<RECORD 1>

Accession number:20142917960265
Title:Design and manufacture of horizontal continuous biomass carbonization equipment
Authors:Yuan, Yanwen (1); Tian, Yishui (1); Zhao, Lixin (1); Yao, Zonglu (1)
Author affiliation:(1) Key Laboratory of Energy Resource Utilization from Agricultural Residues, Ministry of Agriculture, Chinese Academy of Agricultural Engineering, Beijing 100125, China
Corresponding author:Tian, Y.(yishuit@yahoo.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:203-210
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The burning of fossil fuels, the changes in agricultural and land utilization, as well as the industrial processes produce a lot of carbon dioxide and other greenhouse gases causing global warming. Climate increasingly has become one of the most far-reaching global environmental issues. The carbon can be stabilized by biochar for hundreds of years while the carbon element is very difficult to break down after mineralization. With the function of carbon sequestration and soil improvement in agriculture, it turns out to be one of the main ways to reduce carbon emissions in the future. Currently, the producing of biochar has become a hot topic both at home and abroad. In this paper, aiming at the existence of unstable operations, low percentage of biochar outputs, as well as the difficultly of recycling of by-products of China biochar, equipment designs of the horizontal equipment for continuous carbonization of biomass, which uses external thermal heating carbonization of feedstock. The difference requires an external heating fuel, the heat required for the dissertation utilizes the high temperature and gas combustion-generated calorie to carbonize the raw materials., Combustion flue gas during start-up and insufficient supply combined with diesel auxiliary heating of the equipment, the pyrolytic reactor of which is double-layer structure, with the inner layer carbonization chamber equipped with the built-in screw conveyor while the out layer high-temperature flue sleeve, using the motor speed, to ensure the continuous feeding of material, mixing and uniform heat transfer to achieve a biological continuous production of charcoal and carbonization temperature-controlled. The reactor outer sleeve for the high temperature flue gas, the use of high temperature gas to heat biomass, and the outer cylinder has baffles and fins, extending the residence time of the flue gas, and increasing the heat transfer coefficient to achieve a sufficient heat exchange. The paper chooses pyrolysis parameters, thermal design and conducts gas combustion thermal calculation., The 100 kg corn stalks can be producing 30 m³ of combustion gas, completing combustion flue gas flow rate of 96.9 m³, consuming 15.3 m³/h of gas that can meet the requirements, the remaining 14.7 m³/h of gas can be used for other purposes. While the key components of the carbonization chamber, flue gas temperature structural design of the sleeve, etc., come to the heating equipment length 4.24 m, inner tube inner diameter of 0.5 m, the outer tube inner diameter of 0.55 m. Finally taking the rice hulls for the carbonization experiment, the results of which indicates that the horizontal equipment for continuous carbonization of biomass has the realization of sustainable stable operation, reasonable designing of carbonization equipment, as well as the wide range of applicability. The productivity of which is 45 kg/h, the terminal temperature of carbonization 500&deg;C and the ratio of char yield 42%, and taking advantage of all the by-products of carbonization, reducing pollutant emissions. With the realization of a designing goal and the improvement of biochar percentage, the dissertation provides a theoretical basis and technological support for the biochar industry of China.
Number of references:24
Main heading:Carbonization
Controlled terms:Agriculture - Auxiliary equipment - Biological materials - Biomass - Carbon dioxide - Charcoal - Combustion - Design - Flue gases - Global warming  - Greenhouse gases - Heating equipment - Pyrolysis - Structural design - Tubes (components)
Uncontrolled terms:Continuous - Continuous production - Design and manufactures - Double layer structure - Flue gas temperatures - High temperature flue gas - Horizontal - Technological supports
Classification code:408 Structural Design - 408.1 Structural Design, General - 451 Air Pollution - 451.1 Air Pollution Sources - 461.2 Biological Materials and Tissue Engineering - 521 Fuel Combustion and Flame Research - 521.1 Fuel Combustion - 524 Solid Fuels - 616.1 Heat Exchange Equipment and Components - 642.2 Industrial Furnaces and Components - 802.2 Chemical Reactions - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 901 Engineering Profession
DOI:10.3969/j.issn.1002-6819.2014.13.025
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 2>

Accession number:20142917960242
Title:Design and experiment on banana stalk chopper with feeding type spindle flail
Authors:Gan, Shengbao (1); Li, Yue (1); Zhang, Xirui (1); Zhang, Guojian (2); Wang, Neng (3)
Author affiliation:(1) School of Mechanics and Electrics Engineering, Hainan University, Haikou 570228, China; (2) Boiler Pressure Vessels and Special Equipment Inspection of Hainan Province, Haikou 570203, China; (3) Hainan Jin Lu Agriculture Mechanism Development, CO. LTD., Haikou 571100, China
Corresponding author:Li, Y.(liyue_888888@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:10-19
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Bananas occupy an extremely important position in the world of fruit trade; it is the most important fruit in tropical and subtropical areas. China is one of the world's largest producers of bananas, and bananas have become an agricultural pillar industry in China's subtropical regions. However, the banana stalks are a major agricultural waste. According to the Food and Agriculture Organization (FAO), in 2010, 24 million tons of annual output of waste is banana straw in China. If such a large amount of waste straw is not handled in time, it would seriously pollute the environment and affect the renewal of the banana plantation. Because banana stalks are thick with a high level of moisture and other issues, there are less mature mechanical equipments for banana stalks treatment at the present. There are usually two main types of banana stalk treatment: one is to cut down and pile the stalk in the fields by laborers, and then let it rot; the other one is a centrally smash processing with machines. This kind of machine can achieve a certain crushing effect, but, due to the characteristics of its own design, can't achieve the field operations, and thus brings great inconvenience for the laborers. In view of above situations, according to craft about the banana stalks' crushing and returning in the field, this study designed a feeding type vertical shaft flail extracting machine for banana stalks' crushing and returning, and expounded the machine's overall configuration and the main components of the structure, and determined the key parameters of the optimal value through the analysis of the relationship between components and performance test. The machine could work directly in the field under the tractor traction, for the stalks to achieve down, tackle, grab, feed, crush and return. Field experiments showed that: with the speed for forwarding at 2.16 - 3.60 km/h, for the feed roller at 127.39 r/min, and for the vertical sling knife at 1080 r/min, this machine could achieve a qualification rate of straw smashing of 94.9%, field coverage of 88.61%, stem stubble height of 30 - 35 mm, energy consumption of 4.625 kg/h, and working efficiency of 0.39 hm²/h. This machine was easy to operate and its crushing effect was satisfactory. Its successful implementation could not only greatly improve the production efficiency, and solve the problem of large-scale banana cultivation facing massive stalks processing, but also prevent the pollution of the environment and had important economic and ecological benefits.
Number of references:29
Main heading:Fruits
Controlled terms:Agricultural machinery - Agricultural wastes - Crushing - Cultivation - Design - Energy utilization - Feeding - Machine components - Piles - Straw  - Tropics
Uncontrolled terms:Ecological benefits - Filamentous sludge - Food and agriculture organizations - Mechanical equipment - Production efficiency - Spindle flail - Subtropical regions - Working efficiency
Classification code:408 Structural Design - 408.2 Structural Members and Shapes - 443 Meteorology - 525.3 Energy Utilization - 601.2 Machine Components - 691.2 Materials Handling Methods - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2014.13.002
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 3>

Accession number:20142917960264
Title:Applicability evaluation of AMSR-E remote sensing soil moisture products in Qinghai-Tibet plateau
Authors:Xi, Jiaju (1); Wen, Jun (1); Tian, Hui (1); Zhang, Tangtang (1)
Author affiliation:(1) Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; (2) University of Chinese Academy of Sciences, Beijing 100049, China
Corresponding author:Wen, J.(jwen@lzb.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:194-202
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil moisture products generated from satellite remote sensing have wide applications, but their accuracy has drawn great attention in the relevant research studies. In this paper, to evaluate the accuracy of soil moisture estimated by passive microwave remote sensing, three kinds of Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) soil moisture products have been inter-compared and analyzed. First, the ground measured soil moisture data was used for evaluating the precision of three kinds of soil moisture products and analyzing the effects of different vegetation coverage and precipitation on passive microwave soil moisture estimates. For this purpose, four soil moisture observation networks, which were displayed in the Qinghai-Tibet Plateau, were taken into account to ensure that this experiment considered most land cover types. In each network, at least six field measurement points were used to calculate the mean value of the corresponding pixels to reduce the deviation caused by scale effect. The results showed that the estimated soil moisture in a flat and bare soil area was more accurate with its correlation coefficient above 0.7 and RMSE below 0.16, while in the high vegetation density area, the correlation coefficient was less than 0.7 and RMSE could reach to 0.2. In general, NASA's soil moisture product performs well in all land cover types with stable relativity. VUA's soil moisture product has less RMSE in high soil moisture areas. Otherwise, JAXA's soil moisture product's relativity rises in low soil moisture areas. Especially in the area where the soil moisture was less than 0.12m3/m3, JAXA's soil moisture product had the highest correlation coefficient of three kinds of soil moisture products. It showed potential for drought monitoring. When precipitation occurs, the accurate of the three kinds of soil moisture products all decreased to different degrees. However, NASA's product sustained preferable stability with a 0.69 correlation coefficient. Based on this, the soil moisture maps of the Qinghai-Tibet Plateau were generated to analyze the space-temporal distributed characteristics of the three kinds of soil moisture products. It proved that NASA's and VUA's soil moisture products were in solid agreement with the actual situation. In addition, the monthly variations of NASA's and VUA's soil moisture were basically the same with the monitoring results of the China Meteorological Administration. But the magnitudes of these two kinds of soil moisture products had a great difference with the actual situation, while JAXA's soil moisture product was not in accordance with the reality in spatial distribution in the northwest and southeast of Qinghai-Tibet Plateau.
Number of references:34
Main heading:Soil surveys
Controlled terms:Moisture - NASA - Relativity - Remote sensing - Soil moisture - Soils - Space optics - Vegetation
Uncontrolled terms:Advanced microwave scanning radiometer for earth observing systems - AMSR-E - Applicability - Applicability evaluation - Distributed characteristics - Passive microwave remote sensing - Qinghai Tibet plateau - Satellite remote sensing
Classification code:483.1 Soils and Soil Mechanics - 655 Spacecraft - 656 Space Flight - 656.1 Space Flight - 731.1 Control Systems - 801.4 Physical Chemistry - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 931.5 Gravitation, Relativity and String Theory
DOI:10.3969/j.issn.1002-6819.2014.13.024
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 4>

Accession number:20142917960255
Title:Leaf stomatal resistance of maize affected by different furrow irrigation methods
Authors:Li, Caixia (1); Zhou, Xinguo (1); Sun, Jingsheng (1); Li, Xinqiang (1)
Author affiliation:(1) Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Xinxiang 453002, China; (2) Key Lab for Crop Water Requirement and Regulation of Ministry of Agriculture, Xinxiang 453002, China
Corresponding author:Sun, J.(jshsun623@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:119-126
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Stomatal regulation plays a pivotal role in the adaption of plants to different water conditions. In order to understand characteristics of stomatal resistance of crops with different irrigation methods, differences in leaf stomatal resistance and contribution of stomatal aperture to water vapor transfer were investigated with a field experiment conducted under alternative deficit water supply and under conventional furrow irrigation. Results indicated that for individual maize leaf, regardless of irrigation methods, the stomatal resistance decreased gradually from the base to the tip of the maize leaf. At the population level, the stomatal resistance of maize leaf increased gradually from canopy top to bottom. For the change of the leaf stomatal resistance in time, diurnal variation of leaf stomatal resistance was in a W shape. Diurnal and daily changes in the leaf stomatal resistance in the upper canopy were relatively small. The upper surface of maize leaf contributed more to CO<inf>2</inf> and water vapor transfer than the ones underside. Except at the seedling stage, the leaves in the upper and middle part of maize canopy contributed more than 80% of the total CO<inf>2</inf> and water vapor. Stomatal resistances of maize leaves decreased with the increase in leaf age during the vegetative growth stage. Differences in stomatal resistance among maize leaves of different ages were increased by the alternative deficit water supply. During the reproductive growth phase, leaf age had no significant influence on the stomatal resistance in matured leaves. Compared with the conventional furrow irrigation with sufficient water supply, the alternative deficit water supply increased the ratio of the stomatal resistances between the upper side and underside of maize leaves. The vertical gradient of stomatal resistance from canopy top to bottom increased significantly (P&lt;0.05), decreasing leaf stomatal conductivity rapidly, and improving the contribution of the stomatal aperture in the upper canopy to water vapor transfer. Therefore, the leaf stomatal resistance of maize was regulated by furrow irrigation methods and soil water condition, and it was affected by the leaf age, leaf area index and natural feature of stomatal aperture. The study is useful for controllable irrigation technology and water vapor cycle in soil plant atmosphere continuum (SPAC).
Number of references:34
Main heading:Irrigation
Controlled terms:Carbon dioxide - Crops - Moisture - Plants (botany) - Soil moisture - Water supply - Water vapor
Uncontrolled terms:Furrow irrigation - Furrow irrigation methods - Maize - Reproductive growth - Stomatal apertures - Stomatal conductivity - Stomatal resistance - Water vapor transfer
Classification code:446.1 Water Supply Systems - 461.9 Biology - 483.1 Soils and Soil Mechanics - 641 Heat and Mass Transfer; Thermodynamics - 801.4 Physical Chemistry - 804.2 Inorganic Compounds - 821.3 Agricultural Methods - 821.4 Agricultural Products
DOI:10.3969/j.issn.1002-6819.2014.13.015
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 5>

Accession number:20142917960241
Title:Effect of side contraction on long-throated flume calibration
Authors:Guan, Guanghua (1); Liu, Ting (1); Wang, Changde (1); Chen, Hui (2); Yao, Xiong (2)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China; (2) South to North Water Diversion Project Construction Management Bureau, Beijing, 100038, China
Corresponding author:Guan, G.(GGH@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:1-9
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Long-throated flume has been widely used as a flow measurement structure in irrigation channel systems. The key element of the long-throated flume is a throat, the length of which is longer than one and one-half times of the upstream energy head referenced to the throat invert or crest. Measurement accuracy of this flume is based on an accurate prediction of head-loss. This long throat causes the streamlines to be straight enough to sufficiently approximate hydrostatic pressure distributions. Replogle proposed a mathematic model for discharge calculation of various kinds of measurement structures. It is claimed that the model can achieve an accuracy within 2% based on the results of laboratory studies (within the range 0/07 &lt; H<inf>1</inf>/L &lt; 0.7). However, the additional inaccuracy is associated with errors in measured water level, which can also be improved by proper design of stilling well. When the calibration error is combined with the measurement error, the resulting accuracy of the measurement can be lower than 5%. A series of experiments were carried out in China to verify the effectiveness of this structure. In this experiment, three sets of flume were used: 1) five trapezoid flumes with only side contraction; 2) five trapezoid flumes with only vertical contraction; 3) two flumes with both side and vertical contractions, one with a trapezoid cross section and one with a U-shaped cross section. For the five flumes with only side-contractions, four upstream converging rates (length to width: 2, 2.5, 3, and 4:1) were used. The downstream side expansion rate was the same for all fumes, namely EM'=6. An extra set of models was created from the set with an upstream converging rate of 3:1 by cutting off the half-length of the downstream diverging section. For vertical contraction experiments, the sill height was p<inf>1</inf>=p<inf>2</inf>=0.2 m. Four upstream vertical-converging rates (2, 2.5, 3, and 4:1, horizontal to vertical) were used, and the downstream vertical convergence rate remained fixed at EM=6. An extra set of model runs was created from the set with vertical-converging rate of 3:1 by cutting off the half-length of the downstream diverging section similar as with the side contracted flumes. For flumes with side and vertical converge, both trapezoid and U-shaped cross sections were tested. Laboratory experiments showed that the long-throated flume was an effective flow-measurement structure with simple shape, low head loss, high modular limit, high robustness and accuracy. The best side contraction rate and vertical rate was 1:3 for accurate field calibration. When designed properly, downstream water level did not influence measurement accuracy. This should be advocated in most irrigation canals. Based upon test results, a modification was made to the original head loss equation to further increase the calculation accuracy. A local head loss &Delta;H<inf>con</inf> was introduced to the original model to account for the head loss associated with a side contraction. This included a local head loss parameter c<inf>i</inf> that was used to calculate this extra head loss at the entrance to the throat section. In this paper, the recommended c<inf>i</inf> value for side contraction rates of 1:2, 1:2.5 and 1:3 were 0.317, 0.263 and 0.203, respectively. For flumes with only one side contraction, the modified method reduced the calculation error from 9.59% to 4.14%. With this new energy loss, calculation accuracy was significantly improved for long-throated flumes with side contractions, this will be helpful for water management.
Number of references:23
Main heading:Structural design
Controlled terms:Acoustics - Boundary layers - Calibration - Energy dissipation - Experiments - Flow measurement - Hydrostatic pressure - Irrigation - Irrigation canals - Measurements  - Models - Rivers - Water levels - Water management
Uncontrolled terms:Calculation accuracy - Discharge calculation - Flow measurement structures - Head loss - Laboratory experiments - Long-throated flume - Measurement structures - Water measurements
Classification code:408.1 Structural Design, General - 444 Water Resources - 444.1 Surface Water - 446 Waterworks - 525.4 Energy Losses (industrial and residential) - 614.2 Steam Power Plant Equipment and Operation - 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 751 Acoustics, Noise. Sound - 821.3 Agricultural Methods - 901.3 Engineering Research - 902.1 Engineering Graphics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 943.2 Mechanical Variables Measurements - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.13.001
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 6>

