<RECORD 1>

Accession number:20151000594697
Title:Effect of mixed metal salts on pyrolysis characteristics of rice straw
Authors:Ji, Dengxiang (1); Sheng, Jiafeng (1); Yu, Fengwen (1); Zeng, Qingzhuo (1); Ai, Ning (1); Ji, Jianbing (1)
Author affiliation:(1) Zhejiang Province Key Laboratory of Biofuel, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, China
Corresponding author:Yu, Fengwen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:246-252
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To explore the effects of mixed metal salts on rice straw (RS) pyrolysis behavior, pyrolysis process of RS mixed with basal additives, i. e. carbonates Li<inf>2</inf>CO<inf>3</inf>-Na<inf>2</inf>CO<inf>3</inf>-K<inf>2</inf>CO<inf>3</inf> (LNK), added with metal chlorides or sulfates (MCS) were investigated by Thermogravimetry and Fourier Transform Infrared Spectroscopy (TG-FTIR), respectively. Coats-Redfern method was adopted to calculate the kinetic parameters of pyrolysis process. The results showed that the activation energy of pyrolysis decreased under the action of carbonates, and further decreased as metal chlorides were added, which indicated that the reaction needed less energy to support the pyrolysis process. FTIR analysis indicated that the constituent concentrations (CO, CH<inf>4</inf>, toluene, phenol, formic acid, H<inf>2</inf>O) of RS samples decreased after LNK was added, while CO<inf>2</inf> concentration increased. Compared to LNK-RS, the concentration increased when MCS were added to LNK-RS, which indicated MCS promoted the conversion of RS into light species. Particularly, LNK promoted Boudouard reaction when temperature was over 550, and the LNK added with MCS was capable of facilitating this reaction. Among these MCS, NiCl<inf>2</inf> and CoCl<inf>2</inf> had better effectiveness on the conversion of RS. The research provided the theoretical reference for better utilization of biomass resources. The rice straws were obtained from the countryside of Hangzhou City, Zhejiang Province. The rice straws were dried under sunlight, with physical impurities separated, and ground in a rotary cutting mill and screened into fractions less than 100 mesh (particle size &lt;0.15 mm). The spectrum scope was in the range of 650-4 000 cm^-1 and the resolution factor was 4 cm^-1. The sample was dried at 90 for 24 h prior to the experiments. Pyrolysis was conducted at the heating rate of 70 K/min from 30 to 650. According to the thermogravimetric/derivative thermogravimetric (TG/DTG) curves, RS pyrolysis in the temperature range of 30-650 was characterized by three mass loss stage: 30-208, 208-376, 376-650. The results showed that the values of maximum mass-loss temperature and maximum mass-loss rate both decreased after adding additives. The kinetic analysis showed that the activation energy was lowered under catalyzed pyrolysis added with metal additives, compared to that without extra cations and anion, and metal chlorides had better catalytic effectiveness than metal sulphates. FTIR analysis showed that peaks of CO<inf>2</inf> and H<inf>2</inf>O corresponding to RS added with CuSO<inf>4</inf> and CuCl<inf>2</inf> were stronger than that of RS in the first peak. It was known that the carboxylates in RS would undergo decomposition at relatively low temperatures. In this way, CuSO<inf>4</inf> and CuCl<inf>2</inf> were more likely to associate with the -COO group at the outer particle surface, resulting in the release of CO<inf>2</inf> if the bond between the -COO group and the RS matrix was broken first. It should be pointed out here that the NiCl<inf>2</inf>-form sample behaved quite differently from other samples. The study here did not exclude the possibility that trivalent cations (Fe³⁺) had more sites to connect with the-COO group. In fact, further studies are needed to make sure of the forms of cations during pyrolysis. With increasing temperature, not only the characteristic absorbance bands of CO<inf>2</inf>, but also the absorbance bands of H<inf>2</inf>O and CO emerged. However, the absorbance of C-H&upsilon;<inf>s</inf>, C=O, C=C, and C-O(H) apparently decreased in catalyzed pyrolysis. The reduced CO<inf>2</inf> and tars (C-O(H), C=C, C=O) were responsible for the decrease of mass loss. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Metal analysis
Controlled terms:Activation analysis - Activation energy - Carbon dioxide - Carbonates - Carboxylation - Catalysis - Chemical activation - Chlorine compounds - Fourier transform infrared spectroscopy - Metallic compounds  - Metals - Particle size - Positive ions - Pyrolysis - Salts - Straw - Sulfur compounds - Thermogravimetric analysis
Uncontrolled terms:Chlorides - Coats-redfern - Coats-Redfern method - Increasing temperatures - Mass loss temperatures - Pyrolysis characteristics - Sulfates - TG-FT-IR
Classification code:531 Metallurgy and Metallography - 801 Chemistry - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 804.2 Inorganic Compounds - 821.5 Agricultural Wastes - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.02.035
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 2>

Accession number:20151000594707
Title:Increasing disease resistance by low dose of UV-C radiation in harvested apple
Authors:Yin, Ming'an (1); Li, Yujuan (1); Ren, Xiaolin (1)
Author affiliation:(1) College of Horticulture, Northwest A&amp;F University, Yangling, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:324-332
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Influences of low dose short wave ultraviolet (UV-C) on disease resistance in apple and its action mechanisms were studied for providing scientific basis of UV-C application in apple storage. The test material was'Red Fuji' apple and common ultraviolet germicidal lamp with wavelength of 254 nm was used as the radiation source. The apples were irradiated with the radiation dose of 0, 2.5, 5.0, 7.5, 10.0, 12.5 kJ/m², respectively. Then we conducted the experiment that the influence of optimal dose UV-C on penicillium disease resistance under low temperature. At the same time, we studied the resistance of apple with appropriate dose of UV-C treatment to Botrytis cinerea at normal and low temperature. Apple fruits treated with optimal dose of UV-C were stored under the condition of 20 and 0, respectively. Total phenol content, malondialdehyde (MDA) content and activities of protective enzymes (polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), superoxide dismutase (SOD), peroxidase (POD)) were measured periodically during storage. There was a significant difference between all dose of UV-C treatments and control under room temperature in disease incidence and decay diameter, and the disease resistance of apple enhanced with increasing dose of UV-C at the beginning. However, the resistance of apple to postharvest decay decreased with UV-C above 7.5 kJ/m². Therefore 7.5 kJ/m² was the optimum dose in this study. The treatment with optimal dose of UV-C has good effects on disease resistance in harvested apple inoculated Penicilium expansum or Botrytis cinerea under low temperature. Under room temperature, the disease incidence of UV-C treated apples was 66.7%, significantly lower than that of control (90%) at 4d after inoculated Botrytis cinerea. The results showed that apple fruits resistance to different diseases increased with UV-C treatment. Treatment with UV-C 7.5 kJ/m² can effectively reduce the accumulation of MDA, protect cell membranes, increase the total phenolics accumulation and enhance disease resistance. Under the condition of room temperature, total phenolics of UV-C treatment apples was significantly higher than that of control at 7 d (the treatment is 1.18 times of control). ; MDA content of treated fruits was lower than that of control at 2 d and 7 d. Total phenolics of UV-C treated apples was higher than that of control after 37 days storage at low temperature. And MDA content of treatment group was lower than that of control throughout the storage. PAL and PPO activities of fruits treated with 7.5 kJ/m² UV-C were higher than that of control during the whole storage period at room and low temperature. SOD and POD activities were significantly increased especially at 2 d and 7 d under room temperature. We concluded that UV-C treatment can effectively suppress the occurrence and expansion of Penicillium at room temperature, and the optimal dose of UV-C in this research was 7.5 kJ/m². The activities of protective enzymes and the disease resistance of apple were improved by 7.5 kJ/m² UV-C treatment. Suitable dose of UV-C can be used for postharvest apple to increase the disease resistance and prolong the storage period. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Diseases
Controlled terms:Amino acids - Cell membranes - Cytology - Disease control - Electric lamps - Enzymes - Fruits - Oxygen - Plants (botany) - Storage (materials)  - Temperature - Ultraviolet radiation
Uncontrolled terms:Disease resistance - Phenylalanine ammonia-lyase - Polyphenol oxidase - Postharvest decays - Short-wave ultraviolets - Storing - Superoxide dismutases - Total phenol contents
Classification code:461 Bioengineering and Biology - 641.1 Thermodynamics - 694.4 Storage - 707.2 Electric Lamps - 741.1 Light/Optics - 804 Chemical Products Generally - 821.4 Agricultural Products
DOI:10.3969/j.issn.1002-6819.2015.02.045
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 3>

Accession number:20151000594701
Title:Spatial-temporal pattern differentiation and its mechanism analysis of using efficiency for provincial cultivated land in China
Authors:Zhang, Rongtian (1); Jiao, Huafu (1)
Author affiliation:(1) The College of Territorial Resources and Tourism, Anhui Normal University, Wuhu, China
Corresponding author:Jiao, Huafu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:277-287
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Cultivated land is the key resource and environment factor affecting human survival and development. With the progress of industrialization and urbanization in China, cultivated land resource is facing great challenges: cultivated land degradation, ecological environment pollution, lacking of cultivated land reserve, etc. Meanwhile, the growth rate of cultivated land resource investment is greater than the output, and the overall efficiency is relatively low. Especially, in the background of new urbanization, enhancing cultivated land's regional use efficiency is of great importance for the supplement of agricultural products and the rise of farmers' income, and it has significant theoretical and practical values. Taking 31 provinces in China as the research object, the paper built up the evaluation system of cultivated land's provincial use efficiency, and discussed the differentiation and mechanism of spatial-temporal pattern of cultivated land's provincial use efficiency from 1994 to 2012, using improved DEA (data envelopment analysis) method, ESDA (exploratory spatial data analysis), R/S (rescaled range) analysis method and Tobit regression model. The results showed that: DEA optimal ratio of cultivated land's provincial use efficiency was relatively small, and spatial characteristics showed a distribution pattern of the East high and the Mid-west low; the comprehensive efficiency was higher in the eastern coastal, northern coastal and northeastern areas, where a rising trend was presented; technical efficiency change was similar to the comprehensive efficiency, and scale efficiency showed a trend of first upward and then downward; cultivated land's provincial use efficiency had a positive autocorrelation characteristics, and there existed a spatial cluster feature; on the local, efficiency of provincial cultivated land use could be divided into four types: H-H (high-high) efficiency areas, H-L (high-low) efficiency areas, L-H (low-high) efficiency areas and L-L (low-low) efficiency areas; partial H-H efficiency areas were mainly located in the Beijing-Tianjin area and the Yangtze River Delta, and extended to the Pearl River Delta; L-L efficiency areas formed a stable "L"-shaped pattern which were mainly concentrated in the western China; efficiency of cultivated land use had obvious fractal characteristics and showed a growing trend that the areas with significant growth were located in the eastern coast and northern coast. Economic development and agricultural technology advancement were important factors that influenced the spatial differentiation of cultivated land's provincial use efficiency, and natural condition was the basis factor; farmer's characteristics have a certain impact on the efficiency of spatial-temporal differentiation. Lastly, this paper put forward some suggestions for improving cultivated land's provincial use efficiency to promote the sustainable utilization of cultivated land resource in China: 1) Strengthen the agricultural science and technology, cultivate talents with agricultural technology, improve farmers' farming skills, and constantly promote new technologies; 2) Increase the intensity of cultivated land consolidation, guide the redrawing and circulation of cultivated land, and promote scale operation and comprehensive production capacity of cultivated land; 3) Adjust regional agricultural industrial structure, change the traditional way of extensive use, and promote agricultural modernization development; 4) Build "high efficiency, high compensation" operation mechanism, encourage reasonable utilization of cultivated land resource in different regions, and gradually implement cultivated land use policy from "quantitative" to "efficient". Meanwhile, it should be pointed out that this paper also has somewhat limitations. This paper only chose the experimental data from 1994 to 2012, so the time scale was narrow, and evolution differentiation characteristics of cultivated land's use efficiency was ignored in a longer time scale. Based on two basic dimensions of the input and output, the measured results of cultivated land's use efficiency were objective, but the microscopic index of science and technology investment such as improved crop varieties and field management techniques was also needed to be considered. In addition, the output should focus more on environmental bearing capacity of cultivated land resource. On mechanism analysis, the factors of policy system and farmer willingness to which the cultivated land's regional use efficiency had a positive response were not deeply discussed. Next, based on system (macro) and farmers (micro) perspectives, studying the mechanism of spatial-temporal pattern differentiation of cultivated land's regional use efficiency would be the domain and direction for the deep research. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Land use
Controlled terms:Agricultural products - Agriculture - Cultivation - Data envelopment analysis - Economic and social effects - Economics - Efficiency - Fractals - Modernization - Natural resources  - Regression analysis - River pollution - Water analysis
Uncontrolled terms:Agricultural modernizations - Agricultural science and technologies - Agricultural technologies - Comprehensive efficiencies - Cultivated lands - Dea methods - Exploratory spatial data analysis - Spatial temporals
Classification code:403 Urban and Regional Planning and Development - 444 Water Resources - 453 Water Pollution - 501 Exploration and Prospecting - 512 Petroleum and Related Deposits - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession - 913.1 Production Engineering - 921 Mathematics - 922 Statistical Methods - 922.2 Mathematical Statistics - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.02.039
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 4>

Accession number:20151000594663
Title:Influential factors decomposition for China's grain yield based on logarithmic mean Divisia index method
Authors:Zhou, Zhigang (1); Zheng, Mingliang (1)
Author affiliation:(1) School of Economics and Management, Weifang College, Weifang, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:1-6
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The premise for establishment of appropriate grain production policies is to analyze the contributions of different influence factors to the variation of grain production. However, the existing studies focus on the overall comparison of influence factors affecting the grain production in China, and thus cannot reflect the annual differences or changes. Therefore, in this study, we built a complete (zero residual) decomposition model based on logarithmic mean Divisia index (LMDI) method for investigation into grain production in China. With this model, the changes of grain production were decomposed into the contributions from four factors, including yield per cultivated area, planting structure, multi-cropping index, and changes of cultivated land area. Based on the data from 1996 to 2012, we decomposed and analyzed the factors affecting the changes of grain production in China during this period. The results showed that the total grain production in China generally increased from 1996 to 2012, but it also fluctuated at a severe rate inter-annually. From the perspective of increments, the effect size of yield per cultivated area was 85.9225 million t, and yield per cultivated area was a major influence factor promoting the increments of grain production in China. The effect size of planting structure was -39.0911 million t, and planting structure was a major influence factor inhibiting the increments of grain production in China. However, the effect of planting structure on grain production became strongly positive from 2004 to 2006, and planting structure was a major influence factor promoting the increments of grain production during this period. From the perspective of fluctuation, the fluctuation of grain production in China from 1996 to 2003 was mainly attributed to the effect of yield per cultivated area and the effect of planting structure. From 2004 to 2007, the effects of yield per cultivated area, planting structure and multi-cropping index on grain production were contributive alternatively, but no effect was absolutely dominant. Since 2008, the effect of yield per cultivated area and the total effect changed in very similar ways. The results above show that the effect of yield per cultivated area is mainly responsible for the changes of grain production in China at the current stage, while the effect of planting structure can be enhanced greatly in the future. Moreover, the effect of multi-cropping index will not bring about great changes, but its sudden reduction may cause fluctuation. In comparison, the effect of cultivated land area can be ignored. Thus, regarding how to enhance China's grain production ability in the future, the main developing trends are to stably improve the yield per cultivated area, to raise the enthusiasm of peasants for grain production, to modify the planting structure, to prevent natural disasters, and to avoid the abrupt changes of multi-cropping index. These findings provide some valuble information for relevant governmental departments to establish grain production development plans and to formulate related industrial policies. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Grain (agricultural product)
Controlled terms:Agriculture - Crops - Decomposition - Disaster prevention - Disasters - Land use
Uncontrolled terms:Changes of cultivated lands - Decomposition model - Divisia index - Divisia index method - Governmental departments - Influencing factors - Non-residual - Yield
Classification code:403 Urban and Regional Planning and Development - 802.2 Chemical Reactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 914.1 Accidents and Accident Prevention
DOI:10.3969/j.issn.1002-6819.2015.02.001
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 5>

Accession number:20151000594666
Title:Fast tracking and recognition of overlapping fruit for apple harvesting robot
Authors:Zhao, Dean (1); Shen, Tian (1); Chen, Yu (1); Jia, Weikuan (1)
Author affiliation:(1) School of Electrical Information Engineering, Jiangsu University, Zhenjiang, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:22-28
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Fruit identification and location are the primary tasks and difficulties for fruit-harvesting robot, whose accuracy closely relates to the efficiency of robot. Many scholars, at home and abroad, have carried out a large number of researches on overlapping fruits and have achieved some initial results. However, these studies are limited to static conditions, which are not available for moving state. In recent years, some scholars have studied dynamic identification of harvesting robot and have proved that image processing time could be effectively reduced by using the correlation of a series of images, but the recognition of overlapping fruits is not included. In order to solve the problem of identification of overlapping fruits in moving state and real-time harvesting of robot, the research of fast tracking identification of overlapping fruits is conducted. Firstly, the collected image should be segmented and denoised by mophology method, then the location of the center is determined by calculating the maximum value of minimum distance between the edge of contour and points within the circle. Four scanning directions are defined in order to improve the timeliness; in direction A, the points are scanned from left to right and from top to bottom; in direction B, from right to left and from top to bottom; in direction C, from right to left and from bottom to top; in direction D, from left to right and from bottom to top. The radius is determined by calculating the distance from the center to the edge contour, but in the case of overlapping fruit, the distance from the center to the edge may be the distance to another apple, so a new method is used to avoid this situation. The distances from the center to the edge in different directions are calculated and the minimum distance is used as the final radius. After that, the template of the follow-up match is intercepted by the center and radius. The experiment proves that the algorithm can accurately find the center and radius of overlapping fruit. Then, the centers of images which are collected continuously should be determined. According to the center position of each image and the sampling time of the robot, the motion path of the robot is fitted and predicted. In this experiment, seven-order curve fits robot trajectory well. The processing scope of the next image is determined by radius and anticipated path. Finally, fast normalized cross-correlation match is used to identify overlapping fruit. Fast normalized cross-correlation method is simple and eliminating the issue of light sensitivity, so it is applied to apple images under different light intensities, besides, its matching result is also accurate when the image is slightly displaced and rotated. 268&times;252 pixel images are used in the experiments and the apples approximately account for 55% of the entire image; matching recognition time is 0.185 s without anticipation, and after anticipation, the time is 0.133 s, which means that the processing time of the improved algorithm is reduced by 28.1%. The comparison experiment demonstrates that the new method accelerates the speed of robot and makes it more practical. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Image processing
Controlled terms:Curve fitting - Fruits - Harvesting - Image matching - Robots
Uncontrolled terms:Dynamic identification - Fast normalized cross correlations - Harvesting robot - Image pre-sentence - Matching recognition - Minimum distance - Overlapping fruits - Static conditions
Classification code:731.5 Robotics - 741 Light, Optics and Optical Devices - 821.3 Agricultural Methods - 821.4 Agricultural Products - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.02.004
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 6>

Accession number:20151000594686
Title:Theoretical analysis and experimental verification of heat transfer through thick covering materials of solar greenhouse
Authors:Liu, Chenxia (1); Ma, Chengwei (1); Wang, Pingzhi (1); Zhao, Shumei (1); Cheng, Jieyu (1); Wang, Minglei (2)
Author affiliation:(1) Key Laboratory of Agricultural Engineering in Structure and Environment, College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China; (2) China Agricultural Machinery Testing Center, MOA, Beijing, China
Corresponding author:Ma, Chengwei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:170-176
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The quantity of nocturnal heat loss from conventional single skin greenhouse is high due to low thermal resistance of the single plastic materials. Therefore it is necessary for solar greenhouse that the thick covering material is covered on the single plastic covering material at night in China. There are lots of studies on heat transfer through thin cover of greenhouse, but limited reports about heat transfer through thick cover. However, the characteristics of heat transfer through thick covering materials of solar greenhouse are different from through thin covering. In order to master the heat transfer properties and thermal insulation characteristics of thick covering materials and its influencing factors, a model of heat transfer through greenhouse thick covering materials was developed based on the heat transfer theory in this paper. According to the theoretical model, a computer program was also designed and compiled to simulate the radiation, convection, conduction and other forms of heat transfer process of thick covering materials, and the quantity of heat transfer and the heat transfer coefficient were calculated. In the model there were some assumptions: the heat transfer process was regarded as a steady-state heat transfer; the sky was regarded as an infinite blackbody; the plant, ground, wall, roof inside the greenhouse were considered as one radiator which participated in radiation heat transfer with the under surface of thick cover, and the temperature, radiation emissivity and reflectivity of the radiator were the averages of theirs; the ground and the sky outside the greenhouse were also considered one radiator that participated in radiation heat transfer with the upper surface of thick cover; the surface of the thick cover, indoor ground, plant, wall, roof were regarded as grey body; the condensation heat transfer on the surface of the cover was neglected. The model used an analysis method on the effective radiation and the projection radiation of each surface to determine the quantity of radiation heat transfer between the upper surface and outdoor environment, the under surface and indoor environment. According to the principle of energy balance, the relationship between each part with various forms of heat transfer of thick cover was established. Based on the thermophysical characteristics, the construct parameters of greenhouse and the environment conditions etc., the heat transfer flux density and heat transfer coefficient of covering could be simulated and forecasted by this model. There was an apparatus to measure the overall transfer coefficient of covering materials, which was a static-hot box device. We used the device to test seven different combination types of thick covers of insulation materials. The results showed that the simulated heat transfer coefficient of thick covers was consistent with the values from experiments. This indicated that the theoretical model is highly accurate. The model can be used for quantitative analysis of heat transfer through thick covers and evaluation on the thermal insulation property. The theoretical model provides a method for the thick cover research and development as well as analysis of thermal environment about horticulture. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Heat transfer
Controlled terms:Greenhouses - Heat resistance - Heat transfer coefficients - Insulation - Models - Radiation - Radiators - Roofs - Solar heating - Thermal insulation
Uncontrolled terms:Condensation heat transfer - Emissivity and reflectivities - Simulation - Solar greenhouse - Thermal insulation characteristics - Thermal insulation properties - Thermophysical characteristics - Thick thermal covering
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 413 Insulating Materials - 413.2 Heat Insulating Materials - 616.1 Heat Exchange Equipment and Components - 641.2 Heat Transfer - 643.1 Space Heating - 711 Electromagnetic Waves - 902.1 Engineering Graphics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.02.024
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 7>

