<RECORD 1>
Accession number:20171503569164
Title:Establishment and experiment of ultrasonic measuring system for characteristic parameters of roll waves on slope surface
Authors:Yang, Miao (1); Gong, Jiaguo (2); Zhang, Kuandi (1); Fan, Dian (1); Zhao, Yong (2); Wang, Hao (2)
Author affiliation:(1) College of Water Conservancy and Architectural Engineering, Northwest A&F University, Yangling; 712100, China; (2) Department of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing; 100038, China
Corresponding author:Gong, Jiaguo(jiaguogong@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:134-139
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The precise study of free surface flows is explored mostly because of their importance in construction of soil erosion models. The accurate and efficient observation methods can lay a solid foundation for the further study of characteristics of slope flow. The objective of this work was to design an experimental system for measuring roll waves. The system was based on a high-precision ultrasonic sensor. The measurement system was composed of ultrasonic sensors, data acquisition box and the computer. The experiment was carried out in a hydraulic flume. The unit discharge varied from 0.167 to 0.500 L/(m·s), and slope gradient was from 3<sup>o</sup>to 15<sup>o</sup>. The system was calibrated and the results showed that the average relative error of the measurement system was 0.23%. The average coefficient of variation was 0.66%. The main parameters of roll waves included wave velocity, wave frequency, wave length and wave peak. In this study, by recording roll waves observed in the same section, the relationship between water depth and time was obtained by ultrasonic flowmeter. The average interval time of data acquisition was 15 ms so that the sensor could catch the change of water level in time. Roll wave frequency was obtained by observing the cross section peaks in unit time. Wave velocity could be obtained by two sensors. The two sensors recorded the time that the same roll wave passed through the section and also measured the distance of the two sensors. The wave velocity was calculated as the ratio of distance and duration. The wave length was calculated by the wave velocity and the frequency. The results measured by the proposed system were compared with that obtained from the stylus method and visual method. The results showed that the wave peak measured by the system was mostly similar with that from the stylus method, followed by roll wave frequency, wave velocity and wave lengths. The measuring system had better accuracy and reliability to reach measurement requirements of characteristic parameters of roll waves on slope surface. For the same observation section, the rolling wave was not constant in the measurement process. The wave peak, wave velocity and the frequency had the average coefficient of variation of 0.238, 0.806 and 0.430. The ultrasonic measuring system can continuously work and provide reliable measurements for roll wave parameters. As compared with the conventional method, the measuring system greatly reduced test time and effort to improve test efficiency. The research results have wide application foreground in the improvement of the water flow measurement method on the slope surface. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Flow rate
Controlled terms:Acoustic wave velocity - Data acquisition - Flow measurement - Flow of water - Flowmeters - Measurements - Parameter estimation - Ultrasonic flowmeters - Ultrasonic measurement - Ultrasonic sensors - Velocity - Water levels - Wave propagation
Uncontrolled terms:Average relative error - Coefficient of variation - Conventional methods - Measurement process - Reliable measurement - Roll waves - Sheetflows - Slope surfaces
Classification code:631 Fluid Flow - 723.2 Data Processing and Image Processing - 751.1 Acoustic Waves - 753.1 Ultrasonic Waves - 753.2 Ultrasonic Devices - 943.1 Mechanical Instruments - 943.2 Mechanical Variables Measurements
Numerical data indexing:Percentage 2.30e-01%, Percentage 6.60e-01%
DOI:10.11975/j.issn.1002-6819.2017.03.018
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 2>
Accession number:20171503569172
Title:Wavelet denoising method for grain flow signal based on Mallat algorithm
Authors:Chen, Jin (1); Wang, Kun (1); Li, Yaoming (2)
Author affiliation:(1) School of Mechanical Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:190-197
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aiming at the problem that combine harvester cannot obtain reliable grain flow information in complex noise background, wavelet transform (WT) is proposed to denoise the output signal of grain flow sensor. The method is as follows: using the LabVIEW data acquisition card to acquire the output signal of the grain flow sensor and analyzing the amplitude-frequency characteristics of signal, in which the energy-dominant frequency band is set as the grain effective signal, and the chaotic and the frequency band with flat amplitude change are set as the noise signal. The spectrum of original signal and noise is used to determine how to choose the wavelet function and decomposition scale. By analyzing the amplitude-frequency characteristics of the original signal, the energy-dominant center frequency in the grain flow is 40 Hz, and the noise is distributed in 2 frequency bands, of which the signal energy attenuation is faster, the bandwidth distribution is narrower and the change trend is consistent with the original signal in 500-600 Hz band, so the bands are the vibration noise of the yield platform. Above 800 Hz the signal changes slowly in energy attenuation, the bandwidth distribution is wide and the changes are random, so the bands are the high-frequency noise of the yield platform. In the research, the yield measuring system is designed to obtain the yield information. The Mallat algorithm is applied to decompose and remove the noise components of grain flow signal, the DB4 wavelet is chosen as the wavelet function and the decomposition scale is 6. The effective data of grain flow are reconstructed by wavelet and calibrated by the analog to digital converter channel of microcomputer. The maximum relative error of the grain mass is 1.68% under different grain flow after calibration. The position data are obtained by the Beidou Navigation Satellite System (BDS) with the pseudo-range differential position technology. The yield measuring system is installed on the combine harvester to simulate the rice operation experiment. The quantitative rice is transported to the grain tank and output at different rates per unit time, and the speed of driving wheel of the grain-conveying auger is gradually increased in the grain flow experiment. After the WT for the output signal of the flow sensor, reconstructing the base frequency of the grain flow information can be removed by the vibration noise. The relative error of the grain flow measurement is 6.18% and the average relative error is 5.37%. The yield data recorded in the production system are imported into the PC (personal computer) to plot the yield map. The map confirms that the BDS differential location data are reliable and the grain flow information in the test area is consistent with the experiment. Through the WT of the information output by grain flow sensor, the spectrum of the signal after the wavelet denoising is compared with the original signal, and the feasibility and the accuracy of the flow signal denoising are validated as well as the grain flow information reconstructing method based on the Mallat algorithm. This research can provide a reference for the original information denoising and the reconstructing of effective information in the complex operating environment of agricultural machinery. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Signal denoising
Controlled terms:Agricultural machinery - Algorithms - Analog to digital conversion - Bandwidth - Calibration - Data acquisition - Error analysis - Errors - Frequency bands - Grain (agricultural product) - Harvesters - Operations research - Personal computers - Radio navigation - Tracking (position) - Vibration analysis - Wavelet decomposition - Wavelet transforms
Uncontrolled terms:Amplitude frequency characteristics - Analog to digital converters - Bandwidth distribution - Beidou navigation satellite systems - Combine harvesters - Maximum relative errors - Wavelet denoising method - Yield maps
Classification code:716.1 Information Theory and Signal Processing - 716.3 Radio Systems and Equipment - 722.4 Digital Computers and Systems - 723.2 Data Processing and Image Processing - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 912.3 Operations Research - 921.3 Mathematical Transformations
Numerical data indexing:Frequency 4.00e+01Hz, Frequency 5.00e+02Hz to 6.00e+02Hz, Frequency 8.00e+02Hz, Percentage 1.68e+00%, Percentage 5.37e+00%, Percentage 6.18e+00%
DOI:10.11975/j.issn.1002-6819.2017.03.026
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 3>
Accession number:20171503569156
Title:Effects of mechanical dry direct-sowing modes on absorption, translocation and distribution of nitrogen, phosphorus and potassium in rice
Authors:Sun, Yongjian (1); Zheng, Hongzhen (1); Yang, Zhiyuan (1); Wang, Haiyue (1); Zhang, Shaowen (1); Ma, Jun (1)
Author affiliation:(1) Rice Research Institute of Sichuan Agricultural University/Key Laboratory of Crop Physiology, Ecology, and Cultivation in Southwest, Ministry of Agriculture, Chengdou; 611130, China
Corresponding author:Ma, Jun(majunp2002@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:73-80
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to clarify the nutrient utilization characteristics of mechanical dry direct-sowing rice, the objective of this experiment was to study the effects of different mechanical dry direct-sowing modes on absorption, translocation and distribution of nitrogen (N), phosphorus (P), potassium (K), and yield in rice. Two rice cultivars of indica hybrid rice F you 498(143 days growth duration) and conventional japonica rice Xudao 4 (145 days growth duration) were planted with two mechanical dry direct-sowing modes, including no-tillage land and mechanic drilling simultaneously (B<inf>1</inf>), regulating soil moisture and two rotary tillage before mechanic drilling (B<inf>2</inf>). Manual broad-cast sowing (B<inf>3</inf>) was set as control. The dry direct-sowing machine of this study was modified by Nanjing Agricultural University and was re-modified by Sichuan Agricultural University. This machine had 6 drills and sowing depth 2.0 cm, drill spacing 28.0 cm, working width 1.50 m. Motive power of this machine was the Shanghai New Holland tractor (SNH504). This test adopted row spacing 20.0 m × 1.50 m, each plot covered 30 m<sup>2</sup>of seeding amount was 30.0 kg per hectare of indica hybrid rice F you 498, 37.5 kg per hectare of conventional japonica rice Xudao 4 respectively. The nitrogen fertilizer amount was 180 kg/hm<sup>2</sup>. The N application ratios was applied on 4 splits: 50% basal, 30% tillering fertilizer at 3rd leaf stage, 10% panicle N-fertilizer at 4th leaves emerged from the top, 10% ear granular fertilizer at full heading stage. The phosphate fertilizer application was only one base fertilizer. The potash fertilizer application ratio of basic fertilizer, tillering fertilizer and ear granular fertilizer was 2:1:1. The other management measures were at a uniform with high-yield cultivation. The results showed that there was an obvious regulatory effect of rice cultivars and direct-sowing modes on grain yield, absorption and translocation of N, K at the mainly growth stages. There existed significantly positive correlations between the amounts of N, P and K absorption and utilization, which could promote nutrient translocation during filling stage and yield, but the correlation coefficient of P and N, P and K significantly decreased at the mainly growth stages. Under different direct-sowing treatments, the various indicators on yield and nutrient utilization characteristics of F you 498 were significantly higher than those of Xudao 4. Compared with B<inf>3</inf>treatment, mechanical direct-seeding treatments under the same variety promoted the accumulations of N, P, and K at the mainly growth stages, increased nutrient translocation in leaf and stem-sheath during filling stage, especially significantly enhanced transportation efficiency of N and K in hybrid rice, and further facilitated translocation conversion rate of N and K in different vegetative organ, played the coupling effect of absorption and utilization of N and K, then to promoted yield, which is the important reason for mechanical direct-sowing rice further to increase yield. Under different mechanical direct-sowing treatments, compared with B<inf>1</inf>, B<inf>2</inf>treatment was the best model in this paper referred as the mechanical direct-sowing treatments, which could further increase nutrient accumulation and translocation from heading to maturity stage in various degrees consequently, promote nutrient accumulation in panicle as well as promote yield. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Nitrogen fertilizers
Controlled terms:Absorption - Agricultural machinery - Agriculture - Couplings - Cultivation - Drills - Fertilizers - Grain growth - Nitrogen - Nutrients - Phosphate fertilizers - Phosphorus - Potassium - Potassium fertilizers - Soil moisture
Uncontrolled terms:Correlation coefficient - Direct-seeding - Fertilizer applications - Nutrient translocation - Positive correlations - Rice - Translocation and distribution - Transportation efficiency
Classification code:483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 603.2 Machine Tool Accessories - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 933.1.2 Crystal Growth
Numerical data indexing:Age 3.92e-01yr, Age 3.97e-01yr, Area 3.00e+01m2, Mass 3.00e+01kg, Mass 3.75e+01kg, Percentage 1.00e+01%, Percentage 3.00e+01%, Percentage 5.00e+01%, Size 1.50e+00m, Size 2.00e-02m, Size 2.80e-01m
DOI:10.11975/j.issn.1002-6819.2017.03.010
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 4>
Accession number:20171503569163
Title:Effects of freeze-thaw status and initial water content on soil mechanical properties
Authors:Zhang, Huiren (1, 2); Li, Fahu (1); Lü, Wei (1)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agriculture University, Beijing; 100083, China; (2) Beijing Municipal River and Lake Management Office, Beijing; 100089, China
Corresponding author:Li, Fahu(lifahu@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:128-133
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The freeze-thaw conditions affect soil shear strength and hence threaten engineering safety, soil slope stability, and soil loss in seasonal frozen-soil region. Shear strength was tested for 2 kinds of soils (sandy loam in Qinghai-Tibet Plateau (S1) and silt loam in Beijing region (S2)) under 3 freeze-thaw statuses (unfrozen soil, frozen soil, and thawing soil after frozen) and different initial water contents (8.0%-31.0% in mass fraction) by direct shear apparatus in the laboratory. The unfrozen soil specimen did not suffer freeze-thaw processing in the laboratory, the thawing soil specimen was sheared after frozen at -18℃ for 24 h, and the thawed soil specimen was done after frozen at -18℃ for 24 h and then thawed at 27℃ for 12 h. The shear velocity was set to 2.4 mm/min. Experimental results showed that the shear strength of the 2 types of soils increased approximately linearly with the increasing of normal stress, and the shear strength envelope of unsaturated thawing soil could be expressed by total stress Mohr-Coulomb failure criteria under tested normal stress, freeze-thaw status and soil water content conditions. The shear strengths of unfrozen and thawed soils were similar to each other and their difference was averagely 3.4%-3.7% after one freeze-thaw cycle, and they decreased with the increased initial soil water content for the 2 types of soils. The shear strength of soil sample S1 was 7.5%-9.7% greater than that of S2 under the unfrozen and thawed statuses. Under the thawing status, the shear strength of S1 increased with the initial soil water content but that of S2 decreased with it. The shear strength of the thawing S1 soil was smaller than that for the unfrozen and thawed soils at low soil water content (13.5%) but it was on the contrary when the water content was higher; the shear strength of the thawing S2 soil was smaller than that for the unfrozen and thawed soils under all the soil water contents. Under the unfrozen, thawed, and thawing statuses, the internal friction angle for both types of soils declined with the increase of soil water content. The internal friction angles under the unfrozen and thawed statues were similar to each other but they were significantly greater than that under the thawing status. The soil cohesion under the unfrozen or thawed statuses decreased with the increased soil water content and that under the thawed status was smaller than that under the unfrozen status for both types of soils. Under the thawing status, the soil cohesion of S1 increased significantly with the increased initial soil water content but that of S2 first increased and then decreased with it. The soil cohesion of both types of soils under the thawing status generally was significantly greater than that under the unfrozen and thawed statuses. The variation ranges of the internal friction angle for the 2 types of soils were similar to each other but their soil cohesion was significantly different under experimental conditions. The soil at the thawing status had a relatively low shear strength compared with that at the unfrozen or thawed statuses, and hence the thawing status should be adopted as the basic status for engineering design or soil loss prevention in seasonal frozen-soil regions. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Shear strength
Controlled terms:Adhesion - Freezing - Friction - Frozen soils - Internal friction - Shear flow - Silt - Slope stability - Soil mechanics - Soil moisture - Soils - Thawing - Tribology - Water content
Uncontrolled terms:Direct shear apparatus - Experimental conditions - Freeze-thaw - Initial water contents - Internal friction angle - Qinghai Tibet plateau - Soil cohesion - Soil mechanical properties
Classification code:406.2 Roads and Streets - 483.1 Soils and Soil Mechanics - 631.1 Fluid Flow, General - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science
Numerical data indexing:Percentage 1.35e+01%, Percentage 3.40e+00% to 3.70e+00%, Percentage 7.50e+00% to 9.70e+00%, Percentage 8.00e+00% to 3.10e+01%, Time 4.32e+04s, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2017.03.017
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 5>
Accession number:20171503569167
Title:Effects of raindrop splash on aggregate particle size distribution of soil plough layer
Authors:Fu, Yu (1); Li, Guanglu (1, 2); Zheng, Tenghui (1); Li, Baiqiao (3); Zhang, Teng (4)
Author affiliation:(1) Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China; (2) College of Resources and Environment, Northwest A&F University, Yangling; 712100, China; (3) Mianyang Academy of Agriculture Sciences, Mianyang; 621023, China; (4) Power China Huadong Engineering Corporation Limited, Hangzhou; 311122, China
Corresponding author:Li, Guanglu(guangluli@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:155-160
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Splash erosion, which is a main dynamic for the detachment and transport of soil aggregates, is the initial stage of soil water erosion. Soil aggregate is a crucial indicator determining the plough layer soil fertility. Destruction of the plough layer aggregate has a negative effect on the content of soil available water and soil fertility, destroying the soil structure and restricting agricultural development of the Loess Plateau. To determine the effect of raindrop diameters on the breakdown of soil aggregates of plough layer and the characteristic of splashed fragment size distribution in the process of raindrop splash erosion, an artificially simulated raindrop splash experiment was conducted with 4 raindrop diameters (2.67, 3.05, 3.39 and 3.79 mm) using a self-designed simulated device that had a circular room with a 10-cm diameter for placing soil samples. The soil sample was collected from the soil plough layer (0-20 cm) with a steel ring (10 cm in diameter). The sampling site was located in a traditional agricultural planting region in Yangling of Shanxi Province (108°03'29″E, 34°18'24″N). Each raindrop diameter splash test was replicated 3 times. For each raindrop diameter, 5000 raindrops were dripped from a generator device on sample, and splashed aggregate fragments were collected every 1000 raindrops. The splashed fragments were sieved with aperture (2, 1, 0.5, 0.25, 0.106, 0.053 mm) using an aggregate analyzer (HR-TTF-100). All aggregate fragments were oven dried for 24 h at 105°C and weighed. The results showed that the splash amount among the collected order was not significantly different for raindrop diameter 2.67 and 3.05 mm, whereas, the splash amount of the II-V order was significantly lower than that of the I order for raindrop diameter 3.39 and 3.79 mm. An exponential function could be used to describe the relationship between splash amount and raindrop diameter when raindrop accumulation number was 2000-4000 (P<0.05). For all the raindrop diameters, the total splash amount presented an up-down-up trend as the particle size decreased. The amount of splashed fragments >2 mm was almost 0 for each raindrop diameter test. However, the amounts of splashed aggregates <0.053 mm increased with the increase of raindrop diameter. There was no significant difference in mean weight diameter of splashed fragments among different accumulation raindrop numbers or different raindrop diameters (P>0.05). The variation in enrichment ratio with the fragment size was consistent under different raindrop diameters. Compared with the undisturbed soil, the splashed fragments in particle size >1 mm and < 0.053 mm were decreased for all raindrop diameters. However, the enrichment ratios of splashed fragments of the other particle sizes were greater than 1. The results can provide valuable information for agricultural development in the Loess Plateau. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Drops
Controlled terms:Aggregates - Agricultural machinery - Agriculture - Erosion - Exponential functions - Landforms - Particle size - Particle size analysis - Sediments - Size distribution - Soil moisture - Soil surveys - Soil testing - Soils
Uncontrolled terms:Agricultural development - Enrichment ratio - Fragment size distribution - Loess Plateau - Mean weight diameter - Soil available waters - Splash erosion - Undisturbed soils
Classification code:406 Highway Engineering - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Size 0.00e+00m to 2.00e-01m, Size 1.00e-01m, Size 2.67e-03m, Size 3.05e-03m, Size 3.39e-03m, Size 3.79e-03m, Size 5.30e-05m, Temperature 3.78e+02K, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2017.03.021
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 6>
Accession number:20171503569178
Title:Effect of labor migration on cultivated land planting structure in rural China
Authors:Qi, Yuanjing (1, 2, 3); Tang, Chong (4)
Author affiliation:(1) School of Soil and Water Conservation, Beijing Forestry University, Beijing; 100083, China; (2) Key Laboratory of State Forestry Administration on Soil and Water Conservation (Beijing Forestry University), Beijing; 100083, China; (3) Engineering Research Center of Forestry Ecological Engineering, Ministry of Education (Beijing Forestry University), Beijing; 100083, China; (4) Institute of Agricultural Development and Investment, Chinese Academy of Agricultural Engineering, Beijing; 100125, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:233-240
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The purpose of this study was to evaluate the impacts of rural labor migration on planting structure in China by using multivariate regression models, which had great significance for the adjustment of planting structure under the background of rapid urbanization. The data came from a nationwide questionnaire survey conducted in 2014 and 2015. The total number of valid household questionnaires was 1580 from 13 provinces, which involved 100 villages in 25 counties. These survey sites covered all main geographic and economic regions across China and the representativeness of the sample could thus be fully guaranteed. The results indicated: 1) Approximately 80.4% of the 1580 households planted grain crops and about 37.2% of the households planted at least one kind of cash crop, such as vegetable, fruit, cotton, and medicinal herb. The cultivation area of cash crops accounted for 13.77% of the total planting area. 2) In general, rural labor migration had significant negative effects on the investment intensity of farmland and the proportion of cash crops in total planting area. However, the significance varied with the migration distance, namely, the households with members working outside their home provinces or near their home villages were more likely to plant fewer cash crops than others. 3) Separate regression for households located around and far away from cities and for those in plains and mountainous areas indicated different impacts of labor migration on agricultural planting and investments in various regions. This regional heterogeneity fully demonstrated the moderating effects of geography and market factors in determining the planting behaviors of rural households. 4) The abundance, quality, and tenure of land resources were important factors influencing the planting behavior of Chinese rural households. Households in regions with denser population, less per capitafarmland area and larger proportion of mountainous area tended to plant more cash crops and invest more capital on the farmland. The improvement of irrigation facilities could significantly improve the planting proportion of vegetables. The land tenure security also had positive influence on the investment intensity of farmland and the proportion of cash crops. 5) The planting structure was also influenced significantly by demographic characteristics of rural households, such as the family size, the number of children in the family and the age and education level of the household head. The social capital of rural households was proven to have significant positive effect on the planting of vegetables, but not on the planting of fruits or the investment intensity of farmland. 6) Households in villages near to a city often had larger proportions of cash crops in total planting area and higher levels of investment intensity on farmland than those in remote areas, representing the importance of market proximity and information accessibility in determining the planting structure in rural China. The 2 rural policies introduced by the central government and vigorously promoted by local governments had different influences on the planting behavior of rural households. Specifically, the effective implementation of farmland transfer could significantly encourage farmers to plant more cash crops by learning from the behavior of agricultural investors from outside of the village, while the development of rural specialized cooperatives did not have similar positive effects on the improvement of rural planting structure or farmland investment. Therefore, this study can provide a reference for the optimization and adjustment ofcultivated landplanting structure in China. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Investments
