<RECORD 1>
Accession number:20190706490383
Title:Performance of solar active-passive combined heating system in Tibetan areas of southern Gansu
Authors:Li, Jinping (1, 2, 3, 4); Wang, Hang (1, 2, 3, 4); Wang, Zhaofu (1, 2, 3, 4); Huang, Juanjuan (1, 2, 3, 4); Wang, Chunlong (1, 2, 3, 4)
Author affiliation:(1) Western China Energy & Environment Research Center, Lanzhou University of Technology, Lanzhou; 730050, China; (2) Key Laboratory of Energy Supply System Drived by Biomass Energy and Solar Energy of Gansu Province, Lanzhou; 730050, China; (3) China Northwestern Collaborative Innovation Center of Low-carbon Urbanization Technologies, Lanzhou; 730050, China; (4) College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou; 730050, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:1-7
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The traditional heating methods in winter, in Tibetan areas in China are relatively backward, and the indoor living environment is poor. Owing to the abundant solar energy in the Tibetan areas of China, the potential of solar heating is huge. In order to use solar energy to achieve the clean heating, two single buildings with a passive sunlight area of 170 m<sup>2</sup> in Shanglangkanmu, a village of Hezuo in Gansu Province, were studied, as research objects, one of which used passive sunspace and cow dung direct-fired furnace for heating, and the other used passive sunspace and solar collectors for heating. The solar collector system has 7 sets of all-glass vacuum tube solar collectors. The collector surface was placed at an angle of 45° to the ground. It was positioned in the south, and the amount of collectors of each group was 30. All-glass vacuum tube was 1.8 m of length, 0.058 m of diameter, and 20.2 m<sup>2</sup> of heat collection area. Under the same environmental conditions, the theoretical and experimental methods were used to compare the indoor thermal environment, systemic economic and environmental benefits. The test time was from March 20th to May 8th, 2018. The indoor and outdoor temperature, indoor and outdoor wind speed, solar radiation intensity and other parameters were investigated. The data were automatically recorded by computer. The research results show that in the 48 d test period, the days of living temperature higher than 14℃ in experimental building with the solar energy active and passive combined heating system is 47 d, indoor minimum temperature of 13.3℃ is for only 1 day, the heat supply of the system in addition to individual extreme weather, can satisfy the heating needs of the building well, indicating that the system's energy supply stability is well, anti-interference ability is strong. When the outdoor environment minimum temperature is -8.6℃, the average indoor temperature of experimental building with combined sunspace and active solar heating system is 16.3℃, which is 7.3℃ higher than that of the contrast building, between the two buildings the highest temperature difference is 11.5℃, and the temperature fluctuation of the experimental building is small. The temperature in vertical height is evenly distributed, the indoor thermal comfort is well, the temperature of experimental building can completely reach the indoor temperature by 14℃ through the solar active heating, and the temperature of kang can be maintained at 22.3-34.7℃ during night sleep time, it belongs to the human body sleep comfort temperature which improves the comfort of people during sleep. The solar energy active and passive combined heating system satisfies the heating demand of the building well. The temperature in contrast building with the passive sunspace and the cow dung direct combustion furnace is nonuniform, the difference of temperature is distinguished, the living room temperature is generally lower than 12℃. Compared with the contrast building, the experimental building with solar energy active and passive combined heating system can reduce 4.3 t standard coal in the heating season, which can reduce the CO<inf>2,</inf> dust, SO<inf>2</inf>, and NO<inf>x</inf> emissions by 10.7, 2.92, 0.322 and 0.161 t, respectively. The dynamic investment payback period is 4.9 a. It proves the feasibility, energy saving and economy of the system, and can be utilized to guide the optimal design and popularization of solar energy active and passive combined heating systems in different regions.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Solar heating
Controlled terms:Coal combustion - Coal dust - Economics - Electron tubes - Energy conservation - Glass - Heating - Heating equipment - Investments - Sleep research - Solar buildings - Solar collectors - Solar energy - Space heating - Temperature - Thermal comfort - Wind
Uncontrolled terms:Economic and environmental benefits - Environmental conditions - Experimental buildings - Indoor thermal environments - Solar radiation intensity - Sunspace - Temperature fluctuation - Thermal economy
Classification code:443.1 Atmospheric Properties - 461.4 Ergonomics and Human Factors Engineering - 503 Mines and Mining, Coal - 521 Fuel Combustion and Flame Research - 524 Solid Fuels - 525.2 Energy Conservation - 641.1 Thermodynamics - 643 Space Heating, Ventilation and Air Conditioning - 643.1 Space Heating - 657.1 Solar Energy and Phenomena - 714.1 Electron Tubes - 812.3 Glass - 971 Social Sciences
Numerical data indexing:Age 2.74e-03yr, Area 1.70e+02m2, Area 2.02e+01m2, Size 1.80e+00m, Size 5.80e-02m
DOI:10.11975/j.issn.1002-6819.2018.21.001
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 2>
Accession number:20190706490411
Title:Methanogenesis kinetics of anaerobic digestion of acetate and propionate at mesophilic and thermophilic conditions
Authors:Qiao, Wei (1, 2); Jiang, Mengmeng (1, 2); Zhao, Jing (1, 4); Wandera, S.M. (1, 2); Dong, Renjie (1, 2, 3)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing; 100083, China; (3) Institute of Yantai, China Agricultural University, Yantai; 264670, China; (4) Faculty of Science and Engineering, University of Groningen, Groningen; 9747AG, Netherlands
Corresponding author:Dong, Renjie(rjdong@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:234-238
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:During anaerobic fermentation is strongly influenced by temperature and volatile fatty acids (VFAs). When the temperature in anaerobic reactors is too high, the VFAs are easy to accumulate, especially acetate and propionate. High VFAs will inhibit the activity of methanogens, the fermentation process as well as the methane yield will become unstable even make the anaerobic system failed. In order to investigate the ability of adapting different concentration of acids and temperature, batch experiments with different concentrations of acetate and propionate were carried out at both mesophilic and thermophilic conditions. Modified Gompertz model and first order model were used to analyze the methane production kinetics. The inoculum was got from coffee mate anaerobic digestion, because coffee mate contains 2% protein, 34% fat and 56% carbohydrates, which can simulate the real ingredients in anaerobic fermentation. The concentrations of acetate acid were set for 0, 2 000, 5 000, 10 000 and 20 000 mg/L; and the concentrations of propionate were set for 0, 500, 1 000, 2 000, 4 000 and 8 000 mg/L. In addition, sodium hydroxide was used to adjust the pH value in a range of 7.2-7.6 in every batch bottle, and every concentration had 3 parallels to ensure the veracity of this experiment. The result showed that both of acetate and propionate degradation faster at the lower concentration. Acetate was easily degraded at mesophilic condition, when the concentration of acetate was 5 000 mg/L; mesophilic reactors had the maximum methane production rate which was 101 mL/d, while the thermophilic reactor had the maximum methane production rate which was 77 mL/d when the acetate concentration was 10 000 mg/L. With the acid concentration increasing, methane production rate decreased and the thermophilic reactor had a higher tolerance for the acetate concentration. In contrast, propionate was easily decomposed under the thermophilic condition and the lag phase under mesophilic was greatly affected by the acid concentration; when the propionate concentration increased from 500 to 4 000 mg/L, the lag phase doubled under the mesophilic condition while a half fold increase under the thermophilic condition. The maximum methane production rate was 96 mL/d when the concentration of propionate was 4 000 mg/L, while the maximum methane production rate under mesophilic condition was 75 mL/d when the concentration of propionate was 4 000 mg/L as well. The lag phase of gas production was longer at higher acid concentration, while the first-order kinetic constants reduced. In addition, the degradation rate constant of both mesophilic and thermophilic under same acid condition showed that the effect of temperature on anaerobic degradation is greater than that of acid concentration to some extent.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Volatile fatty acids
Controlled terms:Anaerobic digestion - Bottles - Degradation - Enzyme kinetics - Fermentation - Kinetics - Methane - Rate constants - Sodium hydroxide - Temperature
Uncontrolled terms:Acetate - Acetate concentrations - Anaerobic fermentation - Degradation rate constants - Modified-Gompertz model - Propionate - Thermophilic conditions - Volatile fatty acids (VFAs)
Classification code:641.1 Thermodynamics - 694.2 Packaging Materials - 802.2 Chemical Reactions - 804.1 Organic Compounds - 931 Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Mass_Density 1.00e+01kg/m3, Mass_Density 4.00e+00kg/m3, Mass_Density 5.00e-01kg/m3 to 4.00e+00kg/m3, Mass_Density 8.00e+00kg/m3, Percentage 2.00e+00%, Percentage 3.40e+01%, Percentage 5.60e+01%
DOI:10.11975/j.issn.1002-6819.2018.21.029
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 3>
Accession number:20190706490408
Title:Complex insulation shutter improving winter thermal and humidity environment of open-ended cowshed in cold region
Authors:Zhao, Wanying (1); Zhang, Qi (1, 2); Shi, Zhengxiang (1)
Author affiliation:(1) College of Water Resource and Civil Engineer, China Agricultural University, Beijing; 100083, China; (2) Suzhou Sanovo Machinery Technology Co., Ltd, Suzhou; 215215, China
Corresponding author:Shi, Zhengxiang(shizhx@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:215-221
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The health and production status of dairy cows was affected by low temperature in winter in the cold regions in the north of china. If cows are kept in low temperature for a long time, it will lose a lot of heat, the resistance decreases, and the energy utilization efficiency of the diet decreases, the welfare condition decreases. According to the climate character in Heilongjiang province and the design target is not less than -5℃ in test cowshed, this experiment analyzed heat transfer coefficient of single-layer shutter and compared the heat transfer coefficient, surface density and thickness of combination of different materials that can be used to make up new composite insulation shutters. This experiment made some kinds of composite insulation layers, and then selected 2 new insulation shutters from those and conducted a field experimental study in a cattle farm in Heilongjiang province. The determined 2 new combined insulation shutters were the white insulation shutter (white polyester cloth + pearl cotton + spraying-bonded wadding + pearl cotton + white polyester cloth, 1.01 W/(m<sup>2</sup>•℃)) and grey insulation shutter (PE intertexture cloth + spraying-bonded wadding + needled cotton felt + Aluminized PE intertexture cloth, 0.89 W/(m<sup>2</sup>•℃)). The study choice one cowshed in a farm as tested house. This cowshed was installed the two insulation shutters on east and west sides adopting the symmetrical installation of north and south which spilt the house into two parts. Then, this study choices the other same cowshed with single-layer shutter as control house. The experiment compared the temperature, humidity and illumination of test house and control house. The results showed that there was significant difference in illumination between the 2 new insulation shutters (P<0.05) and no difference in temperature (P>0.05), thus the illumination of shutters is a important factor in practical production. However, the illumination of the 2 new insulation shutters were significantly lower than the single-layer shutter (P<0.05). On the three working conditions that the south and north shutter both opened 25cm, only the south opened 25cm and both sides closed, the average temperature and relative humidity (RH) in tested house were significantly higher than that of control house and outside (P<0.05). The average temperature range in tested house, control house and outside are -12.45--16.70℃, -14. 38--18.50℃ and -16.16--21.56℃, respectively, and the average relative humidity range are 88.53%-97.73%, 82.78%-93.62% and 74.75%-79.24 %, respectively. So, though the new combined insulation shutters have better thermal insulation performance than single-layer shutter, the cowshed is still in the low temperature and high humidity conditions. This paper suggests that in order to ensure the good environmental conditions of the cowshed in winter, we should continue to improve the building envelope at the same time and improve the ventilation system to dehumidifying the air. When we choose the insulation shutter, we should pay attention on its airtight with the wall around. In conclusion, the form of open-ended cowshed with insulation layers should be cautiously adopted in cold areas.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Thermal insulation
Controlled terms:Cotton - Energy utilization - Environmental management - Heat resistance - Heat transfer coefficients - Heating - Houses - Humidity control - Insulating materials - Low temperature production - Temperature - Ventilation
Uncontrolled terms:Cowshed - Energy utilization efficiency - Environmental conditions - Environmental control - Heat preservation - Relative humidity range - Temperature and relative humidity - Thermal and humidity environments
Classification code:402.3 Residences - 413 Insulating Materials - 413.2 Heat Insulating Materials - 454.1 Environmental Engineering, General - 525.3 Energy Utilization - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.5 Ventilation - 821.4 Agricultural Products
Numerical data indexing:Percentage 7.48e+01% to 7.92e+01%, Percentage 8.85e+01% to 9.77e+01%, Size 2.50e-01m
DOI:10.11975/j.issn.1002-6819.2018.21.026
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 4>
Accession number:20190706490399
Title:Durability of pumice concrete under chloride erosion and wet-dry cycling conditions
Authors:Liu, Qian (1); Shen, Xiangdong (1); Xue, Huijun (1); Wang, Renyuan (1); Liu, Zheng (1)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot; 010018, China
Corresponding author:Shen, Xiangdong(ndsxd@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:137-143
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are a large number of salt lakes distributed in Northwest China. The salt lake water is mainly composed of compound brine with multiple ions. The chloride ion shows the highest ion concentration in the salt lakes of Inner Mongolia, and a large area of saline soil is distributed around the salt lake. Due to the harsh climatic conditions and complex soil environment, concrete engineering structures and materials are often suffered from chloride erosion. In order to study the chloride ion erosion mechanism of pumice concrete under dry-wet cycle conditions, the indoor accelerated corrosion simulation test method is applied with pumice concrete and ordinary concrete as the test group and control group to study the mass loss of pumice concrete, the relative dynamic elastic modulus and the maximum depth of chloride ion erosion by chloride salt erosion and dry-wet cycle test in this paper. The nuclear magnetic resonance technology is used to invert the relaxation time T<inf>2</inf> spectrum of pumice concrete on 0, 30, 60, 90, and 120 days. According to the relationship between the relaxation time T<inf>2</inf> and pore radius, the T<inf>2</inf> spectrum distribution can convert into the pore radius distribution. Thus, the 0-100 μm pores of concrete are divided into five grades: micro pores (0-0.01 μm), small pores (>0.01-0.1 μm), mid-small pores (>0.1-1.0 μm), medium pores (>1.0-10 μm) and large pores (>10-100 μm). Based on the comprehensive analysis of porosity, bound fluid saturation and free fluid saturation, the microscopic pore structure of pumice concrete under dry-wet cycles is analyzed. Moreover, the X-ray diffraction phase analysis and scanning electron microscope analysis are conducted on the internal microstructure of pumice concrete after chloride erosion to investigate the resistance to chloride ion erosion of pumice concrete. The results show that the mass loss rates of pumice concrete and ordinary concrete are consistent with the trend of relative dynamic elastic modulus under the action of chloride salt erosion; the maximum chloride ion erosion depths of pumice concrete and ordinary concrete increases with chloride salt erosion; with the level of chloride salt erosion upgrading, the spectral areas of pumice concrete and ordinary concrete gradually increased; the pore radius ranges of the first and second peaks of pumice concrete decreased, while that of the third peak increased; the pore radius ranges of the first and third peaks of ordinary concrete increase, while that of the second peak decreased; the pumice concrete erosion damage is mainly caused by large pores and cracks which are developed from the small and mid-small newborn pores, whereas the ordinary concrete erosion damage is primarily induced by the micro and small pores developing towards large pores and cracks. After chloride salt erosion, both pumice concrete and ordinary concrete produce a variety of corrosion crystals represented by Friedel salt. This paper can provide a theoretical basis for pumice concrete in the construction of agricultural water conservancy under the environment of chloride salt.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Concretes
Controlled terms:Abrasives - Chlorine compounds - Corrosion - Elastic moduli - Erosion - Ions - Lakes - Pore structure - Porosity - Relaxation time - Scanning electron microscopy - Testing - Water management
Uncontrolled terms:Chloride salts - Comprehensive analysis - Dry-wet cycle - Internal microstructure - Micromorphologies - Microscopic pore structures - Nuclear magnetic resonance technology - Pore radius distribution
Classification code:412 Concrete - 606.1 Abrasive Materials - 931 Classical Physics; Quantum Theory; Relativity - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
Numerical data indexing:Age 3.29e-01yr, Size 0.00e+00m to 1.00e-04m, Size 0.00e+00m to 1.00e-08m
DOI:10.11975/j.issn.1002-6819.2018.21.017
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 5>
Accession number:20190706490394
Title:Rational irrigation and nitrogen supply methods improving grain yield and water-nitrogen use efficiency of seed maize
Authors:Qi, Dongliang (1, 2); Hu, Tiantian (1); Song, Xue (3)
Author affiliation:(1) Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education, Northwest A &F University, Yangling; 712100, China; (2) College of Agriculture, Yangtze University, Jingzhou; 434025, China; (3) Zhengzhou University Multi-functional Design and Research Academy CO., LED, Zhengzhou; 450002, China
Corresponding author:Hu, Tiantian(hutiant@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:98-104
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ridge planting-furrow irrigation has been widely used, but information on rational irrigation and nitrogen (N) supply methods under ridge planting-furrow irrigation has received only limited attention. To improve harvest index (HI) and resource use efficiency of crop through different irrigation and N supply methods in arid areas, we carried out field experiments to investigate the effect of different irrigation and N supply methods on HI and water-nitrogen use efficiency of seed maize (Zay mays, Gold northwestern 22) grown in the arid area of northwest China in 2013 and 2014. All experimental ridges were built in a west-east direction. The experiment was comprised of 3 irrigation methods and 3 N supply methods in 2013. The 3 irrigation treatments included alternate furrow irrigation (AI), fixed furrow irrigation (FI) and conventional furrow irrigation (CI). In the CI treatment, all the furrows were irrigated for every irrigation event. In the AI treatment, the 2 neighboring furrows were alternately irrigated during consecutive watering events. In the FI treatment, only 1 (south furrow) of the furrows was irrigated. At each irrigation treatment, the 3 N supply treatments were used and they included alternate N supply (AN), fixed N supply (FN) and conventional N supply (CN). In the CN treatment, N fertilizer was applied to all furrows. In the AN treatment, N fertilizer was alternately applied to 1 of the neighboring 2 furrows in consecutive fertilization. In the FN treatment, N fertilizer was only supplied to 1 of every 2 furrows. Evapotranspiration (ET) during maize grown season, and biomass, grain yield and its components as well as nitrogen uptake at maturity stage of maize were measured. The HI, water use efficiency (WUE) and nitrogen use efficiency (NUE) were calculated. Based on the results of 2013, the fixed treatments (fixed furrow irrigation and fixed nitrogen supply) were excluded in 2014. The results showed that, the grains per row per plant were greatly affected by irrigation and nitrogen supply methods. Thousand seed weight was only influenced by irrigation method. The ET during maize grown season was only influenced by irrigation method, and AI significantly reduced ET compared to the other irrigation methods. The WUE of maize for AN and CN was higher than that for FN in any irrigation method; AI had the highest WUE, followed by CI and FI in any nitrogen supply method. Nitrogen uptake, HI and NUE of maize showed similar results compared to WUE. AI coupled with CN achieved the highest HI, WUE and NUE in 2013, and these increased by 5.46%, 11.41% and 19.73%, respectively if compared with CI coupled with CN. AI coupled with AN (irrigation and N fertilization were conducted within a same furrow) showed a similar result compared to AI coupled with CN. The 2014 experiment verified the above results. Therefore, alternate furrow irrigation coupled with conventional nitrogen supply and alternate furrow irrigation coupled with alternate nitrogen supply (irrigation and N fertilization were conducted within a same furrow) are useful to improve grain yield and water-nitrogen use efficiency of seed maize.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Irrigation
Controlled terms:Arid regions - Biomass - Efficiency - Nitrogen - Nitrogen fertilizers - Water supply
Uncontrolled terms:Alternate furrow irrigation - Harvest index - Irrigation methods - Irrigation treatments - Limited attentions - Nitrogen-use efficiency - Water-use efficiency - Yield
Classification code:443 Meteorology - 444 Water Resources - 446.1 Water Supply Systems - 804 Chemical Products Generally - 821.3 Agricultural Methods - 913.1 Production Engineering
Numerical data indexing:Percentage 1.14e+01%, Percentage 1.97e+01%, Percentage 5.46e+00%
DOI:10.11975/j.issn.1002-6819.2018.21.012
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 6>
Accession number:20190706490396
Title:Analysis on runoff and sediment regimes and its causes of the Yellow River in recent 70 years
Authors:Zhao, Yang (1); Hu, Chunhong (1); Zhang, Xiaoming (1); Wang, Yousheng (1); Cheng, Chen (1); Yin, Xiaolin (1); Xie, Min (1)
