further compare the performances of the two models for each stage, the coefficients of determination (R<sup>2</sup>) and the corresponding root mean square errors (RMSE) for the estimated-versus-measured LAI were calculated respectively on the basis of the corresponding validation data. The results indicated that RF outperformed ANN at each stage. For RF models, the R<sup>2</sup>for the estimated-versus-measured LAI values for the three stages were 0.79, 0.67, and 0.59, respectively, in contrast to 0.57, 0.90, and 0.78 from RMSE. For ANN models, the R<sup>2</sup>for the three stages was 0.67, 0.31, and 0.30, respectively, and the corresponding RMSE was 0.82, 1.94, and 1.43. Furthermore, RF showed the vegetation index of model that noticeably contributed to the LAI estimation for each stage (i.e., EVI at jointing, MTVI2 at booting, and MSR at anthesis). Thus, the RF algorithm provides an effective way to improve the prediction accuracy of LAI in wheat on a large scale. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Learning algorithms
Controlled terms:Algorithms - Artificial intelligence - Charge coupled devices - Crops - Data acquisition - Decision trees - Estimation - Forecasting - Learning systems - Mean square error - Neural networks - Remote sensing - Statistical tests - Vegetation
Uncontrolled terms:Environmental satellites - Leaf Area Index - Random forest algorithm - Random forests - Remote sensing applications - Root mean square errors - Spectral reflectances - Wheat
Classification code:714.2 Semiconductor Devices and Integrated CircuitsSemiconductor Devices and Integrated Circuits
- 723.2 Data Processing and Image ProcessingData Processing and Image Processing
- 723.4 Artificial IntelligenceArtificial Intelligence
- 821.4 Agricultural ProductsAgricultural Products
- 921 MathematicsMathematics
- 922.2 Mathematical StatisticsMathematical Statistics
- 961 Systems ScienceSystems Science
DOI:10.11975/j.issn.1002-6819.2016.03.021
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 23>
Accession number:20161002077954
Title:Characteristics of residual mulching film and residual coefficient of typical crops in North China
Authors:Zhang, Dan (1); Hu, Wanli (2); Liu, Hongbin (1); Du, Lianfeng (3); Xu, Yu (4); Cheng, Zhenhua (5); Sun, Shiyou (6); Wang, Hongyuan (1)
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Key Laboratory of Nonpoint Source Pollution Control, Beijing, China; (2) Institute of Agricultural Environment and Resources, Yunnan Academy of Agricultural Sciences, Kunming; Yunnan, China; (3) Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China; (4) Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences, Ji'nan, China; (5) Tianjin Agro-Environment Monitoring Station, Tianjin, China; (6) Institute of Agricultural Resources and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang, China
Corresponding author:Wang, Hongyuan(wanghongyuan@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:1-5
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plastic films have been used extensively as mulching for crops in modern agriculture, and remarkably improved crop yields in the past decades. However, the vast amount of residual plastic films results in serious pollution in the arable land. In order to expound the status of residual films and the residual coefficient of mulch in typical croplands in North China, the amounts of the residual films were studied by using the methods of farm survey with questionnaires and quadrat sampling in 124 study sites from 2008 to 2011 in Beijing, Tianjin, Hebei, Shandong, Shanxi, Henan, Inner Mongolia. During questionnaire survey, the relevant status of mulching application including soil characteristics, crop type, mulching time and recovery method etc. was investigated. Based upon this, the residual coefficient of typical crops (peanut and cotton) was calculated through the methods of field monitoring from 2011 to 2014, by determining the amount of residual film before and after test. The results showed that the amount of film mulch residue in North China fields ranged from 0.2 to 82.2 kg/hm<sup>2</sup>, with an average value of 26.8 kg/hm<sup>2</sup>. Among the surveyed sites, 4.8% of fields presented a greater mulch residual volume than the national film residue standard (65 kg/hm<sup>2</sup>), and 16.1% of fields showed a residual film amount approaching this threshold. The residual amount was significantly different (P<0.05) between different crops and provinces. The residual amount of mulch film in peanut and cotton field was highest, reaching 32.0 and 31.8 kg/hm<sup>2</sup>, respectively. The high residue film in peanut and cotton field was caused by different reasons. For peanut, it was attributed to the small mulching thickness which was mostly less than 0.005 mm, while for cotton the reason was the long mulching time. Meanwhile, Hebei was the one with the most residual mulching film (36.8 kg/hm<sup>2</sup>), because of the large proportion of peanut and cotton fields. In the year of 2011, the total amount of residual film in North China was 1.5×10<sup>5</sup>t. Vegetables, cotton and peanut field had great contributions to the total amount of residual film in this region, and the amount of residual film was 5.5×10<sup>4</sup>, 3.9×10<sup>4</sup>and 3.0×10<sup>4</sup>t, respectively. Three years of residual coefficient test showed that the residual coefficient of peanut and cotton were 9.7% and 14.3%. If the present mulching pattern was carried on, the quantity of residual film in peanut and cotton fields would reach up to 69.1 and 70.4 kg/hm<sup>2</sup>in 2021, becoming polluted areas that exceed the national standard of film residue. Although the pollution of residual film was not serious at present, it will become a significant issue if no measure was taken to solve it. It is in urgent need to elevate mulch film standards, develop biodegradable mulch film and enhance mulch film recycling. This study will eventually contribute to promoting effective control and management of residual mulch pollution in North China. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:15
Main heading:Crops
Controlled terms:Agriculture - Cotton - Films - Oilseeds - Plastic films - Pollution - Pollution control - Soil pollution - Soils - Surveys
Uncontrolled terms:Coefficient tests - Control and management - Modern agricultures - National standard - North China - Questionnaire surveys - Residual coefficient - Soil characteristics
Classification code:483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 817.1 Polymer ProductsPolymer Products
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 821.4 Agricultural ProductsAgricultural Products
DOI:10.11975/j.issn.1002-6819.2016.03.001
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 24>
Accession number:20161002077986
Title:Phosphorous transformation during cattle farm biogas slurry treatment using struvite crystallization
Authors:Li, Honggang (1); Chen, Yucheng (1, 2); Xiao, Guangquan (1, 2); Huang, Lei (1); Yang, Zhimin (1, 2)
Author affiliation:(1) College of Resources and Environment, Southwest University, Chongqing, China; (2) Chongqing Key Lab of Agricultural Resources & Environment, Chongqing, China
Corresponding author:Xiao, Guangquan(xiaogq@swu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:228-233
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Struvite (or MAP) crystallization is a promising method for removing and recovering phosphorus from wastewater such as biogas slurry which is a wastewater high in phosphorus content. In this research, we analyzed different forms of phosphorus in cattle farm biogas slurry and phosphorous transformation in cattle farm biogas slurry during struvite crystallization. The transformation processes under pH value of 8.5, 9.0 and 9.5 were respectively observed based on measurement of the P content in liquid and solid phases which was mainly magnesium ammonium phosphate (MAP) obtained by centrifugation. Struvite was determined by the following steps: 1) The solid was recovered by centrifugation after the crystallization; 2) It was then washed and dried repeatedly; 3) It was dissolved by 1 mol/L of HCl; 4) The ammonium was detected; 5) The amount of struvite was calculated based on each MgNH<inf>4</inf>PO<inf>3</inf>6H<inf>2</inf>O molecule which contained one ammonium molecule only. Phosphorus of liquid phase was classified into particulate phosphorus (PP), ortho phosphate (Ortho-P) and reductive dissolved phosphorus (RDP). In other phases, it was classified into phosphorus extracted by deionized water (H<inf>2</inf>O), NaHCO<inf>3</inf>, NaOH and HCl, respectively. Among them, H<inf>2</inf>O-P and NaHCO<inf>3</inf>-P was regarded as soluble phosphorus, while NaOH-P was regarded as a phosphorus compound which was combined with iron & aluminum (Fe-P/Al-P) and HCl-P was regarded as a phosphorus compound which was combined with calcium & magnesium (Ca-P/Mg-P). Before struvite crystallization, total phosphorus of (56.21±0.75) mg/L in liquid phase existed in the form of PP, Ortho-P and RDP with contents of 41.01%, 53.69% and 5.30%, respectively. Meanwhile, 5.69%, 25.45%, 12.32% and 32.16% of total phosphorus of (79.97±1.84) mg/L in solid phase was extracted successively by deionized water, 0.5 mol/L NaHCO<inf>3</inf>, 0.1 mol/L NaOH and 1.0 mol/L HCl, respectively, while the remained 24.38% was residual phosphorus (Re-P). During the struvite crystallization at about pH value 8.5, 9.0, and 9.5, the content of Ortho-P of (30.18±0.37) mg/L in liquid phase decreased to (17.98±0.30), (11.43±0.73) and (6.23±1.32) mg/L, respectively. The content of NaOH-P of (9.85±0.18) mg/L in solid phase decreased to (1.47±0.11), (1.29±0.07) and (1.44±0.27) mg/L, respectively. Meanwhile, the content of HCl-P in solid phase increased significantly (P<0.05). In most cases, the fraction of other forms of phosphorus such as PP and RDP in liquid phase and H<inf>2</inf>O-P, NaHCO<inf>3</inf>-P and Re-P in solid phase did not vary significantly (P>0.05). According to the experiment, we can speculate that Ortho-P and NaOH-P (Fe-P/Al-P) were transformed into struvite and the other forms. Ortho-P and NaOH-P occupying 29.39% of biogas slurry phosphorus made greatest contribution to struvite formation among all forms, and 80.84% of them were removed from cattle farm biogas slurry, of which 91.28% of them were the struvite formed at about pH 9.5. After the crystallization, 10.96% (mass proportion) of the precipitation could be regarded as struvite at about pH 9.5, and the proportions were 6.97% and 9.25% at about pH 8.5 and pH 9.0, respectively. Thus, pH 9.5 was regarded as the proper pH for struvite crystallization among the values pH value 8.5, 9.0 and 9.5. In this paper, we clarified the transformation of different forms of phosphorus in cattle farm biogas slurry. In this way, it can be used as a reference for struvite crystallization condition optimization in the future. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Phosphorus
Controlled terms:Biogas - Calcium - Centrifugation - Crystallization - Deionized water - Extraction - Iron compounds - Liquids - Magnesium - Molecules - pH - Phosphorus compounds - Pollution control - Precipitation (chemical) - Water pollution - Water pollution control
Uncontrolled terms:Biogas slurry - Crystallization conditions - Dissolved phosphorus - Magnesium ammonium phosphates - Particulate phosphorus - Phosphorus contents - Struvites - Transformation process
Classification code:445.1 Water Treatment TechniquesWater Treatment Techniques
- 453 Water PollutionWater Pollution
- 453.2 Water Pollution ControlWater Pollution Control
- 522 Gas FuelsGas Fuels
- 549.2 Alkaline Earth MetalsAlkaline Earth Metals
- 801.1 Chemistry, GeneralChemistry, General
- 802.3 Chemical OperationsChemical Operations
- 804 Chemical Products GenerallyChemical Products Generally
- 931.3 Atomic and Molecular PhysicsAtomic and Molecular Physics
DOI:10.11975/j.issn.1002-6819.2016.03.033
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 25>
Accession number:20161002077961
Title:Calculation of concrete with mineral admixture hydration products volume fraction and its influential factors
Authors:Wu, Fufei (1); Dong, Shuangkuai (2); Gong, Jingwei (1); Chen, Liangliang (1); Li, Dongsheng (1); Shi, Kebin (1)
Author affiliation:(1) College of Civil and Hydraulic Engineering, Xinjiang Agricultural University, Urumqi, China; (2) College of Pratacultural and Environmental Sciences, Xinjiang Agricultural University, Urumqi, China
