<RECORD 1>

Accession number:20213610853570
Title:Effects of cavitation on pressure fluctuation of draft tube and runner vibration in a Kaplan turbine
Title of translation:&#31354;&#21270;&#23545;&#36724;&#27969;&#24335;&#27700;&#36718;&#26426;&#23614;&#27700;&#31649;&#21387;&#21147;&#33033;&#21160;&#21644;&#36716;&#36718;&#25391;&#21160;&#30340;&#24433;&#21709;
Authors:Zhu, Guojun (1); Li, Kang (1); Feng, Jianjun (1, 2); Luo, Xingqi (1, 2)
Author affiliation:(1) Institute of Water Resources and Hydro-electric Engineering, Xi'an University of Technology, Xi'an; 710048, China; (2) Zhejiang FINE Institute of Hydraulic Machinery, Hangzhou; 311121, China
Corresponding author:Feng, Jianjun(jianjunfeng@xaut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:40-49
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Hydropower energy is one of the most important clean energy sources in the world. Since the medium and high head hydropower energy presents a high economic index and exploitability, only a few resources are available at present in China. By contrast, low head hydropower resources become one of the key directions of hydropower development in the future. A Kaplan turbine has also been one of the main unit types for the low head hydropower resources. Nevertheless, cavitation has been only one factor to limit the application, although a wide range was achieved in the high efficiency region. Furthermore, the runner erosion and vibration induced by the cavitation can greatly shorten the normal operating cycle of the Kaplan turbine, even seriously detrimental to the economic benefits of water stations. The vibration and pressure fluctuation are the commonly-used indicators to report the stability of hydraulic turbines. As such, the effect of cavitation on the vibration and pressure fluctuation directly determines the stability and optimization of the Kaplan turbine. In this study, a synchronous test system was constructed to investigate the influence of cavitation on the pressure fluctuation of the draft tube and the runner vibration in a Kaplan turbine. The system included a high-speed camera, a Laser Doppler Vibrometer (LDV), and a high-frequency pressure fluctuation sensor. A Kaplan turbine model was also selected as the research object. The pressure fluctuation, radial vibration, and cavitation images of the runner were first captured under different cavitation coefficients in the synchronous test system. The Variational Mode Decomposition (VMD), the spectrum analysis, and the cross-correlation were then combined to explore the influence of cavitation on the radial vibration of the runner, and the pressure fluctuation on the draft tube. Finally, it was found that there was a significant increase in the amplitudes of pressure fluctuation on the draft cone tube, and the radial vibration velocity of the runner, with the decrease of cavitation coefficient. There was an obvious nonlinearity in the peak-to-peak value of pressure fluctuation on the draft cone tube and the radial vibration velocity of the runner, with the variation of cavitation coefficient. Specifically, the peak-to-peak values after complete cavitation reached 9.16 and 10.12 times that without cavitation, respectively. The increased severity of runner cavitation made the dominant frequency of pressure fluctuation on the draft cone tube change to blade passing frequency. But only a little influence was observed on the dominant frequency of runner radial vibration velocity. The dominant frequency of radial vibration velocity of the runner was basically the passing frequency of blades. The runner cavitation also induced the local migration of extreme value in the high-frequency energy, which increased the energy of low-frequency region of pressure fluctuation. The possibility of Kaplan turbine resonance was enhanced in this case. Moreover, the cavitation contributed to enhancing the energy in the high-frequency region of runner radial vibration in a Kaplan turbine.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Vibration analysis
Controlled terms:Cavitation - High speed cameras - Hydraulic motors - Hydroelectric power - Hydroelectric power plants - Kaplan turbines - Laser Doppler velocimeters - Spectrum analysis - Tubes (components) - Velocity
Uncontrolled terms:Blade passing frequency - Clean energy sources - Hydro-power development - Hydro-power resources - Laser Doppler vibrometers - Low frequency regions - Peak-to-peak values - Pressure fluctuation
Classification code:611.1  Hydroelectric Power Plants - 617.1  Hydraulic Turbines - 619.1  Pipe, Piping and Pipelines - 631.1.1  Liquid Dynamics - 632.2  Hydraulic Equipment and Machinery - 742.2  Photographic Equipment - 744.9  Laser Applications
DOI:10.11975/j.issn.1002-6819.2021.11.005

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 2>

Accession number:20213610853496
Title:Accumulation characteristics and risk prediction of Cu and Zn contents in typical facility soils in China
Title of translation:&#20013;&#22269;&#20856;&#22411;&#35774;&#26045;&#26685;&#22521;&#22303;&#22756;Cu, Zn&#32047;&#31215;&#29305;&#24449;&#21450;&#39118;&#38505;&#39044;&#27979;
Authors:Lu, Weihong (1, 3, 4); Liu, Juan (1, 3); Zhang, Naiming (1, 2, 3); Li, Fangyan (2, 3); Han, Dongjin (2, 3); Yu, Hong (2, 3); Li, Jiaqi (2, 3); Han, Zheng (2, 3, 5)
Author affiliation:(1) College of Plant Protection, Yunnan Agricultural University, Kunming; 650201, China; (2) College of Resource and Environmental Science, Yunnan Agricultural University, Kunming; 650201, China; (3) Yunnan Soil Fertility and Pollution Restoration Laboratory, Kunming; 650201, China; (4) Henan Xinlianxin Chemical Industry Group Co., Ltd., Xinxiang; 453700, China; (5) College of Information Engineering, Jiangsu College of Engineering and Technology, Nantong; 226007, China
Corresponding author:Zhang, Naiming(zhangnaiming@sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:189-196
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Excessive accumulation of trace elements in the protected cultivation soil has become an important factor for the degradation of soil quality. In particular, both copper (Cu) and zinc (Zn) are micronutrient elements required for plant growth and heavy metal in the soil environment. It is highly demanding to consider the Cu, Zn cumulative risks. Therefore, this study aims to investigate the accumulation characteristics and risk prediction of Cu, Zn content in the protected cultivation soil. A total of 131 soil samples were also collected using 5-point sampling in the typical regions of 16 cities in 7 provinces and 1 autonomous region (including Liaoning, Hebei, Shandong, Henan, Shaanxi,, Jiangsu, Yunnan, and Ningxia) in China. The cumulative status and risk characteristics of Cu and Zn were systematically analyzed using the total and available content of the soil. The relationship between the accumulation of available Cu, Zn, and the planting years was fitted to predict the risk of Cu and Zn accumulation exceeding the limit value. The results showed that: 1) The total Cu and Zn exhibited an accumulative characteristic in the protected cultivation soil, except that Cu presented a slight decrease in Jiangsu. The effective state content of Cu and Zn (except that Zn at a relatively rich level both in Shaanxi and Jiangsu) reached an extremely rich level, where there was no state below the critical value. Noted that the soil background values in each province were compared with the abundance and deficiency indexes of soil available trace elements in the agricultural system. 2) The total amount of Cu and Zn in the soil exceeded the standard by 16.03% and 4.58%, respectively, compared with the screening value of farmland soil. The average exceeding limit rate reached 16.92%, while Liaoning, Henan and Yunnan were observed the most serious up to 33.33%, 62.50%, and 32.00%, respectively, compared with the risk limits of soil available Cu and Zn. 3) The risk assessment showed that the overall performance of protected cultivation soil was safe using the effective state. The samples from Liaoning, Henan, and Yunnan reached the level of lightly, lightly pollution, and warning value level, respectively. The cumulative risks of elemental Cu were more serious than Zn element. 4) There was a significant positive correlation between the accumulations of soil available Cu and Zn with the corresponding planting years (P&lt;0.05). The continuous replanting for 6.7, 20.5, and 19.3 years led to the accumulation of available Cu in soils with acidic, neutral, and alkaline limit values of characteristics reach risk, respectively, under the current protected cultivated conditions. At the same time, the continuous replanting for 32.5, 67.9, 91.9 years led to the accumulation of available Zn in the soils with acidic, neutral, and alkaline limit values of characteristic reach risk. The bioavailable state of trace element was used to evaluate the exceeding limit rate of Cu and Zn, while the cumulative risk in the protected cultivated soil, in order to achieve the safe utilization via transforming the excess bioavailable to low state, (such as residue, oxidizable, and reducible state). Therefore, there was a high risk in the accumulations of Cu and Zn in the protected cultivated soil in the practice, where the trends were ever increasing year by year. Consequently, it is necessary to take reasonable and safe measures (including restoration technology and selection of agricultural materials), further to ensure the healthy and sustainable development of protected cultivated agriculture.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Soils
Controlled terms:Agricultural robots - Cultivation - Forecasting - Heavy metals - Risk assessment - Sustainable development - Trace elements
Uncontrolled terms:Accumulation characteristics - Agricultural system - Available trace elements - Cultivated soils - Positive correlations - Risk characteristics - Risk predictions - Soil environment
Classification code:483.1  Soils and Soil Mechanics - 531  Metallurgy and Metallography - 821.3  Agricultural Methods - 914.1  Accidents and Accident Prevention
Numerical data indexing:Age 1.93e+01yr, Age 9.19e+01yr, Percentage 1.60e+01%, Percentage 1.69e+01%, Percentage 3.20e+01%, Percentage 3.33e+01%, Percentage 4.58e+00%, Percentage 6.25e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.021

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 3>

Accession number:20213610853451
Title:Effects of local compression on the mechanical damage of tomato with different maturity
Title of translation:&#23616;&#37096;&#25353;&#21387;&#23545;&#19981;&#21516;&#25104;&#29087;&#24230;&#30058;&#33540;&#26426;&#26800;&#25439;&#20260;&#30340;&#24433;&#21709;
Authors:Zhang, Yongnian (1); Zhang, Renfei (1); Sun, Ye (1); Zheng, Enlai (1); Sun, Guoxiang (1); Wang, Xiaochan (1)
Author affiliation:(1) College of Engineering, Nanjing Agricultural University, Nanjing; 210031, China
Corresponding author:Wang, Xiaochan(wangxiaochan@njau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:292-298
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Tomato is the most consumed vegetable in the world. The annual yield of tomato products has been over 50 million tons in China in recent years. Mechanical damage easily occurs on tomato during automatic picking, which affects the quality and edibility of tomato. Many tomatoes with little damage were discarded during harvest, which resulted in serious losses in the picking-selling system. Therefore, it is necessary to establish an evaluation model of tomato mechanical damage, while the effect of pressing pressure on mechanical damage of tomato should be explored to reduce the losses during harvest. Therefore, this study aims to explore the effect of local compression on mechanical damage of tomatoes at three maturity stages (Breakers, Turning and Pink). Three points of the tomato top were pressed by a hardness tester, where all tomatoes were placed under ambient temperature and pressure for 30 days. The damage phenomenon was observed, and the number was recorded on the first day. An electronic scanning microscope was then used to characterize the microstructure change of pressed points on the tomato. Four levels of mechanical damage were studied, including decay, rind wrinkle, indentation occurred, and no indentation. The evaluation indicators were also set as the day that the damage phenomenon was observed. A compression test was performed to clarify the influence of local pressure on the mechanical damage of each level. The area of pressure distribution was obtained at each damage level of tomato with each maturity, thereby establishing the local mechanical damage and classification model of tomato. Finally, a grabbing test was carried out in an articulated three-finger electric manipulator. The number of tomatoes was counted, whose damage level was consistent with that in the local mechanical damage assessment and classification model in the test. The results showed that there was a very high coincidence degree between the test data and the damage assessment and classification model, not less than 95 %. Experimental results indicated that: 1) The mechanical damage of tomato increased, as the compression pressure and maturity raised. 2) The days of observable damage decreased with the increase of maturity. There was little correlation between the days when tomatoes decayed with the compression pressure. The days when tomato rind wrinkled decreased with the increase of compression pressure. 3) A median level was used to represent the compression pressure. In the first level mechanical damage, the represented compression pressure from low to high was 366, 355, and 337 kPa, according to maturity, about 30% higher than that of the second level mechanical damage in a sequence of 265, 245, and 225 kPa. In the third level mechanical damage, the represented compression pressure was ranked in descending order of 165, 115, and 90 kPa according to maturity. Tomato decay occurred in the range of 3-7 days, about 50% ahead compared with the wrinkled days of the tomato rind in the range of 7-17 days. Consequently, the findings can provide a sound reference for the design of a multi-finger harvesting manipulator in modern tomato production.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Damage detection
Controlled terms:Compression testing - Fruits - Harvesting - Indentation - Manipulators
Uncontrolled terms:Classification models - Compression pressures - Electronic scanning - Evaluation indicators - Evaluation modeling - Mechanical damages - Microstructure changes - Temperature and pressures
Classification code:821.3  Agricultural Methods - 821.4  Agricultural Products
Numerical data indexing:Age 1.92e-02yr to 4.66e-02yr, Age 8.22e-02yr, Age 8.22e-03yr to 1.92e-02yr, Percentage 3.00e+01%, Percentage 5.00e+01%, Percentage 9.50e+01%, Pressure 2.25e+05Pa, Pressure 3.37e+05Pa, Pressure 9.00e+04Pa
DOI:10.11975/j.issn.1002-6819.2021.11.033

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 4>

Accession number:20213610853491
Title:Decomposition and nutrient release characteristics of co-incorporated wheat straw and common vetch in Qinghai-Tibetan Plateau
Title of translation:&#38738;&#34255;&#39640;&#21407;&#23567;&#40614;&#31224;&#31174;&#21644;&#31661;&#31560;&#35916;&#35910;&#28151;&#21512;&#33104;&#35299;&#35268;&#24459;&#21644;&#20859;&#20998;&#37322;&#25918;&#29305;&#24449;
Authors:Li, Zhengpeng (1); Song, Mingdan (1, 2); Li, Fei (1); Zhan, Shuting (1); Han, Mei (1)
Author affiliation:(1) Academy of Agriculture and Forestry Sciences, Qinghai University, Xining; 810016, China; (2) Xi'ning Observation and Experiment Station of National Agricultural Environment, Xining; 810016, China
Corresponding author:Song, Mingdan(hi0045@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:104-111
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">A mixture of wheat straw and common vetch is widely used for synthetic fertilizers returning to the cropland of the Eastern Qinghai-Tibetan Plateau in China. Their decomposition and nutrient release characteristics are essential to improve soil fertility, while reducing chemical fertilizer application. In this study, a field experiment was performed on the wheat straw (S), common vetch (J) and mixtures in soil by litter bags. Four treatments were set as the wheat straw (S), common vetch (J), the mixture of low ratio of S to J (S<inf>H1</inf>J), and the mixture of high ratio of S to J (S<inf>H2</inf>J). The results showed that the decomposition rates were relatively fast at the beginning, and then slowed down gradually. The 0-33 d after incorporation into the soil was the rapid decay stage with the highest decay rate for J (83.8-208.5 mg/d), whereas, the 34-97 d was the slow decay stage with the highest decay rate for S, while the 97-333 d was the steady decay stage with no significant differences for the decay rate among treatments. At the end of decomposition, the decomposition rates of S, J, S<inf>H1</inf>J, and S<inf>H2</inf>J were 51.5%, 82.2%, 78.6%, and 75.2%, respectively, indicating that the wheat straw decayed the slowest, while the common vetch decayed the fastest, and the mixtures fell in between. Nitrogen (N) release in the 0-33 d accounted for 70%-83% in the whole decay stages, indicating that N in organic materials released mainly in the first month. At the end of decomposition, the cumulative N release ratios of S, J, S<inf>H1</inf>J, and S<inf>H2</inf>J were 21.3%, 81.5%, 79.3%, and 79.0%, respectively. Phosphorus (P) release of common vetch in the 0-33 d and wheat straw in the 0-97 d accounted for 90% and 88% of the total P release, indicating that P in J and S released mainly during 0-33 d and 0-97 d, respectively. At the end of decomposition, the cumulative P release ratios of S, J, S<inf>H1</inf>J and S<inf>H2</inf>J were 60.1%, 76.2%, 74.2%, and 82.2%, respectively. As such, the potassium release ratio in the 0-33 d was accounted for more than 95% of the total release ratio. A bi-pool exponential decay model was selected to characterize the decomposition of dry matter, where the N and P had a determination coefficient of above 0.93. The mixture of wheat straw and common vetch increased the labile fraction of N pools, to significantly prolong the average turnover time of labile N. Specifically, the labile fraction of N pool and average turnover time of S were 19.4% and 23 d, while those of CV were 78.8% and 18 d, respectively. The mixture of S and J improved the labile fraction of N pools (14% by S<inf>H1</inf>J and 25% by S<inf>H2</inf>J), but prolonged the turnover time (5 d by S<inf>H1</inf>J and 6 d by S<inf>H2</inf>J). The mixture of high ratio of S to J also significantly improved the labile fraction of the P pool, 21% higher than the predicted values. Additionally, the K released quickly for both wheat straw and common vetch. The 0-33 d after incorporation into the soil was the rapid decay and nutrient release stage, where the wheat straw decayed and released nutrients the slowest. The mixtures significantly enhanced the labile fraction of N and P pool, thereby prolonging the average turnover time of N, particularly beneficial to nutrient uptake by succession crops. Consequently, the finding can provide promising theoretical and technical support for crop residue incorporation in the cropland of the Eastern Qinghai-Tibetan Plateau in China.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Decay (organic)
Controlled terms:Crops - Fertilizers - Lakes - Mixtures - Nutrients - Soils - Straw
Uncontrolled terms:Chemical fertilizers - Decomposition rate - Determination coefficients - Exponential decay models - Organic materials - Qinghai-Tibetan plateau - Synthetic fertilizers - Technical support
Classification code:483.1  Soils and Soil Mechanics - 801.2  Biochemistry - 804  Chemical Products Generally - 821.4  Agricultural Products - 821.5  Agricultural Wastes
Numerical data indexing:Percentage 1.40e+01%, Percentage 1.94e+01%, Percentage 2.10e+01%, Percentage 2.13e+01%, Percentage 2.50e+01%, Percentage 5.15e+01%, Percentage 6.01e+01%, Percentage 7.00e+01% to 8.30e+01%, Percentage 7.42e+01%, Percentage 7.52e+01%, Percentage 7.62e+01%, Percentage 7.86e+01%, Percentage 7.88e+01%, Percentage 7.90e+01%, Percentage 7.93e+01%, Percentage 8.15e+01%, Percentage 8.22e+01%, Percentage 8.80e+01%, Percentage 9.00e+01%, Percentage 9.50e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.012

