<RECORD 1>
Accession number:201446200463
Title:Application effects on side hole open plug during tomato seedling
Authors:Yan, Shi (1); Zhang, Liying (1); Wu, Zhanhui (1); Yu, Pingbin (1); Wu, Zhen (2); Liu, Mingchi (1)
Author affiliation:(1) Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing , China; (2) College of Horticulture, Nanjing Agricultural University, Nanjing , China; (3) Key Laboratory of Urban Agriculture (North), Ministry of Agriculture, Beijing , China
Corresponding author:Liu, Mingchi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:250-256
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:At present, plug seedling cultures are common in China. The traditional plug has a hole on the bottom, which could cause the root growing through the bottom hole, thus the roots will be easily hurt when moving and plug needs to water frequently, which wasted water. In order to solve these problems, Beijing Vegetables Research Center(BVRC)developed the side opening plug, open double vertical holes surrounding each plug, each vertical hole is not lower than the bottom of the plug, which would help by keeping water in the plug. At the same time, it could avoid the roots growing through the bottom. To understand the effects of this new side opening plug method, tomato (Solanaceous vegetables) was used as the test materials in this paper. And we observed the effects of different opening methods in summer on seedlings' growth, development and water use efficiency. The main contents are as follows: Tomato cultivar 'Ouguan' was used as materials, to study the effects of the side opening and bottom opening plug methods on seedlings' growth and water use efficiency in summer. The test had two treatments, bottom opening and side opening; each treatment was repeated 4 times. In order to precisely control the amount of watering, the water was injected to each plug by a gun. The lower limit for irrigation was substrate water content decreasing to 50% of the maximum moisture capacity. Irrigation lower limit and upper limit was determined by the weighing method. Every time before and after irrigation, the weight of the trays were recorded. The amount of water irrigated and the outflow water were recorded. We also recorded the plant growth index. The results showed that the seedlings in side opening trays grew better than those in bottom opening trays in summer and autumn. The seedlings growing in side opening plug are higher and thicker with a larger biomass and higher seedling index (0.0178, 22.76%). During the whole seedling stage, the average watering amount is 25.58 kg of the side opening plugs, which is 11.7% less than bottom opening treatment. The results have shown that, the side opening plug method could promote the seedling growth and save water. The new tray supplies the seedling with a better environment, including water, fertilizer, gas and temperature, which make the tomato seedlings grow well, effectively increasing the biomass of the seedlings and seedling index. The new tray can also reduce the use of water and save labor.
Number of references:22
Main heading:Growth (materials)
Controlled terms:Cultivation - Ecology - Fruits - Irrigation - Vegetables - Water conservation - Water content
Uncontrolled terms:Application effect - Bottom hole - Moisture capacity - Plug seedling - Seedling growth - Side hole open plug - Tomato seedlings - Water use efficiency
Classification code:444 Water Resources - 454.3 Ecology and Ecosystems - 821.3 Agricultural Methods - 821.4 Agricultural Products - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.030
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 2>
Accession number:201446200435
Title:Design and test of drive and control system for electric wheeled mobile car
Authors:Zhang, Tiemin (1); Huang, Han (1); Huang, Penghuan (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou , China
Corresponding author:Zhang, Tiemin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:11-18
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Electric wheeled mobile car plays an important role in agricultural production, but when the mobile car's loads or road conditions change, the drive motor controller of the existing wheeled mobile car is difficult to control the motor efficiently and in real time, leading to difficulties in modularization and productization. Therefore, on the basis of the architecture developed in laboratory, a system for driving and controlling the motor of the car was developed, and a master-slave control system structure based on the main control chip STM32F103RCT6 and the underlying motor control chip ATMEGA48PA was proposed. In this paper, the drive control system included a control board and six driver boards, and master-slave electric wheel drive control system, steering drive control systems, overload and undervoltage alarm circuit of four-wheel drive moving car were designed. Following the transmission speed signal, the signal and various control signals of the host machine or hand control board changed with speed that was solved by the main control chip, and then the speed of the 4 brushless DC motor and the cornor of the 2 DC motor were controlled, allowing the car to achieve driving, steering, translation, rotation and braking. The control system used the main control MCU STM32F103RCT6 to calculate the mathematical model of the car and got the respective speed of the four driving wheels for the torque distribution of the drive motor, and then controlled the speed of the four in-wheel motors, the angle of the two steering motors and two breaking motors. Through the control of the motors, the car could be kept straight road, cornering, parallel displacement and rotation. The commutation mode of the BLDC motor driver control system was controlled by MCU ATmega48PA. The control system used the driver chip IR2113 to control the MOSFET, and calculated the pulse signal of the motor's internal hall sensor for the speed detection of the brushless DC motor, and the over current protection circuit was based on the amplifier LM358. The system used the kinematic strategy, that was, when car turned left, turning into a left turn signal acquisition angle on the left side of the wheel, the gathering speed signal was set to the left of the wheel speed; when car turned right, turning into a right turn signal acquisition angle on the right side of the wheel, the gathering speed signal was set to the right side of the wheel speed. According to the equations of motion car, the angle and the other side of the wheel speed signal was calculated. The drive control system has achieved a four-wheel drive and four-wheel independent electronic differential, and has initially achieved the distribution of torque; under the effect of the control system, the four-wheel car can run smoothly and reliably, and can run with a load in the cement pavement, dry dirt roads, slopes and meadows, which basically meets the demand for car transport and operations at the facility agriculture. A series of experimental results show that, the brushless DC motor drive control system has stable performance, reliable data communications, open source, modular controllers. The developed control system of four-wheel car has achieved the four electronic differential and torque distribution, and has realized effective control of car's four-wheel drive moves. The car with stable and reliable system performance and better load performance, can meet the needs of agricultural transportation and agricultural operations, reduce people's physical labor, and improve production efficiency.
Number of references:20
Main heading:Brushless DC motors
Controlled terms:Agricultural machinery - Agriculture - Alarm systems - All wheel drive vehicles - Automobile steering equipment - Behavioral research - Control systems - Controllers - DC motors - Digital storage - Electric drives - Electric motors - Equations of motion - Four wheel steering - Hall effect transducers - Mathematical models - Modular construction - Open systems - Roads and streets - Signal analysis - Signal processing - Speed - Torque - Vehicles - Wheels
Uncontrolled terms:Agricultural operations - Agricultural productions - Brushless dc motor drives - Electronic differential - Four-wheel drives - Master-slave control systems - Mobile car - Wheel-hub motors
Classification code:405.2 Construction Methods - 406.2 Roads and Streets - 421 Strength of Building Materials; Mechanical Properties - 432 Highway Transportation - 601.2 Machine Components - 662 Automobiles and Smaller Vehicles - 662.4 Automobile and Smaller Vehicle Components - 663 Buses, Tractors and Trucks - 663.2 Heavy Duty Motor Vehicle Components - 705 Electric Generators and Motors - 714 Electronic Components and Tubes - 716.1 Information Theory and Signal Processing - 722 Computer Systems and Equipment - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 732.1 Control Equipment - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 914.2 Fires and Fire Protection - 921 Mathematics - 931.1 Mechanics - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2014.19.002
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 3>
Accession number:201446200462
Title:Design and cooling effect of cooling fan-duct displacement ventilation system with up-fixing diffusers in beef cattle barn
Authors:Liu, Tongshuai (1); Liu, Jijun (1); Wang, Meizhi (1); Jin, Wei (1); Chen, Zhaohui (1); Yang, Shitang (3)
Author affiliation:(1) College of Animal Science and Technology, China Agricultural University, Beijing , China; (2) State Key Laboratory of Animal Nutrition, Beijing , China; (3) Gao'an Yufeng Aguriculture Co., Ltd, Gao'an , China
Corresponding author:Chen, Zhaohui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:240-249
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to search for an effective cooling system that is energy saving with low running cost in beef cattle barns, this study investigated the displacement ventilation with up-fixing diffusers system to reduce heat stress of grain-fed beef cattle using an evaporative cooling air conditioner combining fabric air dispersion with rational layout and opening design. Four wet curtain cooling fans with air volume at 12 000 m<sup>3</sup>/h and 1 kW of electric power were used as the cooling source. Along the wall, four fabric ducts were connected to one cooling fan paralleled to the longitudinal wall. The diameter of the duct was 0.8 m and the bottom of the duct was 2.1 m from the floor. The duct was designed with twenty rows of big holes with 4.0 mm of diameter and 10 degrees to the vertical direction, twenty rows of small holes with 2.0 mm of diameter and 10mm from the big hole respectively. Both small and big holes directed the cooling air to the cattle bodies. As a result of the designing, the wind velocity gradient was developed at the same distance from the openings, which could avoid large jet entraining and thereby facilitated the displacement ventilation. The design of this experiment was validated with numerical simulation based on computational fluid dynamics (CFD), and the time of running and stopping the cooling system was set according to experimental measurement. Wind speed around the cattle was 0.5 m/s faster than the wind speed of feeding aisle at average. However, wind speed near the floor was less than 0.5 m/s which fits the requirement of displacement ventilation. The temperature and humidity difference of the vertical height between 2 m and 3 m from the floor in treatment barn were (1.11±0.11) and6.1%±0.5% respectively, while the difference in the control barn between 2 and 3 m from the floor were (0.6±0.05) and 3.9%±0.3% respectively. The results showed that cooling air from the fabric air dispersion mainly flowed to the area where the cattle stood, and that the temperature and humidity gradient in the treatment barn was larger than the control barn with using the ceiling fan, thus the system achieved locally cooling and reduced the energy waste. In addition, during 10:00-18:00, the average temperature and humidity of treatment barn were (31.5±0.7) and 78.6%±4.4% respectively,whereas those of the control barn were (36.4±1.4) and 51.8%±10.3% respectively. There was a significant difference of average temperature and humidity in both the treatment and control barns (P<0.01). Compared with the control barn, during 10:00-18:00, the heat load index (HLI) was 8.1 lower in the treatment cattle barn, the respiration rate and average daily body weight gain was significantly different by reducing 12 breaths per minute (P<0.01) and increasing 0.37 kg (P<0.01) in the treatment cattle barn, respectively, which demonstrated this design of ventilation could be effective to alleviate heat stress and improved the production performance of the beef cattle. However, the relative humidity and the concentration of CO<inf>2</inf> and NH<inf>3</inf> in the treatment barn was higher compared to the control barn, as a result of the shortage of air circulation outside, but the air quality in the treatment barn still could meet the requirement of relative industry standards. This study could provide parameters and suggestions for cooling fan-duct cooling system design, thus optimize and improve the cooling effect of the system.