Corresponding author:Shi, Kebin(xndsg@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:48-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Powers theory proposes calculation method for the pure volume of cement hydration products, which does not apply to calculate the volume of cementitious materials with mineral admixture. The formula of cementitious materials volume was proposed that based on the basic principles of cement and mineral admixture hydration, and the proposed method of reliability was verified by the results of Powers theoretical model and volume fraction of cement hydration products. On this basis, the factor such as water-cement ratio, the ratio of admixture and types was further researched for the volumes of cementitious materials hydration products. Mixture in test were designed 2 water-cement ratio (0.30 and 0.40, respectively), two content (20% and 60%, respectively) of mineral admixture, and 3 kinds of mineral admixture (lithium slag, fly ash and steel slag, respectively), forming paste that was stirred according with the designed ratio in 5 mL centrifuge tube in a blender and curing to 1, 7, 14, 28, 60 and 90 d in curing room (temperature was (20±1), humidity was not less than 95%), and then testing reaction extent of cement and mineral admixture (such as fly ash, steel slag. lithium slag) according with the chemical bound water and HCl dissolution method. The results showed that hydration extent of lithium slag, fly ash and steel slag at 28d decreased by 46.63%, 69.56% and 74.82% (P<0.05) when mineral admixture content varied from 20% to 60% and water-cement ratio was 0.30. Hydration extent of cement at 28 d was increased by 7.25% when water-cement ratio increased from 0.30 to 0.40. When mineral admixture content varied from 20% to 60%, hydration extent of lithium slag, fly ash and steel slag at 28 d increased by 24.14% 18.56%, 17.61% and 8.84%, 12.21%, and 29.37% (P<0.05), respectively. In contrast, the influence of the mineral admixture content was bigger than water-cement ratio for the hydration extent of composite cementitious materials. In different water-cement ratio and the same mineral admixture content, the hydration extent of cement-based materials with lithium slag was maximal, followed by fly ash, steel slag was minimal, and it could be improved when curing period was extended. The calculated volume fractions of composite cementitious material, CSH, aluminates phase AF and CH in composite cementitious material were lower than cement paste, the volume fraction of unhydrated particles and pores were higher than cement slurry. The volume fraction of unhydrated particles, CSH, CH, aluminates phase AF and pores in lithium slag-cement based was 36.64%, 37.01%, 9.48%, 17.45% and 8.68%, respectively. The volume fraction of unhydrated particles, CSH, CH, aluminates phase AF and pores of fly ash and steel slag-cement based was 100.93%, 91.49%, 101.79%, 102.81%, 131.80% and 97.59%, 91.38%, 106.33%, 97.71%, 170.16% that of lithium slag-cement based. The volume of the pores and CSH gel increased because of the secondary reactions between CH in cement and SiO<inf>2</inf>and Al<inf>2</inf>O<inf>3</inf>in mineral admixture when lithium slag, fly ash and slag were incorporated. But the volume fraction of CSH in cement-lithium slag slurry and the volume fraction of AF in cement- fly ash slurry were larger than others, even if the water-cement ratio was from 0.30 to 0.40. Mineral admixtures was different because of chemical composition of mineral admixtures, pozzolanic activity, particle morphology and origin and processing techniques was different, therefore, the volume fraction of unhydrated particles, pores, CSH, CH and aluminates phase were affected by water-cement ratio with content and admixture species, water-cement ratio, water-cement ratio and admixture species and content, respectively. On the whole, the performance of cement-lithium slag slurry was the best, followed by cement-fly ash slurry, and cement-steel slag was the minimum. This study can provide valuble information for lithium slag, fly ash and steel slag to use in cement and concrete, and to reduce energy consumption and conserve resources. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Cements
Controlled terms:Aluminum compounds - Blending - Concrete products - Concretes - Curing - Energy utilization - Fly ash - Hydration - Lithium - Minerals - Slag cement - Slags - Steel testing - Volume fraction
Uncontrolled terms:Admixture - Cement based material - Cementitious materials - Composite cementitious materials - Hydration products - Particle morphologies - Performance of cement - Reduce energy consumption
Classification code:412 ConcreteConcrete
- 412.1 CementCement
- 482.2 MineralsMinerals
- 525.3 Energy UtilizationEnergy Utilization
- 542.4 Lithium and AlloysLithium and Alloys
- 545.3 SteelSteel
- 641.1 ThermodynamicsThermodynamics
- 802.2 Chemical ReactionsChemical Reactions
- 802.3 Chemical OperationsChemical Operations
DOI:10.11975/j.issn.1002-6819.2016.03.008
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 26>
Accession number:20161002077972
Title:Risk analysis of raising reservoir flood limited water level based on Bayes theorem and flood forecast error
Authors:Zhou, Rurui (1); Lu, Di (2); Wang, Bende (1); Zhou, Huicheng (1)
Author affiliation:(1) School of Hydraulic Engineering, Dalian University of Technology, DaLian, China; (2) PowerChina Huadong Engineering Corporation Limited, Hangzhou, China
Corresponding author:Lu, Di(ludi_dlut@aliyun.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:135-141
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The development of hydrometeorological forecast technology offers important opportunities for reservoir dynamic control of flood limited water level. Economic benefits can be improved by raising the flood limited water level, but there is certain flood control risk. The purpose of this study was to propose a risk analysis method of upper bound of dynamic control of flood limited water level in order to provide the support for the development of dynamic control of flood limited water level. The proposed risk analysis method was based on Bayes theorem and flood forecast error characteristics. Qinghe reservoir, located in the northeast of China, was taken as an example. 21 flood events of actual and forecast runoff from the year 1964 to 2013 were used. For large reservoirs that has the ability for multi-year regulation, decision makers of flood control operation concern a lot about runoff forecast accuracy because the design flood is controlled by the flood volume. First, maximum entropy method was selected to simulate the runoff prediction error probability density function of 21 flood events, also forecast error range was calculated. According to the actual need of runoff forecast error in Qinghe reservoir, the range was divided into 6 zones, and distribution probabilities of runoff forecast errors in each zone, namely the prior probability distributions of flood forecasting errors were obtained by integrating the density function. Then, the probabilities of the highest water levels being higher than corresponding designed levels within different flood forecast error bounds were studied, and the risks of different flood forecast errors were inferred by Bayes theorem when the highest water level in flood regulation met with the design flood frequency. Based on the risk analysis method, risks of each design water level considering flood forecast information were compared with risks of conventional mode. The proposed risk analysis method of upper bound of dynamic control of flood limited water level was compared with the conventional mode risk calculation results, which could be concluded that upper bound of dynamic control of flood limited water level considering forecast errors was safe and feasible. The risk method of single condition calculation was compared with Bayesian risk, which could be concluded that the proposed method was reasonable. The results showed that for the design flood level of 138.06 m, the risk rate of raising the flood limited water level as 127.80 m for flood forecast operation was 0.00077%, smaller than the original design risk rate (0.01%). It demonstrated that the risk of taking flood forecast results as discriminant index to raise the reservoir flood control level was smaller than the original routine operation risk. It was also fully proved that the Qinghe reservoir forecast operation mode used to determine the water level of reservoir flood control was safe and feasible. The upper bound of dynamic control of flood limited water level 127.80 m according to forecast operation mode in Qinghe reservoir is safe. The calculation results of single condition risk were smaller than the Bayesian posterior probability calculation, and the sum probability of mutually exclusive events was not equal to 1. Because the single condition of the completeness of time was irrespective, and the risk was calculated under the condition of incomplete calculation results. In addition, the distribution probability of flood forecast error multiplying the design flood frequency was lack of rationality. Using Bayesian formula to calculate the posterior probability had not only considered the conditions of mutually and complete event occurrence, but also combined the weighted probability, which was more reasonable than conventional irrespective of the posteriori probability calculation results. Above all, the proposed risk analysis method has certain theoretical meaning and practical value, and it can be used as the reference of the same type reservoir. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Floods
Controlled terms:Decision making - Design - Error analysis - Errors - Flood control - Forecasting - Maximum entropy methods - Petroleum reservoirs - Probability - Probability density function - Probability distributions - Reservoirs (water) - Risk analysis - Risk assessment - Risks - Runoff - Water levels - Weather forecasting
Uncontrolled terms:Bayes theorem - Bayesian posterior probabilities - Dynamic controls - Flood control operations - Flood forecast - Flood forecasting errors - Flood limited water levels - Mutually exclusive events
Classification code:441.2 ReservoirsReservoirs
- 442.1 Flood ControlFlood Control
- 443 MeteorologyMeteorology
- 512.1.1 Oil FieldsOil Fields
- 716.1 Information Theory and Signal ProcessingInformation Theory and Signal Processing
- 912.2 ManagementManagement
- 914.1 Accidents and Accident PreventionAccidents and Accident Prevention
- 922 Statistical MethodsStatistical Methods
- 922.1 Probability TheoryProbability Theory
DOI:10.11975/j.issn.1002-6819.2016.03.019
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 27>
Accession number:20161002077964
Title:Greenhouse tomato dry matter production and distribution model under condition of irrigation based on product of thermal effectiveness and photosynthesis active radiation
Authors:Shi, Xiaohu (1, 2); Cai, Huanjie (1, 2); Zhao, Lili (1, 2); Yang, Pei (1, 2); Wang, Zishen (1, 2)
Author affiliation:(1) Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education, Northwest A&F University, Yangling, China; (2) Chinese Arid Area Research Institute of Water-saving Agriculture, Northwest A& F University, Yangling, China
Corresponding author:Cai, Huanjie(caihj@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:69-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To know the applicability of dry matter production and distribution model in greenhouse environment in northwest of China, we conducted a tomato deficit irrigation experiment in 2013-2015 in Yangling Shaanxi Province. Four treatments were set up including no deficit in whole growth period, deficit of 50% only in seedling stage, deficit of 50% both in seedling stage and flowering stage and deficit of 50% in whole growth period. We analyzed the dynamic changes of tomato stems, leaves, fruits and roots under different irrigation treatment in 2013-2014, and established a dry matter production and distribution model by using water consumption, aboveground and root distribution index, aboveground organ allocation index. Then the experimental data in 2014-2015 was used to validate the dry matter production and distribution. Total radiation, temperature, and water consumption of tomato under different treatments and dry matter weight of tomato including stems, leaves, fruits and roots in different growth stages were observed. Meteorological data was measured by artificial weather station, and water consumption was calculated based on water balance theory, and dry matter weight of each organ was measured by weighing method. The results showed that the total cumulative of thermal effectiveness and PAR (TEP) and water condition influenced tomato's dry matter most. For full irrigation treatment, dry matter increased rapidly in seedling stage and flowering stage. In mature stage the increase rate of dry matter reduced to the minimum level, and the total amount of dry matter increased to the maximum level. Water deficit in seedling stage would not significantly reduce the total amount of dry matter. Water deficit both in seedling stage and flowering stage would significantly reduce the total amount of dry matter in mature stage, and longer durations would result in larger reduction. The process of dry matter production under different water condition could be simulated by using total cumulative of TEP as an input variable in a dry matter production and distribution model. The dry matter allocation index of aboveground and root only changes with TEP while irrigation amount influenced it little. The aboveground index increased with TEP, and reached minimum in establishment stage, i.e.0.79, reached maximum in mature stage, i.e.0.95. While the root index decreased with TEP, and reached maximum in establishment stage, i.e. 0.21, reached minimum in mature stage, i.e. 0.05. Before flowering, tomato only underwent vegetative growth, distribution indexes of stem and leaf were 0.24-0.26 and 0.74-0.76, respectively in establishment stage. Distribution indexes of stem and leaf became closer in later vegetative growth stage, and were 0.49-0.51 and 0.49-0.51 respectively in the end of seedling stage. The distribution index of fruit increased with TEP after flowering. A high precision could be attained when using this dry matter production and distribution model to calculate tomato's stem, leave, fruit and root dry matter under different water condition, and absolute errors were 0.24-9.46 g per plant, root mean square errors were 0.35-10.01 g per plant, and coefficients of determination were 0.78-0.89. This model could be used to simulate production and distribution of tomato's dry matter under different water condition when fertilizer supply was sufficient. This research provides useful information for greenhouse tomato production under different water conditions. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Fruits
Controlled terms:Greenhouses - Irrigation - Mean square error - Meteorology - Models - Plants (botany) - Water management - Water treatment
Uncontrolled terms:Different growth stages - Different treatments - Dry matter production - Greenhouse environment - Irrigation treatments - Root mean square errors - Thermal effectiveness - Tomato
Classification code:445.1 Water Treatment TechniquesWater Treatment Techniques
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.011
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 28>
Accession number:20161002077973
Title:Soil moisture retrieval using multi-temporal Sentinel-1 SAR data in agricultural areas
Authors:He, Lian (1); Qin, Qiming (1); Ren, Huazhong (1); Du, Jun (1); Meng, Jinjie (1); Du, Chen (1)
Author affiliation:(1) Institution of Remote Sensing and Geographical Information System, Peking University, Beijing, China
Corresponding author:Qin, Qiming(qmqin@pku.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:142-148