Accession number:20142917960270
Title:Impact of urbanization on drainage modulus in tidal river networks
Authors:Xiao, Junjian (1); Luo, Qiang (1); Wang, Xiugui (1); Luo, Wenbing (1); Zhang, Xiaochun (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China; (2) Hubei Institute of Urban Planning and Design, Wuhan 430071, China
Corresponding author:Luo, Q.(qluo@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:247-255
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Drainage modulus is the rate of water removal per unit of area used in drainage design. Reasonable drainage modulus is of great importance for waterlogging control. With the urbanization in tidal river networks, more and more impermeable areas are gradually replacing original permeable areas, thus changing the rainfall-runoff process of drainage areas. Different from rural areas, storm water in urban areas is collected by drainage pipe network, routing storm water runoff directly to main pipes or channels, causing less infiltration, but more overland runoff. Urbanization, with the loss of vegetation and replacement of soil with impervious surfaces, makes traditional computing methods of drainage modulus inadequate for urbanized areas. While inland river stage is affected by tidal backwater in tidal river networks, waterlogging risks increase. Based on the characteristics of urbanized drainage areas in tidal river networks, a two-layer computing model of drainage modulus was built. In the model, the catchment of first layer was divided into two sub-drainage areas, urban and rural, which adopted SWMM and Guangzhou comprehensive unit hydrograph method to establish rainfall-runoff models, respectively. On the second layer, based on their shared drainage channels (rivers), a river networks dynamic model was established by MIKE11 HD. Lateral inflows of rainfall runoff were derived from the simulated data of first layer, coupled with MIKE11 HD. Using the Dagang drainage area as a case study, the impact of urbanization on drainage modulus was studied through this two-layer computing model of drainage modulus. Drainage modulus under different designed rainstorm in 2003 and in 2012 was calculated. The relationship between drainage modulus and return periods under different underlying surface condition in 2003 and 2012 was analyzed. Results showed that due to the increasing ratio of urban area from 9.69% to 24.25% from year 2003 to 2012, drainage modulus under design standards with return period of 20 years increased from 1.766 m³/(s&middot;km²) to 2.808 m³/(s&middot;km²), drainage modulus under design standards with return period of 30 years increased from 2.909 m³/(s&middot;km²) to 4.197 m³/(s&middot;km²), which showed that the resistibility of waterlogging was weakening. When drainage modulus reached the 1.766 m³/(s&middot;km²), the drainage area can meet design standards with return periods of 20 years in 2003, but it can only satisfy design standards with return periods of about 15 years in 2012. When drainage modulus reached the 2.909 m³/(s&middot;km²), the drainage area can meet design standards with return periods of 30 years in 2003, but it was not able to satisfy design standards with return periods of about 20 years in 2012, which showed that waterlogging control standards of the study area was reduced in the process of urbanization. The result of this study may provide a reference for computing drainage modulus and help determine a reasonable value of drainage modulus for drainage engineering design in tidal river networks of urbanized areas.
Number of references:31
Main heading:Drainage
Controlled terms:Catchments - Design - Models - Rain - Rivers - Runoff - Rural areas - Standards - Storms - Urban growth
Uncontrolled terms:Pipe networks - Rainfall-runoff models - Rainfall-runoff process - SWMM models - Tidal river network - Traditional computing - Unit hydrograph methods - Urbanization
Classification code:401 Bridges and Tunnels - 403.1 Urban Planning and Development - 406 Highway Engineering - 442 Flood Control; Land Reclamation - 442.1 Flood Control - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 502 Mines and Quarry Equipment and Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics - 902.2 Codes and Standards
DOI:10.3969/j.issn.1002-6819.2014.13.030
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 7>

Accession number:20142917960245
Title:Motion analysis and performance test of corn paper pot seedlings transplanter
Authors:Yang, Li (1); Su, Yiming (1); Zhang, Dongxing (1); Cui, Tao (1); Zhang, Rui (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Zhang, D.(zhangdx@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:35-42
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Compared with other methods of cultivating corn seedlings, seedlings growing in paper tube have the advantage of high efficiency in transplanting. To solve the problems of labor intensity, low efficiency and high cost of conventional transplanting, a transplanter for corn seedlings growing in paper tube was designed in the paper. The critical part of the transplanter is the transplanting disc, which affects the operation performance of the whole machine. To determine the structural and working parameters of the transplanting disc, the physical parameters of paper tube seedlings were measured, the motion process and velocities of paper tube seedlings in the transplanting disc were analyzed. The trajectory equation of paper tube seedlings was designed, and the effects of the structural and working parameters on the motion trajectory of paper tube seedlings were simulated using MATLAB. The optimal parameters were determined, i.e., the rotary speed of the transplanting disc (w) is 7 rad/s, the distance between the center of seedling tube and transplanting disc (L) is 275 mm and the angle that the seedling tube rotating with the transplanting disc (&alpha;) is 80&deg;. Field experiments were conducted in a research field at Gu'an county, Hebei province. The working speed of the transplanter was maintained at 5 km/h and the theoretical seedling spacing was set as 200 mm. The experiments were repeated three times. 100 seedlings in the middle of 200 seedlings which were transplanted one time were taken as samples. The upright degree, seedling depth and seedling spacing were measured and their qualified indices were calculated to evaluate the working performance of the transplanter. The results showed that the percentage of upright seedlings is 91%, the qualified index of seedling spacing is 92.6%, and the qualified index of transplanting depth is 79.3%. All the indices are better than standard values and the performance of the new transplanter is better than that of conventional transplanting machines. The coefficient of variation of transplanting depth is 7.4%, which means the transplanter has good uniformity of transplanting depth. The percentage of upright seedlings indicates that the theoretical analysis method for determining the structural and working parameters of the transplanting disc used in this research is feasible. The transplanting depth of seedlings was influenced by soil condition. To obtain desired transplanting depth, the depth of loose soil layer must be deeper than the transplanting depth when preparing field. Although the qualified index of seedling spacing is more than 90%, the coefficient of variation of seedling spacing is as high as 21%. The main reason is that the distances between seedlings were changed in seedling delivery system before them coming into the transplanting disc. So the seedling delivery system should be optimized in further study. The data revealed that the transplanter for paper tube corn seedlings performed well in actual operation and the transplanting efficiency can meet the needs of Chinese peasants properly. The new design and the theoretical analysis method in this research can provide a reference for design and application of transplanters.
Number of references:30
Main heading:Disks (machine components)
Controlled terms:Agricultural machinery - Cultivation - Efficiency - Mechanisms - Research - Soils - Structural analysis - Transplants - Tubes (components)
Uncontrolled terms:Coefficient of variation - Corn - Design and application - Operation performance - Paper-tube seedling - Transplanting machine - Transplanting mechanisms - Working performance
Classification code:408.1 Structural Design, General - 462.4 Prosthetics - 483.1 Soils and Soil Mechanics - 601.2 Machine Components - 601.3 Mechanisms - 616.1 Heat Exchange Equipment and Components - 821.1 Agricultural Machinery and Equipment - 821.3 Agricultural Methods - 901.3 Engineering Research - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2014.13.005
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 8>

Accession number:20142917960248
Title:Effect of impeller inlet condition on non-overload performance of serial-parallel centrifugal pump
Authors:Su, Xiaozhen (1); Yang, Congxin (1); Li, Yibin (1); Li, Qiang (2)
Author affiliation:(1) School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China; (2) Chemical Machinery Research Institute, Hefei University of Technology, Hefei 230009, China
Corresponding author:Yang, C.(ycxwind@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:60-67
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aiming at influences of different inlet flow on non-overload performance of Serial-Parallel Centrifugal Pump (SPCP), establishment of accurate prediction methods is necessary. In fact, the motor of the pump can easily burn out when the pump is working with a large flowing capacity and a high head. A pump is deemed as one with non-overload characteristics when its motor power is larger than 120% of the max shaft power, therefore the non-overloaded characteristic analysis of the SPCP plays a significant role for the safe running of the pump. In this paper, the average angle of inlet velocity (&theta;&macr;), which the impeller inlet flow distribution can be efficiently assessed, is firstly introduced to calculate the maximum shaft power (P<inf>max</inf>) of Single-Stage Model Pump (SSMP) in the case of impeller inlet about no-pressure straight pipe, and relevant flow (Q'<inf>t</inf>) formula based on velocity triangle theory. Then, having researched the applications of SPCP in the case of two different impeller inlets: No-pressurehalf spiral and pressurehalf spiral. Once more, Computational Fluid Dynamics (CFD) is used to simulate the external characteristic curve of each model, and the enclosed experiment settings are adopted to firstly conduct analysis on the single stage model pump and then on SPCP after modifying the inlet and outlet pipes. In conclusion, analysis indicates that the results of calculation and experiments coincide with each other well. Under the design condition, the head error and the power error are respectively 1.20% and 2.40%, and when the SPCP is in the serial working condition, the head error and the power error are respectively 3.80% and 4.10%; in parallel working condition, the head error and the power error are respectively 2.90% and 3.50%. Therefore, those head errors and power errors are less than 5%, which proves the correctness of numerical simulation. What's more, with the different inlet flow state, axial velocity is distributed uniformly with a little change while the value of &gamma;, the angle between the speed vector of unit nodes and the axial-surface streamline, has a big change. By comparing the values of the &gamma; in different working conditions, it can be found that the non-uniform flow in serial working status is more obvious than that in parallel working status. In addition, a.k.a. &theta;&macr;= &gamma;, by putting these results into formulas, the theoretical Q'<inf>t</inf> and P<inf>max</inf> values can be obtained, which are later compared with the experimental results. The Q'<inf>t</inf> and P<inf>max</inf> values in non-overloaded working condition have much smaller errors when compared with experiment results, which are respectively 1.38% and 0.47% in the SSMP. However, when the SPCP is in serial working condition, it is easy to go overload. When Q'<inf>St</inf>=78.10 m³/h, the pump is at its max power point; in parallel working condition, with Q'<inf>Pt</inf>=168.50 m³/h, the pump is at its max power point, since the volume of flow is double that of before, for single-stage single-suction centrifugal pumps, it has its max power point only when Q'<inf>t</inf>=84.25 m³/h. In actuality, when the rated power of a SPCP motor reaches P<inf>motor</inf> &ge; P<inf>max</inf>, e.g. P<inf>motor</inf> &ge; 56.64 kW, the pump can achieve its non-overloaded characteristics. This research shows an excellent theoretical innovation, holds a high perspective and provides theoretical reference for designing the hydraulic property of SPCP.
Number of references:26
Main heading:Inlet flow
Controlled terms:Centrifugal pumps - Computational fluid dynamics - Errors - Experiments - Impellers - Intake systems - Numerical methods - Pumps - Testing
Uncontrolled terms:Characteristic analysis - External characteristic - Hydraulic properties - Inlet conditions - Non-overload - Non-overload characteristics - Serial parallels - Theoretical innovations
Classification code:423.2 Non Mechanical Properties of Building Materials: Test Methods - 601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 731 Automatic Control Principles and Applications - 901.3 Engineering Research - 921 Mathematics - 921.6 Numerical Methods
DOI:10.3969/j.issn.1002-6819.2014.13.008
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 9>

Accession number:20142917960243
Title:Design and experiment on handheld air-assisted pollination device
Authors:Ding, Suming (1); Xue, Xinyu (1); Cai, Chen (1); Qin, Weicai (1); Fang, Jinbao (2); Sun, Zhu (1)
Author affiliation:(1) Nanjing Research Institute of Agricultural Mechanization, Ministry of Agriculture, Nanjing 210014, China; (2) Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
Corresponding author:Xue, X.(735178312@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:20-27
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pollination is a very important process for high yield and quality of fruits production. The artificial and bee pollinations are wildly used in fruits production, but they are unadaptable to large scale production. So a kind of handheld air-assisted pollination device was developed. Through theoretical calculation, the air supply device was determined to adopt 6 impellers, the impeller diameter is 38 mm and the guide blades width is 18 mm. The motor is driven by DC power. A wind velocity indicator was used and the test ring was put at 500 mm ahead of the air inlet which is connected with a set of rams to fan pipes. The ram's diameter is 38 mm, same as the impeller. The results of fan performance test showed that the air volume was 3.0(10^-3 m³/s at 8000 r/min of fan speed, which can meet the design requirements. The highest total pressure efficiency is 43% at 9000 r/min of fan speed. With the speed increase, the total pressure efficiency dropped rapidly but the power increased and the variation trends of the air volume and air pressure are not significant. The fan property was tested and the performance curve graphic was drawn. The air velocity field at different rotational speeds of the handheld air-assisted pollination device were studied and validated by the experiment data. The results showed that the velocity of central plane diffused at a fixed angle and decayed along the centre line, and the theoratical values closely related to the experiment data. In order to study the effect of airflow speed on pollination, the basic principle of pneumatic pollination was analyzed. Tests were conducted to validate the effect of airflow speed on pollens distribution based on pollens density, horizontal distribution and vertical distribution in the lab. The results show that the flow rate of nozzle is affected by wind velocity significantly. When the winds velocity reaches 25 m/s, the variation trends of the flow rate of nozzle are not significant with the speed increase. And the pollens distribution is affected by wind velocity significantly, and the dusting rate on horizontal and vertical distribution increase with the wind velocity increase. A peak in horizontal and vertical distribution is far away from the pollen source with the wind velocity increased. And the peak in vertical distribution keeps stable within a certain distance, which suggests that the pollens can be spread in straight line with a certain speed and directional airflow. The field experiment was conducted in a kiwi grove which was grown with "Hongyang" kiwi trees. The row space is 3 m&times;2 m, the height of the tree is 1.8 m. Three trees were randomly selected as sample trees, 10 flowers were selected in each tree, and the distance of pollination is 15-20 cm. The pollen coverage ratio of stigma in each flower was measured by micro camera and droplets image processing system. The results show that the pollen coverage increases significantly with the increase of the fan speed. When the nozzle outlet velocity is 19.5 m/s, the pollen coverage is 57.66%. The research can provide a reference for structural design and optimization of working parameters in same type device.
Number of references:20
Main heading:Fruits
Controlled terms:Agricultural machinery - Atmospheric pressure - Birds - Experiments - Flow rate - Flow velocity - Forestry - Image processing - Impellers - Nozzles  - Optimization - Pressure control - Structural design - Velocity - Wind
Uncontrolled terms:Air-assisted - Design and optimization - Horizontal distribution - Image processing system - Kiwi - Large scale productions - Pollination - Theoretical calculations
Classification code:408.1 Structural Design, General - 443.1 Atmospheric Properties - 461 Bioengineering and Biology - 601.2 Machine Components - 631 Fluid Flow - 631.1 Fluid Flow, General - 731.3 Specific Variables Control - 741 Light, Optics and Optical Devices - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 822 Food Technology - 901.3 Engineering Research - 921.5 Optimization Techniques - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2014.13.003
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 10>