Controlled terms:Agriculture - Commerce - Crops - Cultivation - Economics - Education - Farms - Fruits - Land use - Plants (botany) - Regression analysis - Rural areas - Surveys - Vegetables
Uncontrolled terms:Central government - Cultivated lands - Demographic characteristics - Information accessibility - Migration distance - Multivariate regression models - Questionnaire surveys - Rapid urbanizations
Classification code:403 Urban and Regional Planning and Development - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 971 Social Sciences
Numerical data indexing:Percentage 1.38e+01%, Percentage 3.72e+01%, Percentage 8.04e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.032
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 7>
Accession number:20171503569152
Title:Structural modeling and performance analysis of load-sensing variable pump
Authors:Chen, Suiying (1); Zhao, Jianjun (1); Mao, Enrong (1); Song, Zhenghe (1); Zhu, Zhongxiang (1); Du, Yuefeng (1)
Author affiliation:(1) Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment, College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Du, Yuefeng(dyf@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:40-49
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, to meet the development requirements of green production and energy efficiency of modern agriculture, the closed-center load-sensing hydraulic system has been widely used in the domestic and overseas agricultural machinery because of its low energy consumption and strong adaptability. As a key power component of the hydraulic system of the modern agricultural equipment, the performance of the load-sensing variable pump plays an important role in the performance of the whole hydraulic system. At present, the domestic scholars have mainly concentrated in the optimization and characteristics analysis of hydraulic valve, while have done little about the hydraulic pump. Therefore, this paper focused on the mathematical modeling, performance simulation and testing of the load-sensing variable pump, which was composed of swashplate piston pump, plunger cylinder, pressure control valve, flow control valve, load feedback check valve, and so on. In order to better analyze the performance of the pump, the mathematical models of these parts were established by using the pressure-flow equation, flow continuity equation, force balance equation, and so on. Taking into account the effective travel range of the moving parts such as valve spool and swashplate, the nonlinear mathematical model of the load-sensing variable pump based on the boundary conditions was constructed by using the state space method. Then, the simulation model of the pump was established using MATLAB/Simulink based on the mathematical model. By using the fourth order Runge-Kutta algorithm, the steady-state and dynamic performances of the pump were simulated. At the steady state, the compensating pressure of the variable pump was about 1.6 MPa. And in the dynamic state, the outlet pressure and swashplate angle of the pump could respectively follow the step changes of the load and system flow very well, the adjustment time of which was about 0.4 and 0.5 s, respectively. The simulation results showed that the load-sensing variable pump could adjust the inclination angle of the swashplate in real time according to the required flow and pressure of the load, and thus had a good pressure-flow compensation characteristic. Finally, to verify the correctness of the mathematical model and the simulation analysis, an indoor test platform of the load-sensing hydraulic system was built, including hydraulic pump station, proportional control valve, proportional relief valve, flowmeter, pressure sensor, and so on. The dynamic performance test of the load-sensing variable pump was carried out by using the platform. Among them, the step change of the load pressure could be achieved by controlling the proportional valve's opening pressure, while the step change in flow could be achieved by controlling the spool opening of the proportional relief valve. The test results showed that the load-sensitive pump could output its required flow when the proportional valve spool encountered a step change. And when the load made a step change, the outlet pressure of the variable pump changed almost synchronously with the load pressure. Compared with the simulation results, the steady-state error of the compensation pressure was about 0.1 MPa, which verified the correctness of the nonlinear mathematical model of the load-sensing variable pump. It can be seen that the output flow and pressure of the load-sensing variable pump can be adapted to the load in real time, thus effectively improving the efficiency of the hydraulic system and reducing the system heat, which meets the field work demands of the modern agricultural equipment operation unit. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Load testing
Controlled terms:Agricultural machinery - Agriculture - Boundary conditions - Computer simulation - Energy efficiency - Energy utilization - Equipment - Error compensation - Hydraulic equipment - Hydraulic machinery - Loads (forces) - Mathematical models - MATLAB - Pressure relief valves - Pumps - Reels - Runge Kutta methods - Safety valves - State space methods
Uncontrolled terms:Agricultural equipment - Characteristics analysis - Dynamic performance tests - Flow continuity equations - Fourth-order runge-kutta - Load sensing - Nonlinear mathematical model - Steady-state and dynamic performance
Classification code:408 Structural Design - 525.2 Energy Conservation - 525.3 Energy Utilization - 601.2 Machine Components - 618.2 Pumps - 619.1.1 Pipe Accessories - 632.2 Hydraulic Equipment and Machinery - 691.2 Materials Handling Methods - 723.5 Computer Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 901 Engineering Profession - 921 Mathematics - 921.6 Numerical Methods
Numerical data indexing:Pressure 1.00e+05Pa, Pressure 1.60e+06Pa, Time 4.00e-01s, Time 5.00e-01s
DOI:10.11975/j.issn.1002-6819.2017.03.006
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 8>
Accession number:20171503569177
Title:Utilization model and its efficiency analysis of biochar-gas-oil polygeneration by straw pyrolysis
Authors:Huo, Lili (1); Zhao, Lixin (1); Yao, Zonglu (1); Meng, Haibo (1); Cong, Hongbin (1)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agricultural Residues, Ministry of Agriculture, 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:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:227-232
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are about 7 tons of straw produced in China each year, about half of them have not been used effectively. Straw pyrolysis polygeneration technology changed wastes and straw into biochar, which can not only provide clean energy, improve the energy structure, but also fix carbon and realize carbon reapplication, so it has good application potential. Three kinds of process characteristics of internal heating type moving bed of biomass carbon gas cogeneration technology, and external heating type moving bed pyrolysis carbon gas cogeneration technology, external heating type moving bed pyrolysis carbon gas generation technology were analyzed, the suitability of three technologies were evaluated. Three processes have their own technological advantages. With internal heating type pyrolysis carbon gas production technology, the calorific value of gas is slightly lower, which is 3-6 MJ/kg; but investment cost is low, because its equipment is relatively simple and almost no external energy consumption, which effectively reduced the cost of equipment and fuel consumption. So it is suitable for hundreds of thousands of households to thousands of natural villages. The pyrolysis gas production technology mode of the primary pyrolysis gas after secondary pyrolysis, its heating rate is twice as high as that of the internal heating type, and its energy conversion rate is 40% to 60%; This mode can be directly used to provide cooking through the gas pipeline directly to the village community to focus on gas supply. Although the equipment cost and energy consumption of external heating and secondary pyrolysis are increased, the problem of difficult to deal with the by-products such as tar is solved, ensured the environmental benefits of the application of technical engineering. That is suitable for the rural community centralized gas supply of over 1000 households; The pyrolysis gas, carbon and oil three-state products of the external heating pyrolysis multi-generation technology are effectively collected. As a terminal product, the efficiency of energy conversion is high, maximizing the use of the pyrolysis process of all the energy. The gas calorific value is higher than that of the process one and lower than process two, which can be used for cooking more than 10 000 households, industrial park gas supply or power generation, etc. Therefore, it is suitable for large-scale pyrolysis carbon gas production technology model. The annual utilization of 2000, 5000 and 10000 t straw raw materials for three models as an example, the cost of three different models of straw consumption per ton of straw were 362, 569, 536 yuan/t, income were 449, 704, 678 yuan/t, net profit were 87, 135 and 141 yuan/t, sales were about 20% profit margin, the greenhouse gas carbon emission trading income is 7.8, 13.1, 10.8 yuan/t, the greenhouse gas emissions of carbon dioxide emissions of 0.48, 0.82, 0.67 t, carbon emissions trading price was 16 yuan/t, respectively, an increase was 8.2%, 8.8%, 7.1% of the net profit, good economic and environmental benefits, respectively. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Gas emissions
Controlled terms:Calorific value - Carbon dioxide - Commerce - Cost engineering - Costs - Energy conversion - Energy utilization - Equipment - Fuel consumption - Gallium - Gas supply - Gases - Global warming - Greenhouse gases - Heating - Investments - Oils and fats - Profitability - Pyrolysis - Rural areas - Straw
Uncontrolled terms:Application modes - Bio chars - Carbon dioxide emissions - Cogeneration technologies - Economic and environmental benefits - Energy conversion rates - Gas production technology - Process characteristics
Classification code:443.1 Atmospheric Properties - 451.1 Air Pollution Sources - 522 Gas Fuels - 525.3 Energy Utilization - 525.5 Energy Conversion Issues - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 802.2 Chemical Reactions - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 821.5 Agricultural Wastes - 901 Engineering Profession - 911 Cost and Value Engineering; Industrial Economics - 911.2 Industrial Economics
Numerical data indexing:Mass 6.35e+03kg, Percentage 2.00e+01%, Percentage 7.10e+00%, Percentage 8.20e+00%, Percentage 8.80e+00%
DOI:10.11975/j.issn.1002-6819.2017.03.031
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 9>
Accession number:20171503569174
Title:Simulation on temperature variation characteristics of soil around buried pipe in process of heat storage and release
Authors:Wu, Xuan (1); Liu, Wei (1); Lu, Ziye (1); Liang, Panlong (1); Jin, Guang (1)
Author affiliation:(1) School of Energy and Environment, Inner Mongolia University of Science and Technology, Baotou; 014010, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:204-213
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ground source heat pump (GSHP) has been very popular for space heating and cooling due to its high energy efficiency and low operating cost and thus it is still a very important research subject. Ground heat exchanger is a key component of GSHP. The comprehensive understanding about the heat transfer characteristic of the ground heat exchangers and the soil temperature distribution around the ground heat exchangers is crucial to the performance of GSHP and a large number of researches were carried out, because the operating conditions of GSHP were related closely to the soil temperature field around the ground heat exchangers. Besides, the heat imbalance of GSHP has been become a serious problem, because the amount of heat extracted from and rejected to the soil is usually not equal. It is an especially obvious problem for heating-dominated buildings in the cold and severely cold regions. So, the temperature recovery ability of soil has attracted wide attention. This paper presents the study of the temperature variation characteristics of soil around the ground heat exchangers in the process of heat storage and release of GSHP in the center of Inner Mongolia, China. Based on the finite element method, two-dimensional physical and mathematical models of transient heat transfer were established for the soil around the vertical U-tube ground heat exchanger. The heat storage, heat release and the coupling process were studied on the basis of experimental verification. The variation laws of thermal influencing radius, heat exchange of unit pipe and soil temperature with the operation time and operation mode of GSHP were revealed. The soil heat equilibrium problems in the heat storage, heat release and the coupling process were discussed. The influence of fluid inlet velocity, inlet temperature, soil types and GSHP operation model on the soil temperature field were explored. The results indicated that the thermal influencing radius increased with the increase of operation time and became gentle eventually. With the 25 and 28 days running-time of GSHP, thermal influencing radius is 3.3 and 3.4 m, respectively. The fluid inlet temperature has a great influence on the thermal influencing radius and heat flux of unit pipe, while the fluid inlet velocity has a small impact on these. The fluid inlet temperature and inlet velocity are 40, 60 ℃ and 0.6, 1.2 m/s, respectively. And the corresponding thermal influencing radius is 3.7, 4.5 and 3.5, 3.6 m. The proper intermittent operation mode could improve the heat transfer rate and the temperature recovery ability of soil around the ground heat exchanger. The recovery time and recovery effect of soil temperature were better with the increase of the thermal conductivity of soil. With the running time of 84 h (heat rejection of 12 hour and recovery of 72 hour), the soil temperature is 9.3℃ with a thermal conductivity of 3.1 W/(m·K) (the initial temperature of soil is 9.5℃). In addition, the unequal heat transfer had a great influence on the soil heat balance in the coupling mode of heat storage and release. The experimental validation indicated that enough accuracy could be achieved using the model developed in this study with a maximum difference of 5.35%. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Geothermal heat pumps
Controlled terms:Energy efficiency - Finite element method - Heat exchangers - Heat flux - Heat pump systems - Heat storage - Heat transfer - Inlet flow - Recovery - Soils - Specific heat - Temperature - Temperature distribution - Thermal conductivity - Uranium
Uncontrolled terms:Buried pipes - Experimental verification - Ground heats - Groundsource heat pump (GSHP) - Heat transfer characteristics - Influencing radius - Operation mode - Vertical U-tube ground heat exchangers
Classification code:483.1 Soils and Soil Mechanics - 525.2 Energy Conservation - 547 Minor, Precious and Rare Earth Metals and Alloys - 616.1 Heat Exchange Equipment and Components - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 921.6 Numerical Methods
Numerical data indexing:Age 6.85e-02yr, Age 7.67e-02yr, Percentage 5.35e+00%, Size 3.30e+00m, Size 3.40e+00m, Size 3.60e+00m, Thermal_Conductivity 3.10e+00W/m*K, Time 2.59e+05s, Time 3.02e+05s, Time 4.32e+04s, Velocity 1.20e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.03.028
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 10>
Accession number:20171503569179
Title:Land consolidation spatial pattern and diagnosis of its obstacle factors based on pressure-state-response model
Authors:Qu, Yanbo (1); Zhu, Weiya (2); Yun, Wenju (3); Zhang, Yong (2); Gao, Yu (1)
Author affiliation:(1) School of Public Management, Shandong University of Finance and Economic, Jinan; 250014, China; (2) Shandong Land Survey and Planning Institute, Jinan; 250014, China; (3) Centre of Land Consolidation, Ministry of Land and Resource, Beijing; 100035, China
Corresponding author:Zhu, Weiya(zhangyongjeff@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:241-249
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Spatial pattern analysis of land consolidation is to classify space for different conditions of land consolidation. It not only helps to clear regional land management direction and implementation strategy, but also is the important basis of task decomposition and project arrangement of land consolidation, which has become the necessary content of land consolidation planning. Therefore, scientifically carrying out the analysis of spatial pattern of land consolidation and its impact factor is important theoretical basis to clear the direction of regional land consolidation and make differential strategies in land consolation planning. Firstly, the paper made the concept framework of pressure-state-response (PSR) as theoretical basis, and built the PSR evaluation system of land consolidation with 18 indices. Secondly, the urgency, suitability and motivation of land consolidation were analyzed through applying the entropy weight TOPSIS (technique for order preference by similarity to an ideal solution) model, and the analysis of the spatial pattern and types of land consolidation was carried out with the PSR combination matrix model. At last, the main obstacle factors of land consolidation in different regions and its frequencies were analyzed by using the obstacle degree model, and some different optimization strategies were proposed. Based on the data of the land consolidation planning and projects from 2011 to 2015 at the district or county level in Shandong Province, the empirical analysis showed that: (1) 69.04% of the counties on the P (pressure) value were higher than provincial average, 50.68% of the counties on the S (state) value were lower than provincial average, and 70.51% of the counties on the R (response) value were lower than provincial average, which indicated that the provincial comprehensive pressure of land use was high, the integrated suitability conditions was in the medium level, and the enthusiasm of land consolidation was low. (2) The spatial pattern of land consolidation in Shandong Province was divided into prior, focused and moderate consolidation area with the corresponding 6 types of regulation based on PSR grading strength and their combination characteristics. The number ratios of counties in 3 main areas were 37.41%, 28.78% and 33.81% respectively, and their spatial distribution was relatively concentrated. But the number ratios of counties for 6 types were 20.86%, 16.55%, 20.86%, 7.91%, 13.67% and 20.14%, respectively, and the spatial heterogeneity of land consolidation pattern was significant. Therefore, regional comprehensive evaluation of "top-down" and difference identification of "bottom up" should be balanced in the process of land consolidation space division. (3) The obstacle factors of land consolidation PSR system and their working frequencies both had a certain regional similarity and an obvious spatial heterogeneity. There were 3 similar aspects in different areas, which were high pressure on cultivated land occupancy, low potential of land development and reclamation and weak planning response on rural residential consolidation. From prior area to focused area and moderate area, the obstacle factors' working frequency of land consolidation PSR system was becoming higher, the difficulty was becoming bigger and the urgency was becoming stronger for carrying out land consolidation. (4) Land consolidation potential difference and funding gap widening between regions were the main causes to hinder the land consolidation response. We suggested that Shandong should introduce market mechanism and attract social capital investment to promote land consolation development, and discuss efficient governance modes and differential strategies to adapt the local conditions. This paper is an effective supplement for the "bottom up" method of land consolidation pattern division, which not only perfects the theory and method of land consolidation zoning, but also provides useful reference for task decomposition and project deployment in land consolidation planning. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Land reclamation
Controlled terms:Economics - Grading - Investments - Land use - Models - Spatial variables measurement - Zoning
Uncontrolled terms:Implementation strategies - Land consolidation planning - Obstacle degree - Pressure state response (PSR) - Pressure- State-Response models - Psr models - Shandong province - Vspatial pattern
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 943.2 Mechanical Variables Measurements - 971 Social Sciences
Numerical data indexing:Percentage 1.37e+01%, Percentage 1.66e+01%, Percentage 2.01e+01%, Percentage 2.09e+01%, Percentage 2.88e+01%, Percentage 3.38e+01%, Percentage 3.74e+01%, Percentage 5.07e+01%, Percentage 6.90e+01%, Percentage 7.05e+01%, Percentage 7.91e+00%
DOI:10.11975/j.issn.1002-6819.2017.03.033
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 11>
Accession number:20171503569160
Title:Numerical simulation on flow field of screen filter with torpedo in micro-irrigation
Authors:Abulimiti, Alifujiang (1, 2, 3); Tumaerbai, Hudan (1); Yusaiyin, Mulati (1, 3); Awa, Mukeran (3)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Xinjiang Agricultural University, Urumqi; 830052, China; (2) Xinjiang College of Water Resources and Hydropower Engineering, Urumqi; 830013, China; (3) Xinjiang Xinshui Modern Water Resources Engineering Co., Ltd., Urumqi; 830019, China
Corresponding author:Tumaerbai, Hudan(hudant@hotmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:107-112
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to deeply understand the flow distribution of the torpedo screen filter, the Reynolds-averaged Navier-Stokes (RANS) equation and Re-Normalization Group (RNG) k-Ε turbulence closure model were used to simulate the flow field of this filter system. To ensure the reliability of the numerical simulation, the physical experiment results were compared to the numerical simulation results, and the result showed that the maximum relative error between the head loss in the physical experiment and the numerical simulation was 5.99% when the filtering system was operated at a maximum flow rate of 360 m<sup>3</sup>/h, indicating reliability of the simulation method. The simulation results showed that the torpedo components and the boundary conditions of the outlet notably affected the distribution rules of both the velocity and the pressure fields for the filter, especially for the torpedo components. The distributions of the flow velocities of inside and outside of the screen along the X-axis were not uniform during the filtering process. And the flow velocity distributions inside and outside of the filter screen along the X-axis were divided into 3 stages: 1) a rapid increase; 2) a rapid decrease; and 3) a gradual decrease. The maximum velocities inside and outside of the screen and their spatial locations along the X-axis were different. For the upper part of the screen, the inside flow velocity increased in a larger amplitude than did the outside flow velocity, and the flow velocity achieved its maximum (5.53 m/s) at the X value of 0.29 m. The outside water flow velocity of the upper part of the screen achieved its maximum value (3.9 m/s) at the X value of 0.33 m. When the X value ranged from 0.2 to 0.6 m, the inside flow velocity of the upper part of the screen was larger than that of the outside; however, the difference in the flow velocity along the X-axis continually decreased from the maximum difference of 4.1 m/s. For the lower part of the screen, the maximum flow velocity and its position of lower part of the screen was 5.4 m/s and 0.42 m, respectively. When the X value was 0.41-0.51 m, the flow velocity of the water in the outside area of the lower part of the screen was larger than that of water in the inside area. Nonetheless, the flow velocities of water in the other inside of lower screen were higher than those of water in the outside, and the maximum difference in the flow velocity was 2.28 m/s. There was a notable difference in the pressure distributions along the inside and outside of the screen. The pressure of the inside along the X-axis first rapidly increased, then gradually decreased, and finally stabilized. In contrast, the pressure of the outside along the X-axis exhibited a greater variation; for example, the pressure rapidly decreases at the outlet, and the fluctuations along the X-axis are relatively large. The pressure of the inside of the screen was larger than that of the outside; however, the pressure differences along the X-axis continually decreased, and the maximum and minimum pressure differences between the two were approximately 23 and 0.5 kPa, respectively. This indicated that the screen clogging was not evenly distributed, and the screen clogging began at the downstream end of the screen and developed progressively upstream towards the outlet. This phenomenon significantly affected the cleaning process of the filter. Therefore, it is strongly suggested that in a practical application the optimum drainage differential pressure must be circumspectly considered. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Flow velocity
Controlled terms:Bandpass filters - Cleaning - Computer simulation - Flow fields - Flow of fluids - Flow of water - Navier Stokes equations - Numerical methods - Numerical models - Pressure - Rivers - Torpedoes - Turbulence models - Velocity - Velocity distribution