Author affiliation:(1) Research Center on Soil and Water Conservation of the Ministry of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing; 100048, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:112-119
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The future trend of runoff and sediment variation is closely related to the governance of the Yellow River. To accurately predict the future runoff and sediment regimes of the Yellow River, the spatial distribution and its variation process of runoff and sedimentation in the main stream of the Yellow River in various periods were systematically analyzed. Specifically, runoff and sediment loads from 4 main stem hydrometric stations and 7 major primary tributaries above Tongguan section on the Yellow River, during the period from 1950 to 2016, were analyzed by using multiple methods such as double cumulative curves. In this paper, we systematically analyze the characteristics of runoff and sediment yield and changes in its main source areas, and the impact of different environmental factors on runoff and sediment changes in the Yellow River were also discussed. The results showed that, 1) The annual runoff and sediment yield at the Lanzhou, Toudaoguai, Longmen, and Tongguan hydrometric stations of the Yellow River showed a significant decrease (P<0.05) in the past 70 years, the annual runoff decreased by 17.93% to 40.79%, and the annual sediment transport decreased by more than 70%. Under the influence of changes in various environmental factors, the runoff and sediment in the Yellow River have reduced mutations in the 1980s and 1990s. 2) The evolution process of average annual runoff in the Lanzhou-Tongguan section changed from an accumulative increase along the distance from the river source to the trend of an accumulative decrease. Although the average annual sediment accumulation amount did not change, the increase rate decreased by 90% more. 3) It is obvious that the transfer characteristics of the main sediment source area of the Yellow River from the Toudaoguai-Longmen section change to the Longmen-Tongguan section, and we argued that soil erosion control in the Longmen-Tongguan section needs to be further strengthened. At last, human activities play a leading role in the sharp decline in runoff and sediment yield in the middle reaches of the Yellow River, with an average contribution rate of 91.52%. The reduction in average annual runoff of Lanzhou is mainly affected by the climate change, and the contribution rate reaches 66.57%. The results can provide a basis for a deep understanding of the temporal and spatial status and causes of runoff and sediment in the Yellow River, and provide a reference for future direction of soil and water conservation.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Runoff
Controlled terms:Climate change - Hydrology - Rivers - Sediment transport - Soil conservation - Water conservation
Uncontrolled terms:Assessment - Mainstream - Primary tributaries - Runoff and sediment yields - Yellow river
Classification code:443.1 Atmospheric Properties - 444 Water Resources - 444.1 Surface Water - 483.1 Soils and Soil Mechanics
Numerical data indexing:Age 7.00e+01yr, Percentage 1.79e+01% to 4.08e+01%, Percentage 6.66e+01%, Percentage 7.00e+01%, Percentage 9.00e+01%, Percentage 9.15e+01%
DOI:10.11975/j.issn.1002-6819.2018.21.014
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 7>
Accession number:20190706490414
Title:Evaluation of ecological sensitivity of mineral resources city under economic transformation
Authors:Guan, Qingchun (1, 2); Hao, Jinmin (1, 2); Wang, Hongliang (1, 2); Li, Mu (1, 2); Chen, Aiqi (1, 2); Xie, Baopeng (3)
Author affiliation:(1) College of Resources and Environment, China Agricultural University, Beijing; 100193, China; (2) Key Laboratory for Agricultural Land Quality Monitoring and Control, The Ministry of Land and Resources, Beijing; 100193, China; (3) School of Management, Gansu Agricultural University, Lanzhou; 730070, China
Corresponding author:Hao, Jinmin(jmhao@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:253-262
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the ecological sensitivity characteristics of mineral resource cities and to protect and manage them in different areas, taking Datong city of Shanxi province as an example, in this paper, we selected topographic geology, cover type and water system protection from 3 aspects: natural ecological attribute, natural and social-ecological compound attribute and social-ecological attribute. The index system of ecological sensitivity evaluation was constructed by 4 types of index, considering the influence of farmland factors which were easily affected by human disturbance in mineral resource cities under the background of transition. We discussed the influence of farmland ecological factors before and after adding, and made a classification and quantitative evaluation and grading study on ecological sensitivity of Datong city of Shanxi province by means of factor space overlay mapping method and maximum method in 2015. The results showed that: 1) The ecological sensitivity of Datong city was relatively high. The area of high sensitive area and low sensitive area was larger, and it was easy to cause ecosystem instability under the influence of human activity intensity or external force. The high sensitive area, ecological sensitive area and ecological low sensitive area of the urban area accounted for 25.20%, 47.10% and 27.70%, respectively. Without farmland factor, ecological high sensitive area, ecological sensitive area and ecological low sensitive area of urban area accounted for 20.60%, 36.30%, 43.10%, respectively. 2) The ecological sensitivity of Datong city was different in space, and the distribution pattern was as follows: the high sensitive area mainly distributes in the northwest, including the Xinrong district, Nanjiao district; The middle part, including the border area between Datong district and Hunyuan county, the south area of Hunyuan county; The southwest, including the border area between Guangling county and Lingqiu county. The low sensitive areas were mainly distributed in the northeast, including Yanggao county, Tianzhen county; Northwest, including Zuoyun county; the middle part, including Datong county, Guangling county; and the south part, including the central area of Lingqiu county. The middle sensitive area distributes mainly along the northwest of the terrain to the two sides of the southeast axis. 3) Farmland ecosystem had a strong response to human activities and was an important factor affecting ecological sensitivity evaluation. Adding farmland factors would affect the proportion of sensitive areas and low sensitive areas in ecology. Through the spatial distribution map of ecological sensitivity evaluation, it could be seen that the spatial distribution of ecological sensitivity changes, the low sensitive area decreases obviously, the middle sensitive area increased obviously, and the high sensitive area changed little after adding farmland factors. After adding farmland factors, there was a great difference in the proportion of ecological sensitivity area in this region, in which the lowly sensitive area decreased by 15.40%, and the moderately sensitive area and highly sensitive area increased by 10.80% and 4.60%, respectively. The results can provide important theoretical basis for ecological protection and land spatial renovation in resource-based cities, and provide scientific reference for mineral resources cities to better handle the relationship between regional economic transformation and ecological environment protection.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Farms
Controlled terms:Ecosystems - Grading - Mineral resources - Minerals - Models - Regional planning - Spatial distribution
Uncontrolled terms:Datong city in Shanxi province - Ecological environment protections - Ecological sensitive areas - Ecological sensitivity - Economic transformation - Farmland - Spatial distribution map - Zonal protection
Classification code:403.2 Regional Planning and Development - 454.3 Ecology and Ecosystems - 482.2 Minerals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics
Numerical data indexing:Percentage 4.31e+01%, Percentage 4.60e+00%, Percentage 4.71e+01%, Percentage 1.08e+01%, Percentage 1.54e+01%, Percentage 2.06e+01%, Percentage 2.52e+01%, Percentage 2.77e+01%, Percentage 3.63e+01%
DOI:10.11975/j.issn.1002-6819.2018.21.032
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 8>
Accession number:20190706490401
Title:Winter wheat planting area extraction using multi-temporal remote sensing images based on field parcel
Authors:Deng, Liuyang (1, 2); Shen, Zhanfeng (1, 2); Ke, Yingming (1, 2); Xu, Zeyu (1, 2)
Author affiliation:(1) Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing; 100101, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Shen, Zhanfeng(shenzf@radi.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:157-164
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The estimation of winter wheat area based on remote sensing images is one of important contents in filed of agriculture information monitoring. However, it is difficult to solve the problems of spectrum heterogeneity in the same farmland and spectra similarity between different farmlands timely and accurately using mid-resolution images. In order to maximally avoid problems metioned above and accurately map the planting area of winter wheat, a object-parcel classification method was developed in the study area of Lankao Cunty, Henan Province. An improved identification procedure for geo-parcel based winter wheat identification was presented, combining fine-resolution image and multi-temporal medium-resolution images. Combined spectrum and filed parcel information, precisely extraction of winter wheat planting area was realized from multi-temporal OLI images and Google earth high-resolution images (resolution of 0.49 m) through the following several steps. 1) Constructing winter wheat decision tree extraction models to extract the simplified winter wheat area based on spectral feature. Crops performed different phenological characteristics during the growth and development stage, which displayed spectral differences on remote sensing images. And to obtain the optimum temporal phases to extract winter wheat planting area, temporal phase among typical crops in study area was analyzed based on the phenological characteristics; 2) The field parcel information generated from high-resolution imagery by multi-scale segmentation algorithm. And then, according to the field parcels obtained on the high-resolution images, the two simplified OLI images of winter wheat were superimposed on the parcel respectively. Partition statistics ratio (proportion of simplified winter wheat in each field parcels) was calculated, and then the winter wheat parcels on the high-resolution images were obtained based on partition statistics ratios. Finally, analyzing the extraction accuracy under different statistics ratio threshold, then generating high-resolution winter wheat plots based on the parcel; 3) Through cross validation, the winter wheat planting area was extracted. Identification results of the winter wheat with the parcel statistics ratio threshold of 0. 20 in the phase-1 (OLI image on 2017-03-04, with higher extraction correctness ratio and lower misjudgment ratio) and the recognition result with the phase-2(OLI image on 2017-05-07) threshold of 0. 30 were selected for cross-validation. The experiment result showed that the method could recognize winter wheat area accurately. The higher recognition accuracy (95.9%) was obtained under the lower misjudgment ratio (1.3%). Last but not least, an application of proposal method in Lankao County was performed to verify the accuracy of winter wheat extraction with the correctness ratio of 91.5%. And the accuracy of winter wheat recognition could be expected higher in regions with simple planting structure or less fragmental parcels. The omission of winter wheat extraction based on per-parcel classification mostly happened in the fragmental parcels, coupled with the accuracy of segmentation, because the parcels were not completely segmented according to the single crop type. Finally the performance of partition statistics ratio analysis in distinguishing pure winter wheat parcels and mixed winter wheat parcels was tested by controlling the partition statistics threshold. The identification results indicated that the integration of high spatial-temporal resolution imagery is promising for crop identification based on geo-parcel.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Image enhancement
Controlled terms:Crops - Decision trees - Extraction - Farms - Image segmentation - Monitoring - Remote sensing - Statistics
Uncontrolled terms:Classification methods - High resolution imagery - Identification procedure - Multi-temporal remote sensing - Multiscale segmentation - Planting areas - Spectrum heterogeneities - Winter wheat
Classification code: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:Percentage 1.30e+00%, Percentage 9.15e+01%, Percentage 9.59e+01%, Size 4.90e-01m
DOI:10.11975/j.issn.1002-6819.2018.21.019
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 9>
Accession number:20190706490407
Title:Cooling effects of fan-pad negative pressure ventilation system on summer environmental conditions in beef cattle barn in Southern China
Authors:Chen, Zhaohui (1, 2); An, Jie (1, 2); Wang, Jinhuan (1, 2); Liu, Jijun (1, 2); Yang, Shitang (3)
Author affiliation:(1) College of Animal Science and Technology, China Agricultural University, Beijing; 100193, China; (2) State Key Laboratory of Animal Nutrition, Beijing; 100193, China; (3) Gao'an Yufeng Agriculture Co., Ltd, Gao'an; 330800, China
Corresponding author:Liu, Jijun(liujijun@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:208-214
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Although fan-pad evaporative cooling system is a kind of energy-saving and environment-friendly cooling method, its application in beef cattle barn is still very rare. A negative pressure ventilation system for wet curtain fan was tested in this study to improve the summer environmental conditions of beef cattle barn in Southern China and find out its suitability for hot and humid climates. The study was conducted in 2 cattle beef barns located at Gao'an, Jiangxi Province, where is hot and humid in summer. The system consists of a cellulosic cooling pad and 4 axial flow fans with an air volume of 38 048 m<sup>3</sup>/h and an electric power of 1. 1 kW. According to the results of the preliminary experiment, the operation time of the cooling system was from 09: 00 to 19: 00. In this study, simmental beef cattle were randomly allotted in 2 confined barns where feed and water were freely available. The data of environmental factors and beef physiology were collected. Temperature-humidity-velocity index (THVI) and heat load index (HLI) value were calculated to estimate the effects of climatic variable and heat accumulation. The cooling effect of the system was affected by the ambient temperature and relative humidity. With the ambient temperature increased by 1℃, the cooling effect increased by 0.6℃; with the relative humidity increased by 10%, the cooling effect decreased by 1.6℃ There was a temperature gradient along the airflow direction, and the temperature increased 0.033℃ for every 1 meter increase in the distance from the cooling pad. The air velocity parallel to the direction of the airflow was also inconsistent. The air velocity near the cooling pad was higher than that at the fan outlet and the middle area (P<0.01), and the air velocity of the outlet of the fan was higher than that at the middle area (P<0.01). During the measurement period, the average temperature in the experiment barn was (29.7±0.5)℃, compared with the control barn, decreased by 3.2℃ (P<0.01); the average relative humidity was (89.9±1.9)%, increased by 21.3% (P<0.01); the average air velocity near the cow was (0.75±0.02) m/s, increased by 0.30 m/s (P<0.01); the average effective temperature was (29.1±0.4)℃, decreased by 1. 8℃(P<0.01); the average concentration of CO<inf>2</inf> was (498±14)×10<sup>-6</sup>, deceased by 44×10<sup>-6</sup> (P<0.01) ; and the average concentration of NH<inf>3</inf> was (3.63±0.33)×10<sup>-6</sup>. However, because of the high relative humidity, HLI value of the experiment barn was slightly higher than that of the control barn(P>0.05). The average respiration rate in the experiment barn was (57±1)breaths/min, compared with the control barn, decreased by 13 breaths/min (P<0.01); the average skin temperature was (35.54±0.09)℃, decreased by 0.92℃ (P<0.01); the average rectal temperature was (38.74±0. 04)℃, decreased by 0.11℃ (P>0.05); and the average daily weight gain was (0.65±0.52) kg/d, increased by 0.13 kg/d (P>0.05). The results indicated that fan-pad evaporative cooling system was able to improve the environmental conditions for beef cattle barns in Southern China, thus relieving heat stress of beef cattle. This provides a scientific basis for the extension and application of evaporative pad cooling systems in Southern China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Evaporative cooling systems
Controlled terms:Air - Ammonia - Axial flow - Beef - Cooling - Energy conservation - Evaporation - Fans - Farm buildings - Humidity control - Temperature - Thermoelectric equipment - Velocity - Ventilation - Wind
Uncontrolled terms:Beef cattle - Effective temperature - Energy-saving and environments - Environmental conditions - High relative humidities - Negative pressures - Temperature and relative humidity - Wind speed
Classification code:402.1 Industrial and Agricultural Buildings - 443.1 Atmospheric Properties - 525.2 Energy Conservation - 615.4 Thermoelectric Energy - 618.3 Blowers and Fans - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.5 Ventilation - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 822.3 Food Products
Numerical data indexing:Percentage 1.00e+01%, Power 1.00e+03W, Size 1.00e+00m
DOI:10.11975/j.issn.1002-6819.2018.21.025
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 10>
Accession number:20190706490387
Title:Kinematics model and parameter optimization of planting process of rape carpet seedling transplanter
Authors:Jiang, Lan (1, 2); Wu, Chongyou (1); Tang, Qing (1); Zhang, Min (1); Wang, Gang (1)
Author affiliation:(1) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture and Rural, Nanjing; 210014, China; (2) College of Engineering, Anhui Agricultural University, Hefei; 230036, China
Corresponding author:Wu, Chongyou(cywu59@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:37-46
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rape carpet seedling transplanter is suitable for the transplantation in rice stubble field. During the operation of planting mechanism, the seedling needle takes out the seedling block from feeder mechanism by cutting and tearing. Then the seedling block is carried and transported by the seedling needle to the point of seedling pushing. Once the seedling block separates the seedling needle automatically and falls to soil, it can not be planted into the soil. Therefore, it is urgent to effectively reduce the seedling separation phenomenon in mechanized transplanting process of rape carpet seedlings and improve seedling-standing quality. In this paper, a kinematics model of rape carpet seedling block in the process of seedling transportation is established. The friction coefficient, normal adhesion force and tangential adhesion force of the rape carpet seedling substrate are measured under different moisture content. In order to obtain the mass center, morphological characteristic parameters of seedling block are measured. By establishing the mathematical model of planting mechanism, the trajectory curve and acceleration curve of the tip point of the seedling needle are obtained. The relationship between the tip point of the seedling needle and the mass center of seedling block is established. Thus, the variation curve of resultant force for the seedling block in the process of seedling transportation is analyzed. The critical conditions for seedling separation in seedling transportation course which is divided into 3 stages are studied. The main factors affecting the occurrence of seedling separation are established. Combined with the high speed photography, effects are tested by the single factor test which consists of the substrate moisture content, planting mechanism rotation speed and longitudinal picking seedling-standing length on seedling separation rate. With the increase of planting mechanism rotation speed, the seedling separation rate is stable first and then increases gradually. With the increase of the substrate moisture content, the seedling separation rate reduces sharply and then remains stable. With the increase of the longitudinal picking seedling length, the seedling separation rate decreases first and then increases. The critical range of each factors obtained by single factor test are basically consistent with the theoretical analysis, which verifies the accuracy and feasibility of the model. Using the data analysis software Design-Expert 8.0.6, the response surface design (RSD) is applied to establish a mathematical regression model between main influence factors and inspection index by analyzing the substrate moisture content, planting mechanism rotation speed and longitudinal picking seedling length. The horizontal ranges of response surface test are selected through the influence result of the single factor test and operation requirement. And finally the optimal parameter combination is obtained. The optimal parameter combination is modified and verified through the same test method. When the moisture content of the substrate is 56.72%, and the rotation speed of the planting mechanism is 22 rad/s, and the longitudinal seeding length is 15 mm, the test results shows that the seedling separation rate is 1.52%, with an absolute error of 0.16 percentage points compared to the predicted value. This study may provide the technical support for the research and development of rape carpet seedling transplanting with great seedling-standing quality.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Seed
Controlled terms:Adhesion - Agricultural machinery - Factor analysis - Friction - High speed photography - Kinematics - Mechanisms - Models - Moisture - Moisture determination - Needles - Optimization - Regression analysis - Rotation - Separation - Software design - Speed - Surface properties - Testing
Uncontrolled terms:Different moisture contents - Morphological characteristic - Optimal parameter combinations - Research and development - Response surface designs - Separation condition - Substrate moisture contents - Transplanter
Classification code:601.3 Mechanisms - 723.1 Computer Programming - 742.1 Photography - 802.3 Chemical Operations - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 931.1 Mechanics - 944.2 Moisture Measurements - 951 Materials Science
Numerical data indexing:Angular_Velocity 2.20e+01rad/s, Percentage 1.52e+00%, Percentage 5.67e+01%, Size 1.50e-02m
DOI:10.11975/j.issn.1002-6819.2018.21.005
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 11>
Accession number:20190706490400
Title:Review on data assimilation of remote sensing and crop growth models
Authors:Huang, Jianxi (1, 2); Huang, Hai (1); Ma, Hongyuan (1); Zhuo, Wen (1); Huang, Ran (1); Gao, Xinran (1); Liu, Junming (1, 2); Su, Wei (1, 2); Li, Li (1, 2); Zhang, Xiaodong (1, 2); Zhu, Dehai (1, 2)
Author affiliation:(1) College of Land Science and Technology, China Agricultural University, Beijing; 100083, China; (2) Key Laboratory of Remote Sensing for Agri-Hazards, Ministry of Agriculture and Rural Affairs, Beijing; 100083, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:144-156