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 5>

Accession number:20213610853567
Title:Non-destructive detection of moisture content of leafy vegetables based on microwave free space traveling-standing wave method
Title of translation:&#22522;&#20110;&#24494;&#27874;&#31354;&#38388;&#39547;&#27874;&#27861;&#30340;&#21494;&#31867;&#34092;&#33756;&#21547;&#27700;&#29575;&#26080;&#25439;&#26816;&#27979;
Authors:Li, Chenxiao (1); Yu, Xiaoting (1); Zhao, Chenyu (1); Ren, Yuan (1); Xu, Yanlei (1)
Author affiliation:(1) College of Information and Technology, Jilin Agricultural University, Changchun; 130118, China
Corresponding author:Xu, Yanlei(yanleixu@jlau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:307-314
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Vegetables are one of the most essential food products for body health in daily life. Edible parts are normally reserved in roots, stems, and leaves of plants, particularly containing 70%-98% of water, rich chlorophyll, vitamins, and minerals. Vegetable freshness has also been one of the key factors affecting food quality. The storage time, moisture, chlorophyll, and carotene content usually determine the vegetable freshness. A chemical or spectral analysis can be used to measure the chlorophyll and carotene content, but the time-consuming and laborious procedure cannot achieve rapid and real-time detection in intelligent agriculture. Additionally, the storage time depended mainly on the storage environment. In this study, non-destructive detection of freshness was investigated to predict the moisture content of the vegetable using free space traveling-standing wave attenuation. The microwave method was characterized by fast, non-destructive, and high precision, suitable for the detection of moisture content in many fields, compared with the traditional drying, azeotropic distillation, capacitance, resistance, and infrared methods. Nevertheless, some specific measuring errors were found in the detection of vegetable moisture content. The reason was that the microwave was easy to penetrate the sample, and produce multiple reflections because the leaves of the vegetable were thin. Therefore, free space travelling-standing wave was selected to predict the freshness of the vegetable. The changes of moisture content were explored in vegetable leaves during storage, using the traveling-standing wave formed by multiple reflections in the system. The network structure was relatively simple without the need for complex equipment, such as a vector network analyzer. The system was composed of a microwave oscillator, a microwave transmitting antenna, a receiving horn antenna, a detector, a sample container, a slide rail, and a controller. The X-band of the microwave was selected, because of the strong dipole moment of water molecules at microwave frequency. Particularly, the electric energy was strongly absorbed by water, and then the polarization reaction occurred inside the material, when the external electric field was applied to the water-containing material. By contrast, the microwave frequency in the X-band was facilitated more sensitive to the change of moisture content, where the dielectric constant and dielectric loss factor changed obviously. A voltage conversion circuit was designed to convert the microwave into voltage signals. STM32F103ZET6 micro control unit was used as the controller. An internal program was designed to realize microwave data acquisition, system control, data processing, and display output. Fresh and intact Chinese cabbage and lettuce without mechanical damages in the greenhouse were taken as the research objects. 226 groups of experimental data were collected, where 50 groups were used as the modeling dataset, and the remaining 176 groups were the verification dataset. Linear regression was used to establish the prediction models of moisture content in vegetables. The prediction model was then written into the measurement system to realize the subsequent prediction of water content in vegetables. The measurement results showed that the goodness-of-fit values of prediction equations were 0.992 0 and 0.991 9, while the Root Mean Square Error(RMSE) errors were 1.188% and 0.803%, and the performance standard errors were 1.071% and 1.179%, for the water content of cabbage and lettuce, respectively, compared with the standard direct drying released in GB 5009.3-2016. Consequently, a rapid, non-destructive, and high-precision detection of vegetable moisture content was realized without multiple reflections in the process of microwave measurement. The simple device with excellent practicability can also be expected to serve food processing and storage in modern agricultural production.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Microwave oscillators
Controlled terms:Agricultural robots - Agriculture - Capacitance - Chemical detection - Chlorophyll - Controllers - Data acquisition - Dielectric losses - Digital storage - Distillation  - Driers (materials) - Elastic waves - Electric fields - Electric network analyzers - Errors - Food products - Food storage - Forecasting - Horn antennas - Infrared drying  - Mean square error - Microwave antennas - Microwave frequencies - Moisture - Moisture determination - Molecules - Plants (botany) - Predictive analytics - Spectrum analysis - Vegetables  - Voltage measurement
Uncontrolled terms:Agricultural productions - Azeotropic distillation - Dielectric loss factors - External electric field - High precision detections - Nondestructive detection - Root mean square errors - Vector network analyzers
Classification code:701.1  Electricity: Basic Concepts and Phenomena - 708.1  Dielectric Materials - 713.2  Oscillators - 722.1  Data Storage, Equipment and Techniques - 723.2  Data Processing and Image Processing - 732.1  Control Equipment - 801  Chemistry - 802.3  Chemical Operations - 803  Chemical Agents and Basic Industrial Chemicals - 804.1  Organic Compounds - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4  Agricultural Products - 822.1  Food Products Plants and Equipment - 822.3  Food Products - 922.2  Mathematical Statistics - 931.1  Mechanics - 931.3  Atomic and Molecular Physics - 942.2  Electric Variables Measurements - 944.2  Moisture Measurements
Numerical data indexing:Percentage 1.07e+00%, Percentage 1.18e+00%, Percentage 1.19e+00%, Percentage 7.00e+01% to 9.80e+01%, Percentage 8.03e-01%
DOI:10.11975/j.issn.1002-6819.2021.11.035

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 6>

Accession number:20213610853532
Title:Heat collection performance of different modes of fan-coil units-heat pump combined heat collection system
Title of translation:&#34920;&#20919;&#22120;-&#28909;&#27893;&#32852;&#21512;&#38598;&#28909;&#31995;&#32479;&#19981;&#21516;&#36816;&#34892;&#27169;&#24335;&#30340;&#38598;&#28909;&#24615;&#33021;
Authors:Song, Weitang (1, 2); Geng, Ruo (1); Wang, Jianyu (1); Liu, Pingjian (3); Chen, Xianzhi (4); Wang, Pingzhi (1, 2)
Author affiliation:(1) College of Water Resources and Civil Engineering, China Agricultural University, Beijing; 100083, China; (2) Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture and Rural Affairs, Beijing; 100083, China; (3) Caoxian Baicaozhuangyuan Agricultural Development Company Limited, Heze; 274400, China; (4) Wenzhou Vocation College of Science & Technology, Wenzhou; 325006, China
Corresponding author:Wang, Pingzhi(wpz@cau.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:230-238
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Solar greenhouses with various types of walls gradually appear to replace the traditional ones that occupied large areas with high construction costs in various regions of China. In this case, the back wall has no function of heat storage, but only the function of heat preservation. Therefore, this new type of back wall greenhouse needs auxiliary heating measures to increase the night temperature. Among them, the air temperature in the greenhouse is relatively high during the day, while containing abundant heat energy of air for the night warming. A thermal collecting and releasing developed with fan-coil units and heat storage pool for heat collection (TSFU) was employed to avoid high cost and air pollution in conventional heating. However, the efficiency and capacity of heat collection decreased in this system, with the decrease of difference between the heat storage pool and indoor air temperature. It is difficult to ensure an appropriate temperature for a solar greenhouse in a frigid region, or when it encountered weather conditions with weak solar radiation. An energy-saving and high-efficiency energy lifting device, namely a heat pump, was utilized to collect low-level heat energy from water for high-level heat energy. Therefore, the heat pump has widely been applied to improve the potential of heat collection and release devices in a greenhouse. In this study, a combined heat collection system with fan-coil units and a heat pump (FUHPS) was designed to improve the heat collection performance of TSFU. The system included fan-coil units, heat collection pool, heat storage pool, water and heat pump. The heat pump unit was used to transfer the heat from the heat collection pool to the heat storage pool at any time, particularly to reduce the circulating water temperature for high efficiency of heat collection. The FUHPS was divided into three modes of heat collection: fan-coil units heat collection mode (fan mode); fan-coil units + heat pump mixed heat collection mode (mixed mode); combined heat collection mode of fan-coil units + heat pump (combined mode). On sunny days in the test, the coefficient of performance (COP) of heat collection in fan mode was the highest of 6.0&plusmn;0.7, while the amount of heat collected in the combined mode was the highest of (763.9&plusmn;17.1) MJ, while the COP and amount of heat collected in the mixed mode were in the middle. On cloudy days, the heat collection COP of the mixed mode was the highest of 4.8&plusmn;0.3, and the amount of heat collected in the combined mode was the highest of (519.7&plusmn;30.5)MJ. The best mode of heat collection under different weather conditions was determined, where the assigning indexes to each heat collection mode were adopted: the mixed mode was the best on sunny days; whereas, the combined mode was the best on cloudy days. The system presented significant energy saving and emission reduction benefits. On sunny days, it was assumed that the system needed to collect 400 MJ of heat in three modes, and the amount of CO<inf>2</inf> released by coal-fired hot water heating mode was 93.4%, 88.0%, and 84.7% higher than that of the fan, mixed and combined mode, respectively. In addition, the system was also expected to achieve real zero emission of greenhouse gases, particularly with the gradual popularization and application of clean energy power generation, indicating outstanding environmental benefits. Moreover, the system was a mature industrial product to collect the heat energy in indoor air for a broad application prospect in various gardening and breeding facilities.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Solar energy
Controlled terms:Air pollution - Atmospheric temperature - Coefficient of performance - Emission control - Energy conservation - Greenhouse gases - Greenhouses - Heat pump systems - Heat storage - Lakes  - Meteorology - Pumps - Solar heating - Thermal pollution
Uncontrolled terms:Circulating waters - Coefficient of performances (COP) - Construction costs - Conventional heating - Energy saving and emission reductions - Environmental benefits - Indoor air temperature - Industrial product
Classification code:443.1  Atmospheric Properties - 451  Air Pollution - 525.2  Energy Conservation - 616.1  Heat Exchange Equipment and Components - 618.2  Pumps - 657.1  Solar Energy and Phenomena - 821.6  Farm Buildings and Other Structures
Numerical data indexing:Energy 4.00e+08J, Percentage 8.47e+01%, Percentage 8.80e+01%, Percentage 9.34e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.026

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 7>

Accession number:20213610853511
Title:Identification of drought stress state of tomato seedling using kinetic parameters of chlorophyll fluorescence
Title of translation:&#21033;&#29992;&#21494;&#32511;&#32032;&#33639;&#20809;&#21160;&#21147;&#23398;&#21442;&#25968;&#35782;&#21035;&#33495;&#26399;&#30058;&#33540;&#24178;&#26097;&#32961;&#36843;&#29366;&#24577;
Authors:Long, Yan (1, 2, 3); Ma, Minjuan (1, 2, 3); Wang, Yingyun (1, 2, 3); Song, Huaibo (1, 2, 3)
Author affiliation:(1) College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; 712100, China; (2) Key Laboratory of Agricultural Internet of Things, Ministry of Agriculture and Rural Affairs, Yangling; 712100, China; (3) Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service, Yangling; 712100, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:172-179
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Water is highly critical to the growth of crops. Water deficit can cause to be lower than normal levels for the water potential and turgor pressure in the crops. The normal metabolic functions can be destroyed in this case, even to seriously threaten the growth and development of crops. Therefore, it is very necessary to timely identify crop drought stress for the better growth of plants, rational irrigation, and yield. Alternatively, chlorophyll fluorescence imaging technology has widely been used to represent the crop photosynthesis data, such as the absorption and transformation of light energy by leaves, the energy transmission and distribution, and the state of the reaction center. Furthermore, various stress states of plants can be early monitored before the symptoms are visible to the naked eyes. Many efforts have been made to identify crop abiotic stress using the chlorophyll fluorescence technology. However, there are still the following challenges: 1) Most studies focused only on the minimum fluorescence and the maximum light quantum efficiency after dark adaptation, but failed to use all chlorophyll fluorescence parameters; 2) Fluorescence parameters were collected at only a few points to assume as the image dataset of one leaf, much less to the entire plant. Therefore, this research aims to systematically identify tomato seedling under different drought levels using chlorophyll fluorescence imaging and machine learning. Firstly, four levels of drought stress were set in the soil moisture content, including the suitable water, mild, moderate, and severe drought. Secondly, the chlorophyll fluorescence imaging system was used to collect the dataset of plant canopy under various drought stress levels. The image pixels were averaged as the chlorophyll fluorescence parameter value of the plant. Successive Projections Algorithm (SPA), Iterative Retained Information Variable (IRIV), and Variable Iterative Space Shrinkage Approach (VISSA) were then used to extract the chlorophyll fluorescence parameters highly related to drought stress. Five common parameters were achieved to analyze the correlation with the drought stress, including the actual light quantum efficiency at L2 time, and the non-actinic fluorescence quenching at L3 time during the light adaptation, the light adaptation-photochemical quenching at L2 time, steady-state light adaptation-photochemical quenching, and the light adaptation-photochemical quenching at D3 time during the dark relaxation in the "Lake" model. Finally, a recognition model of drought stress state was established using Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), and k-Nearest Neighbor (KNN). Subsequently, a confusion matrix was also constructed to determine the accuracy of the model for different drought states. The results showed that the LDA recognition model of drought stress presented the highest average recognition accuracy, followed by SVM, and KNN. The modeling accuracy of the selected parameters of SPA, IRIV, and VISSA was equal to or slightly higher than that of the full-parameter modeling. It showed that the selected parameters contain most of the photosynthesis information of plants under drought stress and proves the effectiveness of the fluorescence parameters extracted by the three parameter optimization algorithms. In the LDA drought identification model, the accuracy of IRIV-LDA for identifying suitable moisture, mild drought, moderate drought and severe drought was improved by 6%, 4%, 2% and 2% respectively compared with full parameter-LDA, and the accuracy reached 100%, 95%, 98% and 98% respectively. Consequently, the kinetic parameters of chlorophyll fluorescence can be used to accurately detect the drought stress state of tomato seedlings. This finding can provide a new insight for early monitoring of drought stress and determination of damage levels in tomato seedlings and similar crops.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:29
Main heading:Fluorescence imaging
Controlled terms:Chlorophyll - Crops - Discriminant analysis - Drought - Forestry - Fruits - Imaging techniques - Iterative methods - Kinetic parameters - Light  - Metadata - Nearest neighbor search - Parameter estimation - Photons - Photosynthesis - Plants (botany) - Quantum efficiency - Quenching - Soil moisture - Support vector machines
Uncontrolled terms:Chlorophyll fluorescence - Chlorophyll fluorescence imaging - Chlorophyll fluorescence parameters - Fluorescence parameters - K nearest neighbor (KNN) - Linear discriminant analysis - Photochemical quenching - Successive projections algorithms (SPA)
Classification code:444  Water Resources - 483.1  Soils and Soil Mechanics - 537.1  Heat Treatment Processes - 723  Computer Software, Data Handling and Applications - 741.1  Light/Optics - 746  Imaging Techniques - 804.1  Organic Compounds - 821.4  Agricultural Products - 921.5  Optimization Techniques - 921.6  Numerical Methods - 922  Statistical Methods - 931  Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Percentage 1.00e+02%, Percentage 2.00e+00%, Percentage 4.00e+00%, Percentage 6.00e+00%, Percentage 9.50e+01%, Percentage 9.80e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.019

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 8>

Accession number:20213610853553
Title:Classifying irrigation water use efficiency in Hetao Irrigation District using SPA-VFS coupling model
Title of translation:&#22522;&#20110;SPA-VFS&#32806;&#21512;&#27169;&#22411;&#30340;&#27827;&#22871;&#28748;&#21306;&#28748;&#28297;&#29992;&#27700;&#25928;&#29575;&#20998;&#32423;
Authors:Huang, Yongjiang (1); Qu, Zhongyi (1)
Author affiliation:(1) Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot; 010018, China
Corresponding author:Qu, Zhongyi(quzy_imau@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:85-92
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Water Use Efficiency (WUE) can serve as an integrated functional indicator to guide the modernization construction of irrigation districts. Therefore, an accurate WUE classification can make a great contribution to the targeted improvement measures, particularly to the main controlling factors. Set Pair Analysis theory (SPA) and Variable Fuzzy Set theory (VFS) are widely used in water resources carrying capacity assessment, water quality assessment and environmental assessment. However, the classification and evaluation of water use efficiency in large-scale irrigation districts have the characteristics of many influencing factors and dynamic change of evaluation index classification standards. Both Set Pair Analysis theory and Variable Fuzzy Set theory have certain shortcomings in their applications. The SPA-VFS coupling model can realize the complementary advantages of variable fuzzy theory and set pair analysis, and make up for the shortcomings of the above two evaluations. Taking the Hetao Irrigation District as the research area, a WUE evaluation index system was constructed here from the aspects of water use level, engineering condition, agronomic measures, management level, planting structure, and ecological environment. The water efficiency of the irrigation system was divided into five grades: high, higher, medium, lower, and low, according to the current planning, standards, and the development status in large-scale irrigation areas in China. The graded standard of each index was determined according to the evaluation grade. An improved entropy method was used to assess the weight of each index. A SPA-VFS coupling model was selected for the WUE classification evaluation in the study area. Results showed that the WUE level was &#8546; in the study area using the SPA-VFS coupling model, in good consistent with the VFS and SPA model. The SPA-VFS coupling model was verified to be feasible for the grade in the irrigation area. The stability range of the level eigenvalue was 3.12-3.17 in the SPA-VFS coupling model, whereas, that was 3.00-3.33 in the VFS model under different parameter combinations, indicating a significantly lower stability range of the level eigenvalue in the SPA-VFS coupling model than that in the VFS model. It inferred that the SPA-VFS coupling model was more suitable for accurate grade evaluation of large-scale irrigation areas. Consequently, a strong recommendation was made to subsequently strengthen the daily management of the supporting projects in the canal system and the drainage ditch in the Hetao Irrigation District. It was also highly demanding to timely repair, transform, and update the supporting projects beyond the normal operation. An autumn irrigation system was necessary to deepen the reform, in order to reduce appropriately the autumn irrigation water quota, and then the water consumption for irrigation per unit area. Many efforts, whether engineering, chemical, or biological measures, can be made to enhance the soil quality of saline-alkali land according to the degree of saline-alkali, and to reduce the share of salinization regions for a better ecological environment of irrigated areas. An emphasis should be laid on the lining of field channels, the promotion of efficient water-saving, the transformation of field water saving, and the information construction of irrigation areas.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Quality control
Controlled terms:Chemical analysis - Ecology - Efficiency - Eigenvalues and eigenfunctions - Fuzzy set theory - Fuzzy sets - Irrigation - Irrigation canals - Soils - Water conservation  - Water quality - Water resources - Water supply
Uncontrolled terms:Classification and evaluations - Hetao irrigation districts - Irrigation water use efficiency - Modernization construction - Set pair analysis (SPA) theory - Set-pair analysis theories - Variable fuzzy set theories - Water resources carrying capacities
Classification code:444  Water Resources - 445.2  Water Analysis - 446.1  Water Supply Systems - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 821.3  Agricultural Methods - 913.1  Production Engineering - 913.3  Quality Assurance and Control - 921.4  Combinatorial Mathematics, Includes Graph Theory, Set Theory
DOI:10.11975/j.issn.1002-6819.2021.11.010

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 9>

Accession number:20213610853583
Title:Test and analysis of vibration characteristics of transplanting machine based on time frequency and power spectral density
Title of translation:&#22522;&#20110;&#26102;&#39057;&#21644;&#21151;&#29575;&#35889;&#23494;&#24230;&#30340;&#31227;&#26685;&#26426;&#25391;&#21160;&#29305;&#24615;&#27979;&#35797;&#19982;&#20998;&#26512;
Authors:Geng, Lingxin (1); Li, Kang (1); Pang, Jing (1); Jin, Xin (1); Ji, Jiangtao (1)
Author affiliation:(1) College of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang; 471003, China
Corresponding author:Pang, Jing(pangjing@haust.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:23-30
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">A large-amplitude vibration commonly occurs in most agricultural machinery at present in China. The resulting high failure rate and low reliability have posed great damage to the structural safety and driver comfort of the machine. Many efforts have been made on the vibration modes and testing in agricultural harvesting machines. But only a few focused on the vibration of planters, especially a high-speed transplanting machine. Most previous tests show that the variable speed rotation or swing of the mechanism can significantly cause the impact vibration and inertia force of components, particularly with the increase of picking speed. As such, there is a huge decline in the success rate of picking seedlings, while leading to a high missing rate of seedlings, due mainly to the operational instability and high errors. However, no good solutions were reported to deal with that so far. In this study, taking a top clamp-type pneumatic transplanter (2ZZT-2) of vegetable as the research object, the vibration characteristics of a transplanter was investigated using the time-frequency analysis. A dynamic signal instrument (DH5902) and 3-way acceleration sensor (356A16 type) were first used for the data acquisition. A time-frequency analysis was performed on the MATLAB software, where the power spectral density was adopted to analyze the vibration data. The distribution characteristics of signal energy were obtained on the time- and frequency-axis. Secondly, the local resonance was also verified for the test components. The hammering and multi-point excitation were utilized to determine the response of hammering excitation and vibration data in the measuring points of components. Correspondingly, a specific relationship was obtained between the frequency of each measuring point and the first five natural frequencies. The experimental results showed that the main sources of vibration in the transplanter were derived from the swing of the mechanical arm and the transverse movement of the seedling plate. The secondary sources of vibration were the opening and closing of the seedling picking manipulator, and the stretching of the top seedling mechanism in the whole machine. The energy intensity of vibration was distributed mainly at the low frequency (0-10 Hz) during the transplanting operation. The amplitude was 5.43 m/s², when the seedling manipulator swung, and 1.71 m/s² when the whole machine working, indicating the amplitude decreased by 68.51% than before. In addition, the vibration frequency (6.10 Hz) caused by the swinging of the seedling taking manipulator was close to the fifth natural frequency (6.25 Hz) at the measuring point, when the transplanter was working normally, indicating the resonance occurred. The finding can provide a sound reference to improve the vibration performance for the high reliability of a transplanter.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Vibration analysis
Controlled terms:Agricultural machinery - Agricultural robots - Agriculture - Data acquisition - Failure analysis - Manipulators - MATLAB - Natural frequencies - Power spectral density - Spectral density
Uncontrolled terms:Agricultural harvesting - Distribution characteristics - Large amplitude vibrations - Multi-point excitation - Time and frequencies - Time frequency analysis - Transplanting machine - Vibration characteristics
Classification code:723.2  Data Processing and Image Processing - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1  Agricultural Machinery and Equipment - 921  Mathematics
Numerical data indexing:Acceleration 1.71e+00m/s2, Acceleration 5.43e+00m/s2, Frequency 0.00e+00Hz to 1.00e+01Hz, Frequency 6.10e+00Hz, Frequency 6.25e+00Hz, Percentage 6.85e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.003