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil moisture is a key variable that links the water and energy cycles. Its information is also essential for many applications, such as agricultural drought monitoring, crop status monitoring and crop yield prediction. Sentinel-1 of the European Space Agency (ESA) is composed of 2 satellites, Sentinel-1A and Sentinel-1B, which share the same orbital plane with a 180° orbital phasing difference. The Sentinel-1 mission can provide C-band synthetic aperture radar (SAR) data with a global revisit time of just 6 days and high spatial resolution of about tens of meters, thus showing a strong potential for global soil moisture monitoring at high/moderate spatial resolutions. The aim of this study was to investigate the capability of multi-temporal Sentinel-1 C-band SAR data with a short repeating cycle in soil moisture estimation over agricultural fields. In order to retrieve soil moisture, an algorithm based on the change detection technique was utilized. This algorithm (referred to as alpha approximation approach) relies on the assumptions that the contributions of vegetation and surface roughness to the radar backscattered signal are multiplicative. Therefore, the effects of vegetation and surface roughness on radar backscattering coefficients can be decoupled from the effects of soil moisture changes by rationing multi-temporal like-polarized (HH and VV) intensities between two close acquisition dates. The ratio is expected to track changes in soil moisture only since the changes of surface roughness, canopy structure and vegetation biomass take place at longer temporal scales than soil moisture changes. The alpha approximation approach was firstly evaluated by comparing with data sets simulated by a theoretical radiative transfer (RT) scattering model. It was found that the alpha approximation approach was overall in good agreement with the RT scattering model without introducing significant errors for bare surface and low vegetation area, which confirmed that the alpha approximation approach was a simple and effective way to reduce the influences of vegetation and surface roughness. Furthermore, under the assumption of alpha approximation, the ratio of 2 consecutive backscatter measurements could be approximately represented as the squared ratio of corresponding Bragg scattering coefficients. For Sentinel-1 SAR data with only one like-polarized channel (i.e. VV), N SAR acquisitions would result in N - 1 linear equations in N unknown Bragg scattering coefficients. To solve this underdetermined system of equations, a bounded linear least-squares optimization was applied. Once the unknown Bragg scattering coefficients were retrieved, the relative dielectric constant could be analytically derived with the soil moisture being estimated by the inversion of microwave dielectric model. The alpha approximation approach was then applied to 4 consecutive Sentinel-1 SAR images acquired over Huailai experiment field. Soil moisture maps were successfully obtained for each date. The results were validated using ground measurements on one acquisition date, with root mean squared error (RMSE) value of 0.06 cm<sup>3</sup>/cm<sup>3</sup>and mean bias value of 0.01 cm<sup>3</sup>/cm<sup>3</sup>. The results demonstrated the overall good performance of the alpha approximation approach. These results imply that multi-temporal Sentinel-1 SAR data show great potential in achieving high resolution and accurate soil moisture retrievals over agricultural fields. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soil moisture
Controlled terms:Agriculture - Approximation algorithms - Backscattering - Crops - Electromagnetic wave scattering - Mean square error - Moisture - Moisture control - Optimization - Radar - Remote sensing - Soil surveys - Soils - Space-based radar - Surface roughness - Synthetic aperture radar - Vegetation
Uncontrolled terms:Agricultural fields - Multi-temporal - Radar backscattering coefficient - Relative dielectric constant - Retrieval - Soil moisture estimation - Soil moisture monitoring - Soil moisture retrievals
Classification code:483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 711 Electromagnetic WavesElectromagnetic Waves
- 716.2 Radar Systems and EquipmentRadar Systems and Equipment
- 731.3 Specific Variables ControlSpecific Variables Control
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 821.4 Agricultural ProductsAgricultural Products
- 921 MathematicsMathematics
- 921.5 Optimization TechniquesOptimization Techniques
- 922.2 Mathematical StatisticsMathematical Statistics
- 931.2 Physical Properties of Gases, Liquids and SolidsPhysical Properties of Gases, Liquids and Solids
DOI:10.11975/j.issn.1002-6819.2016.03.020
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 29>
Accession number:20161002077978
Title:Heat transfer process of soil wall in Chinese solar greenhouse and its theoretical simplification methods
Authors:Li, Ming (1, 2); Zhou, Changji (1, 2); Zhou, Tao (3); Yin, Yilei (1, 2); Fu, Jianlu (1, 2); Wang, Zhiqiang (4); Qi, Changhong (5)
Author affiliation:(1) Institute of Facility Agriculture, Chinese Academy of Agricultural Engineering, Beijing, China; (2) Key Laboratory of Farm Building in Structure and Construction, Ministry of Agriculture, Beijing, China; (3) Beijing Energy Conservation and Environmental Protection Center, Beijing, China; (4) China Agricultural Engineering Consulting Center, Beijing, China; (5) Beijing Changping District Agricultural Service Center, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:175-181
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil wall of the Chinese solar greenhouse (hereafter referred to as "solar greenhouse") has problems of occupying large area and damaging the cultivation land. The simplification of soil wall, which means decreasing the thickness and soil use of the soil wall, becomes very important. The purpose of this study is to develop simplification methods of soil wall. A simplification wall with less soil use was proposed based on the measured temperature of soil wall and analysis of feasibility of those methods. The tested solar greenhouse was located in Yongqing county, Lanfang city, Hebei province (116°44' E, 36°27' N). It is 50 m long and 10 m wide. The top and bottom thicknesses of the soil wall were 2.0 and 5.3 m, respectively. Its average thickness was 3.6 m. The test period was from Dec. 01, 2013 to Mar. 30, 2014. During that time, the tested solar greenhouse was used to growing cucumber with surface irrigation. The heat insulation sheet of the solar greenhouse was rolled up and down at 8:30 am and 5:00 pm daily, respectively. The wind vent was open if the indoor air temperature was high during daytime. The indoor and outdoor air temperatures, solar irradiating on the inner surface of the wall, the temperatures in the soil wall and indoor soil were measured continuously at a time interval of 10 min. The data collected in a typical cloudy day ( 08:30 am of Dec. 29, 2013 to 08:30 am of Dec. 30, 2013) and a typical sunny day (08:30 am of Jan. 16, 2014 to 08:30 am of Jan. 17, 2014) were used to study the heat transfer pattern of the soil wall. Based on the measured temperature in the soil wall, the soil wall can be divided into heat storage layer and heat insulation layer. The heat storage layer had large temperature fluctuation and can be used for storing heat during daytime and release heat into the solar greenhouse during nighttime. The temperature of the heat insulation layer was lower than that of the heat storage layer and mainly used to prevent the heat in the heat storage layer from losing. Under the test conditions, the thicknesses of heat storage and insulation layers were 47 cm and 313 cm, respectively. Considering that the heat resistance of the heat insulation layer equals that of 7 cm polystyrene board, a composite wall with 7 cm polystyrene board and 47 cm rammed soil in the direction from exterior to interior was proposed. The results showed that under same conditions, the differences between the measured inner surface temperature of the soil wall and the simulated inner surface temperature of the composite wall was less than 5% in both sunny and cloudy days. The application of the polystyrene board can reduce the thickness and occupied area of soil wall by 85.0% and 89.8%, respectively in comparison with the conventional soil wall. On the other hand, the heats released by the indoor soil during the nights of sunny and cloudy day were 1.3 and 2.9 times more compared to those released by the soil wall. According to the simulation results, by increasing the 20 cm surface soil temperature from 17.0 to 23, the heat released by the indoor soil during nighttime were more than the measured heat released by both soil wall and indoor soil. In this case, the soil wall can be replaced by the wall build with thermal insulation material only. The thickness of soil wall can be further decreased. We concluded that the soil wall can be simplified by the following methods: 1) building its heat insulation layer with thermal insulation material, or 2) building the wall with thermal insulation material and increasing the indoor soil temperature. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Thermal insulation
Controlled terms:Atmospheric temperature - Cultivation - Digital storage - Greenhouses - Heat resistance - Heat storage - Heat transfer - Insulating materials - Insulation - Polystyrenes - Soils - Solar heating - Storage (materials) - Surface properties - Temperature - Thermal insulating materials - Walls (structural partitions)
Uncontrolled terms:Chinese solar greenhouse - Indoor air temperature - Indoor and outdoor airs - Simplification - Surface soil temperatures - Temperature fluctuation - Thermal insulation materials - Walls
Classification code:408.2 Structural Members and ShapesStructural Members and Shapes
- 413 Insulating MaterialsInsulating Materials
- 413.2 Heat Insulating MaterialsHeat Insulating Materials
- 443.1 Atmospheric PropertiesAtmospheric Properties
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 641.1 ThermodynamicsThermodynamics
- 641.2 Heat TransferHeat Transfer
- 657.1 Solar Energy and PhenomenaSolar Energy and Phenomena
- 694.4 StorageStorage
- 722.1 Data Storage, Equipment and TechniquesData Storage, Equipment and Techniques
- 815.1.1 Organic PolymersOrganic Polymers
- 821.3 Agricultural MethodsAgricultural Methods
- 821.6 Farm Buildings and Other StructuresFarm Buildings and Other Structures
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.025
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 30>
Accession number:20161002077955
Title:Parameter optimization and experiment on cone canvas belt type seed-metering device
Authors:Yang, Ranbing (1); Zhang, Xiang (1); Li, Jiandong (1); Shang, Shuqi (1); Chai, Henghui (2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Qingdao Agricultural University, Qingdao, China; (2) Jier Machine-tool Group Co., Ltd., Ji'nan, China
Corresponding author:Shang, Shuqi(sqshang@qau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:6-13
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The seed-metering link plays an important role in the process of plot sowing, and mechanized seed metering can reduce the labor intensity, improve the production efficiency and ensure the work quality. The seed-breeding seed-metering technology has been vigorously developed in China. However, at present, there are many disadvantages in the existing seed-breeding seed-metering device. In order to make plot sowing seed-metering device meet the requirements of high level test in plot sowing, this paper designed a cone canvas belt type metering device which applied a new type of structural material, analyzed the characteristics of the structure, and furthermore, optimized the parameters by means of composite test. This seed-metering device could avoid the serious defects that the cone grid plate type seed-metering device has, i.e. uneven seeding and seed injury. The mechanism consisted of a seed hopper, a seed-dispersing hand shank, a canvas belt type metering mechanism, a lever mechanism of adjusting tension, a base plate of seeding device, a receiving funnel and a spiral bevel gear. The structure parameters of the cone grid plate type metering device were not easy to distinguish and appraise. Some of them directly affected the performance of seed-metering device. Before further studying the parameter, the working process was divided into 3 links, which were discharging seeds, dispersing seeds and carrying seeds. By analyzing the seed mechanics, the seed kinematics and the conditions of space configuration about discharging seeds, dispersing seeds and carrying seeds, this paper found that a number of parameters had significant impact on the operation performance of the machine, and at the same time there was internal relationship between these parameters. Aiming at comparatively evaluating these parameters, this paper conducted the single factor experiment on discharging seeds. Through the above methods, the main parameters which influenced the performances of seed metering were identified: cone rotational speed, cone angle, and unit configuration amount in wedge-shaped ring domain. Through three-factor quadratic orthogonal rotation design, the regression equation of factors and test index (coefficient of variation of seed-metering uniformity) was established; the optimization of calculation showed that when the cone speed was 3.46 rad/s, the body bottom angle was 45.8°, and the unit configuration amount in wedge-shaped ring domain was 7 grains per centimeter, the comprehensive performance evaluation index reached the best level in the breeding test. Implementing the reproducibility test showed that the result of parameter optimization was accurate. The seed-metering technology was applied by 2BZH-6 type wheat nursery seeder for planting operation in different plot area. Under the condition of wheat seedling emergence, the statistical results were obtained by measuring the distance of the wheat plants: the average plant spacing was 51 cm for the cone grid plate type seed-metering device; and the coefficient of variation of uniformity distribution was 27.43%, which was relatively low. In addition, there was no phenomenon of residual seeds or broken seeds. The research results provide the reference for improving the design of the existing wheat nursery seeder's seed-metering component. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Seed
Controlled terms:Agricultural machinery - Agriculture - Bevel gears - Dispersions - Experiments - Flow measurement - Optimization - Plates (structural components) - Pneumatic materials handling equipment - Shape optimization - Structural design - Testing
Uncontrolled terms:Coefficient of variation - Comprehensive performance evaluation - Internal relationships - Parameter optimization - Quadratic orthogonal rotation - Seed metering devices - Single-factor experiments - Structure parameter
Classification code:408.1 Structural Design, GeneralStructural Design, General
- 408.2 Structural Members and ShapesStructural Members and Shapes
