<RECORD 1>
Accession number:20173304046230
Title:Straw substrate with decomposition agent improving seedling quality and yield of machine-transplanted rice
Authors:Lü, Weisheng (1, 2); Huang, Guoqiang (1); Shao, Zhengying (1); Zeng, Yongjun (1); Shi, Qinghua (1); Pan, Xiaohua (1); Wei, Saijin (1)
Author affiliation:(1) College of Biology Science and Engineering, Jiangxi Agricultural University/Collaborative Innovation Center for the Modernization Production of Double Cropping Rice/Jiangxi Key Laboratory of Crop Physiology, Ecology and Genetic Breeding/Jiangxi Agricultural Microbial Resource Development and Utilization Engineering Lab, Nanchang; 330045, China; (2) Jiangxi Institute of Red Soil/National Engineering and Technology Research Center for Red Soil Improvement/Scientific Observational and Experimental Station of Arable Land Conservation in Jiangxi, Ministry of Agriculture, Nanchang; 331717, China
Corresponding author:Wei, Saijin(weisaijin@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 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:Machine-transplanted rice had many advantages, such as maintaining high efficiency, saving cost, freeing labor, and stabilizing yield, so the area of machine-transplanted rice becomes larger and larger in China in recent years. With the expansion area of machine-transplanted rice, the demand for high quality of rice seedling becomes more and more important. However, traditional seedling raising method such as using paddy soil as the seedbed substrate is difficult to meet the growing demand of machine-transplanted rice seedling. It is predicted that more new seedbed substrates for rice seedlings such as mixed substrate and light soilless substrate will replace nutrient soil for raising rice seedling. Organic waste substituted as raising substrate, such as straw seedling substrate is widely used on vegetable production. In recent years, we have developed an organic compound decomposing agent, which can decompose the straw rapidly. And also, straw composting plus straw decomposition agent can improve the quality of compost. Inspired by these, we need to study the effect of straw decomposition agent applied to straw substrate seedbed and machine-transplanted rice production. Field experiments were conducted with hybrid rice cultivar Hyou518 at the experimental farm of Jiangxi Agricultural University, Jiangxi Province, China in late-growing season in 2015. And the experiments were conducted under the condition of mechanical seedling and transplanting with high-yield agronomy technology during the whole growth period of late rice, and with three replicates for each treatment. In the field experiments, three types of rice seedbed substrates: straw substrate plus straw decomposition agent (T1), straw substrate without straw decomposition agent (T2) and paddy soil (CK) were used to compare their physical and chemical properties. The effects of different seedbed substrates on seedling and transplanting quality and yield formation of machine-transplanted rice were also analyzed. The results showed that, bulk density of T1 and T2 were 58.65% and 63.46% lower (P<0.05) than CK, while the porosity (aeration porosity and water-holding porosity) and water content were significantly higher (P<0.05) than CK (except water-holding porosity of T2). Inoculating straw decomposition agent to straw seedbed substrate was beneficial to improve the physical and chemical properties of straw seedbed substrate, reduce organic content, improve available nutrient concentrations, and decrease C/N ratio. Compared with T2 and CK, T1 had better seedling and transplanting quality, earlier and faster growth of tillering at early growth stage, and higher LAI, dry matter production and nutrient (N, P, K) absorption. Moreover, T1 had more panicles and total spikelet, and higher grain yield. The grain yield of T1 was 2.25% and 4.37% higher than that of T2 and CK, respectively. The results suggest that straw seedling substrate plus straw decomposition agent fulfilled the condition of seedling growth, and the seedlings were more suitable for current mechanized transplanting technology than paddy soil. In summary, the straw seedbed substrate added with the decomposition agent is a suitable seedling substrate of machine-transplanted rice because of its superiority on improving the grain yield and the utilization of straw resources. The production process technology of multifunctional substrate that produces strong seedling, improves soil fertility and disease resistance, and produces high yield still needs to be further studied, even though straw seedbed substrate from this study is more suitable for current mechanized transplanting technology than traditional seedling raising pattern. In addition, it is noted that this study just included one year experimental data in late rice field. Future studies on the validation and perfection of multiple years and sites are needed in the future. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Substrates
Controlled terms:Agricultural machinery - Agriculture - Chemical properties - Composting - Decomposition - Forestry - Grain (agricultural product) - Machinery - Mechanization - Nutrients - Porosity - Soils - Straw - Water aeration
Uncontrolled terms:Available nutrients - Dry matter production - Physical and chemical properties - Production process - Seedling quality - Seedling raising method - Vegetable productions - Yield formations
Classification code:445.1 Water Treatment Techniques - 483.1 Soils and Soil Mechanics - 601 Mechanical Design - 801 Chemistry - 802.2 Chemical Reactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 2.25e+00%, Percentage 4.37e+00%, Percentage 5.86e+01%, Percentage 6.35e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.025
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 2>
Accession number:20173304046218
Title:Influence of reservoir seepage prevention measures and drainage ditch behind dam on groundwater depth of surrounding farmland
Authors:Mao, Haitao (1); Wang, Zhengcheng (1); Wang, Xiaoju (1, 2); Huang, Qinghao (3); Liu, Yang (3)
Author affiliation:(1) College of Civil Engineering, Chongqing Three Gorges University, Chongqing; 404100, China; (2) College of Environment, Hohai University, Nanjing; 210098, China; (3) College of Water Conservancy and Civil Engineering, Xinjiang Agriculture University, Urumqi; 830052, China
Corresponding author:Wang, Zhengcheng(wangzhengcheng194@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:98-107
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Reservoir leakage has a great influence on water-salt dynamic, which is easy to cause soil secondary salinization and swamping in arid area. Groundwater depth of farmland behind dam is reduced by anti-seepage body and drain measure usually. Drainage ditches are set up behind dam, which can cut off seepage water and discharge water, therefore reducing the leakage loss. But how to choose parameters of drain, how to be combined with impervious body, and so on, these questions need to be studied further. Based on unsaturated soil seepage theory, aimed to the farmland around Qiala Reservoir, this paper calculated the combination measures by numerical simulation, and analyzed the relationship between groundwater depth and depth and position of drainage ditch by vertical cutoff wall, horizontal impervious blanket or non anti-seepage measures. Besides, we analyzed the downstream slope stability and adopted the field experiment to validate it. This research showed that the buried depth of farmland groundwater is characterized by a "funnel-shaped" downward trend taking the central axis of drainage ditch as a symmetrical axis in different seepage control schemes. The groundwater depth increased gradually before the drainage ditch, and decreased a little after the drainage ditch. Therefore, the "anti-seepage body and drain measure" reduce seepage into the farmland from the source, which can make farmland maintain a low groundwater depth. Different seepage control schemes of "anti-seepage body and drain measure" were different on the curbing and the effect of reducing the leakage of reservoir to farmland. The hanging cutoff wall and the non-impervious body cannot reduce the leakage of the reservoir effectively, and we found the combination of the former 2 ways has a weaker effect on anti-seepage. By comparing the 3 schemes, it was considered that the horizontal impervious blanket with a length of 22 times water head was better than the suspended cutoff wall and non-impervious body in seepage control. After combining it with the drainage ditch and the drainage in time, we controlled the groundwater depth at about 2.72 m effectively, which was greater than the local critical groundwater depth of 2.45 m, and curbed the trend of soil salinization after dam effectively. Drainage ditch position and depth had some effect on dam; we calculated the actual construction (length of 22 times water head) and found the downstream dam slope anti slide safety coefficient was 1.358, which was larger than the minimum slope anti slide safety coefficient of 1.242, so the downstream slope of the dam was in a safe state. After the drainage ditches were set up, the length of hydrops from the dam toe to drainage ditch was the main reason to the soil swamping. By calculating and measurement in the actual condition, we found the length of hydrops was 0.27 m, and the swamping area was smaller. In addition, calculations also revealed that the minimum depth of drainage ditches corresponding to avoiding field swamping was 5.18 m. Drain depth was 6 m in practical project, and thus the present cutoff wall, the distance between drainage ditch and dam toe, and the drain depth were reasonable. The study also found that water level changing and making sure draining timely have great effects on groundwater depth; drainage ditch was an auxiliary measure, and it can be combined with drainage and impervious body and farmland irrigation system, which can have a more effective influence. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Reservoirs (water)
Controlled terms:Dams - Drainage - Embankment dams - Farms - Groundwater - Groundwater resources - Models - Seepage - Slope stability - Soils - Underground reservoirs - Water levels
Uncontrolled terms:Anti-seepage measures - Drainage ditches - Ground water depths - Horizontal impervious blanket - Soil salinization - Soil secondary salinizations - Suspended cut-off wall - Vertical cutoff wall
Classification code:406.2 Roads and Streets - 441.1 Dams - 441.2 Reservoirs - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Size 2.45e+00m, Size 2.70e-01m, Size 2.72e+00m, Size 5.18e+00m, Size 6.00e+00m
DOI:10.11975/j.issn.1002-6819.2017.11.013
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 3>
Accession number:20173304046228
Title:Optimization experiment of light transmittance and active lighting mechanism of solar greenhouse
Authors:Zhang, Yong (1); Zou, Zhirong (1)
Author affiliation:(1) Key Laboratory of Protected Horticultural Engineering in Northwest, Ministry of Agriculture, College of Horticulture, Northwest University of Agriculture & Forestry, Yangling; 712100, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:178-186
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solar greenhouses without heating systems have been utilized extensively for vegetable production in Northeast China since the 1980s. Solar greenhouses play a critical role in self-researched and self-developed greenhouse structure and technologies in China. Solar greenhouses rely on sunlight, of course, as their primary energy source in the absence of a heating system. They are simple in structure, and relatively inexpensive to build and maintain through the winter. Sunshine is a scarce resource from November to next February, so the available light must be very efficiently utilized. Optical light transmittance is the most important characteristic of the solar greenhouse. Unfortunately for greenhouse designers, there exist few theories related or methods for analyzing the light transmittance characteristics of transparent materials. When natural light propagates from its origin into the greenhouse, a complex process of reflection and refraction is generated in the rough air/lighting-surface interface; the relationship between the inclined angle of the lighting surface and the transmitted natural light intensity was investigated at length in this study. We investigated the light transmission properties of typical Chinese solar greenhouse materials according to solar energy application theory. We developed a corresponding mathematical model, which was then used to simulate and analyze variations of indirect solar radiation in a typical greenhouse under varying parameters, (such as structural shape, latitude, azimuth, skeleton, covering material). We found that direct light intensity for a solar greenhouse could be improved by changing the inclined angle of the lighting surface from 25° to 35°; this improvement was predicted according to classical optical theory and verified through experimentation. The transmitted direct light intensity remained nearly constant when the incident angle was less than 10°, and then declined steadily when the incident angle exceeded 10°. Direct light intensity transmittance values were 85.68%, 76.47%, and 64.72% at the incident angles of 20°, 30°, and 40°, respectively. The transmitted direct light intensity significantly decreased when the angle of incidence exceeded 40°; the transmittance values were 53.38% and 39.67% at the angles of 50° and 60°, respectively. There was a highly significant correlation between the theoretical analysis and experimental results, which confirmed that the light intensity transmittance of the greenhouse lighting surface can be dramatically increased by slightly increasing the inclined angle of the lighting surface. The theoretical and experimental values of light intensity transmittance improved by 22.8% and 20.7%, respectively, when raising the incident angle from 25° to 35°. By comparison, the calculated values were, again, in good agreement with experimental values; the deviations in the calculated values can be amended through further research. The conclusions presented here may provide a theoretical reference for future studies on greenhouse lighting surface optimization design, as well as a practical reference for future solar greenhouse developers. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Greenhouses
Controlled terms:Geometrical optics - Heating equipment - Light - Light transmission - Lighting - Solar energy - Solar heating - Temperature - Thermal processing (foods)
Uncontrolled terms:Chinese solar greenhouse - Day lightings - Primary energy source - Reflection and refractions - Solar energy applications - Transmission property - Transmittance - Vegetable productions
Classification code:641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 741.1 Light/Optics - 821.6 Farm Buildings and Other Structures - 822.2 Food Processing Operations
Numerical data indexing:Percentage 2.07e+01%, Percentage 2.28e+01%, Percentage 3.97e+01%, Percentage 5.34e+01%, Percentage 6.47e+01%, Percentage 7.65e+01%, Percentage 8.57e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.023
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 4>
Accession number:20173304046212
Title:Biodiesel modified by catalytic transfer hydrogenation improving combustion performance
Authors:Yuan, Yinnan (1, 2); Gu, Meng (1); Dai, Pengfei (1); Mei, Deqing (1)
Author affiliation:(1) School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) School of Energy, Soochow University, Suzhou; 215006, China
Corresponding author:Mei, Deqing(meideqing@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:54-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biodiesel has received extensive attention as a kind of renewable and clean fuel. However, because of its intrinsic unsaturated composition, it is prone to auto-oxidation and corruption in long-term storage. Fortunately, the partial hydrogenation of biodiesel, in which the high unsaturated fatty acid esters are selectively converted to the low unsaturated or saturated fatty acid esters, has been an effective measure to improve the oxidation stability as well as the cetane number. In this study, the partially hydrogenated soybean methyl ester (PHSME) was produced from soybean methyl ester (SME) via the catalytic transfer hydrogenation. The catalytic transfer hydrogenation of SME was implemented using isopropanol as the hydrogen donor, water as the reaction medium and Raney-Ni as the catalyst. The ratio of solvent water, isopropanol and SEM was 100: 32: 7, and the catalyst loading accounted for 13% of SME approximately. The hydrogenation reaction was progressing under the water bath of (85±1)℃ with a magnetic stirring speed of 600 r/min. After about 100 min, the degree of hydrogenation for biodiesel was found to reach the maximum, and the final product PHSME was collected by suitable separation. By the gas chromatography-mass spectrometry (GC-MS) analysis, methyl palmitate (C16: 0), methyl stearate (C18: 0), methyl oleate (C18: 1), methyl linoleate (C18: 2), methyl linolenate (C18: 3), methyl eicosanoate (C20: 0) and methyl docosanoate (C22: 0) were detected out in sequence for SME sample, however, C18: 3 did not exist in the PHSME. The total amount of unsaturated components C18: 3, C18: 2 and C18: 1 in the SME was 70.9%. After moderate hydrogenation, the high unsaturated components C18: 3 and C18: 2 containing 3 and 2 double bonds were converted into C18: 1 and C18: 0 preferentially, and the conversion rate could reach 37.8%. In view of the number of unsaturated double bonds in carbon chain, the unsaturation degree of SME was reduced by 46.2%. Compared with SME, although the kinematic viscosity of PHSME increased slightly, its oxidation stability was improved significantly, and the cetane number of PHSME rose to a desirable level as well. In air atmosphere, the oxidation and combustion characteristics of SME and PHSME were comprehensively explored in a thermal analyzer. Due to the molecular structure change and increased kinematic viscosity, the start of weight loss for PHSME was a little late, whose TG (thermogravimetry) profile shifted to the high temperature region with respect to that for SME, however eventually the finish of weight loss advanced by 7.2℃, which affirmatively indicated that PHSME, owning a greater average oxidation rate than SME, was more prone to be oxidized and burned. Meanwhile, in DSC (differential scanning calorimeter) profiles, due to the desirable cetane number, the exothermic onset temperature of PHSME was 10.7℃ earlier than that of SME. In summary, the fuel properties including the oxidation stability, iodine value and cetane number of SME are beneficially upgraded by moderate hydrogenation. The better quality of partially hydrogenated biodiesel makes it more popular in the fuel blend market. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Hydrogenation
Controlled terms:Biodiesel - Calorimeters - Carbon - Catalysts - Chromatography - Combustion - Differential scanning calorimetry - Drug products - Esters - Fatty acids - Fuels - Gas chromatography - Kinematics - Mass spectrometry - Oxidation - Palmitic acid - Saturated fatty acids - Thermoanalysis - Thermogravimetric analysis - Unsaturated fatty acids - Viscosity - Viscosity of liquids
Uncontrolled terms:Catalytic transfer hydrogenation - Combustion characteristics - Combustion performance - Differential scanning calorimeters - Gas chromatography-mass spectrometries (GC-MS) - High unsaturated fatty acid - Hydrogenation reactions - Unsaturated double bonds
Classification code:523 Liquid Fuels - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 944.5 Temperature Measuring Instruments - 944.6 Temperature Measurements
Numerical data indexing:Percentage 1.30e+01%, Percentage 3.78e+01%, Percentage 4.62e+01%, Percentage 7.09e+01%, Rotational_Speed 6.00e+02RPM, Time 6.00e+03s
DOI:10.11975/j.issn.1002-6819.2017.11.007
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 5>
Accession number:20173304046241
Title:Design and experiment of continuous single grain typed on-line grain moisture test apparatus
Authors:Wu, Huichang (1); Xie, Huanxiong (1); Hu, Zhichao (1); Gu, Fengwei (1); You, Zhaoyan (1); Yan, Jianchun (1); Wei, Hai (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing; 210014, China
Corresponding author:Hu, Zhichao(nfzhongzi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:282-290
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Grain drying operation is an important part of food safe storage. In recent years, many scholars and engineers have done a lot of work on grain drying technology aiming to reduce energy consumption and realize automatic control of drying devices, but online moisture accurate detection in the grain drying that is core technique is still application difficulty to be solved, which restricts the development of grain drying system. Based on the analysis of the advantages and disadvantages of the technical principle of current online grain moisture meters, this paper presented a continuous single grain online moisture meter based on the water detection principle of resistance method. Physical dimensions of main varieties in main paddy, wheat and barley producing areas in China were measured, statistics of grain equivalent diameter were made, and pitch diameter and helix angle of stainless-steel incongruous sine screw rod were calculated by applying static sliding friction angle between single grain and metal surface. Therefore, the grain sampling device of moisture tester was designed, which was composed of a double-screw rod and a split grain knife. The grain sampling device screened out sundries and excess grain, and ensured single grain and continuity at the same time when sampling. According to the results of the experiment and simulation, 3 kinds of knurling forms with 0.4 mm modulus were chosen, including straight lines, oblique lines and net-mesh lines, and net-mesh lines had the optimal rolling smoothness among them, followed by straight lines knurling and oblique lines knurling. Considering the removal effect of adhesion on roller, the brushing effect of oblique lines knurling was the best, so the roller surface chose oblique lines form. Yangjing 239, Huaimai 33, and Yangnongpi 4 were chosen respectively as the test samples of paddy, wheat and barley, prepared as multiple samples with different moisture content. Meanwhile, when 105℃ drying method was adopted to test moisture content of each sample in the laboratory, the direct-current (DC) resistance of single grain with different moisture content compacted by the roller was measured by using universal electronic testing machine, programmable DC power supply with high precision, digital multimeter and other equipment; the steady resistance value was taken when the distance between the 2 rollers was 0.4 mm, and average resistance value was obtained after testing 100 samples for the samples with the same moisture content. Regression curves between the grain moisture content and single grain resistance of paddy, wheat and barley were built according to the experimental data. The calculation function expression of grain moisture content was obtained through polynomial regression on curve. Multiplex proportional circuit was designed, providing possibility to solve precise detection of extremely wide resistance of specific volume ranging from 10<sup>-2</sup>to 10<sup>10</sup>Ω·cm. Second order voltage-controlled active low-pass filter based on four-channel amplifier AD8643, and 50 Hz band-stop filter circuit consisting of operational amplifier LM358 were designed to meet the electromagnetic compatibility requirements for on-line grain moisture tester detection. Hardware and software platforms of ARM CortexTM-M3 core's low power 32-bit microprocessor STM32L151CBQ6 were applied to finish both the sampling of grain moisture and the design of processing program. Online detection comparison tests on site showed that, when the drying temperature ranged from -5 to 55℃ and the moisture content ranged from 10% to 35% for paddy, wheat and barley, the online moisture measurement accuracy of the tester was less than ±0.5%, which satisfied online moisture detection requirements for the drying of the 3 kinds of grains. The design method can provide a reference for the online detection of water in the drying process of grain. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Grain (agricultural product)
Controlled terms:Automation - Design - Digital storage - Drying - Electric power supplies to apparatus - Electric power systems - Electric resistance - Electronic equipment testing - Energy utilization - Food storage - Low pass filters - Low temperature drying - Mesh generation - Moisture - Moisture determination - Moisture meters - Notch filters - Operational amplifiers - Rollers (machine components) - Sampling - Screws - Stainless steel - Thermal processing (foods)
