<RECORD 1>
Accession number:20164603020656
Title:Prediction for nitrogen content of rice leaves in cold region based on hyperspectrum
Authors:Wang, Shuwen (1); Zhao, Yue (1); Wang, Lifeng (1); Wang, Runtao (1); Song, Yuzhu (1); Zhang, Changli (1); Su, Zhongbin (1)
Author affiliation:(1) College of Electric and Information, Northeast Agricultural University, Harbin; 150010, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:187-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, in order to realize the quick, non-destructive and accurate diagnosis of rice nutritional status, we use hyperspectral imaging techniques as an approach for nitrogen content prediction of rice leaves in cold region. The experiments were carried out for two years (2014 and 2015) at Fangzheng country, Heilongjiang province, China. Longdao 20 was chosen as the test cultivar. 6 nitrogen fertilization rates were applied in our experiments, i.e., N0 (0 kg/hm<sup>2</sup>), N1 (60 kg/hm<sup>2</sup>), N2 (90 kg/hm<sup>2</sup>), N3 (120 kg/hm<sup>2</sup>), N4 (150 kg/hm<sup>2</sup>), and N5 (180 kg/hm<sup>2</sup>). The hyperspectral reflectance and nitrogen content of rice leaves under different nitrogen levels at jointing stage were separately measured using American Headwall imaging spectrometer and German AA3 analyzer. The hyperspectral images of 240 rice leaf samples in the spectral range of 400-1 000 nm were acquired. Average spectrum was extracted from the region of interest (ROI) of each sample. Several regression analysis (RA) estimate models have been built based on different characteristic spectral parameters using different algorithms which include successive projections algorithm (SPA) and segmented principal components analysis (SPCA) combined with correlation analysis (CA) for testing and screening. The first method, a nitrogen content value estimation model based on multiple stepwise regression analysis (MSRA) in the whole wavelength region of 400~1000nm has been built and been predicted. Wavelengths 899, 890 nm were retained as the model independent variables. The second method, 8 characteristic wavelengths i.e., 454, 460, 475, 504, 525, 685, 700 and 735 nm were chosen by SPA and selected as modeling variables of MSRA. Wavelengths 735, 525 nm were chosen as the model independent variables. The third method, we divided the whole wavelength into 5 parts which are 400-504, 505-670, 671-697, 698-724 and 725-1 000 nm using correlation coefficient matrix method. The principal component analysis (PCA) was carried out on each part, and 7 sensitive bands were selected according to the contribution rate of each component. The correlation between the nitrogen content of rice leaves and the characteristic spectral parameters which consist of sensitive bands was analyzed, and 11 characteristic spectral parameters, i.e., single band index (SI<inf>(558)</inf>, SI<inf>(866)</inf>), red edge position index (REPI<inf>(709)</inf>), ratio index (RI<inf>(866,670)</inf>), difference index (DI<inf>(730,715)</inf>, DI<inf>(730,558)</inf>), double difference index (DDI<inf>(730,715,685)</inf>, DDI<inf>(866,685,558)</inf>), normalized difference index (NDI<inf>(866,670)</inf>, NDI<inf>(866,685)</inf>) and green normalized difference index (GNDI<inf>(730,558)</inf>) were selected to establish simple regression analysis (SRA) models. 4 kinds of characteristic spectral parameters with the highest coefficients of determination (R<inf>C</inf><sup>2</sup>and R<inf>P</inf><sup>2</sup>) were selected to establish multiple regression analysis (MRA) models. We predicted all the estimate models so that testing its accuracy and stability. The results indicated that, reflectance of rice leaves decreases in the visible region, and increases in the near infrared region, with the raise of nitrogen level. From the calibration performance index, the whole wavelength model based on MSRA is the best with a coefficient of determination (R<inf>C</inf><sup>2</sup>=0.821) and root mean square error (MRSEC) of 0.079. From the prediction performance index, the multivariate SI<inf>(866)</inf>, DI<inf>(730,715)</inf>, DDI<inf>(730,715,685)</inf>, DDI<inf>(866,685,558)</inf>based on SPCA-CA combined MRA is the best with a coefficient of determination (R<inf>P</inf><sup>2</sup>=0.869) and the root mean square error (RMSEP) of 0.085. The study provides technical support and theoretical basis for the rapid detection of nitrogen content in rice leaves and the precise fertilization management during rice growth. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Principal component analysis
Controlled terms:Algorithms - Forecasting - Grain (agricultural product) - Image segmentation - Imaging techniques - Infrared devices - Mean square error - Nitrogen - Nondestructive examination - Reflection - Regression analysis - Spectroscopy - Spectrum analysis
Uncontrolled terms:Hyperspectral imaging techniques - Multiple regression analysis - Multiple stepwise regression - Normalized difference indices - Principal components analysis - Rice - Successive projections algorithm - Successive projections algorithms (SPA)
Classification code:746 Imaging Techniques - 804 Chemical Products Generally - 821.4 Agricultural Products - 922.2 Mathematical Statistics
Numerical data indexing:Size 4.00e-07m to 1.00e-06m, Size 5.25e-07m, Size 7.25e-07m to 1.00e-06m, Size 7.35e-07m, Size 8.90e-07m
DOI:10.11975/j.issn.1002-6819.2016.20.024
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 2>
Accession number:20164603020665
Title:Spatial distribution and formation mechanism of cultivated land transfer price in Henan Province
Authors:Du, Ting (1, 2); Zhu, Daolin (1, 2); Zhang, Lixin (1, 2); Zhao, Yue (1, 2)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China; (2) Key Laboratory of Agricultural Land Quality, Ministry of Land and Resources, Beijing; 100193, China
Corresponding author:Zhu, Daolin(dlzhu@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:250-258
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the spatial distribution and formation mechanism of the cultivated land transfer rent, the spatial agglomeration and spatial layout of the cultivated land transfer rent in Henan Province was studied by applying spatial correlation analysis, such as global spatial autocorrelation analysis and hot spot analysis. Based on the study, the system of driving force indicators was constructed from the field of nature, society and economics according to "Regulations for valuation on agricultural land", which includes the classification of agricultural land, gross domestic product (GDP), proportion of the first industry, public revenue, public expenditure, urbanization rate, per capita GDP, and rural per capita net income. Meanwhile, correlation analysis and spatial econometric models were used to reveal the spatial pattern of cultivated land transfer rent and its forming mechanism. The results showed that, in general, the cultivated land transfer rent in Henan Province presented patterns of apparent invert U in the east-west direction and gradually emerged a descending trend from north to south. In the global spatial autocorrelation analysis, Moran's index reached 0.63, which indicated that the cultivated land transfer rent showed a significant clustering phenomenon in space, and specifically, the space pattern showed a high-high and low-low clustering. Furthermore, by applying hot spot analysis, it was found that the hot spots and sub hot spots were intensively distributed in the piedmont plain of Taihang Mountains and eastern plain of Henan Province, the sub cold spots in the periphery of the sub hot spots, such as cities of Pingdingshan, Eastern Nanyang and Zhumadian, and the cold spots mostly in Funiu Mountainous region and Dabie Mountainous region. The results of correlation analysis indicated that driving factors, including the classification of agricultural land, GDP, public revenue, urbanization rate, and rural per capita net income, were significantly correlated with the cultivated land transfer rent, in which the classification of agricultural land showed a significant negative correlation with the cultivated land transfer rent, while GDP, public revenue, urbanization rate, and rural per capita net income were positively associated with it. Moreover, among above factors, the significant spatial coupling with the cultivated land transfer rent still existed in the classification of agricultural land, GDP, public revenue and rural per capita net income. Spatial Error Model (SEM) was proved to be more effective and robust when compared with Spatial Lag Model (SLM) in the process of spatial econometric analysis by comparing precision parameters, such as R<sup>2</sup>, LogL, AIC, and SC. In the Spatial Error Model, the classification of agricultural land, GDP and rural per capita net income could satisfy the regression accuracy of 0.01, and public revenue also reached up to 0.05 significant level. The result of collinearity diagnostics showed that multiple collinearity existed among GDP, public revenue and rural per capita net income, and explained the puzzle of the coefficient of GDP being negative in spatial econometric model. In the ensuing analysis, stepwise regression model could achieve optimal result when the classification of agricultural land and rural per capita net income were just introduced into the model. Based on the analysis above, it was reckoned that the cultivated land transfer rent was not randomly distributed but showed a strong spatial autocorrelation in space; the cultivated land transfer rent was markedly influenced by the natural and social economic factors; Compared with the GDP and public revenue, the effects of the classification of agricultural land and rural per capita net income on the cultivated land transfer rent were more significant. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Spatial variables measurement
Controlled terms:Agriculture - Autocorrelation - Correlation methods - Economic analysis - Economic and social effects - Economics - Factor analysis - Land use - Landforms - Light modulators - Models - Regression analysis - Spatial distribution
Uncontrolled terms:Correlation analysis - Cultivated lands - Henan Province - Spatial econometric models - Spatial relations
Classification code:403 Urban and Regional Planning and Development - 481.1 Geology - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911.2 Industrial Economics - 921 Mathematics - 922.2 Mathematical Statistics - 943.2 Mechanical Variables Measurements - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2016.20.033
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 3>
Accession number:20164603020660
Title:Flowing boiling heat transfer characteristics test for microchannels with different surface energy in refrigeration system
Authors:Luo, Xiaoping (1); Deng, Cong (1); Feng, Zhenfei (1); Zhou, Jianyang (1)
Author affiliation:(1) School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou; 510640, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:217-222
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the development of many applications in modern industrial system and equipment, the ability to dissipate a large amount of heat from small surface area has been becoming increasingly urgent. Flow boiling in microchannels provides unique advantages when applied in micro-module equipment. Therefore, the microchannel heat exchangers have a broad industrial and market prospects for their high heat transfer coefficients and appreciable reduction in weight and volume. Flow boiling heat transfer in microchannels becomes one of popular researching hot spots. But the researches about flow boiling in microchannels with different surface energy are still lacked and further researches are needed. In this study, the current experiments fabricated 3 different modules with the identical sizes of 240 mm × 400 mm × 7.5 mm and with the different surface energy. Flow boiling experiments were conducted with the refrigerant R141b in a test module containing 22 microchannels which were 2 mm wide and 1 mm deep. During the experiments, the heat flux imposed on the aluminum substrate varied from 9 to 26 kW/m<sup>2</sup>and the mass flux flowing into the channel varied from 50 to 583 kg/(m<sup>2</sup>·s). The effects of the microchannels with different energy on boiling heat transfer under a certain pressure were experimentally investigated with different heat flux and mass flux. The results showed that the thermodynamic equilibrium quality increased fairly linearly with axial variation, with the slope inversely proportional to mass flow rate. The two-phase boiling heat transfer came earlier when mass flow rate was smaller and the increase of mass flow rate was beneficial to boiling heat transfer, but leading to the increasing of the length of the subcooled region. Heat transfer coefficient was relatively stable in the saturated boiling region of the microchannels and had a tendency to decrease along the flow direction due to the rise of gas phase proportion. Compared to the microchannels with the surface energy of 84.16 mN/m, the heat transfer coefficient of the microchannels with the surface energy of 21.12 and 62.99 mN/m increased by 18.42% and 9.28%, respectively. The augment of surface energy of microchannels was attributed to the boiling heat transfer coefficient. One reason was that the microchannels with higher surface energy had better wettability, which increased the liquid layer thickness and promoted dry patch rewetting, thus avoiding local dryout at heat transfer surface. Another was that there was more active nucleation in the microchannels with high surface energy, which made bubbles coalesce laterally during the growth phase before they departed from the surface. Three popular correlations were compared, and the correlation of Lazarek showed the best predictive capability with the mean absolute error (MAE) of 21.2%. In order to further improve the accuracy, the Jacobi number and thermodynamic equilibrium quality were introduced. The new correlation based on the correlation of Lazarek was obtained by fitting, which showed good predictions and was evidenced by an overall MAE of 9.76%. This research is beneficial to the parameter optimization of the predictive tool of the two-phase heat transfer coefficient and also provides the reference for the design of the microchannel heat exchangers. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Microchannels
Controlled terms:Cooling - Heat exchangers - Heat flux - Heat transfer - Heat transfer coefficients - Heating equipment - Interfacial energy - Mass transfer - Models - Phase transitions - Refrigeration
Uncontrolled terms:Boiling heat-transfer coefficients - Flow boiling - Flow boiling heat transfer - Micro-channel heat exchangers - Parameter optimization - Predictive capabilities - Thermodynamic equilibria - Two-phase heat transfer
Classification code:616.1 Heat Exchange Equipment and Components - 641.2 Heat Transfer - 641.3 Mass Transfer - 644.1 Refrigeration Methods - 801.4 Physical Chemistry
Numerical data indexing:Percentage 1.84e+01%, Percentage 2.12e+01%, Percentage 9.28e+00%, Percentage 9.76e+00%, Size 1.00e-03m, Size 2.00e-03m, Size 7.50e-03m, Surface_Power_Density 9.00e+03W/m2 to 2.60e+04W/m2, Surface_Tension 6.30e-02N*m, Surface_Tension 8.42e-02N*m
DOI:10.11975/j.issn.1002-6819.2016.20.028
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 4>
Accession number:20164603020637
Title:Performance optimization test on air-suction potato seed metering device with positive pressure airflow and zero-speed seeding
Authors:Lü, Jinqing (1); Yang, Ying (1); Shang, Qinqin (1); Li, Zihui (1); Li, Jicheng (1); Liu, Zhongyuan (1); Wang, Yingbo (1)
Author affiliation:(1) Department 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:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:40-48
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The existing zero-speed seeding technology has many disadvantages, such as being not suitable for high speed operation and the seed charge position too high. To make up for these shortcomings, a new technique of zero-speed seeding was proposed. This technology can also improve the precision of potato sowing. The positive pressure air was used as the driving force making the dropping tuber accelerated along the opposite direction of the seeding machine. In the process of falling, the horizontal velocity of tuber was zero relative to the ground. The zero-speed seeding technique was applied to sowing potato with this method. On the basis of the analysis of the throwing process, the main factors that affected the performance of zero-speed seeding were obtained, and the range of the test values of each factor was determined. These main factors were positive pressure, throw angle and rotation speed of the device. With these parameters as the experimental factors, a dual quadratic orthogonal rotational regressive test was designed. The qualified index, multiple index, missing index and coefficient of variation were selected as evaluation indices according to the national standards. The regression mathematical models between the indices and the factors were established after the test. The impacts of the factors on the evaluation indices were analyzed by using these mathematical models. The effects of positive pressure and rotation speed on the 4 indices were significant or highly significant. The throw angle had only a slightly significant effect on the coefficient of variation. When the seed metering device's rotation speed was 25-31 r/min, the main factor affecting the performance of seeding was the rotation speed. Each index value changed slightly with the change of positive pressure. When the seed metering device's rotation speed was 31-40 r/min, zero-speed seeding function of the positive pressure could effectively improve the quality of seeding. The qualified index increased and the coefficient of variation decreased with the increase of the positive pressure. At the same time, these 2 indices, the multiple index and the missing index, both had different degrees of decline. Parameters were optimized based on regression models. With the maximum qualified index, the minimum variation coefficient, the minimum multiple index and the minimum missing index as the optimization objectives, the ranges of the factors were as follows: the positive pressure of 5-15 kPa, the throw angle of 45°-75° and the rotation speed of 25-40 r/min. And taking into account the agronomic requirements of potato cultivation, the missing index was expected to be not greater than 3%. Optimization results showed that, the qualified index was 95.22%, the multiple index was 3.51%, the missing index was 1.27% and the variation coefficient was 9.43% under the condition of the positive pressure of 15 kPa, the throw angle of 57° and the rotation speed of 35 r/min. The seeding performances of developed device met the requirement of precision seeding. Results in the research give the guidance for the optimization of air-suction potato seed metering device, and provide a technical support for improving the seeding accuracy of potato and many other crops. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Speed
Controlled terms:Agricultural machinery - Air navigation - Cultivation - Pneumatic equipment - Pneumatic materials handling equipment - Regression analysis - Rotation - Seed
Uncontrolled terms:Coefficient of variation - Experimental factors - High-speed operation - Performance optimizations - Potato - Seed metering devices - Variation coefficient - Zero speed
Classification code:431.5 Air Navigation and Traffic Control - 632.4 Pneumatic Equipment and Machinery - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 931.1 Mechanics
Numerical data indexing:Percentage 1.27e+00%, Percentage 3.00e+00%, Percentage 3.51e+00%, Percentage 9.43e+00%, Percentage 9.52e+01%, Pressure 1.50e+04Pa, Pressure 5.00e+03Pa to 1.50e+04Pa, Rotational_Speed 2.50e+01RPM to 3.10e+01RPM, Rotational_Speed 2.50e+01RPM to 4.00e+01RPM, Rotational_Speed 3.10e+01RPM to 4.00e+01RPM, Rotational_Speed 3.50e+01RPM
DOI:10.11975/j.issn.1002-6819.2016.20.005
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 5>
Accession number:20164603020633
Title:Enhancing agricultural mechanization level through information technology
Authors:Luo, Xiwen (1); Liao, Juan (1); Zou, Xiangjun (1); Zhang, Zhigang (1); Zhou, Zhiyan (1); Zang, Ying (1); Hu, Lian (1)
Author affiliation:(1) Key Laboratory of Key Technology for South Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:1-14
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Since 1978, great progress has been achieved in Chinese agriculture. However, the problems still exist in the development process, such as low labor productivity, high production cost, low land productivity, low yield, low rate of resource utilization and lacking international competitiveness of agricultural products. One important reason for these problems lies in the low agricultural mechanization level in China. The informationization of agricultural machinery is a fundamental way to enhance agricultural mechanization level. In order to keep the sustained growth of agricultural mechanization level and accomplish the agricultural sustainable development in China, it is critical to take full advantages of advanced information technology to improve the design, manufacturing, operation and management of agricultural machinery, and then to enhance the level of agricultural mechanization. This paper mainly introduced: 1) The key information technologies for agricultural machinery design: parametric design, agricultural machinery product design based on knowledge engineering, and concurrent and collaborative design based on product data management; 2) The key information technologies for agricultural machinery manufacturing: flexible manufacturing, computer integrated manufacturing, and virtual and network manufacturing; 3) The key information technologies for agricultural machinery operation: agricultural information acquisition, agricultural machinery navigation, and field management; 4) The key information technologies for agricultural machinery management: agricultural machinery management, and agricultural machinery scheduling. The deficiencies of current information technologies were analyzed, the development trend was summarized for the countries all over the world, and the core issues of enhancing the agricultural mechanization level in China for present information technologies were proposed. In order to further enhance the level of agricultural mechanization by using information technology, some suggestions are proposed in this paper: 1) To make the breakthrough in key technologies of digital design of intelligent equipment, coordinated control of auto-navigation and fieldbus technology of agricultural equipment; 2) To strengthen the innovation of major precision production equipment, such as precision production equipment for field operation and facilities agriculture, orchard production and livestock, and poultry and aquaculture production; 3) To construct the precision operating system for modern agricultural machinery, and to research and develop a series of major technical products, such as precision operating system of water, fertilizer and pesticide, automatic feeding system and automated processing production line of livestock, poultry and aquaculture. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:107
Main heading:Agriculture
Controlled terms:Agricultural machinery - Agricultural products - Aquaculture - Computer integrated manufacturing - Equipment - Information management - Information technology - Machine design - Manufacture - Mechanization - Planning - Product design - Productivity - Scheduling - Sustainable development
Uncontrolled terms:Agricultural informations - Agricultural mechanization - Automatic feeding systems - Concurrent and collaborative design - International competitiveness - Machinery manufacturing - Modern agricultures - Operation and management
Classification code:601 Mechanical Design - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession - 903 Information Science - 912.2 Management - 913 Production Planning and Control; Manufacturing
DOI:10.11975/j.issn.1002-6819.2016.20.001
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 6>
Accession number:20164603020653
Title:Erosion morphology and runoff generation and sediment yield on ephemeral gully in loess hilly region in field scouring experiment
Authors:Kang, Hongliang (1); Wang, Wenlong (1, 2); Xue, Zhide (3); Guo, Mingming (1); Shi, Qianhua (1); Li, Jianming (4); Guo, Junquan (5)
Author affiliation:(1) State Key Laboratory of Erosion and Dryland Agriculture on the Loess Plateaus, Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China; (2) Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling; 712100, China; (3) College of Natural Resources and Environment, Northwest A&F University, Yangling; 712100, China; (4) Soil and Water Conservation Department, Yangtze River Scientific Research Institute, Wuhan; 430010, China; (5) Yan'an Vocational & Technical College, Yan'an; 716000, China
Corresponding author:Wang, Wenlong(wlwang@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:161-170
