<RECORD 1>

Accession number:20185206314574
Title:Law of nitrate transfer and loss in purple sloping farmland and its numerical simulation
Authors:Xie, Meixiang (1); Zhang, Zhanyu (1); Zhang, Pingcang (2); Xu, Jinxin (2); Lin, Qingming (2)
Author affiliation:(1) College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing; 210098, China; (2) Soil and Water Conservation Department, Yangtze River Scientific Research Institute, Wuhan; 430010, China
Corresponding author:Zhang, Zhanyu(zhanyu@hhu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:147-154
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The nitrate transfer and loss plays a critical role in groundwater contamination. Specially, the purple soil sloping field accounts for large areas of farmlands in China and the nitrate transport and loss in purple soils causes serious pollution towards waterbodies. To research the transfer and loss of nitrate in sloping field of purple soil, we conducted laboratory experiments using soil tanks and artificial rainfall device to study nitrate loss features by surface flow (SF) and subsurface flow (SSF) subjected to various precipitation intensities and slope gradients. In this study, 3 precipitation intensities (0.4, 1.0, 1.8 mm/min) coupled with 3 slope gradients (5&deg;, 15&deg;, 20&deg;) were used, and totally 9 treatments were conducted with 2 repetition. Besides, numerical modelling approach was also applied to investigate the nitrate transfer and loss characteristics of purple soil in sloping field. The modified effective mixing depth model and convective-dispersion equation were applied in simulations of nitrate loss via SF and SSF, respectively, with the effective mixing model was modified by a time-increasing effective mixing depth and convective-dispersion equation was solved by HYDRUS-2D software. The results showed: 1) exponential decrease between nitrate concentration and time through SF and linear increment through SSF. 2) The loss concentration of nitrate in SSF was 19-72 folds more than that in SF, and the nitrate loss cumulative loss loads through SF and SSF both presented linear increments with time. Additionally, the variabilities of measured nitrate concentration in SSF were much larger than that in SF. 3) The nitrate loss load presented linear increment over time subjected to all treatments and the proportion of nitrate loss load in SF increased with increasing precipitation intensities. As a result, the loss load of nitrate was mainly through SF in response to large precipitation intensity, but nitrate loss was mainly through SSF subjected to low precipitation intensity. In detail, the proportion of nitrate loss through SF increased from 17.3% to 66.0% as response to increasing rainfall intensity from 0.4 to 1.8 mm/min. 4) The precipitation intensity was a very influential factor for nitrate nitrogen loss, while the impact of slope gradient on nitrate loss showed no consistent pattern. 5) The linear regressions between model prediction results and experimental data and evaluation index of accuracy for simulation results both revealed good agreements for nitrate transfer and loss through SF and SSF, respectively. The mean absolute error (MAE), root mean square error (RMSE), coefficient of Nash-Suttcliffe E<inf>NS</inf> and R² reached 0.872 mg/L, 1.009 mg/L, 0.590 and 0.826 7, respectively, for nitrate loss via SF. Similarly, the MAE, RMSE, E<inf>NS</inf> and R² of prediction for subsurface nitrate loss reached 9.889 mg/L, 13.084 mg/L, 0.792 and 0.842 6, respectively. This study provided better understanding for nitrate transfer and loss mechanism of purple soil in sloping farmland.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Nitrates
Controlled terms:Concentration (process) - Dispersions - Farms - Groundwater - Groundwater pollution - Loading - Mean square error - Mixing - Models - Numerical models  - Rain - Runoff - Soils
Uncontrolled terms:Advection dispersions - Convective dispersion equation - Effective mixing depths - Groundwater contamination - Laboratory experiments - Precipitation intensity - Root mean square errors - Subsurface Flow
Classification code:443.3  Precipitation - 444.1  Surface Water - 444.2  Groundwater - 483.1  Soils and Soil Mechanics - 691.2  Materials Handling Methods - 802.3  Chemical Operations - 804.2  Inorganic Compounds - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 921  Mathematics - 922.2  Mathematical Statistics - 951  Materials Science
Numerical data indexing:Mass_Density 1.01e-03kg/m3, Mass_Density 1.31e-02kg/m3, Mass_Density 8.72e-04kg/m3, Mass_Density 9.89e-03kg/m3, Percentage 1.73e+01% to 6.60e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.019

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 2>

Accession number:20185206314587
Title:Analysis of driving forces of urban land expansion in Wuhan metropolitan area based on Logistic-GTWR model
Authors:Wang, Haijun (1, 2); Liu, Yiming (1); Zhang, Bin (1); Xu, Shan (3); Jia, Kejing (4); Hong, Song (1)
Author affiliation:(1) School of Resource and Environmental Science, Wuhan University, Wuhan; 430079, China; (2) Key Laboratory of Geographic Information Systems, Ministry of Education, Wuhan University, Wuhan; 430079, China; (3) Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing; 100101, China; (4) China Land Surveying and Planning Institute, Beijing; 100035, China
Corresponding author:Xu, Shan(xushan@chinasus.org)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:248-257
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Under the background that the country pushes forward the new-type urbanization, spatial planning and urban agglomeration planning, it is of great significance to scientifically cognize the driving forces mechanism of urban land expansion for the urban agglomeration, which is important for the sustainable development of urban agglomeration land use and planning. Taking the Wuhan metropolitan area as an example, the paper uses the land use data, socio-economic factors, neighborhood factors and natural factors in 1995, 2000, 2005, 2010 and 2015 to construct the Logistic-GTWR (Logistic - geographically and temporally weighted regression) model, which couples the spatial heterogeneity and temporal non-stationarity. The model is used to explore the driving forces and its spatio-temporal differentiation pattern of urban land expansion in Wuhan metropolitan area. The results highlight that: 1) The Logistic-GTWR model with coupling spatial heterogeneity and temporal non-stationarity has a better performance than the global logistic regression model and the Logistic-GWR (Logistic-Geographically Weighted Regression) model which only considers the spatial heterogeneity, verifying the applicability of Logistic-GTWR model in driving force analysis of urban land expansion. 2) There are significant disparities on the spatio-temporal patterns for various driving forces of urban expansion in Wuhan metropolitan area. For example, the distribution area of high values for population factor shrank, spread and then stabilized around Wuhan, finally forming a circular distribution pattern around the central part of Wuhan metropolitan area as time went by. The distribution area of high value for per capita GDP (gross domestic product) firstly transferred to the west, then gradually balanced, and finally concentrated around Wuhan, Macheng and Chongyang. The effect of polarization plays a dominant role in the process of urbanization in Wuhan, and its influence range is constantly expanding. The effect of rent seeking is apparent. 3) Population and economy are the core driving forces of urban expansion in Wuhan metropolitan area in 20 years and the influence of the 2 factors has been increasing year by year. The influence of the national highways, highways and provincial roads has been slightly increased. 4) The central and eastern cities are mostly such cities where population and economic factors are the core driving forces. The influence of elevation is gradually prominent in the development of Wuhan on account of a rapid development and decreasing land source. The cities in the west are mainly restricted by elevation and driven by traffic, where the differences between the east and the west are obvious. However, the intensities of the population and economy in western cities have gradually increased since 1995. The effects of population and economy on western cities have been an uptrend since 1995. Similarly, the intensity of population has been gradually increasing in Xianning and Huanggang. In Wuhan, Xiaogan, Xiantao, Tianmen and Qianjiang, economic factor has an increasing trend over year. This research provides a model that couples the spatial heterogeneity and temporal non-stationarity, depicting more detailed spatio-temporal differentiation characteristics of driving factors, which is beneficial to the meticulous management of land resource.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Urban planning
Controlled terms:Agglomeration - Economic and social effects - Economics - Expansion - Land use - Logistics - Models - Regression analysis
Uncontrolled terms:Driving forces - Geographically weighted regression - Gross domestic products - Management of land resources - Metropolitan area - Spatio-temporal differentiations - Urban expansion - Weighted regression
Classification code:403  Urban and Regional Planning and Development - 403.1  Urban Planning and Development - 802.3  Chemical Operations - 922.2  Mathematical Statistics - 951  Materials Science - 971  Social Sciences
Numerical data indexing:Age 2.00e+01yr
DOI:10.11975/j.issn.1002-6819.2018.19.032

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 3>

Accession number:20185206314583
Title:Traits of milled wood lignin isolated from different crop straw based on FT-IR
Authors:Yang, Zengling (1); Mei, Jiaqi (1); Cao, Cong (1); Ji, Guanya (1); Han, Lujia (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:219-224
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As vast agricultural byproduct and an important source of lignocellulosic biomass in China, straws of maize, cotton and wheat are now being developed as renewable energy resources to address a serious energy shortage and environmental issues related to other energy sources. It is necessary to improve the comprehensive utilization efficiency of the three types of straw. Although maize (monocotyledon), cotton (dicotyledon) and wheat (monocotyledon) belong to therophyte herbage from the perspective of phytology, but their straw forms are totally different. For the sake of the difference among them, the utilization cannot be generalized without regard to the effect of chemical composition, in particular the characteristics of lignin. It is composed of phenyl propane monomers connected by the ether and carbon-carbon bonds, containing a variety of active groups. There are three types of phenylpropane, p-hydroxy phenyl, guaiacyl and syringyl, which correspond to hydroxy phenyl lignin (H-lignin), syringyl lignin (S-lignin) and guaiacyl lignin (G-lignin), respectively. Lignin within plants has different shares of the three constitutional units. The heterogeneity of linkage types among the phenyl propane monomers has different effects on the pretreatment for the utilization and removal of lignin. Previous researches have shown that the relative ratio of G-lignin/S-lignin (G/S value) is relevant to the ease or complexity of delignification. Therefore, the higher the ratio, the harder the delignification is. In this paper, three samples of each kind of straw were collected, coarse grinded, degreased, dewaxed, and fine grinded, in sequence. Then the milled wood lignin (MWL) was isolated from the straws of cotton, corn and wheat. After the all procedures above, MWL was studied with FT-IR, by potassium bromide pellet technique. Normalization was conducted with 9 spectra obtained, at the wavelength of 1 506 cm^-1 (to make A1 506=1) as spectral pretreatment. Then the spectra were compared in 3 aspects: the relative G/S ratio represented by A1 265/A1 329, the identification of lignin types based on plant taxonomy, and the differences and similarities comparing with the MWL from eucalyptus. The results indicate that there is more guaiacyl and less syringyl in the MWL isolated from the samples, the relative ratio of G/S among the three kinds of straws was not significant difference, and no evident regularity is found. Secondly, the identification results based on plant taxonomy show that the MWL from cotton straw is the type of GS1, while that from corn and wheat straw belong to the type of HGS; the content of basic units of lignin in mole percent in these straws have following laws: for H-lignin, corn straw&gt;wheat straw&gt;&gt;cotton straw; for G-lignin, cotton straw&gt;corn straw&gt;wheat straw; for S-lignin, corn straw&gt;wheat straw&gt;cotton straw. Thirdly, the MWL isolated from straw of corn and wheat share the generality of gramineous plants, while the MWL from cotton straw is closer to ligneous plants, which have distinguish peak at 1 265 and 1 226 cm^-1.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Wood
Controlled terms:Carbon - Cotton - Crops - Delignification - Lignin - Mercury compounds - Monomers - Potassium compounds - Propane - Renewable energy resources  - Spectrum analysis - Straw - Taxonomies
Uncontrolled terms:Agricultural by-products - Carbon-carbon bond - Comprehensive utilizations - Effect of chemicals - Environmental issues - Lignocellulosic biomass - Milled wood lignin - Spectral pre treatments
Classification code:525.1  Energy Resources and Renewable Energy Issues - 804  Chemical Products Generally - 811  Cellulose, Paper and Wood Products - 821.4  Agricultural Products - 821.5  Agricultural Wastes - 903  Information Science
DOI:10.11975/j.issn.1002-6819.2018.19.028

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 4>

Accession number:20185206314577
Title:Changes of spectral characteristics of plant leaves before and after dust-retention under hyperspectral imaging
Authors:Zhang, Aiwu (1, 2); Zhang, Taipei (1, 2); Kang, Xiaoyan (1, 2); Guo, Chaofan (1, 2)
Author affiliation:(1) Key Laboratory of 3D Information Acquisition and Application, Ministry of Education, Capital Normal University, Beijing; 100048, China; (2) Engineering Research Center of Spatial Information Technology, Ministry of Education, Capital Normal University, Beijing; 100048, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:170-176
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recent years, due to the influence of natural and human factors, air pollution has become one of the serious problems in the world, which affects people's life, physical and mental health and daily production. So this paper tried to address this problem by the monitoring and governance of haze. Analyzing the spectral characteristics of vegetation leaves before and after dust retention is an effective way to monitor haze. Plant leaves have the ability to adsorb airborne particles. By comparing the spectral curves of plant leaves before and after dust detention, it provides a scientific basis for the control of haze. In this study, the leaves of 10 common trees were collected for 26 consecutive days in October and November. Ten common tree species included Holly, Chinese rose, Platanus acerifolia, Ginkgo, Potentilla fruticosa, Lilac, Euonymus maackii, Lonicera maackii, Lagerstroemia indica and Magnolia. The hyperspectral image of leaf before and after dust retention was obtained by the hyperspectral imaging device developed by our research group. The hyperspectral image is segmented by thresholding method, and the average spectral curve of the whole leaf is extracted. The comparison of 10 kinds of leaves before and after dust retention was performed, excluding the influence of water, internal structure, and so on, and controlling dust to be the single variable. The changes of spectral characteristics of a single leaf, a variety of spectral characteristics of leaves, and the spectral differences before and after dust retention were analyzed. The basic trends of spectral changes of leaves before and after dust retention were obtained: 1) The variation trend of 10 kinds of leaves was basically the same, and the obvious spectrum changes of them before and after the dust retention were in the 500-550, 550-700 and 730-760 nm bands. 2) There was no change in the position of the red edge of the leaves before and after the dust retention, and the dust retention did not affect the internal physiological structure of the leaves. 3) The spectral response at the 765 nm band of Potentilla fruticosa and Platanus acerifolia differed greatly from other tree species; Euonymus maackii, Lonicera maackii, Lagerstroemia indica, and Magnolia had less sensitivity to dust retention in the 550-570 nm band. The spectral curves of 10 species of leaves were compared and analyzed from 3 aspects: Single leaf spectral characteristics, multiple leaf spectral characteristics, and spectral difference before and after dust retention. The spectral curves of 10 species of leaves were consistent with typical vegetation spectral curves; the spectral reflectance curves of 10 species changed obviously before and after dust retention, and the variation ranges were different, which indicated that different species had different sensitivity to dust retention. The study provides reference for monitoring atmospheric dustfall and controlling haze, and also provides theoretical support for further hyperspectral detection of typical components of haze.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Air pollution
Controlled terms:Dust - Forestry - Hyperspectral imaging - Sensitivity analysis - Spectroscopy - Spectrum analysis - Vegetation
Uncontrolled terms:Dust retention - Hyperspectral detections - Leaf spectrum - Physiological structures - Plants - Spectral characteristics - Spectral differences - Spectral reflectance curves
Classification code:451  Air Pollution - 451.1  Air Pollution Sources - 921  Mathematics
Numerical data indexing:Size 5.50e-07m to 5.70e-07m, Size 7.30e-07m to 7.60e-07m, Size 7.65e-07m
DOI:10.11975/j.issn.1002-6819.2018.19.022

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 5>

Accession number:20185206314582
Title:Cd removal from aqueous solution using magnetic biochar derived from maize straw and its recycle
Authors:Hu, Xueyu (1); Chen, Yaojun (1); Zhang, Shasha (1); Wang, Xiangqian (1); Li, Chengcheng (1); Guo, Xiao (1)
Author affiliation:(1) School of Environment, China University of Geosciences (Wuhan), Wuhan; 430074, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:208-218
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:China is a large agricultural country whose output of crop straw is more than 800 million tons, but the effective resource utilization technology of straw is still lacking. Heavy metal pollution in water is also one of the major environmental problems at present. Adsorption methods are widely used in removing heavy metals from water environment due to the simple operation, no need to add a large amount of chemical agents, and low energy consumption. The preparation of biochar from maize straw provides a resource utilization approach for agricultural waste. Besides, maize straw biochar can be used as a new type of environmentally friendly material for the treatment and repair of polluted water. Based on the premise of resource utilization of crop straw wastes in farmland ecosystems, the objective of this study was to remove the heavy metal cadmium (Cd) from water using biochar and realize the recycling of biochar. The original maize straw biochar (MSB) and magnetic maize straw biochar (MMSB) that cracked at 500 &#8451; were used as experimental materials for this purpose. Based on the characterization of the original biochar and the magnetic biochar, the adsorption and removal effects of the 2 kinds of biochar on Cd(II) in polluted water and the possibility of recycling biochar were explored. The results showed that the adsorption of Cd(II) by biochar increased first and then decreased with the increase of the pH value of the solution, and the adsorption of Cd(II) by MSB and MMSB reached the maximum at the pH value of 5. The maximum adsorption capacities were 27.52 and 33.45 mg/g, respectively. When MSB and MMSB were added at 1.4 and 0.8 g/L, the removal rates of Cd(II) were up to 85.15% and 95.48% respectively, and the difference was significant (P&lt;0.05). Langmuir equation could better simulate the isothermal adsorption behavior, the fitting coefficients of MSB and MMSB were both over 0.970 0, and the maximum adsorption capacities at equilibrium reached 26.03 and 43.45 mg/g respectively, which approached the actual values. The kinetic data had a higher fitting degree with the second-order kinetics equation. The theoretical values of equilibrium adsorption capacity of MSB and MMSB were 13.42 and 24.31 mg/g respectively, which had only differences of 2.26% and 3.84% with the actual values respectively. The maximum desorption rates of MSB and MMSB were 41.10% and 29.88%, respectively, and the desorption rates of MMSB were significantly lower than that of MSB. The adsorption process of Cd(II) by biochar was a combination of various mechanisms, mainly chemical mechanism, and the adsorption mechanism mainly includes electrostatic adsorption, ion exchange, surface complexation and cation-&pi; action. The enhancement of adsorption efficiency and fixation ability of magnetic biochar on Cd(II) might be related to its higher pH value, larger specific surface area, and more polar oxygen-containing functional groups. In addition, in the case of external magnetic fields, magnetic biochar could be recovered and reused by magnetic action. The research results are of great significance to promote the resource utilization of agricultural waste and the advancement of heavy metal purification technology in the water environment.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:47
Main heading:Cadmium compounds
Controlled terms:Adsorption - Agricultural wastes - Biomass - Chemicals removal (water treatment) - Crops - Desorption - Ecosystems - Energy utilization - Heavy metals - Ion exchange  - Magnetism - pH - Purification - Solutions - Waste utilization - Water pollution - Water recycling
Uncontrolled terms:Bio chars - Electrostatic adsorption - Environmental problems - Equilibrium adsorption capacity - Experimental materials - External magnetic field - Heavy mental - Oxygen-containing functional groups
Classification code:453  Water Pollution - 454.3  Ecology and Ecosystems - 525.3  Energy Utilization - 531  Metallurgy and Metallography - 701.2  Magnetism: Basic Concepts and Phenomena - 801.1  Chemistry, General - 802.2  Chemical Reactions - 802.3  Chemical Operations - 803  Chemical Agents and Basic Industrial Chemicals - 804  Chemical Products Generally - 821.4  Agricultural Products - 821.5  Agricultural Wastes
Numerical data indexing:Mass_Density 1.40e+00kg/m3, Mass_Density 8.00e-01kg/m3, Percentage 2.26e+00%, Percentage 2.99e+01%, Percentage 3.84e+00%, Percentage 4.11e+01%, Percentage 8.52e+01%, Percentage 9.55e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.027