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Data assimilation technology, which can combine the advantages of remote sensing and crop growth models, has great potential in large-scale application of agricultural monitoring and yield forecasting. This review included 5 parts. And the first part introduced the framework of data assimilation system of crop growth model and remote sensing. The data assimilation system contained 3 basic components: dynamic model, observation data and assimilation algorithm. Taking the WOFOST model as an example, a schematic representation of assimilating remotely sensed data into a crop model was shown. The second part summarized the progress of data assimilation of crop growth model and remote sensing. The parameter optimization methods based on cost function and the sequential filtering methods based on estimation theory were two major groups of modern data assimilation strategies. The main difference between the two groups was that each subsequent observation for sequential filtering assimilation would only influence the change nature of the model from the current state; in contrast, parameter optimization methods adjusting the estimation using all of the available observations throughout the assimilation window. In general, MODIS data was the most commonly used remotely sensed data for large regional assimilation research, and data of Landsat TM, ETM+ and OLI were the major remotely sensed data used at regional scale. General models, like WOFOST, CERES, etc. were most widely used in agricultural data assimilation researches. The main object of these researches was food crops such as wheat, corn and rice. LAI (leaf area index) was most commonly used as the assimilation variable linking remote sensing and crop models. In addition, a number of studies found that time series of reflectance, vegetation index or backscattering coefficient could be directly assimilated into a coupled crop growth-radiative-transfer model to avoid the process of regional LAI retrieval. In general, yield estimation and forecast was the most important application. The third part discussed some key aspects affecting the assimilation accuracy, including 5 parts: 1) The pixel size for assimilation, which depended mainly on the specific application. However, heterogeneous, smallholder farming environments presented significant challenges for remotely sensed data assimilation for crop yield forecasting, as field size within these highly fragmented landscapes was often smaller than the pixel size of remote sensing products that were freely available. 2) The uncertainty of remote sensed parameter inversion, which needed to be quantitatively evaluated to ensure the accuracy of data assimilation. 3) The uncertainty of crop growth models, which caused by model structure, model parameters and weather driven data. 4) Data assimilation strategies and linking parameters. Two main data assimilation strategies, parameter optimization and sequential filtering methods, both had pros and cons. Therefore, more effective assimilation algorithms still needed to be developed. 5) The scale effect. Due to the variability of land cover and the complexity of the crop planting pattern in agricultural landscapes, the scale mismatch between the remotely sensed observations and the state variables of crop growth models remained a difficult challenge. The fourth part summarized the research trend of data assimilation for crop growth model and remote sensing. It included 5 directions: 1) from single assimilated parameter to multiple ones. 2) from single remotely sensed data to multiple ones, especially the combination of optical remote sensing and SAR(synthetic aperture radar). 3) from monitoring to forecasting. Based on former researches, an application framework combining data assimilation and numerical prediction was proposed. 4) from single crop growth model to multi-crop model coupling. 5) from single machine system to the high-performance parallel computing system, especially considering the recent advances in Google Earth Engine.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:126
Main heading:Remote sensing
Controlled terms:Backscattering - Cost functions - Crops - Forecasting - Models - Parameter estimation - Pixels - Radiative transfer - Synthetic aperture radar
Uncontrolled terms:Agricultural monitoring - Crop growth model - Data assimilation - High performance parallel computing - Parameter optimization methods - Remotely-sensed observations - SAR(synthetic aperture radar) - Yield forecasting
Classification code:701 Electricity and Magnetism - 716.2 Radar Systems and Equipment - 821.4 Agricultural Products - 921.5 Optimization Techniques
DOI:10.11975/j.issn.1002-6819.2018.21.018
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 12>
Accession number:20190706490392
Title:Design of irrigation pipeline emptying anti-freezing mode in seasonal frozen soil region
Authors:Xie, Chongbao (1); Bai, Jing (1); Wu, Zhiqin (2); Zhang, Jiayang (2)
Author affiliation:(1) China Irrigation and Drainage Development Center, Beijing; 100054, China; (2) Heilongjiang Provincial Hydraulic Research Institute, Harbin; 150080, China
Corresponding author:Bai, Jing(625540202@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:82-88
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to meet the anti-freeze requirements, traditional irrigation pipelines generally are laid below the ground frozen layer in seasonal frozen region. Although the deep-buried mode of the pipeline solved the freezing problem of pipelines, it has increased investment in irrigation projects and prolonged construction schedules, affecting the development of water-saving irrigation projects relying on ground water. Since irrigation was suspended during the winter, which provided the possibility that irrigation pipelines could be buried in the frozen ground. In order to solve the problem of pipelines damage, we proposed an anti-freeze mode for irrigation pipelines based on evacuation. First the emptying mode of pipelines and version of air compressors were recommended through analysis and comparisons. Because of the limited volume of irrigation pipelines, micro reciprocating piston compressor was recommended. Working pressure, rated discharge capacity of air compressors were 0.4 MPa and 2.5 m<sup>3</sup>/min, respectively. The laying out of pipelines was obtained according to similar designing rules. The pipeline distribution, length, diameter, as well as the volume of typical plots with different length to width ratios and areas were estimated through a series of design and calculation. The pipeline capacity increased along with the length to width ratio as well as the plot area. The dimensionless pipeline volume formula was obtained based on calculations and regression analysis. A mode of working-suspending-working was introduced into water drainage of pipelines. We estimated the working time of an air compressor by the pipeline volume and discharge capacity of air compressor, and the suspending time was set according to experiences. After that draining time of all typical plots was calculated and the time per area for the plots of 6.67 hm<sup>2</sup> was longer than any others. The covering area of the recommended air compressor was suggested to be 266 hm<sup>2</sup> under the conditions of 8 hours per day in a weekly working period. We conducted field experiment in Heilongjiang province in order to verify the effect of the emptying mode of pipelines. With the impact of carrying machinery, reducing the potential investment and the need for pipe insulation, the burial depth of pipelines was selected to be 80 cm. Frost heaving and thaw settlement is another key factor in the seasonal frozen earth region. When the pipe was buried in the ground frozen layer, it was necessary to carry out the pipe trench filling. Replacement by non-frost materials was a common and effective measure. We set up 3 types of pipeline ditches backfilling conditions including original soil, medium sand, slag. We dynamic monitored the temperature in pipelines from November 2017 to March 2018. The result showed that the calculated drainage time could meet the need of pipeline emptying. The temperatures fell first and then increased slowly and the lowest temperature was -3.66, -2.62 and -3.22℃ in the ditches with backfilling with original soil, slag and medium sand. When the burying depth of pipelines was 80cm, the temperature differences in the pipelines were not obvious, which varies from 0.8 to 1.23℃, under the three condition. Using original soil or non-frost materials (such as sand and slag, etc. ) for replacement and backfilling, the pipelines would be safe if the forced draining and evacuation mode is used through an air compressor.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Trenching
Controlled terms:Drainage - Freezing - Frozen soils - Groundwater - Investments - Irrigation - Pipelines - Reciprocating compressors - Regression analysis - Slags - Temperature - Water conservation
Uncontrolled terms:Construction schedules - Design and calculation - Length-to-width ratio - Reciprocating piston compressor - Seasonal frozen earth - Temperature differences - Traditional irrigation - Water-saving irrigation
Classification code:444 Water Resources - 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 618.1 Compressors - 619.1 Pipe, Piping and Pipelines - 641.1 Thermodynamics - 821.3 Agricultural Methods - 922.2 Mathematical Statistics
Numerical data indexing:Pressure 4.00e+05Pa, Size 8.00e-01m, Time 2.88e+04s
DOI:10.11975/j.issn.1002-6819.2018.21.010
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 13>
Accession number:20190706490406
Title:Vertical walls-evaporative cooling pad and gable-exhaust-air- ventilation system improving poultry house thermal environment in Northwest region of China
Authors:Wang, Yang (1, 2, 3); Zheng, Weichao (1, 2, 3); Li, Xuanyang (1, 2, 3); Li, Baoming (1, 2, 3); Wan, Daifu (4)
Author affiliation:(1) Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing; 100083, China; (2) College of Water Resources and Civil Engineering, China Agricultural University, Beijing; 100083, China; (3) Beijing Engineering Research Center for Animal Healthy Environment, Beijing; 100083, China; (4) Fukang Yuan Poultry Co. LTD, Urumchi; 830001, China
Corresponding author:Li, Baoming(libm@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:202-207
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Large temperature variations and non-uniformity of air distribution are founded in the poultry houses by using tunnel ventilation and evaporative cooling systems. Poultry suffer from large variations of temperatures, cold stress near the evaporative cooling pads region and heat stress near fans region. These adverse factors negatively influence poultry health, production performance, mortality rate, and consequently resulting in significant economic losses. In order to improve the welfare of the poultry and mitigate the large variations of air temperatures, heat stress in the poultry occupied zones. The poultry houses were equipped with a new ventilation system-vertical walls intake air and gable exhaust air ventilation system in China Northwest region. The evaporative cooling pads separately and uniformly on both vertical walls and exhausting air through fans located on the gable. When the indoor air temperature was higher than the set-point, the fans created a slightly negative pressure to draw fresh air through the evaporative cooling pad into the poultry houses. This was in contrast to other time in poultry houses which have fresh air directly entering into the poultry houses without cooling through the wall inlets. In order to determine the environmental condition of the poultry house that was equipped with the new ventilation system and its existing problems, this study had been conducted to detect and analyze the thermal environment. The performance of the new ventilation system in an experimental poultry house was evaluated in comparison with the tunnel ventilation and evaporative cooling systems in control poultry house by measuring the thermal environment. Results showed that the maximum air temperature fluctuation in the experimental poultry house and in control poultry house was 2.7 and 10.3℃, respectively. The air temperature and relative humidity difference were not significantly different (P>0.05) along the horizontal and vertical direction in the experimental poultry house, and the air temperatures and relative humidity difference were significantly different (P<0.05) along the horizontal and vertical direction in control poultry house. The heat stress degree in control poultry house was larger than that in the experimental poultry house, and the normal level of no heat stress in the control poultry house was lower by 9.9% compared with in the experimental poultry house, alert level was higher by 2.7%, danger level was higher by 7.2% and emergency level was higher by 0.1%. There was no emergency heat stress in experiment poultry house but the control poultry house was suffered from different degrees of heat stress. The economic cost of using the new ventilation system-sidewall intake air and gable exhaust air ventilation system in the experimental poultry house is 1.6 times the cost of the traditional tunnel ventilation cooling system in control poultry house. Comprehensive evaluation, the new ventilation system can mitigate the large variations of air temperatures, heat stress in the poultry occupied zones in China Northwest region poultry houses. Thus, this new ventilation system of the poultry house is suitable to be promoted and applied in China Northwest region and it is necessary to equipped with evaporative cooling pads in gable wall of the opposite side of the fans. The study expectation was to develop a guideline on ventilation and cooling systems design and automation control for poultry houses under continental climate zones.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Evaporative cooling systems
Controlled terms:Air - Air intakes - Atmospheric humidity - Atmospheric temperature - Cooling - Evaporation - Heating - Houses - Humidity control - Losses - Temperature - Temperature distribution - Thermal stress - Thermoelectric equipment - Ventilation - Ventilation exhausts
Uncontrolled terms:Comprehensive evaluation - Environmental conditions - Evaporative cooling pads - Heat stress - Large temperature variations - Poultry house - Production performance - Ventilation systems
Classification code:402.3 Residences - 443.1 Atmospheric Properties - 615.4 Thermoelectric Energy - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.5 Ventilation - 802.3 Chemical Operations - 804 Chemical Products Generally - 911.2 Industrial Economics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 1.00e-01%, Percentage 2.70e+00%, Percentage 7.20e+00%, Percentage 9.90e+00%
DOI:10.11975/j.issn.1002-6819.2018.21.024
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 14>
Accession number:20190706490420
Title:Quality change and its mechanism of quick-frozen rice dumplings under condition of different frozen temperatures
Authors:Pan, Zhili (1, 2); Luo, Yangxiang (1, 3); Ai, Zhilu (1); Yang, Lianzhi (4); Fan, Wen (5); Huang, Zhongmin (1)
Author affiliation:(1) College of Food Science and Technology, Henan Agricultural University, Zhengzhou; 450002, China; (2) Key Laboratory of Staple Grain Processing, Ministry of Agriculture, Zhengzhou; 450002, China; (3) Henan Engineering Research Center of Cold-chain Food, Zhengzhou; 450002, China; (4) School of Chemical and Food Engineering, Zhongzhou University, Zhengzhou; 450044, China; (5) Zhengzhou Synear Food. co., LTD, Zhengzhou; 450002, China
Corresponding author:Huang, Zhongmin(zmhuang2000@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:304-310
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Constant refrigeration temperature has a great influence on the quality of quick-frozen sweet dumplings. For the purpose of investigating the effects of different temperatures on the quality of quick-frozen sweet dumplings, quick-frozen sweet dumplings were exposed under the constant temperature of -5, -15, and -25℃, and then the quality indices including moisture content, acid value, peroxide value, texture were termly measured. The nuclear magnetic resonance imaging, rapid viscosity analyzer and scanning electron microscopy were used to determine the moisture migration, gelatinization characteristics and microstructure of quick-frozen sweet dumplings respectively, and to reveal the influence of frozen temperature on the quality of quick-frozen sweet dumplings. The results showed that the frozen temperature had a significant effect on all these aspects below: the moisture content, peroxide value, acid value and texture (P<0.05). With the extension of frozen storage time, the moisture content of quick-frozen glutinous sweet dumplings decreased fast at first and then decreased gradually. In addition, the effect of the prolongation of the freezing time on the filling of the quick-frozen sweet dumplings was as follows: The oxidation of the filling oil appeared to rise quickly and then slowly, and the hardness and chewiness of the texture properties of the stuffing of the quick-frozen sweet dumplings gradually increased. The higher the frozen storage temperature of the quick-frozen sweet dumplings was, the more the moisture content in the dumplings dropped. At the same time, the higher the degree of the oxidation of fillings in the dumplings was, the more the hardness and chewiness of fillings increased. The longer the frozen storage time and the higher the frozen temperature, the more the moisture content decreasing of quick-frozen sweet dumplings, and the more the peroxide value, acid value, hardness, and chewiness increasing. On the 40th day, the moisture content of quick-frozen sweet dumplings at -5℃ fell to a plateau, faster than that under -15 and -25℃ refrigeration condition. The 14% and 20% growth rates of peroxide value and acid value of quick-frozen sweet dumplings under -5℃ were much higher than that of the other 2 groups. On the 90th day, the moisture content of the quick-frozen sweet dumplings under -5℃ decreased by 11.32%, the peroxide value increased by 23%, and the acid value increased by 30%. Determination of the quick-frozen sweet dumplings' texture properties showed that the hardness increased from 392.11 to 511.78 g, and the chewiness increased from 66.24 to 90.11 g, and significant difference was observed at the -25℃ refrigeration condition (P<0.05). The results of nuclear magnetic resonance, gelatinization characteristics, and scanning electron microscopy showed that the higher the refrigeration temperature was, the more the hydrone's freedom degree of quick-frozen sweet dumplings increased, which facilitated the growth of ice crystals and the formation of large ice crystals. Due to the effect of vapor pressure and temperature, the sublimation of ice crystals and the oxidation of the oil were accelerated, however the moisture content was rapidly decreased. At the same time, the growth of ice crystals and the formation of large ice crystals also had influence on glutinous sweet dumplings starch to a certain degree and did damage the glutinous sweet dumplings starch granules mechanically. And the broken glutinous sweet dumplings starch filled the glutinous sweet dumplings flour mass network, and the dense network space inhibited the entry of moisture and the transfer of heat during cooking process, making quick-frozen sweet dumplings' hardness and chewiness raised sharply. Damaged glutinous sweet dumplings starches were prone to water swelling and occupied more space, resulting in lower peak viscosity, lower breakdown value and lower final viscosity of quick-frozen glutinous sweet dumplings starch group, which would affect the quality characteristics of quick-frozen sweet dumplings. Studying the effect of refrigeration condition on the quality of quick-frozen sweet dumplings is of great significance to the quality control of quick-frozen sweet dumplings. This study can provide a theoretical reference for the quality maintenance of quick-frozen sweet dumplings during frozen storage.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Quality control
Controlled terms:Filling - Gelation - Hardness - Ice - Magnetic resonance imaging - Moisture - Moisture determination - Nuclear magnetic resonance - Oils and fats - Oxidation - Peroxides - Refrigeration - Scanning electron microscopy - Starch - Temperature - Textures - Viscosity
Uncontrolled terms:Constant temperature - Gelatinization characteristics - Pressure and temperature - Quality characteristic - Quality maintenances - Quick-frozen rice dumpling - Refrigeration temperatures - Texture properties
Classification code:631.1 Fluid Flow, General - 641.1 Thermodynamics - 644.1 Refrigeration Methods - 691.2 Materials Handling Methods - 746 Imaging Techniques - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804.1 Organic Compounds - 913.3 Quality Assurance and Control - 944.2 Moisture Measurements - 951 Materials Science
Numerical data indexing:Mass 3.92e-01kg to 5.12e-01kg, Mass 6.62e-02kg to 9.01e-02kg, Percentage 1.13e+01%, Percentage 1.40e+01%, Percentage 2.00e+01%, Percentage 2.30e+01%, Percentage 3.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.21.038
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 15>
Accession number:20190706490384
Title:Design of pneumatic seed-metering device with single seed-metering plate for double-row in soybean narrow-row-dense-planting seeder
Authors:Chen, Meizhou (1); Diao, Peisong (1); Zhang, Yinping (1); Gao, Qimin (1); Yang, Zhuang (1); Yao, Wenyan (1)
Author affiliation:(1) School of Agricultural and Food Engineering, Shandong University of Technology, Zibo; 255000, China
Corresponding author:Diao, Peisong(dps2003@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:8-16
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Narrow-row-dense planting technology of soybean can generally increase production by more than 15% compared with conventional ridge cultivation. However, it has less research on this model and supporting equipment in the Huang-huai-hai area. At present, the traditional soybean planter has such problems as large sowing distance, poor seed-metering performance, poor stability of the device and complex structure. Due to the above problems, it's difficult to meet the requirement of narrow-row-dense planting operation of soybean. Therefore, a novel design of a pneumatic seed-metering device with single seed-metering plate for double-row was presented, which could realize 120 mm narrow-row spacing sowing together with the distributor. Despite a large number of study of other seed-metering devices, this pneumatic seed-metering device with single seed-metering plate for double-row could overcome the traditional limitations of regulating the row spacing by adjusting spacing between left and right monomers or mounting the monomers front and after. In addition, the row spacing could be changed through the use of different angle distributor, which was impossible for other seed-metering devices. Its basic structure and working principle were analyzed. It could determine the influence factors of seed-metering performance through the mechanical and dynamic analysis of the movement of seeds in filling zone, carrying zone and outside throwing point. To verify the feasibility of 120 mm narrow-row spacing sowing, the test device of pneumatic seed-metering device was built, which included the conveyor belt, seed-metering device, suction belt and transmission system, and the whole structural working mechanism of the machine was introduced in detail in this research. Three parameters, i. e. negative pressure vacuum, seed-metering plate's rotational speed and suction holes number of each lap were chosen as the influence factors of the test experiment. And the test index included leak seeding index, repeating sowing index and qualified index of inner and outer which could represent the seed-metering performance of the seed-metering device. Through the single factor experiment, the impacts of three factors were analyzed. Reasonable variation rage of various factors for better seed-metering performance was determined, while the negative pressure vacuum raged from 4.5 to 5.5 kPa, the seed-metering plate's rotational speed raged from 15 to 21 r/min and the suction holes number of each lap was changed in 3 levels of 56, 64, 72 in turn. According to the single factor test results, three-factor and three-level orthogonal experiment was carried out. The results showed that the factors had significant influence on the seed-metering performance of the outer and inner, and the inner was always better than the outer. The order of influence factors on qualified index was seed-metering plate's rotational speed, negative pressure vacuum and suction holes number of each lap; the order of influence factors on repeating sowing index was negative pressure vacuum, seed-metering plate's rotational speed and suction holes number of each lap; the order of influence factors on leak seeding index was negative pressure vacuum, seed-metering plate's rotational speed and suction holes number of each lap. The optimal conditions were as below: the suction holes number of each lap was 64, the seed-metering plate's rotational speed was 18 r/min and the negative pressure vacuum was 5 kPa. Under the above conditions, the inner qualified index was 98. 45%, the inner repeating sowing index was 0.72% and the inner leak seeding index was 0.53%. In addition, the outer qualified index was 97.82%, the outer repeating sowing index was 0.63%, and the leaking seeding index was 1.35%. The verification test showed that the seed-metering device had good performance and the test index was better than this given in industrial standard. This research provides a reference for the research and development of pneumatic seed-metering device for the soybean narrow-row and close planting seeder.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Seed