Uncontrolled terms:Differential pressures - Maximum flow velocities - Maximum relative errors - Physical experiments - Pressure differences - Reynolds-Averaged Navier-Stokes equations - Screen filters - Turbulence closure models
Classification code:404.1 Military Engineering - 631 Fluid Flow - 703.2 Electric Filters - 723.5 Computer Applications - 802.3 Chemical Operations - 921 Mathematics - 922.2 Mathematical Statistics - 931.1 Mechanics
Numerical data indexing:Percentage 5.99e+00%, Pressure 2.30e+04Pa, Pressure 5.00e+02Pa, Size 2.00e-01m to 6.00e-01m, Size 2.90e-01m, Size 3.30e-01m, Size 4.10e-01m to 5.10e-01m, Size 4.20e-01m, Velocity 2.28e+00m/s, Velocity 3.90e+00m/s, Velocity 4.10e+00m/s, Velocity 5.40e+00m/s, Velocity 5.53e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.03.014
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 12>
Accession number:20171503569166
Title:Inhibiting effects and mechanism experiment of flue-gas desulfurization gypsum on soil phosphorus loss
Authors:Chen, Xiaohua (1); Qian, Xiaoyong (1); Li, Xiaoping (2); Zhang, Hui (1); Hu, Shuangqing (1); He, Kun (2); Li, Jing (3)
Author affiliation:(1) Shanghai Academy of Environmental Sciences, Shanghai; 200233, China; (2) State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai; 200062, China; (3) College of Environmental Science&Engineering, Donghua University, Shanghai; 201620, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:148-154
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Increased phosphorus (P) losses from land to waterbody via runoff and drainage are one of the important factors causing eutrophication of surface waterbody. Flue gas desulfurization gypsum (FGDG) is a synthetic by-product generated from the flue gas desulfurization process in coal power plants. Due to the high Ca<sup>2+</sup>content of FGDG it can potentially be used to immobilize P in soils. To study the effects of FGDG on soil P losses, not only to open up a new way of FGDG resource utilization, but also to enrich engineering technologies for controlling agricultural non-point source P load. In this study, soil column leaching experiment and artificial soil slope & rainfall simulation experiment were conducted to examine the impact of FGDG which came from one of Shanghai coal-fired power plant, on the leaching and runoff P losses from coastal plains soil of Chongming East Headland, Shanghai. Four mass rates of FGDG (0, 1%, 2.5% and 5%) were applied to soil column and two mass rates of FGDG (0 and 1%) applied to artificial soil slope. The results indicated that: 1) Ca<sup>2+</sup>dissolved from FGDG transformed water-soluble P to insoluble P in soil, and turned Ca<inf>2</inf>-P, Al-P into Ca<inf>8</inf>-P and Ca<inf>10</inf>-P which were more inclined to fix in soil. Compared with the control group, the reduction rate of total dissolved phosphorus (TDP) loss of the soil columns applied with FGDG reached 92.8%-94.8% and there was no significant difference among three FGDG treatments (P>0.05). 2) FGDG significantly improved soil permeability and anti-erosion ability (P<0.05), 1%-5% FGDG made the saturated permeability of soil columns increase nearly 10 times, there was no significant difference among three FGDG treatments (P>0.05). Compared with the non-FGDG slopes, 1% FGDG addition achieved the maximum runoff reduction rate of 37.5%, the maximum reduction rate of sediment loss of 59.5%. It was indicated that much adsorbed P on suspended sediment was prevented from migrating along with surface runoff. 3) The reduction rate of TP loss of soil columns with FGDG addition was 23.6%-79.5% and ascended as the adding amount of FGDG increased. Up to 61.5% more TP was held in slope soil with 1% FGDG addition than the non-FGDG treatment. The ratio of TDP loss accounted for TP loss was only 0.6%-6.1%, reflecting enhancement of soil permeability and reduction of surface runoff and sediment loss were the primary mechanisms of FGDG to control P loss from soil, and the deposition reaction of calcium and phosphoric acid belonged to subordinate P-fixing mechanism. When the mass ratio of FGDG was more than 1%, the effect of FGDG on reducing the loss of soil P was not significant (P>0.05), which indicated that the effect of FGDG on soil P loss was also influenced by Ca<sup>2+</sup>dissolution efficiency of FGDG, the TDP content and soil particle physical characteristics and other factors together. On the whole, using FGDG to control phosphorous losses from soil can achieve both resource utilization of desulfurization solid waste and reduction of water eutrophication risk due to P transportation. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Soils
Controlled terms:Calcium - Coal - Desulfurization - Eutrophication - Flue gases - Flues - Fossil fuel power plants - Gas plants - Gypsum - Gypsum plants - Leaching - Phosphorus - River pollution - Runoff - Sediments - Suspended sediments
Uncontrolled terms:Dissolution efficiencies - Flue gas desulfurization - Flue gas desulfurization gypsums - Inhibiting - Phosphorus loss - Physical characteristics - Soil permeability - Total dissolved phosphorus
Classification code:442.1 Flood Control - 451.1 Air Pollution Sources - 453 Water Pollution - 482.2 Minerals - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 522 Gas Fuels - 524 Solid Fuels - 549.2 Alkaline Earth Metals - 802.3 Chemical Operations - 804 Chemical Products Generally
Numerical data indexing:Percentage 0.00e+00%, Percentage 1.00e+00%, Percentage 1.00e+00% to 5.00e+00%, Percentage 2.36e+01% to 7.95e+01%, Percentage 2.50e+00%, Percentage 3.75e+01%, Percentage 5.00e+00%, Percentage 5.95e+01%, Percentage 6.00e-01% to 6.10e+00%, Percentage 6.15e+01%, Percentage 9.28e+01% to 9.48e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.020
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 13>
Accession number:20171503569153
Title:Verification of comparability and analysis of inner flow fields on scaling models of submersible well pump
Authors:Shi, Weidong (1); Yang, Yang (1); Zhou, Ling (1); Lu, Weigang (1); Pan, Bo (2)
Author affiliation:(1) National Research Center of Pumps, Jiangsu University, Zhenjiang; 212013, China; (2) Shandong Xingyuan Mining Equipment Group Co., Ltd., Jining; 272300, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:50-57
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Similar transformation design method is one of the most frequently-used ways of centrifugal pump design. In order to verify the similarity of the scaling model, a typical submersible well pump was chosen as the model pump in this paper, and based on the scaling model conversion algorithm, the designed pump was obtained. And the designed pump model was directly scaled without any factor correction by the model pump with a scaling factor of 0.66. By the numerical simulation and the experiments, both the comparability between the model pump and the designed pump and the difference between their inner flow fields were analyzed. Ansys CFX software was adopted to simulate the flow fields of the designed pump and the model pump. The calculation domains were created based on two-stage pump models, which were meshed with the structured grids. The numerical simulations under multi-conditions were performed based on standard k-ω turbulence and standard wall function. Also, different number of grids were divided both for the model pump and the designed pump in this paper to determine the unrelated relationship between the number of meshes used in the calculation and the calculated results. The flow filed of liquid in the main flow passage were analyzed emphatically. The streamline on blade to blade surface and the turbulent kinetic energy distributions on middle section of the impeller were analyzed to get the flow state and the hydraulic loss inside the impellers for both the model pump and the designed pump. In the meantime, the static pressure distributions and the vortex core region inside the diffusers were investigated. By the comparative analysis between performance predicted, it was found that the designed pump and the model pump had basically consistent variation tendency of their head, efficiency and shaft power under 0.4-1.6 times rated flow conditions, Which meant the performance predicted meet the similar conversion rules. The designed pump and the model pump both have wide high efficiency area, and the highest efficiency points are both at 1.2 times rated flow rate condition. Compared to the model pump, the maximum shaft power point of designed pump shifted to the heavy flow rate conditions, and the ratio of maximum power and the rated power increased. But the designed pump still has better performance of non-overload. The streamline on blade to blade surface and the turbulent kinetic energy distributions on middle section of the impellers showed that the fluid flow field and the vortex area inside the impeller were consistent. Also, the static pressure distributions and the vortex core region inside the diffusers showed that the pressure distributions inside the diffusers were similar, but the vortex core area inside the designed pump was smaller than the model pump. So, the liquid inside the designed pump had a good internal flow state, which would make the designed pump having a hydraulic efficiency. By the comparison between results of numerical calculation and experiment of model pump, the head and power of numerical simulation predicted were slightly lower than the test results, the predicted efficiency was slightly higher than the test results, but the changing trend were almost the same. The results of this study could provide a basis and reference for the improvement of submersible well pump performance. As we can see, the designed pump narrowed by the model pump had good hydraulic performance, which meant that the model direct scaling method can meet the design requirements of deep well centrifugal pumps. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Pumps
Controlled terms:Centrifugal pumps - Computational fluid dynamics - Experiments - Flow fields - Flow of fluids - Impellers - Kinetic energy - Kinetics - Numerical models - Pressure distribution - Rating - Scaling laws - Submersibles - Vortex flow - Wall function - Well pumps
Uncontrolled terms:Hydraulic efficiency - Hydraulic loss - Hydraulic performance - Numerical calculation - Similar transformation - Static pressure distributions - Transformation designs - Turbulent kinetic energy distribution
Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 674.1 Small Marine Craft - 901.3 Engineering Research - 921 Mathematics - 931.1 Mechanics - 961 Systems Science
DOI:10.11975/j.issn.1002-6819.2017.03.007
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 14>
Accession number:20171503569180
Title:Performance testing of vegetable chopping machine based on LabVIEW and operation parameter optimization
Authors:Xu, Shun (1, 2); Tong, Jin (1, 2); Li, Mo (1, 2)
Author affiliation:(1) The College of Biological and Agricultural Engineering, Jilin University, Changchun; 130025, China; (2) Key Laboratory of Bionic Engineering (Ministry of Education, China), Changchun; 130025, China
Corresponding author:Li, Mo(moli@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:250-256
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to make the vegetable waste processing easier and more efficient, machinery is replacing the manual labor step by step. The chopping machine has been gradually more and more applied in China. Vegetable-chopping machine can cut the vegetable into small fragments continuously and quickly, and it is especially applied to chop root, stem, and foliage vegetables. However, the development of the vegetable chopping machine is extremely slow, which leads to a low production efficiency, and even brings harm to personal or property safety. In order to improve the work performance of the chopping machinery, a performance testing platform for vegetable chopping was built and a cutterhead was designed in this study. The testing platform consists of chopping system, data acquisition system and product granularity analysis system. Data acquisition system is used to collect the torque, revolving speed and power of cutterhead, whose controlling program is compiled in LabVIEW. The main function of product granularity analysis system is to investigate the chopping degree of product. With this performance testing platform, a series of vegetable chopping experiments were conducted to find out the influence of the blade number and cutting speed on cutterhead. The chopping experiments were operated in 2stages. In the first stage, Chinese cabbage samples were respectively chopped by 1, 2 and 3 blades with different rotation speeds of 1000, 1200 and 1400 r/min. The experiment in this stage was to obtain the reasonable usable range of blade number and rotation speed of cutterhead. In the second stage, potato and celery samples were minced based on the results of former stage. Then, the exact number of blades in cutterhead and the suitable rotation speed were discussed for different vegetables. All related experiments were performed at the Key Laboratory of Bionic Engineering (Ministry of Education, China), Jilin University in 2015. Experimental investigation showed that for leafy vegetables like Chinese cabbage, the chopping performance of cutterhead was the best when the number of blades in cutterhead was 2 and its rotation speed was 1400 r/min; for root or stem vegetables like potato, the suitable number of blades in cutterhead was 3 and the rotation speed was 1400 r/min; for leafy or stem vegetables like celery whose fiber is more abundant and longer, 3 blades with 1400 r/min was better for cutterhead. In short, the most applicable blade number for vegetable cutterhead was 2 or 3 and the rotation speed was 1400r/min, with which the cutterhead had an ideal ability to mince the common root, stem and leafy vegetables. In addition, the experiment showed that the performance testing platform had the advantages of high work stability, high precision, favorable using interface, and so on, which could not only implement the test with the visualization device, but also increase the processing velocity. It could be generalized to other mechanical testing benches effectively. This work provides the strong technical support for design and improvement of vegetable cutterhead. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Vegetables
Controlled terms:Agricultural machinery - Data acquisition - Design - Machine design - Mechanical testing - Mechanization - Rotation - Shafts (machine components) - Speed - Well pumps
Uncontrolled terms:Cutterhead - Data acquisition system - Experimental investigations - LabViEW - Ministry of Education - Production efficiency - Testing platforms - Visualization devices
Classification code:601 Mechanical Design - 601.2 Machine Components - 618.2 Pumps - 723.2 Data Processing and Image Processing - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 931.1 Mechanics - 943.2 Mechanical Variables Measurements
Numerical data indexing:Rotational_Speed 1.20e+03RPM, Rotational_Speed 1.40e+03RPM
DOI:10.11975/j.issn.1002-6819.2017.03.034
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 15>
Accession number:20171503569148
Title:Design and experiment of wide band seeding rice seeder with reversed stubble cleaning and anti-blocking
Authors:Zhang, Yinping (1); Du, Ruicheng (1); Diao, Peisong (1); Yang, Shandong (1); Wang, Zhenwei (2)
Author affiliation:(1) College of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo; 255049, China; (2) Nanjing Research Institute for Agricultural Mechanization, Ministry of Agriculture, Nanjing; 210014, China
Corresponding author:Du, Ruicheng(drc@sdut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:7-13
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There are some serious problems in the rice planting, such as wasting lots of time for rice seedlings transplantation, and high demands of direct planting in rice-wheat planting area. In order to solve these problems, the techniques of reversed stubble cleaning and active anti-blocking, along with the technique of wide band and precision seeding were used in a rice direct seeder. The designed direct seeder included the following parts: reversed stubble cleaning device, active ant-blocking device and wide band seeding device, and so on. It could implement the following function at one time: rotary tillage, stubble cleaning, anti-blocking, furrow opening, deep fertilizing, wide seeding, active covering soil and compacting. The way seeds covered by soil was active, in which soil was thrown in reversed rotary tillage, so the distance between reverse stubble cleaning device and seeding device was an important factor. It would influence the soil covering performance. The soil throwing in the reversed rotary tillage was analyzed, and the soil movement curve was drawn. Then the ensemble method was used to test the soil throwing performance. The results showed that the soil throwing distance ranged from 650 to 870 mm under the radius of 245 mm and the rotating speed of 320 r/min. Considering both the soil covering performance and the length of the rice seeder, the optimal distance between the reverse stubble cleaning device and the forward anti-blocking device was 738 mm, which was gotten by soil throwing test. At the same time, a wide band seeding device was designed according to the technique used in wheat wide band planting proposed by the academician Yu Songlie. The theoretical width of the seeding device was designed as 140 mm and the triangular bulge was designed in the middle which divided the width 140 mm into 3 sections i.e. 35, 70 and 35 mm. In order to obtain the best performance of separating seeds evenly, the seed arrangement test was carried out, and 2 influence factors, i.e. the angle and the middle bulge height of the seeding device, were designed in different values. Through the test of 2 factors and 3 levels, the optimum angle and bulge height were designed as 40° and 4 mm, respectively, which could arrange seeds smoothly and separate seeds evenly. At last the field experiments were carried out in rice-wheat planting area, and the results showed that stubble cleaning could be well finished by the reversed stubble cleaning device and the congestion could be well solved by the active anti-blocking device. With the reversed and forward rotary tillage, soil of seedbed was finely divided and soil covering was uniform. The variation coefficients of sowing depth and fertilizing depth were 4.58% and 2.40% respectively, and the variation coefficient of the distance between seed and fertilizer was 4.72%, which met the national standard. The average seeding band width was 138.4 mm with no significant difference with the theoretical width designed. In the different width of the seeding band, the number of seeds was different, but the difference was not significant, which met the demand of design. The growing states of crops showed that the width of seeding band had influence on the rice growing, and the effective tillering and the percentage of earbearing tiller on the sides of the seedling band were higher than that in the middle (P<0.05). The passing ability of this seeder satisfied the agronomic requirements. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Seed
Controlled terms:Agricultural machinery - Agriculture - Cleaning - Crops - Cultivation - Design - Machine design - Soils
Uncontrolled terms:Ant-blocking - National standard - Precision seeding - Reverse rotary - Rice - Throwing distances - Variation coefficient - Wide-band
Classification code:483.1 Soils and Soil Mechanics - 601 Mechanical Design - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 2.40e+00%, Percentage 4.58e+00%, Percentage 4.72e+00%, Rotational_Speed 3.20e+02RPM, Size 1.38e-01m, Size 1.40e-01m, Size 2.45e-01m, Size 3.50e-02m, Size 4.00e-03m, Size 6.50e-01m to 8.70e-01m, Size 7.00e-02m, Size 7.38e-01m
DOI:10.11975/j.issn.1002-6819.2017.03.002
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 16>
Accession number:20171503569184
Title:Optimization of sensor array of electronic nose for aging time detection of pecan
Authors:Xu, Keming (1); Wang, Jun (1); Deng, Fanfei (1); Wei, Zhenbo (1); Cheng, Shaoming (1)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou; 310058, China
Corresponding author:Wang, Jun(jwang@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:281-287
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As one of the most popular nuts produced in China, pecan contains large amounts of protein and a variety of unsaturated fatty acids required for human body. However, pecans are prone to rancidity because of the influence of environmental factors such as light, oxygen, and moisture. Therefore, the detection of pecan's quality has a certain practical significance. As a bionic electronic system, electronic nose (E-nose) detects the quality of pecan qualitatively and quantitatively through the analysis of sample volatile gas's fingerprint information, and is pretty suitable for pecan quality detection. However, pecan odor is comprised of complicated compositions and small differences exist among pecans with different qualities, which makes the detection difficult. In order to improve the accuracy of detection, it's essential to optimize the sensor array of E-nose during the application. In this research, an embedded E-nose based on digital signal processer (DSP) was designed for pecan detection, and 4 batches of pecans with different aging time were used for experiment. According to the existing GC-MS (gas chromatography - mass spectrometer) analysis of pecan volatile, 13 gas sensors were selected, and part of them with small response were obsoleted by analyzing the response curve of each sensor firstly. Then, 3 feature extraction methods were applied to each sensor's abstraction to generate the initial feature matrix, thus the mean differential coefficient value, stable value and response area value. After that, a series of data analysis methods were applied to select the features with good performance and realize the optimization of array. First, features with smaller otherness were rejected by the mean analysis. Then, variation coefficient was used to remove the features with poor stability. Afterwards, the features reserved were classified through the cluster analysis based on the correlation, and the feature with the minimum redundancy in each class was selected according to the result of correlation coefficient analysis. Eventually, the degree of matrix's multicollinearity was decreased by removing the features with high value of variance inflation factor, and the optimized sensor array was chosen according to the ultimate feature matrix. To verify the validity of optimization, principal component analysis (PCA) and partial least squares regression (PLSR) were used to compare the ability of discrimination and forecast between the data before and after optimization. Results indicated that pecans different in aging time were well classified by using the optimized array. Each group of samples were clustered closely in PCA score plot, and the contribution rates of the first 2 principal components of the optimized array (they were 76.01% and 14.60%, respectively) were obviously better than that of pre-optimized array (they were 66.36% and 13.45%, respectively). Meanwhile, the result of PLSR showed that the fitting determination coefficients and root mean square error (RMSE) of the regression model based on the optimized array (R<sup>2</sup>=0.933 4, RMSE=1.452 9 d) performed better than that based on the pre-optimized array (R<sup>2</sup>=0.888 7, RMSE=2.509 2 d), and there was little difference of prediction parameters between the training set and validation set, which meant the phenomena of over-fit didn't exist and the ability of forecast was better for the optimized array. As a result, through the optimization of sensor array, E-nose can perform better in the detection of pecan's quality and reduce the dimension of data, and the research provides an efficient method for E-nose's application in various fields. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Principal component analysis
Controlled terms:Cluster analysis - Electronic nose - Fatty acids - Feature extraction - Forecasting - Gas chromatography - Least squares approximations - Matrix algebra - Mean square error - Optimization - Quality control - Regression analysis - Sensors - Signal processing - Unsaturated fatty acids
Uncontrolled terms:Determination coefficients - Electronic nose (e-nose) - Feature extraction methods - Feature matrices - Gas chromatography-mass spectrometers - Optimization of sensor arrays - Partial least squares regression - Partial least squares regressions (PLSR)
Classification code:716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 801 Chemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 913.3 Quality Assurance and Control - 921 Mathematics - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.34e+01%, Percentage 1.46e+01%, Percentage 6.64e+01%, Percentage 7.60e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.038
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 17>
Accession number:20171503569149
Title:Field experiment and seeding performance analysis of pneumatic cylinder-type precision direct seed-metering device for rice
Authors:Zhang, Shun (1); Xia, Junfang (2); Zhou, Yong (2); Wu, Delin (1); Cao, Chengmao (1); Xia, Ping (1)
Author affiliation:(1) College of Engineering, Anhui Agricultural University, Hefei; 230036, China; (2) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China
Corresponding author:Xia, Junfang(xjf@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:14-23