Accession number:20142917960257
Title:Photosynthesis characteristics and yield of broomcorn millet under film mulching on ridge-furrow for harvesting rainwater model in semi-arid region of Northern Shaanxi
Authors:Su, Wang (1); Qu, Yang (1); Feng, Baili (1); Chai, Yan (1)
Author affiliation:(1) State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A and F University, Yangling 712100, China; (2) Baoji Research Institute of Agricultural Science, Qishan 722400, China
Corresponding author:Feng, B.(7012766@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:137-145
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The crop productivity is low and unstable in arid and semi-arid region, and water is an important factor limiting crop yield. How to effectively use water and steadily increase crop productivity becomes the focus of attention. Broomcorn millet is one of important crops with large planting area in semi-arid region of Northern Shaanxi, China. In this study, the mechanism of increasing yield under film mulching on ridge-furrow for harvesting rainwater was investigated to provide theoretical support about high yield farming technology of broomcorn millet in arid and semi-arid areas. To explore the effects of film mulching on ridge-furrow for harvesting rainwater on photosynthesis characteristics and yield of broomcorn millet in semi-arid region of Northern Shaanxi, China, a three-year field experiment was conducted with four different widths of ridge and furrow from 2010 to 2012, and the bare land flat sowing as the control (CK). The width of ridge and furrow were 40 cm: 40 cm (P<inf>40</inf>), 60 cm: 60 cm (P<inf>60</inf>), 80 cm: 80 cm (P<inf>80</inf>), and 100 cm: 100 cm (P<inf>100</inf>), respectively. The field experiment used a randomized block arrangement with three replications. The plant density was 5.0&times;10⁵ plants/hm², and the average row spacing was 40 cm. Before sowing, soil preparation, fertilization and film covering had been performed. The organic fertilizer, urea and calcium phosphate were applied in 7500, 75 and 75 kg/hm², respectively. The white plastic film used in the experiment was 0.008 mm thick. Net photosynthetic rate, stomatal conductance and intercellular CO<inf>2</inf> concentration were measured at 9:00-11:00 am on sunny and windless day, and yield traits were measured in the maturity stage of broomcorn millet. The results showed that film mulching on ridge-furrow for harvesting rainwater could significantly increase the photosynthetic rate and stomatal conductance, and decrease the intercellular CO<inf>2</inf> concentration at each growth stage of broomcorn millet. With the increase of ridge and furrow width, the photosynthetic rate and stomatal conductance increased at first and then decreased, and the intercellular CO<inf>2</inf> concentration decreased at first and then increased in the same growth stage of broomcorn millet. The film mulching on ridge-furrow for harvesting rainwater had little influence on main agronomic characters, but increased significantly plant height and yield of broomcorn millet. The photosynthesis of broomcorn millet was controlled by non-stomatal factor at each growth stage, and film mulching on ridge-furrow for harvesting rainwater could reduce the non-stamatal limitation on the photosynthesis significantly. In conclusion, film mulching on ridge-furrow for harvesting rainwater could enhance leaf photosynthesis capacity, improve broomcorn millet yield formation variables, and the treatment P<inf>60</inf> was the best among all the treatments, which could be recommended as an efficient planting pattern in the production of broomcorn millet in semi-arid region of Northern Shaanxi, China.
Number of references:47
Main heading:Film growth
Controlled terms:Arid regions - Atmospheric composition - Carbon dioxide - Catchments - Crops - Fertilizers - Film preparation - Harvesting - Photosynthesis - Plastic films  - Productivity - Urea
Uncontrolled terms:Arid and semi-arid areas - Arid and semi-arid regions - Broomcorn millet - Net photosynthetic rate - Northern shaanxi - Organic fertilizers - Stomatal conductance - Yield
Classification code:444 Water Resources - 712.1 Semiconducting Materials - 741.1 Light/Optics - 801 Chemistry - 804 Chemical Products Generally - 817.1 Polymer Products - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2014.13.017
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 11>

Accession number:20142917960254
Title:Modelling evapotranspiration in provincial regions based on FY-3/VIRR remote sensing data
Authors:Zhao, Hong (1); Zhao, Yujin (1); Li, Feng (1); Zhang, Haibo (1)
Author affiliation:(1) Climate Centre of Shandong, Jinan 250031, China
Corresponding author:Zhao, Y.(zhaoyujin999@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:111-118
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to expand meteorological satellite FY-3 in scientific research, the application of remote sensing inversion of the data is needed for evapotranspiration studies. Based on FY-3/VIRR channel characteristics and use of Shandong as a case study area, we proposed to use FY-3 satellite remote sensing data for regional evapotranspiration inversion and to establish a provincial regional daily evapotranspiration estimation system based on the surface energy balance equation in combination with ground meteorological elements (air temperature and wind speed). To test our newly developed system for estimation of evapotranspiration, we used May 11, August 20, October 16, 2013 as our study dates. The results showed that evapotranspiration estimated from the inversion of the FY-3/VIRR data was respectively -0.19 mm/d, -0.12 mm/d, and 0.16 mm/d difference for the three tested dates as compared to the results obtained from the Penman equation. The relative deviation of the results between the two methods was 10%, 12% and 11% for the three tested dates, respectively. The tested results showed a better FY-3 data quality for the distribution patterns that reflected different types of surface evapotranspiration and features including the daily highest evapotranspiration in a variety of water surfaces. Followed by the types of water surface was the artificial influence of land uses such as arable land, urban, etc. The least affected by human activities for the evapotransiration was mainly natural vegetation and land cover types, such as woodlands, shrubs. The bare land had the lowest evapotranspiration inversion which accurately revealed the different land cover types in the area of evapotranspiration and the space characteristics and differences. Evapotranspiration spatial distribution of farmland has important implications for drought monitoring, irrigation, etc., It is necessary to conduct further analysis of cropland evaporation. Depending on grain yield, farmland can be divided into high, medium and low-yield fields. Evapotranspiration over the different grain yield types showed that amount evapotranspiration was high in the high and middle yield field and low in the low yield field. In the high and middle yield field, paddy water conditions were relatively good, soil water supply was adequate and crop growth was good resulting large amount of actual evapotranspiration. For the low yield field, soil water supply was poor resulting poor crop growth and hence small amount of actual evapotranspiration. The estimated result conformed to the water consumption characteristics of grain filling stage of wheat. The segment EOS/MODIS evapotranspiration product comparison analysis showed that: two kinds of daily ET overall spatial distribution was very similar with correlation coefficients &gt;0.99 and the mean square root difference &lt;0.36 mm. The above analysis showed that in the absence of data for measured evapotranspiration for all land cover types, the estimated daily ET using FY-3/VIRR through mutual comparison and verification of the results of the past studies were reasonable. This study showed a great potential in future evapotranspiration retrieval operation using Chinese FY-3/VIRR satellite data.
Number of references:32
Main heading:Evapotranspiration
Controlled terms:Crops - Energy balance - Farms - Grain (agricultural product) - Interfacial energy - Land use - Remote sensing - Soil moisture - Space optics - Spatial distribution  - Water supply - Weather satellites
Uncontrolled terms:Actual evapotranspiration - Daily evapotranspirations - EOS/MODIS - FY-3/VIRR - Meteorological elements - Regional evapotranspiration - Satellite remote sensing data - Surface evapotranspiration
Classification code:403 Urban and Regional Planning and Development - 444.1 Surface Water - 446.1 Water Supply Systems - 483.1 Soils and Soil Mechanics - 655.2 Satellites - 731.1 Control Systems - 741.1 Light/Optics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 921 Mathematics - 931 Classical Physics; Quantum Theory; Relativity - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2014.13.014
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 12>

Accession number:20142917960252
Title:Modelling soil water content in plow layer using co-kriging interpolation based on hyperspectral data
Authors:Xu, Chi (1); Zeng, Wenzhi (1); Huang, Jiesheng (1); Wu, Jingwei (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
Corresponding author:Huang, J.(jshuanga@public.wh.hb.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:94-103
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Understanding the distribution of soil water content of plow layer (0-40 cm) is important for agriculture water management for plant growth. In our study, Hyperion data (EO-1, USGS) was firstly used to inverse topsoil water content and then the measured water content values of 0-40 cm depth were used to calculate the average water content of plow layer. Both data can be used together to obtain a distribution of regional plow layer water content. By use of such method, a study was carried out by taking soil samples in a 64 hm² area located in Hetao Irrigation District, Inner Mongolia, China in late April. The soil samples were arranged in gird and the grids size were 20, 50, and 100 meters respectively. There were 136 different sampling points and 103 of them had soil samples (0-40 cm depth with 10 cm increment). The time of Hyperion data was April 11, 2013 and it was pre-processed by EVNI 5.0 software. Then derivative filter (1st) was used to remove the scattering and other disturbance. Both raw and filtered images were used to inverse the water content of topsoil using the flag index method and partial least square regression (PLS). After that, the water content of topsoil obtained by Hyperion data were used as the co - variable and the average water contents of 0-40 cm depth were used as the main variable in the co - kriging method to map the water content of plow layer (0-40 cm depth) in the study area. The results indicated that sensitive wavelength bands for topsoil water content were ranged from 1295 nm to 2224 nm when using the flag index method, and the accuracy of prediction models of the flag index method was poor (r&lt;0.2 in the validation process). However, prediction models established by PLS method can yield higher accuracy compared to the flag index method (r&gt;0.5 in both calibration and validation process. The co-kriging interpolation had a consideration of water content of both topsoil (0-10 cm) and plow layer (0-40 cm), and the C<inf>0</inf>/(C<inf>0</inf> C) values in the models were all &lt;25%, demonstrating small random variations in these interpolation models. In addition, compared with the method of linear fitting using topsoil water content and plow layer water content, the co-kriging method can increase 72.6% of r² and 89.9% of NSE. Therefore, combined hyperspectral inversion with the co-kriging interpolation can be used to predict soil water content of plow layer effectively.
Number of references:43
Main heading:Water content
Controlled terms:Calibration - Interpolation - Mathematical models - Remote sensing - Soil moisture - Soil surveys - Soils - Water management
Uncontrolled terms:Calibration and validations - Co-Kriging - Hetao irrigation districts - Hyperspectral Data - Partial least square regression - Quantitative inversion - Sensitive wavelengths - Soil water content
Classification code:444 Water Resources - 483.1 Soils and Soil Mechanics - 731.1 Control Systems - 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.1002-6819.2014.13.012
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 13>

Accession number:20142917960271
Title:Development of heat transfer coefficient model for external heated rotary kiln with low filling large particles
Authors:Wu, Jing (1); Li, Xuanyou (2); Chen, Baoming (3); Gao, Ling (2); Wang, Ruixue (2); Zhao, Gaiju (2); Wang, Chengyun (2)
Author affiliation:(1) School of Energy and Power Engineering, Shandong University, Jinan 250061, China; (2) Shandong Tianli Drying Technology Co. Ltd, Jinan 250101, China; (3) Department of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, China
Corresponding author:Li, X.(lixuanyou@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:256-262
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Heat transfer coefficient is one of the most crucial parameters in thermal calculation and design for an externally heated rotary kiln. Suitably designed kiln dimensions, structure and operating parameters rely on the accuracy of the employed heat transfer coefficient. For an externally heated kiln, heat transfers from an outside source to inside particles through a wall. Generally, the filling ratio in an externally heated rotary kiln is low. So, the heat transfer mechanism for large particles with a low filling ratio in an externally heated rotary kiln is quite different from that in an internally heated rotary kiln, whose filling ratio is usually more than 15 percent. Despite the existence of some achievements in particles motion behavior and heat transfer mechanisms in an internally heated rotary kiln, so far, there is no reliable heat transfer model to describe the heat transfer process between the kiln's surface and particles in an externally heated rotary kiln with low filling large particles. As a result, the main approach of heat transfer coefficient determination is still an experimental test. On the basis of heat transfer mechanism analysis, this paper regards the heat transfer process between the kiln's surface and large particles as consisting of heat conduction between the kiln's surface and gas film, heat convection between the gas film and particles, and heat radiation between the kiln's surface and particles. Finally, a mathematical model is created for the prediction of the heat transfer coefficient between the kiln's surface and large particles. To validate the developed model, a series of experimental tests are performed. Alumina spherical grains with a diameter of 6 mm are used as testing particles. When the filling ratio is 5 percent, the heat transfer coefficients are measured in the range of 220&deg;C-420&deg;C at 20&deg;C surface temperature intervals, corresponding to the rotary speeds of 1r/min, 2r/min, and 3r/min, respectively. The tests find that the heat transfer coefficient only slightly increases with rotary speed increase. However, the coefficient increases intensely when the kiln's surface temperature increases. Comparisons of the experimental results and predictions show that the maximum relative error (e<inf>max</inf>) is about 9.8 percent, and the average error (e<inf>ave</inf>) is 5.86 percent. According to the engineering design heat transfer coefficient model experience, the model is able to well match the engineering requirement that it can refer to thermal calculation. The results also show that, for the testing material in this paper, the fraction of radiation heat transferred from kiln's surface to particles is more than 75 percent of the total heat transfer when the surface temperature is higher than 220&deg;C. If the surface temperature is beyond 320&deg;C, a more intense increasing percentage of cure will appear. The error analysis shows that the prediction values are all larger than testing results, which could be caused by the assumptions of both particle distribution and radiation heat transfer between the kiln's surface and particles. To obtain a more accurate heat transfer coefficient model for large particles with low filling ratio in an externally heated rotary kiln, it is necessary to carry out further investigate into the performance of the motion behavior of particles. The achievement in this paper is helpful for further investigation of heat transfer mechanism in an externally heated rotary kiln.
Number of references:29
Main heading:Heat transfer coefficients
Controlled terms:Alumina - Atmospheric temperature - Filling - Heat radiation - Heat transfer - Mathematical models - Models - Rotary kilns - Surface properties - Temperature
Uncontrolled terms:External heated - Heat transfer mechanism - Heat transfer process - Maximum relative errors - Operating parameters - Particle distributions - Surface temperatures - Transfer coefficient
Classification code:443.1 Atmospheric Properties - 641.1 Thermodynamics - 641.2 Heat Transfer - 642.2 Industrial Furnaces and Components - 691.2 Materials Handling Methods - 812.1 Ceramics - 902.1 Engineering Graphics - 921 Mathematics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.13.031
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 14>