Controlled terms:Belt conveyors - Crops - Design - Machinery - Mechanization - Monomers - Plates (structural components) - Pneumatic materials handling equipment - Pneumatics - Speed - Structural design - Testing
Uncontrolled terms:Increase productions - Narrow-row-dense planting - Orthogonal experiment - Research and development - Seed metering devices - Single seeds - Single-factor experiments - Soybean seeds
Classification code:408.1 Structural Design, General - 408.2 Structural Members and Shapes - 601 Mechanical Design - 632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 692.1 Conveyors - 804 Chemical Products Generally - 821.4 Agricultural Products
Numerical data indexing:Percentage 1.35e+00%, Percentage 1.50e+01%, Percentage 4.50e+01%, Percentage 5.30e-01%, Percentage 6.30e-01%, Percentage 7.20e-01%, Percentage 9.78e+01%, Pressure 4.50e+03Pa to 5.50e+03Pa, Pressure 5.00e+03Pa, Rotational_Speed 1.50e+01RPM to 2.10e+01RPM, Rotational_Speed 1.80e+01RPM, Size 1.20e-01m
DOI:10.11975/j.issn.1002-6819.2018.21.002
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 16>
Accession number:20190706490402
Title:Establishment and application of crop growth simulating and monitoring system in China
Authors:Hou, Yingyu (1); He, Liang (1); Jin, Ning (2); Zheng, Changling (1); Liu, Wei (1); Zhang, Lei (1)
Author affiliation:(1) National Meteorological Center, Beijing; 100081, China; (2) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling; 712100, China
Corresponding author:He, Liang(heliang_hello@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:165-175
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agro-meteorological services can provide a strong guarantee for agricultural disaster prevention and reduction, national food security and sustainable development of agriculture. In this paper, we systematically described a Crop Growth Simulating and Monitoring System in China (CGMS-China). The system was established based on 4 crop models, i. e. WOFOST, Oryza2000, WheatSM, ChinaAgrosys. The CGMS-China could be applied to national agro-meteorological services. The CGMS-China includes database layer, model layer and application layer. In the model layer, 4 crop models were integrated by application program interface. They were driven by daily-scale data. The WOFOST model was for winter wheat and maize simulation, the WheatSM was for winter wheat simulation, Oryza2000 was for rice simulation and ChinaAgrosys was for remote sensing data assimilation. The data assimilation method included SCE-UA, particle swarm optimization, and so on. The CGMS-China was used for crop growth monitoring, agro-meteorological disaster assessment and crop yield forecast. The crop growth monitoring was based on leaf are index, aboveground biomass and dry weight of storage organs. The agro-meteorological disaster was estimated based on yield reducing rate. The yield could be predicted by relative yield prediction method based on aboveground biomass or yield in the CGMS-China system. The output of CGMS-China for crop growth monitoring could be used for comparison with those in last 5 years, last year, and normal year. The case study in Tailai, Heilongjiang and Fuxin, Liaoning showed that the CGMS-China was a reliable agro-meteorological service product with good quality for crop growth monitoring, crop yield forecast and yield loss assessments of agro-meteorological disasters. Crop growth assessment index was established using outputs of CGMS-China which included aboveground biomass, leaf area index and weight of storage organs. They were applied to real-time monitoring of wheat, maize and rice growth. The drought assessment was also conducted by the CGMS-China system. The CGMS-China performed well at yield loss assessment of spring maize caused by drought in the middle of August, 2014 and yield loss assessment of early rice caused by heat stress on the 22nd June, 2016. The comparison of real-time monitoring and simulating could well reflect the crop growth during the drought events. The CGMS-China was used to predict winter wheat yield in 2014 in China. The average forecast relative error was 7% and the relative error in most provinces (autonomous region) was less than 10%. In the meantime, application of remote sensing assimilation with crop model was also introduced in this paper. The relative error used CGMS-China combined with remote sensing data assimilation was less than 11% in Hongtong county, Shanxi province, China. Finally, we discussed the future directions of application of crop model in agro-meteorological services. In sum, the CGMS-China can provide services well in crop growth development simulation, meteorological disaster monitoring and yield prediction.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Monitoring
Controlled terms:Application programs - Biomass - Crops - Digital storage - Disaster prevention - Disasters - Drought - Ecology - Errors - Food supply - Meteorology - Models - Particle swarm optimization (PSO) - Plants (botany) - Remote sensing - Weather forecasting
Uncontrolled terms:Agricultural disasters - Application program interfaces - Assimilation - Crop growth - Data assimilation methods - Meteorological disasters - Remote sensing data assimilations - Yield prediction
Classification code:443 Meteorology - 444 Water Resources - 454.3 Ecology and Ecosystems - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 821.4 Agricultural Products - 822.3 Food Products - 914.1 Accidents and Accident Prevention
Numerical data indexing:Age 5.00e+00yr, Percentage 1.00e+01%, Percentage 1.10e+01%, Percentage 7.00e+00%
DOI:10.11975/j.issn.1002-6819.2018.21.020
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 17>
Accession number:20190706490393
Title:Analysis of water saving and yield increasing mechanism in maize field with drip irrigation under film mulching based on transpiration estimated by sap flow meter
Authors:Zhang, Yanqun (1); Wang, Jiandong (1); Gong, Shihong (1); Xu, Di (1); Sui, Juan (1, 2); Wu, Zhongdong (3)
Author affiliation:(1) Department of Irrigation and Drainage, China Institute of Water Resources and Hydropower Research, Beijing; 100048, China; (2) Institution of Remote Sensing and Geographical Information System, Peking University, Beijing; 100871, China; (3) School of Agricultural Engineering and Food Science, Shangdong University of Technology, Zibo; 255049, China
Corresponding author:Wang, Jiandong(wangjd@iwhr.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:89-97
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Determine evapotranspiration (ET) and its components is important for us to understand the influence of mulching on filed water consumption, to develop precision irrigation scheduling and to improve water use efficiency in the field. In this study, the net radiation, field soil evaporation and crop transpiration, crop growth and yield of film mulching (M) and non-mulching (NM) maize fields were measured in a continuous 2 years field experiment in the drip irrigation with mulching area of Northeast China. Net radiation was measured by two net radiometers in the center of every representative plot of the M and NM treatments at height of 50 cm above the canopy adjusted with the increase of plant height and 30 cm above ground. Soil evaporation was measured by micro-lysimeters made from polyvinyl chloride (PVC) tubes and it was weighed every day. Transpiration during the middle and late growth period was measured and scaled up from the sap flow rates. Transpiration of the whole growth period were calculated the by using the dual crop coefficient method with the adjusted medium-term basal crop coefficient from the FAO-56 manual. The medium-term basal crop coefficient were adjusted with the measured transpiration. The results showed that: The net radiation above the canopy of M treatment reduced by 7.7%, i. e. the energy available for evapotranspiration reduced. The net radiation under the canopy of M treatment reduced by 34.0%, i. e. the energy available for soil evaporation (E<inf>s</inf>) reduced. However, the net radiation absorption by the canopy of M treatment increased by 14.0% for crop transpiration (T<inf>r</inf>). The film mulching could reduce the total amounts of evapotranspiration by 3.9%-5.2%. ET of M was 471. 3mm in 2014, which was 5.2% lower than that of NM treatment (497.4 mm). In 2015, ET of M was 413.4 mm, 3.9% lower than that of NM treatment (430.0 mm). The film mulching had a significant effect on the water consumption distribution between E<inf>s</inf> and T<inf>r</inf>. Total E<inf>s</inf>of the whole growth stage for M and NM treatments were 58.8 and 108.8 mm in 2014, 60.0 and 107.6 mm in 2015. Plastic mulching decreased E<inf>s</inf> by 44.7% and increased T<inf>r</inf> by 7.8% in this area for the two years, comparing to those of NM treatments. The ratios of E<inf>s</inf> to ET in 2014 and 2015 were 12.5%-14.5% for the M treatment, and which were up to 21.7%-25.0% for the NM treatment. The ratios of T<inf>r</inf> to ET were 85.5%-87.5% and 75%-78. 3% for M and NM treatments, respectively. The plant height of maize, the stem diameter at 20 cm height above the ground, biomass at the maturity stage and the maximum leaf area index of treatment M were significantly higher than those of treatment NM by 7.1%, 5.8%, 4.8% and 1.7% in 2014 and 5.4%, 8.8%, 6.9% and 2.2% in 2015. The yield of M treatment increased by 5.9%-8.8%, and water use efficiency increased by 12.0%-13.1%. In summary, the film mulching reduced the total amount of ET in maize field by changing the canopy radiation energy distribution, and finally enhanced the plant growth, increased grain yield and water use efficiency in maize field with drip irrigation in this area.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Evapotranspiration
Controlled terms:Chlorine compounds - Crops - Evaporation - Film growth - Flowmeters - Irrigation - Polyvinyl chlorides - Radiation - Soil moisture - Soil surveys - Transpiration - Water conservation - Water supply
Uncontrolled terms:Basal crop coefficients - Crop growth and yields - Drip irrigation - Film mulching - Maximum leaf area index - Polyvinyl chloride (PVC) - Water use efficiency - Yield
Classification code:444 Water Resources - 446.1 Water Supply Systems - 461.9 Biology - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 815.1.1 Organic Polymers - 821.3 Agricultural Methods - 821.4 Agricultural Products - 943.1 Mechanical Instruments
Numerical data indexing:Age 2.00e+00yr, Percentage 1.20e+01% to 1.31e+01%, Percentage 1.25e+01% to 1.45e+01%, Percentage 1.40e+01%, Percentage 1.70e+00%, Percentage 2.01e+03%, Percentage 2.17e+01% to 2.50e+01%, Percentage 2.20e+00%, Percentage 3.00e+00%, Percentage 3.40e+01%, Percentage 3.90e+00%, Percentage 3.90e+00% to 5.20e+00%, Percentage 4.47e+01%, Percentage 4.80e+00%, Percentage 5.20e+00%, Percentage 5.40e+00%, Percentage 5.80e+00%, Percentage 5.90e+00% to 8.80e+00%, Percentage 6.90e+00%, Percentage 7.10e+00%, Percentage 7.70e+00%, Percentage 7.80e+00%, Percentage 8.55e+01% to 8.75e+01%, Percentage 8.80e+00%, Size 1.08e-01m, Size 1.09e-01m, Size 2.00e-01m, Size 3.00e-01m, Size 3.00e-03m, Size 4.13e-01m, Size 4.30e-01m, Size 4.97e-01m, Size 5.00e-01m, Size 5.88e-02m, Size 6.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.21.011
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 18>
Accession number:20190706490388
Title:Adaptive fuzzy sliding mode control of spray boom active suspension for large high clearance sprayer
Authors:Xue, Tao (1); Li, Wei (1); Du, Yuefeng (1); Mao, Enrong (1); Wen, Haojun (2)
Author affiliation:(1) Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment, College of Engineering, China Agricultural University, Beijing; 100083, China; (2) Xinjiang Academy of Agricultural and Reclamation Science, Shihezi; 832000, China
Corresponding author:Mao, Enrong(gxy15@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:47-56
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The large high clearance self-propelled sprayers with the advantages of high efficiency, environmental protection and intelligentization have been widely used worldwide. The spray boom suspension system is an important part of the large high clearance self-propelled sprayer, whose structure and performance have an important influence on the stability and life of the spray boom as well as the uniformity of spray. In order to solve the problems that the spray boom is easily affected by the body swing of the sprayer to generate harmful motions such as rotation, deflection, shaking and the like, the structure and function of the existing spray boom suspension systems were comprehensively analyzed, and a two-link trapezoidal spray boom suspension system was designed. In view of the problems of poor performance of isolated interference body swing of spray boom passive suspension, a hydraulic cylinder is added on the spray boom passive suspension to obtain an active suspension, which can not only take advantage of the input of external energy to actively adjust the spray boom posture, but also retain the high-frequency isolation performance of the spray boom passive suspension to avoid the high frequency response of the active suspension that consumes a lot of energy. In the light of the dynamics and the hydraulic system characteristics of spray boom active suspension, the control method based on adaptive fuzzy sliding model control algorithm of boom active suspension were developed with the spray boom inclination angle as the control object and the control objectives of fast response, stability and accuracy. On the basis of the established dynamic model of the spray boom active suspension, the dynamic characteristics of the active suspension were simulated and analyzed by Matlab/Simulink, which provides the basis for the effectiveness of the control method. A real vehicle test platform of the spray boom suspension system based on high clearance self-propelled sprayers developed by the research group were built. The dynamic characteristics of the active and passive suspensions of spray boom were tested by the actual vehicle following test and field test, and the results were compared and analyzed with the simulation results of the model. The test result shows that: when adopting the active boom suspension control method based on adaptive fuzzy sliding mode control algorithm, the step response time and the following error of the boom dip angle is 2 s and 0.002 rad, which are decreased compared to PID control. In the field test, the spray boom active suspension can keep the inclination angle of the boom in the range of -0.005-0.005 rad. The results show that the active suspension control method proposed in this paper has good responsiveness, stability and accuracy, and can effectively isolate the disturbing body swing and keep the spray rod stable. The study promote the development of theory for the spray boom active suspension in China, and it is conducive to the development of the large high clearance sprayer in China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Active suspension systems
Controlled terms:Adaptive control systems - Agricultural machinery - Automobile bodies - Automobile suspensions - Automobile testing - Control engineering - Control theory - Frequency response - Fuzzy systems - Hydraulic equipment - Hydraulic machinery - MATLAB - Sliding mode control - Spraying - Suspensions (components) - System stability - Three term control systems
Uncontrolled terms:Active suspension - Active suspension control - Adaptive fuzzy sliding mode controls (AFSMC) - Dynamic characteristics - High frequency response - High-frequency isolation - Large high clearance sprayer - Structure and performance
Classification code:601.2 Machine Components - 632.2 Hydraulic Equipment and Machinery - 662 Automobiles and Smaller Vehicles - 662.4 Automobile and Smaller Vehicle Components - 731.1 Control Systems - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 961 Systems Science
Numerical data indexing:Time 2.00e+00s
DOI:10.11975/j.issn.1002-6819.2018.21.006
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 19>
Accession number:20190706490410
Title:Effect of spray times and inoculum content on biogas production performance of sequencing batch dry anaerobic digestion with mixed straw and cow dung
Authors:Yu, Jiadong (1); Zhao, Lixin (1); Feng, Jing (1); Yao, Zonglu (1); Huang, Kaiming (1); Luo, Juan (1); Wei, Shimeng (1)
Author affiliation:(1) Center of Energy and Environmental Protection, Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agriculture Residue, Beijing; 100125, China
Corresponding author:Zhao, Lixin(zhaolixin5092@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:228-233
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The Chinese large-scale biogas engineering is generally based on wet anaerobic fermentation technology, the solid content of feedstock is about 6%, but treating the high solid content of agricultural waste still have a series of problems. Using the sequencing batch dry anaerobic digestion technology (SBD-AD) for treating agricultural wastes not only increases the amount of feedstock, increases the volumetric biogas production rate, but also reduces the slurry production and the cost of post-treatment. A stable technical model has been formed in European Union countries. However, the development of the SBD-AD biogas engineering using agricultural wastes as feedstock in China is slow. Further research is needed to promote the efficiency of the SBD-AD according to the characteristics of local agricultural wastes, such as cornstalks and cow dung. Cornstalk is rich in lignocellulose, and it is difficult to digest. And no systematic research has been taken on the performance of the SBD-AD with straw as the main feedstock. Moreover, previous studies have shown that the spray times and inoculum content were the key factors affecting the methane production efficiency of the SBD-AD process. This paper studied the biogas production characteristics of SBD-AD using corn stalks as main feedstock by controlling spray time and inoculum content, and explored factors that affect the hydrolysis and methane production using methods of model fitting and hydrolysate analysis. The results showed that both of the spray times and inoculum content had significant effects on biogas production (P<0.05). Low (3 times per day) and high spray times (12 times per day) were not conducive to biogas production, and the inoculum content should not be less than 20%, and the most biogas yield reached 251.6 L/kg, when the spray times and inoculum content was 4 times/d and ≥20% (w/w), respectively. Moreover, the methane content was about 55% at the peak stage of biogas production and rapid decline after 20 day. Increasing the inoculum content and spray times could promote substrate hydrolysis efficiency ranging 20%-30%. However, the methane yield and the maximum methane production rate increased first and then decreased, it was limited obviously by the accumulation of organic acid, which the organic acid concentration reached 1 302-1 956 mg/L in the fermentation prophase, and propionic acid concentration accounts for 58.2%-79.9%. In addition, the system had inhibition risk of ammoniacal nitrogen (527.3 mg/L). The conversion efficient of hydrolysate played an important role in improving biogas production efficiency. This study can provide theoretical guidance for improving process optimization quality of SBD-AD based on straw waste.<br/> © 2018, 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:Agricultural wastes - Agriculture - Biogas - Efficiency - Feedstocks - Fermentation - Hydrolysis - Methane - Optimization - Propionic acid - Straw
Uncontrolled terms:Acid concentrations - Anaerobic fermentation - Biogas production rates - Dry anaerobic digestions - European Union countries - Inoculum content - Organic acid concentration - Substrate hydrolysis
Classification code:802.2 Chemical Reactions - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 913.1 Production Engineering - 921.5 Optimization Techniques
Numerical data indexing:Age 5.48e-02yr, Mass_Density 1.30e+00kg/m3 to 1.96e+00kg/m3, Mass_Density 5.27e-01kg/m3, Percentage 2.00e+01%, Percentage 2.00e+01% to 3.00e+01%, Percentage 5.50e+01%, Percentage 5.82e+01% to 7.99e+01%, Percentage 6.00e+00%, Specific_Volume 2.52e-01m3/kg
DOI:10.11975/j.issn.1002-6819.2018.21.028
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 20>
Accession number:20190706490404
Title:Method for wheatear counting and yield predicting based on image of wheatear population in field