Number of references:31
Main heading:Cooling
Controlled terms:Air quality - Air quality standards - Beef - Carbon dioxide - Computational fluid dynamics - Cooling systems - Design - Dispersions - Ducts - Evaporative cooling systems - Farm buildings - Floors - Gas dynamics - Humidity control - Jets - Meats - Quality control - Temperature - Thermal stress - Thermoelectric equipment - Ventilation - Waste treatment - Wind
Uncontrolled terms:Air dispersion - Beef cattle - Displacement ventilation - Displacement ventilation system - Evaporative cooling - Production performance - Temperature and humidities - Vertical direction
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 443.1 Atmospheric Properties - 452.4 Industrial Wastes Treatment and Disposal - 615.4 Thermoelectric Energy - 631.1 Fluid Flow, General - 631.1.2 Gas Dynamics - 641.1 Thermodynamics - 641.2 Heat Transfer - 643 Space Heating, Ventilation and Air Conditioning - 804.2 Inorganic Compounds - 822.3 Food Products - 902.2 Codes and Standards - 913.3 Quality Assurance and Control - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.029
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 4>
Accession number:201446200472
Title:Applications of near field communication of internet of things in supply chain information system of agricultural products
Authors:Sun, Xu (1); Yang, Yinsheng (1); Guo, Hongpeng (1)
Author affiliation:(1) School of Biological and Agricultural Engineering, Jilin University, Changchun , China; (2) Jilin Technology College of Electronic Information, Jilin , China
Corresponding author:Yang, Yinsheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:325-331
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Agricultural products safety has become an important global public-health issue. With the exposure and the emergence of some agricultural products' quality and safety issues in China, safety issues for the quality of agricultural products has become the bottleneck of the sustainable development of agricultural and agricultural products for import and export trade. In response to the risk in the agricultural products supply chain and to improve services, the traceable platform of the agricultural products supply chain is highly required. Quality problems of agricultural products could occur in every aspect of the agricultural products supply chain, including breeding, processing, distribution, and sale. So not only policies, but also technical supports are needed to ensure the quality and safety of agricultural products and to bottom out the safety hazards. In response to these issues, this paper took broiler as the object of study and designed and developed a information system platform of the agricultural products supply chain based on near field communication (NFC) and internet of things. The integration applications of NFC technology and internet of things have become a focus research issues at home and abroad. In this paper, we reviewed supply chain information systems research progress of domestic agricultural products, summarized the key function of information technology in the agricultural supply chain and information systems platform, and analyzed the application feasibility of NFC technology in the agricultural supply chain information systems. In this paper, we designed chicken supply chain information system framework based on the integration applications of NFC and internet of things, and designed hierarchical, data structure, information processing of information system. This information systems platform has the following characteristics:1) It had a monitoring function of broiler farming, and can track and trace all aspects of information from breeding, production, processing, and distribution to sale; 2) It bringed out informationization on the production and management of enterprises, and achieved all-the-way monitoring of broiler's quality and safety through the construction of information technology; 3) It had three functions including feed and culture environment etc monitoring, early warning of broiler's epidemic, and early warning of the risks of broiler's quality and safety, which facilitated enterprise management and supervision of broiler's quality for quality supervision departments; 4) Consumers can inquire and complain about broiler product information with the NFC-enabled mobile phone or device; 5) NFC technology can read and write agricultural production, distribution and sale data automatically and can record and store all product information, which completely solve the problem of information distortion of traditional RFID technology; 6) NFC technology can solve the poor security problems of traditional RFID tag. NFC tags required to write data in every aspect of production and circulation, every vendor had the permissions of modify the corresponding sectors only, and prohibited the manufacturers modify data writing by time constraints. When writing data, vendors used geographic information encryption, scrolling encryption, RSA or EDS, and ensured the integrity and authenticity of data. The results showed that the supply chain information system based on the application of NFC technology enabled the broiler supply chain information full record, ensured the safety of each node information of broiler supply chain, improved the efficiency of broiler supply chain, and provided trace and recall examples for other agricultural products.
Number of references:30
Main heading:Information management
Controlled terms:Agricultural products - Agriculture - Cellular telephone systems - Chains - Cryptography - Information systems - Internet - Internet of things - Mobile phones - Mobile telecommunication systems - Network security - Problem solving - Product design - Quality control - Radio frequency identification (RFID) - Safety engineering - Supply chains - Sustainable development - Systems analysis
Uncontrolled terms:Agricultural productions - Agricultural supply chains - Application feasibility - Geographic information - Import and export trade - Integration application - Near field communications - Supply chain information systems
Classification code:602.1 Mechanical Drives - 716 Telecommunication; Radar, Radio and Television - 716.3 Radio Systems and Equipment - 717 Optical Communication - 718 Telephone Systems and Related Technologies; Line Communications - 718.1 Telephone Systems and Equipment - 723 Computer Software, Data Handling and Applications - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 903.2 Information Dissemination - 911.2 Industrial Economics - 912 Industrial Engineering and Management - 912.2 Management - 913 Production Planning and Control; Manufacturing - 914 Safety Engineering - 921 Mathematics - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.19.039
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 5>
Accession number:201446200438
Title:Numerical simulation and test on nozzle spraying uniformity in evaporative condenser
Authors:Zhu, Jinlin (1); Xie, Jing (1); Wang, Jinfeng (1); Du, Zizheng (1); Zhou, Hongjian (3)
Author affiliation:(1) Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai , China; (2) College of Food Science and Technology, Shanghai Ocean University, Shanghai , China; (3) Shanghai Baofeng Machinery Manufacturing Co., Ltd., Shanghai , China
Corresponding author:Xie, Jing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:38-47
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the evaporative condenser, the heat transfer performance was directly influenced by the spraying effect. When the evaporative condenser is in its working state, the cooling water passed through the top spray nozzle, and sprayed uniformly on the outside surface of condenser tubes, and formed a layer of water film. The low temperature water film took away a large amount of heat, the high temperature refrigerant vapor inside the tubes was cooled, and the purpose of the cooling fluid was achieved. In this paper, the spraying effects of two types of nozzles were simulated by CFD numerical calculation software, the real spraying effect was tested on a test platform, and the structure and layout of nozzles were improved at last. In order to get the spraying effect difference of the two types of spray nozzles, the pressure field and velocity field changes were analyzed when the spray nozzles were in different working states. The experimental and simulation results showed that the outer dynamic pressure field of each spray nozzle was irregularly distributed, which was caused by the change of the fluid motion trajectory under the minimum spraying amount. The local dynamic pressure of nozzle two was significantly higher than that of nozzle one. The outer velocity field distribution was directly influenced by the irregular distribution of the dynamic pressure field. The outer dynamic pressure of the two types of spray nozzles were 6000Pa and 13000Pa, and the outer local maximum velocity had reached 3m/s and 5m/s with the water inlet at the velocity of 2m/s. In the simulation, the outer dynamic pressure of nozzle two was always greater than that of nozzle one. The ratio of local dynamic pressure between the two types of spray nozzles was 2.33 when the velocity of water inlet was set to be 3m/s. Compared with spray nozzle one, the condenser cavity static pressure distribution of spray nozzle two was more uniform and reasonable, the local dynamic pressure and spray area were much bigger, and the fluid motion trajectory was simple and clear. The spraying effect could be improved by the design of a shunt channel. At last, the real spraying effect of the two types of spray nozzles was tested on a evaporative condenser test platform. 15 spray nozzles of every type were installed on the water inlet pipeline, and the spraying effect was caught by a high pixel camera when the evaporative condenser was under stable operation state. The water spraying effect showed that spray nozzle two had a much bigger spraying angle and spraying area, and it was better to enhance the spraying effect. In the future study, the internal flow field uniformity of nozzle one can be improved by adding a two-tier shunt platform. Furthermore, the diameter of the shunt base can be increased and more shunt channels can be added on the original base of nozzle two to optimize the spraying water effect and the heat transfer efficiency of the condenser.
Number of references:30
Main heading:Spray nozzles
Controlled terms:Computational fluid dynamics - Computer simulation - Condenser tubes - Evaporative cooling systems - Heat transfer - Nozzles - Numerical methods - Rocket nozzles - Software testing - Steam condensers - Tubes (components) - Velocity
Uncontrolled terms:Dynamic pressure fields - Evaporative condenser - Heat transfer efficiency - Heat transfer performance - Internal flow field - Numerical calculation - Spraying uniformity - Static pressure distributions
Classification code:614.2 Steam Power Plant Equipment and Operation - 616.1 Heat Exchange Equipment and Components - 631.1 Fluid Flow, General - 641.2 Heat Transfer - 644.3 Refrigeration Equipment and Components - 723.5 Computer Applications - 801.1 Chemistry, General - 921.6 Numerical Methods - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2014.19.005
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 6>
Accession number:201446200452
Title:Effects of tillage and crop residue management on soil respiration and its mechanism
Authors:Zhao, Yali (1); Xue, Zhiwei (1); Guo, Haibin (1); Mu, Xinyuan (1); Li, Chaohai (1)
Author affiliation:(1) College of Agronomy, Henan Agricultural University, Zhengzhou , China; (2) Collaborative Innovation Center of Henan Grain Crops, Zhengzhou , China; (3) National Key Laboratory of Wheat and Maize Crop Science, Zhengzhou , China; (4) Zhumadian Academy of Agricultural Sciences, Zhumadian , China
Corresponding author:Li, Chaohai
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:155-165
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In Huang-Huai-Hai area in China, winter wheat (Triticum aestivum)/summer maize (Zea mays) rotation is the dominant two-crop-per-year cropping system. Crop residue removal and subsoil compaction have become limiting factors for yield improvement in the area. Tillage and crop residue retained are two effective ways to improve soil properties and increase crop yield. Soil tillage and crop residue retained can reduce soil bulk density, improve water storage and aeration in the soil, increase soil microorganism and enzyme activities, improve soil biological properties, thus promote plant root growth and increase crop production. However, studies in the past mainly focused on the effects of single tillage or single crop residue retained on soil respiration. There is a need currently for research in the effects of tillage, crop residue retained and their interaction on soil respiration under the two-crop-per-year cropping system. A two-year field study from 2010 to 2012 was conducted to determine effects of tillage practice and crop residue management on soil respiration, soil temperature, soil water content, soil compaction, soil organic carbon content, dry matter accumulation of plant and root in the wheat-corn double crop cropping system. The study was conducted at the Wen County Experimental Station, Henan, China. The experiment was arranged in a split-plot design with three replications. Tillage practice and crop residue management were two factors of interest. The tillage treatment was randomly assigned to main plots and crop residue treatment was randomly assigned to sub-plots. The tillage practice treatments were: moldboard plough (MP) to a maximum depth of 15 cm, deep moldboard plough (DMP) to a maximum depth of 30 cm, and chisel plough (CP) to a maximum depth of 30 cm. All three tillage treatments were implemented after corn harvested in October of 2010 and 2011. In addition to different plough treatments, all plots were disc harrowed before wheat planting. There were no direct tillage implements for corn as corn was seeded using a no-till planter. Crop residue management included two levels: crop residue retained (CRRet) and crop residue removed (CRRem). For the CRRet treatment, the wheat straw produced in 2011 and 2012 remained in fields as straw mulching for the following no-till corns, and the 2010 and 2011 corn stover was also incorporated into soil by tillage implements. For the CRRem treatment, both wheat straw and corn stover were removed from the field. The results indicated that there were significant (P<0.05) effects of tillage and crop residue management on soil respiration. Both soil tillage and crop residue retained significantly (P<0.05) increased soil respiration. Crop residue retained increased soil respiration during winter wheat season, but decreased soil respiration during summer maize season. During the growth period of winter wheat, DMP and CP increased soil respiration by 31.8% and 21.9%, respectively, relative to MP. The CRRet increased soil respiration by 14.3% compared with CRRem. On average, DMP CRRet and CP CRRet treatments increased soil respiration by 45.5% and 38.2%, respectively, as compared with MP CRRem treatment. During the growth period of summer maize, DMP and CP increased soil respiration by 47.6% and 47.8%, respectively, relative to MP, and CRRet decreased soil respiration by 18.0% compared with CRRem. On average, DMP CRRet and CP CRRet treatments increased soil respiration by 19.7% and 22.2%, respectively, compared with MP CRRem treatment. The soil respiration was significantly positively correlated with soil temperature and soil carbon, while negatively correlated with soil compaction. The correlation coefficient of soil respiration and soil temperature was highest among the correlation coefficients that affected soil respiration. Compared with the MP CRRem treatment, the dry matter accumulation of the DMP CRRet and CP CRRem treatments increased by 34.9% and 38.2%, the root dry weight density increased by 45.0% and 39.4%, respectively. Therefore, we concluded that deep moldboard plough or chisel plough with crop residue retained was the most appropriate tillage practice in Huang-Huai-Hai area.
