<RECORD 1>

Accession number:20171503565294
Title:Effects of silt diameter and silt concentration on cavitation flow in centrifugal pump
Authors:Zhao, Weiguo (1, 2); Han, Xiangdong (1, 2); Li, Rennian (1, 2); Zheng, Yingjie (1, 2); Pan, Xuwei (1, 2) 
Author affiliation:(1) School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China; (2) Key Laboratory of Fluid machinery and System, Gansu Province, Lanzhou; 730050, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:117-124
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To study the effects of sand particles on the cavitation flow in the centrifugal pump, the method of computational fluid dynamics (CFD) was employed to study the internal cavitation flow field of the centrifugal pump in the pure water and sand water respectively. Based on Fluent 15.0, Mixture model, RNG k-&Epsilon; (renormalization group k-&Epsilon;) turbulence model and Schnerr-Sauer cavitation model were used to research the cavitation flow. For the cavitation flow in the sand water, sand mean diameters selected were 0.005, 0.010 and 0.015 mm and sand concentrations were 0.5%, 1.0% and 1.5% respectively. Unstructured grids constructed by ANSYS-ICEM(Integrated Computer Engineering and Manufacturing), were applied to disperse the computational domain. Accuracy of numerical calculation was improved by grids independence check and the total number used was 2 817 398. Numerical results of pure water performance of the centrifugal pump and cavitation flow around the flat-nosed cylinder were compared with the experimental results to verify the reasonableness of the algorithm used in the simulations. Numerical results revealed that the algorithm designed was appropriate to simulate cavitation flow. To lower the turbulent viscosity in cavitation region, RNG k-&Epsilon; turbulence model was modified. Cavitation performance curves were built, the vapor had the volume fraction of 0.1 in different cavitation periods, and the effect of sand particles on the cavitation flow was investigated. To study the effect of sand mean diameter, sand concentration was 1.0% and sand mean diameter was increased from 0.005 to 0.015 mm gradually. When the outlet pressure was 6.0&times;10⁵Pa, cavitation did not occur in the pure water of the centrifugal pump and vapor did not exist in the pure water. In the sand water, a few cavitation bubbles appeared. For the critical net positive suction head (NPSHc) which was the NPSH when the head was reduced by 3.0%. In the pure water, it was 3.721 4 m and in the sand water with sand mean diameter of 0.005, 0.010 and 0.015 mm, it was 4.952, 3.747 9 and 3.638 m respectively, and when cavitation developed fully, the NPSH was 3.436, 3.541, 3.438 and 3.337 m respectively for the pure water and the sand water with 3 different sand mean diameters, indicating that the effects of sand particles on the cavitation flow were accelerative at first, and then inhibited. When sand mean diameter was 0.010 mm, in the critical cavitation stage and cavitation full development stage, NPSH in the pure water and sand water had inconspicuous difference. Compared with cavitation occurring in the pure water, when sand mean diameter was 0.010 mm, sand particles had little effect on the development of cavitation in the sand water. To study the effect of sand concentration, sand mean diameter was 0.010 mm and sand concentration increased from 0.5% to 1.5% gradually. Under outlet pressure of 6.0&times;10⁵Pa, cavitation did not occur in the pure water of the centrifugal pump and vapor did not appear in the pure water too. And a few cavitation bubbles existed in the sand water, stating clearly that sand particles had a close relation with the formation of cavitation bubbles. In the critical cavitation period, NPSHc was 3.721 4, 4.780 1, 3.747 9 and 3.490 6 m respectively for the pure water and the sand water with 3 different sand concentrations of 0.5%, 1.0% and 1.5%, and in the cavitation full development period, NPSH was 3.436, 3.841, 3.438 and 2.960 4 m separately, explaining that effects of sand concentration on the cavitation flow were accelerative at first, and then inhibited too. When sand concentration was 1.0%, in the critical cavitation period and cavitation full development period, NPSH in the pure water and sand water had little difference, illustrating that compared with cavitation occurring in the pure water, sand particles had little effect on the development of cavitation under the 1.0% sand concentration. When sand particles promoted the development of cavitation, volume of vapor with volume fraction of 0.1 in sand water was larger than that in the pure water. During sand particles inhibiting the development of cavitation, the volume was smaller than that in the pure water. For sand particles had little effect on the evolution of cavitation, the distribution was similar. During cavitation fully evolving, interaction of abrasion and cavitation erosion made the head in sand water less than that in the pure water. With sand concentration being invariant, when sand mean diameter increased and with sand mean diameter being constant, when volume fraction increased gradually, head in sand water decreased continuously. Number of cavitation nuclei, virtual mass force, slip velocity, and so on had a close connection with sand particles promoting the development of cavitation. Viscosity, abrasion effect, and so on had a close relationship with sand particles inhibiting the evolution of cavitation. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Sand
Controlled terms:Abrasion - Cavitation - Centrifugal pumps - Computational fluid dynamics - Computer integrated manufacturing - Computer simulation - Models - Pumps - Silt - Statistical mechanics  - Turbulence models - Viscosity - Volume fraction
Uncontrolled terms:Cavitation performance - Computational domains - Computer engineering - Internal cavitation - Mean diameter - Numerical calculation - Renormalization group - Silt concentrations
Classification code:483.1  Soils and Soil Mechanics - 618.2  Pumps - 631.1  Fluid Flow, General - 631.1.1  Liquid Dynamics - 641.1  Thermodynamics - 723.5  Computer Applications - 922.2  Mathematical Statistics - 951  Materials Science
Numerical data indexing:Size 9.00e+00m, Percentage 1.00e+00%, Percentage 1.50e+00%, Percentage 3.00e+00%, Percentage 5.00e-01% to 1.50e+00%, Percentage 5.00e-01%, Size 1.00e-05m, Size 1.50e-05m, Size 3.34e+00m, Size 3.44e+00m, Size 3.64e+00m, Size 5.00e-06m to 1.50e-05m
DOI:10.11975/j.issn.1002-6819.2017.04.017

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 2>

Accession number:20171503565317
Title:Effects of rolling time and frequency on mechanochemical properties of corn starch
Authors:Niu, Kai (1); Li, Guixiao (1); Dai, Yangyong (1); Dong, Haizhou (1); Hou, Hanxue (1); Zhang, Hui (1); Liu, Chuanfu (1) 
Author affiliation:(1) College of Food Science and Engineering, Shandong Agricultural University, Tai'an; 271018, China 
Corresponding author:Dai, Yangyong(dyyww@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:293-301
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Starch is one of the most abundant renewable biological resources and the primary source of stored energy in most plants. But native starch possesses many limitations such as low water solubility, thermal decomposition and chemical activity and high tendency towards retrogradation, which to some extent restricts its processing and application. Rolling technology is an effective physical modification means. It is simple, safe and has no pollution. In addition, it has significant impact on properties and structure of starch, which has a significant and great prospect in future. In this paper, a variety of advanced instrumental analysis techniques were used, which included scanning electron microscope (SEM), polarizing microscope (PLM), confocal laser scanning microscopy (CLSM), X-ray diffraction (XRD), differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FTIR), and Rapid Visco Analyzer (RVA). Normal corn starches processed by different rolling time and speeds were investigated to demonstrate the effect of rolling on structure and physicochemical properties of corn starch. Structures of normal corn starch such as granular structure, channel structure, particle size distribution, crystalline structure and functional group were analyzed. The properties of starch, including water soluble index, swelling power, transparency, paste stability of corn starch, were studied. And pasting properties and thermal characteristics were comparatively analyzed. Under the frequency of 20 Hz, the results showed that when grinding mill processed for 3-6 h, the particle size of granule underwent a corresponding change with the morphological structure of corn starch changing erratically. The central cavity became larger and the channel was blurred. The DSC results indicated the gelatinization temperatures of the starches were not significantly altered by rolling, but the gelatinization enthalpies were significantly reduced in line with the reduction in the amount of double helices. At the same time, there was no significant decline in the degree of crystallinity. The results showed that the double helices content decreased after rolling treatment but the crystalline structure was seldom destroyed. In other word, rolling treatment had merely impact on double helix structure of amorphous region of corn starch granule. With the increasing of processing time, some bulbous protuberances were formed on the granule surface. And the water solution index, welling power, and transparency presented a significant decrease. Furthermore, peak viscosity and enthalpy of the corn starch also decreased gradually with the rolling time increasing. And crystalline regions still experienced a little damage. It was supposed that aggregation occurred in crystalline regions, which resulted in the formation of bulbous protuberance and the change of properties of corn starch. As the rolling processing time increased to 12 h, the SEM and CLSM analysis revealed that bulbous protuberances of particle surface became less obvious, some debris attached to large particles and the number of channels was increased. Particle size of granules was found to increase but opposite trend was found in enthalpy. Meanwhile, the feature of diffraction peaks observed in the diffractogram was gradually weakened, and crystal structure was severely damaged. At this stage, rolling destroyed the crystalline area of corn starch granules in accompany with the double helical content decreasing. Under the frequency of 30 Hz, due to the shear force is stronger, the effect of rolling treatment on structure and properties of normal corn starch was more obvious. The FTIR analysis showed that rolling treatment significantly decreased the absorption peak intensity at the band of 1 047 cm^-1corresponding to the amorphous part of starch structure, which confirmed the results of enthalpy. In conclusion, the above results demonstrate that rolling treatment has different mechanochemical effect on the amorphous and crystalline regions of corn starch granule, and leads to typical aggregation and agglomeration effects occurring successively in the interior of the starch granules. This study offers significant evidences for further investigations on the mechanochemical theory. What is more, it provides a convenient, rapid, efficient and green new modification technology for starch deep processing. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Crystal structure
Controlled terms:Chemical analysis - Crystalline materials - Decomposition - Differential scanning calorimetry - Enthalpy - Fourier transform infrared spectroscopy - Gelation - Granulation - Particle size - Particle size analysis  - Particles (particulate matter) - Physical properties - Pressure - Rolling - Scanning - Scanning electron microscopy - Shear flow - Starch - Structural properties - Structure (composition)  - Transparency - X ray diffraction
Uncontrolled terms:Confocal laser scanning microscopy - Differential scanning calorimeters - Frequency - Gelatinization temperature - Morphological structures - Physicochemical property - Structure and properties - Time
Classification code:631.1  Fluid Flow, General - 641.1  Thermodynamics - 741.1  Light/Optics - 801  Chemistry - 802.2  Chemical Reactions - 802.3  Chemical Operations - 804.1  Organic Compounds - 931.1  Mechanics - 931.2  Physical Properties of Gases, Liquids and Solids - 933.1  Crystalline Solids - 933.1.1  Crystal Lattice - 944.6  Temperature Measurements - 951  Materials Science
Numerical data indexing:Frequency 2.00e+01Hz, Frequency 3.00e+01Hz, Time 1.08e+04s to 2.16e+04s, Time 4.32e+04s
DOI:10.11975/j.issn.1002-6819.2017.04.040

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 3>

Accession number:20171503565281
Title:Design and experiment of automatic feed mechanism with half nuts structure of portable digging machine
Authors:Ma, Li'na (1); Wang, Jingliang (1); Zong, Wangyuan (1); Huang, Xiaomao (1); Feng, Jun (1) 
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China 
Corresponding author:Zong, Wangyuan(zongwangyuan@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:25-31
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Digging machine is a kind of digging and tillage machine. Because its structure is simple and it can be operated conveniently, it is widely used as a hole digger. There are mainly 4 types of digging machines, i.e. suspension type, portable type, traction type and self-propelled type. On the mountains, hills, ravines and other complex terrain conditions, portable type of digging machine is popularly used to dig a hole so as to plant or transplant trees. Hence, this paper designed a new portable digging machine with a half-nut mechanism to keep the feed rate stable and decrease the torque of the drilling bit as far as possible when drilling the hole. In addition, the support structure was also designed for the digging machine for the sake of guaranteeing the verticality of the hole and ensuring the reliability and stability of the digging machine, as well as making the structure more secure. The feed rate of the digging machine was an important factor, which affected the torque and work efficiency of the drilling bit greatly. Research on the effect of the feed rate on the dynamic mechanical parameters of digging machine was of great significance for developing a new model of digging machine. However, the power of the digging machine was gasoline engine, so the power output shaft could not reversely rotate, and it could not be used for actual digging. Thus there was a great need to design a new structure that could solve the gasoline engine's problem of rotating only in one direction. Accordingly, the half-nut mechanism was designed. According to the working principle of the half-nut, the motion characteristics of half-nut mechanism were analyzed by using the analytic method. The straight track angle of half-nut picks was decided as 105&deg;, and thus a portable digging machine with half-nut mechanism was designed. The new designed digging machine could not only realize the digging operation automatically, but also complete the return movement rapidly. Then based on the working principle of digging machine, the relationship between the feed rate and the effect of lifting soil was studied. In order to verify the result, the experiment of testing the torque and rotational speed during the process of drilling a hole was conducted by using the torque measuring device JN338-100A made by Beijing Xinyuhang Century Science and Technology Co., Ltd. to collect the data afterward. Therefore it successfully provided a theoretical basis for the determination of feed rate of a new type of digging machine. It showed that when the pitch of half nut was taken as 3 or 5 mm, the torque and its fluctuation both were small. However when the pitch of half nut was taken as 8 mm, for it did not satisfy the working principle of digging machine, the torque and its fluctuation varied greatly, and the digging machine could not lift soil smoothly. In order to improve the work efficiency, the pitch of half nut was taken as 5 mm for this new designed digging mechanism finally. This paper provides a theoretical basis for the design of automatic feed mechanism of a new portable digging machine. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Structural design
Controlled terms:Bits - Design - Efficiency - Engines - Gasoline - Machinery - Mechanization - Soils - Torque
Uncontrolled terms:Dynamic mechanical parameters - Feed-rates - Half nuts - Motion characteristics - Reliability and stability - Science and Technology - Support structures - Suspension types
Classification code:408.1  Structural Design, General - 483.1  Soils and Soil Mechanics - 523  Liquid Fuels - 601  Mechanical Design - 603.2  Machine Tool Accessories - 913.1  Production Engineering - 931.2  Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Size 5.00e-03m, Size 8.00e-03m
DOI:10.11975/j.issn.1002-6819.2017.04.004

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 4>

Accession number:20171503565308
Title:Remote sensing estimation of biomass in winter wheat based on CASA model at region scale
Authors:Liu, Zhenzhen (1, 2); Zhang, Xiwang (1, 2); Chen, Yunsheng (1, 2); Zhang, Chuancai (1, 2); Qin, Fen (1, 2); Zeng, Hongwei (3) 
Author affiliation:(1) Key Laboratory of Geospatial Technology for Middle and Lower Yellow River Regions, Ministry of Education, Kaifeng; 475004, China; (2) College of Environment &amp; Planning of Henan University, Kaifeng; 475004, China; (3) Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing; 100094, China 
Corresponding author:Zhang, Xiwang(zxiwang@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:225-233
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Remote sensing can dynamically monitor crop, in real-time, all-weather, also simulate process of crop growth by extracting remote sensing parameters. It was the first step to estimate NPP (net primary productivity) for biomass estimation, and the CASA(Carnegie-Ames-Stanford Approach) model, one of the most popular biomass estimation model, was used for NPP estimation of winter wheat to realize the winter wheat biomass estimation in study area. We analyzed deeply and developed both the NDVI extracting method and FPAR algorithm based on the original CASA model. After comprehensively absorbing the experience of related literature, and the maximum value of light energy utilization efficiency was determined. Then we got an improved CASA model which was suitable for study area. The quantile fractile with winter wheat NDVI maximum probability distribution was extracted to determine NDVI<inf>max</inf>and NDVI<inf>min</inf>, and previous algorithm of improved FPAR with a correction factor was used in this paper. Solar radiation (SOL) around the area of the site data were used for the interpolation by natural neighbor spatial interpolation method. Temperature, precipitation and other meteorological data in the study area were used to calculate the real light energy utilization efficiency. Finally, we entered the above parameters into the improved CASA model to calculate winter wheat NPP. The study area is located in Handan city, Hebei province. The winter wheat at the county scale was taken as the research object. HJ-1A/B products were used as data support to estimate the winter wheat NPP and biomass of study area in 2014. The accuracy was verified. Results showed that the average NPP in March, April, May were 78, 297 and 320 g/m², respectively. The difference was caused by growth characteristics of winter wheat in different periods. In March, winter wheat was in the green period, the leaf area of winter wheat increased gradually. In April, winter wheat was in exuberant growth period, leaf area was continued to increase, and the NPP also increased. In May, the winter wheat was gradually into flowering, grain filling, and milk stage etc, during the time most parts of NPP was more than 250 g/m², which was consistent with wheat physiological characteristic, it showed that winter wheat grew well. And the average biomass of winter wheat in the study area was 1 485 g/m², more than half of study area was between 1 500 and 2 000 g/m². The correlation between measured biomass and predicted biomass of winter wheat reached significant level, R²was 0.811 5, and the average relative error was 2.13%, the maximum error was 11.54%, the minimum error was 0.33%. Average predicted biomass was 1 807.54 g/m², the absolute error was 86.80 g/m², compared with the average measured biomass 1 720.74 g/m². This study can provide theoretical support for estimating both winter wheat biomass and yield at country scale. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Crops
Controlled terms:Biomass - Ecology - Ecosystems - Energy efficiency - Energy utilization - Errors - Interpolation - Light - Meteorology - Probability distributions  - Remote sensing - Sols
Uncontrolled terms:CASA - HJ-1A/B - Light energy - Net primary productivity - Physiological characteristics - Remote sensing estimations - Spatial interpolation method - Winter wheat
Classification code:454.3  Ecology and Ecosystems - 525.2  Energy Conservation - 525.3  Energy Utilization - 741.1  Light/Optics - 804  Chemical Products Generally - 821.4  Agricultural Products - 921.6  Numerical Methods - 922.1  Probability Theory
Numerical data indexing:Percentage 1.15e+01%, Percentage 2.13e+00%, Percentage 3.30e-01%, Surface_Density 1.49e+00kg/m2, Surface_Density 1.50e+00kg/m2 to 2.00e+00kg/m2, Surface_Density 2.50e-01kg/m2, Surface_Density 2.97e-01kg/m2, Surface_Density 3.20e-01kg/m2, Surface_Density 7.21e-01kg/m2, Surface_Density 8.08e-01kg/m2, Surface_Density 8.68e-02kg/m2
DOI:10.11975/j.issn.1002-6819.2017.04.031

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 5>

Accession number:20171503565312
Title:Comparison of pyrolysis characteristics and kinetics of sawdust and its hydrochar
Authors:Xing, Xianjun (1, 2); Yang, Jing (3); Fan, Fangyu (4); Li, Yongling (3); Zhang, Xianwen (1, 2) 
Author affiliation:(1) Institute of Advanced Energy Technology &amp; Equipment, Hefei University of Technology, Hefei; 230009, China; (2) School of Automobile and Transportation Engineering, Hefei University of Technology, Hefei; 230009, China; (3) School of Mechanical Engineering, Hefei University of Technology, Hefei; 230009, China; (4) School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei; 230009, China 
Corresponding author:Zhang, Xianwen(xianwen.zhang@hfut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:258-264
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rapid industrialization and urbanization have brought a severe problem of energy shortage and environmental pollution into our life. As the fourth-largest energy, Nowadays, Lignocellulosic biomass is increasingly regarded as an eco-friendly renewable feedstock for producing various bio-based products. Recently, hydrothermal carbonization (HTC) as a hot topic has attracted a great deal of attention because the process requirements of HTC are comparably low and are able to treat wet feedstock without an energy extensive drying process. But so far, some literatures have focused on the morphology, chemical structure and adsorption capacity of hydrochar, etc. Only few reports have provided a detailed description on the kinetic analysis of hydrochar. Pyrolysis is considered as the first step of the process of gasification, liquefaction, carbonization, and combustion. On the other side, the knowledge of the pyrolysis kinetics is fundament for predicting the pyrolysis behavior of materials and the design of the suitable reactor. In this study, pine sawdust was provided by a factory in Anhui province in 2015. The hydrochar was hydrothermally obtained from 5 g of sawdust immersed in 40 mL of distilled water in the stainless steel autoclave keeping temperature at 200&#8451; for 6 h, then as-prepared hydrochar was dried in an oven at 105&#8451; for 24 h. Pyrolysis characteristics and organic structure of both pine sawdust and hydrochar were investigated via thermogravimetric analysis and Fourier transformation infrared spectrometer, respectively. Different heating rates (10, 20, 30&#8451;/min) were chosen to study the influence of pyrolysis process. Meanwhile, the distributed activation energy model (DAEM) was used to study the pyrolysis kinetics by means of the relation between conversion rate and activation energy. The results indicated that:1) Compared with pine sawdust organic structure of hydrochar treated by hydrothermal carbonization process was changed, and the organic function groups of pine sawdust and hydrochar decreased in the different ways with the increase of pyrolysis temperature, but the organic function groups of hydrochar decreased faster than pine sawdust's when the temperature was over 200&#8451;; 2) Thermogravimetric curves showed that hydrochar needed higher temperature and led to the faster loss weight rates than pine sawdust during the pyrolysis process, but the trend of thermogravimetric curves of both products changing with heating rates was same; 3) The values of pyrolysis activation energies of hydrochar and pine sawdust were different ranging within 99.33-252.72 and 63.77-211.68 kJ/mol, respectively. But the trends of the pyrolysis activation energies of hydrochar and pine sawdust were very similar with the increment of conversion rate. In summary, hydrothermal treatment process destroyed organic functional groups and lowered volatile content of pine sawdust, resulting in the changes of pyrolysis characteristics. Specifically, the whole pyrolysis process shifted to higher temperature, the reaction rate was accelerated and the main pyrolysis process occurred in a narrower temperature range shortening the pyrolysis time. Activation energy also was influenced due to the hydrothermal process, leading the reduction of the values at the dominating stage of volatile loss, however, the increase of the values at the initial and final stage of volatile loss. This study provides reference for pyrolysis and mechanism of hydrochar production. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Activation energy
Controlled terms:Carbonization - Chemical activation - Chemical analysis - Feedstocks - Fourier transforms - Heating rate - Kinetics - Pyrolysis - Sawdust - Stainless steel  - Thermochemistry - Thermogravimetric analysis
Uncontrolled terms:Distributed activation energy model - Environmental pollutions - Hydrochar - Hydrothermal carbonization - Infrared spectrum - Organic functional groups - Pyrolysis characteristics - Stainless steel autoclaves
Classification code:545.3  Steel - 641.1  Thermodynamics - 641.2  Heat Transfer - 801  Chemistry - 801.4  Physical Chemistry - 802.2  Chemical Reactions - 811.2  Wood and Wood Products - 921.3  Mathematical Transformations - 931  Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Volume 4.00e-05m3, Mass 5.00e-03kg, Time 2.16e+04s, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2017.04.035