Authors:Li, Yinian (1); Du, Shiwei (1); Yao, Min (1); Yi, Yingwu (1); Yang, Jianfeng (1); Ding, Qishuo (1); He, Ruiyin (1)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing; 210031, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:185-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:At present, the wheatear number and grain number for unit area wheat in field can be measured when predicting yield. Generally, phenotype parameters should be obtained by manual count technique. It is time-consuming and needs great effort. In order to quickly measure the yield of unit area wheat in field, the wheatear population image was obtained by tilting the wheatear with specific device in field. The contour information on wheatear image in field was collected. Firstly, the color space of wheatear population image was converted from RGB (red green blue) to HSI (hue saturation intensity) for the sake of improving the uniformity of image color. Then the saturation component of image was extracted from the HSI color space of wheatear population image. Binary image of the saturation component of image was obtained by using image binary algorithm, morphological opening operation and removing of small regions algorithm. Then binary image was smoothed by linear mean filtering algorithm. The adherent and narrow part was removed by setting distance threshold between boundary points. Then the adhesive wheatear in image was judged out by its boundary and region characteristic parameters from the binary image. The boundary characteristic parameters included the length of entire boundary and the angle of on boundary point. The region characteristic parameters included the region area and shape factor of region and duty cycle of convex closure. Then image edge of adhesive wheatear was smoothed by using concave domain smoothing method. Then concave points on the boundary of adhesive wheatear were extracted by using included angle method and area method. The concave point pairs were found by 6 matching principles of concave points. The adhesive wheatear in image was segmented by connecting concave point which was already detected and matched on the binary image boundary. The separated wheatears and non-adhesive wheatears were superimposed on a binary image. The connected regions on the binary image were marked by image labeling algorithm. The number of wheatears in one binary image was counted. And the total number of wheatears in 0.25 m<sup>2</sup> area was obtained by summing the number of wheatears in corresponding 4 wheatear images. Meanwhile, the area pixels number of each wheatear in binary image was extracted. The grain number prediction formula of wheatear in image was obtained by the linear relationship between actual grain number and area pixels number of pre-marked wheatear. Then the grain number of each wheatear in binary image was forecasted by using grain number prediction formula. The total grain number of wheatear in one image was obtained by summing the grain numbers of each wheatear in binary image. The total grain number of wheatear in 0.25 m<sup>2</sup> area was obtained by summing the grain numbers in corresponding four wheatear images. The 1 000-grain weight of 3 varieties of wheat which included Suke wheat 1, Yang wheat 22 and Su wheat 188 was measured respectively. Finally the yield of wheat in 0.25 m<sup>2</sup> area was calculated according to the 1 000-grain weight and the total grain number of wheatear. Compared with the actual wheatear number, grain number in a wheatear image and actual yield information of wheat in 0.25 m<sup>2</sup> area, the experiment results manifest that the average identification precision of the wheatear number in a wheatear image for 3 varieties of wheat is 91.63%, and the average prediction precision of the grain number in a wheatear image for 3 varieties of wheat is 90.73%. And the average prediction precision of the total wheatear number, total grain number and yield of wheat in 0.25 m<sup>2</sup> area for 3 varieties of wheat are 93.83%, 93.43% and 93.49%, respectively. The automatically predicting yield information of wheat in unit area can be realized by using wheatear image features method.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Binary images
Controlled terms:Adhesives - Algorithms - Color - Crops - Forecasting - Grain (agricultural product) - Image enhancement - Image segmentation - Pixels
Uncontrolled terms:Grain numbers - Wheat - Wheatear number in unit area - Wheatear population image - Yield prediction
Classification code:723.2 Data Processing and Image Processing - 741.1 Light/Optics - 821.4 Agricultural Products
Numerical data indexing:Area 2.50e-01m2, Percentage 9.07e+01%, Percentage 9.16e+01%, Percentage 9.34e+01%, Percentage 9.35e+01%, Percentage 9.38e+01%
DOI:10.11975/j.issn.1002-6819.2018.21.022
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 21>
Accession number:20190706490415
Title:Establishment of agricultural land appraisal model based on deep belief network
Authors:Wang, Hua (1, 2); Luo, Ping (1); Zhao, Zhigang (1); Nie, Ke (1)
Author affiliation:(1) Key Laboratory of Urban Land Resources Monitoring and Simulation, Ministry of Land and Resources, Shenzhen; 518034, China; (2) School of Computer and Communication Engineering, Zhengzhou University of Light Industry, Zhengzhou; 450002, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:263-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The basic prices of agricultural land appraisal (ALA) has the extremely vital significance on establishing a complete set of agricultural land price system and smoothly carry out land assets, such as reasonable allocation of land consolidation rural land management. Existing models such as artificial neural networks, support vector machines, multivariable regression cannot build the complex function relationship fully between the affecting factors and land prices, and the above-mentioned models with shallow structure have no ability to handle a high-dimensional sample set for land appraisal. So deep learning method was firstly introduced into ALA, and a novel method for ALA based on deep belief networks (DBN) was proposed. A group of 19-dimensional original features reflecting status of land location and quality were employed as inputs, and the land prices were used as outputs of DBN model. The parameters of DBN model were firstly initialized by unsupervised learning method with no-label samples, and then fine-tuned by supervised learning method with labeled samples. The land price of each assessment unit can be calculated by using the well-trained DBN deep neural network with the input of feature vector, and the level of assessment unit can be determined by taking advantage of total value frequency distribution histogram, then the benchmark land price for each level can be calculated via the method of area weighted technique. Take the city of Puning in Guangdong province as a case study, feasibility and validity of the model was validated. The results of the present study indicate that: 1) With respect to the artificial neural networks and support vector machines models, the DBN model get better assessment accuracy with a slight increase of 3.61% and 3.12% because of it is able to take the advantage of feature extraction of deep structure, and can enhance its generation ability by a large amount of no-label land price samples; 2) The simulating error of DBN model for land price appraisal is 16.43% when the number of training samples is only 300, which is less than the artificial neural networks and support vector machines models with a least reduction of 6.76%, DBN model gets high assessment accuracy with a small amount of training samples resorting to its unsupervised learning framework, and the assessment accuracy increases with the number of no-label samples; 3) The running time and memory usage of DBN for single training sample is higher than the artificial neural networks and support vector machines models, and the running time of support vector machines model is 193 and 187 s for DBN model when the assessment accuracy reaches about 95%, both of which are equal because of the DBN model need less training samples than the SVM model; 4) The cultivated land assessment units of Puning city are divided into 5 levels based on the their land price results which are calculated based on the DBN model, and the benchmark land price of Puning city ranges from 21.34 to 26.23 yuan/m<sup>2</sup> which are calculated based on the area weighted technique. The above experiment results indicate that the assessment accuracy of DBN model is significantly better than the models with shallow structure, and the spatial distribution pattern of benchmark land price and quality level of cultivated land for Puning city are consistent with each other. It is concluded that the method is feasible and effective in measurement and calculation on agricultural base land price.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Deep neural networks
Controlled terms:Agriculture - Bayesian networks - Benchmarking - Costs - Deep learning - Land use - Machine learning - Models - Neural networks - Sampling - Support vector machines - Unsupervised learning - Vectors
Uncontrolled terms:Agricultural land - Deep belief network (DBN) - Deep belief networks - Land prices - Puning - Spatial distribution patterns - Supervised learning methods - Unsupervised learning method
Classification code:403 Urban and Regional Planning and Development - 723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911 Cost and Value Engineering; Industrial Economics - 921.1 Algebra - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory
Numerical data indexing:Percentage 1.64e+01%, Percentage 3.12e+00%, Percentage 3.61e+00%, Percentage 6.76e+00%, Percentage 9.50e+01%, Time 1.87e+02s, Time 1.93e+02s
DOI:10.11975/j.issn.1002-6819.2018.21.033
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 22>
Accession number:20190706490389
Title:Effect of fan nozzle structure and pressure on distribution and activity of microbial pesticide droplets
Authors:Liu, Dongmei (1, 2); Zhou, Hongping (1); Ru, Yu (1); Qu, Rongjia (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) Jinhua Polytechnic, Jinhua; 321017, China
Corresponding author:Zhou, Hongping(hpzhou@njfu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:57-64
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The flat fan nozzle is the most common type of nozzle for various boom sprayers. From the perspective of reducing damage and improving activity, in order to screen the nozzle pattern and spray pressure suitable for spraying microbial pesticide in flat fan nozzles, the comparative experiments of bioactivity damage were carried out for extended range fan nozzle XR, wide-angle fan nozzle TT and air suction fan nozzle AI. The nozzle atomization test system was used to test the droplet distribution of three different spray samples of Bacillus thuringiensis, Brassica californica polyhedrosis virus and water. The influence of nozzle structure and spray pressure on the activity damage of bacteria and virus biological pesticide was quantified by spore germination rate of Bacillus thuringiensis and mortality of Plutella xylostella. The experimental results showed that the XR series fan nozzles with a single direction of flow had less impact on the biological activity than the TT series with multiple flow mutations and the AI series fan nozzles with interference from external air flow. When the XR11002 nozzle sprayed microbial pesticide, the fluid flew through the 2 channels of the same flow direction to the nozzle hole, and there was no sudden change of the fluid direction and no external airflow interference during the spraying process. However, the TT11002 nozzle forcibly changed the direction of the liquid, forcing the fluid to entered the horizontal mixing chamber from the vertical direction, and then changing from the horizontal flow channel to the almost vertical orifice channel, resulting in microbial damage caused by shear stress and normal stress. The AI11003 nozzle was provided with a front hole, and in the hole, the air was sucked into the nozzle due to the Venturi effect. The gas and liquid mixed flow structure caused the microorganism to be subjected to multiple interferences and force, causing damage to biological structures. At 0.5 MPa, after 16 hours culture, the spore germination rate of Bacillus thuringiensis sprayed with XR11002 sprinkler was 83.76%, while that of TT11002 and AI11003 were 65% and 68.33% respectively. Pressure on the bacterial and viral biological pesticide activity difference was obvious. The pressure had a negative correlation to the activity damage of bacteria, and had no obvious effect on the damage of the virus activity, it was mainly related to the structure of bacteria and virus. The bacteria had the cell structure, the increase of pressure caused the increase of damage degree to cell wall and cell membrane, resulting in the decrease of the living bacteria and subalgebra. The virus had no cell structure, its genetic material was wrapped in the protein shell, and the destruction of the shell did not affect the virus activity. The damage degree of nozzle to virus biologic pesticides was less than that of bacteria, which was caused by the different structure of the 2 organisms. Therefore, when using the flat fan nozzle to spray the microbiological pesticide, the XR series fan nozzle was preferred. Therefore, when using the flat fan nozzle to spray the microbiological pesticide, the XR series fan nozzle was preferred. From the angle of reducing the activity damage, it was suggested that the spray pressure of XR11002 and TT11001 were not greater than 0.15MPa, and the spray pressure of AI11003 was not greater than 0.3MPa. In combination with various factors, when spraying microbial pesticides with fan nozzles, XR11001 in XR series fan nozzles was preferred from the viewpoint of droplet distribution and activity, and the spraying pressure was 0.15 MPa. In the spraying of virus pesticides, the impact of the type of nozzle and pressure on the viral activity damage can be ignored. This paper provides a reference for screening the optimal nozzle type and spraying pressure suitable for bio-pesticide spraying.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Spray nozzles
Controlled terms:Air - Algebra - Bacteria - Bacteriology - Bioactivity - Cells - Channel flow - Cultivation - Cytology - Drops - Fans - Nozzles - Pesticides - Pressure - Pressure effects - Shear flow - Shear stress - Viruses
Uncontrolled terms:Bacillus thuringiensis - Biological structures - Comparative experiments - Different structure - Droplet distribution - Microbial pesticides - Multiple interferences - Negative correlation
Classification code:461 Bioengineering and Biology - 618.3 Blowers and Fans - 631.1 Fluid Flow, General - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 821.3 Agricultural Methods - 921.1 Algebra - 931.1 Mechanics
Numerical data indexing:Percentage 8.38e+01%, Pressure 1.50e+05Pa, Pressure 3.00e+05Pa, Pressure 5.00e+05Pa, Time 5.76e+04s, Percentage 6.50e+01%, Percentage 6.83e+01%
DOI:10.11975/j.issn.1002-6819.2018.21.007
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 23>
Accession number:20190706490418
Title:Addition of Brassica oleracea L. seed water extract improving colour, flavour and anti-oxidation of cantonese cured meat
Authors:Liu, Wenying (1); Li, Xiang (1); Cheng, Xiaoyu (1)
Author affiliation:(1) China Meat Research Center, Beijing Key Laboratory of Meat Processing Technology, Beijing Academy of Food Sciences, Beijing; 100068, China
Corresponding author:Cheng, Xiaoyu(chxyey@aliyun.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:288-294
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The meat products quality is influenced by the raw meat, ingredients, processing amd storage condition, and the auxiliary material addition scheme is the main determinant that is associated with lipid oxidation, protein oxidation, colour stability and flavour formation, while the colour information, oxidation states and flavour characteristic often need to be simultaneously considered. Lipid oxidation of meats during processing and storage has been related to its deterioration in terms of sensory characters, processability and nutritional quality, which would remarkably affect consumers' perception, and this deterioration sometimes could be relieved by innovative supplement which with antioxidant activity. The appearance of natural antioxidants has not only avoided the potential toxic effects of chemical anti-oxidants, but also improved the products quality to a certain extent. With the development of modern meat processing industry, the applicability of innovative materials in traditional food processing also need to be studied. In order to evaluate the antioxidant activity of Brassica oleracea L. seed extract (BSE) in vitro and the application effect in cantonese cured meat, a verification experiment was executed, meanwhile the effect of butylated hydroxytoluene (BHT) addition was also analyzed. Six treatments were carried out, CT (basic formula), 0.2% BSE (basic formula+0.2% BSE), 0.5% BSE (basic formula+ 0.5% BSE), 1.0% BSE (basic formula + 1.0% BSE), 1.5% BSE( basic formula+1.5% BSE) and BHT (basic formula + 0.02% BHT) respectively. The ferric reducing ability of plasma results showed that the total antioxidant activity of BSE in vitro increased as the adding amount increasing (P <0.05), while the inhibition of induced oxidative effect in the lipid system showed a tendency to decrease after increased to 5.09±0.04 h, the inhibition was significantly reduced (P<0.05) at 1.5% BSE addition, compared with 1.0% addition. Within the BSE products, the thiobarbituric acid reactive substance (TBARS) value appeared to be increasing after decreasing at 1. 0% BSE addition, similar to inhibition of induced oxidation, and the TBARS value of BHT treatments fell to the value between 1.0% and 1.5% BSE addition. Based the outcome of principal component analysis(PCA) and linear discriminant analysis(LDA), the results showed that the principal component could represent the flavor characteristics of the individual products, in particular, especially the BHT product was obviously different from the other products. The 1.5% BSE treatment had the highest lightness (L*) and yellowness (b*) value, and the redness (a*) value of 1.5%BSE was similar to CT and other BSE treatment, while the BHT treatment had an advantage in a* value. Both types and quantities of volatile substances were vary, the types decreased as the content of BSE increased, while the quantities of volatile substances showed a trend of first decreasing and then increasing. The 1.5%BSE product with the desired L* and b* value, the TBARS value was less than BHT treatment (P>0.05), and there was no obvious difference in flavor from traditional processing products. From the analysis of sensory quality and physical characteristics, 1.5% BSE addition would be the ideal alternative in cantonese cured meat processing.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:46
Main heading:Principal component analysis
Controlled terms:Antioxidants - Chemical analysis - Color - Curing - Deterioration - Discriminant analysis - Extraction - Food processing - Meats - Oxidation - Plants (botany) - Quality control - Sensory analysis - Sensory perception
Uncontrolled terms:Antioxidant capacity - Brassica oleracea - Cured meats - Ferric reducing ability of plasmas - Linear discriminant analysis - Meat-processing industry - Sensory characteristics - Thiobarbituric acid reactive substances
Classification code:461.4 Ergonomics and Human Factors Engineering - 741.1 Light/Optics - 802.2 Chemical Reactions - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 822.2 Food Processing Operations - 822.3 Food Products - 913.3 Quality Assurance and Control - 922 Statistical Methods - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 0.00e+00%, Percentage 1.00e+00%, Percentage 1.00e+00% to 1.50e+00%, Percentage 1.50e+00%, Percentage 2.00e-01%, Percentage 2.00e-02%, Percentage 5.00e-01%
DOI:10.11975/j.issn.1002-6819.2018.21.036
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 24>
Accession number:20190706490398
Title:Estimation of erosion amount in collapsed gully based on CA-Markov model and ANUDEM interpolation
Authors:Ji, Xiang (1, 2); Huang, Yanhe (1); Lin, Jinshi (1); Jiang, Fangshi (1); Yu, Mingming (1); Li, Shaoxin (1)
Author affiliation:(1) College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou; 350002, China; (2) Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, Fuzhou; 350002, China
Corresponding author:Huang, Yanhe(yanhehuang@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:128-136
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Collapsed gully is a kind of soil erosion in South China threating agriculture production and ecological environment due to its considerable sediment yield. Therefore, the prediction and estimation of erosion amount play a significant role in its prevention and control. However, collapsed gullies normally cover a relatively smaller area and eroded more severely than other kinds of soil erosion, which made existing methods and approaches hardly to apply on it. In this research, cellular automation-Markov (CA-Markov) model and Australian National University digital elevation model (ANUDEM) are employed to estimate and predict the erosion amount of collapsed gully. The former is taken to simulate the transition of collapsed gully elevation classes, and the latter is taken to spatial interpolate on the simulation results of collapsed gully elevation classes. Based on the two processes, the continuous elevation data of collapsed gully can be simulated and predicted. Then the erosion amount is computed according to the prediction result and base time data. To test this approach, a collapsed gully located in the Longmen Town, Anxi County, Fujian Province is chosen as the case study. And it contains two parts, which are the confirmation of simulating accuracy and the prediction under 3 types of scenes for annual erosion amount. The results show that the modified CA-Markov model performances well on the simulation of collapsed gully elevation classes, which resulted from a lower area error between simulation results and actual value (1.47%), and a higher Kappa coefficient of 0.958. The goodness of fit (R<sup>2</sup>) of the interpolation result using ANUDEM is 0.998 7 and its mean error (ME) is 0.27 m, which means ANUDEM is good at the integral restoration of collapsed gullies terrain but not sufficient at details. As a consequence, two types elevation at the base time are chosen to estimate the erosion amount, one is original DEM, and the other one is the elevation data through classes division and interpolated processing. The erosion amount calculated from the second type of base data performances difference rates of 17.55% and 8.66%, which are much lower than the one derived from the first type of base data. Thus, the second type of base data is accessible for computing collapsed gully erosion amount, and the huger the real erosion amount, the higher the accuracy. After the confirmation of modeling accuracy, 3 types of rainfall scenes were set based on the historical records of rainfall, which are normal years, drought years and rainy years. The annual erosion amounts of case collapsed gully under the 3 types of rainfall scenes are 824.69, 731.03 and 924.57 m<sup>3</sup>, and the difference of the two extreme rainfall scenes is 193.54 m<sup>3</sup>, which means that the difference of erosion amount between different rainfall scenes should be taken into account when building a sediment storage dam to control the damage of a collapsed gully. The methods proposed in this research can not only provide a novel way to study the erosion process and erosion amount of collapsed gully, but also supply a reasonable reference for the prevention and control of collapsed gully erosion.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Coefficient of performance
Controlled terms:Digital storage - Erosion - Forecasting - Interpolation - Landforms - Markov processes - Models - Rain - Surveying
Uncontrolled terms:Agriculture productions - ANUDEM - Australian National University - CA-Markov - Collapsed gully - Digital elevation model - Ecological environments - Erosion amounts
Classification code:405.3 Surveying - 443.3 Precipitation - 481.1 Geology - 722.1 Data Storage, Equipment and Techniques - 921.6 Numerical Methods - 922.1 Probability Theory
Numerical data indexing:Percentage 1.47e+00%, Percentage 1.76e+01%, Percentage 8.66e+00%, Size 2.70e-01m, Volume 1.94e+02m3, Volume 7.31e+02m3, Volume 9.25e+02m3
DOI:10.11975/j.issn.1002-6819.2018.21.016
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 25>
Accession number:20190706490403
Title:Automatic calibration of parameters for crop phenological predicting model based on adaptive differential evolution algorithm
Authors:Jiang, Haiyan (1, 2); Zhao, Kongnuan (1); Tang, Liang (2); Li, Yushuo (1); Yang, Hua (1)
Author affiliation:(1) College of Information Science and Technology, Nanjing Agricultural University, Nanjing; 210095, China; (2) National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing; 210095, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:176-184