Accession number:20142917960272
Title:Difference in wettability of lotus leaves in typical states and its mechanism analysis
Authors:Sun, Yanhong (1); Yang, Xiaodong (2); Yang, Zhuojuan (1); Wang, Qingcheng (1); Men, Yuzhuo (2)
Author affiliation:(1) Department of Mechanics Engineering, Jilin Teachers' Institute of Engineering and Technology, Changchun 130052, China; (2) Department of Mechanical and Electronic Engineering, Changchun Institute of Technology, Changchun 130012, China
Corresponding author:Yang, X.(y86908051@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:263-267
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Recent studies have made great progress on the superhydrophobicity and self-cleaning functions of lotus (nelumbo nucifera) leaves. However, studies on the self-cleaning function of lotus leaves at different states are still lacking. It is still unclear about whether the self-cleaning function of the lotus leaves remains at different states. In this study, the wettability of lotus leaves under four typical states, including fresh leaves, old leaves, sick leaves and dried-up leaves, was compared to explore the hydrophobic mechanism of lotus leaves. Wettability of different lotus leaves was determined. Another measurements included contact angle tests, scanning electron microscope (SEM) measurement for the microcosmic patterns of the lotus leaves, and the chemical analysis of the wax extracted from the leaf surface were done. From the contact angle results and the distribution of water drops on the lotus leaves under different states, it was found that the water droplets were of different wetting degree at different lotus leaves. On the fresh lotus leaves, water could roll together into an almost perfect sphere, and roll freely on the leaves. On the old lotus leaves, some of water droplets could form approximate spheres although the edges of the leaves were curled. The hydrophobicity of dried-up leaves remained well on the surface without peeling. However, the water droplets spread very fast on the sick leaves, displaying the hydrophilicity. The contact angle values of the fresh leaves, old leaves, and dried-up leaves were 153&deg;&plusmn;3&deg;, 141&deg;&plusmn;3&deg;, 150&deg;&plusmn;3&deg;, respectively, showing hydrophobicity or superhydrophobicity. The contact angle value of the sick leaves was 58&deg;&plusmn;2&deg;, displaying hydrophilicity. The results above were consistent with the observations. According to SEM measurements to visualize the surface microstructure of lotus leaves, the fresh lotus leaves had micro- and nanoscale hierarchical structures, for example the papillae microstructures were covered by wax clusters. The microcosmic pattern of dried-up lotus leaves was mostly similar except that papilla and wax clusters were slightly converged. The surface of the old lotus leaves was much rougher, which was composed of batten-like convexes, papillae and wax. Different from fresh and old lotus leaves, the sick lotus leaves had the surface with irregular linear fiber network structure rather than the papilla wax hierarchical structure. In addition, obvious difference of the surface wax content determined by comparing the wax extraction results was also observed for these four different kinds of lotus leaves. The wax content was only 1.03% for the sick leaves, much lower than that for the fresh (1.98%), old (1.94%), and dried-up (2.09%). In summary, the results here showed that the difference in the wettability for these four different lotus leaves could be attributed to the different microstructures of the leave surfaces as well as the difference in the surface wax contents. Among them, the microcosmic pattern was the major factor affecting the hydrophobicity of the lotus leaves.
Number of references:19
Main heading:Wetting
Controlled terms:Cleaning - Contact angle - Hydrophilicity - Hydrophobicity - Mechanisms - Microstructure - Scanning electron microscopy - Waxes
Uncontrolled terms:Distribution of water - Hierarchical structures - Hydrophobic mechanisms - Mechanism analysis - Microcosmic pattern - Nelumbo nucifera - Superhydrophobicity - Surface microstructures
Classification code:601.3 Mechanisms - 802.3 Chemical Operations - 804.1 Organic Compounds - 931.2 Physical Properties of Gases, Liquids and Solids - 933 Solid State Physics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.13.032
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 15>

Accession number:20142917960250
Title:Optimal design of reversible pump-turbine runner
Authors:Wang, Xuhe (1); Zhu, Baoshan (1); Cao, Shuliang (1); Tan, Lei (1)
Author affiliation:(1) State Key Laboratory of Hydro Science and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China
Corresponding author:Zhu, B.(bszhu@mail.tsinghua.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:78-85
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a key component of a reversible pump-turbine unit, a pump-turbine runner rotates at two opposite directions under the pump and turbine modes. The flow states in the runner are quite different under the pump and turbine modes, which creates a great challenge for the design of a pump-turbine runner. Nowadays, a pump-turbine runner is always designed in one mode and verified with the other mode. Since there are several parameters affecting the runner's performances and one parameter might have contrary effects on runner performances under the pump and turbine modes, it is hard to obtain a runner with high performance at both the pump and turbine modes by a trial and error method. In the present paper, a 3D inverse design method, CFD calculations, and multi-objective optimization strategy were coupled, and an optimal design system was built to improve the performances of a reversible pump-turbine runner. In the system, by using a 3D inverse design method, the runner shape was obtained by inputting corresponding parameters. A validated CFD method was used to estimate runner performances under different operating conditions. A multi-objective optimization strategy was then adopted to search runners with good performances at both operating modes in the design space based on a response surface model between input parameters and runner performances. The optimal design system was capable of solving some difficulties in pump-turbine runner design, such as a long design cycle and difficulties in obtaining good performances at both pump and turbine modes. The system was used to optimally design a middle-high head reversible pump-turbine runner, in which blade loading and blade lean were chosen as the input parameters, runner efficiency at the pump design point and the turbine rated point were set as optimization objectives, and the head at pump design point was set as a constraint. Since the optimization calculations were based on a response surface model, performances of nearly 10000 runners under different operating modes were estimated in several minutes. Three runners from the Pareto frontier were chosen for detailed validation. CFD results showed that the optimal runner had a high hydraulic efficiency of over 95% at both the pump and turbine modes, which indicated a great improvement in runner efficiency in the turbine mode and the maintenance of high efficiency at the pump mode as compared with the initial design. The effects of the input parameters on runner interior characteristics under different operating modes were also analyzed in this paper. The results showed that fore-loaded blade loading distribution on the shroud was helpful in improving the flow state at the inlet under the pump mode by reducing the low-pressure area on the suction side. The blade lean at the high pressure side not only changed the work distribution along the span wise direction, but also improved the flow state by bringing down the pressure difference at the inlet in the turbine mode, and played an important role in improving runner efficiency, especially in the turbine mode.
Number of references:30
Main heading:Multiobjective optimization
Controlled terms:Computational fluid dynamics - Design - Efficiency - Hydraulic motors - Hydraulic turbines - Inlet flow - Loading - Optimal systems - Pumps - Surface properties  - Turbine components - Turbines - Turbomachine blades
Uncontrolled terms:Different operating conditions - Hydraulic efficiency - Inverse design methods - Inverse designs - Optimization calculation - Response surface modeling - Reversible pump-turbine - Trial-and-error method
Classification code:408 Structural Design - 617 Turbines and Steam Turbines - 617.1 Hydraulic Turbines - 618.2 Pumps - 631 Fluid Flow - 632.2 Hydraulic Equipment and Machinery - 672 Naval Vessels - 913.1 Production Engineering - 921.5 Optimization Techniques - 921.6 Numerical Methods - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.13.010
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 16>

Accession number:20142917960253
Title:Applicability assessment of reference evapotranspiration models in Beijing based on lysimeter measurement
Authors:Yuan, Xiaohuan (1); Yang, Xuejun (1); Chen, Chao (1); Wu, Juying (1)
Author affiliation:(1) Beijing Research and Development Center for Grass and Environment, Key Laboratory of Urban Agriculture (North), Ministry of Agriculture, Beijing 100097, China
Corresponding author:Wu, J.(wujuying1@263.net)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:104-110
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Reference evapotranspiration (ET<inf>0</inf>) is the basic parameter for the vegetation evapotranspiration calculation, the regional water balance analysis, and the water resources management. The ET<inf>0</inf> models have different adaptability for different regions because of the difference in meteorological conditions among regions. Measurement using lysimeter is the classical method for ET<inf>0</inf> model evaluation in European and American areas, but is seldom used in China, and no research reported for North China. Assessment of four ET<inf>0</inf> models, Penman-Monteith (FAO-56), Hargreaves-Samani, Priestley-Taylor, and Penman-van Bavel were conducted in Beijing using tall fescue (Festuca arundinacea L.) turf evapotranspiration measurement by auto-weighing lysimeter during the growing season (April - October) of 2012. Two lysimeters were established in cold-season grass tall fescue for standard ET<inf>0</inf>. The weather station (Dynamet, Dynamax Co. Ltd.) was set up in the experiment site to measure and record automatically the meteorological data of air temperature, air relative humidity, solar radiation and wind speed at 2 meter height above ground for the ET<inf>0</inf> calculation by the models. The linear regression and the root-mean-square error (RMSE) and the index of agreement (d) were used for assessing the prediction accuracy of the different models. The results indicated that the solar radiation showed a linear relationship (R²=0.95, p=2.72&times;10^-7) with the monthly reference evapotranspiration, indicating that the solar radiation energy was the main force to drive water from the vegetation to the atmosphere in SPAC system. The accuracy of the models declined with the time scale. The models showed different deviations in ET<inf>0</inf> calculation because of the different parameters input. The monthly ET<inf>0</inf> was underestimated by Priestley-Taylor model but overestimated by Penman-Monteith?Hargreaves-Samani and Penman-van Bavel models. For the daily ET<inf>0</inf>, Hargreaves-Samani and Penman-van Bavel models had a slight overestimation with the rate of 1.0167 and 1.0526, respectively, but Penman-Monteith and Priestley-Taylor models had an underestimation with the rate of 0.8204 and 0.7593, respectively. For the timely ET<inf>0</inf>, Priestley-Taylor had the lowest value among the models, while other models resulted in different values under different weather conditions. The overall estimation for the ET<inf>0</inf> at the monthly, daily, and hourly scales showed that the Penman-van Bavel equation was the most precise method for calculating reference evapotranspiration, with a RMSE of 0.63 mm/d and a d-index of 0.96 (monthly), a RMSE of 1.43 mm/d and a d-index of 0.89 (daily), a RMSE of 0.087 mm/h and a d-index of 0.87 (hourly). The calculating accuracy of Penman-Monteith model was a little lower than that of Penman-van Bavel with a d-index of 0.73-0.93.
Number of references:19
Main heading:Evapotranspiration
Controlled terms:Heat radiation - Lysimeters - Meteorology - Models - Soil surveys - Solar radiation - Sun - Vegetation
Uncontrolled terms:Calculating accuracy - Meteorological condition - Penman-Monteith models - Reference evapotranspiration - Regional water balance - Root-mean-square errors - Tall fescue - Water resources management
Classification code:406.2 Roads and Streets - 443 Meteorology - 444.1 Surface Water - 631.1 Fluid Flow, General - 641.2 Heat Transfer - 657.1 Solar Energy and Phenomena - 657.2 Extraterrestrial Physics and Stellar Phenomena - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 902.1 Engineering Graphics
DOI:10.3969/j.issn.1002-6819.2014.13.013
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 17>

Accession number:20142917960249
Title:Calculation method of slip factor for impeller outlet of centrifugal pump as hydraulic turbine
Authors:Shi, Guangtai (1); Yang, Junhu (1)
Author affiliation:(1) Scholl of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China
Corresponding author:Yang, J.(lzyangjh@lut.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:68-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hydraulic turbine is a kind of prime motor, it can convert pressure energy of the high pressure fluid into mechanical energy of the rotation of the turbine rotor, which can be used to generate electricity or drive the machine of energy consumption work, and achieve the goal of recycling the energy of the high pressure fluid. At present, scholars mainly concentrated on the research of choosing the suitable pump as hydraulic turbine by positive and negative working conditions, and efficient design method of hydraulic turbine. The research methods for pumps mainly focus on the combination of theory analysis, numerical calculation and experimental study. As for the hydraulic turbines, some scholars adopted numerical calculation and experimental study to predict their performances, but there are rare related literature reports on research of theoretical method. The slip factor is an important parameter when predicting the performance of hydraulic turbine. In order to predict the performance of hydraulic turbine through theoretical method, this paper analyzed the flow mechanism of fluid within the channel of impeller. The correctness was proved for the analysis results that take advantage of the potential theory. The calculation formula was deduced for the slip factor of impeller outlet of hydraulic turbine under the finite blade numbers, as while as the basic energy equation of hydraulic turbine when considering slip of impeller inlet and outlet based on the flow mechanism of fluid within channel of impeller. Combined with the Stodola method, the correctness and accuracy of these formulas were verified with examples. The study found that with the increase of specific speed, the slip degree of the impeller out of hydraulic turbine decreased gradually, and the slip degree of the impeller inlet was lower than that of the outlet for most of the low specific speed hydraulic turbine, but the slip degree of the impeller inlet was greater than that of the outlet for the medium and high specific speed hydraulic turbine. From research on ten models, it was found that the errors between the results of theory calculation and experiment are less than 5% for the low specific speed models, but relative large for the medium and high specific speed models. In other words, the calculation formula of slip factor of impeller outlet is more accurate to predict the performance of low specific speed hydraulic turbine. With the increase of inlet diameter of impeller and outlet blade angle, the slip degree of the impeller outlet of hydraulic turbine increased gradually. With the increase of blade numbers, the slip degree of the impeller outlet decreased gradually. With the increase of inlet blade angle, the slip degree of the impeller outlet first increased and then decreased. The effects of outlet diameter and inlet width of impeller on slip factor of impeller outlet of hydraulic turbine are less.
Number of references:28
Main heading:Hydraulic turbines
Controlled terms:Energy utilization - Flow measurement - Flow of fluids - Forecasting - Hydrodynamics - Impellers - Inlet flow - Research - Speed control - Turbines  - Turbomachine blades - Well pumps
Uncontrolled terms:Calculation formula - Generate electricity - High-pressure fluids - Mechanical energies - Numerical calculation - Relative velocity - Slip factor - Theoretical head
Classification code:446.1 Water Supply Systems - 525.3 Energy Utilization - 601.2 Machine Components - 617.1 Hydraulic Turbines - 631 Fluid Flow - 731.3 Specific Variables Control - 901.3 Engineering Research - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2014.13.009
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 18>

Accession number:20142917960247
Title:Effects of biofuels on performance and emissions of diesel engine under high-altitude hypoxic condition
Authors:Liu, Shaohua (1); Shen, Lizhong (1); Bi, Yuhua (1); Lei, Jilin (1); Zhang, Shengbin (1)
Author affiliation:(1) Yunnan Province Key Laboratory of Engines, Kunming University of Science and Technology, Kunming 650500, China
Corresponding author:Shen, L.(lzshen@foxmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:53-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to study the influence of different categories of oxygenated biofuels on the performance and emissions of a diesel engine in a high-altitude anoxic condition, comparative experiments on a horizontal two cylinder diesel engine by use of three fuels: pure diesel, ethanol-diesel E10 (containing 10% ethanol in volume percentage and 90% petroleum diesel in the blend fuel), and biodiesel-ethanol-diesel B10E10 (containing 10% biodiesel, 10% ethanol, and 80% petroleum diesel) blends were carried out. In the process of the test, the engine was not adjusted or modified. The test results showed that when fueled with the E10 and B10E10 oxygenated blended biofuels respectively, the power performance of the diesel engine decreased, and the average drop of the engine brake torque at full-load are 4.24% and 5.49%. And the brake specific energy consumptions (BSEC) of the blended fuels were basically lower than those of the diesel fuel, and the fuel economy improved. The properties of the blended fuels had effects on the changes of the engine fuel economy, and the changes were also related to the engine speed and load. When fueled with the E10 blended fuel, the carbon monoxide (CO) emissions of the engine increased at low loads and decreased at high loads. The hydrocarbon (HC) emissions of the engine were higher than those of the diesel fuel and the percentage range of increment was 4.9%~27.4%. And the nitrogen oxide (NO<inf>X</inf>) emissions were lower than those of the diesel fuel at low loads, which tended to be the same level of the diesel fuel at high loads. When fueled with the B10E10 blends, the carbon monoxide (CO) emissions and the hydrocarbon (HC) emissions of the engine tended to be the pure diesel fuel level at low loads and decreased at high loads. And the nitrogen oxides (NO<inf>X</inf>) emissions decreased at low loads, and increased at high loads. The soot emissions of the engine with the E10 and B10E10 fuels both decreased. The hydrocarbon (HC) emissions, the soot emissions, and the carbon monoxide (CO) emissions at low loads of the diesel engine fueled with the B10E10 fuel were all lower than those of the E10 fuel, while the nitrogen oxide (NO<inf>X</inf>) emissions were basically higher than the E10 fuel level. Compared with the E10 fuel, the B10E10 blended fuel had a better effect on the improvement of the carbon monoxide (CO) emissions, the hydrocarbon (HC) emissions, and the soot emissions of the diesel engine. But the decline in the engine power performance was larger, and the nitrogen oxide (NO<inf>X</inf>) emissions increased. The study can provide a reference for the application of oxygenated biofuels in high-altitude anoxic regions.
Number of references:31
Main heading:Diesel engines
Controlled terms:Biodiesel - Biofuels - Brakes - Carbon monoxide - Diesel fuels - Engines - Ethanol - Ethanol fuels - Fuel economy - Fuels  - Hydrocarbons - Neutron emission - Nitrogen oxides - Soot
Uncontrolled terms:Anoxic conditions - Comparative experiments - Hypoxic condition - Performance - Performance and emissions - Power performance - Specific energy consumption - Volume percentage
Classification code:521 Fuel Combustion and Flame Research - 523 Liquid Fuels - 602 Mechanical Drives and Transmissions - 612 Engines - 612.2 Diesel Engines - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 932.1 High Energy Physics
DOI:10.3969/j.issn.1002-6819.2014.13.007
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 19>