Accession number:20151000594683
Title:Spectral differences of plant litter and soil in loess hilly-gully region
Authors:Liu, Yongmei (1); Wang, Buwei (2); Li, Jingzhong (1); Pang, Guowei (1)
Author affiliation:(1) College of Urban and Environmental Sciences, Northwest University, Xi'an, China; (2) Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing, China; (3) University of the Chinese Academy of Sciences, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:147-154
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plant litter plays a critical role in controlling and protecting soil against water erosion and increasing soil organic carbon. The presence of plant litter efficiently reduces erosion and surface runoff, and influences the cycle of nutrients, carbon, and energy in ecosystem. Remote sensing can provide a new way to differentiate litter from soil, and spectral difference of plant litter and soil is the primary basis for the remotely sensed estimation of plant litter coverage. By using spectral measurement of the soil and litter samples of typical vegetation communities in the Yanhe River basin of Northern Shaanxi, the difference of spectral characteristics between soil and litter in the VIS-NIR (400-1 100 nm) and SWIR (1 100-2 500 &mu;m) wavelengths and main impact factors were analyzed; the effectiveness of NDVI (normalized difference vegetation index) and typical senescent vegetation indexes such as NDSVI (normalized difference senescent vegetation index), NDTI (normalized difference tillage index) and CAI (cellulose absorption index) was evaluated to distinguish litter from soil. The results showed that the spectral behaviors of soil and litter were similar in the VIS-NIR wavebands, and the main difference between soil and litter was that the slopes of spectra of the litter samples were slightly greater than that of the soil samples. The two water absorption bands, centered at 1 400 and 1 900 nm, had the common spectral features in soil and litter within the SWIR waveband, while diagnostic features could be observed at 1 700 and 2 100 nm in the reflectance spectra of the dried litter samples, which were associated with the cellulose-lignin absorptions. Water content influenced the reflectance spectra of soil and litter samples obviously, and the reflectance of wet soil and litter was reduced by half compared to dry soil and litter. The cellulose-lignin absorption at 2100 nm obscured and disappeared in the reflectance spectra of wet litter samples, the spectra shape of the wet litter appeared very similar to that of wet soil, and hence it was indistinguishable between soil and litter. The existence of residue line which presents the linear regression relationship between any couple of TM bands was first verified with the litter samples. According to the relationship of soil line and residue line in feature space of two TM bands, residue line existed (R²=0.86) and was closed to soil line (R²=0.97) between TM3-TM4 wavebands, the NDVI values of soil samples were similar to the litter samples, and spectral differences of soil and litter can't be characterized by NDVI. The R² of 0.81 illustrated the existence of soil line, but residue line (R²=0.10) can't be observed between TM3-TM5 wavebands, and the NDSVI values of soil and litter samples were mixed and featureless. Both soil line (R²=0.95) and residue line (R²=0.65) existed between TM5-TM7 wavebands, and NDTI values of soil and litter samples were still in proximity to each other. Due to low spectral resolution, there were limitations for multispectral indexes (like NDSVI and NDTI) to extract the information of litter. The spectral separability between soil and litter can be represented by the hyperspectral index CAI, which takes the advantage of obvious difference between soil and litter at 2 100 nm and thereby presents a good result for distinguishing litter from soil. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Soil surveys
Controlled terms:Carbon - Cellulose - Erosion - Infrared devices - Landforms - Lignin - Organic carbon - Reflection - Remote sensing - Sediments  - Soil conservation - Soils - Spectrum analysis - Vegetation - Water absorption
Uncontrolled terms:Cellulose absorption indices - Loess hilly gully region - Normalized difference vegetation index - Normalized differences - Plant litter - Regression relationship - Remotely sensed estimations - Spectral characteristics
Classification code:481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 711 Electromagnetic Waves - 731.1 Control Systems - 741.3 Optical Devices and Systems - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.02.021
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 8>

Accession number:20151000594704
Title:Development and experiment about recombination heating circulation defrosting system of mini cold storage house
Authors:Zhao, Songsong (1); Yang, Zhao (1); Chen, Aiqiang (1); Zhang, Na (1); Chen, Mingfeng (1); Liu, Xinghua (2)
Author affiliation:(1) Key Laboratory of Medium-Low Temperature Energy Efficient Utilization of Ministry of Education, Thermal Energy Research Institute of Tianjin University, Tianjin, China; (2) Engineering Research Center of Refrigeration Technology of Ministry of Education, School of Mechanical Engineering, Tianjin University of Commerce, Tianjin, China
Corresponding author:Yang, Zhao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:306-311
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, mini cold storage house has developed rapidly. The evaporator is extremely easy to frost as a result of locating in the condition of low temperature and high humidity. However, defrosting energy consumption accounts for more than 10% of system's total energy consumption. To overcome the defect about high energy consumption, temperature and humidity fluctuation of traditional defrosting technology in mini cold storage house, we investigated a new framework by changing the structure of the defrosting system and optimizing the control technology. Firstly, we developed a new defrosting system named as recombination heating circulation defrosting (RHCD) based on overhead coil auxiliary refrigeration. After that, the time-differential pressure (TDP) combining intelligent control method was used innovatively to determine the best defrosting point. Finally, OMRON programmable logic controller was applied to combine some devices to finish the defrosting. In the defrosting process, the electric-air valves installed on the incubator were closed timely to restrain heat and vapor into the cold storage house, and hot air flow was forced to circulate in the bypass channel under the working of blowers. Meanwhile overhead coil auxiliary refrigeration system was started to maintain stability of temperature and humidity. After defrosting, coil auxiliary refrigeration system was terminated and the electric-air valves were kept closed to finish cooling and dehumidification of incubator until temperature of incubator was reduced to be consistent with cold storage house. Accurate and complicated logic control of RHCD system, including TDP method and the working about some defrosting devices, was based on OMRON programmable logic controller. This paper made theoretical analysis and simulation about temperature and velocity field of the defrosting process by COMSOL. The results showed that RHCD has higher heat transfer coefficient between air and frost for the reason that incubator has higher air velocity (2 m/s) and steady-state temperature. Moreover, we also completed an experimental research to analyze the working performance and energy consumption of RHCD and other methods. The results showed that RHCD, compared with the traditional electric heating defrosting (EHD), reduced the fluctuation of temperature by 3.8 degrees and relative humidity by 21.1%. Defrosting time was shortened by 14 minutes. Energy consumption of electric heater was decreased by 50 percent and energy-saving rate could reach 34.5 percent in total defrosting process. The RHCD can not only improve performance of food preservation but also save energy efficiently. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Defrosting
Controlled terms:Air - Cold storage - Cold working - Control - Controllers - Design - Electric heating - Energy conservation - Energy efficiency - Energy storage  - Energy utilization - Food preservation - Food storage - Heat transfer - Heating - Hot working - Houses - Humidity control - Programmed control systems - Refrigeration  - Temperature - Velocity
Uncontrolled terms:Analysis and simulation - Auxiliary refrigeration - Differential pressures - Energy efficiency analysis - High energy consumption - Steady-state temperature - Temperature and humidities - Total energy consumption
Classification code:402 Buildings and Towers - 402.3 Residences - 408 Structural Design - 525.2 Energy Conservation - 525.3 Energy Utilization - 535.2 Metal Forming - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.1 Space Heating - 644 Refrigeration and Cryogenics - 702 Electric Batteries and Fuel Cells - 704.2 Electric Equipment - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 732 Control Devices - 732.1 Control Equipment - 804 Chemical Products Generally - 822.1 Food Products Plants and Equipment - 822.2 Food Processing Operations - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.02.042
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 9>

Accession number:20151000594674
Title:Identification of plant morphology induced by water stress and comparison of indices using laser scan 3D images
Authors:Zheng, Lijia (1); Sun, Yurui (1); Cai, Xiang (2)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing, China; (2) School of Information, Beijing Forestry University, Beijing, China
Corresponding author:Sun, Yurui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:79-86
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Leaf wilting is a common symptom in plants responding to drought stress. Early wilting detection is very important for precision crop management. In this paper, plant morphology was monitored to determine plant water status. A laser scanner was used to obtain three-dimensional (3D) images of plants based on the principle of triangulation. Four wilting indices based on plant morphology were developed and tested using different mathematical methods. The plant wilting indices included differential geometry; 2D Fourier transformatio; top projected leaf area (TPLA); and standard deviation (SD). Experiments were conducted to verify the effectiveness of each wilting index for characterizing plant water status. Zucchini plants were selected because of their sensitivity to variations in soil water content and environmental parameters. These parameters included solar radiation, air temperature and ambient relative humidity. Zucchini seeds were individually sown in greenhouse pots. Two weeks later, the young plant emerged from the pot soil, and three of the healthiest plants were chosen as test samples. The substrate water content for these plants was maintained at 0.06-0.08 kg/kg (relatively dry), 0.17-0.20 kg/kg (moderately dry) and 0.30-0.32 kg/kg (wet). The fourth leaf of each plant was scanned at 30-minute interval between 8 am and 5 pm over 10 days. Concurrently, the environmental parameters and plant stem diameter were measured at 5-minute interval. The data obtained indicated a correlation between the wilting indices and the environmental parameters. It also showed that the wilting indices were affected by the diameter of the plant stem. The results showed that the diurnal variation process on wilting index based on differential geometry correlated with environmental parameters. For example, stronger solar radiation and higher air temperature lead to a larger index value and vice versa. The wilting index exhibited strong linear correlations with solar radiation, ambient temperature and stem diameter, where the coefficients of correlation were 0.734, 0.785 and 0.845, respectively. The quantitative regression between wilting index based on differential geometry and stem diameter indicated that wilting index based on differential geometry could be used to reflect plant water deficit stress conditions, which was consistent with previous studies. A correlation analysis was carried out to determine the effectiveness of each index. The absolute values of correlation coefficients between TPLA and wilting index based on differential geometry, wilting index based on 2D Fourier transformation, were above 0.895, suggesting that these indices were well-correlated with plant wilting. The correlation coefficients between SD and other wilting indices were around 0.76, indicating a poor approach for comparison. To verify the accuracy of these indices, the correlations between each wilting index and the environmental parameters were analyzed. The regression results showed well-correlated linear relations with R² above 0.806 between wilting index and air temperature, and R² above 0.720 between wilting index and solar radiation. However, the correlation between wilting indices and stem diameter was poor. The correlation coefficients of wilting index based on differential geometry, wilting index based on 2D Fourier transformation and TPLA with stem diameter were above 0.800, while only 0.64 between SD and stem diameter. It was concluded that wilting index based on differential geometry, wilting index based on 2D Fourier transformation and TPLA performed better than SD for identifying plant water status. This paper suggests a novel, non-invasive and accurate method for monitoring plant water status. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Geometry
Controlled terms:Atmospheric temperature - Crops - Diffusers (optical) - Fourier transforms - Identification (control systems) - Image processing - Image recognition - Mathematical morphology - Morphology - Plants (botany)  - Sensitivity analysis - Soil moisture - Solar radiation - Sun
Uncontrolled terms:Correlation coefficient - Environmental parameter - Fourier transformations - Sensitivity to variations - Stem diameter - Three-dimensional (3D) image - Water stress - Wilting index
Classification code:443.1 Atmospheric Properties - 461.9 Biology - 483.1 Soils and Soil Mechanics - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 716 Telecommunication; Radar, Radio and Television - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.3 Optical Devices and Systems - 821.4 Agricultural Products - 921 Mathematics - 921.3 Mathematical Transformations - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.02.012
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 10>

Accession number:20151000594692
Title:Multi-objective optimization modeling for non-point pollution management measures in small watershed
Authors:Geng, Runzhe (1); Wang, Xiaoyan (1); Duan, Shuhuai (3); Yang, Hua (4); Nan, Zhe (1)
Author affiliation:(1) College of Resource Environment and Tourism, Capital Normal University, Beijing, China; (2) Research Center of Aquatic Environment in the Capital Region, Beijing, China; (3) Water Soil Conservation Station of Beijing, Beijing, China; (4) Huairou Water Authority, Beijing, China
Corresponding author:Wang, Xiaoyan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:211-220
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Eutrophication caused by the enrichment of nutrients from diffusing sources is degrading surface water quality throughout the world, while an increased loss of agricultural nutrients is a growing concern for water quality in drinking water areas of Beijing. Best management practices (BMPs) have been proven to actually reduce nitrogen (N), phosphorus (P) and sulfur (S) pollutant loads from agricultural areas. However, in a watershed with multiple farms and multiple BMPs feasible for implementation, it becomes a daunting task to choose the right combination of BMPs that provides maximum pollution reduction with least implementation costs. Several studies have shown that best BMPs are effective in controlling water pollution. However, those issues affecting water quality need water management plans that take into consideration BMPs selection, placement and affordability. In this study, a framework of "Risk assessment - Planning and zoning - differentiated management" was developed, and it included three tools: 1) A new "risk assessment" tool was introduced for potential loads estimation of N, P and S pollution in BeiZhai small watershed by analyzing social economic data, land use, soil type, water and soil conservation practices and agricultural management measures under current conditions, and then the critical source area was identified according to the pollution loads based on GIS technology; 2) A multi-criteria index ranking system for the BMPs was devised. First, each individual second-level index was assigned a numeric value that was based on site characteristics and information on LIDBMPs. The quantified indices were normalized and then integrated to obtain the score for each first-level index. The final evaluation score of each BMP was then calculated based on the scores for the first-level indices. Finally, the appropriate BMP types for a specific installation site were determined according to the rank of the final evaluation scores, and furthermore the final scores could be served as a first screen and selective reference for the BMP placement and optimization in next step; 3) Three typical areas with different spatial scales were extracted from the BeiZhai small watershed, and a Non-dominated Sorting Genetic Algorithm (NSGA-II) was selected as an optimization engine to evaluate the optimal fitness of each BMP combination based on the initial pollutant loadings, targets of pollutant reduction and the costs of BMPs implemented at different spatial scales. The results indicated that: 1) Potential risk evaluation of non-point source pollution in the study area proved that the potential of non-point source pollution was closely related with land use patterns affected by human activities; 2) Comprehensive index values for different measures in a descending order were constructed wetlands, infiltration basin, green roof, wet detention pond and porous pavement, and these could be used as the main practices for the BMP planning; 3) The pollutants loads were reduced by 45% while the total cost (TC) was 574 560 yuan for watershed scale, the pollutants loads were reduced by 46% while the TC reached to 374 660 yuan for the community scale, the total N and P load was reduced by 65% while the TC reached to 1 518 yuan for the farm scale. Therefore, this framework can be served as a decision-making support for non-point source pollution control in the upper watershed of Huairou Reservoir. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Soil pollution control
Controlled terms:Agriculture - Cost benefit analysis - Cost effectiveness - Cost reduction - Costs - Decision making - Eutrophication - Genetic algorithms - Geographic information systems - Information management  - Land use - Multiobjective optimization - Nutrients - Optimization - Pollution - Pollution control - Pollution induced corrosion - Potable water - Reservoirs (water) - Risk assessment  - Risk perception - River pollution - Soil conservation - Surface waters - Water - Water management - Water pollution - Water pollution control - Water quality - Watersheds  - Wetlands
Uncontrolled terms:Best management practice (BMPs) - Best management practices - Cost effectiveness analysis - Multi-objective optimization models - Non dominated sorting genetic algorithm (NSGA II) - Non-point source pollution - Spatial scale - Water and soil conservations
Classification code:403 Urban and Regional Planning and Development - 441.2 Reservoirs - 442.2 Land Reclamation - 444 Water Resources - 444.1 Surface Water - 453 Water Pollution - 453.2 Water Pollution Control - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 723 Computer Software, Data Handling and Applications - 723.3 Database Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911 Cost and Value Engineering; Industrial Economics - 912.2 Management - 921 Mathematics - 921.5 Optimization Techniques - 922.1 Probability Theory
DOI:10.3969/j.issn.1002-6819.2015.02.030
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 11>

Accession number:20151000594679
Title:Influence of sodium carboxyl methyl cellulose on soil aggregate structure and soil water movement
Authors:Wu, Junhu (1); Tao, Wanghai (2); Wang, Haiyang (2); Wang, Quanjiu (2)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling; Shaanxi, China; (2) State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area, Xi'an University of Technology, Xi'an, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:117-123
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil amendment agent plays important role in improving soil structure and enhancing crop growth. Sodium carboxyl methyl cellulose (CMC) is anion linear polymer cellulose ether, which is odorless, tasteless and nontoxic. It is regarded as an effective soil amendment agent because of its strong water absorption capacity. In this paper, a laboratory study was carried out to investigate the influence of sodium carboxyl methyl cellulose on soil aggregate structure and soil water movement in the soil columns by respectively adding 0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g CMC into each 1 000 g soil collected from Changwu agro-ecological experiment station in the loess plateau. The results indicated that water stable aggregate content increased from 3.36% to 15.05%, and the soil fractal dimension reduced from 2.53 to 2.37 with increasing CMC content. In the meantime, clay content reduced from 3.47% to 0.84%, silt content reduced from 86.19% to 61.27%, but sand content increased from 10.35% to 37.89%. Clay and silt contents were negatively correlated with soil fractal dimension, and sand content was positively correlated with soil fractal dimension. The influence of clay content was most significant on soil fractal dimension. The content of soil particle less than 0.1 mm reduced from 85. 59% to 48.41%, but the content of soil particle between 0.1 and 0.2 mm, 0.2 and 0.3 mm, 0.3 and 0.4 mm, 0.4 and 0.5 mm, 0.5 and 0.6 mm increased from 9.53% to 22.56, 2.14% to 10.99%, 1.31% to 6.69%, 0.84% to 4.31%, 0.43% to 2.81% respectively, and the content of soil particle larger than 0.6 mm increased slightly. The relationship between water stable aggregate content, soil fractal dimension, clay content, silt content, sand content and CMC content followed quadratic function (R²&ge;0.95, P&le;2.92&times;10^-3). The relationship between clay content, silt content, sand content and soil fractal dimension followed linear function (R²&ge;0.95, P&le;1. 85&times;10^-6). The soil infiltration capacity and the stable infiltration rate reduced with increasing CMC content. The cumulative infiltration volume reduced from 14.36 cm to 3.28 cm after 700 minutes. The stable infiltration rate reduced from 0.0150 to 0.0028 cm/min, and the relationship between stable infiltration rate and CMC content followed linear function (R²=0.96, P=2.99&times;10^-6). Infiltration rate in Philip formula reduced from 0.46 to 0.13, the empirical coefficient K in Kostiakov formula reduced from 0.29 to 0.16, but the exponent increased from 0.41 to 0.53. Soil water retention capacity was enhanced with the increasing CMC content. The residual water content, saturated water content and coefficient associated with intake value in van Genuchten formula were increased, but the shape coefficient decreased with increasing CMC content. The residual water content increased from 0.12 to 0.14, saturated water content increased from 0.42 to 0.46, coefficient associated with intake value increased from 0.0031 to 0.0054 and shape coefficient reduced from 1.75 to 1.40. The results suggested that CMC can hinder water movement by reacting with water to form gel and then the smaller soil particles can be combined into the bigger soil aggregates. In conclusion, CMC additions agent could change soil structure and decrease soil infiltration capacity effectively. This study may provide valuble information for the application of CMC in soil improvement. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Soil conditioners
Controlled terms:Aggregates - Cellulose - Ethers - Fractal dimension - Fractals - Infiltration - Moisture - Sand - Silt - Sodium  - Soil moisture - Soils - Water absorption
Uncontrolled terms:Aggregate structures - Cumulative infiltrations - Empirical coefficients - Residual water content - Sodium carboxyl methyl cellulose - Soil water retention - Water absorption capacity - Water stable aggregates
Classification code:406 Highway Engineering - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 801.4 Physical Chemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.02.017
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 12>

Accession number:20151000594689
Title:Fluid-solid interaction modeling analysis of wind-energy concentration devices with polycarbonate
Authors:Tian, De (1); Ji, Zhongtao (1)
Author affiliation:(1) State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University), Beijing, China; (2) College of Physics and Electronic Engineering, Qujing Normal University, Qujing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:191-196
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The concentrated wind energy device is the core of the concentrated wind energy generator, and its material can directly affect the widespread application of the concentrated wind energy generator. This research adopts a fluid-solid interaction (FSI) method. At first, a solid-field model of a concentrated wind energy device is created with the help of the CAD software according to the size of the model. And a cylindrical area is established after the solid-field model is imported into the finite element analysis software. The cylindrical area has a radius of 10 m and a length of 30 m and the distance between the inlet of the fluid-field area and the inlet of the concentrated wind energy device is 5 m. Then in the cylindrical area, a geometric fluid field is established through Boolean subtraction of the solid field area. Based on the CFD software analysis of the fluid field, the wind flow is simulated in a specific wind field. A non-uniform tetrahedron meshing and an SST k-&omega; turbulence model are adopted. The fluid medium is air, with the temperature of 296.75 K, the density of 1.044 kg/m³, the pressure of 88 800 Pa, the viscosity of 1.85&times;10^-5 kg/(m&middot;s), the thermal conductivity coefficient of 0.02623 W/(m&middot;K), and the constant-pressure specific heat capacity of 1 013 J/(kg&middot;K). During the simulation, the wind speed is set to 25 m/s, the mass flow rate is set to 8199.557 kg/s, and the corresponding turbulent kinetic energy and the specific dissipation rate are respectively 0.714963 m²/s² and 24.67 s^-1. The mass flow inlet and pressure flow outlet are adopted. The roughness height of surface is set to 0.3 mm. When the component residual reaches 1. 0&times;10^-4 kg/s, the equation converges and the distribution of the wind speed and wind pressure in the fluid field is obtained. The result shows that the maximum wind speed that the central cylinder can work on the wind turbine blades is 35 m/s and the fluent speed increases along the radial direction of the wall, with a maximum speed of 38.8 m/s at the central cylinder. This indicates that the concentrated wind energy device has increased wind speed and concentrated its energy. In the structural static module, the whole solid field is divided into tetrahedral meshes and the size of each structural unit is 0.02 m. The stress cloud plot and the solid-field deformation plot are obtained after the calculated results of the fluid field are loaded on the concentrated wind energy device. The plots show that the maximum stress area is on the outer edge of the diffusion pipe with a maximum stress of 3.267 MPa, which is far less than the yield strength of 66 MPa, the fracture stress of 65 MPa and the bending strength of 98 MPa in the candidate German Bayer's makrolon-2407 polycarbonate. Therefore, it is concluded that this type of polycarbonate can be used to make the concentrated wind energy device. Meanwhile, the results of the analysis can provide theoretical basis and reference for the later structural improvement and design optimization. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Finite element method
Controlled terms:Air - Bending strength - Computational fluid dynamics - Computer aided design - Concentration (process) - Cylinders (shapes) - Diffusion in liquids - Flow interactions - Inlet flow - Kinetic energy  - Kinetics - Mass transfer - Materials - Oceanography - Polycarbonates - Specific heat - Speed - Structural analysis - Structural dynamics - Thermal conductivity  - Turbomachine blades - Turbulence models - Wind - Wind effects - Wind power - Wind turbines
Uncontrolled terms:Concentrated wind energies - Energy concentration - Finite element analysis software - Fluid solid interaction - Specific dissipation rate - Structural improvements - Thermal conductivity coefficient - Turbulent kinetic energy
Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 443.1 Atmospheric Properties - 471.1 Oceanography, General - 615.8 Wind Power (Before 1993, use code 611 ) - 631.1 Fluid Flow, General - 641.1 Thermodynamics - 641.3 Mass Transfer - 723.5 Computer Applications - 802.3 Chemical Operations - 804 Chemical Products Generally - 815.1.1 Organic Polymers - 921.6 Numerical Methods - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.02.027
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 13>