Uncontrolled terms:Active low-pass filters - Different moisture contents - Grain moisture content - Grain moisture testers - Hardware and software - Low Power - Reduce energy consumption - Single grains
Classification code:525.3 Energy Utilization - 545.3 Steel - 601.2 Machine Components - 605 Small Tools and Hardware - 701.1 Electricity: Basic Concepts and Phenomena - 703.2 Electric Filters - 706.1 Electric Power Systems - 713.1 Amplifiers - 722.1 Data Storage, Equipment and Techniques - 723.5 Computer Applications - 731 Automatic Control Principles and Applications - 802.3 Chemical Operations - 821.4 Agricultural Products - 822.1 Food Products Plants and Equipment - 822.2 Food Processing Operations - 944.1 Moisture Measuring Instruments - 944.2 Moisture Measurements
Numerical data indexing:Frequency 5.00e+01Hz, Percentage 1.00e+01% to 3.50e+01%, Size 4.00e-04m
DOI:10.11975/j.issn.1002-6819.2017.11.036
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 6>
Accession number:20173304046235
Title:Influences of different technological strategies on performance of anaerobic co-digestion of pig manure with straw in solid-state
Authors:Song, Xiangyu (1); Zhang, Keqiang (1); Fang, Fang (2); Kong, Dewang (1, 3); Liang, Junfeng (1); Du, Lianzhu (1)
Author affiliation:(1) Agro-environmental Protection Institute, Ministry of Agriculture, Tianjin; 300191, China; (2) Tianjin Huankeyuan Environmental Science and Technology Ltd, Tianjin; 300191, China; (3) College of Land and Environment, Shenyang Agricultural University, Shenyang; 110866, China
Corresponding author:Du, Lianzhu(dulianzhu99@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:233-239
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Solid-state anaerobic digestion has advantages of water conversation, convenient management and low energy consumption in winter. After the digestion, substrate contains low water and can be easily treated, thereby achieving zero emission. Under the condition of increasingly scarce water resource in the world, this technology conforms to the demand of resource utilization and water conversation. However, the process of solid-state anaerobic digestion was very complex and the solid-state anaerobic digestion of pig manure could easily lead to serious accumulation of volatile fatty acids (VFAs), which was the main inhibiting factor in solid-state anaerobic digestion of pig manure. Due to the low water content, the reaction of solid-state anaerobic digestion could not proceed normally, or even be ceased. Several measures could be used to minimize the accumulation of VFAs. Leachate recycling was one way to accelerate mass transfer rate, and proper recirculation rate could optimize the digestion process and improve the quantity and quality of biogas. Stratified inoculation was an alternative method for solid-state anaerobic digestion, in which inoculum was separated with substrate layer by layer. The reaction hypothesis suggests that stratified inoculation could be used to decrease accumulation of VFAs, however, only a few studies had investigated its effect to decrease VFAs accumulation. This study was mesophilic batch fermentation under the same temperature (37℃) and water content (80%) condition. To investigate the most efficient treatment of starting the fermentation and the variations of methane production and VFAs, co-digestions of pig manure with maize straw, leachate recycling and stratified inoculation were carried out with the solid-state anaerobic digestion of pig manure as control. Ammonia nitrogen content and soluble chemistry oxygen demand were analyzed. The performances of VFAs production and methane production in the treatments of co-digestion with dried maize straw, leachate recycling, and stratified inoculation in solid-state anaerobic digestion of pig manure were compared. The results were as follows: The performances in stratified inoculation reactors were the best, characterized by no lag time, the highest methane yield of 9.4 mL/(g·d) and the highest cumulative methane yield of 139.2 mL/g; leachate recycling could retain TVFAs at a low level of around 0.66 mg/g, and its cumulative methane yield was 16.7% lower than the stratified inoculation treatment; the concentration of TVFAs in the co-digestion and mono pig manure digestion reactors reached 19.08 and 19.83 mg/g, respectively, and methane yield was less than 0.1 mL/(g·d) in the first 15 days in both reactors. The most efficient treatment with the highest methane production and the quickest initiating can be obtained by contrasting different treatments, which thereby provides the reference for environmental disposal and utilization of the wastes with high solid and high organic matter content. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Anaerobic digestion
Controlled terms:Chemical analysis - Energy utilization - Fatty acids - Fermentation - Fertilizers - Leachate treatment - Manures - Mass transfer - Methane - Radioactive waste disposal - Recycling - Straw - Volatile fatty acids - Waste disposal - Waste utilization - Water resources
Uncontrolled terms:Anaerobic co-digestion - Different treatments - Leachate recycling - Low energy consumption - Resource utilizations - Solid-state anaerobic digestions - VFAs - Volatile fatty acids (VFAs)
Classification code:444 Water Resources - 452.3 Industrial Wastes - 452.4 Industrial Wastes Treatment and Disposal - 525.3 Energy Utilization - 622.5 Radioactive Wastes - 641.3 Mass Transfer - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.5 Agricultural Wastes
Numerical data indexing:Age 4.11e-02yr, Percentage 1.67e+01%, Percentage 8.00e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.030
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 7>
Accession number:20173304046216
Title:Design and experiment of high precision forest resource investigation system based on UAV remote sensing images
Authors:Shi, Jieqing (1); Feng, Zhongke (1); Liu, Jincheng (1)
Author affiliation:(1) Precision Forestry Key Laboratory of Beijing, Beijing Forestry University, Beijing; 100083, China
Corresponding author:Feng, Zhongke(fengzhongke@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:82-90
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For the sustainable development and the accurate monitoring and information-based management of forestry resources, in this paper, we constructed a forest resource inventory system for forestry investigation and management. This research was based on the unmanned aerial vehicle (UAV) images data with the help of photogrammetric technique, UAV image post-processing technology and geographic information system technology, etc. In the system, we used C# programming language and fully used ArcGIS Engine10.2 embedded component technology. We also used UAV images to achieve efficient functions, such as forest spatial division, area adjustment and forest sub-compartment investigation, vegetation information extraction in high-precision and large-scale. The system can timely update resource database, greatly shorten the traditional investigation period, and achieve the scientific management of forest resources. The extraction of landform factors by software is based on UAV image data, DEM data, and spatial data from spatial division. It can be divided into two steps. The first is to extract the topographical attributes among the UAV image of whole area; the second is to ultimately extract landform factors combined with spatial data to finish attribute tables of each division, which is based on the first step. The goal of the stand factor extraction module is to obtain and store the vegetation information such as sub-compartment volume, stand density, average crown diameter, average tree height, average DBH and canopy coverage. Due to the difficulties for UAV to extract canopy coverage information in the dense forest area, in the study, we divided stand factor extraction module into the sparse forest area and the dense forest area. In the dense forest area, canopy coverage information of each sub-compartment was manually interpreted with the help of pattern spot border, and the input data were directly stored in its corresponding attribute database. In the sparse forest area, based on UAV images and spatial data, the system allowed its users to circle a nearly round sample area within the sub-compartment border, collect information of each single tree in the circle, automatically store the statistical results of all sample information into the corresponding sub-compartment, namely its vegetation information. The empirical study of this forest resource investigation system has been conducted in Lao Tudingzi, Liaoning Province. The results have proven its simple interface, high automation and good interactivity on system operation. The relative error in extraction of slope and elevation were about 5.17% and 5.41% respectively. Before the stand factors were acquired, the relationship between crown diameter and DBH and the relationship between tree height and DBH in test area were fitted by 1stOpt software, then the evaluation indexes, such as coefficient of determination, standard error estimate and total relative error, were introduced to determine the optimal model. The stand factors of the test area have been extracted based on the optimal model with the statistical value of stand density and sub-compartment volume measurement. The results showed the relative error of stand density is 2.68%, and that of sub-compartment volume is 4.01%. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Information management
Controlled terms:Data mining - Errors - Forestry - Geographic information systems - Image processing - Image reconstruction - Landforms - Natural resources - Photogrammetry - Remote sensing - Software testing - Timber - Unmanned aerial vehicles (UAV) - Vegetation
Uncontrolled terms:Coefficient of determination - Component technologies - Forest resource inventory - Forest resources - Images - Photogrammetric technique - Post-processing technologies - Vegetation information extraction
Classification code:405.3 Surveying - 481.1 Geology - 652.1 Aircraft, General - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 903.3 Information Retrieval and Use
Numerical data indexing:Percentage 2.68e+00%, Percentage 4.01e+00%, Percentage 5.17e+00%, Percentage 5.41e+00%
DOI:10.11975/j.issn.1002-6819.2017.11.011
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 8>
Accession number:20173304046227
Title:Algorithm and realization for cattle face contour extraction based on computer vision
Authors:Cai, Cheng (1); Song, Xiaoxiao (1); He, Jinrong (1)
Author affiliation:(1) College of Engineering Information Engineering, Northwest A&F University, Yangling; 712100, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:171-177
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Since cattle facial information is very rich, ranging from skin color, chewing conditions to health status, it is of great importance for cattle disease monitoring. This paper proposed a scheme on cattle facial automatic extraction to cope with the problems caused by different camera angles, varied illumination and partial occlusion. Three classical human facial contour extraction algorithms were employed in the study: Supervised descent method (SDM), local binary features (LBF) and fast active appearance model (FAAM). For contour extraction performance evaluation, 800 cattle facial images were collected from a cattle farm at Northwest A&F University. For each cattle face, 29 facial feature points were manually labeled. In order to cope with cattle face scale and rotation, all the labeled facial feature points were aligned to a normalized model. Compared with human face, cattle face height-width ratio was much larger. Based on the characteristics of cattle face, this study used the AdaBoost detector to train cattle face detector. Because cattle face was rather long, we cut the image to the size of 15×25 pixels. And the background was a negative sample with the same size. The detection rate of the cattle face detector for 800 cattle face images was 96%. Considering the characteristics of cattle face, we improved the algorithms and optimized our parameters. Also because of the long face, a split model was used to initialize the cattle face model. The first part included an eye contour with cheeks on both sides, and the second part included the nose and mouth contour. The results showed that the accuracy of the contour extraction was improved significantly. We then analyzed and compared the time efficiency and the accuracy of the 3 algorithms. Finally, the performance of each method was evaluated by the Euclidean errors normalized by the left and right corners of the eyes and their corresponding computational time costs. The average computational costs of the 3 contour information extraction methods were 1.75, 0.35, and 60.62 s respectively. The average pairwise Euclidean errors normalized by the left and right corners of the eyes were 0.018 8, 0.024 5, and 0.018 4 pixel. The experiment verified the feasibility and practicability of the facial contour extraction methods. Results showed that the FAAM algorithm achieved the highest accuracy with the minimal alignment errors while the LBF algorithm was the most efficient. Therefore, in the process of facial contour extraction, we can choose proper algorithm in varied situation which requires different accuracy and efficiency. The contour extraction algorithm can effectively extract cattle facial contour information, which provides a theoretical basis for the further analysis of cattle facial expressions. As this is the first time that the contour extraction algorithm is applied to cattle face analysis, the present study serves as a good guide for other researches, which provides feasible data for computer vision based cattle disease analysis and a comprehensive guideline on cattle facial analysis under different circumstances in intelligent farm. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Image processing
Controlled terms:Adaptive boosting - Algorithms - Computer vision - Data mining - Efficiency - Errors - Models - Pixels
Uncontrolled terms:Active appearance models - Automatic extraction - Cattle face - Computational costs - Contour Extraction - Contour information - Facial feature points - Image features
Classification code:723 Computer Software, Data Handling and Applications - 913.1 Production Engineering
Numerical data indexing:Percentage 9.60e+01%, Time 6.06e+01s
DOI:10.11975/j.issn.1002-6819.2017.11.022
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 9>
Accession number:20173304046219
Title:Inversion and verification of salinity soil moisture using microwave radar
Authors:Wang, Xue (1); Liu, Quanming (1); Qu, Zhongyi (1); Wang, Liping (1); Li, Xiangjun (1); Wang, Yaoqiang (1)
Author affiliation:(1) Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot; 010018, China
Corresponding author:Liu, Quanming(nndlqm@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:108-114
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil dielectric constant is the physical basis for soil moisture simulation based on microwave remote sensing, and especially the real part of the dielectric constant is of great significance to the research of the soil dielectric characteristics. Main aim of this study was to investigate capability of C-band RADARSAT-2 SAR (synthetic aperture radar) data applied in the soil dielectric characteristics monitoring and the soil moisture inversion over agricultural fields. Bare area of Jiefangzha sub-district of Hetao Irrigation District in Inner Mongolia of China was selected as the study region, which was influenced by soil salinization seriously. In order to achieve above purposes, an image of Radarsat-2 SAR was bought in April 2016, which has a kind of four fine polarization SLC (single look complex) format, covering an area of 25 km × 25 km with 8 meter ground resolution. Taking spatial uneven distribution of the saline soil into account, 100 sampling points were designed in the study area, and soil digging depth was 10 cm. Hand-held GPS (global positioning system) receiver was used to record coordinates of the sampling points. The experiment data included the soil dielectric real constant, surface roughness, surface temperature, percentages of clay and sand particles, soil bulk density and soil moisture. Agilent microwave network analyzer was used to measure the real part value of soil dielectric constant with coaxial probe method. Surface roughness was measured using centimeter grid profile plate to calculate the value of RMS (root mean square) height and the correlation length, and then composite roughness was got to represent the surface roughness in later research. Real-time ground temperature of the sampling points was measured by geothermometer. Particle analysis was fulfilled with laser particle size analyzer named Helos/B, obtaining the percentage content of clay and sand particles. Soil bulk density was measured by ring cutter. Soil moisture was measured by way of drying. SAR scape module of ENVI software was mainly used to perform the radar image processing, including radiometric calibration, geometric correction, slant range turning and filtering. Four polarization back scatter coefficient values corresponding to the sampling points were extracted based on previous results by spatial analysis module of ArcGIS software. In order to analyze complex relationship between the real part of the dielectric constant with SAR four polarization back scattering coefficients and surface roughness, firstly Oh empirical model was established, for which the relative relationship was significant between simulated and measured soil moisture, and the value of R<sup>2</sup>was 0.8209. Results showed that Oh model can offer precise real part value of the dielectric constant to inverse the soil moisture based on the soil dielectric model by means of the remote sensing and surface roughness data. Then Dobson semi-empirical dielectric models and simplified Hallikainen real part experience model were verified, and the R<sup>2</sup>between the measured and simulated real part values was 0.935 9 and 0.869 respectively, which indicated that the 2 models can simulate close relationship of the surface soil moisture and the real part of the dielectric constant. Finally Dobson model and Hallikainen simplified real part soil moisture inversion model were constructed. Compared with the statistical regression model, it looked like that relative relationship between simulated and measured value was significant, and the value of R<sup>2</sup>was 0.803 8, 0.737 4, and 0.842 1, respectively, for the former 2 models and the statistical regression model, the RMSE (root mean square error) value was 5.2%, 5.7%, and 5% respectively. The inversion results of Dobson model and statistical regression model were similar with the field soil moisture distribution, so they had good precision and applicability. Without considering the surface roughness, the simulation result of Hallikainen simplified real part model was then slightly worse than the other 2 models. The soil dielectric characteristics researching system and the moisture retrieval models established in this study can promote the application of the microwave remote sensing in the soil moisture monitoring. © 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:Backscattering - Complex networks - Dielectric properties - Global positioning system - Image processing - Instrument scales - Mean square error - Microwaves - Models - Moisture - Moisture control - Particle size - Particle size analysis - Polarization - Radar - Radar imaging - Radar signal processing - Regression analysis - Remote sensing - Soil moisture - Soils - Surface roughness - Synthetic aperture radar
Uncontrolled terms:Hetao irrigation districts - Laser particle size analyzer - Real part - RMSE (root mean square error) - Salinization - SAR(synthetic aperture radar) - Soil dielectric properties - Statistical regression model
Classification code:483.1 Soils and Soil Mechanics - 711 Electromagnetic Waves - 716.2 Radar Systems and Equipment - 722 Computer Systems and Equipment - 731.3 Specific Variables Control - 922.2 Mathematical Statistics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Percentage 5.00e+00%, Percentage 5.20e+00%, Percentage 5.70e+00%, Size 1.00e-01m, Size 2.50e+04m, Size 8.00e+00m
DOI:10.11975/j.issn.1002-6819.2017.11.014
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 10>
Accession number:20173304046244
Title:Discussion on method of nonlinear fitting dry and wet edges of LST/ NDVI feature space better than traditional linear fitting method
Authors:Wang, Xinghan (1, 2, 3); Cong, Peitong (1); Kang, Qing (2); Fu, Qinghua (2); Liu, Chaoqun (2); Wang, Xiaogang (2)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, South China Agriculture University, Guangzhou; 510610, China; (2) Pearl River Institute of Hydraulic Research, Pearl River Water Resources Commission, Ministry of Water Resources, Guangzhou; 510611, China; (3) Key Laboratory of the Pearl River Estuarine Dynamics and Associated Process Regulation, Ministry of Water Resources, Guangzhou; 510611, China
Corresponding author:Cong, Peitong(congpeitong@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:306-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land surface temperature / vegetation index feature space has important applications in quantitative retrieval of water content in soil and crop evapotranspiration. However, at present, the research on the fitting of the dry and wet edges of the land surface temperature/vegetation index feature space was relatively lacking. In the tradition, for dry edge of the model, a simple linear negative correlation was adopted to fit the parameters, and wet edge was considered as a simplified treatment parallel to the coordinate axis. Whether it is appropriate is the focus of this paper that needs to be discussed. The study area was located in Oklahoma, the United States. Based on Landsat TM5 image data, land surface temperature (LST) and normalized difference vegetation index (NDVI) were calculated, and LST was calculated by radiation equation model and NDVI by pixel dichotomy model. And the fitting of dry edges and wet edges of LST/NDVI feature space was carried out with different functions, which included linear function, exponential function, logarithm function, power function and polynomial function. All of them were used to fit dry edges and wet edges respectively, and the results were evaluated by the measured data of water content in soil. The results showed that for the fitting of 5 different functions, r<sup>2</sup>value as a whole was between 0.4 and 0.7, and there were some differences in the fitting precision between different fitting methods. For the fitting of dry edges, r<sup>2</sup>value of exponential function fitting was 0.64, r<sup>2</sup>value of linear function fitting was 0.60, r<sup>2</sup>value of logarithm function fitting was 0.41, r<sup>2</sup>value of power function fitting was 0.43, and r<sup>2</sup>value of polynomial function fitting was 0.67 which was the best fitting way for dry edges. For the fitting of wet edges, r<sup>2</sup>value of exponential function fitting was 0.59, r<sup>2</sup>value of linear function fitting was 0.63, r<sup>2</sup>value of logarithm function fitting was 0.67, r<sup>2</sup>value of power function fitting was 0.69, and r<sup>2</sup>value of polynomial function fitting was 0.70 which was the best fitting way for wet edges. For the fitting of dry edges and wet edges, polynomial function was the best method. And the results of 5 kinds of function fitting were compared with those from the soil moisture stations in the study area. Root mean square error (RMSE) and mean absolute error (MAE) were calculated, and 5, 25 and 60 cm depth were selected. In the 3 different depths, RMSE and MAE of polynomial function were the smallest. RMSE at 5 cm depth was 0.29, RMSE at 25 cm depth was 0.27, and RMSE at 60 cm depth was 0.28; MAE at 5 cm depth was 0.26, MAE at 25 cm depth was 0.23, and MAE at 60 cm depth was 0.25. The results indicated that the LST/NDVI feature space inversion based on dry edges and wet edges fitting with the polynomial function was the most accurate for the soil surface water content in this study area, and it was most sensitive to water content at 25 cm depth in soil. For an optimal fitting, it must be an optimal solution between fitting accuracy and fitting efficiency. In the process of this study, only small amount of data were involved, so the main consideration was the accuracy of dry edges and wet edges fitting, not taking into account the time cost of computer computing process. But for the large amount of data operations in the actual application process, the time efficiency still needs to be considered. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Exponential functions
Controlled terms:Atmospheric temperature - Efficiency - Functions - Mean square error - Moisture - Polynomials - Soil moisture - Soils - Surface measurement - Surface properties - Surface waters - Temperature - Vegetation