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Evolutionary algorithms have been widely used in the field of crop model parameter calibration. Since the crop model structure includes multiple sets of ordinary differential equations with nonlinear, discontinuous and multi-peak characteristics, it is especially important to select appropriate evolutionary algorithms based on crop model characteristics. At the same time, the parameters of the evolutionary algorithm have a great influence on the performance of the algorithm. These parameter selections are often based on experience, which increases the uncertainty of the optimization algorithm in the model parameters calibration process. This article was targeted on problem of selection and parameter uncertainty of the evolutionary algorithm applied to the crop phenological model parameter correction quasi-process. In this paper, the rice RiceGrow phenological predicting model was applied to compare the correction accuracy, convergence speed and stability robustness of 3-tyepe evolutionary algorithms in application. Comparison algorithms included differential evolution series algorithms (standard differential evolution algorithm(DE) and adaptive control parameters modified differential evolution algorithm(ACPMDE)), co-evolutionary genetic algorithm series (individual advantage genetic algorithm, M-elite co-evolution algorithm) and particle swarm optimization series (standard particle swarm optimization, multi-subgroup particle swarm optimization based on autonomous learning and elite groups). Using the multi-year field experiment data of 5 species of Wuyujing and Xuehuanian in different ecological points such as Yixing, Xinghua in Jiangsu province and Gaoyao in Guangdong province, the accuracy, convergence rate and stability robustness of the automatic correction of the model parameters was quantitatively analyzed with different evolutionary algorithms. The results showed that: 1) the correction accuracy of the model parameters of the model with adaptive control parameters modified differential evolution algorithm was higher than other algorithms, and the parameters of the algorithm were easier to determine. The cross-probability factor and scaling factor of the algorithm were adaptively adjusted with the individual fitness function during the evolution process, in which the dependence of the standard DE algorithm parameters on the optimization problem was avoided and the robustness of the algorithm was improved. The RMSE(root mean square error) between the predicted and observed values of jointing, heading and maturity stage was 1. 7-4. 6 days; The normalized root mean spuare error was 1.8%-5.8%; MAD(mean absolute difference) was 1.4-3.3 days, and determination coefficient R<sup>2</sup> was 0.977-0.997, which was 0.634 days, 0.608%, 0.453 days, 0.09% smaller than co-evolutionary genetic algorithm series, 1.399 days, 1.35%, 1.039 days, 0.23% smaller than PSO series. 2) Applying adaptive control parameters to improve the differential evolution algorithm showed good convergence speed and stable robustness on the phenomenological model parameter correction. The standard deviation of the objective function value of 100 times repeated calibration experiment approached 0, and the standard deviation of the variety parameter values obtained by each correction was also smaller than other algorithms. With the same accuracy, the adaptive control parameter modified differential evolution algorithm converges 117 iterations faster than the standard differential evolution algorithm. The research showed that the automatic correction quasi-method of crop phenological model parameters based on adaptive control parameters modified differential evolution algorithm had good accuracy and stability and was suitable for practical application.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Parameter estimation
Controlled terms:Adaptive control systems - Calibration - Crops - Evolutionary algorithms - Genetic algorithms - Mean square error - Meteorology - Models - Nonlinear equations - Ordinary differential equations - Particle swarm optimization (PSO) - Robust control - Robustness (control systems) - Statistics - System stability
Uncontrolled terms:Adaptive Control - Adaptive differential evolution algorithms - Differential Evolution - Differential evolution algorithms - Modified differential evolution algorithms - Parameter calibration - Phenological model - RMSE (root mean square error)
Classification code:723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 821.4 Agricultural Products - 921.2 Calculus - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Age 1.24e-03yr, Age 1.74e-03yr, Age 2.85e-03yr, Age 3.83e-03yr, Age 3.84e-03yr to 9.04e-03yr, Percentage 1.35e+00%, Percentage 2.30e-01%, Percentage 6.08e-01%, Percentage 9.00e-02%
DOI:10.11975/j.issn.1002-6819.2018.21.021
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 26>
Accession number:20190706490386
Title:Design of joint-style automatic machine for placing planted vegetable seeding tray
Authors:Zhang, Xiuhua (1); Xie, Xiaodong (1); Yi, Jinggang (1); Yang, Shuhua (1); Kong, Degang (1); Yuan, Yongwei (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:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:27-36
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A great deal of soft seeding trays is required nursing seedlings industry, but transporting and placing these trays always have been done by hands in most companies in China. In recent years, some universities and research institutes have begun to pay attention to factory seedling technology and related equipment, but the existing equipment have shown a few problems, such as covering large floor areas, no mobility and lack of flexibility. In order to deal with the above problems, this paper puts forward an automatic joint-style placement machine. The overall structure and working principle of joint-style placement machine were described, and the performance tests were done. In this machine, chassis walking steering device, lifting device, stacking, rotating and pushing device, and placement device were arranged to solve the problem of placing soft tray after sowing the vegetable seeds. In the chassis walking steering device, the diagonal arrangement of the steering wheel could guarantee the machine to turn in radius 0. In the lifting device, lifting scissors mechanism was used to adjust the height of the whole machine to suit to the height of the seeding planter machine, which could make the connecting between the seedling planter and the automatic joint-style placement machine easily and automatically. Stacking, rotating and pushing device could store 20 trays in the automatic joint-style placement machine, which could save the time for transporting the trays. The more important functions of stacking, rotating and pushing device were switching trays position and pushing trays out to the ground or other place smoothly. Placement device lay in the end of the machine. A joint-style type of mechanical arm and a small conveyer belt were used as the manipulator which adapted to different placing height of the trays. Based on these structural characteristics, the joint-style automatic machine for placing planted vegetable seeding tray could be used for placing soft seeding trays and moving independently, and the stacking, transporting and placing trays would be finished together in one time. High integration and flexibility were the most important features. The mathematical modeling was performed, and the kinematics equation of the manipulator was obtained referencing robotics space D-H method. According to the structural parameters and the machine working principle, 3 key parameters affecting the performance of the joint-style automatic machine placing sowed tray were chosen and analyzed respectively. 3 test factors included conveying height, conveying angle and conveying speed. Through the single factor test, range of the 3 key parameters was determined. Furthermore, Design-Expert software was used to design an orthogonal test including 3 test factors and 3 response indicators. The test index included the qualified rate of trays spacing, tray straighten rate and tray aligned rate. Analyzing the test data and the variance, a mathematical regression equation of the response indicators and influencing factors was established, presenting the effects of the test factors on the qualified rate of trays spacing, tray straighten rate and tray aligned rate. Response surface analysis was performed and the best combination of the 3 key parameters affecting the tray placement effect was obtained. The optimal combination of the 3 key factors for tray placement were as follows: the tray conveying speed was 60 mm/s, the tray conveying angle was 31°, the tray conveying height was 40 mm. Under the optimal condition, the corresponding tests were done and the test result was as follows: the qualified rate of the tray spacing was 97.6%, the tray straighten rate was 96.5%, and the tray aligned rate was 95.7%, respectively. The test results showed that the placement method was reasonable and the joint-style automatic machine placing sowed tray was stable and reliable. This research work can greatly improve the production efficiency for placing soft seeding tray and promote the development of mechanized seedling industry in China.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Seed
Controlled terms:Belt conveyors - Chassis - Design - Machinery - Manipulators - Mechanization - Optimization - Problem solving - Software testing - Surface analysis - Vegetables
Uncontrolled terms:Kinematics equation - Optimal combination - Production efficiency - Research institutes - Response surface analysis - Structural characteristics - Structural parameter - Tray placement
Classification code:601 Mechanical Design - 662.4 Automobile and Smaller Vehicle Components - 692.1 Conveyors - 723.5 Computer Applications - 821.4 Agricultural Products - 921.5 Optimization Techniques - 951 Materials Science
Numerical data indexing:Percentage 9.57e+01%, Percentage 9.65e+01%, Percentage 9.76e+01%, Size 4.00e-02m, Velocity 6.00e-02m/s
DOI:10.11975/j.issn.1002-6819.2018.21.004
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 27>
Accession number:20190706490416
Title:Effect of ultrasonic-assisted degreasing on preparation and physicochemical properties of yak bone powder
Authors:Qin, Xiaojie (1); Shen, Qingshan (1); Jia, Wei (1); Zhang, Chunhui (1, 2); Zheng, Qiankun (2)
Author affiliation:(1) Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing; 100193, China; (2) Delisi Group co. LTD, Weifang; 262216, China
Corresponding author:Zhang, Chunhui(r_zch@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:272-280
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to reduce the degreasing rate and improve the quality of yak bone powder, the ultrasonic assisted organic solvent degreasing method was studied based on the thighbone of Qinghai yak in this paper, and the nutrient contents and physicochemical properties were analyzed comparing with the traditional boiling degreasing method. Firstly, the degreasing solvent was screened according to degreasing rate and applicability among four common organic solvents. Basing on the single factor test, Box-Behnken test was designed to optimize the parameters including ultrasonic power, degreasing time and the ratio of liquid to material. After that, the analysis of the degreasing rate, the loss rate of protein, collagen, main minerals and the microstructure of yak bone treated by ultrasonic and boiling was carried out. Subsequently, the particle size distribution, microstructure, chemical structure and calcium release rate of yak bone powder dealt with the planetary ball mill were shown as well. Results suggested that ethyl acetate was the optimal degreasing solvent with a higher degreasing rate and better applicability under the same conditions. In addition, the two regression model built by response surface design had a good fitting degree with the correlation coefficient of 0. 9484 indicating that the model fitted well in the whole regression region. Considering the energy consumption, the optimum degreasing conditions were finally determined as follows: ultrasonic power is 500 W, ultrasonic time is 30min, and the ratio of liquid to material (mL/g) is 6, under which conditions the degreasing rate could reach 92.00%±0.20% and the relative error of the predicted value was 1. 08% which was less than 5% revealing that the model was effective. Besides that, it was also found that the degreasing rate of ultrasonic (92.00%±0.20%) was significantly higher than that of boiling method (71.25%±2.31%) (P<0.05). Meanwhile, the loss rate of protein and collagen were 8.11%±0.48%, 11.05%±2.45%, respectively, which were dramatically lower (P<0.05). And there was a serious loss of Na, K, Fe, Mn in cooked yak bone that were 19.00%±1.44%, 58.95%±1.04%, 14.32%±2.46% and 20.86%±1.29% respectively while the loss about Fe, Zn, Mn in ultrasonic skimmed yak bone was slightly, and the contents of P, Ca, Mg, Cu, Se, Mo, Sr in the bone treated with the two methods were similar (P>0.05). As for the microstructure of yak bone, the boiling one was looser and more porous. After pulverization, the median diameter of ultrasonic defatted bone powder was (35.84±0.60) μm while the other was (11.73± 0.29) μm, which was in agreement with the result of scanning electron microscope. Moreover, no significant difference had been observed in the chemical structure, and there were mainly phosphate and carbonate in two kinds of bone powder. For the calcium release rate of bone powder, result indicated that both methods had no significant difference (P>0.05). In conclusion, the ultrasonic assisted organic solvent degreasing method could remain more nutrients with the higher degreasing rate. This study provided a high efficient degreasing method, which has the value for improving the processing technology for preparing the yak bone powder.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:47
Main heading:Powder technology
Controlled terms:Boiling liquids - Bone - Calcium - Collagen - Energy utilization - Manganese - Microstructure - Nutrients - Organic solvents - Particle size - Particle size analysis - Physicochemical properties - Regression analysis - Scanning electron microscopy - Solvents - Structure (composition) - Ultrasonics
Uncontrolled terms:Bone powders - Correlation coefficient - De-greasing - Nutrient contents - Planetary ball mill - Processing technologies - Response surface designs - Ultrasonic power
Classification code:461.2 Biological Materials and Tissue Engineering - 525.3 Energy Utilization - 543.2 Manganese and Alloys - 549.2 Alkaline Earth Metals - 641.2 Heat Transfer - 753.1 Ultrasonic Waves - 803 Chemical Agents and Basic Industrial Chemicals - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 5.00e+00%, Percentage 8.00e+00%, Power 5.00e+02W, Time 1.80e+03s
DOI:10.11975/j.issn.1002-6819.2018.21.034
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 28>
Accession number:20190706490419
Title:Process optimization on separation and purification of bound polyphenol in black highland barley bran by macroporous resin
Authors:Yang, Xijuan (1, 2, 3); Dang, Bin (1, 2, 3); Zhang, Jie (1, 2); Zhang, Wengang (1, 2); Chen, Danshuo (4)
Author affiliation:(1) Academy of Agricultural and Forestry Sciences, Qinghai University, Xining; 810016, China; (2) Tibetan Plateau Key Laboratory of Agric-Product Processing, Xining; 810016, China; (3) State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining; 810016, China; (4) Qinghai Engineering Technology Research Center of Highland Barley Resources Comprehensive Utilization, Xining; 810016, China
Corresponding author:Dang, Bin(danbgin811@tom.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:295-303
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Highland barley grows in the Qinghai-Tibet Plateau at an elevation of 1 400~4 700 m, and it is the major crop in the Qinghai-Tibet Plateau region, as well as the main food for farmers and herdsmen in Tibetan areas for sustenance. Black highland barley is a precious germplasm resource. Black highland barley has attracted extensive attention due to its rich nutrition and functional chemical components in the Qinghai-Tibet Plateau region. It has been developed into various types of food. But in the process of black highland barley, lots of brans were produced and wasted. The black barley bran is rich in phenolic compounds including phenolic acids and flavonoids. At present, most of the reports on polyphenols in black highland barley have been about free phenolics. There are few reports about bound phenolics. There have been no reports regarding research on separation and purification of bound phenolic compounds and their antioxidant activities in black highland barley bran from the Qinghai-Tibet Plateau region. This paper focuses on the separation and purification technology of bound polyphenols in barley highland bran and its antioxidant activity. The aim of this study was selecting a resin which has a good adsorption and desorption performance of phenols of black highland barley bran, optimizing the separation process parameters and evaluating its antioxidant activity in vitro, thus improving value of processing and utilization about black highland barley barley bran. The separation and purification process of black highland barley barley bran polyphenol was established by macroporous resin. The static adsorption and desorption performance of ten different polarities macroporous resins (NKA-9, NKA-2, HPD-826, HPD-100, H1020, D101, X-5 and AB-8) to total phenolics and flavonoids of black highland barley barley bran bound extraction were compared to select suitable resin for purification of phenolic compounds. AB-8 macroporous resin exhibited the best capability of adsorption and desorption of total phenolics and total flavonoids in black highland barley bran, it was selected as the best adsorption resin type of separation and purification of bound phenolics. And the macroporous resin reached equilibrium within 4 h. The optimum conditions for adsorption and desorption of bound phenolics were as following: pH value of black highland barley bran bound phenolic extract was adjustment to 3.0, sample concentration was 1.5 mg/mL, the polyphenol was passed through the AB-8 resin at a flow rate of 1.5 mL/min, followed by desorption with 60% ethanol at a flow rate of 1. 5 mL/min. Under optimum technology conditions, Ab-8 macroporous resin could significantly increase the content of over 71.43% individual phenolics, the most abundant bound phenolics were ferulic acid, syringic acid, benzoic acid, ellagic acid, myricetin and rutin in the purified black highland barley bran. Among the three antioxidant systems, the crude and purified extracts of bound polyphenols in black highland barley bran both showed a relatively higher capacity to scavenge DPPH∙ and ABTS∙+. It also had a relatively stronger ferric reducing antioxidant power (FRAP). But the antioxidant capacity of the purified bound polyphenol performed was better than crude sample on this study. In conclusion, AB-8 macroporous resin could be applied to purify total phenolics and total flavonoids of bound polyphenol in litchi pulp black highland barley bran. It has potential industrial application prospect.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Purification
Controlled terms:Adsorption - Antioxidants - Benzoic acid - Conservation - Desorption - Flavonoids - Fruit juices - Grain (agricultural product) - Optimization - Phenols - Resins
Uncontrolled terms:Anti-oxidant activities - Black highland barley - Macroporous resin - Polyphenols - Separation and purification
Classification code:802.3 Chemical Operations - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 821.4 Agricultural Products - 822.3 Food Products - 921.5 Optimization Techniques
Numerical data indexing:Mass_Density 1.50e+00kg/m3, Percentage 6.00e+01%, Percentage 7.14e+01%, Size 1.40e+03m to 4.70e+03m, Time 1.44e+04s
DOI:10.11975/j.issn.1002-6819.2018.21.037
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 29>
Accession number:20190706490385
Title:Numerical simulation and experiment on seeding performance of slide hole-wheel precision seed-metering device for rice
Authors:Zhu, Dequan (1); Li, Lanlan (1); Wen, Shichang (1); Zhang, Shun (1); Jiang, Rui (1); Wu, Liquan (2)
Author affiliation:(1) School of Engineering, Anhui Agricultural University, Hefei; 230036, China; (2) School of Agriculture, Anhui Agricultural University, Hefei; 230036, China
Corresponding author:Zhang, Shun(shunzhang@ahau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:17-26
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Precision planting is the advanced technology that sows seeds in the predetermined position of soil accurately and quantitatively by precision planter. Precision seed-metering device is the key component of precision planter and its seeding performance directly affects the quality of rice sowing, which divided into two types according to the working principle. The one is the mechanical metering device, and the other type is the pneumatic seed-metering device. The hole-wheel precision seed-metering device is a kind of mechanical seed-metering device and its seed-filling performance directly affects the seeding quality, which has been increasingly widespread due to its advantages of high planting quality when sowing rice seeds. But it has disadvantages of bad uniformity not to meet the seeding requirement of different size rice seeds. There are many dry direct seeding varieties rice and the sizes of their seeds are different. The adaptability of the seed-metering device to different sizes rice seeds is different. High speed work will also have a great influence on the seed-filling of the seed-metering device. For the problems of poor adaptability and low precision of the current rice drought direct seeding machine, a slide hole-wheel seed-metering device was designed to improve the direct seeding performance for rice. The sphericity was selected as the indicator of 3-dimension size of rice seeds. According to the simulation test by EDEM software for seeding process in 3 varieties of rice seeds with different sphericity (Gangyou 898, Guofeng No. 1 and Gangyou 3551) under 6 seed-metering device rotational speeds, the changing laws of seeding performance of rice seeds with different sphericity under different rotational speeds were obtained and the influences of rotational speeds and seed sphericity on seeding performance were analyzed. The simulation results showed that the seeding performance of rice seeds of Gangyou 898 was better than other 2 varieties of rice seeds when the rotational speed of seeding wheel was between 15 to 40 r/min, when the rotational speed of seeding wheel was between 15 to 30 r/min, the seeding qualified rate of those 3 varieties rice seeds floated between 84. 01% to 87.91%, and the seeding qualified rate had a increasing trend of overall presentation as the rotational speed of seeding wheel increases, when the rotational speed of seeding wheel was faster than 30 r/min, the seeding qualified rate declined significantly with the increasing of rotational speed. 5 varieties of rice seeds with different sphericity (Guofeng No. 1, Liangyou 628, Gangyou 898, Gangfeng 188 and Gangyou 3551) were selected as experimental materials. The rotational speeds of seeding wheel and seed sphericity were selected as influence factors, and seeding qualified rate, missing rate and replay rate were taken as evaluation standards. The bench test was done with the quadratic regression orthogonal combination design method. The regression equation and response surface between the performance index and the rotational speed and seed sphericity were acquired to verify the simulation results after analyzing those data by Design-Expert 8.0.6 software. Finally, the optimal parameter combination was obtained through the regression equation: the rotational speed of seeding wheel was 27.12 r/min and seed sphericity was 44.61%. In this case, the qualified rate is 83.90%, the missing rate is 5.43% and the replay rate is 10.67%, which is the best seeding performance for the seed-metering devices. The results from bench test were in accordance with that from simulation. The changing trends of seeding performance in bench test with rotational speed and seed sphericity were also basically consistent with that in simulation experiments. The field test result showed that, when the average rotational speed was 27.12 r/min and the forward velocity was 5.85 km/h, the seeding performance of seed-metering device could meet the requirements of precision sowing for all size grades of rice seeds. The research results provide a reference for structure optimization and performance improvement of slide hole-wheel precision seed-metering device.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Seed