Number of references:33
Main heading:Soils
Controlled terms:Agricultural machinery - Agricultural wastes - Agriculture - Carbon - Compaction - Crops - Cultivation - Grain (agricultural product) - Organic carbon - Soil mechanics - Soil moisture - Straw - Temperature - Tools - Water aeration - Water content
Uncontrolled terms:Affecting factors - Crop residue management - Dry matter accumulation - Root - Soil tillage
Classification code:444 Water Resources - 445.1 Water Treatment Techniques - 483.1 Soils and Soil Mechanics - 536.1 Powder Metallurgy Operations - 603 Machine Tools - 605 Small Tools and Hardware - 641.1 Thermodynamics - 804 Chemical Products Generally - 804.1 Organic Compounds - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2014.19.019
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 7>
Accession number:201446200473
Title:Establishing relationship between hydrophobicity and emulsification of caseins using generalized-regression-neural-network
Authors:Yang, Min (1); Zhang, Keping (2); Wang, Jiangyu (1); Yang, Jitao (1); Yang, Xi (1)
Author affiliation:(1) College of Science, Gansu Agricultural University, Lanzhou , China; (2) College of Engineering, Gansu Agricultural University, Lanzhou , China
Corresponding author:Zhang, Keping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:332-338
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Yaks (Bos grunniens) from the Qinghai-Tibetan plateau are the sole source of milk of local inhabitants. In the past years, yak milk has attracted more and more attention, due to its increasing demand. Yak milk is widely used to produce butter, soft and hard cheeses, yogurt, milk powder, Qula, and casein-containing products. Caseins, the major protein in milk, are commonly used in the food, chemical, cosmetic, and pharmaceutical industries. Yak caseins are widely used to produce high quality food ingredients and soaps, glues, leather polishing reagents, and clothing, among others. However, compared to cow caseins, yak caseins have poor solubility, which affects the other functional properties. The poor solubility of yak caseins is mostly attributed to its conformation. Succinylation is the most frequently used modification method, which changes the conformation and increases the net charge of protein, which improves its functional properties consequently. It was indicated that the reaction conditions were mild and easy to control, the modified level was higher than other chemical modification, and its modification effect was outstanding.
Number of references:24
Main heading:Emulsification
Controlled terms:Casein - Chemical modification - Complex networks - Conformations - Fluorescence - Forecasting - Hydrophobicity - Neural networks - pH - Proteins - Solubility
Uncontrolled terms:Complex relationships - Emulsifying activity - Emulsifying property - Functional properties - Generalized regression neural networks - Pharmaceutical industry - Qinghai-Tibetan plateau - Succinylation
Classification code:722 Computer Systems and Equipment - 723.4 Artificial Intelligence - 741.1 Light/Optics - 801.1 Chemistry, General - 801.4 Physical Chemistry - 802.3 Chemical Operations - 804.1 Organic Compounds - 921 Mathematics - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2014.19.040
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 8>
Accession number:201446200457
Title:Radiometric calibration of low altitude multispectral remote sensing images
Authors:Wang, Pei (1); Zhang, Junxiong (3); Lan, Yubin (1); Zhou, Zhiyan (1); Luo, Xiwen (1)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou , China; (2) Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou , China; (3) College of Engineering, China Agricultural University, Beijing , China
Corresponding author:Luo, Xiwen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:199-206
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The small size and low cost micro-UAV information acquisition technology platforms have been widely applied in agricultural field in recent years. It has become the inevitable trend of development of precision agriculture and has offered a fast and flexible way to acquire data for crop management and monitoring, capable of timely provision of high resolution images. The key technology for remote Sensing information acquisition based on micro UAV in the world, which includes the development of micro UAV remote sensing platforms, information acquisition technology, image processing, and analysis and application of crop management, is reviewed in this paper. Micro UAV mainly has two types: rotor helicopter and fixed-wing aircraft. The rotor helicopter has been used more widely in acquiring information of the field, because it has the ability of taking off and landing vertically, fixed-point hovering, and slow cruising. Japan was the first country that has used the micro-UAV in agricultural production, and is one of the countries that have the best and most mature technologies in using remote UAV in agriculture today. The United States, Netherlands, Israel, and the United Kingdom also have a very good development all over the world. The beginning of research and development of micro UAV in China was much later than the other developed countries, but it has a booming development and grows rapidly. In this paper, parameters and characteristics of different models of the micro UAVs from eight companies in China have been listed for comparison. In remote sensing information acquiring systems, due to the limited load capacity of micro-UAV, digital camera and light-weight multispectral camera are two main instruments that are used on micro UAV for remote sensing information acquiring. How to adjust the posture of airborne remote sensors quickly and accurately so that the detecting target is always in the center of monitoring view, and how to realize remote controlling, image and information capturing, and transmission wirelessly are some of the focuses of UAV remote sensing technology at present. Limited by the stability and load capacity of the micro UAV, the remote sensing image always appears with the defects including a small view, large angle inclination, and serious irregular image overlap. So, solving the problem of correction, matching, mosaicing, fusing, and analyzing of the remote sensing images is one of the most important research work in this field. Nowadays, the main application of micro UAV focuses on the detection of growing nitrogen levels and the generation of fertilization strategy for rice, cotton, and other staple crops. However, the usage of micro UAV is limited due to the following defects: 1) its small size, making it easily influenced by wind, and short battery life; 2) poor accuracy of navigation system and balance control system; 3) serious leakage or reduplication of capturing images caused by the imprecise heading overlapping and routes bending; 4) difficulty of image correcting, matching, mosaicing, fusing, and analyzing for the remote sensing images; 5) the error of UAV equipment and usage is difficult to control. According the review, the further research on key technology focusing on high stability, big load capacity, long life time, and high resolution data for crop management have been proposed. The micro UAV information acquisition platform is a good complement of satellite and aerial remote sensing technologies for monitoring agricultural information and generating prescription maps for precision agriculture.
Number of references:23
Main heading:Remote sensing
Controlled terms:Agriculture - Aircraft control - Calibration - Crops - Cultivation - Defects - Fixed wings - Flight control systems - Helicopter rotors - Helicopters - Image processing - Image reconstruction - Leakage (fluid) - Monitoring - Navigation systems - Nitrogen - Nitrogen removal - Radiometry - Technology transfer
Uncontrolled terms:Cloud removal - Multispectral images - Nitrogen detection - Radiometric - Spectral calibration
Classification code:423 Non Mechanical Properties and Tests of Building Materials - 434.4 Waterway Navigation - 452.3 Industrial Wastes - 652 Aircraft and Avionics - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 802.2 Chemical Reactions - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 911.2 Industrial Economics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 944.8 Radiation Measurements - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.024
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 9>
Accession number:201446200459
Title:Parameter design of LCL filter for three-level converter based on space vector pulse width modulation
Authors:Zhang, Guorong (1); Li, Xun (1); Zhou, Tonglu (1)
Author affiliation:(1) Education Ministry Engineering Research Center of Photovoltaic System, Hefei University of Technology, Hefei , China
Corresponding author:Zhang, Guorong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:214-221
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The neutral-point-clamped (NPC) three-level inverter is used more and more in the grid-connected renewable energy generation system. In order to achieve the lower current harmonic, an LCL filter is also widely utilized due to its superior filtering performance. The LCL filter has the advantages of a high-frequency stopband with good performance and low-frequency compensation ability, but the parameters of LCL are hard to design. Especially the different modulation methods between three-level and two-level inverters, and the different ripple current, all these factors lead to a more difficult design of the parameters. The key of LCL design is the arm-side inductance design, due to the fact that an improper design of arm-side inductance will conduct to a completely different ripple current of the inverter, power loss of the filter components, and larger stress switch stress, thus resulting in poor performance of output current. Moreover, the control of the inverter will be affected. In the design of arm-side inductance, the most important thing is to strike a maximum ripple current. On the basis of establishing the mathematical model of a three-level grid-connected inverter, this paper takes output current control under the unity power factor into consideration, combining with the characters of space vector pulse width modulation (SVPWM) to reach the arm-side ripple current's variation regularity. The maximum ripple current could be obtained at the peak of a grid side current based on this research. There will always be three latest vectors for the synthesis of the reference vector in accordance with the principle of the Nearest Three Vectors (NTV). In addition, seven-segment modulation on the action time allocation of each vector was applied. Considering the worst case, the value of max ripple current can be obtained when the middle vector was neglected, coupled with the engineering demand for ripple current, and upper limits of arm-side inductance can be given. The lower limit of arm-side inductance can be obtained by taking the tracking requirements of grid-side current transient into account, and then the design range of arm side inductance was given. After that, with regard to the effect of LCL filter resonance and the limitation of reactive power in the system, the parameters of the filter capacitor were determined. And the grid-side inductance can be obtained according to the demand of ripple current attenuation of the grid-side current. Synthetically considering the demand for system stability and power loss, the damping resistor was designed after the LCL filter parameters were determined. At last, a simulation was performed at a 30 kW prototype in which the output current was 60A, and in contrast an experimentation was conducted at a 15 kW prototype, the output current was 30A proportionally. Simulation and experimental results validated the correctness of the ripple current in the paper. The ripple current had been well limited to the requirements of the project in the role of the arm-side inductance. At the same time, a good attenuation of ripple current had been obtained by the help of the filter capacitor and grid side inductance, leading to a high quality of output current which was displayed in both simulation and experimentation. The method of the parameter design of LCL which was employed in the paper was much more reasonable, and has a high value in practical applications.
Number of references:23
Main heading:Modulation
Controlled terms:Capacitors - Design - Electric currents - Electric power factor - Experiments - Filters (for fluids) - Inductance - Mathematical models - Power converters - Pulse width modulation - Renewable energy resources - System stability - Vector spaces - Vectors
Uncontrolled terms:Grid connected inverters - Neutralpoint-clamped (NPC) - Output current control - Renewable energy generation - Space vector pulse width modulation - Three-level - Three-level converters - Three-level inverters
Classification code:408 Structural Design - 445.1 Water Treatment Techniques - 525.1 Energy Resources and Renewable Energy Issues - 701.1 Electricity: Basic Concepts and Phenomena - 704.1 Electric Components - 704.2 Electric Equipment - 716 Telecommunication; Radar, Radio and Television - 901.3 Engineering Research - 921 Mathematics - 921.1 Algebra - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.19.026
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 10>
Accession number:201446200439
Title:Performance simulation and experiment of different leading edge back-swept angle on double blade sewage pump
Authors:Chen, Keqiang (1); Shi, Weidong (1); Zhang, Desheng (1); Lang, Tao (1); Cheng, Cheng (1)
Author affiliation:(1) Technical and Research Center of Fluid Machinery Engineering, Jiangsu University, Zhenjiang , China
Corresponding author:Shi, Weidong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:48-54
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The back-swept double blade sewage pump studied in the paper belongs to the new high efficiency non-clogging pump. It has a self-cleaning ability, and can effectively solve the problem of fiber winding and congestion. This research study designed to probe the effect of the leading edge back-swept angle on a forward-extended double blade sewage pump. By changing the leading edge shape to get different degrees of back-swept blade, four models of impellers with different back-swept angles of 60°, 100°, 140°, and 180° were created by BladeGen. According to the structure of the pump, we divided the fluid domain into six parts, namely entrance region, impeller, volute, front chamber, back chamber, and outlet section, which were modeled by Unigraphics NX. ICEM CFD software was used for dividing the structured mesh of each part, and the numerical simulation of the whole flow field was performed based on a standard k-Ε turbulence model and scalable wall function. The total pressure inlet condition and mass flow rate outlet condition were adopted in the computational domains. The impeller was defined as rotating domain with a speed of 1 450 r/min. Both front and back of the pump cover plate walls were set to the rotating walls with the speed of 1 450 r/min. Other domains and walls were defined as static fields or walls. The discrete control equations were based on the finite element of finite volume method. The convective term was a high resolution format and convergence precision was set to 10<sup>-4</sup>. At the same time, the trend of the pump head, efficiency, and power curves were leveling out to ensure the credibility of the calculation results. To further ensure the accuracy of the simulation results, a sewage pump of 100° back-swept angle was produced and tested. Comparison between the numerical simulation and experimental results was presented to prove the accuracy of the numerical simulation. Comparing performance curves concluded from the simulation, we found that the best efficiency point of pump shifts to the high flow condition and the required shaft power increases when the back-swept angle increases from 60° to 140°, and the best efficiency point of the pump apparently decreased when the back-swept angle increased from 140° to 180°. To probe the cause of the efficiency decrease, we did an analysis of the internal flow field when the flow ratio Q/Q<inf>n</inf> was 1.2, and found that, with the back-swept angle β increases, the value and range of turbulent kinetic energy had a sharp increase in the impeller inlet, namely, the hydraulic loss appeared in the inlet. Therefore, by further analysis of the leading edge in axial velocity distribution, it can be known that there are refluxes at the leading edge near the front shroud, which causes large hydraulic losses. And with the back-swept angle increasing, the flow passage near the outer periphery was much narrower, causing the region of reflux to become larger. So it was suggested that the back-swept angle of the leading edge should not more than 140°, otherwise the efficiency of the pump would apparently decrease. The results are instructive for the design and optimization of a forward-extended double blade sewage pump.