Uncontrolled terms:Crop evapotranspiration - Feature space - Land surface temperature - Normalized difference vegetation index - Polynomial functions - Root mean square errors - Water content in soil - Wet edge
Classification code:443.1 Atmospheric Properties - 444.1 Surface Water - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 913.1 Production Engineering - 921 Mathematics - 921.1 Algebra - 922.2 Mathematical Statistics - 943.2 Mechanical Variables Measurements - 951 Materials Science
Numerical data indexing:Size 2.50e-01m, Size 5.00e-02m, Size 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.11.039
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 11>
Accession number:20173304046223
Title:Wind tunnels test on anti-wind erosion effect of conservation tillage farmland and caragana collocated with grassland in strip
Authors:Sun, Yuechao (1); Ma, Shuoshi (2); Chen, Zhi (2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Lingnan Normal University, Zhanjiang; 524048, China; (2) College of Mechanical and Electrical Engineering, Inner Mongolia Agricultural University, Hohhot; 010018, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:140-146
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to analyze the anti-wind erosion mechanism and anti-wind erosion effect of the protective tillage farmland and the strip arrangement of Caragana to restore deteriorated grassland, the mobile erosion wind tunnel and related supporting equipment are used to conduct the field in-situ test of wind tunnel of the protective tillage, the traditional dry farmland, the degraded grassland, and the grassland with the strip arrangement of Caragana in the cold and dry area of Ulanqab, Inner Mongolia. In the test, the wind speed profiles near surface, sediment transport fluxes and wind sand flow structure are studied, and the windbreaks of farmland and Caragana korshinskii in grassland are analyzed and compared. The results show that the wind speed from the protective tillage farmland and the grassland with Caragana banded configuration of 30 cm height is significantly lower than their corresponding traditional tillage farmland and degraded grassland in the same wind speed of wind tunnel center. And the corresponding sediment transport flux also decreases. The sand flux of the protective tillage and strip-shaped arrangement of Caragana to restore grassland presents a C-shaped distribution with the changes in surface height, which is different from the rapid exponential decline in the sand flux of traditional farmland and degraded grassland with the increase of surface height. In the same wind speed of wind tunnel center, the wind speed of the restoration belt of Caragana is higher than that of the corresponding protective tillage farmland at the same height above the ground surface. Then the largest sediment transport flux of the grassland with Caragana belt appears at the height of 30 cm above the ground surface, and the maximum sediment transport flux occurs at 25 cm above the ground surface for the protective tillage farmland. The anti-wind erosion mechanism of conservation tillage farmland and Caragana microphylla grassland mainly is that the vertical stubble of the protective tillage farmland and the Caragana belt of the degraded grassland can block, decompose and evacuate the wind speed near the surface, so that the wind speed near the ground surface is weakened in different degrees. When the wind speed of the wind tunnel is 11 m/s, compared with the traditional tillage, the protective tillage has a wind speed reduction rate of 86.44% at 50 mm above the surface, while the grassland with the strip arrangement of Caragana has a wind speed reduction rate of 70.69% compared with the degraded grassland. The reduction of wind speed near the ground surface is the fundamental cause of the effective prevention and control of soil wind erosion in the farmland with protective tillage and the grassland with strip arrangement of Caragana. For the conservation tillage farmland and the grassland with Caragana belts, the aeolian sand flow is mainly concentrated on the height less than 40 cm above the ground surface, accounting for about 90% of the total sediment discharge, while for the traditional cultivated farmland and the degraded grassland, the aeolian sand flow is mainly below 20 cm, which accounts for more than 85% of the total sediment discharge. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Farms
Controlled terms:Agricultural machinery - Agriculture - Conservation - Cultivation - Erosion - Restoration - Sand - Sediment transport - Sedimentation - Sediments - Soil conservation - Soil testing - Speed - Wind - Wind tunnels
Uncontrolled terms:Caragana Korshinskii - Conservation tillage - Land degradation - Prevention and controls - Shrub grass strip - Transportation flux - Wind erosions - Wind-sand flow structures
Classification code:443.1 Atmospheric Properties - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 651.2 Wind Tunnels - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Size 4.00e-01m, Size 5.00e-02m, Velocity 1.10e+01m/s, Percentage 7.07e+01%, Percentage 8.50e+01%, Percentage 8.64e+01%, Percentage 9.00e+01%, Size 2.00e-01m, Size 2.50e-01m, Size 3.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.11.018
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 12>
Accession number:20173304046220
Title:Effect of tillage depth on soil physical properties and yield of winter wheat-summer maize
Authors:Zhai, Zhen (1); Li, Yuyi (1); Guo, Jianjun (2); Wang, Jing (1); Dong, Guohao (2); Guo, Zhihui (2); Pang, Huancheng (1)
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing; 100081, China; (2) Dezhou Academy of Agricultural Sciences, Dezhou; 253000, China
Corresponding author:Pang, Huancheng(panghuancheng@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:115-123
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Given the common problem of plow pan which affects the growth of crops in Huang-Huai-Hai Plain (HHHP), agronomists are calling for a management practice to ameliorate plow pan. Little information is currently available on the effects of breaking the plow pan partially or thoroughly on the soil water content, penetration resistance and crop growth in HHHP. In order to better understand the effect of plow pan on soil water retention and crop yield, 4 treatments were conducted including the original plow pan (RT15), breaking the plow pan by 1/3 of thickness (DL20), breaking the plow pan by 2/3 of thickness (DL25) and breaking the plow pan thoroughly (DL40) in the HHHP, aiming to explore the effect of different thickness of plow pan on soil water characteristics, the dynamics of penetration resistance and crop yield. The result showed that breaking the plow pan could reduce the bulk density and penetration resistance for 10-30 cm soil layer significantly, with a trend of DL40 < DL25 < DL20 < RT15. Breaking plow pan could increase water infiltration after irrigation or rainfall, and the average soil water content of 20-70 cm soil layer increased by 5.3%-23.6% and 7.7%-15.8% compared with RT15 treatment at seedling stage of summer maize and winter wheat separately. Because of uneven seasonal distribution of precipitation in HHHP, breaking the plow pan was beneficial for winter wheat to make full use of soil water in the deep soil layers, and could reduce the ineffective dissipation of soil water by promoting the water storage during summer maize season. The water consumption of DL20, DL25 and DL40 treatment increased by 4.9%, 10.2% and 11.6% separately compared with RT15 during winter wheat season, however, the water consumption of DL20, DL25 and DL40 treatment decreased by 5.8%, 7.6% and 10.5% respectively compared with RT15 during summer maize season. Because of the influence of temperature, soil water content, tillage practice and crop growth, the dynamic changes of penetration resistance under different topsoil structures were different from each other. The dynamic changes of penetration resistance of 0-15 and 15-30 cm during winter wheat season were similar with that of 0-15 and 15-30 cm during summer maize season. However, the penetration resistances of 30-45 cm under different treatments at the late growth stage of winter wheat and summer maize were different from each other. The penetration resistance of 30-45 cm under different treatments at the late growth stage of winter wheat was manifested as DL40 > DL25 > DL20 > RT15, while that of summer maize was DL40 < DL25 < DL20 < RT15. Compared with traditional topsoil structure, breaking plow pan could improve water use efficiency, and eventually promoted crop yield. However, the highest yields of winter wheat and summer maize were found at DL25, and the crop yield of the treatment with plow pan broken thoroughly (DL40) was relatively lower. Considering the yield of winter wheat and summer maize under DL40 treatment decreased by 4.2% and 2.4% respectively compared to DL25, the relatively better way to transform the plow pan without consuming much energy was DL25 which not only possessed permeable performance, but also could promote the crop yield. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soils
Controlled terms:Agricultural machinery - Agriculture - Crops - Soil moisture - Water content - Water supply
Uncontrolled terms:Different treatments - Penetration resistances - Plow pan - Seasonal distributions - Soil bulk density - Soil physical property - Soil water characteristics - Water use efficiency
Classification code:446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.02e+01%, Percentage 1.05e+01%, Percentage 1.16e+01%, Percentage 2.40e+00%, Percentage 4.20e+00%, Percentage 4.90e+00%, Percentage 5.30e+00% to 2.36e+01%, Percentage 5.80e+00%, Percentage 7.60e+00%, Percentage 7.70e+00% to 1.58e+01%, Size 1.00e-01m to 3.00e-01m, Size 1.50e-01m to 3.00e-01m, Size 2.00e-01m to 7.00e-01m, Size 3.00e-01m to 4.50e-01m
DOI:10.11975/j.issn.1002-6819.2017.11.015
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 13>
Accession number:20173304046215
Title:Prediction of vibration response for pipeline of cascade pumping station based on PSO-SVM algorithm
Authors:Zhang, Jianwei (1); Jiang, Qi (1); Liu, Xuanran (1); Ma, Xiaojun (1)
Author affiliation:(1) College of Water Conservancy, North China University of Water Conservancy and Electric Power, Zhengzhou; 450011, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:75-81
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pipeline is a carrier of cascade pumping station with long distance water conveyance. Therefore, it is particularly important to keep the stable operation of pipeline structure. Because of the complexity and diversity of pipeline structure, it is difficult to measure vibration response signal of pipeline of pumping station. In order to minimize risks and ensure safe operation of pipeline, it is significant to search for some methods that use fewer unit monitoring data to forecast pipeline vibration state. Support vector machine (SVM) was designed as the core for the proposed prediction model considering its advantages in solving the small sample size, nonlinear and high dimensional pattern recognition, and so on. For the purpose of the improvement of data utilization efficiency, particle swarm optimization (PSO) algorithm was applied because of its advantage of special memory function. Combining advantages of PSO algorithm and SVM, a PSO-SVM prediction model was proposed in this paper. Global search tracking algorithm of PSO was used to optimize the kernel functions and penalty factors of SVM, which weakened the problem of low accuracy of prediction caused by SVM parameters optimization deficiency. The No.2 pipeline of Pumping Station 3 in Jindian River pumping irrigation was selected as the research object, which was connected with No.4 and No.5 units, and 3 points were set up at the top of the volute of the unit and on both sides of the tail of the volute respectively for these 2 units. First of all, based on the vibration monitoring data of units and pipeline, with the mathematical statistics theory and spectrum analysis, the dominant frequencies of pipeline structure were counted and the contribution rates of vibration sources were determined for pipeline vibration. At the same time, correlation coefficients of vibration between unit and pipeline were calculated. Except No.3 measuring point, the correlation coefficients of the other 5 measuring points were greater than 0.57, of which the correlation coefficients of No.1 and No.6 measuring points were relatively large. Strong coupling relationship between units and pipeline was determined. Selecting the unit monitoring vibration data in the different periods as input factors, and the pipeline vibration response data of vibration sensors #1, #2, #16 and #17 during corresponding periods as output factors, the PSO-SVM prediction model of pump station was established. In order to compare prediction accuracy, back propagation (BP) neural network was established with the same data for training and test. The results showed that the PSO-SVM prediction result coincided highly with actually measured data, and BP neural network only reflected the trend of pipeline vibration response. PSO-SVM prediction model had a fairly high promotion in prediction compared to BP neural network. Aiming to quantitatively compare 2 methods, mean relative error (MRE) and root mean square error (RMSE) were introduced as the evaluation indices. The maximum values of MRE and RMSE for PSO-SVM were 6.8% and 0.261, respectively, much lower than BP neural network. The research shows that, in this test condition, when the correlation coefficient between unit and pipeline is above 0.67, this proposed method can realize effectively vibration prediction of pipeline, which has stronger generalization ability so as to achieve the purpose of pipeline safe operation and online monitoring. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Vibration analysis
Controlled terms:Backpropagation - Couplings - Forecasting - Mean square error - Monitoring - Neural networks - Optimization - Particle swarm optimization (PSO) - Pattern recognition - Pipelines - Pumping plants - Pumps - Spectrum analysis - Statistics - Support vector machines - Vibration measurement
Uncontrolled terms:Back propagation neural networks - Correlation coefficient - Generalization ability - Parameters optimization - Particle swarm - Particle swarm optimization algorithm - Root mean square errors - Vibrations
Classification code:446 Waterworks - 618.2 Pumps - 619.1 Pipe, Piping and Pipelines - 723 Computer Software, Data Handling and Applications - 723.4 Artificial Intelligence - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 943.2 Mechanical Variables Measurements
Numerical data indexing:Percentage 6.80e+00%
DOI:10.11975/j.issn.1002-6819.2017.11.010
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 14>
Accession number:20173304046231
Title:Agricultural eco-environment efficiency and shadow price measurement in Three Gorges Reservoir area under non-point source pollution constraints
Authors:Li, Nanjie (1, 2); Xiao, Xincheng (3); Cao, Guoyong (3); He, Binghui (1)
Author affiliation:(1) College of Resources and Environment, Southwest University, Chongqing; 400715, China; (2) Chongqing Engineering Technology Research Center for Information Management in Development, Chongqing Technology and Business University, Chongqing; 400067, China; (3) School of Economics and Management, Yichun University, Yichun; 336000, China
Corresponding author:He, Binghui(hebinghui@swu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:203-210
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The modernization process of agriculture has led to serious agricultural non-point source pollution. It is a new direction to study the evaluation framework of agricultural production efficiency by including the ecological environment effect of agriculture. Agricultural eco-environmental efficiency which combines both economic and ecological performance is a valid way for agricultural sustainability analysis. Based on the non-radial and non-angle SBM-DEA model and the directional distance function, the agricultural eco-environmental efficiency of the Three Gorges Reservoir area in Chongqing during the period from 2003 to 2015 was investigated. The marginal price of agricultural non-point source pollution was estimated by introducing the shadow price cost of emission reduction. The results showed that: 1) During the period of 2006 to 2015, the agro-ecological environment efficiency of the Three Gorges Reservoir area in Chongqing tended to increase steadily, but the overall level was low;2) The input and output of each district (county) were needed to change to optimize the efficiency of agro-ecological environment. The areas with high agro-ecological environment were concentrated in the urban core area and the urban fringe of the reservoir, while the eco-environmental efficiency of the low mountain and hill area, parallel ridge valley area, mountainous area in the hinterland and surrounding mountain area in the hinterland were relatively low; 3) From the reasons of the efficiency loss, the excessive use of chemical fertilizers and pesticides and their corresponding adverse ecological and environmental effects were outstanding, mainly due to the inefficiency of agricultural investment and the inefficiency of undesired output; 4) The shadow prices of agricultural non-point source pollution in Dadukou, Nan'an, Jiangbei, Beibei and Yubei area were at the forefront, and the pollution abatement space was small, therefor, the task of reducing agricultural non-point source pollution should be commissioned. Fengdu, Kaixian and Wanxian district's shadow prices of agricultural non-point source pollution emission were low, thus those three areas should be assigned to agricultural non-point source pollution reduction. Chongqing section of Three Gorges Reservoir Area had an enormous potential for reduction of agricultural non-point source pollution and for the decrease of resource inputs to enhance the agricultural eco-environmental efficiency. Agricultural eco-environmental efficiency evaluation plays an important role in promoting agriculture ecological and sustainable development. The eco-environmental efficiency optimization provides further implications on resource and environmental protection strategies in Chongqing section of Three Gorges Reservoir Area. Meanwhile, we should evaluate agricultural eco-environmental efficiency according to resources endowment, factor substitution, adverse impact on ecology and environment and consider the regional development and different stages, we should promote differently the development of ecological agriculture. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Agriculture
Controlled terms:Costs - Ecology - Economics - Efficiency - Emission control - Environmental protection - Fertilizers - Landforms - Pollution - Pollution control - Regional planning - Sustainable development
Uncontrolled terms:Agricultural non-point source pollutions - Agricultural productions - Agricultural sustainability - Directional distance function - Eco-environmental - Non-point source pollution - Shadow price - Three gorges reservoir area
Classification code:403.2 Regional Planning and Development - 451.2 Air Pollution Control - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 481.1 Geology - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911 Cost and Value Engineering; Industrial Economics - 913.1 Production Engineering - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2017.11.026
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 15>
Accession number:20173304046239
Title:National land spatial pattern distribution method based on ecological carrying capacity
Authors:Ye, Jing (1); Xie, Qiaoqiao (1); Tan, Ningyan (1)
Author affiliation:(1) School of Public Administration, China University of Geosciences, Wuhan; 430074, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:262-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:National land spatial pattern optimization is an important step for the ecological civilization construction, and ecological carrying capacity study plays an indispensable role on spatial pattern optimization. Taking Ezhou City, Hubei Province as a demonstration area, based on the analysis of the characteristics of the resource, environment and socioeconomic state, this research used township as a unit, carried out a comprehensive evaluation and ecological capacity divisions, discussed the city's spatial pattern optimization plan, and put forward the guidelines for each main function zone. Firstly, the ecological capacity comprehensive evaluation model was built. Based on the cognition and analysis on compound ecosystem, this research built the hierarchical index model for the ecological capacity comprehensive evaluation on "capacity on resource environment, ecology elasticity and socioeconomic coordination". A total of 15 support indices and 10 pressure indices were set to reflect the level of each criterion layer, and the space state method was used to show each element state, which were prepared for the interconnection of the 3 criterion layers. Secondly, an empirical research on ecological capacity comprehensive evaluation was made. According to the ecological capacity comprehensive evaluation model, the entropy method and expert scoring method were used to determine the weight of every index. And the space state method counted the number of hierarchical indices and the number of capacity comprehensive indices for each evaluation unit. The results show: From the resource and environment capacity aspect, the low values are distributed in the main urban zone, including 4 administration communities i.e. Gulou, Fenghuang, Xishan, and Fankou, and the maximum value is located in Liangzi Town; from the ecological elasticity aspect, the maximum value is located in 11 towns such as Liangzi, Huahu, and Fenghuang; from the social-economic coordination aspect, the high value is distributed in the towns of Xisan, Fenghuang, Gulou, and so on, and the low value is mainly distributed in the northern Duandian, Huarong, Linjiang, and so on; from the ecological capacity comprehensive index value, the maximum value occurs in Liangzi, and the medium value zone is located in Gulou, Fenghuang, Fankou, and so on. Those areas either have high value in social-economic coordination but medium or low value in source and environment capacity and ecology elasticity, or have high value in source and environment capacity and ecology elasticity but low value in social-economic coordination ability. Thirdly, the relationships framework between ecological capacity comprehensive model and national land spatial pattern distribution optimization was built. According to the ecological capacity, a correlation analysis was made between criterion layers of ecological capacity and main function types, and the results were showed in magic cube: The resource and environment capacity, ecological elasticity, social-economic coordination corresponded to agriculture production zone, ecological protection zone and economic development zone, respectively. Fourthly, a scheme for the national land spatial pattern distribution optimization was put forward. Taking account of the differentiation characteristics of resource and environment capacity, ecology elasticity and social-economics coordinating ability, combining the current situation and development potential of the empirical city, this research finally divided the spatial pattern into 5 parts, including city economic core zone, city economic development zone, agriculture producing zone, ecology conservation zone and forbidden development zone. The conclusions included: The maximum value of comprehensive ecological capacity index was 0.233 8, located in Liangzi Town, and the minimum value was 0.050 9, located in Linjiang Town; the medium value of ecological capacity comprehensive index was from 0.076 8 to 0.112 8. This method provides a new feasible thought and effective measure for theory study on the national land spatial development pattern optimization. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Spatial distribution
Controlled terms:Agriculture - Ecology - Economic and social effects - Economics - Ecosystems - Elasticity - Function evaluation - Land use - Optimization - State space methods
Uncontrolled terms:Comprehensive evaluation - Comprehensive evaluation model - Distribution optimization - Ecological carrying capacity - Ezhou city - Magic cubes - Resource and environment - Spatial patterns
Classification code:403 Urban and Regional Planning and Development - 454.3 Ecology and Ecosystems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2017.11.034
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 16>
Accession number:20173304046207
Title:Parameter optimization and experiment of negative pressure precision seed-metering device for wheat
Authors:Zhao, Xiaoshun (1); Yu, Huali (1); Ma, Yuejin (1); Zhang, Jinguo (1); Sang, Yongying (1); Huo, Xiaojing (1)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Hebei Agricultural University, Baoding; 071001, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:11-18