Accession number:20142917960267
Title:Pressure on base plate of lightweight square steel tube column for greenhouse and its simplified calculation model
Authors:Ding, Min (1); Li, Xiao (1); Fu, Xiangrong (1); Jiang, Xiugen (1)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
Corresponding author:Jiang, X.(jiangxg@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:219-227
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Prefabricated light steel structures have been widely used in multi-span greenhouses, agricultural facilities structures, temporary prefabricated building structures, and simple infrastructures due to its light weight, simple structure, and quick construction. Thin-walled square steel tube columns are good for two-way performance of a frame structures and becomes the most common structure member in a light steel structure. The column base is an important structure member to transfer the load in a light steel structure. Uneven distribution of the column base rigidity leads to nonlinear distribution of pressure on the base plate. It is important to achieve pressure distribution on the base plate for analyzing base rotation stiffness, ensuring bearing capacity of base and base plate, and preventing local compression failure of the concrete foundation. To present the pressure distribution of a semi-rigid base plate, taking a light square steel tube column base plate for example, 24 base models with 4 ribbed stiffener types and 6 eccentricity values were calculated by a numerical simulation method with consideration of the nonlinear static contact effect between base and concrete foundation. The base plate pressure distribution was obtained. Then a tri-linear model of base plate pressure distribution was achieved. At the same time, a simplified calculation model of light square steel tube column base plate pressure was proposed, and the corresponding key parameters were determined. The base plate pressure calculated by this simplified calculation model was compared with that by a numerical simulation, an analytical solution based on a Winkler elastic foundation beam model, and a triangular pressure distribution. The results showed that the maximum base plate pressure value calculated by a triangular pressure distribution locates the base plate end. That by numerical simulation, analytical solution, and the simplified calculation model all locates the column flange. The maximum base plate pressure value calculated by the simplified calculation model was obviously lower than that obtained by triangular pressure distribution, but close to that obtained by numerical simulation. Base plate pressure distribution curves calculated by the simplified calculated model, numerical simulation, and analytical solution met well with each other. The tri-linear simplified calculation model of light square steel tube column base plate pressure had the following three sections: base plate displacement within the scope of the two-column flange was one straight line, and that outside column flange was another two straight lines. The slope ratios of the two straight lines outside column flange and the one straight line within the scope of column flange were respectively 1/4 and -1 respectively. The fruits put forward an accurate and efficient base plate pressure calculation method for a light square steel tube column base design.
Number of references:25
Main heading:Structural design
Controlled terms:Analytical models - Calculations - Compression testing - Computer simulation - Concretes - Facilities - Greenhouses - Mathematical techniques - Models - Numerical models  - Plates (structural components) - Pressure distribution - Steel structures
Uncontrolled terms:Base plates - Eccentric compression - Non-linear distribution - Numerical simulation method - Pressure calculation - Simplified calculation models - Square steel tube - Winkler elastic foundation
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 408.1 Structural Design, General - 408.2 Structural Members and Shapes - 412 Concrete - 723.5 Computer Applications - 902.1 Engineering Graphics - 921 Mathematics - 931.1 Mechanics - 943 Mechanical and Miscellaneous Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.13.027
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 20>

Accession number:20142917960262
Title:Analysis on estimation accuracy of crop area caused by spatial sampling factors based on remote sensing data
Authors:Zhang, Huanxue (1); Li, Qiangzi (1); Wen, Ning (2); Du, Xin (1); Tao, Qingshan (2); Dong, Taifeng (1)
Author affiliation:(1) Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, China; (2) Hunan Province Land and Resources Planning Institute, Changsha 410007, China
Corresponding author:Li, Q.(liqz@radi.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:176-184
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Crop acreage estimation is important for the assurance of food security and establishment of national socio-economic development planning. During the current development period, rapid, accurate and reliable estimation for crop acreage is particularly significant in China since the estimation can be affected by many factors such as ecological degradation and farmland reduction. Spatial sampling technology plays an important and irreplaceable role in crop acreage investigation and estimation. However, the effects of sampling factors on estimation are unclear. This study analyzed data on late-season rice in paddy field of Hunan province of China, an area with significant flooded paddy rice agriculture and mixed rice cropping patterns, in order to quantitatively evaluate the influence and sensibility of various monitoring factors (sampling ratio, sampling grid, and sample distribution) on sampling efficiency of the existing space sampling techniques for estimating crop planting acreage. Nine kinds of sampling units and 31 kinds of sampling ratio levels were designed. Spatial stratified sampling was used, and the late rice planting proportion was considered as the stratification symbol. 1000 times repeated trials were conducted based on every kind of sampling plan. Spatial distribution (Variance to Mean Ratio, VMR) of every sampling units and sampling ratio levels were determined. Spatial statistics methods and manifold accuracy evaluation indices (relative estimation error and standard deviation) were used to analyze the acreage estimation results obtained based on the different sampling plans. Then a comprehensive model based on sampling grid, sampling ratio, and sample distribution was developed to assess the sampling monitoring error rate of crop acreage estimation. The result demonstrated that: 1) With the increasing of the sampling grid, the average estimation error increased (R²=0.92), and when the sampling grid was less than 5 km, the estimation error rate was controlled within 5%, the standard deviation was not more than 0.12; 2) With the increasing of the sampling ratio, the average estimation error decreased (R²=0.82), and when the sampling ratio was greater than 0.4%, the estimation error rate was controlled within 5%, and the standard deviation was less than 0.12; 3) Under the condition in which the sampling ratio had been determined, the sample spatial distribution of the sample was an important factor affecting the accuracy of sampling. With the sample distribution tending to cluster distribution, the average estimation error rate increased, and when the variance to mean ratio (VMR) was less than 0.7 the estimation error rate and the standard deviation was controlled within 5% and 0.1, respectively; 4) The quantitative model reflecting the influence of the three factors on crop acreage estimation accuracy was developed. In summary, this study revealed the influence rules and sensibility of sampling factors (sampling ratio, sampling grid, and sample distribution) on crop acreage estimation. In addition, a good method was developed for optimizing spatial sampling and improving the accuracy of crop acreage estimation based on the particular sampling program.
Number of references:30
Main heading:Importance sampling
Controlled terms:Crops - Error analysis - Estimation - Food supply - Sampling - Spatial distribution - Statistics
Uncontrolled terms:Cluster distributions - Ecological degradations - Planting acreage - Quantitative modeling - Sample distributions - Socio-economic development - Spatial sampling - Variance-to-mean ratio
Classification code:404.2 Civil Defense - 801 Chemistry - 821.4 Agricultural Products - 921 Mathematics - 921.6 Numerical Methods - 922 Statistical Methods - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.13.0176
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 21>

Accession number:20142917960260
Title:Design of movable remote crop monitoring system on fixed truss
Authors:Han, Wenting (1); Cui, Lihua (3); Chen, Wei (1); Li, Min (1); Ooi, Su Ki (4); Wu, Pute (2)
Author affiliation:(1) College of Mechanical and Electric Engineering, Northwest A and F University, Yangling 712100, China; (2) Institute of Water-saving Agriculture in Arid Areas of China, Northwest A and F University, Yangling 712100, China; (3) Engineering Research Institute, Beiqi Foton Motor Co., Ltd., Beijing 102206, China; (4) Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville VIC 3010, Australia
Corresponding author:Wu, P.(gjzwpt@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:160-168
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The image obtaining angle and scope for the fixed image acquisition device is limited for obtaining an image of the desired crop; with the high cost of running the system, a vehicle-mounted mobile multipoint access method needs to move the car as the carrier, and affects the image acquisition system automation level. In order to obtain a crop image in an enlarged acquisition scope, a crop image acquisition system was developed that the image acquisition device can move on a fixed truss. The system has five parts: an image acquisition device, rotation and pitching motion, vertical movement, horizontal movement, a remote control, and database management. The image color of crop growth information is at least 24 bit, and a resolution up to 640 &times;480 pixels. A high-definition network camera was used as the image acquisition device. A comprehensive intelligent control Pan Tilt Zoom (PTZ) was selected as the rotation and pitching motion, in order to expand the scope of monitoring, to increase the space rotation and to add pitching motion. The image acquisition device was installed on the intelligent control PTZ to achieve 360&deg; rotation and pitching movement. A helix four bar mechanism was designed for the vertical movement and the PTZ was fixed on it to achieve vertical movement for the camera. A sliding block guide mechanism was developed and the helix four bar mechanism was installed on it to achieve horizontal movement for the camera. Vertical movement and horizontal movement were driven by two stepper motors. Both stepper motors were checked, to ensure the system dynamics. In addition, the control software for the crop image remote acquisition system was developed. For the vertical movement and horizontal movement, the steering, speed, and step size control of stepper motor were realized by an intelligent stepper motor controller with a port of RJ45. For the rotation and pitching motion, the 360&deg; rotation, the four directions moving of PTZ and pitch motion control of PTZ were realized, by an intelligent control PTZ. For the image acquisition device, the functions of the camera such as the lens, focus, action of the camera, adjustment of aperture and video recording, were realized. The crop image database and the remote management system were also established with the functions such as image storage, download and upload statistical inquiries and so on. The system in a greenhouse was carried out in five months, with the system running stably, with a clear crop image and video information. Response of the control system time was less than 1 s, with the precision reaching 96.2%, the control accuracy reaching 96.2%, the crop image transmission response time was less than 2.5 s, which satisfied the use requirement. The image database management system is mainly used for image storage, download and upload, statistical query, etc. This crop image acquisition system provides a platform to diagnose the water and fertilize remotely by the obtained image in different parts for all plants within the monitoring area.
Number of references:28
Main heading:Search engines
Controlled terms:AC motors - Cameras - Crops - Database systems - Image acquisition - Intelligent control - Management - Management information systems - Monitoring - Remote control  - Rotation - Stepping motors - Trusses - Video recording
Uncontrolled terms:Four-bar mechanisms - Horizontal movements - Image acquisition systems - Images - Monitoring system - Statistical queries - Stepper motor controller - Transmission response
Classification code:408.2 Structural Members and Shapes - 601.1 Mechanical Devices - 705.3 Electric Motors - 705.3.1 AC Motors - 716.4 Television Systems and Equipment - 723 Computer Software, Data Handling and Applications - 723.3 Database Systems - 731.1 Control Systems - 742.2 Photographic Equipment - 821.4 Agricultural Products - 912.2 Management - 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.1002-6819.2014.13.020
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 22>

Accession number:20142917960274
Title:Evaluation of apple quality based on principal component and hierarchical cluster analysis
Authors:Gong, Liyan (1); Meng, Xianjun (1); Liu, Naiqiao (3); Bi, Jinfeng (1)
Author affiliation:(1) College of Food Science, Shenyang Agricultural University, Shenyang 110866, China; (2) Key Laboratory of Agricultural Product Processing and Quality Control, Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (3) Department of Biological Engineering, Liaoning Economic Management Cadre Institute, Shenyang 110122, China
Corresponding author:Meng, X.(mengxjsy@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:276-285
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The purpose of this study was to investigate the variations in physical and chemical characteristics of apple fruit from 30 varieties grown in the same place using pattern recognition tools. Twenty quality parameters of apple samples (e.g. weight, volume, density, color, hardness, sugar-acid ratio, Vitamin C, etc.) were analyzed. Interrelationships between the parameters and the apple variety were investigated by descriptive statistics, principal component analysis (PCA) and hierarchical cluster analysis (HCA). PCA is a mathematical tool which performs a reduction in data dimensionality and allows the visualisation of underlying structure in experimental data and relationships between data and samples. In hierarchical cluster analysis, samples are grouped on the basis of similarities, without taking into account the information about the class membership. The results obtained following HCA are shown as a dendrogram in which five well-defined clusters are visible. Samples will be grouped in clusters in terms of their nearness or similarity. Cluster analysis uses less information (distances only) than PCA. It is interesting to observe what kind of classification can be made on the basis of distances only. The results showed that density, fruit shape index and water content of 30 apple varieties were not significantly different. The remaining seventeen measurements were investigated by principal component analysis. The first six components represented 83.56% of the total variability on the base of the total variance explained and screen plot of principal component analysis. The first principal component was related to titratable acidity, sugar-acid ratio and solid-acid ratio attributes, which were the taste quality factor. The second principal component was related to L, a, and b attributes, which were the color factor. Following that were sweetness factor, texture factor, quality factor and size factor. The sample score plots visually displayed the relationship between measurements and apple varieties. The varieties of Liaofu, Lixiang, Golden Delicious and Rome Beauty were located on the first quadrant of the plot for PC1 vs. PC2. They had better quality of among the mid-early maturity apples with high content of sugar-acid and solid-acid ratios which were good characteristics of taste even though their skin color was green. The varieties of Hanfu, Rainier and Fuji were located on the fourth quadrant of the same plot. They were common late maturity apples with red color and good quality for eating. Priam, Baixing and Pvma were located on the second quadrant of the plot, which may be suitable for processing not for eating, and they had a green skin color and sour taste. The varieties located on third quadrant were red but had low sugar-acid and solid-acid ratios, which can be used as breeding materials for red color and good quality of the early maturity apple. HCA classified 30 varieties into five main groups on the basis of the measured parameters, which was consistent with the results of PCA score plots. These results can be used preliminarily to determine whether the 30 apple varieties were appropriate for eating or for processing or for use as a breeding stock for future apple variety development.
Number of references:38
Main heading:Principal component analysis
Controlled terms:Cluster analysis - Color - Data handling - Fruits - Hierarchical systems - Pattern recognition
Uncontrolled terms:Apples - Chemical characterization - Data dimensionality - Descriptive statistics - First principal components - Hierarchical cluster analysis - Physical and chemical characteristics - Principal Components
Classification code:723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 741.1 Light/Optics - 821.4 Agricultural Products - 922 Statistical Methods - 922.2 Mathematical Statistics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.13.034
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 23>

Accession number:20142917960275
Title:Analysis on factors affecting plasmin activity of raw milk quality
Authors:Zhang, Shuwen (1); Liu, Lu (1); Sun, Jie (2); Li, Hongjuan (1); Cui, Wenming (1); Lu, Jing (1); L&#252;, Jiaping (1)
Author affiliation:(1) Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (2) Chinese Academy of Agricultural Engineering, Beijing 100125, China
Corresponding author:L&#252;, J.(lvjp586@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:286-292
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plasmin(PL) is by far the predominant and most completely studied endogenous protease in bovine milk. PL activity level is an important factor affecting dairy product quality and its processing characteristics. Raw milk with a high PL level can have detrimental effects on the quality of pasteurized milk and UHT milk, causing undesirable flavor, precipitation and gelation, and shortening the shelf life of the product. Considerable research has focused on minimizing the activity of PL in fluid milk. Many factors, such as pH, mineral content, whey proteins, and storage temperature can influence the kinetics of the PL-induced hydrolysis. However, according to China's current raw milk production situatioin, the objective of this study is to determine how such factors such as cattle breed, parity, dairy farming mode, and milking time affect PL activity in milk; thermal stability of plasmin is also studied. The results show that the PL activity between dairy farming mode, parity, and cow breeds are significant (P&lt;0.05). Although there are effects of dairy farming mode, parity, and cow breeds on plasmin activity, they are lower in large scale farming, parity (1, 4), and Jersey cows. However, the effect of the milking time on PL activity is not significant (P&gt;0.05). PL activity of raw milk gradually decreases with increasing thermal treatment temperature. However, the thermal treatment associated with pasteurization of milk (75&deg;C, 15 sec) has been shown to increase PL levels. This increase in PL activity has long been attributed to inactivation of plasmin inhibitors(PI) and plasminogen activator inhibitors(PAI), but plasminogen activators (PA)is even more heat stable than PIand PAIduring pasteurization and UHT. In this temperature range, plasminogen (PG) loses its naturally occurring tertiary structure, but is not yet inhibited. On the contrary, PG becomes more accessible to the action of PA by unfolding of its kringles. Activation of PG is enhanced upon pasteurization heating. Further heat treatment has been shown to reduce PL levels. PL activity only decreases 25 percent after pasteurized (75&deg;C, 15 sec) treatment. The effects of cysteine addition and heat treatment on PL activity is also studied. The results show that cysteine has some inhibited effect on PL activity in milk. When milk was stored after heat treatment (75&deg;C), there is a decrease in PL activity. PL activity is significantly affected due to interactions with cysteine, which contains free SH groups that cause irreversible denaturation of PL by S-S/S-H interaction. When milk is heated to higher temperatures of 85&deg;C or 90&deg;C, a larger decrease in PG activity and no further increase in PL activity is observed. This is due to PG interaction with cysteine. PG activity is tested in the presence of cysteine, which causes a marked decrease in PG activity. Two-dimensional electrophoresis confirms that heating of PG in the presence of cysteine causes polymerization of PG into dimers, trimers, and polymers through disulfide interchange. Formation of polymers hinders the activation of PG into PL. This result suggests that the addition of cysteine prior to the pasteurization significantly decreases the potential for proteolysis caused by the PL system during storage. This study has certain reference value to the quality evaluation and grading of raw milk.
Number of references:29
Main heading:Dairies
Controlled terms:Amino acids - Chemical activation - Dimers - Electrophoresis - Enzymes - Gelation - Grading - Heat treatment - Pasteurization - Polymers  - Proteolysis - Quality control
Uncontrolled terms:Influence factors - Irreversible denaturation - Plasmin - Plasminogen activator inhibitor - Raw milk - Thermal treatment temperature - Thermostability - Two dimensional electrophoresis
Classification code:461 Bioengineering and Biology - 537.1 Heat Treatment Processes - 801.3 Colloid Chemistry - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.1 Organic Compounds - 815.1 Polymeric Materials - 822.1 Food Products Plants and Equipment - 822.2 Food Processing Operations - 913.3 Quality Assurance and Control
DOI:10.3969/j.issn.1002-6819.2014.13.035
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 24>