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 10>

Accession number:20213610853507
Title:Sweetener classification model based on deep learning
Title of translation:&#22522;&#20110;&#28145;&#24230;&#23398;&#20064;&#30340;&#29980;&#21619;&#21058;&#20998;&#31867;&#27169;&#22411;
Authors:Xiao, Lingjun (1); Chen, Aibin (1); Zhou, Guoxiong (1); Yi, Jizheng (1, 2)
Author affiliation:(1) College of Computer & Information Engineering, Central South University of Forestry and Technology, Changsha; 410004, China; (2) Institute of Artificial Intelligence Applications, Central South University of Forestry and Technology, Changsha; 410004, China
Corresponding author:Chen, Aibin(hotaibin@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:285-291
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Sugars are one of the reasons we feel better when eating. But eating too much high-sugar food can threaten body's health. Therefore, a heat issue is to create novel and safe non-nutritive sweeteners in recent years. However, the development and identification of sweeteners can also be a resource-consuming and long-term process. In this study, a feasible classification system of sweeteners was proposed using ligand and deep learning, in order to accurately sift sweetener candidates from numerous molecular libraries. Firstly, the SMILES strings in the database were imported after the dataset was extended, and then converted into two-dimensional graphics and extended-connectivity fingerprints (ECFP). A series of operations was selected to preprocess the generated two-dimensional images, including random brightness transformation, rotation, and flipping. Secondly, a deep learning model DenseNet was established for the molecular classification. The batch size of the training model was set to 64, and the initial learning rate was 0.005. A batch normalization (BN) was used in every layer of linear convolution to prevent overfitting and gradient extinction. A vector constantly attenuation function was also used for the learning rate, with the attenuation factor of 0.1 at every seven epochs. Thirdly, the attention mechanism was added to the back of each Dense Block module in the DenseNet, where a new layer was formed with the transition layer. After that, the generated ECFP matrix was fused with the extracted matrix. The classification task was finally completed to add two full-junction layers with different numbers of neurons and a Softmax classification layer. Two-dimensional data was the most suitable choice for rapidly sifting in the case of large datasets. Since some specific three-dimensional structures and theoretical difficulties were usually found in the sensory intensity of sweet taste in reality, it was necessary to use the feature fusion for better prediction performance. Finally, an independent test was conducted to verify the proposed model. The experimental results showed that the attention mechanism and feature fusion greatly improved the performance of the model. The model was obviously superior to most machine learning in all indicators, particularly for the tasks with big datasets. The highest accuracy rate was 0.934 (steady at around 0.934), while the fluctuation of loss value and accuracy was less than 0.001 and 0.005, respectively. The average accuracies of bitter, tasteless, weak sweet, and strong sweet classification were 0.96, 0.94, 0.91 and 0.92, respectively. In addition, cosine annealing was selected to adjust the learning rate for better performance of the model. As such, the learning rate was "jump out" of local optimum, and then found the direction of global optimum, because of the sudden increase of learning rate. A local optimal value was avoided because the learning rate generally remained to get smaller when the model was trained. The experiments showed that there was improved efficiency, indicating that the model was suitable for the sweet and bitter tastes. The finding can contribute to the high accuracy of sweetener prediction and the rapid development of low-calorie, even no-calorie sweeteners.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Deep learning
Controlled terms:Classification (of information) - Food additives - Large dataset - Learning systems - Matrix algebra
Uncontrolled terms:Attenuation function - Classification models - Classification system - Classification tasks - Molecular classification - Prediction performance - Three-dimensional structure - Two dimensional images
Classification code:716.1  Information Theory and Signal Processing - 803  Chemical Agents and Basic Industrial Chemicals - 921.1  Algebra
DOI:10.11975/j.issn.1002-6819.2021.11.032

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 11>

Accession number:20213610853446
Title:Potential of three long-term quantitative precipitation products of drought monitoring in Huaihe River Basin
Title of translation:&#19977;&#31181;&#38271;&#26399;&#23450;&#37327;&#38477;&#27700;&#20135;&#21697;&#22312;&#28142;&#27827;&#27969;&#22495;&#24178;&#26097;&#30417;&#27979;&#20013;&#30340;&#28508;&#21147;
Authors:Dong, Xiaohua (1, 2); Zhang, Qingyu (1, 2); Zhang, Te (3); Yu, Dan (1, 2); Liu, Ji (1, 2); Wei, Chong (1, 2)
Author affiliation:(1) College of Hydraulic and Environmental Engineering, Three Gorges University, Yichang; 443002, China; (2) Water Resources Security Protection Collaborative Innovation Center of Hubei Province, Wuhan; 430072, China; (3) College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; 712100, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:93-103
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Accurate and high-resolution precipitation data will help in obtaining an accurate monitoring of drought development spatially and temporally. In such an occasion, the quantitative precipitation products bear the potential advantages of monitoring droughts continuously over a wide-span space coverage, compared to traditional ground-based meteorological data. Three quantitative precipitation products were selected in this study to access their accuracies and drought monitoring potentials in Huaihe River Basin for their suitability in calculating the Standardized Precipitation Index (SPI). They are Multi-Source Weighted-Ensemble Precipitation (MSWEP), Climate Hazards Group Infrared Precipitation with Station (CHIRPS) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR).The precipitation data from 27 meteorological stations in Huaihe River Basin from 1983 to 2016 were collected to test the accuracy of monthly accumulative precipitation data of three quantitative precipitation products. The SPI was used as the drought indicator. The Correlation Coefficient (r), the Root Mean Square Error (RMSE), the Critical Success Index (CSI), and the drought level monitoring Accuracy (ACC) were used as evaluation indicators to evaluate the drought monitoring potential of the three quantitative precipitation products (MSWEP, CHIRPS and PERSIANN-CDR). The results showed that: 1) All three quantitative precipitation products underestimated the actual precipitation both in monthly-, seasonal-, and annual-scale; The accuracy of MSWEP outperformed the other two products, in the sense that, the r values of MSWEP reached 0.92-0.97 and the RMSE values were 26.38-124.73 mm; The accuracies of CHIRPS with resolution of 0.05&deg;&times;0.05&deg; was similar to that of the resolution of 0.25&deg;&times;0.25&deg;; Also CHIRPS and PERSIANN-CDR had similar accuracy performances; 2) For the estimation of extreme shortage of precipitation, the MSWEP also bears the highest accuracy compared to the other two products, in the sense that the RMSE values are less than 50% than the other two products. In the month of extreme precipitation shortage, the three quantitative precipitation products generally overestimated the amount of precipitation compare to the observed precipitation values. 3) MSWEP's overall performance in drought monitoring was better than other products; the monthly SPI, seasonal SPI and annual SPI calculated by MSWEP had higher accuracies (r&ge;0.92, RMSE&le;0.39), higher accuracies in drought month identification (CSI&ge;0.89) and higher accuracies in drought level identification (ACC&ge;80.3%). In case of CHIPRS or PERSIANN-CDR, the CSIs and ACCs in the three time scales were high for the three time scales. It revealed that those two products could also be used for watershed drought monitoring. 4) MSWEP was much more accurate in monitoring different drought levels, especially for that of extreme drought level. It's ACC for determining various drought levels was higher than CHIRPS and PERSIANN-CDR; 5) All the three quantitative precipitation products showed excellent drought monitoring potential in the typical drought events in the Huaihe River Basin; MSWEP identified the spatio-temporal development process of typical drought events from February to June in 2000 more accurately; Compared with the typical drought events monitoring results based on precipitation data of meteorology stations processed by inverse distance weighting interpolation algorithm, the MSWEP's monitoring results were more consistent with the actual drought regime. In general, compared with CHIRPS and PERSIANN-CDR, MSWEP had higher accuracies and greater drought monitoring potential in the Huaihe River Basin. The comparison and evaluation results of the accuracy and drought monitoring potential of quantitative precipitation products presented here can provide a basis for the application of products' precipitation data for meteorological and agricultural drought monitoring.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:38
Main heading:Drought
Controlled terms:Agricultural robots - Chirp modulation - Clock and data recovery circuits (CDR circuits) - Mean square error - Monitoring - Neural networks - Rivers - Watersheds
Uncontrolled terms:Correlation coefficient - Interpolation algorithms - Inverse distance weighting - Precipitation estimation from remotely sensed information - Precipitation products - Root mean square errors - Spatio-temporal development process - Standardized precipitation index
Classification code:444  Water Resources - 444.1  Surface Water - 703.1  Electric Networks - 716  Telecommunication; Radar, Radio and Television - 922.2  Mathematical Statistics
Numerical data indexing:Percentage 5.00e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.011

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 12>

Accession number:20213610853564
Title:Domain partitioned of characteristic curve in a Francis turbine under multiple boundary conditions
Title of translation:&#28151;&#27969;&#24335;&#27700;&#36718;&#26426;&#29305;&#24615;&#26354;&#32447;&#22312;&#22810;&#37325;&#36793;&#30028;&#26465;&#20214;&#19979;&#30340;&#20998;&#21306;&#26041;&#27861;
Authors:Ma, Weichao (1); Yang, Jiebin (1); Zhao, Zhigao (1); Yang, Weijia (1); Yang, Jiandong (1)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan; 430072, China
Corresponding author:Yang, Jiandong(jdyang@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:31-39
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">A complete characteristic curve was fundamental to the simulation of the transition process in a Francis turbine. However, only a high-efficiency region is provided in the efficiency hill diagram and combined characteristic curve in the turbine. It is necessary to expand the characteristic curve of the Francis turbine, thereby improving the simulation precision of the hydraulic turbine model, or the dynamic test. The main expanding was the external and the internal characteristics at present. The external characteristics with over-reliance on experience were only used in the mathematical way to increase the experimental data of the turbine efficiency hill diagram, particularly combing the characteristic curve and runaway speed curve. The internal characteristics were adopted in a theoretical way to process according to the internal laws of the turbine, but suffered from the difficult calculation and inaccurate results at present. In this research, a novel domain partitioned expanding method was proposed for the characteristic curve in a Francis turbine under multiple boundary conditions. The specific procedure was that: feature points were first taken from the boundary conditions of zero speed, zero discharge, runaway speed curve, and zero GVO, as well as the intersection point of unit torque, in order to divide the characteristic curve region, while constraining the extension range of each partition. Then, the structure parameters of a turbine were identified to calculate the boundary conditions of characteristic curves, according to the simplified mathematical model of internal and external characteristic data. Various fitting methods were also proposed for the characteristic curves of each region, according to the features of different regions. Finally, the fitting data on both sides of the boundary were connected smoothly, in order to form a complete turbine characteristic curve for the simulation of the transition process. The method in this study (MIS) was applied in an example of a hydraulic turbine, compared with the typical external characteristic method (TECM) and typical internal characteristic method (TICM). The performances of MIS and TICM were compared using the velocity triangle. The results showed that the MIS was more consistent with the inner structure of the runner. The fitting accuracy of experimental data was improved significantly via effectively integrating TECM and TICM, particularly considering the boundary conditions. The hydraulic characteristics and evolution of the turbine were qualitatively represented in the low-speed area, where the unit discharge was relatively stable. The unit discharge of each guide vane opening (GVO) gradually approached, with the increase of the unit speed and then decreased sharply after the runaway operation. The sign of unit discharge was changed, after passing the zero-discharge boundary. The MIS in the transition was reduced with the relative error of the maximum volute pressure from 2.03% to 1.69%, and the relative error of volute pressure in the small GVO region from 3.48% to 1.47%. It infers that the time-domain response of the dynamic process was closer to the measured data. The absolute average error of MIS was 0.010 MPa, when simulating the volute pressure oscillation in the range of small GVO region. It was reduced by 0.013MPa, compared with the absolute average error of 0.023MPa of TECM, while the relative error was reduced from 3.48% to 1.47%. The simulation of transition showed the time-domain response of the dynamic process was closer to the measured data. Hence, the expanding characteristic curve contributed to the calculation accuracy of transition in the modeling of hydropower units. The finding can provide strong support to the design of similar vane-type agricultural machinery, the expanding of characteristic curves, and the promotion of digital hydropower construction.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Curve fitting
Controlled terms:Agricultural robots - Boundary conditions - Efficiency - Errors - Francis turbines - Hydraulic motors - Hydroelectric power - Hydroelectric power plants - Machine design - Speed  - Time domain analysis
Uncontrolled terms:Calculation accuracy - Characteristic curve - External characteristic - Hydraulic characteristic - Hydraulic turbine models - Internal characteristics - Multiple boundary condition - Simplified mathematical model
Classification code:601  Mechanical Design - 611.1  Hydroelectric Power Plants - 617.1  Hydraulic Turbines - 632.2  Hydraulic Equipment and Machinery - 913.1  Production Engineering - 921  Mathematics - 921.6  Numerical Methods
Numerical data indexing:Percentage 2.03e+00% to 1.69e+00%, Percentage 3.48e+00% to 1.47e+00%, Pressure 1.00e+04Pa, Pressure 1.30e+04Pa, Pressure 2.30e+04Pa
DOI:10.11975/j.issn.1002-6819.2021.11.004

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 13>

Accession number:20213610853431
Title:Temporal and spatial distribution characteristics of rice stalk resources and its potential of synthetic fertilizers substitution returning to farmland in China from 1988 to 2018
Title of translation:1988-2018&#24180;&#20013;&#22269;&#27700;&#31291;&#31224;&#31174;&#36164;&#28304;&#26102;&#31354;&#20998;&#24067;&#29305;&#24449;&#21450;&#36824;&#30000;&#26367;&#20195;&#21270;&#32933;&#28508;&#21147;
Authors:Liu, Shujun (1, 2); Li, Dongchu (1, 2); Huang, Jing (1, 2); Ma, Changbao (3); Wang, Huiying (3); Yu, Zikun (3); Qu, Xiaolin (3); Zhang, Lu (1, 2); Han, Tianfu (1); Du, Jiangxue (1); Liu, Kailou (4); Zhang, Huimin (1, 2)
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/National Engineering Laboratory for Improving Quality of Arable Land, Beijing; 100081, China; (2) Red Soil Experimental Station of CAAS in Hengyang/National Observation and Research Station of Farmland Ecosystem in Qiyang, Qiyang; 426182, China; (3) Center of Cultivated Land Quality Monitoring and Protection, Ministry of Agricultural and Rural Affairs, Beijing; 100125, China; (4) Jiangxi Institute of Red Soil, Nanchang; 330046, China
Corresponding author:Zhang, Huimin(zhanghuimin@caas.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:151-161
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Rice stalk resource in China is plentiful, but in different regions the rice stalk resources, the corresponding nutrient resources and synthetic fertilizers substitute potential through rice stalk incorporation as well as the changes over time have not been very clear. Based on the long-term monitoring data of rice from 1988 to 2018 of the Ministry of Agriculture and Rural Affairs in China's rice-growing areas, this study analyzed the amount of rice stalk and its nutrient resources and synthetic fertilizers substitute potential through rice stalk incorporation in different years in each region of China, aiming to provide basis for rational utilization of rice stalk resources. The results showed that the annual average amount of rice stalk resources and NPK resources reached 1.69&times;10⁸ t and 452.09&times;10⁴ t respectively during 2009-2018, which increased by 0.23&times;10⁸ t and 61.50&times;10⁴ t compared with 1988-1998, with the highest increase in North-East (NE). The annual average amount of rice stalk resources and NPK resources increased with planting years. In the first stage (1990s-2000s) and the second stage (2000s-2010s), the annual changing rate (ACR) of rice stalk resources were 18.11&times;10⁴ t/a and 211.47&times;10⁴ t/a, and the ACR of nutrient resources were 0.15&times;10⁴ t/a of N, 0.02&times;10⁴ t/a of P, 0.31&times;10⁴ t/a of K and 1.76&times;10⁴ t/a of N, 0.25&times;10⁴ t/a of P, 3.66&times;10⁴ t/a of K, respectively. There were more than 70% of rice stalk and its nutrient resources distributed in Yangtze River Delta (YRD), Middle of the Yangtze River (MYR) and South-west (SW), with the highest in YRD (4.15&times;10⁷ t, 111.05&times;10⁴ t of NPK) and the lowest in South China (SC) (2.20&times;10⁷ t, 58.54&times;10⁴ t of NPK). The rice stalk NPK nutrient returning to farmland per unit cultivated land area has increased continually during 1988-2018, accounting for 10.88%-12.53%, 11.83%-17.13%, 116.22%-122.62% of the annual fertilizer application, respectively. The annual average synthetic fertilizers substitution through rice stalk incorporation were (28.90&plusmn;0.14) kg/hm² of N, (5.80&plusmn;0.03) kg/hm² of P and (180.46&plusmn;0.52) kg/hm² of K in China, with the highest in YRD ((34.44&plusmn;0.20) kg/hm² of N, (6.91&plusmn;0.04) kg/hm² of P, (129.23&plusmn;0.74) kg/hm² of K), and the lowest in SC ((25.80&plusmn;0.23) kg/hm²of N, (5.18&plusmn;0.05) kg/hm² of P and (96.83&plusmn;0.87) kg/hm² of K). Therefore, making full use of rice stalk resources could be an important guarantee for reducing fertilizer application and increasing fertilizer use efficiency.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:63
Main heading:Fertilizers
Controlled terms:Agricultural robots - Cultivation - Farms - Nutrients
Uncontrolled terms:Agriculture and rural - Annual average - Cultivated lands - Fertilizer applications - Long-term monitoring datum - Synthetic fertilizers - Temporal and spatial distribution - Yangtze river delta
Classification code:804  Chemical Products Generally - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3  Agricultural Methods
Numerical data indexing:Percentage 1.09e+01% to 1.25e+01%, Percentage 7.00e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.017