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 6>

Accession number:20185206314569
Title:EBM-based social economic loss model of water resources imbalance risk and its application
Authors:Jiang, Qiuxiang (1); Wang, Tian (1); Wang, Zilong (1); Fu, Qiang (1); Zhao, Youzhu (1); Dong, Yujie (1); Zhou, Zhimei (1)
Author affiliation:(1) School of Water Conservancy &amp; Civil Engineering, Northeast Agricultural University, Harbin; 150030, China
Corresponding author:Wang, Zilong(wangzilong2017@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:104-113
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The water resources system is closely related to the regional economy. It is more intuitive to use economic value to reflect the losses caused by water system risks such as water resource imbalance and mismatch. In order to evaluate the risk of water resources system through quantitative economic value, this paper firstly constructed the water loss risk economic loss model, and used the EBM model to calculate the water use efficiency, and combined the water price and per capita wage in Heilongjiang Province to determine the water resource risk value. Then, based on the EBM, a two-stage Tobit model was added to analyze the causes of the risk economic loss of the water resources system. The results show that the least economic loss caused by insufficient water resources investment in Heilongjiang Province from 2000 to 2020 is 7.52 billion yuan (2008), the highest is 42.51 billion yuan (2013); the economic loss of minimum output of water resources is 111.9 billion yuan (2000), the highest is 1 106.8 million yuan (2012). From 2000 to 2015, the economic loss of water resources in Heilongjiang Province increased year by year, and the economic loss of water resources output accounted for more than 90% of the economic loss of water resources system. It is estimated that the economic loss of water resources risk in 2020 is 813.87 billion yuan. Jixi, Suihua, Qiqihar, Harbin, Daqing, Jiamusi, Shuangyashan, Qitaihe and Hegang have lower economic losses caused by input and better water resources allocation. The cities with large economic losses caused by output are Yichun, Mudanjiang and Suihua, which require the government to pay more attention to the utilization of water resources in the region. It is necessary to rationally allocate water resources, improve water use efficiency, and reduce the risk economic loss of water resources systems. Hegang, Qitaihe, Jiamusi and other major grain producing areas have greater risk of water resources, greater economic losses and lower water use efficiency. In general, the agricultural water use efficiency in Heilongjiang Province is low, and the phenomenon of flood irrigation is still serious. It is necessary for the government and farmers to cooperate with each other to improve water use efficiency. During the research period, the risk economic loss of water resources system in Heilongjiang Province was large, and the water use efficiency was low. The water use efficiency in most areas was only in the medium range. From the perspective of spatial distribution, water use efficiency is high in the north-south direction and low in the east-west direction. The water use efficiency in the eastern region is lower than that in the other regions. The water resources system of Heilongjiang Province is affected by industrial structure, per capita GDP, per capita water resources and water resources investment. Water price is correlated with water use efficiency in only a few cities, indicating that the government's purpose of regulating water resources through water prices has not been met, and the government needs to introduce relevant policies to change in the future. This article will support the development of risk aversion measures for subsequent water resources systems.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Water resources
Controlled terms:Agriculture - Economic analysis - Efficiency - Losses - Models - Regional planning - Risk assessment - Risk perception
Uncontrolled terms:Agricultural water use - Flood irrigation - Heilongjiang - Industrial structures - Tobit - Water resources allocations - Water resources systems - Water use efficiency
Classification code:403.2  Regional Planning and Development - 444  Water Resources - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 911.2  Industrial Economics - 913.1  Production Engineering - 914.1  Accidents and Accident Prevention
Numerical data indexing:Percentage 9.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.014

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 7>

Accession number:20185206314556
Title:Theoretical analysis of exergy transfer and conversion in grain drying process
Authors:Li, Changyou (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou; 510642, China
Corresponding author:Li, Changyou(lichyx@scau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:1-8
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The exergy is defined as the maximum useful work possibly during a thermal dynamic process that brings the system into equilibrium. Analysis of exergy utilization provides a fair and effective method for evaluating the energy efficiency. Since drying is a comprehensive process involving complicated interaction among different materials, exergy analysis is especially helpful in rating the efficiency of different drying strategies. However, the mechanism behind the exergy transfer and conversion during drying has not yet been fully investigated and understood. At present, the lack of theoretical analysis is hindering the implementation and progress of the sophisticated applications. The theoretical difficulties include the quantitative understanding and expression of the coupling effects in different exergies. In this article, we analyzed the exergy transfer and conversion between grain and drying medium. In a drying process, the ultimate goal is to reduce the moisture content in the grain until it is in the dryness that is the same as the environment where the grain is stored. Therefore, we define exergy as zero when the system is in equilibrium with the ambient environment. Based on the comprehensive coupling of the potential energy difference, temperature gradient and pressure gradient, the theoretical models of thermal exergy, flow exergy, diffusion exergy and exergy efficiency are given. We also studied the relationships and restrictions of different exergies based on the enthalpy-moisture diagram. Our results revealed that drying is the result of the simultaneous action of thermal exergy, diffusion exergy and flow exergy. The conversion and transfer of thermal exergy can be directly characterized by water vaporization, which is driven by the temperature gradient in the system. Most of the thermal exergy is directly converted to the latent heat of evaporation. Regardless of the number and type of the heat sources, thermal exergy transfer is always directly related to the temperature gradient of the drying system. Diffusion exergy originates from the excess water in grain. The vapor pressure difference between the wet grain and the drying medium will naturally drive the water transfer, making the wet grain to dry medium. The temperature gradient and pressure gradient both have important effects on the diffusion process. When the temperature gradient is opposite to the vapor pressure gradient, the exergy efficiency is enhanced; otherwise, the exergy efficiency is weakened. The flow exergy maintains the potential difference necessary for the transfer of heat exergy and diffusion exergy. Without flow exergy, the transfer of heat and wet exergy cannot be effectively carried out. In a ventilation and drying system, the exergy difference between the wet grain and drying medium is the driving force behind the drying process. Drying can be summarized as the process of exergy transfer and conversion, converting physical conditions of wet grain into to conditions of the drying medium. Different from isolated systems, the thermal equilibrium of a drying process is determined by the ambient environment which is always static regardless of the size of energy and mass transfer. The drying process still follows the second law of thermodynamics. However, the entropy increase of the ambient environment is negligible. The thermal exergy, diffusion exergy and flow exergy can all be expressed in state functions. We provided time-dependent state functions of exergy and exergy efficiency to reveal the change of exergy flow density and efficiency according to the environmental conditions and the conditions of the grain. These theoretical models can be applied to make fair and reasonable evaluation on the energy utilization in practical applications. Based on the theoretical analyses of exergy and its efficiency, the largest exergy loss process can be predicted and prevented. These models provide a scientific basis for evaluating the energy utilization in a drying system, and can be used to optimize the drying process.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Exergy
Controlled terms:Diffusion - Dryers (equipment) - Drying - Efficiency - Energy efficiency - Energy utilization - Function evaluation - Grain (agricultural product) - Hydrostatic pressure - Large scale systems  - Moisture - Potential energy - Pressure gradient - Thermal gradients
Uncontrolled terms:Energy and mass transfer - Energy efficiency evaluation - Environmental conditions - Exergy transfer - Potential difference - Second Law of Thermodynamics - Thermal equilibriums - Vapor pressure differences
Classification code:525.2  Energy Conservation - 525.3  Energy Utilization - 631.1.1  Liquid Dynamics - 641.1  Thermodynamics - 821.4  Agricultural Products - 913.1  Production Engineering - 921.6  Numerical Methods - 944.4  Pressure Measurements - 961  Systems Science
DOI:10.11975/j.issn.1002-6819.2018.19.001

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 8>

Accession number:20185206314566
Title:Evaluation for natural grassland utilization intensity based on GPS and UAV remote sensing for grassland biomass inversion
Authors:Wang, Chuanjian (1, 2); Jiang, Honghong (1, 2); Yin, Xiaojun (1, 2); Sun, Shize (1, 2); Zhang, Ya (1, 2); Li, Dong (1, 2)
Author affiliation:(1) College of Information Science and Technology, Shihezi University, Shihezi; 832000, China; (2) Geospatial Information Engineering Research Center, Xinjiang Production and Construction Corps, Shihezi; 832000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:82-87
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Natural grassland is the most important material basis for the survival of grazing livestock husbandry. Assessment of the utilization of natural grassland provides decision-making basis for livestock management department to implement the natural grassland development projects, and has important research and application value for promoting the sustainable development of the grazing livestock husbandry. However, grassland degradation is getting worse. And overgrazing is one of the main causes of grassland degradation. Therefore, it is particularly important to monitor natural grassland utilization timely and accurately. Grazing is one of the most important ways to utilize natural grassland and has an important impact on the sustainable development of the ecosystem. What's more, grassland is the basis for developing grassland animal husbandry, and grassland biomass is one of the important indicators to determine whether the utilization of natural grassland resources is reasonable. Hence, we put forward that the process of natural grassland utilization was an interactive process between grazing behavior and vegetation growth. Therefore, we studied the evaluation method of the utilization of natural grassland, during which we took grazing behavior and grassland vegetation growth into account at the same time. Firstly, the herd trajectory data acquired from global positioning system (GPS) weaned on the head of sheep was used to analyze feeding intensity. In order to quantify grazing pressure, a feeding intensities (FI) map was created using a grid cell method with the tracking data recorded by the global positioning system (GPS). Secondly, the grassland biomass data was gained by using unmanned aerial vehicle (UAV) remote sensing data. With the existing remote sensing estimation model, the grassland yield distribution of natural grassland was estimated. Thirdly, the feeding intensity and natural grassland biomass was fused by using the multi value extraction point method, and the feeding intensity and grassland biomass of different regions could be obtained. The feeding intensity and biomass were classified, respectively. Finally, according to the hierarchical relationship between the feeding intensity and the biomass, the information about utilization of grassland in various regions was obtained. When the feeding intensity and the natural grassland biomass could meet the following relationship, the information about utilization of grassland could be obtained. If the levels of feeding intensity and biomass were equal, the grassland was moderately used. If the level of feeding intensity was greater than that of biomass, the grassland was overused. If the level of feeding intensity was less than that of biomass, the grassland was light used. Taking pasture of Regiment 151 of the Eighth Division of the Xinjiang Production and Construction Corps as an example, the research area was monitored and assessed. The results showed that the area of grassland that was moderately used in Zone 3 in the study area was the largest, which was 612 m², while in other areas, more than 50% of the area was unreasonably used. The method is of great significance to the rational use of grassland, rotational grazing, and the healthy development of livestock husbandry.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:25
Main heading:Ecology
Controlled terms:Agriculture - Antennas - Biomass - Decision making - Feeding - Global positioning system - Planning - Remote sensing - Research and development management - Sustainable development  - Unmanned aerial vehicles (UAV) - Vegetation
Uncontrolled terms:Development project - Evaluation - Grassland degradation - Grassland vegetation - Interactive process - Remote sensing data - Remote sensing estimations - Research and application
Classification code:454.3  Ecology and Ecosystems - 652.1  Aircraft, General - 691.2  Materials Handling Methods - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 912.2  Management
Numerical data indexing:Area 6.12e+02m2, Percentage 5.00e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.011

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 9>

Accession number:20185206314586
Title:Weight-loss characteristics, components of bio-oil and kinetics during pyrolysis from different types of microalgae
Authors:Wang, Junhao (1); Zhang, Yu (1); Yang, Youyou (2); Zuo, Zhaojiang (3); Ma, Zhongqing (1)
Author affiliation:(1) School of Engineering, Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-Efficiency Utilization, Zhejiang A &amp; F University, Lin'an; 311300, China; (2) School of Agriculture and Food Science, Zhejiang A &amp; F University, Lin'an; 311300, China; (3) School of Forestry and Bio-technology, Zhejiang A &amp; F University, Lin'an; 311300, China
Corresponding author:Ma, Zhongqing(mazq@zafu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:239-247
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:As a kind of new-fashionable biomass material, microalgae has the advantages of large amount, fast-growing, high efficiency of photosynthesis, and less land for cultivating. Biomass fast pyrolysis technology is a promising technology to convert low-grade microalgae into high value-added advanced liquid bio-fuels and bio-chemicals. In this paper, a systematical comparison of components' content, pyrolysis behaviors, kinetics, and evolved gas components, was carried out among 3 types of microalgae (Chlamydomonas reinhardtii, Chlorella vulgaris, and Microcystis aeruginosa) using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TGA-FTIR), pyrolyzer coupled with gas chromatography/mass spectrometer (Py-GC/MS), and distributed activation energy model (DAEM). The result showed that: (1) Based on the TGA analysis, the thermal degradation process of microalgae was composed of 3 stages, namely drying stage (temperature range of 30-150&#8451;), fast pyrolysis stage (temperature range of 150-550&#8451;), and carbonization stage (temperature range of 550- 800&#8451;), and the maximum weight loss rate was observed for Microcystis aeruginosa with a value of 17.34 wt.%/min; the TG/DTG (thermogravimetry/differential thermogravimetry) curves moved to the side of high temperature and the weightlessness rate unit time (wt.%/min) gradually increased as the heating rate increased. (2) The FTIR analysis indicated that there were 6 strong infrared characteristic absorption bands from microalgae pyrolysis, which located at 3734 cm- 1 (-OH), 2 938 cm- 1 (-CH3), 2 360 cm- 1 (-C=O), 1 770 cm- 1 (C=O), 950 cm- 1 (P-O-P) and 667 cm- 1 (CO2). These characteristic functional groups represented the main evolved gas components were CH4, CO2, compounds containing C=O bond, compounds containing N-H and C-N bonds, in which the maximum content of CH4 was evolved from Chlamydomonas reinhardtii, and the maximum content of compounds containing C=O bond was evolved from Microcystis aeruginosa. (3) Based on DAEM analysis, as conversion rate increased, the activation energy values of 3 types of microalgae increased. The activation energy of Microcystis aeruginosa increased from 100 to 680 kJ/mol, the activation energy of Chlorella vulgaris increased from 40 to 265 kJ/mol, and the activation energy of Chlamydomonas reinhardtii increased from 20 to 250 kJ/mol. Among the 3 types of microalgae, Microcystis aeruginosa had the maximum value of activation energy. (4) Based on the Py-GC/MS analysis, the whole components in the bio-oil could be divided into the following categories, such as alkanes, olefins, benzene series, alcohols, ethers, aldehydes, ketones, nitriles, furans, indoles, and acids. Among them, long-chain alkanes, olefins, aldehydes and ketones, fatty acids and esters were mainly derived from pyrolysis of lipids and carbohydrate, while phenols, aromatics, amines and amides, heterocyclic compounds containing nitrogen were mainly derived from pyrolysis of protein. Chlorella vulgaris produced the maximum content of oxygenates compounds reaching up to 30.89%, while Microcystis aeruginosa produced the maximum contents of phenols, aromatic hydrocarbons, amines and amides, and other compounds containing nitrogen reaching up to 10.41%, 13.46%, 13.87% and 14.27%, respectively. In summary, this paper would be useful to supply scientific and basic data for industrial application of microalgae.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Activation energy
Controlled terms:Activation analysis - Aldehydes - Algae - Amides - Amines - Aromatic hydrocarbons - Bacteria - Biofuels - Carbon dioxide - Carbonization  - Cultivation - Enzyme kinetics - Fatty acids - Fourier transform infrared spectroscopy - Gas chromatography - Ketones - Kinetics - Microorganisms - Nitrogen - Olefins  - Paraffins - Phenols - Pyrolysis - Thermogravimetric analysis
Uncontrolled terms:Chlamydomonas reinhardtii - Distributed activation energy model - Fourier transform infrared spectrometry - Infrared characteristics - Micro-algae - Py-GC/MS - TGA-FTIR - Thermogravimetric analyzers
Classification code:461.9  Biology - 801  Chemistry - 802.2  Chemical Reactions - 802.3  Chemical Operations - 804  Chemical Products Generally - 821.3  Agricultural Methods - 931  Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Percentage 1.04e+01%, Percentage 1.35e+01%, Percentage 1.39e+01%, Percentage 1.43e+01%, Percentage 3.09e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.031

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 10>

Accession number:20185206314581
Title:Removing effect of fine particles with different sizes by foam fractionator in recirculating aquaculture system
Authors:Ji, Mingdong (1); Li, Jianping (1); Ye, Zhangying (1); Zhu, Songming (1)
Author affiliation:(1) College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou; 310058, China
Corresponding author:Zhu, Songming(zhusm@zju.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:202-207
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In recirculating aquaculture system (RAS), the main solid wastes are uneaten feed, faeces and bacterial flocs. Solid wastes can decrease water quality and aquacultural benefit if without removed effectively. A higher removal efficiency of solid wastes is the guarantee for improving the environmental sustainability of RAS, and it will promote the development and utilization of RAS in China. The larger particles can be removed by settling basin, drum filter, swirl separator, and so on. But it's difficult to remove fine particles accounting for 95% of total solid wastes smaller than 20 &mu;m and the heterotrophic bacteria can use particulate organic matter for mineralization process. This process not only consumes oxygen, but also produces ammonia, which may aggravate the burden of biofilter for autotrophic nitrifying bacteria to remove ammonia and nitrite. For removing fine particles efficiently, Venturi type of foam separator was optimized by the testing of hydraulic retention time and the air inflow, and combined with relevant theory research, the removal situation of particles with different size ranges was analyzed. In this experiment, the water as original sample from the outlet of drum filter with microscreen mesh size of 125 &mu;m was introduced for batch foam fractionation. The mass concentration of particles in the original sample was (30.33&plusmn;4.54) mg/L, and the size of more than 98% of them was smaller than 10 &mu;m. The removal efficiency of fine particles was applied as the index for optimization of hydraulic retention time and the air inflow. According to the particle size distribution of the original sample, all particles were divided to 4 size ranges, i.e. &le;10, &gt;10-50, &gt;50-90 and &gt;90 &mu;m, and their concentrations in original sample were (6.56&plusmn;0.98), (8.68&plusmn;1.30), (7.75&plusmn;1.16) and (7.35&plusmn;1.10) mg/L respectively. And the changing rate of fine particles' concentration for each interval was applied as the index for analyzing the removal situation of particles with different size ranges. The results showed that the hydraulic retention time and air inflow had significant influences on the removal efficiency of fine particles. When the hydraulic retention time was 2.0 min and the air inflow was 1.3 L/min, the removal efficiency of fine particles was the highest, which was 34.06%&plusmn;4.37%, and particles size range of the foam wastewater discharged from the foam separator was 1-300 &mu;m, more than 95% of which was smaller than 10 &mu;m. Foam fractionation had a good effect on removing the particles whose size was &le;90 &mu;m, and the removal efficiency of the particles with the size of &le;10 and &gt;50-90 &mu;m was relatively higher than that of &gt;10-50 &mu;m, while it was difficult to remove the particles with the size of &gt;90 &mu;m. Removal efficiency can be increased to some extent with the decreasing of bubbles size and the increasing of hydraulic retention time, but there exists an extreme value, and it suggests that the design and operation of foam fractionation is determined by the nature of the particles and size distribution in the aquaculture water. For the sake of improving the fine particles removal efficiency of foam fractionation in RAS, the fractionation mechanism should be further studied, especially the properties of bubbles and particles, such as how to select the bubble size according to the properties and size distribution of particles in different operating conditions of RAS, and how to apply ozone, a kind of strong oxidizer that has been proved to be efficient for improving the removal of solids in actual RAS.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Particles (particulate matter)
Controlled terms:Ammonia - Aquaculture - Bacteria - Biological materials - Efficiency - Elementary particles - Light transmission - Nitrification - Particle size - Particle size analysis  - Separators - Size distribution - Solid wastes - Sustainable development - Waste utilization - Water quality
Uncontrolled terms:Air inflow - Development and utilizations - Different operating conditions - Environmental sustainability - Foam fractionation - Hydraulic retention time - Particulate organic matters - Recirculating aquaculture system
Classification code:445.2  Water Analysis - 461.2  Biological Materials and Tissue Engineering - 741.1  Light/Optics - 802.2  Chemical Reactions - 804.2  Inorganic Compounds - 821.3  Agricultural Methods - 913.1  Production Engineering - 922.2  Mathematical Statistics - 931.3  Atomic and Molecular Physics - 951  Materials Science
Numerical data indexing:Percentage 9.50e+01%, Percentage 9.80e+01%, Size 1.00e-05m, Size 1.00e-06m to 3.00e-04m, Size 1.25e-04m, Size 2.00e-05m, Time 1.20e+02s
DOI:10.11975/j.issn.1002-6819.2018.19.026