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ephemeral gully is a kind of erosion channel formed due to alternative action of runoff scouring and tillage. It can be easily filled by normal tillage and reform again in the same location by erosive rainfall events. Ephemeral gully is not only the main channel of sediment transport, but also is the main source of eroded sediments. A field scouring experiment was conducted on a typical sloping farmland in Yan'er watershed of Baota region (36°11'-37°09'N, 109°21'-110°03'E), Yan'an, Shannxi to investigate runoff characteristics and sediment yield process and morphology parameters on ephemeral gullies with different gradients under different flow discharges. Soil of the farmland was composed of 7.8% clay and 66.5% silt and 25.7% sand. With consideration of physical condition of the farmland, the gradients of ephemeral gullies were selected as 14°-29° according to preliminary field investigations. The range of flow discharge was decided as 5-25 L/min through a theoretical equation, in which rainfall intensity and runoff coefficient and some of topographic factors were given. The size of ephemeral gully plot for the experiment was designed with the length of 5 m and width of 1 m, constructed as "imbricated land-form" with 10 cm of elevation from the bottom to the edge of the channel. A set of equipment was laid out to provide evenly and stable water flow with a valve to obtain a desired and constant flow discharge. Before each test, flow discharge was calibrated repeatedly to guarantee uniformity and veracity. During the experiment, flow velocity was measured with dye tracing method and flow width and depth were measured with a thin steel rule and point gauge every 5min. Runoff sample was firstly taken once a minute within 3 minutes after runoff generation, then once 3 minutes within the rest time. After an event, morphology parameters such as width and depth of erosion gully were measured for every 5 cm of distance for transverse sections from up-slope to down-slope. The results showed that: 1) Runoff generation time ranged from 7.00 s to 68.02 s and a significant power function with a negative index was found between the runoff generation time and the interaction of gradient and flow discharge. Stable runoff rate, with a range of 3.06-23.71 L/min, increased linearly with flow discharge increasing and showed an increasing tendency when the gradient increased. A very significant power function was established between the stable flow velocity and interaction of gradient and flow discharge, and the stable flow velocity changed with the maximum value of 55.59 cm/s and the minimum of 27.35 cm/s; 2) Sediment yield rate varied with time as 2 types of tendency of "decrease with fluctuation - stable" and "increase - decrease with fluctuation - stable". Average sediment yield rate increased as an exponential function with increasing flow discharge and increased firstly and then reduced with increase of gradient with a critical value of 26°; 3) The ranges of average width and depth of erosion gully were 4.45-17.09 cm and 1.88-10.15 cm, respectively. Average width-depth ratio varied with a range of 1.45-2.39. Average cross-section area, ranged from 11.40 to 197.91 cm<sup>2</sup>, was the best one of all the morphology parameters to describe the sediment yield with a super-significant linear function. The results obtained may provide support for the establishment of empirical and process-based model of soil and water loss on ephemeral gullies in Loess Plateau. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Runoff
Controlled terms:Agricultural machinery - Agriculture - Catchments - Erosion - Exponential functions - Farms - Flow of water - Flow velocity - Flowmeters - Landforms - Morphology - Rain - Sediment transport - Sediments - Silt - Soil testing
Uncontrolled terms:Ephemeral gullies - Loess hilly regions - Morphology parameters - Process-based modeling - Runoff characteristics - Runoff coefficients - Scouring experiments - Theoretical equation
Classification code:442.1 Flood Control - 443.3 Precipitation - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 631 Fluid Flow - 631.1.1 Liquid Dynamics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 921 Mathematics - 943.1 Mechanical Instruments - 951 Materials Science
Numerical data indexing:Area 1.14e-03m2 to 1.98e-02m2, Percentage 2.57e+01%, Percentage 6.65e+01%, Percentage 7.80e+00%, Size 1.00e+00m, Size 1.00e-01m, Size 1.88e-02m to 1.02e-01m, Size 4.45e-02m to 1.71e-01m, Size 5.00e+00m, Size 5.00e-02m, Time 1.80e+02s, Time 3.00e+02s, Time 7.00e+00s to 6.80e+01s, Velocity 5.56e-01m/s
DOI:10.11975/j.issn.1002-6819.2016.20.021
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 7>
Accession number:20164603020652
Title:Response of soil shear strength to soil water content in purple soil slope cropland bunds
Authors:Wei, Jie (1, 2); Shi, Binglin (1); Li, Jinlin (1)
Author affiliation:(1) School of Geography and Tourism Science, Chongqing Normal University, Chongqing; 401331, China; (2) Chongqing Key Laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area, Chongqing; 401331, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:153-160
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil bunds play a key role in controlling soil erosion on sloping farmlands, however, the performance and mechanism of purple soil bunds against water erosion is little reported. The objective of the present study was to analyze the soil shear strength features of purple soil bunds under different soil water content scenarios. Samples were selected from 3 types of purple soil bunds in Zhongxian County in the Three Gorges area. An unconsolidated-undrained (UU) triaxial compression test was carried out to study the soil shear strength in terms of the cohesion, internal friction angle and principal stress difference. Considering the actual water content in soil bunds and other soil physical properties, we set 6 levels of water content (from 6% to 31% with an interval of 5%) to prepare soil specimens for the test. The results showed that: 1) Within the testing water content from 6% to 31%, the soil cohesion had significant differences among different water content (P<0.05). It was increasing and then decreasing with the increment of the water content, which could be fitted by a quadratic curve. The maximum of the soil cohesion 85.52 kPa for purple bund soil occurred at the soil mass fraction of water content of 11%. When the mass fraction of water content reached 26%, the decreasing rate of soil cohesion was faster, resulting in a soil shear strength attenuation; 2) The soil water content had significant effects on the internal friction angle of bund soil (P<0.05). It decreased from 33.19<sup>°</sup>to 1.36<sup>°</sup>with the increasing soil water content, showing a first-order exponential decay. However, it decreased slowly at a high water content of 26%; 3) Significant differences (P<0.05) occurred in the soil limit principal stress difference of the purple soil bund under different soil water content. It changed obviously with the varying soil water contents and confining pressures. Under the same confining pressure, the limit soil principal stress difference decreased rapidly with increasing soil water content, indicating the reduction of soil shear strength. Under the same water content, the limit principal stress difference increased with the increment of the confining pressure. It increased relatively fast at low water contents, while slowly at high water contents. When the mass fraction of water content was 11%-25%, the soil shear strength was relatively larger than the other water content conditions. While the soil shear strength tended to be a minimum when the mass fraction of water content was about 26%; 4) The stress-strain curves of purple soil bunds affected by different water content could be categorized into 3 types, that is, softening type, hardening type and weak hardening type. In the condition of small confining pressure and low water content, a maximum appeared in the stress-strain curve, showing a softening type. When the water content and confining pressure increased, the stress-strain curve gradually changed to a hardening type. However, the stress-strain curves gradually transformed into a weak hardening type under a condition of high water content. The results can provide support for bund construction in ecological projects, for example, high standard basic farmland construction, in the Three Gorges Reservoir area. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Soil testing
Controlled terms:Adhesion - Compression testing - Erosion - Farms - Friction - Hardening - Internal friction - Reservoirs (water) - Rock pressure - Shear flow - Shear strength - Soil moisture - Soils - Stress-strain curves - Water content
Uncontrolled terms:Different water contents - Internal friction angle - Purple soils - Sloping farmlands - Soil physical property - Three gorges reservoir area - Tri-axial compression tests - Water content in soil
Classification code:441.2 Reservoirs - 483.1 Soils and Soil Mechanics - 502.1 Mine and Quarry Operations - 537.1 Heat Treatment Processes - 631.1 Fluid Flow, General - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 951 Materials Science
Numerical data indexing:Percentage 1.10e+01%, Percentage 1.10e+01% to 2.50e+01%, Percentage 2.60e+01%, Percentage 5.00e+00%, Percentage 6.00e+00% to 3.10e+01%, Pressure 8.55e+04Pa
DOI:10.11975/j.issn.1002-6819.2016.20.020
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 8>
Accession number:20164603020645
Title:Optimization and experiment of adjustable structural parameters for vertical impact sprinkler with working pressure
Authors:Tang, Pan (1); Li, Hong (1); Chen, Chao (1); Sun, Caizhen (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang; 212013, China
Corresponding author:Li, Hong(hli@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:99-107
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The adjustable structural parameters of sprinkler were optimized in order to get the optimal hydraulic performance of vertical impact sprinkler. The variation coefficient of sprinkler irrigation, average application rate of sprinkler irrigation, uniformity coefficient under square arrangement and uniformity coefficient under regular triangle arrangement were taken as response indices to analyze the influence of distance between counterweight and rotational center, working pressure and nozzle diameter on hydraulic performance. The experimental study on the adjustable parameters of vertical impact sprinkler with working pressure was performed with the central composite design and the response surface methodology. The multiple regression models between the different response indices and working parameters were established. The analysis of variance was used to analyze the influence of the factors and their interactions on different indices according to the analytical results. The multiple regression models were used to optimize the indices by single-objective optimization and multi-objective optimization. Finally, the effectiveness was validated through an experiment. The results showed that: the significance order of impact factors for variation coefficient of sprinkler irrigation was working pressure, nozzle diameter, and distance between counterweight and rotational center; that for average application rate of sprinkler irrigation was nozzle diameter, distance between counterweight and rotational center, and working pressure; that for uniformity coefficient under square arrangement was working pressure, distance between counterweight and rotational center, and nozzle diameter; that for uniformity coefficient under regular triangle arrangement was working pressure, distance between counterweight and rotational center, and nozzle diameter. R<sup>2</sup>value of multiple regression models for variation coefficient of sprinkler irrigation, average application rate of sprinkler irrigation, uniformity coefficient under square arrangement and uniformity coefficient under regular triangle arrangement were 0.9576, 0.9696, 0.9559 and 0.9546 respectively. Under the condition of single-objective optimization, the optimal parameter combination for the minimum variation coefficient of sprinkler irrigation was figured out as follows: the distance between counterweight and rotational center was 126 mm, the working pressure was 600 kPa, and the nozzle diameter was 16.6 mm; the optimal parameter combination for the minimum average application rate of sprinkler irrigation was that the distance between counterweight and rotational center was 115 mm, the working pressure was 219 kPa, and the nozzle diameter was 12.5 mm; the optimal parameter combination for the maximum uniformity coefficient under square arrangement was that the distance between counterweight and rotational center was 143 mm, the working pressure was 585 kPa, and the nozzle diameter was 23.7 mm; the optimal parameter combination for the maximum uniformity coefficient under regular triangle arrangement was that the distance between counterweight and rotational center was 115 mm, the working pressure was 219 kPa, and the nozzle diameter was 12.5 mm. Under the condition of multi-objective optimization, the optimal parameter combination for the minimum variation coefficient of sprinkler irrigation and average application rate of sprinkler irrigation, the maximum uniformity coefficient under square arrangement and uniformity coefficient under regular triangle arrangement was that the distance between counterweight and rotational center was 146 mm, the working pressure was 583 kPa, and the nozzle diameter was 23.4 mm; and its corresponding variation coefficient of sprinkler irrigation, average application rate of sprinkler irrigation, uniformity coefficient under square arrangement and uniformity coefficient under regular triangle arrangement were 0.27, 6.37 mm/h, 87.60% and 87.93%, respectively. The optimization results were validated, and the error between predicted values and experimental values was less than 5%, which indicated the predicting regression models had high credibility. The study provides the reference for designing the vertical impact sprinkler and properly regulating the working parameters to get the optimal hydraulic performance. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Sprinkler systems (irrigation)
Controlled terms:Irrigation - Multiobjective optimization - Nozzles - Optimization - Regression analysis - Surface properties
Uncontrolled terms:Central composite designs - Irrigation uniformity - Multiple regression model - Optimal parameter combinations - Response surface methodology - Single objective optimization - Variation coefficient - Working pressures
Classification code:821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods - 921.5 Optimization Techniques - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Percentage 5.00e+00%, Percentage 8.76e+01%, Percentage 8.79e+01%, Pressure 2.19e+05Pa, Pressure 5.83e+05Pa, Pressure 5.85e+05Pa, Pressure 6.00e+05Pa, Size 1.15e-01m, Size 1.25e-02m, Size 1.26e-01m, Size 1.43e-01m, Size 1.46e-01m
DOI:10.11975/j.issn.1002-6819.2016.20.013
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 9>
Accession number:20164603020662
Title:Analysis of scale aquaculture production efficiency and analysis of its determinants
Authors:Zheng, Sining (1); Liu, Qiang (2); Zheng, Yifang (1)
Author affiliation:(1) School of Public Administration, Fujian Agriculture and Forestry University, Fuzhou; 350028, China; (2) China Academy for Rural Development (CARD), Zhejiang University, Hangzhou; 310058, China
Corresponding author:Zheng, Yifang(zyf7151@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:229-235
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aquaculture park is an important form to promote scale breeding, which has an important significance for the transformation of aquaculture production style and the structural reform of supply side. In this paper, we use the stochastic frontier approach to analyze the production efficiency of aquaculture park with large scale in Zhejiang Province and its influencing factors. The stochastic frontier analysis method is widely used in the studies on agricultural production, yet the research using this method to calculate the technology efficiency of aquaculture park and analyze its influencing factors is relatively few. The technical efficiency of tilapia culture in Guangxi and the technical efficiency of freshwater aquaculture in China have been studied by some scholars. However, most of these studies are limited to a single aquatic species or based on macro data, lacking the analysis of the operating efficiency of the micro main varieties. This paper chooses Zhejiang Province as the research area because of its developed aquaculture industry, typical park construction, standard breeding and industrial organization system. Based on previous studies, we investigate the technical efficiency of aquatic breeding park and its influencing factors, which aimed to provide reference for the healthy development of the aquaculture industry in China. The data of empirical analysis come from the Agriculture Department and the Financial Department of Zhejiang Province, which cover 116 modern fishery parks. Cross-sectional data of both before and after the construction of modern fishery park are collected. Statistical indicators mainly include the scale and efficiency (breeding area, total production, total output value, labor productivity per capita), capital investments (provincial capital investment, capital investment of owners), facilities and equipment investments (reservoir, cold storage preservation, supporting house for production, oxygen increasing machine, feeding machine), technology application and brand building (standardized production area, sewage purification treatment, disease prevention and treatment, aquatic products brand), and business entities (main operating company, cooperatives and farmers). Case data are discarded if key information is missing. At last, a total of 108 valid cases are obtained. In order to eliminate the impact of price changes, the output value of fishery park, the capital investments and other variables are divided by production price index. The results show that: 1) Scale production exerts a positive effect on the aquaculture production efficiency which has increased from 0.673 to 0.712 since the completion of the park; 2) The standardization level effectively improves the breeding technology efficiency of the park, with a regression coefficient of -0.0003; 3) Disease control equipment improves the technical inefficiency (the regression coefficient is 0.0033), which means that excessive investment in infrastructure will lead to idle equipment and hinder the improvement of technical efficiency; 4) Brand building positively influences the breeding technology efficiency of the park, with a regression coefficient of -0.0033; 5) Leading enterprises have the greatest positive effect on the level of technical efficiency, followed by the organization of fishery cooperation and the large professional farmers, with the regression coefficients of technical inefficiency being -0.0017, 0.0015 and -0.0008 respectively. But the regression coefficient of ordinary farmers is 0.0012, which implies no significant effect on the efficiency of aquaculture technology. Some policy implications can be drawn from the results of the empirical study. Increasing production of aquaculture park inputs, investing infrastructure following principle of moderate scale, paying attention to brand building and innovating the mode of fishery organization and so on may enhance the technical efficiency of aquaculture park. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Investments
Controlled terms:Agricultural machinery - Agriculture - Aquaculture - Building codes - Cold storage - Control equipment - Digital storage - Disease control - Efficiency - Equipment - Fisheries - Historic preservation - Industrial research - Productivity - Public policy - Regression analysis - Sewage - Stochastic systems
Uncontrolled terms:Agricultural productions - Industrial organization - Statistical indicators - Stochastic frontier - Stochastic frontier analysis - Stochastic frontier approaches - Technical efficiency - Technology application
Classification code:402 Buildings and Towers - 452.1 Sewage - 644.3 Refrigeration Equipment and Components - 722.1 Data Storage, Equipment and Techniques - 732.1 Control Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession - 901.3 Engineering Research - 913.1 Production Engineering - 922.2 Mathematical Statistics - 961 Systems Science - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2016.20.030
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 10>
Accession number:20164603020640
Title:Analysis on cloud characteristics of wear acoustic emission signal for vehicle cutting tool
Authors:Guan, Shan (1); Kang, Zhenxing (1); Peng, Chang (1)
Author affiliation:(1) School of Mechanical Engineering, Northeast Dianli University, Jilin; 132012, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:63-69
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Tool is the most common part easy to wear and fail in CNC (computer numerical control) system, machining center and other highly integrated and intelligent equipment. Tool wear condition monitoring is of great significance to ensure the machining quality, machining accuracy and machining efficiency of the parts. At present, the common tool wear condition monitoring signal is vibration signal, cutting force signal, current signal and acoustic emission signal. Compared with other monitoring signals, the frequency of acoustic emission signal can reach 50 kHz - 1 MHz with high sensitivity and strong anti-interference ability, which can effectively filter the low frequency noise in the process. Therefore, this paper analyzed the characteristics state of tool wear's acoustic emission signal. Metal in the cutting process will produce a wealth of acoustic emission signals, and these signals are easy to be affected by the comprehensive factors such as processing materials, cutting conditions and cutting parameters. A number of cutting experiments showed that the tool wear was uncertain under the same cutting conditions. Cloud model theory is a kind of qualitative concept to quantitative data uncertainty transformation model proposed by academician Li Deyi. The cloud theory has strong adaptability to the uncertainty problem. In view of the tool wear acoustic emission signal's non-stationarity and uncertainty, signal analysis and feature extraction method were put forward based on cloud theory. This paper aimed at the research topic of tool wear condition monitoring under different cutting condition, and used orthogonal test method to arrange a large number of cutting tests. On the basis of the acquisition of the acoustic emission signal, wavelet packet analysis method was applied to realize the signal filtering processing. A cloud of uncertainty model theory was introduced into the feature extraction of the different cutting tool wear stages. First of all, the different stages of the wear band distribution of acoustic emission signal range were obtained through the spectrum analysis, and served as the wavelet packet decomposition levels of qualitative reference; second, the Shannon entropy in the information entropy theory was applied to characterize the size of the noise in order to determine the best wavelet packet decomposition tree; finally, we used statistical analysis method to determine the best wavelet packet decomposition tree of the optimal branch, and after signal threshold processing, signal was reconstructed, and the denoising effect was verified through the ratio of signal to noise. In view of the tool wear condition monitoring and wear prediction research, feature extraction is a key technology. Therefore, this paper put forward the signal feature extraction method based on cloud theory. First of all, according to the statistical distribution characteristics of reconstructed signal, backward cloud algorithm was utilized to extract the cloud characteristic parameters of signal sensitive band, i.e. expected value, entropy and hyper entropy; the change rule of the 3 types of cloud characteristics parameters of cutting tool with the increase of wear was quantitatively analyzed in different cutting conditions; second, the effectiveness of 3 kinds of parameters characterizing tool wear acoustic emission signal during feature extraction was analyzed through a scatter diagram; finally, the effectiveness of the cloud model to represent knowledge was verified through data histogram and cloud image contrast. The research results show that the tool wear acoustic emission signal has obvious characteristics of cloud, and 3 cloud characteristic parameters and tool wear status have obvious corresponding relation, which can be used for characteristic parameters of tool wear condition monitoring and wear prediction. Cloud theory is applied in the field of tool wear monitoring, expanding the scope of the representation of knowledge. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Cutting tools
Controlled terms:Acoustic emission testing - Acoustic emissions - Acoustic noise - Cloud computing - Computer control systems - Condition monitoring - Cutting - Extraction - Feature extraction - Forestry - Machining - Metadata - Metal cutting - Monitoring - Signal processing - Signal to noise ratio - Spectrum analysis - Testing - Uncertainty analysis - Wavelet analysis - Wavelet decomposition - Wear of materials
Uncontrolled terms:Characteristics parameters - Cloud theory - Computer numerical control - Feature extraction methods - Signal characteristic - Statistical analysis methods - Tool wear condition monitoring - Wavelet Packet Decomposition
Classification code:603.2 Machine Tool Accessories - 604.1 Metal Cutting - 604.2 Machining Operations - 716.1 Information Theory and Signal Processing - 722.4 Digital Computers and Systems - 723.5 Computer Applications - 751.2 Acoustic Properties of Materials - 751.4 Acoustic Noise - 802.3 Chemical Operations - 921 Mathematics - 921.3 Mathematical Transformations - 922.1 Probability Theory - 951 Materials Science
Numerical data indexing:Frequency 5.00e+04Hz to 1.00e+06Hz
DOI:10.11975/j.issn.1002-6819.2016.20.008
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 11>
Accession number:20164603020670
Title:Calculation and validation of moisture uniformity in drying process based on Shannon-Wiener index
Authors:Zhang, Hang (1); Deng, Shengxiang (1)