Number of references:17
Main heading:Computer simulation
Controlled terms:Computational fluid dynamics - Computer software - Finite element method - Finite volume method - Flow fields - Impellers - Inlet flow - Kinetic energy - Kinetics - Numerical methods - Numerical models - Probes - Pumps - Sewage - Sewage pumps - Supersonic aerodynamics - Turbulence models - Wall function
Uncontrolled terms:Axial-velocity distribution - Best efficiency point - Design and optimization - High-resolution formats - Hydraulic designs - Performance simulation - Swept angle - Turbulent kinetic energy
Classification code:452.1 Sewage - 601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 651.1 Aerodynamics, General - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 921 Mathematics - 921.6 Numerical Methods - 931.1 Mechanics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.19.006
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 11>
Accession number:201446200450
Title:Key area identification of pollution sources of drinking water sources in rural areas
Authors:Cheng, Gongde (1); Yin, Guoxi (1); Xie, Chongbao (2); Zhang, Guohua (2); Yang, Jie (3)
Author affiliation:(1) College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing , China; (2) China Irrigation and Drainage Development Center, Beijing , China; (3) Jiangxi Institute of Soil and Water Conservation, Nanchang , China
Corresponding author:Yin, Guoxi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:139-145
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In the upstream of water sources, many pollutants are output from key pollution areas of water sources, and thus identifying key pollution areas of water sources is a key to protection and pollution control of rural drinking water source. In this paper, a method to directly identify key pollution areas was proposed and applied to investigate the pollution situation of rural drinking water sources in Anjishan reservoir area in 2011. Residential areas, farmlands, mines, and other land use types were identified as the pollution sources based on image classification techniques of remote sensing. Hydrology analysis tools for ArcGIS software were used to determine catchment of Anjishan basin. Batch Sub watershed Delineation tool combined with the distribution of the main pollution sources was used to divide Anjishan basin into 19 sub watershed, and land use areas for each sub watershed were summarized. In rural areas, Anjishan reservoir area was mainly affected by pollutants from non-point sources. So, farmland, aquaculture sewage, mines and rural life were considered as main pollution sources of this area. For these sources, COD (chemical oxygen demand), NH3-N (ammonia nitrogen), TN (total nitrogen) and TP (total phosphorus) were the main pollution factors. Source strength coefficient of each factor for each source was obtained from national reports and amended with survey data. Exceeds bid index method was adopted to calculate the weights of pollution factors based on their contributions rates, and degree of pollution was also calculated based on the weights. The pollution degree of water source for each sub watershed was calculated through degree of pollution of each pollution source and its corresponding land use area. The pollution degree of each sub watershed was converted to pollution concentration based on annual rainfall. Environmental quality standards for surface water in China are often used to assess the condition of water sources. In the standard, Class III is for secondary area of centralized drinking water, class IV is for industrial water and recreational water without direct contact to human body, and class V is for agricultural and landscape water. According to the weight of each pollution factor, the surface water environment index standard S was amended. By comparing the pollution concentration and the amended standard values, the sub watersheds was classified into 5 grades including normal area (S is 0-1.35), general pollution key area (S is 1.35-2.04), secondary key pollution area (S is 2.04-2.75), and key pollution area (>2.75). Among the 19 sub watershed, 4 watershed areas were identified as normal area including watershed 8, 14, 16 and 17; 3 general pollution key areas were 9, 10 and 13; the second key pollution areas were 2; and key pollution areas were 1, 3, 4, 5, 6, 7, 11, 12, 15, 18 and 19. The sub watershed 5, 6, 11 and 12 were identified to be polluted seriously. It indicated that the pollution of drinking water sources in Anjishan was mostly from farmland runoff and residential life. The study suggests that the new method is viable for key pollution area identification of rural drinking water sources.
Number of references:17
Main heading:Pollution control
Controlled terms:Catchments - Chemical oxygen demand - Farms - Geographic information systems - Housing - Image classification - Land use - Nitrogen - Pollution - Potable water - Reservoirs (water) - River pollution - Rural areas - Sewage - Surface waters - Water - Water pollution - Water pollution control - Watersheds
Uncontrolled terms:Anjishan - Classification technique - Drinking water sources - Environmental quality standards - Non-point source pollution - Pollution concentration - Rural drinking waters - Source strength
Classification code:403 Urban and Regional Planning and Development - 403.1 Urban Planning and Development - 441.2 Reservoirs - 444 Water Resources - 444.1 Surface Water - 453 Water Pollution - 454.2 Environmental Impact and Protection - 716 Telecommunication; Radar, Radio and Television - 723.3 Database Systems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2014.19.017
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 12>
Accession number:201446200451
Title:Finite element numerical simulation of Black Locust (Robinia pseudoacacia) and Arborvitae (Platycladus orientalis) roots on slope stability on Loess Plateau of China
Authors:Ji, Jinnan (1); Zhang, Zhiqiang (1); Guo, Junting (2); Tian, Jia (3)
Author affiliation:(1) Key Laboratory of Soil and Water Conservation, State Forestry Administration, Beijing Forestry University, Beijing , China; (2) Department of Biology University of Western Ontario,, London; ON, Canada; (3) Agriculture School of NingXia University, Yinchuan , China
Corresponding author:Zhang, Zhiqiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:146-154
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To investigate the effects of major forestry species roots on slope stability on Loess Plateau of China, we used monospecific stands of Robinia pseudoacacia and Platycladus orientalis as a case study. Tree roots provide positive mechanical influence (i.e. additional cohesion) on slope stability. We used two different methods to determine root additional cohesion in this research, i.e. Wu and Waldron's Model (WM) and revised WM (RWM). WM was developed based on limit equilibrium theory and assumed that all root in soil clods were mobilized in tension and fail simultaneously. Although WM approach was considered as a powerful and widely used method, it overestimated root additional cohesion due to all roots breakage simultaneously hypothesis. Therefore, based on many shear tests, a reduction factor for WM is introduced, which is RWM. The most critical parameters for WM and RWM were root area ratio (RAR) and root tensile strength. In this research, RAR was recorded on the soil trench profile, while root tensile strength was obtained by individual root tensile test. To evaluate tree roots effects on slope stability, a 2-D finite element model with terraced and contrast rectilinear surface shape of slope stability was developed and used to calculate the increase in factor of safety (FoS) due to root additional cohesion. Results showed that whether the land was prepared or not, afforestation can significantly increase slope stability. Moreover Robinia pseudoacacia roots were better that Platycladus orientalis roots on soil reinforcement. Terraced slopes were more stable than rectilinear slopes, regardless of the differences in hydrological regimes between these two terrain morphologies. It was also found that the percentage of FoS increase was larger when considering root additional cohesion simulated by RWM and virtual bare slope than root additional cohesion simulated by WM and RWM for both stands. Numerical sensitivity analyses for root additional cohesion illustrated that the relationship between FoS and additional cohesion was not linear, but exhibited as an asymptotic behavior. In detail, FoS value was stable when root additional cohesion reached the threshold value, which indicated that FoS was not sensitive to root additional cohesion calculation method. In addition, although root additional cohesion varied with the slope location, it was hard to find clear pattern to follow in our stands. However, roots in bottom part of slope always had stronger mechanical effects on slope stability. Therefore, more attention should be paid on the toe of slope and fully exerted its positive role for afforestation managers. This research can provide a basic theory of afforestation mode in spatial distribution and hence control shallow landslide.
Number of references:24
Main heading:Slope stability
Controlled terms:Adhesion - Convergence of numerical methods - Finite element method - Forestry - Landforms - Numerical methods - Plants (botany) - Reforestation - Safety factor - Sediments - Sensitivity analysis - Slope protection - Soils - Stability - Tensile strength - Tensile testing
Uncontrolled terms:Finite element numerical simulation - Limit equilibrium theory - Loess Plateau - Loess plateau of chinas - Numerical sensitivity - Platycladus orientalis - Robinia pseudo-acacia - Root additional cohesion
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 422.2 Strength of Building Materials : Test Methods - 461.9 Biology - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 662.1 Automobiles - 801 Chemistry - 821.0 Woodlands and Forestry - 921 Mathematics - 921.6 Numerical Methods - 931 Classical Physics; Quantum Theory; Relativity - 951 Materials Science - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.19.018
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 13>
Accession number:201446200458
Title:Area extraction of maize lodging based on remote sensing by small unmanned aerial vehicle
Authors:Li, Zongnan (1); Chen, Zhongxin (1); Wang, Limin (1); Liu, Jia (1); Zhou, Qingbo (1)
Author affiliation:(1) Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing , China; (2) Institute of Remote Sensing Application, Sichuan Academy of Agricultural Sciences, Chengdu , China
Corresponding author:Chen, Zhongxin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:207-213
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The information of crop lodging, such as spatial distribution and area, is very critical for agricultural hazard assessment and agricultural insurance claims. It is hard work to measure the area of lodging in a ground survey. A survey method using remote sensing technology is fast and efficient, but it was limited by a lack of available satellite remote sensing data. In recent years, Unmanned Aerial Vehicle (UAV) has been rapidly developed in civil applications. A small UAV remote sensing system in which a UAV carries a digital camera is a portable, stable, and efficient tool for a crop field survey while there is no satellite remote sensing data, but only a few studies about a lodging survey using a UAV were published. There was no study of a survey of maize lodging using a RGB image. Therefore, the authors studied a survey method of maize lodging using some images derived from an UAV remote sensing experiment which was carried out in the Wan Zhuang agricultural high-tech industrial park of the Chinese Academy of Agricultural Sciences (Langfang City, Hebei Province of China) on Sept. 11<sup>th</sup> to 13<sup>th</sup> of 2012. In this experiment, some images of maize lodging were acquired after a lodging event on Sept. 12<sup>th</sup> of 2012. In this study, image features were calculated and summarized first. Three color features and 24 texture features were calculated by processing RGB images using HLS color transformation and co-occurrence texture filters. Mean, variance, coefficient of variation (CV), and relative difference (RD) of image features in normal and lodging maize were summarized. The optimum features for classification of normal and lodging maize were chosen from the 27 features by their coefficient of variation and relative difference. Finally, two methods of lodging area extraction, respectively based on RGB grey level and optimum features, were compared. The result of the image features summary showed that many features had a higher CV or lower RD compared to RGB grey levels, and were not suitable for classification of normal and lodging maize. According to CV and RD, three texture features, including the mean of red, the mean of green, and the mean of blue (RD:59.4%, 45.4%, 48.8%; CV of normal: 10.6%, 7.9%, 8.0%; CV of lodging: 7.5%, 5.6%, 7.2%), having a higher RD and a lower CV compared to a RGB grey level (RD:58.5%, 44.7%, 48.1%; CV of normal: 20.1%, 16.2%, 21.3%; CV of lodging: 14.1%, 12.1%, 16.2%), are optimum indicators for the classification. Compared with measurements of a lodging area, the method based on these optimum classification features (0.3%, 3.5%,6.9%) had lower errors than the method based on a RGB grey level (22.3%, 94.1%, 32.0%). The shadow of a high plant might influence the precision of the classification, but the error is negligible. According to the results of these studies, we may safely draw the conclusion that the method to extract lodging maize area using RGB images of UAV remote sensing based on optimum texture features is accurate.