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the seeding performance of pneumatic cylinder-type precision direct seed-metering device for rice, the single factor and central composite experimental experiments were conducted in this paper. The effects of the main working parameters (rotational speed of seeding cylinder, vacuum degree in vacuum gas chamber, air-blowing velocity and clearing blockage positive pressure of chamber) on seeding performance of the direct seed-metering device were analyzed by means of the JPS-12 type performance test rig of metering device. The study object was "Huanghuazhan", which was pre-germinated and its moisture was 21.65%-23.73% (wet basis). Qualified rate, miss-seeding rate, replay rate, average hole distance and variation coefficient of hole distance were regarded as the performance evaluation indexes. The result of single factor experiments showed that rotational speed of seeding cylinder, vacuum degree in vacuum gas chamber and air-blowing velocity had significant influence on the qualified rate, miss-seeding rate and replay rate of metering device, respectively. The clearing blockage positive pressure of chamber had no significant influence on qualified rate, miss-seeding rate, replay rate, the average hole distance and the variation coefficient of hole distance of metering device, respectively. So, it was only necessary to provide the positive pressure chamber with suitable strength of clearing blockage positive pressure to ensure the suction hole not be blocked during the metering device working. The three-factor and five-level quadratic regression rotation design optimization experiment of the 3 influence significant factors on metering device showed that the order affecting qualified rate was rotational speed of seeding cylinder > vacuum degree in vacuum gas chamber > air-blowing velocity, and the order affecting miss-seeding was vacuum degree in vacuum gas chamber > rotational speed of seeding cylinder > air-blowing velocity. The variance analysis of experimental results had a significant affecting of experimental factors on performance evaluation indexes. Through the analysis of effect of various factors on the metering device, the seeding performance of the metering device was better under the condition of low rotational speed of seeding cylinder, high vacuum degree in vacuum gas chamber and higher air-blowing velocity. The optimal combination working parameters of metering device were seeding cylinder rotational speed with 10 r/min, vacuum degree in vacuum gas chamber with 4.6 kPa and air-blowing velocity with 21.88 m/s. All of those were obtained by optimization solution of all factors by use of quadratic regression model equation of performance evaluation indexes in the range of experimental parameters constraints. The results of verification test were consistent with the results of optimization solution. Under the condition of the optimal combination working parameters, the qualified rate, miss-seeding rate, cavity rate and replay rate were 87.73%, 2.93%, 0.53% and 9.34%, respectively. Meanwhile, the seed breakage rate was 0.91%, the average hole distance was 200.07 mm (theoretical hole distance was 200.00 mm), the variation coefficient of hole distance was 4.75%, the apiece row consistency variation coefficient of seeding quantity was 3.07%, the stability variation coefficient of the full seeding quantity was 2.08%. This seeding quality met the direct seeding requirements of hybrid rice. The field sowing experiment of the direct seed-metering device was carried out in the modern agricultural science and technology experiment base of Huazhong Agricultural University. When the average forward speed was about 1.79 km/h of direct seeder, the average vacuum degree in vacuum gas chamber was about 4.6 kPa and the average air-blowing velocity was about 21.88 m/s, the qualified rate, miss-seeding rate, cavity rate and reseeding rate were 79.42%, 15.11%, 3.88% and 5.47%, respectively. Meanwhile, the average hole distance was 175.61 mm, the variation coefficient of hole distance was 20.03%.The study provided the scientific basis for the structure and working parameter optimization of pneumatic cylinder-type precision direct seed-metering device for rice and the improvement of its seeding performance. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Air
Controlled terms:Agricultural machinery - Agriculture - Cylinders (shapes) - Experiments - Factor analysis - Gases - Pneumatic drives - Pneumatic equipment - Pneumatic materials handling equipment - Pneumatics - Regression analysis - Seed - Speed - Velocity
Uncontrolled terms:Agricultural science and technologies - Direct seeds - Experimental parameters - Optimization solution - Performance analysis - Single-factor experiments - Structure and working parameters - Variation coefficient
Classification code:632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.51e+01%, Percentage 2.00e+01%, Percentage 2.08e+00%, Percentage 2.16e+01% to 2.37e+01%, Percentage 2.93e+00%, Percentage 3.07e+00%, Percentage 3.88e+00%, Percentage 4.75e+00%, Percentage 5.30e-01%, Percentage 5.47e+00%, Percentage 7.94e+01%, Percentage 8.77e+01%, Percentage 9.10e-01%, Percentage 9.34e+00%, Pressure 4.60e+03Pa, Rotational_Speed 1.00e+01RPM, Size 1.76e-01m, Size 2.00e-01m, Velocity 2.19e+01m/s, Velocity 4.97e-01m/s
DOI:10.11975/j.issn.1002-6819.2017.03.003
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 18>
Accession number:20171503569176
Title:Adaptation of chlorella to culture liquid with different biogas slurry adding proportion and its purified effect
Authors:Wang, Zhongjiang (1); Sui, Chao (1); Wang, Zeyu (1); Wang, Lili (1); Zhang, Qi (2); Wu, Jing (1); Li, Yan (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin; 150030, China; (2) Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan; 430072, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:221-226
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This study mainly focused on the following problems like the higher cost of adding nitrogen and phosphorus in chlorella culture; the delayed and ineffective use of biogas slurry containing rich nutrient elements just as nitrogen, phosphorus, and so on after anaerobic fermentation; the easily contaminated microalgae caused by undesired microbes in microalgae culture; the higher cost of microalgae culture due to the biogas slurry pretreatments like sterilization and so forth when biogas slurry was serving as the culture medium; etc. The culture medium was the mixture of BG11 medium and biogas slurry from straw by anaerobic fermentation for 30 days. The biogas slurry fermented from straw was non-sterilized and relatively simple in composition. The algae species FACHB-5 and FACHB-8 chlorella were used. An artificial climate incubator was also used, in which the temperature for microalgae culture was kept at (26±1)℃, the light intensity was 4 000 lx, the light time was 24 hours continuously, and the ventilation volume was 1.5 L/min. In the experiment, the total nitrogen at the beginning was 180, 215 and 297 mg/L respectively in the experimental medium groups. The addition content of biogas slurry was 20%, 30% and 40% separately; and the results showed that the total nitrogen content of culture liquid was reduced to 6, 8 and 12 mg/L with the different biogas slurry treatments (20%, 30% and 40%), respectively, and the removal rate of total nitrogen was more than 96%. The total phosphorus content at the beginning was 14, 19 and 24 mg/L respectively in the experimental medium groups with the addition of biogas slurry was 20%, 30% and 40%, separately; At the end of the experiment, they reduced to less than 2 mg/L, and the removal rate of total phosphorus was more than 92%. Chemical oxygen demand (COD) content at the beginning was 4 500, 6 993 and 9 366 mg/L respectively, in the experimental medium groups with the addition of biogas slurry was 20%, 30% and 40%, and at the end of the experiment they reduced to 160, 400 and 540 mg/L respectively, the removal rate of COD was more than 90%. The experimental results showed that both FACHB-5 and FACHB-8 algae species could well adapt to biogas slurry which was relatively high in COD content from straw by anaerobic fermentation, and could well make the use of and remove the organic pollutants from biogas slurry. Compared with FACHB-5 algae species, FACHB-8 algae species needed shorter time to adapt, and had stronger adaptability to biogas slurry. What's more, there was a strong correlation between the degradation of organic pollutants and the growth of chlorella in every experimental medium group. The study may lay a theoretical foundation for the application of biogas slurry which will be directly used in microalgae culture, and may have the magnificent significance for large-scale microalgae culture. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Biogas
Controlled terms:Algae - Chemical oxygen demand - Fermentation - Growth rate - Microorganisms - Nitrogen - Nitrogen removal - Organic pollutants - Phosphorus - Pollution - Straw
Uncontrolled terms:Anaerobic fermentation - Biogas slurry - Micro-algae - Microalgae culture - Nitrogen and phosphorus - Removal rate of cods - Theoretical foundations - Total nitrogen content
Classification code:461.9 Biology - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.5 Agricultural Wastes
Numerical data indexing:Age 8.22e-02yr, Illuminance 4.00e+03lx, Mass_Density 1.20e-02kg/m3, Mass_Density 1.90e-02kg/m3, Mass_Density 2.00e-03kg/m3, Mass_Density 2.15e-01kg/m3, Mass_Density 2.40e-02kg/m3, Mass_Density 2.97e-01kg/m3, Mass_Density 4.00e-01kg/m3, Mass_Density 5.40e-01kg/m3, Mass_Density 6.99e+00kg/m3, Mass_Density 8.00e-03kg/m3, Mass_Density 9.37e+00kg/m3, Percentage 2.00e+01%, Percentage 3.00e+01%, Percentage 4.00e+01%, Percentage 9.00e+01%, Percentage 9.20e+01%, Percentage 9.60e+01%, Time 8.64e+04s
DOI:10.11975/j.issn.1002-6819.2017.03.030
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 19>
Accession number:20171503569181
Title:Design and experiment of bionic-impact type pecan shell breaker
Authors:Ding, Ran (1); Cao, Chengmao (1); Zhan, Chao (1); Lou, Shuaishuai (1); Sun, Si (1)
Author affiliation:(1) Collage of Engineering, Anhui Agricultural University, Hefei; 230036, China
Corresponding author:Cao, Chengmao(caochengmao@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:257-264
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:At present, extruding crack and centrifugal shell-breaking methods are adopted as the main strategies for pecan shell-breaking equipment. But the low production rate is hard to be improved. Meanwhile, the bad processing quality will affect the further processing, which restricts the development of the pecan processing industry. To solve such problems, this study proposed a bionic knock method, which imitated the artificial processing to shell pecan, and developed a bionic knock type shell breaker. Design and experiments were both mainly focused on the structure and parameters of the shell breaker. The paper described the overall structure of prototype and introduced the technical parameters of shell breaker, and the three-dimensional model was built by Pro/Engineer software. In this study, cell feed wheel was designed to translate pecan into feed pipe from hopper one by one like water flow, and thus the method could avoid pecans plugging the feed pipe. The bottom of the pipe was linked with shelling system, which was one of the most important parts during the study. In order to figure out a more efficient shelling method, a bionic knock structure was designed based on the particle properties and mechanical behavior of pecan rupturing under knock loading, and the mathematical model of designing the shelling system was built. The system included 3 parts: disk-cam, support point and mechanical arm. The mechanical arm could roll around the support point in a certain angle range, and through the profile curve of disk-cam, the movement of mechanical arm could be controlled to finish shelling process. The groove structure was designed, which could reduce the deformation of pecan under the knock to protect the kernel from damage, and within a few sockets on the inner wall of groove, it could change the surface load into linear load and achieve a better shell-breaking quality. According to the movement requirements of shelling system, the structure dimension of mechanical parts was built, the push movement angle of the cam was optimized by the inverse method and the practical cam profile curve was designed. What was more, the transmission system and the time sequence relationship on all the actions were both introduced, and the transmission system diagram and the one time sequence diagram on shell breaker were showed in the paper. After the physical prototype of mechanism was manufactured, the field test was performed, and 3 groups of pecans were selected. The results showed that the prototype working performance was stable and high-quality. While the rotating speed of camshaft was 52 r/min, the pecan moisture content was set nearly to 14.55%-16.35%, and the diameter volume was from 18 to 22 mm, the shell-breaking rates of the 3 test groups were 99.59%, 99.40% and 99.31% respectively, which were high, and the kernel damage rates were 5.77%, 7.00% and 6.01% respectively, which were low. The processing efficiency was also higher than the traditional shelling equipment, which could reach 95.54, 98.00 and 91.25 kg/h respectively for the 3 groups of pecans. The test performance of prototype could basically meet the production demands. The research can enrich and perfect the mechanism and method for shell-breaking of walnut, and provide the technology and equipment support to realize the mechanization of pecan processing industry. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Shells (structures)
Controlled terms:Agricultural machinery - Bionics - Cams - Curve fitting - Equipment - Experiments - Flow of water - Inverse problems - Models
Uncontrolled terms:Pecan - Processing industry - Shell breaker - Structure dimensions - Technology and equipments - Three-dimensional model - Transmission systems - Working performance
Classification code:408.2 Structural Members and Shapes - 461.1 Biomedical Engineering - 601.3 Mechanisms - 631.1.1 Liquid Dynamics - 821.1 Agricultural Machinery and Equipment - 901 Engineering Profession - 901.3 Engineering Research - 921.6 Numerical Methods
Numerical data indexing:Mass_Flow_Rate 2.53e-02kg/s, Mass_Flow_Rate 2.72e-02kg/s, Percentage 1.46e+01% to 1.64e+01%, Percentage 5.77e+00%, Percentage 6.01e+00%, Percentage 7.00e+00%, Percentage 9.93e+01%, Percentage 9.94e+01%, Percentage 9.96e+01%, Rotational_Speed 5.20e+01RPM, Size 1.80e-02m to 2.20e-02m
DOI:10.11975/j.issn.1002-6819.2017.03.035
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 20>
Accession number:20171503569171
Title:Design and experiment of wireless image sensor node with real-time adjustable resolution
Authors:Yin, Jianjun (1); Zhang, Tiemin (2); Pan, Chunhua (1); Ye, Yaowen (1); Xiao, Kehui (1); Xiao, Deqin (1)
Author affiliation:(1) College of Mathematics and Informatics, South China Agricultural University, Guangzhou; 510642, China; (2) College of Engineering, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Zhang, Tiemin(tm-zhang@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:182-189
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to overcome the problems of low and non-adjustable resolution existing in wireless images sensor nodes applied in agricultural images acquisition at present, a wireless image sensor node with real-time adjustable resolution was designed and realized in this paper. The node was composed of an image acquisition module, a processor module, a wireless communication module and a power module. The node needed to not only capture, compress, and transmit image data, but also perform multiple task schedules and network protocols, so a powerful ARM (advanced RISC machines) processor S3C6410 was chosen as the processor module of the node. Considering the cost and power consumption, a CMOS (complementary metal oxide semiconductor) type image sensor chip was chosen to design the image acquisition module of the node. The design of image acquisition module included image sensor PCB (printed circuit board) design, chip pin interface design, appropriate lens selection, and development of the sensor chip driver. In order to monitor a larger area of the crop and remotely transmit crop images, the node integrated a WiFi (wireless fidelity) or 4G (the 4th generation) module. A solar power supply system was designed to make the node work stably in the field for a long time. To ensure the stability and reliability of the node, the powerful embedded Linux operating system was employed as the software development platform, and a modular designing method was adopted to program the software system of the node in C/C++ language based on this platform. In order to realize real-time adjustment of the resolution, an algorithm of resolution real-time adjustment based on driver layer and application layer collaboration and multi-thread concurrence was proposed, and all the functions of resolution real-time adjustment of image acquisition, image compression and image transmission were realized in the application layer of software system. In order to verify the performance of the node designed, a series of tests were conducted in Cencun experimental base of South China Agricultural University and Guangdong Dongsheng Farm (Panyu) from April to September in 2016. In the tests, 7 nodes were deployed in the farmland to form an acquisition and transmission network based on WiFi and 4G technologies. To ensure the nodes work stably in the field, where the climate was changeable and the infrastructure was absent, the nodes were encapsulated in a waterproof spherical shield, and a solar panel plus rechargeable batteries was used to supply power for them. The nodes were tested from the aspects of multi-resolution capability, real-time adjustment capability, image acquisition and transmission performance (transmission time and packet loss rate), and the availability of node energy. The test results indicated that the node had 7 different resolutions and its highest resolution was up to a pixel of 5 M, and more importantly, it could adjust its resolution in real time under the control of a remote user, then capture images with different resolution, and finally transmit them to the remote server. The time consumed to capture, compress and transmit 4 images with different resolution of 640×480, 1280×1024, 2048×1536, and 2592×1944 was 4.67, 8.77, 15.38 and 22.74 s respectively, and the average transmission packet loss ratio of 4 images was less than 1%. The tests validate the node designed in this work can capture crop images with different resolution in real time and transmit them remotely, and satisfy the requirement of different users for different crop image precision. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Image compression
Controlled terms:Agricultural machinery - Agriculture - Application programs - Availability - C (programming language) - CMOS integrated circuits - Computer operating systems - Computer software - Computer vision - Concurrency control - Crops - Design - Electric power systems - Image acquisition - Image processing - Image recognition - Image sensors - Integrated circuit design - Metals - MOS devices - Network protocols - Oxide semiconductors - Packet loss - Packet networks - Pixels - Printed circuit boards - Printed circuit design - Sensor nodes - Sensors - Software design - Software reliability - Solar energy - Wi-Fi - Wireless local area networks (WLAN) - Wireless telecommunication systems
Uncontrolled terms:Adjustable resolution - CMOS (complementary metal oxide semiconductor) - CMOS image sensor - Embedded linux operating systems - Packet loss ratio - Stability and reliabilities - Wi-Fi (wireless fidelity) - Wireless transmissions
Classification code:657.1 Solar Energy and Phenomena - 706.1 Electric Power Systems - 714.2 Semiconductor Devices and Integrated Circuits - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Percentage 1.00e+00%, Time 1.54e+01s, Time 2.27e+01s
DOI:10.11975/j.issn.1002-6819.2017.03.025
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 21>
Accession number:20171503569150
Title:Development and performance experiment on grain yield monitoring system of combine harvester based on photoelectric diffuse reflectance
Authors:Fu, Xinglan (1, 3); Zhang, Zhaoguo (1); An, Xiaofei (2, 3, 4); Zhao, Chunjiang (2, 3, 5); Li, Chenyuan (1); Yu, Jiayang (1, 3)
Author affiliation:(1) Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming; 650000, China; (2) National Research Center of Intelligent Equipment for Agriculture, Beijing; 100097, China; (3) Beijing Research Center of Intelligent Equipment for Agriculture, Beijing; 100097, China; (4) Beijing Key Laboratory of Intelligent Equipment Technology for Agriculture, Beijing; 100097, China; (5) Key Laboratory of Agri-informatics, Ministry of Agriculture, Beijing; 100097, China
Corresponding author:Zhang, Zhaoguo(zhaoguozhang@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:24-30
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Development of remote sensing (RS), geographical information system (GIS) and global positioning system (GPS) has provided new methods for obtaining field grain yield information, which allows better description of spatial variability for grain yield. Monitoring grain yield has become an essential component in precision agriculture, which provides better guidance for grain growth and management such as variable fertilizing, irrigating and spraying. In order to further improve the monitoring accuracy of grain combine harvester, a new real-time grain yield monitoring system based on photoelectric principle was developed in this study. The system was composed of sensor module, grain yield data acquisition module, GPS module and grain yield display terminal. The sensor module included diffuse reflectance grain volume senor as key component of the system and rotating speed sensor of elevator. A model of grain mass on the scraper was established based on optical principle of photoelectric diffuse reflection effect and grain kinematic principle. Prediction model and diffuse reflectance grain yield monitoring software were embedded in the grain yield display terminal. When the elevator scraper of the combine harvester with the grain passed the diffuse reflectance grain volume sensor, the light path would be blocked intermittently. As a result, the corresponding pulse signal would be generated and meanwhile the elevator's rotating speed sensor would output the rotating speed signal. According to photoelectric principle, the size of pulse signal was proportional to the thickness of grain on the scraper. Subsequently the grain yield data acquisition module converted sensor signals into standard signals, and grain yield information including real-time grain yield and total yield, elevator rotating speed, combine harvester speed, harvest area, and longitude and latitude would be obtained and displayed on the terminal. In order to evaluate the performance of the grain yield monitoring system, both laboratory platform experiment and field dynamic experiment were conducted. For the platform experiment, an experiment platform was designed, which was composed of LED (light-emitting diode) terminal, diffuse reflectance grain volume sensor, grain inlet, elevator, elevator's rotating speed sensor and motor. The result of platform experiment showed that the rotating speed sensor of elevator had the maximum error of 1.87%, which was less than 2.00%, and the maximum standard deviation of 2.33 r/min, which indicated the sensor had a small discrete degree; the diffuse reflectance grain volume sensor had the maximum error of 3.14%, which was less than 3.50%, and both the accuracy and the stability satisfied the requirements. Field dynamic experiment included 3 parts: field experiment without loading, model calibration experiment and field experiment of wheat yield. The field experiment without loading showed that the pulse signal intensity of diffuse reflectance grain volume sensor decreased with the elevator's rotating speed increasing, the determination coefficient (R<sup>2</sup>) of output curve was 0.941 1, and the measurement error was within 4.00%. For the model calibration experiment, domestic TB60 type combine harvester was calibrated to obtain the calibration factor of 0.071, and the relationship between grain mass and thickness was gotten. The field wheat yield experiment showed that the grain yield monitoring system based on photoelectric principle was maximum error of 3.51%, which was smaller than the double-plate differential method. The system offered a wide range of grain feeding quantity and satisfied the need of field grain yield monitoring. The research provides a new method to monitor real-time grain yield, and the system is applicable to domestic mainstream models of combine harvester in China. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Grain (agricultural product)
Controlled terms:Data acquisition - Elevators - Errors - Geographic information systems - Global positioning system - Grain growth - Harvesters - Light emitting diodes - Monitoring - Photoelectric devices - Photoelectricity - Reflection - Remote sensing - Rotating machinery - Sensors - Speed - Tools
Uncontrolled terms:Combine harvesters - Data acquisition modules - Determination coefficients - Performance experiment - Photoelectric principle - Precision Agriculture - Rotating speed sensors - Yield monitor systems
Classification code:601.1 Mechanical Devices - 692.2 Elevators - 701.1 Electricity: Basic Concepts and Phenomena - 714.2 Semiconductor Devices and Integrated Circuits - 723.2 Data Processing and Image Processing - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 903.3 Information Retrieval and Use - 933.1.2 Crystal Growth
Numerical data indexing:Percentage 1.87e+00%, Percentage 2.00e+00%, Percentage 3.14e+00%, Percentage 3.50e+00%, Percentage 3.51e+00%, Percentage 4.00e+00%, Rotational_Speed 2.33e+00RPM
DOI:10.11975/j.issn.1002-6819.2017.03.004
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 22>
Accession number:20171503569183
Title:Detection of paddy mildew degree based on computer vision
Authors:Pan, Leiqing (1); Wang, Zhenjie (1); Sun, Ke (1); Jia, Xiaodi (1); Du, Lihui (2); Yuan, Jian (2); Tu, Kang (1)
Author affiliation:(1) College of Food Science and Technology, Nanjing Agricultural University, Nanjing; 210095, China; (2) College of Food Science and Engineering, Nanjing University of Finance and Economics, Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing; 210023, China
Corresponding author:Tu, Kang(kangtu@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:272-280