- 601.2 Machine ComponentsMachine Components
- 631.1 Fluid Flow, GeneralFluid Flow, General
- 632.4 Pneumatic Equipment and MachineryPneumatic Equipment and Machinery
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 901.3 Engineering ResearchEngineering Research
- 921.5 Optimization TechniquesOptimization Techniques
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.002
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 31>
Accession number:20161002077967
Title:Meso-structure evolution of cracked expansive soils
Authors:Wang, Xiaoyan (1, 2); Yao, Zhihua (3); Dang, Faning (2); Dong, Zhongji (1)
Author affiliation:(1) Xi'an Engineering Investigation and Design Research Institute of China National Non-ferrous Metals Industry, Xi'an, China; (2) Xi'an University of Technology, Institute of Geotechnical Engineering, Xi'an, China; (3) Department of Airdrome Construction Engineering, Air Force Engineering University, Xi'an, China
Corresponding author:Yao, Zhihua(lightbright@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:92-100
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The crack property of expansive soil is one of the important characteristics, which is different from other types of soils. The development of cracks greatly affects the engineering properties of expansive soils. In order to study the meso-structural characteristic of cracked expansive soil, the dry-wet cycle test, triaxial soaking test and isotropic loading test were carried out on the remolded expansive soil in scientific research station of Logistics Engineering University in Hanzhong city, Shanxi province, China. The data including volumetric strain and deviatoric strain were obtained by these tests. Using CT (computerized tomography), test samples were scanned nondestructively in real-time to obtain CT images. The whole evolving process of cracks in expansive soils was investigated under the action of water and external force from the microscopic view. The effect of the crack on the macro-meso deformation behavior of expansive soil was studied by the relationship between the micro data and macro physical parameters. Test results showed that, under unconstrained conditions of dry-wet cycles, the edges and the gathering holes area of expansive soil sample were easy to form crack. Volume shrinkage caused by dry-wet cycle of expansive soil had a stable asymptote line and would tend to a stable value. The volume change of the expansive soil had experienced 3 stages in triaxial soaking test with the water and external force. Firstly, in the initial stage of triaxial soaking test, expansive force caused by soaking water led to wetting expansive deformation of cracked expansive soil. Secondly, the softening effect appeared and the expansion force gradually decreased with the increase of water content, under the influence of confining pressure and deviatoric stress, the shearing shrinkage was followed. Thirdly, in the late period of soaking test, the shear failure of the specimen under the effect of deviatoric stress caused the phenomenon of slight dilation. Cracked expansive soil during isotropic loading process had obvious yield phenomenon, taking yield point as the cut-off point, the curve of scanning data and pore ratio with the load increases was divided into rapid and slow volume shrink period. The rapid volume shrinkable period was related to cracks and holes closure, and the slow volume shrinkable period was related to the formation of the new structure which had ability to resist the external load. From the CT-scanning images of triaxial soaking test and isotropic loading test, under the action of water and external load, the irregular cracks and holes were gradually evolved into a regular circular hole, and the circular hole tended to close. With only the action of the external force, the crack was more difficult to complete closure. The interaction of water and external force made the expansive soil crack closure effect better than that of only external loading. Therefore, water plays a key role in the effect of the crack 'development of expansive soil. The results would provide valuble information for the further understanding of the influence of cracks on the mechanical properties of expansive soil. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Soil testing
Controlled terms:Computerized tomography - Crack closure - Cracks - Deformation - Loads (forces) - Shear flow - Shrinkage - Soils - Stresses - Structure (composition)
Uncontrolled terms:CT (computerized tomography) - Engineering properties - Evolution law - Expansive deformation - Expansive soils - Logistics engineering - Scientific researches - Structural characteristics
Classification code:408 Structural DesignStructural Design
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 631.1 Fluid Flow, GeneralFluid Flow, General
- 723.5 Computer ApplicationsComputer Applications
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.014
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 32>
Accession number:20161002077992
Title:Analysis on construction of well-facilitated farmland based on land reclamation monitoring and supervision system
Authors:Fei, Jianbo (1, 2); Ling, Jing (2); Wu, Xi (1); Li, Hechao (1); Hu, Jia (2); Hu, Yufu (2); Yang, Rendao (2)
Author affiliation:(1) Center of Land Acquisition and Consolidation in Sichuan Province, Chengdu, China; (2) College of Resource and Environmental Sciences, Sichuan Agricultural University, Chengdu, China
Corresponding author:Wu, Xi(1318841481@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:267-274
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to scientifically analyze the spatial characteristics and implementation status of well-facilitated farmland construction in Sichuan Province, this research, taking province as measurement scale and county as research unit, built a comprehensive appraisal system with the indicators of construction intensity, potential and difficulty, which was based on rural land reclamation monitoring and supervision system, and aimed to reflect the implementation status of high standard farmland construction. This appraisal system adopted Ward clustering analysis to comprehensively partition the well-facilitated farmland construction status in Sichuan Province during 2012-2015, and conducted a contrastive analysis through combining preset planning goal and construction effect for analyzing the gap between current construction implementation status and planning task. Selection of indicators involved newly increased farmland area, newly increased and improved farmland irrigation area, newly increased and improved farmland waterlogging area, newly increased grain productivity, farmer's newly increased annual net income per capita and number of beneficiaries in project areas. For these factors, several aspects were mainly taken into account, such as convenient agricultural operations, enhancing agricultural disaster prevention and mitigation as well as risk resistance ability, and improving agricultural production efficiency, which were to analyze the effect of high standard farmland construction. The conclusions are as follows: from the perspective of single indicator, the construction intensity is higher in the hilly areas of the central basin and the mountain areas surrounding the basin; the construction potential of the whole province is at an intermediate level, while the higher construction potential areas are mainly located in the central Sichuan hilly areas, the mountain areas surrounding the basin and the southwestern Sichuan mountain areas; the construction difficulty is higher in Chengdu Plain and southwestern Sichuan mountain areas; from the perspective of comprehensive zoning, the whole province shows middle-lower construction intensity, intermediate construction potential, and middle-higher construction difficulty. Three indicators of the Chengdu Plain, the hilly areas of the basin, the mountain areas surrounding the basin and the southwestern Sichuan mountain areas perform as medium - medium low- high, medium -medium- medium, medium - medium- medium, as well as medium - medium - high, respectively. Therefore, it suggests that the construction of high standard farmland is suitable for the Chengdu Plain area, especially in the hilly areas of the basin and the mountain areas surrounding the basin, while it should be reduced in the southwest of Sichuan Basin. Research indicates that there exist certain differences between construction status of well-facilitated farmland and planning target currently, especially among different regions. Considering from the regional development, the construction potential and the effect of construction, well-facilitated farmland construction should more focus on the hilly areas of the basin and the mountain areas surrounding the basin during the 13th Five-Year Plan. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Farms
Controlled terms:Agriculture - Cluster analysis - Disaster prevention - Geochronology - Land reclamation - Land use - Landforms - Monitoring - Regional planning - Zoning
Uncontrolled terms:Agricultural disasters - Agricultural operations - Agricultural productions - Contrastive analysis - Current construction - Grain productivities - Regional development - Spatial characteristics
Classification code:403 Urban and Regional Planning and DevelopmentUrban and Regional Planning and Development
- 403.2 Regional Planning and DevelopmentRegional Planning and Development
- 442.2 Land ReclamationLand Reclamation
- 481.1 GeologyGeology
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 914.1 Accidents and Accident PreventionAccidents and Accident Prevention
DOI:10.11975/j.issn.1002-6819.2016.03.039
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 33>
Accession number:20161002077995
Title:Change of physiological stress and flesh quality of Megalobrama amblycephala during suitable waterless keep alive conditions
Authors:Liu, Xiao (1); Xie, Jing (1); Yang, Xi (1); Dong, Hanbo (1); Zhang, Xinlin (1)
Author affiliation:(1) Shanghai Engineering Research Center of Aquatic Product Processing & Preservation, College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
Corresponding author:Xie, Jing(jxie@shou.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:295-300
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Currently circulation mode of freshwater fish was water transport. Commercial cost and several transportation procedures, including catch, temporary culture, transport shake, loading, unloading and distribution, induced harmful stress in fish, caused injury and even death. Related research showed the loss cost accounted for about 10% of the total cost in China, which was 20 times that in developed countries. Therefore, waterless keep alive transport of freshwater fish was more and more taken seriously. Hibernated temperature, packing method, survival time and survival rate of four seasons fish live in waterless environment were researched in order to investigate the effects of physiological stress and flesh quality of Megalobrama amblycephala during suitable waterless keep alive condition. Fish were examined at different time points: living in normal temperature (control), waterlessly keeping alive for 14 h (waterless) and then recovering in normal temperature for 24 h (recover). Blood biochemical items including cortisol (COR), glucose (GLU) and lactic acid (LAC) concentration, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activity were determinated and flesh quality indicators such as water holding capacity, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), texture and free amino acids were studied. The results showed: suitable living temperature of Megalobrama amblycephala for waterless keep alive was (14.8±0.2)(at winter), and then dropped (2/h) living temperature to 2 (hibernated temperature). The hibernated fish were packaged in moist wood-shavings but without added water by plastic bag (120 cm×90 cm) and oxygen-rich atmosphere (80% O<inf>2</inf>), finally plastic bag was sealed and placed at 2 for 14h, survival rate reached 100% after (14.8±0.2) (normal temperature) recovery 24 h. Blood COR and LAC concentration, AST and ALT activity of fish keep alive 14h in waterless were significantly higher than normal level (control) (P<0.05), while blood GLU concentration and ALP activity were significantly lower than normal level (P<0.05). After recovery 24 h, most blood biochemical values returned to normal level, except for blood AST activity was still significantly higher than normal value. Protein and fat content, TVB-N, TBA and the water holding capacity of fish flesh were not influenced in low temperature waterless environment, but the fish flesh hardness and chewiness were significantly decreased (P<0.05). Free amino acids Ser, Glu, Gly, Val and Arg of fish flesh at waterless were significantly higher than normal value (P<0.05), concentrations of Ile, Leu, Tyr, Phe at waterless were not significantly change with normal, however, after recovery 24 h, them were significantly higher than normal (P<0.05). In conclusion, the stress induced by the cold and waterless condition in fish can be eliminated 24 h after recovery, and the changes of fish tasting quality are not significant. The results provide a reference for the application of waterlessly keeping alive in transportation of live freshwater fish. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Atmospheric temperature
Controlled terms:Alkalinity - Amino acids - Blood - Costs - Fish - Lactic acid - Phosphatases - Physiology - Plastic containers - Quality control - Recovery - Stress analysis - Temperature - Unloading - Water
Uncontrolled terms:Alanine aminotransferase - Alkaline phosphatase activity - Aspartate aminotransferase - Keep-alive - Megalobrama amblycephala - Oxygen-rich atmospheres - Physiological stress - Total volatile basic nitrogens
Classification code:443.1 Atmospheric PropertiesAtmospheric Properties
- 461.2 Biological Materials and Tissue EngineeringBiological Materials and Tissue Engineering
- 461.9 BiologyBiology
- 641.1 ThermodynamicsThermodynamics
- 691.2 Materials Handling MethodsMaterials Handling Methods
- 801.1 Chemistry, GeneralChemistry, General
- 804 Chemical Products GenerallyChemical Products Generally
- 804.1 Organic CompoundsOrganic Compounds
- 817.1 Polymer ProductsPolymer Products
- 911 Cost and Value Engineering; Industrial EconomicsCost and Value Engineering; Industrial Economics
- 913.3 Quality Assurance and ControlQuality Assurance and Control