Accession number:20151000594676
Title:Salt and water exchange between drainage ditches and farmland under sub-irrigation condition
Authors:Li, Shan (1); Luo, Wan (2); Jia, Zhonghua (2); Pan, Yanxin (3); Wu, Di (1); Zhang, Dengke (1)
Author affiliation:(1) State Key Laboratory of Eco-Hydraulic Engineering in Shaanxi, Xi'an University of Technology, Xi'an, China; (2) College of Water Resources and Hydro Power Engineering, Yangzhou University, Yangzhou, China; (3) Water and Ecological Engineering, Nanchang Institute of Technology, Nanchang, China
Corresponding author:Luo, Wan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:94-101
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Many downstream irrigation areas are constructed with drainage ditches to prevent the potential threat of soil salinization; but the irrigation water supply to these areas can rarely be guaranteed due to their disadvantage of being located far away from the water source. It is critical for local agricultural development and environmental protection to find practical water management practice for crop production in these downstream irrigation areas. In this paper, we present an analytical study on salt and water exchange between drainage ditches and the farmlands in a downstream irrigation area, where the drainage ditches were periodically filled with a large amount of inflow (irrigation return flow and drainage water) from the upstream irrigation area. Due to its low elevation and poor drainage outlet of the study area, the drainage ditches originally built for salinity control now capacitate water storage for crop fields in the growing season; the high water level in the drainage ditches produced sub-irrigation effect on crop fields to meet some crop water requirement. To investigate the effect of reduced drainage intensity on salt and water balance in the crop fields, we employed the field hydrology model - DRAINMOD to predict the field water table fluctuations under subirrigation condition based on observed data from summer 2009 to fall 2010.Salt and water exchange between crop fields and drainage ditches was then calculated based on the predicted water table variations. The results showed that the water table depth in the study area was generally below 2 m, while the water level in the drainage ditches was generally higher; the salinity level in drainage ditches was much lower than the groundwater in the crop fields. The water table depth predicted by the DRAINMOD model agreed with the field measurements reasonably well; the average deviation was 3.29 cm, the mean absolute error was 8.6 cm, and the correlation coefficient was 0.97. With DRAINMOD simulations of water table depths in the crop fields and the measured water level changes in the drainage ditches, we calculated salt and water exchange between drainage ditches and the subirrigatd fields; the results showed that in one planting year, the drainage ditches received a total inflow water volume of 9.3 m³ per unit length; while considering the outflow from the drainage ditches, the net ditch storage was 5.5 m³ per unit length per annum. The calculated subsurface drainage was only 2.3 mm while the cumulative subirrigation water depth was 49 mm during the study period; subsurface drainage occurred only occasionally during some heavy rain and irrigation time period, the drainage ditches provided subirrigation to crop fields during the rest of the time due to the periodic inflow from the upstream irrigation area. Comparing with the crop evapotranspiration, the subirrigation water amount was relatively small, but the heightened water level in the drainage ditches reduced drainage intensity, resulting in less subsurface drainage in the growing season. The high water level in drainage ditches had positive effect on recharging the water table of the farm fields. The calculated salt load moved into fields with the subirrigation water was about 20 times of that lost with the subsurface drainage discharge, but the actual salinity in the field was much lower than the salt tolerance level of cotton, no significant salinity buildup was observed in the soil profile. Currently, the inflow from the upstream irrigation area had no negative impact on salt and water balance in the study area; instead, it alleviates the draught stress in the downstream irrigation area. The long-term effect of maintaining high water level in the drainage ditches on salt balance in the crop fields, however, needs further investigation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:39
Main heading:Rivers
Controlled terms:Crops - Cultivation - Digital storage - Drainage - Farms - Groundwater - Groundwater flow - Irrigation - Models - Moisture  - Salts - Soils - Subirrigation - Water levels - Water management - Water supply
Uncontrolled terms:Agricultural development - Crop evapotranspiration - Drainage ditches - DRAINMOD - Irrigation return flows - Irrigation water supply - Water balance - Water table fluctuations
Classification code:401 Bridges and Tunnels - 406 Highway Engineering - 442 Flood Control; Land Reclamation - 444 Water Resources - 446 Waterworks - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 502 Mines and Quarry Equipment and Operations - 614.2 Steam Power Plant Equipment and Operation - 722.1 Data Storage, Equipment and Techniques - 801.4 Physical Chemistry - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics
DOI:10.3969/j.issn.1002-6819.2015.02.014
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 14>

Accession number:20151000594685
Title:Radio frequency signal transmission characteristics under multipath in peach orchard
Authors:Zhu, Bingqin (1); Wang, Yi (1); Han, Wenting (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&amp;F University, Yangling, China; (2) Institute of Soil and Water Conservation, China Academy of Sciences, Yangling, China; (3) Institute of Water-saving Agriculture in Arid Areas of China, Northwest A&amp;F University, Yangling, China
Corresponding author:Han, Wenting
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:162-169
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For solving the rapid deployment of wireless sensor network in peach orchard, this paper focused on the radio frequency signal transmission characteristics of 2.4 GHz radio frequency in peach orchard. Four transmission paths were selected according to different angles and packet loss rate and pass-loss of radio frequency signal were calculated under three antenna heights (0.5, 1.5, 2.5 m) at the same time. A correlation analysis was conducted to verify if they were related with each other. Communication distance and antenna height were considered to be the main influencing factors of path-loss. Under any antenna height and transmission path, packet loss rate was very low when communication distance was within six-row spacing and the maximum of packet loss rate was 8.3%. From seven-row spacing, packet loss rate began to increase significantly and with the increase of row spacing, the packet loss rate became increasingly high. Due to the shielding effects from branches and leaves, radio frequency signal could cause the phenomenon such as reflection, diffraction and refraction which might lower the path-loss of radio frequency signal. When the antenna height was 0.5 and 1.5 m separately, the shielding effects were relatively large. The reliable transmission distance was only six-line spacing (27 m). When the antenna height was 2.5 m, the reliable transmission distance was fourteen-line spacing (63 m), and the canopy top was the best position for setting up antenna. Using regression analysis to analyze data of path-loss, it can be concluded that logarithm model was the most suitable model of path-loss under three antenna heights and four transmission paths. The maximum of R² was 0.945 and the minimum of R² was 0.732. The influence of path-loss to radio frequency signal in peach orchard was not very significant. In order to research the path-loss and deploy the nodes quickly and flexibly when nodes were deployed in any site of the peach orchard, Logarithmic regression analysis was used to analyze the data of path-loss under three antenna heights. The maximum of R² was 0.976 and the minimum of R² was 0.939. The two groups of models were validated during peach's young stage and mature stage lastly and it showed that the two models could predict the path-loss of radio frequency signal under three antenna heights and any transmission path in peach orchard. The two models and the analysis of reliable transmission distance can be selected flexibly and conveniently when establishing wireless sensor network. The conclusion in this paper can provide reference for radio frequency signal transmission and wireless sensor network deployment in peach orchard. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Radio transmission
Controlled terms:Antennas - Electromagnetic field measurement - Farms - Fruits - Orchards - Packet loss - Radio waves - Regression analysis - Sensor nodes - Sensors  - Shielding - Signaling - Wireless sensor networks
Uncontrolled terms:Communication distance - Correlation analysis - Multi-path transmission - Radio frequencies - Radiofrequency signals - Reliable transmission - Transmission paths - Wireless sensor network deployment
Classification code:404 Civil Defense and Military Engineering - 622 Radioactive Materials - 716 Telecommunication; Radar, Radio and Television - 716.3 Radio Systems and Equipment - 801 Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2 Mathematical Statistics - 942.4 Magnetic Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.02.023
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 15>

Accession number:20151000594690
Title:Analysis on wind resistance ability of deepwater long-line rope aquaculture facility by finite element method
Authors:Zhang, Guangfa (1); Luan, Jian (1); Zhang, Bin (1); Liang, Jun (2)
Author affiliation:(1) School of Navigation and Naval Architecture, Dalian Ocean University, Dalian, China; (2) Zhangzidao Group CO. LTD, Dalian, China
Corresponding author:Liang, Jun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:197-203
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The deepwater long-line rope aquaculture facility (the raft system) belongs to a raft mariculture method which is mainly composed of buoys, main rope, aquaculture net cages, mooring ropes and anchor stakes embedded into seabed. The buoys are connected with the main rope by rope, the main rope is connected to stake anchor by mooring rope, and the aquaculture net cage is hung on the main rope. The buoyancy of raft system is provided by buoys and the structure stability is ensured by the mooring force from anchor stakes embedded into seabed. The facility stays in deep-open waters with winds, waves, urgent flow, and is influenced by complex sea environment. The raft system will move and deform in the action of environmental load. When the tension force is over the strength of mooring rope or the maximum mooring anchorage force provided by the anchor stake, or the transversal displacement of the main rope is oversize, the raft system will become less stable. The safety and stability of the aquaculture facility will directly affect the success or failure of the whole aquaculture production. Therefore, it's certainly worth researching on the force and motion of the raft system considering the effect of ocean waves and current for structure design, and furthermore analyzing the raft system's wind resistance ability to provide reference for the parameter design of the raft system. In this paper, based on the finite element method, the stress characteristic and deforming of deepwater long-line rope aquaculture facility system were analyzed to establish finite element model equation. For the components in the raft system (buoy, cage, rope) belong to small scale marine structures, the fluent loads were calculated by Morison method, in which in order to calculate different grades of wave, the large wave height should be considered and the nonlinear wave force cannot be ignored, and the two order Stokes wave theory was employed to calculate the speed and acceleration of water particle. Broyden iteration method was used to solve the finite element equation of aquaculture facility system, and then the maximum tensions of the mooring rope in the system in different heights (1-14 m) of sea wave were calculated and compared to its break strength and mooring force of anchoring pile for evaluating wind resistance ability of the aquaculture facility system. As an instance, the wind resistance abilities of deepwater long-line rope aquaculture facilities erected in 30-meter deep sea waters of Zhangzidao aquaculture sea area were analyzed. The result showed that maximum tension of mooring rope was 78.8 kN, the maximum transverse displacement of the raft system was 18.5 m and the wind resistance abilities were at 6-7 level of sea wave (6 m wave height) with 1.5 m/s current. Respectively the actual measured data were 72.7 kN and 16.9 m. By comparison, the values of calculation are well consistent with actual measured ones. By further experimental verification, the analysis model and method can be referenced for practical engineering design of deepwater long-line rope aquaculture facility. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:13
Main heading:Finite element method
Controlled terms:Aquaculture - Bridge cables - Buoys - Design - Hydrodynamics - Iterative methods - Marine biology - Mooring - Mooring cables - Offshore structures  - Piles - Rope - Seawater - Structural design - Water waves
Uncontrolled terms:Experimental verification - Finite element equations - Long line - Non-linear wave forces - Safety and stabilities - Transversal displacement - Transverse displacements - Wind resistance
Classification code:408 Structural Design - 434 Waterway Transportation - 471 Marine Science and Oceanography - 472 Ocean Engineering - 535 Rolling, Forging and Forming - 631.2 Hydrodynamics - 672 Naval Vessels - 674.2 Marine Drilling Rigs and Platforms - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2015.02.028
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 16>

Accession number:20151000594694
Title:Analysis on distribution and use structure of crop straw resources in Huang-Huai-Hai Plain of China
Authors:Fang, Fang (1); Li, Xiang (3); Shi, Zuliang (4); Wang, Fei (1); Chang, Zhizhou (4); Zhang, Shan (5); Sun, Renhua (3); Bao, Zhe (3); Qiu, Ling (1)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A &amp; F University, Yangling, China; (2) Chinese Academy of Agricultural Sciences, Beijing, China; (3) Rural Energy and Environment Agency, Ministry of Agriculture, Beijing, China; (4) Institute of Agriculture Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, China; (5) College of Agriculture, Nanjing Agricultural University, Nanjing, China
Corresponding author:Qiu, Ling
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:228-234
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the continuous increase of crop yields, the amount of straw, as a by-product, also increased progressively. At the same time, since agricultural production style and farmers' lifestyle have changed a lot, the distribution of straw appeared regional, seasonal and structural surplus. More and more straw was thrown away and open burning at will, causing not only a huge waste of resource, but also a series of problems, like atmospheric pollution and traffic interruption and so on. To solve the problems caused by relative straw surplus fundamentally, and to prevent the series of damage brought by open burning, the key point was to realize the full utilization of the total straw. It was of great significance to fully recognize and correctly evaluate the developing potential of straw resource for making better use of total straw and optimizing utilization structure. This study made the research target with five provinces in Huang-Huai-Hai Plain; combined with literature survey and organizing some discussions, the yield, distribution density, amount per capita and utilization status of crop straw resource in Huang-Huai-Hai Plain of China were estimated, and the potential utilization of total straw was discussed. The results showed that crop straw resource in Huang-Huai-Hai Plain was very abundant, the theoretical amount of crop straw in five provinces was 2.4 &times;10⁸ t in 2012, and it was 8.9 &times;10⁷, 9.4 &times;10⁷, 7.4 &times;10⁶, 3.1 &times;10⁷, 7.7 &times;10⁶, 1.9 &times;10⁶, 2.3 &times;10⁶ and 6.5 &times;10⁶ t for maize, wheat, rice, peanut, cotton, legume, potatoes and other crops, respectively. The collectable straw amount was 2.1 &times;10⁸ t. The mean comprehensive utilization efficiency of crop straw reached 76% in this area of five provinces, and straw utilization efficiency of Hebei Province was higher than the other four. Crop straw was mainly used as fertilizer, fodder, stroma, fuel and feed stock, accounting for 49.0%, 31.6%, 4.4%, 8.8% and 6.2%, respectively, in terms of usage amount, but there existed obvious difference in straw use structure among five provinces. The density of straw resource and straw resource per capita in Huang-Huai-Hai Plain were higher than national average value, but the result from Tianjin was opposite. By analyzing potential use ways, it could be forecasted the competitive demand amount for straw resource was 1. 5&times;10⁸ t, of which straw utilization amounts for fertilizer, fodder, stroma and feed stock were 6.7&times;10⁷, 5. 7&times;10⁷, 1.1&times;10⁷ and 1. 8&times;10⁷ t, respectively. Potential straw amount for energy utilization was 8. 8&times;10⁷ t. Based on the results as above, the general trend for total straw utilization in Huang-Huai-Hai Plain could be summarized as 'two increase', 'one decrease' and 'two regulation'. On the basis of original use structure, straw utilization amount for stroma and feed stock would increase by 2.5&times;10⁶ and 6.3&times;10⁶ t, and reduce by 4.8&times;10⁵ t for fodder utilization. Adjustment range of straw amount for fertilizer was from -2.2&times;10⁷ to 7.2&times;10⁷ t, and for fuel utilization was from 0 to 7.2&times;10⁷ t. It should take 'regional planning as a whole', which means that taking county or village and town as a research unit, and setting up a mechanism for long-term operation are suggested to promote total straw utilization in Huang-Huai-Hai Plain. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Crops
Controlled terms:Agriculture - Energy utilization - Fertilizers - Regional planning - Straw
Uncontrolled terms:Agricultural productions - Atmospheric pollution - Comprehensive utilizations - Distribution density - Huang-Huai-Hai Plain - Utilization efficiency - Utilization situations - Waste of resources
Classification code:403.2 Regional Planning and Development - 525.3 Energy Utilization - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2015.02.032
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 17>

Accession number:20151000594678
Title:Effects of mulching with Caragana powder and plastic film on soil water and maize yield
Authors:Chen, Lin (1); Yang, Xinguo (1); Zhai, Deping (1); Song, Naiping (1); Yang, Mingxiu (1); Hou, Jing (1)
Author affiliation:(1) Union Research Center for Ecology and Exploitation of Biological Resources in Western China, Ningxia University, Yinchuan; Ningxia, China
Corresponding author:Song, Naiping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:108-116
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:How to effectively use water and steadily increase crop productivity in arid and semi-arid region has become the focus of attention. It is well known that soil evaporation does little effect on the formation of crop biomass and yield, so reducing soil evaporation is important for improving water use efficiency and agricultural water saving management. Plastic film mulching and straw mulching are effective drought-resistant practices to produce higher crop yield and improve water use efficiency in arid and semi-arid region (Yanchi country, Ningxia Province, China). However, their influences on inter-annual and seasonal dynamics of soil water and crop yield are not quite clear. In this paper, inter-annual and seasonal changes of soil water content in the 0-100 cm soil layer, maize yield, water use efficiency under different mulching methods were studied. At the same time, ecological effects of different mulching measures on cropland were evaluated. The experiment was carried out from May to October in 2013 and 2014 respectively. With the aim of revealing the beneficial effects of straw and plastic mulch on water storage and maize yield, four kinds of different treatments were designed with three replications respectively: whole field surface single film mulching planting (SFP), double film mulching planting (DFP), Caragana powder ditch buried mulching planting (CPDP) and uncovered and flat planting (CK), and the Gannong 118 was taken as an experimental material. Results revealed that the methods of SFP and DFP greatly improved soil water content by 35.65%-47.91% in 0-40 cm soil layer comparing flat planting (CK), especially when there was no rainfall and benefit for the growth of maize. But with the development of maize growth period, the soil water content was closer to or below the wilting coefficient (7.20%) owing to the water consumption of maize growth and soil evaporation. The soil water storage in four treatments all decreased to different degrees after two years of planting. The soil water storage of CPDP and CK were in largest decline (by 68.42 and 68.07 mm, respectively), followed by SFP (53.49 mm) and the least DFP (48.98 mm), which revealed that precipitation couldn't meet the needs of normal growth of maize in the study region. In terms of the effect on yield components, the 100-grain weight of SFP and DFP was significantly higher than CPDP and CK (P&lt;0.05), and the kernel rows per ear in 2 years did not significantly different in four treatments (P&gt;0.05). Excepting the numbers of kernel rows, bare tip length and panicle length of CPDP in 2013 had significant differences with the other three treatments (P&lt;0.05), there were no significant differences between the other treatments (P&gt;0.05). It revealed that the reason why the SFP and DFP treatments produced higher crop yield than the others were the increase of the 100-grain weight (P&lt;0.05). SFP and DFP could increase the utilization of rainfall and soil water, and improved water use efficiency in different years by 12.55%-35.71% and 25.11%-54.70% respectively, comparing with CPDP and CK. There were no significant differences between SFP and DFP in water consumption, maize yield and water use efficiency (P&gt;0.05). Therefore, SFP could be recommended as a suitable method when planting maize in this study area. And due to the lower maize yield, water use efficiency and the higher water consumption, CPDP were not recommended. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Soils
Controlled terms:Agriculture - Arid regions - Crops - Drought - Ecology - Efficiency - Evaporation - Moisture - Plastic films - Rain  - Soil moisture - Storage (materials) - Water conservation - Water content - Water supply
Uncontrolled terms:Arid and semi-arid regions - Different treatments - Experimental materials - Maize - Plastic film mulching - Soil water content - Water use efficiency - Yield
Classification code:443.1 Atmospheric Properties - 443.3 Precipitation - 444 Water Resources - 446.1 Water Supply Systems - 454.3 Ecology and Ecosystems - 483.1 Soils and Soil Mechanics - 694.4 Storage - 802.3 Chemical Operations - 817.1 Polymer Products - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2015.02.016
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 18>

Accession number:20151000594672
Title:Numerical simulation and experiment of soil moisture movement in saturated-unsaturated soil under surge irrigation
Authors:Fu, Yuliang (1); Fei, Liangjun (1); Nie, Weibo (1); Wang, Bo (1)
Author affiliation:(1) Institute of Water Resources Research, Xi'an University of Technology, Xi'an, China
Corresponding author:Fei, Liangjun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:66-71
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Studies have showed that the high water-saving rate and optimal irrigation can be realized by using the surge flow irrigation. However, the investigation is not sufficient in the rule of water movement under intermittent infiltration in saturated-unsaturated soil condition. In order to explore the effect rule of surge irrigation on the water distribution in the aeration zone under the condition of shallow groundwater, we studied the water distribution and the effect law of infiltration through the combinations of intermittent infiltration and indoor water infiltration with model simulation. The laboratory test aimed to observe and analyze the data about soil moisture, cumulative infiltration and wetting front by irrigation with shallow groundwater during surge flow irrigation (step1). The part of numerical simulation mainly included the determination of the design parameters of soil water movement (step2) and the establishment of the mathematical modeling for intermittent infiltration (step3). Finally, a case was used to test the rationality and validity of the numerical simulation results (step4). The laboratory test included three cycling rate levels of treatment (1/2, 1/3 and 1/4, respectively) and each level of treatment included 3 repeats. Based on the theory of soil water dynamics and the technology of surge flow irrigation method, the one-dimensional water movement model in the intermittent infiltration under the saturated-unsaturated soil condition was established. With the application of the measured data for three treatment levels in the Hydrus-1D software based on finite element modeling for the analysis of water flow and solute transport in variably saturated porous media, the water movement parameters (the parameters of Van-Genuchten model) were calculated with the Hydrus-1D software. Furthermore, according to determined optimal parameters, we established a saturated hydraulic conductivity estimation model under different circulation rates and different intermittent cycles in the process of the intermittent infiltration. At last, by comparing the data of simulation and the data measured in the experiment, the validity of the proposed model was tested by the analysis of the relationship among the soil moisture content, cumulative infiltration and wetting front respectively. The results showed that after the simulation, the estimation model could reflect the correlativity among the three parameters (circulation rate, cycle number and cycle time), and the saturated hydraulic conductivity coefficient was calculated with these parameters. To verify the estimation model, the result of calculated values was compared with the simulated ones, and the relative deviation of saturated hydraulic conductivity was as small as -7.7%-8.9%, showing good consistency between the calculated and simulated data. From the comparison between the spot observation and the simulation data of soil moisture, cumulative infiltration and wetting front, we drew the conclusion that the calculated and simulated data had a similar change tendency by using two commonly-used criteria: root mean square error and coefficient of determination. The coefficient of determination of soil moisture was upon 0.952 and the one of cumulative infiltration was up to 0.953. The coefficient of determination of wetting front was 0.93 at least; root mean square error above was all less than 0.5, reaching an extremely remarkable level. The result of simulation could describe the characteristics of the saturated-unsaturated soil water movement in intermittent infiltration well under the condition of shallow groundwater level. The study of the paper laid a scientific basis for the further development of the surge irrigation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Infiltration
Controlled terms:Application programs - Estimation - Finite element method - Flow of water - Groundwater - Hydraulic conductivity - Irrigation - Mean square error - Moisture - Moisture determination  - Numerical methods - Numerical models - Parameter estimation - Porous materials - Soil moisture - Soil surveys - Soil testing - Soils - Solute transport - Water conservation  - Water supply systems - Wetting
Uncontrolled terms:Coefficient of determination - Cumulative infiltrations - HYDRUS-1D - Root mean square errors - Saturated hydraulic conductivity - Shallow groundwater levels - Surge flow - Water movements
Classification code:444 Water Resources - 444.2 Groundwater - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 631.1.1 Liquid Dynamics - 632.1 Hydraulics - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 801.4 Physical Chemistry - 821.3 Agricultural Methods - 921 Mathematics - 921.6 Numerical Methods - 931.2 Physical Properties of Gases, Liquids and Solids - 944.2 Moisture Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.02.010
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 19>