Author affiliation:(1) Department of Energy Science and Engineering, Central South University, Changsha; 410083, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:290-297
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Belt dryers are the most popular equipment for betel nut drying. One of the drawbacks of this dryer is the non-uniformity in the desired moisture content of end product. In order to improve the structure of flow field and the moisture uniformity for the belt dryer, on the theoretical basis of computational fluid dynamics, the effects of the accumulative thickness, air velocity, air temperature and moisture content of hot air on the moisture uniformity of betel nut dried were simulated and discussed by using FLUENT software package. The orthogonal table about 4 factors and 3 levels was designed. In this paper, the betel nut was considered to be a wet porous medium, and the air flow through the areca layer was seen as the flow inside the porous medium, as well as the flow in the layer. By adding momentum equation source term to the momentum equation, the porous medium model was formed. The momentum equation was divided into 2 parts which included viscous item loss and inertia item loss. Experimental verification was carried out. Experimental test was finished in a multilayer belt dryer designed by Hunan Chain Co. Ltd.. The dryer was a five-layer mesh belt with cross flow drying system. Observation hole was set in the 1<sup>st</sup>path (top layer) and the 5<sup>th</sup>path (bottom layer), and the hole position was X=0.8, 2.4, 4.0, 5.6, 7.2 m, respectively. After washing, soaking, air-curing, separating, removing the film, rinsing and draining, betel nut was dried in dryer. The QDF-2B hot ball type electric wind speed meter was set to test the wind speed of the dryer, and the measured data had a good agreement with the calculation results. Based on the Shannon-Wiener index, the water content uniformity index was put forward, which was compared to the conventional index and the calculation result. Two deflectors with different shape (traditional deflector and wing-shape deflector) were put forward and analyzed. Simulation results showed that in the length direction of top path, the wind speed at the positions of X=4 m and X=6 m was relatively larger, which was 0.8 and 0.7 m/s respectively. The wind speed when X was equal to 4-6 m was gradually reduced, while that when X was equal to 4.5-5.5 m was the lowest (0.4 m/s). The wind speed curve had the "camel peak" shape. In the length direction of bottom path, the hot air was divided into 2 parts, most of which flowed along the length direction, and the remaining moved upward through the material layer. The speed was gradually reduced in bottom channel, and the speed through the material layer was maintained above 1.05 m/s. Results showed that the moisture content of the betel nut layer with a thickness of 80 mm was more uniform than 40 or 60 mm. Therefore, the thickness of betel nut had most effect on the uniformity of moisture content than the other 2 factors. The general trends of water content uniformity index, conventional index and "camel peak" curves were similar, but that of the water content uniformity index was more close to the calculation result. It indicated that layer thickness of 80 mm, inlet temperature of 70℃, flow rate of 1.5 m/s, moisture content of 0.24 were more conducive to moisture uniformity. The deflector could obviously improve the uniformity of moisture. Installing simple deflector mildly expanded the contact area of air inlet and slightly reduced the moisture of betel nut, yet there still had partial areas without drying. These areas were mainly distributed in the middle and sides of the dryer. After equipping with wing deflector at the entrance of dryer, hot air was evenly distributed to the entire first path, while moisture content of the betel nut layer decreased from 0.285 to 0.215, and moisture uniformity was improved. In the case of shortening the drying time by 5 min, the water content uniformity index was 0.926, and the drying efficiency was promoted. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Drying
Controlled terms:Air - Computational fluid dynamics - Computer simulation - Curing - Dryers (equipment) - Flow fields - Fluid dynamics - Graph theory - Machinery - Mechanization - Moisture - Moisture determination - Molecular structure - Momentum - Porous materials - Speed - Water distribution systems - Wind
Uncontrolled terms:Belt dryer - Calculation results - Content uniformity - Experimental test - Experimental verification - Momentum equation - Porous medium model - Wiener index
Classification code:443.1 Atmospheric Properties - 446.1 Water Supply Systems - 601 Mechanical Design - 631.1 Fluid Flow, General - 723.5 Computer Applications - 802.2 Chemical Reactions - 804 Chemical Products Generally - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 931.1 Mechanics - 931.3 Atomic and Molecular Physics - 944.2 Moisture Measurements - 951 Materials Science
Numerical data indexing:Size 4.00e+00m to 6.00e+00m, Size 4.50e+00m to 5.50e+00m, Size 6.00e-02m, Size 7.20e+00m, Size 8.00e-02m, Time 3.00e+02s, Velocity 1.05e+00m/s, Velocity 1.50e+00m/s, Velocity 4.00e-01m/s, Velocity 7.00e-01m/s
DOI:10.11975/j.issn.1002-6819.2016.20.038
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 12>
Accession number:20164603020667
Title:Review on rapid detection of pesticide residues in agricultural and food products
Authors:Jiang, Xuesong (1, 2); Wang, Weiqin (2); Xu, Linyun (1); Lu, Liqun (2); Zhou, Hongping (1); Chen, Huihui (2)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) Ningbo Haitong Food Science & Technology Company Limited, Ningbo; 315300, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:267-274
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pesticides were widely applied to eliminate or control a variety of agricultural pests and diseases. However, they exhibited acute or chronic toxicity on human health through their residues in agricultural product and food. Thus, monitoring pesticide residues was extremely crucial to ensure that pesticides in agricultural products were in permitted levels. The identification and quantification of pesticides were generally based on mass spectrometry combined with gas and/or liquid chromatography, or capillary electrophoresis. However, these methods involved large and expensive instruments, time-consuming sample preparation and trained personnel. Therefore, it was important to set up onsite assays and techniques, especially highly sensitive and selective, simple, efficient, and cost effective ones for rapid detection of pesticide residues. This review summarized the application of fast analytical methodologies such as enzyme inhibition assays (EIA), immunoassays, optical spectroscopy assays and various biosensors in the analysis of pesticide residues in agro product and food in the past few years. EIA was widely used for rapid colorimetric or spectrophotometric screening of pesticides in China, which was based on the inhibition of cholinesterase (ChE) activity by organophosphate and carbamate. Immunoassays, such as enzyme-linked immunosorbent assay (ELISA), were quantitative or qualitative methods of analysis for a substance, which took antibodies as the analytical reagents. Immunoassays depended on the use of an analytical reagent that was associated with a detectable marker, such as enzyme, fluorescence, chemoluminescence radioactive element, and so on. Colloidal gold-based immunoassay was proven to be fast, sensitive and cost-effective for pesticide detection. Biosensors were analytical devices, used for the detection of analytes, which combined a biological component with a physicochemical detector. The development of biosensors for pesticides was also an active research area, which offered great advantages over conventional analytical techniques. Aptamers were shown as good candidates to replace the conventional antibodies in more robust and stable biosensors for pesticide detection. Optical spectroscopy assays, including visible/near-infrared, Roman, and Tera Hertz time-domain spectroscopy, had pollution-free and lossless nature, which were regarded as potential methods for qualitative and quantitative analyses of pesticides. The basic principles of these fast screening strategies were discussed, and both advantages and drawbacks of these techniques were then summarized. Special emphasis was placed on the state-of-art techniques including nanobiotechnology, molecular imprinting technique (MIT) and microfluidics, because of their great potential in pesticide residue analyses. Nanomaterials including carbon nanotubes (CNTs), quantum dots and nanoparticles were developed to improve the performance of pesticide detection. MIT, as a burgeoning powerful technology, was gaining increasing attention for its prospect of creating synthetic polymers with highly specific recognition capabilities in complicated samples. Furthermore, the future perspectives and the trends for pesticide residue analysis were also presented. Most studies were focused on the detection of insecticides, which were used in very large quantities. In future, it is necessary to pay more attention to the detection of other families of pesticides with lower mammalian toxicity, such as herbicides and plant growth regulators. The miniaturization and integration, multi-channel detection, wireless communication, higher stability and repeatability of the detection instruments are the development direction of pesticide residue detection in the future. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:60
Main heading:Time domain analysis
Controlled terms:Agricultural products - Agriculture - Analytic equipment - Antibodies - Assays - Bioassay - Biosensors - Capillary electrophoresis - Carbon - Carbon nanotubes - Chemical analysis - Chemical contamination - Chemical detection - Chemical sensors - Cost effectiveness - Diagnosis - Disease control - Enzyme inhibition - Enzymes - Food products - Gas chromatography - Immunology - Liquid chromatography - Mammals - Mass spectrometry - Pesticides - Radioactivity - Semiconductor quantum dots - Spectrum analysis - Toxicity - Wireless telecommunication systems - Yarn
Uncontrolled terms:Enzyme linked immunosorbent assay - Fast detections - Immunoassay - Molecular imprinting techniques - Pesticide residue analysis - Qualitative and quantitative analysis - Time domain spectroscopy - Wireless communications
Classification code:461 Bioengineering and Biology - 622 Radioactive Materials - 714.2 Semiconductor Devices and Integrated Circuits - 761 Nanotechnology - 801 Chemistry - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 819.4 Fiber Products - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 822.3 Food Products - 911.2 Industrial Economics - 921 Mathematics
DOI:10.11975/j.issn.1002-6819.2016.20.035
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 13>
Accession number:20164603020654
Title:Evaluation index system for rural water conservancy modernization in China
Authors:Qiu, Yuanfeng (1); Meng, Ge (2); Lei, Shenglong (1)
Author affiliation:(1) School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan; 430072, China; (2) School of Resource and Civil Engineering, Wuhan Institute of Technology, Wuhan; 430073, China
Corresponding author:Meng, Ge(172246012@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:171-178
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Evaluating China's rural water conservancy modernization level objectively and scientifically is very important. In this paper, an evaluation system of rural water conservancy modernization in China was established based on modernization theory: the first rural water conservancy modernization mainly to improve the ability of disaster prevention and reduction and the second water conservancy modernization mainly on how to realize the sustainable utilization of water resources. It puts forward the first and second rural water conservancy modernization evaluation index system. The first rural water conservancy modernization evaluation indexes were given priority to infrastructure, including 4 indexes such as dependable farmland, projects supporting, drinking water safety and disaster reduction. The secondary rural water conservancy modernization evaluation indexes were given priority to quality, efficiency, and good governance, a total of 17 indicators. Using weighted evaluation model and SAS statistical software to analyze the basic parameters of every province (municipality or autonomous region), such as land treatment,farmers inputs,technology input, irrigation benefit, water supply, water quality, pollution control, resource exploitation, wet land index, charging level, participation level, water right trade and management quality, the first rural and the second rural water conservancy modernization index of every province (municipality or autonomous region) in China were calculated respectively. Results showed that the development trend of China's first rural water conservancy modernization was similar with the development trend of the first modernization of China's economy and the world's economy, and the modernization level was promoted with the growth of the first economic modernization. The modern index of 13 provinces (municipalities or autonomous regions) such as Shanghai, Beijing, Zhejiang and others was higher than the national average index and the index of Shanghai, Beijing, Zhejiang, Jiangsu and Tianjin was on the top levels in order, namely economy developed areas also had the high rural water conservancy modernization level; The modern index of 18 provinces (municipalities or autonomous regions) was lower than the national average and Tibet, Inner Mongolia, Gansu and Qinghai had the lowest index in order. It showed that the underdeveloped areas also had the lower rural water conservancy modernization level. Although the economic levels of some developed provinces and cities in China were close to the first economy modernization level of developed countries, their rural water conservancy modernization levels were still lower than the modern economic development level, such as Guangdong, Tianjin, Beijing and Shanghai, their economic modernization indexes were 84.0, 94.0, 95.0 and 97.0 respectively, but their rural water conservancy modernization indexes were 74.4, 85.0, 88.0 and 96.5 respectively. Unlike the first modernization, the second rural water conservancy modernization indexes showed a larger difference with economic levels. The second rural water conservancy modernization indexes of economic developed provinces and cities were lower than the economic second modernization indexes, for example the second rural water conservancy modernization indexes of Beijing, Shanghai and Tianjin were 47.5, 51.30 and 45.2 respectively, but their second modernization indexes were 78.0, 69.0 and 57.0 respectively. In addition to the economically developed cities such as Beijing, Shanghai and Tianjin, the second rural water conservancy modernization indexes of the rest provinces (municipalities or autonomous regions) were higher than the second economic modernization index. It showed the different development trend. The main reason may be that the rapid economic development exceeds consumption of water resources and causes environmental pollution. The path deviation of the second modernization in China's rural water conservancy reminds people to timely change ideas, implement water conservancy modernization accordingly with new industrialization, and carry on the institutional innovation in the first place. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Modernization
Controlled terms:Disaster prevention - Disasters - Economic and social effects - Economics - Land reclamation - Pollution - Pollution control - Potable water - Quality control - Rural areas - Water - Water management - Water pollution - Water pollution control - Water quality - Water resources - Water supply
Uncontrolled terms:Economic development - Environmental pollutions - Evaluation index system - Index systems - Rural water conservancies - Statistical software - Sustainable utilization - Water conservancy
Classification code:442.2 Land Reclamation - 444 Water Resources - 445.2 Water Analysis - 446.1 Water Supply Systems - 453 Water Pollution - 453.2 Water Pollution Control - 913.3 Quality Assurance and Control - 914.1 Accidents and Accident Prevention - 971 Social Sciences
DOI:10.11975/j.issn.1002-6819.2016.20.022
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 14>
Accession number:20164603020672
Title:High intensity ultrasound-heat pretreatments improving gelation properties of cold-set soy protein isolate induced by glucono-δ-lactone
Authors:Hu, Tan (1); Zhang, Peipei (1); Zheng, Ting (1); Huang, Xingjian (1); Pan, Siyi (1); Hu, Hao (1)
Author affiliation:(1) College of Food Science and Technology, Huazhong Agricultural University, Wuhan; 430070, China
Corresponding author:Hu, Hao(huhao@mail.hzau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:306-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the effects of high intensity ultrasound (HIU) on the gelation properties of glucono-δ-lactone (GDL) induced cold-set soy protein isolate (SPI), this study used HIU-heat pre-treated SPI to form GDL induced cold-set SPI gels. Texture analyzer, circular dichroism (CD) spectrum, fluorescence chromatography, scanning electron microscope (SEM), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and particle sizer were used in this study. Compared with heat pretreatment, HIU-heat pretreatments increased the gel strength and water holding capacity (WHC) of cold SPI gels significantly (P<0.05). HIU-heat pretreatment of SPI could not change the primary structure of SPI. However, the secondary structure, tertiary structure, intermolecular forces, protein solubility and particle size of SPI were changed after HIU-heat pretreatments. For instance, HIU-heat pretreatments increased the α-helix amount but decreased the β-sheet amount as demonstrated by far-CD spectra. Moreover, HIU-heat pretreatments of SPI increased the surface hydrophobicity, free or total sulfhydryl groups of SPI. The near-CD spectra and fluorescence spectra indicated that HIU-heat treatments reduced the tertiary structure and increased the hydrophobic environments of SPI. The protein solubility in different solvents (DW, deionized water at pH value of 8.0; Buffer B, Tris-glycine buffer (0.086 mol/L Tris, 0.09 mol/L glycine, and 4 mmol/L Na<inf>2</inf>EDTA, pH value of 8.0); Buffer BSU, Buffer B containing 0.5% sodium dodecyl sulphate and 6 mol/L urea) suggested that HIU-heat treatments increased the electrostatic interactions but reduced or did not change non-covalent interactions among SPI molecules. SEM showed that the three-dimensional (3D) structure of HIU-heat pretreated SPI gels became denser and more uniform. However, different HIU-heat pretreatments influenced the gelation properties of SPI gels diversely. The gel strength and WHC of gels prepared by Method 1 (M1, HIU for 2, 4 or 10 min then heating at 95℃ for 20 min) increased gradually with the increasing of HIU time (gel strength: from (5.83±0.31) to (46.37±1.15) g, WHC: from 42.03%±1.59% to 81.74%±6.22%), while those of gels prepared by Method 2 (M2, heating at 95℃ for 20 min then HIU for 2, 4 or 10 min) increased rapidly within 4 min under HIU (gel strength: from (5.83±0.31) to (37.57±2.57) g, WHC: from 42.03%±1.85% to 79.31% ± 3.00%). This means that M2 can shorten the total producing time and reduce the energy, which might have more potential in soy bean protein industry. The mechanism for the above differences between M1 and M2 may be due to that the heating pretreatment could facilitate the unfolding of SPI, causing the following HIU treatments to modify SPI more easily. Therefore, M2 could change the conformational structures of SPI within a short time of HIU (within 4 min), resulting in the improvement of exposing hydrophobic groups, the increase of hydrophobic environment, the increase of surface hydrophobicity and the increase of protein solubility in DW, as demonstrated by CD, fluorescence and spectrophotometer data. Moreover, the intermolecular electronic interactions also increased as demonstrated by the protein solubility changes in DW, Buffer B and Buffer BSU. Therefore, a more uniform and denser micro-structure was formed to increase the gel strength and WHC as demonstrated by SEM. The results of this study can facilitate the application of HIU-heat technology in soy protein industry. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Thermoacoustics
Controlled terms:Amino acids - Chemical bonds - Conformations - Deionized water - Dichroism - Electrophoresis - Esters - Fluorescence - Gelation - Gels - Heat treatment - Hydrophobicity - Microstructure - Molecules - Particle size - pH - Processing - Proteins - Scanning electron microscopy - Sodium - Solubility - Structural properties - Ultrasonics - Urea
Uncontrolled terms:Circular dichroism spectra - Conformational structures - Electronic interactions - Gelation properties - High intensity ultrasounds - Hydrophobic environment - Non-covalent interaction - Three dimensional (3D) structures
Classification code:445.1 Water Treatment Techniques - 537.1 Heat Treatment Processes - 549.1 Alkali Metals - 741.1 Light/Optics - 751 Acoustics, Noise. Sound - 753.1 Ultrasonic Waves - 801 Chemistry - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 913.4 Manufacturing - 931.2 Physical Properties of Gases, Liquids and Solids - 931.3 Atomic and Molecular Physics - 951 Materials Science
Numerical data indexing:Molar_Concentration 6.00e+03mol/m3, Molar_Concentration 8.60e+01mol/m3, Molar_Concentration 9.00e+01mol/m3, Percentage 5.00e-01%, Time 1.20e+03s, Time 2.40e+02s, Time 6.00e+02s
DOI:10.11975/j.issn.1002-6819.2016.20.040
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 15>
Accession number:20164603020644
Title:Droplet size distribution of aerial nozzle for plant protection in wind tunnel and flight conditions
Authors:Ru, Yu (1); Zhu, Chuanyin (2); Bao, Rui (1); Li, Zongfei (1); Ding, Tao (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) The Second Research Institute of Civil Aviation Administration of China, Chengdu; 610041, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:94-98
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aerial plant protection has great development potential in the Chinese modern agriculture because of its advantages such as high work efficiency, low cost, ability of dealing with sudden disaster, and being applicable in complex site conditions of large-area agriculture and forestry pest control. Droplet size is a direct factor to reduce the droplet drift and improve spraying effect. For obtaining the spray particle size distribution of GP-81A nozzle, the droplet size distribution test was carried out under the wind tunnel conditions and flight conditions based on the advantages of the 2 methods. In September 2015, droplet size distribution of GP-81A nozzle was tested with the high speed wind tunnel, which simulated the high speed air flow produced by the fight of the fixed-wing Y5B aircraft at Intelligent Agricultural Equipment Technology Research Center, Beijing Academy of Agricultural and Forestry Sciences, and studied the effect of airflow on droplet size. Six kinds of different apertures with the GP-81A nozzle of from 2# to 7# were selected, and spray pressure was set at 0.25 MPa, which was similar with spray pressure of Y5B aircraft. Wind tunnel flow changed from 0 to 84.9 m/s, and the test of droplet size was performed every 5 Hz, in order to obtain droplet size distribution under different airflow condition and different nozzle diameter. The test results indicated that when the wind speed was less than 33.8 m/s, the droplet size increased with the increase of the airflow speed, and when the wind speed was more than 33.8 m/s, the droplet diameter decreased with the increase of the airflow speed, for large enough airflow could make droplet further atomized. When the airflow speed was 33.8 m/s, the droplet diameter of 7# nozzle was the maximum that was 491.1 μm; when the airflow speed was 84.87 m/s, the droplet diameter of 2# nozzle was the smallest that was 202.1 μm. The relative width range of droplet spectrum was 1.067-2.124, showing that this series of nozzle atomization droplets were overall uniform, and with the increase of wind speed, the droplet spectrum relative width increased and the uniformity of droplet size distribution decreased. In October 2015, at the airport in Xuzhou Agricultural Aviation Station, the droplet size distribution was tested under flight conditions with different nozzle. Test aircraft was Y5B aircraft for agricultural application, which had the flight speed of 180 km/h, the flying height of 6 m, and 50 GP-81A air fan nozzles fixed on both sides of the wing. The test objects were 2#, 4# and 7# nozzles and the spray pressure was 0.2-0.3 MPa. Sampling slices of droplets were placed at sampling points and the statistical calculation of droplet size was carried out by the computer system. The test results showed that the volume medium diameters (VMD) of 2#, 4# and 7# nozzles were 151, 260 and 322 μm, respectively. With the increase of the nozzle aperture, the nozzle flow increased, and the droplet size also increased; the droplet spectrum relative width range was 0.637-1.425, indicating that the droplet spectrum width was narrow, the droplet atomization performance was better, and the droplet distribution was uniform. At the same time, the droplet size and distribution were compared between the wind tunnel conditions and the flight conditions with similar spray pressure. Under the same spray pressure conditions, the droplet size in wind tunnel conditions was slightly higher than that in the flight test conditions, and the main reason was that the distance from the nozzle exit to test position was different. According to the results, the droplet relative spectral width values were close to 1 in wind tunnel and flight conditions, indicated that the droplet distribution was uniform, and the droplet distribution in flight conditions was more uniform. The research results provide a reference for the further optimization of working parameters of aerial nozzle to reduce the droplet drift. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Spray nozzles