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 11>

Accession number:20185206314590
Title:Analysis of optimum thermal insulation thickness of double-skin ventilation roof of low temperature granary in Changsha region
Authors:Wang, Haitao (1); Wang, Jun (1); Guo, Chengzhou (1)
Author affiliation:(1) College of Civil Engineering and Architecture, Henan University of Technology, Zhengzhou; 450001, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:276-283
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The thermal insulation performance of granary envelope has important impacts on grain storage safety and granary energy consumption. The roof of a granary is usually very large. Because roof is the position with the strongest solar radiation in granary, the external heat is mainly transferred into granary through roof. Therefore, granary roof is the key part in the design of thermal insulation in building envelope of granary. Double-skin ventilation roof, high reflectivity coatings for roof, and thermal insulation material are three popular techniques for roof of granary for stored grain safety and more energy saving. According to different solar radiation levels and different climatic characteristics, the optimum thermal insulation thicknesses of roofs is different in different areas of China. In this paper, the transient heat transfer model of multi-layer roof was presented and validated for calculating energy consumption of ordinary roof in low temperature granary. By considering the influence of natural ventilation, a heat transfer model of double-skin ventilation roof was proposed and validated for determining energy consumption of double-skin ventilation roof. In this pater, the P<inf>1</inf>-P<inf>2</inf> economic models were used to study the optimum thermal insulation thicknesses of the ordinary multi-layer roof and the double-skin ventilation roof of the low temperature granaries in Changsha region. The effect of different solar radiation reflectivity rates of outside surface was considered in determining the optimum thermal insulation thickness of the low temperature granary roof in Changsha region. The optimum thermal insulation thicknesses of two thermal insulation materials including expanded polystyrene and expanded polystyrene were calculated for ordinary roof and double-skin ventilation roof of the low temperature granary in Changsha region by using P<inf>1</inf>-P<inf>2</inf> economic model respectively. And then, on the basis of life cycle cost analysis, the total life cycle costs, life cycle savings and payback periods were calculated. The results of this research showed that the solar radiation reflectivity of outside surface has a significant impact on the economy and the optimum thermal insulation thickness of the low temperature granary roof in Changsha region. Double-skin ventilation roof can reduce the optimum thermal insulation thickness of low temperature granary roof. Double-skin ventilation roof and high reflectivity coatings for roof should be adopted in roof of low temperature granary in Changsha region for more energy saving and less environmental pollution. The optimum thermal insulation thicknesses range of extruded polystyrene and expanded polystyrene was between 0.106-0.183 m for ordinary roof of low temperature granary. The maximum life cycle savings range from 417 to 633.38 RMB Yuan/m². The payback period ranges from 2.39 to 2.96 years for the optimum thermal insulation thickness of roof. Expanded polystyrene has thicker optimum thermal insulation layer than extruded polystyrene. Expanded polystyrene has shorter payback period of optimum thermal insulation thickness of roof than extruded polystyrene. The optimum thermal insulation thickness of the roof decreases with the increase of the solar radiation reflectivity of outside surface of the roof. The double-skin ventilation roof can shorten the payback period of the optimum thermal insulation thickness of the low temperature granary roof. Besides, this determination method of optimum thermal insulation thickness of roof has a certain guiding significance for guiding design process of thermal insulation thickness of low temperature granary roof.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Thermal insulation
Controlled terms:Coatings - Cost benefit analysis - Costs - Economics - Energy conservation - Energy utilization - Grain elevators - Heat transfer - Investments - Life cycle  - Models - Polystyrenes - Reflection - Roofs - Solar radiation - Structural design - Temperature - Thermal insulating materials - Ventilation
Uncontrolled terms:Environmental pollutions - High-reflectivity coatings - Life cycle cost analysis - Optimum thickness - Thermal insulation layer - Thermal insulation materials - Total life cycle costs - Transient heat transfer
Classification code:408.1  Structural Design, General - 413.2  Heat Insulating Materials - 525.2  Energy Conservation - 525.3  Energy Utilization - 641.1  Thermodynamics - 641.2  Heat Transfer - 643.5  Ventilation - 657.1  Solar Energy and Phenomena - 694.4  Storage - 813.2  Coating Materials - 815.1.1  Organic Polymers - 911  Cost and Value Engineering; Industrial Economics - 971  Social Sciences
Numerical data indexing:Age 2.39e+00yr to 2.96e+00yr, Size 1.06e-01m to 1.83e-01m
DOI:10.11975/j.issn.1002-6819.2018.19.035

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 12>

Accession number:20185206314593
Title:Improving cracking characteristics and kernel percentage of walnut by optimal position of cutting on shell
Authors:Zheng, Xia (1, 2); Zhang, Enming (1, 2); Kan, Za (1, 2); Zhang, Hongwen (1, 2); Li, Hongbin (3); Chou, Weixin (1, 2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi; 832000, China; (2) Key Laboratory of Northwest Agricultural Equipment of Ministry of Agriculture, Shihezi; 832000, China; (3) Xinjiang Koshen Agricultural Equipment Technology Development Co. LTD, Shihezi; 832000, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:300-308
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In view of the difficulty of balancing the cracking shell rate and the whole kernel ratio existing in the traditional single mechanical cracking shell method, this paper conducted the static pressure test of cutting treatment of Xinjiang Xinfeng walnut shell before broken from the pretreatment perspective. In order to more fully reflect the main characteristics of walnuts, the physical properties of walnuts were analyzed. The three-dimensional model of walnuts was built as a thin sphere shell, and three-dimensional modeling was performed with a three-dimensional scanner to make it more similar to real walnut shape. And cutting pretreatment of the model of walnut shell was implemented. Through the finite element static analysis of non-pretreated model of walnuts, the effects of the position of the walnuts shell pretreatment, the magnitude of the loading force and the position of the loading force on the strain, stress and deformation were studied. Through the static pressure test study, it is known that shell breaking force for the untreated Xinfeng walnut when loading force is along the transverse diameter is 93 N larger than that along the edge diameter of walnut. The deformation required to break the shell along the transverse diameter is 0.46 mm greater than that required along the edge loading force. Untreated Xinfeng walnuts had a whole kernel rate of 86% when loading force was applied along the transverse diameter, and a whole kernel rate of 78% along the edge diameter. When the loading force was applied for the untreated Xinfeng walnuts along the transverse diameter, the whole kernel rate is 8 percentage point higher than that along the edge diameter. After the belly cut pretreatment, the breaking force and broken shell deformation of Xinfeng walnut were significantly reduced. When the loading position was coincident with the cutting position, the shell breaking force was reduced by 139 N, a decrease of 38.4%, and the breaking shell deformation was reduced by 0.37 mm, a decrease of 18.2%. When the direction of the loading force was perpendicular to the cut direction, the breaking force was decreased by 18 N, a decrease of 6.6%. The shell deformation was reduced by 0.11 mm, a reduction of 7%. When the loading position coincided with the cut position, the whole kernel rate for Xinfeng walnut pretreated was 12 percentage point higher than that for the untreated Xinfeng walnut. When the direction of the loading force was perpendicular to the direction of the cutting, the whole kernel rate of Xinfeng walnut pretreated with cutting belly was 8% higher than that of the untreated Xinfeng walnut. After the suture line cutting pretreatment, the breaking force of the walnut was obviously lower than that of the walnut without pretreatment. When the loading position coincided with the cut position, the breaking force was decreased by 32 N, and the reduction was 11.9%. The shell deformation was decreased by 0.21 mm, a decrease of 13.4%. When the loading force direction was perpendicular to the cut direction, the shell breaking force was reduced by 82 N, a reduction of 22.7%. The broken shell deformation was reduced by 0.16 mm with a reduction of 7.9%. When the direction of the loading force was perpendicular to the cutting direction, the percentage of the entire Xinfeng walnut after the pretreatment of the suture line cutting was 2 percentage point higher than that of the untreated Xinfeng walnut. When the loading position coincided with the cut position, the whole kernel rate of Xinfeng walnuts with the suture line cut pretreatment was 6% higher than that of untreated Xinfeng walnuts. The finite element static analysis was performed using the related parameters of static pressure test. The results showed that when the same force was applied, the cut pretreated walnuts produced larger strain, stress and deformation on the shell surface of the walnut model than the untreated. The large strain, stress and deformation of the shell surface of the walnut model generally occurred at the loading position or at the cut position. And the maximum strain, stress and deformation were generated on the surface of the walnut shell when the walnut cut position and the position of loading force were both at the walnut belly. It is noted that the shells of the walnuts pretreated are easier to be broken, and the broken position is generally at the loading position or the cut position; when the loading position and the cutting position are at the walnut belly, it is most conducive to cracking. Analysis showed that when the walnut shell is cracked from the belly, it is more conducive to cracking the walnut along the large gap, so as to ensure the walnut whole kernel rate. The results of finite element static analysis basically agree with that of the static pressure test. The study can provide effective technical support for the development of walnut cutting machine and walnut cracking machine.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Loads (forces)
Controlled terms:Balancing - Cracks - Cutting - Deformation - Finite element method - Multispectral scanners - Shells (structures) - Static analysis - Stress analysis
Uncontrolled terms:Cracking characteristics - Cutting-direction - Mechanical cracking - Pre-Treatment - Stress and deformation - Three dimensional scanner - Three-dimensional model - Walnut
Classification code:408  Structural Design - 408.2  Structural Members and Shapes - 601  Mechanical Design - 723.5  Computer Applications - 921.6  Numerical Methods - 951  Materials Science
Numerical data indexing:Force 1.39e+02N, Force 1.80e+01N, Force 3.20e+01N, Force 8.20e+01N, Force 9.30e+01N, Percentage 1.19e+01%, Percentage 1.34e+01%, Percentage 1.82e+01%, Percentage 2.27e+01%, Percentage 3.84e+01%, Percentage 6.00e+00%, Percentage 6.60e+00%, Percentage 7.00e+00%, Percentage 7.80e+01%, Percentage 7.90e+00%, Percentage 8.00e+00%, Percentage 8.60e+01%, Size 1.10e-04m, Size 1.60e-04m, Size 2.10e-04m, Size 3.70e-04m, Size 4.60e-04m
DOI:10.11975/j.issn.1002-6819.2018.19.038

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 13>

Accession number:20185206314575
Title:Improving mollisols organic matter content as downslope tillage replaced by contour tillage in field scale
Authors:Zhai, Xingyu (1, 2); Zhang, Xingyi (2); Li, Hao (2); E, Lili (1, 2); Chen, Shuai (2); Zhen, Huaicai (1, 2); Gu, Siyu (1)
Author affiliation:(1) College of Resources and Environmental Sciences, Northeast Agricultural University, Harbin; 150030, China; (2) Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin; 150081, China
Corresponding author:Zhang, Xingyi(zhangxy@iga.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:155-161
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The Mollisols degradation induced by water erosion is a big issue in the slope farmland of northeast China. Ridge direction as the same with contour line (contour tillage) could markedly decrease surface runoff and soil loss compared to downslope tillage, which was wildly applied to control soil erosion in the northeast of China. In order to identify the recovery of soil organic matter (SOM) under contour tillage, 102 soil samples were collected and measured in a 1.4 hm² and 3.8&deg; slope farmland by standard grid method in Guangrong village, Heilongjiang province, northeast China, and the soil properties such as SOM and soil water content were measured and compared before and after 10 years of contour tillage by classic statistics (CS) and geostatistics (GS) analysis. The results showed: 1) There was no difference of soil water content before and after 10 years of contour tillage by CS analysis, while GS analysis could well reveal the spatial variation of soil properties in the field before and after ridge direction changed by Range, ratio of Nugget to Sill and spatial distribution maps. 2) The Range of soil water content decreased from 510.7 to 193.2 m, which revealed the spatial heterogeneity of soil water content decreased by contour tillage, namely the water redistribution by surface runoff declined after 10 years of contour tilleage. Meanwhile the ratio of Nugget to Sill of soil water content increased from 11.7% to 46.9% indicated that the spatial autocorrelation level changed from intense to medium. 3) The soil erosion was well controlled by contour tillage in the field with the surface runoff coefficient decreased from 9.8% to 0.48%, and annual soil loss changed from 35.2 to 0.43 t/hm². 4) The SOM in the top soil layer of 0-20 cm was increased with 2.61 g/kg and improved by 8.4%, except for a decrease of 3.7% in a small area of the west part of the middle-upper part of the slope after 10 years of contour tillage. 5) The soil total nitrogen (TN) content in the top soil layer of 0-20 cm decreased with 0.04 g/kg and reduced by 2.8%. The TN content increased in the upper slope and foot slope, as that in most part of the middle and lower slope decreased and the area amounted to 63% of the total. Therefore, in order to improve the soil fertility of degraded farmland, water and soil conservation measures are not enough, more nitrogen fertilizer should also be added properly. This study presents important references for soil and water conservation in the Mollisols slope farmland of Northeast China.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:26
Main heading:Soil surveys
Controlled terms:Agricultural runoff - Biogeochemistry - Biological materials - Erosion - Farms - Moisture - Nitrogen fertilizers - Organic compounds - Soil conservation - Soil moisture  - Soils - Spatial distribution - Spatial variables measurement - Water conservation
Uncontrolled terms:Contour tillage - Farmland - Mollisols - Organic matter content - Soil and water conservation - Spatial autocorrelations - Spatial distribution map - Water and soil conservations
Classification code:444  Water Resources - 461.2  Biological Materials and Tissue Engineering - 481.2  Geochemistry - 483.1  Soils and Soil Mechanics - 804  Chemical Products Generally - 804.1  Organic Compounds - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5  Agricultural Wastes - 921  Mathematics - 943.2  Mechanical Variables Measurements
Numerical data indexing:Age 1.00e+01yr, Percentage 1.17e+01% to 4.69e+01%, Percentage 2.80e+00%, Percentage 3.70e+00%, Percentage 6.30e+01%, Percentage 8.40e+00%, Percentage 9.80e+00% to 4.80e-01%, Size 0.00e+00m to 2.00e-01m, Size 5.11e+02m to 1.93e+02m
DOI:10.11975/j.issn.1002-6819.2018.19.020

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 14>

Accession number:20185206314568
Title:Law of frost heave of canal foundation and appropriate thickness of insulation board under different groundwater levels
Authors:Guo, Fuqiang (1, 2); Shi, Haibin (1); Cheng, Manjin (2); Gao, Wenhui (2)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Inner Mongolia Agriculture University, Hohhot; 010018, China; (2) Inner Mongolian Autonomous Region Research Institute on Hydraulic Sciences, Hohhot; 010060, China
Corresponding author:Shi, Haibin(nmndshb@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:95-103
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to find out the difference of canal foundation frost heave in Hetao irrigation area under different underground water levels, and to understand the influence of the changes of groundwater level on soil moisture transfer and mechanical properties of canal foundation, the test was carried out by setting up a test platform for frost heave under different underground water levels. And combined with the prototype channel, the effect of different groundwater levels on frost heave of foundation soil covered with different thickness of polystyrene board was analyzed, the distribution law of frost heave rate and section bending moment along channel slope was described, and a theoretical formula for calculating the suitable thickness of polystyrene board at different underground water levels was presented. It is found that the frost heaving of base soil decreases by 0.15 cm when the groundwater level is reduced by 1 cm. When the groundwater level is reduced by 0.5-1.0 m, the frost heave rate is reduced by 71%-83.8%. The decline of groundwater level effectively prevents or delays the increase of capillary water in soil, reduces the soil moisture of 0-30 cm soil layer, effectively prevents the migration of the water of freezing front, reduces the formation of ice interlayer in soil, and reduces the frost heaving deformation of soil. The frost heaving damage parts of the channel change with the change of the groundwater level. Through the analysis of ground temperature monitoring data, this paper puts forward the lowest temperature under the condition of laying 2-10 cm polystyrene board, fits the relation between the thickness of insulation board and the lowest temperature under the board at different underground water levels, and calculates the laying thickness of polystyrene board under different groundwater levels when the negative temperature does not exist under the board, so as to explore a relation between the suitable thickness for polystyrene board laying and groundwater depth. According to the theoretical formula, the variation rule of soil frost heave rate along the slope is proposed. When the groundwater level is lower than the bottom of the canal, the maximum frost heave of canal foundation soil is located at the foot of the slope of the canal, and the frost heave rate along the slope decreases gradually. When the groundwater level is higher than the bottom of the canal, the maximum frost heave of the slope is located at the 1/3 of the lower part of the slope, and the maximum frost heave of the slope is gradually transferred upward with the decrease of groundwater depth. When the groundwater depth is relatively shallow, the channel's maximum frost heave is located at the middle part of the channel slope. The soil water content in 0-50 cm soil depth decreases under the 2 conditions of actual decrease of groundwater level and ground elevation. And the migration amount increases with the depth. Migration rate difference is 1.75%-4.46%. The results show that the soil water transport has the consistent change rule whether the ground is raised or the groundwater level drops. This study can provide scientific basis and technical support for the research of thermal insulation and anti-expansion technology in the northern seasonal frozen soil area.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Groundwater
Controlled terms:Bending moments - Foundations - Frozen soils - Groundwater resources - Hydraulic structures - Moisture control - Polystyrenes - Soil moisture - Soil testing - Thermal insulation  - Water levels
Uncontrolled terms:Different thickness - Frost heaving - Ground temperature - Ground water depths - Moisture migration - Negative temperatures - Soil water content - Theoretical formula
Classification code:408.2  Structural Members and Shapes - 413.2  Heat Insulating Materials - 444.2  Groundwater - 483.1  Soils and Soil Mechanics - 483.2  Foundations - 731.3  Specific Variables Control - 815.1.1  Organic Polymers
Numerical data indexing:Percentage 1.75e+00% to 4.46e+00%, Percentage 7.10e+01% to 8.38e+01%, Size 0.00e+00m to 3.00e-01m, Size 0.00e+00m to 5.00e-01m, Size 1.00e-02m, Size 1.50e-03m, Size 2.00e-02m to 1.00e-01m, Size 5.00e-01m to 1.00e+00m
DOI:10.11975/j.issn.1002-6819.2018.19.013

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 15>

Accession number:20185206314580
Title:Improvement of cathodic protection of greenhouse buried heat-supply metal pipeline based on thermoelectric cell
Authors:Wang, Lishu (1); Li, Xinran (1); Su, Jiheng (1); Zhang, Xu (1); Sun, Shida (1)
Author affiliation:(1) Institute of Electrical and Information, Northeast Agricultural University, Harbin; 150030, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:195-201
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the development of the global economy and the improvement of people's living standards, the demand for traditional energy is increasing, which has led to serious energy shortage, and increasingly serious environmental pollution. More and more attention has been paid to thermoelectric power generation technology which takes the industrial and automobile waste heat as heat source. In order to plant out-of-season plants and southern plants, the northern greenhouses generally use heating pipeline for heating. Cathodic protection, as the main protective measure for buried pipelines, plays an important role in pipeline protection. In order to alleviate the corrosion rate of heating pipelines, the method of joint use of external anti-corrosion insulation layer and cathodic protection is generally adopted during the deployment of metal pipelines. This is also the most economical and reasonable anti-corrosion measure. Cathodic protection protects the metal from being corroded by the environmental media (such as soil), protect pipeline or equipment by corrosion with auxiliary anode or sacrificial anode materials, thereby achieving the purpose of prolonging the service life of the protected pipeline and improving its safety and economy. However, the cost for conventional external-current cathodic protection method is high with large footprint, and the protection life of the sacrificial anode method is too short. Therefore, in order to provide reliable external-current cathodic protection for greenhouse heating pipelines, this article uses the waste heat from the surface of the underground heating pipelines, through direct conversion of thermal energy into electrical energy by a thermoelectric power plant, to provide the cathodic protection of the external current mode for the buried heating pipeline. The technology has the advantages of green, environmental protection, simple structure, safety and reliability. This article focuses on the research of thermoelectric power generation systems, introduces the basic theory of thermoelectric power generation and derives the relationship of characteristic parameters of the thermoelectric cell. Based on the output characteristics of the thermoelectric cell, this article designs a self-powered system based on BQ25504 chip. The system collects the thermoelectric energy and continuously supplies it in the maximum power point tracking mode during operation. The thermoelectric conversion energy is collected by the BQ25504 chip produced by TI, and then supplied by the step-down regulator chip LM317 to cathodically protect the buried heating pipeline. The design uses the temperature of the pipeline as a heat source, and it has the advantages of almost no land occupation, long-term use, flexible protection and energy saving. Through field tests, the temperature difference between the cold and the hot ends of the device was found to be 33.2 &#8451;, which proved that the greenhouse heating pipeline was a heat source worthy of utilization. Finally, through the natural corrosion test, it was found that when the horizontal distance of the anode bed was 1.69 m and the protective potential provided by the device was -1 100 mV, the degree of protection to the pipeline could reach 92.79%. This study provides a more feasible solution for the protection of greenhouse heating pipelines, and at the same time, the short-distance pipeline protection technology of external current mode is also explored.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Pipeline corrosion
Controlled terms:Anodes - Auxiliary equipment - Cathodic protection - Corrosion rate - Energy conservation - Energy conversion - Environmental technology - Greenhouses - Heating - Maximum power point trackers  - Pipeline laying - Temperature - Thermoelectric energy conversion - Thermoelectric power - Thermoelectric power plants - Underground corrosion - Waste heat
Uncontrolled terms:Environmental pollutions - Maximum Power Point Tracking - Output characteristics - Power - Protective potentials - Temperature differences - Thermoelectric conversion - Thermoelectric energy
Classification code:454  Environmental Engineering - 525  Energy Management and Conversion - 539.1  Metals Corrosion - 539.2  Corrosion Protection - 615.4  Thermoelectric Energy - 619.1  Pipe, Piping and Pipelines - 641.1  Thermodynamics - 704.2  Electric Equipment - 714.1  Electron Tubes - 821.6  Farm Buildings and Other Structures - 901  Engineering Profession
Numerical data indexing:Percentage 9.28e+01%, Size 1.69e+00m, Voltage -1.10e+00V
DOI:10.11975/j.issn.1002-6819.2018.19.025