Accession number:20151000594668
Title:Arm movement law and hydraulic performance of vertical impact sprinkler with counterweight
Authors:Tang, Pan (1); Li, Hong (1); Chen, Chao (1); Zou, Chenhai (1); Jiang, Yue (1)
Author affiliation:(1) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China
Corresponding author:Li, Hong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:37-44
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a kind of advanced water-saving irrigation technology, sprinkler irrigation system is adaptable to many crops, soils, and topographic conditions. At present, the most representative and most widely used sprinkler of the high pressure sprinklers are vertical impact drive sprinkler. In order to study the arm movement law of the sprinkler and the influence of counterweight on the hydraulic performance of the sprinkler, with the vertical impact sprinkler as the research object, this paper analyzed the arm movement characteristics of the vertical impact sprinkler by use of theoretic and experimental methods. The arm movement model of the vertical impact sprinkler was established, and according to this model, the free and non-free arm movement times were deduced and then the calculation formula of arm movement period was obtained. In this calculation formula, the factor of counterweight position change was taken into account. The experimental study on the arm movement of Nelson SR100 sprinkler was made with high-speed photography, then the experimental results of arm movement period were compared with the theoretical values, and the effect of arm movement period change on the hydraulic performance of the sprinkler was studied by changing the counterweight installation positions. The results showed that: the free and non-free arm movement times both decreased with the increase of working pressure under the same counterweight installation position. The free arm movement time was considerably larger than the non-free arm movement time, and over 90% of one arm movement period was free movement. In the free movement period, the curve of the arm angular displacement approximated to a smooth semi-period sine curve with the change of time. The arm movement period values obtained through the experiment of high-speed photography well coincided with the calculated values, with most of the relative errors within 10%, which verified the accuracy of the theoretical period formula. In view of the calculation errors of the theoretical period formula, the theoretical period formula was corrected according to the experimental results, thus further improving the calculation accuracy of the theoretical period formula with all the relative errors within 3%. The maximum rotation angle of the arm increased with the increase of the distance between counterweight and arm rotational axis, which increased the arm movement period and decreased the frequency of breaking water jet. Under the same working pressure, the non-free arm movement time increased while the free arm movement time decreased with the decrease of the distance between counterweight and arm rotational axis. Within one arm movement period, the arm angular velocity approximated to a smooth semi-period sine curve with the change of time. The arm angular velocity and movement period were both related to the counterweight installation positions. The farther the counterweight installation position was from the arm rotational axis, the bigger the arm angular velocity and period values became. Both the increase of the sprinkler working pressure and the distance between counterweight and arm rotational axis could decrease the movement period of the sprinkler. When the distance between counterweight and arm rotational axis was short, the sprinkling irrigation intensity near the sprinkler obviously increased and the water distribution increased by about 40% within 3-10 meters; when the distance between counterweight and arm rotational axis was long, the sprinkling irrigation intensity near the sprinkler decreased correspondingly and the sprinkling irrigation intensity at the end of sprinkling irrigation increased correspondingly. The results can provide valuble information for the establishment of the arm design method of the vertical impact sprinkler as well as the reasonable adjustment of the arm counterweight installation position during the operational process. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Sprinkler systems (irrigation)
Controlled terms:Angular velocity - Errors - High speed photography - Hose - Irrigation - Nozzles - Photography - Pressure - Soils - Water conservation  - Water supply systems
Uncontrolled terms:Correction factors - Impact sprinklers - Installation position - Irrigation uniformity - Law of motions - Sprinkling irrigation - Topographic conditions - Water-saving irrigation
Classification code:444 Water Resources - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 619.1 Pipe, Piping and Pipelines - 631.1 Fluid Flow, General - 731 Automatic Control Principles and Applications - 742.1 Photography - 821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods - 921 Mathematics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.02.006
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 20>

Accession number:20151000594708
Title:Crushing pretreatment parameter optimization of soybean straw used as raw material of mulch
Authors:Liu, Shuang (1); Fang, Xin (1); Zhang, Ying (1); Chen, Hongrui (1); Chen, Haitao (1)
Author affiliation:(1) College of Engineering, Northeast Agricultural University, Harbin, China
Corresponding author:Chen, Haitao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:333-338
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Recently, a large amount of soybean straw was treated as waste and burned, which caused serious pollution. At the same time, for increasing the grain yield, the plastic mulch was applied widely in China which caused serious white pollution. Soybean straw was an excellent raw material of non-wood fiber, and manufacturing biodegradable mulch of soybean straw fiber could not only reduce the pollution, but also raise the value of soybean straw. Before the manufacturing of biodegradable mulch, the raw soybean straw need crushing pretreatment. There have been many domestic and international researches about the equipment of straw crushing. However, these equipments are mainly used for the preparation of straw returning, feeding or the formation of biomass solid fuel, and the straw crushing length is usually too short. According to the requirement of the plant fiber preparing machine, straw crushing length of 70- 85 mm is suitable for manufacturing soybean straw fiber mulch. As there is no special crushing equipment used for preparation raw material of straw fiber mulch, the existing rubbing and cutting machine was improved to process soybean straw with crushing length of 70-85 mm. By removing the chopper, the shearing effect was reduced, and the crushing was mainly realized by hammering effects of chopper holder, hammering on the soybean straw. After improvement the usual operation parameters are not applicable; thus, to optimize soybean straw crushing pretreatment parameters, the machine spindle speed, feed quantity and straw moisture content were selected as experiment factors, and a quadratic orthogonal rotatable central composite design experiment with three factors and five levels was conducted. The results showed that: 1) For the straw crushing length of improved rubbing and cutting machine, from high to low ranking of contribution rate, the factors are the spindle speed, moisture content and feed rate. The spindle speed and moisture content show significant interaction effect on soybean straw crushing length. There are two reasons for the interaction effect. Firstly, the increase of soybean straw moisture content causes the increase of straw plasticity, which weakens the shearing effect caused by increasing spindle speed. Secondly, with the increase of straw moisture content, lubrication film forms between straw and chopper holder, which also weakens the shearing effect caused by increasing spindle speed. 2) The optimized pretreatment parameters are as follows: the feeding quantity is 168 kg/h, moisture content of soybean straw is in range of 36%-58%, and the machine spindle speed is in range of 1 100- 1 300 r/min. Under the optimized parameters, the processed length of soybean straw is in range of 70-85 mm, which meets length requirement of the plant fiber preparing machine for raw materials. To verify the optimization results, 10 random groups of soybean straw were crushed under the optimal combination of parameters, the verification experiment results showed that there was no significant difference between predicted values and observed values. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Crushing
Controlled terms:Cutting equipment - Equipment - Fibers - Fuels - Machinery - Manufacture - Moisture - Moisture determination - Optimization - Pollution  - Shearing - Speed - Straw - Textile fibers - Wood
Uncontrolled terms:Crushing equipments - International researches - Mulch - Operation parameters - Optimal combination - Parameter optimization - Pre-Treatment - Rotatable central composite designs
Classification code:454.2 Environmental Impact and Protection - 522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 537.1 Heat Treatment Processes - 601 Mechanical Design - 604.1 Metal Cutting - 801.4 Physical Chemistry - 802.3 Chemical Operations - 811.2 Wood and Wood Products - 812 Ceramics, Refractories and Glass - 817 Plastics and Other Polymers: Products and Applications - 819.2 Synthetic Fibers - 821.5 Agricultural Wastes - 901 Engineering Profession - 921.5 Optimization Techniques - 931.1 Mechanics - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2015.02.046
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 21>

Accession number:20151000594703
Title:Spatio-temporal variation and source changes of heavy metals in cultivated soils in industrial developed urban areas
Authors:Qiu, Menglong (1); Li, Fangbai (2); Wang, Qi (2); Chen, Junjian (2); Yang, Guoyi (2); Wang, Binwu (1); Liu, Liming (1)
Author affiliation:(1) College of Resources and Environment, China Agricultural University, Beijing, China; (2) Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environment and Soil Science, Guangzhou, China
Corresponding author:Liu, Liming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:298-305
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil samples were collected from cultivated soil in Dongguan, a representative fast-growing economic area of the Pearl River Delta, China. Variation characteristics of mercury (Hg), cadmium (Cd), chromium (Cr), lead (Pb), arsenic (As), copper (Cu), zinc (Zn) and nickel (Ni) over the last decade were described by multivariate statistics. Spatio-temporal variation and source change of 4 pollution elements (Hg, Cd, Cu, Ni) were further analyzed by geostatistics and principal component analysis/absolute principal component scores (PCA/APCS) model. The results indicated that the concentrations of Cd and Zn increased by 71.4% and 15.9% respectively from 2002 to 2012, whereas those of Cr, As, Cu, and Ni remained relatively stable, Hg and Pb decreased respectively by 40.0% and 25. 7%. The use of unleaded petrol in China since 2000 was the significant cause of the decrease in Pb concentration, while the decrease of Hg was attributed to strict emission controls implemented by the government, harvesting, Hg evaporation from farmland topsoil and runoff. These showed that the pollution of heavy metals was strongly impacted by industrial and agricultural activities, and the accumulation of heavy metals could be prevented if human activities were properly constrained. Hg, Cd, Cu and Ni were the pollution elements, which exceeded the second level of the Standards for Soil Environmental Quality in some soil samples. Cd, Cu and Ni among the pollution elements showed an aggravated contamination from 2002 to 2012. The ratios of nugget to sill of Hg, Cd and Cu were 43.4%, 31.9% and 19.4% respectively in 2002, and 49.9%, 54.7% and 25.3% respectively in 2012. This showed that these elements were interfered more seriously by anthropogenic factors in 2012 than in 2002. The results of PCA/APCS model showed that heavy metals were mainly from 3 types of sources in 2002: water area and parent material, electroplating, chemical industry and railway, and electronic industry, electroplating, leather making and highway traffic; there were two main types of sources in 2012: water area and parent material, and electronic industry, electroplating and domestic waste. Hg (69.9%) mainly came from electronic industry, electroplating, leather making and highway traffic, and Cd (68.0%) mainly came from electroplating, chemical industry and railway in 2002. Hg (57.8%) and Cd (52.3%) were both mainly from electronic industry, electroplating and domestic waste in 2012. The reasons of pollution source change were the strengthening of government pollution control, improvements in environmental protection technology of transportation, and the increasing of domestic waste caused by the rapid development of urbanization. Water area and parent material were main sources of Ni both in 2002 (63.8%) and in 2012 (82.0%). Cu mainly came from water area and parent material (46.9%) and electroplating, chemical industry and railway (32.5%) in 2002, while mainly came from water area and parent material (64.4%) in 2012. Industrial upgrading and emission control led to the decreasing of contribution rates of electroplating, chemical industry on copper pollution in 2012. Considering the contribution rate of parent material was stable in short term, the water quality deterioration of river may be the important reason for the rise of contribution rates of water area and parent material. Understanding the law of spatio-temporal variation and source change of heavy metals in the process of social and economic development is a basis for taking appropriate action to control heavy metal pollution and protect environmental quality of soil. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Pollution
Controlled terms:Chemical industry - Copper - Cultivation - Economics - Electroplating - Emission control - Environmental protection - Environmental regulations - Environmental technology - Heavy metals  - Industrial emissions - Industrial railroads - Land use - Lead - Leather - Mercury (metal) - Metals - Multivariant analysis - Nickel - Pollution control  - Principal component analysis - Quality control - Railroads - River pollution - Soil pollution control - Soil surveys - Soils - Supply chains - Transportation - Water quality  - Zinc
Uncontrolled terms:Cultivated lands - Dongguan - Pollution of heavy metals - Social and economic development - Source - Spatio-temporal variation - Variation characteristics - Water quality deterioration
Classification code:403 Urban and Regional Planning and Development - 431 Air Transportation - 432 Highway Transportation - 433 Railroad Transportation - 433.3 Freight Railroad Transportation - 434 Waterway Transportation - 451.1 Air Pollution Sources - 451.2 Air Pollution Control - 453 Water Pollution - 453.2 Water Pollution Control - 454 Environmental Engineering - 454.2 Environmental Impact and Protection - 483.1 Soils and Soil Mechanics - 531 Metallurgy and Metallography - 539.3.1 Electroplating - 544.1 Copper - 546.1 Lead and Alloys - 546.3 Zinc and Alloys - 548.1 Nickel - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 681 Railway Plant and Structures - 681.1 Railway Plant and Structures, General - 682 Railroad Rolling Stock - 805 Chemical Engineering, General - 814.1 Leather - 821.3 Agricultural Methods - 912 Industrial Engineering and Management - 913 Production Planning and Control; Manufacturing - 913.3 Quality Assurance and Control - 922 Statistical Methods - 922.2 Mathematical Statistics - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.02.041
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 22>

Accession number:20151000594698
Title:Microbial community characteristics of semi-dry anaerobic digestion with organic waste
Authors:Yu, Meiling (1); Zhang, Dalei (1); Li, Yuting (1); Dong, Xiaoying (1); Wang, Xiaoming (1); Kou, Wei (1)
Author affiliation:(1) Liaoning Institute of Energy Resources, Yingkou, China
Corresponding author:Kou, Wei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:253-258
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The organic waste mainly refers to the solid waste that is generated by residents' daily life. If the organic waste is converted into energy through anaerobic digestion, it will reduce the adverse impact on the environment and contribute to reduction in consumption of fossil fuel. Analysis of the space and time differences of various kinds of microbial community in fermentation process, plays a very important role for controlling the fermentation process effectively, understanding the fermentation stage, optimization of fermentation conditions and improving the efficiency of biogas production. This paper investigated the temporal and spatial distribution of microbial community during the semi-dry fermentation of organic waste, and studied the relationship of acid production, methane production and ammonia production using most probable number (MPN). The experiment used anaerobic fermentation under one-time charging medium temperature (37), and designed six sampling positions. The inoculum was biogas slurry fermented with pig manure, and the concentration was 30%, pH value was adjusted to 7.0 before anaerobic fermentation. The results showed that, in the early stage of organic waste anaerobic fermentation, large amounts of air existed in the reactor, and there was less number of anaerobic bacteria. With the formation of the anaerobic environment and rich nutrients, the number of anaerobic bacteria began to rise. The anaerobic acidification bacteria and anaerobic ammonification bacteria proliferated earliest, and the acidification bacteria was prior to reach maximum than ammonification bacteria and occupied the dominant position. The methane bacteria didn't proliferate at the start-up phase, they enter the fast growth stage after 15 days, and the peak value was 3. 24&times;10⁹ mL^-1 on the 25th day. In the gas peak decline period, the number of anaerobic ammonification bacteria and anaerobic acidification bacteria began to decline, however, the methane bacteria number kept on the order of magnitude in the whole period. The anaerobic cellulose-decomposing bacteria grew slowly, and the number was only 10⁶ mL^-1 on the 45th day. In the space, numbers of anaerobic acid bacteria and methane bacteria in the central part were more than those at the edge, and the numbers in the bottom were more than on the top; the most number of anaerobic ammoniation bacteria grew in middle edge and center position; at the same height, the numbers of edge position were more than the center position basically. The anaerobic cellulose-decomposing bacteria began to proliferate in the bottom. The number of the anaerobic bacteria on the top was lower than other places, due to the residual air on the top that was not conducive to the growth of anaerobic bacteria. In the reactor design, intermediate feed may be given priority to, edges feed was complementary, which was conducive to make full use of fermentation materials, and to improve the efficiency of the reactor. The dynamic model of anaerobic acidification bacteria and methanogens distribution differences was constructed preliminarily, and the correlation coefficients of fitting model were 0.824 and 0.939, respectively. The established model could predict effectively, and could provide the appropriate reference value of semi-dry anaerobic fermentation technology. The applicability of the model still requires further test to verify, therefore, the reactor enlarged gradually can be used for further study and parameters correction. This paper has theoretical significance for the technological processes of biogas production from organic waste. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Anaerobic digestion
Controlled terms:Acidification - Bacteria - Biogas - Cellulose - Fermentation - Information dissemination - Methane - Microorganisms - Process control - Spatial distribution  - Wastes
Uncontrolled terms:Anaerobic fermentation - Correlation coefficient - Dry anaerobic digestions - Fermentation conditions - Impact on the environment - Microbial communities - Technological process - Temporal and spatial distribution
Classification code:452.3 Industrial Wastes - 452.4 Industrial Wastes Treatment and Disposal - 461.9 Biology - 522 Gas Fuels - 731 Automatic Control Principles and Applications - 802.2 Chemical Reactions - 815.1.1 Organic Polymers - 822.2 Food Processing Operations - 903.2 Information Dissemination - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2015.02.036
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 23>

Accession number:20151000594682
Title:Retrieving canopy leaf total nitrogen content of winter wheat by continuous wavelet transform
Authors:He, Ruyan (1); Qiao, Xiaojun (1); Jiang, Jinbao (1); Guo, Huimin (1)
Author affiliation:(1) College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, China
Corresponding author:Jiang, Jinbao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:141-146
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The aim of this paper is to monitor the nitrogen nutrition status of winter wheat under stripe rust stress by hyperspectral remote sensing. The experiment was carried out at Beijing Xiaotangshan Precision Agriculture Experimental Base, China (40&deg;10.6'N, 116&deg;16.3'E). The cultivar of winter wheat was Jingdong 8 which was very susceptible to stripe rust. Canopy spectral reflectance data of winter wheat was collected by an ASD Fieldspec FR spectroradiometer and the disease index (DI) was measured through counting the number of wheat leaf under stripe rust stress artificially in the field. Leaf total nitrogen (LTN) content of winter wheat used to calculate DI was measured in the laboratory. The relationship between DI of stripe rust and LTN content of winter wheat was analyzed. The canopy spectra were processed by the method of continuous wavelet transform (CWT) on 10 scales, therefore, a series of wavelet coefficients were obtained in this way. The correlation coefficients between wavelet coefficients and LTN content were calculated, and then, the wavelet coefficients, which had strong correlation with LTN content, were chosen. Several hyperspectral indices were also selected according to previous research results, namely SR (simple ratio index), PRI (photochemical reflectance index), NDVI (normalized difference vegetation index), OSAVI (optimized soil-adjusted vegetation index), SIPI (Structure insensitive pigment index), LIC1 (lichtenthaler index 1), LIC2 (lichtenthaler index 2), LIC3 (lichtenthaler index 3), TVI (triangular vegetation index) and MTVI2 (modified triangular vegetation index 2), which had high correlations with LTN content. Both wavelet coefficients and hyperspectral indices were used as independent variables of models to retrieve LTN content of winter wheat, and support vector machine (SVM) regression method was used to establish the estimation models. The above estimation models of different types of variables were made a comparison. Cross-validation method was used to examine estimation model accuracies of winter wheat canopy LTN content. The test results showed that LTN content of winter wheat decreased gradually when DI of stripe rust increased and the correlation coefficient between LTN content and DI was -0.784 (n=33). The research results indicated that the model prediction accuracies of SR, PRI, LIC2, LIC3, TVI and MTVI2 were very low, the values of R² were less than 0.700, and root mean square error (RMSE) and relative error (RE) were both high. The estimated models of NDVI, OSAVI, SIPI and LIC1 had higher accuracies than aforementioned hyperspectral indices. However, the accuracies of LTN content estimation models which were built by wavelet coefficients obtained by CWT were generally higher than those of hyperspectral indices. The optimal model was established by wavelet coefficient 423(4) which was acquired by Mexican hat wavelet function, and RMSE and RE were 0.315 and 7.62%, respectively. The wavelet coefficient 423(4) was located in 423 nm where was near to 430 nm which is the nitrogen absorption waveband. The estimation model of wavelet coefficient 663(5) was secondary, which had the prediction RMSE of 0.345 and RE of 8.28%. The variable of 663(5) obtained by Daubechises (Db5) wavelet function was also close to the nitrogen absorption waveband which lies in 660 nm. Therefore, the method of jointing CWT and SVM regression is feasible to retrieve LTN content of winter wheat under stripe rust stress and the estimation models have high accuracies. There is an important practical meaning for preventing diseases of wheat and instructing crop fertilization. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Wavelet transforms
Controlled terms:Crops - Mean square error - Nitrogen - Plants (botany) - Reflection - Regression analysis - Remote sensing - Support vector machines - Vegetation
Uncontrolled terms:Continuous wavelet transforms - Hyperspectral remote sensing - Leaf - Normalized difference vegetation index - Photochemical reflectance index - Stripe rust - Support vector machine regressions - Winter wheat
Classification code:461.9 Biology - 711 Electromagnetic Waves - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 804 Chemical Products Generally - 821.4 Agricultural Products - 921.3 Mathematical Transformations - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.02.020
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 24>