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Different from traditional cultivation techniques of sowing in lines for wheat, precision seeding technology ensures the most reasonable distribution of wheat seeds in the field through precisely controlling seeding quantity and uniformity. It makes each grain of wheat seed get enough nutrition area and space, absorb water at the most and possess effective tillering. So it ensures stable and high yield in seed-saving, fertilizer-saving and water-saving conditions. In order to meet the agronomic requirements of precision seeding technology, a negative pressure precision seed-metering device for wheat was designed. The seed-metering device was not a traditional single structure, but multiple seed-metering devices shared a hollow shaft. By the CFD (computational fluid dynamics) software STAR-CCM+, the influences of structural parameters of the seed-metering device on vacuum chamber fluid field were simulated and analyzed. The structural parameters included the diameter of seed-metering disc, the width of suction slit, the cross-section shape of ring groove, and the axial depth of gas chamber in the seed-metering disc. The analysis of pressure nephogram, velocity vectogram and streamline graph showed that more ideal structural parameters of seed-metering device are 0.5 mm width of suction slit, 150-200 mm diameter of seed-metering disc, 2.0 mm axial depth of gas chamber in the seed-metering disc, and arc-shaped cross-section of ring groove. Seeding uniformity test of the seed-metering device was done on the JPS-12 test-bed. It tested and analyzed the influence of cross-section shape of ring groove, width of suction slit, diameter of seed-metering disc and axial depth of gas chamber in the seed-metering disc on the qualified index, multiple index, missing index and coefficient of variation of qualified seed spacing. The qualified index of the seed-metering device with arc-shaped cross-section of ring groove is about 10% higher than the v-shaped and inverted-trapezoid-shaped structure, and about 17% higher than the straight-groove-shaped structure. Meanwhile, its multiple index (8.29%) and missing index (5.29%) are the minimum. The influence of the suction slit width on the seeding uniformity is very visible. In certain vacuum conditions, the decrease of suction slit width causes insufficient suction, which affects the uniformity of suction seed. For example, the missing index and the qualified index of seed-metering device with 0.3 mm suction slit respectively are 21.88% and 69.79%. The seeding uniformity of the seed-metering device with less than 200 mm disc diameter meets precision seeding technology agronomic requirements. The influence of seed-metering disc diameter on the seeding uniformity is very little. But when the disc diameter is larger than 250 mm, the missing index (20.94%) clearly increases. The main reason is that the outer edge of the seed-metering disc with large disc diameter has higher linear speed, which causes the filling seed performance of seed-metering device to reduce. The axial depth of gas chamber in the seed-metering disc is not less than 2.0 mm, or its missing index (18.32%) and multiple index (10.26%) significantly increase and its qualified index (71.43%) decreases. The better structural parameters of the seed-metering device were determined as arc-shaped cross-section of ring groove, 0.5-0.8 mm width of suction slit, 170-200 mm diameter of seed-metering disc and 2.0 mm axial depth of gas chamber in the seed-metering disc. Based on these, structural parameters of the seed-metering device were optimized: The diameter of seed-metering disc is 180 mm, the width of suction slit is 0.7 mm, the axial depth of gas chamber in the seed-metering disc is 2.5 mm, and the cross-section shape of ring groove is arc-shaped. The optimization seed-metering device was tested on the JPS-12 test-bed. The qualified index is 86.66%, the missing index is 5.09%, the multiple index is 8.25%, and the coefficient of variation of qualified seed spacing is 24.50%. These testing results fully coincide with the standard JB/T 10293-2013 Specifications of single seed drill (precision drill). The seed-metering device meets fully the requirements of wheat precision drilling. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Pneumatic materials handling equipment
Controlled terms:Agronomy - Computational fluid dynamics - Computer simulation - Drills - Equipment testing - Gases - Machinery - Mechanization - Optimization - Water conservation
Uncontrolled terms:CFD (computational fluid dynamics) - Coefficient of variation - Cross section shape - Parameter optimization - Precision seed-metering devices - Seed metering devices - Structural parameter - Wheat
Classification code:444 Water Resources - 601 Mechanical Design - 603.2 Machine Tool Accessories - 632.4 Pneumatic Equipment and Machinery - 723.5 Computer Applications - 821.3 Agricultural Methods - 921.5 Optimization Techniques
Numerical data indexing:Percentage 1.00e+01%, Percentage 1.03e+01%, Percentage 1.70e+01%, Percentage 1.83e+01%, Percentage 2.09e+01%, Percentage 2.19e+01%, Percentage 2.45e+01%, Percentage 5.09e+00%, Percentage 5.29e+00%, Percentage 6.98e+01%, Percentage 7.14e+01%, Percentage 8.25e+00%, Percentage 8.29e+00%, Percentage 8.67e+01%, Size 1.50e-01m to 2.00e-01m, Size 1.70e-01m to 2.00e-01m, Size 1.80e-01m, Size 2.00e-01m, Size 2.00e-03m, Size 2.50e-01m, Size 2.50e-03m, Size 3.00e-04m, Size 5.00e-04m, Size 5.00e-04m to 8.00e-04m, Size 7.00e-04m
DOI:10.11975/j.issn.1002-6819.2017.11.002
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 17>
Accession number:20173304046224
Title:Analysis crops planting structure and yield based on GF-1 and Landsat8 OLI images
Authors:Ouyang, Ling (1, 2, 5); Mao, Dehua (2); Wang, Zongming (2); Li, Huiying (3); Man, Weidong (2, 5); Jia, Mingming (2); Liu, Mingyue (2, 5); Zhang, Miao (4); Liu, Huanjun (2)
Author affiliation:(1) School of Resource and Environmental Sciences, Chifeng University, Chifeng; 024000, China; (2) Northeast Institute of Geography and Agroecology, Key Laboratory of Wetland Ecology and Environment, Chinese Academy of Sciences, Changchun; 130102, China; (3) College of Earth Science, Jilin University, Changchun; 130000, China; (4) Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing; 100049, China; (5) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Mao, Dehua(maodehua@iga.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:147-156
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Crop classification and yield estimation are key research in remote sensing-based precision agriculture, which have important significance in making agricultural policies. To improve the accuracy of classification based on single-source and single-season images, multi-temporal, multi-source and high spatial resolution image data were used to extract information of crops. Multi-source remote sensing data can play an important role in the coupling process. Multi-spectral data are used to distinguish between different crop species. Based on Landsat8 OLI (operational land imager) and GF-1 images, crop structure was mapped and yield was estimated for Beian County, Heilongjiang Province. According to phonology information and spectral characteristics, the critical period of crop identification and the characteristic parameters were determined, and the model of object-oriented decision-tree classification was built and crop structure was explored. Meanwhile, compositing multi-spectral images of crop maturation period and yield crop data, vegetation indexes were selected. Using correlation analysis, stepwise regression analysis and one-way ANOVA (analysis of variance), the correlation was explored and the model was built between yields of maize and soybeans and vegetation indices, which included NDVI (normalized differential vegetation index), EVI (enhanced vegetation index), GNDVI (green normalized difference vegetation index), OSAVI (optimal soil adjusted vegetation index), RVI (ratio vegetation index), SIPI (structure intensive pigment index), SAVI (soil adjusted vegetation index), NRI (nitrogen reflectance index) and DVI (difference vegetation index). Results show that the multi-source and multi-temporal remote sensing data can be used to show seasonal characteristics of different crops. Characteristic parameters of crops (including NDVI, NDWI, RVI, brightness, rectangular fit and texture) can be used to identify crop characteristics in landsat8 OLI and GF-1 images. After verified by ground investigation, the results of classification were accurate. The overall accuracy and Kappa coefficient were 87.54% and 0.811 5, respectively. The soybean had the largest area (2 204 km<sup>2</sup>) and the areas of maize, rice and wheat were 1 955, 122 and 19 km<sup>2</sup>, respectively. The high-yield maize was concentrated in the western area and the high-yield soybean was distributed in the east of study area. Correlation coefficients between crop yields and vegetation indices were more than 0.85 (P<0.001), which indicated that vegetation indices (including NDVI, EVI, GNDVI, OSAV and RVI) were closely related with the production of maize and soybean. Meanwhile, the sensibility of each vegetation index was different (NDVI>GNDVI>OSAVI>EVI>RVI>NRI>SAVI>SIPI>DVI). After cross validation for the yield-estimation model, the NDVI, EVI and GNDVI model can be used to estimate accurately the yield of maize and soybean, and the yield estimation was significantly correlated to the actual production (R<sup>2</sup>=0.823 7, RMSE=135.45 g/m<sup>2</sup>, accuracy was 80.55%) based on regression analysis which indicated these vegetation indices can be used for crop yields estimation with the yield-estimation model. Total yields of maize and soybean were estimated to be 16.93×10<sup>8</sup>and 6.27×10<sup>8</sup>kg, with per unit area yields of 8 659 and 2 846 kg/hm<sup>2</sup>, respectively. Crop planting structure can be mapped accurately and efficiently using crop key phonological phase, multi-source and multi-temporal remote sensing data. The results provide the reference for the study on remote sensing indicators and the scientific and technological support for the development of precision agriculture science. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Vegetation
Controlled terms:Agriculture - Classification (of information) - Crops - Data mining - Decision trees - Extraction - Forestry - Image processing - Plants (botany) - Regression analysis - Remote sensing - Spectroscopy
Uncontrolled terms:Crop yield - Green normalized difference vegetation index - High spatial resolution images - Multi-Sources - Multi-temporal remote sensing - Normalized differential vegetation indices - Object oriented - Plant structures
Classification code:716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Area 1.22e+08m2, Area 1.90e+07m2, Area 2.20e+09m2, Percentage 8.05e+01%, Percentage 8.75e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.019
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 18>
Accession number:20173304046206
Title:Global bioenergy sustainability initiatives and implications for policy making in China
Authors:Chang, Shiyan (1, 2); Kang, Liping (3)
Author affiliation:(1) Institute of Energy, Environment and Economy, Tsinghua University, Beijing; 100084, China; (2) Laboratory of Low Carbon Energy, Tsinghua University, Beijing; 100084, China; (3) Innovation Center for Energy and Transportation, Beijing; 100020, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:1-10
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the rapid development of bioenergy, the sustainability issue of bioenergy has aroused more and more attention globally. China is also highly concerned about the sustainable development of bioenergy. But, there are only sustainable principles emphasized by government with no specific criteria and indicators, e.g., avoiding bioenergy competition for food crops and land. Therefore, it is necessary to establish systematic criteria and indicators to provide clear and executable guidelines for the sustainable development of bioenergy in China. Several regions in the world have promulgated regulation framework or certification standard to assure the sustainable production and utilization of bioenergy. Also some international institutions, such as Global Bioenergy Partnership (GBEP) and International Organization for Standardization (ISO), have published voluntary sustainable standard for decision makers. Therefore, to learn the global experience is a good option to promote the establishment of sustainable requirements in China. The typical sustainable bioenergy initiatives in the world are introduced in the paper, including regulation frameworks, certification standards and voluntary standards without threshold. The key criteria and indicators are reviewed. It is found that although the principles of sustainable development are the same for diverse initiatives, their focuses on environmental, social or economic aspects are different due to their different starting points and goals. The importance of involving greenhouse gas (GHG) emission as a key indicator is analyzed, and the challenges on how to quantify GHG emission are also discussed, such as, the allocation of byproduct's emission and the impact of direct land use change & indirect land use change. The requirements on GHG emission reduction of bioenergy compared to fossil fuel are also reviewed. The supporting role of bioenergy sustainability initiatives for the bioenergy industrial policies is elaborated based on the practices of the EU (European Union) and the United States. And finally, related policy suggestions in China are proposed. The suggestions include: 1) Sustainability requirement (criteria or indicators) of bioenergy should be proposed in Renewable Energy Law and Bioenergy Development Planning in China to guide the direction of industrial development; 2) the criteria and indicators of sustainable bioenergy should be both scientific and implementable with clear goals and focus, and should be selected based on domestic situation; 3) GHG emissions counting methodology of different kinds of bioenergy should be provided by government to facilitate industries to meet the sustainability requirement, and the threshold of life cycle GHG emission reduction of bioenergy needs to be fully discussed with stakeholders and strengthened gradually; 4) priority should be given to aviation biofuels, bioenergy derived from residues and wastes, and systematic sustainability criteria and indictors should be established for other biofuels for transportation use in the near term; and, 5) the industrial policies and research and development funding of bioenergy should be linked with the sustainability requirements, and the policy support should be inclined to the sustainable production and utilization of bioenergy which can meet the requirements. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:64
Main heading:Sustainable development
Controlled terms:Biofuels - Biomass - Decision making - Economic and social effects - Emission control - Environmental protection - Fossil fuels - Fueling - Greenhouse gases - Indicators (instruments) - Industrial emissions - Industrial research - Land use - Life cycle - Planning - Research and development management - Waste utilization
Uncontrolled terms:Certification standards - Criteria - Criteria and indicators - Indirect land-use changes - International organization for standardizations - Life-cycle GHG emissions - Research and development - Sustainability criteria
Classification code:403 Urban and Regional Planning and Development - 451.1 Air Pollution Sources - 451.2 Air Pollution Control - 454.2 Environmental Impact and Protection - 912.1 Industrial Engineering - 912.2 Management - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2017.11.001
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 19>
Accession number:20173304046209
Title:Design of 6-DOF parallel mechanical leg of wheel-leg hybrid quadruped robot
Authors:Qu, Mengke (1, 2, 3); Wang, Hongbo (1, 3); Rong, Yu (2)
Author affiliation:(1) Parallel Robot and Mechatronic System Laboratory of Hebei Province, Yanshan University, Qinhuangdao; 066004, China; (2) College of Urban Construction, Hebei Normal University of Science and Technology, Qinhuangdao; 066004, China; (3) Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education, Yanshan University, Qinhuangdao; 066004, China
Corresponding author:Wang, Hongbo(hongbo_w@ysu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:29-37
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the field of agricultural engineering, a lot of work is carried out on rough terrains, such as rugged mountains or hills. Mobile robots are very suitable to be used in these areas, and these kinds of robots can work in the rugged mountains or hills environment without caring about the safety of workers. The wheel-leg hybrid quadruped robot is very suitable to be used in agricultural engineering. It can move with the dynamic driving wheels in the road with high speed, and also can walk by stepping alternately in the ruins with its mechanical legs. The wheel-leg hybrid quadruped robot can also skate in a flat road by the wheels without dynamic driving, and in this state, the robot can obtain the maximum speed with the minimum energy consumption. In order to design a kind of wheel-leg hybrid agricultural quadruped robot, which can achieve walking, dynamic wheel moving, and roller-skating, a new mechanical leg based on the 3-UPS(U-universal joint, P-prismatic joint, S-spherical joint) parallel mechanism is proposed. The structure parameters of the mechanical leg are determined. The design schemes of the mechanical leg and the wheel-leg hybrid quadruped robot are given. First, using the vector chain method, the inverse position equation is presented, and the velocity transmission model is established. The workspace analysis of the leg mechanism is performed and the 3D (three-dimensional) map of the workspace is drawn by searching method. The relationship between the structural parameters of the mechanism and the workspace is revealed. The 3D map of condition number of Jacobian matrix is drawn in the workspace based on the velocity transmission model. Also, a set of kinematics performance evaluation indices are defined, and the kinematics dexterity of the leg mechanism is analyzed. And the relationship curves between structure parameters and the kinematics performance evaluation indices are drawn. These curves reveal the influence of structural parameters on the flexibility of the mechanism. Then, based on the indices of workspace and kinematics dexterity, the structure parameters are analyzed by Monte Carlo method. By establishing the probability space model of each structure parameter, an excellent set of structural parameters are found: The distance between two universal joint's rotation center points of the fixed platform is 230 mm, the distance between two spherical joint's rotation center points of the moving platform is 70 mm, the maximum diameter of the telescopic sleeve is 60 mm, and the lengths of each branch's sleeve and the telescopic rod are both 500 mm. Finally, based on the excellent set of structural parameters, the virtual prototypes of wheel-leg hybrid quadruped robot and its parallel mechanical leg are designed. The motion simulation analysis of the virtual prototype is performed, and the driving speed curves of parallel mechanical leg's driving joints are obtained. Simulation results show that: The driving parameters of the mechanical legs are very stable, and the peak values of the driving parameters are within the reasonable range. These prove that the design scheme and the structural parameters of the mechanical leg are very reasonable. The results provide the theoretical reference for further study of wheel-leg hybrid quadruped robot. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Structural design
Controlled terms:Agricultural engineering - Agriculture - Curves (road) - Design - Dynamics - Energy utilization - Fixed platforms - Inverse problems - Jacobian matrices - Kinematics - Machine design - Mechanisms - Monte Carlo methods - Multipurpose robots - Number theory - Offshore oil wells - Roads and streets - Robots - Rotation - Structural analysis - Universal joints - Virtual prototyping - Wheels
Uncontrolled terms:3-D (three-dimensional) - Kinematics performance - Minimum energy consumption - Motion simulation analysis - Parallel mechanical legs - Performance evaluation index - Structural parameter - Workspace analysis
Classification code:406.2 Roads and Streets - 408.1 Structural Design, General - 511.2 Oil Field Equipment - 512.1.1 Oil Fields - 525.3 Energy Utilization - 601 Mechanical Design - 723.5 Computer Applications - 731.5 Robotics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.1 Algebra - 922.2 Mathematical Statistics - 931.1 Mechanics
Numerical data indexing:Size 2.30e-01m, Size 5.00e-01m, Size 6.00e-02m, Size 7.00e-02m
DOI:10.11975/j.issn.1002-6819.2017.11.004
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 20>
Accession number:20173304046234
Title:Pilot scale test on removal effect of odor from pig manure and carcass composting by biofiltration
Authors:Shang, Bin (1); Zhou, Tanlong (1); Dong, Hongmin (1); Tao, Xiuping (1); Li, Lulu (1); Liu, Yang (1)
Author affiliation:(1) Key Laboratory of Energy Conservation and Waste Management in Agricultural Structures (MOA), Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing; 100081, China
Corresponding author:Dong, Hongmin(donghongmin@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:226-232
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As one of the harmless treatment methods for animal carcasses, the composting has attracted more and more attention. There will be odor and volatile organic compounds (VOCs) emission during the composting of pig manure and the carcass composting. In order to study the feasibility of odor and VOCs removal by biofiltration, the pilot mixed composting experiment of dead pig and pig manure was carried out. The fermentation materials were pig manure and corn stalks, pig manure was taken from one pig farm in Anding Town, Daxing District, Beijing City, and the corn stalks were taken from local farms, which were cut to 5 cm by the crusher. Corn straw and pig manure were mixed at a volume ratio of 2: 1; the water content of mixture was 69.4%, and the total carbon and total nitrogen contents of the mixture (dry-basis) were 34.4% and 3.0%, respectively. Blower used for composting ventilation ran intermittently at 10-minute/20-minute (on/off) cycles, and air was supplied to the composting piles at air flow rate of 60 L/(m<sup>3</sup>·min). The fermentation period was 42 d. The fermented mature compost was used as the biofilter medium and activated sludge as added material. The odor concentrations and VOCs components during dead pig composting were analyzed. The key parameter i.e. the residence time of the filter material in biofiltration was studied. The results showed that, during the 7-week composting period, the daily average temperature was maintained above 55℃ for more than 12 days, so all the composting trials could meet the requirement of China national standard, in which more than 50℃ temperature lasting 10 days is required for sterilizations. The odor concentration from pig manure and carcass composting was influenced mainly by composting temperature. The odor concentration was the highest in first 7 days of composting, and relatively weak in the second and third week, but the odor concentration reached another peak value after pile-turning. Thirty-seven kinds of VOCs were discharged during the composting, including 12 kinds of aromatic hydrocarbons, 21 kinds of halogenated hydrocarbons, one kind of ketones and 3 kinds of mercaptans thioethers. Among the VOCs, the smelly and odor-causing matters were trimethylamine, dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide. The biofiltration system presented good performance for odor and VOCs removal. With the retention time of 30-100 s between odor and biofilter medium, the removal efficiency of odor concentration could reach more than 90%, and there was no significant difference between different treatments. And with the retention time of 30-100 s between odor and biofilter medium, the removal efficiencies of the main odorant of VOCs, trimethylamine, dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide, were 82.2%-100%. With the retention time of 60-100 s between odor and biofiltration medium, the removal efficiencies of the main odorant had no significant difference, but was significantly higher than that with the retention time of 30 s. The optimum empty bed retention time (EBRT) of biofiltration for the removal of odor and VOCs was 60 s, and the removal efficiencies of the main odorant of VOCs could reach 82.2%. The study provides data support for mitigating odor and VOCs gas emissions during the composting of pig manure and dead pigs. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Odor removal