Controlled terms:Agriculture - Aircraft accidents - Atomization - Drops - Fighter aircraft - Fixed wings - Forestry - Nozzles - Particle size - Particle size analysis - Pesticides - Sampling - Size distribution - Speed - Spraying - Timber - Tracking (position) - Wind - Wind tunnels
Uncontrolled terms:Agricultural equipment - Atomization performance - Development potential - Droplet distribution - Droplet size distributions - Flight - High-speed wind tunnel - Statistical calculations
Classification code:443.1 Atmospheric Properties - 631.1 Fluid Flow, General - 651.2 Wind Tunnels - 652.1 Aircraft, General - 652.1.2 Military Aircraft - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 951 Materials Science
Numerical data indexing:Frequency 5.00e+00Hz, Pressure 2.00e+05Pa to 3.00e+05Pa, Pressure 2.50e+05Pa, Size 2.02e-04m, Size 3.22e-04m, Size 6.00e+00m, Velocity 0.00e+00m/s to 8.49e+01m/s, Velocity 3.38e+01m/s, Velocity 5.00e+01m/s, Velocity 8.49e+01m/s
DOI:10.11975/j.issn.1002-6819.2016.20.012
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 16>
Accession number:20164603020636
Title:Design and experiment of potato metering device with double-deck seed tank
Authors:Niu, Kang (1, 2); Yuan, Yanwei (2); Luo, Min (2); Liu, Yangchun (2); Lü, Chengxu (2); Fang, Xianfa (2, 3)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China; (2) State Key Laboratory of Soil-Plant-Machine System Technology, Chinese Academy of Agricultural Mechanization Sciences, Beijing; 100083, China; (3) Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha; 410128, China
Corresponding author:Fang, Xianfa(fangxf@caams.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:32-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Potato is the fourth staple food product in China, and Chinese potato planting area of 6.7 million hm2 ranks first worldwide in 2013. However, the mechanized potato seeding percentage in China is only 23%, which is limited by poor performance of potato planter. Cup-chain metering device is the most commonly used for potato planting, whereas it is troubled with high miss-seeding and re-seeding problems. To solve these problems, the simulation model of potato planter is firstly built, and this model is used to analyze potato seed movement during metering process; then a new type of metering device with double-deck seed tank is designed, and finally the parameters of seeding speed, seed cup diameter and seed filling height are optimized. 1) Potato planter simulation: Potato cup-chain metering planter is simulated based on the software of EDEM (enhanced discrete element method). On the one hand, Hertz-Mindlin non-sliding contact model between 2 seeds is built with the recovery coefficient of 0.3, static friction coefficient of 0.56 and dynamic friction coefficient of 0.15; on the other hand, the model between seed and seeder is built with the recovery coefficient of 0.52, static friction coefficient of 0.5 and dynamic friction coefficient of 0.1. 2) Potato seed movement analysis: During the metering process, movement is originated from only a small part of seeds instead of most of them that are immobile. The small part of moving seeds determine the seed charging performance. The major movement area of potato seed is around the chain presenting the shape of inverted cone, which contains 3 areas of high-efficiency charging area, low-efficiency charging area and no seed area. The seed charging performance is directly affected by the volume of high-efficiency charging area and the seed mobility. 3) Seed planter design: Aiming to enlarge high-efficiency charging area and enhance seed mobility, planter with double-deck seed tank is designed, which doubles the volume of high-efficiency charging area and enhance seed mobility. A planter test platform with double-deck seed tank is modified from a 1 220 type potato planter provided by Zhongji Meno Polytron Technology. 4) Performance evaluation and parameter optimization: 2 indicators are employed to evaluate the planter performance, including miss-seeding percentage and re-seeding percentage. The influence of seeding speed, seed cup diameter and seed filling height in the seed tank on seed charging performance is studied. Regression equation and multi-objective optimization method are employed for parameter optimization. In the Chinese national standard for potato planter, miss-seeding percentage is no more than 10% and re-seeding percentage is no more than 20%, the designed planter can operate at the seeding speed of 0.96 m/s to satisfy this national standard. To balance the planting performance, including miss-seeding percentage and re-seeding percentage, and planting efficiency of seeding speed, the parameters of seeding speed, seed cup diameter and seed filling height in the seed tank are optimized as 0.67 m/s, 48.6 mm and 0.28 m, respectively, showing the miss-seeding percentage of 3.8% and re-seeding percentage of 8.8%. This paper demonstrates the potential for a high-performance cup-chain metering device with double-deck seed tank for potato planting. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Seed
Controlled terms:Agricultural machinery - Chains - Computer software - Design - Efficiency - Experiments - Filling - Finite difference method - Friction - Machine design - Machinery - Multiobjective optimization - Regression analysis - Speed - Stiction - Tanks (containers) - Tribology
Uncontrolled terms:Agriculture machinery - Chinese national standard - Dynamic friction coefficient - Metering devices - Parameter optimization - Potato planter - Regression method - Static friction coefficient
Classification code:601 Mechanical Design - 602.1 Mechanical Drives - 619.2 Tanks - 691.2 Materials Handling Methods - 723 Computer Software, Data Handling and Applications - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 901.3 Engineering Research - 913.1 Production Engineering - 921.5 Optimization Techniques - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 931 Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Percentage 1.00e+01%, Percentage 2.00e+01%, Percentage 2.30e+01%, Percentage 3.80e+00%, Percentage 8.80e+00%, Size 2.80e-01m, Size 4.86e-02m, Velocity 6.70e-01m/s
DOI:10.11975/j.issn.1002-6819.2016.20.004
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 17>
Accession number:20164603020638
Title:Application and yield increasing effect on potato using special-designed ridging cultivator
Authors:Gao, Zhongchao (1, 2); Liu, Feng (1); Wang, Qiuju (1, 2); Jiang, Hui (3); Zhang, Jinsong (1); Yao, Chunyu (1); Gao, Pan (1)
Author affiliation:(1) Institute of Soil Fertilizer and Environment Resources, Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China; (2) Key Laboratory of Soil Environment and Plant Nutrient of Heilongjiang Province, Harbin; 150086, China; (3) Scientific Research Department, Heilongjiang Academy of Agricultural Sciences, Harbin; 150086, China
Corresponding author:Wang, Qiuju(bqjwang@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:49-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Potato (Solanum tuberosum L.) is one of the four major crops in the world, after rice, corn (maize) and soybean. In order to meet the increase in demand, its planting area is increasing worldwide. Being no exception, Heilongjiang Province in the Northeast part of the P. R. of China also expanded the potato planting area with 262 thousands hectares by the year of 2015. However average yield in the province was lower than the national average level with only 41 220 kg/hm<sup>2</sup>, because of the factors, such as backward cultivation technologies, irregular planting system, and unreasonable climate conditions. Among them, soil condition affected by cultivation was a fundamental factor for improvement of potato yield and potato tuber rate. As the cultivating soil machinery developed slowly, soil conditions cannot reach the ideal level, which create issues including seedlings seriously injured by mechanical operation pressure, increased green potato rate, low commodity potato rate, and hence farmers' income cannot keep the same pace with the potato planting area increasing. A special-designed ridging cultivator was developed (Patent No.: ZL 201220010382.2) to solve the problems. The cultivator is 4 m long for plough horizontal frame, with five plowshares fixed on the plough frame through quadrilateral spindle. The plough shape is the most special part, as its curved surface is beneficial to create a full ridge. In the paper, a comparative field tests were carried out by using the cultivator and a traditional cultivation soil plow (machine type: 3Z-2A). In the field tests, four ridge spacing with 65, 70, 80 and 90 cm were set by using the cultivator respectively. The cultivator was operated twice during the period from seeding to budding. The results showed that after operation by the cultivator, soil weight of ridge body was increased with 21.7% to 33.4% as much as that of the control (CK). Potato in the treatment applied the cultivator was beneficial for plant growth, main stem prolongation and dry matter accumulation during growth period, meanwhile potato stolon numbers multiplied, and dry matter accumulation weight of potato in the ridge body increased with 4.8 to 5.4 g in the first year, and 4.2 to 4.5 g per plant in the second year. The dry matter accumulation weight changed largely with the ridge spacing increasing, the increasing range was from 11.1% to 23.8% compared with the control (CK). Regarding the dry matter mass underground, the results showed that treatment with 80 cm ridge got the highest with 4.95g per plant as an average value for two years. In addition, the special-designed ridging cultivator not only increased the potato tuber yield, but also kept the potato tuber size uniform. It increased the proportion of large and middle size potato tubers and decreased the proportion of small potato tubers. The average potato yield for two years was increased from 38 215.0 to 43 131.2 kg/hm<sup>2</sup>, 1.1% to 7.3% higher than that of the control (CK). Commercial potato yield for two years was averagely from 33 788.9 to 39 346.7 kg/hm<sup>2</sup>, 4.1%-11.2% higher than that of the control (CK), and the green potato tubers yield for two year averaged from 670.7 to 834.3 kg/hm<sup>2</sup>, 18.7% to 28.8% lower than that of the control (CK). Among all treatments with different ridge spacing, the potato yield with 80 cm ridge spacing was the highest with 43 131.2 kg/hm<sup>2</sup>and green potato rate was the lowest with the yield of 670.7 kg/hm<sup>2</sup>. In the study, 80 cm ridge spacing was recommended when operating the cultivator, as a result it could offer new direction for potato production. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Agricultural machinery
Controlled terms:Crops - Cultivation - Machinery - Mechanization - Plants (botany) - Quality control - Seed - Soils - Tubes (components)
Uncontrolled terms:Climate condition - Cultivation models - Dry matter accumulation - Mechanical operations - Potato - Ridge spacing - Solanum tuberosum - Special-designed ridging cultivator
Classification code:483.1 Soils and Soil Mechanics - 601 Mechanical Design - 619.1 Pipe, Piping and Pipelines - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3 Quality Assurance and Control
Numerical data indexing:Mass 4.20e-03kg to 4.50e-03kg, Mass 4.80e-03kg to 5.40e-03kg, Mass 4.95e-03kg, Percentage 1.10e+00% to 7.30e+00%, Percentage 1.11e+01% to 2.38e+01%, Percentage 1.87e+01% to 2.88e+01%, Percentage 2.17e+01% to 3.34e+01%, Percentage 4.10e+00% to 1.12e+01%, Size 4.00e+00m, Size 8.00e-01m, Size 9.00e-01m
DOI:10.11975/j.issn.1002-6819.2016.20.006
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 18>
Accession number:20164603020666
Title:Spatiotemporal response of land surface temperature to land use/cover change in Yanqi Basin, Xinjiang
Authors:Kadeer, Reyilai (1); Rusuli, Yusupujiang (1); Gao, Qian (1); Wupur, Adilai (1); Jiang, Hong (1)
Author affiliation:(1) Institute of Geographical Science and Tourism, Xinjiang Normal University/Xinjiang Key Laboratory of Lake Environment and Resources in Arid Zone, Urumqi; 830054, China
Corresponding author:Rusuli, Yusupujiang(Yusupjan@xjnu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:259-266
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land-use/land cover change (LUCC) at local, regional, and global scales is one of the fundamental causes of environmental change. LUCC has been of great concern because innumerable consequent changes were produced on the earth surface. Some important researches showed that human-induced LUCC was one of the key factors which influence the regional climate. Rapid population growth and continuous exploitation of natural resources during the past century have caused rapid changes of land-use/cover. This trend has produced a series of environmental impacts on biodiversity, local climate, hydrologic processes, and so forth. The land surface temperature (LST) is the radiative skin temperature of ground. It depends on the albedo, the vegetation cover and the soil moisture. In most cases, LST is a mixture of vegetation and bare soil temperatures. In turn, the LST influences the partition of energy between ground and vegetation, and determines the surface air temperature. In recent decades, geographical information systems and remote sensing techniques are widely employed to investigate the impact of land-use/cover change on land surface temperature. Understanding the interconnection of biological and climatic processes is essential for predicting the effects of climate change on the biosphere. Spatiotemporal distribution of LST is a critical factor of environmental change, and is the driving forces of the land surface processes. Study on the spatiotemporal response of LST to LUCC is an important scientific issue under the circumstances of anthropogenic pressure increasing rapidly. In the paper, characteristics of spatiotemporal distribution of LST and its response to LUCC are studied by LST data retrieved by methods of mono-window algorithm and single-channel from Landsat data of the year 2000, 2009, 2011 and 2015, observed metrological data and field sampling data in Yanqi Basin, Xinjiang, China. Results demonstrated that: 1) LST was classified as high LST, medium LST and low LST. The decreasing ratio of high LST area from the greatest to the least took place in the year of 2000, 2009 and 2015, respectively; the decreasing ratio of low LST area from the greatest to the least took place in the year of 2009, 2000 and 2015, respectively; 2) the distribution of LST had different spatial patters obviously. High LST distributed in deserts and Gobi between mountain and basin, and it had a circular pattern around the Bosten Lake. Low LST distributed in water, wetlands and oasis area; 3) the amplitude of LST change was different depending on LUCC in 2011. The ranks of different land cover types were: desert>saline area>bare land>wheat-corn>other crops>forest>cotton>reeds wetland> waters. To sum, the spatiotemporal distribution of LST is closely related to LUCC. The structure of crop planting and the area of land use type are effecting the spatiotemporal distribution of LST in recent decades in the Yanqi Basin, Xinjiang. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Land use
Controlled terms:Algorithms - Arid regions - Atmospheric temperature - Biodiversity - Climate change - Crops - Environmental impact - Geographic information systems - Landforms - Population statistics - Remote sensing - Soil moisture - Spatial distribution - Surface measurement - Surface properties - Vegetation - Wetlands
Uncontrolled terms:Anthropogenic pressures - Land surface temperature - Land use/land cover change - Remote sensing techniques - Spatiotemporal distributions - Spatiotemporal response - Surface air temperatures - Yanqi basin
Classification code:403 Urban and Regional Planning and Development - 443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 454 Environmental Engineering - 454.2 Environmental Impact and Protection - 481.1 Geology - 483.1 Soils and Soil Mechanics - 821.4 Agricultural Products - 903.3 Information Retrieval and Use - 921 Mathematics - 943.2 Mechanical Variables Measurements - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.20.034
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 19>
Accession number:20164603020647
Title:Effect of irrigation frequency on migration regularity of greenhouse soil salt during different growth stages of pepper
Authors:Du, Lei (1); Zheng, Zicheng (1); Li, Tingxuan (1)
Author affiliation:(1) College of Resources, Sichuan Agricultural University, Chengdu; 611130, China
Corresponding author:Zheng, Zicheng(zichengzheng@aliyun.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:114-121
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Horticultural production has been widely used in China, and produces high social and economic benefits as a new model of rural industry. However, mismanagement of irrigation and fertilization in greenhouse vegetables, resulting in the nutrients enrichment in surface soil profile through evaporative water loss is an important reason for greenhouse soil salinization, which makes the greenhouse soil unsuitable for sustainable use. Soil salinization negatively impacts agricultural productivity, environmental health, and economic welfare. In order to find a proper irrigation frequency for each growth stage of pepper cultivated in greenhouse, simulated experiments of soil box in a laboratory were carried out to investigate the migration mechanisms of greenhouse soil salt during seedling, squaring, mature stage of pepper with different irrigation frequencies (irrigation every 5, 10, 15 days) as well as the same amounts of irrigation. The results indicated that the different irrigation frequency treatments played an important role in salt leaching. At the seedling stage of pepper, Soil salt distribution in soil profile was uniform at seedling stage of pepper in each irrigation frequency, and there was a significant surface convergence phenomenon occurred before irrigation, the zone with the highest value of soil salt for each treatment was at a depth of 0-10 cm. Salts were moved downward with water, the soil salt content changed in the entire profile with treatment progress, the desalinization rates of 0-20 cm soil layer decreased by 33.97%-66.20%, 35.96%-67.36%, 37.94%-67.94%, respectively under high, middle and low irrigation frequency, meanwhile, the ratio of desalinization increased with the decreased irrigation frequency, the salt accumulation decreased by 47.57%, 49.85% and 52.41% with different irrigation frequencies after irrigation. The salt accumulation of 20-50 cm soil layer with the middle irrigation frequency was greater than that of high and low frequency. At the squaring stage of pepper, the maximum salt contents with the irrigation frequency of middle and low frequency before irrigation were observed in 10-20 cm soil layer, and that with the high irrigation frequency was noticed in 30-40 cm soil layer. Salt content in 30-40 cm soil layer decreased most in response to the preferential flow with the high irrigation frequency after irrigation. The results indicated that soil salt transportation were influenced by preferential flow, it is obvious that there showed a phenomenon of preferential flow at squaring stage of pepper under high frequency. Besides, at the mature stage of pepper, the salt accumulation in soil surface with the high and low irrigation frequency were more than that with the middle irrigation frequency before irrigation. After irrigation, the desalinization rate in 0-20 cm soil layer with the high irrigation frequency remained large and there was a preponderance of soil salt accumulation in 20-50 cm soil layer. The salt content decreased largely in 20-50 cm soil layer with the middle irrigation frequency. Salt accumulation in 20-50 cm soil layer with the high irrigation frequency was 18.86% greater than that with the middle irrigation frequency. Soil salt transportation were influenced by preferential flow, it is obvious that there showed a phenomenon of preferential flow at squaring stage of pepper under high irrigation frequency treatment, and which occurred at mature stage of pepper under middle irrigation frequency treatment. These results indicated that the better irrigation should be with appropriate amounts and middle irrigation frequency before the mature stage of pepper, while that should be with small amounts and high frequent irrigation during the mature stage of pepper. The large amounts and low frequency irrigation can easily cause serious salt leaching in soil profile and even groundwater pollution. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Soil pollution
Controlled terms:Agriculture - Greenhouse effect - Greenhouses - Groundwater - Groundwater flow - Groundwater pollution - Irrigation - Leaching - Productivity - Soil structure interactions - Soils
Uncontrolled terms:Agricultural productivity - Different growth stages - Greenhouse vegetables - Growth stages - Irrigation frequency - Salt content - Significant surfaces - Simulated experiments
Classification code:444.2 Groundwater - 451 Air Pollution - 483.1 Soils and Soil Mechanics - 483.2 Foundations - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Age 4.11e-02yr, Percentage 1.89e+01%, Percentage 3.40e+01% to 6.62e+01%, Percentage 4.76e+01%, Percentage 4.99e+01%, Percentage 5.24e+01%, Size 0.00e+00m to 1.00e-01m, Size 0.00e+00m to 2.00e-01m, Size 1.00e-01m to 2.00e-01m, Size 2.00e-01m to 5.00e-01m, Size 3.00e-01m to 4.00e-01m
DOI:10.11975/j.issn.1002-6819.2016.20.015
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 20>
Accession number:20164603020649
Title:Dry matter and yield as well as water-N coupling model of watermelon in gravel mulched field and its validation
Authors:Ma, Bo (1, 2, 3); Tian, Juncang (1, 2, 3); Shen, Hui (1, 2, 3); Li, Wangcheng (1, 2, 3)
Author affiliation:(1) College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan; 750021, China; (2) Ningxia Research Center of Technology on Water-saving Irrigation and Water Resource Regulation, Yinchuan; 750021, China; (3) Efficient Use of Water Resources in Arid Modern Agriculture Ministry of Educational Engineering Research Center, Yinchuan; 750021, China
Corresponding author:Tian, Juncang(slxtjc@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:129-136
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Gravel-mulched field is typical in Northwest of China for watermelon production. Few studies are on dry matter and yield models establishment of watermelon in gravel-mulched field, which is good for prediction of watermelon growth and yield. This study aimed to establish the dry matter and yield models for watermelon in gravel-mulched field based on photosynthesis and water-N coupling. Two experiments were designed in 2009. One was for photosynthesis-based dry matter model validation (Exp. 1) and the other was for water-N coupling model validation (Exp. 2). The experiments were conducted under a rain shelter in order to simulate different types of rainfall years.The experimental site was located in Hongquanzi Village, Zhongwei City of Ningxia (37°56'N, 105°15'E). The soil and gravel were taken from 0-40 cm depth of a typical 2-a gravel-mulched field. Based on experience and previous published papers, volumetric soil moistures of 11%-20%, 13%-24% and 16%-27% simulated dry, normal and wet years, respectively. The organic fertilizer application rate was designed at 4 levels at 0, 600, 1200 and 1800 kg/hm<sup>2</sup>. In Exp.2, five levels of organic fertilizer application rate were 600, 750, 1 200, 1 560 and 1 800 kg/hm<sup>2</sup>and 5 levels of urea at 24, 33, 48, 61.5, 72 kg/hm<sup>2</sup>. All the experiment was conducted in barrels. A photosynthesis-based dry matter accumulation model of watermelon was established based on daily total photosynthetic assimilation amount calculated with Gauss integration method. The dry matter and yield models were also established using multiple regression method. The models were evaluated by indexes of correlation coefficient (r), root mean square of error (RMSE), and normalized RMSE (nRMSE). The results showed that: 1) the photosynthesis-based dry matter model had RMSE of 22.5 kg/hm<sup>2</sup>, nRMSE of 14.5% and r of 0.893, which indicate that the model was reliable in watermelon dry matter accumulation simulation; 2) Water-N coupling model of watermelon dry matter had low accuracy (R<sup>2</sup>=0.30) for ET≥150.2-513.8 mm and available N≥172.1-241.7 kg/hm<sup>2</sup>, and the accuracy became higher (R<sup>2</sup>=0.78, P<0.01) for ET≥213-513.8 mm and available N≥172.1-226.9 kg/hm<sup>2</sup>. The water-N coupling model of watermelon economic yield also had higher accuracy (R<sup>2</sup>=0.88, P<0.01) for ET≥213-513.8 mm and available N≥172.1-226.9 kg/hm<sup>2</sup>. Meanwhile, the water-N coupling model of watermelon dry matter and economic yield had low RMSE (25.2 and 668 kg/hm<sup>2</sup>) and nRMSE (15.4% and 14.1%), which indicated the water-N coupling model was reliable in dry matter and yield simulation of watermelon for ET≥150.2-513.8 mm and available N≥172.1-241.7 kg/hm<sup>2</sup>. The models here could be used for dry matter and yield prediction of watermelon in gravel-mulched field and provide useful tool for improving the utilization efficiency of water and fertilizer. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Gravel
Controlled terms:Biomass - Fertilizers - Models - Photosynthesis - Precipitation (meteorology) - Rain - Regression analysis - Soil moisture - Urea