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 6>

Accession number:20171503565301
Title:Reasonable irrigation mode and water-saving potential for rice in Northern Hubei Province
Authors:Liu, Luguang (1); Tan, Junwei (2); Wu, Xia (1); Wang, Lihong (3); Cao, Junlong (4) 
Author affiliation:(1) Hubei Water Resources Research Institute, Wuhan; 430070, China; (2) State Key Laboratory of Water Resources and Hydropower Science, Wuhan University, Wuhan; 430072, China; (3) Hubei Water Resources Technical College, Wuhan; 430070, China; (4) Changqu Irrigation Station, Xiangyang; 441000, China 
Corresponding author:Tan, Junwei(tanjunwei@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:169-177
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The agricultural water and ecological water have been continuously squeezed due to increasing urban domestic water consumption in China. Moreover, the inconsistency between water supply and demand in agriculture has been threating the regional food security, ecological environment protection, and social stability. Therefore, the study on crop water requirement and water-saving irrigation mode is important to mitigate the water shortage in agriculture. In this paper, yield and water demand regulation of paddy rice under different irrigation modes were analyzed based on the field experiments conducted in 2009-2013 at Changqu Irrigation Station (31&deg;11'N, 112&deg;11'E), Xiangyang, Hubei Province. ORYZA_V3 model was calibrated against the measured rice yield obtained in 2010, and validated with measured rice yield obtained in 2011. Then, the calibrated model was used to simulate the rice growth for 30 years (1981-2010) under three traditional irrigation modes and several drought schemes, which were designed with combinations of lower limits of irrigation, irrigation water quotas, and irrigation times for drought in different rice growing stages. Based on model outputs, evapotranspiration and water consumption were calculated for each growing stage, and irrigation quota, irrigation times, yields and water productivity were compared. Based on that, an optimum irrigation mode was proposed for this region, and its water-saving potential was calculated. The results indicated that, compared to shallow irrigation (SI) mode, the annual average yield under wetting irrigation (WI) mode increased by 2.7% and the irrigation quota decreased by 4.2%, whereas the yield under middle-store irrigation (MI) mode decreased by 2.3% and the irrigation quota decreased by 1.1%. Thus, among the traditional irrigation modes, WI mode is better than SI mode and MI mode from the points of saving water and improving production. Furthermore, lower irrigation threshold less than 90% of saturated soil moisture in tillering stage (TL) reduced evapotranspiration by more than 47%, and in other stages evapotranspiration were reduced by more than 10% when the irrigation threshold was less than 70% of saturated soil moisture. In addition, drought in jointing-booting (JB) and heading flowering (HF) stage had stronger effects on rice yield than that in other stages. After an overall consideration of water-saving, field management efficiency and food security, the optimum irrigation mode for this region was suggested: The maximum water level in field after rain was set as 60 mm, thin water layer should be kept in returning green (RG) and heading flowering (HF) stages, whereas natural fall was advisable in yellow-ripping (YR) stage, and moderate drought was allowed only in jointing-booting (JB) and milky-ripening (MK) stages with lower limit of irrigation between 70%-80% of saturated soil moisture while light drought was suggested in other stages with the lower limit of irrigation higher than 80% of saturated soil moisture, and the irrigation water quota was set as 30-40 mm. The optimum irrigation mode had great water-saving potential, which could save at least 0.168 billion m³water for northern part of Hubei Province. The results of this study were of important significance in guiding the irrigation for paddy rice in this region. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Irrigation
Controlled terms:Agriculture - Drought - Ecology - Economics - Evapotranspiration - Food supply - Models - Moisture - Soil moisture - Soils  - Water - Water conservation - Water levels - Water management - Water resources - Water supply
Uncontrolled terms:Agricultural water - Crop water requirements - Ecological environment protections - Traditional irrigation - Water productivity - Water supply and demands - Water-saving irrigation - Water-saving potentials
Classification code:444  Water Resources - 446.1  Water Supply Systems - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3  Agricultural Methods - 822.3  Food Products - 971  Social Sciences
Numerical data indexing:Percentage 1.00e+01%, Percentage 1.10e+00%, Percentage 2.30e+00%, Percentage 2.70e+00%, Percentage 4.20e+00%, Percentage 4.70e+01%, Percentage 7.00e+01%, Percentage 7.00e+01% to 8.00e+01%, Percentage 8.00e+01%, Percentage 9.00e+01%, Size 3.00e-02m to 4.00e-02m, Size 6.00e-02m
DOI:10.11975/j.issn.1002-6819.2017.04.024

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 7>

Accession number:20171503565304
Title:Dynamic characteristics of leaf area index and plant height of winter wheat influenced by irrigation and nitrogen coupling and their relationships with yield
Authors:Li, Zhengpeng (1, 2); Song, Mingdan (1, 2); Feng, Hao (1, 2, 3) 
Author affiliation:(1) Institute of Soil and Water Conservation, Northwest A&amp;F University, Yangling; 712100, China; (2) Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&amp;F University, Yangling; 712100, China; (3) Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling; 712100, China 
Corresponding author:Feng, Hao(nercwsi@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:195-202
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Leaf area and plant height are 2 important characteristic parameters of canopy structure, which represent the crop vertical extension and horizontal expansion respectively and are closely related to dry matter accumulation and yield formation by influencing the interception and distribution of photosynthetic active radiation. The dynamic process of crop LAI (leaf area index) and height could be influenced by many factors, of which water and nitrogen are the two major ones limiting crop growth and development. Some researchers have analyzed the dynamic process of LAI quantitatively under high yielding conditions, however the dynamic characteristics of LAI under water and nitrogen stress are still not clear. The effect of different cultivars, cultivation practices on the plant height at maturity were studied by most former research, while less information was found about how the management practices influence the dynamic process of plant height. Therefore, this study was aimed to clarify the effects of water and nitrogen on wheat LAIand plant dynamics and to quantify the relationship of LAI and plant height with crop yield. A field experiment during 2012-2014 was conducted with 3 irrigation levels and 4 nitrogen input levels in Guanzhong Plain of Shaanxi Province, and LAIs and plant heights measured were fitted with thermal time using the modified Logistic model and Richards mathematical model, respectively. The results demonstrated that the performances of both models were pretty good with an nRMSE(normalized root mean squared error) of 8% for LAI and an nRMSE of 4% for plant height, respectively. Irrigation enhanced the maximum growth rate of LAI, which increased from 0.004 cm²/(cm²&middot;&#8451;&middot;d) under rainfed condition to 0.006 cm²/(cm²&middot;&#8451;&middot;d) under irrigation condition in over-wintering and jointing period. The corresponding maximum LAI and average LAI increased from 3.50 and 2.64 cm²/cm²to 4.11 and 3.15 cm²/cm², respectively. Nitrogen fertilizer application shortened the thermal time from sowing to the maximum growth rate and maximum value of LAI occurring, and improved the maximum growth rate of LAI. Hence, the maximum LAI and average LAI increased from 1.87 and 1.35 cm²/cm²with no nitrogen input to 4.57 and 3.82 cm²/cm²with 210 kg/hm²input, respectively, and no further significant increase was observed with more nitrogen input. Irrigation enhanced the maximum plant height from 62 to 66 cm, which was resulted from the longer thermal time from sowing to the maximum plant height occurring under the irrigation condition. The thermal time from sowing to the rapid growth stage and to the maximum plant height occurring was shortened and extended by nitrogen fertilizer application, respectively, which brought about a plant height increasing from 58 to 65 cm with 105 kg/hm²input, and then plant height was leveled off with more nitrogen input. Due to more rainfall in the early growth stage, the plant height in 2014 was about 10 cm higher than that in 2013. The stepwise regression analysis of dynamic characteristics of wheat yield with LAI and plant height showed that grain numbers per square meter was only related with average LAI, while 1 000-grain weight depended largely on the maximum plant height. Furthermore, the final yield was determined by both average LAI and the maximum plant height with a larger contribution from average LAI. This research revealed the mechanism that how irrigation and nitrogen fertilizer application affected the plant leaf area and height growth, and then further impacted on yield. The result provides a set of technical support for reasonable regulation of crop community structure. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Plant expansion
Controlled terms:Crops - Cultivation - Fertilizers - Growth rate - Irrigation - Mean square error - Nitrogen - Nitrogen fertilizers - Plants (botany) - Rain  - Regression analysis
Uncontrolled terms:Crop growth and development - Modified Logistic model - Photosynthetic active radiations - Plants - Richards models - Root mean squared errors - Stepwise regression analysis - Yield components
Classification code:443.3  Precipitation - 804  Chemical Products Generally - 821.3  Agricultural Methods - 821.4  Agricultural Products - 922.2  Mathematical Statistics
Numerical data indexing:Percentage 4.00e+00%, Percentage 8.00e+00%, Size 1.00e-01m, Size 5.80e-01m to 6.50e-01m, Size 6.20e-01m to 6.60e-01m
DOI:10.11975/j.issn.1002-6819.2017.04.027

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 8>

Accession number:20171503565310
Title:Comparison experiment of total water consumption and water leakage of different types of drinker for nursery pig
Authors:Wang, Meizhi (1, 2); Zhao, Wanying (1, 2); Wu, Zhonghong (1, 2); Liu, Jijun (1, 2); Chen, Zhaohui (1, 2); L&uuml;, Na (1, 2) 
Author affiliation:(1) College of Animal Science, China Agricultural University, Beijing; 100193, China; (2) State Key Laboratory of Animal Nutrition, Beijing; 100193, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:242-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China is a country with the insufficiency of water resources, where agriculture is segregated from animal husbandry. Waste water that is produced from animal production is difficult to be used in planting production. So it is important to save water in animal husbandry and reduce waste water produced by animal production. In pig production, when the pigs drink water from some types of drinkers, it is obvious that some water that is sprayed from the drinkers will quickly fall into both the ground and the mouth of the pigs, and then the water falling into the ground will be mixed with waste and increase the volume of waste water. The aim of this study was to find water saving type of drinkers or water saving ways of drinking for pig production, thereby declining the water pollution in the field of animal husbandry. Sixty female nursery pigs were studied in 2 blocks, and each block had 3 pens and each pen had 10 animals. The single water drinker was situated at the midpoint of one end side, with a single-space dry feeder situated in an opposite corner. A water meter was installed in the water line to record total water consumption, and totally 6 water meters. Total water consumption data were recorded on a daily basis while water leakage data were recorded on an hourly basis. A tray (30 cm &times; 45 cm) was mounted directly below the drinker under the pen mash bed and funneled waste water to a water meter for water leakage, totally 6 trays. The data were recorded on a minutely basis. The bite drinkers were fixed permanently at 0.28 m above the mash bed, and the bowl drinkers were set at 0.20 m above the mash bed. Swing drinkers were set at 0.05 m above shoulder height of the smallest pig in the pen. In pre experiment (from January 3^rdto January 23^rd2016), bite drinkers and swing drinkers were studied. On January 23^rd2016, the bite drinkers were replaced by bowl drinkers. In the later stage of experiment (from January 23^rdto January 31^st2016), the swing drinkers and bowl drinkers were studied. The result showed that during the whole experiment, the temperature of the house was 20-25 &#8451;, the humidity was 80%-100%, and the concentrations of ammonia and carbon dioxide were 10.54-23.72 mg/m³and 2 036.36-2 800 mg/m³, respectively. Each pig's total water consumption of bowl drinkers, bite drinkers and swing drinkers was 7.46, 7.73 and 8.07 L/d (P&gt;0.05), respectively. The highest figure of each pig's water intake was swing drinkers, representing 6.64 L/d, followed by 6.32 L/d of bowl drinkers and 5.79 L/d of bite drinkers (P&lt;0.05). The bite drinkers presented the highest average water waste for each pig during the entire experiment (1.93 L/d) and differed remarkably (P&lt;0.01) from swing drinkers (1.42 L/d) and bowl drinkers (1.13 L/d). And then, the bite drinkers presented the highest ratio of average water waste to total water consumption (25.10%) and differed remarkably (P&lt;0.01) from swing drinkers (17.58%) and bowl drinkers (15.17%), and there was no significant difference between bowl drinkers and swing drinkers. Therefore, the bowl drinkers and swing drinkers can have the effect of water saving compared to the bite drinkers. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Produced Water
Controlled terms:Agriculture - Animals - Carbon - Carbon dioxide - Inlet flow - Leakage (fluid) - Mammals - Potable water - Societies and institutions - Wastewater  - Water conservation - Water meters - Water pollution - Water resources - Water supply
Uncontrolled terms:Ammonia and carbon dioxide - Animal production - Drinker - Nursery pig - Shoulder heights - Water consumption - Water intakes - Water leakage
Classification code:444  Water Resources - 446.1  Water Supply Systems - 452.3  Industrial Wastes - 453  Water Pollution - 631.1  Fluid Flow, General - 804  Chemical Products Generally - 804.2  Inorganic Compounds - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 901.1.1  Societies and Institutions - 943.3  Special Purpose Instruments
Numerical data indexing:Mass_Density 1.05e-05kg/m3 to 2.37e-05kg/m3, Mass_Density 3.64e-05kg/m3 to 2.80e-03kg/m3, Percentage 1.52e+01%, Percentage 1.76e+01%, Percentage 2.51e+01%, Percentage 8.00e+01% to 1.00e+02%, Size 2.00e-01m, Size 2.80e-01m, Size 4.50e-01m, Size 5.00e-02m
DOI:10.11975/j.issn.1002-6819.2017.04.033

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 9>

Accession number:20171503565297
Title:Groundwater dynamics forecast under conjunctive use of groundwater and surface water in seasonal freezing and thawing area
Authors:Yang, Wenyuan (1); Hao, Peijing (1); Zhu, Yan (1); Liu, Jiashuai (1); Yu, Jian (2); Yang, Jinzhong (1) 
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan; 430072, China; (2) Water Resources Research Institute of Inner Mongolia, Huhhot; 010020, China 
Corresponding author:Yang, Jinzhong(jzyang@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:137-145
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Water resources allocation for agriculture irrigation in the Yellow River basin will be reduced due to water shortage and increasing demand for non-agricultural use. Different measurements should be taken to save water and to ensure the sustainable development of agriculture. The conjunctive use of groundwater and surface water is one of the most promising water-saving measurements by decreasing evaporation and increasing water efficiency. However, it also could result in adverse effects on the local environment such as soil desertification when over-extraction of groundwater occurs. Therefore, it is necessary to estimate the water dynamics accurately when implementing the conjunctive use of groundwater and surface water irrigation in the target district. In this paper, Yongji irrigation sub-area of Hetao irrigation district as the study area to estimate the temporal and spatial groundwater dynamics under the conjunctive use of groundwater and surface water. Yongji irrigation sub-area locates in the arid and semi-arid area, and it has a six months freezing and thawing period from December to May of the next year. The mechanism driving of the groundwater table change in the freezing and thawing period is different from the unfreezing period, with multiple complex impact factors. Temperature is considered as the most important factor to drive the water table change in the freezing and thawing period. An empirical model has been developed in the freezing and thawing period to correlate the groundwater table depth with the air temperature according to the measured date in the past 15 years. The model showed that the water level would drop 61.87 mm with 1&#8451; decline of the air temperature before 46.5 days ago. This empirical model has been integrated to a water balance model to estimate the groundwater dynamics both in the freezing and thawing period and unfreezing period. The model was then applied in the Yongji irrigation sub-area. Model parameters were calibrated with datasets from 2000 to 2010 and were validated with datasets from 2011 to 2012. Then, the calibrated model was applied to estimate the impacts of conjunctive use of groundwater and surface water under 12 kinds of water saving scenarios. The simulating results indicated that exploitation amount of available groundwater and autumn irrigation amount diverting from the Yellow river were two important factors to impact groundwater table depth. For the 12 scenarios, annual average groundwater level decline in the whole district ranges from 0.05 to 0.24 m. The value ranges of groundwater level decline from 0.16 to 0.38 m in the conjunctive groundwater and surface water irrigation district. The irrigation water diverted from Yellow river accounted for 5.7% to 15.5% of the current water diversion every year. During the unfreezing period, the recharge from irrigation contributes the largest supply to the groundwater aquifer, ranging from 1.772&times;10⁸to 2.123&times;10⁸m³/a. The recharge from precipitation ranks secondly to the aquifer with 0.267&times;10⁸m³/a. The conjunctive use of groundwater and surface water can reduce the phreatic water evaporation as 0.108&times;10⁸to 0.374&times;10⁸m³/a. The less phreatic water evaporation and re-use of groundwater were the key points of saving water by the conjunctive use of groundwater and surface water. Meanwhile, the groundwater table depth was closely related with the irrigation water amount. The relationship was described by a quadratic function which could be used as an easy groundwater predicted method when carrying out the conjunctive use of groundwater and surface water. The research results provide important reference to study the groundwater dynamics under the conjunctive use of groundwater and surface water in the similar arid and semi-arid regions. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Surface waters
Controlled terms:Agriculture - Aquifers - Arid regions - Atmospheric temperature - Climate models - Dynamics - Evaporation - Flood control - Freezing - Groundwater  - Groundwater resources - Irrigation - Recharging (underground waters) - River diversion - Rivers - Sustainable development - Thawing - Water - Water conservation - Water levels  - Water resources - Water supply
Uncontrolled terms:Arid and semi-arid areas - Arid and semi-arid regions - Dynamic condition - Freezing and thawing - Groundwater table depth - Hetao irrigation districts - Water balance models - Water resources allocations
Classification code:441  Dams and Reservoirs; Hydro Development - 442.1  Flood Control - 443  Meteorology - 443.1  Atmospheric Properties - 444  Water Resources - 446.1  Water Supply Systems - 802.3  Chemical Operations - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3  Agricultural Methods - 921  Mathematics
Numerical data indexing:Age 1.27e-01yr, Age 1.50e+01yr, Percentage 5.70e+00% to 1.55e+01%, Size 1.60e-01m to 3.80e-01m, Size 5.00e-02m to 2.40e-01m, Size 6.19e-02m
DOI:10.11975/j.issn.1002-6819.2017.04.020

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 10>

Accession number:20171503565299
Title:Hydraulic characteristic of overland flow on loess farmland slope under mulch with different wheat straw lengths
Authors:Li, Chaodong (1, 2); Li, Zhanbin (1); Ma, Jianye (1); Ma, Bo (1) 
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&amp;F University, Yangling; 712100, China; (2) College of Natural Resources and Environment, Northwest A&amp;F University, Yangling; 712100, China 
Corresponding author:Ma, Bo(mabo_916@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:153-160
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Straw mulching is one of the important conservation tillage measures, and has a positive effect on reducing soil erosion on slopping farmland. In order to study the impact of straw length on the hydrodynamic characteristics of overland flow, indoor artificial fixed bed erosion resistance experiments were carried in the Soil and Water Conservation Engineering Laboratory in Northwest A&amp;F University. The study area was located in the southern Loess Plateau, Shaanxi Province, China (34&deg;14'-34&deg;20'N, 107&deg;59'-108&deg;08'E). By the scour trough, the variations of hydrodynamic parameters of overland flow such as flow velocity, runoff depth, Reynolds number, Froude number, Darcy-Weisbach resistance coefficient and Manning roughness coefficient were determined at 4 slope gradients (3&deg;, 5&deg;, 10&deg; and 15&deg;), 5 flow rates (3.0, 4.5, 6.0, 7.5 and 9.0 L/min) and 3 wheat straw lengths (3-5, 8-10 and 13-15 cm). The slope without straw mulch was considered as the control (CK). The results showed that under the experimental condition, the wheat straw length greatly affected the hydrodynamic parameters. Under straw mulching with different straw lengths, Reynolds number ranged from 166 to 558, the overland flow was primarily laminar and subcritical flow when the flow rate was less than or equal to 7.5 L/min, and transformed into transition and subcritical flow while the flow rate was 9.0 L/min. Under the conditions of straw mulching, compared with bare slope, the overland flow ran with smaller flow velocity and higher runoff depth, Darcy-Weisbach resistance coefficient and Manning roughness coefficient. Straw length affected the runoff depth. Compared with the bare slope, the runoff depth of overland flow on slope with the straw length was increased by 107.69%-178.64%. Straw mulching could decrease the flow velocity by 48.30%-60.64% than the CK. The runoff depth decreased as the straw length increased, and the flow velocity increased with the increase in straw length. The flow state index of overflow with straw mulching was reduced with increased of straw length and slope gradient. When the straw length increased from 3-5 cm to 13-15 cm, the average flow state index was decreased from 0.716 to 0.501. The Darcy-Weisbach resistance coefficient was 0.14-1.47 on bare slope, 2.67-8.00 on slope with 3-5 cm straw mulch, 2.39-6.36 on slope with 8-10 cm straw mulch and 1.31-4.28 on slope with 13-15 cm straw mulch, respectively. It averagely increased by 20.89, 15.69 and 8.17 times respectively compared with the bare slope, indicating that the straw mulch could strongly resist the flow movement. Darcy-Weisbach resistance coefficient was decreased with the increase in straw length. The Manning roughness coefficient was 0.013-0.044 on the bare slope, 0.071-0.132 on slope with 3-5 cm straw mulch, 0.067-0.118 on slope with 8-10 cm straw mulch and 0.049-0.083 on slope with 13-15 cm straw mulch, respectively. It increased by 4.38, 3.64 and 2.33 times respectively compared with the bare slope. Manning roughness coefficient was reduced with straw length increased. This study could provide reliable information for clarifying the mechanism behind soil erosion with straw mulching on farmland slope. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Runoff
Controlled terms:Conservation - Erosion - Farms - Flow measurement - Flow of fluids - Flow patterns - Flow velocity - Fluid dynamics - Hydrodynamics - Laboratories  - Reynolds number - Sediments - Soil conservation - Soils - Straw - Velocity - Water conservation
Uncontrolled terms:Engineering laboratories - Fixed bed - Hydraulic characteristic - Hydrodynamic characteristics - Loess farmland - Manning Roughness Coefficient - Overland flow - Soil and water conservation
Classification code:444  Water Resources - 444.1  Surface Water - 483  Soil Mechanics and Foundations - 483.1  Soils and Soil Mechanics - 631  Fluid Flow - 631.1  Fluid Flow, General - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5  Agricultural Wastes - 931.1  Mechanics
Numerical data indexing:Percentage 1.08e+02% to 1.79e+02%, Percentage 4.83e+01% to 6.06e+01%, Size 1.30e-01m to 1.50e-01m, Size 3.00e-02m to 5.00e-02m, Size 8.00e-02m to 1.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.04.022