Number of references:21
Main heading:Unmanned aerial vehicles (UAV)
Controlled terms:Agriculture - Classification (of information) - Crops - Experiments - Extraction - Image processing - Image texture - Insurance - Mobile antennas - Remote sensing - Surveys - Textures
Uncontrolled terms:Agricultural hazards - Classification features - Coefficient of variation - Lodging - Maize - Remote sensing technology - Satellite remote sensing data - Small unmanned aerial vehicles
Classification code:405.3 Surveying - 652.1 Aircraft, General - 716 Telecommunication; Radar, Radio and Television - 716.1 Information Theory and Signal Processing - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 802.3 Chemical Operations - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 901.3 Engineering Research - 911.1 Cost Accounting - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2014.19.025
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 14>
Accession number:201446200442
Title:Influences of finite probe property on soil thermal property estimated by heat pulse technique
Authors:Fu, Yongwei (1); Lu, Yili (1); Ren, Tusheng (1)
Author affiliation:(1) Department of Soil and Water, China Agricultural University, Beijing , China
Corresponding author:Ren, Tusheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:71-77
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil thermal properties, including volumetric heat capacity, thermal diffusivity, and thermal conductivity, are basic physical parameters for determining the change rate of soil temperature, heat storage and transfer. The heat pulse technique, with the advantages of relative easy operation, minimal soil disturbance, and making repeated and automatic readings, has been used widely for measuring in-situ soil thermal properties. A heat pulse is emitted from a line source enclosed in a stainless heating needle and the temperature rises with time at a shorter distance from the heater are recorded for a few minutes. Soil thermal properties are then estimated from the temperature change by time data. For simplicity, the heat pulse probe is normally considered as a line source with infinitesimal probe radius and zero heat capacity when soil thermal properties are calculated. In reality, the finite properties of the probe itself, including finite heat capacity and finite probe radius, can lead to biased thermal property estimations. In this study, we compared the results of soil thermal property estimations with the PILS (pulsed-infinite-line-source) theory and ICPC (identical cylindrical perfect conductors) theory, to evaluate the influences of finite properties of the probe on soil thermal property estimations. The heat pulse probe consist of 3 needles with a diameter of 2 mm and a length of 40 mm. Heat pulse measurements were conducted on a sand soil with water content varied from air dry condition to field capacity, and soil heat capacity, thermal diffusivity, and thermal conductivity were estimated with both the PILS and ICPC methods. In addition, heat capacity estimates with the de Vries model were used to evaluate the accuracy of heat capacity measurements. The results indicated that compared with the PILS theory, the ICPC solution significantly reduced the errors in soil thermal property estimations from the temperature change-by-time curves. For water content ranging from 0.03 to 0.25 m<sup>3</sup>/m<sup>3</sup>, the PILS theory underestimated soil thermal conductivity and thermal diffusivity by 11.8% and 5.2%, respectively. Compared with the theoretical values from the de Vries model, the PILS theory and the ICPC theory overestimated soil heat capacity by 16.1% and 7.9%, respectively. Further analysis showed that that the influences of finite probe properties on thermal property estimations were most significant on dry samples, and the errors were reduced linearly with increasing soil water content. The experimental results from this study support that the theoretical analysis including finite heat capacity and finite probe radius improves the accuracies of soil thermal property estimations. The conclusions also have implications in optimizing the design of heat-pulse probes, especially for probes with relatively larger diameters.
Number of references:28
Main heading:Thermal conductivity
Controlled terms:Algorithms - Diffusion - Digital storage - Errors - Heat storage - Heat transfer - Hybrid materials - Needles - Probes - Soil moisture - Soils - Specific heat - Thermal diffusivity - Thermodynamic properties - Water content
Uncontrolled terms:Heat capacity measurements - Heat pulse method - Physical parameters - Property estimation - Soil thermal conductivity - Soil thermal properties - Temperature changes - Volumetric heat capacity
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 444 Water Resources - 483.1 Soils and Soil Mechanics - 616 Heat Exchangers - 641 Heat and Mass Transfer; Thermodynamics - 712 Electronic and Thermionic Materials - 722.1 Data Storage, Equipment and Techniques - 723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 819.6 Textile Mills, Machinery and Equipment - 921 Mathematics - 931.1 Mechanics - 933 Solid State Physics - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.19.009
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 15>
Accession number:201446200470
Title:Design of equilibrium modified humidity package for postharvest fruits and vegetables and validation test
Authors:Chen, Shoujiang (1); Wang, Haiou (1); Zhang, Liyang (1)
Author affiliation:(1) College of Biochemical and Environmental Engineering, Nanjing Xiaozhuang University, Nanjing , China
Corresponding author:Chen, Shoujiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:309-315
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Fruits and vegetables contain large amounts of water, parts of which are easily lost under low relative humidity conditions because the water vapor pressure at the surface of fresh products is slightly below saturation. Loss of water from fresh products can lead to skin wrinkling, loss of crispiness, and undesirable color changes. Controlling water loss is an important means to maintain quality of postharvest fruits and vegetables. Fruits and vegetables are usually packaged within plastic film and stored at refrigeration temperature in order to prevent excessive water loss and to extend shelf life; however, the low water vapor permeability (WVP) of films combined with the fresh products transpiration rapidly brings about saturation humidity (~100% RH) of the package atmosphere. The saturated in-pack RH condition and inevitable external temperature fluctuation can result in the condensation of water on the inner surface of the packaging film and on the contained products, and lead to defects in the external appearance of commodities and accelerate microbial growth. Equilibrium modified humidity packaging (EMHP) is an effective method for decreasing water loss and avoiding the occurrence of condensed water by modifying the permeability of the packaging film through perforation and optimally regulating the in-package equilibrium water vapor pressure. The water loss of fruits and vegetables packaged in perforated film was influenced by both of transpiration rate of products and the transmission rate of water vapor to the outside of the package. The transmission processes of water vapor in headspace include two ways: permeation through film and diffusion through holes. Water vapor transmission in a perforated package occurs almost entirely through the perforations due to the high permeability of perforated film. Several mathematical models about mass transfer have been proposed, and the majority of them focus on predicting and controlling O<inf>2</inf> and CO<inf>2</inf> exchange in perforation-mediated modified atmosphere packaging in order to create the desired atmosphere for preservation of fresh fruits and vegetables. Little research has been done so far to measure the equilibrium relative humidity within package. Under certain storage temperature, the above two processes are results of water vapor deficit between the commodity and the gas surrounding the commodity and two sides of film, and follow different mathematical models. If there is a good balance of water vapor press, the constant relative humidity in a package can be obtained. Transpiration affects the main quality characteristics of fresh products, and water loss must be controlled within 4.9%±0.2% to avoid loss of freshness in fresh produce, and it is an important parameter to be considered while designing packaging. So, the area of perforation can be calculated based on the total amounts of water loss and mathematical models about water vapor transmission. The objective of our research is to analyze water vapor transmission rate (WVTR) in different perforation areas and design the equilibrium modified humidity packaging according to mathematical model based on Fick's law of diffusion. The proper relative humidity within each package can be obtained through regulating perforation area, and avoiding excess water loss and production of condensed water. The model was validated with mushrooms (Aagaricus bisporus) packaged in perforated plastic bags at 2. The results showed that different perforation areas can affect water loss and shelf life of mushrooms, and the method can guide the design of equilibrium modified humidity packaging for mushrooms storage.
Number of references:31
Main heading:Modified atmosphere packaging
Controlled terms:Atmospheric temperature - Carbon dioxide - Design - Diffusion - Energy storage - Evapotranspiration - Fick's laws - Film growth - Fruits - Fungi - Hydrostatic pressure - Mathematical models - Packaging - Packaging materials - Plastic containers - Plastic films - Plastic products - Product design - Quality control - Storage (materials) - Surface defects - Transpiration - Vegetables - Water vapor
Uncontrolled terms:Equilibrium relative humidity - Fick's law of diffusion - Low relative humidities - Quality characteristic - Refrigeration temperatures - Validation - Water vapor transmission - Water vapor transmission rate
Classification code:408 Structural Design - 421 Strength of Building Materials; Mechanical Properties - 443.1 Atmospheric Properties - 444.1 Surface Water - 461.9 Biology - 631.1.1 Liquid Dynamics - 643 Space Heating, Ventilation and Air Conditioning - 694 Packaging - 702 Electric Batteries and Fuel Cells - 712.1 Semiconducting Materials - 804.2 Inorganic Compounds - 817.1 Polymer Products - 821.4 Agricultural Products - 913.1 Production Engineering - 913.3 Quality Assurance and Control - 921 Mathematics - 931.1 Mechanics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.037
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 16>
Accession number:201446200446
Title:Magnetized water irrigation enhanced rice growth and development, improved yield and quality
Authors:Zhu, Lianfeng (1); Zhang, Junhua (1); Yu, Shengmiao (1); Hu, Zhihua (1); Jin, Qianyu (1)
Author affiliation:(1) State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou , China
Corresponding author:Jin, Qianyu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:107-114
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In 2012 and 2013, a field experiment was conducted to study the effects of magnetized water irrigation on rice growth, rice population structures, yield formation, and grain quality in China National Rice Research Institute located at Hangzhou City, Zhejiang Province, China. The Zhongzheyou 1 an indica type of hybrid rice and Yongyou 9 a japonica type of hybrid rice were used in the experiment. Split plot design was used with cultivars as the main plots and magnetized water irrigation (MTW) and a control (CK) as the sub-plots. The plots area was 35 m2 and repeated 3 times randomized complete block design. The magnetic instrument (Jinan Yishui Tech. Dev Co. Ltd.) was used in water magnetic treatment. The magnetic field in the instrument has an intensity of 0.2 Tesla, and the irrigation water passed throw the magnetic field at velocity of 1.5 m/s. From transplanting to harvesting the MTW plots were irrigated with the magnetic water, while the CK plots were irrigated with untreated water of same source. From transplanting to heading, the water levels of all plots were kept at the depth of 30-50 mm, while from heading to maturity the water levels were kept at the depth of 30-40 mm, then the plots were drained for 5 days before harvest. The results showed that the grain yield of MTW for Zhongzheyou 1 were 5.2% (2012) and 6.7% (2013) higher (P<0.05) than that of CK. and for Yongyou 9 were 8.8% (2012) and 9.3% (2013) higher (P<0.05) than that of CK. Compared with CK, The MTW increased the lower position tillers. During 14 days to 28 days after transplanting, the average tillers per hill of Zhongzheyou 1 and Yongyou 9 were increased significantly by 9.4% to 21.5% and 13.5% to 21.4%, respectively. Compared with CK, the effective panicle number of MTW for Zhongzheyou 1 were increased by 4.0% (2012) and 6.3% (2013) and Yongyou 9 were increased by 6.2% (2012) and 7.9% (2013). Compared with CK, the grain setting rate of MTW for Zhongzheyou 1 were increased by 3.9% (2012) and 5.3% (2013) and Yongyou 9 were increased by 8.7% (2012) and 5.0% (2013). All these differences were significant at 0.05 probability level. The increased effective panicle number and grain setting rate became dominant factors contributing to the high yield of MTW treated rice. Compared with CK, the chlorophyll value from SPAD chlorophyll meter for MTW of top 3 leaves increased by 2.4% to 7.1% for Zhongzheyou 1 and 2.6% to 7.8% for Yongyou 9. The dry matter accumulation per hectare significantly (P <0.05) increased by 5.7% to 18.8% (Zhongzheyou 1) and 6.2% to 16.5% (Yongyou 9) during booting and milk filling stage. Meanwhile, the MTW significantly (P < 0.05) improved the rice qualities. Compared with CK, the percentage of chalky grain of MTW for both Zhongzheyou 1 and Yongyou 9 were significantly (P<0.05) decreased by 13.3% and 12.0%, respectively. The chalkiness of MTW for Zhongzheyou 1 and Yongyou 9 were decreased by 11.4% (P<0.01) and 7.7% (P<0.05), respectively. The gel consistency of MTW for Zhongzheyou 1 and Yongyou 9 were increased (P<0.05) by 6.0 and 4.0 mm, respectively. The alkali spreading value of MTW for Zhongzheyou 1 and Yongyou 9 were increased (P < 0.05) by 4.3% and 4.8%, respectively. All of these indictors showed the improved rice qualities from MTW treatment. The results provided a scientific basis for the magnetic water application in the rice production.