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.042
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 34>
Accession number:20161002077990
Title:Optimization of ethanol production from bagasse and juice of sweet sorghum stem by simultaneous saccharification and fermentation
Authors:Chen, Chaoru (1, 2); Wang, Zhi (2); Ma, Qiang (1); Zhang, Lina (2); Xi, Yajun (1); Dun, Baoqing (2); Li, Guiying (2); Lu, Ming (2); Du, Fengguang (3)
Author affiliation:(1) College of Agronomy, Northwest A&F University, Yangling, China; (2) The National Key Facility for Crop Gene Resources and Genetic Improvement of Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China; (3) State Key Laboratory of Motor Vehicle Biofuel Technology, Nanyang, China
Corresponding author:Xi, Yajun(xiyajun11@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:253-258
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ethanol production from energy crops which are renewable resources has gotten more and more attentions because of the energy crisis and environmental pollution. Sweet sorghum is considered as the most promising energy crop for the production of ethanol. Sweet sorghum stem is usually used to ferment ethanol, one of which is the liquid-state fermentation with the juice of sorghum stem. But a lot of bagasse of sorghum stem is discarded as wastes. The bagasse can be used as the supplemental materials of the fermentation of the juice. So it is absolutely necessary to study on the optimization of ethanol production with the bagasse and juice of the sorghum stem by simultaneous saccharification and fermentation (SSF). The response surface is an effective method to optimize the operating parameters of the SSF for the maximum ethanol yield. In this study, the Plackett-burman design was adopted to select the significant factors from 8 variables which influenced the ethanol yield and its concentration. The results indicated the ethanol yield and concentration were mainly influenced by the fermentation temperature, the amount of cellulase and the ratio of sorghum stem bagasse to its juice (P<0.05). And the other 5 variables which were not significant were remained to be the center level: the pH value was 5.5, the inoculation ratio was 0.2%, the amount of (NH<inf>4</inf>)<inf>2</inf>SO<inf>4</inf>was 5 g/L, the fermentation time was 60 h, and the amount of uracil was 1 g/L. Based on the results of the selection, the steepest ascent experiment was conducted to determine the center point and the step size. The center point of the fermentation temperature was 37 and its step size was 3. The center point of the amount of cellulase was 20 FBU/30 CBU and its step size was 5 FBU/CBU. The center point of the ratio of bagasse to its juice was 7% and its step size was 1.5%. Then we adopted the Box-Behnken design and response surface analysis method to optimize the levels of these 3 significant factors, and the regression and the optimal levels of these significant factors were as follows: the regression model was very significant (P<0.0001, R<sup>2</sup>=0.9987, Adj. R<sup>2</sup>=0.9971 and CV=0.0099), which indicated that the model was reliable, and therefore, the regression model could be used for the theoretical prediction of the SSF for juice and bagasse of sweet sorghum stem; the fermentation temperature was 36.58, the amount of cellulase was 23.5 FBU/35.25 CBU, the ratio of bagasse to juice of sorghum stem was 8.2%, the maximum theoretical yield of ethanol predicted was 89.2%, and the ethanol concentration was 31.829 g/L. The interactive effects were analyzed by response surface analysis. The interactive effect of the fermentation temperature and the amount of cellulase was very significant (P<0.0001); the interactive effect of the amount of cellulase and the ratio of bagasse to juice was very significant (P<0.001); the interactive effect of the fermentation temperature and the ratio of bagasse to juice was not significant (P=0.2946). Under the optimal conditions, the model was proved to be valid by the verification test with 3 repeated tests, and the ethanol yield was 88.98% which was very close to the maximum yield (89.2%). The ethanol concentration was 31.78 g/L, which was very close to theoretical prediction value (31.829 g/L). The results of this optimal technology will provide a reference for the ethanol production technology by simultaneous saccharification and fermentation method for sweet sorghum stem. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Saccharification
Controlled terms:Agriculture - Bagasse - Crops - Energy policy - Ethanol - Fermentation - Optimization - Regression analysis - Surface analysis - Surface properties
Uncontrolled terms:Environmental pollutions - Liquid state fermentation - Response surface analysis - Response surface analysis methods - Response surface methodology - Simultaneous saccharification and fermentation - Steepest ascent experiments - Sweet sorghum stems
Classification code:525.6 Energy PolicyEnergy Policy
- 802.2 Chemical ReactionsChemical Reactions
- 804.1 Organic CompoundsOrganic Compounds
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
- 921.5 Optimization TechniquesOptimization Techniques
- 922.2 Mathematical StatisticsMathematical Statistics
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.037
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 35>
Accession number:20161002077997
Title:Effect of frying cycles on polar components in soybean oil and absorbed lipids of fried potatoes
Authors:Feng, Hongxia (1); Li, Yang (1); Sui, Xiaonan (1); Qi, Baokun (1); Wang, Zhongjiang (1); Jiang, Lianzhou (1); Cao, Wenming (2)
Author affiliation:(1) College of Food Science, Northeast Agricultural University, Harbin, China; (2) Shanghai Grain Science Research Institute, Shanghai, China
Corresponding author:Li, Yang(liyanghuangyu@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:309-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Frying is a traditional and popular processing method for the food preparation throughout the world. Frying can not only confer good flavor and color, but also generate many kinds of reaction products, affecting the quality of the oil and the food. A lot of published literatures focused on the quality of the frying oil. However, for direct consumption, the quality of the fried food affects human's health and safety, and thus addressing the study on the quality of the fried food is needed. As we all know, the content of total polar compound (TPC) is one of the most valid and objective criteria for the evaluation of deterioration of oils during deep frying. Thus, in this study, our research was mainly focused on the content and composition of polar compounds in the lipids absorbed on the surface of fried food during deep frying. Preparative flash chromatography, as a convenient and fast way, was adopted to separate polar compounds from the oil and the absorbed lipids of fried food. The obtained polar compound was further analyzed by high performance size-exclusion chromatography to determine its main compositions. The results indicated that the contents of TPC from both the fried oil and the absorbed lipid of fried food were gradually increasing with the number of frying times. No significant difference of TPC content between the rest oil of treatments and the sample of control was observed for the number of frying times of 1-30 (the heated oil without adding French fries was the control). However, TPC content of the control was significantly higher than that of the rest oil of treatments for the number of frying times of 40-60, indicating that the addition of potatoes to a certain extent could help inhibit the formation of polar compounds. In addition, frying times significantly changed the distribution of polar components, which were oxidized triglyceride oligomers (TGO), oxidized triglyceride dimers (TGD), oxidized triglyceride monomers (ox-TG), diacylglycerols (DG), free fatty acids and sterols (FFA & sterols), and some unknown compounds with small molecule, not only in the frying oil but also in the absorbed lipid of fried food. The contents of TGO, TGD and ox-TG in samples of the control, the rest oil of treatments, and the absorbed lipid of fried food were significantly (P<0.05) increasing with the number of frying times. But under the same condition, the contents of TGO, TGD and ox-TG in the absorbed lipid of fried food were much lower than those in the rest oil of treatment, while the difference of the contents of TGO, TGD and ox-TG between the control and the treatment was affected by the number of frying times. On the other hands, a little change was observed in the content of DG and FFA & sterols of all the samples for the frying times of 60. More kinds of unknown compounds with small molecule were generated with the increase of frying times. In conclusion, the content and the composition of TPC in the frying oil and the absorbed oil of fried potatoes are seriously affected by frying times. And in some extent, the health value of the fried potatoes is also influenced. Taking into account of the potential threat of polar compounds to human health, the frying times must be strictly controlled. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Oils and fats
Controlled terms:Alcohols - Chromatography - Dimers - Fatty acids - Food processing - Food safety - Health - Health risks - Lipids - Molecules - Oligomers - Oxidation - Processing - Size exclusion chromatography - Soybean oil
Uncontrolled terms:Frying cycles - High performance size exclusion chromatography - Oxidized triglycerides - Polar compounds - Potatoes
Classification code:461.6 Medicine and PharmacologyMedicine and Pharmacology
- 461.7 Health CareHealth Care
- 801 ChemistryChemistry
- 802.2 Chemical ReactionsChemical Reactions
- 804.1 Organic CompoundsOrganic Compounds
- 815.1.1 Organic PolymersOrganic Polymers
- 822.2 Food Processing OperationsFood Processing Operations
- 913.4 ManufacturingManufacturing
- 931.3 Atomic and Molecular PhysicsAtomic and Molecular Physics
DOI:10.11975/j.issn.1002-6819.2016.03.044
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 36>
Accession number:20161002077975
Title:Comparison between multispectral and hyperspectral remote sensing for LAI estimation
Authors:Liu, Ke (1); Zhou, Qingbo (1); Wu, Wenbin (1, 2); Chen, Zhongxin (1); Tang, Huajun (1)
Author affiliation:(1) Key Laboratory of Agri-informatics, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China; (2) College of Urban & Environmental Sciences, Central China Normal University, Wuhan, China
Corresponding author:Zhou, Qingbo(zhouqingbo@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:155-162
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hyperspectral remote sensing has been commonly employed for crop LAI estimation in recent years. However, the advantages of hyperspectral data compared with multispectral data in LAI estimation remain debate. To compare multispectral and hyperspectral remote sensing for LAI estimation, five datasets with different spectral resolution, spectral coverage, and band selection were tested for retrieving LAI by inverting the ACRM (A Two-Layer Canopy Reflectance Model) model in this study. The study area is located in Shenzhou, Hebei Province, China. A field experiment was conducted during the jointing and heading stages of winter wheat (Triticum aestivum) in 2014. In situ measurements were performed in five winter wheat cultivars. The canopy spectra and the biophysical variables (LAI, leaf chlorophyll content, and leaf specific weight etc.) were measured. The inversion technique based on a look-up table (LUT) is adopted with the following procedure. Firstly, for determining the free variables of the LUT, sensitivities of the ACRM variables were evaluated using the EFAST algorithm. Two schemes of parameterizations were designed, separately denoted as "S1" and "S2". The scheme S1 had 7 variables, whose EFAST global sensitivity index was larger than 0.1, as free variables. The scheme S2 further was used to fixe leaf mesophyll structure and Markov clumping parameter to their best estimation. Secondly, to select the optimum hyperspectral bands for LAI estimation, stepwise regression was adopted to eliminate the multicollinearity in hyperspectral data. The results of stepwise regression were further adjusted to avoid errors in spectral simulation. Thirdly, five datasets, separately denoted as B1 to B5, were composed based on the in situ measured hyperspectral spectra and the result of band selection, including B1: the synthetic Landsat 5 TM data; B2: hyperspectral data (5 nm spectral resolution) of visible light and near inferred (VNIR, 445-1 065 nm); B3: hyperspectral data covering the sensitive bands of TM within VNIR (445-945 nm); B4: the selected hyperspectral bands for LAI estimation; B5: multispectral data of 20 nm spectral resolution, with their center wavelengths located at the selected hyperspectral bands. The accuracy and stability between LAI retrieval based on the two schemes of ACRM parameterization and using the five datasets were compared. The experiments showed that: first, within the range of VNIR, LAI estimation did not benefit from the wider spectral coverage of in situ measured hyperspectral data than the synthetic TM data. Second, if the bands participating in the inversion were properly selected and the uncertainty in the parameterization of the ACRM model was fairly low, remote sensing data of higher spectral resolution would generally result in a more accurate LAI estimation. In this case, the effects of spectral resolution to the inversion accuracy were not linear. With the increase of spectral resolution, the benefit from higher spectral resolution could decrease. For instance, B5 yielded significantly more accurate LAI estimations than B1; however, B4 performed merely slightly better than B5. Third, if the bands for retrieving LAI were not properly selected (for instance, using dataset B3), or the parameterization of ACRM model was fairly uncertain (for instance, using the scheme S1), remotely sensed data with higher spectral resolution could not result in more accurate LAI estimation. In conclusion, remotely sensed data with higher spectral resolution generally yielded more accurate LAI estimation only when the band selection was properly performed and the uncertainty of the parameters was fairly low. Otherwise, there was no significant difference between multispectral and hyperspectral data for crop LAI retrieval. This study provides information for the advantages of using hyperspectral data to estimate LAI. Moreover, this study reveals the great potential to enhance the accuracy of LAI estimation by using multispectral data with relevantly high spectral resolution, for instance, MODIS, Landsat 8 OLI and WorldView 3. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Parameter estimation