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 11>

Accession number:20171503565290
Title:Design and experiment on solid heat carrier heating device heated by high temperature flue gas for pyrolysis of biomass
Authors:Wang, Shaoqing (1); Li, Zhihe (1); Wu, Houkai (1); Li, Ning (1); Bai, Xueyuan (1) 
Author affiliation:(1) School of Agricultural and Food Engineering, Shandong University of Technology/Shandong Research Center of Engineering and Technology for Clean Energy, Zibo; 255049, China 
Corresponding author:Li, Zhihe(lizhihe@sdut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:89-95
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biomass is one of environment friendly and renewable resources, which is considered as an ideally clean energy. In general, the development and utilization of biomass energy aim at converting the solid agricultural and forestry wastes into gaseous, solid or liquid fuels by physical or chemical processing methods. Solid heat carrier heating biomass is one of the process means of preparing bio-oil from biomass pyrolysis. In order to solve the indirect heating slow and low efficiency problems of solid heat carrier heating, a solid heat carrier heating device heated by high temperature flue gas which was generated by fluidized bed combustor was designed, and its structure and principle were analyzed, including high temperature flue gas generator, feeder of ceramic ball, heat carrier heat exchanger, built-in baffle, data acquisition and control system. The device could carry out the solid heat carrier heating performance and the combustion characteristic of fluidized bed combustor. Furthermore, the heat balance analysis of test results was performed. Biomass powder fuel was conducted on proximate analysis, ultimate analysis and determination of low calorific value, the results showed that the biomass powder fuel was a kind of clean energy. By conducting tests of biomass powder fuel combustion on high temperature gas generating apparatus to determine optimum powder concentration was 240 g/m³. The fluidized bed combustion furnace temperature changes were analyzed under optimal wind powder concentration, which indicated that biomass powder burning had ideal effect, the burner could be continuous, stable producing high temperature flue gas. By studying the temperature variation during the heat exchange process of ceramic balls and high temperature flue gas, the convective heat transfer coefficient of ceramic ball and high temperature flue gas and the heat utilization efficiency of the device were obtained. The convection heat transfer coefficient between ceramic balls and the high temperature flue gas was calculated and heat energy utilization of heating equipment was detected. Results showed that the heat utilization efficiency of the heat carrier heater reached by 66.3%. The high temperature flue gas produced by biomass combustion in fluidized bed could satisfy the need of the heating of ceramic balls for biomass pyrolysis. The convection was the main heat transfer in the heat carrier heater and the convection heat transfer coefficient between ceramic balls and the high temperature flue gas was 475 W/(m²&middot;&#8451;). By heat balance analysis and heating capacity theory analysis of the device, it indicated that study results have important guiding significance for solving the biomass pyrolysis technology in the key solid heat carrier heating up issues. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Fluidized bed combustion
Controlled terms:Biomass - Ceramic materials - Chemical analysis - Chemical industry - Combustion - Combustors - Data acquisition - Energy utilization - Flue gases - Flues  - Fluidized bed combustors - Fluidized bed process - Fluidized beds - Fuels - Gas generators - Gases - Heat convection - Heat exchangers - Heat transfer - Heat transfer coefficients  - Heating - Heating equipment - Pyrolysis - Specific heat - Temperature - Waste incineration - Waste utilization
Uncontrolled terms:Combustion characteristics - Convective heat transfer Coefficient - Development and utilizations - Guiding significances - Heat balance analysis - Heat exchange process - High temperature flue gas - Temperature variation
Classification code:451.1  Air Pollution Sources - 452.4  Industrial Wastes Treatment and Disposal - 521.1  Fuel Combustion - 521.2  Combustors - 522  Gas Fuels - 525.3  Energy Utilization - 616.1  Heat Exchange Equipment and Components - 641.1  Thermodynamics - 641.2  Heat Transfer - 723.2  Data Processing and Image Processing - 802.2  Chemical Reactions - 805  Chemical Engineering, General - 812.1  Ceramics
Numerical data indexing:Mass_Density 2.40e-01kg/m3, Percentage 6.63e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.013

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 12>

Accession number:20171503565302
Title:Optimal irrigation frequency improving photosynthetic characteristics and yield of machine-harvested cotton with drip irrigation under mulch in Northern Xinjiang
Authors:Li, Gan (1); Gao, Lili (1); Zhang, Jusong (1) 
Author affiliation:(1) College of Agronomy, Xinjiang Agricultural University/Research Center of Cotton Engineering, Ministry of Education, Urumqi; 830052, China 
Corresponding author:Zhang, Jusong(xjndzjs@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:178-185
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Due to the unique geographical environment, North of Xinjiang is exceptionally early mature cotton region with short cotton growing season. Therefore, how to achieve efficient allocation of irrigation water saving and high yield efficiency of cotton production in the short growth period has become a key problem in the production of cotton in northern Xinjiang. This study investigated the effects of irrigation treatments on photosynthetic characteristics and yield of machine-harvested cotton. An experiment was carried out in the year of 2015 in Xinjiang Agricultural University Experimental Base (44&deg;39'N, 86&deg;08'E with an altitude of 367 m) of Changji by an single factor randomized block design. Three irrigation times of 10 (D10), 8 (D8) and 6 (D6) were designed following local experience. The total irrigation quota was 4500 m³/hm². The machine-harvested cotton variety of Xinluzao 57 was for the experiment. During the experiment, soil moisture content, photosynthetic parameters, fluorescence parameters and yield formation characteristics were measured. The results showed that the D6 treatment delayed the time of first water, and its stress degree was higher than those of the other treatments. For the D6, the non-stomatal limitation caused the decrease in the net photosynthetic rate, the max photochemical efficiency, photochemical quenching coefficient and photochemical quantum yield of photosystem II were also significantly lower than those of the other treatments. Meanwhile, the non-photochemical quenching coefficient was increased dramatically, while the recovery capability was poor, which limited the accumulation of above-ground biomass. Due to unreasonable irrigation water allocation at flowering and fruiting stages in the D10 treatment, the net photosynthetic rate decreased as affected by stomatal limitation factors under light water stress, while photochemical quenching coefficient was improved effectively by irrigation in the boll opening stage. At the same time, leaf photosynthetic function duration was extended while the biomass was accumulated more for the vegetative growth and the vegetative organs biomass were higher than the other treatments, which resulted in no significant difference in biomass of the reproductive organs. The D8 treatment could ensure the higher efficient photosynthetic capacity during the whole growth period, and the biomass of reproductive organ was 21.1% and 23.5% than the D10 and D6, respectively. Water use efficiency of leaf in the D8 reached the highest among the treatments, and the yield of D8 was not significantly different from the D10 (P&gt;0.05), but 647.4 kg/hm²higher than the D6 (P&lt;0.05). Therefore, under the condition of drip irrigation quota for 4 500 m³/hm², the irrigation allocation method in the D8 treatment was beneficial to improve the photosynthetic capacity of the leaves and promote the distribution of the photosynthetic material to the reproductive organs. Therefore, irrigation before the full budding stage, increasing irrigation quota after the full flowering stage and reducing the water supply in the boll opening stage can effectively improve the photosynthetic capacity of leaves, promote the migration of the photosynthetic substances into the reproductive organs, so as to fulfill the water saving goal and achieve high efficiency of machine-harvested cotton production as well. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Irrigation
Controlled terms:Agricultural machinery - Biomass - Cotton - Cultivation - Design of experiments - Ecology - Efficiency - Fluorescence - Forestry - Harvesting  - Photosynthesis - Plants (botany) - Quenching - Soil moisture - Water - Water conservation - Water resources - Water supply
Uncontrolled terms:Chlorophyll fluorescence - Distribution - Drip irrigation under mulches - Irrigation water allocation - Non-photochemical quenching - Photochemical quantum yield - Photosynthetic characteristics - Yield
Classification code:444  Water Resources - 446.1  Water Supply Systems - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 537.1  Heat Treatment Processes - 741.1  Light/Optics - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3  Engineering Research - 913.1  Production Engineering
Numerical data indexing:Percentage 2.11e+01%, Percentage 2.35e+01%, Size 3.67e+02m
DOI:10.11975/j.issn.1002-6819.2017.04.025

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 13>

Accession number:20171503565305
Title:Combined application of nitrogen and sulfur improving quality of substrate culture garlic bulbs
Authors:Xu, Jian (1, 2); Jia, Kai (1); Zhu, Junfang (1); Hu, Mei (1); Wang, Na (1); Gao, Jie (1) 
Author affiliation:(1) College of Forestry and Horticulture, Xinjiang Agricultural University, Urmuqi; 830052, China; (2) Garden Science and Technology College, Xinjiang Agricultural Vocational Technical College, Changji; 831100, China 
Corresponding author:Gao, Jie(13999803260@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:203-208
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Garlic (Allium sativum L.) was among the earliest cultivated crops, has been planted all over the world. Allicin and garlic polysaccharide are important active ingredients in garlic, which have been popular in medicine, health and functional food. The S fertilization has already been shown to have a strong influence on the formation of S containing secondary metabolites in crops. Along with nitrogen metabolism in the metabolic process of sulfur, so there is synergistic effect between sulfur and nitrogen. The aim of this study was to analyze the response relationship between the garlic quality and the nitrogen and sulfur interaction, and to evaluate the comprehensive quality of garlic bulbs by the method of membership function, a pot experiment was conducted by using three levels N and S applied in factorial combinations of 5, 10, 20 mmol/L and 2, 4, 8 mmol/L in vermiculite and pearlite culture. The results indicated that the main inclusion reacted differently in response to N and S levels. N or S single factor had no significant effect on content of soluble protein, V<inf>C</inf>, garlic polysaccharide, free amino acid, while S had significant effect on allicin. The influence of N, S single factor on garlic quality was far lower than that of the interaction of N and S. The quality of garlic bulbs was raised to different extents by nitrogen and sulfur fertilization, and the interaction of nitrogen and sulfur had a significant effect on the quality formation of garlic. When N concentration was 10-20 mmol/L, sulfur concentration had significant effect on allicin content of garlic bulbs. The content of allicin was increased significantly as the increase of S levels under 4.0 mmol/L, but decreased when the sulfur content reached at 8.0 mmol/L, which showed that high content of sulfur element could inhibit the synthesis of allicin. Content of garlic polysaccharide was promoted by increasing nitrogen or sulfur fertilization. However, it would be inhibited when the nitrogen content exceeded to 10.0 mmol/L or the sulfur content reached at 8.0 mmol/L. Content of polysaccharide was the highest of 40.50% with the N 4.0 mmlol/L and S 10 mmol/L. Garlic quality of treatment with N 20.0 mmol/L and S 4.0 mmol/L was optimal, and the membership function value was 0.81, while the control group was the lowest. The results of comprehensive analysis showed that nitrogen and sulfur fertilization significantly influenced quality of garlic bulbs, N 20.0 mmol/L and S 4.0 mmol/L was optimal to improve garlic quality, and there was a significant interaction between nitrogen and sulfur element. The study would be helpful in providing practical theory guidance for fertilization on garlic. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Quality control
Controlled terms:Crops - Membership functions - Metabolism - Metabolites - Nitrogen - Sulfur
Uncontrolled terms:Active ingredients - Comprehensive analysis - Comprehensive qualities - Garlic - Nitrogen metabolism - Secondary metabolites - Sulfur concentrations - Synergistic effect
Classification code:804  Chemical Products Generally - 821.4  Agricultural Products - 913.3  Quality Assurance and Control - 921  Mathematics
Numerical data indexing:Molar_Concentration 1.00e+01mol/m3, Molar_Concentration 1.00e+01mol/m3 to 2.00e+01mol/m3, Molar_Concentration 2.00e+01mol/m3, Molar_Concentration 4.00e+00mol/m3, Molar_Concentration 8.00e+00mol/m3, Percentage 4.05e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.028

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 14>

Accession number:20171503565286
Title:Effect of height difference of horizontal corn snapping rollers device on grain loss
Authors:Chen, Meizhou (1); Sun, Xuefeng (2); Cheng, Xiupei (1); Jia, Xiaodong (3); Li, Qiyun (1) 
Author affiliation:(1) School of Agricultural and Food Engineering, Shandong University of Technology, Zibo; 255000, China; (2) Changzhou Dongfeng Agricultural Machinery Group Co. Ltd, Changzhou; 213000, China; (3) College of Science, Shandong Jianzhu University, Jinan; 250000, China 
Corresponding author:Li, Qiyun(liqiyun@sdut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:63-68
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, corn acreage has became the first place instead of wheat and rice in China. However, corn mechanical harvesting level is low, which has seriously affected the development of corn mechanization. Corn snapping device is a main component of corn harvesting machine, and plays an important role on the quality of harvester. Compared to other kinds of corn ear picking device, horizontal snapping rollers device is easy to cause serious corn grain loss rate and high impurity rate, which has been the choke points of corn harvester development for a long time. Height difference of snapping rollers is a significant factor that affects the ability of horizontal snapping rollers device to pick corn ears. If the height difference is too small, corn ears will stick on snapping rollers after picking, and the prolonged exposure increases corn grain loss seriously. When the height difference is too large, the center distance of snapping rollers remains constant that leads to small horizontal projection gap, and triangular domain shaped by the front cone of the snapping rollers still makes it difficult to feed for corn plant, finally corn plant will bent and broken off, which leads to serious grain impurity rate. Based on the issue of serious gnawing harm and loss of corn ears, experimental research was conducted to analyze the effect of height difference on grain loss. In order to improve the precision for adjustment on the height difference and determine the parameters, the angle between the line of centers of two snapping rollers and the horizontal surface (the angle &theta;) was employed to represent the height difference. The horizontal snapping rollers device was built, and the grain loss rate was taken as the index to estimate the effect on height difference. Through the single factor experiment, the impact of the angle &theta; was analyzed. The harvesting process was captured with the high-speed photography, which was helpful to analyze comprehensively in the late period. Through the single factor experiment and the analysis of variance, it was found that the grain loss rate reduced quickly from 24&deg;-30&deg; and changes were small and inconspicuous at 33&deg; and 36&deg;. The average grain loss was the least (0.354%) when the angle was 30&deg;. High-speed cameras were used to collect image datum and analyze the datum. And two phenomena were discerned. It revealed that some corn ears stayed on the snapping rollers after picking, and there was also a "bouncing" phenomenon. Those phenomena caused secondary damage of corn ears and high impurity. In addition, when the angle &theta; was too large, it was more difficult for corn stalk feeding, which made the corn stalk bending seriously and even to break, and even if the corn stalk was fed, it was easy to cause blocking on the snapping region. So if the large angle is employed, the gap between snapping rollers needs to be adjusted or the snapping rollers can be designed not to parallel with large backend and small front-end to ensure corn plant smoothly. For these phenomena, a curved bulkhead was installed above the low snapping roller. The contrast test showed that the solution reduced the chance of secondary damage to the corn ears. The single factor experiment showed that the grain loss rate reduced at each angle variously and grain loss rate was the least(0.164%) when the angle was 30&deg;. The contrast test showed that the solution reduced the chance of secondary damage on the corn ears. It also prevented the snapping rollers from impacting on the corn ears, thereby reducing loss of corn grain. This study provides a reference for optimization and improvement on horizontal snapping rolls device. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Grain (agricultural product)
Controlled terms:Agricultural machinery - Analysis of variance (ANOVA) - Experiments - Harvesters - Harvesting - High speed cameras - High speed photography - Image analysis - Plants (botany) - Rollers (machine components)
Uncontrolled terms:Experimental research - Grain loss - Height difference - Horizontal projections - Horizontal snapping rollers device - Horizontal surfaces - Secondary damage - Single-factor experiments
Classification code:601.2  Machine Components - 742.1  Photography - 742.2  Photographic Equipment - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3  Engineering Research - 922  Statistical Methods
Numerical data indexing:Percentage 1.64e-01%, Percentage 3.54e-01%
DOI:10.11975/j.issn.1002-6819.2017.04.009

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 15>

Accession number:20171503565284
Title:Hand-eye calibration method based on Sylvester equation deformation for lychee harvesting robot
Authors:Mo, Yuda (1); Zou, Xiangjun (1); Ye, Min (1); Situ, Weiming (1); Luo, Shaofeng (1); Wang, Chenglin (1); Luo, Lufeng (1) 
Author affiliation:(1) Key Laboratory of Key Technology on agriculture Machine and Equipment, South China Agriculture University, Guangzhou; 510642, China 
Corresponding author:Zou, Xiangjun(xjzou1@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:47-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Establishing the correlation between vision system and robot is the key and premise for the fruit harvesting robot based on binocular vision to successfully harvest fruit. And the robot with eye-in-hand vision system can use the active vision to search harvesting targets in a great scope and find out the position of picking points related to the robot's coordinate in real time. For the accurate hand-eye calibration of the lychee harvesting robot with eye-in-hand vision system, a hand-eye calibration method based on optimization solution of the homogeneous matrix equation was proposed. Binocular camera was installed on the end of the robot's manipulator. The calibration board was placed in front of robot and the calibration board was stationary relative to the robot. By controlling the robot's movement, binocular camera can observe the calibration board from multiple positions. Then the relative position relationship data between binocular camera and calibration board can be collected by stereovision location. Also, position data of manipulator's end relative to robot coordinate system can be calculated using the robot kinematics. These data above can be used to establish an approximate equation of hand-eye calibration. Sylvester equation deformation was used to transform the approximate equation into a linear equation that made the problem into a linear optimization problem with some constraints. Lagrangian-Multiplier method was applied in changing the constrained optimization problem to a global optimization problem, and the conjugate gradient methods was a good choice for solving this global optimization problem. The result calculated by traditional method was used as the initial value that a more accurate solution can be solved out by iteration. This hand-eye calibration method was a module of our software "Stereo Vision Lychee Picking Point Recognition and Localization System" which had already been implemented using C++ and OpenCV. The software ran in an industrial control computer cooperated with the harvest robot and binocular vision system and were tests for three experiments. The first experiment was the robot's mechanical arm movement influence on the ranging error of binocular vision system. This experiment showed that when the binocular cameras had been installed on the terminal of robot's mechanical arm, the mean ranging error of binocular vision was associated with the movement times of robot's mechanical arm. When the binocular cameras' working distance was about 1000 mm, the initial mean ranging error of binocular vision would be 0.55 mm. And then, with the increase of movement times of robot's mechanical arm, the mean ranging error of binocular vision presented a rising tendency. When the movement times of robot's mechanical arm was more than one hundred, the mean ranging error of binocular vision would be more than 2 mm. Hence, the best movement times of robot's mechanical arm used to hand-eye calibration can be 15. This experiment also showed the probable cause of repeat joint positioning error of robot with eye-in-hand visual system. The second experiment was the repeat joint positioning error of the robot with eye-in-hand visual system. The mean repeat joint positioning error of the robot generated by our hand-eye calibration method base on Sylvester deformation equation was 2.929 mm, which was better than the 4.442 mm error generated by traditional method. Meanwhile, the standard deviation of repeat joint positioning error of the robot was 0.454 mm, which was better than the 0.554 mm standard deviation of error generated by traditional method. The second experiment showed our hand-eye calibration method was better than the traditional method in the aspect of precision. At last, we used this harvesting robot to harvest lychee in a real lychee orchard. This experiment can show the reliability of our hand-eye calibration method in the natural environment. We tested 51 times, the ratio of successful picking was more than 76%. Moreover, when the software accurately recognized and located the lychee picking point, the ratio of successful picking could reach 92.3%. This experiment showed that the proposed hand-eye calibration method and the transformation result calculated using our method had a strong reliability and could satisfy the actual picking requirements of lychee harvesting robot. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Stereo image processing
Controlled terms:Binocular vision - Binoculars - Bins - C++ (programming language) - Calibration - Cameras - Computer control systems - Computer software - Computer vision - Conjugate gradient method  - Constrained optimization - Deformation - Errors - Eye movements - Fruits - Global optimization - Harvesting - Iterative methods - Lagrange multipliers - Linear programming  - Manipulators - Mathematical transformations - Matrix algebra - Optimization - Robots - Software testing - Statistics - Stereo vision - Vision
Uncontrolled terms:Constrained optimi-zation problems - Global optimization problems - Industrial control computer - Lagrangian multiplier methods - Linear optimization problems - Lychee - Picking - Stereo
Classification code:694.4  Storage - 723  Computer Software, Data Handling and Applications - 731.5  Robotics - 741.2  Vision - 741.3  Optical Devices and Systems - 742.2  Photographic Equipment - 821.3  Agricultural Methods - 821.4  Agricultural Products - 921  Mathematics - 922.2  Mathematical Statistics - 961  Systems Science
Numerical data indexing:Percentage 7.60e+01%, Percentage 9.23e+01%, Size 1.00e+00m, Size 2.00e-03m, Size 2.93e-03m, Size 4.44e-03m, Size 4.54e-04m, Size 5.50e-04m, Size 5.54e-04m
DOI:10.11975/j.issn.1002-6819.2017.04.007