Accession number:20151000594673
Title:Measuring soil water content in surface layer with heat-pulse technique
Authors:Zhang, Xiao (1); Wang, Yueyue (2); Ren, Tusheng (2)
Author affiliation:(1) Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, China; (2) Department of Soil and Water, China Agricultural University, Beijing, China
Corresponding author:Ren, Tusheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:72-78
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Accurate measurement of near-surface soil water content (0-5 cm) is essential for studying water and heat exchange between land and atmosphere. Heat-pulse technique has potential to measure soil volumetric water content, but only used in laboratory, greenhouse and field at depths below 5 cm. The objective of this study was to test the possibility of heat-pulse technique for measuring water content in near-surface soil layer (0-5 cm) in the field. The experiment was conducted in a sandy loam soil in an experimental plot (2 m&times;2 m&times;2 m) in China Agricultural University. Multi-needle heat-pulse sensor was used to measure volumetric heat capacity in various depths above 5 cm and four multi-needle heat-pulse sensors were used. Average volumetric heat capacity from four multi-needle heat-pulse sensors was calculated at each depth and the values at four depths (3, 9, 21 and 39 mm) were extracted to be analyzed. When calculating soil volumetric heat capacity from temperature change versus time data, the pulse infinite line source theory was used at 9, 21 and 39 mm, while for volumetric heat capacity at 3 mm, the pulse infinite line source-adiabatic boundary condition was used because of the soil-air interface effect. Based on the linear relationship of soil volumetric heat capacity and volumetric water content in mineral soil, soil volumetric water content could be calculated from soil volumetric heat capacity, volumetric heat capacity of water, soil bulk density and solid heat capacity, which was named heat-pulse water content method. When the temporal series of soil volumetric heat capacity were measured, the change in soil water content could be calculated without knowledge of soil-specific properties. With the initial water content measured by another independent method, dynamic of soil water content could be determined from the change in soil water content series data and this method was called heat-pulse water content change method. Water contents at those four depths were calculated by the above two methods respectively. Besides, a ring device was made for collecting and splitting soil samples into nine layers in 0- to 5-cm depth. With the ring device, water contents at 3, 9, 21 and 39 mm were determined by the traditional gravimetric method. Water contents from gravimetric method were used to evaluate accuracy of water contents from heat-pulse technique. The results showed that compared with soil water contents from gravimetric method, root mean square errors of soil water contents from heat-pulse water content method were 0.082, 0.075, 0.018 and 0.018 m³/m³ and mean deviations were 0.076, 0.073, 0.009 and 0.010 m³/m³ at four depths, while for the values from heat-pulse water content change method, root mean square errors were 0.022, 0.006, 0.004 and 0.006 m³/m³ and mean deviations were 0.048, 0.024, 0.017 and 0.025 m³/m³, indicating that heat-pulse water content change method could obtain more accurate results. The maximum standard deviations of water contents from heat-pulse water content method were 0.077, 0.077, 0.044 and 0.059 m³/m³ at four depths. For soil water contents from heat-pulse water content change method, the maximum standard deviations were 0.061, 0.052, 0.019 and 0.021 m³/m³, all smaller than those values from heat-pulse water content method, showing heat-pulse water content change method decreased the differences of water content measurements among four multi-needle heat-pulse sensors. The results showed that heat-pulse water content change method could measure soil water content accurately at depths of 3, 9, 21 and 39 mm, with root mean square error less than 0.022 m³/m³. Heat-pulse technique can accurately measure water content in near-surface soil layer, but further research is needed for accurate water content measurement in 0-3 mm soil layer. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Phase interfaces
Controlled terms:Errors - Heat conduction - Mean square error - Moisture - Needles - Soil moisture - Soil surveys - Soil testing - Soils - Specific heat  - Statistics - Water content
Uncontrolled terms:Adiabatic boundary conditions - Heat pulse - Root mean square errors - Soil volumetric water contents - Surface layers - Volumetric heat capacity - Volumetric water content - Water content measurements
Classification code:444 Water Resources - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 641.2 Heat Transfer - 801.4 Physical Chemistry - 819.6 Textile Mills, Machinery and Equipment - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.02.011
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 25>

Accession number:20151000594693
Title:Optimization on formulation of peat-fiber-cement-based dry-sprayed substrate for slope ecological protection by site experiment
Authors:Xiao, Henglin (1); Ma, Qiang (1); Ye, Jianjun (1); Wan, Juan (1); Li, Lihua (1); Peng, Quan (1)
Author affiliation:(1) Institute of Geotechnical Engineering and Underground Construction, School of Civil Engineering and Architecture, Hubei University of Technology, Wuhan, China
Corresponding author:Ma, Qiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:221-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To rehabilitate the damaged ecosystem of slope formed in civil engineering, Chinese Engineers developed the technology of ecological protection of slope by shotcreting dry-sprayed substrate at the beginning of 21st century based on foreign relative technologies. The technology which suits for steep rock slopes has been widely used in China since it came out. To improve the erosion resistance of the dry-sprayed substrate, fiber and (or) cement were usually included in the substrate formulation to reinforce the substrate. So far, though some research have been conducted about the technology, few studies concerned the formulation design of the dry-sprayed substrate. Aiming at this problem, site experiments with orthogonal design were carried out, in which a new type of plant fiber was used to reinforce cement-based substrate which included five components: peat, plant fiber (made of crushed straw), cement, top soil, water-retaining agent (polyacrylamide, PAM). In this paper, the five components were treated as five factors (four levels for the content of each factor) and plant (Bermuda grass) growth index, pH value of substrate as dependent variables, and the orthogonal experiments were conducted to investigate how the factors and levels influenced plant germination, coverage rate and growth of plant. The results showed that from high to low, the order of importance of factors influencing plant germination and growth was cement, water-retaining agent, PAM, fiber and peat. The content of fiber and peat had no significant effect on plant germination, while cement content had observably adverse effect on germination rate. The cement content (volume ratio) had a linear relationship with the germination rate, and the cement content in the substrate should be less than 10%. For the slope's ecological protection project along the roads in the Three Gorges area, most formulations of the substrate employed in this study could be used while the optimal formulation (volume ratio) for bermuda grass was 34.8% local top soil, 20% peat, 5% cement, 0.05% PAM, 0.15% water-retaining agent, and 40% fiber. In addition, it was found that the plant had the capacity of reducing pH value of the substrates, which had a linear relationship with time, and gradually decreased to eight after 70 days. The results presented in this paper will have the guiding value for the substrate design when the slope's ecological protection projects are carried out in the region of middle or lower reaches of Yangtze river, and the principles found in this paper also suit for the districts with similar soil and climate conditions. The approaches used in this study can be employed to conduct substrate design for the slope's ecological protection in other districts. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:16
Main heading:Substrates
Controlled terms:Cement manufacture - Cements - Cultivation - Design - Ecology - Fibers - Growth (materials) - Peat - pH - Shotcreting  - Slope protection - Soil cement - Soils - Textile fibers
Uncontrolled terms:Dependent variables - Ecological protection - Formulation - Formulation design - Linear relationships - Optimal formulation - Orthogonal experiment - Water-retaining agents
Classification code:408 Structural Design - 412 Concrete - 412.1 Cement - 454.3 Ecology and Ecosystems - 461 Bioengineering and Biology - 483.1 Soils and Soil Mechanics - 503 Mines and Mining, Coal - 524 Solid Fuels - 801 Chemistry - 801.1 Chemistry, General - 812 Ceramics, Refractories and Glass - 817 Plastics and Other Polymers: Products and Applications - 819.2 Synthetic Fibers - 821.3 Agricultural Methods - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.02.031
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 26>

Accession number:20151000594705
Title:Abnormal eggs detection based on spectroscopy technology and multiple classifier fusion
Authors:Zhu, Zhihui (1); Xie, Dejun (1); Li, Wanqing (1); Wang, Qiaohua (1); Ma, Meihu (2)
Author affiliation:(1) College of Engineering, Huazhong Agricultural University, Wuhan, China; (2) National R&amp;D Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
Corresponding author:Ma, Meihu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:312-318
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The aim of the research was to improve detection accuracy of the blood spots and meat spots in eggs, which can provide consumers with high-quality eggs. Spectroscopy technology and multiple classifier fusion for abnormal egg detection were investigated. Micro fiber spectrometer (Ocean Optics company, USB2000+) was used to collect the transmittance spectroscopy of both normal and abnormal eggs, which were from Hubei Shendan Healthy Food Co., Ltd. After outliers detection and elimination, there were 336 eggs in all, which were randomly assigned to training set and test set; among the 336 eggs, 224 (about two-thirds of the total) were assigned to the training set, and the remaining 112 (about one-third of the total) were assigned to the test set. Before multiple classifier fusion, all data collected from micro fiber spectrometer was preprocessed including the methods of SNV (standard normal variate), smoothing and MSC (multiplicative scatter correction). usion of multiple classifiers was used to detect the foreign bodies of eggs on the basis of single-classifier. Firstly, five single-classifiers which was inclusive of Naive Bayes classifier, Mahalanobis distance classifier, PLS-DA (partial least squares-discriminate analysis) classifier, AdaBoost (adaptive boosting) classifier and SVM (support vector machine) classifier were all trained, and five groups of classification results were attained. In order to choose suitable one from these five single-classifiers, according to diversity measure, output disagreement measure and error agreement measure were introduced and used, and Naive Bayes, AdaBoost and SVM classifiers were selected as the single-classifiers; then, on the basis of these three selected single-classifiers, through feature level fusion, 21 base-classifiers were obtained. In order to get the final base-classifiers which were used to accomplish the multiple classifier fusion, in a similar way, through output disagreement measure and error agreement measure again, 5 base-classifiers were chosen from these 21 base-classifiers. Finally, 5 basic-classifiers were fused by weight vote strategy on the decision level. The weight vote strategy was that each base-classifier was allocated a weight value according to its accuracy rate, and the higher accuracy rate a base-classifier had, the larger weight value it would be allocated, because it was more trusted. Detection accuracy rate of ensemble classifier, which was formed after multiple classifier fusion, was 92.86% and 91.07%, respectively for normal eggs and abnormal eggs. As a contrast, among all the single-classifiers and base-classifiers, the highest detection accuracy of normal eggs in the test set was 91.07%, which came from AdaBoost (500-600 nm), and the highest detection accuracy of abnormal eggs in the test set was 89.29%, which came from SVM (550-600 nm). The experiment results showed that the model established by multiple classifier fusion could take full advantage of the information which came from each single-classifier or base-classifier, and in the aspect of the detection accuracy of either normal eggs or abnormal eggs, the model established by multiple classifier fusion was indeed superior to the model established by each single-classifier or base-classifier. Even though the detection accuracy was enhanced by a small margin, considering that a large number of either normal eggs or abnormal eggs were being produced and being detected in lots of companies that were involved in eggs, in this meaning, the slight promotion of detection accuracy was of great significance. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Classification (of information)
Controlled terms:Adaptive boosting - Classifiers - Information fusion - Least squares approximations - Nondestructive examination - Spectrometers - Spectrum analysis - Support vector machines
Uncontrolled terms:Abnormal eggs - Multiple classifier fusion - Multiplicative scatter correction - Naive Bayes classifiers - Partial least square (PLS) - Standard normal variates - SVM(support vector machine) - Transmittance spectroscopies
Classification code:421 Strength of Building Materials; Mechanical Properties - 723 Computer Software, Data Handling and Applications - 801 Chemistry - 802.1 Chemical Plants and Equipment - 903.1 Information Sources and Analysis - 921 Mathematics - 921.6 Numerical Methods - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2015.02.043
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 27>

Accession number:20151000594677
Title:Parameterization of surface soil available moisture and simulation of soil evaporation beneath canopy
Authors:Zhang, Chuan (1); Yan, Haofang (2); Oue, Hiroki (3); Shi, Haibin (4); Wang, Guoqing (5)
Author affiliation:(1) Institute of Agricultural Engineering, Jiangsu University, Zhenjiang, China; (2) Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China; (3) United Graduate School of Agricultural Sciences, Ehime University, 3-5-7 Tarumi, Matsuyama, Japan; (4) Water Conservancy and Civil Engineering College of Inner Mongolia Agriculture University, Huhhot, China; (5) State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, China
Corresponding author:Yan, Haofang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:102-107
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil evaporation consumes a large part of evapotranspiration during the crop growth season, especially during the seedling or sparse crop growth stage. It has been reported that soil evaporation makes little contribution to crop yield, and thus it has been seen as invalid water consumption. Separate determination of soil evaporation and transpiration is required in many irrigation management programs or yield analysis models. However, it is quite difficult to directly measure soil evaporation and transpiration separately. To achieve this purpose, a soil evaporation model was developed using a new defined soil moisture function based on the actual measurement of meteorological data (air temperature, relative humidity, and wind speed), soil surface moisture and soil evaporation data. The model combined two processes of water vapor transfer: one is the vapor transport in air while the other is molecular diffusion of vapor in the surface soil pore with the vapor being carried from the interior soil pore to the land surface. For the field observation, air temperature and relative humidity were measured in three different heights above the buckwheat canopy in order to determine the actual evapotranspiration with Bowen ratio energy balance method. Leaf area index and plant height was measured regularly, with the maximum values of 2.25 and 62.7 cm, respectively. The variation of surface soil water content (5 cm) was from 11.2% to 30.9%. An important parameter, surface moisture availability, in the proposed model was decided by surface soil moisture and wind speed. It was shown that surface soil water content was the main factor affecting surface moisture availability, and wind speed had slight influence on it. The modeled surface moisture availability with soil content and constant wind speed was compared to calculated value with varied wind speed. By assuming surface moisture availability to be 1 in the model, another important parameter, bulk transfer coefficient, could be calculated. It has been reported that the bulk transfer coefficient for bare field is mainly influenced by soil texture and atmospheric stability. In this study, average value of bulk transfer coefficient was applied for three different leaf area stages based on the analysis of its actual variation. Actual evapotranspiration and soil evaporation beneath the buckwheat canopy respectively measured by Bowen ratio energy balance method and micro-lysimeter were compared and the soil evaporation measured by micro-lysimeter was applied to validate the accuracy of the model. It was shown that the soil evaporation beneath the buckwheat canopy during seedling stage was quite close to actual evapotranspiration measured by Bowen ratio energy balance. The average hourly soil evaporation measured by Bowen ratio energy balance and micro-lysimeter were 0.16 and 0.17 mm, respectively; while the average relative error between two methods was 12%, root mean square error was 0.077, and correlation coefficient was 0.89. It was also shown that the soil evaporation beneath the buckwheat canopy could be reproduced using the constructed surface moisture availability model with average relative error of 13.5%, root mean square error of 0.249, and correlation coefficient of 0.95. The study is very important in separately estimating soil surface evaporation beneath the canopy and crop transpiration, and in decreasing invalid water consumption through soil surface beneath the canopy. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Soil surveys
Controlled terms:Atmospheric humidity - Atmospheric temperature - Availability - Crops - Energy balance - Evaporation - Evapotranspiration - Lysimeters - Mean square error - Meteorology  - Moisture - Plants (botany) - Soil moisture - Soils - Speed - Transpiration - Water content - Water supply - Wind
Uncontrolled terms:Actual evapotranspiration - Atmospheric stability - Average relative error - Bowen ratio energy balances - Bulk transfer coefficients - Correlation coefficient - Root mean square errors - Surface soil moisture
Classification code:443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 446.1 Water Supply Systems - 461.9 Biology - 483.1 Soils and Soil Mechanics - 731.1 Control Systems - 802.3 Chemical Operations - 821.4 Agricultural Products - 913.5 Maintenance - 931 Classical Physics; Quantum Theory; Relativity - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.02.015
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 28>

Accession number:20151000594700
Title:Extracting method for agricultural land of SAR image based on optimized three-component decomposition model
Authors:Wu, Shangrong (1); Ren, Jianqiang (1); Chen, Zhongxin (1); Liu, Jia (1); Ding, Yaping (2)
Author affiliation:(1) Key Laboratory of Agri-informatics, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China; (2) Aerors Inc., Xi'an, China
Corresponding author:Ren, Jianqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:266-276
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Because of the long-time influence of rain, cloud and fog in summer and autumn, the information of agricultural land is difficult to obtain instantly and accurately in local agricultural areas in North China. Radar remote sensing has advantages of all-time, all-weather and high penetration etc, and it can be widely used in cloudy regions. In applications of multi-polarization radar data, polarization decomposition model can get effective polarization characteristics to extract land features accurately. The Freeman decomposition model is a polarization decomposition model used frequently, but it can only be used in the circumstances that satisfy the demand of reflection symmetry, which limits the use of the model to further improve the classification accuracy of remote sensing to a certain extent. On the basis of analyzing the reason that the Freeman decomposition model is not suitable for agricultural area, this paper proposed an automatic extracting method of agricultural land of SAR image using optimized three-component decomposition model (OTDM) which is the improvement of the Freeman decomposition model. In this study, firstly, the orientation processing was joined into polarization decomposition model to inhibit the production of negative power. And the Freeman decomposition model was optimized by introducing volume scattering parameter, secondary scattering parameters and Bragg scattering parameters, so as to improve the performance of Freeman decomposition model which has the shortcoming of lacking adjustable parameters, and make the decomposition results adaptable to the scattering characteristics of different surfaces of agricultural area. Then, combining OTDM and fuzzy C-means clustering (FCM), after land feature categories were merged, agricultural land information was extracted in an automatic way. The results of experiments indicated that when parameters were equivalent to 3, 1. 75, 10 and 0.001, respectively, the classification from FCM achieved the better result. Finally, both of the H-Alpha-Lambda and OTDM-FCM were applied in an experiment and compared with the ground samples to verify the effectiveness of OTDM-FCM. In this experiment, the study area was located in Zaoqiang County, Hebei Province in Huang-huai-hai Plain, and Radarsat-2 images were used as the radar data source. The experiment was carried out under the circumstances of full and partial cover crop by selecting the images in appropriate time. The final results of the experiment indicated that under the circumstance of full cover crop, overall accuracy and Kappa coefficient of OTDM-FCM were 96.12% and 0.857, respectively, while the results of H-Alpha-Lambda were 87.43% and 0.520, respectively; under the circumstance of partial cover crop, overall accuracy and Kappa coefficient of OTDM-FCM were 97.53% and 0.902, respectively, while the results of H-Alpha-Lambda were 80.16% and 0.307, respectively. It could be concluded that the classification extraction accuracy of OTDM-FCM was superior to H-Alpha-Lambda classification under the circumstances of both full and partial cover crop. Therefore, under the conditions of different imaging time and different extents of crop covered, OTDM-FCM classification algorithm could effectively extract the information of agricultural land, and it was shown that OTDM-FCM classification had certain feasibility and applicability in the extraction of agricultural land depending on SAR image information. This method put forward in this paper could provide a new thinking for the application of SAR image in the extraction of agricultural land information. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Image processing
Controlled terms:Agriculture - Classification (of information) - Crops - Data mining - Decomposition - Extraction - Models - Polarization - Radar - Remote sensing  - Scattering - Scattering parameters - Synthetic aperture radar
Uncontrolled terms:Agricultural land - Automatic extracting method - Classification accuracy - Classification algorithm - Fuzzy C means clustering - Polarization characteristics - SAR Images - Scattering char-acteristics
Classification code:703.1 Electric Networks - 711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 716.1 Information Theory and Signal Processing - 716.2 Radar Systems and Equipment - 723.3 Database Systems - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 802.2 Chemical Reactions - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 902.1 Engineering Graphics
DOI:10.3969/j.issn.1002-6819.2015.02.038
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 29>

Accession number:20151000594706
Title:Preparation and identification of water-soluble calcium-binding protein from grape (Vitis vinifera L.) seeds
Authors:L, Chenyan (1); Zhao, Guanghua (1)
Author affiliation:(1) College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; (2) State Key Laboratory of Space Medicine Fundamentals and Application, Chinese Astronaut Research and Training Center, Beijing, China
Corresponding author:Zhao, Guanghua
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:319-323
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Calcium is an essential nutrient required for critical biological functions such as nerve conduction, muscle contraction, mitosis, blood coagulation, and structural support of the skeleton. Dietary calcium intake is of general interest for human beings, particularly for infants and young children, when growth is accelerated. Milk and milk products as effective calcium supplements are generally accepted by human race with their high bioavailability. However, less consumption of milk in industrialized countries leads to inadequate calcium intake. Therefore, it is important to explore an alternate source for calcium supplement. On the other hand, dried grape seeds are likewise rich in lipids (22.07%), carbohydrates (12.51%) and proteins (11.94%) (w/w) and grape seeds as by-product during juice production can be an alternative source of protein. Meanwhile, this study demonstrates that grape seeds are rich in calcium ((5.62&plusmn;0.01) g/kg for embryonic cells and (6.32&plusmn; 0.01) g/kg for intact grape seeds), which was identified by ICP-AES. The calcium was mainly distributed in the stroma of the amyloplasts and around the starch granules, which was observed under TEM (Transmission Electron Microscope). Further study indicates that water-soluble protein from grape (Vitis vinifera L.) seeds (WSPG) contained two major components, one of which was 11S globulin-like protein mainly responsible for the binding of calcium in WSPG and the other was a novel protein (Protein A). The calcium contents of protein isolate from each step were identified by ICP-AES as well. When a traditional alkali extraction and acid precipitation method was used for isolation of WSPG, many binding calcium ions were lost. It is worth noting that the protein composition of grape seed protein obtained by both 30%-50% (NH<inf>4</inf>)<inf>2</inf>SO<inf>4</inf> sediment and the alkali extraction and acid precipitation method was nearly identical, which consisted of protein A and protein B at a ratio of 2 to 3, but the content of calcium in the grape seed protein by the ammonium sulfate sediment was approximately 3-fold larger than that by the traditional method, demonstrating that the ammonium sulfate sediment was a better way to isolate mineral-containing protein as compared to the traditional method. A high yield of calcium by the ammonium sulfate sediment could be derived from its mild condition, whereas acid and alkaline used in the alkali extraction and acid precipitation possibly inhibits the binding of calcium ions with grape seed protein. The following FT-IR (Fourier transform infrared spectroscopy) study showed that the prominent band of apo grape seed protein attributed to random coils turns (1 666 cm^-1) was shifted to lower wave number (1 660 cm^-1) with a marked decreased in intensity upon calcium binding with the protein and indicated that the binding of calcium to the protein stabilizes the secondary structure of WGSP by changing state of C=O. Moreover, the abundant amino acid residues were found in WGSP to be glutamic and aspartic acids, which accounted for about 26.7% and 9.0% of the total amino acid, respectively, and these amino acids might be beneficial for calcium binding. This study could provide a foundation for the preparation of mineral-containing protein in food industry. This method may have a potential use in food industry for isolation of mineral-containing protein from other sources. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Proteins
Controlled terms:Air pollution - Amino acids - Atomic emission spectroscopy - Biochemistry - Calcium - Extraction - Fourier transform infrared spectroscopy - Ions - Mineral industry - Minerals  - Precipitation (chemical) - Precipitation (meteorology) - Sediments - Separation - Sulfur compounds - Transmission electron microscopy
Uncontrolled terms:Ammonium sulfate precipitation - Biological functions - Calcium binding proteins - Essential nutrients - Industrialized countries - Secondary structures - Vitis vinifera - Water soluble protein
Classification code:443.3 Precipitation - 451 Air Pollution - 482.2 Minerals - 483 Soil Mechanics and Foundations - 501 Exploration and Prospecting - 549.2 Alkaline Earth Metals - 741.3 Optical Devices and Systems - 801 Chemistry - 801.2 Biochemistry - 802.3 Chemical Operations - 804.1 Organic Compounds
DOI:10.3969/j.issn.1002-6819.2015.02.044
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 30>