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 14>

Accession number:20213610853560
Title:Spatial pattern of rural relative poverty and constraint mechanism of regional carrying capacity in the Yangtze River Economic Belt
Title of translation:&#38271;&#27743;&#32463;&#27982;&#24102;&#20892;&#26449;&#30456;&#23545;&#36139;&#22256;&#26684;&#23616;&#21450;&#21306;&#22495;&#25215;&#36733;&#21147;&#32422;&#26463;&#26426;&#29702;
Authors:Zhou, Kan (1, 2); Fan, Jie (1, 2, 3); Sun, Yong (3)
Author affiliation:(1) Key Laboratory of Regional Sustainable Development Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing; 100101, China; (2) College of Resources and Environment, University of Chinese Academy of Sciences, Beijing; 100049, China; (3) Institutes of Science and Development, Chinese Academy of Sciences, Beijing; 100190, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:249-258
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Rural poverty was a persistent problem in human society, and a common challenge faced by the whole world, where China is no exception. Many untiring efforts have been made to completely eliminate absolute poverty in China to achieve the goal of poverty reduction 10 years ahead of schedule in the United Nations 2030 Agenda for Sustainable Development. After that, the anti-poverty focus has changed into rural relative poverty since 2020. It is necessary to continuously narrow the development gap between urban and rural areas, thereby promoting the rationed sharing of development achievements. It is highly urgent to quantitatively determine the relationship between rural relative poverty and regional carrying capacity, thereby providing a scientific basis for the simultaneous formulation of intervention measures. Taking the Yangtze River Economic Belt (YREB) as the case area, this study aims to explore the spatial pattern of rural relative poverty and the constraint mechanism of regional carrying capacity. Multi-source databases were established using 1 070 county-level administrative units, including the rural social economy, resources, environment, road traffic, and major function zones. The areas of rural relative poverty were defined to identify the change types. The spatio-temporal evolution of rural relative poverty areas since 2010 was then determined from the multi-scale of the river basin, county, and major function zones. At the same time, an index system of regional carrying capacity was established to quantitatively evaluate the level of relative poverty restricted by regional carrying capacity in rural areas of YREB. Six elements were composed of land resources, water resources, environment, ecology, disaster, and transportation. Furthermore, the hierarchical clustering and binary logistic regression model were used to clarify the poverty-causing effect and the constraint level of regional carrying capacity. The results showed that: 1) The number and population size of rural relative poverty areas in the YREB decreased from 353 and 133.666 million in 2010 to 237 and 89.922 million in 2018, indicating that the precise poverty alleviation strategy was achieved to effectively reduce poverty. 2) The spatial pattern of rural relative poverty areas was generally stable and partially shrinking. Key ecological function zones were focused mainly on stable distribution in Wumeng Mountain, Wuling Mountain, Luoxiao Mountain, Yunnan-Guangxi-Guizhou rocky desertification areas, and western Yunnan Border Mountain. The counties without rural relative poverty were located mainly in the urban agglomeration areas or the periphery of central cities. 3) Ordinal logistic regression model showed that transportation, ecology and disaster carrying capacity were the important factors leading to rural relative poverty in the YREB. The probability of rural relative poverty increased by 120.85%, 30.59%, and 42.43%, when the constraint level of three factors increased by one grade. The probability of poverty in urbanized areas and main agricultural production zones was only 19.87% and 66.00% of that in ecological function zones. 4) There was an obvious conjugacy relation among the carrying capacities of each factor in the rural relative poverty areas, showing the characteristics of global transportation dominance and comprehensive constraints of local ecology, disasters, and land resources carrying capacity. It was suggested to design a differentiated anti-poverty policy system using the constraint degree of regional carrying capacity and the type of regional function, thereby realizing the two-way promotion of sustainable development ability on the regional scale, particularly on the individual ability of sustainable livelihood with farmers as the main body.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:41
Main heading:Rural areas
Controlled terms:Agricultural robots - Agriculture - Disasters - Ecology - Hierarchical clustering - Landforms - Logistic regression - Planning - Population statistics - Rivers  - Sustainable development
Uncontrolled terms:Agricultural productions - Binary logistic regression models - Ecological function zones - Ordinal logistic regression - Spatiotemporal evolution - Sustainable development ability - Sustainable livelihood - Urban and rural areas
Classification code:454.3  Ecology and Ecosystems - 481.1  Geology - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 912.2  Management
Numerical data indexing:Age 1.00e+01yr, Percentage 1.21e+02%, Percentage 1.99e+01%, Percentage 3.06e+01%, Percentage 4.24e+01%, Percentage 6.60e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.028

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 15>

Accession number:20213610853504
Title:Recognizing crop diseases using bimodal joint representation learning
Title of translation:&#37319;&#29992;&#21452;&#27169;&#24577;&#32852;&#21512;&#34920;&#24449;&#23398;&#20064;&#26041;&#27861;&#35782;&#21035;&#20316;&#29289;&#30149;&#23475;
Authors:Wang, Chunshan (1, 2, 3, 4); Zhao, Chunjiang (2, 3); Wu, Huarui (2, 3); Zhou, Ji (1, 4); Li, Jiuxi (5); Zhu, Huaji (2, 3)
Author affiliation:(1) Beijing Research Center for Information Technology in Agriculture, Beijing; 100097, China; (2) College of Information Science and Technology, Hebei Agricultural University, Baoding; 071001, China; (3) National Engineering Research Center for Information Technology in Agriculture, Beijing; 100097, China; (4) Hebei Key Laboratory of Agricultural Big Data, Baoding; 071001, China; (5) College of Mechanical and Electrical Engineering, Hebei Agricultural University, Baoding; 071001, China
Corresponding author:Wu, Huarui(wuhr@nercita.org.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:180-188
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Recognition using Deep Convolution Neural Networks (DCNN) performs well in plant disease diagnosis. However, the recognition accuracy and robustness of the model depend mainly on the scale of the training dataset and the quality of annotation. Particularly, the image modal data is only used in DCNN recognition models. It is necessary to build a large-scale disease dataset and complete high-quality annotation in open environments. Nevertheless, the huge economic and technical costs have limited the promotion of DCNN recognition in practical applications. Inspired by multimodal learning, a crop disease recognition model was proposed in an open environment using a flexible image and text bimodal joint representation learning, called bimodalNet. The image-associated text information was brought into the disease recognition task. The input of the network was the image-text pair composed of disease image and description text. The disease images were clipped and adjusted to 224&times;224 pixels. The description character of the disease was Chinese. A series of operations was completed for the text embedding, including normalization, word segmentation, word list construction, and text vectorization. As such, the network structure consisted of two parts: image and text branches. CNN was used in the image branch to extract disease features from images, whereas, the circular neural network was used in the text branch to learn disease features from description text. The correlation and complementarity were utilized between the two modes of disease information, thereby realizing the joint representation learning of disease features in bimodalNet. The output of image and text branches were added, and then fused into the output of networks. Different image and text classifiers were used to meet the needs of various tasks. As such, the best combination of disease feature extraction was selected from six networks in the experiments. The experimental dataset consisted of 1 834 disease image-text pairs. Among them, the disease images were all taken in the field environment, where each image was given a text description. The dataset was divided into training, verification and test dataset, according to the ratio of 7:2:1. The bimodalNet achieved better performances, compared with either image modal or text modal training alone. The accuracy, sensitivity, specificity, and F1 value of the optimal model in the test dataset were 99.47%, 98.51%, 98.61%, 99.68%, and 98.51%, respectively. Experimental results showed that bimodalNet improved significantly the accuracy of crop disease recognition in an open environment, while reduced the technical and economic costs of a large number of disease image acquisition. The reason was that the complementary features were fully utilized between image and text modes. Specifically, the image mode was used to correct the text error description, whereas, the text mode was to correct fuzzy features in an image mode. Since bimodalNet can be expected to be a general framework in actual use, the image and text branches can be replaced with any excellent CNN and recurrent neural network structure, indicating high flexibility in network structure. The finding can provide high feasibility on the disease identification using multimodal and few samples in an open environment.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:36
Main heading:Character recognition
Controlled terms:Classification (of information) - Costs - Crops - Deep neural networks - Diagnosis - Image enhancement - Large dataset - Modal analysis - Recurrent neural networks - Statistical tests
Uncontrolled terms:Complementary features - Convolution neural network - Multi-modal learning - Network structures - Plant disease diagnosis - Recognition accuracy - Recognition models - Word segmentation
Classification code:461.6  Medicine and Pharmacology - 716.1  Information Theory and Signal Processing - 821.4  Agricultural Products - 911  Cost and Value Engineering; Industrial Economics - 921  Mathematics - 922.2  Mathematical Statistics
Numerical data indexing:Percentage 9.85e+01%, Percentage 9.86e+01%, Percentage 9.95e+01%, Percentage 9.97e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.020

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 16>

Accession number:20213610853520
Title:Current status and prospects of precise sampling of pesticide droplets
Title of translation:&#30000;&#38388;&#20892;&#33647;&#38654;&#28404;&#31934;&#20934;&#37319;&#26679;&#25216;&#26415;&#19982;&#21457;&#23637;&#36235;&#21183;
Authors:Wang, Guobin (1, 2); Li, Xuan (3); Andaloro, John (3); Chen, Shengde (4); Han, Xiaoqiang (5); Wang, Juan (6); Shan, Changfeng (1, 2); Lan, Yubin (1, 2, 4)
Author affiliation:(1) College of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo; 255049, China; (2) Shandong Provincial Engineering Technology Research Center for Agricultural Aviation Intelligent Equipment, Zibo; 255049, China; (3) FMC Corporation, Stine Research Center, 1090 Elkton Road, Newark; DE; 19711, United States; (4) College of Electronics Engineering, College of Artificial Intelligence, South China Agricultural University, Guangzhou; 510642, China; (5) College of Agricultural, Shihezi University, Shihezi; 832002, China; (6) Mechanical and Electrical Engineering College, Hainan University, Haikou; 570228, China
Corresponding author:Lan, Yubin(ylan@sdut.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:1-12
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Plant protection machinery to spray pesticides is one of the most effective pest control methods in agriculture. It is necessary to accurately collect and measure the amount of droplets deposition, loss, and drift in the spraying process of pesticides, thereby optimizing the operating parameters of plant protection equipment, while improving the utilization rate of pesticides. Various samplers are available at present for sampling spray deposition, loss, and drift droplets. The selection of the samplers should meet the following requirements. Firstly, high collection efficiencies of samplers were required for the droplets of different sizes in relatively low wind speeds; Secondly, the samplers were not easy to saturate, with a certain sampling volume or area to sample sufficient droplets. A certain sampling volume or area can be used to calculate the deposition per unit area; Thirdly, the samplers should not react with active ingredients or tracers, particularly with high sampling efficiency, and stable recovery rate, where the resulting data can be quantitatively analyzed; Fourthly, the cheap samplers are easy to handle under field conditions. In this study, four types of samplers classified by the analytical approaches were introduced, including the type of image processing, chemical analysis, sensors, and rest. There were special precautions for each sampler. The selection of image processing software, correction of scanned data, and the limitations should be noticed in the type of image processing samplers. Much attention should be paid to the selection of samplers, dye or fluorescent tracer, and the volatility of pesticide active ingredients in the type of chemical analysis samplers; The type and applied scenarios were critical for each sensor and accuracy of sensors in the type of sensor samplers. In addition, there was some adhesion, rebound, or breakage failure, further detrimental to the sampling efficiency, when the droplets came into contact with the sampler. Especially for the type of chemical analysis samplers, special attention should be paid to sampling efficiency and recovery. Except for the selection of samplers, there was a significant effect on the placement position, transportation, and preservation of samplers, meteorological requirements, and sampling test sites. Five requirements or prospects were proposed for the current sampling in the future, including (a) to inspect plant protection machinery before the test, and determine the sampling efficiency and recovery rate of selected samplersfor a high accuracy of sampling, (b) to standardize the sampling or samplers in the development of fast suitable for field sampling; (c) further studies focused on the deposition of droplets containing pesticide active ingredients, (d) to develop new sampling sensors for high sampling efficiency, and (e) to establish a deposition and drift model of plant protection drones. In any way, the standardized and accurate sampling is needed to obtain comparable and highly precise data of pesticide deposition. The finding can make a great contribution to improving the current utilization rate of pesticides, particularly providing potential scientific and technical guidance for the "zero growth" of pesticide usage.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:106
Main heading:Image processing
Controlled terms:Agricultural robots - Chemical analysis - Deposition - Drops - Efficiency - Machinery - Pesticides - Recovery - Tracers
Uncontrolled terms:Analytical approach - High collection efficiency - Image-processing software - Operating parameters - Pesticide active ingredients - Pesticide deposition - Sampling efficiency - Technical guidances
Classification code:802.3  Chemical Operations - 803  Chemical Agents and Basic Industrial Chemicals - 913.1  Production Engineering
DOI:10.11975/j.issn.1002-6819.2021.11.001

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 17>

Accession number:20213610853479
Title:Characteristics of drought events using three-dimensional graph connectedness recognition method in the Yangtze River Basin, China
Title of translation:&#22522;&#20110;&#22270;&#20687;&#19977;&#32500;&#36830;&#36890;&#24615;&#35782;&#21035;&#26041;&#27861;&#30340;&#38271;&#27743;&#27969;&#22495;&#24178;&#26097;&#20107;&#20214;&#29305;&#24449;
Authors:Deng, Cuiling (1, 2); She, Dunxian (1, 2); Zhang, Liping (1, 2); Zhang, Qin (1, 2); Liu, Xin (1, 2); Wang, Shuxia (1, 2)
Author affiliation:(1) State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan; 430072, China; (2) Hubei Key Laboratory of Water System Science for Sponge City Construction, Wuhan; 430072, China
Corresponding author:She, Dunxian(shedunxian@whu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:131-139
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Drought events occur more frequently against global warming in recent years, resulting in a great pressureto the regional water resource management, ecosystem, and sustainable socio-economic development in many regions. Identification of drought events is essential to further understand characteristics of drought onset, evolution, and recovery. In this study, taking the Yangtze River Basin (YRB) as the case study, a new recognition method was proposed to identify the regional drought events using three-dimensional graph connectednessrecognition method. This new identification was first to recognize the three-dimensional continuum with no limitation, and then to split the continuum using the threshold of occurring and overlapping areas, finally to extract the drought events with three-dimensional characteristics. The number of times to calculate the overlaid area in space was reduced significantly compared to the drought identification using clustering method, which identifies drought patches in each month using the threshold of occurring area firstly, and then merges patches in adjacent months using the threshold of overlapping area. The spatial-temporal patterns of droughts were obtained to verify the efficiency of this new method using the three-month Standardized Precipitation Evapotranspiration Index (SPEI3)in YRBfrom 1960-2015. The results showed that: 1) 1.5% of the studyarea was considered as the threshold of occurring and overlapping areas, compared with the previous official reports. The drought events identified by the new method matched very well with the historical occurred onesinthe onset, termination, and propagationin YRB. There was a significant positive correlation between the drought intensity of single drought event and the moisture deficit of surface soil in the affected region. It proved the efficiency of the new method in identifying and extracting three-dimensional drought events; 2) 281 drought events are identified in YRB from 1960-2015 and the drought duration of 64 events are larger than 4 months; 3) The duration of long duration drought events (which duration is larger than 4 months) decreased, while the drought area and drought frequency increased. Long duration droughts occurred 43 times during 1960-1999, the average drought duration and drought area were 8.1 months and 2.74&times;10⁴ km², respectively. And long duration droughts occurred 21 times during 2000-2015, the average drought duration and drought area were 7.6 months and 3.50&times;10⁴ km², respectively. The frequency of long duration drought events in the middle region of YRB is higher than that in the eastern and western regions. 4) The drought events occurred more frequently in Shaanxi, Hubei, and Sichuan provinces, while the north Yunnan and Guizhou provinces presented a relatively lower frequency. Accumulative drought intensity was large in north Guizhou, northwest and east Sichuan, and Hubeiprovinces and Chongqing City, whereas, relatively small in the north Yunnan, Jiangxi and south Jiangsu provinces. The frequency and severity of drought events presented an increasing trend in the middle region of YRB, while a decreasing trend in the western and the eastern. The center of about 50% drought events moved to the northwest, mainly due to the water vapor transference and the migration of precipitation belt. The drought events identification method proposed in this studycan effectively recognize and extract drought events withthree-dimension characteristics. The finding can provide greatly promising guidance for drought and regional water resource management.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:42
Main heading:Drought
Controlled terms:Economics - Efficiency - Global warming - Resource allocation - Water management - Watersheds
Uncontrolled terms:Drought intensities - Identification method - Positive correlations - Recognition methods - Regional water resources - Socio-economic development - Three dimensional graphs - Three-dimensional characteristics
Classification code:443.1  Atmospheric Properties - 444  Water Resources - 444.1  Surface Water - 912.2  Management - 913.1  Production Engineering - 971  Social Sciences
Numerical data indexing:Age 3.33e-01yr, Age 6.33e-01yr, Age 6.75e-01yr, Percentage 1.50e+00%, Percentage 5.00e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.015

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 18>

Accession number:20213610853548
Title:Development and current situation of ester oxygenated fuels application
Title of translation:&#37231;&#31867;&#21547;&#27687;&#29123;&#26009;&#24212;&#29992;&#30740;&#31350;&#29616;&#29366;&#21450;&#36827;&#23637;
Authors:Miao, Changlin (1); Li, Wuhuan (1); Lyu, Pengmei (1); Tan, Xuesong (1); Li, Huiwen (1); Zhuang, Xinshu (1)
Author affiliation:(1) Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou; 510640, China
Corresponding author:Zhuang, Xinshu(zhuangxs@ms.giec.ac.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:197-205
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">With the aggravation of global energy consumption, the limited petrochemical fuel has been difficult to meet people's demand for energy, while the number of vehicles is increasing, which makes the harmful pollutants emitted by vehicles to the atmosphere increase sharply. In order to strictly control the environmental pollution caused by vehicle exhaust emissions, countries around the world have issued increasingly stringent emission standards in recent years. The legislative goal of these emission regulations is to strictly control the emission pollutants including carbon monoxide, hydrocarbons, nitrogen oxides, and soot particles. Therefore, with the increasingly stringent emission standards for motor vehicles, many scholars at home and abroad have paid close attention to new alternative fuels for motor vehicles, including oxygenated fuels. From the perspective of energy security and environmental protection, countries have begun to look for new combustion modes to realize efficient and clean combustion of internal combustion engines.As a substitute or additive of petrochemical fuel, ester oxygenated fuel can provide additional oxygen during combustion, which is helpful to solve the problems of low air pressure and insufficient air intake encountered by motor vehicles in plateau areas. At the same time, it can fully burn the fuel, improve the physicochemical properties of the fuel, and reduce the emissions of air pollution such as carbon monoxide, hydrocarbons and soot particles, so as to reduce the emissions of harmful substances and improve the combustion performance. Therefore, the development of new ester oxygenated fuel has the dual significance of environmental protection and alleviating the dependence on petrochemical fuel. In this paper, the physicochemical properties, emission characteristics and application in internal combustion engines of biodiesel, long chain fatty acid ether ester, carbonate, ether ester and levulinic acid ester clean oxygenated fuels were discussed, the advantages and disadvantages of ester oxygenated fuels were analyzed, and the application trend and future research suggestions of ester oxygenated fuels were pointed out.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:70
Main heading:Fuel additives
Controlled terms:Air intakes - Air pollution control - Air quality - Alternative fuels - Carbon monoxide - Combustion - Energy security - Energy utilization - Environmental protection - Esters  - Ethers - Fatty acids - Internal combustion engines - Nitrogen oxides - Petrochemicals - Physicochemical properties - Soot - Vehicles
Uncontrolled terms:Combustion performance - Emission characteristics - Emission regulation - Environmental pollutions - Internal combustion - Long chain fatty acid - Number of vehicles - Vehicle exhaust emissions
Classification code:451.2  Air Pollution Control - 454.2  Environmental Impact and Protection - 525.3  Energy Utilization - 525.6  Energy Policy - 612.1  Internal Combustion Engines, General - 631.1  Fluid Flow, General - 803  Chemical Agents and Basic Industrial Chemicals - 804  Chemical Products Generally
DOI:10.11975/j.issn.1002-6819.2021.11.022