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 16>

Accession number:20171503565292
Title:Calibration method on improving simulating accuracy of combustion process in diesel engine
Authors:Li, Xiangrong (1); Chen, Yanlin (1); Zhao, Luming (1); Liu, Fushui (1) 
Author affiliation:(1) School of Mechanical Engineering, Beijing Institute of Technology, Beijing; 100081, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:102-110
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To improve the computation accuracy of combustion process simulation in diesel engine, a new calibration method of numerical model was proposed in this paper, and the calibration of spray process and combustion process were combined together. For the calibration of spray process, the key parameters of WAVE spray breakup model and Dukowicz evaporation model should be calibrated with experimental results, including spray liquid penetration, spray penetration and spray profile, which were measured in constant volume combustion bomb. Based on the calibration results of spray process, the simulation of combustion process required appropriate combustion model, the key parameters of which were calibrated by the experimental data in a single cylinder diesel engine, including the in-cylinder pressure and heat release rate. To validate the proposed method, a spray mesh and a moving mesh were established in AVL Fire software to calibrate the spray models and combustion model respectively. As with the meshes for the spray process, spray models parameters (including WAVE model parameter C<inf>2</inf>, Dukowicz parameters E<inf>1</inf>and E<inf>2</inf>) were calibrated. To obtain proper value of C<inf>2</inf>, E<inf>1</inf>and E<inf>2</inf>, the effects of spray model parameters on simulating results were studied and the eventual results were validated by experimental spray liquid penetration, spray penetration and spray profile, which were measured in experiment of free jet spray. Based on the calibration results of spray process, the optimal C<inf>2</inf>, E<inf>1</inf>and E<inf>2</inf>were applied in the simulation of combustion process. Firstly, eddy break-up (EBU) model was selected and calibration of relevant parameter A was completed in different injection conditions. The results showed that the EBU model was precisely appropriate for single injection but not for split injections, for the chemical reaction kinetics was not considered in combustion process simulation as couldn't predict combustion of fuel in pilot injection accurately. Then ECFM-3Z model was adopted and the model parameters include auto-ignition model parameter (Amp), mixing model parameter (Mmp), chemical reaction time (Crt) and extinction temperature (Et). The effect of those parameters on numerical results was also studied. Then based on the results, the value of all parameters was verified and the accuracy of combustion model was validated by experimental results of a single cylinder diesel engine with single injection and split injections respectively. The calibration results showed that the numerical model could predict combustion process precisely both in single injection and in split injection conditions. It could be concluded that the ECFM-3Z model was appropriate for single injection and split injections. As an important reference, the common calibration method was also adopted to calibrate the numerical model. The results showed that the common calibration method couldn't simulate the spray process accurately. The common calibration method only considered the in-cylinder pressure and heat release rate, as may lead much uncertainty in spray development, evaporation and the fuel-air mixture formation, which influence combustion process a lot. Obviously, the application of the new calibration method could accurately simulate the whole working processes including spray, evaporation and combustion both in single injection and split injections, which improved the simulation accuracy and extends the application range compared with the common calibration method. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Calibration
Controlled terms:Chemical reactions - Combustion - Diesel engines - Engine cylinders - Engines - Evaporation - Fuel injection - Fuels - Mesh generation - Models  - Numerical methods - Numerical models - Reaction kinetics - Spraying
Uncontrolled terms:Constant volume combustion bomb - Extinction temperature - Heat Release Rate (HRR) - In-cylinder pressures - Injection conditions - Simulation - Single-cylinder diesel engine - Verification-and-validation
Classification code:612.1.1  Internal Combustion Engine Components - 612.2  Diesel Engines - 802.2  Chemical Reactions - 802.3  Chemical Operations - 921  Mathematics
DOI:10.11975/j.issn.1002-6819.2017.04.015

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 17>

Accession number:20171503565311
Title:Mechanical property analysis and optimization of deep-water net cage guardrail
Authors:Liu, Haiyang (1, 2); Wang, Shaomin (1, 2); Huang, Xiaohua (1, 2); Tao, Qiyou (1, 2); Hu, Yu (1, 2); Guo, Genxi (1, 2); Song, Liming (3) 
Author affiliation:(1) Guangdong Cage Engineering Research Center, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou; 510300, China; (2) Tropical Fisheries Research and Development Center, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Sanya; 572018, China; (3) College of Marine Sciences, Shanghai Ocean University, Shanghai; 201306, China 
Corresponding author:Guo, Genxi(scsggx@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:248-257
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Guardrail is an indispensable component of the deep-water net cage floating system, and it plays an important role to maintain culture volume of net cage and to resist the impacts of wave and current with net cage floating system. But there are few researches on guardrail mechanical properties of deep-water net cage. In order to improve the safety of deep-water net cage structure, three-dimensional solid models of guardrail were established by software Unigraphics NX, these models were calculated by finite element method of the software ANSYS Workbench. Firstly, mechanics properties of hexagon-triangle and circle type guardrails were investigated; Secondly, the collected data in the experiment and numerical simulation were analyzed by using linear and nonlinear regression methods to understand the mechanical performance of guardrails, and finally the design of guardrail was optimized with consideration of experiment and simulation results. The results of statics test showed that for high density polyethylene (HDPE) guardrail, tensile yield strength was 23.8 MPa, Young's modulus was 1 240 MPa, and flexural strength was 25.2 MPa. Results of finite element modal analysis indicate that natural frequency range of guardrail was 14.25-33.59 Hz; stress range was 6.370-21.658 MPa. Fatigue vibration experiment was conducted by using hydraulic servo fatigue testing machine. Vibration frequency was set as 5 Hz, and vibration amplitude was 80% maximum compressive intensity of stress value (19.6 MPa). Results of fatigue test showed that fatigue fracture time was 23.5 h. According to finite element statics analysis, the biggest, medium and smaller displacement, stress and strain of guardrail was occurred in attack angle of 0&deg;, 45&deg;, and 90&deg;. The displacement, stress and strain of concentrated load was higher than those of distributed load. The guardrail failed when the concentrated load was 4 kN in attack angle of 0&deg;, and displacement, stress and strain was 70.47 mm, 28.922 MPa, 0.026 434, respectively. The maximum displacement area was in the center of guardrail-handrail; the maximum stress area was in the bottom of guardrail-column. When attack angle to guardrail is 0&deg;, the column was simplified as cantilever beam model. When attack angle is 90&deg;, handrail was simplified as the form of tension and compression bar model. Based on finite element linear analysis of circular and hexagonal handrails, handrails of circle and hexagon failed when distributed loads were 6 kN and 16 kN, respectively, and stiffness of circular handrail was greater than that of hexagon significantly. Based on finite element nonlinear analysis of circular and hexagonal handrails, HDPE material model was set up by bilinear isotropic hardening model for isotropic materials (BISO). Deviations between simulation value and experimental value of guardrail and handrail at elastic stage were 8.67% and 0.27%, respectively. Deviation between simulation data and experimental data of handrails at plastic stage was analyzed by using method of Kolmogorov-Smirnov (K-S) two-factor fitting goodness examination. And the examined result of hexagonal handrail was p=0.861 3&gt;0.05, namely, there is no significant difference between finite element simulation and mechanics experiment in linear and nonlinear process. The sectional rigidity of guardrail was improved by designing the cross-sectional shape of guardrail-pipe. Compared with hollow-circle section of guardrail, flexural property of hollow-oval section and hollow-square section was increased by 6.58%, 6.83% respectively, in same materials. This study provides theoretical basis for the structural and mechanical properties for guardrail system. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Finite element method
Controlled terms:Bending strength - Density (specific gravity) - Elastic moduli - Fatigue testing - Geometry - Guard rails - High density polyethylenes - Hydraulic machinery - Mechanical properties - Modal analysis  - Nonlinear analysis - Numerical methods - Polyethylenes - Railings - Regression analysis
Uncontrolled terms:Deep Water - Finite element modal analysis - Finite element non-linear analysis - Finite element simulations - High density polyethylene(HDPE) - Non-linear regression method - Structural and mechanical properties - Three-dimensional solids
Classification code:408.2  Structural Members and Shapes - 632.2  Hydraulic Equipment and Machinery - 815.1.1  Organic Polymers - 921  Mathematics - 921.6  Numerical Methods - 922.2  Mathematical Statistics - 931.2  Physical Properties of Gases, Liquids and Solids - 951  Materials Science
Numerical data indexing:Force 1.60e+04N, Force 4.00e+03N, Force 6.00e+03N, Frequency 5.00e+00Hz, Percentage 2.70e-01%, Percentage 6.58e+00%, Percentage 6.83e+00%, Percentage 8.00e+01%, Percentage 8.67e+00%, Pressure 1.24e+09Pa, Pressure 1.96e+07Pa, Pressure 2.38e+07Pa, Pressure 2.52e+07Pa, Pressure 2.89e+07Pa, Pressure 6.37e+06Pa to 2.17e+07Pa, Size 7.05e-02m, Time 8.46e+04s
DOI:10.11975/j.issn.1002-6819.2017.04.034

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 18>

Accession number:20171503565314
Title:Isolation, identification of Chlorella pyrenoides from aquaculture wastewater and its purification of wastewater
Authors:Lu, Hongsheng (1); Liu, Yaqiao (1); Liu, Wenjun (1); Kong, Fanmin (1); Tan, Haochen (1) 
Author affiliation:(1) College of Chemistry and Environmental Engineering, Shandong University of Science and Technology, Qingdao; 266590, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:273-277
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Algae has been studied for many years about its characteristics of rapid breed, easily obtained, high adsorption capacity and low nutrition demands and so on. The emission of aquaculture wastewater will caused severe damage on environment. Therefore, how to remove the compound of nitrogen and phosphorus from aquaculture wastewater becomes a serious problem around the world. Based above, many researchers have been focusing on this field and a lot of achievements have been found. Many environmental factors could influence on the growth of algae, including temperature, illumination and nutrition. For heterotrophism, carbon, nitrogen and phosphorus are the three most important factors influencing on the growth of Chlorella pyrenoides. Microalgae consist of several varieties, including Cyanophyta, Chlorophyta, Chrysophyta and Rhodophyta. Chlorella pyrenoides is belonged to Chlorophyta. Until now, studies of Chlorella pyrenoides have mainly focused on the processing, especially in the field of producing biodiesel, but few studies focused on the wastewater treatment by Chlorella pyrenoides. This study carried out the following experiments: the enrichment, isolation, purification and nutritional ingredient analysis for Chlorella pyrenoides. Then, the effect of treating with wastewater by Chlorella pyrenoides was carried out, including the removal of total nitrogen, total phosphorus and reducing COD. Chlorella pyrenoides was isolated from aquaculture wastewater with BG-11medium. The morphology and components of Chlorella pyrenoides were observed by phase contrast microscope and Fourier transform infrared spectrometer (FT-IR), respectively. The crystal structure of Chlorella pyrenoides was determined with X-ray. Protein and fat contents were measured by Kjeldahl determination and organic solvent extract method, respectively. The effect of treating with wastewater by Chlorella pyrenoides was tested with national standard methods. Chlorophyll a was extracted and analyzed with acetone extract method. The morphology observation with phase contrast microscope showed that Chlorella was belonged to Chlorella pyrenoides. FT-IR analysis showed that two peaks appeared at the wave numbers of 1 080 and 1 240 cm^-1, which proved high contents of protein, carbohydrate and fat contained in Chlorella pyrenoides. X-ray diffraction spectrogram showed two main peaks appeared at about 32&deg; and 20&deg;, which proved both protein and fat were contained in Chlorella pyrenoides. Quantitative analysis indicated that contents of protein and fat were 45.6% and 8.1%, respectively. Correlational study indicated that the negative correlation of the increase of Chlorophyll a in Chlorella pyrenoides with the decrease of total nitrogen (T-N) and total phosphorus (T-P) remained in the wastewater. The removals of COD, total nitrogen (T-N) and total phosphorus (T-P) by Chlorella pyrenoides were 70.9%, 23% and 34.7%, respectively. Based on above results, the capability of treating with wastewater by Chlorella pyrenoides was proved in this study. Therefore, this study could provide a reference for the exploitation of a new bioresource and the water environment treatment. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Wastewater treatment
Controlled terms:Acetone - Algae - Aquaculture - Carbon - Chlorophyll - Crystal structure - Fourier transform infrared spectroscopy - Microscopes - Nitrogen - Nitrogen removal  - Nutrition - Phosphorus - Proteins - Purification - Wastewater - Water treatment - X ray diffraction
Uncontrolled terms:Chlorella pyrenoides - Component analysis - Fourier transform infrared spectrometer - High adsorption capacity - Nitrogen and phosphorus - Nutritional ingredients - Phase contrast microscopes - Treatment effects
Classification code:445.1  Water Treatment Techniques - 452.3  Industrial Wastes - 452.4  Industrial Wastes Treatment and Disposal - 461.7  Health Care - 741.3  Optical Devices and Systems - 801  Chemistry - 804  Chemical Products Generally - 804.1  Organic Compounds - 821.3  Agricultural Methods - 933.1.1  Crystal Lattice
Numerical data indexing:Percentage 2.30e+01%, Percentage 3.47e+01%, Percentage 4.56e+01%, Percentage 7.09e+01%, Percentage 8.10e+00%
DOI:10.11975/j.issn.1002-6819.2017.04.037

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 19>

Accession number:20171503565309
Title:Image detection algorithm for cutting surface roughness of grape hard branch grafting based on light-section method
Authors:Li, Shijun (1); Yuan, Quanchun (1); Xu, Liming (1); Xing, Jiejie (1); Liu, Wen (1); Gao, Zhenming (1); Shi, Lina (1) 
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China 
Corresponding author:Xu, Liming(xlmoffice@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:234-241
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to detect cutting surface roughness of grape grafting hard branch, this paper built a detection system of cutting surface roughness and designed an image detection algorithm of feature extraction based on measurement principle of light-section method. The detection system was made up of 9J light-section microscope, industrial camera and computer. Sampling length was an important role in the calculation of roughness. In order to make up the shortage of single sampling length (1 420 &mu;m), this paper applied image mosaic technology to images acquired by multiple sampling, and thus got a longer sampling length. Meanwhile, a method was proposed to product matching template automatically, which could avoid the manual operation and improve the efficiency of image mosaic when matching the reference image and target image based on gray level information. Then the image mosaic algorithm was tested and the results showed that, the average running time was increased by 1.104 s and the average sampling length was increased by 1 131.77 &mu;m when the number of mosaic image increased by a roughness feature image. Moreover, fuzzy set theory was applied to the process of gray-scale transformation and could effectively guarantee the integrity of the single edge of the image after segmentation. In this paper, Otsu algorithm was used to segment image. In order to filter the defeat profile due to catheter lumen and tracheid cavity contained by cutting surface itself, local pixels of the roughness feature binary image were operated by way of human-computer interaction. The pixels of the defect position in the foreground image were set to zero and not involved in the subsequent roughness calculation. A method was also proposed to extract the single side edge by scanning pixels of per column one by one, the first pixel whose value was not zero at each column belonged to edge pixels set. According to the measurement principle of light-section method, the corresponding position relation could be established between the single edge extracted from roughness feature image and roughness profile in one place of grape cutting surface. So the value of roughness height parameters Ra and Rz could be obtained by calculating the single edge. In order to verify the feasibility of the proposed method, the comparative experiment was conducted between the detection system built and KEYENCE VK-200 laser microscope. The experimental results showed that the relative error of Ra measured by proposed method was 6.73%, which was within the allowable range of measurement error, the image detection algorithm based on light-section method has good feasibility when applied to measure cutting surface roughness of grape hard branch. The study provides technical support for the further research of the impact of cutting parameters on cutting surface roughness and grafting survival rate of grape hard branch. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Image processing
Controlled terms:Algorithms - Binary images - Cutting - Feature extraction - Fuzzy set theory - Fuzzy sets - Grafting (chemical) - Human computer interaction - Image segmentation - Importance sampling  - Pixels - Set theory - Signal detection - Surface roughness - Technology transfer
Uncontrolled terms:Average running time - Comparative experiments - Cutting parameters - Grape - Image mosaic - Image mosaic algorithms - Image mosaic technologies - Light-section methods
Classification code:716.1  Information Theory and Signal Processing - 723.2  Data Processing and Image Processing - 802.2  Chemical Reactions - 921.4  Combinatorial Mathematics, Includes Graph Theory, Set Theory - 931.2  Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Energy 9.00e+00J, Percentage 6.73e+00%, Size 1.32e-04m, Size 1.42e-03m, Time 1.10e+00s
DOI:10.11975/j.issn.1002-6819.2017.04.032

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 20>

Accession number:20171503565315
Title:Partition method of urban development boundary based on constrained cellular automata model
Authors:Chen, Weiqiang (1); Pan, Yuanqing (2); Ma, Yuehong (1); Ma, Huining (1) 
Author affiliation:(1) College of Resource and Environment, Henan Agricultural University, Zhengzhou; 450002, China; (2) Scientific Academy of Land and Rresources of Henan Province, Zhengzhou; 450046, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:278-284
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the problem of urban development boundary delimitation in general land use planning, this study has designed the cellular automata (CA) model for identifying urban development boundaries. To maximize public interest, the general land use plan is made to consist of a system of planning restriction indicators at different spatial levels, embodying the top-down planning pattern. However, existing research of urban evolution CA model is mainly focused on its transition rules. The states of one cell are determined by the threshold value, which is hard to realize the constraint for urban land size. That is to say, the previous studies could not satisfy the needs of the urban development boundaries' delimitation. The CA model, designed in this study, makes a greater contribution to satisfying the planning constraints for the quotas of incremental urban land and incremental urban encroachment on cultivated land. The rationale is enabling CA available for land use planning through adding relevant planning constraints. The planning constraints for urban development boundaries comprise the quotas of land use and incremental urban encroachment on cultivated land. Transition probability of urban land depends on the factors including urban development suitability, neighborhood principles and urban expansion restrictions. Urban development suitability is the determinant of inherent urban development. This suitability is normally represented in the form of probability matrix in the CA model. The urban land transition probability matrix, based on the cellular scale, is calculated by the logistic model. The dependent variable is whether the type of cellular land use is changed into urban land. The changing cellular ones are assigned with the value 1, otherwise the value 0. The independent variables include factors concerning the aspects of terrain, location, fundamental infrastructure, and so on. In this paper, Moore 3&times;3 window is selected as the CA neighborhood model. Cellular status value is binary. That is, cellular type of urban land is assigned with the value 1, otherwise the value 0. This research uses the land use maps of 2 phases for calculating and making statistics of the probability of cellular land type changing into urban land. Spatial constraints of urban development boundaries mainly concern the eco-environmental aspect, basic farmland restriction and competition of various land use types. The CA model applies the selection strategy based on the maximized probability. The CA model of urban development boundary delimitation is established based on the Python language, referring to the Arcpy and Numpy class databases. The software interface is a user-defined tool of ArcGIS, which is easy to be invoked in Geographic Information System (GIS). The Gongyi City in Henan Province is chosen as the case study area to validate the designed CA model, based on the remote sensing images of 3 phases (i.e., the year 2005, 2010 and 2015). The validity of the simulation results has been verified and manifested as the 3 following aspects: 1) The quota requirements of urban land use size (2 865.92 hm²) and incremental construction land through occupying cultivated land (282.80 hm2) have been satisfied; 2) The requirements of space expansion restriction have been met, such as protecting basic farmland and ecological land; and 3) The CA model applies the urban development suitability as the cellular transformation rule, embodying the top-down planning principle. The results of simulation have a higher accuracy. The accuracy is 93.09% and the Kappa coefficient is 90.41%. In a nutshell, the CA model designed in this study meets the requirements of defining the boundaries of urban development in general land use planning and can provide decision support for the plan-making system of urban development boundary. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Land use
Controlled terms:Cellular automata - Decision support systems - Farms - Geographic information systems - Image reconstruction - Models - Planning - Probability - Remote sensing - Urban growth
Uncontrolled terms:Cellular automata modeling - Cellular transformation - Incremental construction - Land Use Planning - Multiple planning - Transition probabilities - Transition probability matrix - Urban development
Classification code:403  Urban and Regional Planning and Development - 403.1  Urban Planning and Development - 723  Computer Software, Data Handling and Applications - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 903.3  Information Retrieval and Use - 912.2  Management - 921  Mathematics - 922.1  Probability Theory
Numerical data indexing:Percentage 9.04e+01%, Percentage 9.31e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.038

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 21>

Accession number:20171503565298
Title:Model test on wave dissipation effect of roughened embankment with permeable prefabricated block for slope protection
Authors:Li, Huokun (1); Du, Lei (1); Li, Yijing (1); Xu, Wangmin (2); Liu, Wugen (2) 
Author affiliation:(1) School of Civil Engineering and Architecture, Nanchang University, Nanchang; 330031, China; (2) Shangrao Hydraulic Reasarch Institute, Shangrao; 334000, China 
Corresponding author:Li, Yijing(ejinn@ncu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:146-152
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wave run-up is a key parameter in determining the crest elevation of earth embankments, and it is considerably affected by the wave reduction effect of protection slope. Smooth concrete prefabricated block is widely used in the slope protection of embankments. However, its wave reduction effect is relatively poor. To solve this problem, 3 new kinds of prefabricated blocks were designed to improve the wave reduction effect by increasing the roughness coefficient of the prefabricated block, including concave and embedded regular hexagon type prefabricated block, Z type prefabricated concrete block and embedded quadrangle type prefabricated hollow block. According to the formula in Handbook of hydraulic structure design, the thickness of prefabricated block was calculated, and then a laboratorial physical model experiment was performed in a wave flume for the slope protection and wave dissipation. Nine tests were carried out under 3 water depths (23.6, 30.6 and 37.15 cm) and 3 wave periods (1.5, 1.875 and 2.5 s). In the experiment, waves were produced by a wave maker, and the wave run-up was measured by a photogrammetric method. The wave reduction effects of the 3 new kinds of prefabricated blocks were assessed by the reduction ratio of the wave run-up compared with the smooth concrete prefabricated block. Additionally, the values of the 3 new kinds of prefabricated blocks' roughness coefficient were proposed. The experiment results showed that, compared with the smooth concrete prefabricated block, the 3 kinds of prefabricated blocks proposed in this paper had obvious inhibiting effects on wave run-up. The concave and embedded regular hexagon type prefabricated block had the most inhibiting effect, followed by the Z type prefabricated concrete block and embedded quadrangle type prefabricated hollow block. Their wave run-up decay rates (the reduction ratio of the new designs to the smooth concrete prefabricated block) were 35.0%, 30.2% and 26.23%, respectively, and corresponding roughness coefficients were 0.76, 0.77 and 0.79, respectively. Finally, the economic benefits of the 3 kinds of new designed prefabricated blocks were analyzed in this paper. It was mainly divided into 2 parts, the revetment concrete amount with the same thickness, and the extent of crest elevation reduction by the wave reduction effects. According to the comprehensive comparison and analysis, the concave and embedded regular hexagon type prefabricated block consumed less concrete amount, which decreased by 17.13% compared with the smooth concrete prefabricated block, and wave run-up was more reduced. For example, if the wave run-up of the smooth concrete prefabricated block was 1.0 m, the concave and embedded regular hexagon type prefabricated block would be 0.65 m, the Z type prefabricated concrete block would be 0.70 m, and the embedded quadrangle type prefabricated hollow block would be 0.74 m. Consequently, considering the effect of revetment wave and economic benefit, the concave and embedded regular hexagon type prefabricated block is the best choice in the slope protection and has popularization value and development prospects. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Economic and social effects
Controlled terms:Concretes - Decay (organic) - Embankments - Prefabricated construction - Revetments - Slope protection
Uncontrolled terms:Comprehensive comparisons - Development prospects - Economic benefits - Infiltration coefficients - Inhibiting effect - Model tests - Physical model experiments - Roughness coefficient
Classification code:405  Construction Equipment and Methods; Surveying - 405.2  Construction Methods - 407.2  Waterways - 412  Concrete - 483  Soil Mechanics and Foundations - 801.2  Biochemistry - 971  Social Sciences
Numerical data indexing:Percentage 1.71e+01%, Size 6.50e-01m, Size 7.00e-01m, Percentage 2.62e+01%, Percentage 3.02e+01%, Size 7.40e-01m, Time 1.88e+00s, Time 2.50e+00s, Percentage 3.50e+01%, Size 1.00e+00m, Size 3.06e-01m, Size 3.71e-01m
DOI:10.11975/j.issn.1002-6819.2017.04.021