Accession number:20151000594671
Title:Vehicle rollover simulation analysis considering road excitation
Authors:Bao, Weining (1); Hu, Sanbao (2)
Author affiliation:(1) School of Electromechanical &amp; Architectural Engineering, Jianghan University, Wuhan, China; (2) Key Laboratory of Advanced Technology of Automotive Parts, Wuhan University of Technology, Wuhan, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:59-65
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Traditional researches on vehicle rollover mainly focused on untrip rollover when vehicle running on the plat road, and 3DOF (three degree of freedom) model including lateral translational motion, yaw rotational motion and roll rotational motion was used widely. Obviously, the 3DOF model does not consider the influence caused by road excitation. But SUV (Sport Utility Vehicle) and commercial vehicle always run on the rough road, and the vehicle rollover characteristic were influence by the road condition impacts. For exploring the influence of road irregularity on vehicle dynamical rollover characteristic, a combined vehicle model was proposed. The model include six degree of freedom such as lateral translational motion, vertical translational motion, yaw rotational motion, roll rotational motion of vehicular body and two vertical translational motion of tires. The calculation program was built in MATLAB/ Simulink, and the vehicle rollover characteristic response parameters were calculated by Simulink with FISHHOOK test. The right road profile was a sine wave road coupling B grade road, the left road profile was B grade. Then a multi-body dynamical vehilcle model was built in Adams software. And the Adams vehicle model was used to calculate the results under the same work conditions with Simulink model, the results through Simulink model were compared with the values in the simulation test data of Adams model. Through comparison of simulation results, the Simulink model was proved correct. Secondly, the influences on roll angle caused by road grade, vehicle velocity and steering angle velocity were investigated. The results of simulation analysis showed that the simulation results of combined model were more accurate than the data of 3DOF and 4DOF model, the combined model results can consistent with Adams model result. The road irregularity, vehicle speed, steering wheel rotation speed have some effects on the vehicle roll characteristic, the roll angle during the steady state region increases as the rise of road grade, and the value during transient state has not obvious change. Vehicle roll angle increases as the rise of vehicle speed. And only the roll angle during the transient state is susceptible to rotation speed of steering wheel, which presented an augment with the increase of rotation speed. Further, the reason using simulation test on vehicle rollover characteristic research and the application of combined rollover model were discussed. Because of extremely dangerous and high economic cost, the majority research institution and automotive factory use the simulation test instead of on road test for vehicle rollover analysis, and commonly method is constructing multi-body dynamical simulaton model by Adams or LMS. Virtual. LAB/Motion. Then, simulation test was carried out based on the Fishhook and J-Turn test procedure. The application of combined rollover model was closely tied with vehicle control technology, such as differential braking, semi-active/active suspension, active steering, integrated chassis control and so on. These control method needs a state estimation to detect the impending vehicle rollover. Obviously, the accuracy of estimator is important to the control effect. The combined model has more accurate calculation result for vehicle roll angle and roll angle velocity than traditional 3DOF and 4DOF model. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Automobile steering equipment
Controlled terms:Airships - Automobile bodies - Commercial vehicles - Computer simulation - Control system synthesis - Degrees of freedom (mechanics) - Fiber optic sensors - MATLAB - Models - Roads and streets  - Rotation - Rotational flow - Software testing - Speed - Steering - Transportation - Vehicles - Wheels
Uncontrolled terms:Accurate calculations - Integrated chassis controls - Research institutions - Road excitations - Rollover - Six degree-of-freedom - Sport utility vehicles - Three degree of freedoms
Classification code:406.2 Roads and Streets - 432 Highway Transportation - 601.2 Machine Components - 631.1 Fluid Flow, General - 652.5 Balloons and Gliders - 663.1 Heavy Duty Motor Vehicles - 663.2 Heavy Duty Motor Vehicle Components - 723.5 Computer Applications - 731.1 Control Systems - 732.2 Control Instrumentation - 902.1 Engineering Graphics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2015.02.009
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 31>

Accession number:20151000594696
Title:Improving methane production efficiency from biomass product gas via pressurized fluidized bed system
Authors:Feng, Fei (1); Shen, Laihong (1); Xiao, Jun (1); L, Xiao (1)
Author affiliation:(1) Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, China; (2) Department of Mechanical Technology, Nanjing College of Chemical Technology, Nanjing, China
Corresponding author:Shen, Laihong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:241-245
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Natural gas is one of the clean primary energy sources and high-quality chemical raw materials. Technology of methane production from biomass thermo-chemical gasification (biomass-to-SNG) is one of the most important pathways to produce synthetic natural gas (SNG) to substitute diminishing natural gas. In the biomass-to-SNG process, the biomass is first converted into product gas through biomass gasification. Then, the product gas full of CO and H<inf>2</inf> is synthesized into methane through the methanation processes after some proper cleaning and conditioning processes. Finally, the crude synthetic natural gas is upgraded with CO<inf>2</inf> removal and gas dehydration. In the whole biomass-to-SNG process, the methanation process of product gas is a key step. A pressurized fluidized bed methanation reactor system was designed and constructed, which is mainly composed of a main reactor and auxiliary equipments. An experimental study of methane production from product gas was carried out on this methantion reactor system with the commercial methanation catalyst as bed material. The Energy Dispersive Spectrometer analysis indicates that the methanation catalyst contains high nickel content and was squashed into small particles for the study. Then, the effects of methanation temperature, pressure, space velocity, and ratio of H<inf>2</inf> to CO on the performance indexes (i. e. methane formation rate and CO conversion rate) were investigated. The results show that methane is efficiently produced on this pressurized fluidized bed methanation reactor system and the typical methane formation rate is higher than 3.2 mol/(L&middot;h) while the CO conversion rate is more than 80%. Higher methanation temperature is favored to the methanation process and the methane formation rate and CO conversion rate achieve the maximum values at the methanation temperature about 350. However, when the methanation temperature is higher than 350, the methane formation rate and CO conversion rate decline slowly since the methanation reactions are exothermic reactions and high temperatures are thus unfavorable to the methanation reactions and may also cause the catalyst to deactivate because of carbon deposition and sintering of catalyst. The methanation process is also benefited from higher methanation pressure since the methanation reactions are volume-contraction reactions. The methane formation rate and CO conversion rate increase with the rise of methanation pressure, especially when the methanation pressure is higher than 0.3 MPa. The methanation process is heavily affected by the space velocity, too. With the increase of space velocity, the methane formation rate increases while the CO conversion rate declines accordingly. The ratio of H<inf>2</inf> to CO is another key influencing factor in the methanation process. With the rise of the ratio of H<inf>2</inf> to CO, the methane formation rate increases accordingly, while the CO conversion rate rises and reaches the highest values when the ratio is about 3 and then the CO conversion rate maintains a high value. In short, to achieve higher methane formation rate and CO conversion rate, suitable methanation temperature is about 350, space velocity is around 10 000 h^-1, the ratio of H<inf>2</inf> to CO is around 3, while the methanation pressure is 0.3 MPa, taking the biomass utilization scale and investment costs into account. These results may lay a solid foundation for further studies of biomass-to-SNG process &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:17
Main heading:Methanation
Controlled terms:Auxiliary equipment - Biogas - Biomass - Carbon dioxide - Catalysts - Fluidization - Fluidized beds - Gases - Gasification - Hydrogenation  - Investments - Methane - Methanol - Natural gas - Sintering - Spectrometers - Velocity
Uncontrolled terms:Chemical raw materials - Conditioning process - Energy dispersive spectrometers - Fluidized bed system - Key influencing factors - Primary energy source - Product gas - Synthetic natural gas
Classification code:522 Gas Fuels - 525.1 Energy Resources and Renewable Energy Issues - 801 Chemistry - 802 Chemical Apparatus and Plants; Unit Operations; Unit Processes - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 901 Engineering Profession - 911.2 Industrial Economics - 931.1 Mechanics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2015.02.034
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 32>

Accession number:20151000594670
Title:Influence of incident angle of swirler on performance of swirl meter
Authors:Cui, Baoling (1); L, Ziqiang (1); Chen, Desheng (1); Chen, Kun (1); Huang, Dunhui (2)
Author affiliation:(1) Provincial Key Laboratory of Fluid Transmission Technology, Zhejiang Sci-Tech University, Hangzhou, China; (2) Hangzhou Guanyi Fluid Technology Company Limited, Hangzhou, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:53-58
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to optimize and expand the measure range of the swirl meter with 150 mm diameter, the incident angle of swirler is investigated to improve the performance of swirl meter. The internal flow fields of the swirl meter with different swirler incident angles are numerically simulated using RNG k-&Epsilon; turbulence model based on CFD (computational fluid dynamics) technique. The pressure loss, instrument coefficient and the distribution of flow field are comparatively analyzed for the swirl meters. First, under the flow rates of 120, 300, 750, 1 200 and 2 100 m³/h, the numerical simulations and experiments are carried out to study the pressure loss characteristics and instrument coefficient of the swirl meter with 150 mm diameter when the incident angle of swirler is 57.5&deg;. The commercial software Gambit is used to obtain the numerical mesh, and the structured and unstructured grids are used for different regions which take both calculation speed and accuracy into consideration. In the process of calculation, FLUENT software is used for the numerical simulation, and the RNG k-&Epsilon; turbulence model is adopted considering its better prediction ability in complex unsteady flow condition; besides, the inlet boundary condition is set as velocity inlet, and the outlet boundary condition is set as outflow, which assumes the flow is fully developed. The medium of simulation is air and the density is 1.225 kg/m³; moreover, for the maximum velocity of air in this study is about 33 m/h (when flow rate is 2 100 m³/h) which is much less than Mach 0.3, therefore, the air is considered as incompressible fluid during the simulation. The experiment research is completed by sonic nozzle calibration device under a standard atmospheric pressure and the temperature of 24. The numerical results are in good agreement with the experimental ones, and therefore, the numerical method adopted in this paper is proved to be feasible for the research of swirl meter and can save lots of time in the future study. It is appropriate to use computational fluid dynamics method to investigate the influence of different incident angles (57.5&deg;, 55&deg; and 60&deg;) on the pressure loss and instrument coefficient for swirl meter, and the design of swirl meter could be more efficient than ever by using CFD technique. As a result, two more swirlers at the incident angle of 55&deg;and 60&deg; are calculated with the same numerical method and geometrical model except for the incident angle. By comparing the pressure loss, instrument coefficient and pressure distribution of three swirl meters, it is found that the larger incident angle is, the bigger pressure loss of swirl meter will be. It is also found that the change of incident angle has some influence on the instrument coefficient, and the larger incident angle is, the larger instrument coefficient will be. As larger incident angle brings stronger vortex, the smaller minimum flow value can therefore be measured by swirl meter. By analyzing the pressure contour distribution of three models, it is found that the pressure drops quickly at the swirler region and leads to part of pressure loss, the lowest pressure is at the center of vortex and the distribution is nonuniform at throat and diffuser region, while the pressure becomes steady at the end of deswirler. As a whole, the swirl meter with swirler incident angle of 55&deg; comes with the best performance. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:14
Main heading:Flowmeters
Controlled terms:Air - Atmospheric pressure - Boundary conditions - Computational fluid dynamics - Computer software - Flow fields - Flow rate - Fluid dynamics - Inlet flow - Losses  - Numerical analysis - Numerical methods - Numerical models - Pressure - Turbulence models - Vortex flow
Uncontrolled terms:CFD (computational fluid dynamics) - Commercial software - Computational fluid dynamics methods - Experiment research - Geometrical modeling - Incompressible fluid - Internal flow field - Outlet boundary condition
Classification code:443.1 Atmospheric Properties - 631 Fluid Flow - 631.1 Fluid Flow, General - 723 Computer Software, Data Handling and Applications - 804 Chemical Products Generally - 911.2 Industrial Economics - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics - 943.1 Mechanical Instruments
DOI:10.3969/j.issn.1002-6819.2015.02.008
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 33>

Accession number:20151000594695
Title:Parameter optimization of hydrogen production by anaerobic fermentation with corn straw
Authors:Luo, Juan (1); Tian, Yishui (1); Song, Chengjun (1); Qi, Yue (1); Wang, Ji (1); Zhao, Lixin (1)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agricultural Residues, Ministry of Agriculture, Beijing, China
Corresponding author:Zhao, Lixin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:235-240
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Energy crisis and environmental pollution make it necessary to find an alternative energy source that is environmentally friendly and renewable. Hydrogen is generally considered as a clean and renewable energy. There are many hydrogen production methods in physical, chemical and biological ways. Hydrogen production from agricultural waste by anaerobic fermentation can not only solve the disposal of agricultural waste, but also obtain clean and efficient energy. This approach achieves the reduction of agricultural waste and resource's harmless utilization with easy operation and low cost, and it is considered to be one of the best and most promising methods of hydrogen production. In this paper, according to the characteristics of corn straw, i. e., compact structure and being difficult to directly degrade, the effect of pretreatment methods on the hydrogen production from corn straw was studied. In the first place, the corn straw was soaked in hydrochloric acid (HCl) solution of 0.2%, 0.4%, 0.6% and 0.8% at room temperature for 24 h, and then the hydrogen production experiments were taken under the warm fermentation condition (38) and the anaerobic activated sludge was used as the inoculum. The results showed that the cumulative hydrogen production and hydrogen production rate of corn straw increased firstly and then decreased with the increase of HCl concentration; 0.6% HCl pretreatment had the best performance: cumulative hydrogen production per unit was 87.90 mL/g, 155% more than the corn straw without pretreatment, and the hydrogen production rate was 3.05 mL/(g &middot; h). Furthermore, different concentrations of HCl had little effect on the hydrogen concentration of gas produced by corn straw fermentation. Next, in the condition of (38&plusmn;2), single factor anaerobic fermentation test and orthogonal anaerobic fermentation test were carried out to investigate the effects of straw particle size, substrate concentration and initial pH value on hydrogen production process, using corn straw pretreated with 0.6% HCl as raw material. The results demonstrated that the smaller the corn straw particle size was, the more the amount of generated hydrogen was produced; a modest increase in substrate concentration could increase the hydrogen production; suitable initial pH value of fermentation was in favor of the growth and reproduction of hydrogen- producing bacteria; optimized parameters of the process were considered to be: Corn straw particle size of 150 &mu;m, substrate concentration of 15 g/L and initial pH value of 7, and the cumulative hydrogen yield was 112. 87 mL/g under the optimized parameters of the process. The main limiting factor for hydrogen production by anaerobic fermentation was corn straw particle size, followed by substrate concentration, and initial pH value of fermentation played less important role in the hydrogen production performance of corn stalk. This paper provided the reference and instruction for hydrogen production with corn straw and other agricultural organic wastes. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Hydrogen production
Controlled terms:Agricultural wastes - Agriculture - Energy policy - Fermentation - Hydrochloric acid - Optimization - Particle size - pH - Photobiological hydrogen production - Straw  - Substrates - Waste disposal
Uncontrolled terms:Alternative energy source - Environmental pollutions - Hydrogen producing bacteria - Hydrogen production method - Hydrogen production performance - Hydrogen production process - Hydrogen production rate - Substrate concentrations
Classification code:452.4 Industrial Wastes Treatment and Disposal - 461 Bioengineering and Biology - 461.8 Biotechnology - 522 Gas Fuels - 525.6 Energy Policy - 801 Chemistry - 803 Chemical Agents and Basic Industrial Chemicals - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 921.5 Optimization Techniques - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2015.02.033
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 34>

Accession number:20151000594664
Title:Analysis on characteristics and influential factors of grain yield fluctuation in China based on empirical mode decomposition
Authors:Liu, Zhong (1); Huang, Feng (1); Li, Baoguo (1)
Author affiliation:(1) Key Laboratory of Land Conservation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
Corresponding author:Li, Baoguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:7-13
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:There is an important significance for China's food security to explore the fluctuation characteristics and influence factors of grain output per sown area (hereinafter referred to as grain yield), and then to take corresponding measures to stabilize and improve the grain yield level. In this paper, the time-series yields of grain and main crops (rice, wheat and maize) from 1978 to 2012 in China were decomposed using empirical mode decomposition (EMD) method, and then multi-scale fluctuation characteristics and its main influence factors of grain yield were analyzed. The results showed: 1) the time series of grain yield could be decomposed into two intrinsic mode functions (IMF) and a residual item. The residual item denotes a slow and steady rising trend in grain yield which is dominated by the technological progress. The IMF1 and IMF2 represent a short-term fluctuation in about 4-yr cycle and a medium-term fluctuation in about 9-yr cycle, which respectively reflect the influence of meteorological and policy factors on grain yields according to the analysis of grain production system. The variance contribution rate of the residual item was greatly larger than that of the IMFs, which means the upward trend in grain yield was more pronounced than fluctuations. 2) Fluctuation of trend yield of grain was distinct before and after 1997: fast rise with an average annual growth rate of 2.28% before 1997 and slow rise with an average annual growth rate of only 0.69% after 1997. The change of trend yield was similar between rice and grain, but the former seemed to rise more slowly after 1997. For wheat and maize, the trend yield was still increased obviously although the growing rate had been significantly slowing down after 1997.3) The IMF2 included 3 complete cycles (1979-1988, 1989-1993, and 1994-2002) and an ongoing cycle (2003 to present) which coincided with adjustment of Chinese agricultural policy. In general, the impact of policy and market factors on fluctuation of grain yield is greater than that of climate factors, but responses of different crops to different policies varied: policies on land, tax, subsidies, incentives and insurance had positive or negative effect on medium-term fluctuation of main crops synchronously, but price policies was not the case for main crops especially for maize. Medium-term fluctuation rate of grain yield was 2.94%, and that of wheat was 3.83%, significantly higher than that of maize (2.38%) and rice (2.18%). It suggested wheat's vulnerability to policies. 4) The short-term fluctuation rate of grain yield was 1.80%, and that of maize, wheat, and rice was 3.38%, 2.55%, and 1.06%, respectively. It indicated that Chinese grain production system had a strong ability to resist against meteorological disaster. The disaster prevention capabilities of different crops was not the same, and maize was more easily affected by meteorological disasters than wheat and rice. 5) Both considering the short-term and medium-term fluctuation rates, rice was the most stable crop in yield. The main problem of rice production was the slow growth of yield trend after 1998, while maize was strongly influenced by meteorological disaster, and fluctuation of wheat was significantly affected by policy cycles. At present, China's agriculture production has entered a new development stage. It is necessary to adjust the agricultural policy in order to adapt to the new situation. The results here can help with decision-making and adjustment of agricultural policies. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Grain (agricultural product)
Controlled terms:Agriculture - Climate change - Crops - Decision making - Disaster prevention - Disasters - Factor analysis - Food supply - Grain growth - Signal processing  - Technology - Time series
Uncontrolled terms:Average annual growth rates - China - EMD - Empirical Mode Decomposition - Fluctuation - Fluctuation characteristics - Intrinsic Mode functions - Per unit
Classification code:404.2 Civil Defense - 451 Air Pollution - 716.1 Information Theory and Signal Processing - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 901 Engineering Profession - 912.2 Management - 914.1 Accidents and Accident Prevention - 922.2 Mathematical Statistics - 933.1.2 Crystal Growth
DOI:10.3969/j.issn.1002-6819.2015.02.002
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 35>

Accession number:20151000594691
Title:Distribution and pollution assessment of heavy metals in surface sediments of aquaculture area in Yueqing bay
Authors:Wang, Chuanhua (1); Cui, Lingzhou (1); Wang, Dong (1)
Author affiliation:(1) College of Life and Environmental Sciences, Wenzhou University, Wenzhou, China
Corresponding author:Cui, Lingzhou
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:204-210
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Yueqing bay is one of the key sea farming areas in Zhejiang province. Because of the rapid development of coastal economy, large quantities of industrial and agricultural wastewater and domestic sewage have been discharged into Yueqing bay. The environmental reports by the local government state that water quality of Yueqing bay has degraded since 1980s, which has caused a serious threat to the sustainable development of mariculture and coastal ecology. Sediments are sinks of various pollutants and inversely affect water quality. But there are lacks in understanding on heavy metals and other pollutants in sediments. In order to understand the current situation of environment pollution and carry out heavy metal pollution assessment to providing reference for pollution remediation, we studied the pollution of heavy metals including copper (Cu), cadmium (Cd), chromium (Cr), lead (Pb), zinc (Zn), mercury (Hg) and arsenic (As) in surface sediment of mariculture area in Yueqing bay. Based on field investigation, 10 samples of surface sediment were collected in typical aquaculture area. By using atomic fluorescence spectrometer (AFS-930) and atomic absorption spectrometer (AA240Fs), heavy metal contents of the surface sediment samples were determined. According to standard value of the first class in China Marine Sediment Quality Standard (GB18668-2002), single factor index method, nemerow comprehensive pollution index method and sediment quality guideline method were used to evaluate pollution degree of individual heavy metal, integrated pollution effects of several heavy metals and potential biological toxicity risk of heavy metal. The results showed that contents of Cu, Cr, Pb and Zn in sampling point S1 were the highest, which were 69.0, 74.0, 36.7 and 190.0 mg/kg respectively. The highest content values of Cd, As and Hg were 0.30, 26.6 and 0.82 mg/kg from sampling points S9 and S5 respectively. Variation coefficient of Hg content was 0.77, which was the highest and showed most significant difference of spatial distribution. Pollution indexes of Cd, Cr and Pb of all the sampling points were less than 1, and the mean values were 0.40, 0.64 and 0.50 respectively, indicating that surface sediment of aquaculture area in Yueqing bay was not polluted and contents of Cd, Cr and Pb met the quality requirements of surface sediment. Pollution index of Cu in each sampling point was more than 1, and the average value was 1.32, which showed that surface sediment of aquaculture area in Yueqing bay was widely polluted by Cu. Pollution index of Hg reached 4.08, which demonstrated that surface sediment of some aquaculture areas in Yueqing bay was seriously polluted by Hg. Among 10 sampling points, nemero comprehensive pollution index of heavy metal only in sampling point S8 was less than 1, being in safety level. Nemero comprehensive pollution indexes in S1 and other 7 sampling points were all above 1, whose pollution levels reached mild. Nemero comprehensive pollution index in sampling point S9 was more than 3, and the pollution level reached severe. The evaluation results of nemero comprehensive pollution index method showed that most of the surface sediment of aquaculture area in Yueqing Bay was slightly polluted by heavy metals. The harmful biological toxic effects of Cu and As may occasionally occur in all of aquaculture areas in Yueqing bay, and harmful biological toxic effects of Hg may frequently happen in some aquaculture areas. It is urgent to carry out heavy metal pollution remediation of Cu and Hg in surface sediment of aquaculture area in Yueqing bay. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:22
Main heading:Copper
Controlled terms:Aquaculture - Cadmium - Chromium - Ecology - Heavy metals - Industrial poisons - Lead - Marine biology - Marine pollution - Mercury (metal)  - Metals - Pollution - Quality control - Sedimentology - Sediments - Sewage - Spectrometers - Submarine geology - Surficial sediments - Sustainable development  - Water pollution - Water quality - Zinc
Uncontrolled terms:Agricultural wastewater - Atomic absorption spectrometers - Atomic fluorescence spectrometers - Heavy metal pollution - Pollution of heavy metals - Sediment quality guidelines - Surface sediments - Yueqing bay
Classification code:453 Water Pollution - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 461.9 Biology - 481.1 Geology - 483 Soil Mechanics and Foundations - 531 Metallurgy and Metallography - 543.1 Chromium and Alloys - 544.1 Copper - 546.1 Lead and Alloys - 546.3 Zinc and Alloys - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 801 Chemistry - 804.1 Organic Compounds - 821.3 Agricultural Methods - 911.2 Industrial Economics - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2015.02.029
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 36>