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 16>

Accession number:20185206314589
Title:Monitoring land use for human activities in Nabanhe National Nature Reserve based on multi-source remote sensing data
Authors:Liu, Xiaolong (1); Xu, Rui (1); Fu, Zhuo (2); Shi, Zhengtao (1); Gao, Shupeng (1)
Author affiliation:(1) College of Tourism &amp; Geography Science, Yunnan Normal University, Kunming; 65050, China; (2) Satellite Environment Center, Ministry of Environmental Protection, Beijing; 100094, China
Corresponding author:Fu, Zhuo(fuzhuo@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:266-275
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Human activities within the Nature Reserves are considered a threat to the endangered species. This study takes the land cover/land use as the representative of human activities within the Nabanhe National Nature Reserve. As optical remote sensing images are frequently contaminated by cloud and frog, which will restrict its practicality in monitoring human activities in Nabanhe National Nature Reserve, this study aimed to fuse the multi-resources of optical remote sensing images to build a high spatio-temporal resolution data (30 m daily surface reflectance) for the year 2000, 2004, 2010 and 2015 using the ESTARFM (Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model). The fused data was assessed during the data fusing procedure, and in a correlation of greater than 0.8 (with P&lt;0.01) with the reference image for each period of time. The fused data was then used to generate the time-series NDVI (Normalized Difference Vegetation Index), which would be used to differentiate each of the 5 land covers (namely natural forest, rubber trees, water, farmland and built-up area) to be classified. Previous to the extraction of the time-series features, denoising of the time-series NDVI was conducted using the double S-G (Savitzky-Golay) filter. 6 features were generated using the denoised NDVI time-series data, and used to classify the 5 land covers above. The Random Forest classifier was used during the classification, and the RF classifier was trained using the reference samples that were selected from high spatial resolution Google Earth images. The overall accuracies of the final classification results were greater than 86.88%, with Kappa values greater than 0.817 6 (the overall classification accuracies for the year 2000, 2004, 2010 and 2015 were 88.13%, 86.88%, 89.38% and 90.63% respectively, and the corresponding Kappa values were 0.834 0, 0.817 6, 0.853 3 and 0.871 1, respectively). This accuracy guaranteed the availability of the classification results in monitoring human activities in Nabanhe National Nature Reserve. The land cover/land use changing trend was analyzed based on the classification results for each period of time, of which the results were as follows: from 2000 to 2004, water area increased mainly due to the conversion of farmland and built-up area, which occupied 0.06% and 0.01% respectively of the entire area of the Nabanhe National Nature Reserve. Farmland area increased, and the increased area was mainly from natural forest and rubber trees. Built-up area increased, and the increased area was from natural forest and farmland. The area of the increased rubber trees is the largest, and the increased rubber trees occupied natural forest and farmland. The only decreased land cover/land use was the natural forest during this period of time. From 2004 to 2010, water areas increased mainly due to the conversion of natural forest and rubber trees, because there was a hydropower station built during this period of time. Increased farmland area was mainly from forest, while increased built-up area was mainly from farmland. Rubber area was increasing due to the conversion of forest, the area of which was decreasing constantly during this period of time. From 2010 to 2015, increased water occupied farmland and the forest was changed to farmland with the largest area (96.47% of all land converted to farmland was forest). Expanded built-up area was from rubber farmland (occupied 76.92% of all land changed to built-up). It was during this time that the farmland changed the most, it was 5.29% of the area of the Nabanhe National Nature Reserve. Obvious land use changing trend corresponding to terrain was found from 2000 to 2015. Built-up distribution changed less, but the corresponding area increased. The rubber was distributed in areas with slopes ranging from 0 to 36 degrees, and it was first expanded from 0 to 12 degrees, and then to 24 degrees and now is distributed to near 36 degrees. The expansion of rubber is pushing the rubber planting to the limit in the Nabanhe National Nature Reserve. Same changing trend was found to the farmland from 2000 to 2015. Both of these land covers are expanding to steeper terrain and larger areas in the Nabanhe National Nature Reserve. The method provided by this study may support the governmental departments in monitoring human activities within Nature Reserves.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Farms
Controlled terms:Conservation - Data fusion - Decision trees - Forestry - Image enhancement - Land use - Monitoring - Reflection - Remote sensing - Rubber  - Time series
Uncontrolled terms:Governmental departments - High spatial resolution - Land-cover/land-use change - Nature reserves - Normalized difference vegetation index - Random forest classifier - Spatio-temporal data - Spatio-temporal resolution
Classification code:403  Urban and Regional Planning and Development - 723.2  Data Processing and Image Processing - 818.1  Natural Rubber - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 922.2  Mathematical Statistics - 961  Systems Science
Numerical data indexing:Percentage 1.00e-02%, Percentage 5.29e+00%, Percentage 6.00e-02%, Percentage 7.69e+01%, Percentage 8.69e+01%, Percentage 8.81e+01%, Percentage 8.94e+01%, Percentage 9.06e+01%, Percentage 9.65e+01%, Size 3.00e+01m
DOI:10.11975/j.issn.1002-6819.2018.19.034

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 17>

Accession number:20185206314584
Title:Process optimization on 5-ethoxymethylfurfural production from cellulose catalyzed by extremely low acid in one-pot reaction
Authors:Xu, Guizhuan (1, 2); Chen, Binglin (1, 2); Zhang, Shaohao (1, 2); Wang, Dongxiang (1); Li, Kai (1)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou; 450002, China; (2) Key Laboratory of New Materials and Facilities for Rural Renewable Energy, Ministry of Agriculture, Zhengzhou; 450002, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:225-231
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:With the inevitable depletion of non-renewable petroleum resources and the rising environmental concerns, renewable biomass has been regarded as a potential resource for sustainable supply of biofuels. The development of simple, cheap and sustainable catalytic process for the production of biofuels has become a major target. Among the promising biofuels, EMF (5-ethoxymethylfurfural) has been considered as a new generation of biofuel or fuel additive due to its unique properties, such as its liquid characteristics under room temperature, non-toxicity, high lubricity, stable flashpoint and excellent flow properties under cold conditions. Recently, an increasing number of reports have been focused on the direct conversion of carbohydrates and platform chemicals such as 5-hydroxymethylfurfural (HMF), fructose, sucrose, or inulin into EMF catalyzed by different catalysts. However, from a point of view that raw materials are cheap and rich, it is more valuable to use cellulose or cellulosic biomass instead of model compounds, such as HMF and fructose, for the production of EMF. In the existing researches, cellulose was usually used as raw material to be converted into intermediate product HMF, 5-chloromethylfurfural (CMF) or 5-bromomethylfurfural (BMF), and so on, and then the target product EMF was obtained through the intermediate product. Using cheap and renewable cellulose as the raw material, and ethanol as the solvent, and combining the dehydration of cellulose to HMF, followed by the etherification of HMF to EMF in one-pot, is a more attractive reaction pathway. This one-pot reaction avoids the isolation and purification of HMF, which saves time, energy and solvent. The side reaction of process using extremely low sulfuric acid is slight, in which standard grade stainless steel facility can be used instead of high nickel alloy, which has a significant cost advantage in the equipment. In this paper, sulfuric acid with ultra low mass concentration (0.1% of the mass of ethanol) was used as catalyst to catalyze cellulose and ethanol to produce EMF in one-pot reaction. The effects of temperature, reaction time and substrate concentration on EMF yield were firstly studied and then the response surface methodology was used to design experiments to optimize the reaction conditions. The interactions of factors and the optimum reaction conditions were obtained. The results showed that the reaction temperature was the factor that mostly impacted the one-pot EMF production from cellulose and ethanol catalyzed by sulfuric acid with ultra low mass concentration. The maximum mean EMF yield of 14.93% was obtained under the optimum reaction conditions: reaction temperature of 200 &#8451;, reaction time of 75 min and substrate concentration of 30 g/L, with the prediction error of 2.03%, which showed that the model had a good fitting property. Compared to other studies, the study showed that EMF can be obtained directly from cellulose catalyzed by extremely low acid in one-pot reaction for the first time. The process conditions for producing EMF from cellulose catalyzed by extremely low acid in one-pot reaction had been optimized. This study can provide reference for the EMF one-pot production from much cheaper and abundant cellulosic biomass such as agricultural wastes catalyzed by sulfuric acid with extremely low concentration.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Low temperature production
Controlled terms:Acidity - Agricultural wastes - Biofuels - Biomass - Catalysis - Catalysts - Cellulose - Ethanol - Fructose - Fuel additives  - Nickel alloys - Optimization - Organic solvents - Sulfuric acid - Temperature
Uncontrolled terms:5 hydroxymethyl furfurals - 5-ethoxymethylfurfural - Extremely low sulfuric acids - Isolation and purification - One-pot reaction - Optimum reaction conditions - Response surface methodology - Substrate concentrations
Classification code:548.2  Nickel Alloys - 641.1  Thermodynamics - 801.1  Chemistry, General - 802.2  Chemical Reactions - 803  Chemical Agents and Basic Industrial Chemicals - 804.1  Organic Compounds - 804.2  Inorganic Compounds - 811.3  Cellulose, Lignin and Derivatives - 821.5  Agricultural Wastes - 921.5  Optimization Techniques
Numerical data indexing:Mass_Density 3.00e+01kg/m3, Percentage 1.00e-01%, Percentage 1.49e+01%, Percentage 2.03e+00%, Time 4.50e+03s
DOI:10.11975/j.issn.1002-6819.2018.19.029

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 18>

Accession number:20185206314565
Title:Speed-sensorless control system of bearingless induction motor based on modified adaptive fading unscented kalman filter
Authors:Sun, Yuxin (1); Shen, Qikang (1); Ye, Haihan (1); Zhu, Huangqiu (1)
Author affiliation:(1) College of Electrical and Information Engineering, Jiangsu University, Zhenjiang; 212013, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:74-81
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Speed sensorless control estimates the speed of the motor by detecting the voltage and current in the motor, thereby avoiding the use of speed sensors in the system. This method can avoid the influence of the sensor on the rotation of the motor and effectively improve the speed regulation performance of the motor. The Kalman filter is widely used in speed estimation algorithm and this method is well applied to ordinary asynchronous motors, but when it is extended to bearingless induction motor(BIM), there is a mismatch, for the strong dependence of the Kalman filter on the system model, but the current mathematical model of the bearingless induction motor is an approximate model. Aiming at this problem, this study proposes a speed identification method based on improved adaptive fade-out unscented Kalman filter. By using the covariance of the residual sequence, to adaptively change the fading factor to adjust the weight of the new interest, so that the filtering algorithm is more convinced of the measured value in the estimation process, which helps to reduce the impact of stale measurement and system model uncertainty on estimation accuracy. At the same time, by normalizing the residuals, the effect of balancing the information between the residuals is achieved, and the speed of information extraction is improved. In addition, the residual part of the system model is regarded as noise. In order to further reduce the model error, the genetic algorithm is used to adaptively adjust the noise matrix. After repeated cycles of selection, crossover and mutation, the conditions for satisfying the whole population convergence can be selected. With the optimal chromosome, the noise matrix Q and R of the Manchester filter satisfying the optimal filtering condition can be obtained, and the model is compensated by the matrix, and the estimation error of the system is optimized again. In order to verify the effectiveness of the algorithm, this study selects dSPACE1005 developed by German dSPACE company as the core controller and designs the experimental platform. The platform consists of the dSPACE1005's arithmetic control unit, computer, current sensor, voltage Hall sensor, photoelectric encoder and IPM module. The platform consists of the dSPACE1005 arithmetic control unit, computer, current sensor, voltage Hall sensor, photoelectric encoder and IPM module. The stator voltage, stator current and rotational speed are measured by current, voltage Hall and photoelectric encoder respectively. These signals are input into dSPACE1005 through signal conditioning board, and then the improved adaptive fade-out unscented Kalman filter algorithm and noise matrix are completed by dSPACE1005. The effectiveness of the proposed method is verified by comparing the estimation results of Kalman filter and the improved adaptive AFUKF. The robustness of the proposed method is verified by comparing the anti-jamming capabilities of the two algorithms. Experimental results show that this control method has high robustness and precision, and can effectively deal with the influence of modeling error and parameter disturbance on the accuracy of speed estimation. Finally, the correctness and feasibility of the proposed scheme are proved by dSPACE experimental platform.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Kalman filters
Controlled terms:Adaptive control systems - Adaptive filtering - Balancing - Control engineering - Errors - Estimation - Genetic algorithms - Hall effect transducers - Induction motors - Motors  - Photoelectricity - Robustness (control systems) - Sensorless control - Signal encoding - Speed - Stators - Uncertainty analysis
Uncontrolled terms:Anti-jamming capability - Bearingless induction motor - Crossover and mutation - Modified AFUKF - Photoelectric encoders - Population convergence - Speed sensorless control - Unscented Kalman Filter
Classification code:601  Mechanical Design - 701.1  Electricity: Basic Concepts and Phenomena - 705.1  Electric Machinery, General - 705.3.1  AC Motors - 716.1  Information Theory and Signal Processing - 731.1  Control Systems - 731.2  Control System Applications - 921  Mathematics - 922.1  Probability Theory
DOI:10.11975/j.issn.1002-6819.2018.19.010

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 19>

Accession number:20185206314571
Title:Spatial variability and its controlling factors of soil moisture on cropland-forestland mixed hillslope in black soil area of Northeast China
Authors:Guo, Xinxin (1); Fu, Qiang (2); Lu, He (1); Gao, Fengjie (1); Hang, Yanhong (1)
Author affiliation:(1) College of Resources and Environment, Northeast Agricultural University, Harbin; 150030, China; (2) College of Water Conservancy and Architecture, Northeast Agricultural University, Harbin; 150030, China
Corresponding author:Fu, Qiang(fuqiang0629@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:123-130
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Black soil area in Heilongjiang plays an indispensable role in safeguarding national food security as an important commodity grain base. Serious soil erosion and environment degradation restrict the sustainable development of local society and economy. Soil moisture is one of the key factors which control vegetation growth, soil erosion, hydrological and ecological processes at the hillslope, and it also exhibits a great degree of spatial variability. Understanding the spatial variability of soil moisture and its influence mechanism at the slope scale is essential for controlling soil erosion, increasing food production, and improving ecological environment. In this study, spatial variability of soil moisture under the effect of land use and topographic variables was investigated on a cropland-forestland mixed hillslope. The research area was characterized by 4 different land use structures (from top slope to toe slope): cropland-cropland-cropland-cropland-cropland (L1), cropland- cropland-forestland-forestland-cropland (L2), cropland-cropland-forestland-forestland-forestland (L3), forestland-forestland- cropland-forestland-cropland (L4). Soil moisture was collected biweekly during mid-August to mid-September (2016) at 20 sites located in Keshan County of Heilongjiang Province, China. Soil moisture was measured by oven drying method at the depth of 0-20, 20-40, 40-60 cm. The relationship between environmental factors and soil moisture variability was conducted by redundancy analysis method (RDA). The results showed that: 1) Soil moisture content varied from 5.77% to 45.57%; and the soil moisture content of cropland was found markedly higher than that of forestland (P&lt;0.05), with the mean soil moisture content ranging from 20.13% to 22.07% in cropland, and from 13.69% to 15.96% in forestland; the differences of soil moisture content at different soil depths were not significant(P&gt;0.05). 2) Soil moisture content showed a moderate variability in the study area, coefficient of variation (CV) in cropland (35.9%-39.6%) was higher than that in forestland (30.0%-36.5%). 3) Soil moisture variations along hillslope under the impact of 4 land use structures differed from each other. The differences of soil moisture content at middle slope and toe slope in L1 were significant (P&lt;0.05). 4) The spatial variation of soil moisture in the single land use structure (L1, CV was 14.82%) was lower than that in other cropland-forestland mixed land use structures (CV of L2, L3 and L4 was 62.70%, 38.25% and 25.70%, respectively), which indicated that land use mosaic patterns increased the variations of soil moisture. 5) RDA ordination showed that spatial variability of soil moisture was strongly influenced by land use types, and it was also affected by slope gradient, slope position and elevation. In addition, different factors control soil moisture distribution at different soil depths. This study presents that it is necessary to optimize the planting structure and take other proper methods aiming at preventing water loss and soil erosion, in order to improve soil fertility and promote the sustainable development.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Soil surveys
Controlled terms:Ecology - Economics - Erosion - Food supply - Forestry - Land use - Moisture - Moisture control - Moisture determination - Planning  - Soil conservation - Soil moisture - Soils - Sustainable development
Uncontrolled terms:Black soil - Coefficient of variation - Ecological environments - Environmental factors - Hillslopes - Mixed structure - Soil moisture distribution - Spatial variability
Classification code:403  Urban and Regional Planning and Development - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 822.3  Food Products - 912.2  Management - 944.2  Moisture Measurements - 971  Social Sciences
Numerical data indexing:Percentage 1.37e+01% to 1.60e+01%, Percentage 1.48e+01%, Percentage 2.01e+01% to 2.21e+01%, Percentage 2.57e+01%, Percentage 3.00e+01% to 3.65e+01%, Percentage 3.59e+01% to 3.96e+01%, Percentage 3.82e+01%, Percentage 6.27e+01%, Size 4.00e-01m to 6.00e-01m
DOI:10.11975/j.issn.1002-6819.2018.19.016