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to realize non-destructive testing of moldy paddy during storage, the present study developed a computer vision system for laboratory analysis. Five kinds of fungi which mainly caused paddy mildew, including Aspergillus oryzae, Aspergillus nige, Aspergillus nidulans, Penicillium citrinum and Aspergillus versicolor, were used as research objects. Five fungi were cultured and prepared as suspension, which was then inoculated into paddy samples. Paddy was stored in the condition of 30 ℃ and 90% relative humidity to speed up the mildew. According to the mildewing degree, paddy was divided into 3 groups, i.e. control (no mildew), slight mildew and severe mildew. Computer vision system was used for image acquisition of 3 groups of paddy samples. A total of 120, 600 and 600 images of paddy samples were obtained for the groups of control, slight mildew and severe mildew, respectively. After image processing, gray scale, color in the color space of RGB (red, green, blue) and texture features (i.e., angular second moment, energy, contrast, entropy) were extracted using gray level co-occurrence matrix with a total of 68 parameters acquired. SVM (support vector machine) and PLS-DA (partial least squares - discriminant analysis) were used to build the discriminating models for paddy mildew and mildew type. To reduce the complexity of the model and the data redundancy, successive projections algorithm (SPA) was used to eliminate collinearity among the 68 characteristic variables. Then, 11, 13 and 14 optimal features were determined for the classification of moldy paddy, fungus type of slightly moldy paddy and fungus type of severely moldy paddy, respectively. The results showed that, using all the extracted features, SVM models could accurately distinguish between the control group and the mildew group of paddy, which got an overall classification accuracy of 99.7% and 98.4% for modeling and validation set, respectively; SVM models presented better distinguishing performance for paddy's severe mildew type than slight mildew type; concerning paddy's severe mildew type, the overall classification accuracy was 100% and 94% for modeling and validation set, respectively, and concerning paddy's slight mildew type, the overall classification accuracy reached 99.3% and 92% for modeling and validation set, respectively. As a whole, SVM model obtained higher accuracy than PLS-DA. Based on the preferred feature selected by SPA, SVM models still distinguished better than PLS-DA models for paddy's mildew. For modeling and validation set, the accuracies were respective 99.8% and 99.5% for the discrimination between no mildew and mildewing paddy, 99.8% and 90.5% for the discrimination among paddy's slight mildew type, and 100% and 95.0% for the discrimination among paddy's severe mildew type. Therefore, the computer vision technique is feasible for paddy's mildew detection; the preferred features determined by SPA can well reflect paddy mildewing features. Using the preferred features, SVM models are able to identify and distinguish paddy mildew with satisfactory results, which can provide technical support for practical application. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Fungi
Controlled terms:Aspergillus - Color - Computer vision - Digital storage - Discriminant analysis - Error detection - Feature extraction - Image processing - Least squares approximations - Models - Nondestructive examination - Support vector machines
Uncontrolled terms:Classification accuracy - Computer vision techniques - Gray level co-occurrence matrix - Mildew - Paddy - Partial least squares - discriminant analysis - Successive projections algorithms (SPA) - SVM(support vector machine)
Classification code:461.9 Biology - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 741.1 Light/Optics - 741.2 Vision - 921.6 Numerical Methods - 922 Statistical Methods
Numerical data indexing:Percentage 1.00e+02%, Percentage 9.00e+01%, Percentage 9.05e+01%, Percentage 9.20e+01%, Percentage 9.40e+01%, Percentage 9.50e+01%, Percentage 9.84e+01%, Percentage 9.93e+01%, Percentage 9.95e+01%, Percentage 9.97e+01%, Percentage 9.98e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.037
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 23>
Accession number:20171503569168
Title:Characteristics of sediment deposition in check dam in small watershed in Loess Hilly Area
Authors:Li, Mian (1); Yang, Er (1); Li, Ping (2); Bao, Hongzhe (1); Li, Li (1); Shen, Zhenzhou (1); Jiao, Peng (1)
Author affiliation:(1) Yellow River Institute of Hydraulic Research, Key Laboratory of Soil and Water Loss Process and Control on the Loess Plateau of the Ministry of Water Resources, Zhengzhou; 450003, China; (2) Suide Soil and Water Conservation Scientific Experimental Station, Yellow River Conservancy Commission, Suide; 718000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:161-167
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As one of engineering measures for conserving soil and water, many check dams have been constructed on the Loess Plateau and played important roles in holding back eroded soil just like sediment ponds. Meanwhile, a lot of information on the erosion and sediment yield is recorded and preserved in the check dams. Understanding the sedimentary characteristics is an essential prerequisite for studying the sediment transport processes and laws for a watershed with check dams. A typical check dam without spillway located in the top of a branch gully in the Wangmaogou watershed in the Loess Hilly Area was selected for this study. In the check dam, 8 open test pits with a depth of 1.5-2.0 m were dug in the longitudinal section and cross section. The boundaries between sedimentation cycles were obvious, and the thickness of each sedimentary cycle and plough layer was measured. A total of 108 soil samples were collected from the 8 open test pits in the check dam. The plough layer was divided into upper (0-20 cm) and lower layers (below the depth of 20 cm). The soil samples were analyzed with the laser diffraction technique using a Mastersizer 2000 laser particle size analyzer, and the soil particle size fractions were determined. Based on the investigation on the sedimentary cycle thickness and particle size composition changes in different deposition profiles in the check dam in the study watershed, the redistribution characteristics of sediment deposition of each flood in the dam were studied. The results showed that the sediment deposition process in the dam had non-uniform distribution, and the differences of the sedimentary cycle thickness in both the longitudinal section and the cross section were obvious, and the fluctuation of early sedimentary cycle thickness was larger than that in the late years. When the rainstorm and sediment yield were large, the sediment thickness was larger and the difference was also large. On the contrary, the sediment thickness and the difference were relatively small. Thus, there was no relationship between the sediment thickness and the soil particle composition in the check dam. The average contents of clay, silt and sand were 4.66%, 58.78% and 36.56%, respectively, and the silt was the main sand size. The change of clay, silt and sand content in each vertical section in the dam was little, but in different locations in the check dam, the size classification occurred. From the tail to the head of the check dam, soil coarsening degree decreased significantly, and the soil particle size composition showed a gradual trend of fining. The mutations of particle size composition occurred in several sedimentary cycles, which had the indicative function on the occurrence of big rainstorm and flood. Combined with precipitation, sediment, topography in this watershed, it can help to reveal the dynamic processes of the flood. To better understand the sediment deposition process and distribution, more research is needed. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Sediments
Controlled terms:Dams - Deposition - Floods - Landforms - Particle size - Particle size analysis - Sediment transport - Sedimentology - Silt - Soil conservation - Soil surveys - Soil testing - Soils - Storms - Watersheds
Uncontrolled terms:Check dam - Hilly areas - Laser particle size analyzer - Sediment transport process - Sedimentary characteristics - Sedimentary cycles - Soil particle-size fractions - Soil textures
Classification code:441.1 Dams - 443.3 Precipitation - 444.1 Surface Water - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 951 Materials Science
Numerical data indexing:Percentage 3.66e+01%, Percentage 4.66e+00%, Percentage 5.88e+01%, Size 0.00e+00m to 2.00e-01m, Size 1.50e+00m to 2.00e+00m, Size 2.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.03.022
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 24>
Accession number:20171503569173
Title:Method for wetland type extraction using remote sensing combing object-oriented and tasseled cap transformation
Authors:Luo, Kaisheng (1, 2); Tao, Fulu (1)
Author affiliation:(1) Key Laboratory for Surface Patter and Processes, Institute of Geographical Sciences and Natural Resources, Chinese Academy of Sciences, Beijing; 100101, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Tao, Fulu(taofl@igsnrr.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:198-203
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wetland is one of the most important ecosystems, and it has high social benefit, economic benefit and scientific research value. However, wetland resources are bearing a heavy pressure because of various natural and anthropogenic factors. The degradation of the wetland quality and quantity has aroused widespread concerns. To conserve and manage wetland resources, it is important to monitor wetlands and their adjacent uplands. Satellite remote sensing has several advantages, such as wild coverage, saving time and labor, multi-temporal, multi-platform, containing a large amount of information, and so on, when monitoring wetland resources especially in large geographic areas. In early work, the satellite imagery used the visual interpretation for classification, which is still used widely today. The most commonly used computer classification methods are unsupervised classification and supervised classification. However, it is difficult to make great progress on improving the accuracy of remote sensing classification because of "different things with the same spectrums" in wetlands. Spectrum confusion among wetlands seriously restricts the extraction of wetland information and the application of remote sensing technology in the monitoring of the wetland. But the traditional pixel-based methods cannot overcome this difficulty because it only used the spectral features of imagery, ignoring other information that the remote sensing imagery carries, although it has been universally applied in land cover information extraction for many years. In order to over this difficulty and promote the application of remote sensing technology in dynamic monitoring of wetland, a new hybrid classification approach for wetland was proposed in this paper, which combined the object-oriented technology and the tasseled cap transformation method. The new proposed approach was further checked by a case study of wetland extraction based on the HJ-CCD and Landsat ETM (enhanced thematic mapper) remote sensing images in 2010 in the eastern Dongting Lake region. We yielded a better classification result using the new approach. The overall accuracy was 90.02% and the Kappa coefficient was 0.88, which were much higher than that of the traditional pixel-based methods. Meanwhile, this method significantly reduced the disturbance of salt-and-pepper noise, and the results were quite compact and smooth compared with that using other traditional classification methods. A higher accuracy was obtained for the proposed approach for vegetation wetlands including wood wetland, shrub wetland and grass wetland, which was attributed to the full mining of imagery spectral information through the tasseled cap transformation. The accuracy of the hybrid approach was much higher than that of others for river, channel, reservoir and lake whose spectrums were extremely similar. This was mainly because the object-oriented technology could fully utilize spatial and shape information of imagery. Hence, according to the experiment results, the proposed approach combing the object-oriented technology and the tasseled cap transformation is an effective method in wetland extraction using the remote sensing technology and can overcome the difficulty of spectrum similarity, which is mainly attributed to making full use of spatial feature on the basis of exploring the spectral features through the tasseled cap transformation. Meanwhile, we can conclude that Chinese HJ-CCD images are an important data source for monitoring the dynamics of wetland. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Remote sensing
Controlled terms:Classification (of information) - Data mining - Economic and social effects - Image processing - Image reconstruction - Lakes - Pixels - Reservoirs (water) - Satellite imagery - Wetlands
Uncontrolled terms:Enhanced thematic mappers - HJ-CCD imagery - Object oriented technologies - Remote sensing classification - Remote sensing technology - Supervised classification - Tasseled cap transformation - Unsupervised classification
Classification code:441.2 Reservoirs - 655.2 Satellites - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 971 Social Sciences
Numerical data indexing:Percentage 9.00e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.027
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 25>
Accession number:20171503569154
Title:Influence of water admission through main shaft central hole on performance of Francis turbine draft tube
Authors:Feng, Jianjun (1); Li, Wenfeng (1); Xi, Qiang (1); Zhu, Guojun (1); Luo, Xingqi (1)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an; 710048, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:58-64
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Low load operation of hydropower station refers to an abnormal working condition in which a hydraulic turbine operates under small guide vane opening. If the turbine operates under low load condition for a long time, it will affect not only the performance of the turbine, but also the stability of the whole power station and even the power system. Practice shows that, when operating under low load condition, the rotating eccentric vortex causes strong pressure fluctuation and vibration to appear in the draft tube, and threatens the safety of the plant. Generally, injecting air to draft tube is one of the most widely used methods to improve pressure fluctuation at present, but it may cause some acoustic effects. This paper proposes a method of injecting high pressure water from the runner cone to reduce the instability in the draft tube of a Francis turbine. The method does not need to modify the runner's geometry, or add any equipment in the draft tube. In order to verify the feasibility of this method, three-dimensional unsteady numerical simulations of a Francis turbine under low load conditions in a power plant were carried out accurately. The results indicated that there obviously existed an eccentric vortex in the draft tube under part load conditions in the investigation, accompanied by large amplitude pressure fluctuation. The CFD (computational fluid dynamics) results on turbine performance in hydraulic efficiency were observed to be in good agreement with the experiment results. According to the above results, the CFD numerical simulation was further applied to verify the technical effect of high pressure water supply in draft tube. The main research results could be summarized as follows. Firstly, the method of injecting high pressure water to draft tube could effectively reduce the energy loss of the flow in the draft tube, and the loss reduced with the increase of the amount of water admission. However, excessive water admission would not only decrease the turbine efficiency due to the increase of the jet efficiency loss, but also cause pressure reduction on runner blades, which can affect the cavitation performance of the Francis turbine. Therefore, the amount of water admission must be considered synthetically. For the current situation, the water admission should not exceed 5% of the inlet flow rate. Secondly, previous studies showed that the pressure fluctuation caused by the spiral vortex was related to the sharp decrease of the axial velocity of the runner. Therefore, injecting high pressure water to draft tube could increase the axial velocity at the outlet of the runner, and the increase of the axial velocity could change the distribution of velocity field in the vortex rope, which could effectively eliminate the backflow phenomenon, but the inhibition of backflow was not obvious when the amount of water admission was too small. Thirdly, when the water admission was 1% of the inlet flow rate (0.488 m<sup>3</sup>/s) in this condition, there was no obvious improvement because the fluctuation amplitude changed slightly. When the water admission was increased to 3% of the inlet flow rate, the vortex shape in the draft tube changed from double-helix to single helix, and the amplitude of pressure fluctuation in the draft tube increased rather than decreased, and thus the instability of the flow in the draft tube increased. When increasing the water admission further to 5% of the inlet flow rate, the amplitude of pressure fluctuation in the draft tube decreased sharply from 18.4% to 1.63%. At the same time, the main frequency of the pressure fluctuation was also changed, which was helpful for avoiding the resonance and improving the stability of the unit. In short, it is feasible and effective to inject high pressure water from the runner cone to the draft tube of the Francis turbine, which can improve the flow field in the draft tube and reduce the instability of the draft tube. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Hydraulic turbines
Controlled terms:Acoustics - Computational fluid dynamics - Computer simulation - Convergence of numerical methods - Energy dissipation - Fighter aircraft - Flow rate - Francis turbines - High pressure effects - Hydraulic machinery - Hydraulic motors - Inlet flow - Models - Numerical methods - Numerical models - Rock drills - Stability - Tubes (components) - Turbine components - Turbomachine blades - Velocity - Vortex flow - Water supply
Uncontrolled terms:CFD (computational fluid dynamics) - CFD numerical simulations - Distribution of velocity - Effect of high pressure - Pressure fluctuation - Runner - Unsteady numerical simulations - Vibrations
Classification code:446.1 Water Supply Systems - 525.4 Energy Losses (industrial and residential) - 617 Turbines and Steam Turbines - 617.1 Hydraulic Turbines - 619.1 Pipe, Piping and Pipelines - 631 Fluid Flow - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 652.1.2 Military Aircraft - 723.5 Computer Applications - 751 Acoustics, Noise. Sound - 921 Mathematics - 921.6 Numerical Methods
Numerical data indexing:Percentage 1.00e+00%, Percentage 1.84e+01% to 1.63e+00%, Percentage 3.00e+00%, Percentage 5.00e+00%
DOI:10.11975/j.issn.1002-6819.2017.03.008
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 26>
Accession number:20171503569188
Title:Effects of flour characteristics of different wheat cultivars on quality of frozen cooked noodles
Authors:Pan, Zhili (1, 2); Tian, Pingping (1); Huang, Zhongmin (1, 4); Wang, Na (1, 4); Suo, Biao (1, 4); Ai, Zhilu (1, 3)
Author affiliation:(1) College of Food Science and Technology, Henan Agricultural University, Zhengzhou; 450002, China; (2) College of Food Science, Northeast Agricultural University, Harbin; 150030, China; (3) Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou; 450002, China; (4) Henan Engineering Research Center for Cold-chain Food, Henan Agricultural University, Zhengzhou; 450002, China
Corresponding author:Ai, Zhilu(zhilafood@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:307-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The purpose of this study was to investigate the relationship between wheat flour quality and texture characteristics of frozen cooked noodles for different wheat cultivars. Thirty kinds of winter wheat flours in Henan Province were collected as the experimental material. The content of protein was studied with the FOSS 2300 automatic Kjeldahl apparatus and the rheology properties and RVA indices were also determined. The texture indices were measured after the flour was made into frozen cooked noodles. Relationships between the wheat flour variety and the texture properties of frozen cooked noodles were investigated by descriptive statistics, principal component analysis (PCA) and hierarchical cluster analysis (HCA). The results showed that hardness was very significantly associated with wet gluten, pasting temperature, degree of softening and farinograph quality number (P<0.01). Firmness was very significantly associate with protein, wet gluten, starch, final viscosity, setback, pasting temperature, water absorption, dough stability, dough development, degree of softening, farinograph quality number, area of drawing curve, extensible resistance and maximum resistance (P<0.01). Breaking strength was significantly associated with all the qualities of flour except breakdown, peak time and extensibility (P<0.01). Based on the scree plot and the contribution rate of variance, 5 principal components were extracted by the principal component analysis, which could reflect 84.023% of the information of original variables. According to the principle of 0.5, the first factor dominated farinogram stability time, development time, degree of softening, farinogram quality index, tensile curve area, the maximum tensile resistance, tensile resistance, tensile ratio and the maximum tensile ratio, which showed a strong positive correlation. The second factor dominated starch, peak viscosity, final viscosity, low viscosity, setback value and peak time. The third index included protein content, wet gluten and extensibility. The forth factor dominated starch, breakdown, peak time and water absorption. The fifth factor dominated amylose content and pasting temperature. HCA classified 30 varieties into 4 main groups on the basis of the measured parameters, which was consistent with the result of PCA score plots. Among the wheat flours of the first and second groups, the starch content, tensile resistance, the maximum tensile resistance, tensile ratio, the maximum tensile ratio and dough formation time were smaller, while the peak viscosity, low viscosity, final viscosity and setback, protein, wet gluten content, amylose and elongation of frozen cooked noodles were slightly larger. The texture indices were larger and the sensory score was higher in the frozen cooked noodles. Seen from the quality index of wheat flour, texture index and sensory score of frozen cooked noodle, we can find that the flour raw material for making frozen cooked noodles cannot be selected only by the index data of wheat flour and texture data of noodles, and the effect of sensory evaluation should also be considered. The result can provide some theoretical basis for the selection and processing of wheat varieties. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Principal component analysis
Controlled terms:Cluster analysis - Cyclodextrins - Hierarchical systems - Open source software - Plants (botany) - Proteins - Quality assurance - Quality control - Starch - Viscosity - Water absorption - Water quality
Uncontrolled terms:Descriptive statistics - Experimental materials - Flour quality - Hierarchical cluster analysis - Positive correlations - Principal Components - Quick frozen cooked noodle - Wheat varieties
Classification code:445.2 Water Analysis - 631.1 Fluid Flow, General - 723 Computer Software, Data Handling and Applications - 802.3 Chemical Operations - 804.1 Organic Compounds - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics - 961 Systems Science
Numerical data indexing:Percentage 8.40e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.042
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 27>
Accession number:20171503569157
Title:Wetting state and dynamic spreading behavior of alkyl polyglycoside drop on cucumber leaf surface
Authors:Zhang, Hongtao (1); Lu, Jun (2); Wei, Deyun (2); Hu, Yuxia (3)
Author affiliation:(1) Institute of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou; 450011, China; (2) Jiyang College of Zhejiang A&F University, Zhuji; 311800, China; (3) School of Electrical Engineering, Zhengzhou University, Zhengzhou; 450001, China
Corresponding author:Lu, Jun(lujun12404@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:81-87
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Improving the wettability of spraying liquid on the target crop surface is one of the effective ways for enhancing the utilization efficiency of pesticide. When the spray liquid reached the surface of target crop, will occur series dynamic process including deposition, retention, spread, penetration, etc. These behaviors of dynamic wetting will decide spraying liquid how to transfer to biological organisms, and make directly influence of the pesticide. As entering the 21st century, the dynamic wetting behavior of liquid on target interface has become a very active research direction in the pesticide application field, which is one of the important research contents of precision spraying technology. Alkyl Polyglycoside (APG) is recognized as an internationally preferred green functional surfactant, it has attracted special attention because of its high surface activity and ecological security. In recent years, more and more domestic and foreign researchers have done a lot of work in improving APG pesticide additives, which focusing on the preparation, modification and its synergism mechanism, and achieved obvious achievements. In order to investigate the dynamic wetting behavior of APG additive solution on the cucumber leaf surface and its change of dynamic contact angle, APG solution of 9 mass fraction (14.35%-85.78%) and their dynamic wetting parameters which includes surface tension (γ), contact angle (θ), dynamic contact angle (θ<inf>d</inf>), advancing contact angle (θ<inf>a</inf>), receding contact angle (θ<inf>r</inf>), spreading diameter (Φ) were measured by using surface tension and contact angle measuring instrument based on hanging drop method and sessile drop method. The contact angle hysteresis and spreading driving force are analyzed and deduced based on Tanner rule, and the relationship curve between spreading diameter (Φ), power value (α) and time (t) were fitted by the application of the power law. With digital image processing technology, the process of dynamic wetting was recorded by CCD camera and their dynamic wetting parameters were obtained and extracted from drop images features. The results showed that these 9 APG solutions' surface tension were within a narrow range from 27.96 to 29.73 mN·m<sup>-1</sup>, but their contact angle were varied from 11.35° to 34.20° in a wide range. It indicated contact angles did not change radically with the increasing concentration of APG solution. As a kind of easily wetting leaves, advancing contact angle (θ<inf>a</inf>) of deionized water drop on cucumber leaf surface increased by 7.54°, while receding contact angle (θ<inf>r</inf>) decreased by 22.85°, its contact angle hysteresis (Δθ) is 46.89° within 10 s. The dynamic wetting process reflects the interface behavior of cucumber leaves accords with the basic law of rough surface contact angle hysteresis. Dynamic contact angle of APG solution of different mass fraction on cucumber leaf surface fell sharply in the first 1 s, then decreased steadily and gradually tended to be stable (1-10 s). The relationship between the spreading diameter (Φ) and time (t) were better conformed to the power law. The power value of APG solution fitting curves were within the range from 0.01 to 0.08, the coefficient C were between 2.787 3 and 3.567 3, the APG solution of lower concentration showed a higher fitting degree. It can be inferred that the dynamic surface tension is the dominant spreading driving force on cucumber leaf surface (interface). This paper provides theoretical basis and technical support for pesticide spraying with cucumber as target crop and APG as adjuvant. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Wetting