Accession number:20151000594665
Title:Automatic positioning for picking point of grape picking robot in natural environment
Authors:Luo, Lufeng (1); Zou, Xiangjun (1); Xiong, Juntao (1); Zhang, Yu (2); Peng, Hongxing (1); Lin, Guichao (1)
Author affiliation:(1) Key Lab of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou, China; (2) College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin, China
Corresponding author:Zou, Xiangjun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:14-21
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In wine brewing process, the most time-consuming and laborious is grape picking. In order to improve the target location accuracy and work efficiency of grape-picking robot, reduce the mechanical damage that was caused by improper positioning of grape picking point, in view of some influence factors such as the various colors of grape stem and the irregular contour of grape, which make picking robot hard to locate picking point accurately, a new method of picking point location based on the improved image segmentation with clustering and the constraint by minimum distance between dot and line was put forward in this paper. Because the picking time was often chosen in sunny or cloudy day, 300 images of summer black grape were collected using D5200 Nikon digital camera in sunny or cloudy days, which were taken as test materials; the shooting distance between camera and grape cluster was about 80 cm, and the sizes of these images were zoomed to 800&times;600 pixels. Firstly, the color space of gathered images was analyzed and the component H of HSI color space that can mostly highlight summer black grape was found. The H component of images was extracted and median filtering was performed on these images. Grape fruit image was segmented by using fuzzy clustering that was improved by artificial swarm. Solving the minimum value of fuzzy objective function of FCM clustering algorithm was transformed into solving the maximum value of artificial swarm fitness function by improving the fitness function of the artificial swarm optimization algorithm. Then, the segmented image was processed with morphological denoising, the maximum connected region was extracted, and the regional barycenter, extreme point and external rectangular were calculated. Secondly, the interest region of picking point was determined according to the barycentric coordinates and edge information of grape image. Taking 0.6 times of the length of the external rectangular as the length of region of interest (ROI), and taking 0.5 times of the vertical distance between hightest point of profile and barycenter as the height of ROI, the image of ROI was preprocessed with bilateral filter, and its edge image was extracted through gradient edge detection to obtain binary edge. And Hoffe's straight line testing of cumulative probability was taken in this ROI, maximum votes were taken to 18, all the detected endpoints of line were recorded, and linear equation was established by the two endpoints; the distances between all the detected straight lines and barycenter were solved by using the method of shortest distance from point to straight line, the straight line whose distance to barycenter was the smallest was chosen as the line where picking point was located, and the midpoint's coordinates of elected line was used as picking point. Finally, in order to verify the method proposed in this paper, a classification experiment based on 300 images of summer black grape gathered under direct sunlight, backlighting in sunny day and overcast light was carried out, using Opencv2.3.1 and Visual C++ as the algorithm programming platform. Through the statistical analysis of 300 testing images, it was discovered that the ratio of location error within 12 pixels between obtained picking point using this paper's method and optimal picking point by hand could reach up to 88.33%, and these obtained points were located in the stems of grapes, which could meet the requirements of picking robot's location. When grape clusters were located in both sides of image frame and their covered parts were less than one-third, and meanwhile the stem located in the ROI had not been covered mostly, the method could be well to solve the position of grape picking point. The average elapsed time of picking point's positioning in natural conditions was 0.3467 seconds. The test results of location error and elapsed time show that the method proposed in this paper can meet the demand of picking robot on picking point's positioning and is a new solution method of picking point for grape-picking robot. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Image segmentation
Controlled terms:Algorithms - C++ (programming language) - Clustering algorithms - Color - Edge detection - Image analysis - Image enhancement - Image processing - Location - Median filters  - Optimization - Pixels - Robots
Uncontrolled terms:Barycentric coordinates - Cumulative probabilities - Fuzzy objective function - Grape - Mechanical damages - Natural environments - Picking point - Swarm optimization algorithms
Classification code:703.2 Electric Filters - 721 Computer Circuits and Logic Elements - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.5 Robotics - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 921 Mathematics - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2015.02.003
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 37>

Accession number:20151000594680
Title:Regularity of individual rainfall soil erosion in bare slope land of red soil
Authors:Qin, Wei (1); Zuo, Changqing (1); Yan, Qinghong (3); Wang, Zhaoyan (1); Du, Pengfei (4); Yan, Nan (1)
Author affiliation:(1) State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China; (2) Research Center on Soil and Water Conservation of the Ministry of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing, China; (3) College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China; (4) International Resesearch and Traning Center on Erosion and Sedimentation, China Institute of Water Resources and Hydropower Research, Beijing, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:124-132
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:It is valuable for soil and water loss control and its benefits evaluation to understand the relationship between rainfall and soil erosion process. In order to make clear what rainfall type accelerates soil erosion on slopes of red soil in south part of China, and to ascertain the response of soil erosion intensity to rainfall characteristic under various rainfall types, data of meteorology and hydrology of 134 individual rainfalls in experimental plots on bare slopes of red soil in north part of Jiangxi Province were collected and analyzed. The amount, duration and intensity of rainfall were selected as the characteristic indices for erosive rainfall. Two methods including quick clustering and discriminant clustering were introduced to classify the rainfall types resulting in soil erosion. Pearson correlation analysis was then used to find the main indices that contributed the most to the slope soil erosion. Further, Mann-Kendall test and the other statistics method were used to determine the relationship between soil erosion intensity and the rainfall characteristic indices under different rainfall types. The results showed that the erosive rainfall in north part of Jiangxi Province could be classified into three types: type A (high frequency, short duration, minor amount of rainfall, and strong rainfall intensity), type B (medium frequency, medium duration, medium amount of rainfall, and medium rainfall intensity) and type C (low frequency, long duration, great amount of rainfall, and low rainfall intensity). Soil erosion on bare slopes of red soil in south part of China was mainly caused by type A. During the process of individual rainfall, soil erosion on bare slopes of red soil was mainly affected by the joint influences of rainfall intensity and amount, the former resulted in erosion change directly through the closest index - maximum 30 min rainfall intensity, the latter had indirectly effects by changing the former. With the increase of maximum 30 min rainfall intensity, soil erosion occurred remarkably different properties at rainfall intensity of 15 mm/h. The soil erosion increased relatively slowly before that critical point but increased rapidly after the point. Generally, soil erosion intensity increased with the amount of rainfall, whereas the erosion ability of different rainfall types varied, which followed the pattern: type A &gt; type B &gt; type C. Excluding the influence of rainfall happened in earlier time, the erosion intensity on bare slopes of red soil had a significant power function relationship with both the maximum 30 min rainfall intensity and the rainfall amount, however, the exponents and coefficients were different when different rainfall types occurred. It has been proven that this model is not only best for intensive rainfall with short duration, but also runs very well while applying to erosion prediction for all three rainfall types - the values of multiple correlation coefficient and the Nash-Suttclife efficiency coefficient were both above 0.9, and the average relative error was less than 25%. In conclusion, this study is very helpful both in exploring further red soil erosion laws and in process-based prediction model establishment. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Rain
Controlled terms:Correlation methods - Erosion - Precipitation (chemical) - Precipitation (meteorology) - Risk management - Soil conservation - Soil testing - Soils - Storms
Uncontrolled terms:Average relative error - Characteristic indices - Efficiency coefficient - Multiple correlation coefficients - Pearson correlation analysis - Rainfall characteristics - Rainstorm types - Red soils
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 443.3 Precipitation - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 802.3 Chemical Operations - 922.1 Probability Theory - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.02.018
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 38>

Accession number:20151000594667
Title:Design and experiment on vacuum pickup hand for banding tissue culture seedlings
Authors:Li, Kai (1); Gu, Song (1); Yang, Yanli (3); Chu, Qi (1); Zhang, Qing (1); Peng, Yuping (1); Feng, Jie (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou, China; (2) Key Laboratory of Key Technology on Agricultural Machine and Equipment, South China Agricultural University, Ministry of Education, Guangzhou, China; (3) Guangzhou Sky Mechanical &amp; Electrical Technology Co., Ltd., Guangzhou, China
Corresponding author:Gu, Song
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:29-36
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:At present, dimension-positioning method is adopted as the main method for grasping tissue culture seedlings in tissue culture transplanting equipments. But the majority of gripper structure based on dimension-positioning is complex, which causes that the precision of the operation can not be improved. Meanwhile, young tissue culture seedlings will certain be damaged by the gripper in the process of clipping, which affects the survival rate of the transplanted tissue culture seedlings. To solve such problems, this study designed a force-positioning pickup system based on vacuum adsorption, which can transplant banding tissue culture seedlings. The pickup system for tissue culture seedlings mainly consists of three parts, including vacuum production part, negative pressure detection part and the suction nozzle part. The suction nozzle part is the key part, which decides the holding effect of tissue culture seedlings. The core of suction nozzle is inner soft tube made of silicone rubber with a metal shaping pipe sleeved outside. To increasing the adsorption area, the suction nozzle lip is shaped as oblong. In this paper, design and experiments are both mainly focused on the structure and parameter of suction nozzle. The process that suction nozzle picks up a tissue culture seedling can be divided into two phases: adsorption phase and holding phase. In adsorption phase, negative pressure flow field in the suction nozzle, which is generated by the vacuum generator, will help the seedling overcome its gravity, so that the seedling can be absorbed and adhered to the suction nozzle lip closely. In holding phase, the suction nozzle lip and the stem of tissue culture seedling joint closely, and a vacuum cavity emerges with less leakage in the suction nozzle, then the vacuum cavity generates the force for holding the tissue culture seedling. In adsorption phase, there are two schemes about negative pressure inner cavity of suction nozzle, and they are deformed cavity and parallel cavity. To get the average velocity of flow field near suction nozzle lip, simulation analysis have been carried out based on each of the two cavity with CFD (computational fluid dynamic) software in adsorption phase. The corresponding verification test also have been done, and the results supported that deformed cavity will be used in the pickup hand system because the suction nozzle using deformed cavity can produce flow field with higher velocity, and hold tissue culture seedling more steadily. In holding phase, a series of orthogonal experiment, single factor experiment and interaction experiment were carried out, to test the impact factor about tissue culture seedling holding strength, including thickness of suction nozzle tube, diameter of suction nozzle tube, radius of oblong suction nozzle lip and height of suction nozzle lip. The experiments results show that the optimum parameters for the tissue culture seedlings of suction nozzle are 0.5 mm thickness of suction nozzle tube, 6 mm diameter of suction nozzle tube, 0.7 mm radius of oblong suction nozzle lip and 1.5 mm height of oblong suction nozzle lip in experiments. With these optimum impact factors, suction nozzle can hold banding tissue culture seedlings steadily whose diameters range from 1.2 to 2 mm. It is noteworthy that overall success rate of negative pressure pickup system for banding tissue culture seedling can reach up to 98%, which successfully meets the requirements of insertion in next operation for transplantation. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:21
Main heading:Tissue engineering
Controlled terms:Adsorption - Computational fluid dynamics - Computer software - Design - Flow fields - Fluid dynamics - Grippers - Nozzle design - Nozzles - Pickups  - Robotic arms - Rocket nozzles - Silicones - Tissue - Tissue culture - Tubes (components) - Vacuum technology
Uncontrolled terms:Negative pressures - Orthogonal experiment - Positioning methods - Simulation - Simulation analysis - Single-factor experiments - Suction nozzles - Vacuum generators
Classification code:408 Structural Design - 461.1 Biomedical Engineering - 461.2 Biological Materials and Tissue Engineering - 616.1 Heat Exchange Equipment and Components - 631 Fluid Flow - 633 Vacuum Technology - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.5 Robotics - 752.3.1 Sound Reproduction Equipment - 802.3 Chemical Operations - 816 Plastics and Other Polymers: Processing and Machinery - 817 Plastics and Other Polymers: Products and Applications
DOI:10.3969/j.issn.1002-6819.2015.02.005
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 39>

Accession number:20151000594669
Title:Development and application of sun-tracking control system for parabolic trough solar collector
Authors:Wang, Jinping (1); Wang, Jun (1); Feng, Wei (2); Wang, Dengwen (3); Zhang, Yaoming (1)
Author affiliation:(1) Solar Energy Technology Research Center, College of Energy &amp; Environment Engineering, Southeast University, Nanjing, China; (2) Solar Energy Technology Co., Ltd., NARI Group Company, Nanjing, China; (3) NangJin Paruote Solar Energy Co., Ltd., Nanjing, China
Corresponding author:Wang, Jun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:45-52
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Heat transfer fluid is heated by sun rays through the solar concentrator, then used as a heat source for a conventional power plant. A wide range of concentrating technologies has existed; the most developed are parabolic trough collector (PTC), linear fresnel reflector system (LF), power tower, and dish/engine system (DE). Parabolic trough collector is considered as one of the most mature applications of solar energy in these four technologies, which makes it worth developing. Sun-tracking system plays an important role in the development of solar energy applications, especially for the high solar concentration systems that directly convert the solar energy into thermal or electrical energy. High accuracy of sun-tracking is required to ensure that the solar collector is capable of harnessing the maximum solar energy throughout the day. Compared to fixed systems, power output of single-axis and dual-axis tracking systems can increase by 25% and 41% respectively under the same condition. It is clear that an accurate sun-tracking control system can make solar collectors receive more solar radiation energy to improve the solar energy utilization. A good sun-tracking system must be reliable and able to track the sun at the right angle even in the periods of cloud cover. Although the tracking system is more complex and costs higher than the fixed system, increasing the annual output power can reduce cost effectively. As for photoelectric tracking mode, a sun position sensor is used to provide feedback signals to judge where the sun is, but they don't work on cloudy days because of the lower sensitivity. The stability of the solar tracking system is a key factor to obtain the maximum sunlight from parabolic trough collector. In order to improve tracking stability and accuracy of the parabolic trough collector sun-tracking control system, this paper chose the more reliable hydraulic drive mechanism to match the system and mainly focused on the design of sun-tracking control system and analysis of operational data from the parabolic trough collector sun-tracking system. Based on the existed working platform of parabolic trough collector system with a length of 50 meters, this paper developed a sun-tracking control system for parabolic trough solar collector. Based on programmable logic controller (PLC), active control mode on the trajectory of the sun was adopted, which could calculate the rotation angle of the parabolic trough solar collector and control commands to drive the hydraulic cylinder to achieve real-time tracking of the sun. The system's basic operating principle, design of sun-tracking, rotation angle algorithm of parabolic trough solar collector and PLC's programs have been analyzed. Experiments were conducted in the 4 typical dates (March 20, June 21, September 23, and December 22, in 2013). The analytical result showed that sun-tracking errors of parabolic trough solar collector were nearly 0.5&deg;. Compared to more accurate SPA (solar position algorithm) algorithm, calculation error of algorithm to calculate the position of the sun was within 0.12&deg;. The maximum error of intermittent operation tracking mode was within 0.398&deg;. The maximum operating speed of parabolic trough collector in the year appeared at noon on the winter solstice, the maximum operating speed was 0.398&deg;/min, and transmission error of an angle sensor was at 0.044&deg; or less. This study may provide the theoretical basis for mechanical transmission design of parabolic trough collector. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:System stability
Controlled terms:Algorithms - Computer systems - Control systems - Controllers - Design - Digital storage - Energy utilization - Heat transfer - Hydraulic drives - Navigation  - Programmable logic controllers - Programmed control systems - Solar collectors - Solar energy - Sun - Surface discharges - Tracking (position)
Uncontrolled terms:Concentrating solar power - Conventional power plants - Development and applications - Linear Fresnel reflector system - Parabolic trough collectors - Parabolic trough solar collectors - Programmable logic controllers (PLC) - Solar energy applications
Classification code:408 Structural Design - 525.3 Energy Utilization - 632.2 Hydraulic Equipment and Machinery - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 701.1 Electricity: Basic Concepts and Phenomena - 716.2 Radar Systems and Equipment - 716.3 Radio Systems and Equipment - 722 Computer Systems and Equipment - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 732.1 Control Equipment - 921 Mathematics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.02.007
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 40>

Accession number:20151000594675
Title:Simulation on water-absorption characteristic curve of infiltrating irrigation materials through Laplace-transform
Authors:Wang, Xiaojian (1); Zhang, Zengzhi (1); Mao, Yijian (2)
Author affiliation:(1) Research Institute of Ecological and Functional Materials, School of Mechanical Electronic and Information Engineering, China University of Mining and Technology (Beijing), Beijing, China; (2) Institute of Automation, Chinese Academy of Science, Beijing, China
Corresponding author:Zhang, Zengzhi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:87-93
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Infiltrating irrigation technology is an effective water-saving irrigation technology. As a new irrigation methods, it is getting a lot of attention. A kind of infiltrating irrigation material composed of montmorillonite (MMT) and polyacrylamide (PAM) developed recently has showed good self-adjustment property for soil moisture, and its water-absorption performance can be used to evaluate the sensitive degree that material responses to the external environment. This study aimed to simulating the water-absorption performance curve using the Laplace-transform method, which transformed a problem of solving differential equations into a problem of solving algebraic equation. Meanwhile, the model had also been used to explore the numerical relationship between water-absorbing capacity and material components. PAM and sodium montmorillonite (Na-MMT) was used as experimental material, circular material cube (4 g for each, 10 mm in height, 5 mm in radius) was for samples. Ten groups testing components of composite materials were designed including the mass proportions of MMT:PAM of 2.5:1, 5:1, 7.5:1, 10:1, 12.5:1, 15:1, 17.5:1, 20:1, 22.5:1, and 25:1. The samples made of the ratios were carried out the first and secondary water absorption performance test. In addition, another six groups with different proportions of composite materials (MMT:PAM 4:1, 14:1, 24:1, 40:1, 50:1, 60:1) were carried out the first water absorption test to verify the model. The water absorbing performance curve of composite was simulated as followed:1) Describing the curves of water-absorption rate with algebraic equation rather than differential equation, which was to calculate the transfer function depending on the Laplace limit theorem; 2) Coding the equation in M file editor of MATLAB software; 3) Inputting the adjusted experimental values of water-absorption rate in the Matlab. Then, the system's transfer function was identified by the step response curve, and parameters of model were automatically formed, thereby the transfer function coefficients of water-absorption curves of samples during the first and second water-asborption test were obtained. Then, the water-absorption curves were simulated with the obtained parameters. The results showed that:the relative error between the simulated and measured water-absorption rate were 0.04%-7.17% and root mean square error (RMSE) was &lt;0.0717, indicating that the water-absorption rate curves characterized by using Laplace transform is effective and accurate. Quantitative relationship between transfer function coefficient indicating the water absorbing capacity of material and material components followed exponential function. The RMSE between simulated transfer function coefficient values with the exponential function and the measured one was less than 0.5. In the validation test, the maximum relative error between the simulated and measured transfer function coefficient values was 4.01%. It suggested the reliability of the exponential function used for describing the relationship between water-absorption capacity of the compound material and its ratios. This study is valuble for design of infiltration irrigation materials and researchers on the water conductivity features of infiltration irrigation materials. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:20
Main heading:Water absorption
Controlled terms:Algebra - Clay minerals - Composite materials - Differential equations - Driers (materials) - Exponential functions - Infiltration - Irrigation - Laplace transforms - Materials  - Materials testing - MATLAB - Mean square error - Sodium - Soil moisture - Soil testing - Soils - Transfer functions - Water conservation
Uncontrolled terms:Absorption characteristics - Absorption performance - Experimental materials - Laplace transform method - Maximum relative errors - Root mean square errors - Water absorption capacity - Water-saving irrigation
Classification code:444 Water Resources - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 731.1 Control Systems - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 821.3 Agricultural Methods - 921 Mathematics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2015.02.013
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 41>