Uncontrolled terms:Correlation coefficient - Dry matter accumulation - Gauss integrations - Multiple regression methods - Organic fertilizers - Utilization efficiency - Volumetric soil moistures - Watermelon
Classification code:443.3 Precipitation - 483.1 Soils and Soil Mechanics - 741.1 Light/Optics - 804 Chemical Products Generally - 804.1 Organic Compounds - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 1.10e+01% to 2.00e+01%, Percentage 1.41e+01%, Percentage 1.45e+01%, Percentage 1.54e+01%, Percentage 1.60e+01% to 2.70e+01%, Size 0.00e+00m to 4.00e-01m
DOI:10.11975/j.issn.1002-6819.2016.20.017
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 21>
Accession number:20164603020671
Title:Effect of yeast products on fermentation characteristics of frozen dough and quality of steamed bread
Authors:Fan, Huiping (1); Li, Rui (1, 3); Zheng, Xueling (2); Wang, Na (1, 3); Chen, Yuehua (1); Ai, Zhilu (1, 3)
Author affiliation:(1) College of Food Science and Technology, Henan Agricultural University, Zhengzhou; 450002, China; (2) College of Food Science and Technology, Henan University of Technology, Zhengzhou; 450001, China; (3) Henan Engineering Research Center for Cold-chain Food, 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:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:298-305
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to determine the yeast quality for making frozen dough and steamed bread better and more stable, we studied the changes of characteristics of fermentation and rheology of frozen dough made by Guoguang low-sugar high-activity dry yeast (No.1), Actis Mali Apple instant high-active dry yeast (No.2), Pinyi high-activity dry yeast (No.3), Mali high-sugar instant high-active dry yeast (No.4), Danbaoli high-sugar instant high-active dry yeast (No.5) and Angel high-sugar-intolerance high-activity dry yeast (No.6) The doughs which were frozen and stored for 35 days, were analyzed by dynamic rheometer and Rheofermentometer F3, and the texture, color, specific volume and sensory quality of steamed bread made by frozen dough were compared. The results showed that frozen doughs made from different commercial yeasts in different frozen time had different rheological properties and fermentation characteristics. After making steamed bread, their hardness, springiness, resilience, chewiness, lightness, redness, yellowness, specific volume and scores of sensory evaluation showed significant difference (P<0.05) among different yeasts. Their texture, color, specific volume and sensory quality were also significantly different (P<0.05) among different frozen time for the steamed bread made by the same yeast. Frozen doughs made by No. 1 and No.2 always maintained higher fermentation activity, No. 6 had the most stable fermentation characteristics parameters of six kinds of yeasts during the frozen storage of 35 days. Then frozen dough made by No.1, No.5 and No.6 had higher elastic modulus and viscous modulus, No.5 had the most stable rheological properties. The steamed bread made by the frozen dough of No.1 and No.6 always had better sensory quality larger specific volume, better color, and better texture quality. Therefore the frozen dough and steamed bread made by No.1 had better quality and stability, followed by No.6. The results provide a theoretical basis for the selection of yeast in the industrial production of steamed bread made by frozen dough. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Yeast
Controlled terms:Cold storage - Color - Fermentation - Food products - Physical properties - Quality control - Rheology - Sensory perception
Uncontrolled terms:Active dry yeasts - Characteristics parameters - Dynamic rheometers - Frozen doughs - Industrial production - Rheological property - Sensory qualities - Steamed bread
Classification code:461.4 Ergonomics and Human Factors Engineering - 644.3 Refrigeration Equipment and Components - 741.1 Light/Optics - 822.3 Food Products - 913.3 Quality Assurance and Control - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Age 9.59e-02yr
DOI:10.11975/j.issn.1002-6819.2016.20.039
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 22>
Accession number:20164603020655
Title:Estimation of wheat yield based on crop and remote sensing assimilation models
Authors:Xie, Yi (1); Wang, Pengxin (1); Wang, Lei (1); Zhang, Shuyu (2); Li, Li (1); Liu, Junming (1)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing; 100083, China; (2) Shaanxi Provincial Meteorological Bureau, Xi'an; 710014, China
Corresponding author:Wang, Pengxin(wangpx@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:179-186
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Data assimilation (DA) has been recognized as a promising approach for regional crop growth monitoring and yield estimation. The widely used DA method, ensemble Kalman filter (EnKF), holds the assumption that the involved probability density functions (PDFs) are Gaussian, and the evolution of the filter can be governed only by its second-order characteristics, leading to a significant loss of information. In comparison with the EnKF, the particle filter (PF) has no restrictive assumption regarding the forms of the PDFs, and thus can be applied to any nonlinear and non-Gaussian systems. Different researchers have used leaf area index (LAI), vegetation indices and soil moisture as the state variables in agricultural data-assimilation systems for estimating crop yields. However, the assimilation of variables that are not very important for crop yields (e.g., LAI at the maturity stage) may decrease the accuracy of yield estimations. Conversely, assimilating highly yield-related variables is important for improving yield estimates. To improve winter wheat yield esimation in the Guanzhong Plain, China and determine whether assimilating highly yield-related variables at each wheat growth stage improved the accuracy of the yield estimation, daily LAI, soil moisture (0-20 cm) and aboveground dry biomass simulated by the CERES-Wheat model were assimilated from the LAI, soil moisture and biomass retrieved from Landsat data using the PF algorithm, for obtaining daily assimilated LAI, soil moisture and biomass values. Then, the daily assimilated LAI and biomass values during the growth stages of winter wheat, including the green-up, jointing, heading-filling and milk stages, were accumulated to obtain the accumulated LAI and biomass values. Linear regression analyses were performed to examine the relationships between accumulated LAI, accumulated biomass or assimilated soil moisture and the field-measured yields respectively for determining the optimal-assimilation variables. The results showed that the PF algorithm combined the remotely sensed LAI, soil moisture and biomass values with the phenological characteristics of simulated LAI, soil moisture and biomass trajectories, which improved the daily LAI, soil moisture and biomass estimation. The field measurements for the sampling sites were compared with the assimilated and simulated LAI, biomass and soil moisture. The RMSE of 0.61 m<sup>2</sup>/m<sup>2</sup>and 790.65 kg/hm<sup>2</sup>of the assimilated LAI and biomassvalues were 0.25 m<sup>2</sup>/m<sup>2</sup>and 154.21 kg/hm<sup>2</sup>lower than those of the simulated LAI and biomass values. Similarly, the RMSE of 0.017 mm<sup>3</sup>/mm<sup>3</sup>of the assimilated soil moisture value was 0.012 mm<sup>3</sup>/mm<sup>3</sup>lower than that of the simulated soil moisture value. At the green-up stage, the linear correlation between the assimilated soil moisture and the field-measured yields was higher than those between the accumulated LAI and the yields or between the accumulated biomass and the yields, that soil moisture was chosen as the optimal-assimilation variable for the green-up stage. At the jointing and heading-filling stages, the accumulated LAI, accumulated biomass or assimilated soil moisture were all highly correlated to the yields, respectively, and thus all of them were chosen as the optimal-assimilation variables for the 2 stage. In addition, biomass was selected as the optimal-assimilation variable for the milk stage. The optimal-assimilation yield estimation model, established based on the optimal-assimilation variables at each growth stage, achieved better estimation accuracy for wheat yields (R<sup>2</sup>=0.91, RMSE=207.76 kg/hm<sup>2</sup>) than the yield estimation model established based on the assimilation of LAI, soil moisture and biomass simultaneously (R<sup>2</sup>=0.84, RMSE=281.69 kg/hm<sup>2</sup>). Moreover, the yield estimation accuracy by assimilating LAI, soil moisture and biomass was higher than that by assimilating LAI and soil moisture (or soil moisture and biomass, or LAI and soil moisture). Therefore, assimilating highly yield-related variables at each crop growth stage provides reliable and promising methods for improving crop yield estimates. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Soil surveys
Controlled terms:Agriculture - Biomass - Crops - Ecology - Estimation - Models - Moisture - Monte Carlo methods - Probability density function - Regression analysis - Remote sensing - Soil moisture - Soils
Uncontrolled terms:Crop yield - Data assimilation - Data assimilation systems - Ensemble Kalman Filter - Nonlinear and non-Gaussian - Particle filter - Probability density functions (PDFs) - Winter wheat
Classification code:454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921 Mathematics - 922.1 Probability Theory - 922.2 Mathematical Statistics
Numerical data indexing:Size 0.00e+00m to 2.00e-01m
DOI:10.11975/j.issn.1002-6819.2016.20.023
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 23>
Accession number:20164603020635
Title:Design on opposed inclined-plate high-speed precision seed-metering device and its working mechanism analysis
Authors:Liu, Hongxin (1); Liu, Junxiao (1); Tang, Shifa (1); Xu, Xiaomeng (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:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:24-31
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Mechanical precision seed-metering device has low price, compact structure, good manufacturability and other advantages. However, in recent years, the pneumatic precision seed-metering device has occupied the dominant position, mainly because of the fatal flaw of the hole filling rate declining rapidly in high speed for mechanical precision seed-metering device, which resulted in grievous decline in the quality of operation and serious seed-leakage phenomenon. Due to the structure characteristic of seed-metering device and mixing characteristic of granular soybean seeds, the value of filling force in the form of compressive stress was limited. For this reason, how to improve the filling force was a crucial factor for mechanical precision seed-metering device. In this paper, the model of filling force of hole was built. And an opposed inclined seed-metering device was innovatively designed by theoretical analysis, which combined the advantages of a variety of mechanical seed-metering devices. It could improve seeding frequency by using double-plate to seed in single line. It changed the seed filling pattern from structure, made full use of the structure of the shell space, improved the compaction force and the filling force type, and further improved the qualified rate and its performance under high-speed operation to adapt to the modern high-speed operation requirements. Relying on gravity cleaning of seed, it effectively avoided the injury of seeds. The double-cavity composite vertical seed-metering device was chosen as a comparison, which also had high speed operation ability. The mathematical models were established according to the working principle. The filling force of the vertical disk seed-metering device and opposed inclined-plate seed-metering device was contrasted and analyzed. Through analyzing the filling force changing rule of the seed-metering device in different angles, and drawing the function image by Matlab (MATrix LABoratory) software, the effective ways to improve the filling ability were found and the best angle was determined to 20°. The single-factor experiments were carried out under the condition of different inclined angles, and the operation indices under 20° were better, which proved the accuracy of the theoretical analysis. The seed-metering device structure both retained the advantages of traditional vertical seed-metering device and solved the problems of seed-leakage increasing phenomenon under high speed. The simulation was done for opposed inclined-plate seed-metering device and double-cavity composite vertical seed-metering device by EDEM (engineering discrete element method) software, and a physical prototype test was performed to verify the superiority of this kind of structure further. The results showed that the simulated and experimental values of variation trend of filling rate were basically the same, and the relative error was small. At the low speed section of 5-8 km/h, the qualified rate was increased by 2% on average, and in 8-12 km/h high speed section, the average qualified rate was increased by 3.6%. The results of simulation and experiment showed the performance of opposed inclined-plate seed-metering device was significantly optimized when its speed was increased and the speed range of mechanical allowing operation was improved. This verifies the gravity and interaction force between seeds as composite force can make a contribution to filling seeds and can be obviously helpful for seeds to come into the hole when increasing the rotational speed of seed-plate, and provides the guidance for the design and development of high-speed precision mechanical seed-metering device. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Pneumatic materials handling equipment
Controlled terms:Agricultural machinery - Computer software - Design - Filling - Machine design - MATLAB - Plates (structural components) - Software prototyping - Software testing - Speed
Uncontrolled terms:EDEM simulation - High-speed operation - Inclined plate - Inclined plate seed metering devices - Precision seed-metering devices - Seed metering devices - Single-factor experiments - Structure characteristic
Classification code:408.2 Structural Members and Shapes - 601 Mechanical Design - 691.1 Materials Handling Equipment - 691.2 Materials Handling Methods - 723 Computer Software, Data Handling and Applications - 821.1 Agricultural Machinery and Equipment
Numerical data indexing:Percentage 2.00e+00%, Percentage 3.60e+00%, Velocity 1.39e+00m/s to 2.22e+00m/s, Velocity 2.22e+00m/s to 3.33e+00m/s
DOI:10.11975/j.issn.1002-6819.2016.20.003
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 24>
Accession number:20164603020664
Title:Application of landscape pattern analysis in arable land based on right to rural land contractual management registration
Authors:Xue, Chunlu (1); Guo, Lin (1); Hu, Hualang (1); Pei, Zhiyuan (1)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Beijing; 100125, China
Corresponding author:Hu, Hualang(150178135@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:242-249
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The outcome data of right to rural land contractual management registration is one of the basic sources of agricultural land resource element data sharing platform, and the foundation of rural collective property rights reform in China. How to expand the outcome data to the application of agricultural development is still being explored. In the study, the outcome data of right to rural land contractual management registration was applied to analyze the arable land landscape pattern. The study area was Zhengjia Town in Liaocheng, Shandong Province. The town was one of the experimental areas of right to rural land contractual management registration. Based on the vector data of registered arable land obtained from measurement in 2015, and with the Multi-spectral remote sensing data, the natural landscape and the tenure landscape in township scale were compared and analyzed in different administrative scales using the landscape indicators. 9 landscape indicators were selected including patch density (PD), total area(TA) (or class area (CA)), number of patches (NP), largest patch index(LPI), landscape shape index(LSI), perimeter-area fractal dimension (PAFRAC), aggregation index (AI), euclidean nearest neighbor distance mean (ENN_MN), and average area of farmer(AA). The indicators can reflect the relationship of arable land use and the human activities from fragmentation, spatial aggregation and land assignment. Respectively, village and township arable land tenure landscape pattern were compared. The results showed that, in township scale, the arable land area was about 60.44% of the total area. The extraction of arable land area was 5.38 km<sup>2</sup>larger than the registered result. The results of NP and PD showed that tenure landscape was more fragmentary than natural landscape. LPI showed that the arable land was continuous in large pieces in natural landscape, but small pieces in tenure landscape. LIS and PAFRAC indicated that the patch shapes in tenure landscape were more complicated than the natural landscape. ENN_MN and AI showed that natural landscape was more concentrated. The results of indicators reflected that right to rural land contractual management registration affected the arable land landscape pattern, which make the natural landscape and the tenure landscape were different. In village scale, the fragmentation, spatial aggregation and land assignment of tenure landscape and natural landscape had the same feature with the township scale. The tenure landscape pattern originated right to rural land contractual management registration was analyzed further. NP and PD were positively correlated. Mostly AAs were between 0.13 and 0.62 hm<sup>2</sup>, but a few AAs were out of scope largely. CA, LPI, ENN_MN, LSI and PAFRAC indicated that arable lands were assigned differently for each village, but the cultivation seemed to be consistency. The whole landscape shows a high degree of aggregation, however, the fragmentation, patch contiguous and patch shapes of the arable land are complicated at different spatial scales. In general, the data of right to rural land contractual management registration can be used to analyze the arable land landscape pattern as tenure landscape at different spatial scales. Tenure landscape and natural landscape have difference features in an administration scale. The results can provide a reference for contracted land allocation, farmland circulation structure and farmland remediation in different levels of administration, which assist wisdom agricultural development. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Rural areas
Controlled terms:Agriculture - Cultivation - Farms - Fractal dimension - Information management - Land use - LSI circuits - Nearest neighbor search - Remote sensing
Uncontrolled terms:Agricultural development - Arable land - Area fractal dimensions - Land managements - Landscape pattern - Landscape pattern analysis - Multi-scales - Nearest neighbor distance
Classification code:403 Urban and Regional Planning and Development - 714.2 Semiconductor Devices and Integrated Circuits - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 921 Mathematics - 921.5 Optimization Techniques
Numerical data indexing:Area 5.38e+06m2, Percentage 6.04e+01%
DOI:10.11975/j.issn.1002-6819.2016.20.032
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 25>
Accession number:20164603020650
Title:Missing data reconstruction and evaluation of retrieval precision for AMSR2 soil moisture
Authors:Zhang, Guixin (1, 2); Hao, Zhenchun (1); Zhu, Shanyou (2); Zhou, Chuxuan (2); Hua, Junwei (2)
Author affiliation:(1) State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing; 210098, China; (2) School of Geography and Remote Sensing, Nanjing University of Information Science & Technology, Nanjing; 210044, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:137-143
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Quality and precision of soil moisture data derived from a newly launched sensor, advanced microwave scanning radiometer 2 (AMSR2), needs to be evaluated before its quantitatively application in such fields as hydrological and energy cycle, agricultural management and so on. AMSR2 level 3 soil moisture data estimated based on the Land Parameter Retrieval Model (LPRM) has the highest spatial resolution of 10 km. The purpose of the paper was to reconstruct missing data and evaluate its retrieval precision of AMSR2 level 3. The missing data reconstruction was based on a penalized least square regression with three-dimensional discrete cosine transform (DCT-PLS) method. In order to evaluate the feasibility of the method, AMSR2 data in 2013 from 2 randomly selected locations (Yugan county of Jiangxi Province and Pingdu of Shandong Province) with continuous data originally were used and 20% pixels were given NaN for DCT-PLS-based missing data reconstruction. The reconstructed result was compared with the original one to evaluate the DCT-PLS method. Meanwhile, the AMSR2 data for the whole China on June 1, 2013 was used for the method validation in reconstructing missing data (eg. Anhui, Shanxi, Taiwan, and East China). Moreover, MODIS products within Shanxi area including land surface temperature (MOD11A2), vegetation index (MOD13A2) and surface albedo (MCD43B3) were combined to downscale AMSR2 level 3 soil moistures obtained on Jun. 1, 2013 and Nov.1, 2012 by using a statistical regression method. The retrieved soil moisture with the spatial resolution of 10 and 1 km were evaluated based on the field measurement of 38 stations as well as temperature vegetation drought index (TVDI) computed based on MODIS products. The results showed that: 1) the correlation coefficient (r) of reconstructed and original data was 0.9834 and 0.9557 (P<0.001) in both locations. In spatial distribution, the reconstructed data for the whole China had high correlation with the original data (r=0.9255, P<0.001). The reconstructed data could reveal a reasonable continuous distribution. Hence, the DCT-PLS method was reliable for missing data reconstruction; 2) Though the spatial distribution of AMSR2 soil moisture at the two different spatial scales was consistent with that of the field measurements, the correlations were low on Nov. 1, 2012 and Jun 1, 2013 respectively and they were improved by downscaling. There was a negative correlation between the AMSR2 soil moisture and TVDI at 10 km resolution. Compared with 10 km, the 1 km resolution showed reasonable spatial distribution of soil moisture. The correlation between the soil moisture and TVDI at 10 km resolution was -0.1869, -0.4720 on Jun 1, 2013 and Nov. 1, 2012 respectively, and it increased to -0.5389, -0.8984 at 1 km resolution. Moreover, the downscaled data at 1 km resolution could reflect more spatio-temporal distribution details of soil moisture, which could reduce unreliable estimation for higher soil moisture at 10 km resolution. Therefore, the 1 km downscaled data was more reliable. In sum, the DCT-PLS reconstruction combined with downscale method is good for soil moisture retrieval with a higher spatial resolution for AMSR2 level 3 data. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Soil surveys
Controlled terms:Atmospheric temperature - Discrete cosine transforms - Drought - Image reconstruction - Image resolution - Least squares approximations - Microwave sensors - Moisture - Moisture control - Quality control - Radiometers - Regression analysis - Sensors - Soil moisture - Soils - Spatial distribution - Temperature - Vegetation
Uncontrolled terms:Advanced microwave scanning radiometer - AMSR2 - Down-scaling - Evaluation - Penalized least square regressions - Spatiotemporal distributions - Statistical regression method - Vegetation drought indices
Classification code:443.1 Atmospheric Properties - 444 Water Resources - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 732.2 Control Instrumentation - 913.3 Quality Assurance and Control - 921 Mathematics - 922.2 Mathematical Statistics - 944.2 Moisture Measurements - 944.7 Radiation Measuring Instruments
Numerical data indexing:Percentage 2.00e+01%, Size 1.00e+03m, Size 1.00e+04m
DOI:10.11975/j.issn.1002-6819.2016.20.018
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 26>
Accession number:20164603020651
Title:Information acquisition and expert decision system in litchi orchard based on internet of things
Authors:Yu, Guoxiong (1, 2); Wang, Weixing (1, 2, 3, 4); Xie, Jiaxing (1, 2, 3, 4); Lu, Huazhong (4, 5); Lin, Jinbin (1); Mo, Haofan (1)
Author affiliation:(1) College of Electronic Engineering, South China Agricultural University, Guangzhou; 510642, China; (2) Key Laboratory of Information Acquisition and Application in Agriculture, Guangzhou Science Technology and Innovation Commission, Guangzhou; 510642, China; (3) Guangdong Engineering Research Center for Monitoring Agricultural Information, Guangzhou; 510642, China; (4) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou; 510642, China; (5) College of Engineering, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Wang, Weixing(weixing@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:144-152