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 20>

Accession number:20185206314588
Title:Identification of boundary about coal-mining influence on ecology by remote sensing in Yanzhou Coalfield based on temperature vegetation drought index
Authors:Li, Jing (1); Han, Ying (1); Yang, Zhen (1); Miao, Hui (1); Yin, Shouqiang (1)
Author affiliation:(1) College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing; 100083, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:258-265
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:How to determine the ecological impact boundary of coal mining is one of the difficulties in the research field of land ecology in mining areas. For a long time, surface subsidence depth of 10 mm is generally used as the coal mining disturbance boundary not only to the developed land but also to the vegetation-covered land in the academic research and planning practice. Land reclamation is still bounded by the subsidence contour with the expected surface subsidence depth of 10 mm as the boundary. In fact, many scholars and other professionals have realized that 10 mm sinking is not adaptable as the boundary of mining influence on land ecology. Our research goal was to find a remote sensing method to identify mining impact boundary, which could be used to evaluate ecological accumulating effect of coal mining on vegetated area. Yanzhou coal field, a typical coal mine area with high groundwater level in the eastern China, was taken as the study area, where the coal mining has caused a lot of impounded water areas, and the spatial distribution characteristics of the temperature vegetation drought index (TVDI), which is linear with soil moisture, were analyzed. Then the influence boundary of mining subsidence on soil moisture was determined, and the difference between the influence boundary using TVDI spatial changing tendency and the expected surface subsidence of 10 mm was analyzed. Firstly, the authors calculated TVDI and found it was mainly concentrated in the range of 0.2-0.6, which meant soil moisture levels were mainly "normal" and "slight drought". The areas belonging to "normal" level and "slight drought" accounted for 45.17% and 40.09% of the whole study area respectively. Secondly, the authors tried to obtain the influence boundary of soil moisture and analyzed the spatial distribution characteristics of TVDI from the edge of the impounded water area by mining subsidence. The impounded water areas i.e. A, B, C, D, F, G and H were taken as the research objects and the different distance ranges from the edge of the impounded water area were divided. With the increase of the distance from the edge of the impounded water area, the median TVDI value increased and then tended to be stable. Due to the differences in coal seam, mining methods and processes, the influence range of coal mining on soil moisture varied in different subsided areas. The authors proposed an exponential model to identify the mining influence boundary, in which the value of asymptotic line was defined as the disturbed boundary. Study results showed that TVDI stable value in each impounded water area is between 0.38 and 0.43. Fitting TVDI value with exponential function, it could be found that the correlation coefficients are greater than 0.60, and the mean square root errors are less than 0.02. The impounded water area H is fragmented, irregular and has strong internal spatial interaction, which has the largest influence distance reaching 781 m. Finally, the ecological disturbance range of coal mining based on TVDI extraction method was expected to be smaller than subsidence depth boundary, namely 10 mm. The paper's innovation is to propose a new method to identify the mining influence boundary, which is the theoretical boundary is the asymptotic line of ecological index changing from the edge of impounded water area to the unmined area by increased disturbance range.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Coal mines
Controlled terms:C (programming language) - Coal - Coal deposits - Cutting machines (mining) - Drought - Ecology - Ecosystems - Exponential functions - Extraction - Groundwater  - Land reclamation - Mining - Remote sensing - Soil moisture - Soil surveys - Spatial distribution - Subsidence - Vegetation
Uncontrolled terms:Coal mining - Correlation coefficient - Distribution characteristics - Ecological disturbance - Mean square root error - Mining subsidence - Mining water - Vegetation drought indices
Classification code:442.2  Land Reclamation - 444  Water Resources - 444.2  Groundwater - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 502.1  Mine and Quarry Operations - 502.2  Mine and Quarry Equipment - 503  Mines and Mining, Coal - 503.1  Coal Mines - 524  Solid Fuels - 723.1.1  Computer Programming Languages - 802.3  Chemical Operations - 921  Mathematics
Numerical data indexing:Size 7.81e+02m, Percentage 4.01e+01%, Percentage 4.52e+01%, Size 1.00e-02m
DOI:10.11975/j.issn.1002-6819.2018.19.033

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 21>

Accession number:20185206314572
Title:Comparison of drought indices for remote sensing drought monitoring in Yunnan-Guizhou Plateau region
Authors:Wang, Wen (1); Huang, Jin (1); Cui, Wei (1)
Author affiliation:(1) State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing; 210098, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:131-139
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Many studies have shown that drought severity is increasing over Yunnan-Guizhou (YG) region in southwestern China. And some studies stated that the deficit of precipitation was the main reason to recent droughts in southwestern China. Although precipitation is the main influence factor of drought formation, many studies have shown that evapotranspiration also plays a vital role in the progress of drought evolution. But how actual and potential evapotranspiration affect drought evolution is not well understood. In order to evaluate the temporal and spatial variations of the climate aridity in recent years as well as the roles of evapotranspiration in drought development in the YG region, monthly actual evapotranspiration and potential evapotranspiration data products during 2000-2014, including satellite-retrieved MODIS MOD16 data and GLDAS-Noah model simulation as well as the observed precipitation data were used to calculate 3 meteorological drought indices, i.e., standardized precipitation index (SPI), standardized reconnaissance drought index (RDIst) and evaporative stress index (ESI). With the Mann-Kendall trend test method, the 15-year temporal variations of SPI, RDIst and ESI in YG region are investigated. Besides, the severe drought that happened during 2009-2010 in YG region is further investigated as an example to analyze the role of actual evapotranspiration and potential evapotranspiration in drought evolution. According to the spatial distribution of annual average precipitation and the trend test results of 12-month SPI, there is a remarkable downtrend in middle Yunnan with an area of 12945 km², indicating that areas with low annual precipitation are getting drier. The spatial patterns of trend tests for RDIst calculated based on different potential evapotranspiration are similar, consistent with that of SPI trend test result, both implying that there is a very significant drying trend in middle Yunnan and a slight drying in its surrounding areas, and the significant drying trend in the middle Yunnan is mainly controlled by the changes of precipitation. In terms of the trend of ESI, its spatial distributions based on MOD16 and GLDAS-Noah evapotranspiration data show great differences, but they both indicate an obvious drying trend in central Yunnan, which is similar to that of SPI and RDIst. Trend analyses of all 3 drought indices show that, the climate aridity in Guizhou Province is stable, while there is a considerable drying trend in middle Yunnan because of the joint effects of significant decline of precipitation and the remarkable increase of potential evapotranspiration. As the regional drying is not only controlled by the changes of precipitation but also affected by the changes of evapotranspiration, drying areal extents indicated by ESI and RDIst are larger than that indicated by SPI. During the 2009-2010 drought happened in YG region, actual evapotranspiration and potential evapotranspiration played little roles at the early stage, but with the evolution of drought, they greatly aggravated drought situations at the late stage. At the end of drought when precipitation returned to its normal condition, potential evapotranspiration kept positively biased for about 1-3 months, whereas actual evapotranspiration kept negatively biased for about 5 months, illustrating that actual evapotranspiration has a longer effect on drought evolution than potential evapotranspiration. The analysis of 2009-2010 severe drought also indicates the effectiveness of different drought indices, that is, ESI considers both actual and potential evapotranspiration, and is more reasonable than SPI and RDIst for monitoring drought evolution. So it can be concluded that when accurate actual evapotranspiration data are available, drought indices based on both actual evapotranspiration and potential evapotranspiration are preferable to those based on only potential evapotranspiration for drought monitoring. Unfortunately, there is a lack of reliable actual evapotranspiration products available most of time while there exist many widely used methods for potential evapotranspiration calculation, therefore when actual evapotranspiration products are not available, a practical option is using drought indices that take potential evapotranspiration into account.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:40
Main heading:Evapotranspiration
Controlled terms:Climate models - Drought - Drying - Monitoring - Remote sensing - Spatial distribution - Testing
Uncontrolled terms:Actual evapotranspiration - Annual precipitation - Drought indices - Meteorological drought - Potential evapotranspiration - Reconnaissance drought indices - Standardized precipitation index - Temporal and spatial variation
Classification code:443  Meteorology - 444  Water Resources - 921  Mathematics
Numerical data indexing:Age 1.00e+00yr, Age 1.50e+01yr, Age 4.17e-01yr, Age 8.33e-02yr to 2.50e-01yr, Area 1.29e+10m2
DOI:10.11975/j.issn.1002-6819.2018.19.017

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 22>

Accession number:20185206314561
Title:Preliminary design of straw cutting simulation test platform based on hardware-in-loop
Authors:Liu, Jun (1, 2); Xie, Shouyong (1, 2); Chen, Chong (1); Xie, Dan (1); Yang, Mingjin (1, 2)
Author affiliation:(1) School of Engineering and Technology, Southwest University, Chongqing; 400715, China; (2) Chongqing Key Laboratory of Agriculture Equipment for Hilly and Mountainous Regions, Chongqing; 400715, China
Corresponding author:Xie, Shouyong(salong198211@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:46-53
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Straw cutting is an important process for harvesting machinery during harvest time, and the cutting performance directly determines the harvest efficiency and the maintenance cost of the machines. However, subject to the influences of the harvest time and the field terrain differences, some problems, such as nonrepeatability, poor data continuity, high difficulty, and low accuracy, exist when obtaining the cutting parameters of the harvesting machinery during experiments. Prior research has designed some experiment platforms to reduce such problems. However, these platforms require excessive consumption of the straw, and need to continuously add the experimental straw manually. This is difficult to verify the reliability of the harvesting machinery's continuous working condition. Therefore, drawing upon these problems, an innovative spiral auger feeding system was proposed to achieve the continuous supply of materials, and a simulation analysis of material collision, movement direction and distribution inside the box was conducted using the discrete element method. Meantime, a simulation physical experimental platform was built up by combining the simulation vibration platform that simulates the field terrain differences and the vibration of the harvesting machinery and by using the hardware-in-the-loop technique. The simulation results revealed that: 1) Adding a fan-shaped blade in the bottom of the spiral auger could increase the load and perturbation area of the spiral, thus increasing the whirlpool intensity formed by materials and then facilitating the formation of continuous flow of materials. 2) The velocity of rod-shaped particles increased along with the increase in the rotation speed of the spiral auger. However, when the rotation speed of the spiral auger reaching 600 r/min, the velocity of rod-shaped particles increased sharply and unstably, which was the no-load high-speed operation situation and was inconsistent with the actual cutting process of the harvesting machinery. When the rotation speed of the spiral auger lowering 300r/min, the velocity of rod-shaped particles has not yet reached the running velocity of the harvesting machinery, which was the low-speed turning operation condition. As a result, for ideal straw feeding system, the rotation speed of the spiral auger should keep during 400-500 r/min in order to marching the harvesting machinery's actual operation status in the field. Following these simulation results, the structure of the proposed spiral auger feeding system was optimized, and the rationality and feasibility of the design idea was also verified. In addition, according to the general vehicle traveling process simulation theory, a shaking table that simulates the walking of the harvesting machinery in the field was designed. The PLC programming software Gxworks2, the touch screen programming software SKWorkshopV5.0.2 and the configuration software kingview6.60SP1 were used for upper computer programming, and to detect and give the control and feedback signals required during the experiment. The results showed that when the speed of the spiral auger reaching 450-500 r/min and the vibration frequency of vibration table keeping 4.12 Hz, the average output torque was approximate to the actual output torque of the straw harvest in the field. That is, the working condition of the cutter was close to the real working environment of the harvesting machinery. This research can provide experimental data for the harvesting machinery design, and can also provide technical support for the current lack of agricultural machinery simulation reliability testing standards.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Machine design
Controlled terms:Agricultural machinery - Augers - Computer programming - Cutting - Cutting tools - Design - Feeding - Hardware - Harvesters - Harvesting  - Materials handling equipment - Rotation - Straw - Touch screens - Turning - Velocity
Uncontrolled terms:Configuration software - Experiment platforms - Experimental platform - Hard-ware-in-the-loop - Hardware in loop - Programming software - Simulation - Simulation reliability
Classification code:502.2  Mine and Quarry Equipment - 601  Mechanical Design - 603.2  Machine Tool Accessories - 604.2  Machining Operations - 605  Small Tools and Hardware - 691.1  Materials Handling Equipment - 691.2  Materials Handling Methods - 722.2  Computer Peripheral Equipment - 723.1  Computer Programming - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 931.1  Mechanics
Numerical data indexing:Frequency 4.12e+00Hz, Rotational_Speed 3.00e+02RPM, Rotational_Speed 4.00e+02RPM to 5.00e+02RPM, Rotational_Speed 4.50e+02RPM to 5.00e+02RPM, Rotational_Speed 6.00e+02RPM
DOI:10.11975/j.issn.1002-6819.2018.19.006

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 23>

Accession number:20185206314560
Title:Traveling trajectory prediction method and experiment of autonomous navigation tractor based on trinocular vision
Authors:Tian, Guangzhao (1); Gu, Baoxing (1); Irshad, Ali Mari (2); Zhou, Jun (1); Wang, Haiqing (1)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing; 210031, China; (2) Khairpur College of Engineering and Technology, Sindh Agriculture University, Khairpur; 66020, Pakistan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:40-45
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to make the autonomous navigation tractors work steadily and continuously without the satellite positioning system, a traveling trajectory prediction system and method based on trinocular vision were designed in this paper. The system was composed of a trinocular vision camera, an IEEE 1394 acquisition card and an embedded industrial personal computer (IPC). The right and left sub cameras constituted a binocular vision system with a long base line. The right and middle sub cameras constituted another binocular vision system with a narrow base line. To obtain more precise measurement results, the two binocular vision systems worked independently and in time-sharing. Then the motion vectors of tractor, which were in presentation of horizontal direction data, were calculated by the feature point coordinate changing in the working environment of the tractor. Finally, the error models which were in the direction of heading were established at different velocities, and the motion vectors of tractor were predicted by the models based on grey method. The contrast experiments were completed with a modified tractor of Dongfanghong SG250 at the speed of 0.2, 0.5 and 0.8m/s. During the experiments, the IPC was used to collect RTK-GPS data and predict movement tracks. The RTK-GPS used in the experiments was a kind of high-precision measuring device, and the measuring precision can reach 1-2 cm. Therefore, the location data of RTK-GPS were supposed as the standard which was used to compare with the data from trinocular vision system. The experimental results showed that the method mentioned above could accurately predict the trajectory of the tractor on the plane with an inevitable error which was mainly caused by the visual measurement error of the forward direction (z direction). When the tractor travelled at the speed of 0.2 m/s, the time and the distance that the error in forward direction exceeded 0.1 m equaled 46.5 s and 9.3 m, respectively. When the speed increased to 0.5 m/s, the time and the distance decreased to 17.2 s and 8.6 m, respectively. When the driving speed increased to 0.8 m/s, the time and distance quickly decreased to 8.5 s and 6.8 m, respectively. It showed that the higher the tractor traveling speed, the faster the error in forward direction increased. After that, the relationship between errors in forward direction and traveling time was acquired and analyzed by the way of nonlinear data fitting. In addition, the experimental results showed that the trend of lateral error (x direction) which was perpendicular to forward direction was not regular. When the speed was 0.2 m/s, the average error was 0.002 5 m with a standard deviation (STD) of 0.003 9. When the speed increased to 0.5 m/s and 0.8 m/s, the average error in lateral direction was 0.008 2 m with an STD of 0.012 4 and 0.003 6 m with an STD of 0.006 4. The result showed that the lateral error was very small and almost invariable. Therefore, the errors of trinocular vision were mainly caused by the errors of the forward direction. The root causes of the error were the natural light and time-delay during the image processing. According to the experimental data and results, the system and method proposed in this paper could be used to measure and predict the traveling trajectory of a tractor in the dry agricultural environment with the sudden loss of the satellite signal in a short period of time. The measured and predicted data could provide temporary help for the operations of autonomous tractors.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Tractors (agricultural)
Controlled terms:Automatic guidance (agricultural machinery) - Binocular vision - Cameras - Computer vision - Errors - Forecasting - Global positioning system - Personal computers - Speed - Stereo image processing  - Time sharing systems - Tractors (truck) - Trajectories
Uncontrolled terms:Agricultural environments - Autonomous navigation - Binocular vision systems - Gray Model - Industrial personal computers - Satellite positioning systems - Trajectory prediction - Trinocular vision system
Classification code:663.1  Heavy Duty Motor Vehicles - 722.4  Digital Computers and Systems - 723.2  Data Processing and Image Processing - 731.2  Control System Applications - 741.2  Vision - 742.2  Photographic Equipment
Numerical data indexing:Size 1.00e-01m, Size 1.00e-02m to 2.00e-02m, Size 6.80e+00m, Size 8.60e+00m, Size 9.30e+00m, Time 1.72e+01s, Time 4.65e+01s, Time 8.50e+00s, Velocity 2.00e-01m/s, Velocity 5.00e-01m/s, Velocity 8.00e-01m/s
DOI:10.11975/j.issn.1002-6819.2018.19.005

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 24>

Accession number:20185206314567
Title:Impacts of gas source and surfactant on gas-water coupling transmission along a long-distance drip tape in one or two line layout under aerated drip irrigation
Authors:Lei, Hongjun (1); Liu, Huan (1); Surya, Bhattarai (2); Ron, Balsys (3); Pan, Hongwei (1)
Author affiliation:(1) School of Water Conservancy, North China University of Water Conservancy and Electric Power, Zhengzhou; 450046, China; (2) School of Medical and Applied Science, CQ University, Rockhampton; QLD; 4702, Australia; (3) School of Engineering and Technology, CQ University, Rockhampton; QLD; 4702, Australia
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:88-94
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Aerated drip irrigation (ADI) is a technique to aerate the rhizosphere by aerated water through the drip irrigation system. The dissolved oxygen (DO) in water, water flow rate and gas flow uniformity are the essential indexes for the evaluation of irrigation quality in ADI. The use of biodegradable surfactant BS1000 and the optimization of transmission modes are of great significance in the existence of microbubble and the retention of DO in water during ADI. To increase the uniformity of gas, oxygen and water and the delivery distance under ADI, transmission characteristics, i.e., gas-oxygen-water mixture produced by aerated irrigation system using Mazzei 1078 venturi air injector, were studied. The impacts of gas source and surfactant on gas-water coupling transmission along a long-distance drip tape in one or two line layout were investigated. Totally 16 combinations were tested, including 2 types of gas (air and oxygen), 2 transmission modes (one and two line transmission), and 4 levels of BS1000 concentrations (0, 1, 2 and 4 mg/L), respectively. During the experiment, parameters and uniformities of water flow rate, DO, gas void fraction (GVF), and water flow rate were observed. The DO and GVF of irrigation water along a drip tape were monitored by a dissolved oxygen meter and a vacuum device of gas void fraction measurement. Main results were given as below. Aeration treatment resulted in the slight reduce in the uniformity of water flow rate during one line transmission under ADI along a drip tape, but the DO concentration and GVF in irrigation water were significantly increased at the level of 0.05. The DO concentration in air and oxygen aerated water were increased by 160.80% and 617.05% compared with non-aerated treatment during one line transmission. However, DO levels in air and oxygen aerated water were increased by 185.26% and 643.23% compared with non-aerated treatments during two line transmission. Use of biodegradable surfactant BS1000 concentration brought an increase in GVF. Under the condition of air aerated treatment during one line transmission, the GVF at 1, 2 and 4 mg/L of BS1000 were significantly increased by 17.42%, 60.41% and 80.32% than the non-use of surfactant treatment, respectively. Similarly, under the condition of oxygen aerated treatment during one line treatment, GVF at 1, 2 and 4 mg/L of BS1000 were significantly increased by 25.00%, 55.05% and 69.27% in contrast to non-use of surfactant treatment. The use of BS1000 had a positive effect on the DO under ADI. With the increasing of BS1000 concentration, there was no significant difference neither in uniformity of DO nor water flow rate. However, compared to non-use of BS1000, the uniformity of gas flow at 4 mg/L of BS1000 was significantly decreased during one line transmission. The uniformity of water flow rate, DO and gas flow during two line transmission under ADI were higher than 95%, 96% and 67%. Compared to one line transmission, the uniformity of water flow rate, DO and gas flow during two line transmission were increased by 14.00%, 4.05% and 30.64%, respectively. Two line transmission was an optimal connection mode under ADI at the long distance of water delivery under ADI. This research will provide valuable information for optimization of aerated technique parameters and drip tape layout under ADI.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Water aeration
Controlled terms:Biochemical oxygen demand - Dissolution - Dissolved oxygen - Flow of gases - Flow of water - Flow rate - Gases - Hydraulics - Irrigation - Soils  - Surface active agents - Transmissions - Void fraction - Water supply
Uncontrolled terms:Drip irrigation - Drip irrigation systems - Gas void fraction - Micro-bubble - Surfactant treatment - Technique parameters - Transmission characteristics - Uniformity
Classification code:445.1  Water Treatment Techniques - 446.1  Water Supply Systems - 483.1  Soils and Soil Mechanics - 602.2  Mechanical Transmissions - 631  Fluid Flow - 632.1  Hydraulics - 802.3  Chemical Operations - 803  Chemical Agents and Basic Industrial Chemicals - 821.3  Agricultural Methods - 951  Materials Science
Numerical data indexing:Mass_Density 2.00e-03kg/m3, Mass_Density 4.00e-03kg/m3, Percentage 1.40e+01%, Percentage 1.61e+02%, Percentage 1.74e+01%, Percentage 1.85e+02%, Percentage 2.50e+01%, Percentage 3.06e+01%, Percentage 4.05e+00%, Percentage 5.50e+01%, Percentage 6.04e+01%, Percentage 6.17e+02%, Percentage 6.43e+02%, Percentage 6.70e+01%, Percentage 6.93e+01%, Percentage 8.03e+01%, Percentage 9.50e+01%, Percentage 9.60e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.012