Accession number:20151000594684
Title:Comparison and optimization of pig mass estimation models based on machine vision
Authors:Li, Zhuo (1); Mao, Taotao (1); Liu, Tonghai (2); Teng, Guanghui (1)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, China Agricultural University, Beijing, China; (2) Department of Computer Science and Information Engineering, Tianjin Agricultural University, Tianjin, China
Corresponding author:Teng, Guanghui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:155-161
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pig's weight is an important index for farmers to monitor pig's growth performance and health. Traditional weighting brings lots of stress to animals and stockmen due to manual operation. Pig weighting based on machine vision is a non-intrusive, fast and precise approach, for it can free the farmer from heavy operational labor. The weighting system precision is assured by the estimation model. A lot of estimation models are addressed in pig weighting based on machine vision by researchers and engineers. Both independent variables and modeling approaches would influence the accuracy of estimated weight. In present work, comparison and optimization of the models were conducted, and the best model was validated in the real farm. In the first experiment, four growing pigs were raised from 30 to 124 kg. The feed was supplied ad libitum, and the lighting was in a 12/12 h light/dark cycle. A machine vision system was assembled and installed with two parallel cameras, an RFID (radio frequency identification devices) reader and a PC for capturing live images of pigs automatically. Using the assembled system, the pigs' back areas were measured. The head and tail of pig in each picture was cut off for pig's back area calculation. Five indexes of pig body (body length, width, height, hip width, and hip height) were measured manually every day. Linear regression, power regression, quadratic regression, principal component regression and RBF (radial basis function) artificial neural network were used to establish estimation models using the 79 sets of data. Those models were compared using the remaining 97 sets of data. The second experiment was carried out in the real farm to validate the favorable model. Five body indexes of 24 adult pigs were measured three times manually. The results of experiment station showed that all the reestablished models were suitable for pig weight estimation with varied accuracies. Linear regression model based on body sizes was the best one with a correlation coefficient (R²) of 0.996, while the linear regression model of hip height had the least correlation. Principal component analysis was used to solve problem of collinearity among body sizes. Nonlinear regression was used to fit pig mass increasing tendency. The power regression model of the principal component fitted the increase of pig weight best and had the highest correlation coefficient (R²) of 0.994. The average relative error of estimation weights was 2.02% compared with the 97 sets of experiment data. The correlation coefficient (R²) and relative estimation error of individual pig were 0.970 and 2.26% respectively, better than the model using back pixel area. Furthermore, the obtained average absolute error was 2.08 kg which was less than that of the model combining area and height, which was 4.6 kg. The established estimation model of pig weight using five body indexes contained more three-dimensional information of the pig body than the model using only area and the model combining area and height. Through the model comparison using the data of experimental station and the validation in the real farm, it is proved that the power regression model of principal component is the desired one for pig weight estimation using machine vision technology. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Mammals
Controlled terms:Agriculture - Animals - Anthropometry - Computer vision - Estimation - Image processing - Linear regression - Models - Neural networks - Principal component analysis  - Radial basis function networks - Radio frequency identification (RFID) - Regression analysis
Uncontrolled terms:Estimating mass - Linear regression models - Machine vision technologies - Pig - Principal component regression - Radio frequency identification devices - RBF(radial basis function) - Three-dimensional information
Classification code:461.3 Biomechanics, Bionics and Biomimetics - 723.4 Artificial Intelligence - 723.5 Computer Applications - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.2 Vision - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.02.022
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 42>

Accession number:20151000594702
Title:Balanced yield increasing potential of grain and its spatial differentiation in Huang-Huai-Hai Plain
Authors:Chen, Li (1); Hao, Jinmin (1); Ai, Dong (1); Zhu, Chuanmin (1); Li, Mu (1); Yuan, Lingbo (1)
Author affiliation:(1) College of Resources Environmental Sciences, China Agricultural University, Beijing, China; (2) Key Laboratory for Agricultural Land Quality Monitoring and Control, The Ministry of Land and Resources, Beijing, China; (3) College of Geosciences, East China Institute of Technology, Nanchang, China
Corresponding author:Hao, Jinmin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:288-297
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the rapid industrialization and urbanization, the food security in China is not only just about maintaining a growth of total grain production, but also about keeping the increase of grain yield at a sustainable and steady pace. For the purpose of food security and social development, it is meaningful to study the yield increasing potential of grain and its spatial differentiation in Huang-Huai-Hai Plai, one of the main grain production areas of China. According to the land use data, this study selected 309 counties in this area as research units and used the method of exploratory spatial data analysis (ESDA) to investigate the spatial distribution pattern of balanced yield increasing potential. On the basis of the balanced thoughts, this study established a theoretical framework of promoting further grain productivity growth in study area. The balanced growth of grain yield consists of 3 progressive types (spatial, temporal and functional balanced growth of grain yield). Spatial balanced growth of grain yield, which is easy to achieve, is to make the small spatial cell (such as county) with different productivities of food reach a balanced and quite higher output. Increasing gain yield evenly in space can be achieved by adopting a series of measures on land consolidation. Using advanced science and technology to achieve multiple cropping is called temporal balanced growth of grain yield. The balanced yield increasing is not only to increase the biological output (grain production) but also to synergistically improve the other functions of cultivated land, which is functional equilibrium. The process to achieve the balanced growth of grain yield is gradual. This paper revealed the spatial balanced yield increasing potential of grain and its spatial differentiation in the main grain production areas in China. The methods included an analysis of the approaches to improve grain yield in Huang-Huai-Hai Plain based on balanced thoughts, calculation of the balanced yield increasing potential by using land use data in 2012, and description of its spatial differentiation of the study area. Then, the spatial distribution pattern of balanced yield increasing potential was analyzed by using the method of spatial autocorrelation analysis and GIS technology. Additionally, according to the distribution result and yield increasing potential of the 309 counties, the land consolidation types of Huang-Huai-Hai Plain were classified. The result showed that the balanced yield increasing potential of grain was 3304.57&times;10⁴ t approximately, the spatial quality potential was 2413.74&times;10⁴ t and the spatial quantity potential was 890.83&times;10⁴ t in Huang-Huai-Hai Plain. By comparing the potential of grain production calculated using different methods, it was easy to conclude that the main mode to increase output was to improve the quality of cropland by upgrading medium-and low-yield farmland. In addition, the potential of the southern part of Huang-Huai-Hai Plain was higher than that of the northwestern part. The spatial balanced yield increasing potential of grain, the yield increasing potential in different ways and the strength index of yield increasing potential all showed the remarkable characteristic of spatial distribution. Meanwhile, there was a positive autocorrelation in spatial distribution of yield increasing potential. Spatial agglomeration types were High-High and Low-Low type. According to the distribution pattern of spatial agglomeration and the yield increasing potential, the land consolidation of Huang-Huai-Hai Plain was divided into 4 types, which were the same as the potential sources of grain yield increasing. This study provides valuble information for setting up directions and developing ways of equilibrium increasing output based on local conditions of Huang-Huai-Hai Plain. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Spatial distribution
Controlled terms:Agglomeration - Agriculture - Autocorrelation - Economic and social effects - Food supply - Geographic information systems - Grain (agricultural product) - Grain growth - Land use - Landforms  - Mobile security - Productivity - Spatial variables measurement
Uncontrolled terms:Distribution patterns - Exploratory spatial data analysis - Huang-Huai-Hai Plain - Spatial autocorrelation analysis - Spatial autocorrelations - Spatial differentiation - Spatial distribution patterns - Yield-increasing
Classification code:403 Urban and Regional Planning and Development - 404.2 Civil Defense - 481.1 Geology - 723.3 Database Systems - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 913.1 Production Engineering - 921 Mathematics - 922 Statistical Methods - 943.2 Mechanical Variables Measurements - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2015.02.040
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 43>

Accession number:20151000594681
Title:Role of Cynodon dactylon L. and Hemarthria altissima in wave attenuation and erosion control
Authors:Zhong, Ronghua (1); He, Xiubin (1); Bao, Yuhai (1); Yang, Kejun (3); Gao, Jinzhang (1); L, Fayou (1)
Author affiliation:(1) Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, China; (2) University of Chinese Academy of Sciences, Beijing, China; (3) State Key Laboratory of Hydraulic and Mountain River Eng., Sichuan University, Chengdu, China
Corresponding author:Bao, Yuhai
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:133-140
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil erosion and bank degradation is a major post-dam concern regarding the riparian zone of Three Gorges Reservoir (TGR). The development and succession of vegetation are the main countermeasures, especially to enhance bank stability and mitigate soil erosion. Thus, the role of for Cynodon dactylon (L.) Pers. and Hemarthria altissima (Poir.) Stapf et C. E. Hubb. in wave attenuation and erosion control was measured via the flume experiments. The results showed that the two grass species play an important role in wave attenuation and erosion control. The effects of wave attenuation and erosion control capabilities for the two species were different. The mean wave dissipation coefficient (MWDC) for Cynodon dactylon (L.) Pers. and Hemarthria altissima (Poir.) Stapf et C. E. Hubb. were 0.37 and 0.30, respectively, with the wave period of 1.2 s to 1.5 s. Nevertheless, the values of MWDC for Hemarthria altissima (Poir.) Stapf et C. E. Hubb. was similar to Cynodon dactylon (L.) Pers. (ranged from 0.15 to 0.30) when the wave period was between 0.8 s to 1.2 s. The MWDC values of 0.43 and 0.30 were responded for Cynodon dactylon (L.) Pers. under 80% and 40% area coverage, respectively. In contrast, the MWDC values for Hemarthria altissima (Poir.) Stapf et C. E. Hubb. were 0.35 and 0.24, respectively, under two different coverage. The MWDC values for Cynodon dactylon (L.) Pers. with a wave height of 8 and 4 cm were 0.34 and 0.39, respectively; whilst, the ones for Hemarthria altissima (Poir.) Stapf et C. E. Hubb. were 0.15 and 0.32, respectively. The MWDC values showed generally increasing trend with increasing wave period. Species studied also significantly reduced wave induced soil erosion. The results of washout tests indicated the soil erosion modulus decreased with increasing eroded time. The largest erosion modulus was measured for bare land (799. 40 g/(m²&middot;min)), followed by Hemarthria altissima (Poir.) Stapf et C. E. Hubb. (57.28 g/(m²&middot;min)), Cynodon dactylon (L.) Pers. (17.63 g/(m²&middot;min)). When the wave height was 8 cm, the mean erosion modulus was 84.81, 224.82 and 1 746.67 g/(m²&middot;min) for Cynodon dactylon (L.) Pers. samples, Hemarthria altissima (Poir.) Stapf et C. E. Hubb. samples and bare land, respectively; whereas, the mean erosion modulus for wave height equal to 4 cm was 13.54, 22.67 and 656.8 g/(m²&middot;min), respectively. The percentage erosion control effectiveness of the two species studied ranges from 89.0% to 98.6%. Erosion control effect for Cynodon dactylon (L.) Pers. was found a bit higher as compared to that for Hemarthria altissima (Poir.) Stapf et C. E. Hubb. under the same test conditions, but not significantly different. Erosion reducing is a combined consequence of above-ground and root system. The relative contribution rates of roots for Hemarthria altissima (Poir.) Stapf et C. E. Hubb. to prevent soil from erosion was as high as 91%, while its shoots only contributed the proportion of 7.4% to 8.6%; Roots of Cynodon dactylon (L.) Pers. afforded a smaller soil conservation contribution rate than Hemarthria altissima (Poir.) Stapf et C. E. Hubb., whilst its aboveground contribution rate, ranged from 23.8% to 28.8%, was significantly higher than Hemarthria altissima (Poir.) Stapf et C. E. Hubb. In summary, the capability of wave attenuation and erosion control for Cynodon dactylon (L.) Pers. was better as compared to the Hemarthria altissima (Poir.) Stapf et C. E. Hubb, which recommending Cynodon dactylon (L.) Pers. as a better selection for soil conservation in the riparian zone of TGR. The efficiency of wave dissipation and erosion reducing capacity for the investigated species were influenced by the vegetation coverage, the morphological features of aboveground and underground root system, the wave size and period. Combined with the knowledge of vegetation dynamics, ecological site properties, and species resistance to erosion, the observations made in this experiment would be useful for species selection in the context of ongoing and future revegetation activities in the riparian zone of TGR and similar riparian areas in the Yangtze River Basin. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Erosion
Controlled terms:Electric grounding - Petroleum reservoirs - Reservoirs (water) - Revegetation - Site selection - Soil conservation - Soil testing - Soils - Supply chains - Vegetation  - Water waves - Waves
Uncontrolled terms:Cynodon dactylon - Erosion control - Hemarthria altissima (Poir.) Stapf et C. E. Hubb - Riparian zones - Three gorges reservoir
Classification code:402 Buildings and Towers - 403 Urban and Regional Planning and Development - 407 Maritime and Port Structures; Rivers and Other Waterways - 441.2 Reservoirs - 442.2 Land Reclamation - 471.4 Seawater, Tides and Waves - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 512.1.1 Oil Fields - 704 Electric Components and Equipment - 706 Electric Transmission and Distribution - 711 Electromagnetic Waves - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 912 Industrial Engineering and Management - 913 Production Planning and Control; Manufacturing
DOI:10.3969/j.issn.1002-6819.2015.02.019
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 44>

Accession number:20151000594699
Title:Land cover/land use classification based on polarimetric target decomposition of microwave remote sensing
Authors:Ma, Teng (1); Wang, Yaoqiang (1); Li, Ruiping (1); Li, Biao (1)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Huhhot, China
Corresponding author:Wang, Yaoqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:259-265
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The objective of this study is to combine polarimetric target decomposition and decision tree classifier for land cover/land use classification. Taking the Jiefangzha irrigation sub-district of Inner Mongolia Hetao Irrigation District as study area, based on the data of full polarization Radarsat-2 in study area after spring, the entropy, average scattering angle, anti entropy, average eigenvalue, characteristic value of relative difference of single reflection, and characteristic value of relative difference of secondary reflection were obtained by using polarization target decomposition method. Combined with the field data in the time of image acquisition, the separability of parameters on building area, bare land, cultivated land, water area containing vegetation was analyzed. The ground sample's mean values of the above parameters were calculated. By analyzing the mean of these parameters, the results show that the average scattering angle, the average eigenvalue, and characteristic value of relative difference of single reflection can be used for the characteristic quantities of classification. The decision tree decision boundary is determined by the minimum distance method. If the average scattering angle is greater than 36.61&deg;, the area is divided into building area and water area containing vegetation, if not, is divided to bare land and cultivated land. In the building area and water area containing vegetation, if the average eigenvalue is greater than 0.18, the pixel is classified as building area, if not, the pixel is classified as water area containing vegetation. In the bare land and cultivated land, if the characteristic value of relative difference of single reflection is greater than 0.89, the pixels is divided into cultivated land, or else bare land area. The overall accuracy of image classification by decision tree is 93.89% and Kappa coefficient is 0.914. The results show that the average scattering angle can be used to accurately distinguish the single scattering, volume scattering and secondary scattering. Because secondary scattering always appeared in building area and vegetation area, the average scattering angle can be used to extract building area or vegetation area. The echo power of vegetation area is weak, so the average characteristic value associated with the echo power can be used to distinguish the building area and water area containing vegetation. Characteristic value of relative difference of single reflection is associated with terrain roughness, and it can be used to distinguish cultivated land and bare land area. Wrong classification of pixel occurred mainly between the cultivated land and bare land area and between the bare land and building area. Part of bare land surface has greater roughness, which is a major cause of confusion with cultivated land. The cause of wrong classification between bare land and building area is that part of bare land area has greater roughness resulting in secondary scattering. In addition, through the study it was found that the average scattering angle for the extraction of building area has a better effect, but if secondary scattering is produced, it will lead to the confusion between vegetation area and building area; it is easily confused between water area and building area if the water contains vegetation. According to the results, the methods of polarimetric target decomposition can fully explain the physical mechanism of object, and thus it can improve the land cover/land use classification accuracy. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Image classification
Controlled terms:Buildings - Classification (of information) - Classifiers - Decision making - Decision trees - Eigenvalues and eigenfunctions - Entropy - Image acquisition - Irrigation - Land use  - Pixels - Polarimeters - Polarization - Remote sensing - Vegetation
Uncontrolled terms:Classification accuracy - Classification of pixels - Decision tree classifiers - Hetao irrigation districts - Microwave remote sensing - Polarimetric target decomposition - Target decomposition - Target decomposition methods
Classification code:402 Buildings and Towers - 403 Urban and Regional Planning and Development - 641.1 Thermodynamics - 711.1 Electromagnetic Waves in Different Media - 716 Telecommunication; Radar, Radio and Television - 716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.1 Control Systems - 802.1 Chemical Plants and Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 912.2 Management - 921.1 Algebra - 922 Statistical Methods - 941.3 Optical Instruments - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2015.02.037
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 45>

Accession number:20151000594688
Title:Development and test on experimental platform for inner environmental control of micro plant factory
Authors:Tu, Junliang (1); Qiu, Quan (1); Qin, Linlin (3); Wu, Gang (3); Zheng, Wengang (1); Meng, Zhijun (1)
Author affiliation:(1) Beijing Academy of Agriculture and Forest Sciences, Beijing, China; (2) Beijing Research Center for Information Technology in Agriculture, Beijing, China; (3) Department of Automation, University of Science and Technology of China, Hefei, China
Corresponding author:Qiu, Quan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:184-190
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a promising agricultural production mode, plant factory has been a hot topic for the last decades. Though a large quantity of efforts have been made on the research on the models of plant factory's inner environment, few attentions have been paid on developing control object models from the prospective of control theory. To solve this model-lacked problem, this paper proposes a novel experimental platform in the form of the micro plant factory, hoping to bring a powerful research tool for control object modeling. In the platform, control algorithms are endowed with direct control authorities for the actuators, such as the heating and cooling equipment. That is, control algorithms can influence the object parameters (micro plant factory's inner temperature and humidity for example), by directly opening or closing the actuators other than indirectly sending expected parameter values to the actuators' onboard controllers. In such a manner, the platform can present the control responses of the inner environment more directly than other existing plant factories, which will be a great advantage in control object modeling. Also, the platform has a more convenient interface for the application of intelligent control algorithms. Among the dominant inner environmental parameters, temperature and humidity are chosen as the main control objects whose model is to be analyzed, considering their control response features and monitoring cost. Aiming at the control and monitoring for the inner temperature and humidity, the control components, sensing components and operating components of the platform are chosen carefully. A computer and a controller are selected as control components. Control algorithms will run in the computer and generate control orders. Then the orders will be sent to the actuators through the controller. The temperature and humidity sensors are chosen as the sensing components, which act as real-time monitors for the control objects. The electro-thermal membrane, the refrigeration system, the lamps and the fans are selected as operating components. The electro-thermal membrane can give a uniform heating performance for the inner environment of the plant factory. The refrigeration system is used to lower the temperature. The lamps are mainly used for artificial lighting, which may lead to trifling heating effect. The fans are mainly used as air exchange tools, which may lead to obscure cooling results. All the components are integrated into a whole system under proper hardware and software design. The platform's planting experiments employing lettuce as the test crop were conducted in the lab from April to June, 2014. During the experiments, the feasibility of the platform in inner environmental control operations, such as heating and cooling, is verified. By analyzing the temperature and humidity changing curves along the time axis, the delay time of the system is determined to be 30 seconds, which helps to carry out the proper sample duration of 3 seconds for further precise control. Also, the correlation of the inner temperature and humidity factors is obtained using the Pearson correlation factors. All the results above will lay a stable foundation for the application of intelligent control algorithms on the platform in future. In the next step, we hope the real control object model for temperature and humidity can be established through a system identification algorithm. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:9
Main heading:Humidity control
Controlled terms:Actuators - Agriculture - Algorithms - Controllers - Cooling - Correlation methods - Environmental engineering - Environmental management - Environmental regulations - Heating  - Identification (control systems) - Intelligent control - Lighting - Plant shutdowns - Position control - Refrigeration - Software design - Structural analysis
Uncontrolled terms:Agricultural productions - Environmental parameter - Experimental platform - Hardware and software designs - Microplants - System identification algorithms - Temperature and humidities - Temperature and humidity sensor
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 408.1 Structural Design, General - 454 Environmental Engineering - 454.2 Environmental Impact and Protection - 641.2 Heat Transfer - 643.1 Space Heating - 644.4 Cryogenics - 707 Illuminating Engineering - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 731.3 Specific Variables Control - 732.1 Control Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2015.02.026
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.

<RECORD 46>

Accession number:20151000594687
Title:Thickness determination of heat storage layer of wall in solar greenhouse
Authors:Li, Ming (1); Zhou, Changji (1); Wei, Xiaoming (1)
Author affiliation:(1) Institute of Facility Agriculture, Chinese Academy of Agricultural Engineering, Beijing, China; (2) Key Laboratory of Farm Building in Structure and Construction, Ministry of Agriculture, Beijing, China
Corresponding author:Wei, Xiaoming
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:31
Issue:2
Issue date:January 15, 2015
Publication year:2015
Pages:177-183
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:A wall of the Chinese solar greenhouse (hereafter referred as "solar greenhouse") included the heat storage layer, heat insulation layer and heat preservation layer. The heat storage layer was part of the wall exposed to the indoor environment of solar greenhouse and mainly used to store and release heat during daytime and night time, respectively. The objective of this study was to develop methods to identify the heat storage layer of solar greenhouse wall and then estimate its width. An earth wall with the top and bottom widths of 2. 0 and 5. 3 m was used. Firstly, it was proposed that the heat storage layer of wall was identified as: 1) The indoor part of the wall, of which the temperature at the end of daytime was 1 higher than that at the start of daytime or at the end of night time; or, 2) The indoor part of the wall, of which the temperature fluctuation was over 1 during a day. Based on the measured earth wall temperature in a sunny day, the earth wall temperature at the end of daytime was higher than those at the start of daytime and at the end of night time. But with the increase in depth of earth wall, the wall temperature at the end of daytime got close to those at the start of daytime and at the end of night time. At the earth wall depth of 30 cm, the wall temperature at the end of daytime was only 1.0 and 0.4 higher than those at the start of daytime and at the end of night time, respectively. According to the first method, the width of heat storage layer was estimated as 30 cm. On the other hand, the temperature fluctuation of the wall decreased with the increase in the wall depth as well. The temperature fluctuation at the earth wall depth of 30 and 40 cm were 3.3 and 0.9, respectively. Based on the second method, the width of heat storage layer was estimated as 40 cm. It was noticed that the maximum temperature at the earth wall depth of 30 cm appeared during the period from 20: 00 to 23: 00. It was 1.4 higher than that at the start of daytime. The results indicated that the inner part of earth wall could store heat not only in the daytime, but also in the night time. Thus, the second method was more reasonable than the first. Secondly, a one-dimensional difference model was developed to simulate the temperature fluctuation of earth wall in a sunny day with two assumptions: 1) The heat flux through the homothermal section was zero; 2) The width of heat storage layer was firstly assumed as 60 cm. When the solar-energy absorbance factor of earth wall was 0.5, the simulated width of heat storage layer was 38.5 cm, which was close to that estimated with the tested value. By using different heat fluxes and assumed widths in the model, it was discovered that the effects of above two assumptions on the accuracy of simulated width of heat storage layer could be neglected. Hence, the proposed model can be applied for designing the wall of solar greenhouse. &copy;, 2015, Chinese Society of Agricultural Engineering. All right reserved.
Number of references:18
Main heading:Greenhouses
Controlled terms:Heat flux - Heat storage - Solar energy - Solar heating - Temperature distribution
Uncontrolled terms:Chinese solar greenhouse - Difference models - Heat insulation layer - Maximum temperature - Solar greenhouse - Temperature fluctuation - Thickness determination - Walls
Classification code:402.1 Industrial and Agricultural Buildings - 615.2 Solar Power - 641.1 Thermodynamics - 641.2 Heat Transfer - 643.1 Space Heating
DOI:10.3969/j.issn.1002-6819.2015.02.025
Database:Compendex
Compilation and indexing terms, Copyright 2015 Elsevier Inc.