Accession number:20142917960268
Title:Mechanical properties of moulding material made from crop stalks and modified UF resin
Authors:Sun, Enhui (1); Huang, Hongying (1); Wu, Guofeng (1); Chang, Zhizhou (1); Xu, Yueding (1)
Author affiliation:(1) Jiangsu Agricultural Waste Treatment and Recycle Engineering Research Center, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Corresponding author:Chang, Z.(czhizhou@hotmail.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:228-237
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Due to advantages in being lightweight, inexpensive, biodegradable, and an easy process, composite materials with plant fiber filler have been widely applied in industry, agriculture, national defense, and other fields. In this study, flowerpots in a friendly environment were moulding-prepared through the procedure of mixing and hot-pressing in an oil hydraulic machine. The flowerpots were made of rice husk, rice husk power, and modified urea-formaldehyde resin. The rice husk or husk power components were added as reinforcing agents, while the resin component was added as a matrix material. The purpose of this paper is to discuss the influence of the dosage of urea-formaldehyde resin (UF), modified urea-formaldehyde resin (SUF), ratio of rice husk and rice husk power, and the wet cycle treatment on the mechanical property of the flowerpots. Thermal stability and microstructure of the flowerpots treated with the rewetting method were analyzed by Thermo-gravimetric Analysis (TGA) and a Scanning electronic microscope (SEM). The results showed that the mechanical properties of the flowerpots could be improved by applying modified urea-formaldehyde resin or adding rice husk power. With the dosage of modified UF, modulus of rupture, modulus of elasticity, and tensile strength of the straw flowerpot all improved. The modulus of rupture, modulus of elasticity, and tensile strength were 75.48 MPa, 16.06 GPa, and 17.44 MPa, respectively, when the ratio of reinforcing agent and matrix material was 1:0.5 (w/w) and the ratio of unbroken rice husk and rice husk power was 3:7 (w/w). Wet cycle treatment led mechanical parameter values of all formula specimens to decline in different degrees, with tensile strength and maximum bending deformation of SUF-pot specimens dropping most significantly. Using rice husk as the reinforcing agent (RH) in the wet cycle treatment resulted in the modulus of rupture, modulus of elasticity, and tensile strength of UF/RH to drop to 21.97%, 24.91%, and 15.09%, while SUF/RH dropped 9.92%, 15.37%, and 30.10%, respectively. TGA analysis showed that the pyrolysis rate and mode of the straw flowerpot materials by wet cycle treatment had been slightly changed; namely materials mass loss rate was reduced and maximum thermal decomposition temperature increased. The SEM graphs of the composites fractured surface showed that the surface of the flowerpots treated by wet cycling had become rough. Some pieces of rice husk divorced from modified urea formaldehyde resin were clearly visible. Obviously, the interface between rice hull and SUF had become weak. This test showed that the straw flowerpots prepared with SUF resin were less stable than those prepared with UF resin, which implied that the former was liable to degrade. In regard to the production costs, the straw flowerpots are more than 10% lower than the plastic flowerpots. Substitution of plastic flowerpots with straw flowerpots would not only be beneficial in reducing white pollution from the use of plastic products, but also in promoting comprehensive utilization of the crop straw. Therefore, there will be an excellent market prospect of straw flowerpots.
Number of references:35
Main heading:Synthetic resins
Controlled terms:Bending (deformation) - Bending strength - Composite materials - Crops - Elastic moduli - Hydraulic machinery - Mechanical properties - Molding - Plastic products - Pyrolysis  - Reinforcement - Straw - Tensile strength - Urea formaldehyde resins
Uncontrolled terms:Bending deformations - Comprehensive utilizations - Flowerpot - Mechanical parameters - Rice husk - Scanning electronic microscopes - Thermal decomposition temperature - Wet cycles
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 421 Strength of Building Materials; Mechanical Properties - 535.2 Metal Forming - 632.2 Hydraulic Equipment and Machinery - 802.2 Chemical Reactions - 815.1.1 Organic Polymers - 817.1 Polymer Products - 821.4 Agricultural Products - 821.5 Agricultural Wastes - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.13.028
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 25>

Accession number:20142917960244
Title:Design and experiment on automatic husking and peeling machine for lotus seeds
Authors:Xu, Xieqing (1); Rao, Honghui (1); Li, Tao (1); Liu, Muhua (1)
Author affiliation:(1) Institute of Technology, Jiangxi Agricultural University, Nanchang 330045, China
Corresponding author:Liu, M.(suikelmh@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:28-34
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Lotus seeds usually are processed by manual and mechanical methods. The manual processing method is time-wasting because it can take about 70 percent of the total time to husk and peel seeds. The mechanical method can save time and have high efficiency of production. But, the existing husking and peeling machines for lotus seeds all adopt the bilateral machine structure, which has the shortcomings of too heavy, high failure rate and difficulty for maintenance and adjustment. In this study, an improved automatic husking and peeling machine for lotus seeds with unilateral machine structure was designed based on the existing lotus seed processing machine. On this machine, a conveyor belt was adopted to transport the lotus seeds, and a rotating concave wheel was used to frict with the lotus seed shell surface for adjusting the lotus seeds' direction to keep the short diameter of lotus seeds in a direction consistent with the movement direction of the conveyor belt. And then a spacing device was used to separate the lotus seeds, a cam device was adopted to control the opening and closing of retaining needle and the dam-board for ensuring that only one lotus seed could be hold between the retaining needle and the dam-board, so the lotus seeds could pass one by one. Then the lotus seed shell was cut in a circle by a shell cutting device using a reciprocating razor blade while the lotus seed rolled ahead on the conveyor belt. The blade beyond the depth of knife rest baseplate was adjustable so that the cutting depth of the lotus seed shell could be controlled. After cutting the shell, the lotus seed rolled ahead under the effect of the conveyor belt and then got into the husking channel, with the rubbing and rolling motions, the lotus shell and kernel were separated. After removing the husks, the lotus seed still rolled ahead into the rinsing device and was grasped by the rinsing device with rotation and water rinsing, so the lotus seed coat was finally completely removed by the water gun. In a test with 1000 lotus seeds, the designed machine with unilateral machine structure here achieved a higher completely processing rate (91.3% vs. 73.25%), higher non-peeling rate (5.0% vs. 4.5%), lower damage rate (1.8% vs. 9.2%), and lower non-husking rate (1.9% vs. 13.1%) than the husking and peeling machine with bilateral machine structure, a widely used machine produced by GuangChang Dongsheng Machinery Factory in China. Since the structures were different, the machine with unilateral machine structure here had lower processing rate (96 vs. 151 seeds per min) and processing efficiency (20 vs. 30 kg/h) than the machine with bilateral machine structure. The performance of the machine could be affected by the lotus seeds' mature conditions. The overripe or too tender lotus seeds may be processed with poor quality. However, the machine with unilateral machine structure here could process various sizes of lotus seeds (13-19 mm in short diameter of lotus seed). It could work smoothly and efficiently with little damage. In addition, it was more stable and reliable, and its maintenance was much simpler compared to machine with bilateral structure. Thus, it would have a good application prospect.
Number of references:20
Main heading:Shells (structures)
Controlled terms:Agricultural machinery - Belt conveyors - Design - Maintenance - Needles - Optimization - Peeling - Plant shutdowns - Processing
Uncontrolled terms:Application prospect - Direction consistent - Husking - Lotus seeds - Machine structures - Manual processing - Mechanical methods - Processing machines
Classification code:402.1 Industrial and Agricultural Buildings - 408 Structural Design - 408.2 Structural Members and Shapes - 692.1 Conveyors - 818.5 Rubber Products - 819.6 Textile Mills, Machinery and Equipment - 821.1 Agricultural Machinery and Equipment - 913.4 Manufacturing - 913.5 Maintenance - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2014.13.004
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 26>

Accession number:20142917960269
Title:Layout and mode partition of high-standard basic farmland construction at county level based on four-quadrant method
Authors:Tang, Xiumei (1); Pan, Yuchun (1); Liu, Yu (1); Ren, Yanmin (1)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing 100097, China; (2) National Engineering Research Center for Information Technology in Agriculture, Beijing 100097, China; (3) Key Laboratory of Agri-informatics, Ministry of Agriculture, Beijing 100081, China
Corresponding author:Pan, Y.(panyc@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:238-246
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to improve the scientificity and rationality of the construction of high-standard basic farmland, this paper explored the layout pattern of high-standard basic farmland construction at county level using four- quadrant method, taking Wuhua County, Guangdong province as an example. By improving the comprehensive productivity of cultivated land and agricultural production conditions, the high-standard basic farmland construction has been playing a key role for the food security of China. The high-standard basic farmland construction is an important part of the local land consolidation plan, therefore, both of the basic condition of cultivated land and the social and economic suitability must be taken into account simultaneously in the high-standard basic farmland construction. This paper evaluated the cultivated land quality from site conditions, physical properties, chemical properties and utilization condition of cultivated land, and evaluated the construction suitability of high-standard basic farmland from infrastructure conditions, regional economic conditions and the desire of the farmers. In the process of evaluation, the selected evaluation factors were first given different weights and then were quantified, and finally comprehensive evaluation on each evaluation unit was made. The results shows that both of the cultivated land quality and the suitability of high-standard basic farmland are higher value along the Wuhua river and Qinjiang region in Wuhua County, and decrease gradually with the increase of the distance to this region. The quality of cultivated land along the river is relatively higher because of the better irrigation condition, more fertilizer application and longer cultivating history along with land improvement. At the same time, the economic conditions and infrastructure conditions in this region are better than other regions. The regions along the river are also the important area of basic farmland, so the cultivated land in this region is relatively suitable for high-standard basic farmland construction. In our study, the cultivated land quality is divided into high quality and low quality, and the suitability of high-standard basic farmland is divided into high suitability and low suitability. Based on four-quadrant method, four zones of high-standard basic farmland are divided, namely high quality and high suitability (HQHS) zone, high quality and low suitability (HQLS) zone, low quality and high suitability (LQHS) zone and low quality and low suitability (LQLS) zone. The area of HQHS zone is 15460.51 hm², accounting for 37.65% of the total area of cultivated land; the area of HQLS zone is 8771.85 hm², accounting for 21.36%, and the area of LQHS zone is 7508.73 hm², accounting for 22.71%. In the end, the limiting factors and the distribution of farmland of each area are analyzed. Based on these, the spatial adjustment method of farmland and the layout pattern of high-standard basic farmland construction are proposed, and the corresponding building mode is advised. This research provides a scientific basis for the consolidation plan and construction programs of high-standard basic farmland. It's also a reference for the potential analysis of high-standard basic farmland construction at county level.
Number of references:30
Main heading:Farms
Controlled terms:Construction - Economics - Food supply - Land use - Quality control - Regional planning - Rivers - Zoning
Uncontrolled terms:Agricultural productions - Comprehensive evaluation - Cultivated land qualities - Fertilizer applications - High-standard basic farmland - Layout - Mode - Wuhua County
Classification code:403 Urban and Regional Planning and Development - 403.2 Regional Planning and Development - 404.2 Civil Defense - 405 Construction Equipment and Methods; Surveying - 407.2 Waterways - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 913.3 Quality Assurance and Control - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2014.13.029
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 27>

Accession number:20142917960256
Title:Effect of waterlogging at jointing and tasseling stages on growth and yield of summer maize
Authors:Yu, Weidong (1); Feng, Liping (1); Sheng, Shaoxue (3); Shi, Lei (3)
Author affiliation:(1) College of Resources and Environment, China Agricultural University, Beijing 100193, China; (2) Henan Provincial Key Laboratory of Agrometeorological Safeguard and Applied Technique, China Meteorological Administration, Zhengzhou 450003, China; (3) Anhui Meteorological Bureau, Hefei 230001, China
Corresponding author:Feng, L.(fenglp@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:127-136
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Huang-huai Plain of China is featured of heavy rainfall in June-September, which accounts for 60%-70% of total annual precipitation. The heavy rainfall-induced soil waterlogging stress during the summer rainy season (June-September) is one of the major constraints for summer maize (Zea mays L.) production in the region. It is necessary to determine the critical days that crops can tolerate stress for minimizing the adverse effect of stress on crop production. In this study, a field experiment was conducted during the summer maize growing season from 2011 to 2012 at Hefei Agrometeorological Experimental Station in Anhui province in order to investigate the effect of waterlogging stress on the growth and grain yield of summer maize and determine the critical days of waterlogging stress. The Xundan No.20 widely cultivated in Huang-huai Plain was used as tested maize. Surface (3 and 5 days) and subsurface (5, 7 and 10 days) waterlogging duration the jointing and tasseling stages were designed. The surface waterlogging was assumed to be 5 cm depth of water on soil surface and the subsurface waterlogging was considered to be 90% of field capacity. Meanwhile, the control soil (CK) had soil moisture kept at 70%-80% of field capacity. Each waterlogging treatment in a plot about 20 m² had three replicates The aboveground dry matter and leaf area per plant were measured at the jointing, tasseling, milking and maturity stages, respectively. Yield characteristics of summer maize, such as ear length, ear diameter, length of bare tip, grain number per spike, 100-seed weight and harvest index were determined. The results showed that the effect of waterlogging on the growth and yield varied with types and duration of waterlogging at different developmental stages of summer maize. Compared with CK, the surface waterlogging for 3 days at the jointing and for 5 days at tasseling stages resulted in an average decrease in yield with 28.4% and 42.8%, while the subsurface waterlogging for 5 days at jointing or tasseling stages resulted in an average decrease in yield with 3.0%(2012)-13.8%(2011) and 3.4%(2012)-5.5%(2011), respectively. The damage degree due to waterlogging stress at the jointing stage was greater (P&lt;0.05) than at the tasseling stage under the same waterlogging duration, and the yield loss rates were increased with the prolonged waterlogging days. The yield loss rates of surface waterlogging for 5 days was 3.1 times that of surface waterlogging for 3 days at jointing stages, while the yield loss rates of subsurface waterlogging for 10 days were 1.3-3.0 times (2011) and 2.4-3.2 times (2012) that of subsurface waterlogging for 5 days, respectively. The yield losses were related with 100-grain weight and grains per spike. Waterlogging stress not only reduced the grain yield of maize, but also affected the characters of spike, harvest index, the accumulation and distribution of aboveground dry matter weight, leaf area per plant and the grain filling rates. Leaf areas per plant at the milky stage were decreased by 21.2%-65.7% and 4.0%-8.5% in the surface waterlogging and subsurface waterlogging treatments, respectively. The aboveground dry matter weight were reduced by 43.6% and 6.5% in the treatments of surface waterlogging for 5 days and subsurface waterlogging for 10 days at jointing stages, respectively, and the proportion of dry matter in corncob was reduced by 18.8% and 4.2%. The grain filling rate at 25-35 days after silking in the surface waterlogging for 5 days at the jointing or tasseling stages and subsurface waterlogging for 10 days at the jointing stage was decreased by 59.6%, 50.0% and 28.9%, respectively. Therefore, effective measures should be taken to avoid waterlogging for 3 days at jointing stages or 5 days at tasseling stages, when heavy rainfall occurred in the growing season of summer maize.
Number of references:35
Main heading:Yield stress
Controlled terms:Cultivation - Grain (agricultural product) - Grain growth - Growth (materials) - Moisture - Plants (botany) - Soil moisture
Uncontrolled terms:Annual precipitation - Developmental stage - Experimental stations - Grain-filling rate - Huang-Huai Plains - Summer maize - Yield - Yield characteristics
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 461.9 Biology - 483.1 Soils and Soil Mechanics - 801.4 Physical Chemistry - 821.3 Agricultural Methods - 821.4 Agricultural Products - 933.1.2 Crystal Growth - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.13.016
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 28>