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 25>

Accession number:20185206314564
Title:Fitting of hydro turbine torque characteristic curves based on load rejection test
Authors:Fu, Liang (1); Bao, Haiyan (2); Tian, Haiping (1); Zhang, Yike (1)
Author affiliation:(1) Electric Science Research Institute of Hunan Provincial Electric Power Corporation, Changsha; 410007, China; (2) School of Hydraulic Engineering, Changsha University of Science &amp; Technology, Changsha; 410114, China
Corresponding author:Bao, Haiyan(83369537@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:66-73
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In hydropower station transient process calculation, the hydro turbine characteristic curve had a very important impact on the calculation results. At present, the torque characteristic curve of hydro turbine is extended and fitted by the experience and mathematical methods. The simulation results are different from the test results, and it is unable to meet the requirements of accurate simulation of load shedding transient process. In this article, the treatment method of hydro turbine torque characteristic curve was studied based on load shedding test. The torque characteristic of the zero guide vane opening was identified by the shedding test data, and the whole torque characteristic curves were extended and fitted combined with the least square method. The curves were compared with the torque characteristic curves obtained by the traditional method. The results showed that the two characteristic curves are basically coincided under the large guide vane opening and relatively high efficiency, and different in the small guide vane opening. The characteristic curve obtained in this article was used to calculate the load shedding transient process under the different governor parameters, and the influence of the governor parameters on the load shedding transient process was analyzed. Two characteristic curves were used to simulate the load shedding transient process of a hydropower unit, and the simulation results are compared with the test results. Through the analysis, it is found that the characteristic curve obtained by this article can reflect the moment characteristic of the unit more accurately than the traditional method under the small guide vane opening, it is used to simulate the load shedding transition process, and the calculated results were compared with the test results, the maximum deviation of the calculated frequency is 1.05%, and the maximum deviation of the guide blade opening is 9.74%, and the simulation accuracy of the transient process is greatly improved. The research of this article can effectively guide the safe operation of hydroelectric unit.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Curve fitting
Controlled terms:Electric load shedding - Electric power plant loads - Governors - Hydraulic turbines - Hydroelectric power - Least squares approximations - Testing - Torque
Uncontrolled terms:Characteristic curve - Least square methods - Load rejections - Moment characteristics - Simulation - Simulation accuracy - Torque characteristic - Transient process
Classification code:602.1  Mechanical Drives - 611.1  Hydroelectric Power Plants - 617.1  Hydraulic Turbines - 706.1  Electric Power Systems - 921.6  Numerical Methods - 931.2  Physical Properties of Gases, Liquids and Solids
Numerical data indexing:Percentage 1.05e+00%, Percentage 9.74e+00%
DOI:10.11975/j.issn.1002-6819.2018.19.009

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 26>

Accession number:20185206314563
Title:Bionic design of turbocharger volute based on spiral shells Neverita didyma improving turbine performance
Authors:Wu, Na (1); Zhang, Kesong (1); Wang, Xibo (1); Ma, Yunhai (2)
Author affiliation:(1) Collage of Automotive Engineering, ShanDong JiaoTong University, Jinan; 250357, China; (2) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun; 130022, China
Corresponding author:Ma, Yunhai(myh@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:60-65
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The performance of the supercharger volute directly affects the overall efficiency and capability of the turbocharger. It is important to improve the efficiency and performance of the turbocharger by reducing the flow resistance and decreasing the energy loss of the volute. Many measures are taken to improve the efficiency of the volute. Ocean spiral shells have evolved to reduce fluid resistance and cut down fluid energy loss during motion. In this paper, the spiral shell was taken as the biomimetic prototype, and the cavity data of the spiral shells were obtained by reverse engineering technology. The internal cavity cross-section data of shells were extracted in the range of 270 degrees. After the cross-section curves were optimized, they were taken as the section curves to construct the bionic volute. And then the volute bionic surface design was realized. The computational models of the prototype and bionic supercharger were finished. Taking the turbocharger volute of the gasoline engine with 1.5-liter displacement as the research object, the numerical analysis method was used to realize the performance difference between the bionic volute and the prototype volute. First, the prototype numerical model's reliability was verified. Then the bionic volute was matched with the prototype turbine system. The numerical simulation of the bionic volute and the prototype volute was carried out in the range of common working conditions, and the difference between the two was explored from the microscopic flow field. During the modeling process, the A/R values of the two turbine volutes were the same, and the outlet width of the volute was consistent with the outlet diameter. The verification test was carried out on a QYZ-2 turbocharger test bench. The inlet flow of the compressor was measured by a double-line flowmeter, and the maximum measurement error was less than 2% FS. Both the inlet and the outlet of the compressor were provided with a pressure sensor and a temperature sensor. The turbine inlet was provided with a turbine inlet pressure sensor and an intake temperature sensor, and the turbine outlet had a turbine exhaust pressure sensor and an exhaust temperature sensor in the extension duct. The maximum error of the pressure sensor was less than 2.5% FS, and the maximum error of the temperature sensor was less than 3% FS. The maximum error of the simulation calculation was within the allowable range. The simulation results showed that the simulation model was in good agreement with the test bench, and has good reliability. Therefore, the numerical model can meet the requirements of subsequent research. In the simulation, 12&times;10⁴, 16&times;10⁴ and 20&times;10⁴ r/min were selected to represent the low, medium and high operation speed of turbine respectively. The evaluation parameters included turbine efficiency, flow characteristics and total volute loss coefficient. The results showed that the turbine flow capacity increases with the increase of the expansion ratio increase. And the turbine flow characteristics of the two volutes were basically the same. The results showed that the turbine efficiency can be increased by 3% and by up to 5% under the condition of keeping the same turbine flow capacity matching two volutes. The flow field analysis results showed that the bionic optimization volute reduces the flow loss near the inner surface of the volute and the airflow friction in the flow channel. And the flow resistance was small, the whole flow in the bionic volute was smooth and uniform, and there was no swirling flow. Therefore, the turbine efficiency can be significantly improved. The bionic design method used in this paper had a significant improvement on turbocharger turbine performance, and can provide reference and method innovation for the design and optimization of automotive and agricultural machinery turbocharging systems.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Turbines
Controlled terms:Biomimetic processes - Bionics - Cascades (fluid mechanics) - Channel flow - Curve fitting - Design - Diesel engines - Energy dissipation - Energy efficiency - Errors  - Experiments - Flow fields - Machine design - Numerical methods - Numerical models - Pressure sensors - Reverse engineering - Shells (structures) - Superchargers - Temperature sensors
Uncontrolled terms:Design and optimization - Efficiency and performance - Flow capacity - Simulation calculation - Spiral shells - Turbine efficiency - Turbine inlet pressure - Turbine volute
Classification code:408.2  Structural Members and Shapes - 461.1  Biomedical Engineering - 461.8  Biotechnology - 525.2  Energy Conservation - 525.4  Energy Losses (industrial and residential) - 601  Mechanical Design - 612.2  Diesel Engines - 631.1  Fluid Flow, General - 901.3  Engineering Research - 921  Mathematics - 921.6  Numerical Methods - 944.3  Pressure Measuring Instruments - 944.5  Temperature Measuring Instruments
Numerical data indexing:Percentage 3.00e+00%, Percentage 5.00e+00%, Volume 1.50e-03m3
DOI:10.11975/j.issn.1002-6819.2018.19.008

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 27>

Accession number:20185206314592
Title:Favor quality of different fruit and vegetable juices fermented by Lactobacillus plantarum
Authors:Li, Biansheng (1, 2); Lu, Jiayi (1); Ruan, Zheng (1)
Author affiliation:(1) College of Food Science and Engineering, South China University of Technolog, Guangzhou; 510640, China; (2) Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou; 510640, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:293-299
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Composition and concentration of volatile flavor compounds of fruit and vegetable juices have important influence on sensory properties and consumer acceptance. The effect of lactic acid bacteria metabolism on the production of bioactive compounds during growth of fruit substrate is well studied, however, the characteristics of the volatile flavor compounds of the fermented juices are less investigated. This paper aims to study the changes of flavor substances and flavor quality of orange juice, apple juice, pear juice, grape juice and cucumber juice before and after fermentation by Lactobacillus plantarum LP-115 400B. Flavor of juices is characterized by interactions between volatile and non-volatile compounds, mainly acids, sugars, and free amino acids (FAA). Quantitative descriptive analysis (QDA) method was adopted to perform the sensory evaluation combed with the analysis of the FAA, sugars and acids. Principal component analysis (PCA) was applied to the sensory evaluation. Volatile flavor compounds were measured by gas chromatography - mass spectrometry (GC-MS) after the preparation of samples by static headspace solid-phase microextraction (HS-SPME). After fermentation, the kind of volatile flavor compounds in different juices increased, which enriched the flavor. The aldehydes were largely reduced to alcohols or oxidized to acids under microbial action. The relative content of alcohols and esters increased significantly, which was beneficial to the apple juice and pear juice, while the wine and pungent smell was increased in the fermented cucumber juice. Plenty of aromatic hydrocarbon was detected in grape juice after fermentation, which enriched the sensory flavor. Because of the changes in terpene, the fresh smell of orange juice decreased and the fermentation odor increased. Due to the metabolism of the lactic acid bacteria during fermentation, the total FAA content significantly reduced, but it still had certain influence on the flavor of fruit juices. The content of sweet amino acids, umami amino acids and bitter amino acids decreased, but the content of aromatic amino acids increased. The changes of FAA in various fruit and vegetable juices showed the correlation between FAA and volatile flavor compounds, such as the increase of the aromatic amino acids and the corresponding increase of the benzene derivatives in different juices after fermentation. The PCA of sensory evaluation showed that the fermented juices were mainly discriminated by the higher intensity of floral, fruity, fermented taste and sour (especially the apple juice and pear juice). The sweet taste of fruit juices was decreased after fermentation, which was related to the decrease of total sugar content and the decrease of sweet amino acids content. After fermentation, pear juice and apple juice showed the most comfortable sweet and sour feeling with the sugars-acids ratio of 21.00 and 17.79 respectively. These findings suggested that apple juice and pear juice may be more suitable substance for lactic acid fermentation to improve the flavor. For the other 3 kinds of juices, reducing the number of initial viable bacteria, terminating the fermentation in advance or adding flavor substances may help to optimize the flavor. In a word, lactic acid fermentation may be considered as an interesting option to enhance the flavor compounds of fruit juices and ensure a better control of flavor changes during juice processing.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Flavor compounds
Controlled terms:Amino acids - Aromatic hydrocarbons - Aromatization - Bacilli - Bacteria - Citrus fruits - Drug products - Fermentation - Fruit juices - Gas chromatography  - Hydrocarbon refining - Lactic acid - Mass spectrometry - Metabolism - Odors - Principal component analysis - Sensory analysis - Substrates - Sugars - Vegetables  - Volatile organic compounds
Uncontrolled terms:Free amino acids - Gas chromatography-mass spectrometries (GC-MS) - Lactic acid bacteria - Lactic acid fermentation - Lactobacillus plantarum - Non-volatile compounds - Quantitative descriptive analysis (QDA) - Volatile flavor compounds
Classification code:461.9  Biology - 801  Chemistry - 802.2  Chemical Reactions - 802.3  Chemical Operations - 804.1  Organic Compounds - 821.4  Agricultural Products - 822.3  Food Products - 922.2  Mathematical Statistics
DOI:10.11975/j.issn.1002-6819.2018.19.037

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 28>

Accession number:20185206314558
Title:Design of chain-sieve type residual film recovery machine in plough layer and optimization of its working parameters
Authors:Luo, Kai (1, 2); Yuan, Panpan (1, 2); Jin, Wei (1, 2); Yan, Jinshan (1, 2); Bai, Shenghe (1, 2); Zhang, Chaoshu (3); Zhang, Xuejun (1, 2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Xinjiang Agricultural University, Urumqi; 830052, China; (2) Innovative Design Laboratory of Agricultural Engineering Equipment, Urumqi; 830052, China; (3) Alar City Tiandian Agricultural Machinery Manufacturing Company with Limited Liability, Alar; 843300, China
Corresponding author:Zhang, Xuejun(tuec@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:19-27
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Plastic film is large used in Xinjiang area, and it is hard to separate and collect the residual film of plough layer because of seriously fragmented. To solve the problem of residual film recovery in plough layer, chain-sieve type plastic residual film recovery machine was designed and developed. The machine was consisted of excavating shovel, barrier clearing mechanism, transmission mechanism, eccentric wheel, link mechanism, chain-tooth mechanism, film separating roller, vibration mechanism, frame and film box. Power of each part was provided by the transmission mechanism. The soil film mixture was excavated into the chain tooth mechanism by excavating shovel, then the chain-tooth mechanism was used for the first separation and sieving of the soil film mixture, then the sieved soil film mixture was transported to the vibration mechanism. The tail part of the chain-tooth mechanism was equipped with a film seperating roller, which scraped the film wound on the mechanism. After that, residual film was sent to film box by vibration mechanism. Vibration mechanism consists of vibration sieve and link mechanism, vibration and swing of vibration sieve was controlled by link mechanism, the soil film mixture was separated by the vibration sieve and then was conveyed to the film box. The size and parameters of the machine was determined by analysis and calculation. The key working parts of the machine were simulated and analyzed in ADAMS, and relevant motion parameters were obtained. The separation of the soil film mixture by the vibration mechanism requires that the speed range of the eccentric wheel was 25.79 rad/s&le;&omega;&le;31.40 rad/s. According to theoretical calculation and test, the speed of eccentric wheel was determined to be 255 r/min. The central composite design method of Box-BenhnKen was used to analyze the effect of working parameters on the residual film recovery rate. Three factors, three levels and one regression orthogonal test design were adapted, and moving speed, depth into soil and speed of driving wheel of conveyor chain were selected as the influence factors. In April 2017, field test was carried out in the six regiment of the first agricultural division of Xinjiang production and Construction Corps. Test area was divided into 17 test plots (each plots is 25 m&times;4 m), residual film recovery rate of plough layer at each test plot was calculated. The test results showed that average residual film recovery rate (&Epsilon;) of plough layer was 83.34%. Response surface methodology was used to analyzed the effects of various factors on the recovery rate, the regression model optimization results were that moving speed was 1.317 m/s, depth into soil was 117.066 mm and speed of driving wheel of conveyor chain was 65.106 r/min. When the amplitude of the vibration mechanism was 79.1 mm and speed of driving wheel of conveyor chain was 255 r/min, the residual film recovery rate of field test was 85.07%, parameters optimization results meets requirements, the machine meets the performance requirements of plough layer residual film recovery. The method of combining chain-tooth mechanism with vibration mechanism provided a new idea for residual film recovery of plough layer.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Agricultural machinery
Controlled terms:Agriculture - Conveyors - Design - Experiments - Machine design - Mixtures - Recovery - Regression analysis - Separation - Shovels  - Sieves - Soils - Speed - Vibrations (mechanical) - Wheels
Uncontrolled terms:Analysis and calculations - Central composite designs - Parameters optimization - Performance requirements - Residual films - Response surface methodology - Theoretical calculations - Transmission mechanisms
Classification code:483.1  Soils and Soil Mechanics - 601  Mechanical Design - 601.2  Machine Components - 692.1  Conveyors - 802.3  Chemical Operations - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1  Agricultural Machinery and Equipment - 901.3  Engineering Research - 922.2  Mathematical Statistics - 931.1  Mechanics
Numerical data indexing:Percentage 8.33e+01%, Percentage 8.51e+01%, Rotational_Speed 2.55e+02RPM, Rotational_Speed 6.51e+01RPM, Size 1.17e-01m, Size 7.91e-02m, Velocity 1.32e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.19.003

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 29>

Accession number:20185206314579
Title:Review and trend of water quality detection in aquaculture by spectroscopy technique
Authors:Li, Xinxing (1, 2); Zhu, Chenguang (1); Zhou, Jing (1); Sun, Longqing (1); Cao, Xiamin (3); Zhang, Xiaoshuan (2, 4)
Author affiliation:(1) College of Information and Electrical Engineering, China Agricultural University, Beijing; 100083, China; (2) Beijing Laboratory of Food Quality and Safety, Beijing; 100083, China; (3) School of Biology and Basic Medical Sciences, Soochow University, Suzhou; 215200, China; (4) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Zhang, Xiaoshuan(zhxshuan@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:184-194
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The water quality of aquaculture is a key factor concerning the economic benefits of aquaculture and the quality of aquatic products. In recent years, with the development of economy, the discharge of industrial wastewater and domestic sewage has greatly increased, resulting in environmental pollution, for example, the water quality of aquaculture ponds has been polluted. In order to achieve the goal of high yield and safe breeding at the same time of environmental protection and energy conservation, scholars have paid attention to the rapid and accurate acquisition of aquaculture water quality information, which was the important research content of the smart agriculture and agricultural Internet of Things. Water quality monitoring technology based on spectral analysis is an important development direction of aquaculture water quality monitoring. Compared with traditional chemical analysis, electrochemical analysis and chromatographic analysis methods, spectral analysis technology is more simple and convenient, consumes a small quantity of reagents, and is reproducible. This article summarizes and sorts the existing domestic and foreign research literatures, and systematically analyzes and discusses the important parameters of water quality monitoring, data preprocessing methods, feature band extraction, and detection model algorithms based on spectroscopy. This article reviews the COD (chemical oxygen demand) water quality monitoring methods, total nitrogen water quality monitoring methods, total phosphorus water quality monitoring methods, heavy metal water quality monitoring methods, covering traditional chemical methods and spectral analysis methods of these parameters. This article compares and analyzes the spectral method and the traditional methods. We find that compared with the traditional water quality monitoring methods, the spectral technology is non-invasive, rapid rapid monitoring, repeatable and accurate. The sensitive spectral bands of the above parameters are summarized. The data preprocessing algorithm includes Savitzky-Golay smoothing, wavelet analysis, and multivariate scatter correction, the feature band extraction algorithm includes continuous projection algorithm, no-information variable elimination algorithm, and principal component analysis, and the model includes partial least squares algorithm, least squares algorithm, and artificial neural network. The advantages, disadvantages and scopes of application of these algorithms are summarized and compared. The spectrum detection process of these algorithms is analyzed. Among them, a detailed review of the application of model algorithms in water quality monitoring is conducted, and the prediction results of each water quality prediction model algorithm are statistically analyzed. The results show that online aquaculture water quality testing will be the focus of research. Multi-parameter monitoring is the development direction of aquaculture water quality monitoring. For the processing of spectral data, the combination of multiple data processing algorithms will still dominate. Nonlinear modeling will become the mainstream method for water quality data analysis of aquaculture and will become the mainstream method for the application of spectral technology to water quality detection of aquaculture.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:104
Main heading:Quality control
Controlled terms:Agriculture - Aquaculture - Chemical oxygen demand - Chromatographic analysis - Data handling - Data mining - Economic and social effects - Economics - Extraction - Heavy metals  - Least squares approximations - Monitoring - Neural networks - Principal component analysis - Sewage - Spectroscopy - Spectrum analysis - Water pollution - Water quality
Uncontrolled terms:Electrochemical analysis - Environmental pollutions - Monitoring models - Partial least squares algorithms - Spectral analysis method - Water quality information - Water quality monitoring - Water quality predictions
Classification code:445.2  Water Analysis - 452.1  Sewage - 453  Water Pollution - 531  Metallurgy and Metallography - 723.2  Data Processing and Image Processing - 802.3  Chemical Operations - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3  Agricultural Methods - 913.3  Quality Assurance and Control - 921.6  Numerical Methods - 922.2  Mathematical Statistics - 971  Social Sciences
DOI:10.11975/j.issn.1002-6819.2018.19.024