Number of references:26
Main heading:Grain (agricultural product)
Controlled terms:Chlorophyll - Experiments - Grain growth - Irrigation - Magnetic devices - Magnetic fields - Magnetism - Population statistics - Water levels - Water treatment
Uncontrolled terms:Chlorophyll meters - Dry matter accumulation - Grain yield - Probability levels - Research institutes - Rice (O. stiva L.) - Rice qualities - Split plot designs
Classification code:445.1 Water Treatment Techniques - 614.2 Steam Power Plant Equipment and Operation - 701.2 Magnetism: Basic Concepts and Phenomena - 704 Electric Components and Equipment - 714 Electronic Components and Tubes - 804.1 Organic Compounds - 821.3 Agricultural Methods - 821.4 Agricultural Products - 901.3 Engineering Research - 922.2 Mathematical Statistics - 933.1.2 Crystal Growth
DOI:10.3969/j.issn.1002-6819.2014.19.013
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 17>
Accession number:201446200455
Title:Surface soil moisture estimation using IEM model with calibrated roughness
Authors:Huang, Dui (1); Wang, Wen (1)
Author affiliation:(1) State key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing , China
Corresponding author:Wang, Wen
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:182-190
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The ENVISAT/ASAR image is an important remote sensing data source for estimating soil moisture, and the integral equation model (IEM) is the most widely used, physically based radar backscatter model for bare soil and sparsely vegetated landscapes. However, the soil moisture retrieval from ASAR images using the IEM is not fully operational at present, mainly due to the difficulties in the parameterization of soil surface roughness and the elimination of spatial and temporal variation of soil roughness. The IEM simulated backscattering coefficients are often in poor agreement with satellite radar measurements because of un-accurate description of the surface roughness, especially the correlation length l parameter. Baghdadi proposed to replace correlation length l with a fitted parameter l<inf>opt</inf> for the IEM, which can be expressed as the function of root mean square height h<inf>RMS</inf> and incidence angle. So far, there is still lack of application of this method in semi-arid areas. This paper applied this approach in the Walnut Gulch Experimental Watershed of southeast Arizona, and showed that the IEM performed better in simulating radar backscattering coefficient when l<inf>opt</inf> was used as the input. Based on the improvement in radar backscattering coefficient simulation, l<inf>opt</inf> and h<inf>RMS</inf> are replaced by the combined roughness Z<inf>s</inf> (h<inf>RMS</inf><sup>2</sup>/ l<inf>opt</inf>), and the relationship between surface roughness Z<inf>s</inf>, soil moisture and the simulated backscatter coefficients is analyzed. The results showed that the simulated backscattering coefficient was logarithmically correlated with both Z<inf>s</inf> and soil moisture. Then, maps of Z<inf>s</inf> in two dates are estimated with a logistic regression equation using the difference between backscattering coefficients at incidence angles of IS6 and IS2. Using Z<inf>s</inf> estimates and IEM simulated backscattering coefficients, the empirical formula of soil moisture inversion under two incidence angles was established with the nonlinear least squares method for VV (vertical vertical) polarization mode. On analyzing the parametric formula of simulated IEM data, a semi-empirical method was further applied based on Taylor series expansion. Therefore, two surface roughness and two soil moisture maps are obtained using ASAR images in two dates, i.e., August 18 and August 24, 2004. Comparison between the surface roughness maps in two dates shows that the surface roughness has similar spatial distribution characteristics, but the surface roughness on August 18 was less than that on August 24. Dynamic changes of the surface roughness in two dates are consistent with the occurrence of rainfall events. Comparison between the estimated soil moisture with observations of 19 stations in the Walnut Gulch watershed shows that the correlation coefficients were 0.785 and 0.837 between the observed and the empirically estimated soil moisture, and 0.900 and 0.863 between the observed and the semi-empirically estimated soil moisture, for August 18 and August 24 respectively. It means that both the empirical method and the semi-empirical method are effective, but the semi-empirical method performs better. The method quantifies the impact of surface roughness on IEM model simulations and the influence of roughness change on surface roughness estimation, which is effective for retrieving soil moisture at the watershed scale.
Number of references:32
Main heading:Surface roughness
Controlled terms:Arid regions - Backscattering - Computer simulation - Geodetic satellites - Integral equations - Least squares approximations - Moisture - Radar - Radar measurement - Remote sensing - Soil moisture - Soil surveys - Soils - Watersheds
Uncontrolled terms:Distribution characteristics - IEM model - Logistic regression equations - Microwave remote sensing - Nonlinear least squares methods - Radar backscattering coefficient - Spatial and temporal variation - Surface-soil-moisture estimation
Classification code:405.3 Surveying - 443 Meteorology - 443.1 Atmospheric Properties - 444 Water Resources - 444.1 Surface Water - 483.1 Soils and Soil Mechanics - 711 Electromagnetic Waves - 716.2 Radar Systems and Equipment - 723.5 Computer Applications - 731.1 Control Systems - 921.2 Calculus - 921.6 Numerical Methods - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2014.19.022
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 18>
Accession number:201446200456
Title:Estimation of winter wheat nitrogen nutrition index using hyperspectral remote sensing
Authors:Wang, Renhong (1); Song, Xiaoyu (2); Li, Zhenhai (2); Yang, Guijun (2); Guo, Wenshan (1); Tan, Changwei (1); Chen, Liping (2)
Author affiliation:(1) Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou , China; (2) Beijing Research Center for Information Technology in Agriculture, Beijing , China; (3) Key Laboratory for Information Technologies in Agriculture, The Ministry of Agriculture, Beijing , China
Corresponding author:Chen, Liping
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:191-198
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Nitrogen has significant effect on the growth and development in crop, the formation of yield and quality. Precision diagnosis and dynamic regulation of crop is the important content and scientific basis of precision agriculture. Thus, predicting crop N status accurately and applying appropriate rate N to crop are the focus for many studies in agricultural sciences. The crop canopy nitrogen status estimation based on spectroscopy is important tool for crop nitrogen management, but its accuracy of estimation is often affected by other factors such as canopy structures.
Number of references:31
Main heading:Parameter estimation
Controlled terms:Agriculture - Crops - Diamonds - Models - Nitrogen - Nitrogen fertilizers - Nutrition - Regression analysis - Remote sensing - Spectrum analysis
Uncontrolled terms:Above ground biomass - Growth and development - Hyperspectral remote sensing - Nitrogen nutrition - Precision Agriculture - Quantitative diagnosis - Remote sensing technology - Winter wheat
Classification code:461.7 Health Care - 482.2.1 Gems - 731.1 Control Systems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 902.1 Engineering Graphics - 922.2 Mathematical Statistics
DOI:10.3969/j.issn.1002-6819.2014.19.023
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 19>
Accession number:201446200449
Title:Characteristics of vertical runoff output on red-soil slope under natural rainfall condition
Authors:Xie, Songhua (1); Mo, Minghao (2); Tu, Anguo (2); Liu, Yuanqiu (1)
Author affiliation:(1) College of LandScape and Art, Jiangxi Agricultural University, Nanchang , China; (2) Jiangxi Institute of Soil and Water Conservation, Nanchang , China
Corresponding author:Liu, Yuanqiu
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:132-138
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Surface runoff, interflow and underground runoff are components of runoff on sloping land, which exert an important impact on runoff generation and nutrient loss at watershed scale. This study was conducted to analyze the characteristics of vertical runoff output in different soil strata on a red-soil slope under three conditions: vegetation coverage, litter mulch, and bare land for three years from 2010 to 2012. The study area lies in Jiangxi Provincial Eco-Science Park of Soil and Water Conservation (29°16'37″-29°17'40″N, 115°42'38″-115°43'06″E), which is located in Boyang River watershed of Poyang Lake Basin, in De'an County, Jiangxi Province, China. This region is characterized by a subtropical humid monsoon climate with mean annual precipitation of 1397.3 mm. The soil is red soil. In order to investigate characteristics of runoff output in different soil strata on the red-soil slope with drainage lysimeter, the experiment was laid out using three 5 m × 15 m plots with slope of 14°. The treatments were 1) planted Bahia grass, 2) mulching dry Bahia grass, and 3) bare land. There were four discharge outlets used to collect surface runoff: interflow 30 cm underground, interflow 60 cm underground, and underground runoff 105 cm underground in each plot. The results showed that the total runoff of litter mulch treatment was maximum, followed by the bare land, and the vegetation coverage treatment under natural rainfall conditions. Besides, surface runoffs of vegetation coverage and litter mulch treatment were far less than that of the bare land treatment, which were 7.9% and 9.8% of bare land, respectively. It indicated that the planted grass and the litter mulch can reduce surface runoff significantly. Interflow of the bare land treatment was the least, which was respectively 56.4% of the vegetation coverage and 35.6% of the litter mulch treatments. It demonstrated both vegetation and litter can increase water seepage. Underground runoff of the vegetation coverage and the litter mulch treatments were both above 90% of total runoff output and the bare land accounted for 68.4% in the three years. For the three treatments, the amounts of surface runoff, interflow and underground runoff and total runoff were the highest in the spring, accounting for 37% to 49% of the whole year, followed by summer (26%-37%), but they were lower in autumn and winter. This phenomenon was attributed to annual precipitation that was mainly concentrated in spring and summer in Jiangxi Province. On a small scale, whether by annual or monthly runoff analysis, underground runoff was the main way of runoff output on red soil slope under different treatments, and interflow and surface runoff were directly related to the presence or absence of ground coverage. Measures of vegetation coverage and litter mulch can be taken to reduce surface runoff, conserve water, increase seepage and change surface water into underground water. The research can provide references for reducing soil erosion and making full use of soil and water resources on red-soil slope.