Controlled terms:Additives - CCD cameras - Contact angle - Crops - Curve fitting - Deionized water - Drops - Hysteresis - Image processing - Liquids - Pesticides - Rolling resistance - Surface active agents - Surface tension
Uncontrolled terms:Advancing contact angle - Contact angle hysteresis - Digital image processing technologies - Dynamic surface tensions - Dynamic wetting - Pesticide applications - Rough surface contacts - Utilization efficiency
Classification code:445.1 Water Treatment Techniques - 714.2 Semiconductor Devices and Integrated Circuits - 803 Chemical Agents and Basic Industrial Chemicals - 818.5 Rubber Products - 821.4 Agricultural Products - 921.6 Numerical Methods - 931.2 Physical Properties of Gases, Liquids and Solids - 961 Systems Science
Numerical data indexing:Percentage 1.43e+01% to 8.58e+01%, Surface_Tension 2.80e-02N*m to 2.97e-02N*m, Time 1.00e+00s, Time 1.00e+00s to 1.00e+01s
DOI:10.11975/j.issn.1002-6819.2017.03.011
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 28>
Accession number:20171503569158
Title:Design and test of attitude stabilization control system of multi-rotor unmanned aerial vehicle applied in farmland information acquisition
Authors:Liao, Yihua (1); Zhang, Tiemin (1); Lan, Yubin (2)
Author affiliation:(1) Key Laboratory of Key Technology for South Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China; (2) National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou; 510642, China
Corresponding author:Zhang, Tiemin(tm-zhang@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:88-98
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Farmland information acquisition is the basis of precision agriculture. Multi-rotor unmanned aerial vehicle (UAV) can obtain farmland information quickly, efficiently and accurately. But as an under actuated system, the flight stability of multi-rotor UAV is susceptible to natural wind, electromagnetic interference and the near surface factors in farmland environment. The flight stability control method is important in multi-rotor UAV flight and affects qualified information acquisition. In this paper, multi-rotor UAV was adopted as research object and its body coordinate system and navigation coordinate system were established. Based on its motion analysis, changing 4 motors speed can realize multi-rotor UAV attitude regulation. The multi-rotor UAV platform consisted of brushless motors, electric speed controllers and composite-fiber fabric propellers. The flight control system was designed based on STM32F407 as master controller, MPU6050 as motion sensor integrated with 3-axis accelerometer and 3-axis gyroscope, AK8975 as 3-axis magnetometer. The attitude of multi-rotor UAV was measured and computed by the sensors above. The timers in the controller were used for capturing the input signals from remote control and generating PWM output signals for motors control. Multiple tasks including attitude measurement remote control input process, attitude stabilization management and motors control output were scheduled by task scheduling method in the control system. The mathematical model of multi-rotor UAV attitude control was established. Through matrix calculation, the multi-rotor UAV attitude angle and throttle control inputs were mapped to each motors speed control. Then the control principle applied in this study was explained. The double closed-loop proportional integral differential (PID) control strategy with angular velocity as the inner feedback loop and angle as the outer feedback loop was proposed. A multi-rotor UAV experimental platform was built to gain the proper PID control parameters of inner and outer control loops through engineer debugging method. The double closed loop PID control method was further improved by expert control strategy. The expert control rules included throttle input ratio definition, angle and angular velocity integration limitation, angle differential control parameter variation, input and output control limitation. By introducing the expert rules, the control parameters were diverse to be adapted to the multi-rotor UAV attitude change. Anti-interference tests and step response tests were taken to testify the designed control system on the experimental platform. In the traditional PID control, when interference angle increased, the rise time and the adjustment time of the system increased. But under the effect of variable derivative, when the interference angle became large, the rise time did not increase. The rise time of the system was less than 0.27 s. When the system was subjected to 30° interference angle, the adjustment times for roll angle, pitch angle and yaw angle restored to balance were less than 3.4 and 4 s respectively. In the step response tests, rise time, maximum overshoot, adjustment time and oscillation frequency of the system were recorded. According to the statistics, the maximum adjustment times for roll angle, pitch angle and yaw angle were less than 2.2 s and 3.4 s respectively. It proved that the double closed-loop PID expert control strategy adopted in this paper made the multi-rotor UAV have quick response, small fluctuation and stable control performance. Rice breeding base was chosen as outdoor farmland circumstance to test the multi-rotor UAV attitude control performance. Because the multi-rotor UAV flight cannot avoid wind interference in outdoor, higher inner loop proportion value, outer loop proportion and differential value in roll and pitch control made the multi-rotor UAV more agile, responsive to control input and stronger resistance to wind disturbance. In the outdoor farmland flight tests, the collected information were sent to computer through wireless data transmission and were stored and analyzed in computer. From the experiment results, it could be concluded that the multi-rotor UAV can regulate its motors speed in a short while and adjust its attitude according to the remote control input in 1-2 s. When the multi-rotor UAV flight control was disturbed by wind, the angular velocities measured by gyroscope were larger than 3 (°)/s, the control strategy made the multi-rotor UAV automatically adjust its attitude to keep stable flight and effectively resist to the wind disturbance. It proved that the control strategy designed in this research is suitable for multi-rotor UAV applied in farmland information acquisition. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Flight control systems
Controlled terms:Aircraft control - Angular velocity - Attitude control - Closed loop control systems - Control systems - Controllers - Electric machine control - Electromagnetic pulse - Farms - Feedback - Flight dynamics - Gyroscopes - Interference suppression - Proportional control systems - Remote control - Scheduling - Speed control - Stabilization - Step response - Three term control systems - Two term control systems - Unmanned aerial vehicles (UAV) - Vehicles
Uncontrolled terms:Attitude stabilization - Flight experiments - Information acquisitions - Oscillation frequency - PID controllers - Proportional integral differential control - Under-actuated systems - Wireless data transmission
Classification code:652 Aircraft and Avionics - 652.1 Aircraft, General - 701 Electricity and Magnetism - 731 Automatic Control Principles and Applications - 732.1 Control Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 912.2 Management
Numerical data indexing:Time 1.00e+00s to 2.00e+00s, Time 2.20e+00s, Time 2.70e-01s, Time 3.40e+00s, Time 4.00e+00s
DOI:10.11975/j.issn.1002-6819.2017.03.012
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 29>
Accession number:20171503569147
Title:Quantitative estimation on straw nutrient resources and emission of pollutants from straw burning in Beijing-Tianjin-Hebei region
Authors:Fang, Fang (1); Wang, Fei (2); Shi, Zuliang (2); Zheng, Xiangqun (3); Shao, Yuhang (4); Li, Xiang (2); Qiu, Ling (1)
Author affiliation:(1) College of Agronomy, Northwest A&F University, Yangling; 712100, China; (2) Rural Energy and Environment Agency, Ministry of Agriculture, Beijing; 100125, China; (3) Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin; 300191, China; (4) College of Agriculture, Nanjing Agricultural University, Nanjing; 210095, China
Corresponding author:Qiu, Ling(QL2871@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:1-6
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China is a vast agricultural country which produces a large amount of crop straw. If the crop straw was used irrationally, the airborne pollutant concentration would increase, and the soil moisture and organic matter content would reduce. It does harm to ecological environment. Beijing-Tianjin-Hebei region is the political, economic and cultural center of China and plays an essential role in the development of social economy of China. There are severe environment problems occurring in this region such as smog happening frequently. Burning of crop straw is concerned to be one of the main reasons for the smog in this region. The research of crop straw resource was carried out in the Beijing-Tianjin-Hebei region aimed to promote the comprehensive utilization of crop straw. The production and utilization of crop straw resources and their application potential were evaluated and analyzed. Furthermore, the emission characteristics of gaseous pollutants generated from open burning of major crop straw in the region were quantitatively estimated that. The results showed that the theoretical amount of crop straw in the Beijing-Tianjin-Hebei region was 5.4×10<sup>7</sup>t in 2012, and the main crop species were corn and wheat straw. Crop straw resources could be used as high quality fertilizer with high contents of nitrogen (N), phosphorus (P) and potassium (K), and the amounts were 3.7×10<sup>4</sup>, 7.4×10<sup>4</sup>and 1.0×10<sup>6</sup>t for N, P and K respectively. Straw returned to field was the major utilization method for crop residue in the Beijing-Tianjin-Hebei region. However, the returned amounts were accounting for 67.7%, 27.3% and 61.2% of the total crop residue amounts in Beijing, Tianjin and Hebei respectively. Interestingly, the returned amount of wheat residue in Beijing was accounting for 94.5%, which was higher than Hebei (78.5%) and Tianjin (47.1%). The amount of wasted and burned straw accounted for 1.7%, 0.5% and 1.4% respectively in Beijing, Tianjin and Hebei. The nutrient resource such as N, P and K of crop straw returned to soil in the Beijing-Tianjin-Hebei region was 2.4×10<sup>4</sup>, 1.9×10<sup>4</sup>and 6.1×10<sup>5</sup>t, respectively. However, there was still a large amount of crop straw abandoned or open burned. Wheat and maize residue were the major crop residue open burned in the region, which accounted for 93.0% of the total straw amount open burned. In Hebei, 14.9% and 31.8% of total straw resource were abandoned and open burned respectively, while 8.2% and 5.9% in Tianjin, and 0.6% and 0.8% in Beijing. According to the statistical data, 8.7×10<sup>4</sup>t CO, 9.6×10<sup>5</sup>t CO<inf>2</inf>, 2.5×10<sup>2</sup>t NO<inf>2</inf>, 5.5×10<sup>2</sup>t NO and 8.1×10<sup>2</sup>t NO<inf>x</inf>from open burning of wheat and maize straw were emitted to atmosphere in Hebei Province, which were as three times as that in Tianjin City. Due to farmers' high cognitive level and policy of government, a very small amount of straw was open burned in Beijing, and only 1.2×10<sup>3</sup>t CO, 1.3×10<sup>4</sup>t CO<inf>2</inf>, 4.3 t NO<inf>2</inf>, 8.5 t NO and 12.8 t NO<inf>x</inf>were emitted to atmosphere due to open burning of straw. The total amounts of pollutants emitted from wheat and maize straw open burning were 1.0×10<sup>6</sup>and 4.8×10<sup>5</sup>t, respectively. According to regional straw resource endowment and utilization potential, county (township) should be the unit to develop the "5 kinds of material" technology strategy based on the local conditions. What's more, system supporting policy measures should be formulated and taken based on straw returning mechanism, use mechanism out of the field, organization and management mechanism, and technology research and development mechanism. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Crops
Controlled terms:Agricultural wastes - Agriculture - Air pollution - Carbon dioxide - Fog - Nitrogen fertilizers - Nitrogen oxides - Nutrients - Pollution - Research and development management - Soil moisture - Soil pollution - Straw
Uncontrolled terms:Beijing-tianjin-hebei regions - Comprehensive utilizations - Ecological environments - Emission characteristics - Organic matter content - Organization and management - Policy mechanisms - Quantitative estimation
Classification code:443.1 Atmospheric Properties - 451 Air Pollution - 483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research
Numerical data indexing:Percentage 1.40e+00%, Percentage 1.49e+01%, Percentage 1.70e+00%, Percentage 2.73e+01%, Percentage 3.18e+01%, Percentage 4.71e+01%, Percentage 5.00e-01%, Percentage 5.90e+00%, Percentage 6.00e-01%, Percentage 6.12e+01%, Percentage 6.77e+01%, Percentage 7.85e+01%, Percentage 8.00e-01%, Percentage 8.20e+00%, Percentage 9.30e+01%, Percentage 9.45e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.001
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 30>
Accession number:20171503569162
Title:Determination of groundwater depth-based drainage index against waterlogging and submergence for winter wheat in Jianghan Plain
Authors:Wu, Qixia (1); Zhu, Jianqiang (1, 2); Chen, Lunguo (3); Yan, Jun (1); Xu, Xiaoxiao (1)
Author affiliation:(1) College of Agriculture, Yangtze University, Jingzhou; 434025, China; (2) Hubei Collaborative Innovation Center for Grain Industry, Jingzhou; 434025, China; (3) Irrigation and Drainage Experimental Station of the Four Lake Engineering Management Bureau, Jingzhou; 434125, China
Corresponding author:Zhu, Jianqiang(zyjb@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:121-127
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Jianghanplain area is characterized by plenty of rainfall in spring, which results in frequent occurrence of waterlogging of wheat field. Subsurface waterlogging is often found in these fields. It is necessary to investigate the influence of shallow groundwater table and waterlogging followed by submergence on the growth and yield and develop a suitable groundwater depth drainage index for the waterlogged fields. In order to achieve the objectives, tube-shaped concrete facilities were used for the irrigation and drainage adjustment experiment in 2014 and 2015. Wheat was planted in the facility. The treatment of shallow groundwater table at 0, 20, 40 and 60 cm sustained 18 d and different degrees of waterlogging followed by submergence were designed. The treatments were conducted in the booting and filling stages of wheat. The flooding depth in the waterlogging treatment was kept at 5 cm. Meanwhile, the facility for wheat cultivation in soil with moisture kept at 70%-80% of water holding capacity was used as a control. The results showed when the 0-cm groundwater table sustaining 18 d at booting and filling stage could reduce wheat yield by 44.78% and 67.72%, the 20-cm groundwater table sustaining 18 d could reduce the yield by 17.31% and 33.70%, the 40-cm groundwater table sustaining 18 d decreased the yield by 10.44% and 10.34% and the 60-cm groundwater table sustaining 18 d could had higher yield than the that under 100 cm, suggesting that the groundwater table kept at 50 cm at booting and filling stage of winter wheat was suitable. The yield reduction might be due to the decrease of kernels per and thousand seed weight. The regression showed that the yield could reach 95.1%-99.8% and 89.8%-96.9% of the control when the underground water depth was 40- 50 cm, it could reach 100% of the control when the underground water depth was 50.7 and 57.1 cm and it may slightly increase when the underground water depth was 60-80 cm. The wheat suffering from the damage of waterlogging followed by submergence after anthesis caused a severe reduction in wheat yield, and the surface waterlogging had the larger influence than subsurface waterlogging on yield of winter wheat. Different types of drainage indexes including surface and subsurface waterlogging duration days, sum of waterlogging or water table within 50 cm of soil surface, sum of both flood depth and water table within 50 cm of soil surface under surface waterlogging, sum of water table within 50 cm of soil surface after draining surface water logging, and comprehensive water depth of waterlogging were evaluated. The regression between relative yield and these indexes showed that the indexes with surface and subsurface waterlogging duration days, drainage model based on time classification and comprehensive water depth of waterlogging were reliable. If the wheat yield decrease by 15% was allowed, the comprehensive water depth of waterlogging should be 275.6-283.6 cm·d after anthesis. The research may provide support for wheat drainage management in booting and filling stage in the middle and lower reaches of the Yangtze River. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Water treatment
Controlled terms:Crops - Drainage - Filling - Floods - Groundwater - Groundwater resources - Injection molding - Soils - Stages - Stresses - Surface waters
Uncontrolled terms:Ground water depths - Growth stages - Middle and lower reaches of the yangtze rivers - Shallow groundwater tables - Underground water depth - Water holding capacity - Waterlogging followed by submergence - Winter wheat
Classification code:402.2 Public Buildings - 444.1 Surface Water - 444.2 Groundwater - 445.1 Water Treatment Techniques - 483.1 Soils and Soil Mechanics - 691.2 Materials Handling Methods - 821.4 Agricultural Products
Numerical data indexing:Percentage 1.00e+02%, Percentage 1.03e+01%, Percentage 1.04e+01%, Percentage 1.50e+01%, Percentage 1.73e+01%, Percentage 3.37e+01%, Percentage 4.48e+01%, Percentage 6.77e+01%, Percentage 7.00e+01% to 8.00e+01%, Percentage 8.98e+01% to 9.69e+01%, Percentage 9.51e+01% to 9.98e+01%, Size 0.00e+00m, Size 1.00e+00m, Size 2.00e-01m, Size 4.00e-01m, Size 4.00e-01m to 5.00e-01m, Size 5.00e-01m, Size 5.00e-02m, Size 5.07e-01m, Size 5.71e-01m, Size 6.00e-01m, Size 6.00e-01m to 8.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.03.016
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 31>
Accession number:20171503569159
Title:Spray head selection and hydraulic performance optimization of roll wheel line move sprinkling irrigation machine
Authors:Sun, Wenfeng (1); Wang, Yanhua (1); Wang, Teng (1); Hou, Shouyin (1); Chong, Baozhong (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin; 150030, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:99-106
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Roll wheel line move sprinkling irrigation machine is a kind of important sprinkler irrigation equipment and it is one of the suitable systems for large area of the north China management pattern and level of productivity. However, the hydraulic performance of roll wheel line move sprinkling irrigation machine, which are put into use currently, is poor, limiting the development of roll wheel line move sprinkling irrigation machine. In order to solve these problems, the spray heads of roll wheel line move sprinkling irrigation machine were selected, and the optimal combination of the structure and working parameters of roll wheel line move sprinkling irrigation machine were investigated. Six kinds of popular spray heads including 30PS type, 2000S type, DY-1 type, ZY-2 type, FPY-1 type and 8034D type were used. Then the single spray head hydraulic performance tests were conducted. The test spray heads were mounted vertically on the car of 1-m height, rain gauges were arranged radically with 6 rows and centered on the spray head. During the test, the time taken for each revolution of the spray head and the water depth in the rain gauges were recorded. The spray stability, radial water distribution and rectangular combination sprinkler irrigation uniformity were determined. The suitable sprinkler head for GYP-300 type roll wheel line move sprinkling irrigation machine was chosen. The results showed that the 8034D type spray head had the advantages of high spraying stability, and well combination sprinkler irrigation performance, improving the hydraulic performance of roll wheel line move sprinkling irrigation machine fundamentally. At the same time, the method of 3 factors 5 levels quadratic regression orthogonal rotation center combined was applied to find the optimum parameters combination of roll wheel line move sprinkling irrigation machine. Working pressure of 8034D type spray head, spray head spacing, and spraying distance were selected as the influencing factors, and irrigation uniformity and application intensity were selected as the objective functions. The results showed that the contribution rate on irrigation uniformity was highest for the spraying distance, followed by working pressure and spray head spacing. The contribution rate on irrigation intensity was highest for the spraying distance, followed by spray head spacing and working pressure. The optimum parameter combination that could met the design requirements and had high working efficiency was the working pressure of 0.4 MPa, spray head spacing of 12 m, spraying distance of 18 m. In this condition, the irrigation uniformity could reach 0.91 and application intensity could reach 10.43 mm/h. By comparing with the existing 12 m × 12 m roll wheel line move sprinkling irrigation machine, the numbers moving units per unit area was decreased by 33.3%, the work efficiency was greatly improved and the labor force was reduced. The study can provide valuable information for the further development of roll wheel line move sprinkling irrigation machine. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Sprinkler systems (irrigation)
Controlled terms:Efficiency - Experiments - Gages - Hydraulic machinery - Irrigation - Nozzles - Rain - Rain gages - Sprinkler systems (fire fighting) - Water supply systems - Wheels
Uncontrolled terms:Hydraulic performance - Impact drives - Irrigation intensities - Irrigation uniformity - Parameters optimization - Quadratic regression - Sprinkling irrigation - Structure and working parameters
Classification code:443.3 Precipitation - 446.1 Water Supply Systems - 601.2 Machine Components - 632.2 Hydraulic Equipment and Machinery - 821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods - 901.3 Engineering Research - 913.1 Production Engineering - 914.2 Fires and Fire Protection - 943.3 Special Purpose Instruments
Numerical data indexing:Size 1.80e+01m, Electrical_Conductance 2.00e+03S, Percentage 3.33e+01%, Pressure 4.00e+05Pa, Size 1.00e+00m, Size 1.20e+01m
DOI:10.11975/j.issn.1002-6819.2017.03.013
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 32>
Accession number:20171503569187
Title:Molecular dynamics simulation of self-assembling process of ternary nanoparticle
Authors:Feng, Tao (1, 2); Wang, Ke (1); Zhou, Jinjie (1); Deepak, Bhopatkar (2); Chen, Feng (3); Campanella, Osvaldo (2); Hamaker, Bruce R. (2); Carignano, Marcelo (4); Zhuang, Haining (5)
Author affiliation:(1) School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai; 201418, China; (2) Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette; 47906-2009, United States; (3) Rosen Center for Advanced Computing, Information Technology at Purdue, Purdue University, West Lafayette; 47907-2108, United States; (4) Qatar Environments and Energy Research Institute, Doha; Qatar; 5825, Qatar; (5) Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Shanghai; 201403, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:300-306
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ternary complex system of amylose/whey protein/free fatty acid has attracted significant interest in food nutraceuticals or functional compounds in food delivery systems due to the well-known low toxicity, excellent biocompatibility, and solubility. Maize amylose, β-lactoglobulin, α-linoleic acid were self-assembled and characterized by the TEM. Then, in order to understand the mechanism of the self-assembling actions of such a ternary system (interaction among amylose, β-lactoglobulin and α-linoleic acid) deeply, all-atom molecular dynamics simulations were performed to analyze the self-assembling of the 3 components by the Gromacs software. An amylose segment of 55 glucose residues was used to form a 6-fold left-handed helix with 55 nm inner diameter and 135 nm outer diameter approximately and a length of 738 nm. A β-lactoglobulin peptide segment was used on the basis of the three-dimensional (3D) structure determined from an NMR (nuclear magnetic resonance) analysis. The PDB (protein data bank) file for α-linoleic acid was obtained from the Heterocompound Information Centre in Uppsala, Sweden. The glucose force field was chosen and all simulations for the amylose-like molecule were carried out using the glucose force field. The Gromacs 4.6.1 MD package (ScalaLife Competence Center, European Research Council) was used for the simulation. The MD simulations were performed using the leapfrog motion routine with a 2×10<sup>-15</sup>s time step. A total of 250 000 000 simulation steps (for a total of 500 ns simulation time) were performed to assess the progression of the self-assembly process. The LINCS algorithm was used to constrain all bond lengths. In the simulation, the temperature was set at 100 °C, necessary for the initial formation of the nanoparticle. This was performed using the modified Berendsen thermocouple between the different groups with a relaxation time of 0.1 ps, and the pressure was maintained at 1.0×10<sup>5</sup>Pa using the Parrinello-Rahman coupling to a pressure bath via an isotropic coordinate scaling with a relaxation time of 2×10<sup>-12</sup>s. Non-chemical bond interactions were handled using a neighboring grid cell cutoff scheme. Within a neighboring molecules list's cutoff distance of 0.9 nm in a short range, the interactions were evaluated at every time step based on a pair list. A short-range electrostatic cutoff radius of 0.9 nm and a long-range Van der Waals' cutoff radius of 1.4 nm were evaluated simultaneously with each list updating. The binding order of the 3 components could be obtained through the self-assembly snapshot diagram of ternary nanoparticles within 500 ns. The TEM images showed that ternary nanoparticles had a rod-like conformation, which could be confirmed by the snapshot at 500 ns of ternary system from molecular dynamic simulation. Further analyses of their gyration radius and solvent accessible surface area showed that the ternary nanoparticles were highly hydrosoluble, which indicated that the nanoparticles could significantly enhance the aqueous solubility of some hydrophobic nutraceuticals or functional compounds. It also indicated that the formation of the ternary nanoparticles was a thermodynamically spontaneous process among amylose, β-lactoglobulin and α-linoleic acid interaction through the free energy curved-surface map of the ternary nanoparticle. The present work provides insights into the mechanism of the atomic structures of aqueous soluble self-assembled nanoparticles and presents new perspective for the design of nutraceuticals delivery systems with desirable properties. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Linoleic acid