Controlled terms:Aromatic hydrocarbons - Biofilters - Biofiltration - Carbon - Composting - Efficiency - Fermentation - Fertilizers - Gas emissions - Hydrocarbons - Ketones - Manures - Mixtures - Odors - Organic compounds - Piles - Removal - Sulfur compounds - Volatile organic compounds
Uncontrolled terms:Biofiltration systems - Composting temperature - Dead pigs - Different treatments - Empty bed retention time - Halogenated hydrocarbons - Removal efficiencies - Total nitrogen content
Classification code:408.2 Structural Members and Shapes - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.5 Agricultural Wastes - 913.1 Production Engineering
Numerical data indexing:Age 1.92e-02yr, Age 2.74e-02yr, Age 3.29e-02yr, Percentage 3.00e+00%, Percentage 3.44e+01%, Percentage 6.94e+01%, Percentage 8.22e+01% to 1.00e+02%, Percentage 8.22e+01%, Percentage 9.00e+01%, Size 5.00e-02m, Time 3.00e+01s to 1.00e+02s, Time 6.00e+01s to 1.00e+02s
DOI:10.11975/j.issn.1002-6819.2017.11.029
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 21>
Accession number:20173304046213
Title:Extracting weak fault characteristics with adaptive singular value decomposition and stochastic resonance
Authors:Li, Zhixing (1, 2); Shi, Boqiang (1)
Author affiliation:(1) School of Mechanical Engineering, University of Science & Technology Beijing, Beijing; 100083, China; (2) School of Mechanical Engineering, University of Science & Technology Inner Mongolia, Baotou; 014000, China
Corresponding author:Shi, Boqiang(shiboqiang@ustb.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:60-67
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Bearings are the important component of agricultural machinery and equipment, whose failure may seriously endanger the healthy operation of equipment and even lead to bodily injury. So the fault diagnosis of agricultural machinery and equipment gains more and more attention. Using the vibration signal to extract the fault characteristics is the most common method, but it is difficult to extract the weak fault characteristics in strong background noise. Therefore, the extraction of weak fault characteristics with very low SNR (signal-to-noise ratio) under strong background noise becomes the key to the fault diagnosis of agricultural machinery bearings. There are 2 general methods for weak feature extraction under weak background noise. One method is to extract weak faults from the perspective of suppressing or eliminating noise. The other one is not to eliminate noise but using noise to improve the SNR to extract the weak fault characteristics, such as stochastic resonance (SR) theory. Compared to the traditional noise reduction method, SR makes use of noise energy transfer to weak signal, so the weak fault characteristics are enhanced while some of the noises are weakened. Because of the excellent features of extracting weak fault characteristics in strong background noise, SR has become a hot topic for many scholars in recent years. In this paper, the weak fault characteristics extraction method of SR based on adaptive SVD (singular value decomposition) was proposed. In the method, firstly, the original signal was decomposed by singular value and reconstructed to obtain the component signal; the difference spectrum of mutual information was constructed, the mutual information of each component signal and the original signal was weighed, and the number of valid singular values was selected adaptively, in order to overcome the problem of existing methods including human subjective choice or only considering the size of singular values and other deficiencies. Using the mutual information difference spectrum, 3 and 10 effective singular values were obtained in the simulation signal and bearing outer ring signal, respectively. Secondly, the adaptive SR was performed for the component signal corresponding to the selected effective singular value which enhances weak fault characteristics. Finally, the enhanced component signals were statistically averaged to extract the weak fault characteristics. In this paper, constructing the mutual information differential spectrum, and considering the mutual information of the component signal and the original signal, on the one hand, it avoids the elimination of the useful signals; on the other hand, the adaptive selection is realized which avoids the subjectivity of the artificial selection. In addition, due to the presence of strong background noise, the larger singular value may have smaller mutual information, but it is not valid singular value. It indicates that large singular value does not necessarily contain useful information, and there may be noise interference. Hence, the selection of effective singular values should not be based on the size of the singular value. The above analysis shows that it is difficult to extract the weak fault characteristics by SVD in strong background noise. We combine the 2 methods to process the effective component signal selected by mutual information difference spectrum in SR, and the maximum spectral frequency of each component is obtained. The statistical average is used to achieve noise filtering in order to highlight the characteristics of weak fault frequency. The results of simulation and bearing outer ring test show that, the proposed method is superior to the SVD and SR method. The method can effectively extract 100 and 155.5 Hz weak fault characteristics respectively for simulation signal and bearing outer ring signal. The proposed method can be applied not only to the fault diagnosis of bearing in strong noise background, but also to provide reference for bearing fault diagnosis of agricultural machinery and equipment. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Fault detection
Controlled terms:Agricultural machinery - Agriculture - Circuit resonance - Data mining - Energy transfer - Equipment - Extraction - Failure analysis - Magnetic resonance - Resonance - Signal processing - Signal to noise ratio - Singular value decomposition - Stochastic systems
Uncontrolled terms:Bearing fault diagnosis - Effective singular values - Fault characteristics - Mutual informations - Noise reduction methods - SVD(singular value decomposition) - Vibrations - Weak characteristic
Classification code:701.2 Magnetism: Basic Concepts and Phenomena - 703.1 Electric Networks - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 901 Engineering Profession - 921 Mathematics - 931.1 Mechanics - 961 Systems Science
Numerical data indexing:Frequency 1.00e+02Hz, Frequency 1.56e+02Hz
DOI:10.11975/j.issn.1002-6819.2017.11.008
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 22>
Accession number:20173304046221
Title:Quantification study of rainfall intensity and slope gradient impacts on ephemeral gully morphological characteristic on steep loessial hillslope
Authors:Xu, Ximeng (1); Zheng, Fenli (1, 2); Wu, Min (3)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China; (2) Institute of Soil and Water Conservation CAS & MWR, Yangling; 712100, China; (3) College of Water Conservancy, Shenyang Agriculture University, Shenyang; 110866, China
Corresponding author:Zheng, Fenli(flzh@ms.iswc.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:124-132
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ephemeral gully is formed in the cycle of concentrated flow and tillage practices, and contributed a lot to the sediment yield on the loessial hillslope as well as in the watershed. Ephemera gully morphology is the base of establishing ephemeral gully erosion prediction model on the steep loessial hillslope. Thus, to quantify the ephemeral gully morphological characteristics on steep loessial hillslope in different rainfall intensities and slope gradients, an 8 m long, 2 m wide and 0.6 m deep slope adjustable soil pan was used to make an initial ephemeral gully channel on the soil bed according to the topographic characteristics of natural ephemeral gully after tillage and before rainy season. The initial ephemeral gully was placed at the middle of the soil bed with a depth of 12 cm. The soil used in this study was loess soil (fine-silty and mixed, with 28.3% sand, 58.1% silt, 13.6% clay), classified as Calcic Cambisols (USDA Soil Taxonomy). Soil materials were collected from 0 to 20 cm in the Ap horizon of a well-drained site in Ansai County, Shaanxi Province, and packed according to natural soil structure of the farmland on Loess Plateau. Two rainfall intensities (50 and 100 mm/h) and three typical slopes on which ephemeral gully occurred and developed (15°, 20°, and 25°) were designed in this experiment. Simulated rainfall and runoff scouring experiments were carried out at rainfall simulation laboratory of the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau. Needle board method was used to measure the topography after 70 min experiment and the DEMs (digital elevation models) were generated in Surfer 10 with a resolution of 3 cm ×10 cm. The results showed that, the increasing of rainfall intensity and slope gradient accelerated the ephemeral gully erosion processes on the steep loessial hillslope. Average ephemeral gully width and depth in 25<sup>o</sup>and 100 mm/h condition were 1.40 and 0.61 times larger than those in 15° and 50 mm/h condition. Based on DEMs after rain and flow path figures, it could be concluded that the increasing of slope gradient increased the slope length required for the converging of rills and ephemeral gully channel, and the angle of rill and ephemeral gully channel at converging point was decreased; while the increasing of rainfall intensity decreased the slope length required for the converging of rills and ephemeral gully channel. Gully density, surface dissected degree and tortuosity complexity of ephemeral gully increased with the increase of rainfall intensity and slope gradient, varying from 0.74 to 1.48 m/m<sup>2</sup>, from 0.13 to 0.29, and from 1.64 to 2.84, respectively, while ephemeral gully channel width to depth ratio ranged from 0.65 to 1.27 and was the smallest when slope gradient was 20<sup>o</sup>. Directional derivative distribution was generated from original DEMs after rain according to the relationship between the neighbor grids, and it could be concluded that contour map of directional derivative grids reflected the length, surface area and gully bottom position of ephemeral gully and rills. More studies should be done on the ephemeral gully morphology and hillslope ephemeral gully erosion prediction model. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Landforms
Controlled terms:Agricultural machinery - Agriculture - Erosion - Forecasting - Forestry - Precipitation (meteorology) - Rain - Runoff - Sediments - Silt - Soils
Uncontrolled terms:Directional derivative - Ephemeral gullies - Hillslopes - Morphological characteristic - Simulated experiments
Classification code:442.1 Flood Control - 443.3 Precipitation - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment
Numerical data indexing:Percentage 1.36e+01%, Percentage 2.83e+01%, Percentage 5.81e+01%, Size 0.00e+00m to 2.00e-01m, Size 1.20e-01m, Size 2.00e+00m, Size 6.00e-01m, Size 8.00e+00m, Time 4.20e+03s
DOI:10.11975/j.issn.1002-6819.2017.11.016
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 23>
Accession number:20173304046237
Title:Experiment on characteristics of continuous heat absorption/release for pumping and recharging in same thermal well
Authors:Song, Wei (1, 2); Ni, Long (2); Yao, Yang (2)
Author affiliation:(1) School of Civil Engineering, North China University of Technology, Beijing; 100144, China; (2) School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin; 150090, China
Corresponding author:Ni, Long(nilonggn@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:248-253
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Groundwater heat pump system is an ideal approach to heat and cool the building due to its attractive advantages. When using groundwater as a primary energy source in combination with heat pump, the groundwater is pumped from the pumping area, heated/cooled in the heat exchanger of the heat pump, and then reinjected into the irrigation area. Single well groundwater heat pump (SWGWHP) is a new member of groundwater heat pump, which has become increasingly popular for using because of the economic advantages. In general, SWGWHP includes standing column well (SCW), pumping & recharging well (PRW), and forced external circulation standing column well (FECSCW). Their pumping and injection pipes are placed in a same well, the low part of which is pumping water and the top part recharging water. The SCW needs to drill hole in the bedrock directly, and then most of the water circulates in the well bore and the heat exchange takes place in the well wall, while small part of water goes out of the borehole and exchanges the heat with aquifer raw water. There are some clapboards in PRW that make the thermal well divided into 3 parts, i.e. injection zone (in the top part), seal zone (in the middle part), and production zone (in the low part). The FECSCW is similar to PRW. The difference between them is that the diameter of borehole in FECSCW is larger than the one in PRW. Moreover, the gap of borehole in FECSCW is filled with sorted gravel. Through previous research on the thermal features of three kinds of thermal wells, PRW has obvious advantages in 3 kinds of SWGWHP. Because its middle partition area exists, the backwater is reinjected into the aquifer completely, while thermal transfixion occurs rarely. In view of less experimental research on continuous operation, this paper selects the PRW as the research object. According to the heating/cooling period in Shenyang and Shanghai, 2 different modes of continuous operation in PRW have been carried out using a physical simulation experimental sandbox of SWGWHP, which can accurately reflect the actual physical phenomena. In this experimental research, time of operating condition has been distributed by heating season, air-conditioning season, and recovery season, while 2 test conditions are continuous heating mode and continuous cooling mode. In the heat/cold load dominant area, the results show that the aquifer can't be restored to its original state during the natural recovery period. In continuous heating conditions of 6 cycles, the decreasing amplitude of accumulative heat absorption quantities of 6 cycles reaches 23.0%. Compared to the cooling condition, the decreasing amplitude of accumulative heat rejection quantities in 6 cycles is only 6.0%. These data show that the PRW is more sensitive in heating mode, while the heat absorption is more difficult than heat rejection. Additionally, in continuous heating condition, the aquifer is more obvious in the initial disturbance. The reduced amplitude of cumulative heat in the second operating cycle is 57.1% of all reduced amount in 6 cycles. Thus, in the heat/cold load dominant area, it is necessary to carry on the energy recharge to the aquifer in time according to the building load, in order to ensure the system in a long-term reliable operation. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Injection (oil wells)
Controlled terms:Air conditioning - Aquifers - Boreholes - Groundwater - Groundwater resources - Heat exchangers - Heat pump systems - Heat sinks - Heating - Recharging (underground waters) - Water injection - Wells
Uncontrolled terms:Continuous operation - Experimental research - Experimental sandbox - External circulation - Groundwater heat pumps - Operating condition - Primary energy source - Standing column wells
Classification code:444.2 Groundwater - 511.1 Oil Field Production Operations - 612.1 Internal Combustion Engines, General - 616.1 Heat Exchange Equipment and Components - 643.3 Air Conditioning
Numerical data indexing:Percentage 2.30e+01%, Percentage 5.71e+01%, Percentage 6.00e+00%
DOI:10.11975/j.issn.1002-6819.2017.11.032
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 24>
Accession number:20173304046229
Title:Sun-tracking multi-layer stereo-cultivation system improving light and temperature environment and increasing yield for strawberry
Authors:Wang, Chungling (1, 2); Song, Weitang (1, 3); Zhao, Shumei (1, 3); Qu, Mingshan (4)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing; 100083, China; (2) College of Water Resources and Architectural Engineering, Tarim University, Alar; 843300, China; (3) Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, Beijing; 100083, China; (4) Beijing Soil and Fertilizer Working Station, Beijing; 100029, China
Corresponding author:Song, Weitang(songchali@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:187-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to efficiently solve the shading problem between the upper layer and lower layer in the same cultivation system and between adjacent cultivation systems in multi-layer stereo-cultivation of strawberry, and to improve the fixed A-shaped frame system, a novel sun-tracking cultivation system was developed, which could keep the line of cultivation frame parallel to sunray to make the best use of direct light. In this study, some instruments, including the CANUOL intelligent remote control door opener, supporting multi-function controller, and the time control switch, were installed on the fixed A-shaped frame. So the fixed frame could rotate about its central axis according to a preset procedure, and the door opener revolved through the multi-function controller operation, thus boosting the cultivation frame motion. Time controller may set the start time of cultivation shelf running, running times, running time interval and the time length of operation as cultivation shelf homing according to the different needs of different seasons. The operating parameters of the cultivation frame were determined according to the changes of solar elevation and azimuth of the sun in winter in Beijing, based on the characteristics of the light environment of Beijing. This test set the running time of the sun-tracking frame to be 9: 00-16: 00 every day from November 2015 to March 2016, rotating once every 55 min, and turning 9 times every day. In November and next February and March, the total daily movement angle was 103.5°, each rotation angle was 11.5°, and each exercise took 4 s; the total daily movement angle was 96°, each rotation angle was 10.5°, and each exercise took 3.6 s in December and January next year. Parameters could be adjusted according to the actual situation in the process of actual production and application. In this study, the strawberry planting time was September 8th, 2015, and the harvest time was from January 13th to March 17th, 2016. Experimental design was that 5 sun-tracking frames were set as the test group, and 5 fixed frames were as a control group; then the difference between the 2 light environments was compared, and the temperature of canopy and root, the yield and the profit of strawberry were used to validate whether the sun-tracking frames could improve light environment and increase the production. Results showed that integrated photosynthetic photon flux density (PPFD) of sun-tracking system was higher than that of fixed system on both middle and lower layers. Within 3 months of winter, compared with fixed system, integrated PPFD on upper, middle and lower layer of sun-tracking system increased by 28.0%, 79.3% and 38.6% respectively in the east side and 30.1%, 41.0% and 18.2% respectively in the west side. So, the sun-tracking frame could change the light-shielding. The strawberry canopy and rhizosphere temperature of the sun-tracking cultivation were better than the fixed stereo cultivation frame, and the minimum value of the cultivated strawberry rhizosphere temperature of fixed frame at each layer was lower than the sun-tracking cultivation frame. Meeting the most suitable rhizosphere temperature of 15-20℃ for upper, middle and lower layer of west side, the time of the sun-tracking cultivation frame was 60, 40 and 120 min longer than the corresponding position of the fixed cultivation frame, respectively. Accordingly, the time of the former canopy temperature below 5℃ was 130, 170, 230 min shorter than the latter, respectively. The strawberry yield per plant on sun-tracking frame was higher than the corresponding position on fixed frame. During the trial, compared with the fixed system, the strawberry output of the sun-tracking system was increased by 214.8 kg/667 m<sup>2</sup>. Benefits were increased by 6 498.5-12 942.5 yuan. So, the sun-tracking system can improve the light and temperature environment condition, which promotes the output of strawberry and benefit. Therefore, it is valuable cultivation technology and should be widely applied. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Fruits
Controlled terms:Controllers - Forestry - Greenhouses - Light - Plants (botany) - Remote control - Soils - Solar radiation - Temperature - Tracking (position)
Uncontrolled terms:Intelligent remote controls - Operating parameters - Photosynthetic photon flux densities - Rhizosphere temperature - Strawberry - Sun-tracking - Temperature environments - Yield
Classification code:483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 657.1 Solar Energy and Phenomena - 731.1 Control Systems - 732.1 Control Equipment - 741.1 Light/Optics - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures
Numerical data indexing:Age 2.50e-01yr, Percentage 1.82e+01%, Percentage 2.80e+01%, Percentage 3.01e+01%, Percentage 3.86e+01%, Percentage 4.10e+01%, Percentage 7.93e+01%, Time 1.38e+04s, Time 2.40e+03s, Time 3.30e+03s, Time 3.60e+00s, Time 7.20e+03s
DOI:10.11975/j.issn.1002-6819.2017.11.024
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 25>
Accession number:20173304046243
Title:Effects of heat denaturation degree of soybean protein on gel property of instant soybean curd
Authors:Tao, Ruqing (1); Xia, Ning (1); Teng, Jianwen (1); Wei, Baoyao (1)
Author affiliation:(1) College of Light Industry and Food Engineering, Guangxi University, Nanning; 530004, China
Corresponding author:Xia, Ning(50597864@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:299-305
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For the heat treatment of soybean is very necessary for the preparation process of instant soybean curd, the thermal denaturation degree of soy protein in the heat treatment process has significant influence on the gel formation strength and gel formation time in the gel forming of instant soybean curd, but there is no suitable standard for the heat treatment degree of soybean milk in the production process of instant soybean curd. In this paper, soybean, soybean protein isolate (SPI), glycinin (11S) and beta-conglycinin (7S) were used as raw material to investigate the gel formation property of instant soybean curd affected by different thermal denaturation degree of soybean protein in soybean. The study showed, the glycinin component was harder to be completely denatured than the beta-conglycinin component, and the beta-conglycinin component and the glycinin component in soybean protein isolate were harder to be completely denatured than the beta-conglycinin component and glycinin component separated from soybean protein isolate. The traditional preparation method, the pre-heat treatment and then spray drying or freeze-drying preparation method, the pre-spray drying or pre-freeze drying and then heat treatment preparation method of soybean curd had different effect on gel formation property. The study found that the traditional preparation of soybean curd had the best gel effect, and the pre-spray drying or pre-freeze drying and then heat treatment preparation of soybean curd had better gel effect than pre-heat treatment and then spray drying or freeze drying preparation of soybean curd. The main reason to the difference in gel strength of soybean curd was the different thermal denaturation degree of soybean protein in soybean, and the beta-conglycinin component and the glycinin (component in the soybean protein isolate had different thermal denaturation degree. When preparing the same gel strength of soybean curd, the lower temperature in the heat treatment needs longer time, and the higher temperature in the heat treatment needs shorter time. When obtaining higher gel strength of soybean curd, the heat treatment temperature and time range of soybean milk would be narrower than to obtain lower gel strength of soybean curd. When the beta-conglycinin component is fully denatured and the glycinin component is incompletely denatured, the suitable conditions for the degeneration degree of soybean protein for preparing instant soybean curd should be controlled as follows: the heat treatment temperate is 80℃ with the heat treatment time of 20-65 min, the heat treatment temperate is 85℃ with the heat treatment time of 15-50 min, the heat treatment temperate is 90℃ with the heat treatment time of 10-35 min and the heat treatment temperate is 95℃ with the heat treatment time of 5-20 min. The results of this study provide the important theoretical basis for regulating and controlling the gel characteristics of instant soybean curd. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Heat treatment