Controlled terms:Agricultural machinery - Computer simulation - Crops - Numerical models - Pneumatic materials handling equipment - Regression analysis - Software testing - Speed - Structural optimization - Testing - Wheels
Uncontrolled terms:Experimental materials - Optimal parameter combinations - Precision seed-metering devices - Quadratic regression - Rice - Seed metering devices - Seeding performance - Structure optimization
Classification code:601.2 Machine Components - 632.4 Pneumatic Equipment and Machinery - 723.5 Computer Applications - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 921 Mathematics - 921.5 Optimization Techniques - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.00e+00% to 8.79e+01%, Percentage 1.07e+01%, Percentage 4.46e+01%, Percentage 5.43e+00%, Percentage 8.39e+01%, Rotational_Speed 1.50e+01RPM to 3.00e+01RPM, Rotational_Speed 1.50e+01RPM to 4.00e+01RPM, Rotational_Speed 2.71e+01RPM, Rotational_Speed 3.00e+01RPM, Velocity 1.63e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.21.003
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 30>
Accession number:20190706490409
Title:Settling characteristics of suspended solids in greenhouse turtle aquaculture water
Authors:Ji, Mingdong (1); Li, Haijun (1); Li, Jianping (1); Ye, Zhangying (1); Zhu, Songming (1)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou; 310058, China
Corresponding author:Zhu, Songming(zhusm@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:222-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The settling characteristics and size distribution of solid wastes in aquaculture water play a critical role in designing rearing tank and sedimentation basin. The greenhouse turtle culture is a widely used farming mode, due to its high efficiency and easy to control. The main solid wastes are uneaten feed, faeces and bacterial flocs. Solid wastes can lead to poor water quality and aquacultural benefit if without effectively removed. Research showed that the heterotrophic bacteria can use particulate organic matter for mineralization process. This process not only consumes oxygen, but also produces ammonia. The metabolism of reared organisms also produces ammonia, which lead to a rapid deterioration of water quality. Solids management and removal is the basis for maintaining the aquaculture system operating stably, it is also of great significance for increasing density and ensuring the safety of reared organisms, especially the suspended particles with long contact time and large contact area. Turtle culture is an important economic industry in Yangtze river delta region. In the rearing process, the low removal efficiency of solids, a lot of water exchange and sewage discharge restrict the development of this economic industry. In the middle and later stage of turtle culture, the accumulation of suspended particles caused the water quality to deteriorate and a frequent water exchange, resulting in the increase of rearing cost. The particles under the influence of turtle frequent activities, those large particles are easily broken into suspended particles which is very terrible for the turtle culture. This research took the turtle culture water near the bottom of rearing tank for a simple static sedimentation experiment. The water depth of settling device was 80 cm, the length of two sampling points was 30 cm and the shallow one away from liquid level was also 30 cm. The two sampling points can characterize the difference of suspended particles at different depths in the settling process. The 8 groups of static settling time were 5, 10, 15, 20, 30, 40, 50 and 60 min, respectively. Each group of settling time for static settling experiment was repeated for 3 times. The particle size-volume distribution of water samples was measured by a non-invasive laser scatter instrument. The presentation method of particle size-volume distribution includes interval volume distribution and cumulative volume distribution which can reflect the characteristics of particles size-volume distribution in different aspects and can also be converted to each other. The mass concentration of suspended particles in the original sample was (763±15.3) mg/L and the particles size ranged from 1 to 300 μm. The particles size >100 μm in total volume accounted for 20.4%, the particles size 50-100 μm in total volume accounted for 39.1%, and particles size <50 μm in total volume accounted for 40.5%. The results of static sedimentation experiment showed that the depth of the sedimentation will not affect the settling velocity, but it must ensure a certain depth to avoid higher concentration of particles accumulating in the settling zone which will occur hindered and compression settling. For the water in the middle stage of turtle culture, when the overflow rate was 0.0167 cm/s in the sedimentation basin, the removal efficiency of suspended particles was 24.9%. 90% in total volume of the particles in the outflow water was less than 98.4 μm, and 50% in total volume was less than 41.9 μm. For greenhouse turtle culture, the flat flow sedimentation basin can effectively remove suspended particles, and with the increase of fine particles in the aquaculture water, the overflow rate of sedimentation basin can be reduced accordingly.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Industrial economics
Controlled terms:Ammonia - Aquaculture - Biological materials - Deterioration - Efficiency - Elementary particles - Greenhouses - Particle size - Particle size analysis - Sedimentation - Settling tanks - Sewage - Size distribution - Solid wastes - Water quality
Uncontrolled terms:Cumulative volume distributions - Heterotrophic bacterias - Low removal efficiencies - Mineralization process - Particulate organic matters - Removal efficiencies - Settling characteristics - Volume distributions
Classification code:445.2 Water Analysis - 452.1 Sewage - 461.2 Biological Materials and Tissue Engineering - 802.3 Chemical Operations - 804.2 Inorganic Compounds - 821.3 Agricultural Methods - 821.6 Farm Buildings and Other Structures - 911.2 Industrial Economics - 913.1 Production Engineering - 922.2 Mathematical Statistics - 931.3 Atomic and Molecular Physics - 951 Materials Science
Numerical data indexing:Percentage 2.04e+01%, Percentage 2.49e+01%, Percentage 3.91e+01%, Percentage 4.05e+01%, Percentage 5.00e+01%, Percentage 9.00e+01%, Size 1.00e-06m to 3.00e-04m, Size 3.00e-01m, Size 4.19e-05m, Size 5.00e-05m to 1.00e-04m, Size 8.00e-01m, Size 9.84e-05m, Time 3.00e+03s, Time 3.60e+03s, Velocity 1.67e-04m/s
DOI:10.11975/j.issn.1002-6819.2018.21.027
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 31>
Accession number:20190706490412
Title:Environmental impacts and returning effects of garden wastes under different disposal methods
Authors:Chen, Haotian (1); Zhang, Difang (1); Zhang, Baoli (1); Li, Guoxue (1)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China
Corresponding author:Li, Guoxue(ligx@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:239-244
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The rapid increases of the garden wastes and the related low resources use efficiency have been paid great attention. In order to reuse the garden wastes, the effects of three treatments on garden wastes was investigated. The garden wastes were treated by aerobic composting, pyrolysis and direct incineration. The carbon and nutrient losses, the greenhouse gas emissions, and the effects of corresponding products on the physical and chemical properties of soil were investigated. Incineration was carried out in a closed greenhouse. Muffle furnace under 400℃ was used to pyrolysis. Garden waste composting was performed for 29 days using a 60 L composting vessels. A pot-scale test with white clover was carried out to investigate the physical and chemical properties of soil under different treatments of garden wastes. The results showed that the organic carbon loss rate of the garden wastes was 98.62% under the incineration, which was 39.77% and 41.64% higher than that under the aerobic composting and pyrolysis, respectively. The total nitrogen loss rate of wastes was 95.51% under the incineration, which was higher than that under the aerobic composting (22.72%) and pyrolysis (36.65%) respectively. There were no significant differences for the total phosphorus and total potassium loss rates among the three garden wastes treatments. The CO<inf>2</inf> emission of incineration was 1271.62 g/kg, which was much higher than that of the aerobic composting with the value of 210.71 g/kg, but both the CH<inf>4</inf> and N<inf>2</inf>O emissions were relatively low under these two treatments. Generally, both the compost and biochar returning to soil significantly improved the structure of soil aggregates with diameter 0.25-0.053 mm and increased the content of N, P and K; which also improved water permeability. Both of them improved capillary porosity and saturated hydraulic conductivity of the soil, and the effect of compost was better than biochar. Further more, biochar significantly increased the content of soil organic carbon. Aerobic composting is an ideal way to improve soil porosity and decrease pH of the soil. However, the incineration ash return to the soil mainly improved the soil P, K nutrient contents and large particle size aggregates with diameter >0.053 mm, the other effects were not significant. In summary, pyrolysis and aerobic composting are suitable ways for the treatments of garden waste, which provides reference for the better utilization of the resources of the garden wastes.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Waste incineration
Controlled terms:Aggregates - Chemical properties - Composting - Environmental impact - Gas emissions - Greenhouse gases - Hydraulic conductivity - Incineration - Nutrients - Organic carbon - Particle size - Porosity - Pyrolysis - Soil testing - Soils - Waste disposal - Waste treatment
Uncontrolled terms:Bio chars - Different treatments - Garden wastes - Large particle sizes - Physical and chemical properties - Returning effect - Saturated hydraulic conductivity - Soil organic carbon
Classification code:406 Highway Engineering - 451.1 Air Pollution Sources - 452.4 Industrial Wastes Treatment and Disposal - 454.2 Environmental Impact and Protection - 483.1 Soils and Soil Mechanics - 632.1 Hydraulics - 801 Chemistry - 802.2 Chemical Reactions - 804.1 Organic Compounds - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Age 7.95e-02yr, Percentage 2.27e+01%, Percentage 3.66e+01%, Percentage 3.98e+01%, Percentage 4.16e+01%, Percentage 9.55e+01%, Percentage 9.86e+01%, Size 2.50e-04m to 5.30e-05m, Volume 6.00e-02m3
DOI:10.11975/j.issn.1002-6819.2018.21.030
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 32>
Accession number:20190706490395
Title:Effect of interaction of high temperature at jointing stage and waterlogging on growth and development of rice
Authors:Zhen, Bo (1); Zhou, Xinguo (1); Lu, Hongfei (1); Li, Huizhen (1)
Author affiliation:(1) Framland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang; 453002, China
Corresponding author:Zhou, Xinguo(firizhouxg@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:105-111
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Huanghuai region is characterized by high temperature and plenty of heavy precipitation during the jointing-booting stage of rice, which may result in frequent occurrence of waterlogging and hot damage on rice field. Waterlogging and high temperature may interactively impact on rice growth and yield. This study aimed to investigate the response of rice growth and yield to the interaction of waterlogging and high temperature stress. In order to make a deep understanding on the effects of high temperature and waterlogging stress on rice (Oryza sativa L., Huodao 008) morphological characters and yield at jointing stage, 6 treatments were set up as follows: high temperature stress (T1), high temperature × light waterlogging stress (water depth of 10 cm, T2), high temperature × heavy waterlogging stress (water depth of 15 cm, T3), light waterlogging stress (T4), heavy waterlogging stress (T5), as well as a regular irrigation with shallow water (water depth of 0-5 cm) except for yellow maturity (CK). After stress treatment, the rice plant height, leaf area, shoot dry matter and yield factors were observed. Logistic equation and Gaussian Function were used to fit curves. The change trend of rice morphological characters and yield factors under interaction of high temperature and waterlogging stress were analyzed. The results showed that: 1) Compared with CK, rice plant height under high temperature stress (T1) and heavy waterlogging (T5) treatments was decreased by 5.63 and 5.96 cm at the heading stage, respectively. The interaction stress of high temperature and waterlogging had a weak inhibitory effect on rice growth compared to T1 or T5.2)With advance of the growth period, rice leaf area showed a decrease trend after a first increase and the leaf area reached the maximum at the late jointing stage. The leaf area under the interaction of high temperature and waterlogging stress (T2, T3) was increased. Dry matter accumulation of the above-ground part of rice under high temperature and heavy waterlogging stress (T3) was increased compared to CK, but it was reduced under only high temperature stress (T1). 3) Except for light waterlogging stress (T4), the rice yield in all stress treatments were significantly reduced. Compared with CK, the rice yield under the interaction of high temperature and light waterlogging stress (T2) and high temperature and heavy waterlogging stress (T3) were significantly decreased by 44.16% and 22.29%, respectively, which was due to the decrease of filled grain rate. Through the analysis of two factors interaction, temperature stress and the interaction stress of water and temperature had significant influence on the yield factors of rice, but the water stress only had significant influence on the spikelet length, the number of effective panicles and the yield. In sum, rice yield were reduced under heavy waterlogging, high temperature and interaction of high temperature and waterlogging stress, but interaction of high temperature and heavy waterlogging stress can effectively weaken rice yield reduction.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Yield stress
Controlled terms:Crops - Morphology - Oil well flooding - Plants (botany) - Stresses
Uncontrolled terms:Dry matter accumulation - Growth and development - High temperature - High temperature stress - Morphological characters - Rice - Shoot drying weight - Yield
Classification code:511.1 Oil Field Production Operations - 821.4 Agricultural Products - 951 Materials Science
Numerical data indexing:Percentage 2.23e+01%, Percentage 4.42e+01%, Size 0.00e+00m to 5.00e-02m, Size 1.00e-01m, Size 1.50e-01m, Size 5.63e-02m, Size 5.96e-02m
DOI:10.11975/j.issn.1002-6819.2018.21.013
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 33>
Accession number:20190706490391
Title:UAV real-time monitoring for forest pest based on deep learning
Authors:Sun, Yu (1); Zhou, Yan (1); Yuan, Mingshuai (1); Liu, Wenping (1); Luo, Youqing (2); Zong, Shixiang (2)
Author affiliation:(1) School of Information, Beijing Forestry University, Beijing; 100083, China; (2) School of Forestry, Beijing Forestry University, Beijing; 100083, China
Corresponding author:Liu, Wenping(wendyl@vip.163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:74-81
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The unmanned aerial vehicle (UAV) remote sensing featured by low cost and flexibility offers a promising solution for pests monitoring by acquiring high resolution forest imagery. So the forest pest monitoring system based on UAV is essential to the early warning of red turpentine beetle (RTB) outbreaks. However, the UAV monitoring method based on image analysis technology suffers from inefficiency and depending on pre-processing, which prohibits the practical application of UAV remote sensing. Due to the long process flow, traditional methods can not locate the outbreak center and track the development of epidemic in time. The RTB is a major forestry invasive pest which damages the coniferous species of pine trees in northern China. This paper focuses on the detection of pines infected by RTBs. A real-time forest pest monitoring method based on deep learning is proposed for UAV forest imagery. The proposed method was consisted of three steps: 1) The UAV equipped with prime lens camera scans the infected forest and collects images at fixes points. 2) The Android client on UAV remote controller receives images and then requests the mobile graphics workstation for infected trees detection through TensorFlow Serving in real time. 3) The mobile graphics workstation runs a tailored SSD300 (single shot multibox detector) model with graphics processing unit (GPU) parallel acceleration to detect infected trees without orthorectification and image mosaic. Compared with Faster R-CNN and other two-stage object detection frameworks, SSD, as a lightweight object detection framework, shows the advantages of real-time and high accuracy. The original SSD300 object detection framework uses truncated VGG16 as basic feature extractor and the 6 layers (named P1-P6) prediction module to detect objects with different sizes. The proposed tailored SSD300 object detection framework includes two parts. First, a 13-layer depthwise separable convolution is used as basic feature extractor, which reduces several times computation overhead compared with the standard convolutions in VGG16. Second, most loss is derived from positive default boxes and these boxes mainly concentrated in P2 and P3 due to the constraints of crown size, UAV flying height and lens' focal length. Therefore, the tailored SSD300 retains only P2 and P3 as prediction module and the other prediction layers are deleted to further reduce computation overhead. Besides, aspect ratio of default boxes is set to {1, 2, 1/2}, since the aspect ratio of crown is approximate 1. The UAV imagery is collected on 6 experimental plots at 50-75 m height. The photos of No. 2 experimental plot are considered as test set and the rest are train set. A total of 82 aerial photos are used in the experiment, including 70 photos in the train set and 12 photos in the test set. The AP and run time of five models are evaluated. The average precision (AP) of the tailored SSD300 model reaches up to 97.22%, which is lower than the AP of original SSD300. While the proposed model has only 18.8 MB parameters, reducing above 530 MB compared with the original model. And the run time is 0. 46 s on a mobile workstation equipped with NVIDIA GTX 1050Ti GPU, while the original model needs 4.56 s. Experimental results demonstrate that the downsize of basic feature extractor and prediction module speed up detection with a little impact on AP. The maximum coverage of aerial photo captured at 75 m height is 38.18 m×50.95 m. When the UAV has a horizontal speed of 15 m/s, it takes 3.4 s to move to the next shooting point without overlap, longer than the detection time. Therefore, the proposed method can simplify the detection process of UAV monitoring and realizes the real-time detection of RTB damaged pines, which introduces a practical and applicable solution for early warning of RTB outbreaks.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Aircraft detection
Controlled terms:Aerial photography - Antennas - Aspect ratio - Computer graphics - Computer graphics equipment - Convolution - Cost reduction - Deep learning - Diseases - Feature extraction - Forecasting - Forestry - Graphics processing unit - Monitoring - Object detection - Object recognition - Program processors - Remote control - Remote sensing - Unmanned aerial vehicles (UAV)
Uncontrolled terms:Computation overheads - Coniferous species - Detection framework - Mobile workstations - Ortho-rectification - Real time monitoring - Real-time detection - UAV remote sensing
Classification code:652.1 Aircraft, General - 716.1 Information Theory and Signal Processing - 716.2 Radar Systems and Equipment - 722.2 Computer Peripheral Equipment - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 731.1 Control Systems - 742.1 Photography
Numerical data indexing:Percentage 9.72e+01%, Size 5.00e+01m to 7.50e+01m, Size 7.50e+01m, Time 4.56e+00s, Time 4.60e+01s, Velocity 1.50e+01m/s
DOI:10.11975/j.issn.1002-6819.2018.21.009
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 34>
Accession number:20190706490405
Title:Identification algorithm and application of peanut kernel integrity based on convolution neural network
Authors:Zhao, Zhiheng (1); Song, Huan (1); Zhu, Jiangbo (1); Lu, Lei (1); Sun, Lei (2)
Author affiliation:(1) School of Electrical Engineering & Automation, Harbin Institute of Technology, Harbin; 150001, China; (2) Shanghai Anzai Manufacturing Co., Ltd., Shanghai; 201109, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:195-201