Controlled terms:Biocompatibility - Cyclodextrins - Fatty acids - Free energy - Glucose - Molecular dynamics - Molecules - Nanoparticles - Nuclear magnetic resonance - Protactinium - Proteins - Relaxation time - Self assembly - Solubility - Ternary systems - Thermocouples - Van der Waals forces
Uncontrolled terms:Amylose - European Research Council - Lactoglobulin - Molecular dynamics simulations - Self assembled nanoparticles - Self-assembling process - Solvent accessible surface areas - Three dimensional (3D) structures
Classification code:461.9.1 Immunology - 622.1 Radioactive Materials, General - 641.1 Thermodynamics - 761 Nanotechnology - 801.4 Physical Chemistry - 804.1 Organic Compounds - 931 Classical Physics; Quantum Theory; Relativity - 931.3 Atomic and Molecular Physics - 933 Solid State Physics - 944.5 Temperature Measuring Instruments - 951 Materials Science
Numerical data indexing:Size 1.35e-07m, Size 1.40e-09m, Size 5.50e-08m, Size 7.38e-07m, Size 9.00e-10m, Temperature 3.73e+02K, Time 1.00e-13s, Time 5.00e-07s
DOI:10.11975/j.issn.1002-6819.2017.03.041
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 33>
Accession number:20171503569165
Title:Quantitative determination of preferential flow characteristics of loess based on nonuniformity and fractional dimension
Authors:Pan, Wangsheng (1, 2); Xu, Yufeng (1); Lu, Yudong (2); Gao, Li'an (1); Yao, Xing (1)
Author affiliation:(1) School of Tourism and Resources Environment, Qiannan Normal University for Nationalites, Duyun; 558000, China; (2) School of Environment Science & Engineering, Chang'an University, Xi'an; 710054, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:140-147
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Understanding the seepage characteristics of loess preferential flow is important for loess landslide risk control. In order to study the seepage characteristics of loess preferential flow, in this study, eight test pits were designed in 2 regions of the abandoned farmland in Nanyuan Dongfeng village, Jingyan county, China (108°50'48″E, 34°29'25″N). The soil was developed in loess parent material. In each region, soil texture was homogenous without obvious macropore and cracks. The test pits were labeled with 1#-8#. In region I, the first 3 pits had same size, but different designed infiltration amount with 30, 60 and 90 mm, respectively. The 4# pit was similar with the 2# pit, but the former had high initial soil moisture. The 5#, 6# and 7# were same with 1#, 2# and 3#, respectively but in the region II. The 8# pit was similar with 4#, but had a bigger size. The dye tracer method was conducted and the soil profile was pictured. The images after binarization were used for preferential flow characteristics analysis. The infiltration depth and amount non-homogeneous coeffeicients were determined. The fractal dimension and fractal feature parameter were also determined. The results showed that infiltration had an obvious impact on the infiltration depth. The nonuniformity of the preferential flow infiltration depth became more obvious with increasing infiltration. However, the nonuniformity of the preferential flow infiltration depth was less obvious when the initial moisture content was high. The development of the preferential flow was lower, its velocity was higher, the average infiltration was greater and the fractal dimension was smaller. The loess porosity size also significantly influenced the correlation coefficient of the preferential flow infiltration depth. The nonuniformity of the infiltration coefficient and the nonuniformity of the preferential flow infiltration depth became more obvious and the fluctuation range of depth thresholds was greater when porosity increased. The test scale of loess for the same treatment did not show an appreciable effect on the fractal dimension of the wet peak trace. Within the 0-0.5 times of maximum infiltration depth of preferential flow in southern tableland in Jingyang County, when the value of the fractal characteristic was high, the nonuniformity of the preferential flow was higher, and the preferential flow was more developed. Without obvious preferential flow seepage channel, the maximum infiltration depth was less than 120 cm under irrigation water volume of 90 mm. Considering normal evaporation and no crack, we considered that the surface irrigation water was not easy to directly lead to the rise of ground water level. Therefore, the preferential flow plays an important role in the whole process from the surface water to the groundwater. At the same time, the influence of preferential flow on loess landslide should not be ignored. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Infiltration
Controlled terms:Cracks - Fractal dimension - Fractals - Groundwater - Groundwater flow - Irrigation - Landslides - Moisture - Porosity - Sediments - Seepage - Soil moisture - Soils - Surface waters - Water - Water levels
Uncontrolled terms:Fractal feature parameters - Infiltration coefficients - Initial Moisture Content - Loess - Preferential flows - Quantitative determinations - Seepage characteristics - Tracer tests
Classification code:444.1 Surface Water - 444.2 Groundwater - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 821.3 Agricultural Methods - 921 Mathematics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Size 1.20e+00m, Size 6.00e-02m, Size 9.00e-02m
DOI:10.11975/j.issn.1002-6819.2017.03.019
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 34>
Accession number:20171503569175
Title:Structure optimization and validation of goose house ventilation system based on airflow field simulation by CFD
Authors:Yao, Jiajun (1); Guo, Binbin (1); Ding, Weimin (1); Shao, Xibing (3); Shi, Zhendan (2)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing; 210031, China; (2) Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing; 210014, China; (3) Professional Cooperatives of Goose Industry, Changzhou Yang Lake, Changzhou; 213101, China
Corresponding author:Ding, Weimin(wmding@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:214-220
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Goose is seasonal breeding animal, the goslings and adult geese supply show seasonal changes, so that the sale price of the geese is fluctuating. The out-of-season breeding technology was employed to balance annual goose production and achieve higher economic benefits by regulating the normal breeding of geese in the spring and summer of non-breeding season. This technique has been popularized in the last few years, however, the high temperature in the summer is adverse to the goose production in the process of out-of-season breeding. It is known that the quality of thermal environment and the concentration of harmful gases are important factors to the health of livestock. In order to reduce or eliminate adverse effects of heat stress and lack of water on the geese during the process of out-of-season breeding, the ventilation-cooling mode with fans and evaporative pad was employed in conventional goose house, while a large amount of airflow diffusion located in the upper part of the goose house due to that these airflow of small density flowed upward. The use of computational fluid dynamics (CFD) techniques to solve complex fluid problems has greatly increased in the last few years. In this study, the goose house with mechanical ventilation had a large number of airflow diffusion in the upper part of the goose house, this may cause a problem that the ventilation effect of the ground geese was obstructed. So a structure optimization scheme based on computational fluid dynamics (CFD) has been proposed, multiple stretching film structures were installed below the girders of goose house to change the airflow directions as well as to increase the airflow flux in the lower part of goose house around the geese. Based on that, the two factors of vertical angle between stretching film and girder, drop height of stretching film were investigated to obtain uniform airflow and higher ventilation efficiency in the goose house. A three-dimensional steady goose house model was developed by the field measured boundary conditions data. Comparison between simulations and measurements for the 40 test points of wind speed showed that the RMSE, maximum absolute error and average relative error was 0.152 m/s, 0.29 m/s and 2.04%, respectively. It proved that the CFD method is reliable to estimate the distribution of air velocity in the goose house. The validated CFD model was then used to get the optimal combination scheme of 27 different construction cases: In the 42-meter-long goose house, we find that when 10 roll films are installed in the shed, and the angle between roll film and the vertical direction of girder is 60° with maximum drop height of 1.2 meters, the ventilation in the shed has the highest efficiency and its air distribution is more homogeneous, and this simulation is concluded to be the optimal one.Through in-situ test, 40 points are compared before and after the transformation of the wind speed value, the average airflow velocity at the height of 0.5 meters above the ground is up to 1.01 m/s, and the average airflow velocity in the conventional goose house without film is only 0.483 m/s. The test results show that: after transforming averaged wind velocity increased by 0.527 m/s, and the airflow uniformity coefficient decreased by 32.2%, the structure of the film increases the airflow velocity in the lower position significantly. The results of this experiment provide a reference for structure optimization of similar poultry house, the internal environment regulation and the structure design of goose house. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Computational fluid dynamics
Controlled terms:Agriculture - Air - Beams and girders - Computer simulation - Diffusion in liquids - Drops - Dynamics - Efficiency - Flow fields - Fluid dynamics - Heating - Houses - Optimization - Rope - Shape optimization - Structural design - Structural optimization - Velocity - Ventilation - Wind
Uncontrolled terms:Average relative error - Environment regulations - Film structure - Mechanical ventilation - Simulations and measurements - Structure optimization - Ventilation effects - Ventilation efficiency
Classification code:402.3 Residences - 408.1 Structural Design, General - 408.2 Structural Members and Shapes - 443.1 Atmospheric Properties - 631.1 Fluid Flow, General - 643.5 Ventilation - 723.5 Computer Applications - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.1 Production Engineering - 921.5 Optimization Techniques - 931.1 Mechanics
Numerical data indexing:Percentage 2.04e+00%, Percentage 3.22e+01%, Size 1.20e+00m, Size 5.00e-01m, Velocity 1.01e+00m/s, Velocity 1.52e-01m/s, Velocity 2.90e-01m/s, Velocity 4.83e-01m/s, Velocity 5.27e-01m/s
DOI:10.11975/j.issn.1002-6819.2017.03.029
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 35>
Accession number:20171503569186
Title:Pesticide residue photoelectric detection method based on paper-based microfluidic chip
Authors:Yang, Ning (1, 2); Li, Zhen (1); Mao, Hanping (2); Wang, Pan (1); Xiang, Changhua (1); Sun, Jun (1)
Author affiliation:(1) School of Electrical and Information Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) Institute of Agricultural Engineering, Jiangsu University, Zhenjiang; 212013, China
Corresponding author:Mao, Hanping(maohp@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:294-299
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A photoelectric detection method based on paper-based microfluidic chip in pesticide residues is proposed because the existing equipment has the problems of high cost, low degree of automation and large amount of reagent consumables. We design a kind of simple, portable, inexpensive paper-based microfluidic chip, whose bridge composite structure can enhance the uniformity of the color reaction of microfluidic enzyme, and also design the light path and circuit structure suitable for optical absorption reflection detection. The signal amplifying circuit and filter circuit are built to eliminate the interference of clutter and noise in photoelectric detection. Finally, a portable detection system of pesticide residue is established, which is an integrated test platform of the chemical reaction, the reflection effect in light absorption and the control of environment parameters. We observe and optimize the light source, chip placement angle, temperature and other process parameters of test platform in Jiangsu University in 2016. The reflection absorption effect of red LEDs (light-emitting diodes) is tested to be the best among the LEDs with different colors through detecting the paper-based chip color area. The response effect of the system is better when the angle is 10° according to the chip placement angle and reflected voltage data of photoelectric detection during the reaction. It is concluded that light absorption is the most under 35 ℃ and the chemical reaction is the most sufficient via comparing the color effect of the biochemical reaction of enzyme inhibition under different temperatures. We design different concentrations of pesticides, which are used for biochemical reactions of enzyme inhibition in different paper-based microfluidic chips. The resulting product displays blue color region in the paper-based chip, which can be characterized by the color of the different concentrations of pesticides. We use the photoelectric detection device to detect the color zone of the chip; the reflected voltage data can be obtained with this method, which correspond to different concentrations. Based on the experimental data, the model is established by the reflected voltage and the concentration of pesticide. The pesticide residues of test samples can be analyzed quantitatively based on the detection model. It can be concluded from the experimental results that with the method of photoelectric detection, the minimum detection limit of pesticide residues (trichlorfon and parathion) can reach 0.05 mg/L, meeting the national standard, and the resolution can reach 0.002 mg/L, much higher than that with the traditional method. Within the concentration range of pesticide residues, compared with the pesticide residues detector and the rapid detection card, the detection limit for the photoelectric detection is equivalent, but the consumable items are respectively 5.21% and 41.7% of the former 2 methods, and the reduction of time is respectively 23% and 33%. We propose a kind of pesticide residues detection system, which combines the photoelectric detection system and the paper-based microfluidic chip, and possesses the advantages of easy integration and low consumption. The research provides the theoretical basis and realistic foundation for making the pesticide residues detection develop to be portable and universal. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Pesticides
Controlled terms:Agricultural products - Chemical detection - Chemical reactions - Color - Electromagnetic wave absorption - Enzyme inhibition - Enzymes - Fluidic devices - Light absorption - Light emitting diodes - Light reflection - Light sources - Microfluidics - Optical resolving power - Photoelectricity - Structural design
Uncontrolled terms:Biochemical reactions - Fast detections - Minimum detection limits - Paper-based microfluidics - Photoelectric detection - Photoelectric detection systems - Reflection absorption - Reflection detections
Classification code:408.1 Structural Design, General - 632.2 Hydraulic Equipment and Machinery - 632.5.1 Microfluidics - 711 Electromagnetic Waves - 714.2 Semiconductor Devices and Integrated Circuits - 741.1 Light/Optics - 801 Chemistry - 802.2 Chemical Reactions - 803 Chemical Agents and Basic Industrial Chemicals - 821.4 Agricultural Products
Numerical data indexing:Mass_Density 2.00e-06kg/m3, Mass_Density 5.00e-05kg/m3, Percentage 2.30e+01%, Percentage 3.30e+01%, Percentage 4.17e+01%, Percentage 5.21e+00%
DOI:10.11975/j.issn.1002-6819.2017.03.040
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 36>
Accession number:20171503569155
Title:Mechanical properties of bamboo-concrete composite structures with dowel-type connections
Authors:Wei, Yang (1); Ji, Xuewei (1); Zhou, Mengqian (1); Zhao, Longlong (1); Duan, Maojun (1)
Author affiliation:(1) College of Civil Engineering, Nanjing Forestry University, Nanjing; 210037, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:65-72
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Bamboo is a novel engineering structural material, and it can be effectively applied in some specific structures of low-rise, multi-storey buildings and landscape bridges. Bamboo structures have a lot of advantages such as environmental protection, ecology, low caron, and so on. Existing studies have shown that the ordinary bamboo structures have insufficient load bearing capacity, low section stiffness and limited spanning capability as flexural members. In this paper, concrete and bamboo materials were composited to form a novel bamboo-concrete composite structure, in which the bamboo and the concrete materials were located in the lower and upper cross-section respectively, and the 2 types of materials worked together, connected by the dowel type connections. To investigate the mechanical properties of bamboo-concrete composite structures with dowel type connections, the mechanical test and theoretical analysis of bamboo-concrete composite connections and beams were carried out. Three dowel-type shear connections with identical parameters were designed and prepared for the push-out shear test. The test results showed that the dowel-type shear connections exhibited an excellent slip deformation capacity under the loading and the failure mode was the ductile failure. The load-slip curves of 3 connection specimens were quite homogeneous and consisted with 3 stages of elasticity, elasticity-plasticity and full plasticity. Based on the test results, the load-slip models that could describe the obvious features in the 3 stages of the load-slip curves were provided for the dowel-type shear connections, which could be used in the fine numerical analysis of the load-displacement curve for the dowel-type bamboo-concrete composite structures. One dowel-type bamboo-concrete composite beam and one bamboo beam were investigated by four-point bending test. The failure mode of bamboo-concrete composite beam was the bamboo fiber fracture on the bottom of the beam and no concrete crushing was found in the upper compression zone. At the later loading stage, there was a strain jump in the interface of 2 kinds of materials, and the interface slip increased from the mid-span to the both ends of the beam. The phenomena showed the characteristics of partial composite structures. Ultimate load enhanced by 89% and the load corresponding to the limiting value of deflections for beams prescribed in Chinese timber structures code of the bamboo-concrete composite beam increased by 274% compared to values for the bamboo control beam, respectively. Due to the composite effect generated by the 2 kinds of materials, the load-carrying capacity and the section stiffness of the bamboo-concrete composite beam were greatly improved. According to the test results, the equivalent stiffness method was suggested, in which slip stiffness of shear connections was considered to predict the displacement of the bamboo-concrete composite beam, and when the reduction factor of 0.8 was used for the equivalent sectional stiffness, the predicted load-displacement curves were in good agreement with the experimental curves. This study demonstrates that the bamboo-concrete composite structures have excellent flexural performance, and can be used for the flexural members in some potential landscape bridge or building structures. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Bamboo
Controlled terms:Bridges - Composite beams and girders - Composite structures - Concrete blocks - Concretes - Elasticity - Fracture - Interfaces (materials) - Loads (forces) - Mechanical properties - Plasticity - Shear flow - Stiffness - Structure (composition)
Uncontrolled terms:Bamboo concrete composites - Bamboo structures - Dowel-type connection - Four-point bending test - Load-bearing capacity - Load-displacement curve - Multistorey buildings - Shear connector
Classification code:401.1 Bridges - 408 Structural Design - 408.2 Structural Members and Shapes - 412 Concrete - 631.1 Fluid Flow, General - 811.1 Pulp and Paper - 951 Materials Science
Numerical data indexing:Percentage 2.74e+02%, Percentage 8.90e+01%
DOI:10.11975/j.issn.1002-6819.2017.03.009
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 37>
Accession number:20171503569170
Title:Apple tree canopy geometric parameters acquirement based on 3D point clouds
Authors:Guo, Cailing (1, 2); Zong, Ze (1); Zhang, Xue (1); Liu, Gang (1)
Author affiliation:(1) Key Lab of Agricultural Information Acquisition Technology, Ministry of Agricultural of China, China Agricultural University, Beijing; 100083, China; (2) Department of Electromechanical Engineering, Tangshan University, Tangshan; 063000, China
Corresponding author:Liu, Gang(pac@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:175-181
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Accurate structural parameters and crown characterization of large isolated apple trees were vital for adjusting spray doses, trimming, autonomous harvesting. According to previous research, canopy measurement methods to characteristic the whole tree structure could be classified in two groups: Manual measurements and electronic procedures to estimate tree dimensions. These methods were time consuming and required specialist knowledge, so a simpler crown characterization measurement method was required. Terrestrial laser scanning (TLS) could provide accurate canopy information through non-destructive methods, which filled the gap between tree scale manual measurements and large scale LiDAR measurements. Laser scanning delivers a dense cloud of points, and this raw point data were filtered for deriving a digital terrain model and subsequent fitting of a parametric stem model. In this study, Trimble TX8 had been used to getting point clouds of the apple tree canopy with trees height 3.2-5.1 m and 7 years old, in the orchard environment. A method and registration algorithm for reconstructing the three-dimensional (3D) apple tree canopy based on terrestrial laser scanner point cloud data from apple trees was presented. After an initial alignment had been obtained from this last set of correspondences, the object ball point clouds were extracted, and the noise was deleted by hands. In order to improve convergence speed, KD-tree improved ICP(iterated closest points), and combined with object ball, to estimate the optimal transform. The object residual errors and fitting errors at different distances between object and scanner were analyzed. Results showed that, the average residual errors was 1.3 mm, and the average fitting errors was 0.95 mm at the distance from 1 000 to 13 000 mm. All the errors were less than the traditional registration accuracy 5 mm. In addition, wind as an importance factor always influenced point clouds quality. In order to find the influence between them, several pieces of branches, apples and 80 pieces of leaves had been extracted in the wind speed from 0.9 to 4.5 m/s. And the branches and apple structures, the leaf characteristics were studied under different wind speed. Results showed that, the branches and apple outline clearly, both the single tree and group trees, the geometric parameters, such as apple diameter, stem diameter, trunk detection, canopy height, canopy diameter, planting distance, line spacing, could been extracted easily even if the average wind speed was 4.5m/s in the scanning instant. Great changes had taken place in the leaves edge and thickness, when the wind speed changed from 0.9 to 2.4 m/s. The thickness of the leaf profile had changed from 2.2 to about 35.8 mm, and the original point clouds Delaunay triangular mesh also became irregular. And long and narrow triangle appeared at the moment of the average wind speed 1.9 m/s. The three leaf thickness fitting curves, as quadratic curve, cubic curve and exponential curve, were in good agreements for the whole range of studied volumes (R<sup>2</sup>=0.976, R<sup>2</sup>=0.986 and R<sup>2</sup>= 0.983, P < 0.001). The fitting curve showed that, apple canopy 3D point cloud data could be obtained with good quality in orchard environment. Comparing with the traditional manual measurement, the relative errors of the canopy parameter measurement values obtained from 3D point clouds data were less than 4%. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Trees (mathematics)
Controlled terms:Curve fitting - Errors - Farms - Fruits - Laser applications - Lasers - Measurement errors - Nondestructive examination - Optical radar - Orchards - Parameter estimation - Scanning - Speed - Surface analysis - Surveying instruments - Wind
Uncontrolled terms:Accuracy - Apple canopy - Characterization measurement - Nondestructive methods - Point cloud - Registration algorithms - Terrestrial laser scanners - Terrestrial laser scanning
Classification code:405.3 Surveying - 443.1 Atmospheric Properties - 716.2 Radar Systems and Equipment - 744.1 Lasers, General - 744.9 Laser Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 921.6 Numerical Methods - 951 Materials Science
Numerical data indexing:Age 7.00e+00yr, Percentage 4.00e+00%, Size 1.00e+00m to 1.30e+01m, Size 1.30e-03m, Size 3.20e+00m to 5.10e+00m, Size 3.58e-02m, Size 5.00e-03m, Size 9.50e-04m, Velocity 1.90e+00m/s, Velocity 4.50e+00m/s, Velocity 9.00e-01m/s to 2.40e+00m/s, Velocity 9.00e-01m/s to 4.50e+00m/s
DOI:10.11975/j.issn.1002-6819.2017.03.024