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 22>

Accession number:20171503565306
Title:Influencing factor analysis of rill erosion section morphology development on slope and its dynamic characteristic experiment
Authors:Ma, Xiaoling (1); Zhang, Kuandi (1, 2); Yang, Fan (1); Yang, Mingyi (2); Dong, Xu (1) 
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&amp;F University, Yangling; 712100, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&amp;F University, Yangling; 712100, China 
Corresponding author:Zhang, Kuandi(zhangkuandi428@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:209-216
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rill erosion is the process of soil particles separating in the groove and handling by rill flow, and it is one type of surface corrosion, and the rill formed can be completely filled by normal farming activities. In the loess plateau region, rill erosion of slope accounts for more than 70% of the total erosion, and rill erosion is a major erosion in the loess plateau hilly land, and is also an important part of mechanism of slope erosion prediction. Rills are small channels which function as both sediment sources and sediment transport vehicles on hill slopes. It is a quantum leap during the process of soil erosion on slopes, and is also the beginning of qualitative changes in the process of soil erosion. The rill morphology development plays an important role in the understanding of rill erosion. Rill morphology changes have many influence factors in the process of rill erosion, so systematically studying the relationship between rill shape coefficient and influencing factors can make us better understand the process of rill erosion and erosion mechanism. For the study of rill morphological development process, the combination scouring tests of 6 slopes (2&deg;, 4&deg;, 6&deg;, 8&deg;, 10&deg;, and 12&deg;) and 5 discharges (8, 16, 24, 32, and 40 L/min) were carried out, and the effect mechanism of rill transverse profile morphological development on the loess slope surface was investigated, as well as the dynamic characteristics of the impact. The results showed that rill width-depth ratio ranged from 3.006 to 4.841, and according to the hydraulic optimum section, the rill flow was far from steady state. In rill erosion, downward erosion and lateral erosion gradually transited to downward erosion. Because of incised and lateral erosion, rill cross-sectional shape was gradually widened and deepened with the increase of slope and time. Along with the change of slope, cross-sectional shape coefficient varied within the range of 0.36-0.522. Research showed that: The rill cross-sectional shape was approximating to the trapezoidal hydraulic best section with the increase of the flow, slope and scour lasted time, namely the section with the least resistance. With the increase of water flow length, cross section shape changed gradually from wide and deep to narrow, and the cross-sectional shape coefficient was reduced. Through calculation, the groove profile form ranged within 0.6-11.26, and increased with the increase of slope, but had no significant correlation with discharge. With the increase of slope, the average spacing of drop pit on bed face decreased, the depth of drop pit increased, and the groove profile shape coefficient increased. Comprehensive resistance coefficient and energy dissipation showed a good power function relationship with groove profile shape coefficient, and with the increase of profile shape coefficient, the slope shape resistance increased. Rill hydraulic characteristics and groove shape showed the role of mutual connection and restriction and reaction system. Groove profile shape coefficient was larger, the bed surface shape resistance increased, and drop pit also would be developed more maturely. The water in drop pit had strong turbulence and aeration, which had significant effect on energy dissipation. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Erosion
Controlled terms:Crashworthiness - Drops - Dynamics - Energy dissipation - Experiments - Flow of water - Landforms - Morphology - Sediment transport - Sediments  - Soil testing - Soils - Surface discharges - Surface resistance
Uncontrolled terms:Cross section shape - Cross-sectional shape - Dynamic characteristics - Hydraulic characteristic - Morphological development - Morphology development - Qualitative changes - Resistance coefficients
Classification code:481.1  Geology - 483  Soil Mechanics and Foundations - 483.1  Soils and Soil Mechanics - 525.4  Energy Losses (industrial and residential) - 631.1.1  Liquid Dynamics - 701.1  Electricity: Basic Concepts and Phenomena - 901.3  Engineering Research - 914.1  Accidents and Accident Prevention - 951  Materials Science
Numerical data indexing:Percentage 7.00e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.029

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 23>

Accession number:20171503565293
Title:Performance evaluation method and experiment for diesel engine under idle transient operation condition based on smoke emission limit
Authors:Lou, Diming (1); Sun, Yuze (1); Yu, Huayang (2); Tan, Piqiang (1); Hu, Zhiyuan (1) 
Author affiliation:(1) School of Automotive Studies, Tongji University, Shanghai; 201804, China; (2) SAIC Volkswagen Automobile Company Limited, Shanghai; 201805, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:111-116
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nowadays, the performances of diesel engines under transient conditions become the research focus. Because of the frequent start and stop of the series hybrid diesel engine, the diesel engine is always in the steady state or idle speed switching state. In order to study the transient performance of diesel engine during the idle transient conditions, 3 indices are firstly adopted: The lag coefficient, which is an evaluation index for performance of diesel engine transient lag, the deterioration coefficient, which is an evaluation index for performance of diesel engine transient deterioration, and the transient mean, which is an evaluation index for comprehensive performance of diesel engine transient process. And then an analysis is carried out from the 3 dimensions of time, peak and mean value, and the influences of idle transient transition time and injection parameters on the maximum cylinder pressure, fuel flow and emissions are investigated. The test results show that the cylinder pressure, fuel consumption and emission performance of the diesel engine are worse than the steady state during the transient conditions. The deterioration of the engine can be reduced in the idle speed transient process by adjusting the transition time and smoke emission limit. With the increase of the transition time, the transient mean and lag coefficient of the maximum cylinder pressure decrease, and the deterioration coefficient increases; with the smoke limit increasing, the lag coefficient of the maximum cylinder pressure increases, and the deterioration coefficient and transient mean decrease. When the transition time is 10 s and the smoke emission limit is reduced by 10%, the lag coefficient of the maximum cylinder pressure gets the minimum value of 0.7. When the transition time is 3 s, and the smoke emission limit increases by 10%, the deterioration coefficient obtains the minimum value of 0.69. When the transition time is 10 s, and the smoke emission limit increases by 10%, the transient mean of the maximum cylinder pressure takes the minimum value of 5.79 MPa. With the increase of the transition time, the lag coefficient, deterioration coefficient and transient mean of fuel flow first increase and then decrease; with the increase of smoke emission limit, the lag coefficient and deterioration coefficient of fuel flow increase, and the transient mean decreases. When the transition time is 10 s, and the smoke emission limit is reduced by 10%, the lag coefficient of fuel flow gets the minimum value of 1.1. When the transition time is 3 s, and the smoke emission limit increases by 10%, the deterioration coefficient obtains the minimum value of 1.01. When the transition time is 10 s, and the smoke emission limit is increased by 10%, the fuel flow gets the minimum value of 12.49 kg/h. With the increase of the transition time, the lag coefficient and the transient mean of NOx emission decrease, and the deterioration coefficient increases; with the smoke emission limit increasing, the lag coefficient and the deterioration coefficient of NOx emission increase, and the transient mean decreases. When the transition time is 10 s, and the smoke emission limit is reduced by 10%, the lag coefficient of NOx emission gets the minimum value of 1.1. When the transition time is 5 s, and the smoke emission limit is reduced by 10%, the deterioration coefficient obtains the minimum value of 1.046. When the transition time is 10 s, and the smoke emission limit is invariable, the transient mean of NOx emission takes the minimum value of 7.23&times;10^-4. With the increase of the transition time, the lag coefficient of smoke emission first increases and then decreases, and the deterioration coefficient and transient mean increase; with the smoke emission limit increasing, the lag coefficient of smoke emission increases, and the deterioration coefficient and transient mean decrease. When the transit time is 10 s, and the smoke emission limit is reduced by 10%, the lag factor of smoke emission obtains the minimum value of 0.7. When the transition time is 3 s, and the smoke emission limit increases by 10%, the deterioration coefficient obtains the minimum value of 5.2. When the transition time is 3 s, and the smoke emission limit is increased by 10%, the transient mean of smoke emission takes the minimum value of 0.025 m^-1. These 3 indices can be used to evaluate the performance of the diesel engine in the transient process, which can provide the basis for further optimization. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Diesel engines
Controlled terms:Deterioration - Emission control - Engine cylinders - Engines - Experiments - Fuels - Nitrogen oxides - Smoke - Smoke abatement
Uncontrolled terms:Comprehensive performance - Emission performance - Injection parameters - Maximum cylinder pressure - Performance evaluation - Smoke Emission - Transient performance - Transient process
Classification code:451.2  Air Pollution Control - 612.1.1  Internal Combustion Engine Components - 612.2  Diesel Engines - 804.2  Inorganic Compounds - 901.3  Engineering Research - 951  Materials Science
Numerical data indexing:Mass_Flow_Rate 3.47e-03kg/s, Percentage 1.00e+01%, Pressure 5.79e+06Pa, Time 3.00e+00s, Time 5.00e+00s
DOI:10.11975/j.issn.1002-6819.2017.04.016

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 24>

Accession number:20171503565319
Title:Effect of retrograded resistant starch types on forming rice starch gel
Authors:Xie, Tao (1); Li, Ying (2); Yi, Cuiping (3); Liu, Xiaolong (1) 
Author affiliation:(1) College of Chemical Engineering, Hunan Institute of Engineering, Xiangtan; 411104, China; (2) Library, Hunan Institute of Engineering, Xiangtan; 411104, China; (3) College of Chemistry and Biology Science, Changsha University of Science &amp; Technology, Changsha; 410015, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:309-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the structure and qualities of general rice starch products, effects of retrograded resistant starches (RSIII) made from Castanea henryi (C. henryi), potato and mung bean on microstructure and physicochemical properties of rice starch gels were investigated by using modern analysis methods, including RVA-4 rapid viscosity analyzer, S-3400N scanning electron microscope, TA-XT Plus structure analyzer, D/max2500 automatic X-ray diffractometer and DSC200 differential scanning calorimeter. The results demonstrated that the structure and properties of rice starch gel had a significant change (P&lt;0.01)after adding C. henryi, potato and mung bean RSIII, respectively. Especially the role of C. henryi RSIII was the most prominent. The C. henryi, potato and mung bean RSIII had no effect (P&gt;0.05) on viscosity properties of rice starch pastes. Rice starch gel without RSIII had a lot of irregular, deep and shallow large holes, while the net structure of rice starch gel with RSIII became more uniform and dense. RSIII had little influence on gumminess and cohesiveness of rice starch gel (P&gt;0.05). The C. henryi, potato and mung bean RSIII could accelerate the formation of rice starch gel. Compared with the rice starch gel without RSIII, their hardness increased by 2.38, 1.97 and 1.25 times (P&lt;0.01), stickness increased by 2.56, 1.99 and 1.32 times (P&lt;0.01), and spring increased by 1.07, 0.81 and 0.53 times (P&lt;0.01), respectively. A-type crystal was dominant in rice starch, and V-type crystal was dominant in C. henryi RSIII, while B-type crystal was dominant in potato and mung bean RSIII. Whether or not adding RSIII, V-type crystal in rice starch gel powders was transformed as the main crystal shape, and their total relative crystallinities had not changed (P&gt;0.05). In addition to a low temperature endothermic peak, rice starch pastes with RSIII showed a high temperature endothermic peak. Whether or not to add RSIII, the change of temperature parameters of low temperature endothermic peak was a little (P&gt;0.05), but its endothermic enthalpy decreased significantly (P&lt;0.01). As for the high temperature endothermic peak, all parameters of rice starch pastes with potato and mung bean RSIII had no difference (P&gt;0.05), but they were significantly higher than those of rice starch paste with C. henryi RSIII (P&lt;0.01). To sum up, adding RSIII with different sources can effectively improve the structure and quality of rice starch gel. The present results can provide an important reference for using the RS to improve the qualities and nutritional functions of the rice products. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Starch
Controlled terms:Chemical properties - Differential scanning calorimetry - Gels - Physical properties - Scanning electron microscopy - Structural properties - Temperature - Viscosity
Uncontrolled terms:Change of temperatures - Differential scanning calorimeters - Endothermic enthalpy - Physicochemical property - Resistant starch - Rice starch - Structure and properties - X ray diffractometers
Classification code:408  Structural Design - 641.1  Thermodynamics - 801  Chemistry - 804  Chemical Products Generally - 804.1  Organic Compounds - 931.2  Physical Properties of Gases, Liquids and Solids - 944.6  Temperature Measurements - 951  Materials Science
DOI:10.11975/j.issn.1002-6819.2017.04.042

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 25>

Accession number:20171503565295
Title:Analysis on hydraulic characteristics of dynamic flow around vane in hydro-turbine channel using large eddy simulation
Authors:Huang, Jianfeng (1); Zhang, Lixiang (2); Yang, Song (1); Yao, Ji (2) 
Author affiliation:(1) Faculty of Water Conservation, Yunnan Agricultural University, Kunming; 650201, China; (2) Department of Engineering Mechanics, Kunming University of Science and Technology, Kunming; 650500, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:125-130
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Numerical simulation of turbulent flow around a vane in the channel with guide vane closure based on the two-dimensional transient N-S equation was conducted with the large eddy simulation (LES) technique on Smargorinsky-Lilly model and Arbitrary Lagrange-Euler (ALE) dynamic mesh technology. In order to explore nonlinear mechanics of fluid-structure interaction between the fluid and guide vane which produced strong transient flow in the adjustment process of hydro-turbine, the Non-iterative Time Advancement (NITA) scheme was used in such a unsteady flow problem. The Reynolds number in calculation condition corresponding to chord length based on guide vane was 120 421. The model mesh was divided into triangular cell with strong adaptability. The number of mesh nodes was about 90 366, and the number of mesh elements was about 1 793 528. The finite volume method was used to disperse the LES-ALE form of transient N-S equation. The discretization of the convection term was based on the central difference scheme. The convergence of each time step in NITA scheme did not require an outer iteration. Compared with the original Iterative Time Advancement (ITA) scheme, the computation time of NITA scheme was reduced to 1/3 or 1/2. The coupling of pressure and velocity was solved by using fractional-step format. The format could save nearly 20% time compared with the PISO (pressure-implicit with splitting of operators)format in each time step. The velocity inlet and the free flow outlet were adopted in boundary condition. The non-slip boundary condition was used in the wall. The straight line of the guide vane closure law was controlled by the UDF (user defined function) method. The initial solution for unsteady calculation was used to the steady flow field by the standard k-&Epsilon; turbulence model. The dynamic mesh model was used to simulate the transient process of a vane in the channel with guide vane closure. The dynamic mesh model was updated by the spring smoothing method and local remeshing method in each time step. The time step was 0.001 s. The time for a straight line closure was 6 s. The hydrodynamic characteristics and vortex induced vibration of the flow around a vane in the channel were analyzed. The fields of pressure, velocity and vorticity in the channel showed obviously unsteady characteristics. The results showed that the Karman vortex frequency was about 0.3 times of the runner rotating frequency. It was easily induced by low-frequency pressure pulsation. With the end closure of time the wake vortex morphology in the channel showed an obvious Karman vortex shedding process. The lift and drag coefficients of the guide vanes in the closing process showed nonlinear dynamic response characteristics. The formation of the low-frequency pressure oscillation was related to the Karman vortex in the tail of the vane with the closing action of the guide vanes. The nonlinear flow induced vibration by Karman vortex was the main factor that affected the hydraulic stability of hydro-turbine and the hydraulic resonance of upstream pressure conduit. The method can be used to effectively simulate the transient nonlinear fluid-structure interaction problem of hydraulic machinery. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Large eddy simulation
Controlled terms:Boundary conditions - Buoyancy - Computational fluid dynamics - Computer simulation - Finite volume method - Fluid structure interaction - Hydraulic machinery - Hydraulic motors - Hydraulic turbines - Incompressible flow  - Iterative methods - Mesh generation - Models - Navier Stokes equations - Nonlinear analysis - Reynolds number - Steady flow - Turbine components - Turbines - Turbulence models  - Vibration analysis - Vibrations (mechanical) - Vortex flow - Vortex shedding - Wakes
Uncontrolled terms:Dynamic mesh - Hydraulic characteristic - Hydroturbines - Vane - Vibrations
Classification code:617  Turbines and Steam Turbines - 617.1  Hydraulic Turbines - 631  Fluid Flow - 631.1  Fluid Flow, General - 632.2  Hydraulic Equipment and Machinery - 723.5  Computer Applications - 921  Mathematics - 931.1  Mechanics - 931.2  Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 2.00e+01%, Time 1.00e-03s, Time 6.00e+00s
DOI:10.11975/j.issn.1002-6819.2017.04.018

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 26>

Accession number:20171503565287
Title:Design and experiment on flexible seedling seat of pneumatic pick-up for seedlings
Authors:Zhang, Qing (1, 2); L&uuml;, Yajun (1); Chu, Qi (1); Li, Bo (1); Wang, Yuewen (1); Yang, Yanli (3); Gu, Song (1) 
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou; 510642, China; (2) School of Mechanical and Automotive Engineering, Chuzhou University, Chuzhou; 239000, China; (3) Guangzhou Sky Mechanical &amp; electrical Technology CO., Ltd, Guangzhou; 510642, China 
Corresponding author:Gu, Song(sgu666@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:69-75
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, under the dual pressures of labor and mechanization, the demand for gardening equipment in the facility is increasing in China. Especially the nursery part has the heavy workload, and there is the most urgent demand for automatic production equipment. Pick-up mechanism is a key part of most nursery production equipment, the pneumatic pick-up is a flexible clamping technology, and it is developed for the seedling clamping job in recent years, but the existing flexible pneumatic pick-up method is based on a rigid platform to pick up seedlings. Because there are individual differences of seedlings, the existing pick-up mechanism is difficult to adapt to the changes of seedlings size and morphology, which results in the stationary adsorption distance that makes it difficult to adsorb all the seedlings on the rigid platform. In the pick-up operation, the negative pressure sucker is set to contact with the seedlings, but the seedlings with true leaves on the rigid platform are not kept at the horizontal state, which will lead to the problems of being difficult of adsorbing seedlings, long operating time, and consuming energy. To solve the above problems, based on vacuum adsorption principle, the study comes up with a flexible pneumatic pick-up method for seedlings. The method is constituted by the negative pressure pick-up finger and flexible seedling seat. The flexible seedling seat designed in this study consists of the plate to put seedling, the buffering steel cable and the fixing plate. The eggplant seedlings are manually placed on the plate with the V-notch, so the eggplant seedlings are limited by the V-notch in the diameter direction. The flexible seedling seat has a certain height, and the seedlings is in the horizontal state on the buffering steel cable, thus solving the problem that the pick-up operation is unstable because it is one end high and one end low for the seedlings due to the existence of the true leaves. At the same time the seedlings are supported by the buffering steel cable. The seedlings on buffering steel cable can avoid rigid extrusion when they are on the rigid platform. By the stress analysis, buffering steel cable diameter is calculated to be 0.32 mm. Because the maximum leaf span is 100.3 mm, the height of seedling seat is designed as 50 mm. In summary, the flexible seedling seat is better than the rigid platform on locating seedlings. The flexible seedling seat can correct the seedling place position. Because of the buffering effect of the flexible seedling seat, it can resolve the problem that the rigid platform is difficult to adapt to the size and morphology of seedlings. On this basis, the experiment is performed to optimize the structural parameter of flexible seedling seat. And the comparison test of the pick-up performance between the rigid platform and the flexible seedling seat is carried out. Test shows that: The support spacing between 2 buffering steel cables of the flexible seedling seat is 9 mm, the notch depth to holding seedling is 6 mm, and the side distance between the fixation point of buffering steel cable and the plate is 4 mm. At the above conditions, the adsorption pick-up success rate can be guaranteed to be over 90% within 2.8-5.1 mm range for eggplant seedlings. On the base of absorbing eggplant seedlings scion successfully with the diameter of the seedling of 4 mm (the diameter of the seedling between 3.8 to 4.2 mm also is classified as the diameter 4 mm), when it is on the rigid platform, the average seedling injury rate is 21%, the average response time for the adsorption is 0.08 s; when it is on the flexible seedling seat with the best combination of structural parameters, the average seedling injury rate is 5%, which is decreased by 16% compared with the rigid platform, the average adsorption response time reduces to 0.03 s, and the productivity increases by 62.5% compared with that on the rigid platform. The findings will provide an important reference for the development of picking device for agricultural robot. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Seats
Controlled terms:Adsorption - Cables - Design - Equipment - Machinery - Mechanization - Optimization - Pickups - Plates (structural components) - Pneumatics  - Problem solving - Stress analysis
Uncontrolled terms:Automatic production - Individual Differences - Negative pressures - Nursery production - Productivity increase - Rigid platform - Seedlings - Structural parameter
Classification code:408.2  Structural Members and Shapes - 601  Mechanical Design - 632.3  Pneumatics - 802.3  Chemical Operations - 901  Engineering Profession - 921.5  Optimization Techniques - 951  Materials Science
Numerical data indexing:Percentage 1.60e+01%, Percentage 2.10e+01%, Percentage 5.00e+00%, Percentage 6.25e+01%, Percentage 9.00e+01%, Size 1.00e-01m, Size 2.80e-03m to 5.10e-03m, Size 3.20e-04m, Size 3.80e-03m to 4.20e-03m, Size 4.00e-03m, Size 5.00e-02m, Size 6.00e-03m, Size 9.00e-03m, Time 3.00e-02s
DOI:10.11975/j.issn.1002-6819.2017.04.010