Controlled terms:Denaturation - Drying - Gels - Low temperature drying - Proteins - Spray drying
Uncontrolled terms:Gel characteristics - Heat treatment process - Heat treatment temperature - Heat treatment time - Soybean curd - Soybean protein isolates - Soybean protein isolates (SPI) - Thermal denaturations
Classification code:461.9 Biology - 537.1 Heat Treatment Processes - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds
Numerical data indexing:Time 1.20e+03s to 3.90e+03s, Time 3.00e+02s to 1.20e+03s, Time 6.00e+02s to 2.10e+03s, Time 9.00e+02s to 3.00e+03s
DOI:10.11975/j.issn.1002-6819.2017.11.038
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 26>
Accession number:20173304046236
Title:Experiment on performance of all-glass vacuum tube solar array heating system
Authors:Li, Jinping (1, 2, 3); Kong, Ying (1, 2, 3); Xu, Zhe (1, 2, 3); Si, Zetian (1, 2, 3)
Author affiliation:(1) Western China Energy & Environment Research Center, Lanzhou University of Technology, Lanzhou; 730050, China; (2) China Northwestern Collaborative Innovation Center of Low-carbon Urbanization Technologies, Lanzhou; 730050, China; (3) Key Laboratory of Energy Supply System Drived by Biomass Energy and Solar Energy of 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:11
Issue date:June 1, 2017
Publication year:2017
Pages:240-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a kind of conversion device of solar energy, the solar collector is the most important part of the solar heating system. Among various solar collectors, all-glass vacuum tube solar collector is regarded as more favourable than other collectors in both technical and economic perspectives, so domestic and foreign experts have studied several aspects of it. But the current studies usually focus on the heating performance of the solar system during the whole heating season and the influence factors of the collecting efficiency of the all-glass vacuum tube solar collector, and there is barely research on the hourly and dynamic heating performance of solar heating system in a monomer building under different operating ways. With the purpose of studying the above problems, an all-glass tube solar heating system is fabricated on a monomer building, combined with a low-temperature floor radiation heating. The system is composed of 6 groups of standpipe all-glass vacuum tube solar collectors which have uniform structure parameters, a low-temperature floor radiation heating device, a circulating pump, a valve, a conductor and other accessories. Every group of solar collector comprises 40 all-glass vacuum tubes with the external diameter of 58 mm and the length of 1 800 mm, and a storage tank with the volume of 400 L, which is installed on a rack with an angle of 45° facing south. The contour aperture area of solar collector is about 3.85 m<sup>2</sup>, so the total contour aperture area of the array is about 23.1 m<sup>2</sup>. The monomer building locates in Minqin County, Gansu Province, China. Its building area is 117 m<sup>2</sup>and actual heating area is 87 m<sup>2</sup>. The operation mode of system is as follows: Daily 17: 30-23: 00 is set to be heating time; during this period, the controller controls the water pump to circulate hot water at a constant flow rate, stop for 5 min every operating for 8 min. In the experiment, the values of various parameters, such as the solar irradiance, the inlet and outlet temperatures of collector array, the tank water temperature, the ambient temperature, the circulating water flow rate and the wind speed, are measured by different sensors. All measured variables are collected and recorded automatically by Agilent 34970A data acquisition instrument every 10 s. The testing period was from November 24th to December 5th, 2015. Then, many important parameters such as the total heat loss coefficient of storage tank, the collection efficiency of solar collector array, the solar energy utilization and the solar heating fraction of the system, and hourly variation of building heat load are theoretically and experimentally investigated. Furthermore, in the actual operation state, the heating effect of the solar heating system is analyzed, and the improvement proposals of operating strategy are provided. The results show that the total heat loss coefficient of storage tank in this system is 25.82-31.53 W/℃, the collection efficiency of solar collector array is 38%-72%, and the solar energy utilization and the solar heating fraction of the system are 37.1% and 48.3%, respectively; only 54.6% of heat collected by the solar collector is used, the remaining heat is emitted to the environment, and thus the heat loss of system accounts for a large proportion of the total collected heat; under the actual operating state, the heat supply is much more than the heat consumption of building, and especially in the initial period of heating, heat supply reaches more than 10 times that consumed by building, and heat supply and heating time are excessively concentrated. As a consequence, improvement proposals of operating strategy are provided for the solar heating system of the monomer building to reduce the water flux of heating system and advance the heating time. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Solar heating
Controlled terms:Buildings - Collector efficiency - Data acquisition - Digital storage - Electron tubes - Energy efficiency - Energy utilization - Enthalpy - Floors - Flow of water - Glass - Heat losses - Heating - Heating equipment - Instrument testing - Monomers - Solar cell arrays - Solar collectors - Solar energy - Space heating - Tanks (containers) - Temperature - Tubes (components) - Water towers - Wind
Uncontrolled terms:Collecting efficiency - Collection efficiency - Constant flow rates - Economic perspective - Floor radiation heating - Heat consumption of buildings - Heating performance - Solar heating system
Classification code:402 Buildings and Towers - 443.1 Atmospheric Properties - 446.1 Water Supply Systems - 525.2 Energy Conservation - 525.3 Energy Utilization - 619.1 Pipe, Piping and Pipelines - 619.2 Tanks - 631.1.1 Liquid Dynamics - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.1 Space Heating - 657.1 Solar Energy and Phenomena - 702.3 Solar Cells - 714.1 Electron Tubes - 722.1 Data Storage, Equipment and Techniques - 723.2 Data Processing and Image Processing - 804 Chemical Products Generally - 812.3 Glass
Numerical data indexing:Area 1.17e+02m2, Area 2.31e+01m2, Area 3.85e+00m2, Area 8.70e+01m2, Electric_Current 3.50e+04A, Percentage 3.71e+01%, Percentage 3.80e+01% to 7.20e+01%, Percentage 4.83e+01%, Percentage 5.46e+01%, Size 1.80e+00m, Size 5.80e-02m, Time 3.00e+02s, Time 4.80e+02s
DOI:10.11975/j.issn.1002-6819.2017.11.031
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 27>
Accession number:20173304046217
Title:Mechanical analysis on frost heave damage of cast-in-place concrete trapezoidal canal considering influence of groundwater table
Authors:Xiao, Min (1); Wang, Zhengzhong (1, 2); Liu, Quanhong (1); Wang, Yi (1); Ge, Jianrui (1)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; 712100, China; (2) State Key Laboratory of Frozen Soil Engineering, Cold and Arid Region Environmental and Engineering Research Institute, CAS, Lanzhou; 730000, China
Corresponding author:Wang, Zhengzhong(wangzz0910@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:91-97
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Groundwater migration and supply is the main influence factor causing frost heave damage of concrete lining trapezoidal canals with high groundwater table. Considering the influence of groundwater table on frost heave of canal foundation soil, the article puts forward a method to calculate the distribution of frost heave force acting on concrete trapezoidal canal lining, presents the design formulas to calculate the distribution of frost heave intensity and frozen depth of canal foundation soil, and then proposes the analytical expression to determine the maximum bending moment of cast-in-place concrete trapezoidal canal lining and the position on canal lining plate which is the easiest to crack. The inhomogeneity of distribution of frost heave force is quantitatively analyzed both locally and integrally, and a new indicator to judge frost heave resistance of canal lining and a method for cross-section pattern optimization are provided. For specific region with fixed groundwater table, the smaller the canal cross-section depth, the more homogeneous the distribution of frost heave force integrally. For specific region with fixed groundwater table from canal top, the smaller the inclination of canal slope plate, the smoother the variation tendency of frost heave force locally. In a word, when the canal cross-section depth is shallower and the inclination of canal slope lining plate is smaller, the distribution of frost heave force is more homogeneous, and the canal lining is harder to be damaged by frost heave force, therefore revealing the reason that the frost heave resistance of trapezoidal canal with wide and shallow cross-section is favorable. By taking a trapezoidal concrete lining canal in Tarim irrigation area as prototype, the frost heave characteristics of canal lining are analyzed, as well as the distribution of frost heave force acting on trapezoidal canal lining with different groundwater table, and the rationality of the method is confirmed by comparing the calculated value with the measured value. The results of comparison show that the maximum relative error of frozen depth of canal foundation soil is 3.5%, and the position of the section undergoing the maximum bending moment estimated is 63.9% of the length of canal slope lining plate from canal top. In addition, the analysis results also show that different groundwater table remarkably influences frost heave characteristics of canal lining and distribution of frost heave force acting on canal lining with high groundwater table. The tendency of variation of frost heave force becomes more linear when groundwater table is higher and the maximum bending moment on canal slope lining plate increases following exponential law. Therefore, the canal with high groundwater table is extraordinarily easy to suffer serious frost heave damage. Eventually, the mechanism of frost heave damage of trapezoidal canal with high groundwater table is analyzed. Because of long and severe winter in North China, in addition to slowly decreasing of air temperature, frozen rate of canal foundation soil is small, and then soil water has sufficient time to migrate and supply. While groundwater table is shallow, groundwater migration and supply is enough to cause serious frost heave damage to canal lining. On account of specific characteristics of canal cross-section, different distances from each position of canal slope plate to groundwater table result in inhomogeneous distribution of the intensity of groundwater supply, and then cause transverse difference of intensity of frost heave and frozen depth of canal foundation soil, and therefore the distribution of frost heave force and the deformation of canal lining can be inhomogeneous. In fact, inhomogeneous distribution of frost heave force acting on canal lining is also a main reason causing serious frost heave damage to canal lining. The research can provide theoretical basis for relevant study and frost heave resistance design of cast-in-place concrete trapezoidal canal with high groundwater table. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Irrigation canals
Controlled terms:Bending moments - Canal linings - Canals - Cast in place concrete - Concretes - Foundations - Frozen soils - Groundwater - Hydraulic structures - Irrigation - Linings - Moisture - Soil moisture - Soils - Structural optimization
Uncontrolled terms:Analytical expressions - Damage mechanism - Frost heave - High groundwater table - Inhomogeneous distribution - Irrigation area - Maximum bending moments - Maximum relative errors
Classification code:407.2 Waterways - 408.2 Structural Members and Shapes - 412 Concrete - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 483.2 Foundations - 821.3 Agricultural Methods - 921.5 Optimization Techniques - 951 Materials Science
Numerical data indexing:Percentage 3.50e+00%, Percentage 6.39e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.012
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 28>
Accession number:20173304046208
Title:Development of corn seed directional positioning machine based on machine vision
Authors:Wang, Qiao (1); Chen, Bingqi (1); Kou, Chunrong (2); Zhu, Deli (3); Geng, Baipeng (2)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) Modern Fubo (Tianjin) Intelligent Equipment Technology Co., Ltd, Tianjin; 301700, China; (3) College of Computer and Information, Chongqing Normal University, Chongqing; 400047, China
Corresponding author:Chen, Bingqi(fbcbq@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:19-28
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Directional seeding of corn seed can improve the light energy utilization of corn plants and the ventilated effect of field, which is of great significance to increase the corn yield per unit area. In order to realize directional seeding of corn seed, this study developed a kind of corn seed directional positioning machine based on image processing technology, and its main components included seed-metering device, conveying device, image acquisition and processing unit and directional positioning device. First, the compulsory clamp-type precision seed-metering device was chosen to complete seed feeding, and combined with the process of feeding seed when duckbilled seeding mouth was opened by roller, a guide-localization method was proposed for positioning process of seed onto conveyer belt. Based on this method, a kind of guide-localization tube was designed, and its structural dimension and installation position were determined through empirical analysis and theoretical calculation. And then the actual position distribution of corn seeds fed onto conveyer belt was acquired by the experiment. Also, locating notch of concave shape was designed to position seed by a mechanical way, and through speed and displacement analysis of each phase of seed positioning process, the conditions that seed could be positioned by locating notch effectively and continuously were obtained. At the same time, on the basis of previous studies, the image detection algorithm toward seed germ surface orientation and seed tip orientation of qualified seed was improved. In the end, the directional positioning device, the most important component of this machine, was developed with motors as rotary power. Location of seed was found according to image detection information as well as photoelectric positioning signal. After that, seed was grabbed by the way of suction to complete the following directional positioning work: On one hand, according to the image detection information about seed tip orientation, a specified motor drove a specified rotating mechanism of the machine to adjust seed tip orientation, which made seed towards the target direction; on the other hand, based on the image detection information about seed germ surface orientation, i.e. the front or the back, another specified motor drove another specified rotating mechanism of the machine to put seeds in 2 different positions located on each side of the machine. In addition, the required precision of revolving position was analyzed, and accordingly the positioning control mode was discussed and the corresponding operation parameters were set up. In the experiment, the results showed that the detection accuracy of germ surface orientation was 98%, the detection deviation of seed tip orientation was not more than 8°, the locating accuracy of concave notch was 97%, the locating and sucking accuracy of rotating arm was 94%, the locating accuracy of seed placing was 99%, and the angular deviation of seed placing was not more than 10°, which met the design requirements. If one viscous seed band is placed on each side of this machine, which is used to load seeds whose positioning and directing are completed and to make seeds stick on the seed bands evenly and orderly, it will provide condition and foundation for the subsequent directional packaging and seeding. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Seed
Controlled terms:Belt conveyors - Computer vision - Conveying - Conveyors - Crops - Energy utilization - Image processing - Image recognition - Location - Machine components - Machinery - Mechanization - Pneumatic materials handling equipment
Uncontrolled terms:Corn seeds - Displacement analysis - Image processing technology - Installation position - Precision seed-metering devices - Structural dimensions - Surface orientation - Theoretical calculations
Classification code:525.3 Energy Utilization - 601 Mechanical Design - 601.2 Machine Components - 632.4 Pneumatic Equipment and Machinery - 692.1 Conveyors - 723.5 Computer Applications - 821.4 Agricultural Products
Numerical data indexing:Percentage 9.40e+01%, Percentage 9.70e+01%, Percentage 9.80e+01%, Percentage 9.90e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.003
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 29>
Accession number:20173304046210
Title:Design and experiment of automatic leveling control system for orchards lifting platform
Authors:Fan, Guiju (1, 2); Wang, Yongzhen (1); Zhang, Xiaohui (1, 2); Zhao, Jinying (3); Song, Yuepeng (1, 2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shandong Agricultural University, Tai'an; 271018, China; (2) Shandong Provincial Key Laboratory of Horticultural Machinery and Equipment, Tai'an; 271018, China; (3) Chinese Academy of Agricultural Mechanization Sciences, Beijing; 100083, China
Corresponding author:Zhang, Xiaohui(Zhangxh@sdau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:38-46
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Lifting platform for orchards plays a significant role in the fruit industry, because it successfully solves many difficult problems of picking fruit and trimming branches. However, there are some uncontrollable problems such as leveling instability, poor operational capacity in current machines. So it is necessary to design better leveling system to improve their working efficiency and stability. Domestic and foreign scholars have done a lot of researches on the leveling system for high-altitude lifting platforms, which provide important academic reference for the design and improvement of the leveling system for orchards lifting platform. There are higher leveling requirements because of poor terrain in orchards. United States, Australia and Japan are the earlier countries to produce lifting platform for orchards and their devices have achieved the automatic leveling. They are yet too expensive for Chinese farmers to afford. In China, it was not until 1980s that the lifting platform for orchards was made. Some types of the lifting platforms made in China realized mechanical leveling, but their leveling accuracy and working efficiency were lower. To this end an auto leveling control system was designed on the basis of the related information at home and abroad. Such a leveling control system consisted of lifting platform, leveling mechanism, hydraulic system and control system. By analyzing forces and movement of the leveling mechanism of the leveling control system, the dynamic mathematical model for the control system was set up. As we all know, the fuzzy control can decrease the overshoot, and PID (proportion, integral, derivative) control can increase the response speed, and Kalman filter can reduce signal interference. So the fuzzy PID control system with Kalman filter was designed. According to the information collected by inclinometer, the control system makes a decision, and then controls electromagnetic valve to drive the leveling cylinder to extend or retract, which can change the motion of the work platform and keep it level. The results of simulation showed that the performance of fuzzy PID control system was better than that of traditional PID. Firstly its rise time was 0.09 s, it's peak time was 0.12 s, its regulation time was 0.41 s, and they were respectively shortened by 43.75%, 47.82%, and 48.10%, respectively, which indicated the initial and overall speed of fuzzy PID control system were better. Secondly the maximum overshoot was 17%, which was reduced by 52.78% of traditional PID's, so fuzzy PID control system realized a good stabilization. Moreover in combination with Kalman filter, the leveling precision of fuzzy PID control system was improved greatly. Its steady state error was about 0.051° and was reduced by 44.57% of PID's. The experiments were done in different slopes (5.1°, 10.5°, 14.5° and 18.8°) and different loads (0, 50, 100, and 150 kg). The results showed that the performance of automatic leveling system was better compared with the original leveling control system. The response time of automatic leveling control system was shorter and was about 0.078 s. When the platform wasn't lifted, under the maximum load and the slope of 18.8°, the maximum automatic leveling error was 1.08°, the automatic leveling precision was increased by 1.69°. In the process of the platform lifted, the maximum automatic leveling error was 1.74°, and the automatic leveling precision was increased by 1.91°. In addition, there were some occasional phenomena such as leveling inaccurately and running slowly in the process of experiments. There were following main 3 reasons: 1) Irregular terrain disturbed the signals collected by angle sensors; 2) The workbench deviated from the set position because of hinge clearances; 3) With the action of motion inertia, the workbench swung back and forth when rising or falling too fast. So the following works will be carried out, including modifying the mechanical structure of lifting platform, and researching control algorithm and mathematical model of the control system to improve control accuracy and leveling efficiency. In conclusion, the automatic leveling control system can meet the design requirements and effectively improve leveling degree and work efficiency, and is well suitable for orchards. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Three term control systems
Controlled terms:Algorithms - Control - Control systems - Design - Efficiency - Errors - Farms - Fruits - Fuzzy control - Fuzzy filters - Hydraulic equipment - Hydraulic machinery - Kalman filters - Leveling (machinery) - Orchards - Proportional control systems - Signal processing
Uncontrolled terms:Automatic leveling controls - Automatic leveling systems - Dynamic mathematical model - Electromagnetic valves - Leveling control systems - Lifting platform - Mechanical structures - Operational capacity
Classification code:603.1 Machine Tools, General - 632.2 Hydraulic Equipment and Machinery - 716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.1 Production Engineering
Numerical data indexing:Percentage 5.28e+01%, Time 1.20e-01s, Time 4.10e-01s, Time 7.80e-02s, Time 9.00e-02s, Mass 1.50e+02kg, Percentage 1.70e+01%, Percentage 4.38e+01%, Percentage 4.46e+01%, Percentage 4.78e+01%, Percentage 4.81e+01%
DOI:10.11975/j.issn.1002-6819.2017.11.005
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 30>
Accession number:20173304046214
Title:Transient characteristic analysis of ultra-low specific-speed centrifugal pumps during startup period under shut-off condition
Authors:Wang, Yong (1); Chen, Jie (1); Liu, Houlin (1); Shao, Chang (1); Zhang, Xiang (2)
Author affiliation:(1) National Research Center of Pumps, Jiangsu University, Zhenjiang; 212013, China; (2) Key Laboratory of Fluid and Power Machinery, Ministry of Education, Xihua University, Chengdu; 610039, China
Corresponding author:Zhang, Xiang(zhangxiang@mail.xhu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:68-74