Controlled terms:Crops - Parameterization - Plants (botany) - Regression analysis - Remote sensing - Spectral resolution - Spectrum analysis - Table lookup - Vegetation
Uncontrolled terms:Band selection - Canopy reflectance model - High spectral resolution - Hyperspectral Data - Hyperspectral remote sensing - Inversion - Leaf Area Index - Leaf chlorophyll content
Classification code:723.1 Computer ProgrammingComputer Programming
- 741.1 Light/OpticsLight/Optics
- 821.4 Agricultural ProductsAgricultural Products
- 921 MathematicsMathematics
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.022
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 37>
Accession number:20161002077996
Title:Application of jet-cooking in preparation of digestible corn protein concentrates
Authors:Wang, Chaoyue (1); Wang, Yonghui (1); Yang, Xiaoquan (1); Wang, Jinmei (1); Guo, Jian (1)
Author affiliation:(1) Protein Research and Development Center, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China
Corresponding author:Yang, Xiaoquan(fexqyang@scut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:301-308
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Corn protein concentrates (CPC) were prepared continuously from corn gluten meal (CGM). Firstly, sub-critical fluid and α-amylase were used to remove crude fat and degrade starch. Then, the resultant protein suspension was concentrated and separated by ultra-filtration membrane. The ultra-filtration membrane process was used to remove the impurities produced by the first process such as soluble carbohydrate. The concentrated protein suspension was incubated with 0.2 M citric acid and treated by jet cooking device at 140 for 90 s. Finally, 3 samples could be acquired by spray-drying process. In order to study the effect of jet cooking on the functional properties of CPC, solubility profile, deamidation degree, and amino acid composition were investigated. Moreover, the digestibility in vitro and the antioxidant activity of digestive product were investigated. We expected to provide an effective and continuous process technology for the application of CGM, and prepared a kind of CGM which exhibited excellent functional properties and digestibility in vitro. The results showed that protein content of CGM was improved after the removing of crude fat and starch. However, there was no difference among CPC, JC-CPC (jet cooking CPC) and HT-CPC (heat treatment CPC) in the amino acid composition, protein content and recovery rate (P>0.05). The results of solubility suggested that CPC, HT-CPC and JC-CPC exhibited a typical U-shaped solubility curve, with the minimum at the pH value of 5.0-6.0 and gradually increasing at the pH value below 4.0 and above 7.0. When the pH value was below 4.0 and above 7.0, the solubility of JC-CPC was superior to CPC and HT-CPC. These results may be ascribed to the effect of deamidation that led to translate insoluble amino acid (Asn or Gln) to soluble amino acid (Asp or Glu), and the high temperature and high shear force during the treatment of jet cooking process which made the protein unfold and disaggregate. And owing to the effect of high temperature and high shear force during the jet cooking process, the foaming capacity and the foaming stability of JC-CPC were improved significantly (P<0.05) compared to CPC and HT-CPC. In the process of digestion in vitro, the nitrogen release of 3 samples increased rapidly at the beginning, and then gradually slowed down. After digestion, the nitrogen release of JC-CPC cloud reached up to 62.05%±0.75%, higher than the CPC (21.02%±0.19%) and HT-CPC (40.25%±0.72%) (P<0.05), and the degree of hydrolysis cloud reached up to 24.02%±0.49%, higher than the CPC (9.23%±0.45%) and HT-CPC (14.52%±1.26%) (P<0.05). These results were mainly due to the improvement of protein's solubility and the protein unfolding which may expose more protease binding sites and hence led to enzymatic hydrolysis more efficient during the jet cooking process. In addition, the reducing capacity of digestive product of JC-CPC was better than that treated by alcalase alkaline protease (P<0.05), while the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) inhibition of JC-CPC after pepsin and trypsin treatment was similar to that treated by alcalase alkaline protease. We can draw a conclusion that the product of JC-CPC after digestion in vitro possesses good antioxidant activity and physiological activity which may be beneficial to human beings, as well as the product treated by alcalase alkaline protease. It also means that the digestive product of JC-CPC cloud can be directly absorbed by human beings in the gastrointestinal tract. JC-CPC exhibits excellent functional properties, and digestibility property in vitro is attributed to the effect of jet cooking. The outcomes of the above research may prove a valid way to the application of CGM in further processing of plant proteins. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Fighter aircraft
Controlled terms:Alkalinity - Amino acids - Antioxidants - Binding sites - Chemical reactions - Enzymatic hydrolysis - Enzymes - Filtration - Hydrolysis - Microfiltration - Nitrogen - pH - Proteins - Removal - Shear flow - Sludge digestion - Solubility - Spray drying - Starch - Suspensions (fluids) - Ultrafiltration
Uncontrolled terms:1 ,1-diphenyl-2-picrylhydrazyl - Amino acid compositions - Anti-oxidant activities - Deamidation - Gastrointestinal tract - Physiological activity - Soluble carbohydrates - Ultra-filtration membranes
Classification code:452.2 Sewage TreatmentSewage Treatment
- 631.1 Fluid Flow, GeneralFluid Flow, General
- 652.1.2 Military AircraftMilitary Aircraft
- 801 ChemistryChemistry
- 802.2 Chemical ReactionsChemical Reactions
- 802.3 Chemical OperationsChemical Operations
- 804 Chemical Products GenerallyChemical Products Generally
- 804.1 Organic CompoundsOrganic Compounds
DOI:10.11975/j.issn.1002-6819.2016.03.043
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 38>
Accession number:20161002077985
Title:Sewage purification effect of multi-series surface flow constructed wetland
Authors:Wan, Yuwen (1, 2); Guo, Changqiang (1); Mao, Zhi (1); Li, Xinjian (3); Cui, Yuanlai (1); Zhao, Shujun (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China; (2) Guangxi College of Water Resources and Electric Power, Nanning, China; (3) Guangxi Zhuang Autonomous Region Center Station of Irrigation Experiment, Guilin, China
Corresponding author:Guo, Changqiang(cqguo@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:220-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rural domestic sewage has become one of the main sources of agricultural non-point source pollution. In order to develop effective treatment of domestic sewage in less development rural areas with low cost in construction and simple in maintenance, we studied a multi-series system of surface flow constructed wetland to treat rural sewage in Qingshitan irrigation district in Guilin City, Guangxi Province, China. The purification effect of different subsystems and the nutrient concentration variation at each stage were studied and analyzed. The results showed that the nutrient removal efficiency of the overall wetland system presented a trend of gradual decline over time. At the same time, the greater the surface area of the wetland was, the higher the removal rate of nitrogen and phosphorus were. However, the differences of removal rate of nitrogen and phosphorus affected by temperature could be ignored because the change of daily temperature was relatively stable during the test period (April to September). Total nitrogen (TN) and NH<inf>4</inf><sup>+</sup>-N (ammonium nitrogen) was high at earlier stage and low at late period of the inlet for the whole study period. The average removal rate decreased from 83.8% and 84.7% to 65.0% and 57.0%, for TN and NH<inf>4</inf><sup>+</sup>-N, respectively. There was no significant correlation between inlet concentration and removal rate (P>0.05) for nitrogen. The inlet concentration of TP (total phosphorus) showed no obvious change, but its removal rate presented sharply decline from 82.2% at the inlet to 21.2% at the outlet. This was caused by a strong phosphorus adsorption by sediment and phosphorus use by microorganisms. Nevertheless, there was still 21.2% TP was not removed. This demonstrated limitations of TP removal capacity on surface flow constructed wetlands in comparison with the subsurface flow constructed wetlands. The average removal rate of TN, NH<inf>4</inf><sup>+</sup>-N and TP were 76.3%, 70.8% and 60.5%, respectively of the whole system. There could be a better purification result with a larger aspect ratio and surface area. This study also revealed that this wetland system displayed a fast and stable purification effect for high nutrient influent concentration, but less effect for removal low nutrient concentration. From the experiment, we received ten sets of concentration data, including the data of each wetland bed. Of them six groups of measured data were used for the curve fitting of nitrogen and phosphorus concentration. We established the exponential, the linear, and the quadratic polynomial model which related to the inlet concentration of the wetland system through the monadic linear regression analysis of model coefficients. Then these three models were used for prediction and evaluation on the basis of the other four groups of testing data. Correlation analysis revealed that exponential decay model had a smaller relative root-square-error value with the best performance. The wetland system showed good purification effect during the whole test period, reducing the emissions of nitrogen and phosphorus of rural domestic sewage greatly, and mitigating the damage of domestic sewage to freshwater environment. The establishment of exponential attenuation model provided reference for the prediction of concentration changing along the multistage tandem constructed wetland system. The model can be used to easily predict nutrient concentration in any wetland subsystem when the influent concentration of the system is known. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Wetlands
Controlled terms:Aspect ratio - Curve fitting - Eutrophication - Forecasting - Nitrogen - Nitrogen removal - Nutrients - Phosphorus - Pollution - Purification - Regression analysis - Rural areas - Sewage - Water pollution
Uncontrolled terms:Agricultural non-point source pollutions - Attenuation step by step - Exponential decay models - Multi-series - Nutrient removal efficiency - Subsurface flow constructed wetlands - Surface flow constructed wetlands - Water purification
Classification code:452.1 SewageSewage
- 453 Water PollutionWater Pollution
- 804 Chemical Products GenerallyChemical Products Generally
- 921.6 Numerical MethodsNumerical Methods
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.032
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 39>
Accession number:20161002077993
Title:Land use pattern simulation based on ecosystem service value and ecological security pattern
Authors:He, Ling (1, 2); Jia, Qijian (3); Li, Chao (4); Zhang, Li (1, 2); Xu, Hao (1, 2)
Author affiliation:(1) College of Land and Resources, Agricultural University of Hebei, Baoding, China; (2) Cangzhou Field Research Station, Hebei-land Use of Circum Bohai Sea for the Ministry of Land and Resources, Cangzhou, China; (3) College of Rural Development, Agricultural University of Hebei, Baoding, China; (4) College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
Corresponding author:Xu, Hao(xuhao22003@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:275-284
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The rapid development of coastal economy in Hebei Province has caused rapid transition of coastal land use pattern, which has threatened land ecological safety. Specifically calculating ecosystem services value (ESV) and constructing ecological security pattern (ESP) and optimizing land use pattern have become an inevitable choice for providing decision support for land use planning and control as well as regional ecological security. Using RS (remote sensing), meteorological and field investigation data, the article chooses the following functions including material production, nutrient cycling, gas regulation, climate regulation, water conservation, environment purification, biodiversity maintenance, and entertainment and culture function, uses CASA (carnegie-ames-stanford approach) model to calculate EV, and then the article takes accumulative resistance model to determine ecological corridors and ecological node in Huanghua City. ESP is constructed, which takes ecosystem services value(ESV) as resistance. At last, taking ESP as one of influencing factors, a study on land use scenario simulation with different constraints has been carried out by the CA (cellular automaton) -Markov model. Two scenarios are no ecological conservation scenario and ESP conservation scenario. The results show that ESV per unit area for wetland is the largest, which is 14.95 Yuan/(m<sup>2</sup>·a), and that for construction land is the smallest, only 2.44 Yuan/(m<sup>2</sup>·a). ESV per unit area in different land use types is listed from high to low as follows: wetland, water, garden, cultivated land, grass, other land, saltern, saline land, and construction land. The contribution of nutrient cycling function is the largest, and environment purification function is the smallest. The largest percentage is 26.89%, and the smallest is 0.22%. The order of ESV for different functions from high to low is: nutrient cycling, water conservation, entertainment and culture, material production, biodiversity maintenance, gas regulation, climate regulation, and environment purification function. The ecological corridors and ecological node in Huanghua City are mainly distributed in the river in western areas, and the eastern coastal wetland. The study area can be divided into ecological core protection zone, ecological buffer zone, ecological restoration zone and human activity core zone. The proportion of ecological core zone is the smallest, which is only 168.58 km<sup>2</sup>, while the proportion of ecological buffer zone is the largest, which is 1 400.33 km<sup>2</sup>. Ecological restoration zone is 436.58 km<sup>2</sup>and human activity core zone is 172.34 km<sup>2</sup>. Simulation under 2 scenarios is carried out to compare the impact of different land use patterns. No ecological conservation scenario is a continuation of the current trends and involves only limited constraints. The ESP conservation scenario simulation incorporates ESP and basic cultivated land conservation constraints, i.e. the ecological source land and basic cultivated land cannot be changed into construction land. The results indicate that under ESP conservation scenario, the newly increasing construction land declines to 8.90 km<sup>2</sup>, which is 19.06 km<sup>2</sup>under no ecological conservation scenario. In the scenario simulation with ESP conservation, the areas of wetland, water and cultivated land are larger than that under no ecological conservation scenario. ESV rises to 9.57 billion Yuan in the scenario simulation with ESP conservation, and without ecological conservation it is 9.41 billion Yuan. An increase of 0.16 billion Yuan indicates that ESP conservation scenario is more effective to environment protection. Especially within the range of ecological core protection zone, the quantity of newly increasing construction land is zero under ESP conservation scenario, while it is 11.20% without ecological conservation. This method and the results can provide guidances and references not only for general land use planning and city planning, but also for ecological conservation in Huanghua City and other cities. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Ecology