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 27>

Accession number:20171503565278
Title:Parameters solving and optimization of long working stroke hydraulic support mechanism using regional approximation and dynamic graphical solution
Authors:Liu, Hongxin (1); Jia, Ru (1); Li, Yanlong (1); Gai, Guangwei (1) 
Author affiliation:(1) Engineering College, Northeast Agricultural University, Harbin; 150030, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:1-9
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a result of substantial improvements in agricultural mechanization in China, large farm implements have been widely utilized. However, a problem has arisen concerning how to guarantee safety, effectiveness and convenience when such wide-breadth farm implements switch between road transport and operational modes. At present, there are 3 methods of resolution: Folded frames, which can be subdivided into supero-inferior fold, horizontal fold and lifting fold; a trailer for longitudinal traction along the girder of a wide-breadth farm implement; and combined double-frame agricultural implement with common mechanism for raising/lowering and rotating a lift frame about a vertical axis. Nevertheless, folded frames have complex structures and are expensive to manufacture; a dedicated shoring trailer has to be furnished, and field operation is very inconvenient; and the complex structure of combined double frames are more expensive. To address these technical problems, a high-mobility universal frame platform for wide-breadth farm implements, which can benefit operation and transport, was designed at Northeast Agricultural University. Its land wheel mechanism outperforms conventional land wheels on the frames of farm implements that only have depth-limiting and transmission functionality. The land wheel mechanism ensures easy tilling depth adjustment, good conformality, the ability to produce a large driving force, and convenient and quick switch modes. To realize the mode switching of land wheel mechanism for operation and transport purposes, a novel hydraulic support scheme was selected based on a part of trunnion mounted cylinder on a common rod. It adapted to the structural characteristics of the land wheel actuation device that required a long working stroke within a limited mounting space. Toward mechanics and kinematic models for this mechanism, support structure parameters were regionally approximated according to a spatial geometric relationship and subject to dynamic constraints. After the feasible region of the mounting position and dimensions of the hydraulic cylinder were determined, a dynamic graphical solution was used to simulate the motion situation of mechanism. As the swing arms rotated stepwise, the curve describing the cylinder length on one side was observed to find its point of intersection with a feasible boundary. The optimal solutions for the mounting position and cylinder dimensions could be determined using this information. When the hydraulic system pressure was 16 MPa, the length of the mounting arm was found to be 175 mm, the mounting arm was 357 mm away from the pivot point, the length of the hydraulic cylinder was 916 mm, and the inside diameter of the cylinder was 71 mm. The study and prototype trial indicate that the non-end supported opposed twin-cylinder hydraulic support mechanism enables the land-wheel mode to switch and is characterized by a compact structure and a long working stroke. The study also demonstrates that regional approximation and dynamic graphical solutions can be effectively used in the optimization and parameter solving for such mechanisms. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Dynamics
Controlled terms:Agricultural implements - Agricultural machinery - Agriculture - Approximation theory - Cylinders (shapes) - Hydraulic equipment - Hydraulic machinery - Kinematics - Maneuverability - Mechanical actuators  - Mountings - Truck transportation - Wheels
Uncontrolled terms:Agricultural mechanization - Geometric relationships - Graphical solution - Long strokes - Mode transitions - Point of intersections - Regional approximation - Structural characteristics
Classification code:432.3  Cargo Highway Transportation - 601.2  Machine Components - 632.2  Hydraulic Equipment and Machinery - 732.1  Control Equipment - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1  Agricultural Machinery and Equipment - 921.6  Numerical Methods - 931.1  Mechanics
Numerical data indexing:Pressure 1.60e+07Pa, Size 1.75e-01m, Size 3.57e-01m, Size 7.10e-02m, Size 9.16e-01m
DOI:10.11975/j.issn.1002-6819.2017.04.001

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 28>

Accession number:20171503565288
Title:Comparative test between displacement and four-bar indirect measurement methods for tractor guide wheel angle
Authors:Hu, Shupeng (1, 2); Shang, Yehua (2, 3); Liu, Hui (1); Li, You (2, 3); Zhao, Chunjiang (2, 3); Fu, Weiqiang (2, 3) 
Author affiliation:(1) College of Information Engineering, Capital Normal University, Beijing; 100048, China; (2) Beijing Research Center for Information Technology in Agriculture, Beijing; 100097, China; (3) National Engineering Research Center for Information Technology in Agriculture, Beijing; 100097, China 
Corresponding author:Fu, Weiqiang(fuwq@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:76-82
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wheel swivel angle is regarded as a critical parameter in agriculture automatic navigation system, and it can always be measured by using angle sensor. In engineering practice, angle sensor is difficult to fix, and the shaft is easily broken. In order to solve the problem, displacement indirect measurement method and four-bar indirect measurement method are proposed in this paper. Wheel rotation depends on steering cylinder piston movement, and the movement of steering cylinder piston causes the movement of steering trapezoidal mechanism. Therefore it is available to apply displacement sensor in measuring the position of the steering cylinder piston rod, and the displacement sensor is parallel fixed with the steering cylinder. Referring to the motion of steering trapezoidal mechanism, it is proposed to use the front axle, knuckle arm, connecting rod and pendulum rod to form a four-bar linkage. According to the fixed location of the displacement sensor and four-bar angle sensor, it is available to establish measurement models for those 2 indirect measurement methods, and calibrate the relation between sensor measurement and wheel swivel angle, but those 3 measurement methods are incapable to measure the real wheel swivel angle. In the 2 kinematic models of wheel vehicle, wheel swivel angle is the angle between wheel axis and vehicle body axis, and thus Ackerman transformation must be used for converting the test angle into wheel swivel angle. However, different vehicles are different in the transformation of Ackerman, and the ideal Ackerman transformation cannot be used. In fact, the rotation angles of left and right wheels have little bias with the wheel swivel angle when the wheel swivel angle is being in a small range in the middle of the pair. Therefore it is supposed that the measurement angle is the wheel swivel angle. Through automatic navigation precision comparison experiment, the advantages and disadvantages of different measurement methods are compared. The experiment is performed on basis of the LOVOL tractor M800, in which the self developed automatic navigation system was used, and an experiment platform was built. The experiment is completed on the asphalt pavement and the field, and the platform can be utilized to compare the accuracy of 3 measurement methods of wheel swivel angle and compare the accuracy of navigation through statistical analysis. The result shows that the four-bar angle sensor can provide the highest angle measurement accuracy and navigation accuracy. When the vehicle keeps the speed of about 4.2 km/h, the mean value of lateral deviation is -0.028 2 cm by using the four-bar angle sensor in the field, and the mean value of lateral deviation is -0.014 6 cm by using the hall angle sensor and 0.109 0 cm by using the displacement sensor in the same experiment environment. Therefore the four-bar indirect measurement method offers almost a navigation accuracy equal with the direct angle measurement, but the standard deviation of lateral deviation for automatic navigation of the four-bar indirect measurement method is 1.297 5 cm, which is less than the direct measurement method. But considering the displacement sensor wear, when the sensor has been used for about 50 h in the same environment, the mean value of lateral deviation is -0.456 1 cm. Thus the displacement angle measurement is incapable of replacing the direct angle measurement, while the four-bar angle sensor is capable to replace direct angle measurement method and can be further applied in practice, which is easily fixed and protected. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Four wheel steering
Controlled terms:Agricultural machinery - Agriculture - Angle measurement - Automobile steering equipment - Automobile testing - Cylinders (shapes) - Displacement measurement - Front axles - Kinematics - Models  - Navigation systems - Pistons - Steering - Tractors (truck) - Vehicles - Wheels
Uncontrolled terms:Automatic navigation - Displacement - Four bar - Navigation accuracy - Swivel angle
Classification code:601.2  Machine Components - 612.1.1  Internal Combustion Engine Components - 662  Automobiles and Smaller Vehicles - 662.4  Automobile and Smaller Vehicle Components - 663.1  Heavy Duty Motor Vehicles - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1  Agricultural Machinery and Equipment - 931.1  Mechanics - 943.2  Mechanical Variables Measurements
Numerical data indexing:Size 1.00e-02m, Size 2.00e-02m, Size 6.00e-02m, Time 1.80e+05s, Velocity 1.17e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.04.011

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 29>

Accession number:20171503565316
Title:Enzymatic synthesis of chitosan-gallic acid derivative and its preservation effect on fresh-cut apple
Authors:Wu, Hao (1); Zhen, Tianyuan (1); Chen, Cunkun (2); Wang, Yiying (1); Luo, Dan (1); Zhang, Xiao (1); Wang, Chengrong (1) 
Author affiliation:(1) College of Food Science and Engineering, Qingdao Agricultural University, Qingdao; 266109, China; (2) National Engineering and Technology Research Center for Preservation of Agricultural Products, Tianjin; 300384, China 
Corresponding author:Wang, Chengrong(qauwcr@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:285-292
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to broad the application scope and improve the preservation effect of chitosan (CTS) and gallic acid (GA), CTS derivative with GA was synthesized by laccase catalysis method. The grafting rate and solubility, structural characterization and preservation effect of derivative on fresh-cut apple were investigated. Results showed that the grafting rate and solubility were respective 72.80% and 92.77%. The preliminary characterization of derivative was studied through a series of testing methods including ultraviolet spectrum, FTIR (Fourier transform infrared spectroscopy), X-ray diffraction spectra and superconducting magnetic resonance spectrum. Ultraviolet spectrum analysis result showed that benzene ring and auxochrome-OH were introduced into CTS molecules. FTIR result showed that-NH<inf>2</inf>of CTS molecules decreased, which reacted with GA by amid linkage and did not change the main chain structure of CTS. X-ray diffraction analysis result indicated that with the addition of GA, CTS conformation was changed, a new kind of crystal was formed gradually, the area of amorphous area increased, the order of the structure reduced, the intermolecular and intramolecular hydrogen bonding in polymer were destroyed, and the crystallinity of CTS reduced.¹³C-NMR (nuclear magnetic resonance) analysis result demonstrated that CTS-GA exhibited the resonance absorption peak of C=O.¹H-NMR analysis result proved that CTS-GA exhibited the benzene ring and alcoholic hydroxyl proton peaks. All above analysis results confirmed the successful grafting of GA onto CTS. The conjugation of GA onto CTS probably occurred between amine (C-2) and carboxyl groups of GA, forming amide linkage. Effects of chitosan (CTS), derivative of chitosan and gallic acid (CTS-GA), physical compound of chitosan and gallic acid (CTS.GA) and deionized water (CK) treatment on fresh-cut apples' biochemical properties, such as hardness, soluble solid, polyphenol, vitamin C, glutathione (GSH) content, activities of polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and total number of bacteria colony. Analytical determinations were made every day. After 4-day storage at 14&#8451;, the loss of hardness of CTS-GA group was only 10.23%, which was significant lower than those of CK (20.90%), CTS (16.60%) and CTS.GA (15.60%). The soluble solid, vitamin C, GSH and polyphenol content of CTS-GA group were 12.93 %, 1.23 mg/100g, 6.26 mg/100g and 6.24 mg/100g, which were 16.47%, 48.78%, 24.92% and 43.75% respectively higher than those of CK, while the activity of PPO and POD of CTS-GA group were 36.73% and 76.94% lower than CK treatment. And the amount of microorganism in CTS-GA group was 16.00&times;10⁴CFU/g, obviously lower than CK, CTS and CTS.GA groups. These results suggested appropriate CTS-GA treatment provided better maintenance of hardness, effectively reduced the loss of vitamin C, soluble solid content, polyphenol content and GSH, inhibited the PPO activities, and also maintained higher activity of SOD and CAT, and suppressed the microbial growth. Therefore CTS-GA treatment can delay the senescence rate and exert an excellent effect on fresh keeping of fresh-cut apple. The results clearly indicate that enzyme-mediated pattern of CTS and GA can provide a novel 'green' pathway of preparing and broaden the application fields of CTS and GA such as food preservation industry. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Quality control
Controlled terms:Benzene - Benzene refining - Chitin - Chitosan - Crystal structure - Deionized water - Energy storage - Enzymes - Food preservation - Fourier series  - Fourier transform infrared spectroscopy - Fruits - Grafting (chemical) - Hardness - Hydrogen bonds - Magnetic resonance spectroscopy - Molecules - Nuclear magnetic resonance - Oxygen - Resonance  - Solubility - Spectroscopy - Spectrum analysis - Testing - Ultraviolet spectroscopy - Water treatment - Wood preservation - X ray diffraction analysis
Uncontrolled terms:Analytical determination - Gallic acids - Intramolecular hydrogen bonding - Laccases - Magnetic resonance spectra - Structural characterization - Ultraviolet spectrum analysis - X-ray diffraction spectrum
Classification code:445.1  Water Treatment Techniques - 525.7  Energy Storage - 801  Chemistry - 801.4  Physical Chemistry - 802.2  Chemical Reactions - 804  Chemical Products Generally - 804.1  Organic Compounds - 811.2  Wood and Wood Products - 821.4  Agricultural Products - 822.2  Food Processing Operations - 913.3  Quality Assurance and Control - 921.3  Mathematical Transformations - 931.1  Mechanics - 931.3  Atomic and Molecular Physics - 933.1.1  Crystal Lattice - 951  Materials Science
Numerical data indexing:Age 1.10e-02yr, Percentage 1.02e+01%, Percentage 1.29e+01%, Percentage 1.56e+01%, Percentage 1.65e+01%, Percentage 1.66e+01%, Percentage 2.09e+01%, Percentage 2.49e+01%, Percentage 3.67e+01%, Percentage 4.38e+01%, Percentage 4.88e+01%, Percentage 7.28e+01%, Percentage 7.69e+01%, Percentage 9.28e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.039

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 30>

Accession number:20171503565280
Title:Design and experiment of profiling sliding-knife opener
Authors:Jia, Honglei (1, 2); Zheng, Jiaxin (1, 2); Yuan, Hongfang (1, 2); Guo, Mingzhuo (1, 2); Wang, Wenjun (1, 2); Jiang, Xinming (1, 2) 
Author affiliation:(1) College of Biological and Agricultural Engineering, Jilin University, Changchun; 130025, China; (2) Key Laboratory of Bionics Engineering, Ministry of Education, Jilin University, Changchun; 130025, China 
Corresponding author:Yuan, Hongfang(yhf1984828@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:16-24
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To improve the seedbed quality and enhance the even distribution of soybean seeds and the consistency of deep seeding in the field, and targeting the double-row high-yield planting techniques on soybean ridges, we manufactured the profiling sliding-knife openers that could dig out V-shaped seed furrows and function as single profiling based on a self-invented double-V shape opener. This new opener can build favorable seedbeds, thereby reducing variation coefficient of qualified grain space and variation coefficient of deep seeding and improving seeding quality. The profiling sliding-knife opener mainly functions to dig out V-shaped seed furrows, improve opener passing rate by holding blades, and guarantee the consistency of furrowing depths and the even distribution of seeds. The profiling sliding-knife opener is composed of connecting bar, soil-compressing profiling wheels, profiling device, squeezing knife, and sliding knife. Interaction mechanism between squeezing knife assembly and soil as well as force condition was illustrated, sliding-knife blade force and curve were analyzed, and structure of profiling compacting wheels and force condition were elaborated. Through soil-bin trials, a three-level four-variable central composite rotatable design was applied by Design Expert software. Based on the force analysis and the actual operating condition of machine, the furrowing angle, machine forward velocity, furrowing depth and pressure were selected as influence factors. And the test index was the quantity of backfill. Experiment data obtained were assessed by the analysis of variance (ANOVA) and the quadratic regression model was set up for optimization with response surface methodology. Through the lack of fit test of the regression model, the P value of lack of fit was 0.489 5, which was larger than 0.05. The determination coefficient and adjusted determination coefficient were close to 1, which indicated that the regression equation was precise and effective. The precision was 16.449 which was larger than 4, indicating that the regression equation had sound estimation performance within the design domain. The significance sequence of influence factors on quantity of backfill from large to small was pressure, furrowing angle, machine forward velocity and furrowing depth. The optimal parameter combination of profiling sliding-knife openers was selected: load of 689.66 N, furrowing angle of 40.43&deg;, furrowing depth of 51.62 mm, and machine forward speed of 2.12 m/s. Under these working conditions, the soil disturbing quantity by the profiling sliding-knife opener was the minimum, which indicated a humidity-improving function and a seedling-promoting effect. It could be learned from the expectation analysis that sound operating effect of ditching could be achieved when the furrowing angle was 40.43&deg;, the furrowing depth was 51.62 mm, the operating velocity was within 2-2.3 m/s, the pressure scope was 600-700 N, and the expectation degree was close to 1. Field verification test and comparative test showed the sowing width mean absolute deviation was 4.42 after seeding by profiling sliding-knife openers, which was similar to the double-V shape opener (4.34) and smaller than the disk openers (6.55). These results suggested that under the same operating conditions, the scope of seed transverse fluctuation was smaller for the profiling sliding-knife opener or double-V shape opener versus the disk opener. The probability of seeds falling into the middle of the seed furrow was larger. The variation coefficient of seeding depth for the profiling sliding-knife openers was 6.06%, which was reduced by 10.88% compared with the double-V shape opener, smaller than that of disk openers (11.52%), indicating the seeding linearity and consistency of deep seeding were both better for our profiling sliding-knife openers. In the 50-75 mm soil layer, the soil cone index after furrowing and soil-covering by profiling sliding-knife opener, double-V shape opener and disc opener was 0.261, 0.248, and 0.165 MPa respectively. The profiling sliding-knife opener has a better operating effect compared with the double-V shape opener and disc opener. It can be used to improve the seedbed quality and sowing depth consistency, and the seedbed will be more compact, and the emergence rate will be higher. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Analysis of variance (ANOVA)
Controlled terms:Depth profiling - Design - Machinery - Mechanization - Optimization - Regression analysis - Soils - Wheels
Uncontrolled terms:Adjusted determination coefficient - Central composite rotatable design - Mean absolute deviations - Openers - Optimal parameter combinations - Profiling - Response surface methodology - Seeding depth
Classification code:483.1  Soils and Soil Mechanics - 601  Mechanical Design - 601.2  Machine Components - 801  Chemistry - 921.5  Optimization Techniques - 922  Statistical Methods - 922.2  Mathematical Statistics
Numerical data indexing:Force 6.00e+02N to 7.00e+02N, Force 6.90e+02N, Percentage 1.09e+01%, Percentage 1.15e+01%, Percentage 6.06e+00%, Pressure 1.65e+05Pa, Size 5.00e-02m to 7.50e-02m, Size 5.16e-02m, Velocity 2.00e+00m/s to 2.30e+00m/s, Velocity 2.12e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.04.003

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 31>

Accession number:20171503565283
Title:Design of virtual test system based on hardware-in-loop for picking robot vision localization and behavior control
Authors:Luo, Lufeng (1, 2); Zou, Xiangjun (1); Cheng, Tangcan (2); Yang, Zishang (2); Zhang, Cong (2); Mo, Yuda (1) 
Author affiliation:(1) Key Lab of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China; (2) College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin; 300222, China 
Corresponding author:Zou, Xiangjun(xjzou1@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:39-46
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the process of developing picking robot prototype, the traditional picking tests are usually performed in orchard, which are limited by certain factors such as the harvesting season, weather condition and venue. So, the investigated and designed algorithm for the vision and control system of picking robots can't be verified effectively and timely, and the prototype development cycle has to last longer. To test the vision and control algorithm of picking robot, a hardware-in-the-loop virtual experimental system based on binocular stereo vision for grape-picking robot was designed in this paper, which was composed of hardware and software units. The hardware units consisted of binocular camera, grape clusters, grape imitative leaf and stems, support structure of grape clusters and its guide rail, calibration board, and so on. The software units included vision processing part and virtual picking robot. Firstly, the spatial information such as the picking point and the anti-collision bounding volume of the grape cluster was extracted by binocular stereo vision. The picking point on the peduncle of the grape cluster was detected by using a minimum distance restraint between the barycentre of the pixel region of grape cluster and the detected lines in the ROI (region of interest) of peduncle. The anti-collision bounding volume of the grape cluster was calculated by transforming the spatial coordinates of the picking point and all detected grape berries into the coordinate system of grape clusters. Secondly, the three-dimensional models of the picking robot were constructed according to the picking robot prototype with 6 degrees of freedom which already existed in our laboratory. The Denavit-Hartenberg (D-H) method was adopted to establish the robot coordinate transformation. The direct and inverse solutions of the robot kinematics were solved by using the inverse transformation method, and then the only inverse solution was obtained. Thirdly, the moving path of picking robot was planned based on the artificial potential field theory. The collision between the robot manipulator and the grape clusters in the virtual environment was detected by using the hierarchical bounding box algorithm which can validate the reasonability of path planning. The motion simulation of the virtual picking robot was programmed by combining the modular programming and the routing communication mechanism. Finally, the spatial information of the grape clusters was extracted by programming the application code using Visual C++ and OpenCV (open source computer vision library), and the path planning and the motion simulation of the virtual picking robot were performed based on the virtual reality platform EON, Visual C++ and JavaScript. The hardware-in-the-loop virtual experimental platform was established by combining the binocular stereo vision and virtual picking robot. On this platform, 34 tests were performed by changing the position of the grape clusters under laboratory environment while the binocular cameras kept still. And every test included 3 steps, the first step was vision locating, the second was path planning and the last was clamping and cutting operation. In all the tests, 29 tests were successful in vision locating, and 5 tests were failed in vision locating. Among those 5 failed tests, 2 tests were wrong in picking point detection and 3 tests were failed in stereo matching on the picking point. There was one test failed in path planning when the grape clusters were located correctly, and all of the clamping and cutting operation for the grape clusters ran smoothly when the anti-collusion path was planned successfully. In general, the success rates of the tests on visual localization, path planning, clamping and cutting operation were 85.29%, 82.35%, 82.35%, respectively. The results showed that the method developed in this study can be used to verify and test the visual location and behavior algorithm of the picking robot, and then provide the support to the harvesting robot development, test and continuous improvement. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Robot programming
Controlled terms:Algorithms - Binoculars - Bins - C++ (programming language) - Cameras - Clustering algorithms - Collision avoidance - Computer hardware - Computer programming - Computer software  - Computer vision - Degrees of freedom (mechanics) - Design - Digital libraries - Hardware - Image segmentation - Inverse problems - Location - Machine design - Manipulators  - Motion planning - Open source software - Open systems - Robot applications - Robots - Software testing - Stereo image processing - Stereo vision - Synthetic apertures - Testing  - Virtual reality - Visual servoing
Uncontrolled terms:Artificial potential fields - Binocular stereo vision - Co-ordinate transformation - Continuous improvements - Grape - Hard-ware-in-the-loop - Inverse transformations - Three-dimensional model
Classification code:601  Mechanical Design - 605  Small Tools and Hardware - 694.4  Storage - 716.2  Radar Systems and Equipment - 722  Computer Systems and Equipment - 723  Computer Software, Data Handling and Applications - 731.5  Robotics - 731.6  Robot Applications - 741.3  Optical Devices and Systems - 742.2  Photographic Equipment - 903.1  Information Sources and Analysis - 914.1  Accidents and Accident Prevention - 931.1  Mechanics
Numerical data indexing:Percentage 8.23e+01%, Percentage 8.53e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.006