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to realize the real time remote monitoring and precise management of the environment in litchi orchard, an information acquisition and intelligent irrigation expert decision system based on Internet of things in litchi orchard was designed. The system collected real-time environmental information such as soil moisture, air temperature and humidity, light intensity, wind speed and rainfall of litchi orchard through information collecting terminal modules then transmitted data packets of environmental information to gateway through wireless sensor network. The data packets would be processed and then transmitted to the cloud server through the GPRS network by the gateway. Combined with the environmental data and expert knowledge, the expert-decision system would establish multiple mathematical models of decision to achieve some decision-making functions such as the crop water requirements computing, irrigation time prediction, optimum quantitative irrigation decision-making and irrigation scheduling. The decision results were fed back to the control terminal module for intelligent controlling. The system was tested at the litchi orchard of College of Horticulture in South China Agricultural University from Feb. 11th, 2016 to Mar. 15th, 2016. In the test of the monitoring accuracy of information collecting terminal module, the results obtained from TES-1317 resistance thermometer, DT-8896 wet and dry bulb hygrometer, AR813A light illumination measuring instrument and so on were compared with those obtained information collecting terminal module. The results revealed the maximum relative error of the temperature 2.98%, that of the humidity 3.06%, that of the illumination was 6.25%, that of soil moisture 4.13%, that of wind speed 4.76% and precipitation 2.25%. It indicated that the monitoring accuracy of information collecting terminal module was high and was able to provide precise decision-making data for expert decision system. The decision-making system with multi-parameter and single parameter was tested to measure the accuracy of the expert decision system and determine the accuracy of the system according to the comparison between drought condition and actual situation. The result showed that the accuracy of multi-parameter decision was higher than the simple single parameter decision. The system gained the number of days automatically during the tests of the decision-making instantaneity of the system. When the soil water content was lower than the minimum of the litchi optimum water content which was 15.55%, the system opened the solenoid valve and began to do drip irrigation. On the other hand, the system stopped doing drip irrigation when the soil water content was higher than 19.14%. The result showed that the average soil water content of irrigation area was 17.4%, satisfying the requirement of the soil water content in the growth process of litchi trees, which illustrated that the irrigation decision made by system had strong real-time. The result from subtracting the days interval for predicting irrigation of the system by the days when the soil water content was below the minimum from the system began to irrigate showed that the system prediction accuracy could reach 75%, which illustrated that the predicting real-time of the system was better. This system realizes environmental information acquisition and intelligent irrigation in litchi orchard, guiding the users manage the litchi orchard better. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Information management
Controlled terms:Agriculture - Decision making - Expert systems - Farms - Forecasting - Functions - Gateways (computer networks) - Internet of things - Irrigation - Moisture - Orchards - Reconfigurable hardware - Soil moisture - Soils - Solenoid valves - Thermometers - Wind - Wireless sensor networks
Uncontrolled terms:Crop water requirements - Decision-making function - Decision-making systems - Environmental information - Information acquisitions - Litchi orchards - Maximum relative errors - Real-time remote monitoring
Classification code:443.1 Atmospheric Properties - 483.1 Soils and Soil Mechanics - 619 Pipes, Tanks and Accessories; Plant Engineering Generally - 716.3 Radio Systems and Equipment - 721.3 Computer Circuits - 723 Computer Software, Data Handling and Applications - 723.4.1 Expert Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 912.2 Management - 921 Mathematics - 944.5 Temperature Measuring Instruments
Numerical data indexing:Percentage 1.56e+01%, Percentage 1.74e+01%, Percentage 1.91e+01%, Percentage 2.25e+00%, Percentage 2.98e+00%, Percentage 3.06e+00%, Percentage 4.13e+00%, Percentage 4.76e+00%, Percentage 6.25e+00%, Percentage 7.50e+01%
DOI:10.11975/j.issn.1002-6819.2016.20.019
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 27>
Accession number:20164603020639
Title:Experiment of parameter optimization of fiber roller-scraping device for banana stalk
Authors:Zhang, Xirui (1); Wang, Chao (1); Liang, Dong (1); Li, Yue (1)
Author affiliation:(1) School of Mechanics and Electrics Engineering, Hainan University, Haikou; 570228, China
Corresponding author:Liang, Dong(xjn04@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:55-62
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Banana stalk is the main byproduct of banana after harvest. According to statistics, the annual banana production is more than 9 000 000 t in China, and the banana stalk is about 36 600 000 t. Traditionally, quantities of banana stalk are discarded in the field to naturally decay in the main banana planting areas in China, which leads to serious environment pollution, disease spread, waste of resources and other problems due to thick and large banana stalk as well as its high moisture content. Recent studies find that the banana stalk not only contains a variety of nutrients and organic matter, which can effectively increase the organic content of soil, but also is rich in high-quality plant fiber that is light-weight with good moisture absorption and heat dissipation, so it suits for the production of high-grade paper, clothes, ties, and so on. But nowadays domestic and foreign researches most focuse on the immersion method and the biochemical method, and the development of banana stalk fiber extracting device is rarely reported both at home and abroad. Based on the above issues, a fiber roller-scraping device for banana stalk was put forward in this paper, which is mainly composed of clamping device, scraping anvil, scraping roller, cabinet, grid plate, smoothing device, output belt, rack, and recycling box. Before experiment, the roller scraping device needs to be installed in the platform of fiber scraping device for banana stalk, and the banana stalk needs to be cut into slices. After the machine operates steadily, the slices of banana stem are continuously brought into the space between scraping roller and scraping anvil (the distance is 5 mm) in the scraping device with the transmission of the clamping device. Scraping roller rotates with high speed by means of adjustable-speed electric motor power through conveyor belt, and when it scraping, the constant hit makes the banana stem fiber's biological tissue broken, and separates the disintegrating slag from banana stalk fiber. Meanwhile the disintegrating slag will drop into the recycling box along the tangent direction of scraping roller's motion under wind force created by scraping roller's rotation. After that, banana stalk fiber is brought into smoothing device by its own gravity. Then the remaining moisture of banana stalk fiber is exhausted in recycling box, and banana stalk fiber is output through output belt. In order to get the optimal parameter combination, the fiber extraction rate and fiber trash content were set as experimental indices and the scraping roller rotating speed, scraper number and scraping anvil arc length were set as test factors, and the single factor test was performed to get the best value range of factors and the change law. Then an orthogonal experimental design of response surface methodology (RSM) was employed to find the optimum technical parameter combination for preparing fiber from banana stalk. The results indicated that the optimum combination was that the scraping roller rotating speed was 1 800 r/min, the scraper number was 16, and the scraping anvil arc length was 60 mm. According to the results of verification test on experimental index, the output was 207.6 kg/h, the fiber extraction rate was 93.2%, the fiber trash content percentage attained was 15.7% and the energy consumption was 22.1 kW·h/100 kg. The device meets the standards of agronomic production and raw material in related industries. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Fruits
Controlled terms:Belt conveyors - Carbon dioxide arc welding - Clamping devices - Crops - Energy utilization - Experiments - Extraction - Fibers - Machinery - Mechanization - Moisture - Optimization - Recycling - Rollers (machine components) - Rotating machinery - Slags - Tools
Uncontrolled terms:Banana stalk - Environment pollution - High moisture contents - Optimal parameter combinations - Orthogonal experimental design - Parameter combination - Parameter optimization - Response surface methodology
Classification code:452.3 Industrial Wastes - 525.3 Energy Utilization - 538.2.1 Welding Processes - 601 Mechanical Design - 692.1 Conveyors - 802.3 Chemical Operations - 821.4 Agricultural Products - 901.3 Engineering Research - 921.5 Optimization Techniques
Numerical data indexing:Mass_Flow_Rate 5.77e-02kg/s, Percentage 1.57e+01%, Percentage 9.32e+01%, Rotational_Speed 1.80e+03RPM, Size 5.00e-03m, Size 6.00e-02m
DOI:10.11975/j.issn.1002-6819.2016.20.007
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 28>
Accession number:20164603020648
Title:Growth and development dynamic model of watermelon in gravel-mulched field based on physiological development time
Authors:Ma, Bo (1, 2, 3); Tian, Juncang (1, 2, 3)
Author affiliation:(1) College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan; 750021, China; (2) Ningxia Research Center of Technology on Water-saving Irrigation and Water Resource Regulation, Yinchuan; 750021, China; (3) Efficient Use of Water Resources in Arid Modern Agriculture Ministry of Educational Engineering Research Center, Yinchuan; 750021, China
Corresponding author:Tian, Juncang(slxtjc@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:122-128
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Studies on growth and development dynamics of watermelon in gravel-mulched field are helpful in improving utilization efficiency of nutrient, reducing influence of ageing gravel-mulched field on watermelon growth and development and scientifically regulating and controlling watermelon growth and development. This article took into consideration of soil moisture, nutrient, temperature and illumination and established watermelon growth and development dynamic model and leaf area index (LAI) model of watermelon in gravel-mulched field. In 2006, a field experiment was performed in Yinxi Group, Hongquanzi Village, Zhongwei City, Ningxia (37°0'N, 105°12'E). In 2009, two different barrel experiments were conducted under rain shelter. Since the development dynamic model was built based on experience and previous published results. Data from the field and barrel experiments were used to validate the model. The LAI model was established by logistic model, a regression model. The model establishment was based on the results from one barrel experiment in 2009 and the model validation was based on those from the other barrel experiment in 2009. All the experiment simulated dry year, normal year and wet year with volumetric soil moisture of 11-20, 13-24 and 16-27 cm<sup>3</sup>/cm<sup>3</sup>, respectively. In the field experiment, organic fertilizer was 150 kg/hm<sup>2</sup>for all types of years. In the barrel experiment for LAI model establishment, organic fertilizer was 0, 600, 1 200 and 1 800 kg/hm<sup>2</sup>. In the barrel experiment for LAI model validation, in addition to application amount above, organic fertilizer amount expanded to 1 560 kg/hm<sup>2</sup>and urea was also used with different amount of 48, 61.5 and 33 kg/hm<sup>2</sup>. The experiment was under drip irrigation under film mulching. Model evaluation was based on root mean square of error(RMSE), normalized RMSE (nRMSE), and correlation coefficient (r). The results showed that: 1) the growth and development dynamic model had the RMSE of 0.95 and 1.78 d, nRMSE of 9.6% and 5.45, and r about 1. It suggested that the model was reliable in simulating growth and development dynamics of watermelon in gravel-mulched field; 2) the LAI model had RMSE of 0.00074-0.0033 d, nRMSE of 0.34%-2.3%, and r of 0.98 under all the type of year. The simulation results of the logistic model were consistent with the measured values and it could fit well the peaks of LAI curves. The LAI model had high accuracy of simulation of watermelon LAI in gravel-mulched field. The models here could be used for understanding watermelon growth dynamics in gravel-mulched field, and provide technical support for improving the utilization efficiency of water and fertilizer, and regulating and controlling watermelon growth process effectively. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Physiological models
Controlled terms:Dynamic models - Dynamics - Efficiency - Fertilizers - Gravel - Irrigation - Models - Moisture - Nutrients - Regression analysis - Soil moisture - Urea
Uncontrolled terms:Correlation coefficient - Development - Development dynamics - Growth and development - Leaf Area Index - Utilization efficiency - Volumetric soil moistures - Watermelon
Classification code:483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.3 Agricultural Methods - 913.1 Production Engineering - 921 Mathematics - 922.2 Mathematical Statistics
Numerical data indexing:Percentage 3.40e-01% to 2.30e+00%, Percentage 9.60e+00%
DOI:10.11975/j. issn.1002-6819.2016.20.016
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 29>
Accession number:20164603020658
Title:Weak fault detection method in complex strong noise condition based on empirical wavelet transform
Authors:Chen, Zhixin (1); Liu, Xin (1); Lu, Chenglin (1); Ma, Xiangguo (1)
Author affiliation:(1) Logistics School, Beijing Wuzi University, Beijing; 101149, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:202-208
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Empirical wavelet transform (EWT) is able to extract the intrinsic modes of the signal by completely adaptive wavelet basis, which has a complete theoretical base as well as the classical wavelet transform. When the large-scale mechanical equipment in the industrial field is diagnosed and analyzed, and the analyzed vibration signal collected from the equipment often contains complex strong noise, especially a lot of pulse noise. Some recent methods, like the empirical mode decomposition (EMD), propose to decompose a signal accordingly to its contained information. Even though its adaptability seems to be useful for many applications, the main issue with this approach is its lack of theory. Using the adaptive methods to analyze a signal is of great significance to find sparse representations in the context of fault diagnosis. Aiming at the complicated problem of detecting nonstationary vibration signal of weak fault and compound fault with a large amount of background noise, EWT is introduced to improve the accurate diagnosis rate. A detection method for weak faults in complex strong noise condition based on EWT is proposed. By using the peak characteristic of autocorrelation function to judge the periodicity of the decomposed signals, the most obvious decomposition signal is being as the characteristic signal to be detected. The steps of this method are as follows: 1) The original signal is decomposed by EWT; 2) The first sub signal is decomposed continuously by EWT, and then the trend signal in the original signal is obtained until the variance change is less than 0.01; 3) Using the peak characteristic of autocorrelation function to judge the periodicity of each signal, the most obvious signal is the characteristic signal. The EWT analysis of the simulated signal with complex strong noise and the actual signal is carried out, and by the comparison with the EMD, the feasibility and effectiveness of weak fault detection by EWT are verified. Finally, the conclusions are obtained through this research: 1) To the unsteady fluctuating phenomenon of the actual vibration signal in industrial field, EWT can remove the trend item almost perfectly to get more clear spectrum; 2) EWT can suppress impulse noise, and reduce unwanted noise interference as far as possible; 3) Compared with the EMD method, the theory on EWT is more rigorous; 4) EWT is suitable for analyzing nonstationary multicomponent signal, and can extract the mono- component signal. If it is combined with the Hilbert transform, the instantaneous frequency and instantaneous amplitude of the equipment can be obtained, so it can be used to monitor the time frequency condition of the equipment which has the nonstationary vibration of frequency fluctuation and amplitude fluctuation in the industrial field. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Signal detection
Controlled terms:Autocorrelation - Correlation detectors - Equipment - Fault detection - Gears - Impulse noise - Industrial research - Mathematical transformations - Signal processing - Vibration analysis - Vibrations (mechanical) - Wavelet decomposition - Wavelet transforms
Uncontrolled terms:Adaptive signal decomposition - Autocorrelation functions - Classical wavelet transforms - Empirical Mode Decomposition - Noise - Non-stationary vibration - Non-stationary vibration signals - Vibrations
Classification code:601.2 Machine Components - 716.1 Information Theory and Signal Processing - 901 Engineering Profession - 901.3 Engineering Research - 921 Mathematics - 921.3 Mathematical Transformations - 931.1 Mechanics
DOI:10.11975/j.issn.1002-6819.2016.20.026
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 30>
Accession number:20164603020646
Title:Effects of mulch and tillage methods on soil water and temperature as well as corn yield in Hetao irrigation district
Authors:Qi, Zhijuan (1, 3); Feng, Hao (1, 2); Zhang, Tibin (1); Zhou, Lifeng (2)
Author affiliation:(1) Research Center of Soil and Water Conservation and Ecological Environment, Chinese Academy of Sciences and Ministry of Education, Yangling; 712100, China; (2) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; 712100, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China
Corresponding author:Feng, Hao(nercwsi@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:108-113
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil hydrothermal condition is one of the most important factors affecting crop growth and development in semi-arid areas. In this study, we aimed to investigate effects of different film and tillage technology modes on spring maize yield and soil hydrothermal condition in Hetao Irrigation District. The experiment included four treatments: ridge tillage with full film mulching (LQ), ridge tillage with partial film mulching (LB), flat tillage with full film mulching (PQ) and flat tillage with partial film mulching (PB). The results showed that the soil moisture and soil temperature of LQ were higher (P<0.05) than the LB, PQ and PB treatments in the whole growing stage in 2014 and 2015. The suitable soil thermal conditions in LQ made plant grow vigorously, and it consumed large amount of soil water to enhance biomass and leaf area accumulation. In addition, the full film mulching was more effective at enhancing component factors influencing yield and reserving water in soil profile than partial film mulching, which resulted in higher yield and water use efficiency (WUE). There was an inverse correlation between soil temperature and soil moisture in arable layer. With the increasing of temperature and crop water consumption during growing period, LQ showed significant effect on soil water conservation. In 2014 and 2015, the soil temperature was higher (P<0.05) in LQ than in other treatments while the lowest value was recorded in the PB treatment. However, the soil temperature in LB was higher (P<0.05) than in PQ in 2014; it was opposite that higher soil temperature was recorded in PQ compared with LB in 2015. It implied that tillage technology had a significant influence on average temperature compared with mulching mode under drought conditions in 2014. Conversely, mulching mode played an more important role in preserving thermal conditions than tillage technology during the humid year in 2015. Overall, ridge tillage efficiently transferred and accumulated heat from shallow soil layer to deeper layers. Additionally, the higher the soil surface temperature, the more significant the film insulation effect. LQ can not only enhance the number of rows per ear and grain number, but also were conducive to the accumulation of dry biomass, promote the formation of maize yield under drip irrigation, and increase water use efficiency. LQ efficiently promoted water infiltration and regulated the surface temperature resulting in soil moisture conservation and evaporation inhibition. These effects were much clearer and more consistent with ridge tillage. In addition, full plastic film mulch had an insulation effect compared with partial plastic film mulch, and thus thermal energy could be effectively transferred and stored at the tillage layer where it was essential for maize growth. This study could provide a theoretical basis for improving soil hydrothermal conditions in Hetao Irrigation District and thus enhance crop productivity and quality. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Soil conservation
Controlled terms:Agricultural machinery - Agriculture - Atmospheric temperature - Crops - Ecology - Film growth - Inverse problems - Irrigation - Moisture - Moisture control - Plastic films - Soil moisture - Soils - Surface properties - Temperature - Thermal insulation - Water - Water conservation - Water supply
Uncontrolled terms:Corn - Crop growth and development - Drip irrigation - Hetao irrigation districts - Hydrothermal conditions - Soil surface temperatures - Soil temperature - Tillage methods
Classification code:413.2 Heat Insulating Materials - 443.1 Atmospheric Properties - 444 Water Resources - 446.1 Water Supply Systems - 454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 731.3 Specific Variables Control - 817.1 Polymer Products - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 951 Materials Science
DOI:10.11975/j.issn.1002-6819.2016.20.014
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 31>
Accession number:20164603020669
Title:Effect of packaging and storage temperature on water holding capacity of catfish fillets during storage based on low field NMR
Authors:Zhu, Yingchun (1); Ma, Lizhen (2); Dang, Xiaoyan (1); Wang, Yang (3)
Author affiliation:(1) College of Food Science and Engineering, Shanxi Agriculture University, Taigu; 030801, China; (2) College of Food Engineering and Biotechnology, Tianjin Agriculture College, Tianjin; 300384, China; (3) College of fisheries, Tianjin Agriculture College, Tianjin; 300384, China
Corresponding author:Ma, Lizhen(Malizhen-6329@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:281-289
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The effect of packaging and storage temperature on the water holding capacity (WHC) of catfish fillet (Clarias gariepinus) was investigated using the low-field nuclear magnetic resonance (LF-NMR). The catfish fillets were stored at 4°C or -0.7°C with air-packaging (AP), vacuum-packaging (VP) or modified atmosphere-packaging (MAP, 60% CO<inf>2</inf>and 40% N<inf>2</inf>). The fillets were sampled on the 0, 1, 4, 7, 10, 15, 20, 30 day since storage to analyze the pH value, cooking loss and water loss after centrifugation. The WHC changes of catfish fillets were illustrated by relaxation time, relaxation area and proton density in LF-NMR, and muscle fiber structure changes were visualized by the scanning electronic microscopy. The present study aimed to give a comprehensive judgment on the process of WHC changes of the catfish fillet during the storage at different temperatures and with different packaging styles, and aimed to reveal the underlying mechanism. The results demonstrated that the WHC of the catfish fillet decreased during the storage period. The pH value significantly declined in each treatment group during the first 4 days; later, the pH value of the AP and VP groups stored at both 4℃ and -0.7℃ rose significantly (P<0.05), while that of MAP groups (4℃ and -0.7℃ ) was maintained at low levels of 6.51-6.88. The highest cooking loss occurred in the 4℃ VP group which increased from 11.54% (the initial day) to 23.70% (the 4<sup>th</sup>day). Water loss after centrifugation significantly rose from 15.98% (the initial day) to 31.35% (the 15<sup>th</sup>day) in the 4℃ VP group. Therefore it can be concluded that the VP is not an effective package style to maintain the WHC. The relaxation time showed a downward tendency from 63.67 (the initial day) to 54.82 (4℃ AP group, the 10<sup>th</sup>day) and 57.10 ms (0.7℃ AP group, the 15<sup>th</sup>day), which was because the binding force of water increased, and the degree of freedom and the mobility of water decreased. The relaxation area increased from 85.49 %(the initial day) to 88.06%-94.77% (the 1<sup>st</sup>day), and later showed a downward tendency. On the 30<sup>th</sup>day in storage, the relaxation area of the -0.7℃ MAP group reduced to 86.38%, and that of the -0.7℃ VP group decreased to 81.11%. The reason was that the contraction of muscle fiber caused the water within the muscle fiber cells to extrude and flow outside of the cell, and part of the immobilized water was transformed to free water. Through the comparison of the WHC among all the 6 groups, the -0.7℃ MAP is the best storage way for catfish fillet. Pearson correlation coefficient analysis indicated that the content of immobilized water was significantly correlated with the storage time (P<0.05), pH value (P<0.05), as well as cooking loss and water loss (P<0.01). The results of MRI (magnetic resonance imaging) indicated that the water migrated out of the myofibril cell and was aggregated outside the muscle cell membrane during the storage. The scanning electronic microscopy demonstrated that the muscle fiber of fresh catfish was arranged closely with intact connective tissue and clear muscle fiber boundaries, but during the storage muscle distortion, fracture, voids, damaged membrane of connective tissue, and ambiguous boundaries of muscle fiber were visible. Hence such changes of myofibril cell structure were also the reason causing the decrease of WHC. In summary, LF-NMR is efficient for rapid evaluation of WHC in catfish fillets. The results of the study can provide the storage and package guidance for the manufacture of high quality catfish fillet. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Modified atmosphere packaging