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 30>

Accession number:20185206314576
Title:Nitrogen nutrition diagnosis of winter wheat based on ASD Field Spec3
Authors:Liu, Changhua (1); Fang, Zheng (1); Chen, Zhichao (1); Zhou, Lan (2); Yue, Xuezhi (1); Wang, Zhe (1); Wang, Chunyang (1); Miao, Yuxin (3)
Author affiliation:(1) Institute of Surveying-mapping and Land Information Engineering, Henan Polytechnic University, Jiaozuo; 454000, China; (2) College of Resources and Environmental Sciences, China Agricultural University, Beijing; 100193, China; (3) Department of Soil, Water, and Climate, University of Minnesota, St.Paul; MN; 55108, United States
Corresponding author:Chen, Zhichao(logczc@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:162-169
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:For crop's prediction model of nitrogen nutrition index (NNI), how to select the pretreatment and modeling method is unclear as well as different pretreatments and their influence degrees on prediction accuracy. So it is of great significance to take more systematic related research for building crop nitrogen nutrition diagnosis rapidly and accurately, which can provide important technical support for precision agriculture management, and realize high yield with high efficiency of nitrogen utilization. Taking Nanxia Village, Laoling City in North China Plain as the research area, based on ASD Field Spec3, the prediction model of winter-wheat nitrogen nutrition index was established with hyperspectral technology in this study. PLSR combined with different pretreatments was applied to establish an prediction model of winter-wheat nitrogen nutrition index, whose average value of model-set model decision coefficient R² was 0.683, with the maximum one 0.789, the minimum root mean square error (RMSE) 0.142, and the minimum of relative medium error (RE) 12.3%. The prediction-set model's mean value of decision coefficient R² is 0.588, with the maximum one 0.717, the minimum value of root mean square error (RMSE) 0.150, and the minimum of relative medium error (RE) 12.8%. The comparison shows that the pretreatment methods with SG(Savitzky-Golay), SNV(standard normal variate transformation), SG+SNV and SG+BC(baseline correction) are effective when partial least square method is used to build the model, especially SG smoothing is the optimal one as mentioned above with the R² of 0.789, the RMSE of 0.142, the RE of 12.3%, and the R² of the prediction accuracy of 0.717. Meanwhile, BP neural network method combined with different pretreatments was used to establish an prediction model of nitrogen nutrition index, whose average value of model-set model decision coefficient R² was 0.834, with the maximum one 0.861, the minimum RMSE 0.115, and the minimum of RE 9.8%. The prediction-set model's mean value of decision coefficient R² was 0.714, with the maximum one 0.780, the minimum value of RMSE 0.133, and the minimum of RE 12.3%. It can be known that the regression model constructed by BP neural network is significantly more accurate than the one constructed by PLSR model. The decision coefficient of all the models pretreated by BP neural network was above 0.8, while the average one was increased to 0.834 from 0.683 under PLSR model. All pretreatment modeling accuracy combined with SG, SG+MSC(multiple scatter correction), SG+SNV and SNV+D(De-trending) reached above 0.85, when the predictive effect reached above 0.7 except BC, MSC and SNV. SG pretreatment R² with the best modeling effect reached 0.861, with mean square root error 0.115, relative error 9.8% and predicted effect R² 0.780 as mentioned above. The NNI estimation model RF algorithm combined with different pretreatments was used to establish an prediction model of NNI, whose average value of model-set model decision coefficient R² was 0.945, with the maximum one 0.959, the minimum RMSE 0.061, and the minimum of RE 5.3%. The prediction-set model's mean value of decision coefficient R² is 0.742, with the maximum 0.795, the minimum value of RMSE 0.125, and the minimum of RE 11.7%. It can be known that the regression model constructed by RF is significantly improved compared with PLSR model and BP neural network. The decision coefficient of all the models by RF are all above 0.9, and the prediction model accuracy R² is above 0.7. After 10 spectral pretreatment methods and 3 modeling ones have been comprehensively compared in this study, it is found that different pretreatment and modeling methods have great impacts on modeling precision. The optimal hyperspectral modeling method is RF(random forest) algorithm. The average value of decision coefficient R² for the prediction-set model obtained through RF algorithm was higher than the biased least squares model and BP(back-propagation) neural network respectively, with lower RMSE and RE. Therefore, it can be seen that 10 pretreatment methods combined with RF model have higher prediction accuracy, which is a robust modeling method to invert nitrogen nutrition index. From above, to preprocess the spectrum for winter wheat can improve modeling accuracy. The best spectral pretreatment method in this experiment is SG convolution smoothing. Therefore, by comparing three models, the average R² increase range of SG convolution smoothing compared with the other nine pre-processed prediction set models is 0.054~0.121, with average RMSE decrease range 0.016~0.032 and average RE decrease range 1.7~3.1 percentage points. In terms of single preprocessing, other preprocessing transformations can be carried out after combining with SG convolution smoothing, which can also improve the prediction accuracy of its single preprocessing model.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Least squares approximations
Controlled terms:Backpropagation algorithms - Convolution - Crops - Decision trees - Diagnosis - Error correction - Forecasting - Mean square error - Neural networks - Nitrogen  - Nutrition - Regression analysis - Spectrum analysis
Uncontrolled terms:BP (back propagation) neural network - Mean square root error - Nitrogen nutrition - Partial least square methods - Root mean square errors - Spectral pre treatments - Standard normal variate transformations - Winter wheat
Classification code:461.6  Medicine and Pharmacology - 461.7  Health Care - 716.1  Information Theory and Signal Processing - 723.4  Artificial Intelligence - 804  Chemical Products Generally - 821.4  Agricultural Products - 921.6  Numerical Methods - 922.2  Mathematical Statistics - 961  Systems Science
Numerical data indexing:Percentage 1.17e+01%, Percentage 1.23e+01%, Percentage 1.28e+01%, Percentage 5.30e+00%, Percentage 9.80e+00%
DOI:10.11975/j.issn.1002-6819.2018.19.021

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 31>

Accession number:20185206314591
Title:Effect of contact ultrasound power on internal moisture migration of pear slices during ultrasound enhanced hot air drying
Authors:Liu, Yunhong (1); Sun, Changying (1); Zeng, Ya (1)
Author affiliation:(1) College of Food &amp; Bioengineering, Henan University of Science and Technology, Luoyang; 471023, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:284-292
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Ultrasound strengthening technology has gained more and more attention in drying research, however, the strengthening mechanism of ultrasound on water status and moisture migration during drying has been unclear until now. In order to investigate the strengthening effect of contact ultrasound on moisture migration of pear slices during hot air drying process, the experiments of ultrasound reinforced hot air drying on pear slices were conducted with different ultrasound powers. The scan electric microscope was used to observe the surface microstructure of dried pear slices at different ultrasound powers. The low-field nuclear magnetic resonance (LF-NMR) technology and nuclear magnetic resonance imaging (MRI) technology were applied to analyze the influence of ultrasound power on internal water state and moisture migration of pear slices during hot air drying. The results showed that hot air drying of pear slices belongs to internal diffusion control, and the reduction ratios of drying time were 60.0%, 58.3% and 57.8% when contact ultrasound of 48 W was applied in hot air drying of pear slices at 35, 45 and 55&#8451;, respectively, which indicated that the application of contact ultrasound could significantly accelerate drying process. The drying time reduced from 1440 min to 1260, 960, 780, 600 min when contact ultrasound assistance at 12, 24, 36, 48 W was applied in hot air drying of pear slices at 45&#8451;, which showed that higher ultrasound power could lead to higher water removal rate and shorter drying time. The results of scan electric microscope showed that the application of ultrasound could improve the number of micro-capillaries as well as enlarge the size of micro-capillaries, and higher ultrasound power produced looser microstructure of pear surface that was contacted with ultrasound radiation board, which was favorable to moisture migration and water diffusion. The LF-NMR results showed that the peak amplitudes of inversion spectrum kept decreasing during the drying process and higher ultrasound power led to faster decreasing rate of the amplitudes, which represented that free water, immobilized water and bound water inside pear slices changed and migrated during drying process, and higher ultrasound power could accelerate the migration of the 3 kinds of water. Free water, with the greatest mobility and the highest content, was the first kind of water for total removal. The removal time of free water was 720, 660, 600, 480 and 360 min at ultrasound powers of 0, 12, 24, 36 and 48 W, respectively. Ultrasound showed great strengthening effect on free water removal, which indicated that ultrasound could achieve good energy transmission and strong water turbulence at the existence of free water. The contents of immobilized water and bound water decreased during the drying, however, the immobilized water and bound water inside pear slices could not be removed completely. The peak areas became smaller with the increase of ultrasound power, which indicated that the increase in ultrasound power could improve water mobility and reinforce moisture migration. The MRI results showed the change of moisture content and water distribution at different ultrasound powers during the drying process, and higher ultrasound power caused faster moisture reduction, which indicated that the MRI images could visually illustrate the change and transformation of water inside pear slices and the application of ultrasound could accelerate internal moisture migration significantly and increase drying rate. The research can present reference to the theoretical study and technical application of ultrasound enhanced hot-air drying technology.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:37
Main heading:Ultrasonics
Controlled terms:Capillarity - Drying - Fruits - Lead removal (water treatment) - Magnetic resonance imaging - Magnetism - Microstructure - Moisture - Nuclear magnetic resonance - Solar dryers  - Water supply systems
Uncontrolled terms:Low field nuclear magnetic resonance - Low field nuclear magnetic resonance (LF NMR) - Moisture migration - Pear - Strengthening mechanisms - Strengthening technologies - Surface microstructures - Technical applications
Classification code:445.1  Water Treatment Techniques - 446.1  Water Supply Systems - 631.1  Fluid Flow, General - 657.1  Solar Energy and Phenomena - 701.2  Magnetism: Basic Concepts and Phenomena - 753.1  Ultrasonic Waves - 821.4  Agricultural Products - 951  Materials Science
Numerical data indexing:Percentage 5.78e+01%, Percentage 5.83e+01%, Percentage 6.00e+01%, Power 3.60e+01W, Power 4.80e+01W, Time 2.16e+04s, Time 2.88e+04s, Time 3.60e+04s
DOI:10.11975/j.issn.1002-6819.2018.19.036

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 32>

Accession number:20185206314562
Title:Design and test of biomimetic wear resistant for wet clutch friction plate for heavy tractor
Authors:Tan, Lidong (1); Zong, Xuanjie (1); Chang, Zhiyong (2); Wang, Yanbo (1); Chen, Donghui (2)
Author affiliation:(1) Jilin University, Jiaotong Collage, Changchun; 130022, China; (2) Jilin University, Key Laboratory of Bionics Engineering, Ministry of Education, Changchun; 130022, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:54-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Wet clutch of heavy tractor is an important executive component of power shift gearbox. The wear failure of the friction pair is one of the main reasons for the overall performance degradation of the transmission system. To reduce the huge resource and economic loss caused by it, a wear-resistant clutch friction plate was designed. In this paper, from the perspective of bionics, the big tree frog was used as the experimental research object, and the toe end was observed by scanning electron microscopy. The microstructure of the toad end of the tree frog is quadrilateral, pentagon, hexagonal, and the hexagonal structure is mostly. The structure is uniform in size and has a diameter of about 10 &mu;m. The microstructures have a groove between the outlines and a groove width of about 1 &mu;m. Studies have shown that the mucus secreted by the body surface of the tree frog circulates in the groove surrounding the hexagonal structure, enhancing its adhesion, which is the coefficient of friction, in a humid environment. Tree frogs exhibit strong adhesion and friction when in contact with slippery substrates. With these characteristics, the bionic friction linings can better meet the requirements of transmission motion and torque. The toad parameters of the tree frog were extracted, the surface structure of the friction lining was optimized, and the dense hexagonal groove division structure of the toad end of the tree frog was further highlighted and simplified. The oil sump structure on the surface of the wet clutch friction plate of the heavy tractor was similarly designed. Nine kinds of bionic samples were designed for the design idea and the samples were made by laser processing technology. The friction and wear tests were carried out on a micro-friction and wear tester, and the differences of friction and wear with different hexagonal diameters and different groove widths were studied. The test results showed that the bionic non-smooth structure has better wear resistance than the smooth structure, and the regular hexagon has a diameter of 12 mm. When the groove width is 1.5 mm, the wear amount is the lowest and the friction coefficient is relatively high. The combined shape diameter and groove width can minimize wear and improve the service life of the friction plate, thus achieving the requirement of improving the wear resistance of the clutch.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:23
Main heading:Wear resistance
Controlled terms:Adhesion - Automobile testing - Biomimetics - Bionics - Clutches - Design - Electric power transmission - Forestry - Friction - Losses  - Microstructure - Plates (structural components) - Scanning electron microscopy - Tractors (agricultural) - Tractors (truck) - Wear of materials
Uncontrolled terms:Coefficient of frictions - Experimental research - Friction coefficients - Friction plate - Laser processing technology - Performance degradation - Transmission systems - Tree frog
Classification code:408.2  Structural Members and Shapes - 461  Bioengineering and Biology - 602.2  Mechanical Transmissions - 662  Automobiles and Smaller Vehicles - 663.1  Heavy Duty Motor Vehicles - 706.1.1  Electric Power Transmission - 911.2  Industrial Economics - 931.2  Physical Properties of Gases, Liquids and Solids - 951  Materials Science
Numerical data indexing:Size 1.00e-05m, Size 1.00e-06m, Size 1.20e-02m, Size 1.50e-03m
DOI:10.11975/j.issn.1002-6819.2018.19.007

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 33>

Accession number:20185206314559
Title:Detecting seed suction performance of air suction feeder by photoelectric sensor combined with rotary encoder
Authors:Jia, Honglei (1, 2); Lu, Yun (1, 2); Qi, Jiangtao (1, 2); Zhang, Zhe (1, 2); Liu, Huili (1, 2); Li, Yang (1, 3); Luo, Xiaofeng (1, 2)
Author affiliation:(1) Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun; 130025, China; (2) School of Biological and Agricultural Engineering, Jilin University, Changchun; 130025, China; (3) Graduate School of Agriculture, Kyoto University, Kyoto; 606-8502, Japan
Corresponding author:Qi, Jiangtao(qijiangtao@jlu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:28-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The air suction type soybean seed-metering device is the core component of the air suction soybean planter. Therefore, the stability and reliability of the machine in working determines the seeding quality of the whole machine. Therefore, high-speed and precision sowing is one of the main development directions of soybeans, corns and other sowing crops. The working state of the seeding machine in the working process is difficult to be directly observed with the naked eye. Once the fault of the metering device occurs, it is very difficult to find and deal with it in time. In this paper, the application of air suction type seed-metering device in high-speed and precision seed metering was discussed, and the seed disc suction performance detection system (SDSPS) was designed. The system used a concave photoelectric sensor to collect the information of seed suction of the platters and used the photoelectric rotary encoder to collect information of the rotation angle of the seed-bearing shaft. By processing the output signal of the photoelectric sensor and the pulse signal of the photoelectric encoder, the seed disc suction performance detection system (SDSPS) can detect every suction holes' sucking condition, so that the working condition of the whole metering device can be detected. It is of great significance to improve the working performance of air-sucking soybean seed metering device. Bench tests were carried out under six working conditions, and the experimental data were collected. At the same time, the feasibility tests were carried out to detect the absorption of single hole to the seeds. All the test data were collected and compared with the test data of the commonly used system which called Seeding Detecting System based on Image Processing (SDSIP)). Through F-test and t-test (&alpha;=0.05), it was found that the total variances of the two systems were the same and the mean values were the same. The results of accuracy analysis showed that the maximum relative error of SDSPS was 0.31% compared with that of SDSIP. The results of system stability analysis showed that the fluctuation amplitude of SDSPS was similar to that of SDSIP, and the maximum relative deviation between SDSPS and SDSIP was less than 1%. The maximum relative error of the SDSPS in the detection of the suction amount of single suction hole was 16.67%. Through the field test,for the effects of SDSPS on the amount of seed lost and the amount of multiple species absorbed, the average relative error of detection value and real value of detection system was 3.87% and 8.42% respectively, and the maximum relative error values were 10.34% and 20.00% respectively. The reason for the error is the complex conditions of the fields, such as the uneven surface environment and so on. The vibration of the machines and tools caused by the rough ground makes the data measured by this method deviate, resulting in abrupt errors. SDSPS can effectively measure the seed absorption performance of seeding suction. There is also a high reliability in the detection of the amount of seed absorbed by a single suction hole. It can provide technical support for the performance detection and improvement of the air suction type seed-metering device. The test system designed in this paper can effectively detect the working performance of sucking holes in the metering disk. It can also find out the problem of seed suction hole, and provide reference for subsequent improvement and performance improvement of seed tray so as to speed up the research and development of the metering device.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:27
Main heading:Seed
Controlled terms:Agricultural machinery - Disks (machine components) - Error detection - Image processing - Photoelectricity - Pneumatic materials handling equipment - Sensors - Signal encoding - System stability - Testing
Uncontrolled terms:Air suction - Detecting systems - Maximum relative errors - Performance improvements - Research and development - Stability and reliabilities - Suction performance - System stability analysis
Classification code:601.2  Machine Components - 632.4  Pneumatic Equipment and Machinery - 701.1  Electricity: Basic Concepts and Phenomena - 716.1  Information Theory and Signal Processing - 821.1  Agricultural Machinery and Equipment - 821.4  Agricultural Products - 961  Systems Science
Numerical data indexing:Percentage 1.00e+00%, Percentage 1.03e+01%, Percentage 1.67e+01%, Percentage 2.00e+01%, Percentage 3.10e-01%, Percentage 3.87e+00%, Percentage 8.42e+00%
DOI:10.11975/j.issn.1002-6819.2018.19.004