Accession number:20142917960246
Title:Effect of different mechanical direct seeding methods on tiller characteristics and yield of rice
Authors:Xu, Ke (1); Tang, Lei (1); Zhang, Hongcheng (1); Guo, Baowei (1); Huo, Zhongyang (1); Dai, Qigen (1); Wei, Haiyan (1); Wei, Haihe (1)
Author affiliation:(1) Innovation Center of Rice Cultivation Technology in Yangtze River Valley, Ministry of Agriculture/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou 225009, China
Corresponding author:Zhang, H.(hczhang@yzu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:43-52
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Little information is available on tillering characteristics and their relationships with high yield in the different patterns of water mechanical-direct-seeding cultivation in rice have not been understood. The experiments were conducted using four varieties, conventional rice Changnongjing 7, super rice Nanjing 44, hybrid rice Yongyou 2638, and Yongyou7, to investigate the characteristics of tillers emergence and panicle formation and its productivity and contribution to yield by the two mechanical-direct-seeded planting patterns - hole seeding and seeding in drill cultivation. The results indicated that the tillers emergence and the panicle rates were significantly affected by the different mechanical-direct-seeding patterns. In the two planting patterns, the leaf position number of tillers emergence in the main stem were five, namely leaf 1/0 to leaf 5/0 and secondary tillers group emerged mainly in 1/1, 2/1, and 1/2 with the difference in four varieties. The percentage of primary tillers emergence of different leaf positions in hole seeding pattern was lower than that of seeding in drill pattern, but was higher than the percentage of secondary tillers emergence. The percentage of primary tillers emergence in 3/0 and 4/0 was 100%. Tertiary tillers and even more grades tillers did not initiate in the two planting patterns. The grain yield of all four rice varieties under the hole seeding pattern was higher than that of the seeding in drill pattern (p&lt;0.05), and the different planting patterns affected the earbearing percentage of tillers and their contribution to high yield (p&lt;0.05). The tillers of 1/0 to 5/0 in the main stem were able to earbear, among them 1/0 to 3/0 were main leaf positions with higher percentage of panicle formation (more than 50%), and the percentage of panicle formation of the hole seeding cultivation was higher than that of the seeding in drill cultivation. The main leaf positions of panicle formation of secondary tillers were 1/1 and 1/2 with a very low earbearing percentage, and earbearing percentage of the hole seeding pattern was lower than that of the seeding in drill pattern. The percentage of yield of primary tillers group contribution to total population yield was significant in different tillers (p&lt;0.05) and the tiller 3/0 had maximum productivity and contributive proportion, and the contributive proportion of tillers in the hole seeding pattern was higher than that of the seeding in drill pattern. But the contributive proportion of the secondary tillers was lower with the trend of the hole seeding pattern higher. By analysis of characteristics of panicles and spikelets, in tiller 3/0 the panicles number per area and spikelets number per panicle were bigger, and the hole seeding pattern had bigger spikelets number per panicle than the seeding in drill pattern. The appropriate production application and available regulation approach of the different patterns of water mechanical-direct-seeding cultivation in rice, such as management measures of manure and water, etc., are also discussed in the present paper. The experiment indicates the rules of tillers emergence and panicles formation for rice in water mechanical-direct-seeding cultivation, which provides a theoretical basis for high yield of the farm equipment in field production.
Number of references:29
Main heading:Seed
Controlled terms:Agricultural machinery - Crops - Drills - Experiments - Productivity
Uncontrolled terms:Direct-seeding - Group contributions - Management measures - Maximum productivity - Mechanical-direct-seeded - Panicle formation - Rice - Tillering characteristic
Classification code:603.2 Machine Tool Accessories - 821.1 Agricultural Machinery and Equipment - 821.4 Agricultural Products - 901.3 Engineering Research - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2014.13.006
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 29>

Accession number:20142917960251
Title:Turbid water desilting characteristics of circular-ring desilting and sediment ejection basin
Authors:Zhang, Jun (1); Shi, Kebin (1); Gao, Yaping (2); Wang, Jin (2)
Author affiliation:(1) College of Hydraulic and Civil Engineering of Xinjiang Agricultural University, Urumqi 830052, China; (2) XinJiang Scientific Research Institute of Water Resources and Hydropower, Urumqi 830000, China
Corresponding author:Shi, K.(xndsg@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:86-93
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Circular rings desilting and sediment ejection basin are new secondary sediment treatment facilities, which was first applied in Xinjiang Hutubi Aweitan canal head. Agricultural water was solved emphatically in the Aweitan irrigated area. "Circular rings" have worked satisfactorily since 2006. Taking Xinjiang Hutubi Aweitan "circular rings" as a prototype, the experimental model on turbid water movement characteristics has been studied. Sediment concentration distribution was tested by the computer aided sediment meter of CYS-III-Type. The sediment particle diameter was measured in the outflow channel and different radius range of"circular rings. Meanwhile, the desilting rate and water consumption were calculated, as well as the maximum particle diameter in the outflow channel. The research showed that the distribution of sediment concentration, desilting range, desilting diameter and desilting production are non-uniform in the ring direction of "circular rings". However, sediment concentration distribution and particle diameter size are inversely proportional to the radius in the radial direction. Sediment concentration is inversely proportional to water depth in the vertical direction, vertically non-uniform within 1/2 radius. Meanwhile, sediment grain size is crude. In other ranges, vertical distribution is more uniform and sediment grain size is smaller. Distribution of sediment concentration, desilting diameter and desilting production are larger in the range of 135&deg;-225&deg; in "circular rings". Under the design discharge and sediment concentration conditions, the desilting rate is 90.9 percent of "Circular rings". The maximum particle-size is 0.935mm in the outflow channel. The desilting rate for grain which diameter is more than 1 mm is 100 percent, while the water consumption is only 6.6 percent. When considering the annual flow and sediment concentration conditions, the water consumption well is reduced, but the amplitude reduction should be further studied. Discharging of sediment is achieved by means of the water flow energy, steeper inverted cone bottom slope, self-weight sediment, as well as high-speed circulation. The experiment proved that the model test results are in accordance with the prototype in "circular rings". The sorting phenomenon of the sediment particle was obviously existed. Separating water and sediment was decided by gravity sedimentation. One of the most important reasons is that the high desilting efficiency obtained by the long overflow weir. It has a high desilting rate, desilting particle range and low water consumption, especially taking advantage of the draining bed sediment of coarse grain. Meanwhile, automatically discharging of the sediment is achieved by an intermittent way. Therefore, promoting the use of "circular rings" has important significance for improving the agricultural water-saving irrigation efficiency and sufficiently utilizing water resources.
Number of references:32
Main heading:Sediments
Controlled terms:Agriculture - Grain (agricultural product) - Grain size and shape - Hydraulic structures - Irrigation - Microchannels - Particle size - Sedimentation - Water conservation - Water resources
Uncontrolled terms:Circular ring - Experimental modeling - Gravity sedimentation - Maximum particle diameter - Sediment concentration - Sediment concentration distributions - Vertical distributions - Water-saving irrigation
Classification code:441 Dams and Reservoirs; Hydro Development - 444 Water Resources - 483 Soil Mechanics and Foundations - 604 Metal Cutting and Machining - 611 Hydroelectric and Tidal Power Plants - 631 Fluid Flow - 801.4 Physical Chemistry - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 943.2 Mechanical Variables Measurements
DOI:10.3969/j.issn.1002-6819.2014.13.011
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 30>

Accession number:20142917960266
Title:Economic and environmental analysis of decentralized heating using biomass gasification gas and household biogas in rural areas
Authors:Xia, Zongpeng (1); Yang, Mengjun (2); Chen, Guanyi (1); Yan, Beibei (1); Zhou, Weihong (1); Tian, Xue (2)
Author affiliation:(1) School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; (2) Sino-Singapore Tianjin Eco-City Energy Ltd., Tianjin 300467, China; (3) State Key Laboratory of Engines (Tianjin University), Tianjin 300072, China; (4) Key Laboratory of Efficient Utilization of Low and Medium Grade Energy(Tianjin University), Ministry of Education, Tianjin 300072, China; (5) School of Civil Engineering, University of Science and Technology Liaoning, Anshan 114051, China
Corresponding author:Yan, B.(yanbeibei@tju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:211-218
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the rapid development of the economy and the significant improvement in people's living conditions, clean and convenient heating has gained attention due to being required by farmers in the northern rural areas of China. The centralized heating usually requires a long-distance transporting pipe network, thus it is not applicable to most rural villages. The decentralized heating is applicable by using biomass gasification gas coupled with a household gas-burning furnace and by digestion biogas coupled with a household gas-burning furnace. These two methods of heating are much cleaner and more convenient compared to the decentralized heating using coal, char, wood, etc. They potentially become the two main kinds of heating in rural villages in the near future. This paper presents the analysis for economic and greenhouse gas reduction referring to the Xiaoguta village in Tianjin. It goes into detail about all kinds of investments, such as the equipment cost, fuel cost, electricity charge, labor cost, and maintenance management cost. It also shows how greenhouse gas reductions, such as CO<inf>2</inf> reduction and CH<inf>4</inf> reduction, exist in the two decentralized heating. The results show that the initial investment in biogas heating is nearly 186% of gasification heating. Operation costs of biogas heating has many advantages compared to gasification when the byproduct of biogas (299 thousand RMB/a) is used. Fuel cost of the decentralized heating is 164 thousand RMB/a when using BG gas and 185 thousand RMB/a when using biogas. The electricity charge of the decentralized heating is 62.9 thousand RMB/a when using BG gas and 35 thousand RMB/a when using biogas. The labor cost of the decentralized heating using BG gas is 12 thousand RMB/a, while the decentralized heating using biogas has no labor cost. The maintenance management cost of the decentralized heating using biogas is 37.5 thousand RMB/a, while the decentralized heating using BG gas has no maintenance management cost. The greenhouse gas CO<inf>2</inf> reduction of the two decentralized heating methods are also similar, i.e. reducing 561.18 t/a of CO<inf>2</inf> in life cycle, when compared with coal-based heating. The CH<inf>4</inf> reduction of decentralized heating using biogas is also equal to that of biomass gasification gas. The CH<inf>4</inf> reduction of the two decentralized heating methods ranges from 1328.4 to 2120.3 kg/a. Overall, the economy of decentralized heating using BG gas has more advantages than using biogas. The advantages of decentralized heating using BG gas is especially more prominent in the low level management rural areas. Villages, such as those in the rural areas of suburbs in Tianjin, should use BG gas as a heating fuel when they need a lot of gas. The results appear valuable when guiding the rural heating modes to use local biomass resources.
Number of references:22
Main heading:Heating
Controlled terms:Biogas - Biomass - Carbon dioxide - Cost accounting - Costs - Economic analysis - Employment - Fuels - Gasification - Greenhouse gases  - Maintenance - Rural areas - Wages
Uncontrolled terms:Biomass Gasification - Decentralized heating - Environmental analysis - Greenhouse gas reductions - Household biogas - Living conditions - Maintenance management - Transporting pipes
Classification code:522 Gas Fuels - 523 Liquid Fuels - 524 Solid Fuels - 643.1 Space Heating - 802.3 Chemical Operations - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes - 911 Cost and Value Engineering; Industrial Economics - 912 Industrial Engineering and Management - 913 Production Planning and Control; Manufacturing - 913.5 Maintenance
DOI:10.3969/j.issn.1002-6819.2014.13.026
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 31>

Accession number:20142917960259
Title:Improved Huffman coding-based data transmission and compression method for agricultural machinery operation
Authors:Yang, Jingfeng (1); Zhang, Nanfeng (1); Li, Yong (3); Xue, Yueju (4); L&#252;, Wei (1); He, Kun (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou, 510642, China; (2) Guangzhou Entry-exit Inspection and Quarantine, Guangzhou 510623, China; (3) Guangzhou Institute of Geography, Guangzhou 510070, China; (4) College of Information, South China Agricultural University, Guangzhou 510642, China
Corresponding author:Xue, Y.(xueyueju@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:153-159
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the poor communication environment problem of agricultural machinery operation state data transmission caused by the unbalanced coverage of a mobile communication base station, a data filtering and data compression method based on an improved Huffman coding technique was proposed for data selecting, compression, transmission, parsing, and extracting in this paper. First, the agricultural machinery operation data types, exchange mode, and compression mode were defined. Then, data collection and exchange were realized based on a Compass/GPS dual-mode state data collection terminal. Finally, an improved Huffman coding technique was proposed. At present, most of the data transmission is using a compression-decompression method to ensure data integrity of data transmission, which can reduce the data traffic and save many communication costs, but its disadvantages are also obvious. The disadvantages are fewer on the terminal in the data transmission, and are mainly manifested in the need to compress the data of each group, leading to delayed transmission time, which will affect the platform performance. Considering the common problem of an agricultural machinery state data collection terminal and monitoring platform, a driving state data optimization method combined with platform data recognition was proposed in this paper, whose research has practical significance for the platform designing of data collection, transmission, and monitoring. To achieve data transmission and access, the design of a monitoring platform necessarily must use data extraction methods combined with terminal data optimization. That is, adding the terminal data processing optimization algorithm while designing a terminal data transmission module to overcome the pressure of the data management system for wireless communications and the corresponding pressure for a backstage management system. At the same time, adding data extraction and recognition algorithms while monitoring platform receiving data could optimize the expression of data and reduce the amount of data, so as to improve the efficiency of the whole system. Data compression and decompression testing results showed that it could obtain a 55.08% compression ratio with 412.56 kb transmission operation data length by the data acquisition cycle of 5 seconds, and the error rate of data transmission and data transmission packet loss rate were 2.47% and 4.18% respectively, while the error rate of data transmission and data transmission packet loss rate fell to 2.06% and 0.78% respectively at the same screening requirements of the selecting compression and transmission. This method can achieve the requirements of agricultural machinery operation state data compression and transmission. In the compression and transmission mode of single data packet with less data and short transmission time, it could obtain a lower transmission error rate and transmission packet loss rate. Moreover, the method has less computation and high compression efficiency characteristics, which are suitable for data transmission in the agricultural machinery operation area.
Number of references:29
Main heading:Data compression
Controlled terms:Agricultural machinery - Algorithms - Codes (symbols) - Communication - Data acquisition - Data communication systems - Data mining - Data transfer - Electric power transmission - Information management  - Optimization - Security of data - Wireless telecommunication systems
Uncontrolled terms:Communication environments - Data transmission and compression - Huffman coding - Machinery operation data - Mobile communication base station - Operation state - Processing optimizations - Wireless communications
Classification code:706.1.1 Electric Power Transmission - 716 Telecommunication; Radar, Radio and Television - 723 Computer Software, Data Handling and Applications - 723.2 Data Processing and Image Processing - 821.1 Agricultural Machinery and Equipment - 903.2 Information Dissemination - 921 Mathematics - 921.5 Optimization Techniques
DOI:10.3969/j.issn.1002-6819.2014.13.019
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 32>