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 19>

Accession number:20213610853501
Title:Experimental study on the improvement effects of TCD combustion system on combustion and emission performance of diesel engine
Title of translation:TCD&#29123;&#28903;&#31995;&#32479;&#23545;&#26612;&#27833;&#26426;&#29123;&#28903;&#21644;&#25490;&#25918;&#24615;&#33021;&#25913;&#21892;&#25928;&#26524;&#30340;&#35797;&#39564;&#30740;&#31350;
Authors:Kang, Yuning (1); Li, Xiangrong (1); Bo, Dawei (2); Chen, Yanlin (1); Liu, Dong (1); Chang, Jiang (1)
Author affiliation:(1) School of Mechanical Engineering, Beijing Institute of Technology, Beijing; 100081, China; (2) Military Delegate Room of People's Liberation Army Ground Force Armaments Department in Beijing Area, Beijing; 100072, China
Corresponding author:Li, Xiangrong(lixr@bit.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:50-59
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Diesel engines find wide use in the mechanic industry depending particularly on high power density and reliability. Energy saving and emission reduction of diesel engines can remarkably contribute to national security and environmental protection. However, the introduction of spray injection pressure has restricted the performance of diesel engines in recent years. The reason is that the spray impingement can concurrently increase soot emission subjected to a prolonged combustion period. Therefore, a wall-flow-guided combustion system was developed to greatly apply for many products using the fuel momentum produced by the high injection pressure. Deutz's TCD2015 (T for turbocharger, C for charge air cooling, and D for diesel particle filter) type engine is one of the typical diesel engines with a wall-flow-guided combustion system. The TCD combustion system is characterized by a shallow basin to form the circular ridge, especially for high performance and emission reduction. Current similar combustion system also appears in many types of engine with a prominent ability. This study aims to explore the effect of the TCD combustion system on the combustion process and emission in a diesel engine. A single-cylinder diesel engine experiment was performed at different speeds, loads, and excess air coefficients (&phi;). Test results showed that the brake specific fuel consumption (BSFC) and the soot emission of the TCD combustion system were lower than those of the conventional &omega; combustion system at different operation conditions. The BSFC drop tended to be the maximum of 7.01% at 1 800 r/min, &phi;=1.2 operation. The maximum drop of 86.67% on soot emission appeared at 1 800 r/min, and the brake power of 54 kW. Furthermore, the TCD combustion system outperformed at a low excess air coefficients between 1.2 to 1.6. A diesel engine simulation model was also built in AVL Fire to reveal the improvement mechanism of fuel-air-mixing quality in the TCD combustion system. The simulation model configured k-&zeta;-f turbulence, wave spray breakup, Dukowicz spray evaporation, and ECFM-3Z combustion model. A verification for mesh size independence confirmed the unit size around 1mm. The spray total penetration (including vapor phase), in-cylinder pressure, and heat release rate were evaluated to ensure the accuracy of simulation in spray liquid penetration. The operations at 1 800 r/min with different loads and excess air coefficients were chosen to evaluate the TCD combustion system performance. Simulation results for equivalent ratio distributions showed that the cyclic ridge formed the fuel stream towards the inner and outer chambers, and then guided the fuel diffusion towards the combustion chamber center and the cylinder head, where the shallow basin wall became the fuel guider to avoid fuel gathering in the clearance at 28&#8451;A. The velocity distributions demonstrated that a smaller region of low-velocity presented in the TCD combustion system, compared with the &omega; combustion system, indicating smaller collision energy loss and better fuel-air-mixing quality. A better performance was achieved at the brake power of 72 kW and &phi;=1.2 operations, due to the faster spray motion. The fuel mass ratios in four equivalence ratio intervals were smaller than 1, 1-2, 2-4, and larger than 4, further to evaluate the fuel-air-mixing quality in the cylinder. Results showed that the fuel mass ratios of TCD combustion system in the equivalence ratio 2-4 and larger than 4 were smaller than those of &omega; combustion system in 0-30&#8451;A with a maximum of 9.75% at &phi;=1.2 operation, while in 30-60&#8451;A the fuel mass ratios in the equivalence ratio smaller than 1 and 1-2 were larger with 7.45% the maximum drop at the brake power of 72 kW. Hence, the great performance of the TCD combustion system relied mainly on the sufficient fuel-air-mixing facilitated by the chamber structure. The finding can provide a sound technical reference for the development and optimization of the combustion system in diesel engines.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Fuel systems
Controlled terms:Air - Brakes - Cylinder heads - Diesel engines - Drops - Emission control - Energy conservation - Energy dissipation - Fuels - Mixing  - National security - Quality control - Soot - Wall flow - Walls (structural partitions)
Uncontrolled terms:Brake specific fuel consumption - Combustion and emission performance - Diesel engine simulations - Energy saving and emission reductions - Heat Release Rate (HRR) - High injection pressures - Performance and emissions - Single-cylinder diesel engine
Classification code:404.1  Military Engineering - 408.2  Structural Members and Shapes - 451.2  Air Pollution Control - 525.2  Energy Conservation - 525.4  Energy Losses (industrial and residential) - 602  Mechanical Drives and Transmissions - 612.1.1  Internal Combustion Engine Components - 612.2  Diesel Engines - 631.1  Fluid Flow, General - 802.3  Chemical Operations - 804  Chemical Products Generally - 913.3  Quality Assurance and Control
Numerical data indexing:Percentage 7.01e+00%, Percentage 7.45e+00%, Percentage 8.67e+01%, Percentage 9.75e+00%, Power 5.40e+04W, Power 7.20e+04W, Rotational_Speed 1.80e+03RPM, Size 1.00e-03m
DOI:10.11975/j.issn.1002-6819.2021.11.006

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 20>

Accession number:20213610853453
Title:Design and experiments of vineyard variable spraying control system based on binocular vision
Title of translation:&#22522;&#20110;&#21452;&#30446;&#35270;&#35273;&#30340;&#33889;&#33796;&#22253;&#21464;&#37327;&#21943;&#38654;&#25511;&#21046;&#31995;&#32479;&#35774;&#35745;&#19982;&#35797;&#39564;
Authors:Yan, Chenggong (1); Xu, Liming (1); Yuan, Quanchun (1); Ma, Shuai (1); Niu, Cong (1); Zhao, Shijian (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing; 100083, China
Corresponding author:Xu, Liming(xlmoffice@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:13-22
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Variable rate spraying is one of the most high-efficiency and low-cost technologies in the sustainable development of precision agriculture. Recently, the online detection of the canopy has been a key challenge to realize variable spraying in an orchard. Many state-of-the-art technologies are emerging for the fast and accurate acquisition of canopy data, including stereo vision, ultrasonic, and laser sensors. Previous studies have shown that a high-resolution binocular camera can be utilized to measure the canopy structure of fruit trees. However, no attempt has been made to apply this camera for the variable spray in an orchard. In this study, a precise control system of variable-rate spraying was designed based on the 3WF-400Z orchard wind sprayer. This system was composed of binocular cameras, solenoid valves, a touch screen, an encoder, and a control program. The specific procedure was: first to detect the depth of grape canopy using binocular cameras, then to calculate the canopy volume with the forward speed of the sprayer, while to regulate the duty cycle of several solenoid valves in real time under the Pulse-Width Modulation (PWM), finally to realize variable spray using grape canopy volume. A calculation method was proposed for the canopy volume of the grape canopy, where the detection program was compiled using the characteristics of a binocular camera. An accuracy test of volume detection was carried out to verify the calculated data in a vineyard. Each sample was measured manually to compare with the detection data of the binocular camera. It was found that there was a strong correlation between the camera detecting and manual data, where the determination coefficient of linear fitting was 0.933 after 150 mm compensation, indicating the binocular camera suitable for the canopy volume detection in actual practice. An experimental calibration was utilized to determine the flow control model of nozzles in the sprayer. The simulated depth was also sent to the control system, where the same forward speed was set under the static condition, thereby verifying the consistency of variable rates. The results showed that the linear determination coefficient between the actual and theoretical flow was 0.990, when the volume of the canopy was larger than 0.036 m³, indicating an excellent real-time performance of the program, the high response ability of the hardware, and the good consistency of the variable spray. A field experiment showed that the variable spray system reduced significantly the diameter of droplets, while increased the density of the droplet, where the coverage rate remained basically unchanged. Specifically, the Volume Median Diameter (NMD) and Number Median Diameter (VMD) of droplets decreased by 87.71 and 182.79 mm, respectively, whereas, the density of droplets increased by 79.31/cm². Combined with the observed spray at the experimental sites, it was found that the spray volume in the conventional mode exceeded the actual demand, resulting in the droplet condensation again after reaching the canopy surface, whereas, the variable mode cannot generate excessive spray to improve the droplet size and spatial distribution. The determination coefficients between the predicted and actual flow of left and right sprinklers were 0.897 and 0.877, respectively, indicating a strong correlation. The overall trend of actual flow and canopy volume was all the same, indicating the control system suitable for variable spraying according to the volume of the target canopy. The variable spray mode saved about 55.27% of pesticide, compared with the traditional constant spray. The finding can provide a sound reference for the application of orchard variable spraying, further to achieve a high efficiency pesticide application for an expected production level in modern agriculture.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Spray nozzles
Controlled terms:Agricultural robots - Binocular vision - Binoculars - Cameras - Control systems - Drops - Efficiency - Hose - Orchards - Pesticides  - Pulse width modulation - Solenoid valves - Solenoids - Stereo image processing - Stereo vision - Touch screens - Ultrasonic applications - Voltage control
Uncontrolled terms:Determination coefficients - Droplet condensation - Experimental calibration - Modern agricultures - Pesticide applications - Real time performance - State-of-the-art technology - Variable rate spraying
Classification code:619  Pipes, Tanks and Accessories; Plant Engineering Generally - 619.1  Pipe, Piping and Pipelines - 631.1  Fluid Flow, General - 704.1  Electric Components - 722.2  Computer Peripheral Equipment - 723.2  Data Processing and Image Processing - 731.1  Control Systems - 731.3  Specific Variables Control - 741.2  Vision - 741.3  Optical Devices and Systems - 742.2  Photographic Equipment - 753.3  Ultrasonic Applications - 803  Chemical Agents and Basic Industrial Chemicals - 821.3  Agricultural Methods - 913.1  Production Engineering
Numerical data indexing:Percentage 5.53e+01%, Size 1.50e-01m, Size 1.83e-01m, Size 8.77e-02m, Volume 3.60e-02m3
DOI:10.11975/j.issn.1002-6819.2021.11.002

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 21>

Accession number:20213610853552
Title:Identification of critical ecological land in Dianchi Watershed based on the perspective of ecosystem service function
Title of translation:&#22522;&#20110;&#29983;&#24577;&#31995;&#32479;&#26381;&#21153;&#21151;&#33021;&#30340;&#28359;&#27744;&#27969;&#22495;&#20851;&#38190;&#24615;&#29983;&#24577;&#29992;&#22320;&#35782;&#21035;
Authors:Liu, Lin (1); Lei, Dongmei (1); Ran, Yuju (1); Zhang, Yuan (1, 2)
Author affiliation:(1) School of City and Environment, Yunnan University of Finance and Economics, Kunming; 650221, China; (2) School of Geography and Tourism, Zhaotong University, Zhaotong; 657000, China
Corresponding author:Lei, Dongmei(dmLei@ynufe.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:277-284
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Critical ecological land is one of the most important areas to maintain the stability of ecosystem service function, due to water conservation and resistance to soil erosion for the biodiversity. However, a fierce contradiction is ever increasing between ecological protection and economic development under the rapid urbanization in China. Therefore, a coordinating relationship is greatly significant to maintain regional ecological security and environmental protection. Previous ecological land focuses mainly on the concept, type division, and function zoning. It is also lacking in the identification of critical ecological land at present. Accurate identification of critical ecological land in plateau lakeside areas can contribute to ensuring the stability of regional ecological function, and maintaining the virtuous circle of the ecosystem service function. Taking the Dianchi watershed as the study area, the minimum cumulative resistance model was utilized to identify the critical ecological land using a perspective of ecological land importance. Firstly, the ecosystem service functions were selected to evaluate the importance of ecological lands, such as water, biological, soil, and water conservation, as well as landscape leisure, according to the present situation of land use. Then, the cumulative correction and summation were utilized to superimpose four levels for the comprehensive identification of ecological land importance. Five grades were divided into extremely important, important, generally important, and non-important. Finally, the "Resistance Surface" was obtained to assign land use type, where the ecological land with the extremely important grade was selected as the "Source" of the minimum cumulative resistance model. The critical ecological land was identified in Dianchi watershed using the ArcGIS technology and the minimum cumulative resistance model through COST-DISTANCE tools. The results showed that: 1) The "Source" land was mainly the water area and woodland that were distributed in the north, central and western areas of the basin, covering an area of 984.40 km² and accounting for 33.71% of the total area. 2) The "Resistance Surface" was divided into the high, middle, and low resistance zones, covering the area of 769.12, 960.06, and 1 190.82 km², respectively. The high resistance zone was distributed in the middle of the study area, where the main land types were construction land, and roads. The low resistance area included the forest land, water area, and other land types with a high ecological service function. The medium resistance area played a transitional role between the high and low zones. 3) The critical ecological land area of Dianchi watershed was 1 216.30 km² in 2019, accounting for 41.65% of the total area, which was distributed mainly in the northern, central, western, and eastern boundaries of the basin. The main land types were the water area of 306.39 km² and woodland of 774.53 km², which were widely distributed throughout the Dianchi watershed. The identification can contribute to the ecological land to maintain ecological function. Consequently, the minimum cumulative resistance model was also feasible to identify the critical ecological land in the watershed.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Surface resistance
Controlled terms:Biodiversity - Economics - Ecosystems - Land use - Soil conservation - Water conservation - Watersheds
Uncontrolled terms:Ecological functions - Ecological protection - Ecological security - Ecological services - Ecosystem service functions - Present situation - Rapid urbanizations - Resistance modeling
Classification code:403  Urban and Regional Planning and Development - 444  Water Resources - 444.1  Surface Water - 454  Environmental Engineering - 454.3  Ecology and Ecosystems - 483.1  Soils and Soil Mechanics - 951  Materials Science - 971  Social Sciences
Numerical data indexing:Area 1.91e+08m2, Area 2.16e+08m2, Area 3.06e+08m2, Area 7.75e+08m2, Area 9.84e+08m2, Percentage 3.37e+01%, Percentage 4.16e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.031

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 22>

Accession number:20213610853505
Title:Retrieval for soil moisture in farmland using multi-source remote sensing data and feature selection with GA-BP neural network
Title of translation:&#22522;&#20110;&#29305;&#24449;&#36873;&#25321;&#21644;GA-BP&#31070;&#32463;&#32593;&#32476;&#30340;&#22810;&#28304;&#36965;&#24863;&#20892;&#30000;&#22303;&#22756;&#27700;&#20998;&#21453;&#28436;
Authors:Zhao, Jianhui (1, 2, 3); Zhang, Chenyang (1, 2, 3); Min, Lin (2, 3, 4); Li, Ning (1, 2, 3); Wang, Yinglin (1, 2, 3)
Author affiliation:(1) College of Computer and Information Engineering, Henan University, Kaifeng; 475004, China; (2) Henan Key Laboratory of Big Data Analysis and Processing, Kaifeng; 475004, China; (3) Henan Engineering Research Center of Intelligent Technology and Application, Kaifeng; 475004, China; (4) Network Information Center Office, Henan University, Kaifeng; 475004, China
Corresponding author:Min, Lin(mlin@henu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:112-120
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Measurements of soil moisture have great significance for agricultural production and environmental protection. A variety of technologies have been introduced into the current monitoring of surface soil moisture, particularly widely-used optical remote sensing and synthetic aperture radar (SAR) microwave remote sensing. In this study, retrieval for surface soil moisture in farmland was proposed using multi-source remote sensing data and feature dimension reduction with GA-BP neural networks. Sentinel-1 microwave and Sentinel-2 optical remote sensing data were used with a high spatial and temporal resolution. Three field surveys and sampling were carried out simultaneously during the transit time of the Sentinel-1 satellite. A total of 20 sampling points were set on the ground in the study area to collect soil moisture in the longitude and latitude coordinates. Firstly, Sentinel-1 and Sentinel-2 data were preprocessed to extract 21 feature parameters, including 9 backscatter coefficient, 5 polarization characteristic parameters, surface roughness, and 6 vegetation indices. Then, the differential evolution feature selection (DEFS) was utilized to obtain an optimal feature subset with 10 parameters, including the incident angle, &sigma;<inf>vv</inf>⁰, &sigma;<inf>VH</inf>⁰, &sigma;<inf>VH</inf>⁰/&sigma; <inf>VV</inf>⁰, Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Water Band Index (WBI), and Fusion Vegetation Index (FVI). Principal component analysis (PCA) was used to further reduce the dimension of the optimal feature subset. The feature subset was reduced to eight dimensions, where an eight-dimensional feature matrix was obtained. After that, back propagation (BP) neural network was established to describe the nonlinear relationship between characteristic parameters and surface soil moisture, whereas, genetic algorithm (GA) was used to optimize the node weights and accelerated the learning speed of the BP neural network. The feature matrix after dimension reduction and some measured data of soil moisture were input into the GA-BP network for training, where the distribution map of soil moisture was obtained in the study area. Finally, taking a winter wheat field in Henan Province as the study area, three comparative experimental schemes were set to verify the accuracy of inversion using the measured data. The experimental schemes with DEFS and PCA presented the highest accuracy, where the coefficient of determination was 0.789 3, and the root mean square error was 0.028 7 cm³/cm³, compared with the genetic BP neural network, indicating the coefficient of determination increased by 0.215 7, and the root mean square error was reduced by 0.029 5 cm³/cm³. Meanwhile, the frequency distribution of soil moisture inversion was basically consistent with the measured soil moisture of sampling points. The experimental results demonstrated that the GA-BP network combining with DEFS and PCA can eliminate the redundant characteristic parameters for high inversion accuracy, and a high-resolution distribution map of surface soil moisture with a large area. The finding can offer some advantages and application potentials to the surface soil moisture retrieval in farmland.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:32
Main heading:Backpropagation
Controlled terms:Agricultural robots - Dimensionality reduction - Farms - Feature extraction - Genetic algorithms - Matrix algebra - Mean square error - Neural networks - Remote sensing - Soil moisture  - Soil surveys - Surface roughness - Synthetic aperture radar - Vegetation
Uncontrolled terms:Back propagation neural networks - Coefficient of determination - Normalized difference vegetation index - Normalized difference water index - Optical remote sensing data - Polarization characteristics - Spatial and temporal resolutions - Surface soil moisture retrieval
Classification code:483.1  Soils and Soil Mechanics - 716.2  Radar Systems and Equipment - 723.4  Artificial Intelligence - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 921.1  Algebra - 922.2  Mathematical Statistics - 931.2  Physical Properties of Gases, Liquids and Solids
DOI:10.11975/j.issn.1002-6819.2021.11.013

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 23>

Accession number:20213610853433
Title:Establishment of firmness evaluation indexes for irregular shapes pears based on Fourier descriptor and resonance frequency
Title of translation:&#22522;&#20110;&#20613;&#37324;&#21494;&#25551;&#36848;&#23376;&#21644;&#20849;&#25391;&#39057;&#29575;&#30340;&#19981;&#35268;&#21017;&#26524;&#24418;&#26792;&#26524;&#30828;&#24230;&#35780;&#20272;&#25351;&#26631;&#26500;&#24314;
Authors:Wang, Peng (1); Wu, Jie (1, 2)
Author affiliation:(1) College of Mechanical and Electrical Engineering, Shihezi University, Shihezi; 832000, China; (2) Research Center of Agricultural Mechanization for Economic Crop in Oasis, Ministry of Education, Shihezi; 832003, China
Corresponding author:Wu, Jie(wjshz@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:299-306
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Firmness is one of the important indicators for the internal quality of fruits. Natural frequency has widely been expected to evaluate the fruit firmness in recent years. Several indices have successfully been applied for the firmness of sphere-shaped fruits using the natural frequency and fruit mass. However, the fruit with non-spherical or irregular shapes cannot be suitable for firmness evaluation, due mainly to the fact that the fruit shape can interfere with the resonance frequency. Thus, some dual-frequency indices were established to measure the firmness of fruit with ellipsoidal shapes. Nevertheless, these indices cannot accurately evaluate the firmness of complex and irregular pears. In this study, a Fourier descriptor was established as a reliable shape descriptor to evaluate the firmness, thereby representing complex, irregular, or a larger variation of pear shapes. Firstly, the shape images of pears were captured by a camera. Then, the boundary edges of pear images were extracted to calculate the normalized radiuses. After that, a Fourier transform was performed on the normalized radius to obtain the Fourier descriptor. Finally, the first 15 Fourier descriptors were screened to describe the complex shapes of pears. Meanwhile, an experimental modal combined with the Finite Element Method (FEM) was utilized to analyze the effect of fruit shape on the natural frequency. Three modes included bending, compression, and breathing during a test. The natural frequency was easy to measure the equatorial region of the pear fruit in the compression mode. The largest deformation appeared, when the pear was impacted on this region. As such, the pear was assumed to be linearly elastic, homogeneous and isotropic material in the FEM. A process of reverse engineering was utilized to form the geometric model of pears. The 3D 4-node tetrahedral structural solid element was selected, allowing three translational and three rotational degrees of freedom at each node. Consequently, three shapes and natural frequencies in FE modal analysis were highly related to the experimental data. Therefore, the FEM model was expected to analyze the influence of Fourier descriptors on the natural frequency of the pear. These results indicated that the first Fourier descriptor (F<inf>1</inf>) had a significant effect on the natural frequencies of three modes. The frequency decreased linearly for the bending and compression mode, and increased linearly for the breathing mode, with the increasing of the F<inf>1</inf>. A new firmness index was established using the relationship between the F<inf>1</inf> and frequency in the compression mode. Finally, an M-T penetration test was conducted to investigate the correlation between the nondestructive and destructive firmness indices. By comparison, the Coefficient of Determination (COD) was 0.892 for the new index S<inf>E(F1)</inf> with the destructive M-T firmness tester. Two dual-frequency firmness indices for the ellipsoidal fruit and firmness index S<inf>E(q)</inf>, the COD were 0.733, 0.775, 0.765, and 0.746, respectively, for traditional spherical firmness index. Therefore, the new firmness index can accurately evaluate the firmness of complex and irregular shape pears. Consequently, this finding can provide promising practical guidance for the nondestructive detection of the firmness of differently shaped pears using resonance in intelligent agriculture.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Fruits
Controlled terms:Agricultural robots - Degrees of freedom (mechanics) - Fourier series - Modal analysis - Natural frequencies - Reverse engineering - Spheres
Uncontrolled terms:Coefficient of determination - Fourier descriptors - Geometric modeling - Homogeneous and isotropic - Nondestructive detection - Resonance frequencies - Rotational degrees of freedom - Structural solid elements
Classification code:821.4  Agricultural Products - 921  Mathematics - 921.3  Mathematical Transformations - 931.1  Mechanics
DOI:10.11975/j.issn.1002-6819.2021.11.034