Number of references:22
Main heading:Runoff
Controlled terms:Climate change - Groundwater - Land reclamation - Rain - Seepage - Soil conservation - Soils - Surface waters - Vegetation - Water conservation - Water resources - Watersheds
Uncontrolled terms:Annual precipitation - Different treatments - Interflow - Mean annual precipitation - Red soils - Soil and water conservation - Surface runoffs - Underground runoffs
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 441 Dams and Reservoirs; Hydro Development - 442.2 Land Reclamation - 443.3 Precipitation - 444 Water Resources - 451 Air Pollution - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2014.19.016
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 20>
Accession number:201446200448
Title:Simulation of response law for soil surface roughness and hydraulics parameters of runoff
Authors:Liang, Xinlan (1); Zhao, Longshan (1); Wu, Jia (2); Wu, Faqi (1)
Author affiliation:(1) College of Natural Resources and Environment, Northwest A & F University, Yangling , China; (2) Institute of water Resources and hydro-electric Engineering, Xi'an University of Technology, Xi'an , China
Corresponding author:Wu, Faqi
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:123-131
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Soil surface roughness (SSR) is used to describe irregularities in the soil surface at a small scale. It is affected by tillage systems, soil properties, runoff, micro topography, and climate. The objective of this paper was to study the mutual influence of SSR and characteristic of runoff as well as its hydraulic parameter under four different tillage systems. Artificial shallow plowing (ASP), artificial deep plowing (ADP), contour plowing (CP), and no treatment tillage (CK) were simulated in the laboratory to form four different soil surface roughness. Soil sample was filled into a 2.0 m × 1.0 m × 0.5 m iron slope-adjustable box. The soil in the box were exposed to 60 mm/h and 120 mm/h simulated rainfall for 90 min at slope 36%. Soil surface roughness was measured before and after each rainfall event. Runoff was measured in every two min since runoff occurred. The shape of runoff and runoff pattern were observed during the rainfall events. Reynolds number, Froude number, Resistance coefficient and Flow shear stress were calculated. Results showed that SSR was in an order of CP > ADP > ASP > CK before and after the rainfall simulation. In the same condition of rainfall intensity and duration, soil surfaces with different SSR showed significant difference in runoff. The higher the initial SSR was, the easier the runoff was in stable state and the flow was a laminar flow. On the contrary, the smaller initial SSR was, the easier the runoff was in turbulent flow state. Tillage with bigger initial SSR showed smaller quantity of flow, runoff, and sediment yield. Under 60 mm/h rainfall, the initial SSR of CP was 6.51 mm, which had the smallest runoff volume of 75.79 L. The initial SSR of ADP and ASP were 4.90 mm and 4.17 mm, respectively. The runoff volume of ADP and ASP were respectively 85.93 L and 87.13 L. The initial SSR of CK was the smallest one (0.36 mm). Its runoff volume was 97.83 L. The initial SSR was negatively correlated to the runoff volume significantly as well as Reynolds number, Froude number, and flow shear stress, but it showed a positive correlation with the resistance coefficient of runoff. The 120 mm/h rainfall had the same variation trend as 60 mm/h intensity. The SSR change rate was also calculated from the SSR before and after the rainfall events. This parameter can reflect the effect of runoff on SSR change. The pattern of runoff and flow shear stress affected SSR during runoff process. On the one hand, runoff can cut the surface peak area and fill the depression area to decrease SSR at inter-rill area. On the other hand, runoff scoured rills, shear rills bed off, corroded soil particles of rills to increase SSR. Both the decrease and the increase coexisted in the process of the runoff. However, after rill erosion occurred, inter-rill area was domination while rill erosion was subordinate. Hence, runoff showed decreasing effect on SSR apparently after a complete rainfall. The Reynolds number and flow shear stress of runoff presented a negative correlation with the decreasing effect on SSR. The Reynolds number and flow shear stress of CK were the largest, it were 239 and 8.62 Pa for 60 mm/h rainfall, 1893 and 27.23 Pa for 120 mm/h rainfall. The SSR of CK decreased 27.61% for 60 mm/h rainfall and 70.48% for 120 mm/h rainfall, which were the lowest among the four tillage systems. Reynolds number and flow shear stress of CP were the smallest, it were 82 and 6.67 Pa for 60 mm/h rainfall, 738 and 20.05 Pa for 120 mm/h rainfall. But the SSR of CP decreased by 34.49% for 60 mm/h rainfall and by 84.25% for 120 mm/h rainfall, respectively. The research results provide reference for further understanding of the interaction between surface roughness and its hydrological characteristics.
Number of references:34
Main heading:Runoff
Controlled terms:Agricultural machinery - Agriculture - Erosion - Flow patterns - Froude number - Laminar flow - Rain - Reynolds number - Shear flow - Shear stress - Soils - Surface roughness
Uncontrolled terms:Hydraulic parameters - Hydrological characteristics - Negative correlation - Positive correlations - Resistance coefficients - Simulation - Soil surface roughness - Soil surface roughnesses (SSR)
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 421 Strength of Building Materials; Mechanical Properties - 443.3 Precipitation - 444.1 Surface Water - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics - 631.1 Fluid Flow, General - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 931.2 Physical Properties of Gases, Liquids and Solids
DOI:10.3969/j.issn.1002-6819.2014.19.015
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 21>
Accession number:201446200447
Title:Rational indicators for water deficiency diagnosis of sugarcane based on stem diameter variations
Authors:Chen, Haibo (1); Li, Jiuhao (2); Yu, Changhong (2); Zhang, Liankuan (4)
Author affiliation:(1) College of Engineering, South China Agricultural University, Guangzhou , China; (2) College of Water Conservancy and Civil Engineering, South China Agricultural University, Guangzhou , China; (3) Key Laboratory of Key Technology on Agricultural Machine and Equipment, South China Agricultural University, Ministry of Education, Guangzhou , China; (4) College of Science, South China Agricultural University, Guangzhou , China
Corresponding author:Li, Jiuhao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:115-122
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to test the feasibility of diagnosing water deficiency of sugarcane using parameters related with stem diameter variations, both pot experiment and field experiment were conducted. In the pot experiment, pots were selected with 60 cm in length and width, and 40 cm in depth. Sugarcane t22 was planted in pots and field. Stem diameter variations were continuously measured. The diurnal variations of stem diameter at different growing stages under different water deficits were investigated, and maximum daily shrinkage (MDS) and daily increase (DI) were calculated based on relative variations (RV) of stem. In addition, the correlations between MDS, DI (from pot experiment) and soil moisture were analyzed. A water deficiency diagnosis model was established and assessed by the F test. The results showed that RV values were significantly (P<0.01) different among different soil moisture treatments during the stem growing period include of seedling, tillering and elongating stage. The overall growth of sugarcane stem diameter was reduced by about 41.7% to 100% as soil moisture was less than 60% of field capacity. Elongating stage was most sensitive to soil moisture deficiency, followed by tillering stage and seedling stage. At the stem mature period (that was sugarcane's mature stage), the total amount of stem diameter growth (sugarcane planted in pots) was 0.049, 0.055, 0.048 and 0.033 mm in 16 observation days under conditions of normal irrigation, light drought, moderate drought and severe drought, respectively. The growth of stem diameter basically stopped at this stage and thus it was the least sensitive to water deficits. The regression analysis showed that MDS and DI were significantly correlated (P<0.01) with soil water content at different growing stages of stem except for DI at mature stage, the coefficient of determination was 0.501-0.765. During the stem growing period include seedling, tillering and elongating stage, MDS and DI both had high response to water stress, and hence could be reliable indicators for diagnosing water status in sugarcane. MDS was more reliable at seedling and elongating stage, while DI was better indicators at tillering stage from the results of the coefficient of determination and root mean squared error. At the mature stages, MDS was more reliable due to its high sensitivity to water deficits. The upper and lower values of soil moisture were inputted as variable values into the regression equation, and thereby the threshold range of MDS and DI under water stress was determined. At the seedling stage, the MDS of 0.026-0.052 mm or DI of 0.087-0.160 mm indicated the soil was in a moderate drought condition, and the MDS of 0.052-0.078 mm or DI of 0.012- 0.087 mm indicated the soil was in a severe drought condition. At the tillering stage, the MDS of 0.046-0.099 mm or DI of 0.256-0.111 mm indicated the soil was in a moderate drought condition, and the MDS of 0.099- 0.153 mm or DI of -0.038-0. 111 mm indicated the soil was in a severe drought condition. At the elongating stage, the MDS of 0.082-0.174 mm or DI of -0.013-0.189 mm indicated the soil was in a moderate drought condition, and the MDS of 0.174-0.266 mm or DI of -0.216--0.013 mm indicated the soil was in a severe drought condition. At the mature stage, the MDS of 0.072-0.111 mm indicated the soil was in a severe drought condition. The F test indicated that the established models could reliably predict water deficiency, and the coefficient of determination for prediction was between 0.515-0.787. The determined indicator, as well as the established water deficiency diagnosis models, is valuable for studies on irrigation scheduling for sugarcane based on stem diameter variations.
Number of references:18
Main heading:Soils
Controlled terms:Diagnosis - Drought - Elongation - Experiments - Irrigation - Moisture - Plants (botany) - Regression analysis - Scheduling - Shrinkage - Soil moisture - Sugar cane
Uncontrolled terms:Coefficient of determination - Daily increase (DI) - Irrigation scheduling - Maximum daily shrinkage (MDS) - Root mean squared errors - Soil-moisture deficiency - Stem diameter - Water deficiency
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 444 Water Resources - 461.6 Medicine and Pharmacology - 461.9 Biology - 483.1 Soils and Soil Mechanics - 801.4 Physical Chemistry - 821.3 Agricultural Methods - 821.4 Agricultural Products - 901.3 Engineering Research - 912.2 Management - 922.2 Mathematical Statistics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.014
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 22>
Accession number:201446200471
Title:Design of online monitoring system for material moisture content in air-impingement drying process
Authors:Wang, Dong (1); Lin, Hai (2); Xiao, Hongwei (1); Liu, Yanhong (1); Ju, Haoyu (1); Dai, Jianwu (1); Gao, Zhenjiang (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing , China; (2) Faculty of Electrical and Control Engineering, Liaoning Technical University, Huludao , China
Corresponding author:Gao, Zhenjiang
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:316-324
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Moisture content is an important quality index of drying products, which can be obtained by automatic weighing and analyzing its mass in the drying process. Compared with other moisture content measurement technology, the automatic weighing method has good versatility, high accuracy, and simple architecture. Relative humidity of drying air has significant effect on drying kinetics and product quality, while, for interior weighing devices, the humidity of hot air can easily be kept stable during drying process. In order to mitigate the effects of air velocity, equipment operating vibration, drying temperature, and other factors on the interior automatic weighing system of air-impingement drying, a new drying monitoring system based on Modbus communication protocol and RS 485 bus was designed. This system consists of five parts: an HMI (human machine interface) as master, a weighing system, a drying temperature control system, humidity control system, and air velocity control system. This paper mainly focuses on the measurement of material mass and moisture content. For the hardware of weighing system, strain gauge load cell and 0-5 V analog voltage transmitting instrument XST were applied in this system, and in order to implement temperature compensation to weighing system, the Pt100 type temperature sensor was adopted to sample the temperature of the weight sensor. Besides, signal acquisition, processing circuit with 8-bit microprocessor chip PIC16F1829 as core was designed, among which the analog transmission signal of weighting instrument is collected and converted by using 12-bit A/D chip TLC2543, and signal is converted by level conversion chip MAX487 to complete communication between master (HMI) and microprocessor PIC16F1829. And the weighting measurement range of this system is 0-2000 g and the resolving power is 1 g. For software design, median filtering algorithm, "shutdown-maintain-weight-start" automatic weighting procedures, linear calibration at different temperature sections, and load ranges were designed to eliminate the effect of accidental errors on automatic weighing, to weaken the effect of air velocity and equipment operating vibration on automatic weighing without affecting the drying process, and to reduce the effect of higher drying temperature and change of the temperature in wider range on automatic weighing, respectively. Through the above measures, automatic weighing accuracy was ensured effectively. In addition, the status of the slave controllers was incorporated into the run logic judgment of the system to guarantee the system's operational safety. This monitoring system could also realize the functions such as isochronal and instant measurement of material mass and moisture content, real-time display, and storage of experiment data in the drying process. After the completion of the system's hardware and software design, monitoring system' detection accuracy of mass and moisture content were tested in air-impingement dryer. Results of the weighing test showed that the maximum relative error to the mass of the samples is less than 0.7%. Then a series of drying tests on carrots were conducted. The results indicated that the error of the moisture content is within ±1.0% in drying process, which achieved the requirement of the on-line monitoring moisture content. The online air-impingement drying monitoring system designed in the current work is of great significance for evaluating and regulating the drying process for various materials, ensuring the product quality, and reducing the energy consumption and the labor intensity of drying operators.