Controlled terms:Carbon dioxide - Cells - Centrifugation - Collagen - Correlation methods - Cytology - Degrees of freedom (mechanics) - Energy storage - Fibers - Food processing - Magnetic resonance imaging - Magnetic storage - Magnetism - Muscle - Musculoskeletal system - Nuclear magnetic resonance - Packaging - pH - Relaxation time - Resonance - Tissue
Uncontrolled terms:Catfish fillet - Clarias gariepinus - Low field nuclear magnetic resonance (LF NMR) - MRI (magnetic resonance imaging) - Pearson correlation coefficients - Scanning electronic microscopy - Storage temperatures - Water holding capacity
Classification code:461.2 Biological Materials and Tissue Engineering - 461.3 Biomechanics, Bionics and Biomimetics - 525.7 Energy Storage - 694.1 Packaging, General - 701.2 Magnetism: Basic Concepts and Phenomena - 722.1 Data Storage, Equipment and Techniques - 801.1 Chemistry, General - 802.3 Chemical Operations - 804.2 Inorganic Compounds - 822.2 Food Processing Operations - 922.2 Mathematical Statistics - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics
Numerical data indexing:Age 8.22e-02yr, Percentage 1.15e+01%, Percentage 1.60e+01%, Percentage 2.37e+01%, Percentage 3.14e+01%, Percentage 8.11e+01%, Percentage 8.55e+01%, Percentage 8.64e+01%, Percentage 8.81e+01% to 9.48e+01%, Temperature 2.72e+02K, Temperature 2.77e+02K, Time 5.71e+01m/s
DOI:10.11975/j.issn.1002-6819.2016.20.037
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 32>
Accession number:20164603020642
Title:Solid-liquid two-phase flow characteristics in centrifugal pump with multi-component medium
Authors:Huang, Sijie (1); Shao, Chunlei (1)
Author affiliation:(1) School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing; 211800, China
Corresponding author:Shao, Chunlei(chunlei-shao@njtech.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:77-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In traditional research method, the medium delivered by two-phase flow centrifugal pump contains only one kind of particles with the same diameter, while in actual working condition the medium contains various kinds of particles with much more than one diameter. In order to reveal the characteristics of the solid-liquid two-phase flow in centrifugal pump under actual operating condition, steady numerical calculation of the internal flow in a centrifugal pump was performed by using Fluent software with the Eulerian model and the standard k-Ε turbulence model. The Phase Coupled SIMPLE algorithm was used to solve pressure-velocity coupled equations. The liquid-solid drag coefficient was calculated by the Gidaspow model, and solid-solid drag coefficient was calculated by the Syamlal-Obrien-Symmetric model. The external characteristic test was carried out with the centrifugal pump model. And the experimental results were compared with the numerical results. The results showed that the numerical results were in good agreement with the experimental results. In this paper, the numerical results were used to study the flow in the pump. Three groups of monodisperse particle swarms, whose diameters were respectively 0.02, 0.3 and 0.7 mm, were chosen to be the solid phase. The motion characteristics of monodisperse particle swarm in the pump were studied. It could be seen that the PVF (particle volume fraction) distribution became more nonuniform with the increase of particle diameter. As the particles with large diameter had large mass, the distribution of particles with larger diameter in the impeller passage was closer to the blade pressure surface and the phenomenon of solid-liquid separation became more obvious. The two-phase flow in the pump was researched when the solid phase contained 2 kinds of same monodisperse particles whose diameters were changed simultaneously. For the 2 particle swarm, the PVF difference between them is less than 7×10<sup>-6</sup>%, and the relative velocity between them is less than 5×10<sup>-4</sup>m/s. With the increase of the impeller diameter, the slip velocity of monitoring points in the suction side of the blade increased first and then decreased, while in the pressure side it decreased first and then increased. The slip velocity on the blade surface decreased as the particle diameter decreased. The total pressure at monitoring points on the blade surface increased with the increase of impeller diameter. The head, hydraulic efficiency, and total pressure difference between the inlet and outlet decreased with the increase of particle diameter. When transporting 2 particle swarms with equal diameter, the external characteristics of the centrifugal pump were similar to that when transporting single particle swarm. When the medium contained 2 particle swarms with different diameters, on account of the interaction among big particle, small particle and water, the effect of the particles with different diameters on the characteristics of the pump was complicated. The distribution of big particles and small particles presented different regularity. The volume fraction and relative velocity of the big particles would change when the small particle diameter increased together with the big particle diameter unchanged. The influence law of the small particle in the 2 particle swarms with different diameters was similar to the one in 2 particle swarms with same diameters. The existence of small particles made the distribution of big particles more uniform in the impeller passage. The head and hydraulic efficiency reached the lowest value for the combination of particles with the diameter of 0.7 and 0.02 mm. With the increase of small particle diameter, the head and hydraulic efficiency increased rapidly first, and then decreased gradually. They reached the maximal value (80.12 m and 60.05%, respectively) when the small particle diameter was about 0.15 mm. The research is comprehensive and practical to reveal the characteristics of the two-phase flow centrifugal pump, and can be referenced to pump design and structural optimization. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Two phase flow
Controlled terms:Centrifugal pumps - Computer simulation - Drag - Drag coefficient - Efficiency - Impellers - Liquids - Models - Particle size - Pumps - Structural optimization - Turbulence models - Velocity - Volume fraction
Uncontrolled terms:Distribution of particles - External characteristic - Mono-disperse particles - Multicomponents - Particle diameters - Particle volume fractions - Solid liquid separation - Solid-liquid two phase flows
Classification code:601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 723.5 Computer Applications - 913.1 Production Engineering - 921.5 Optimization Techniques
Numerical data indexing:Percentage 6.00e+01%, Size 1.50e-04m, Size 2.00e-05m, Size 7.00e-04m, Size 8.01e+01m
DOI:10.11975/j.issn.1002-6819.2016.20.010
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 33>
Accession number:20164603020668
Title:Microbial flora analysis of oyster during refrigerated storage by high throughput sequencing technology
Authors:Cao, Rong (1); Liu, Qi (1); Zhao, Ling (1); Meng, Huihui (1)
Author affiliation:(1) Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao; 266071, China
Corresponding author:Liu, Qi(liuqi@ysfri.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:275-280
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Oysters are perishable food due to their high contents in moisture and nutrients, as well as the bacterium amount and diversity of high level. Microorganisms play a key role in the quality deterioration of shellfish. Therefore, the study on the microbial community has great importance in the freshness-keeping and preservation of aquatic products. To analyze microbial flora is greatly limited for traditional cultivation method because only a small part of bacteria can be cultured. Some molecular biology technologies such as real-time polymerase chain reaction (real-time PCR), denaturing gradient gel electrophoresis (DGGE), and terminal restriction fragment length polymorphism (TRFLP) also have their individual shortcomings. Nowadays, high throughput sequencing technology is emerging and has attracted wide attention of researchers. In this study, high throughput sequencing technology based on Illumina MiSeq 2500 PE250 was applied to investigate the changes in bacteria composition of oysters during refrigerated storage. Results showed that high throughput sequencing technology had great advantages and application prospect in food microbiology. The quality of total bacterial DNA (deoxyribonucleic acid) extraction and amplification of the 16SrDNA-V4 area was satisfied and could meet the needs of database construction. The number of raw/effective sequences was 56 867/39 390, 45 210/30 847 and 39 873/27 603 respectively for the sample stored for 0, 4 and 8 d. The number of OTUs (operational taxonomic units) was 587, 699 and 531 respectively. The rarefaction curve indicated that the numbers of sequences were adequate, and the numbers of OTUs were almost saturated. For the sample stored for 0, 4 and 8 d, the Chao1 index was 587.2, 766.6 and 683.0, the Simpson index was 0.945, 0.897 and 0.856, and the Shannon index was 5.48, 5.51 and 4.34, respectively; besides, the goods coverage was 0.996, 0.995 and 0.993, respectively. The research data showed that the dominant bacteria belonged to Proteobacteria in phylum level, Gammaproteobacteria in class level and Vibrionales in order level. In the family level, Vibrionaceae, Shewanellaceae and Pseudoalteromonadaceae were dominant, however their proportions were different among the oyster samples with different storage time. In the genus level, the proportion of Vibrio (28.3%), Shewanella (10.3%) and Pseudoalteromonas (7.2%) was relatively high in the oyster (stored for 0 d). During ice storage, the proportion of Vibrio decreased significantly when stored for 1 d, and reached 6.4% when stored for 4 d. However, the proportion of Vibrio changed little in the later stage, which was 6.2% when stored for 8 d. The proportion of Shewanella decreased to 4.0% when stored for 4 d and increased since then; when stored for 8 d, their proportion increased to 19.5%. The proportion of Pseudoalteromonas increased from 7.2% (0 d) to 32.2% (8 d), because of their strong adaptability to low temperature. Pseudoalteromonas and Shewanella could cause offensive odor by producing small molecule volatile substances, like NH<inf>3</inf>, H<inf>2</inf>S and TMAO. They played important role in the quality deterioration of oysters during cold storage. Therefore, the means that can strategically inhibit the growth and metabolism of Pseudoalteromonas and Shewanella will help to improve the storage quality and extend the shelf life of oysters. This study can provide reference for the microbial ecology research onfresh fishery products, and enrich the basic theory for the freshness keeping of oysters. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Bacteria
Controlled terms:Aquatic organisms - Cold storage - Deterioration - Digital storage - Ecology - Electrophoresis - Food microbiology - Information dissemination - Microbiology - Microorganisms - Molecular biology - Molluscs - Nucleic acids - Polymerase chain reaction - Quality control - Shellfish - Temperature - Throughput
Uncontrolled terms:Denaturing gradient gel electrophoreses (DGGE) - High-throughput sequencing - Microbial flora - Operational taxonomic units - Oyster - Quality deteriorations - Real-time polymerase chain reaction (real-time PCR) - Terminal restriction fragment length polymorphisms
Classification code:454.3 Ecology and Ecosystems - 461.9 Biology - 461.9.2 Microbiology - 471 Marine Science and Oceanography - 641.1 Thermodynamics - 644.3 Refrigeration Equipment and Components - 722.1 Data Storage, Equipment and Techniques - 801 Chemistry - 903.2 Information Dissemination - 913.3 Quality Assurance and Control - 951 Materials Science
Numerical data indexing:Percentage 1.03e+01%, Percentage 1.95e+01%, Percentage 2.83e+01%, Percentage 3.22e+01%, Percentage 4.00e+00%, Percentage 6.20e+00%, Percentage 6.40e+00%, Percentage 7.20e+00%
DOI:10.11975/j.issn.1002-6819.2016.20.036
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 34>
Accession number:20164603020657
Title:Identification and counting method of orchard pests based on fusion method of infrared sensor and machine vision
Authors:Tian, Ran (1, 2); Chen, Meixiang (1); Dong, Daming (1); Li, Wenyong (1); Jiao, Leizi (1); Wang, Yizhong (2); Li, Ming (1); Sun, Chuanheng (1); Yang, Xinting (1)
Author affiliation:(1) National Engineering Research Center for Agriculture Information Technology in Agriculture/Key Laboratory for Information Technologies in Agriculture, Ministry of Agriculture/Beijing Engineering Research Center for Agricultural IOT, Beijing; 100097, China; (2) College of Information and Electrical Engineering, Tianjin University of Science and Technology, Tianjin; 300222, China
Corresponding author:Yang, Xinting(yangxt@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:195-201
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Traditional single monitoring technique in orchard environment has such shortages as weak effectiveness, inaccurate count and pooruniversality. Now existing pest monitoring methods include acoustic measurement, piezoelectric measurement, infrared measurement and machine vision recognition technology. In view of this, the future development trend of pest detection technology will undoubtedly be a variety of detection methods combined with each other. Comprehensive utilization of the existing testing methods will form a multiple information fusion technique to detect and provide reliable scientific decision based on comprehensive prevention and control of fruit pests, and the loss will be reduced to a minimum. In this paper, infrared measurement and machine vision recognition technology are integrated to identify pest species and count pest populations, and information of pests is obtained from 2 aspects. The accuracy of the fusion result is verified by comparing with the manual count. Taking Grapholitha molesta, Dichocrocis punctiferalis, Adoxophyes orana and disruptors as research objects, recognition results of infrared sensors and machine vision are obtained using the laboratory artificially randomly scattered test samples. Test samples were collected in Xiaotangshan National Precision Agriculture Research and Demonstration Base from July to September in 2015. For the infrared method, infrared circuit is mainly composed of infrared detector, photoelectric detector, filter, amplifier, communication module, and so on. Due to the different size of insect pests, the infrared output is different. The bigger the pest, the bigger the value of the infrared output. Therefore, the influence of ambient light on the detection results is significant. For example, Adoxophyes orana is larger than Grapholitha molesta and smaller than Dichocrocis punctiferalis. To go along with this, the thresholds of Grapholitha molesta, Adoxophyes orana, Dichocrocis punctiferalis and disruptors are 5.655, 13.47 and 23.13, respectively. The system is mainly composed of infrared sensor unit and machine vision unit. The infrared sensor unit introduces the phase lock amplifier technology to extract the weak useful signal from the noise environment, and to solve the problem of the influence of the natural light environment. The core of the lock-in amplification technology is correlation detection, and using the characteristic of useful signals and noise signals being not related to each other to extract the useful signal from the noise by the correlation operation. Using Matlab environment feature extraction algorithm, normalized entropy and normalized energy are chosen as texture feature indices for the HSV three-channel texture feature based on the 'DB4' wavelet decomposition. Infrared image fusion and pest identification are mainly based on the time stamp of infrared and image recognition. Fusion count results are obtained by a formula operation which is derived from the linear regression analysis of SPSS. The results of infrared sensor and machine vision are the input of the formula. We can get the conclusion that the infrared output value ranges are (0,5], (5,13], (13,23], and (23,32], and the infrared recognition accuracy rates of Grapholitha molesta, Dichocrocis punctiferalis, Adoxophyes orana and disruptors are 92%, 78%, 80% and 88% respectively. The image recognition accuracy rates are 92%, 88%, 92% and 90%, respectively, and the fusion recognition accuracy rates are 98%, 92%, 94% and 96%, respectively. Obviously, the fusion of infrared sensor and image recognition technology can improve the accuracy and efficiency of the identification of fruit pests. This method has very high innovation in both theory and practical application. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Signal detection
Controlled terms:Computer vision - Correlation detectors - Data fusion - Farms - Feature extraction - Fruits - Image fusion - Image processing - Image recognition - Infrared detectors - Infrared devices - Infrared imaging - Locks (fasteners) - Monitoring - Orchards - Regression analysis - Sensor data fusion - Signal processing - Testing - Trees (mathematics) - Wavelet decomposition
Uncontrolled terms:Comprehensive preventions - Comprehensive utilizations - Feature extraction algorithms - Fruit trees - Image recognition technology - Infra-red sensor - Multiple information fusions - Piezoelectric measurements
Classification code:716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 723.5 Computer Applications - 746 Imaging Techniques - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921.3 Mathematical Transformations - 921.4 Combinatorial Mathematics, Includes Graph Theory, Set Theory - 922.2 Mathematical Statistics - 944.7 Radiation Measuring Instruments
Numerical data indexing:Percentage 7.80e+01%, Percentage 8.00e+01%, Percentage 8.80e+01%, Percentage 9.00e+01%, Percentage 9.20e+01%, Percentage 9.40e+01%, Percentage 9.60e+01%, Percentage 9.80e+01%
DOI:10.11975/j.issn.1002-6819.2016.20.025
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 35>
Accession number:20164603020663
Title:Production of bio-oil by direct liquefaction of Spartina alterniflora in ethanol-water co-solvent
Authors:He, Zhixia (1, 2); Ji, Changhao (1); Xu, Guisheng (1)
Author affiliation:(1) School of Energy and Power Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) Institute for Energy Research, 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:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:236-241
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biomass is considered to the most promising feedstock with low carbon intensity for producing renewable and clean alternative fuels due to their abundant reserves, wide distribution and carbon neutral. In this study, direct liquefaction of Spartina alterniflora was performed in a 50 mL bath reactor with ethanol and water as a co-solvent. Experiments for optimal operating conditions such as reaction temperature, ethanol volume fraction in ethanol-water co-solvent and solvent to biomass ratio were conducted to understand its influence on liquefaction product distribution. Raw material and bio-oil were analyzed by thermogravimetry analysis and gas chromatography-mass spectrometry (GC-MS). Results showed that thermogravimetric (TG) and differential thermogravimetric (DTG) curves of Spartina alterniflora were almost the same with the increase of heating rate from 10 to 40℃ /min. However, the temperature where the maximum rate of weight loss occurred, tended to move to higher value. This suggested that there was a hysteresis phenomenon on thermogravimetric characteristics of Spartina alterniflora with respect to the heating rate, which was caused by the combination of time and temperature. The bio-oil yield tended to increase but the solid residue yield tended to decrease with increasing temperature up to 340℃, while further increasing temperature increased the residue yield but decreased the bio-oil yield. The similar tendency for bio-oil yield and solid residue yield was observed when increasing ethanol volume fraction in ethanol-water co-solvent between 0 and 100%. As the solvent to biomass ratio increased from 6 to 10 mL/g, the bio-oil yield increased obviously and after that the trend went opposite. Meanwhile, the solid residue yield reduced gradually with the solvent to biomass ratio in the range of 6-10 mL/g and leveled after higher than about 15 mL/g. Optimal operating conditions were reaction temperature of 340℃, ethanol volume fraction in co-solvent of 50% and solvent to biomass ratio of 10 mL/g, resulting the highest bio-oil yield of 44.2% and minimum solid residue yield of 12%, respectively. Compared with single solvent like pure water or ethanol, ethanol-water co-solvent showed an obvious synergistic effect during direct liquefaction of Spartina alterniflora. Not only the yield of bio-oil was enhanced but also the quality of bio-oil was improved with ethanol-water co-solvent as the reaction medium. The result of GC-MS analysis indicated that the bio-oil obtained from direct liquefaction of Spartina alterniflora at optimal operating conditions was a complex and oxygen-containing organic mixture, mainly including acids, phenols, esters and ketones. The major components of bio-oil were phenols (29.62%) and esters (11.27%). The presence of ethanol could promote the formation of esters by reacting with acids through esterification while the majority of phenols were derived from the decomposition of lignin. Ester compounds were similar to biodiesel in composition. Thus, it was desirable to increase the amount of esters in bio-oil for a better bio-oil quality. The energy recover rate of bio-oil obtained from direct liquefaction in ethanol-water co-solvent with 50% ethanol volume fraction reached up to 76.5%, which was significantly higher than that in single solvent. Therefore, ethanol-water co-solvent was a potential medium with higher bio-oil energy recover during direct liquefaction of biomass. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Organic solvents
Controlled terms:Alternative fuels - Biofuels - Biomass - Chromatography - Esters - Ethanol - Gas chromatography - Heating rate - Ketones - Liquefaction - Mass spectrometry - Phenols - Solvents - Temperature - Thermogravimetric analysis - Volume fraction
Uncontrolled terms:Cosolvents - Differential thermogravimetric - Direct liquefaction - Gas chromatography-mass spectrometries (GC-MS) - Optimal operating conditions - Spartina alterniflora - Thermogravimetric characteristics - Thermogravimetry analysis
Classification code:641.1 Thermodynamics - 641.2 Heat Transfer - 801 Chemistry - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804.1 Organic Compounds
Numerical data indexing:Percentage 0.00e+00% to 1.00e+02%, Percentage 1.13e+01%, Percentage 1.20e+01%, Percentage 2.96e+01%, Percentage 4.42e+01%, Percentage 5.00e+01%, Percentage 7.65e+01%, Specific_Volume 1.00e-02m3/kg, Specific_Volume 1.50e-02m3/kg, Specific_Volume 6.00e-03m3/kg to 1.00e-02m3/kg, Volume 5.00e-05m3
DOI:10.11975/j.issn.1002-6819.2016.20.031
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 36>
Accession number:20164603020634
Title:Development and experiment of peanut no-till planter under full wheat straw mulching based on "clean area planting"
Authors:Gu, Fengwei (1); Hu, Zhichao (1); Chen, Youqing (1); Wu, Feng (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Nanjing; 210014, China
Corresponding author:Hu, Zhichao(nfzhongzi@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:15-23