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 24>

Accession number:20213610853463
Title:Topographic gradient effects of habitat quality and its response to land use change in Hubei Section of the Three Gorges Reservoir
Title of translation:&#19977;&#23777;&#24211;&#21306;&#29983;&#22659;&#36136;&#37327;&#30340;&#22320;&#24418;&#26799;&#24230;&#25928;&#24212;&#21450;&#23545;&#22303;&#22320;&#21033;&#29992;&#21464;&#21270;&#30340;&#21709;&#24212;
Authors:Zhou, Xiaoyan (1); He, Yiyi (1); Huang, Xin (1); Zhang, Miaomiao (1)
Author affiliation:(1) School of Resource and Environmental Sciences, Wuhan University, Wuhan; 430079, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:259-267
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">The Three Gorges Project has brought great changes to the regional land use and ecological environment in China in recent years. The temporal and spatial changes in land use and habitat quality are essential to promote the development and protection of territorial space, as well as the transformation of high-quality development in the reservoir area. In this study, land-use data were used from several phases in Hubei section of the Three Gorges Reservoir Area, according to the construction time node. An InVEST model was used to evaluate the spatial and temporal differentiation characteristics of habitat quality. The distribution index, topographic potential index, and geographically weighted regression model were finally utilized to investigate the topographic gradient effect of habitat quality and the response to land-use change. The results showed that: 1) The characteristics of land-use changes in the study area were mainly the large expansion of construction land and water areas, and a small increase in the area of cultivated land, while a small decrease in the area of forest and grassland. 2) The quality of habitats improved in some areas after the first-phase resettlement of the Three Gorges Project. The habitat quality significantly degraded around some cities and towns in the reservoir area and the Three Gorges Dam after the first-phase resettlement to the full completion of the Three Gorges Project. The quality of habitats in the reservoir area remained stable after the full operation. 3) The habitat quality of contiguous urbanization and engineering construction areas located in low topography was degraded to a greater extent, while the habitat quality of cultivated land reclamation areas scattered in the middle topography was slightly degraded, and the habitat quality of high topography areas with high forest and grass coverage was basically stable, from the perspective of spatial distribution. 4) Geographically weighted regression models showed that there were spatial differences in the response of habitat quality to the change of different land types. The habitat quality responded significantly to changes in forestland in southern Xingshan County, northern Yiling District, and the junction of southern Zigui and Badong County. The habitat quality in the villages and towns responded significantly to the changes of cultivated land in the south of Badong County, such as Yesanguan Town. Furthermore, the habitat quality responded significantly to changes in the construction and cultivated land distributed in the northern part of Xingshan County, around Badong County, and near the Three Gorges Dam. The findings can be expected to reveal the temporal and spatial change of habitat quality, particularly providing decision-making references for the sustainable development of land use and protection in the Hubei section of the Three Gorges Reservoir areas.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Land use
Controlled terms:Concrete dams - Decision making - Ecosystems - Forestry - Land reclamation - Population distribution - Regression analysis - Reservoirs (water) - Sustainable development - Topography
Uncontrolled terms:Changes of cultivated lands - Ecological environments - Engineering constructions - Geographically weighted regression models - Temporal and spatial changes - Three gorges reservoir - Three gorges reservoir area - Topographic gradients
Classification code:403  Urban and Regional Planning and Development - 405.3  Surveying - 412  Concrete - 441.2  Reservoirs - 442.2  Land Reclamation - 454.3  Ecology and Ecosystems - 912.2  Management - 922.2  Mathematical Statistics - 951  Materials Science
DOI:10.11975/j.issn.1002-6819.2021.11.029

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 25>

Accession number:20213610853486
Title:Benefits of soil and water reduction on spoil heaps by vegetation under two driving forces
Title of translation:&#20004;&#31181;&#39537;&#21160;&#21147;&#20316;&#29992;&#19979;&#26893;&#34987;&#35843;&#25511;&#22534;&#31215;&#20307;&#22369;&#38754;&#20943;&#27700;&#20943;&#27801;&#25928;&#30410;
Authors:Li, Jianming (1, 2, 3, 4); Niu, Jun (3, 4); Sun, Bei (3, 4); Yang, Hefei (3, 4); Wang, Wenlong (1, 5); Huang, Jinquan (3, 4); Nie, Huiying (5); Pu, Jian (1, 2, 3, 4); Sun, Baoyang (3, 4); Chen, Zhuoxin (5); He, Xihong (5)
Author affiliation:(1) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling; 712100, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) Changjiang River Scientific Research Institute of Changjiang Water Resources Commission, Wuhan; 430010, China; (4) Research Center on Mountain Torrent & Geologic Disaster Prevention of the Ministry of Water Resources, Wuhan; 430010, China; (5) State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling; 712100, China
Corresponding author:Wang, Wenlong(wlwang@nwsuaf.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:76-84
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Soil erosion on spoil heaps has become an important environmental issue and it causes serious soil erosion, geological disasters and even limits land resources. The influence of grass on soil loss on steep spoil heaps remains elusive. This study aimed to investigate the effects of Artemisia gmelinii on runoff and erosion processes of spoil heaps with silt loam soil. The effects of vegetation on runoff and sediment reduction benefits were quantified. Field rainfall experiment and rainfall with scouring experiment were performed. A series of rainfalls at three rainfall intensities (0.8, 1.2, and 1.8 mm/min) and fixed discharge flow rate (15 L/min) were simulated in four plots (3 m &times; 2 m, including repeats). The spoil heaps were characteristics with the gravel content of 10% and slope gradient degree of 30. The characteristics and differences of vegetation's regulation of hydrological and erosion processes of spoil heaps under two driving forces were analyzed. The results showed: 1) Artemisia gmelinii reduced average soil loss rate and runoff rate by 57.28%-98.51% and 13.17%-83.11%, respectively, under the two driving forces, and the benefits of soil reduction and runoff reduction were decreased by 17.01% and 68.74%, respectively after adding the upper catchment flow. The vegetation not only decreased the erosion of the spoil heaps, but also made the erosion process of the spoil heaps smoother. 2) The benefits of soil and water loss reductions were decreased by 4.32%-21.10% with the increase of rainfall intensity for Artemisia gmelinii spoil heaps under rainfall experiment, and it was 26.85%-56.30% for runoff reduction benefits. However, the benefits of soil loss reduction were increased by 45.55%-46.35% and runoff rate reduction was decreased by 54.21%-55.54%, respectively, under rainfall and scouring experiment. Significant difference analysis also showed that rainfall intensity had a significant impact on soil and water yield of bare and Artemisia gmelinii spoil heaps (P&lt;0.01) under the two driving forces, and the effect of discharge flow was significant than rainfall. 3) The soil loss rate was decreased with runoff duration for bare spoil heaps under rainfall and rainfall with scouring experiment, while it was increased for Artemisia gmelinii spoil heaps only under rainfall condition. The fluctuation of erosion and runoff on bare and Artemisia gmelinii spoil heaps was increased significantly with time as the driving force changed from rainfall to rainfall with scouring. The average soil loss rate was increased by 6.63-7.15 times and 4.92-192.81 times for bare soil and Artemisia gmelinii spoil heaps, respectively, when a fixed discharge flow was added. They were 4.96-10.81 times and 6.77-44.04 times for the average runoff rate. The change of driving forces had greater impact on Artemisia gmelinii than bare spoil heaps. 4) The average soil loss rate for bare spoil heaps during the early stage was 1.06-2.90 times that of the later stage under both driving forces, while it was 35.21%-59.30% for Artemisia gmelinii spoil heaps under rainfall condition. However, the stage with serious soil loss changed with rainfall intensity under rainfall and scouring experiment for Artemisia gmelinii spoil heaps. The results can provide guidance for the prevention and control of soil erosion and runoff loss in the spoil heaps of production projects. These results have significant value for guiding engineering practice.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:33
Main heading:Soil conservation
Controlled terms:Catchments - Erosion - Rain - Runoff - Silt - Vegetation
Uncontrolled terms:Discharge flow rates - Engineering practices - Environmental issues - Geological disaster - Prevention and controls - Runoff and sediments - Scouring experiments - Soil and water loss
Classification code:442.1  Flood Control - 443.3  Precipitation - 483.1  Soils and Soil Mechanics
Numerical data indexing:Percentage 5.42e+01% to 5.55e+01%, Percentage 5.73e+01% to 9.85e+01%, Percentage 6.87e+01%, Size 2.00e+00m, Percentage 1.00e+01%, Percentage 1.32e+01% to 8.31e+01%, Percentage 1.70e+01%, Percentage 2.69e+01% to 5.63e+01%, Percentage 3.52e+01% to 5.93e+01%, Percentage 4.32e+00% to 2.11e+01%, Percentage 4.55e+01% to 4.64e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.009

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 26>

Accession number:20213610853506
Title:Enforcing energy balance closure by evaporation ratio method and its effect on evapotranspiration estimation of paddy fields
Title of translation:&#33976;&#21457;&#27604;&#27861;&#33021;&#37327;&#24378;&#21046;&#38381;&#21512;&#21450;&#20854;&#23545;&#31291;&#30000;&#33976;&#25955;&#37327;&#20272;&#31639;&#31934;&#24230;&#30340;&#24433;&#21709;
Authors:Liu, Xiaoyin (1, 2); Gao, Mingyi (1); Zhou, Xinyi (1); Xu, Junzeng (1, 2)
Author affiliation:(1) College of Agricultural Science and Engineering, Hohai University, Nanjing; 210098, China; (2) State Key Laboratory of Hydrology-water Resources and Hydraulic Engineering, Hohai University, Nanjing; 210098, China
Corresponding author:Xu, Junzeng(xjz481@hhu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:121-130
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Given its importance as a hydrological variable for agricultural water management, Evapotranspiration (ET) should be accurately quantified. Turbulent flux is the key to the research on water and heat conditions of near surface layer and the basis for further calculation of actual ET. Evaporative fraction (EF, defined as the ratio between latent heat flux and available energy at the land surface), which is known to exhibit variation in response to changes in crop species, soil and meteorologic conditions, plays an important role in interpreting the components of energy balance budget and estimating ET, while such information is scarce for humid rice fields. In order to explore the influence of change characteristic of EF of Water-Saving Irrigated (WSI) paddies and energy balance closure on the calculation of ET, a field experiment was conducted at the experimental research base of the State Key laboratory from 2014 to 2016. Controlled irrigation practice was adopted in the monitoring paddy fields of observation sites from 2014 to 2016. The eddy covariance system was installed in the downwind direction of the test area to observe the Sensible Heat Flux (Hs), Latent Heat Flux (LE), net solar radiation, soil heat flux, air temperature, air relative humidity, atmospheric pressure, wind speed, wind direction and rainfall and so on. The study used the system to monitor the turbulent flux process of WSI paddies in 2014-2016. By means of forced closure of EF and filtering interpolation method, the data of day-time and night flux were corrected respectively, the seasonal variation characteristics of EF in paddy fields were analyzed, the proportion and process changes of turbulent flux before and after energy forced closure were compared, and the influence of energy forced closure on ET of WSI rice fields were explored. The results showed that EF in WSI paddies was larger than that in dry lands, and varied within a narrow range from 0.7 to 1.0. EF reached the maximum which was supposed to be 1.0 at the heading-flowering or milk maturity period. It quickly dropped below 0.8 at the last growth period. From 2014 to 2016, the average of EF was about 0.93. The data showed that latent heat flux accounted for the largest part of turbulent flux, and heat flux was absolutely the main energy consuming-term of water-saving irrigation paddy fields. The turbulent flux was increased significantly after enforced energy closure in the daytime and the diurnal peak value differentiated the most. The latent heat flux and sensible heat flux were increased by 32.1% and 19.8% on average respectively from 2014 to 2016. The latent heat flux after closure correction was much lower than that before correction at night, which indicated that the energy balance of paddies was in an over-closed state during day-night cycle. The sensible heat flux also was increased after correction, but the increment was smaller than that of latent heat flux. The ET calculated after enforced energy closure was increased evidently whether on an hourly or daily temporal scale. Rice ET in the WSI paddies was smaller than the result of during the summer growing season of flooded rice. The average daily ET calculated after enforced energy closure was about 3.85 mm/d from 2014 to 2016, which was 1.31 times of ET before energy forced closure. It indicated that the energy balance deficit resulted in underestimation of ET by eddy covariance system. The correction of the energy balance deficit is necessary and helpful for accurate estimation of crop evapotranspiration. The research results can provide important data support and methods for the accurate measurement of ET in paddies and the extensive research of ET model.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:49
Main heading:Heat flux
Controlled terms:Agricultural robots - Atmospheric humidity - Atmospheric pressure - Budget control - Crops - Energy balance - Evapotranspiration - Irrigation - Latent heat - Water conservation  - Water management - Wind
Uncontrolled terms:Agricultural water management - Controlled irrigations - Crop evapotranspiration - Eddy covariance systems - Evaporative fraction - Experimental research - Hydrological variables - Water-saving irrigation
Classification code:443.1  Atmospheric Properties - 444  Water Resources - 641.1  Thermodynamics - 641.2  Heat Transfer - 821.3  Agricultural Methods - 821.4  Agricultural Products - 931  Classical Physics; Quantum Theory; Relativity
Numerical data indexing:Percentage 1.98e+01%, Percentage 3.21e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.014

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 27>

Accession number:20213610853472
Title:Method for forecasting winter wheat first flowering stage based on machine learning algorithm
Title of translation:&#22522;&#20110;&#26426;&#22120;&#23398;&#20064;&#31639;&#27861;&#30340;&#20908;&#23567;&#40614;&#22987;&#33457;&#26399;&#39044;&#25253;&#26041;&#27861;
Authors:Xu, Min (1); Zhao, Yanxia (2); Zhang, Gu (3); Gao, Ping (1); Yang, Rongming (4)
Author affiliation:(1) Climate Center of Jiangsu Province, Nanjing; 210008, China; (2) Chinese Academy of Meteorological Sciences, Beijing; 100081, China; (3) Meteorological Service Center of Jiangsu Province, Nanjing; 210008, China; (4) Plant Protection and Plant Quarantine Station of Jiangsu Province, Nanjing; 210036, China
Corresponding author:Zhao, Yanxia(zhaoyanxia@cma.gov.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:162-171
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">The first flowering stage of winter wheat depends strongly on meteorological factors, particularly on climate-sensitive elements. Therefore, it is remarkably significant to develop prediction models using machine learning for precise control of wheat scab. In this study, Random Forest (RF), Back Propagation neural network (BP), and Multiple Linear Regression (MLR) were integrated to establish precise prediction models for the first flowering period. The winter wheat phenology and daily meteorology were collected in 10 observation points of Jiangsu Province, China, during the period from 1980 to 2019. Five kinds of parameters were set in the RF and BP. The optimal model of each parameter was achieved after hundreds of times of automatic learning. The determination coefficient, the root mean square error, and the prediction accuracy were applied as the evaluation indicators to evaluate the forecast ability of the models. The results showed that there were obviously interannual fluctuations in the first flowering period of winter wheat, where most regions tended to be ahead of time. There were also great differences in the first flowering period among different regions. The specific difference was more than 21 d between the latest and the earliest days for the first flowering stage of winter wheat. The influence of temperature factors on the first flowering stage was more important than that of precipitation and sunshine factors. The five most important factors were ranked as follows, the active accumulated temperature of daily average temperature &ge;0&#8451; from December of last year to March of that year, the average temperature from December of last year to March of that year, the accumulated days of daily minimum temperature &le;0&#8451; from December of last year to March of that year, the average temperature in March of that year, and the active accumulated temperature of daily average temperature &ge;0&#8451; from December of last year to February of that year. Furthermore, the important characteristic variables were selected to predict the first flowering stage in early April. Correspondingly, RF, BP, and MLR were utilized to predict 5 days ahead at the shortest, while 32 days in advance at the longest. The integrated prediction of the optimal RF model corresponding to the five M<inf>try</inf> parameters was better than that of the single optimal BP model. The highest prediction accuracy was the RF, followed by the BP, and the MLR was relatively low. The RF and BP normally considered the nonlinearity between the predictors, but the MLR could not. Additionally, fewer predictors of MLR could better characterize the impact on the first flowering stage. The RF simulation value for the extreme years at the first flowering stage was smaller than the actual observation value, whereas, the BP presented the excessive simulation of fluctuation range at the first flowering stage. Consequently, the RF can accurately simulate the fluctuation trend at the first flowering period, where the prediction accuracy was over 85.0% among most stations. This finding demonstrates that the RF has high reliability and potential capacity for the forecast application of winter wheat at the first flowering stage.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:34
Main heading:Backpropagation
Controlled terms:Crops - Decision trees - Forecasting - Learning systems - Linear regression - Mean square error - Predictive analytics
Uncontrolled terms:Accumulated temperatures - Back propagation neural networks - Determination coefficients - Integrated prediction - Interannual fluctuations - Meteorological factors - Multiple linear regressions - Root mean square errors
Classification code:723.4  Artificial Intelligence - 821.4  Agricultural Products - 922.2  Mathematical Statistics - 961  Systems Science
Numerical data indexing:Age 1.37e-02yr, Age 8.77e-02yr, Percentage 8.50e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.018