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 32>

Accession number:20171503565303
Title:Effect of alternative wetting and drying irrigation and nitrogen coupling on rhizosphere environment of rice
Authors:Xu, Guowei (1, 2); Lu, Dake (1); Sun, Huizhong (1); Wang, Hezheng (1); Li, Youjun (1) 
Author affiliation:(1) Agricultural College, Henan University of Science and Technology, Luoyang; 471003, China; (2) Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou; 225009, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:186-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil moisture and nitrogen nutrient are the principal factors affecting rice (Oryza sativa L.) production. Elucidation of their influences and coupling effects on grain yield of rice would have great significance for high yield and high efficiency. Domestic and foreign scholars have conducted extensive research on the interaction of water and fertilizer. The former focuses on the ground, such as crop growth development, physiological function, hormone change, nutrient absorption and utilization, water use efficiency and other aspects of the studies, few papers are for soil and root secretion characteristics, and their interaction and the conclusions are not consistent. The purposes of this study were to investigate the effects of water and nitrogen coupling on soil enzyme activity, microorganism quantity, root secretion and coupling effect. A mid-season japonica rice cultivar of Xindao 20 was pot-grown. Three treatments of different nitrogen levels, i.e. 0N, MN (240 kg/hm²) and HN (360 kg/hm²) and three irrigation regimes, i.e. submerged irrigation (0 kPa), alternate wetting and moderate drying (-20 kPa) and alternate wetting and severe drying (-40 kPa) were conducted in 2014 and 2015. Some indices, such as urease enzyme, sucrose enzyme, catalase enzyme, bacteria, fungi, actinomycetes quantity and total organic acid in root at different stages were investigated in the experiment. Results showed that there was a significant interaction between irrigation regimes and nitrogen levels, and no significant difference was observed between the 2 years. In the same nitrogen levels, urease enzyme, sucrose enzyme, catalase enzyme activity in soil at main growth stages were higher under the condition of alternate wetting and moderate drying compared with the submerged irrigation, and meanwhile bacteria, fungi and actinomycetes quantity in soil were also increased at main stages, and total content of organic acid was enhanced. So mild water stress and MN enhanced soil enzyme, microorganism and organic acid content, and formed the best mode in this paper, which was referred as the water-nitrogen coupling management model. The opposite result was observed under the condition of alternate wetting and severe drying. Soil enzyme, microorganism quantity and organic acid content in the root secretion at main stages were decreased significantly. In the same irrigation regime, soil enzyme and microorganism quantity at main growth stages were higher under the condition of MN treatment when compared with no nitrogen applied, and meanwhile total content of organic acid was enhanced significantly. The opposite result was observed under the condition of HN treatment, which indicated that heavy nitrogen application decreased soil enzyme and microorganism quantity, and organic acids of root secretion were also reduced significantly. Correlation analysis showed that there was significant or extremely significant positive correlation between soil enzyme, microorganism quantity and total organic acid content at main growth stages. Positive effects were observed in the effect of nitrogen fertilizer for soil enzyme activities, microbial quantity and total content of organic acid, and water stress and interaction effect were also positive under the condition of alternate wetting and moderate drying, while negative effect was observed under the condition of alternate wetting and severe drying. These results suggest increasing soil enzyme activity and microorganism quantity, and improving organic acids of root secretion through the appropriate regulation of water and nitrogen, will create a good rhizosphere environment for the growth of rice. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Bacteria
Controlled terms:Drying - Efficiency - Enzyme activity - Enzymes - Fertilizers - Fungi - Grain (agricultural product) - Irrigation - Microorganisms - Nitrogen  - Nitrogen fertilizers - Nutrients - Organic acids - Physiology - Soil moisture - Soils - Sugar (sucrose) - Underwater soils - Water absorption - Wetting
Uncontrolled terms:Catalase enzyme activities - Correlation analysis - Physiological functions - Positive correlations - Rice - Rice (Oryza sativa L.) - Soil enzymes - Water use efficiency
Classification code:461.9  Biology - 483.1  Soils and Soil Mechanics - 802.3  Chemical Operations - 804  Chemical Products Generally - 804.1  Organic Compounds - 821.3  Agricultural Methods - 821.4  Agricultural Products - 822.3  Food Products - 913.1  Production Engineering
Numerical data indexing:Age 2.00e+00yr, Pressure -2.00e+04Pa, Pressure -4.00e+04Pa, Pressure 0.00e+00Pa
DOI:10.11975/j.issn.1002-6819.2017.04.026

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 33>

Accession number:20171503565318
Title:Comprehensive evaluation on quality and safety of ganoderma lucidum based on improved analytic hierarchy process
Authors:Wang, Minjing (1); Pei, Haisheng (1); Sun, Junshe (1); Tan, Xiaoyan (2); Zhang, Xiuqing (2); Sun, Tian (3); Liu, Fengsong (3); Xu, Zhangyang (1); Yang, Yue (1); Chen, Zhou (1) 
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Beijing; 100125, China; (2) College of Food Science and Nutritional Engineering, China Agricultural University, Beijing; 100083, China; (3) Infinitus (China) Co., Ltd., Guangzhou; 510623, China 
Corresponding author:Sun, Junshe(sunjsh61@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:302-308
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Traditional Chinese medicine is the material basis for the inheritance and development of traditional Chinese medical science, it is a strategic resource in the national economy and people's livelihood. Ganoderma lucidum, as a traditional Chinese herbal medicine and edible fungus, has a long history in China. This paper explored on comprehensive evaluation method to quality and safety of ganoderma lucidum through improved AHP (analytic hierarchy process, referred to as AHP) method, it takes reference for ganoderma lucidum cultivation of safety and effectiveness. According to the fluctuations of sample size and improved AHP method, the calculation for quality and safety indicators (polysaccharide, Pb, As, Hg, Cd) of ganoderma lucidum's fruiting body was based on the traditional Chinese medicinal materials quality safety standards, and through this method, we evaluated the risk levels of quality and safety indicators in typical planting areas, such as Wuyi mountain (Southeast of China), Changbai mountain (Northeast of China) and the Dabie mountain (South Central of China), which was based on AHP method key growth period (4 layers, 5 layers and 6 layers) by comprehensive weighted index, and compared with Nemerow index method widely used for the risk calculation. Besides, we compared it with the one calculated with the widely-used Nemerow index method. The results showed:1) The general rules for quality and safety for five kinds of single index of ganoderma lucidum indicators (polysaccharide, Pb, As, Hg, and Cd) were Cd&gt;Hg&gt; polysaccharide &gt;As&gt;Pb, and they were lower than traditional Chinese medicinal materials quality and safety standards. 2) The quality risk index calculated with the improved AHP method ranged from 0.237 6 to 0.759 8, less than 1, for the safety level, while the one calculated with Nemerow index method ranged from 0.257 9 to 0.729 2, less than 1, for the safety level. On the whole, the difference was not significant. The analysis showed that the quota polysaccharide, Hg and Cd of heavier weight was larger in the single risk index. 3) In order to compare the advantages and disadvantages of these two methods further, we exchanged Hg and Cd of larger single risk index and weight with quotas Pb and As to the contrary. The risk index of more harmful quotas Hg and Cd decreased, while that of the less harmful quotas Pb and As increased. The results demonstrated that the comprehensive quality risk index declined by 68.03%. So the improved AHP method could more precisely reflect the quality risk of ganoderma lucidum than Nemerow index method. The research is a good reference to the quality safety evaluation of ganoderma lucidum and provides support for the whole course control of the plantation of it (including preproduction, production, and postproduction). We suggest that this research should continue to advance, which is based on commercial specification and grade standards of Chinese herbal medicines, an important criterion in clinical curative effect of traditional Chinese medicine for the quality standard of ganoderma lucidum, production process quality and safety grade control. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Quality control
Controlled terms:Analytic hierarchy process - Food safety - Heavy metals - Hierarchical systems - Landforms - Lead - Medical applications - Medicine - Plant extracts - Plants (botany)  - Polysaccharides - Risk assessment - Safety engineering - Standards
Uncontrolled terms:Chinese herbal medicines - Composite index - Ganoderma Lucidum - Improved AHP - Nemerow index - Traditional Chinese herbal medicine - Traditional chinese medical science - Traditional Chinese Medicine
Classification code:461.6  Medicine and Pharmacology - 461.9  Biology - 481.1  Geology - 531  Metallurgy and Metallography - 546.1  Lead and Alloys - 804.1  Organic Compounds - 902.2  Codes and Standards - 913.3  Quality Assurance and Control - 914  Safety Engineering - 914.1  Accidents and Accident Prevention - 961  Systems Science
Numerical data indexing:Percentage 6.80e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.041

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 34>

Accession number:20171503565291
Title:Pyrolysis characteristics of particulate matter from diesel engine fueled with methanol/bio-diesel
Authors:Wang, Zhong (1); Zhao, Huaibei (1); Qu, Lei (1); Zhang, Dengpan (1); Feng, Yuan (2) 
Author affiliation:(1) School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) School of Automotive and Traffic, Wuxi Institute of Technology, Wuxi; 214121, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:96-101
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Diesel exhaust particle matter is the main source of air pollutants PM2.5. It is limited not only on the quality but also on the number. Therefore, the widespread use of clean alternative fuel in diesel engine is one of the effective ways to reduce particulate emission. Previous study reported the effects of methanol/biodiesel blending fuel on the volatilization, oxidation process parameters and kinetic parameters of particle matter emitted from diesel engine. The volatilization, oxidation process parameters of particle matter varied with the methanol/biodiesel blending ratio (100%, 5%, 10%, 15%) were measured by the TGA/DSCI thermal analyzer, manufactured by Mettler, Switzrland. The mass change curves of the particles in the surroundings of N<inf>2</inf>and O<inf>2</inf>were obtained by thermo-gravimetric analyzer. Further, the volatilization and oxidation features of the particles were studied according to the pyrolysis curves (TG/DTG), the characteristic temperature and activation energy of pyrolysis of particles were calculated by tangent method and Flynn-Wall-Ozawa (FWO) pyrolysis kinetics. The results showed that when the content of H<inf>2</inf>O in particle matter was increased from 2.6% to 3.5%, the quality of soluble organic fraction (SOF) in particle matter could be increased from 26.1% to 32.5%, the peak of mass change rate and the temperature of the peak of SOF would be increased with the increasing of the methanol ratio. In O<inf>2</inf>surroundings, the derivative thermal gravimetry curves of particle matter under 4 kind of blending fuels showed that the change way of SOF was consistent with that in N<inf>2</inf>surroundings, but the peak value in O<inf>2</inf>atmosphere was obviously greater. The soot mass showed a decreasing trend with the increase of ratio of methanol, which was decreased from 70.3% to 63.8%. In addition, the peak of mass change rate of soot was increased and the temperature of the peak was decreased, which indicated that the particles were more easily oxidized. The initial combustion temperature of soot was decreased from 488&#8451; to 458&#8451;. Meanwhile, the SOF initial combustion temperature and the burnout temperature were slightly lower, and the total time of pyrolysis reaction of particles was shortened. The activation energy of particle matter was reduced from 140.3 to 117.3 kJ/mol. In summary, the pyrolysis properties of the particles were enhanced and the thermo chemical reaction of particles was easily carried out. These results could provide a theoretical basis for the treatment of methanol/biodiesel combustion particulates, and it is helpful to the design and application of diesel particulate filter (DPF). &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Methanol fuels
Controlled terms:Activation energy - Alternative fuels - Biodiesel - Blending - Chemical activation - Combustion - Cracking (chemical) - Diesel engines - Engines - Enzyme kinetics  - Fueling - Fuels - Gravimetric analysis - Kinetics - Methanol - Oxidation - Oxidation resistance - Particles (particulate matter) - Pyrolysis - Soot  - Thermoanalysis - Thermogravimetric analysis
Uncontrolled terms:Characteristic temperature - Diesel exhaust particles - Diesel particulate filters - Particulates - Pyrolysis characteristics - Soluble organic fraction - Thermo-Chemical reactions - Thermogravimetric analyzers
Classification code:523  Liquid Fuels - 612.2  Diesel Engines - 801  Chemistry - 802.2  Chemical Reactions - 802.3  Chemical Operations - 804  Chemical Products Generally - 804.1  Organic Compounds - 931  Classical Physics; Quantum Theory; Relativity - 951  Materials Science
Numerical data indexing:Percentage 1.50e+01%, Percentage 2.60e+00% to 3.50e+00%, Percentage 2.61e+01% to 3.25e+01%, Percentage 5.00e+00%, Percentage 7.03e+01% to 6.38e+01%, Percentage 1.00e+01%, Percentage 1.00e+02%
DOI:10.11975/j.issn.1002-6819.2017.04.014

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 35>

Accession number:20171503565300
Title:Distribution characteristic analysis of preferential flow paths in highway slope soils based on o-ring statistic
Authors:Zhang, Dongxu (1); Cheng, Jinhua (1); Wang, Wei (2); Zhang, Hongjiang (1); Liu, Tao (2) 
Author affiliation:(1) College of Soil and Water Conservation, Beijing Forestry University, Beijing; 100083, China; (2) China Academy of Transportation Sciences, Beijing; 100029, China 
Corresponding author:Cheng, Jinhua(Jinhua_cheng@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:161-168
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The soil layer structure of the slope would be disturbed during highway construction, leading to heterogeneity of soil properties. Water and solute are always moving in a non-equilibrium flow. Introducing the theory of preferential flow to analyze the migration mechanism of chloride pollutants in slope soil is of great significance to reveal the law of the migration of industrial salt in the protection of road environment. In order to observe the distribution of preferential flow paths in slope soil directly, dye infiltration experiment was used in soils of low subgrade slope of Heda highway. Image processing techniques and morphological computation procedures were used to determine the influence radius and coordinates of preferential flow paths. Spatial point pattern analysis method (O-ring statistic) of landscape ecology with 19 times simulation tests by using Monte Carlo stochastic was used to analyze the spatial distribution characteristics and the spatial correlation of the preferential flow paths with different influence radius. The results showed that the development depth of preferential flow paths in slope soil could reach to 40 cm by dye infiltration experiment. Plant roots were concentrated in topsoil (0-10 cm), and there was no trace of plant roots and biological activities in deeper soil. The number of preferential flow paths with same influence radius decreased as the soil depth increased, while the number of preferential flow paths decreased with the increasing of influence radius in the same soil layer. In the scale of this research, preferential flow paths showed a random distribution state at the range of 1.0&le;R&lt;5.0 mm and an aggregation distribution state when R&ge;5.0 mm. With the gradual increase of influence radius, aggregated distribution pattern was more evident. At the range of 5&le;R&lt;10.0 mm, preferential flow paths showed an uniform distribution state in small scale (0-20 mm). The peak of aggregation state usually appeared at a smaller scale (0-40 mm). A large number of gravels lead to a change in the direction of actual movement of water flow, and preferential flow paths will be separated and then merged. The difference of soil particle composition can also lead to lateral water flow, which shows poor correlation between adjacent soil layers. The spatial correlation analysis of preferential flow path shows that the correlation between different preferential flow paths is relatively independent which related to the structure of soil. Large pores in slope soil are mainly formed by the filling of the fine particles of gravel soil, which has strong randomness, good stability, and not easy to collapse. This kind of non-random distribution condition shows that it is very necessary to study the distribution of preferential flow paths in slope soil. O-ring statistic is much more simple and intuitive than the traditional water breakthrough curve method, and it can enrich soil preferential flow research methods. It can also quantitatively analyze the distribution characteristics and spatial correlation of soil preferential flow paths from a statistical point of view. In future, landscape ecology spatial point pattern analysis method will be used well in study on spatial distribution of soil preferential paths. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soil surveys
Controlled terms:Computation theory - Ecology - Environmental regulations - Flow of water - Gravel - Groundwater flow - Highway engineering - Hydraulics - Image processing - Infiltration  - Monte Carlo methods - O rings - Plants (botany) - Road construction - Slope protection - Slope stability - Soil testing - Soils - Spatial distribution - Spatial variables measurement  - Statistics - Stochastic systems - Transportation
Uncontrolled terms:Distribution characteristics - Highway slopes - Paths - Preferential flows - Spatial point pattern analysis
Classification code:406  Highway Engineering - 406.2  Roads and Streets - 454.2  Environmental Impact and Protection - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 619.1.1  Pipe Accessories - 631.1  Fluid Flow, General - 631.1.1  Liquid Dynamics - 632.1  Hydraulics - 721.1  Computer Theory, Includes Formal Logic, Automata Theory, Switching Theory, Programming Theory - 921  Mathematics - 922.2  Mathematical Statistics - 943.2  Mechanical Variables Measurements - 961  Systems Science
Numerical data indexing:Size 0.00e+00m to 1.00e-01m, Size 0.00e+00m to 2.00e-02m, Size 0.00e+00m to 4.00e-02m, Size 4.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.04.023

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 36>

Accession number:20171503565313
Title:Estimation of non-point source pollution loads of Beijing-Tianjin-Hebei region considering precipitation and topography
Authors:Cheng, Xian (1, 2); Chen, Liding (1); Sun, Ranhao (1) 
Author affiliation:(1) State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing; 100085, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China 
Corresponding author:Sun, Ranhao(rhsun@rcees.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:265-272
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the advantages of fewer model parameters, fewer difficulties in obtaining necessary data, and more combinations with geographic information system (GIS), remote sensing (RS) technologies, the export coefficient model (ECM) is an applicable model for estimating non-point source (NPS) pollution loads. Based on the traditional ECM, the model can be improved by considering the impacts of precipitation and topographical factors on NPS pollution. The simulation accuracy of improved ECM (IECM) on NPS pollution is higher and it has been successfully used in China, such as the upper reaches of the Yangtze River basin, the Miyun Reservoir basin, and the Baoxiang River basin in Yunnan Province. Beijing-Tianjin-Hebei region, namely Beijing-Tianjin-Hebei, located in North China, is an economically developed region with a dense population and fast urbanization. There is a serious lack of water resources in this region and the water quality is bad. Seventeen drinking-water reservoirs in Beijing-Tianjin-Hebei region were selected in this study, and the meteorological, topographical, land use, social and economic data of their watersheds in the year of 2010 were collected. The IECM was applied to estimate the loads and intensities of total nitrogen (TN) and total phosphorus (TP) of NPS in the 17 reservoir watersheds, and the sources of TN and TP were also analyzed. The results were as follows: (1) TN and TP load had the same spatial pattern, namely the TN load was large, and the TP load was large too. The average ratio of TN to TP load was 6.73. (2) TN and TP load intensities had obvious spatial heterogeneities. The TN load intensity was 1.04-24.91 t/km²&middot;a, ranging from the minimum value in Yunzhou Reservoir watershed to the maximum value in Taolinkou Reservoir watershed. The TP load intensity was 0.11-3.89 t/km²&middot;a, with the minimum value in Yunzhou Reservoir watershed and the maximum value in Yanghe Reservoir watershed. The TN and TP load intensities were both relatively high in Taolinkou, Yanghe, Daheiting, Qiuzhuang Reservoir watershed, indicating that the reservoirs located in the northeast Beijing-Tianjin-Hebei region (Tangshan City and Qinhuangdao City) had higher risk of nitrogen and phosphorus pollution. (3) Based on the source analysis results, a conclusion could be drawn that the order of the mean contribution to TN load was land use &gt; rural life &gt; livestock, while the order of the mean contribution to TP load was rural life &gt; land use &gt; livestock. Rural life was an important source of both TN and TP load in this region. (4) We used the water eutrophication index (EI) of drinking-water reservoirs which was published by Haihe River Water Conservancy Commission in 2010 to test the modeling results. EI was significantly correlated to TN and TP load intensities. Person correlation analysis was employed and the correlation coefficient between TN load intensity and EI and that between TP load intensity and EI were 0.562 (P&lt;0.05) and 0.558 (P&lt;0.05), respectively. Model test results showed that the IECM has a high application value, and the TN and TP load of NPS can be well estimated by IECM at large watersheds which lack large numbers of measured data of water quality. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:River pollution
Controlled terms:Agriculture - Eutrophication - Geographic information systems - Land use - Models - Nitrogen - Petroleum reservoirs - Phosphorus - Pollution - Potable water  - Remote sensing - Reservoirs (water) - Rivers - Rural areas - Surface waters - Water - Water management - Water pollution - Water quality - Water resources  - Watersheds
Uncontrolled terms:Beijing-tianjin-hebei regions - Correlation coefficient - Export coefficient models - Nitrogen and phosphorus - Non-point resources - Non-point source pollution - Total nitrogen - Upper reaches of the yangtze rivers
Classification code:403  Urban and Regional Planning and Development - 441.2  Reservoirs - 444  Water Resources - 444.1  Surface Water - 445.2  Water Analysis - 453  Water Pollution - 512.1.1  Oil Fields - 804  Chemical Products Generally - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 903.3  Information Retrieval and Use
DOI:10.11975/j.issn.1002-6819.2017.04.036