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aiming at the shortcomings of the existing color sorter machine for crop sorting, such as slow processing speed, low accuracy, and the dependence on experience value, a granular crop integrity identification algorithm based on convolutional neural network was proposed. Taking the classification of intact peanuts, skin damaged peanuts and half peanuts as instance, the three types of peanut images were acquired. After comparing the filtering effects of mean filtering, median filtering and Gaussian filtering, median filtering was adopted for image preprocessing. 407 effective peanut images were divided into the above three categories and manually labeled. Then the images were divided into training sets and validation sets, and the above three types of peanut pictures in the training set and the validation set were evenly distributed. A convolutional neural network with 4 convolutional layers, 4 pooling layers and 3 fully connected layers was built to extract the peanut image features. The accuracy of testing peanut classification on the CPU(central processing unit) platform combined GPU(graphics processing unit) was 90.91%. In contrast, the classification accuracy of the traditional BP neural network was 85.45%. It could be seen that the convolutional neural network algorithm constructed in this paper effectively improved the accuracy of granular crop recognition. In order to further improve the accuracy and real-time performance of the classification algorithm, it was necessary to optimize the established convolutional neural network. Over-fitting referred to the fact that when a model was overly complex, it could "memorize" the portion of random noise in each training data and forgot to "learn" the tendencyof the training data. In this paper, the regularization method was used to reduce the over-fitting, and the experimental results of L1 regularization and L2 regularization were compared. It was proved that the L2 regularization on the data set effectively improved the classification accuracy and reduced the over-fitting. In the process of training, the neural network used the back propagation algorithm, namely gradient descent and chain derivation rule, to optimize the neural network. The learning rate was an important parameter in the gradient descent algorithm. In this paper, the exponential decay method was used to set the learning rate. Firstly, a large learning rate was used to quickly obtain a better solution. Then, as the iteration continued, the learning rate was gradually reduced, making the model more stable in the later stage of training. The accuracy increase was larger, the latter was smaller, and the overall improvement was better than that before optimization, and the expected effect was achieved. In this paper, the moving average model was used to reduce the influence of noise in the training data on the model, and the training convergence speed was accelerated. The experiment proved that the accuracy fluctuation was reduced and the model stability was enhanced. Since the algorithm needed to be applied to the color sorting system, real-time judgment and processing of the materials on the conveyor belt required high real-time performance. Considering that the image information of peanut was relatively simple, the network structure could be simplified to improve the real-time performance. The simplified convolutional neural network consisted of 2 convolutional layers, 2 pooling layers, and 2 fully connected layers. The final optimization scheme included L2 norm regularization, exponential decay learning rate, moving average model and simplified network structure. The accuracy of optimized classification algorithm applied on the peanut data set was 98.18%, and the average processing time for detecting one peanut image was 18.3 ms, which demonstrated that the optimized convolutional neural network significantly improved the classification accuracy and real-time performance. The research work in this paper showed that the application of deep learning in the crop sorting field was feasible and effective.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Classification (of information)
Controlled terms:Agricultural products - Backpropagation algorithms - Belt conveyors - Color - Computer graphics - Computer graphics equipment - Convolution - Crops - Data mining - Deep learning - Feature extraction - Graphics processing unit - Image enhancement - Image processing - Iterative methods - Learning algorithms - Median filters - Neural networks - Oilseeds - Optimization - Program processors - Screening - Sorting
Uncontrolled terms:Classification accuracy - Classification algorithm - Color sorting system - Convolution neural network - Convolutional neural network - Gradient descent algorithms - Identification algorithms - Recognition
Classification code:692.1 Conveyors - 716.1 Information Theory and Signal Processing - 722.2 Computer Peripheral Equipment - 723 Computer Software, Data Handling and Applications - 741.1 Light/Optics - 802.3 Chemical Operations - 821.4 Agricultural Products - 921.5 Optimization Techniques - 921.6 Numerical Methods
Numerical data indexing:Percentage 8.55e+01%, Percentage 9.09e+01%, Percentage 9.82e+01%, Time 1.83e-02s
DOI:10.11975/j.issn.1002-6819.2018.21.023
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 35>
Accession number:20190706490413
Title:Extraction process of mucilaginous from seeds of Seriphidium transiliense and its purification effect on livestock manure sewage
Authors:Lu, Weihua (1); Jin, Shengfei (1); Wang, Shulin (1); Xin, Huailu (1); Jing, Pengcheng (1); Chen, Yishi (1); Sun, Hairong (1); Li, Nana (1)
Author affiliation:(1) College of Animal Science and Technology, Shihezi University, Shihezi; 832003, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:245-252
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, the consumption of livestock and poultry products has increased rapidly in China, which has accelerated the development of livestock and poultry industry. At the same time, it also brings the problem of waste pollution. The direct discharge of untreated or improperly treated animal manure waste water will cause pollution to the soil, air and water, and be harmful to livestock's and poultry's and human's health. Seriphidium transiliense is a semi-shrub of the Compositae Seriphidium. Its seeds can secrete mucilaginous in contact with water. Mucilaginous substances are harmless to the human body and are cost-effective and biodegradable. It can be used as a potentially environment friendly flocculant because it can be used to treat various kinds of sewage. The purpose of this study was to preliminarily explore the extraction process of seed mucus from Seriphidium transiliense and the effect of mucilaginous as flocculant on the treatment of common animal husbandry fecal wastewater. The flocculation rate and COD were taken as the determination index. The optimum conditions were obtained through the influence of different pH value (6.0, 6.5, 7.0, 7.5, 8.0, 8.5) and the different leaves of dosage flocculant (10, 20, 30, 40, 50 mL/g) on the flocculation effect of livestock and poultry waste water. In this study, three factors (extraction time, liquid-solid ratio and extraction temperature) effecting the rate of mucilaginous extraction were studied by screening clean seed of Seriphidium transiliense as material for mucilaginous extraction. The results of response surface method showed that the highest extraction effeciency of seed mucilaginous of Seriphidium transiliense was 16.76%, the extraction time was 3 h, liquid-solid ratio was 60: 1, and the extraction temperature was 64℃. When the dosage of mucilaginous was 50 mg/L, the flocculation rate was 28%, the COD removal rate was 32. 7%, pH value was 6, the flocculation rate was 46%, and the COD removal rate was 44.6%. The combination of aluminum had a remarkable effection on flocculation rate. The maximum flocculation efficiency and COD removal rate were 72.3% and 61.3%, respectively. During the treatment of pig feces, When the dosage of mucilaginous was 20 mg/L, the flocculation rate was 30.9%, the COD removal rate was 32.7%, pH value was 7, the flocculation rate was 29.3%, and the COD removal rate was 50%. The combination of aluminum had a remarkable effection on flocculation rate. The maximum flocculation efficiency and COD removal rate were 62.6% and 68.3%, respectively. Therefore, the flocculation rate and COD removal rate also increased with the increase of mucilaginous dosage during the treatment of cattle and pig manure. The combined use of alum and mucilaginous could significantly improve the flocculation rate and COD removal rate. When the addition of mucus was 50 mg/L and the pH value was 6, used together with alum, the flocculation and COD removal rates of bovine feces were 72.3% and 61.3%. When the addition of mucilaginous was 20 mg/L and the pH value was 7, used together with alum, the flocculation and COD removal rates of bovine feces were 62.6% and 68.3%, respectively. This study provides a reference for the development and application of Seriphidium transiliense germplasm resources in the sewage treatment of livestock and poultry feces waste water.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Extraction
Controlled terms:Agriculture - Aluminum - Body fluids - Chemical water treatment - Conservation - Cost effectiveness - Efficiency - Fertilizers - Flocculation - Mammals - Manures - Ostwald ripening - pH - Seed - Sewage treatment - Surface properties - Wastewater treatment - Water pollution
Uncontrolled terms:Animal manure - Development and applications - Extraction temperatures - Flocculation effects - Flocculation efficiency - Response surface method - Response surface methodology - Sriphidium transiliense
Classification code:452.2 Sewage Treatment - 452.4 Industrial Wastes Treatment and Disposal - 453 Water Pollution - 461.2 Biological Materials and Tissue Engineering - 541.1 Aluminum - 801.1 Chemistry, General - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911.2 Industrial Economics - 913.1 Production Engineering - 951 Materials Science
Numerical data indexing:Mass_Density 2.00e-02kg/m3, Mass_Density 5.00e-02kg/m3, Percentage 1.68e+01%, Percentage 2.80e+01%, Percentage 2.93e+01%, Percentage 3.09e+01%, Percentage 3.27e+01%, Percentage 4.46e+01%, Percentage 4.60e+01%, Percentage 5.00e+01%, Percentage 6.13e+01%, Percentage 6.26e+01%, Percentage 6.83e+01%, Percentage 7.00e+00%, Percentage 7.23e+01%, Specific_Volume 5.00e-02m3/kg, Time 1.08e+04s
DOI:10.11975/j.issn.1002-6819.2018.21.031
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 36>
Accession number:20190706490390
Title:Transient heat load variation of piston top surface under steady and transition conditions
Authors:Lei, Jilin (1); Wang, Dongfang (1); Deng, Xiwen (1); Xin, Qianfan (1); Wen, Jun (1, 2)
Author affiliation:(1) Yunnan Province Key Laboratory of Internal Combustion engines, Kunming University of Science and Technology, Kunming; 650500, China; (2) Chengdu Galaxy Power Co., Ltd., Chengdu; 610505, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:65-73
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are 2 kinds of thermal fatigue failure modes of engine pistons. One is the high-cycle-fatigue failure mode caused by cyclic thermal shock loading in steady-state conditions. The other is the low-cycle-fatigue failure mode caused by thermal shock loading under transition conditions such as cold start, rapid acceleration, and fast deceleration. Although piston thermal loading has been widely studied by previous domestic and foreign researchers, the work focused on the thermal loading of steady-state conditions and overlooked the impact of the drastic variations of piston transient thermal loading on piston reliability and useful life, and the research result cannot reflect true realistic variations of piston thermal loading, and cannot accurately predict and evaluate the thermal fatigue life of the piston. In order to study the thermal loads of diesel engine pistons in different operating conditions, a non-road high-pressure-common-rail diesel engine was analyzed by using the method of thermal-mechanical decoupling. The finite-element simulation model of piston thermal loading under the steady-state condition of rate power and the above-mentioned transient condition was established. The simulation model was developed based on the experimental results of transient temperature measurements of the piston top. The model was successfully used to reveal the variation trends of the transient thermal loads of the pistons under these conditions. The analysis results showed that the time-dependent or crank-angle-dependent fluctuation of the piston thermal load under the steady-state condition of rated power was only limited to the piston top, the firing deck, and the first ring groove. As the fluctuation penetration distance measured from the piston top increased, the fluctuation amplitude decreased. The maximum fluctuation penetration distance of temperature was 3 mm, and the maximum fluctuation penetration distance of thermal stress was 5 mm. Under the transient conditions, the fluctuation amplitudes of the thermal loads were greater than those under the steady-state conditions, with the fluctuation of the cold start process being the greatest. Specifically, the maximum fluctuation amplitudes of the temperature, thermal stress, and thermal strain of cold start process were 200℃, 40 MPa, and 0.3 mm, respectively. During the process of rapid acceleration, although the maximum fluctuation amplitudes of the piston temperature and thermal strain were smaller than those of the cold start process, being 120℃ and 0.12 mm, respectively, the maximum fluctuation amplitude of the piston thermal stress reached the greatest, being 50 MPa. Such a large variation of stress had a great impact on piston durability life. During the process of rapid deceleration, the maximum fluctuation amplitudes of the piston temperature, thermal stress, and thermal strain were the smallest among all operating process, being 20℃, 10 MPa, and 0.02 mm, respectively. During the rapid deceleration process, the measured metal temperatures of the piston in various locations all increased shortly, then gradually decreased by a small magnitude, and finally reached stable after 200 s. The maximum fluctuation amplitudes of the piston temperature, thermal stress, and thermal strain during fast deceleration conditions were the smallest among all operating conditions, being 30℃, 10 MPa, and 0.02 mm, respectively. The research of this study can provide good guidance for the design of highly intensified aluminum-alloy pistons of diesel engines.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Engine pistons
Controlled terms:Aluminum alloys - Diesel engines - Electronics packaging - Failure modes - Outages - Pistons - Shock problems - Soldering - Temperature - Temperature measurement - Thermal fatigue - Thermal load - Thermal shock - Thermal stress
Uncontrolled terms:Different operating conditions - Finite element simulation model - High pressure common rail diesel engine - Steady conditions - Thermal fatigue failures - Thermal strain - Transient conditions - Transient thermal loading
Classification code:538.1.1 Soldering - 541.2 Aluminum Alloys - 612.1.1 Internal Combustion Engine Components - 612.2 Diesel Engines - 641.1 Thermodynamics - 706.1 Electric Power Systems - 931.2 Physical Properties of Gases, Liquids and Solids - 944.6 Temperature Measurements - 951 Materials Science
Numerical data indexing:Pressure 1.00e+07Pa, Pressure 4.00e+07Pa, Pressure 5.00e+07Pa, Size 1.20e-04m, Size 2.00e-05m, Size 3.00e-03m, Size 3.00e-04m, Size 5.00e-03m, Time 2.00e+02s
DOI:10.11975/j.issn.1002-6819.2018.21.008
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 37>
Accession number:20190706490397
Title:Effect of cotton stalk returning to fields on residual film distribution in cotton fields under mulched drip irrigation in typical oasis area in Xinjiang
Authors:Wang, Zhenhua (1, 2); He, Huaijie (1, 2); Zheng, Xurong (1, 2); Zhang, Jinzhu (1, 2); Li, Wenhao (1, 2)
Author affiliation:(1) College of Water and Architectural Engineering, Shihezi University, Shihezi; 832000, China; (2) Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production and Construction Group, Shihezi; 832000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:120-127
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The drip irrigation under mulching film technology was applied in Shihezi reclamation area of Xinjiang in 1996. It is more difficult to recover the mulching after the growing period of cotton, so that the density of residual plastic film in cotton fields exceeds the national standard (75. 0 kg/hm<sup>2</sup>) which causes serious soil contamination in experiment area. Stalk returning to fields is a common method in the film mulching area. This study investigated the effect of cotton stalk returning to fields on residual film distribution. A total of 3 cotton fields were selected in typical oasis area of Xinjiang. The 3 fields were different only in the mulching duration. They were governed by the same owner. The mulched drip irrigation started from the year of 1998, 2002 and 2006. By the year of 2017, the mulching duration was 20, 16 and 12 years, respectively. Soil samples were taken from 0-40 cm layer before cotton stalk returning in 2016 and after 1 year of stalk returning in 2017. The cotton stalk was cut into 4-6 cm pieces and applied to the tillage layer with an application rate of 7 500-8 000 kg/hm<sup>2</sup>. By comparison, the effect of stalk returning was discussed. In the sampling field, the soil blocks (4 800 cm<sup>2</sup> in area and 40 cm in height) were collected for determination of area and weight of residual film and weight of cotton stalk residue. The results showed that: 1) the residual plastic film density in the soil tillage layer of drip irrigation cotton fields increased yearly with increasing mulching years, and the cotton fields of mulched film drip irrigation more than 10 year were seriously polluted. 2) After the cotton stalks were crushed and returned to the fields, the cotton stalks in the soil of 0 to 40 cm in the 3 sampling plots were increased from top to bottom and then decreased and concentrated in the soil depth of 15-25 cm. The cotton stalks were evenly distributed on the surface after being chopped, and because the large-scale machinery was used to carry out the arable land operation, the cotton stalks on the soil surface were ploughed into the soil tillage layer of 15-25 cm depth, which was the main reason for the peaks of cotton stalks residue appeared in the soil depths of 18, 20 and 18 cm, respectively. 3) After the cotton stalks were returned to the fields, the residual plastic film area of the 0-15 cm soil layer of the 3 sampled cotton fields accounted for more than 58%, and the residual film weight accounted for more than 60%. In the soil of 0-15 cm tillage layer, the residual plastic film with the area >5-30 cm<sup>2</sup> and the weight >50-100 mg increased significantly, and the average was about 20% and 10% higher than that in 2016, respectively. The mulched plastic film with a thickness of 0.008 mm has been broken at different degrees at the end of the cotton growth period, and it is relatively difficult to recover. In the process of smashing and returning cotton stalks with large-scale mechanical arable land, the plastic film is broken into small film in the area and weight and they accumulated continuously in the deep soil. Therefore, local area should increase the degradable biological film and the use of 0.010 mm thickness of the plastic film, improve the efficiency of residual plastic film recovery and other measures to reduce the plastic film residue in the soil layer of the fields, in order to ensure the sustainable development of agriculture in the typical oasis.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Soil pollution
Controlled terms:Cotton - Cultivation - Films - Irrigation - Land use - Machinery - Plastic films - Recovery - Scales (weighing instruments) - Soils
Uncontrolled terms:Drip irrigation - Mulched drip irrigations - National standard - Plastic film residues - Reclamation areas - Soil contamination - Stalks returning to fields - Typical oasis area
Classification code:403 Urban and Regional Planning and Development - 483.1 Soils and Soil Mechanics - 817.1 Polymer Products - 821.3 Agricultural Methods - 821.4 Agricultural Products - 943.3 Special Purpose Instruments
Numerical data indexing:Age 1.00e+00yr, Age 1.00e+01yr, Age 1.20e+01yr, Age 1.60e+01yr, Area 4.80e-01m2, Percentage 1.00e+01%, Percentage 2.00e+01%, Percentage 5.80e+01%, Percentage 6.00e+01%, Size 0.00e+00m to 1.50e-01m, Size 0.00e+00m to 4.00e-01m, Size 1.00e-05m, Size 1.50e-01m to 2.50e-01m, Size 1.80e-01m, Size 2.00e-01m, Size 4.00e-01m, Size 4.00e-02m to 6.00e-02m, Size 8.00e-06m
DOI:10.11975/j.issn.1002-6819.2018.21.015
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
<RECORD 38>
Accession number:20190706490417
Title:Inactivation characteristics and effect of bacillus subtilis spores from spoiling shrimp by microwave sterilization
Authors:Guo, Quanyou (1); Wang, Xiaojin (1, 2); Jiang, Chaojun (1)
Author affiliation:(1) East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai; 200090, China; (2) College of Food Science and Technology, Shanghai Ocean University, Shanghai; 201306, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:21
Issue date:November 1, 2018
Publication year:2018
Pages:281-287
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Penaeus vannamei is one of the three major cultured shrimps in the world, which has high nutritional and commercial value, containing various mineral elements, high proteinlow fat and a good proportion of fatty acids. Alive, fresh, frozen and preserved Penaeus vannamei are main products in retail and wholesale market. Among them, ready-to-eat shrimp was one of popular products by the way of low temperature drying, mild sterilization and vacuum packaging and other minor processing, which has high nutrition value and easy to carry. However, the vacuum packaging ready-to-eat shrimp meat is easy to spoil and difficultly to store during processing, packaging and distribution. In previous study, the shelf life and dominated spoilage organisms of ready-to-eat shrimp stored at ambient temperature were carried out, and Bacillus spp. (eg. Bacillus licheniformis) isolated from them at the end of shelf life were identified as dominated spoilage organisms. In order to investigate sterilization effects and mechanisms of microwave sterilization on Bacillus licheniformis spores isolated from ready-to-eat shrimp meat, the effects of different temperatures (including 80, 85, 90, 95 and 100℃) and different treated time by the microwave sterilization on Bacillus licheniformis spores were carried out, which water bath sterilization was used as a control group. The differences and changes of Bacillus licheniformis spores in physico-chemical properties before and after water bath sterilization and microwave sterilization were analyzed. The results showed that at the same sterilizing temperature, the effects of microwave sterilization on Bacillus licheniformis spores were significantly different with water bath sterilization. Bacillus licheniformis spores were finally killed by means of microwave and water bath sterilization, but the microwave sterilization needed only two minutes, the water bath needed at least five minutes. R<sup>2</sup> analysis showed that the weibull model (R<sup>2</sup>>0.89) could better fit the inactivation curves of the two sterilization methods, but the linear model was more intuitive than weibull model. The time of protein and nucleic acid leakage in the spore suspension caused by the microwave treatment was earlier than that of the water bath, microwave treatment reached the maximum value of OD<inf>260 nm</inf> and OD<inf>280 nm</inf> within 10 min, while water bath treatment reached the maximum value of OD<inf>260 nm</inf> and OD<inf>280 nm</inf> within 40 min. Compared with the water bath, the spore germination curve after microwave treatment had a longer lag phase, 95℃ water bath process 100 min, lag time can extend 8 min, and 95℃ with microwave for 10 min, spore germination. The difference of microwave sterilization water bath sterilization under different temperatures and time were investigated. It will provide theoretical and practical basis for optimization of product sterilization technology, targeted sterilization and reduction of bag expansion rate. Meanwhile, the mechanisms and dynamical equations of different sterile means are also further studied.<br/> © 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Sterilization (cleaning)
Controlled terms:Bacteriology - Chemical analysis - Cultivation - Curve fitting - Fatty acids - Food processing - Food storage - Low temperature drying - Microwave heating - Microwaves - Minerals - Nucleic acids - Nutrition - Shellfish - Spoilage - Suspensions (fluids) - Temperature - Water treatment
Uncontrolled terms:Bacillus licheniformis - Bacillus subtilis spores - Dynamical equation - Microwave sterilization - Microwave treatment - Spores - Sterilization technology - Sterilizing temperature
Classification code:445.1 Water Treatment Techniques - 461.7 Health Care - 461.9 Biology - 482.2 Minerals - 641.1 Thermodynamics - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.3 Agricultural Methods - 822.1 Food Products Plants and Equipment - 822.2 Food Processing Operations - 921.6 Numerical Methods
Numerical data indexing:Time 2.40e+03s, Time 4.80e+02s, Time 6.00e+02s, Time 6.00e+03s
DOI:10.11975/j.issn.1002-6819.2018.21.035
Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.
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- 主管单位 中国科学技术协会
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