Accession number:20142917960263
Title:Monitoring rice leaf area index using time-series SAR data
Authors:Zhang, Xiaoqian (1); Guo, Lin (1); Ma, Shangjie (1); Zhao, Zhanying (1); Pei, Zhiyuan (1)
Author affiliation:(1) Agriculture Resource Monitoring Station, Chinese Academy of Agricultural Engineering, Beijing 100125, China
Corresponding author:Zhang, X.(zxqsun@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:185-193
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Rice is one of the most important food crops in China, so timely obtaining accurate rice growth information in regional scale is highly significant for crop management and decision making. However, there are plenty of rain and dense cloud cover in rice growth season, that makes it difficult to monitor rice paddy information by optical remote sensing data. It is an accepted fact that Synthetic Aperture Radar (SAR) data is a suitable alternative for crop monitoring in cloud-prone and raining area. In this paper, we investigated the potential of Radarsat-2 SAR data for rice paddy growth monitoring at regional scale. Four C-band SAR backscattering coefficients (VH, VV, HH, HV) and HH/VV ratio backscattering coefficient were employed for setting up the relationship with leaf area index (LAI) in rice growing season. The test site located in Leizhou (20&deg;52'N, 110&deg;05'E), Guangdong province. Four Radarsat-2 products in fine quad polarization mode were acquired during the critical rice growth stage. In situ measurement in year 2013 was also made concurrently with the satellite pass. 25 plots were selected for measuring the rice growth parameters, such as LAI, plant height, sowing date, etc. The backscattering coefficients with multi-incidence angle were extracted from multi-temporal SAR images and then normalized to same angle. Firstly, the study analyzed the temporal behavior of microwave backscattering coefficients (VH, VV, HH, HV, HH/VV) and LAI in rice growth season. Secondly, correlation analyses between the backscattering coefficients in different polarization and LAI were also carried out in vegetative stage, reproductive stage and whole growth period respectively, then picking the polarization and growth stage corresponding with high correlation coefficient which was above 0.8 to build water cloud model and evaluate the performance of each model. Finally, based on the previous result, the LAI distribution map in time domain was generated using the best model of entire growth period. The results showed that, (1) In flat area, the correlation coefficient in different stage from high to low is: vegetative stage, whole growth period, reproductive stage. There is a positive correlation between HH, HV (VH) and LAI, a negative correlation between VV, HH/VV and LAI. The correlation coefficients of VV, HH/VV and LAI were both above 0.8; (2) The VV, HH/VV water cloud models (R²=0.77, R²=0.87 respectively) in vegetative stage performed better than in full rice growth stage (R²=0.73, R²=0.8 respectively); (3) The better prediction model was applied in multi-temporal SAR image for computing LAI value in rice area. The LAI distribution map of each single date can point out the rice growth condition in different area, while multi-temporal LAI distribution maps in rice growth season can point out the LAI changes in the same region. In conclusion, the study proved the potential of timely rice monitoring by multi-temporal FQ mode SAR data in regional scale, and also provided a reliable approach for rice LAI prediction. As the development of precision agriculture, C-band SAR data can be used in quantitative rice crop monitoring and it will become an increasingly important data source.
Number of references:30
Main heading:Synthetic aperture radar
Controlled terms:Backscattering - Cloud computing - Crops - Forestry - Monitoring - Polarization - Radar
Uncontrolled terms:Growth stages - LAI - Rice - SAR - Temporal signatures
Classification code:711 Electromagnetic Waves - 711.1 Electromagnetic Waves in Different Media - 716.2 Radar Systems and Equipment - 722.4 Digital Computers and Systems - 821.0 Woodlands and Forestry - 821.4 Agricultural Products - 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.1002-6819.2014.13.023
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 33>

Accession number:20142917960273
Title:Changes in nutritious component and water molecule of peeled shrimp during dense phase carbon dioxide treatment
Authors:Chen, Yali (1); Qu, Xiaojuan (1); Liu, Shucheng (1); Ji, Hongwu (1); Hao, Jiming (1); Huang, Wanyou (1); Guo, Minghui (1)
Author affiliation:(1) College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Zhanjiang 524088, China
Corresponding author:Liu, S.(Lsc771017@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:268-275
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Dense phase carbon dioxide (DPCD) is a non-thermal processing technology, which affects microorganisms and enzymes through molecular effects of CO2 under pressures below 50 MPa and 60&deg;C. DPCD has had less of a significant effect on the quality of food and has been applied to the process of meats, vegetables, seeds and food powders, fruits, spices and herbs, and fish. Currently, most of research are more focused on microorganisms and enzymes that are inactivated by DPCD. However, some research indicated that DPCD has an effect on the quality of meat and its products, mainly related to muscle pH value, color, water holding capacity, texture, etc. The nutritional composition of meat and its products also has a decisive effect on their qualities. Water is the highest content in meat and its products composition. Water can directly affect color, tenderness, juiciness, flavor, and the processing characteristics of meat and its products. Water content and its distribution showed dynamic changes in the processing and storage of meat and its products, which is an important factor in determining quality and shelf life. Litopenaeus vannamei is a favorite of consumers in aquatic products due to tender meat and high nutritional value. In our previous study, Litopenaeus vannamei was treated for sterilization and inactivation of polyphenol oxidase by DPCD. In order to further investigate the effect of DPCD on shrimp muscle quality, peeled shrimp were used as the studied object. The effects of temperature (35-55&deg;C), pressure (5-25 MPa), and time (10-60 min) on nutritious components and water molecules of shrimp muscle were studied. The results showed as follows: when using the untreated peeled shrimp, the content of nutritious components (moisture, crude protein, crude fat, and ash), especially fat, significantly decreased (P&lt;0.05) after DPCD treatment. With the increasing of DPCD treatment intensity, fat was extracted and water was dried out by DPCD. Partially ionized minerals and small molecular compounds containing nitrogen (e.g. free amino acids) were carried out with CO<inf>2</inf> in the unloading process. While using the untreated peeled shrimp, the contents of myofibrillar and sarcoplasmic protein decreased significantly (P&lt;0.05) and the content of insoluble protein increased significantly (P&lt;0.05) with exposure to time, temperature, and pressure when DPCD was increasing. The reason for that was myofibrillar and sarcoplasmic protein were denatured and transformed to insoluble protein by DPCD. The results of low field nuclear magnetic resonance (LF-NMR) showed that peeled shrimp contained four kinds of water molecules with different mobility. With exposure to time, temperature, and pressure when DPCD was increasing, the degree of freedom of bound water increased while the degree of freedom of immobilized water and free water decreased. Nonetheless, the content of bound water and free water increased significantly (P&lt;0.05) while the content of immobilized water decreased significantly (P&lt;0.05), when the peeled shrimp was treated for 30 min at 15 MPa and 55&deg;C of DPCD. Microorganism and PPO from Litopenaeus vannamei were inactivated, but the content of moisture, crude protein, crude fat, and ash decreased by 7%, 3%, 25%, and 11%, respectively. Sarcoplasmic and myofibrillar protein were denatured, and the free water ratio increased significantly (P&lt;0.05). The research results will provide a reference for the application of DPCD in shrimp processing.
Number of references:36
Main heading:Carbon dioxide process
Controlled terms:Amino acids - Carbon dioxide - Degrees of freedom (mechanics) - Enzymes - Meats - Microorganisms - Moisture - Molecules - Muscle - Nuclear magnetic resonance  - Proteins - Quality control - Research - Shellfish - Temperature - Unloading
Uncontrolled terms:Dense phase carbon dioxide - Effects of temperature - Low field nuclear magnetic resonance - Non-thermal processing - Nutritional compositions - Nutritious components - Water holding capacity - Water molecule
Classification code:461 Bioengineering and Biology - 534.2 Foundry Practice - 641.1 Thermodynamics - 674.1 Small Marine Craft - 801.4 Physical Chemistry - 804.1 Organic Compounds - 804.2 Inorganic Compounds - 822.3 Food Products - 901.3 Engineering Research - 913.3 Quality Assurance and Control - 931 Classical Physics; Quantum Theory; Relativity
DOI:10.3969/j.issn.1002-6819.2014.13.033
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 34>

Accession number:20142917960258
Title:Effect of green manure rotation on soil fertility and organic carbon pool
Authors:Lan, Yan (1); Huang, Guoqin (1); Yang, Binjuan (1); Chen, Hongjun (1); Wang, Shubin (1)
Author affiliation:(1) Research Center on Ecological Science, Jiangxi Agricultural University, Nanchang 330045, China
Corresponding author:Huang, G.(hgqjxnc@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:146-152
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The area of fall-planted cover crop in China is quite low in paddy field, and multiple cropping index declines yearly, resulting in tremendous waste of soil resources. This reduction in fall-planted cover crop can lead to decrease in soil fertility. Most paddy field in southern China is suitable for growing winter green manure because of abundant light and heat resources. Winter green manure in general contains 15% - 20% of the organic matter. It can be used to improve soil nutrients cycling and facilitate the mineralization of soil organic matter. Comprehensive evaluation of green manures in different crop rotations in paddy fields of southern China region is needed in order to develop sustainable multiple cropping systems. The objective of this study was to determine the effect of green manure on different cropping systems (A: fallow-early rice-late rice&rarr;fallow-early rice-late rice (CK); B: milk vetch- rice- rice&rarr;rapeseed/peanut-rice; C: rapeseed/peanut- rice&rarr; potato/maize soybean- rice; D: potato/maize soybean- rice&rarr;vegetable/peanut maize- rice; E: vegetable/peanut maize- rice&rarr;milk vetch- rice- rice) on soil nutrients, soil organic carbon, and carbon pool management indexes in southern China where two rice crops per year were common. The experiment was conducted during September 2011 - November 2013. Soil samples (at depths of 10-20 cm) were taken after rice was harvested in 2013 for analysis. The results showed that compared with CK, green manure rotation treatments had significantly (P&lt;0.05) improved organic matter, alkaline hydrolytic nitrogen and available potassium by 8.73%-15.59%, 11.79%-19.64%, and 5.80%-37.19%, respectively. Soil organic of green manure rotation treatments of B and C were 15.59% and 11.19% higher (P&lt;0.05) than CK. Soil active organic carbon of all green manure rotation treatments was 29.03%, 19.96%, 16.67% and 21.75% respectively higher (P&lt;0.05) than CK. Compared with CK, the soil carbon pool index significantly (P&lt;0.05) increased by 15.70% for the treatment B, and soil carbon management index significantly (P&lt;0.05) increased by 32.07 for the treatment B, 21.98 for the treatment C, 18.64 for the treatment D and 24.47 for the treatment E, respectively. Among the treatments, milk vetch- rice- rice&rarr;rapeseed/peanut- rice had the highest values for the soil carbon pool index and soil carbon management index. The soil organic matter and total nitrogen, available phosphorus, total organic carbon, active organic carbon, and carbon pool management index were highly significantly (P&lt;0.01) correlated. Soil total nitrogen, alkaline hydrolytic nitrogen, and available phosphorus had a significant (P&lt;0.05) correlation with carbon pool management index. In addition, soil organic carbon was significantly (P&lt;0.05) positively correlated with active organic carbon and carbon pool management indexes. Therefore, green manure rotation, especially milk vetch- rice- rice&rarr;rapeseed/peanut- rice could increase soil organic carbon contents and soil carbon pool management index, improve soil quality and soil fertility under the local soil fertility conditions, and was important for promoting sustainable development of agriculture.
Number of references:30
Main heading:Manures
Controlled terms:Biogeochemistry - Biological materials - Carbon - Crops - Cultivation - Management - Nitrogen - Nutrients - Organic carbon - Rotation  - Soils
Uncontrolled terms:Available phosphorus - Carbon pool - Comprehensive evaluation - Green manures - Multiple cropping index - Multiple cropping systems - Organic carbon pools - Soil organic carbon content
Classification code:461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 481.2 Geochemistry - 483.1 Soils and Soil Mechanics - 601.1 Mechanical Devices - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 912.2 Management
DOI:10.3969/j.issn.1002-6819.2014.13.018
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.

<RECORD 35>

Accession number:20142917960261
Title:Detection of chlorophyll content distribution in cucumber leaves based on hyperspectral imaging
Authors:Zou, Xiaobo (1); Zhang, Xiaolei (1); Shi, Jiyong (1); Li, Zhihua (1); Shen, Tingting (1)
Author affiliation:(1) School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
Corresponding author:Zou, X.(zou_xiaobo@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:13
Issue date:July 1, 2014
Publication year:2014
Pages:169-175
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The content and distribution of chlorophyll in leaves are important indicators of nutrition information in plants. The objective of this study was to investigate the spectral behavior of the relationship between reflectance and chlorophyll content and to develop a technique for non-destructive chlorophyll estimation and distribution in leaves by using hyperspectral images. The hyperspectral imaging data cube of cucumber (Cucumissativus) leaves in the range of 450-850 nm were selected and preprocessed. A rectangle mesophyll about 100&times;200 pixels between the second and the third branch left of the main vein was selected as the region of interest (ROI). Spectra information of characteristic bands was extracted and used to set a model with measured chlorophyll content (spectra region extracted corresponding to region chlorophyll measured). The existing modeling methods, such as artificial neural networks (ANN), support vector machines (SVM), etc., can be used to achieve better results but are inconvenient for online applications due to the introduction of sophisticated algorithms. As an operation result of multiple spectrum values (addition, subtraction, multiplication, and division, combined with linear or nonlinear ways), vegetation indices, which play a role in indicating growth and biomass of vegetation, are significant in simplifying the model. Eight representative optical indices (or signatures), which were proposed as a function of the associated reflectance (R<inf>&lambda;</inf>) at the special wavelength (&lambda;) nm, were used to predict the total chlorophyll content in cucumber leaves. Finally, (R<inf>695-705</inf>)^-1-(R<inf>750-800</inf>)^-1 was identified as an optimum index, predicting the content of chlorophyll fairly well. The correlation coefficients of each model for calibration data set (r<inf>c</inf>) and validation data set (r<inf>p</inf>) were 0.8410 and 0.8286, while RMSEC (root mean square error of calibration) and RMSEP (root mean square error of predication) were the smallest (0.2045 mg/g and 0.2190 mg/g). The optimal model showed good stability and robustness due to two major advantages, namely the effects of "red edge" and baseline removal. On one hand, two feature bands (695-705 and 750-800 nm) of the model can be used to develop a kind of portable multispectral device. On the other hand, according to the model, chlorophyll content of the leaf was estimated at every pixel. A pseudo-color map was used to describe the law of chlorophyll distribution. On the map, it is evident that the content of chlorophyll is more in the mesophyll around the veins than in the veins. The edge is seen as less than the middle of the leaf, which is consistent with the actual distribution in the leaf. That is to say, it is a feasible analysis of chlorophyll content and distribution in cucumber leaves via the technique of hyperspectral images. Our results indicated that hyperspectral imaging was considerable for predicting chlorophyll content in leaves, thus allowing the chlorophyll content to be non-destructively detected in situ in living plant samples. In addition, the distribution map can also be used to analyze the accumulation of chlorophyll in spatial plants. Besides, it is easy to facilitate monitoring distribution and variation of chlorophyll in the tissues of plants. Further studies will provide a reliable way for processes that use photosynthetic pigments to participate in such as biochemical pathway, plant growth, and mechanisms of aging.
Number of references:31
Main heading:Chlorophyll
Controlled terms:Calibration - Forecasting - Linear regression - Mean square error - Neural networks - Pixels - Plants (botany) - Reflection - Spectrographs - Spectroscopy  - Support vector machines
Uncontrolled terms:Chlorophyll distribution - Correlation coefficient - Hyperspectral imaging datum - Leaf index - Photosynthetic pigments - Root mean square error of calibrations - Root mean square errors - The region of interest (ROI)
Classification code:461.1 Biomedical Engineering - 461.9 Biology - 711 Electromagnetic Waves - 723 Computer Software, Data Handling and Applications - 801 Chemistry - 801.2 Biochemistry - 922.2 Mathematical Statistics - 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.1002-6819.2014.13.021
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.