Controlled terms:Air purification - Biodiversity - Climate models - Conservation - Decision support systems - Economics - Ecosystems - Land use - Markov processes - Nutrients - Optimization - Purification - Remote sensing - Restoration - Saline water - Water conservation - Wetlands
Uncontrolled terms:Different land use types - Ecological conservation - Ecological security - Ecosystem service values - Ecosystem services value - Environment protection - Huanghua city - Net primary productivity
Classification code:403 Urban and Regional Planning and DevelopmentUrban and Regional Planning and Development
- 443 MeteorologyMeteorology
- 444 Water ResourcesWater Resources
- 454 Environmental EngineeringEnvironmental Engineering
- 454.3 Ecology and EcosystemsEcology and Ecosystems
- 643 Space Heating, Ventilation and Air ConditioningSpace Heating, Ventilation and Air Conditioning
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 921 MathematicsMathematics
- 921.5 Optimization TechniquesOptimization Techniques
- 922.1 Probability TheoryProbability Theory
- 971 Social SciencesSocial Sciences
DOI:10.11975/j.issn.1002-6819.2016.03.040
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 40>
Accession number:20161002077981
Title:Optimization of tank-volume-to-collector-area ratio for balcony wall-mounted flat-plate solar water heater in mild region of China
Authors:Wei, Shengxian (1, 3); Hu, Fene (2); Yan, Cuiqiong (1, 3)
Author affiliation:(1) College of Physics and Electronic Engineering, Qujing Normal University, Qujing, China; (2) College of Chemistry and Chemical Engineering, Qujing Normal University, Qujing, China; (3) Yunnan Higher Universities Key Laboratory of Advanced Functional and Low Dimensional Materials, Qujing Normal University, Qujing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:195-201
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solar water heaters are widely used in urban and rural China. The Home Appliances to the Countryside program from government further expands its application in rural areas. In the end of 2010, there were 168 million square meters of installed solar heaters, with an annual primary energy saving of 20 Mtce. The total installation is very likely to reach 250 million square meters in 2015 and at least 600 million square meters in 2020. In the 2009 Copenhagen UN Climate Change Summit, president Hu Jintao pledged to the international community to reduce the CO<inf>2</inf>intensity of the economy by 40% to 45% by 2020 on the baseline level of 2005. Meanwhile, the share of non-fossil energy is also expected to rise to 15%. Application of solar water heaters will help to achieve this goal. The thermal performance of the flat-plate type solar energy water heater has been studied globally. In order to ensure the efficient operation of the solar water heater and user's demand to the terminal temperature of a tank, the countries all over the world with different climate have given different recommended value for water-mass-to-collector-area ratio (the ratio is abbreviated as MAR) of the flat-plate solar water heater. However, China has a vast territory and its climate is complex. The value range of recommended value from literatures is too large to be used to practical application. The main residential buildings in large and medium-sized cities are mostly high-rise buildings. The solar water heater installed on roof can only meet hot water use for the top six to eight floors. The application of the balcony wall-mounted solar water heater is one of the effective ways to solve hot water needs for the rest of users in high-rise buildings. Based on the typical meteorological data of nine cities in mild region of China, the values of MAR of the balcony wall-mounted flat-plate solar water heater have been calculated by using the established mathematical model. The water tank terminal temperature of 60, the collector angle of 60°-90° and the azimuth angle of 0-90° were used in model analysis. Calculation results for south-facing balcony wall-mounted solar water heater in mild region showed that the appropriate MAR of spring, summer, autumn, winter and the whole year was 28-51, 21-41, 31-53, 37-57 and 31-47 kg/m<sup>2</sup>, respectively. For convenience of practical application, the linear regression relation between seasonal and annual average MAR and the tilt angle for south-facing balcony wall-mounted solar water heater. The correlation coefficients between them were greater than 0.99. In this paper, we introduced a new concept "azimuth factor of MAR" which was easy to calculate MAR for the collector with different azimuth angle. For the non-south-facing balcony wall-mounted solar water heater, the seasonal and annual average azimuth factors of MAR decreased with the increase of the azimuth angle. The seasonal and annual average azimuth factors of MAR ranged from 0.57 to 1.00 and 0.72 to 1.00 when the tilt angle and azimuth angle were respectively at 60°-90° and 10°-90°. The azimuth angle had about 5% effect on MAR for winter and spring, summer, autumn and the whole year when the azimuth angle was less than or equal to 20° and 30°. The azimuth angle had about 10% effect on the above-mentioned MAR when the azimuth angle was less than or equal to 30° and 40°. In conclusion, the annual average solar fraction ranges should be in 0.55-0.70 for the south-facing balcony wall-mounted flat-plate solar water heater used in mild region of China. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Rural areas
Controlled terms:Application programs - Carbon dioxide - Climate change - Domestic appliances - Energy conservation - Meteorology - Optimization - Solar energy - Solar equipment - Solar water heaters - Tall buildings - Tanks (containers) - Walls (structural partitions) - Water - Water heaters - Water tanks
Uncontrolled terms:Area ratios - Azimuth angles - Azimuth factor - Correlation coefficient - International community - Primary energy savings - Residential building - Solar fraction
Classification code:402 Buildings and TowersBuildings and Towers
- 408.2 Structural Members and ShapesStructural Members and Shapes
- 443.1 Atmospheric PropertiesAtmospheric Properties
- 525.2 Energy ConservationEnergy Conservation
- 619.2 TanksTanks
- 657.1 Solar Energy and PhenomenaSolar Energy and Phenomena
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 804.2 Inorganic CompoundsInorganic Compounds
- 921.5 Optimization TechniquesOptimization Techniques
DOI:10.11975/j.issn.1002-6819.2016.03.028
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 41>
Accession number:20161002077958
Title:Verification and simulation analysis of wind turbine control based on linear parameter varying gain scheduling
Authors:Deng, Ying (1); Zhou, Feng (1); Chen, Zhonglei (1); Tian, De (1); Gao, Shang (1)
Author affiliation:(1) Renewable Energy School, North China Electric Power University, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:29-33
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the installed capacity of wind turbines increasing, the wind turbine output characteristics and optimal operation obtain much more concerns in the industry. This paper discusses the influence of wind turbulence on the performance of wind turbines. Wind turbine is a complex nonlinear system. Due to structure load coupling, wind variation and pitch actions, the parameters of aerodynamic subsystem are changing with operation state. Usually, PI (proportional integral) control algorithm is satisfied for a linear time invariant system. To obtain better performance, a nonlinear system needs an advanced control algorithm. To address this issue, we propose a linear parameter varying (LPV) gain scheduling control to mitigate the influence of wind turbulence on wind turbine performance. At different wind speed with variable pitch and rotor speed, the LPV control can adjust feedback gain to satisfy the changing operation point. First, we introduce the stability of LPV system and LPV controller design process. Once the stability conditions are reached, the closed-loop system is stable. Then, we derive a control model with a 2 MW wind turbine based on an actual double-fed induction generator. The input is a recommended turbulence model, Kaimal. In order to check the simulation model, the field data are compared with simulation results. The generator power and torque have similar statistic characteristics. So the model is suitable for simulation and the simulation results are credible. According to the analysis of field data, wind turbulence has a great impact on wind turbine performance, such as fatigue damage of gearbox and decreasing power generation efficiency. Therefore the economic benefits are reduced in the entire lifetime of wind turbine. Simulation results of LPV control algorithm and PI control algorithm are obtained by the software Bladed under 12 and 16 m/s wind turbulence, respectively. In time domain, the generator speed and torque are varying due to the wind turbulence. The amplitude of fluctuations under PI controller is bigger than that under LPV controller. However, the differences are not significant. To illustrate the characteristics of wind turbulence affecting wind turbine performance, the simulation results are also analyzed in frequency domain. Through spectrograms, it is observed that the peaks are concentrated on multiple rotational frequencies. The primary components are multiple 3P frequencies. Therefore, decreasing the components of multiple 3P frequencies can mitigate load fluctuation. At rated wind speed, the tower shadow effect is dominant in the load fluctuations of wind turbine. However, at high wind speed, the fluctuation does not occurs only on multiple rotational frequencies, so the turbulence has bigger influence on wind turbine performance compared with the situation at rated wind speed. In the simulation, the wind speed is 16 m/s and the turbulence intensity is 0.16; compared with PI controller, the fluctuations of gearbox's low speed shaft torque and power are reduced by 41.8% and 35.1% respectively on 3P frequency by LPV controller. Less load fluctuation on shaft torque leads to less fatigue damage on gearbox. Also smooth power output is friendly to the grid. Therefore, the proposed control algorithm can alleviate the influence of wind turbulence and enhance the performance of wind turbine, which can bring lower wind energy cost and longer wind turbine lifetime. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:13
Main heading:Controllers
Controlled terms:Algorithms - Asynchronous generators - Closed loop systems - Computer software - Electric generators - Electric load management - Fatigue damage - Frequency domain analysis - Gears - Invariance - Linear control systems - Linear systems - Models - Nonlinear systems - Press load control - Scheduling - Speed - System stability - Time domain analysis - Time varying control systems - Torque - Turbulence models - Two term control systems - Wind - Wind power - Wind turbines
Uncontrolled terms:Advanced control algorithms - Amplitude of fluctuations - Double fed induction generator - Gain Scheduling - Linear time invariant systems - Power generation efficiency - Statistic characteristics - Wind turbulence
Classification code:443.1 Atmospheric PropertiesAtmospheric Properties
- 601.2 Machine ComponentsMachine Components
- 615.8 Wind Power (Before 1993, use code 611 )Wind Power (Before 1993, use code 611 )
- 705.2 Electric GeneratorsElectric Generators
- 705.2.1 AC GeneratorsAC Generators
- 706.1 Electric Power SystemsElectric Power Systems
- 723 Computer Software, Data Handling and ApplicationsComputer Software, Data Handling and Applications
- 731.1 Control SystemsControl Systems
- 731.3 Specific Variables ControlSpecific Variables Control
- 732.1 Control EquipmentControl Equipment
- 912.2 ManagementManagement
- 921 MathematicsMathematics
- 921.3 Mathematical TransformationsMathematical Transformations
- 931.2 Physical Properties of Gases, Liquids and SolidsPhysical Properties of Gases, Liquids and Solids
- 951 Materials ScienceMaterials Science
- 961 Systems ScienceSystems Science
DOI:10.11975/j.issn.1002-6819.2016.03.005
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 42>
Accession number:20161002077988
Title:Optimization of pyrolysis carbonization conditions based on energy efficiency for cotton stalk
Authors:Xu, Jia (1, 2); Liu, Ronghou (1, 2); Wang, Yan (1, 2)
Author affiliation:(1) Biomass Energy Engineering Research Centre, School of Agriculture and Biology, Shanghai JiaoTong University, Shanghai, China; (2) Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai, China
Corresponding author:Liu, Ronghou(liurhou@sjtu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:241-246