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 28>

Accession number:20213610853545
Title:Effects of mulching time on water use efficiency and yield of cotton in southern Xinjiang simulated by RZWQM2 model
Title of translation:RZWQM2&#27169;&#22411;&#27169;&#25311;&#22320;&#33180;&#35206;&#30422;&#26102;&#38388;&#23545;&#21335;&#30086;&#26825;&#30000;&#27700;&#20998;&#21033;&#29992;&#25928;&#29575;&#21450;&#20135;&#37327;&#30340;&#24433;&#21709;
Authors:Xia, Wen (1); Lin, Tao (2); Chu, Xiaosheng (3); Ding, Dianyuan (4); Yan, An (5); Er, Chen (1); Tang, Qiuxiang (1, 5)
Author affiliation:(1) College of Agronomy, Engineering Research Centre of Cotton of Ministry of Education, Xinjiang Agricultural University, Urumqi; 830052, China; (2) Institute of Cash Crops Research, Xinjiang Academy of Agricultural Sciences, Urumqi; 830091, China; (3) Institute of Water-saving Agriculture in Arid Areas of China, Northwest A&F University, Yangling; 712100, China; (4) Hydraulic Science and Engineering College, Yangzhou University, Yangzhou; 225009, China; (5) Xinjiang Key Laboratory of Grassland Restoration and Environmental Information, Urumqi; 830052, China
Corresponding author:Tang, Qiuxiang(790058828@qq.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:140-150
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Plastic film mulching plays an important role in Xinjiang cotton production. The main function of mulching is to maintain soil temperature and moisture. Plastic film mulching during the whole growth period may lead to soil temperature overheat and root respiration obstruction. In addition, the biodegradable film is expected to replace traditional plastic films. However, several studies have shown that the degradation period of biodegradable mulch film does not match the growth requirements of cotton. Therefore, balancing the relationship among mulching time, crop growth demand and the changes of farmland environmental factors is the key scientific issue to control the pollution of residual plastic film in Xinjiang. Field experiments were conducted in 2016 and 2017 to investigate the mechanisms behind the effects of mulching time on cotton (Gossypium hirsutum Linn.) growth. Six mulching time (40 d, 55 d, 70 d, 85 d, 100 d and whole growing season mulching) were designed. The cotton yield and Water Use Efficiency (WUE) were simulated by using Root Zone Water Quality Model-Version 2 (RZWQM2) model. The parameters of the RZWQM2 model were calibrated and verified by the measured data of 2016 and 2017. Then, the formation processes of biomass, yield and water use efficiency under the influence of different mulching times were simulated at intervals of 3 days, and the similar processes mentioned above were predicted in 2018 and 2019. The objective of this work was to provide a decision method for the model to simulate soil moisture changes and predict crop yields under the conditions of crop mulching, and it would be helpful to determine the reasonable mulching time and reduce the residual plastic film pollution in cotton field on the premise of ensuring high and stable yield. The model validation results showed that the Root Mean Square Error (RMSE) and Mean Square Error (MRE) between the simulated and measured soil water content in each layer of soil ranged from 0.02 to 0.04 cm³/cm³ and 5.90% to 28.66%. The simulation effect of the upper soil layer was not as good as that of the lower soil layer because of more complex temporal and spatial changes of soil surface organic matter content, macropores and other properties than deep soils. The aboveground biomass of two years increased with the extension of mulching time, and the seed cotton yield and WUE showed a trend of first increasing and then decreasing. The growth rate of seed cotton yield and water use efficiency was the highest when the mulching time was 73-81 d, and the yield was higher when the mulching time was mid-to-early August. At this time, the cotton canopy has been closed, and the surface receives less solar radiation, which maximally inhibits soil evaporation, thus reducing the non-productive water consumption and increasing the proportion of productive water consumption. At the same time, the soil ventilation and air permeability are improved after uncovering the film, and the soil microbial activity is enhanced. Therefore, it can be concluded that uncovering film in this period had little effect on cotton growth, and the tensile strength of mulching film at this time was still high, which was more conducive to mechanical recovery. The optimum mulching time of 91-99 d in southern Xinjiang was beneficial to reduce the risk of residual film contamination and maintain high seed cotton yield and water use efficiency. The mechanism of film mulching cycle on key physiological and ecological processes, such as water consumption structure transformation, salt distribution, nutrient migration and absorption in cotton field need further studies. Related work needs to be carried out in the future research, so as to improve the level of cognition and optimize relevant supporting measures.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:47
Main heading:Growth rate
Controlled terms:Balancing - Biodegradable polymers - Cotton - Crops - Efficiency - Entertainment industry - Film growth - Mean square error - Plastic films - Plastics industry  - Pollution control - Soil moisture - Temperature - Tensile strength - Water absorption - Water quality - Water supply
Uncontrolled terms:Above ground biomass - Environmental factors - Organic matter content - Plastic film mulching - Root mean square errors - Root zone water quality models - Soil microbial activities - Temporal and spatial changes
Classification code:445.2  Water Analysis - 446.1  Water Supply Systems - 483.1  Soils and Soil Mechanics - 601  Mechanical Design - 641.1  Thermodynamics - 802.3  Chemical Operations - 815.1  Polymeric Materials - 817.1  Polymer Products - 821.4  Agricultural Products - 913.1  Production Engineering - 922.2  Mathematical Statistics
Numerical data indexing:Age 8.22e-03yr, Percentage 5.90e+00% to 2.87e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.016

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 29>

Accession number:20213610853482
Title:Thermal performance analysis of multiple borehole heat exchangers in the heat conduction and advection coupled layered soil
Title of translation:&#28909;&#28183;&#32806;&#21512;&#30340;&#20998;&#23618;&#22303;&#22756;&#20013;&#31649;&#32676;&#25442;&#28909;&#22120;&#28909;&#24615;&#33021;&#20998;&#26512;
Authors:Jin, Guang (1); Gong, Jianqiang (1); Zhang, Wenjuan (1); Xu, Fangqiang (1); Hu, Aowen (1)
Author affiliation:(1) School of Energy & Environment, Inner Mongolia University of Science & Technology, Baotou; 014010, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:213-221
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Safe, clean, and efficient geothermal energy has been widely popular in various countries, particularly for reducing carbon dioxide emissions and achieving the transition from fossil energy to renewable energy. A rational design of heat pump systems depends mainly on the accurate acquisition for the heat transfer of multiple Borehole Heat Exchangers (BHE) in complex soil. In the present study, a multiple-layered numerical model was established for three-dimensional multiple BHE considering the groundwater advection using Fluent software. The accuracy of the model was validated using a 48h thermal response test data. Two indexes were introduced to evaluate the performance, including the regional thermal efficiency (E) and Dynamic Performance Loss (DPL). Furthermore, an analysis was made to clarify the influence of the location and thickness of the advection layer on the heat transfer of multiple BHE in layered soil. The result indicated that there was a small difference of E between the layered and homogeneous models, when the advection velocity was 100 m/a, and the thickness of the advection layer was large. The heat transfer of multiple BHE in the layered soil was simplified as that in homogeneous soil under this condition. The E of multiple BHE was ignored, only to adjust the position and thickness of the soil layer with different thermal conductivities at a groundwater advection velocity of 100 m/a. It infers that there was a small effect of the variation in thermal conductivity in different depths of soil layers on the heat transfer of multiple BHE. Therefore, the backfill material with higher thermal conductivity should be balanced to use in the backfill layer of buried pipe in the multiple BHE, when the advection velocity of groundwater was 100 m/a. There was no influence of variable equivalent inlet velocity (0.115, 0.158, and 0.237 m/s) and inlet temperature (300, 310, and 320 K) on E the multiple BHE. The downstream DPL of the staggered arrangement multiple BHE with 3 m pipe spacing was only 1.27 percentage points higher than that of the aligned multiple BHE with 6 m pipe spacing, after 2 000 h of continuous operation under the groundwater advection velocity of 100 m/a. It was suggested that the borehole spacing of aligned and staggered arrangement should be 4 and 3 m, respectively, when advection velocity was 100m/a and the thickness of the advection layer was large. The average unit heat transfer rate of multiple BHE with 105 m advection layers increased by 24.4%, compared with that with 35 m advection layer. When the advection velocity was 100 m/a, the inlet temperature was 300 K, and the equivalent velocity in the pipe was 0.115 m/s, there was no effect of the advection layer location on the heat transfer of multiple BHE, whereas there was an obvious effect of the advection layer thickness on the heat transfer of multiple BHE. In addition, the E of multiple BHE was greater, while the DPL was lower, and the rate of stabilization was faster, as the advection velocity was larger. The findings can provide a sound reference for the rational design of multiple BHE in the layered soil with groundwater advection.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:30
Main heading:Thermal conductivity
Controlled terms:Advection - Boreholes - Carbon dioxide - Geothermal energy - Global warming - Groundwater - Heat conduction - Heat pump systems - Soils - Velocity  - Well spacing
Uncontrolled terms:Borehole heat exchangers - Carbon dioxide emissions - Continuous operation - Dynamic performance - Groundwater advections - Staggered arrangement - Thermal performance analysis - Thermal response test
Classification code:443.1  Atmospheric Properties - 444.2  Groundwater - 481.3.1  Geothermal Phenomena - 483.1  Soils and Soil Mechanics - 616.1  Heat Exchange Equipment and Components - 641.1  Thermodynamics - 641.2  Heat Transfer - 804.2  Inorganic Compounds
Numerical data indexing:Percentage 2.44e+01%, Size 1.05e+02m, Size 3.00e+00m, Size 3.50e+01m, Size 4.00e+00m, Size 6.00e+00m, Temperature 3.00e+02K, Temperature 3.20e+02K, Time 1.73e+05s, Time 7.20e+06s, Velocity 1.15e-01m/s, Velocity 2.37e-01m/s
DOI:10.11975/j.issn.1002-6819.2021.11.024

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 30>

Accession number:20213610853437
Title:Simulation of the response of blue and green water to land use change in the Weihe River Basin
Title of translation:&#28205;&#27827;&#27969;&#22495;&#34013;&#32511;&#27700;&#23545;&#22303;&#22320;&#21033;&#29992;&#21464;&#21270;&#30340;&#21709;&#24212;&#27169;&#25311;
Authors:Yang, Xiaoli (1, 2); Li, Wenting (2); Ren, Liliang (1, 2); Gao, Tian (2); Ma, Huijun (2)
Author affiliation:(1) State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing; 210098, China; (2) College of Hydrology and Water Resources, Hohai University, Nanjing; 210098, China
Corresponding author:Ren, Liliang(RLL@hhu.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:268-276
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Land use change is one of the key factors that directly dominate the hydrological process of the watershed. Human activities have changed land-use patterns, thereby indirectly posing an impact on surface infiltration, evapotranspiration, and soil water in the water cycle process. The water resources were also evolved for the water balance in the basin. This study aims to further explore the impact of land-use evolution on the spatiotemporal changes of blue and green water in the Weihe River Basin. A Cellular Automata-Markov (CA-Markov) model was selected to predict the land-use pattern in 2035 using land-use data in 1995 and 2015. Firstly, a standardized preprocessing was performed on the constraint data using a FUZZY module, including elevation, slope, highway, and railway. Secondly, the Markov module was superimposed onto the land use data to obtain the land transfer probability matrix from 1995 to 2015. Thirdly, the multi-criteria evaluation (MCE) module was used to make land-use maps suitability. The CA-Markov model was used to predict land-use structure in 2035. A variety of land-use change scenarios were set to quantitatively analyze the temporal and spatial responses of land-use change and blue-green water using the soil and water assessment tool (SWAT). The results showed that: 1) The CA-Markov model was effective in simulating the land-use pattern in 2015, where the Kappa coefficient was 0.89, suitable for the prediction. 2) During 1995-2035, the cropland was mainly transferred to building land and grassland, while the grassland was mainly transferred to woodland and cropland. Meanwhile, the cropland showed a decreasing trend, with the single attitude of -0.27%, and the building land had the largest growth rate, with the dynamic attitude of 3.75%. 3) The model calibration showed that the evaluation indicators of five hydrological stations all met the standards of R²&gt;0.6 and ENS&gt;0.5, indicating that the SWAT model presented good applicability in each basin of the Weihe River Basin. 4) The blue water increased by 2.38 mm/a, and green water decreased by 18.74 mm/a from 1995 to 2035. By contrast, the blue water increased by 14.82 mm/a, and the green water decreased by 15.23 mm/a from 2015 to 2035. As such, the evapotranspiration was reduced in the basin, but the runoff was increased. 5) Returning cropland to woodlands and grasslands contributed to reducing the blue and green water, where the blue water volume decreased by 9.27, 11.37 mm/a, while the green water volume decreased by 32.94, 21.13 mm/a, respectively, under the extreme land-use scenarios. The main reason was that the cropland increased the runoff and evapotranspiration in the basin. The amount of blue and green water decreased, after a large area of cropland was converted into woodland and grassland. Therefore, it is necessary to reasonably plan the cropland, woodland, and grassland for the control of soil erosion, thereby promoting the improvement of the ecological environment in the study area. These findings can be expected to provide a sound scientific reference for land-use planning and water resources management in the Weihe River Basin.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Land use
Controlled terms:Cellular automata - Evapotranspiration - Forecasting - Forestry - Markov processes - Rivers - Runoff - Soil conservation - Soil moisture - Watersheds
Uncontrolled terms:Ecological environments - Evaluation indicators - Multi-criteria evaluation - Scientific references - Soil and water assessment tool - Spatio-temporal changes - Temporal and spatial - Water resources management
Classification code:403  Urban and Regional Planning and Development - 444.1  Surface Water - 483.1  Soils and Soil Mechanics - 723  Computer Software, Data Handling and Applications - 921  Mathematics - 922.1  Probability Theory
Numerical data indexing:Percentage -2.70e-01%, Percentage 3.75e+00%
DOI:10.11975/j.issn.1002-6819.2021.11.030

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 31>

Accession number:20213610853461
Title:Intelligent fault diagnosis of rolling element bearing using hierarchical multiscale dispersion entropy
Title of translation:&#22522;&#20110;&#23618;&#27425;&#22810;&#23610;&#24230;&#25955;&#24067;&#29109;&#30340;&#28378;&#21160;&#36724;&#25215;&#26234;&#33021;&#25925;&#38556;&#35786;&#26029;
Authors:Yan, Xiaoan (1); Jia, Minping (2)
Author affiliation:(1) School of Mechatronics Engineering, Nanjing Forestry University, Nanjing; 210037, China; (2) School of Mechanical Engineering, Southeast University, Nanjing; 211189, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:67-75
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Fault diagnosis has normally been utilized to effectively identify bearing fault patterns and severities in the whole life cycle in modern intelligent agriculture. In this study, an intelligent fault diagnosis was proposed for the rolling element bearing using hierarchical multiscale dispersion entropy. Firstly, a signal complexity assessment called the hierarchical multiscale dispersion entropy (HMDE) was proposed to integrate the theories and ideas of hierarchical decomposition and multiscale analysis using dispersion entropy theory. Secondly, a swarm intelligence optimization named bird swarm (BSA) was employed to determine the important parameters. The HMDE with the optimized parameter was utilized to extract multilevel and multiscale fault features hidden in the raw bearing vibration signal and avoid empiric selection of HMDE parameters. Finally, the multi-dimensional fault feature matrix was constructed and then fed into the support matrix machine (SMM) for the training of the SMM model. The well-trained SMM model was adopted to automatically identify different fault patterns and severities of rolling bearing. A two-group test of bearing accelerated life was carried out to verify the model. Experimental results showed that the diagnostic accuracy reached 99.66% in the first group, whereas, the diagnostic accuracy of seven (i.e., refined composite multiscale dispersion entropy (RCMDE), generalized composite multiscale permutation entropy (GCMPE), generalized refined composite multiscale sample entropy (GRCMSE), hierarchical fuzzy entropy (HFE), hierarchical sample entropy (HSE), modified hierarchical multiscale dispersion entropy (MHMDE) and hierarchical multiscale permutation entropy (HMPE)) were 95.77%, 87.32%, 93.03%, 90.51%, 92.57%, 98.85%, and 97.03%, respectively. In the second group, the diagnostic accuracy reached 99.34%, whereas, the diagnostic accuracy of seven (i.e., RCMDE, GCMPE, GRCMSE, HFE, HSE, MHMDE and HMPE) were 97.17%, 95.83%, 93.17%, 89.83%, 87.83%, 98.17%, and 96.33%, respectively. It was clearly found that the average accuracy in the first group was improved by the percent point of 3.89, 12.34, 6.63, 9.15, 7.09, 0.81 and 2.63, respectively, where that in the second group increased by the percent point of 2.17, 3.51, 6.17, 9.51, 11.51, 1.17, and 3.01, respectively, compared with the seven (RCMDE, GCMPE, GRCMSE, HFE, HSE, MHMDE, and HMPE). The diagnostic accuracy demonstrated that the different fault patterns and severities of rolling bearings were identified in the whole life cycle. In addition, the broader and richer feature information of bearing faults was achieved with a greatly better identification performance, compared with the traditional fault diagnosis using multiscale or hierarchical entropy. The finding can provide a new idea to improve the fault diagnosis accuracy of rolling bearings in the whole life cycle.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:28
Main heading:Roller bearings
Controlled terms:Agricultural robots - Dispersions - Entropy - Failure analysis - Fault detection - Life cycle
Uncontrolled terms:Diagnostic accuracy - Feature information - Hierarchical decompositions - Hierarchical entropies - Intelligent fault diagnosis - Multi scale analysis - Rolling Element Bearing - Swarm intelligence optimization
Classification code:601.2  Machine Components - 641.1  Thermodynamics - 951  Materials Science
Numerical data indexing:Percentage 8.73e+01%, Percentage 8.78e+01%, Percentage 8.98e+01%, Percentage 9.05e+01%, Percentage 9.26e+01%, Percentage 9.30e+01%, Percentage 9.32e+01%, Percentage 9.58e+01%, Percentage 9.63e+01%, Percentage 9.70e+01%, Percentage 9.72e+01%, Percentage 9.82e+01%, Percentage 9.88e+01%, Percentage 9.93e+01%, Percentage 9.97e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.008

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 32>

Accession number:20213610853550
Title:Microbial diversity and dominant microbial communities in wheat straw aerobic composting
Title of translation:&#23567;&#40614;&#31224;&#26438;&#22909;&#27687;&#22534;&#32933;&#36807;&#31243;&#20013;&#24494;&#29983;&#29289;&#22810;&#26679;&#24615;&#19982;&#20248;&#21183;&#33740;&#32676;&#20998;&#26512;
Authors:Zhang, Yang (1, 2); Ai, Weidang (1); Feng, Haiyan (2); Jin, Xiangdan (3); Chen, Yanwu (3); Zhang, Liangchang (1)
Author affiliation:(1) China Astronaut Research and Training Center, Beijing; 100094, China; (2) School of Earth Science and Rasources, China University of Geosciences, Beijing; 100083, China; (3) Space Science and Technology Institute, Shenzhen; 518117, China
Corresponding author:Ai, Weidang(aiweidang@126.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:206-212
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Wheat is one of the main food crops in the Controlled Ecological Life Support System (CELSS). Wheat planting can lead to the accumulation of solid waste, such as wheat straw. Aerobic composting can be used to ferment wheat straw into organic fertilizers, thereby realizing renewable source recycling in CELSS. However, only a few studies were focused on the microbial diversity of wheat straw in the process of aerobic composting. In this study, an experiment was designed to identify the dominant microbial communities in different typical fermentation phases of wheat straw in aerobic composting. A forced aerobic composting device was adopted, including a plastic barrel, temperature control, and ventilation system. The wheat straw and food wastes were used as the main materials and nutrient additives. Three microbial agents (named QD, DH, and VT) were selected in aerobic composting. The temperature, organic content, C/N ratio, and microbial diversity were measured during the experiment. Three typical fermentation stages were divided to collect the samples for microbial diversity, according to the temperature variations during the composting process. High-throughput sequencing was used to characterize the microbial diversity in various fermentation phases. The results showed that the processes with QD, DH, and VT addition all experienced heating, thermophilic, and cooling phases, where the peak temperature reached 58.2, 54.7, and 53.7 &#8451;, while the high-temperature period remained 9, 6, and 6 d, respectively. The organic contents were reduced by 18.87%, 24.48%, and 22.08%, respectively. The C/N ratio decreased from the initial 30:1 to less than 12:1, which reached the standard of reactor decay. The properties of the reactor were obviously changed under inoculating three kinds of agents. Correspondingly, the agents determined the community structure of microorganisms in the reactor, and the degradation effects on the materials, particularly representing by the peak temperature, high-temperature duration, and degradation rate of organic content. The microbial diversity and dominant communities were different in each typical fermentation phase. Pediococcus, Lactobacillus, and Aspergillus were mainly detected in the heating phase. Specifically, Pediococcus degraded lignocellulose in corn straw silage fermentation, and then converted lignocellulose into monosaccharides. Lactobacillus was commonly found in various yoghurt fermentation processes. Aspergillus was secreting cellulase at degrading cellulose. The dominant microorganisms were Bacillus, Thermomyces, and Rhizomucor in the thermophilic phase. Bacillus was widely distributed in fecal compost, further degrading organic matter and lignocellulosic. Thermomyces and Rhizomucor were highly reactive to the degradation of cellulose and xylan. The dominant microorganism evolved into Chloroflexaceae, Chelatococcus, Thermomyces, and Mycothermus during the cooling phase. Chelatococcus shared the function of degrading penicillin. Chelativorans was a kind of aerobic denitrifying bacteria, further degrading EDTA to some extent. Mycothermus had a certain ability to degrade hemicellulose. There were rich metabolic pathways of microbial communities in the process of composting. The metabolic functions were closely related to sugars, oils, and lignocellulose. This experiment can provide the theoretical basis to screen and cultivate efficient bacterial strains for wheat straw composting. Some solutions also contributed to the resourceful treatment of biomass solid waste (particularly wheat straw) in CELSS.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:31
Main heading:Waste treatment
Controlled terms:Additives - Aerobic bacteria - Aspergillus - Bacteriology - Biodegradation - Cellulose - Composting - Degradation - Denitrification - Fermentation  - Fertilizers - Lignin - Metabolism - Oils and fats - Solid wastes - Straw - Ventilation
Uncontrolled terms:Community structures - Controlled ecological life support systems - Denitrifying bacteria - Fermentation process - High-throughput sequencing - Microbial communities - Organic fertilizers - Temperature variation
Classification code:452.4  Industrial Wastes Treatment and Disposal - 461  Bioengineering and Biology - 643.5  Ventilation - 802.2  Chemical Reactions - 803  Chemical Agents and Basic Industrial Chemicals - 804  Chemical Products Generally - 804.1  Organic Compounds - 811.3  Cellulose, Lignin and Derivatives - 821.5  Agricultural Wastes
Numerical data indexing:Percentage 1.89e+01%, Percentage 2.21e+01%, Percentage 2.45e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.023