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 38>
Accession number:20171503569161
Title:Optimization of drip irrigation uniformity model considering location of clogged emitters
Authors:Zhang, Ruochan (1); Niu, Wenquan (1, 2, 3); Duan, Xiaohui (3); Li, Yuan (3)
Author affiliation:(1) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; 712100, China; (2) Institute of Soil and Water Conservation, Chinese Academy of Science and Ministry of Water Resources, Yangling; 712100, China; (3) Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China
Corresponding author:Niu, Wenquan(nwq@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:113-120
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Uniformity is one of the most important indicators for the evaluation of drip irrigation quality, and is also regarded as an important parameter for drip irrigation system design. Soil water distribution uniformity is the ultimate expression of drip irrigation uniformity, but the present drip irrigation uniformity indexes can't reflect it directly. In this study, we used soil water distribution coefficient as the standard to evaluate the rationality and accuracy of 3 typical drip irrigation uniformity coefficients (Christiansen uniformity coefficient, Keller uniformity coefficient and the uniformity coefficients considering location of clogged emitters) and finally optimized the best one among these 3 coefficients. Three factors (clogged degree, proportion of clogged emitter, location of clogged emitters) influencing the drip irrigation uniformity were considered, and a total of 27 kinds of drip irrigation situations (clogged degree of 40%, 60% and 80%; proportion of clogged emitter of 20%, 30% and 40%; location of clogged emitters of even distribution, relative uniform and nonuniform distribution) were designed. The soil water distribution of each irrigation situation was simulated by HYDRUS-2D program and verified by an actual infiltration experiment. We matched soil water distribution coefficient and the irrigation uniformity coefficients of each irrigation situation, then compared and evaluated them by linear fitting. Soil water distribution coefficient was significantly influenced by sampling arrangement, therefore 9 kinds of sampling arrangements were set up and a desirable one was chosen through variance analysis. Results showed that under the condition of the simulation test, the desirable sampling interval and depth were 60 and 20 cm respectively for soil moisture monitoring. Based on the desirable sampling arrangement, there was a significant linear relevance between soil water distribution uniformity and irrigation uniformity. Among them, the uniformity coefficient considering location of clogged emitters could reflect the soil water distribution accurately; it had the optimal linear relationship with soil water distribution coefficient. According to this linear relationship, the uniformity coefficient considering location of clogged emitters could be optimized when the regression coefficient ratio for the content of clogged emitters' location uniformity and the Christiansen uniformity coefficient was 2:8. A field experiment was done in a solar heated greenhouse in order to verify the accuracy of the optimized uniformity coefficient considering location of clogged emitters. The field experiment result was consistent with the simulation result, both of which showed a significant linear relationship between soil water distribution coefficient and the optimized uniformity coefficient considering location of clogged emitters. With the increase of clogged emitters, the influence of clogged emitters' location on soil water distribution uniformity would also increase. If the clogged emitter accounted for a large proportion (>10%), the relationship between soil water distribution coefficient and the optimized uniformity coefficient considering location of clogged emitters was closer than it between soil water distribution coefficient and the other uniformity coefficients (R<sup>2</sup>=0.970, P<0.01). Therefore, the optimized uniformity coefficient considering location of clogged emitters was more proper when evaluating the irrigation uniformity. Its evaluation result was consistent with the soil moisture situation and could reflect the actual irrigation quality comprehensively. But in general, soil water distribution coefficient was higher than the optimized uniformity coefficient considering location of clogged emitters, indicating that the soil moisture was more uniform because of the soil matrix suction and the redistribution of soil water. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Soil surveys
Controlled terms:Irrigation - Location - Moisture - Moisture control - Optimization - Quality control - Soil moisture - Soils - Water supply systems
Uncontrolled terms:Drip irrigation systems - Emitter clogging - Irrigation uniformity - Non-uniform distribution - Soil moisture monitoring - Soil-water distribution - Soil-water distribution coefficients - Solar-heated greenhouse
Classification code:446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 731.3 Specific Variables Control - 821.3 Agricultural Methods - 913.3 Quality Assurance and Control - 921.5 Optimization Techniques
Numerical data indexing:Percentage 2.00e+01%, Percentage 3.00e+01%, Percentage 4.00e+01%, Percentage 6.00e+01%, Size 2.00e-01m, Size 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.03.015
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 39>
Accession number:20171503569169
Title:Physicochemical property change regularities of coal gangue with different weathering ages in Huainan minging area
Authors:Yan, Jiaping (1); Chen, Xiaoyang (2); Cai, Yi (2); Huang, He (2)
Author affiliation:(1) College of Surveying and Mapping, Anhui University of Science and Technology, Huainan; 232001, China; (2) College of Earth and Environment, Anhui University of Science and Technology, Huainan; 232001, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:168-174
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Coal gangue is the solid waste from coal mining. Because of weathering, the physico-chemical properties of the coal gangue exposed on the ground's surface changes constantly. In order to study the change of coal gangue physico-chemical properties under the effects of weathering, the electrical conductivity, pH value and cation exchange capacity, 3 major physico-chemical indices are chosen to analyze their change characteristics and general regularities with the weathering time and the buried depth of coal gangue. The research chooses the distributing area of coal gangue with different weathering age, and divides the research layer into upper layer and lower layer, which are from surface to 30 cm depth and from 30 to 60 cm depth, respectively. A total of 135 samples from 5 coal gangue hills with different weathering age in Panbei, Panyi as well as Xinzhuangzi coal mines in Huainan mining area are collected with the stratified sampling method. The results show that there are certain change regularities of the physico-chemical properties of the coal gangue. The electrical conductivity and pH value of coal gangue decrease with the increasing of weathering age. And the cation exchange capacity increases along with the increasing of weathering age. The 3 indices of fresh coal gangue have a faster decrease rate within the early 2 a. The electrical conductivity reduces by 30% and the pH value falls by nearly 10% within the early 2 a. Then they change slowly. The cation exchange capacity can be increased by 17% within the early 2 a, and then its change grows slower. The change characteristics of physico-chemical properties of the coal gangue in profile are also obvious. Through the comparative analysis of the upper and lower layers, it is found that the electric conductivity and pH value in the upper layer are generally slightly higher than that of the lower layer, while the cation exchange capacity in the upper layer is slightly lower than that of the lower layer. The difference of pH value between the 2 layers is only from 0.1 to 0.3. The spatial and temporal variations of coal gangue conductivity, pH value and cation exchange capacity are all closely related to the weathering time or the degree of weathering. The great change occurs in the physico-chemical properties of coal gangue exposed to the ground's surface within 2 a. It shows that the weathering is significant. Of course, the temperature effect and hydrolysis as well as other physical processes play the role in the process. Lumpiness decrease of coal gangue due to physical weathering can speed up the change of chemical and other physical indicators. From the angle of the mining area land reclamation, these changes of the physical and chemical properties of coal gangue will be in favor of land reclamation in the mining area. The results provide the theoretical basis for land reclamation of coal gangue storage area. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:pH
Controlled terms:Chemical analysis - Chemical properties - Coal - Coal mines - Coal reclamation - Coal storage - Coal tailings - Electric conductivity - Indicators (chemical) - Land reclamation - Land use - Positive ions - Reclamation - Weathering
Uncontrolled terms:Cation exchange capacities - Coal gangues - Degree of weatherings - Electrical conductivity - Huainan mining area - Physical and chemical properties - Physicochemical property - Spatial and temporal variation
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 503.1 Coal Mines - 524 Solid Fuels - 701.1 Electricity: Basic Concepts and Phenomena - 801 Chemistry - 801.1 Chemistry, General
Numerical data indexing:Percentage 1.00e+01%, Percentage 1.70e+01%, Percentage 3.00e+01%, Size 3.00e-01m, Size 3.00e-01m to 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2017.03.023
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 40>
Accession number:20171503569182
Title:Design and test of automatic control system for egg electronic weighing and grading packaging production line
Authors:Wang, Shucai (1); Wu, Manlin (1); Wu, Chuang (2)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan; 430070, China; (2) Dongfeng Design Institute Co. Ltd, Wuhan; 430056, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:265-271
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is generally known that egg weight classification is one of the most important processes of egg production, processing and sales. In order to improve the production efficiency and accuracy of egg grading, this paper introduces a synchronous tracking automatic control system, which is used for electronic weighing and grading packaging of eggs. This new system is based on the task group design of egg grading packaging machine, and composed of 4 parts, namely, a weighing part, a grading part, a loading plate part and an automatic feeding part. The egg grading packaging process includes egg weight detection, data processing, data communication, egg position synchronous tracking and quick boot and reset of electromagnet. Advanced RISC machines (ARM) are used to process egg weight signals collected by multiple-channel sensors, and the weight signal is intercepted in a stable period of time for about 70 ms after the simulation of filter, nonlinear correction, and frequency compensation. Then the system uses the average value to perform filter processing. Firstly the processing of information is through the free port communication protocol, which is sent to the programmable logic controller (PLC) of the register; secondly, the PLC controls to start the corresponding discharge electromagnet by judging the grade of egg weights. Then, as the reference signal frequency of external pulse, the high-speed pulse produced by the encoder precisely is applied to locate the position of the movement of the egg by using the method of data location transmission. Then the corresponding actuators are controlled together with the movement of the mechanical device, and the links of weight acquisition, classification of unloading, traying and sending the disc are completed to achieve accurate grading and packing for the eggs in different weight level range. Three hundred eggs are randomly selected as the experimental samples, and electronic scale weighs actual weight and records data. After using ARM to measure the weight of the egg, the weight information is sent to PLC, which is then real-time displayed in the upper computer and compared with the actual weight. At the same time, PLC controls the corresponding discharge solenoid action, so that the eggs of different weights can fall into the egg transfer tray of corresponding level. After we finish the measurement and grading of 300 eggs, each egg is tested continuously for 10 times and the data are recorded. The experimental results show that the weighing error of this control system is between -1 and 1 g, which accounts for 85.6%; the weighing error of this control system is between -1.5 and 1.5 g, which accounts for 95.3%; and the classification accuracy rate reaches 98%. When the egg weight is at the boundary value of 2 levels, it is likely to be assigned to the wrong class because of the measurement error, which greatly affects the accuracy. The research results can help to improve the production efficiency of egg grading, which provides a reference for the localization of egg grading technology. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Grading
Controlled terms:Actuator disks - Automation - Classification (of information) - Control systems - Data handling - Efficiency - Electromagnets - Electronic scales - Errors - Mechanical actuators - Packaging - Process control - Scales (weighing instruments) - Sensors - Signal processing - Unloading - Weighing
Uncontrolled terms:Advanced RISC machines - Classification accuracy - Data-communication - Frequency compensation - Nonlinear correction - Packaging production - Production efficiency - Programmable logic controllers (PLC)
Classification code:602.1 Mechanical Drives - 691.2 Materials Handling Methods - 694.1 Packaging, General - 704.1 Electric Components - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 732.1 Control Equipment - 913.1 Production Engineering - 943.3 Special Purpose Instruments
Numerical data indexing:Mass -1.00e-03kg to 1.00e-03kg, Mass -1.50e-03kg to 1.50e-03kg, Percentage 9.80e+01%, Time 7.00e-02s
DOI:10.11975/j.issn.1002-6819.2017.03.036
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 41>
Accession number:20171503569151
Title:Optimizing calibration of design points for non-road high pressure common rail diesel engine base on response surface methodology
Authors:Wang, Jun (1); Shen, Lizhong (1); Yang, Yongzhong (2); Bi, Yuhua (1); Wan, Mingding (1)
Author affiliation:(1) Yunnan Province Key Laboratory of Internal Combustion Engines, Kunming University of Science and Technology, Kunming; 650500, China; (2) Kunming Yunnei Power Co., Ltd., Kunming; 650500, China
Corresponding author:Shen, Lizhong(lzshen@foxmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:31-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China Stage III emission standard for diesel engine of non-road mobile machinery has been executed since April 1, 2016. Some manufactures have begun to adopt a high pressure common rail system to cope with this emission regulation. Fuel injection parameters can be adjusted flexibly by using the high pressure common rail system. Therefore, combustion process can be improved. However, it brings the problem of increasing the workload of the calibration and optimization significantly. With the increasing of calibration variables, the calibration combinations will increase exponentially. The traditional calibration method, such as the single variable search method or the single variable sweep method, their calibration results may not be able to make the engine to achieve best performance, especially when the number of calibration parameters is more than two. Nowadays, a majority of optimization calibration methods are using a non-parametric modeling method to fit the calibration model and optimizing the calibration model by using an intelligent optimization algorithm. However, the non-parametric modeling method cannot give the descriptions of the model structure or the model coefficients. Meanwhile, it needs a large number of test data to fit an accurate calibration model. Moreover, the non-parametric modeling method and the intelligent optimization algorithm are both very complex. A polynomial modeling method has a good compromise between complexity and computational efficiency of the model. Therefore, in allusion to the calibration stage of a non-road high pressure common rail diesel engine, 4 calibration variables, i.e., main injection quantity, pilot injection quantity, main injection timing and injection pressure, were chosen as the factors. The non-road diesel engine design index and related constraint parameters were chosen as the responses at the peak torque speed of 1 600 r/min and the rated power speed of 2 600 r/min, respectively. The reasonable factor levels of the design of experiments (DoE) were selected. By using the response surface methodology (RSM) of Box-Behnken design, the DoE matrices were obtained at the engine speed of 1 600 r/min and 2 600 r/min, respectively. Meanwhile, the corresponding test was conducted according to the experiment design. The second order regression models of all the responses were got and evaluated. The interaction effects of the 4 calibration parameters on engine performance were investigated by using the RSM. The corresponding optimization was conducted respectively at the engine speed of 1 600 and 2 600 r/min taking the target torque and target power as the setting target under the principle of the minimum brake specific fuel consumption, the maximum air-to-fuel ratio, the minimum peak cylinder pressure and gas temperature of exhaust manifold. The combination of calibration variables was obtained at 2 engine speeds, and the proposed method was verified by experiments. The results showed that all the quadratic response surface regression models had a good accuracy and a good predictive ability. The determination coefficient R<sup>2</sup>, the adjusted determination coefficient R2 adj, and the prediction determination coefficient R2 pred were all above 0.92. The maximum error between test value and predicted value was less than 3.07 %. With the optimized calibration parameters, the peak torque and the rated power of the non-road high pressure common rail diesel engine reached 200.7 N·m and 40.1 kW, respectively. The engine achieved the design index, and moreover, the brake specific fuel consumption, air-to-fuel ratio, peak cylinder pressure, and gas temperature of exhaust manifold were all under the range of acceptance. It is feasible to optimize the diesel engine design point by using the RSM. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Diesel engines
Controlled terms:Automobile engine manifolds - Brakes - Calibration - Computational efficiency - Design of experiments - Engine cylinders - Engines - Exhaust manifolds - Fuel consumption - Fuels - Highway planning - Machine design - Machinery - Optimization - Parameter estimation - Regression analysis - Roads and streets - Speed - Surface properties - Transportation
Uncontrolled terms:Adjusted determination coefficient - Brake specific fuel consumption - High pressure common rail - High pressure common rail diesel engine - High pressure common rail system - Intelligent optimization algorithm - Non-road - Response surface method
Classification code:406.2 Roads and Streets - 432.1 Highway Transportation, General - 525.3 Energy Utilization - 601 Mechanical Design - 602 Mechanical Drives and Transmissions - 612.1.1 Internal Combustion Engine Components - 612.2 Diesel Engines - 661.2 Automotive Engine Components - 901.3 Engineering Research - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 3.07e+00%, Power 4.01e+04W, Rotational_Speed 1.60e+03RPM, Rotational_Speed 2.60e+03RPM, Torque 2.01e+02N*m
DOI:10.11975/j.issn.1002-6819.2017.03.005
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
<RECORD 42>
Accession number:20171503569185
Title:Nano-TiO<inf>2</inf>modified low-density polyethylene packaging preserving storage quality of Chinese hickory (Carya cathayensis Sarg.)
Authors:Lu, Hongyan (1); Li, Li (1); Luo, Zisheng (1)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou; 310058, China
Corresponding author:Luo, Zisheng(luozisheng@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:33
Issue:3
Issue date:February 1, 2017
Publication year:2017
Pages:288-293
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nanoparticle usually has unique physical and chemical characteristics and has become attractive to researchers in recent years. Chinese hickory is well known because of its high polyunsaturated fatty acid (PUFA) content. However, high PUFA content limits the shelf life of the products due to the susceptibility of PUFA to oxidation. Lipid oxidation decreases economic value of walnuts during the storage. Oxidation resulting in an undesirable rancid taste makes Chinese hickory unacceptable for the consumer. Oxygen concentration is one of the most important environmental factors affecting lipid oxidation. Lipid oxidation can be inhibited by using packaging material with low oxygen permeability. Improving barrier properties through the use of nanocomposites is an important topic of research, especially for the food packaging industry. Nano-titanium dioxide (nano-TiO<inf>2</inf>) is a kind of nano metallic oxide which has been researched in some academic fields. Adding nanoparticles to the polyethylene (PE) could significantly decrease the oxygen, water vapor permeability and longitudinal strength, and inhibit spore germination. TiO<inf>2</inf>has been the focus of photocatalysts because of its physical and chemical stability, low cost, ease of availability and non-toxicity. Nanoparticle composite material has revealed its importance in agricultural products preservation these years. In this study, nano-TiO<inf>2</inf>modified low density polyethylene (LDPE) film packaging was prepared by blending LDPE with nano-TiO<inf>2</inf>. The effects of nanoparticle modified LDPE film packaging on both physiology and quality of postharvest Chinese hickory stored under 20℃ were investigated. During the storage the physical and chemical indicators included CO<inf>2</inf>and O<inf>2</inf>volume fraction in packing, oxidation value, hexanal, total fat, total soluble sugar, activities of peroxidase, lipoxygenase and lipase, total phenol and total tocopherol, which were detected every 30 d to determine the Chinese hickory quality. Results showed that most physical and chemical indicators of Chinese hickory in each group were significantly changed (P<0.05) during the whole storage time. Compared with the control group, nano-TiO<inf>2</inf>modified LDPE film was more effective in forming high CO<inf>2</inf>and low O<inf>2</inf>, delaying the increase of peroxide value and hexanal, slowing the decrease of fat, soluble sugar, total tocopherol and total phenols, and inhibiting the activities of peroxidase, lipoxygenase and lipase. After 180 d, O<inf>2</inf>content of nano-TiO<inf>2</inf>modified LDPE film was 36.36% lower and CO<inf>2</inf>content was 7.25% higher than that of the control. The results indicated that nano-TiO<inf>2</inf>modified LDPE film had low gas permeability (P<0.05). Oxidation value and hexanal content were respectively 35.03% and 41.21% lower than that of the control (P<0.05). Total fat, soluble total sugar, total phenol and total tocopherol were respectively 4.07% (P>0.05), 6.9%, 11.37% and 8.87% higher than that of the control (P<0.05). Activities of peroxidase, lipoxygenase and lipase were respectively 17.21%, 8.96%, and 20.55% lower than that of the control (P<0.05). All these were maybe due to the lower gas permeability of nano-TiO<inf>2</inf>modified LDPE film. These results indicated nano-TiO<inf>2</inf>modified LDPE film is effective in maintaining the quality and prolonging the storage life of Chinese hickory and has a potential application prospect in the packaging of postharvest Chinese hickory. This paper provides the reference for the application of nanoparticle modified composite film materials in the preservation of Chinese hickory. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Nanocomposite films
Controlled terms:Agricultural products - Blending - Carbon dioxide - Chemical stability - Composite films - Energy storage - Fatty acids - Gas permeability - Gas permeable membranes - Indicators (chemical) - Metallic compounds - Metals - Nanoparticles - Oxidation - Oxides - Oxygen - Packaging - Packaging materials - Packing - Phenols - Polyethylenes - Polyunsaturated fatty acids - Quality control - Storage (materials) - Titanium - Titanium dioxide - Titanium oxides
Uncontrolled terms:Chinese hickory - Environmental factors - Food packaging industry - Longitudinal strength - Low density polyethylene(LDPE) - Nano-TiO - Physical and chemical characteristics - Water vapor permeability
Classification code:525.7 Energy Storage - 542.3 Titanium and Alloys - 694 Packaging - 712.1 Semiconducting Materials - 761 Nanotechnology - 801 Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 815.1.1 Organic Polymers - 821.4 Agricultural Products - 913.3 Quality Assurance and Control - 931.2 Physical Properties of Gases, Liquids and Solids - 933 Solid State Physics
Numerical data indexing:Percentage 1.14e+01%, Percentage 1.72e+01%, Percentage 2.06e+01%, Percentage 3.50e+01%, Percentage 3.64e+01%, Percentage 4.12e+01%, Percentage 6.90e+00%, Percentage 7.25e+00%, Percentage 8.87e+00%, Percentage 8.96e+00%
DOI:10.11975/j.issn.1002-6819.2017.03.039
Database:Compendex
Compilation and indexing terms, Copyright 2017 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
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- Bioresource Technology
- Industrial Crops and Products
- Biomass & Bioenergy
- Biosystems Engineering
- Aquacultural Engineering
- International Journal of Agricultural and Biological Engineering
- Journal of Irrigation and Drainage Engineering
- Paddy and Water Environment
- Journal of Agricultural Engineering
- Transactions of the ASABE
- Revista Brasileira de Engenharia Agricola e Ambiental
- Applied Engineering in Agriculture
- Engenharia Agricola
- AMA-Agricultural Mechanization in Asia Africa and Latin America
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- 中国科学技术协会CAST
- 国家新闻出版署
- 中华人民共和国科学技术部
- 国家自然科学基金委员会
- U.S. DEPARTMENT OF AGRICULTURE
- CIGR
- ASABE
- EurAgEng-European Society for Agricultural Engineers
- American Society of Agronomy
- Crop Science Society of America
- Soil Science Society of America
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