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the characteristics of the ultra-low specific-speed centrifugal pump during startup period under shut-off condition, an ultra-low specific-speed centrifugal pump with the specific-speed of 25 was chosen as the research object. Unsteady numerical calculation under shut-off condition and transient condition was conducted for the ultra-low specific-speed centrifugal pump. The accuracy of numerical simulation was verified by experimental contrast. Based on the numerical results, the influence of different starting acceleration on the transient impact head, the difference between steady state and transient impact head, and the internal flow field were analyzed. The results showed that: The variation tendency of performance curve on shut-off condition under steady state condition was similar with the experiment, and along with the increase of rotational speed, the head under shut-off condition increased gradually. When the start was completed, the transient head was 8.32%, 6.13% and 4.19% higher than the steady state head, respectively, at 3 different starting accelerations, which indicated that the valve head change during the startup process had a significant transient effect. There was a significantly higher impact head at the end of startup processes with 3 different start accelerations, and with the increase of start acceleration, the impact head was also increased. With the rotation of the impeller acting fluid, the static pressure increased gradually with the increase of the radius. In addition to the impeller flow close to the tongue, the pressure distribution in the other channels was uniform, and the pressure gradient of the tongue was larger, which indicated that the volute tongue structure had an important influence on the distribution of the static pressure in the pump. With the increase of rotation speed, the static pressure increased gradually, and the pressure difference between the inlet and outlet of the pump increased gradually. When the time was 0.4 s, a high pressure concentration area occurred at impeller outlet near the blade pressure surface, and along with the increase of rotation speed, the high pressure concentration area gradually disappeared. The pump pressure distribution gradually grew uniform with pump pressure increasing. At the same speed, static pressure distribution, absolute speed streamline, and relative speed streamline shaft section of inlet pipe during stable process were different from the distribution during transient startup process. The differences were narrow with the increase of rotational speed. At the same speed, the development of inside transient flow field during transient startup process generally lagged after stable condition. At the same speed, static pressure of steady state and startup period under shut-off condition was obviously different. At the beginning of startup period, the static pressure distribution difference was the maximum, and with the increase of speed, the static pressure distribution difference gradually decreased. The relative velocity of steady state and startup period under shut-off condition was obviously different. At the beginning of the startup process, the difference of the streamline distribution of relative velocity was the biggest; with the increase of rotating speed, the difference of pump flow field decreased gradually. The relative velocity of inlet pipe in the process of steady state was larger than that in the process of startup, and the ranges of vortex region and vortex number were greater than the transient process at the same time. Based on the above results, it was found that with the decrease of starting acceleration, the transient effect was weakened. The research results provide the reference for the further study of the characteristics of transient process of the ultra-low specific-speed centrifugal pump. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Transient analysis
Controlled terms:Acceleration - Centrifugal pumps - Computer simulation - Experiments - Flow fields - Impellers - Pressure control - Pressure distribution - Pumps - Speed - Stability criteria - Vortex flow
Uncontrolled terms:Low specific speed centrifugal pump - Shut off conditions - Static pressure distributions - Steady characteristic - Steady state and transients - Steady-state condition - Streamline distributions - Transient characteristic
Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 723.5 Computer Applications - 731.3 Specific Variables Control - 901.3 Engineering Research - 931.1 Mechanics - 961 Systems Science
Numerical data indexing:Percentage 4.19e+00%, Percentage 6.13e+00%, Percentage 8.32e+00%, Time 4.00e-01s
DOI:10.11975/j.issn.1002-6819.2017.11.009
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 31>
Accession number:20173304046242
Title:Effect of different drying methods on flavor components of Chinese shrimp (Fenneropnaeus Chinensis)
Authors:Cai, Luyun (1); Nian, Linyu (1); Cao, Ailing (2); Li, Dongmei (3); Li, Xiuxia (1); Lü, Yanfang (1); Yi, Yuting (1); Li, Jianrong (1)
Author affiliation:(1) Food Safety Key Lab of Liaoning Province, College of Food Science and Engineering, Bohai University, Jinzhou; 121013, China; (2) Xiaoshan Entry-Exit Inspection and Quarantine Bureau, Hangzhou; 311208, China; (3) Haidian District Institute of Products Quality Supervision and Inspection, Beijing; 100094, China
Corresponding author:Li, Jianrong(li34008@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:291-298
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the flavor components of Chinese Shrimps (Fenneropenaeus Chinensis) with different drying methods, dried products were prepared by different drying methods in this paper. The methods included hot air (temperature: (50±2)°C, wind speed: 1.5 m/s, time: 8 h), cold air (temperature: 18-20°C, wind speed: 1.5 m/s, time: 56 h), microwave vacuum (power: 500 W, vacuum: 70 kPa, time: 40 min) and microwave vacuum united with cold air (first the cold air drying with the temperature of 18-20°C, the wind speed of 1.5 m/s, and the time of 27 h, and then the microwave vacuum drying with the power of 500 W, the vacuum of 70 kPa and the time of 10 min). The total free amino acid compositions, flavor nucleotides, equivalent umami concentrations and volatile components were determined in this paper. The results showed that the total free amino acid content of Chinese Shrimps was 63.31 mg/g after hot air drying, which was lower than the fresh shrimp (72.04 mg/g) (P>0.05). The mass fraction of flavor nucleotides of the shrimps after hot air drying was 7.9 mg/g, which was a serious loss on mass fraction of flavor nucleotides compared to the control, and the value of the control was 9.05 mg/g (P<0.05). The equivalent umami concentration of shrimps after hot air drying was the lowest among 4 drying methods, and the value was 127 g/100 g, which was significantly different from the fresh shrimp (180 g/100 g) (P<0.05). The resulting products presented barbecue and seafood flavor due to their main volatile components after hot air drying. The losses on mass fraction of total free amino acids of Chinese Shrimps made by cold air drying were low, and the values were 63.70 (P<0.05), but the equivalent umami concentration after cold air drying was lower than the control, whose value was 155 g/100 g (P<0.05). The volatile constituents after cold air drying were mainly dominated by hydrocarbon compounds, which made dried shrimp flavor insipid. The loss on mass fraction of total free amino acids in dried Chinese Shrimps with microwave vacuum drying method was 55.81 mg/g, which was a serious loss (P<0.05), but the flavor nucleotides and equivalent umami concentrations changed little (P>0.05), the values of which were 9.17 mg/g and 176 g/100 g respectively. And the volatile components of microwave vacuum drying mainly provided meat and roast flavor. The shrimps dried by microwave vacuum united with cold air had the highest mass fraction of flavor nucleotides and the equivalent umami concentrations, the values of which were 9.90 mg/g and 189 g/100 g (P<0.05) respectively. Although the mass fraction of total free amino acids was decreased (62.84 mg/g) compared with the fresh shrimps, it changed little (P<0.05), and the main volatile components were barbecue and seafood flavor. Therefore, the microwave vacuum united with cold air drying method has a promising prospect in the future, which has fewer losses on nutritional value, including total free amino acid compositions, flavor nucleotides, equivalent umami concentrations and volatile components. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Drying
Controlled terms:Amino acids - Flavor compounds - Flavors - Meats - Microwave heating - Microwaves - Nucleotides - Quality control - Shellfish - Solar dryers - Thermal processing (foods) - Volatile organic compounds - Wind
Uncontrolled terms:Chinese shrimps - Equivalent umami concentrations - Flavor nucleotides - Free amino acids - Volatile constituents
Classification code:443.1 Atmospheric Properties - 461.9 Biology - 657.1 Solar Energy and Phenomena - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 804.1 Organic Compounds - 822.2 Food Processing Operations - 822.3 Food Products - 913.3 Quality Assurance and Control
Numerical data indexing:Power 5.00e+02W, Pressure 7.00e+04Pa, Temperature 2.91e+02K to 2.93e+02K, Time 2.02e+05s, Time 2.40e+03s, Time 2.88e+04s, Time 6.00e+02s, Time 9.72e+04s, Velocity 1.50e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.11.037
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 32>
Accession number:20173304046232
Title:Analysis on characterization of heterogeneities and uncertainty for non-point source pollution loads at different basin scales
Authors:Wang, Kang (1); Ran, Ning (1); Zhang, Renduo (2); Lin, Zhongbin (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan; 430072, China; (2) School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou; 510275, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:211-218
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The objectives of this study were to characterize heterogeneities in agricultural non-point source (NPS) pollution loads, and to identify the uncertainty of time series of water flow and NPS pollution loadings at different scales. The Daily flow rates, concentrations of ammonium nitrogen (NH<inf>3</inf>), total nitrogen (TN), total phosphorus (TP), and the permanganate index (I<inf>Mn</inf>) and the degradation coefficients of pollutants were measured in a river basin during the period from 2013 to 2015. The dynamic time warping distance (DTW) was used to characterize the differences of runoff flow rates and NPS pollution (i.e., NH<inf>3</inf>, TN, TP, and I<inf>Mn</inf>) loadings under different underlying surfaces at the sub-basin and basin scales. Information entropy and complexity were used to measure the uncertainty and predictability of different variables at the 2 scales. At both sub-basin and basin scales, NPS pollution loadings increased nonlinearly with rainfall until the rainfall reached 40 mm, and then the NPS pollution loadings maintained stable. The coefficients of variation for NH<inf>3</inf>, TN, TP, and I<inf>Mn</inf>at the basin scale were 69.1%, 47.0%, 14.2%, and 85.8% higher than those at the sub-basin scale, respectively, with the rainfall higher than the threshold amount. During the dry seasons, the differences in NPS pollution loads between the sub-basins were higher than those between the sub-basins and basin, which were mainly affected by the different pollution sources in the regions. The differences in NPS pollution loadings were significantly higher during the wet seasons than during the dry seasons at both the sub-basin and basin scales. Compared with the NPS pollution loads during the dry seasons, the differences in the NPS pollution loads between the 2 sub-basins and between the sub-basins and the basin increased by 3.18 times and 2.44 times, respectively, during the wet seasons. The differences in fluxes of NH<inf>3</inf>, TN, and TP between the sub-basins and between the sub-basins and basin were mainly attributed to the underlying surface conditions and the pollutions sources. Compared with the results at the sub-basin scale, the information entropy values for the time series of the water flux per unit area, TN, TP and I<inf>Mn</inf>loads at the basin scale were decreased by 4.8%, 9.3%, 31.9% and 10.7%, respectively, but NH<inf>3</inf>were increased by 15.3%. The efficient measure complexity increased with the spatial scale. Compared with the sub-basin scale, the efficient measure complexity values at the basin scale for the water flux per unit area, NH<inf>3</inf>, TN, TP and I<inf>Mn</inf>loads increased 4.6%, 15.4%, 17.4%, 49.5% and 19.8%, respectively. The result indicated that more parameters were required at the basin scale than at the sub-basin scale for the efficient prediction. The NPS pollutions load and flow processes were not synchronous at different spatial scales. For the flow rates and the NPS pollution loads, the information entropy decreased and effective measure complexity increased with the basin scales, indicating that the uncertainty decreased and the predictability decreased with the scales. The investigation on the sensitivity of NPS loadings to the rainfall and underlying surface at different scale, and physical basis of the NPS loadings at different scales will provide an insight into the theories of distributed hydrology and NPS simulation model. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:River pollution
Controlled terms:Agriculture - Drought - Flow of water - Flow rate - Nitrogen - Phosphorus - Pollution - Rain - Runoff - Time series - Uncertainty analysis - Water pollution - Water treatment
Uncontrolled terms:Agricultural non-point source pollutions - Basin scale - Coefficients of variations - Degradation coefficients - Dynamic time warping distance - Efficient predictions - Non-point source pollution - Uncertainty
Classification code:442.1 Flood Control - 443.3 Precipitation - 445.1 Water Treatment Techniques - 453 Water Pollution - 631 Fluid Flow - 631.1.1 Liquid Dynamics - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.1 Probability Theory - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.07e+01%, Percentage 1.42e+01%, Percentage 1.53e+01%, Percentage 1.54e+01%, Percentage 1.74e+01%, Percentage 1.98e+01%, Percentage 3.19e+01%, Percentage 4.60e+00%, Percentage 4.70e+01%, Percentage 4.80e+00%, Percentage 4.95e+01%, Percentage 6.91e+01%, Percentage 8.58e+01%, Percentage 9.30e+00%, Size 4.00e-02m
DOI:10.11975/j.issn.1002-6819.2017.11.027
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 33>
Accession number:20173304046240
Title:Urban expansion steady-state index of urban expansion based on remote sensing and GIS and its applications
Authors:Zhao, Guoliang (1); Zheng, Xinqi (1); Liu, Dongya (1); Liu, Fei (1)
Author affiliation:(1) School of Information Engineering, China University of Geosciences, Beijing; 100083, China
Corresponding author:Zheng, Xinqi(zxqsd@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:272-281
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Urban expansion is a globalization trend nowadays, and how to measure the growing degree is a hotspot in the research of urban expansion. Road network is an extremely important factor that drives the increase of urban land. There is an interactive relationship between road network and urban land expansion. The research on the quantitative relationship between those 2 factors is helpful to provide an effective method for sustainable urban development. For the purpose of studying the quantitative index for steady-state urban expansion, in this paper, Beijing, New York, London and other 13 world-class cities were taken as the study areas, and the multi-period remote sensing images and vector data of urban road networks were adopted. Firstly, urban land use vector data were obtained through image interpretation with the aid of a remote sensing and GIS (geographic information system) platform. Then, overlay analysis was utilized to extract urban expansion information. A map of road network density was further generated and manufactured using the density analysis tool in ArcGIS. Secondly, the urban expansion - road network density model was established by regression analysis, which was used for fitting the relationship between road network density and urban expansion speed. Through the calculation and comparison of the sample cities' values of the turning point and thresholds for urban expansion, urban expansion steady-state index (UESI) was proposed, and then 13 sample cities' UESI values were calculated. Finally, the urban expansion state of Beijing in 2025 was predicted by using CA (cellular automaton) - Markov model and Logistic regression model. The results proved that (1) compared with the developed cities, Beijing's urban land expansion was in a serious situation in the past 30 years, and Beijing required the dispersal of population and function in the future; the road network density in Beijing was relatively low and presented a single center, which should be improved and optimized; (2) UESI could effectively quantify the trend of urban expansion; assuming that external environment of urban development was stable, the urban expansion was in a relatively steady state, while UESI reached 0.30. New York, London, Tokyo and other cities' UESIs were close to or greater than 0.30, while Beijing and Sao Paulo's UESIs were less than 0.20; Sydney's USEI was 0.21, which meant Sydney had a great potential for urban land expansion in the future; (3) according to urban expansion quantitative analysis and the theory of urban life cycle, the period of urban expansion could be divided into development period, growth period, maturity period and transition period; and the corresponding typical cities were Mexico City, Beijing, New York and Paris separately; (4) if the current city development trend was kept, the UESI of Beijing in 2025 would be 0.19, more than 0.17 in 2015, and the urban land expansion would remain in the growth period. UESI has the reference value for urban planning in fast-developing cities. The index effectively quantifies the status and potential of urban expansion, and enriches the quantitative study of urban expansion. Understanding the quantitative relationship between road network density and urban expansion is beneficial to define urban development phases, avoid the irregular expansion, and provide new ideas for addressing the inefficient utilization of land and other issues. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Urban growth
Controlled terms:Digital storage - Geographic information systems - Image reconstruction - Land use - Markov processes - Motor transportation - Networks (circuits) - Regression analysis - Remote sensing - Roads and streets - Transportation - Urban planning
Uncontrolled terms:Interactive relationships - Logistic Regression modeling - Megalopolis - Remote sensing and GIS - Remote sensing images - Steady state - Sustainable urban development - Urban expansion
Classification code:403 Urban and Regional Planning and Development - 403.1 Urban Planning and Development - 406.2 Roads and Streets - 703.1 Electric Networks - 722.1 Data Storage, Equipment and Techniques - 903.3 Information Retrieval and Use - 922.1 Probability Theory - 922.2 Mathematical Statistics
Numerical data indexing:Age 3.00e+01yr
DOI:10.11975/j.issn.1002-6819.2017.11.035
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 34>
Accession number:20173304046225
Title:Scheduling optimization for rural micro energy grid multi-energy flow based on improved crossbreeding particle swarm algorithm
Authors:Zhang, Xin (1, 2); Zhang, Man (1); Wang, Weizhou (3); Yang, Jianhua (1); Jing, Tianjun (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing; 100083, China; (2) College of Information Engineering, Inner Mongolia University of Science and Technology, Baotou; 014010, China; (3) State Grid Gansu Provincial Electric Power Research Institute, Lanzhou; 730050, China
Corresponding author:Zhang, Man(cauzm@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:157-164
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There is poor infrastructure and weak power grid in Chinese western rural areas. Photovoltaic (PV) and wind power pro-poor investments do not consider supporting transmission and distribution facilities. The economy of biogas from biomass waste is not good, due to that it is affected by seasonal variations in temperature. Utilizing PV and wind power to supply energy for biogas can improve biomass energy utilization and solve the problem of environmental pollution, while the absorptive capacity of the PV and wind power is increased, and the comprehensive utilization of biomass and renewable energy in place can be achieved. It has important significance for development of new countryside. Based on national PV and wind power poverty relief policy, this paper proposed rural micro energy grid architecture that combines PV system, wind power system, micro turbine, biogas fired boilers, heat recovery boiler, lithium-bromide absorption-type refrigerator, battery storage, heat and cooling storage, air-source heat pumps for cooling exchange, air-source heat pumps for heating exchange, and so on. Mathematical models of micro turbine CCHP (combined cooling heating and power) system, air-source heat pumps system, heat and cooling storage system and battery storage system were built up. With micro energy grid cost in a single day as an objective function, considering electric power balance, heating power balance, cooling power balance, power exchange with electricity grid and the other constraints, the micro energy grid optimal model was established. Because of premature and local optimization problem for particle swarm algorithm, this paper uses dynamic inertia weight crossbreeding particle swarm optimization algorithm for solving. Taking Chinese west village as an example, according to the actual situation, electric and heating power were supplied in the winter, but electric and cooling power were supplied in the summer. Electricity price applied the time of use price issued by the National Development and Reform Commission. Parameters of energy supply equipment and energy storage equipment, time of use price, and equipment maintenance cost per unit power were determined. Forecasted data were given, which combine PV and wind power outputs, electricity heating and cooling load for typical day. Simulation platform was built in MATLAB 2014a. Electric heating and cooling balance curve of typical day was acquired. System running cost comparison of typical day based on improved and basic algorithm was performed. In addition, according to forecasted curve referred to above, parameters of various devices, time of use price and equipment maintenance cost, the un-optimized system running cost was calculated. Results showed that, through the dispatch of each device in the system, the outputs of energy supplying devices were more reasonable, and energy storage devices played a role of load shifting. The daily running cost based on dynamic inertia weight crossbreeding particle swarm optimization algorithm was less than that based on basic particle swarm and un-optimized cost. To sum up, the proposed algorithm is adopted to dispatch various devices in micro energy grid, it can reduce system running cost effectively, and micro energy grid can be operated economically; the correctness of the models and algorithms can be proved. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Electric load dispatching
Controlled terms:Absorption cooling - Absorption refrigeration - Air source heat pumps - Algorithms - Biogas - Biomass - Boilers - Cooling - Costs - Curve fitting - Digital storage - Economics - Electric batteries - Electric energy storage - Electric power transmission networks - Energy storage - Energy utilization - Equipment - Heat pump systems - Heating - Investments - Maintenance - MATLAB - Meteorology - Optimization - Particle swarm optimization (PSO) - Rural areas - Thermal management (electronics) - Turbines - Waste heat - Wind power
Uncontrolled terms:Energy internet - Heating power - Micro energy grids - Particle swarm algorithm - Power
Classification code:522 Gas Fuels - 525 Energy Management and Conversion - 614 Steam Power Plants - 615.8 Wind Power (Before 1993, use code 611 ) - 616.1 Heat Exchange Equipment and Components - 641.2 Heat Transfer - 644.1 Refrigeration Methods - 702.1 Electric Batteries - 706.1.1 Electric Power Transmission - 722.1 Data Storage, Equipment and Techniques - 901 Engineering Profession - 911 Cost and Value Engineering; Industrial Economics - 913.5 Maintenance - 921 Mathematics - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2017.11.020
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 35>
Accession number:20173304046226
Title:Crop rows detection based on image characteristic point and particle swarm optimization-clustering algorithm
Authors:Jiang, Guoquan (1); Yang, Xiaoya (1); Wang, Zhiheng (1); Liu, Hongmin (1)
Author affiliation:(1) School of Computer Science and Technology, Henan Polytechnic University, Jiaozuo; 454000, China
Corresponding author:Wang, Zhiheng(wzhenry@eyou.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:165-170