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 33>

Accession number:20213610853563
Title:Review of precision agriculture development situations in the main countries in the world and suggestions for China
Title of translation:&#19990;&#30028;&#20027;&#35201;&#22269;&#23478;&#31934;&#20934;&#20892;&#19994;&#21457;&#23637;&#27010;&#20917;&#21450;&#23545;&#20013;&#22269;&#30340;&#21457;&#23637;&#24314;&#35758;
Authors:Chen, Yuanyuan (1); You, Jiong (1); Xing, Zefeng (1); Hu, Hualang (1); Mei, Guotao (2); Shi, Zhifeng (1); Liu, Haiqi (1)
Author affiliation:(1) Key Laboratory of Cultivated Land Use, Ministry of Agriculture and Rural Affairs/Academy of Agricultural Planning and Engineering, Ministry of Agriculture and Rural Affairs, Beijing; 100121, China; (2) Weichai Lovol Heavy Industry Co., Ltd, Weifang; 260000, China
Corresponding author:Liu, Haiqi(liuhaiqimoa@vip.sina.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:315-324
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">It is needed to solve the problems such as relatively low input-output ratio and environmental pollution for Chinese agriculture, with the large amount of agricultural production and consumption. In the background of changing international situation and frequent natural disasters, transforming traditional agricultural production methods in China is an urgent. Driven by emerging technologies such as artificial intelligence, internet of things, cloud platform, automatic control, and new generation communication and so on, precision agriculture came out and was undoubtedly an effective way. Precision agriculture has become a common choice for developing sustainable and high-yield agriculture around the world. In order to obtain the development orientation of precision agriculture and successful practices in the world, this paper reviews the studies on precision agriculture developing status. The aim of this paper is to refine the experiences of precision agriculture developing in the main developed countries and regions and take a look at the precision agriculture development in China. Adopting the method of systematic literature analyzing and summary, Section 1 studies the development status of precision agriculture in the main developed countries and regions, such as America, Japan, European Union and Israel. The idea of precision agriculture was first proposed in America. Until today, America has developed mature precision agriculture system, which benefits from the highly developed technologies. Considering the serious contradiction between large population and less farmland, during 1970s, Japan took measures of consolidating farmland on a large scale and building farmland infrastructure and so on to improve the agricultural production conditions. The agricultural community was also formed to operate collaboratively the agricultural production. The development of precision agriculture in European Union is driving by digital technologies. The water-saving agriculture represented by drip-irrigation and sprinkler-irrigation has made remarkable results in Israel. The development experiences of precision agriculture in the main developed countries and regions enlighten us that: 1) the leading by government is the key; 2) the informatization construction is the foundation; 3) the advanced technology is the core; 4) the cultivation of new type of farmers is the guarantee. Section 2 analyzed the basements and weaknesses for developing precision agriculture in China. The weaknesses are the emphasis in this section. First, the farmland in China is scattered and the infrastructure is not perfect. Taking the informatization perspective, even though number of agriculture related information systems exist, the data and information are not interoperable between these systems. Second, at the present stage, we cannot acquire the temporal and spatial continuous agricultural information due to the rarity domestic satellite data and ground sensors for agriculture monitoring. Third, automatic variable operating system and equipment are lacking since the technology integration of information technology, communication and agricultural machine has not been achieved. Fourth, insufficient high-quality agricultural talents. Facing these weakness and Chinese conditions, Section 3 provided five suggestions to develop precision agriculture in China. Firstly, our government should overall plan and give guarantee in police making, infrastructure construction and financial support, etc. Secondly, we should improve the agricultural production condition through expanding moderately the operating scale of farmland and constructing the field infrastructure net and the national agricultural information platform. Thirdly, the key technology research, such as the information retrieval using remote sensing and technology integration of communication, automatic controlling, spatial information and smart machinery must be focused. Fourthly, the new type of personnel in agricultural field can be cultivated. Fifthly, pilot demonstration can be carried out according to the regional difference.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:76
Main heading:Cultivation
Controlled terms:Agricultural robots - Artificial intelligence - Automation - Disasters - Farms - Information use - Interoperability - Machinery - Precision agriculture - Remote sensing  - Sprinkler systems (irrigation) - Water conservation
Uncontrolled terms:Agricultural informations - Agricultural productions - Agriculture development - Development orientations - Environmental pollutions - Informatization constructions - Infrastructure construction - Water-saving agricultures
Classification code:444  Water Resources - 723.4  Artificial Intelligence - 731  Automatic Control Principles and Applications - 821  Agricultural Equipment and Methods; Vegetation and Pest Control - 903.3  Information Retrieval and Use
DOI:10.11975/j.issn.1002-6819.2021.11.036

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 34>

Accession number:20213610853456
Title:Effects of fuel diluting low-viscosity oil on lubrication property of cylinder liner piston ring in diesel engine
Title of translation:&#29123;&#27833;&#31232;&#37322;&#20302;&#40655;&#24230;&#26426;&#27833;&#23545;&#26612;&#27833;&#26426;&#32568;&#22871;&#27963;&#22622;&#29615;&#28070;&#28369;&#24615;&#33021;&#30340;&#24433;&#21709;
Authors:Xu, Bo (1); Yin, Bifeng (1); Jia, Hekun (1); Wei, Mingliang (2); Shi, Kunpeng (2)
Author affiliation:(1) School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang; 212013, China; (2) State Key Laboratory of Power System of Tractor, YTO Group Corporation, Luoyang; 471000, China
Corresponding author:Yin, Bifeng(ybf@ujs.edu.cn)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:60-66
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">The cylinder liner-piston ring is one of the most significant friction pairs in diesel engines. This study aims to explore the effects of fuel diluting low-viscosity oil on the lubrication property. Taking a farm diesel engine as the research object, the typical wall wetting was utilized to clarify the variation in the lubricant viscosity of diluting oil. The results indicated that the lubricant viscosity first dropped rapidly, and then remained stable, as the diluting ratio increased. Specifically, the lubricant viscosity dramatically declined by 44.9%, when the diluting ratio of oil rose from 0 to 10%, whereas, the dynamic viscosity decreased by 38.8% when the diluting ratio of oil was continuously elevated from 10% to 30%. It infers that there was a great effect of a little fuel diluting in the lubricating oil on the lubricant viscosity, while this effect became weaker than before when the diluting ratio reached a critical value. A mixed lubrication model was then built to investigate the tribological properties of the cylinder liner-piston ring, where the percentage of fuel diluting lubricant was changing. The simulated data showed that the minimum thickness ratio of fuel film decreased significantly, as the diluting ratio rose, indicating that the specific thickness of fuel film decreased between the cylinder liner-piston rings in a diesel engine. The area of hydrodynamic lubrication also decreased on the friction pair of the cylinder liner-piston rings, while the mixed lubrication area expanded with the increase of the fuel dilution ratio. Furthermore, the thickness of the oil film was too thin between the friction pair of cylinder liner and piston rings, especially at the diluting ratio of 30%. It was found that the whole process was in a mixed lubrication state, where the fuel lubrication was not enough. The hydrodynamic lubrication was therefore dominated by the mixed lubrication between cylinder liner and piston ring when the external load of the piston ring was relatively small. Even if the viscosity of lubricant was very low, a certain thickness of the oil film was also enough to bear the external load. Correspondingly, the external load of the piston ring was extremely large, while the oil film thickness was very thin in the compression stroke and expansion stroke. The mixed lubrication between cylinder liner and piston ring was dominant in the whole process, where the pressure of the oil film cannot fully bear the external load eventually. Additionally, the area of mixed lubrication was extended to the threshold, as the region of hydrodynamic lubrication shrank constantly, where the film pressure declined, while the asperity friction force increased significantly. Therefore, the average asperity pressure increased in turn to nearly double times at a 30% diluting ratio, compared with that without dilution. As such, the probability and pressure of direct contact surface were higher between the cylinder liner-piston rings near the top dead center of reciprocating stroke, when much more diesel fuel was mixed in the lubricating oil. In this case, there was a negative impact on the surface wear of friction pair with the growing diluting ratio. The asperity friction force increased in turn to a large friction, as the dilution ratio increased from 0 to 30%, indicating there was a significant effect on the total friction of cylinder liner and piston ring. The viscosity decreased gradually with the increase of diluting ratio, which made the fluid friction decrease. The asperity pressure also contributed to the asperity friction, thereby to the total friction. In addition, the cycle friction loss on the ring/liner pair decreased at first and then increased, finally reached the lowest point at a 10% diluting ratio. An engine test bench was built to carry out the motored friction test. The testing data verified that the variations of motored torque were consistent with the simulated ones under different diluting ratios. Consequently, potential guidance was that the diluting ratio should be controlled under 20% to keep the lubrication effects in the application of low-viscosity lubricating oil.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:24
Main heading:Lubrication
Controlled terms:Diesel engines - Engine cylinders - Engine pistons - Friction - Fuels - Hydrodynamics - Lubricating oils - Piston rings - Pistons - Viscosity  - Wetting
Uncontrolled terms:Dynamic viscosities - Engine test benches - Hydrodynamic lubrication - Lubricant viscosity - Lubrication property - Mixed lubrication models - Reciprocating stroke - Tribological properties
Classification code:607.1  Lubricants - 607.2  Lubrication - 612.1.1  Internal Combustion Engine Components - 612.2  Diesel Engines - 631.1  Fluid Flow, General
Numerical data indexing:Percentage 0.00e+00% to 1.00e+01%, Percentage 0.00e+00% to 3.00e+01%, Percentage 1.00e+01%, Percentage 1.00e+01% to 3.00e+01%, Percentage 3.00e+01%, Percentage 3.88e+01%, Percentage 4.49e+01%
DOI:10.11975/j.issn.1002-6819.2021.11.007

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 35>

Accession number:20213610853577
Title:Fish behavior simulation in fishway based on agent and cellular automata
Title of translation:&#22522;&#20110;&#26234;&#33021;&#20307;&#21644;&#20803;&#32990;&#33258;&#21160;&#26426;&#30340;&#40060;&#36947;&#20869;&#40060;&#31867;&#34892;&#20026;&#27169;&#25311;
Authors:Wang, Jingyang (1, 3); Qie, Zhihong (1); Sun, Shuangke (2); Zhang, Chao (2)
Author affiliation:(1) College of Urban and Rural Construction, Hebei Agricultural University, Baoding; 071001, China; (2) State Key Laboratory of Watershed Water Cycle Simulation and Control, China Institute of Water Resources and Hydropower Research, Beijing; 100038, China; (3) National Agricultural Engineering Technology Research Center of Northern Mountain Area, Baoding; 071001, China
Corresponding author:Qie, Zhihong(qiezhihong@163.com)
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:239-248
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Fish passing is closely related to the water flow and fish behavior in a fish-way experiment. The complex mechanism is often simulated on the basis of the flow field in most model tests, although the numerical simulation is still time-consuming and laborious. Moreover, a typical fish is generally selected to conduct the fish passing experiments, but the fish habits vary mainly on the type of fish, particularly on the contradiction of "fishway cannot meet the needs of all fish". Therefore, it is very necessary to consider the fish behavior in the numerical simulation of the flow field in the fish-way. An Agent-based model was widely used to simulate the fish behavior in recent years. However, the complicated calculation and difficult implementation usually occur especially in the case of complex behavior in the fish movement. Alternatively, a Cellular Automata (CA) model was highly suitable for the various complex systems. In this study, a feasible fish behavior model was proposed for the fish movement system in the fish-way using the integrated Agent-CA. The fish was treated as agents with independent behavior, where each agent was randomly chosen in the direction of movement through the probability of grid attraction, thereby evolving the whole process of fish behavior in the combined Agent-CA model. The model assumed that the different movement modes were taken for the fish, according to the velocity fields. Three velocity zones were divided according to fish behavior. The variety of movement patterns were set in each velocity field, while the probability of grid attraction was calculated using the patterns of fish movement behavior in the model. The patterns of fish movement behavior included obstacle-avoiding, mainstream seeking, random, upstream forward, upstream backward, and sprint behavior. A field experiment of fish passing was conducted to verify the efficiency of the model in the simulation. First of all, three kinds of vertical slot fish-ways were built with G/B=0.1, 0.25, and 0.5, by changing the relative length G/B of the guide wall. An experimental fish was selected as an eighty-five grass carp with a body length range of (10&plusmn;2) cm. Secondly, the fish experiments were conducted in the three types of vertical slot fish-ways to record the track, particularly the characteristic track. And then, the velocity fields of three fish-ways were calculated using CFD numerical calculation, thereby serving as the Cellular space data in the fish behavior model. Finally, a randomly generated Agent (fish) was selected to simulate the fish behavior, with the body length in the range of (10&plusmn;2) cm in the last fish-way chamber. The distribution of simulated and characteristic track of the Agent (fish) was obtained after repeating 85 times. Specifically, the scope of simulated track (W/B) for G/B=0.1, 0.25 and 0.5 were 42.5%, 1.1%, and 34.4%, while, the scope of simulated characteristic track (W/B) for G/B=0.1, 0.25 and 0.5 were 23.5%, 7.7%, and 2.3%, respectively. The data demonstrated that the constructed model can represent the main track of actual fish, but it is difficult to simulate the movement of a few fish deviating from the mainstream. The Agent-CA fish behavior model in fish-way can greatly contribute to clarifying the behavior laws of fish movement in modern aquaculture production.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:35
Main heading:Fish
Controlled terms:Autonomous agents - Cellular automata - Computational fluid dynamics - Computational methods - Fisheries - Fishways - Flow fields - Flow of water - Numerical models - Robots  - Transpiration - Velocity
Uncontrolled terms:Agent-based model - Cellular space - Complex mechanisms - Field experiment - Movement pattern - Numerical calculation - Obstacle-avoiding - Relative length
Classification code:461.9  Biology - 631.1  Fluid Flow, General - 631.1.1  Liquid Dynamics - 723.5  Computer Applications - 731.5  Robotics - 921  Mathematics
Numerical data indexing:Percentage 1.10e+00%, Percentage 2.30e+00%, Percentage 2.35e+01%, Percentage 3.44e+01%, Percentage 4.25e+01%, Percentage 7.70e+00%
DOI:10.11975/j.issn.1002-6819.2021.11.027

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.

<RECORD 36>

Accession number:20213610853526
Title:Effects of hydrochloric acid washing and torrefaction pretreatment on the components of bio-oil from sweet sorghum straw pyrolysis
Title of translation:&#30416;&#37240;&#27927;&#28068;&#19982;&#28888;&#28953;&#39044;&#22788;&#29702;&#23545;&#29980;&#39640;&#31921;&#31224;&#31174;&#28909;&#35299;&#29983;&#29289;&#27833;&#32452;&#20998;&#30340;&#24433;&#21709;
Authors:Chen, Dongyu (1); Zhang, Ting (1); Huang, Shunchao (1); Gao, Dongxiao (1); Li, Jin (1); Liu, Xinyue (1); Niu, Weisheng (1); Liu, Yueyang (1); Wang, Zhefeng (1); Kang, Yujia (1)
Author affiliation:(1) College of Engineering, Shenyang Agricultural University, Shenyang; 110161, China
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:37
Issue:11
Issue date:June 2021
Publication year:2021
Pages:222-229
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:<div data-language="eng" data-ev-field="abstract">Biomass has drawn much attention, due to renewable and green energy against environmental degradation and energy shortage in recent decades. Pyrolysis of biomass in anaerobic/anoxic conditions can be an important way to produce high value-added biofuels, such as alkanes, hydrocarbons, aromatics, and phenol derivatives. However, the bio-oil from biomass direct pyrolysis is a type of complex oxygen-containing mixture, composed of organic acids, aldehydes, ketones, alcohols, phenols, and sugars. The bio-oil is difficult to be directly used, because of high acidity, low calorific value, and thermal stability. In this study, a combination of hydrochloric acid washing and torrefaction pretreatment was proposed to improve the quality of bio-oil from biomass pyrolysis, in order to deal with the high oxygen content, strong corrosiveness, and a wide variety of compounds in bio-oil. The physical and chemical properties of sweet sorghum straw were measured before and after pretreatment. The results showed that the simple pickling was beneficial to the generation of volatiles, whereas, the torrefaction pretreatment alone reduced the ratio of H/C and O/C, while increased the energy yield up to 95.13%, particularly on the increased generation of carbon. The combination of pickling and torrefaction pretreatment also significantly increased the biochar and non-condensable gases. A pyrolysis test was carried out in a horizontal tube furnace (OTF-1200X). The high purity N<inf>2</inf> was used as the protective gas, and the flow rate was 100 mL/min. The program was set to raise the temperature to 500&#8451;, and the quartz boat containing 10 g samples was quickly pushed into the central constant temperature section of the tubular furnace. At this time, the temperature changed within &plusmn;2&#8451; and returned to 500 &#8451; within 1 min. The heating stopped after 30 min. The test results showed that the acid washing, torrefaction, and combined pretreatment reduced 62, 58, and 68 compounds in the bio-oil from sweet sorghum straw pyrolysis, compared with 111, respectively, while the contents of ketones, acids, and furans were all reduced. There was a weak catalytic effect of most metal ions that were removed by pickling on the acetyl group in the pyrolysis process. A significant decrease was observed in the acetic acid content and the acidic components in the bio-oil for a better corrosion resistance of bio-oil. Furthermore, the pickling and torrefaction pretreatment improved the carbohydrate compounds, and the precious D-Allose, a kind of very rare monosaccharide in nature, particularly with the very limited synthesis amount but a high medicinal value. Allosose was expected to inhibit the proliferation of tumor cells, while protecting islet &beta; cells of diabetic animals. In addition, the combined pickling and pretreatment also promoted the formation of nonanoic acid and valeric acid, with a high yield of furfural, where the yield was higher at about 500&#8451;. Furfural was a kind of chemical product with high added value, widelyused in resin, varnish, and organic reagent in the food industry. Simple torrefaction was beneficial to increase the relative content of cellulose in biomass, rich in -OH functional group, thereby for the high content of phenols in bio-oil. Although no new substances were formed, the pH value was significantly improved in the bio-oil.<br/></div> &copy; 2021, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Number of references:43
Main heading:Hydrochloric acid
Controlled terms:Aldehydes - Aromatic hydrocarbons - Biomass - Corrosion resistance - Furfural - Heating furnaces - Ketones - Metal ions - Metals - Oils and fats  - Oxygen - pH - Phenols - Pickling - Pyrolysis - Saturated fatty acids - Washing
Uncontrolled terms:Biomass pyrolysis - Combined pre treatments - Constant temperature - Horizontal tube furnaces - Non-condensable gas - Phenol derivatives - Physical and chemical properties - Pyrolysis process
Classification code:531.1  Metallurgy - 539  Metals Corrosion and Protection; Metal Plating - 539.1  Metals Corrosion - 801.1  Chemistry, General - 802.2  Chemical Reactions - 804  Chemical Products Generally
Numerical data indexing:Mass 1.00e-02kg, Percentage 9.51e+01%, Time 1.80e+03s, Time 6.00e+01s
DOI:10.11975/j.issn.1002-6819.2021.11.025

Database:Compendex
Compilation and indexing terms, Copyright 2022 Elsevier Inc.