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 34>

Accession number:20185206314557
Title:Design and experiment of horizontal pneumatic screw combination adjustable quantitative fertilizer feeding device for granular fertilizer
Authors:Lei, Xiaolong (1, 2); Li, Mengliang (1); Zhang, Lihua (1); Ren, Wanjun (2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Sichuan Agricultural University, Ya'an; 625014, China; (2) Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Ministry of Agriculture, Chengdu; 611130, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:9-18
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nutrients including the elements of N, P and K are beneficial to the growth and yield of crops. Reducing the application amount of chemical fertilizer and increasing the utilization rate have become the important ways and means of high quality and high efficiency green agriculture. Granular fertilizer has been widely used in agricultural production because of its low fluidity, strong hygroscopicity and cohesion. Meanwhile, the amount of fertilizer applied depends on the crops, the fertilization application time, and the fertilizer varieties. In order to adjust the requirements of fertilization and precision fertilization, the horizontal pneumatic centralized feeder of fertilizer was developed. The fertilizing device is the core part of the horizontal pneumatic centralized feeder. According to the mechanical and physical properties, and fertilizer requirements of granular fertilizers, the inclined screw-type model-hole and combined fertilizer feeding unit was designed. The main structural parameters of the inclined screw-type model-hole and the fertilizing unit were determined. The bottom width, upper width and depth of model-hole were 12.0 mm, 30.0 mm and 18.0 mm, respectively. The left inclined angle, right inclined angle and number of screw-type model-hole was 24&deg;, 37&deg; and 6, respectively. The helical pitch, helix angle and length of fertilizer feeding unit were 450 mm, 60&deg; and 40 mm, respectively. The number of fertilizing unit could be adjusted from 1 to 4. The amount of fertilizer applied varied with the number of fertilizing units and the rotational speed. The mechanical models of fertilizer combination in fertilizer filling and feeding zone were established. The results showed that filling and feeding performance of fertilizer could be improved significantly by tilting angle between left and right. The fertilization performance experiments were performed in the bench test. The effects of fertilization unit number of and rotation speed on fertilizer application and coefficient of variation were studied using Zhushang Fertilizer. Furthermore, the fertilizer adaptability of fertilization device was studied with Zhushang Fertilizer, Sanning Fertilizer and Yunding Fertilizer. The results showed that: 1) When the fertilization unit number and rotational speed were 1-4 and 10-40 r/min, respectively, the fertilization amount increased with the increase of number of fertilization unit number and rotational speed. The range of fertilizer feeding rate was 912.67-13 164.26 g/min. 2) The amount of fertilizer application was significantly affected by the fertilizer types, rotation speed and interaction between fertilizer types and rotation speed. With the same rotation speed of 10-30 r/min, the fertilizer feeding rate of Sanning Fertilizer was the largest, while that of Yunding Fertilizer was the lowest. The difference of fertilizer feeding rate among three fertilizer types was less than 5%. It indicated that the fertilizer feeding device could be applied to different compound granular fertilizer. 3) The quadratic regression predicted model of fertilizer amount was established with the factors of fertilization unit number and rotational speed. The determination coefficient of the regression prediction model was 0.995 8, which indicated that the prediction model was feasible. The fertilizer feeding rate was studied under the condition of target fertilizer application range of 150-750 kg/hm² and tractor velocity of 2.52-5.88 km/h. The deviations between the experimental value and the predicted value of fertilizer feeding rate were not more than 3%. In addition, the coefficients of variation of fertilizer feeding rate in each treatment were less than 1.0%. The results showed that the model can accurately predict the fertilizer feeding rate and calculate the fertilizer feeding unit number and rotational speed. The field experiment showed that the relative error between the fertilizer feeding amount and the theoretical value was 3.54%. The structure of the inclined screw-type model-hole and combined fertilizer feeding unit can realize the adjustment of fertilizer feeding rate in a wide range for granular fertilizer. The fertilizer feeding performance of fertilizer feeding device could meet the requirements of fertilizer application amount and fertilizer feeding stability. This research can provide the basis for the structue design of horizontal pneumatic centralized feeder and variable-rate precision fertilization.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Fertilizers
Controlled terms:Agricultural machinery - Crops - Design - Experiments - Feeding - Forecasting - Machine design - Pneumatics - Rotation - Screws  - Speed
Uncontrolled terms:Agricultural productions - Coefficient of variation - Coefficients of variations - Determination coefficients - Granular fertilizers - Mechanical and physical properties - Precision fertilizations - Screw type
Classification code:601  Mechanical Design - 605  Small Tools and Hardware - 632.3  Pneumatics - 691.2  Materials Handling Methods - 804  Chemical Products Generally - 821.1  Agricultural Machinery and Equipment - 821.4  Agricultural Products - 901.3  Engineering Research - 931.1  Mechanics
Numerical data indexing:Mass_Flow_Rate 2.74e-03kg/s, Percentage 1.00e+00%, Percentage 3.00e+00%, Percentage 3.54e+00%, Percentage 5.00e+00%, Rotational_Speed 1.00e+01RPM to 3.00e+01RPM, Rotational_Speed 1.00e+01RPM to 4.00e+01RPM, Size 1.20e-02m, Size 1.80e-02m, Size 3.00e-02m, Size 4.00e-02m, Size 4.50e-01m, Velocity 7.00e-01m/s to 1.63e+00m/s
DOI:10.11975/j.issn.1002-6819.2018.19.002

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 35>

Accession number:20185206314570
Title:Optimization of irrigation scheduling for organic rice based on AquaCrop
Authors:Shao, Dongguo (1); Le, Zhihua (1); Xu, Baoli (1); Hu, Nengjie (1); Tian, Yini (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan; 430072, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:114-122
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Along with the continuous exploration in enhancing agricultural productivity, the traditional agriculture which needs high input of chemical fertilizer and pesticide is gradually turned into an ecologically and environmentally friendly organic agriculture. However, there are few studies on water consumption characteristics and irrigation schedule of organic rice. To reveal the pattern of water consumption and the relationship between irrigation and yield under different precipitation types, field experiments were carried out during the rice growth period in 2015-2016 in Zhanghe Irrigation District, Hubei Province. In 2015, the same rice variety was cultivated in different modes:1) in traditional mode, the chemical fertilizer was used; 2) in organic mode, the manure was used. The irrigation schedule was similar for the both modes: to keep water depth to 20-50 mm. If the rainfall was over the 50 mm, drainage was conducted. Based on the experimental results, we analyzed the difference of water consumption between organic rice and traditional rice, and obtained information on water consumption and yield characteristics of the organic rice. Based on the results of 2015, an optimization experiment of organic rice cultivation was set up: the irrigation amount was 0, 50, 120, 230 and 330 mm, respectively. Then we proposed a multi-objective and multi-scenario optimization method of irrigation scheduling by using AquaCrop model and entropy method. One of the treatments was used for model calibration and the others were for validation. The results showed: 1) the evapotranspiration of traditional rice and organic rice from the period of steeping field and reviving to milk ripening were 420 mm and 235 mm, respectively. The drainage of organic rice and traditional rice were 99.61 and 23.75 mm, respectively. The mean TN concentration of water discharge in organic rice were lower than that in traditional rice, and the TP concentration of water discharge in organic rice were also lower than that in traditional rice. 2) The yield of organic rice accounted for 84% of the traditional rice yield,plant height were 7.6% higher than that of traditional rice, the empty shell rate were 10.5% higher than of the traditional rice. 3) the model measurement and simulation matched well with Nash-Sutcliffe efficiency above 0.7, relative root mean square of error 0.15-0.28, and coefficient of determination higher than 0.7, indicating that the model could simulate the yield well under different conditions. 4) After optimization, the irrigation schedule of organic rice in southern China were: in dry year, the lowest limit of soil volume water content were 108%RAW (readily available soil water), irrigation quota were 30 mm, frequency of irrigation were 8 to 9 times; in normal year, the lowest limit of soil volume water content were 113.85 %RAW, irrigation quota were 32.31mm, frequency of irrigation were 6 to 7 times and in wet year, the lowest limit of soil volume water content were 116.92%RAW, irrigation quota were 32.31 mm, frequency of irrigation were 3 to 4 times. The study validated the applicability of AquaCrop model in rice growth simulation and irrigation schedule optimization in China and established a method of optimizing irrigation schedule by coupling AquaCrop model and entropy method, providing technical guidance to organic rice production.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Irrigation
Controlled terms:Cultivation - Evapotranspiration - Fertilizers - Models - Multiobjective optimization - Productivity - Scheduling - Soil moisture - Water supply
Uncontrolled terms:Agricultural productivity - AquaCrop - Available soil waters - Coefficient of determination - Continuous exploration - Entropy methods - Organic rice - Yield characteristics
Classification code:446.1  Water Supply Systems - 483.1  Soils and Soil Mechanics - 804  Chemical Products Generally - 821.3  Agricultural Methods - 912.2  Management - 921.5  Optimization Techniques
Numerical data indexing:Percentage 1.05e+01%, Percentage 7.60e+00%, Percentage 8.40e+01%, Size 2.00e-02m to 5.00e-02m, Size 2.30e-01m, Size 2.35e-01m, Size 2.38e-02m, Size 3.00e-02m, Size 3.23e-02m, Size 3.30e-01m, Size 4.20e-01m, Size 5.00e-02m, Size 9.96e-02m
DOI:10.11975/j.issn.1002-6819.2018.19.015

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 36>

Accession number:20185206314578
Title:Crop classification based on nonlinear dimensionality reduction using time series remote sensing images
Authors:Zhai, Yongguang (1, 2); Qu, Zhongyi (1)
Author affiliation:(1) College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot; 010018, China; (2) Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing; 100101, China
Corresponding author:Qu, Zhongyi(quzhongyi@imau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:177-183
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Compared with the traditional method of ground statistics, remote sensing technology has the unique advantages of high efficiency, fast speed and high precision. It is suitable for agricultural monitoring, especially the time series remote sensing data can provide spectral information covering the whole growing season of crops. At present, most of the crop classification methods based on time series remote sensing data need many expert knowledge and manual intervention, which are difficult to automate and transplant to other areas. The application of dimensionality reduction (DR) technique to time series remote sensing image analysis can solve this problem efficiently. The imaging process of remote sensing image will experience multiple scattering between different scene components. This scattering is influenced by many factors such as wavelength, observation angle, illumination condition, and three-dimensional structure of scene component. Therefore, the remote sensing image has inherent nonlinear characteristics, and the nonlinear DR technology is more suitable for remote sensing images. The nonlinear spectral DR method has been successfully applied to hyperspectral data and obtained better results than linear DR methods. However, the nonlinear DR method cannot make full use of the temporal information in time series remote sensing images. In this study, a nonlinear DR algorithm, Laplacian Eigenmaps (LE), is refined for crop classification in time series remote sensing images. This method emphasizes the phenological characteristics difference of different crop growing seasons. In the refined LE algorithm, the dynamic time warping (DTW) measurement with different weight value is used to calculate the similarity between the time series. If the two phases of the calculated path are consistent or close, a smaller weight should be given, and a greater weight should be given when the two phases correspond to the path are far away. In addition, the refined LE method can be applied to time series data with unequal length and reduce the preprocessing operation of time series data. Moreover, the proposed method is simple to run and only requires two input parameters. One is the midpoint of time series, and the other is the number of retained bands after DR. Both two parameters are easily to obtain. The refined LE algorithm is applied to the Landsat time series images of the whole growing season of crops in Illinois, USA. A series of classification experiments based on the training data provided by the United States Department of Agriculture National Agricultural Statistics Services Cropland Data Layer (CDL) are completed and compared with the traditional interpolation method without DR and the LE-DTW method proposed for land cover classification. The experimental results show that the refined LE DR method has completed a higher classification accuracy and per-class accuracy than other methods. And the overall classification accuracy of the proposed method reaches 85.37%, which is 9.05 and 3.45 percentage points higher than that of temporal interpolation (TI) method and LE-DTW method respectively. And the method can achieve a given degree of classification accuracy with only a small number of training samples. When the proportion of training samples is higher than 1%, the positive and negative standard deviations of the proposed method is below 1%. The overall classification accuracy of the proposed method tends to be stable when the proportion of training samples reaches 2%. The refined LE dimensionality reduction method is an automatic method and can be directly applied to other research areas without manual intervention. It provides an effective method for crop identification and extraction on different scales in the future.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Classification (of information)
Controlled terms:Crops - Cultivation - Data processing - Data reduction - Image classification - Interpolation - Remote sensing - Sampling - Time series - Time series analysis
Uncontrolled terms:Crop classification methods - Dimensionality reduction - Dimensionality reduction method - Dynamic time warping - National agricultural statistics services - Nonlinear dimensionality reduction - Three-dimensional structure - United states department of agricultures
Classification code:716.1  Information Theory and Signal Processing - 723.2  Data Processing and Image Processing - 821.3  Agricultural Methods - 821.4  Agricultural Products - 921.6  Numerical Methods - 922.2  Mathematical Statistics
Numerical data indexing:Percentage 1.00e+00%, Percentage 2.00e+00%, Percentage 8.54e+01%
DOI:10.11975/j.issn.1002-6819.2018.19.023

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 37>

Accession number:20185206314573
Title:Estimation of surface speed of river flow based on machine vision
Authors:Feng, Quan (1); Zhang, Yanhong (2); Zhao, Xiaogang (1)
Author affiliation:(1) School of Mechanical and Electrical Engineering, Gansu Agricultural University, Lanzhou; 730070, China; (2) College of Water Conservancy and Hydropower Engineering, Gansu Agricultural University, Lanzhou; 730070, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:140-146
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The wave represents the motion of river flow. The surface speed of river can be estimated through motion analysis for the wave. In the paper, a method was proposed based on computer vision to estimate the surface speed of river directly. The method tried to capture the motion of wave caused by flowing river from the video. However, even taken by HD camera, the contrast between moving waves and even surface in an image is still not obvious since they are homogeneous and all moved as a whole. In order to enlarge details of the motion of waves, the map of motion saliency was calculated by the way of frame difference method. In the map, the key points were extracted and characterized by SURF features. These key points represented the most salient positions of waves. Through the point matching algorithm, a key point in one map and its counterparts in next map were searched. The correspondence between the 2 matched points indicated the motion of wave in the video and the distance between them was computed. In principle, with this distance and the parameters of camera, we could estimate the immediate speed of flow. However, the distance was noisy essentially. For robust and accurate estimation, we estimated the average speed instead of immediate speed. So, we calculated the histogram of the distances during the period of time. We found that most of these histograms appeared as uni-modal distribution. However, there existed some histograms which appeared with 2 adjacent peaks, or appeared with a flat peak. This resulted in the difficulty for estimation of distance accurately. To address the problem, we utilized the Gaussian curve to fit the histogram. The peak of the fitted curve could be searched accurately and its corresponding distance was viewed as the optimal estimation of average distance. Finally, with the speed formula derived from pinhole model, the optimal distance and the time between 2 maps, we could estimate the average surface speed of the river flow. To validate the availability of the proposed method, we compared the speeds estimated by our method with the baselines measured by the current meter. In our experimental setting, we selected gently surface for measurement task, without whirlpool and reflection. We conducted 8 measurements, with the speeds being limited between low and middle range. The experimental results showed that maximal relative error of speed between ours and the baseline was 3.12% while the min relative error only 1.39%, indicating good accuracy of our method. The min and max coefficient of variation was 1.04% and 1.63% respectively, showing high reliability. The correlation coefficients of Pearson and Spearman between our estimators and measured values were respectively 0.998 and 0.990. Bland-Altman regression P is 0.16, higher than 0.05 and in Bland-Altman scatter plot, most of points fell into the limits of agreement. These results showed that the flow speed estimated by our method had a good consistency with the baselines. In addition, our method was compared to the image processing method by previous literatures, the results showed that the time consumption was shortened by our study, which was only 4.4% of that of the literature, indicating that our method is faster than the previous method. In sum, this study provides an effective method for the estimation of flow speed of rivers with complex background.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Speed
Controlled terms:Cameras - Computer vision - Graphic methods - Rivers - Statistical methods - Stream flow
Uncontrolled terms:Coefficient of variation - Correlation coefficient - Flow - Frame difference methods - Frame differences - Image processing - methods - SURF feature - Video
Classification code:407.2  Waterways - 723.5  Computer Applications - 742.2  Photographic Equipment - 922.2  Mathematical Statistics
Numerical data indexing:Percentage 1.04e+00%, Percentage 1.39e+00%, Percentage 1.63e+00%, Percentage 3.12e+00%, Percentage 4.40e+00%
DOI:10.11975/j.issn.1002-6819.2018.19.018

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.

<RECORD 38>

Accession number:20185206314585
Title:Synergistic catalytic pyrolysis of biomass using molten salts and nickel for hydrogen-rich syngas
Authors:Liu, Ming (1, 2, 3); Wang, Xiaobo (1, 3); Zhao, Zengli (1, 3); Li, Haibin (1, 3)
Author affiliation:(1) Guangzhou Institute of Energy Conversion, CAS, Guangzhou; 510640, China; (2) Nano Science and Technology Institute, University of Science and Technology of China, Suzhou; 215123, China; (3) Key Laboratory of Renewable Energy, Chinese Academy of Science, Guangzhou; 510640, China
Corresponding author:Wang, Xiaobo(wangxb@ms.giec.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:34
Issue:19
Issue date:October 1, 2018
Publication year:2018
Pages:232-238
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The effects of Na<inf>2</inf>CO<inf>3</inf>-NaOH molten salts and nickel on the pyrolysis of 3 components of biomass, i.e. cellulose, hemicellulose and lignin, were studied in the thermogravimetric (TG) analyzer and fixed bed reactor. In the TG experiment, the addition of molten salt makes the peak of cellulose TG curve appear ahead of the TG curve of cellulose without catalyst. The corresponding differential thermogravimetric (DTG) curve has 2 separation peaks, while there is only one peak appearing in the DTG curve of cellulose without catalyst. In DTG curve of hemicellulose, compared with the hemicellulose pyrolysis alone, the temperature corresponding to the maximum pyrolysis rate of the peak is decreased by 82 &#8451; after adding molten salt. As for lignin, the DTG and TG curve with catalyst basically coincide with that without catalyst, indicating that the low dose addition of molten salt and nickel had little effect on the pyrolysis of lignin. The results of fixed-bed experiment show that the molten salt can effectively absorb CO<inf>2</inf>, which promote the increase of H<inf>2</inf> and the reduction of CO simultaneously in water-gas shift reaction. In the process of catalytic cellulose pyrolysis, the OH^- contained in molten salt motivates the rearrangement of the ring-opening products of cellulose monomer at relatively low temperature, and the rearrangement products are easily decomposed, thus leading to an acceleration of cellulose decomposition. The Na⁺ contained in molten salt can react with phenolic hydroxyl groups in lignin structural units and decrease activation energy of ring-opening reaction of hemicellulose monomer, resulting in an easy decomposition of both lignin and hemicellulose. Under the optimum conditions, the amount of hydrogen produced by cellulose, hemicellulose and lignin can reach 913, 738 and 1 148 mL/g, respectively, and the content of H<inf>2</inf> can reach 85.6%, 78.2% and 90.7%, respectively. The CH<inf>4</inf> content can be reduced by the synergistic effect of molten salt and nickel, under which the CH<inf>4</inf> yields of cellulose, hemicellulose and lignin are decreased by 35.0%, 24.5% and 12.0%, respectively compared with the single addition of molten salt. The synergistic effect of molten salt and nickel can effectively reduce the content of CO, CO<inf>2</inf> and CH<inf>4</inf> in syngas, which is beneficial to the pyrolysis of biomass to produce hydrogen-rich gas. Under the optimum conditions, the contents of CO, CO<inf>2</inf> and CH<inf>4</inf> in the lignin are only 0.5%, 0.4% and 5.9%, respectively. Meanwhile, in the presence of molten salt and nickel, the maximum hydrogen yields of cellulose, hemicellulose and lignin reach 910, 714 and 1 106 mL/g, respectively, and the contents of H<inf>2</inf> are 77.6%, 77.8% and 91.6%, respectively. From 700 to 900 &#8451;, with the increase of temperature, the reaction of residual carbon and H<inf>2</inf>O, CO is promoted, so high temperature is conducive to the conversion of residual carbon. At the same time, CH<inf>4</inf> production tends to decrease with the increase of temperature, because CH<inf>4</inf> is easily decomposed at high temperatures. It can be seen that high temperature is conducive to the production of H<inf>2</inf> and CO, and promotes the cracking of CH<inf>4</inf>, which is in favor of biomass pyrolysis to produce hydrogen-rich gases.<br/> &copy; 2018, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Cellulose
Controlled terms:Activation energy - Biomass - Carbon - Carbon dioxide - Catalysts - Chemical reactors - Chemical shift - Fused salts - Hydrogen - Hydrogen production  - Lignin - Monomers - Nickel - Pyrolysis - Sodium Carbonate - Sodium hydroxide - Synthesis gas - Temperature - Water gas shift
Uncontrolled terms:Catalytic pyrolysis of biomass - Cellulose decomposition - Differential thermogravimetric - Molten salt - Phenolic hydroxyl group - Ring opening reaction - Ring-opening products - Water gas shift (WGS) reaction
Classification code:522  Gas Fuels - 548.1  Nickel - 641.1  Thermodynamics - 802.1  Chemical Plants and Equipment - 802.2  Chemical Reactions - 804  Chemical Products Generally - 804.2  Inorganic Compounds - 811.3  Cellulose, Lignin and Derivatives - 931.3  Atomic and Molecular Physics
Numerical data indexing:Percentage 1.20e+01%, Percentage 2.45e+01%, Percentage 3.50e+01%, Percentage 4.00e-01%, Percentage 5.00e-01%, Percentage 5.90e+00%, Percentage 7.76e+01%, Percentage 7.78e+01%, Percentage 7.82e+01%, Percentage 8.56e+01%, Percentage 9.07e+01%, Percentage 9.16e+01%, Specific_Volume 1.11e+00m3/kg, Specific_Volume 1.15e+00m3/kg, Specific_Volume 7.14e-01m3/kg, Specific_Volume 7.38e-01m3/kg
DOI:10.11975/j.issn.1002-6819.2018.19.030

Database:Compendex
Compilation and indexing terms, Copyright 2019 Elsevier Inc.