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to extract the crop rows of wheat quickly and accurately, a new method of wheat crop row detection was proposed based on particle swarm optimization (PSO) - clustering. The first step is image segmentation. The purpose of image segmentation was to separate the green plants from background, and it required the following 2 steps: Firstly, gray-level transformation, which could be done in RGB color space. In this paper, the color excess green index 2G-R-B was used; Secondly, image binarization was conducted. Among the global thresholding techniques for image binarization, Otsu method is one of the best threshold ways. So, this paper used Otsu algorithm to binarize the above obtained gray-level image. In order to reduce the burden of the next work, it was essential to extract a number of feature points indicating the crop rows. The specific algorithm can be divided into 2 steps: Firstly, get the left and right boundary points of each crop row. Secondly, extract the midpoint between left and right boundary points. After the original crop image was processed by the above steps, we got the feature points of the crop rows. According to the characteristics that the distances from the feature points around the crop row centreline to this straight line were all smaller than a certain distance threshold, we used the clustering method based on PSO to determine the real center points indicating crop rows. In the crop rows detection algorithm based on the PSO-clustering, the line in the data space composed of the feature points was considered as a particle. Finally, the centrelines were detected by fitting a straight line with the least square method. In order to prove the superiority of the algorithm, we compared the algorithm with standard Hough transform and the algorithm proposed in another literature. We tested the performance from the aspects of the detection accuracy and processing time for different images. Here, a total of 350 images have been tested. The number of the wheat images in overwintering stage was 197 and the number of the wheat images in green stage was 153. For the algorithm proposed in this paper, the number of the wheat images in overwintering stage successfully detected was 190 and that in green stage successfully detected was 143. Comparatively speaking, for the algorithm with standard Hough transform, the numbers of the wheat images in overwintering and green stage that were successfully detected were 180 and 100, respectively. For the algorithm proposed in another literature, the numbers were 168 and 93, respectively. Three representative pictures were selected in the experiment, which included the different environment i.e. the lack of crops, soil block, and high density weed. For the 3 images, the identification errors of the proposed algorithm were 0.631 0°, 0.773 5° and 1.065 7°, respectively. The identification errors of the standard Hough were 0.968 3°, 2.715 8° and 4.463 3°, respectively. The identification errors of the algorithm proposed in another literature were 2.260 5°, 1.531 9° and 5.829 1°, respectively. Therefore, compared with the other 2 algorithms, the proposed algorithm has the advantages of high real time and high accuracy, which can meet the practical requirements of field operation of agricultural robots. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Clustering algorithms
Controlled terms:Agriculture - Algorithms - Bins - Color - Crops - Errors - Feature extraction - Hough transforms - Image enhancement - Image processing - Image segmentation - Information dissemination - Least squares approximations - Optimization - Particle swarm optimization (PSO)
Uncontrolled terms:Clustering - Crop rows detection - Gray-level transformation - Identification errors - Image characteristics - Least Square - Practical requirements - Standard hough transforms
Classification code:694.4 Storage - 741.1 Light/Optics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 903.1 Information Sources and Analysis - 903.2 Information Dissemination - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2017.11.021
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 36>
Accession number:20173304046222
Title:Influence factor analysis related to strength and anti-erosion stability of silt slope with microbial mortar protective covering
Authors:Shao, Guanghui (1, 2); Feng, Jianting (1); Zhao, Zhifeng (1, 2); Liu, Peng (1, 2); Li, Ze (1); Zhou, Ningna (1)
Author affiliation:(1) School of Civil Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing; 210037, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:133-139
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Microbial mortar protective covering is a new technology for controlling silt slope surface dust and water erosion. The anti-erosion performance of the protective covering depends to a large extent on the strength and stability of covering. However, the factors that govern the protective property of covering have not been fully studied. Based on microbial induced calcite precipitation (MICP) technology, the surface protective covering experiments were carried out to treat silt slope surface against rainfall erosion. Indoor model tests on silt surface protective covering by microbial mortar were performed to investigate the properties such as strength, water stability and anti-erosion. Sand was covered on dredger fill silt surface to form a thin layer, and then some Sporosarcina pasteurii and a kind of cementing solution containing a mixture of CaCl2 and urea were sprayed on the sand layer surface to obtain a crustose protective covering. The micro-penetration test was adopted to investigate the penetration resistances change of uncovered silt and protected silt covered with microbial mortar crust. The property of protective strength ratio measured by micro-penetration test was used to evaluate the strength of microbial mortar protective covering relative to uncovered silt surface. The collapse ratio and strength loss ratio were tested on the microbial mortar protective covering by immersed in water for 12 h to assess its water stability performance. The change laws of protective covering strength and water stability were drawn from different covering thickness, mixed cementing solution concentration of CaCl<inf>2</inf>and urea, and spraying times. On the basis of the tests of protective covering, the rainfall model experiments were conducted. A slope angle variable steel tank with the size of 1.4 m × 0.3 m× 0.06 m (length × width × height) was applied for holding test material and simulating the silt slope, which was subjected to strong rainfall scour under a rainfall simulating system. The soil detachment rates were investigated from the rainfall simulation experiment by changing slope angle from 5° to 25° and rainfall time from 4 to 20 min. The experimental results revealed that: 1) The minimum effective thickness of microbial mortar protective covering was 5 mm. The strength and water stability of protective covering increased with the cementing solution concentration, protective covering thickness and spraying times. 2) After treated 4 times with 0.50 mol/L cementing solution, a protective covering was formed, which had high strength, good anti-collapse property and excellent water stability. A 5 mm thick protective covering could reach penetration resistance of 310 kPa, protective strength ratio of 77.5, collapse ratio of 2.3%, and strength loss ratio of 5.4% when immersed in water. 3) Compared with untreated silt slope, the treated silt slope reduced soil detachment rate from over 29.6 g/(m<sup>2</sup>·s) to under 6.8 g/(m<sup>2</sup>·s). The soil detachment rate of treated silt slope was between 5.4 and 6.8 g/(m<sup>2</sup>·s) and insensitive to the slope angle. Under 20 min heavy rainfall scouring, the soil detachment rate of treated silt slope was only 3.6 g/(m<sup>2</sup>·s). The microbial mortar protective covering presented significant anti-erosion capacity. 4) The strength of protective covering and the permeability of substratum silt had coupling effect on the anti-erosion mechanism of microbial mortar protective covering. The coarse and porous covering played an important role in resisting raindrop splash and surface flow erosion by the high strength of crust. Meanwhile, the low permeability of silt under the covering resisted piping and suffusion erosion. The anti-erosion effectiveness of protective covering was dominated by the microbial mortar crust strength. For effective microbial mortar protection, at the microstructure level it was essential that the cement calcite from MICP formed surrounding cementation structure around soil particles surface. The results provide valuable information for applying MICP technology on silt slope anti-erosion. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Strength of materials
Controlled terms:Calcite - Cementing (shafts) - Cements - Erosion - Metabolism - Mortar - Precipitation (meteorology) - Rain - Silt - Slope stability - Soil cement - Soil testing - Soils - Stability - Testing - Thickness control - Urea - Well cementing
Uncontrolled terms:Influence factor analysis - Microbially induced carbonate precipitations (MICP) - Penetration resistances - Protective engineering - Protective properties - Soil detachment - Solution concentration - Water stability
Classification code:406.2 Roads and Streets - 412.1 Cement - 414.3 Mortar (Before 1993, use code 412) - 443.3 Precipitation - 483.1 Soils and Soil Mechanics - 731.3 Specific Variables Control - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 951 Materials Science
Numerical data indexing:Molar_Concentration 5.00e+02mol/m3, Percentage 2.30e+00%, Percentage 5.40e+00%, Pressure 3.10e+05Pa, Size 5.00e-03m, Size 6.00e-02m, Time 1.20e+03s, Time 2.40e+02s to 1.20e+03s
DOI:10.11975/j.issn.1002-6819.2017.11.017
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 37>
Accession number:20173304046238
Title:Effects of fan cavities on fluid flow and heat transfer in helical and straight mini-channels of heat exchanger
Authors:Feng, Zhenfei (1, 2, 3); Zhu, Li (1); Lin, Qingyu (1, 2); Li, Huan (1); Liu, Penghui (1); Hu, Huayu (1); Yang, Mei (1); Huang, Zuqiang (1)
Author affiliation:(1) School of Chemistry and Chemical Engineering, Guangxi University, Nanning; 530004, China; (2) Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, Guangxi University, Nanning; 530004, China; (3) School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou; 510641, China
Corresponding author:Huang, Zuqiang(huangzq@gxu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:254-261
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the rapid development of microminiaturization technology and the urgent requirements of industrial field, the sizes of many devices are reduced continually. This causes the thermal load to increase sharply when the device is working, and further leads to the decreasing of the working stability gradually. So the conventional heat exchanger can't meet the heat transfer requirement for these micro-devices. Thus, the micro/mini-channel heat exchanger emerges as the times require. This exchanger has many advantages, such as compact structure, high efficiency for heat dissipation, low power consumption and few coolant requirements. These advantages motivate many researchers to conduct numerous studies on the micro/mini-channel heat exchanger continuously to further enhance heat transfer performance. Adding cavities, fins or ribs on the wall of the channel is a solution for enhancing heat transfer performance in the micro/mini-channel heat exchanger. As we know, the helical and straight channels are widely applied to the heat exchanger. The difference between both channels is the existence of secondary flow in former, inducing heat transfer enhancement. Therefore, it is important to understand the effects of cavities or fins on the fluid flow and heat transfer enhancement in the helical and straight micro/mini-channel heat exchangers. As a consequence, the cavities are added on the both sidewalls of helical and straight mini-channels in this work, and the effects of the cavities on the fluid flow and heat transfer in the helical and straight mini-channels are studied using numerical simulation method. Specifically, the comparative analysis in the effects of cavities on the flow, heat transfer, entropy generation and overall performance in the helical and straight mini-channels is performed based on the first and second thermodynamics law. This aims to analyze the different effects of cavities on both mini-channels. The cross-sections for both mini-channels are the same, and the width and height of this cross-section are 3 and 3 mm, respectively. The working conditions include the Reynolds number of 168-2017, the heat flux density of 1.145 98×10<sup>5</sup>and 1×10<sup>5</sup>W/m<sup>2</sup>for helical and straight mini-channels, respectively, based on the condition of different heating area and same power input. The numerical results show that for helical mini-channel, the cavities can increase flow resistance, and the maximum increasement reaches up to 23%. But they have no obvious influence on heat transfer performance. For straight mini-channel, the cavities can slightly reduce flow resistance and heat transfer performance when the Reynolds number is less than 1 008. However, they rapidly increase flow resistance and heat transfer performance when the Reynolds number is greater than 1 008, and the friction factor and Nusselt number grow to 50% and 45% respectively. In the whole Reynolds number range, the cavities can't improve the overall performance in the helical mini-channel. Although the cavities slightly weaken the overall performance in the straight mini-channel at low Reynolds number, they obviously enhance the overall performance at high Reynolds number, and the maximum heat transfer augmentation factor grows to 1.27. The results of entropy generation analysis indicate that the cavities can reduce irreversible loss in the flow and heat transfer process for helical and straight mini-channels, thereby improving effective utilization of thermal energy. However, the decrement rate of irreversible loss for straight mini-channel with the cavities is greater than that for helical mini-channel, for the former's decrement rate is about 2 times that of the latter. This work provides a reference for improving the performance of heat exchanger with mini/micro-channels. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Heat exchangers
Controlled terms:Computer simulation - Energy efficiency - Entropy - Fins (heat exchange) - Flow of fluids - Fluids - Heat flux - Heat resistance - Heat transfer - Heat transfer coefficients - Numerical methods - Numerical models - Reynolds number - Thermodynamics
Uncontrolled terms:Cavity - Entropy generation - Entropy generation analysis - Fluid flow and heat transfers - Heat Transfer enhancement - Heat transfer performance - Mini channels - Numerical simulation method
Classification code:525.2 Energy Conservation - 616.1 Heat Exchange Equipment and Components - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 723.5 Computer Applications - 921 Mathematics - 921.6 Numerical Methods
Numerical data indexing:Percentage 2.30e+01%, Percentage 4.50e+01%, Percentage 5.00e+01%, Size 3.00e-03m
DOI:10.11975/j.issn.1002-6819.2017.11.033
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 38>
Accession number:20173304046211
Title:Mechanism analysis and experiment on vibration harvesting of wolfberry
Authors:He, Miao (1); Kan, Za (1); Li, Chengsong (1); Wang, Lihong (1); Yang, Lantao (1); Wang, Zhe (1)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi; 832003, China
Corresponding author:Li, Chengsong(lcs_shz@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:47-53
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wolfberry acreage is growing increasingly year by year in China. However, artificial harvesting is labor intensive and inefficient, so harvest problem has become a bottleneck in the development of Chinese wolfberry industry. Literature shows that vibration device in fruit harvest has obvious advantages. In order to further study the mechanism of wolfberry vibration harvesting, fruit-pedicle separation conditions and dynamic transfer characteristics of wolfberry branch were analyzed, and then harvest conditions of wolfberry were obtained. Vibration harvesting usually uses vibration source to directly vibrate fruit branch (fourth branch) to achieve fruit separation, but when fruit branch is not directly vibrated, it needs to rely on vibration energy of third branch to achieve fruit-pedicle separation. Vibration separation test bench was set up, which included electric vibration test system, motion control system, vibration separation test rack, and so on. Vibratory separation test device was used to carry out fruit-pedicle vibration separation test of fruit branch, which was designed by quadratic regression universal rotary combination design method. The main factors affecting fruit-pedicle separation rate were as follows: excitation frequency, excitation amplitude and vibration time (replaced by branches travelling speed), with mature fruit separation rate and immature fruit separation rate as response index. Searching for the optimum vibration parameter combination of fruit-pedicle separation, high-speed camera system was used to analyze acceleration response of vibrated part and end part, and as a result vibration separation conditions of wolfberry were obtained. The experimental results showed that the optimal combination parameters were the excitation frequency of 18.22 Hz, the excitation amplitude of 7.87 mm and the branches traveling speed of 20.93 mm/s. And the results showed that the separation rate of mature fruit was 95.18% and the separation rate of immature fruit was 6.43%. Dynamic responses of the optimal vibration combination parameters were analyzed, and the results showed that the acceleration of vibration was 518.38-551.06 m/s<sup>2</sup>when fruit branch was directly vibrated; the vibration energy was transferred to end of fruit branch by direct excitation of third branch when fruit branch was not vibrated, and fruit branch acceleration was required to reach 347.64-390.56 m/s<sup>2</sup>. In this experiment, a single random stimulus was used to wolfberry third branch, vibration transfer of third and fruit branch was tracked by high-speed camera system, and wolfberry branch dynamic response was analyzed by a high speed motion analysis software ProAnalyst. The Shapiro-Wilk's normal test was performed with acceleration data of third branch and fruit branch of wolfberry, corresponding confidence intervals were calculated, and then acceleration response relationship of third branch and fruit branch was obtained. The acceleration required for wolfberry vibration harvesting under different excitation conditions was obtained. Firstly, when all the fruit branches were directly vibrated, acceleration of vibration was required to reach 518.38-551.06 m/s<sup>2</sup>; secondly, when all third branches (parent third branch and adjacent third branch) were directly vibrated and part of fruit branches could not be vibrated, only the dynamic response of parent third branch and fruit branch needed to be considered, and the maximum acceleration from parent third branch to fruit branch was reduced by 5 times, with the lag time of 0.032 s, and the acceleration of parent third branches vibration needed to reach 1 738.20-1 952.80 m/s<sup>2</sup>; thirdly, when partial fruit branch and third branch (adjacent third branch) were not vibrated, the maximal acceleration value from adjacent third branch to fruit branch was attenuated by 6 times and the lag time was 0.048 s. Acceleration of adjacent third branch vibration needed to reach 2 085.84-2 343.36 m/s<sup>2</sup>. As large vibration acceleration can cause wolfberry branch injury, in the design of wolfberry harvesting device, the structure should ensure that all fruit branches are directly vibrated as far as possibly, and at least ensure that all third branches are directly vibrated; vibrating rods can use nylon and other flexible material with less damage to branches. The results of this study can provide theoretical basis for the mechanized harvest of wolfberry. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Vibration analysis
Controlled terms:Acceleration - Cameras - Crops - Dynamic response - Dynamics - Fruits - Harvesting - High speed cameras - Machinery - Mechanization - Motion control - Separation - Source separation - Speed
Uncontrolled terms:Acceleration response - Excitation amplitudes - High speed camera systems - High speed motion analysis - Transfer characteristics - Vibration test system - Vibrations - Wolfberry
Classification code:601 Mechanical Design - 716.1 Information Theory and Signal Processing - 731.3 Specific Variables Control - 742.2 Photographic Equipment - 802.3 Chemical Operations - 821.3 Agricultural Methods - 821.4 Agricultural Products
Numerical data indexing:Acceleration 3.43e+02m/s2, Acceleration 3.48e+02m/s2 to 3.91e+02m/s2, Acceleration 5.18e+02m/s2 to 5.51e+02m/s2, Frequency 1.82e+01Hz, Percentage 6.43e+00%, Percentage 9.52e+01%, Size 7.87e-03m, Time 3.20e-02s, Time 4.80e-02s, Velocity 2.09e-02m/s
DOI:10.11975/j.issn.1002-6819.2017.11.006
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 39>
Accession number:20173304046233
Title:Heating characteristics and field control effect of rapid citrus huanglongbing steam heat treatment
Authors:Jia, Zhicheng (1, 2); Reza, Ehsani (2); Zheng, Jiaqiang (1); Xu, Linyun (1); Zhou, Hongping (1); Ding, Rui (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) Citrus Research and Education Center, University of Florida, Lake Alfred; 33850, United States
Corresponding author:Zheng, Jiaqiang(jqzheng@njfu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:11
Issue date:June 1, 2017
Publication year:2017
Pages:219-225
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The citrus Huanglongbing (HLB), caused by the bacterium limited in the phloem, Candidatus Liberibacter spp, is a highly destructive citrus disease for the worldwide citrus industry. Until now, the field thermotherapy has showed effect in HLB control. However, all sorts of thermotherapies only focus on the canopy temperature without considering the inner bark or phloem temperature. In this study, indoor and field steam treatment system consists of enclosure, circumstance temperature monitoring system, outer and inner bark temperature testing system. Temperature distribution of outer and inner bark when heating up with different steam supplying pressure and heat preserving time showed that: 1) For the 1-year-old plants, the 65℃ was the deadly outer temperature limit. The confirmation of deadly outer bark temperature was the most important in field heat treatment. Based on the inner bark temperature increasing effect, the outer temperature of 60℃ was better than lower temperature for inner bark temperature increasing. For achieving the higher outer temperature, more heating time is needed, which allows more heat transfer from the outer to inner bark. For the 9-year-old plants, the 60℃ was the better outer temperature without obvious heat damage to the plants. 2) For effective control of HLB, the inner bark temperature was more important than the outer bark temperature. The heat preserving time following steam treatment is beneficial for inner bark temperature increasing. The preserving temperature increase from the treatment with higher transfer pressure was higher than lower pressure. However, based on the total heating effect of inner bark, comprehensively considering the temperature increase from treatment and the following heat preserving, the lower pressure was the better choice. 3) For the 9-year plants, after field heat treatment with the 60℃-0.03 MPa-30 s, the results of quantitative polymerase chain reaction (qPCR) after treatment showed significant change in the 'Ca.L.asiaticus' bacterial titer, combined with vigorous growth from all 4 treated infected trees. The qPCR testing also confirmed that 2 previously infected plants with heat treatment showed no detectable levels of 'Ca.L.asiaticus', while untreated infected plants remained highly infected. 4) Based on the steam treatment, it was concluded that the procedure should be as follows: Based on the inner bark temperature increase, first of all, confirm the deadly outer temperature of the specific plant; then, compare the heating effect with different combination of the steam supplying pressure and the following heat preserving time. As a conclusion, from the view of heat transfer, the best steam treatment parameters should be determined based on the analysis of inner bark temperature increase. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Temperature
Controlled terms:Bacteria - Disease control - Heat transfer - Heat treatment - Heating - Physical therapy - Polymerase chain reaction - Pressure effects - Steam
Uncontrolled terms:Canopy temperature - Huanglongbing(HLB) - Phloem - Phloem temperatures - Quantitative polymerase chain reaction - Temperature increase - Temperature monitoring - Temperature testing
Classification code:461.5 Rehabilitation Engineering and Assistive Technology - 537.1 Heat Treatment Processes - 641.1 Thermodynamics - 641.2 Heat Transfer - 801.2 Biochemistry - 931.1 Mechanics
Numerical data indexing:Age 1.00e+00yr, Age 9.00e+00yr
DOI:10.11975/j.issn.1002-6819.2017.11.028
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
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- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
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- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
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- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
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