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Huang-Huai-Hai region is the main production area of peanut, where currently exist some outstanding problems, such as multiple operations of multiple machines in routine machine sowing work, high production cost, high energy and time consumption, and missing farming season. In addition, the traditional way of no-till seeding is not fit for peanut no-till seeding under the coverage of the wheat straw, and 3 major technical problems exist: soil-buried parts of machine are blocked with grass, which can't guarantee the smooth operation; the seeds may be planted on the wheat straw, causing the seeds are above the soil and not into the soil; soil-covering is unreliable, causing the seeds are not covered by soil. In this paper, a no-till peanut planter under the coverage of the wheat straw based on "cleaned area seeding" was developed. Firstly, smash the wheat straw on the surface of the fields which would be seeded, then pick up and collect them, and spread backwards after loading; secondly, finish stubble cutting and seed-bed preparation before the straw fell down, and finish fertilization and seeding work in "cleaned area"; finally, the smashed straw was evenly covered on the fields after planting, and the whole process, including crushing the wheat straw, cleaning the field, fertilizing, and covering the seed bed with wheat straw, was all finished in relatively "cleaned area". With the combination of analytical calculation and experimental optimization, 4 parts of the whole machine were involved to be designed based on the working principle of the machine, and Y typed cutting device was adopted in the link of crushing and collecting straw. In order to meet straw smashing and picking requirements, the optimized working parameters and structure parameters of knife roller were obtained by analyzing the absolute speed of the swung knife, which was synthesized by the machine forward speed and the rotary speed of knife shaft. Meanwhile, the parameters such as the rotary speed of the horizontal screw feeder were determined through wheat straw pushing volume. Impeller type lifting and throwing structure was used during the links of straw loading, throwing and evenly covering. According to the energy conservation law, combined with the configuration of the machine, the main structural and motional parameters such as throwing impeller, pipes, and lifting height were designed by calculation. According to the principle of non dynamic passive rotation, the impeller type evenly throwing mechanism was designed, achieving high speed rotation of the impeller through the wind force generated by the fan, which was installed in the machine, and then the straw was scattered and spread to the surface of the field evenly. The reverse shallow rotary tillage method was designed to break the stubble and soil during the seeding bed preparation. Compared with traditional rotary parameters, the smaller the shallow rotary tillage tactical diameter and rotational speed were, the better the stubble and soil breaking effect would be, and meanwhile, the energy and power consumption were eased. Matched with the designed peanut no-till planter during fertilizing and seeding session, the furrow opener, one of the key soil-buried components, was designed to prevent the soil blocking, solving the clogging problem of seed spout. Peanut no-till planter under the coverage of the wheat straw, affiliated with high-powered tractor of over 75 kW, had the working width of 2 400 mm and the pure productivity over 0.53 hm<sup>2</sup>/h. The field tests and measurement results showed that the average length of straw was 115 mm after work, the uniformity ratio of straw mulching was 83%, the average depth of sowing and fertilizing was 46 and 59 mm respectively, the qualified rate was 98% and 89% respectively, and the yield was about 5 749.5 kg per hektare. This machine is suitable for the coverage of the straw, which can crush the wheat straw, clean the seedbed, fertilize, and cover the soil and seed bed with wheat straw at one time; the operation is smooth and reliable and has high seeding quality, and all the operating indices can meet the requirements for main peanut producing areas. Meanwhile, the research on the method of "cleaned area" seeding may be applicable for other dryland crops such as wheat, corn, and soybean, providing appropriate equipment to promote the mechanization of prohibiting straw burning. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Seed
Controlled terms:Agricultural machinery - Agriculture - Crops - Crushing - Feeding - Impellers - Oilseeds - Problem solving - Soils - Speed - Straw
Uncontrolled terms:Analytical calculation - Energy conservation law - Experimental optimization - High-powered tractors - Multiple operations - No-till planters - Peanut - Structure parameter
Classification code:483.1 Soils and Soil Mechanics - 601.2 Machine Components - 691.2 Materials Handling Methods - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
Numerical data indexing:Mass 7.50e+02kg, Percentage 8.30e+01%, Percentage 8.90e+01%, Percentage 9.80e+01%, Power 7.50e+04W, Size 1.15e-01m, Size 2.40e+00m, Size 5.90e-02m
DOI:10.11975/j.issn.1002-6819.2016.20.002
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 37>
Accession number:20164603020659
Title:Property and heat storage performances of Glauber's salt-based phase change materials for solar greenhouse in Qinghai-Tibet plateau
Authors:Jiang, Zipeng (1); Tie, Shengnian (1)
Author affiliation:(1) New Energy (photovoltaic) Industry Research Center, Qinghai University, Xining; 810016, China
Corresponding author:Tie, Shengnian(tieshengnian@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:209-216
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Thermal energy storage (TES) is considered as one of the most important energy storage methods, and it can reduce the imbalance between solar heat supply and consumption and help to save costs. The phase change materials (PCMs) are the materials storing and releasing latent heat during the phase change. Low temperature PCMs are widely used in greenhouse study. Glauber salt (NaSO<inf>4</inf>·10H<inf>2</inf>O) based composite PCMs affect the greenhouse temperature change directly and their phase change temperature is suitable for greenhouse application, but the problems of supercooling phase separation and low thermal conductivity exist in their application. Related studies have showed that borax is the best substance which can decrease the supercooling problem, and CMC (R<inf>n</inf>OCH<inf>2</inf>COONa) is effective to reduce their phase separation. In order to enhance its thermal conductivity, we chose graphitic material as the heat-removing agent. In this paper, we studied the properties of Glauber salt based phase change energy storage material and it's performance of heat storage in winter in the Qinghai-Tibet Plateau region. Firstly, we prepared the Glauber salt based composite PCMs in laboratory, and then their thermal properties were measured by the differential scanning calorimetry (DSC). Samples were put in an alumina pan and heated from -10 to 40℃ at a rate of 1.0℃ /min in purified nitrogen atmosphere (50 mL/min). The thermal cycling tests were carried out in an oven (Themo SCIENTIFIC HAAKE A 40) by heating and cooling the samples from 10 to 40℃ repeatedly. Thermal conductivities were determined by the transient plane source (TPS) method (Hot Disk, TPS 2200). The tested simple solar greenhouse was located in Xining City, Qinghai Province (101°44' E, 36°43' N). It was 3.5 m long and 2.7 m wide. The wall included 5 cm flexible foam (polyurethane) and 20 cm gypsum brick, as well as 0.1 cm iron sheet. The test period was from December 20th, 2015 to February 4th, 2016. The heat insulation sheet of the simple solar greenhouse was rolled up and down at 9:00 am and 5:00 pm on every sunny day, respectively. The temperatures of outdoor, and indoor air and gypsum wall, and solar irradiation were measured continuously at a time interval of 10 min. The data collected on a typical sunny day were used to study the heat-retaining properties in greenhouse with PCMs. When the temperature was higher than PCMs freezing and melting point, the PCMs released heat and froze. This paper explored the property about its undercooling, phase separation, thermal conductivity and phase change cycle. Two simple greenhouses were built, and the change of temperature was analyzed. Results showed that when adding the 4% borax (mass fraction), the supercooling of PCMs almost disappeared; adding 1.5% CMC, the phase separation did not exist; adding 1% graphite powder, the thermal conductivity significantly improved. Latent heat of PCMs measured by DSC was 127 kJ/kg. After the phase changing cycle of 300 times, PCMs still could keep good performance, which was suitable for greenhouse to keep warm in cold climate. The test results of greenhouse temperature showed that when the mass of phase change materials was 25, 35 and 45 kg, the lowest greenhouse temperature increased by 1, 3.6 and 4.4℃, respectively before sunrise in the morning. The test results also showed that when the mass of phase change materials was 25, 35 and 45 kg, the highest temperature of gypsum back wall in noon decreased by 1.1, 2.2 and 3.0℃ and the lowest temperature before sunrise in the morning increased by 0.4, 2.4 and 4.0℃ respectively compared with the contrast greenhouse. We can conclude that the adding of the PCMs can obviously increase the lowest temperature inside the greenhouse and the back wall, and it is suitable for solar greenhouse heating application in extremely cold climate environment. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Phase change materials
Controlled terms:Alumina - Borate minerals - Differential scanning calorimetry - Digital storage - Dye-sensitized solar cells - Energy storage - Greenhouses - Gypsum - Heat storage - Latent heat - Phase separation - Separation - Sodium borate - Sodium sulfate - Solar heating - Storage (materials) - Supercooling - Temperature - Thermal conductivity - Walls (structural partitions)
Uncontrolled terms:Change of temperatures - Low thermal conductivity - Phase change energy storage - Phase change temperature - Qinghai Tibet plateau - Sodium sulfate decahydrate - Solar greenhouse - Transient plane sources
Classification code:408.2 Structural Members and Shapes - 482.2 Minerals - 525.7 Energy Storage - 641.1 Thermodynamics - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 694.4 Storage - 702.3 Solar Cells - 722.1 Data Storage, Equipment and Techniques - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821.6 Farm Buildings and Other Structures - 944.6 Temperature Measurements
Numerical data indexing:Mass 4.50e+01kg, Percentage 1.00e+00%, Percentage 1.50e+00%, Percentage 4.00e+00%, Size 1.00e-03m, Size 2.00e-01m, Size 2.70e+00m, Size 3.50e+00m, Size 5.00e-02m, Specific_Energy 1.27e+05J/kg, Time 6.00e+02s
DOI:10.11975/j.issn.1002-6819.2016.20.027
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 38>
Accession number:20164603020641
Title:Matching analysis of fuel in inner chamber and outer chamber of double swirl combustion system in diesel engine
Authors:Li, Xiangrong (1); Zhou, Haiqin (1); Wan, Yuanliang (2); Su, Liwang (3); Liu, Fushui (1)
Author affiliation:(1) School of Mechanical and Vehicular Engineering, Beijing Institute of Technology, Beijing; 100081, China; (2) Technology Center of DongFeng Commercial Vehicle Company Limited, Wuhan; 430056, China; (3) China North Engine Research Institute, Tianjin; 300400, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:70-76
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Direct injection (DI) diesel engines are used in the field of transportation and engineering machinery due to their excellent thermal efficiency and practical economic value. In order to reduce air pollution, diesel engines are continuously forced to improve the combustion processes, especially to reduce emitted particulate matter (PM) and nitrogen oxidants (NOx). Fuel-air mixing and fuel-air distribution play a vital role to reduce harmful emissions. Therefore, a homogeneous fuel/air mixture in the combustion chamber and an increase of the fuel/air mixture area can significantly improve the utilization of air and restrict the soot formation in diesel engines. Double swirl combustion system (DSCS) has excellent thermal efficiency in practical application, but its mass fraction of fuel in inner chamber has not been studied yet. It is hypothesized that mass fraction of the fuel in inner chamber is 10%. To verify the hypothesis, the best range of mass fraction in inner chamber and the effect of dynamic performance and the emission were researched in present paper. First, we analyzed the changes of mass fraction of fuel in inner chamber under different spray angles. Spray angle was conducted at 140°, 145°, 150°, 155° and 160°, and at this time, the injection advance angle was 12° and the speed was 2 500 r/min. Meanwhile, the power characteristics and emission characteristics were analyzed with CFD (computational fluid dynamics) simulation. We researched the soot and NOx at different spray angles. We then analyzed the effect of injection advance angles on the mass fraction of fuel in inner chamber. Injection advance angle was conducted at 10° (corresponding to crank angle of 350°), 12°, 14°, 16°, 18° and 20°, and at this time, the spray angle was 145° and the speed was 2 500 r/min. Meanwhile, the mass fraction of fuel on TDC (top dead center) in inner chamber and mass fractions of NOx and soot were analyzed. We also researched the soot and NOx at different injection advance angles. The engine speeds (1 300, 1 600, 1 900, 2 200, 2 500 and 2 800 r/min) were selected to study its effect on mass fraction of fuel in inner chamber. The mass fraction of fuel on TDC in inner chamber and emission characteristics were also analyzed. At last we analyzed the combined influences of injection advance angle and speed. The result showed that the indicated power and NOx were the highest, and the soot formation was the lowest, when the mass fraction of the fuel in inner chamber was about 10%-20%. The reason could be explained as follows: the fuel/air mixing quality was improved when the mass fraction of the fuel in inner chamber was about 10%-20%. Thus, it can be concluded that about 10%-20% mass fraction of the fuel in inner chamber has a positive influence on improving the utilization of the air inside the cylinder. The air in DSCS is made full use of, thus making the cylinder have an increase in the fuel mixing and burning. With the increase of the fuel injection advance angle, the mass fraction of fuel in inner chamber increased. Soot emissions increased at first and then decreased with the increase of injection advance time, and NOx emissions decreased with injection advance time. With the increase of the speed, the mass fraction of fuel in inner chamber decreased, soot increased and NOx decreased. At last, we researched the comprehensive effect of injection advance angle and speed on the mass fraction of fuel in inner chamber. The result showed that when the speed increased, we could keep the fuel in inner chamber in about 10%-20% by increasing the fuel injection advance angle, which meant the optimal mass fraction of the fuel in inner chamber could be ensured when increasing speed and injection advance angle. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Direct injection
Controlled terms:Air engines - Combustion chambers - Computational fluid dynamics - Diesel engines - Dust - Efficiency - Engines - Fuel injection - Fuel systems - Fueling - Fuels - Machinery - Mixing - Mixtures - Neutron emission - Nitrogen oxides - Soot - Speed
Uncontrolled terms:CFD (computational fluid dynamics) - Direct injection diesel engines - Distribution - Emission characteristics - Fuel injection advance angles - Injection advance angles - Mass fraction - Swirl chambers
Classification code:451.1 Air Pollution Sources - 521 Fuel Combustion and Flame Research - 612.2 Diesel Engines - 641 Heat and Mass Transfer; Thermodynamics - 654.2 Rocket Engines - 723.5 Computer Applications - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 913.1 Production Engineering
Numerical data indexing:Percentage 1.00e+01%, Percentage 1.00e+01% to 2.00e+01%, Rotational_Speed 2.50e+03RPM, Rotational_Speed 2.80e+03RPM
DOI:10.11975/j.issn.1002-6819.2016.20.009
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 39>
Accession number:20164603020661
Title:Simulation and optimization of air flow and heat transfer characteristic of truck for live animals
Authors:Cai, Zhiyu (1); You, Tian (2); Li, Xianting (2)
Author affiliation:(1) Kangfei Mobile Systems Company, Zhenjiang; 212132, China; (2) Department of Building Science, Tsinghua University, Beijing; 100084, China
Corresponding author:You, Tian(youtian@yeah.net)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:223-228
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the development of technology and the improvement of life standard, the poultry and rabbit breeding industry becomes prosperous and the transportation volume of live animal is larger and larger. To improve the living environment of animal during transportation, the special truck equipped with air conditioner is developed. However, the unreasonable air distribution is a universal problem in the body of this specific truck, leading to local air temperature too high or too low which causes the low animal survival rate and low vehicle loading capacity. There were some simulations and experiments on the refrigerator car, but few on the animal truck. With the requirement of the market, a truck carrying rabbits is chosen as the research object, which is produced by Kangfei Mobile Systems Company in Jiangsu Province. There are 98 air inlets with the radius of 25 mm installed uniformly on the roof of the truck body, 2 air returning outlets with the radius of 160 mm on the front wall of the truck body and 5 air exhausting outlets with the radius of 60 mm on each side of the truck body. This truck carries 1 170 adult rabbits with the designed inside temperature of 18-30℃. How to calculate the flow field and temperature field of the existing truck and how to optimize the vent layout to achieve a homogeneous temperature distribution of the truck body are the main work in this research. The air flow and heat transfer condition in the truck body are simulated by the Airpak 3.0, which is used for air flow simulation and developed by the ANSYS. The simulation uses 2 equations to calculate the turbulence flow characteristics. The control equations are the standard k-Ε equation, the quality equation and the energy equation. The finite volume method (FVM) is used as the discrete method, the one order difference format is used as the wind difference scheme, and the SIMPLE algorithm is used for iterative computation. The simulation method turns out to be accurate through verification by experiment, with the error of less than 3.5% between the simulated and the test results. The research shows that the short circuit of air flow in the front is a serious problem of the existing truck, causing that most supplying air in the upper front of the truck is exhausted directly through the front outlets at low temperature and thereby the utilization of the cool air is not enough. Influenced by the flow field, the air temperature in the truck is low at the upper front part and high at the lower front part with the large temperature difference of about 15.20℃ between them. The highest temperature in the truck body exceeds 3.20℃ compared with the design temperature range and nearly 21% of rabbit cages suffer from the high air temperature. To solve this problem, the principle of vent layout is proposed, which is setting the exhausting and returning outlets at the high temperature area to improve the utilization of the cool supplying air as soon as possible. The optimal vent layout of the rabbit truck is keeping inlets at the roof, and placing outlets at the lower part of both side and bottom of the truck. After the optimization, the air supplied from the inlets flows a longer distance and is mixed more adequately with the air inside, solving the previous short circuit problem of the flowing. The air temperature distribution in the truck body is investigated to be more homogeneous and the maximum temperature difference is decreased to 12.18℃. The air temperature of all the rabbit cages keeps in 21.05-29.20℃, satisfying the design well. This work investigates the air flow and temperature distribution of the existing truck, proposes the principle of optimal vent layout and simulates the air temperature distribution of the truck after optimization, and the results are significant for the design and production of the truck carrying rabbits. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Truck transportation
Controlled terms:Air - Air conditioning - Animals - Atmospheric temperature - Automobile bodies - Computer simulation - Finite volume method - Flow fields - Heat transfer - Iterative methods - Optimization - Problem solving - Reconfigurable hardware - Roofs - Temperature - Temperature distribution - Trucks - Vents
Uncontrolled terms:Highest temperature - Inside temperature - Iterative computation - Living environment - Maximum temperature differences - Simulation and optimization - Standard k epsilons - Temperature differences
Classification code:432.3 Cargo Highway Transportation - 443.1 Atmospheric Properties - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.3 Air Conditioning - 662.4 Automobile and Smaller Vehicle Components - 663.1 Heavy Duty Motor Vehicles - 721.3 Computer Circuits - 723.5 Computer Applications - 804 Chemical Products Generally - 921.5 Optimization Techniques - 921.6 Numerical Methods
Numerical data indexing:Percentage 2.10e+01%, Percentage 3.50e+00%, Size 1.60e-01m, Size 2.50e-02m, Size 6.00e-02m
DOI:10.11975/j.issn.1002-6819.2016.20.029
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
<RECORD 40>
Accession number:20164603020643
Title:Analysis and experiment on atomization characteristics of ultra-low-volume swirl nozzle for agricultural unmanned aviation vehicle
Authors:Wen, Sheng (1, 2); Lan, Yubin (1, 2); Zhang, Jiantao (2, 3); Li, Shenghua (1); Zhang, Haiyan (1); Xing, Hang (1, 2)
Author affiliation:(1) Engineering College of South China Agricultural University, Guangzhou; 510642, China; (2) International Lab of Agricultural Aviation Pesticide Spraying Technology, Guangzhou; 510642, China; (3) College of Mathematics and Informatics of South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Zhang, Jiantao(zhangjiantao@yeah.net)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:32
Issue:20
Issue date:October 15, 2016
Publication year:2016
Pages:85-93
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The ultra-low-volume precision spraying of agricultural UAV (unmanned aviation vehicle) is a key technology in the field of plant protection. There are still some problems in the application of the ultra-low-volume spraying of agricultural UAV in China, such as relatively large droplet diameter of hydraulic nozzle, complex centrifugal nozzle structure and high price. Based on the mechanism of swirl atomization and the modular approach, a new swirl nozzle is developed in this paper. The hydrodynamics and the atomization characteristics of the flow field in the nozzle are studied numerically and experimentally. The physical properties of the fluid and the effect of the atomizer geometry on the atomization characteristics are obtained. The results show that the breakup of conical liquid sheet occurs via unstable growth of sinuous waves on the surface of the liquid sheet. In the structural parameters of the swirl nozzle, the diameter of the nozzle orifice has a great effect on the atomizer performance. As the diameter of the nozzle orifice increases from 1 to 1.5 mm, the average flow rate of the spraying is increased by 46.23%. At the same time, the average of spray angle is increased by 29.77% and the SMD (Sauter mean diameter) is increased by 15%. In addition, the flow rate of the spraying is linearly proportional to the number of the swirl slots. The spray angle is also impacted by the inclination angle of the swirl slot. When the inclination angle is increased from 30° to 45°, the spray angle is reduced by 11.6%. The relative flow pressure on the nozzle inlet has a significant impact on the flow rate of the spraying and the diameter of the droplet. The flow rate of the spraying linearly increases with the relative flow pressure, while the Sauter mean diameter decreases nonlinearly with the relative flow pressure. The experiments indicate that the Sauter mean diameters of serial swirl nozzles decrease by 25%-35% with an increment in the relative flow pressure from 70 to 160 kPa. In order to achieve the variable spraying, the flow rate and the diameter of the droplet can be changed by using the PWM (pulse width modulation) controller to control the fluid pressure of the pump. The increment in flow viscosity will decrease the spray angle for the swirl nozzle. The Sauter mean diameter decreases monotonously with a proper increment of flow viscosity (less than 200% of the viscosity of pure water), which can produce higher atomization quality. The experiment shows that when the flow viscosity is 17.6% greater than the pure water and the pressure is 160 kPa, the swirl nozzle can produce the droplets with the Sauter mean diameter of 45.38 μm, which is 18.3% less than the case of pure water. The results from the present study have significant implications for the optimal design of ultra-low-volume atomizer in agricultural UAV. The present method and results on the spraying mechanism of swirl nozzle provide the important reference for researching and developing the ultra-low-volume variable spraying system. © 2016, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Spray nozzles
Controlled terms:Agriculture - Atomization - Atomizers - Combustors - Computer simulation - Crashworthiness - Drop breakup - Drops - Flow rate - Machinery - Mechanization - Nozzles - Optical pumping - Orifices - Pulse width modulation - Rocket nozzles - Spraying - Unmanned aerial vehicles (UAV) - Vehicles - Viscosity - Voltage control
Uncontrolled terms:Atomization characteristics - Atomization quality - Linearly proportional - Sauter mean diameter (SMD) - Structural parameter - Swirl nozzles - Ultra-low-volume - Unmanned aviation vehicle
Classification code:521.2 Combustors - 601 Mechanical Design - 631 Fluid Flow - 631.1 Fluid Flow, General - 652.1 Aircraft, General - 723.5 Computer Applications - 731.3 Specific Variables Control - 802.1 Chemical Plants and Equipment - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 914.1 Accidents and Accident Prevention - 931.2 Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 1.16e+01%, Percentage 1.50e+01%, Percentage 1.76e+01%, Percentage 1.83e+01%, Percentage 2.00e+02%, Percentage 2.50e+01% to 3.50e+01%, Percentage 2.98e+01%, Percentage 4.62e+01%, Pressure 1.60e+05Pa, Pressure 7.00e+04Pa to 1.60e+05Pa, Size 1.00e-03m to 1.50e-03m, Size 4.54e-05m
DOI:10.11975/j.issn.1002-6819.2016.20.011
Database:Compendex
Compilation and indexing terms, Copyright 2016 Elsevier Inc.
期刊信息
- 主管单位 中国科学技术协会
- 主办单位 中国农业工程学会
- 主编 朱明
- 总编/社长 王应宽
- 地址 北京朝阳区麦子店街41号
- 邮编 100125
- 电话 010－59197078/7077/7076
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友情链接
- 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
- 中华人民共和国农业农村部-MARA
- 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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- CNKI
- 万方数据
- 维普