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 37>

Accession number:20171503565289
Title:Design and pilot test for feeder of biomass shaftless screw continuous pyrolysis device
Authors:Wang, Mingfeng (1); Xu, Qiang (1); Jiang, Enchen (1); Ren, Yongzhi (1); Wu, Yujian (1); Chen, Xiaokun (1) 
Author affiliation:(1) College of Materials and Energy, Key Laboratory of Energy Plant Resources and Utilization, Ministry of Agriculture, Guangzhou; 510642, China 
Corresponding author:Jiang, Enchen(ecjiang@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:83-88
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biomass continuous pyrolysis is a promising technology of biomass energy utilization. The technology has a lot of advantages, for example, the device applied in the technology is simple, can run continuously and stably, which is easy to be widely used, reaction conditions are easy to control, the efficiency is high. Continuous feeder is one of the core components of continuous pyrolysis reactor, which is generally a screw feeder, but shaft screw feeder of continuous pyrolysis reactor has problem of high energy consumption because of its high weight. What's more, it is easy to interference between screw and cylinder wall so that the device often need to stop and repair. It is difficult to operate continuously, which leads to low efficiency. However, these problems can be solved by applying shaftless screw to continuous pyrolysis reactor. The design of shaftless screw feeder with feeding capacity of 150 kg/h was introduced in this paper. Rice husk was used to carry out transport tests at room temperature and pyrolysis tests at the temperature of (700&plusmn;50) &#8451; to study its feeding characteristic and pyrolysis characteristic. Shaft diameter, outside diameter, pitch of helix of the screw without shaft is 80, 400, 200 mm respectively. The distance between the outer diameter of the screw and the wall of the pipe is 20 mm. The diameter of pyrolysis tube is 456 mm and the thickness of pyrolysis tube's wall is 8 mm. What's more, a diesel combustion engine was used to produce heat for the feeder. The power of the diesel engine ranged from 58 to 116 kW. In addition, a motor was used to drive shaftless screw rotation, its main technology parameters: power rating: 5.5 kW, rated speed: 1 450 r/min, reduction ratio: 29. Test results showed that When the transport frequency was 50 Hz, the feeding amount of screw feeder without shaft was 224.3 kg/h&gt;150 kg/h. Obviously, the actual feeding amount of screw feeder was higher than the theoretical value. Rice husk was filled in the shaftless screw feeder densely due to the extruding effect of shaftless screw in the process of conveying. Continuous pyrolysis experiments of rice husk under different pyrolysis time were conducted in the case that the maximum temperature of heating chamber was 700&#8451;. With the pyrolysis time increased, the volatile content of rice husk char decreased from 22.45% to 13.6%, the ash content increased from 29.38% to 33.44%, and the fixed carbon content increased from 48.17% to 52.96%. According to the results of industrial analysis of rice husk carbon, most of the volatiles in rice husk have been released. In addition, the pyrolysis time has a slight influence on the calorific value of rice husk char. The high calorific value of rice husk char increased from19.307 MJ/kg to 20.821 MJ/kg with the increase of pyrolysis time. Thus, the shaftless screw feeder designed in this paper reached the requirements, providing design basis for industrial application of biomass continuous pyrolysis reactor. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Pyrolysis
Controlled terms:Biomass - Calorific value - Chemical reactors - Design - Diesel engines - Energy utilization - Engines - Feeding - Screws
Uncontrolled terms:Continuous pyrolysis - Continuous pyrolysis reactors - Feeder - High energy consumption - Pyrolysis characteristics - Shaftless screws - Technology parameters - Transport frequencies
Classification code:525.3  Energy Utilization - 605  Small Tools and Hardware - 612.2  Diesel Engines - 691.2  Materials Handling Methods - 802.1  Chemical Plants and Equipment - 802.2  Chemical Reactions
Numerical data indexing:Percentage 2.24e+01% to 1.36e+01%, Percentage 2.94e+01% to 3.34e+01%, Percentage 4.82e+01% to 5.30e+01%, Power 5.50e+03W, Power 5.80e+04W to 1.16e+05W, Rotational_Speed 1.45e+03RPM, Size 2.00e-01m, Size 2.00e-02m, Size 4.56e-01m, Size 8.00e-03m, Specific_Energy 2.08e+07J/kg, Frequency 5.00e+01Hz, Mass_Flow_Rate 4.17e-02kg/s
DOI:10.11975/j.issn.1002-6819.2017.04.012

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 38>

Accession number:20171503565282
Title:Development and experiment of electric driving insert hill-drop planter on film for plot corn
Authors:Shi, Linrong (1); Zhao, Wuyun (1); Sun, Wei (1); Li, Rongbin (2); Xin, Bingbang (2); Dai, Fei (1) 
Author affiliation:(1) School of Engineering, Gansu Agricultural University, Lanzhou; 730070, China; (2) ZHULONG Agricultural Machinery Company with Limited Liability, Jiuquan; 735000, China 
Corresponding author:Zhao, Wuyun(zhaowy@gsau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:32-38
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In solving the problem on the seed corn mechanization sowing in the northwest area and understanding the corn sowing conditions and agronomic requirements, an electric driving insert hill-drop planter on film for plot corn was developed. The differential motor drives are installed in the front wheel shaft with the front wheel moving ahead. Also, the motor drives are used for the electromagnetic clutch to rotate. Whenever the clutch is switched on, the input power of the motor crank shaft sprocket is used through a different number of the teeth of the deceleration after the transfer to increase the speed compensation mechanism. The uniform rotation of the input crank guide rod achieves a non-uniform rotation that drives the non-uniform rotary motion of the parallel four-bar mechanism, which means that when the planter moves forward, the duckbill in the sowing period goes straight up and down relative to the ground. The sowing device assembly makes the toggle wheel move by the up and down movement of the brace, driving the wheel wrench to turn to take or discharge seeds, and to pull the trigger on the active duckbill to achieve the seed discharging. The sowing device components are attached to the sowing rod through the slider and spring damper. When the hard ground or rock spring damper is compressed, it protects the duckbill. When there is a leakage sowing, the sowing alarm installed on metering device will alarm the module to remind the artificial sowing. As part of the core components of the forward speed compensation mechanism, the depth limiting and rear-wheel height adjusting mechanisms were designed and simulated. The forward speed compensation mechanism consists mainly of crank rod, slider, guide rod, driving rod, driven rod, and bunch rod. The core function of attaining the forward speed compensation under the periodically rotating guide bar drives the parallel four-bar mechanism. Compensation under the buried and unearthed planting bars, which is near zero speed, promotes the corn growth around the bed (deficient in the upper bed and excess in the lower bed), makes the corn less damaged, and reduces the planting bar to tear the plastic film. Considering the tread of the front wheel of the planters is small, the seed sowing performance and the pass rate of sowing depth for the seed sowing device are affected by the ground roughness. Also, the corn seeds germinate better under the same sowing depth. With this, the depth limiting mechanism was designed. In meeting the demand of the film mulching and ridge tillage, the walking machine maintains the level, and when there is no operation the duckbill of the planter avoids touching the surface and tearing film, and the rear height adjusting mechanism designed is mainly composed of push rod, DC (direct current) linear electric push rod, rotating shaft, bottom bar and land wheel. In the perform test, the results showed that the hole rate was 1.1%, the qualified rate of seeds number per cavity was 93.2%, and the pass rate of sowing depth under the film was 90.1%. The three sowing core indicators have reached the standard of NY/T 987-2006 PU film dibbling machine operation quality, and the film hole qualified rate was 98.5%. The test results show the operation of compensation device is stable and reliable in the forward speed, which was placed on the 2 lines of symmetry and greatly reduced the vibration of the whole machine cycle. The film holes of the duckbill inserted were smaller, and hole and film hole have not slipped, and the qualified rate of sowing depth was higher. After encountering stones, the duckbill will not insert into it forcedly. The results of this study met the design and agronomic requirements as cited. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Electric drives
Controlled terms:Agricultural machinery - Agriculture - Agronomy - Bars (metal) - Crops - Design - Drives - Drops - Electric discharges - Electric motors  - Film growth - Machine design - Mechanisms - Seed - Speed - Wheels
Uncontrolled terms:Adjusting mechanism - Corn - Device assemblies - Electromagnetic clutch - Insert hill-drop planter - Machine operation - Parallel four-bar mechanisms - Speed compensation
Classification code:535.1.2  Rolling Mill Practice - 601  Mechanical Design - 701.1  Electricity: Basic Concepts and Phenomena - 705.3  Electric Motors - 821  Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.10e+00%, Percentage 9.01e+01%, Percentage 9.32e+01%, Percentage 9.85e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.005

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 39>

Accession number:20171503565285
Title:Obstacle avoidance path planning of hybrid harvesting manipulator based on joint configuration space
Authors:Yang, Hanjiang (1); Li, Lijun (1); Gao, Zicheng (1) 
Author affiliation:(1) School of Mechanical and Electrical Engineer, Central South University of Forestry and Technology, Changsha; 410000, China 
Corresponding author:Li, Lijun(junlili1122@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:55-62
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aiming to realize the obstacle avoidance of fruit harvesting robot manipulator in unstructured environments, a kind of obstacle avoidance path planning algorithm of hybrid harvesting manipulator based on joint configuration space was proposed in this study. The structure of the 2P4R hybrid camellia oleifera fruit harvesting robot manipulator composed of a palletizing manipulator and a spherical wrist serial manipulator was simplified, and the link connecting the palletizing manipulator and serial manipulator was named as moving platform. The manipulator could accomplish six kinds of movements, including waist rotation, translational motions of vertical slider and horizontal slider, as well as three kinds of rotational motions of the wrist part. In this study, only five joint motions were taken into consideration. It means that the last link was considered as a fixed part of its previous link when a collision-free path planning operation was conducted. This is because that the motion of the last link was not related to the position of the end effector which could only affect its posture. Firstly, a goal point for the moving platform of the manipulator in Cartesian space was selected with the proposed algorithm. The goal point should be located in the workspace of the parallel manipulator, rather than inside the obstacles. The initial and goal configurations of the serial manipulator were determined by the moving platform of the goal point, the goal position of the end effector and the initial posture of the serial manipulator. Secondly, the obstacle mapping model in serial manipulator joint configuration space was built by using traversal method. Then, an attempt was made to search for a collision-free route from the initial point to the goal point in this space with each point uniquely corresponding to a configuration of the serial manipulator by using rapid-exploring random tree (RRT) algorithm. Thirdly, if the algorithm failed to find such a route in the previous step, the selection of goal point and collision-free route searching operation would be repeated. Otherwise, the joint configuration space of the parallel manipulator would be established. Fourthly, the unique posture of the parallel manipulator was determined based on the mapping relationship between driving joint value and the position coordinates of the moving platform. The obstacle model was built in the joint configuration space of the parallel manipulator. Subsequently, the goal point of the moving platform would be selected again, if the point in parallel manipulator configuration space corresponding to the goal configuration was located in the mapping model of obstacle. Otherwise, a collision-free route from the start point to the goal point in the configuration space corresponding to the initial posture and goal configuration of the parallel manipulator respectively should be searched by using RRT algorithm. The obstacle avoidance path of the hybrid manipulator was obtained from the synthesized results of the collision-free paths of the serial manipulator and parallel manipulator. In order to verify the feasibility and effectiveness of the proposed algorithm, the path planning simulation of a hybrid manipulator in Matlab was carried out. The proposed algorithm was also applied in the obstacle avoidance path planning experiment on the camellia oleifera fruit harvesting manipulator. According to the simulation and experiment results, the path planned by the proposed algorithm could successfully drive the end effector from its initial position to the goal position without any collision. That is to say, these results can validate the feasibility and effectiveness of the proposed algorithm. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Manipulators
Controlled terms:Algorithms - Collision avoidance - End effectors - Flexible manipulators - Fruits - Harvesting - Industrial manipulators - Industrial robots - Mapping - MATLAB  - Modular robots - Motion planning - Redundant manipulators - Robot applications - Robot programming - Robots - Trees (mathematics) - Wave functions
Uncontrolled terms:Camellia oleifera fruits - Collision-free path-planning - Hybrid - Joint configuration - Mapping relationships - Path-planning algorithm - Translational motions - Unstructured environments
Classification code:405.3  Surveying - 731.5  Robotics - 731.6  Robot Applications - 821.3  Agricultural Methods - 821.4  Agricultural Products - 914.1  Accidents and Accident Prevention - 921  Mathematics - 921.4  Combinatorial Mathematics, Includes Graph Theory, Set Theory
DOI:10.11975/j.issn.1002-6819.2017.04.008

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 40>

Accession number:20171503565296
Title:Design of two and a half parabola-shaped canal and its effect in improving hydraulic property
Authors:Han, Yancheng (1); Xu, Zhenghe (1); Gao, Xueping (2); Easa, Said M (3) 
Author affiliation:(1) College of Resources and Environment, University of Jinan, Jinan; 250022, China; (2) State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin; 300072, China; (3) Dept. of Civil Engineering, Ryerson Univ., Toronto; ON; M5B 2K3, Canada 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:131-136
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Shapes of canal cross sections affect their discharge capacity, water depth and construction cost. Researches have shown that the curve-shaped canal such as quadratic parabolic and semi-cubic parabolic shape has good hydraulic property. However, the less smooth base of the quadratic parabolic and semi-cubic parabolic shape canal can affect the discharge capacity. To improve the hydraulic property and increase the discharge of the quadratic parabolic sections of canals, a section with two and a half parabola shape was proposed in this paper. Formulas for flow area, shape factor and water surface width for this new section were derived. The theoretical formula for the wetted perimeter was deduced using Gauss super-geometric functions. A model of the optimum hydraulic section that minimized the flow area for a given discharge was developed based on the Manning formula. The partial differential equation for the optimum hydraulic section was deduced using Lagrange's multiplier method. After substituting the derivatives of wetted perimeter and flow area with respect to water depth and water surface width into this partial differential equation, the optimum model was successfully converted into an equation about the water surface width-depth ratio. Various explicit formulas to compute the characteristic's parameters such as wetted perimeter, shape factor, flow area, normal water depth and critical water depth for the best hydraulic section were obtained. Using these formulas, the hydraulic design could be achieved easily. The results showed that the best ratio of water surface width-depth ratio for the optimum hydraulic section of the two and a half parabola-shaped canal was a constant (2.0 883). The two and a half parabola-shaped canal had better hydraulic properties than that with quadratic or semi-cubic parabolic sections. Comparisons with quadratic and semi-cubic parabolic sections showed that the flow discharge of the two and a half parabola-shaped section was the largest under the same water depth, which means it is an economical section. Under the same discharge, the water depth of the two and a half parabola-shaped section was smaller than the quadratic parabolic and semi-cubic parabolic sections. The flow area, wetted perimeter and water surface width of the two and a half parabola-shaped section was the least under the same discharge among the three sections. Minimum wetted perimeter and flow area implied that the cost of construction (excavation and lining cost) was minimized. In theory, the comparisons with quadratic and semi-cubic parabolic sections also showed that the construction cost of the proposed best hydraulic section was the lowest under the same discharge. To aid practical use, the 3-point and 4-point method of Gauss-Legendre approximate algorithm were presented for the wetted perimeter calculation. The application example with the water depth of 1.0-3.5 m showed that the approximate algorithm was highly accurate. The 3-point approximate format formula could meet the practical use and design with the maximum absolute error of 0.004 01 m. The results from the 4-point format formula almost equaled to those of the theoretical results with the maximum absolute error of 0.000 97 m. This research provides a theoretical basis for the design of the two and a half parabola-shaped canals with improved hydraulic properties. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Canals
Controlled terms:Costs - Design - Hydraulic structures - Hydraulics - Lagrange multipliers - Partial differential equations - Space platforms - Wetting
Uncontrolled terms:Application examples - Approximate algorithms - Discharge capacities - Hydraulic properties - Maximum absolute error - Optimum hydraulic section - Two and a half parabola-shaped section - Wetted perimeters
Classification code:407.2  Waterways - 632.1  Hydraulics - 655.1  Spacecraft, General - 911  Cost and Value Engineering; Industrial Economics - 921.2  Calculus
Numerical data indexing:Size 1.00e+00m to 3.50e+00m
DOI:10.11975/j.issn.1002-6819.2017.04.019

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 41>

Accession number:20171503565279
Title:Mechanical analysis and contrast experiment on collecting residual plastic film with different side-film shovels
Authors:Zhang, Jiaxi (1); Zhang, Li (2); Liu, Xuanfeng (2); Jiang, Yongxin (2); Wang, Jikui (3) 
Author affiliation:(1) College of Mechanical Engineering and Traffic, Xinjiang Agricultural University, Urumqi; 830052, China; (2) Agricultural Mechanization Institute, Xingjiang Academy of Agricultural Sciences, Urumqi; 830091, China; (3) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi; 832003, China 
Corresponding author:Wang, Jikui(shzwjk@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:10-15
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the pollution controlling of the residual plastic films in the farmland, due to the lack of preferable side-film shovel mechanics in autumn plastic film recycling, the side-film can't be recycled by the side-film shovel but be buried under the ground surface. A large amount of residual plastic film into soil due to long-term using film on the crops has caused great serious influence on the high quality of farmland planting, crop growth, the rural ecological environment. The side-film accounted for 16% of the whole plastic film, which would result in the lower recovery rate for plastic film recycling and the recovery rate was generally maintained at about 80%, nearly 20% of the plastic film still remained in the soil, which caused definite pollution to the soil and the environment. Current research on the recovery mechanism is limited to the equipment of plastic film enwinding recycling itself. In order to solve these problems, the more widespread used mechanics for collecting the side-film was chosen such as furrow opener and double wing shovel. Then the mechanical analysis of one wing shovel newly designed was carried out with opener and double wings shovel. The forces of collecting the side-film were compared among three different structural shovels and the field contrast tests were carried out in Yuli county, Korla city in Xinjiang. The working performances of different side-film collecting shovels were compared in the field test. The three key factors were assessed about the integrity rate, film recovery rate and no heap soil phenomenon of residual plastic film. Results showed that the force of the side-film shovel taken was related with the angle into soil and blade length of the side-film shovel during the shovels picking the side-film. According to analyze the force of three types of shovels, we gained the balance equation, the equation involved some kinds of forces, such as the friction along the slant, the normal load along the slant, the shear force of soil internal shear failure, the friction force between the internal soil and the accelerating force of soil movement. Theoretical analysis of three side-film shovels showed that the force of one wing shovel was maximum while the stress of furrow opener device was minimum, the stress of double wing shovel was relatively reasonable. However, the performance effect of the one wing shovel was the best in the field testing although the force of one wing shovel was maximum. The integrity rate of the side-film was reached at 100%, the film recovery rate was at 95.4%, and without obstructing the soil in working performance. Taking the prominent operational effectiveness into account, the one wing shovel was highly recommended as autumn residual side-film recovery machine of the plastic film collecting structure. The research results can be provided a reference for the design of the side-film collecting mechanism section during the whole residual film recovery machine and also provide theory basis for the development of the plastic film recycling machine. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Film growth
Controlled terms:Agriculture - Crops - Farms - Films - Friction - Plastic films - Plastic recycling - Pollution - Recovery - Recycling  - Shovels - Soils
Uncontrolled terms:Balance equations - Contrast experiment - Mechanical analysis - Operational effectiveness - Performance effect - Recovery mechanisms - Rural ecological environments - Working performance
Classification code:452.3  Industrial Wastes - 483.1  Soils and Soil Mechanics - 817.1  Polymer Products - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4  Agricultural Products
Numerical data indexing:Percentage 1.00e+02%, Percentage 1.60e+01%, Percentage 2.00e+01%, Percentage 8.00e+01%, Percentage 9.54e+01%
DOI:10.11975/j.issn.1002-6819.2017.04.002

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.

<RECORD 42>

Accession number:20171503565307
Title:GF-1 image clear sky PAR inversion assisted by MODIS data
Authors:Wang, Limin (1); Liu, Jia (1); Yang, Lingbo (1); Teng, Fei (1); Yang, Fugang (1); Shao, Jie (1) 
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing; 100081, China 
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:4
Issue date:February 15, 2017
Publication year:2017
Pages:217-224
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:GF-1 satellite was launched in April 2013. Since then various researches and operations using the GF-1 imagery have been conducted. This study tries to establish the inversion model for the biophysical variable photosynthetically active radiation (PAR) derived from GF-1 imagery. The inversion of the variable aerosol optical depth (AOD) is first carried out using the surface reflectance product of MODIS (moderate-resolution imaging spectroradiometer) (it is MOD09A1). Based on the typical ground-object spectral library data provided by the United States Geological Survey (USGS), and spectral response function of the GF-1/WFV sensors, the study has found that the difference in terms of the blue band surface reflectance generated by 2 sensors of GF-1/WFV and MODIS is very small. MODIS data can thus be assimilated to create GF-1 surface reflectance library. The second simulation of satellite signal in the solar spectrum (6S) atmospheric radiation transfer model is applied to produce an atmospheric parameter look-up table (LUT). By comparing solar incident irradiance at top of atmosphere (TOA) and radiation brightness value at the entrance pupil of the sensor, and using surface reflectance product from MODIS, the authors have achieved the ground-air decoupling and the inversion of AOD. After establishing AOD library, the atmospheric parameters such as atmospheric transmittance, atmospheric hemisphere albedo, and atmospheric diffuse transmittance are computed and interpolated to LUT. Combined with the calculation of sun incident radiation intensity, the ground solar radiation intensities at red, green and blue bands of GF-1 are produced. By analyzing the relationship between the ground solar radiation intensities and overall 400-700 nm PAR values provided by MOD09A1, 3 conversion coefficients are computed. The coefficients have the values of 0.091 56, 0.099 51, and 0.100 7 respectively for the blue, green and red bands, realizing the inversion from the ground solar radiation intensity of 3 discrete wavebands to PAR. By selecting Yucheng region, Shandong Province as a study area, and using 13 GF-1 images registered from January to December in 2014, the authors generated the values of PAR for the study region and conducted the accuracy assessment for the inversion using the ground measured values of PAR. The results show that the PAR acquired by the inversion approach described in this paper has an overall accuracy of 92.63%, with an averaged absolute value of error of 14.56 W/m²and an averaged relative error of 7.37%. Study shows that GF-1 data can be effectively applied for the inversion of PAR; the establishment of reflectance library is feasible by including MOD09A product, and generating LUT through the 6S model. Finally this PAR inversion approach can provide reliable data support for crop growth monitoring, and parameter estimation based on GF-1 imagery. &copy; 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Incident solar radiation
Controlled terms:Aerosols - Atmospheric aerosols - Atmospheric radiation - Heat radiation - Image reconstruction - Optical properties - Plasma diagnostics - Radiation - Radiometers - Reflection  - Remote sensing - Satellite imagery - Solar radiation - Spectrum analysis - Table lookup
Uncontrolled terms:Aerosol optical depths - Atmospheric diffuse transmittance - Atmospheric radiation transfer model - GF-1 - Look up table - Moderate resolution imaging spectroradiometer - Photosynthetically active radiation - Photosynthetically available radiations
Classification code:443.1  Atmospheric Properties - 641.2  Heat Transfer - 655.2  Satellites - 657.1  Solar Energy and Phenomena - 723.1  Computer Programming - 741.1  Light/Optics - 932.3  Plasma Physics - 944.7  Radiation Measuring Instruments
Numerical data indexing:Percentage 7.37e+00%, Percentage 9.26e+01%, Size 4.00e-07m to 7.00e-07m, Surface_Power_Density 1.46e+01W/m2
DOI:10.11975/j.issn.1002-6819.2017.04.030

Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.