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the use and depletion of fossil fuels, environmental pollution and energy crisis have become the biggest obstacles to the survival and development of human beings. Biomass energy utilization is an important way to solve this problem as it has wide source of raw material, and is clean and renewable. Biochar is an important form of biomass energy utilization, and it can not only change the waste straw into biomass energy, but also help reduce the greenhouse effect. The yield is a basic index in the study of pyrolysis technology; while the biochar is used as fuel, its calorific value is the factor directly reflecting the quality. These 2 indices are both necessary during the research. However, the existing research on the pyrolysis process of biochar is limited to all kinds of independent indices, and the optimal pyrolysis process is always not the same. In this paper, the advantages and disadvantages of pyrolysis process for biochar production were evaluated by the yield, calorific value and energy efficiency in order to design and optimize the process of carbonization of cotton stalk. The effects of the temperature, retention time and particle size on the yield and heating value of the biomass were studied; and the typical cotton stalk was taken as raw material to produce biochar under nitrogen gas atmosphere by slow pyrolysis. The results showed that: 1) The effects of pyrolysis temperature on the yield and heating value of the biomass were significant; the biochar yield was negatively correlated with heating value, and with the increase of the temperature, the yield of biochar decreased gradually, while the calorific value increased gradually. 2) The effect of retention time on the yield and heating value of the biochar was obvious, but it was not as obvious as the pyrolysis temperature; at the same time, it could be seen that the yield and heating value were negatively correlated, and with the increase of the retention time, the biochar yield decreased, while the calorific value increased. 3) Compared with the first 2 conditions, there was no significant change in the yield and heating value when the raw material particle size changed, which showed that the effects of particle size on the yield and calorific value were small. In addition, according to the general trend, we could still see a negative correlation between heating value and yield. Energy efficiency (ratio of total energy yield of biochar to energy yield of raw material) was proposed to coordinate the yield and calorific value, and the response surface analysis of the energy efficiency was carried out, from which the energy efficiency model was got. The results showed that when the temperature was 429, the retention time was 1.29 h, and the particle size was 0.32 mm, the predicted energy efficiency from the model reached the highest value, which was 78.95%. The model is validated by the experiment. The model can be used to guide the production of biochar with high energy efficiency, and provide the reference for energy efficient utilization. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Energy efficiency
Controlled terms:Atmospheric temperature - Biomass - Calorific value - Carbonization - Cotton - Energy policy - Energy utilization - Fossil fuels - Greenhouse effect - Heating - Nitrogen - Optimization - Particle size - Pyrolysis - Straw - Surface analysis
Uncontrolled terms:Bio chars - Carbonization conditions - Environmental pollutions - High energy efficiency - Negative correlation - Pyrolysis temperature - Response surface analysis - Yield
Classification code:443.1 Atmospheric PropertiesAtmospheric Properties
- 525 Energy Management and ConversionEnergy Management and Conversion
- 802.2 Chemical ReactionsChemical Reactions
- 804 Chemical Products GenerallyChemical Products Generally
- 821.4 Agricultural ProductsAgricultural Products
- 821.5 Agricultural WastesAgricultural Wastes
- 921.5 Optimization TechniquesOptimization Techniques
- 951 Materials ScienceMaterials Science
DOI:10.11975/j.issn.1002-6819.2016.03.035
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 43>
Accession number:20161002077982
Title:Prediction of pH value in industrialized aquaculture based on ensemble empirical mode decomposition and improved artificial bee colony algorithm
Authors:Xu, Longqin (1); Li, Qianchuan (2); Liu, Shuangyin (1); Li, Daoliang (3)
Author affiliation:(1) College of Information, Guangdong Ocean University, Zhanjiang, China; (2) College of Letters and Science, University of California, Los Angeles, United States; (3) Beijing ERC for Internet of Things in Agriculture, China Agricultural University, Beijing, China
Corresponding author:Liu, Shuangyin(hdlsyxlq@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:202-209
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The pH value in industrialized cultivation ponds is crucial to the survival of Litopenaeus Vannamei. Grasping the trend of the pH value timely and accurately is the key for the high-density healthy Litopenaeus Vannamei culture. Therefore, in order to solve the low prediction accuracy of the single model in pH value prediction, this paper proposes a pH value combination forecasting model in Litopenaeus Vannamei industrialized cultivation based on ensemble empirical mode decomposition (EEMD) and improved artificial bee colony (IABC) algorithm. In the modeling process, the non-linear time sequences of the original pH value are de-noised and decomposed into a series of stable and uncoupling sequences by the EEMD. Based on the changed characteristics of each sequence, the appropriate forecasting method is selected and a new independent prediction model is established. The independent prediction values are reconstructed to obtain the ultimate prediction results. But whether the weight of the combined forecasting model is appropriate restricts the prediction accuracy and performance seriously. Therefore, we choose the IABC optimized method to seek the optimal weight of the combined forecasting model, which overcomes the blindness and the impact of human factors in parameter selection of the combined forecasting model in order to accelerate its convergence rate and forecast accuracy. The combinations of the best weights are obtained automatically after the optimization, and in the process the nonlinear combination prediction model of pH value in industrialized cultivation is constructed. With this model, the pH value change has been predicted for industrialized cultivation pond from September 8 to September 15 in 2014 in Zhanjiang City, Guangdong Province. The experimental results show that the proposed combination prediction model of EEMD-IABC has better prediction effect than the optimized back propagation neural network based on simulated annealing algorithm (SA-BPNN) and genetic algorithm-least square support vector regression (GA-LSSVR) method. And the relative mean absolute percent error (MAPE), root mean square error (RMSE), mean absolute error (MAE) and determination coefficient (R<sup>2</sup>) for the pH values between the EEMD-IABC and GA-LSSVR models are 14.6%, 28.6%, 27% and 1.1% respectively under the same experimental conditions. The relative MAPE, RMSE, MAE and R<sup>2</sup>for the pH values between the EEMD-IABC and SA-BPNN models are 56.8%, 61.4%, 62.8% and 6.16% respectively. It is obvious that the EEMD-IABC has high forecast accuracy and generalization ability. It can meet the actual demand for the pH value controlling in the Litopenaeus Vannamei industrialized cultivation and also provide a reference for water quality predictions in other fields. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Forecasting
Controlled terms:Algorithms - Aquaculture - Backpropagation - Backpropagation algorithms - Errors - Evolutionary algorithms - Genetic algorithms - Lakes - Least squares approximations - Mean square error - Neural networks - Optimization - pH - Simulated annealing - Water quality
Uncontrolled terms:Artificial bee colonies - Artificial bee colony algorithms - Back propagation neural networks - Combination predictions - Ensemble empirical mode decomposition - Ensemble empirical mode decompositions (EEMD) - Least square support vector regressions - Litopenaeus vannamei
Classification code:445.2 Water AnalysisWater Analysis
- 537.1 Heat Treatment ProcessesHeat Treatment Processes
- 723.4 Artificial IntelligenceArtificial Intelligence
- 801.1 Chemistry, GeneralChemistry, General
- 821.3 Agricultural MethodsAgricultural Methods
- 921.5 Optimization TechniquesOptimization Techniques
- 921.6 Numerical MethodsNumerical Methods
- 922.2 Mathematical StatisticsMathematical Statistics
DOI:10.11975/j.issn.1002-6819.2016.03.029
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612
<RECORD 44>
Accession number:20161002077969
Title:Soil N<inf>2</inf>O emission characteristics of greenhouse tomato fields under aerated irrigation
Authors:Chen, Hui (1, 2); Hou, Huijing (1, 2); Cai, Huanjie (1, 2); Zhu, Yan (1, 2)
Author affiliation:(1) Key Laboratory for Agriculture Soil and Water Engineering in Arid Area Ministry of Education, Northwest A&F University, Yangling, China; (2) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, China
Corresponding author:Hou, Huijing(hjhou@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:3
Issue date:February 1, 2016
Publication year:2016
Pages:111-117
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Global warming and ozone depletion caused by greenhouse gas emissions are two major global environmental issues. The contribution of facility vegetable fields abundant with high N input to soil nitrous oxide emissions cannot be negligible. Crop growth, yield and water use efficiency under aerated irrigation have been done much work, while the effects of aerated irrigation on greenhouse gas emissions have never been reported. Changes of oxygen content in the soil caused by the aerated irrigation are bound to affect the production and emissions of nitrous oxide. Field experiments by using the method of static chamber/gas chromatography were conducted to determine the effects of aerated irrigation on seasonal N<inf>2</inf>O fluxes, and cumulative emissions of N<inf>2</inf>O from soils in greenhouse tomato fields in autumn-winter season and soil water-filled pore space (WFPS) at 20 cm depth in the solar greenhouse of the Key Laboratory of Agricultural Soil and Water Engineering in Arid Area sponsored by Ministry of Education (34°20'N, 108°04'E), at Northwest A&F University, in Yangling, Shaanxi Province of China, from August 13, 2014 to December 28, 2014. Two factors (irrigation and aeration) were designed in the experiment to reveal the effects of aerated irrigation on soil N<inf>2</inf>O emissions. Four treatments with three replications (each plot size 4.0 m × 0.8 m) were contained in the experiment: aerated deficit irrigation (A1), unaerated deficit irrigation (CK1), aerated full irrigation (A2) and unaerated full irrigation (CK2). The results showed that N<inf>2</inf>O fluxes under different irrigation methods roughly showed a trend of decrease after the first increase. The first and secondary peaks of N<inf>2</inf>O fluxes were observed at fruit expanding stage and maturing stage of tomato, respectively, while kept at a low level in other periods. Both seasonal N<inf>2</inf>O fluxes and cumulative emissions of N<inf>2</inf>O at different growth stage of tomato followed the same pattern: A2>CK2>A1>CK1. And both N<inf>2</inf>O fluxes and cumulative emissions of N<inf>2</inf>O from soils in tomato fields at different growth stages for each treatment mainly concentrated at fruit expanding stage. In addition, aeration and full water supply treatments increased the soil N<inf>2</inf>O emissions during the whole tomato growth period compared to unaeration and deficit water supply treatments. The average value of N<inf>2</inf>O fluxes (38.00 μg/(m<sup>2</sup>·h)) for A2 treatment increased by 85.9% and 264.7% compared with that for A1 and CK1 treatment (P<0.05), respectively, while the difference was not significant when compared to CK2 treatment (P>0.05). The maximum value about cumulative emission of N<inf>2</inf>O (120.34 mg/m<sup>2</sup>) for A2 treatment was 1.89 and 4.21 times as much as A1 and CK1 (P<0.01), respectively, while the difference was not significant when compared to CK2 treatment (P=0.078). Compared with unaerated irrigation, aerated irrigation did not increase N<inf>2</inf>O emissions from soils in greenhouse tomato fields significantly under full water supply condition (P=0.078), while increased N<inf>2</inf>O emissions significantly under deficit water supply condition (P<0.01). In addition, WFPS kept at a relatively high level for each treatment during the whole tomato growth stage. Except the main peaks, N<inf>2</inf>O fluxes increased with WFPS increasing. Exponential positive correlations between N<inf>2</inf>O fluxes and soil water-filled pore space (WFPS) were observed under unaerated irrigation methods of different irrigation level (P<0.05), while the relationships under aerated irrigation methods were not significant (P>0.05). Furthermore, peaks of N<inf>2</inf>O emissions were negative with WFPS, and N<inf>2</inf>O intense release was observed when WFPS was between 46.0%-52.1%. The results suggested that aerated irrigation increased soil N<inf>2</inf>O emissions in tomato fields, and the difference was significant under deficit water supply condition. This study provides valuble information for assessing farmland ecological effects of aerated irrigation and mitigating greenhouse gas emissions to greenhouse soils. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Water aeration
Controlled terms:Emission control - Fruits - Gas emissions - Global warming - Greenhouse gases - Greenhouses - Irrigation - Nitrogen oxides - Ozone layer - Soil moisture - Soils - Stages - Water supply
Uncontrolled terms:Different growth stages - Emission characteristics - Environmental issues - Ministry of Education - Nitrous oxide emissions - Positive correlations - Tomato - Water use efficiency
Classification code:402.2 Public BuildingsPublic Buildings
- 443.1 Atmospheric PropertiesAtmospheric Properties
- 445.1 Water Treatment TechniquesWater Treatment Techniques
- 446.1 Water Supply SystemsWater Supply Systems
- 451.1 Air Pollution SourcesAir Pollution Sources
- 451.2 Air Pollution ControlAir Pollution Control
- 483.1 Soils and Soil MechanicsSoils and Soil Mechanics
- 804.2 Inorganic CompoundsInorganic Compounds
- 821 Agricultural Equipment and Methods; Vegetation and Pest ControlAgricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.11975/j.issn.1002-6819.2016.03.016
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.Compendex references:YES
201612