Number of references:22
Main heading:Monitoring
Controlled terms:Air - Analog to digital conversion - Control systems - Controllers - Digital storage - Drying - Energy utilization - Hardware - Humidity control - Measurement errors - Median filters - Microprocessor chips - Moisture - Moisture control - Moisture determination - Phase interfaces - Quality control - Signal processing - Social networking (online) - Software design - Software testing - Water content - Weighing
Uncontrolled terms:Automatic weighing systems - Hardware and software designs - Median filtering algorithm - Moisture content measurement - Monitoring system - On-line measurement - On-line monitoring system - Temperature compensation
Classification code:402 Buildings and Towers - 444 Water Resources - 525.3 Energy Utilization - 605 Small Tools and Hardware - 642.1 Process Heating - 716.1 Information Theory and Signal Processing - 721 Computer Circuits and Logic Elements - 722 Computer Systems and Equipment - 723 Computer Software, Data Handling and Applications - 723.5 Computer Applications - 731.1 Control Systems - 732.1 Control Equipment - 801.4 Physical Chemistry - 804 Chemical Products Generally - 913.3 Quality Assurance and Control - 922 Statistical Methods - 941 Acoustical and Optical Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 943.3 Special Purpose Instruments - 944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 944.2 Moisture Measurements
DOI:10.3969/j.issn.1002-6819.2014.19.038
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 23>
Accession number:201446200436
Title:Evaluation and cause analysis of rice-stem lodging resistance for mechanical transplanted indica-japonica hybrid rice
Authors:Jiang, Yuanhua (1); Zhang, Hongcheng (1); Zhao, Ke (1); Xu, Junwei (1); Wei, Huanhe (1); Wang, Wenting (1); Meng, Tianyao (1); Dai, Qigen (1); Huo, Zhongyang (1); Xu, Ke (1); Wei, Haiyan (1); Guo, Baowei (1)
Author affiliation:(1) Innovation Center of Rice Cultivation Technology in the Yangtze Valley Ministry of Agriculture, Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou , China
Corresponding author:Zhang, Hongcheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:19-29
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This study investigated the resistance of rice stem to lodging, and physical and chemical properties of rice culm of different rice varieties under high-yielding cultivation condition in mechanical transplanting with small seedling. Four representative rice varieties were used including indica-japonica hybrid riceA, japonica hybrid rice B, conventional japonica rice C, and indica hybrid rice D as materials. The stem morphological and mechanical traits were analyzed. The results showed that: 1) Compared with B, C, and D, A had higher value of breaking resistance and bending moment, and the lodging index of A was lower than that of D, but higher than that of B and C; 2) In terms of stem structure characteristics, the loading force, springiness, cohesiveness, flexural rigidity, fracturability, hardness, puncture strength, and firmness of basal internode were higher for A than B, C, and D; 3) Plant height, panicle height, gravity center height, internode diameter, stem cross-sectional area, culm wall cross-sectional area, total area of vascular bundles, area of big and small vascular bundles, the number of big and small vascular bundles of A were the highest among the 4 rice types, but the stem type index, the relative area of culm wall cross-sectional, big vascular bundles, small vascular bundles of A were lower than those of B and C, and higher than those of D; 4)The content of soluble sugar, starch, cellulose, lignin, K, Si, Ca, Cu, zinc and other chemical composition in stem and sheath of A were lower than those of B and C, but higher than those of D; Chemical components such as N, Mg, Fe, Mn content of A were higher than those of B and C, but less than those of D; 5) Correlation analysis showed that the lodging index was significantly (P<0.05) positively correlated with gravity center height, culm diameter, cross-sectional area, and highly significantly positively (P<0.01) correlated with relative weight height, culm length, N, Mg, Fe and Mn content, but significanty (P<0.05) negatively correlated with starch and Cu content,and highly significantly (P<0.01) negatively correlated with stem type index, relative stem wall area, the relative area of vascular bundle, and the content of soluble sugar, cellulose, lignin, K, Si, Ca and Zn. Therefore, the resistance of stem to lodging for indica-japonica hybrid rice of Yongyou series under mechanical transplanting condition was better than that of indica hybrid rice, but inferior to that of hybrid japonica rice and conventional japonica rice. Differences in physical and chemical characteristics of culm were closely related with lodging resistance in rice. The study provided a theoretical and technical support for the mechanization and lodging resistance cultivation of indica japonica hybrid rice in the lower reaches of the Yangtze River.
Number of references:26
Main heading:Chemical resistance
Controlled terms:Agriculture - Calcium - Cellulose - Chemical analysis - Cultivation - Hybrid materials - Lignin - Loading - Machinery - Magnesium - Manganese - Rigid structures - Silicon - Starch - Textures - Transplants - Zinc
Uncontrolled terms:Chemical compositions - Cultivation conditions - Japonica hybrid rice - Lodging resistance - Mechanical transplanting - Physical and chemical characteristics - Physical and chemical properties - Rice stem
Classification code:408 Structural Design - 462.4 Prosthetics - 543.2 Manganese and Alloys - 546.3 Zinc and Alloys - 549.2 Alkaline Earth Metals - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 601 Mechanical Design - 672 Naval Vessels - 801 Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 804.1 Organic Compounds - 815.1.1 Organic Polymers - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 933 Solid State Physics
DOI:10.3969/j.issn.1002-6819.2014.19.003
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 24>
Accession number:201446200445
Title:Experiment and simulation of factors affecting flow measurement of water-measuring column with round head in U-shaped channel
Authors:Liu, Ying (1); Wang, Wen'e (1); Hu, Xiaotao (1); Liu, Jiamei (1)
Author affiliation:(1) College of Water Conservancy and Architecture Engineering, Northwest A&F University, Yangling , China
Corresponding author:Wang, Wen'e
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:97-106
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In this paper, water-measuring column with a round head was proposed to measure flow based on the cylindrical flow around theory. In the column, the cylindrical flume was improved by adding a V-shaped empennage behind it to reduce head loss, improve the accuracy of flow measurement and increase sediment transport capacity. The water-measuring column with a round head was installed vertically in a U-shaped channel and its symmetry plane was overlapped with the centerline of the channel bottom. By controlling the length of the V-shaped empennage, it could make the flow pattern steady and reduce head loss. Based on the cylindrical flow around theory and RNG k-Ε turbulence model, hydraulic performance of the whole flow field of water-measuring column with a round head in 18 somatotypes under 5 working conditions were numerically calculated. And we obtained the time-averaged flow field, sectional velocity distribution, flow pattern behind the column as well as the measured values and the simulated values of the related hydraulic parameters. The comparison of simulated and measured hydraulic parameters values showed that they had good consistency. When the channel slope was 1/1000, discharge was 0.045m<sup>3</sup>/s, the contraction ratio was 0.50, and the aspect ratio was 2, the relative error of the maximum velocity of cross-section at a stagnation point between the simulated value and the measured value was 1.51%, and the relative error of the maximum velocity in a profile at 15 cm upward to water surface between the simulated value and the measured value was 0.45%. Therefore, simulation results can provide valuable information for rational design of a water-measuring column with a round head and its analysis of flow field measurements. On the one hand, an oversized contraction ratio may cause excessive upstream backwater and affect the normal operation of the channel. On the other hand, it was difficult to form a critical flow if the contraction ratio was too small. Based on the experimental data, a suitable range of contraction ratio was between 0.50 and 0.70, and it was ultimately determined by the channel slope. When the channel slope was small, the contraction ratio should be bigger. The analysis on the measuring effect of V-shaped empennage in model tests and numerical simulation revealed that V-shaped empennage of suitable aspect ratio could effectively improve the flow pattern. The recommended ranges of the aspect ratio λ were in 3/2~2 when the contraction ratios changed between 0.50 and 0.75. In addition, the aspect ratio should correspondingly increase but should not be more than 5/2 when the contraction ratio was less than 0.50. The flow formula with higher accuracy was fitted by regression analysis, which is based on stagnation-point, contraction ratio, surface width and channel slope. The maximum measuring error was 4.95% and the average error was only 0.10% when the contraction ratio was 0.63. The formula was useful for the further application of the water-measuring column with a round head in a terminal irrigation system in North China, for the reason that it was concise, practical, in line with the principle of dimensionless harmony, and can meet the flow measurement accuracy.
Number of references:24
Main heading:Aspect ratio
Controlled terms:Computer simulation - Empennages - Flow fields - Flow measurement - Flow patterns - Models - Numerical models - Regression analysis - Sediment transport - Turbulence models - Velocity - Velocity distribution
Uncontrolled terms:Flow field measurement - Hydraulic parameters - Hydraulic performance - Irrigation systems - Measurement accuracy - Sediment transport capacity - Time-averaged flow - U-shaped channels
Classification code:631.1 Fluid Flow, General - 631.3 Flow of Fluid-Like Materials - 652.1 Aircraft, General - 723.5 Computer Applications - 902.1 Engineering Graphics - 921 Mathematics - 922.2 Mathematical Statistics - 931.1 Mechanics - 943 Mechanical and Miscellaneous Measuring Instruments
DOI:10.3969/j.issn.1002-6819.2014.19.012
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 25>
Accession number:201446200468
Title:Simulation of land use change of Erhai Lake Basin based on ant colony optimization
Authors:Xu, Quanli (1); Yang, Kun (3); Wang, Guilin (1); Yang, Yulian (3)
Author affiliation:(1) School of Tourism and Geographic Science, Yunnan Normal University, Kunming , China; (2) School of Remote Sensing and Information Engineering, Wuhan University, Wuhan , China; (3) School of Information Science and Technology, Yunnan Normal University, Kunming , China; (4) GIS Technol. Eng. Research Centre for West-China Resources and Environment of Educational Ministry, Yunnan Normal University, Kunming , China
Corresponding author:Yang, Kun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:290-299
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Studies of Erhai Basin indicate that Land use change by human activities in the watershed is the leading cause of regional climate, hydrology, water quality and ecological changes. Therefore, it is necessary to study the relationships between human activities and land use/cover change (LUCC), which is beneficial to offer the scientific decision support for reasonable land planning and land use. Combined with GIS technologies of spatial analysis and using the artificial intelligence algorithm Ant Colony Optimization(ACO) for optimizing, in this paper, we applied the method of Agent-based modeling to establish the spatiotemporal process model of LUCC in order to simulating the dynamic change of land use in whole watershed. Firstly, we made a choice and evaluation for impact factors of land use changes, as well as constructions of the cost of land use change equations in order to construct more reasonable decision rules of land use choice. Then, we have extracted three agents composed by microcosmic and macrocosmic systems which were farm agent, resident agent and government agent. Also, microcosmic rules of decision and behavior were created according to ACO. On the other hand, we have established macrocosmic decision rules according to a resistance coefficient system from the land use planning, as well as a comprehensive decision rule. And then, based on Java language and Repast platform of modeling, the program design, implementation and simulation of model were given in detail. Finally, the validation, calibration and verification of model and analysis of the simulated results were also conducted. Our conclusions from the experiment were three: 1) Ant colony algorithm was more effective in promoting the significant moving and decision of agents, and the simulated results gained better accuracies in both mathematics (up 5.6%) and geometry (up 3.4%) than using a random algorithm. However, the merit of ACO was not suitable for its use in all of land-use types. For an instance, there were no any improvements and sometimes even reduction in accuracy for those land-use types which were less affected by human activities, such as forest, grassland and wetland uses. Thereby, we suggested that ACO was more sensitive to interaction between human and land-use changes, and it was suitable for optimizing human behaviors and decisions of land-use transfer. 2) If the policy on land use was kept unchanged, the major contradiction between human and land in the future ten years should be the persistent reduction of agricultural land (127.64 hm<sup>2</sup> cultivated lands and 11.20 hm<sup>2</sup> garden lands) and the continuous increase of urbanized land (95.80 hm<sup>2</sup>). This indicated a big cost of urbanization in Erhai Lake Basin, which also gave a warning of increasing impervious surfaces (IS) produced in future rapid urbanization, and the IS may raise risks of urban non-point source pollution in the future. 3) The fast increasing of wetlands (growth rate of 50.07% was the fastest in the change of all land use types) indicated that the governmental land use policies to ecosystem protection have played a better role in macro control of land resources allocation. From this research, we suggested that the local government should maintain the existing strategies of ecological environment protection to reduce the risk of water pollution in Erhai Lake Basin. The competition in the market economy model of land-resources-commercial should be encouraged to balance the next major conflicts between human activities and land resources.
Number of references:30
Main heading:Land use
Controlled terms:Agents - Algorithms - Ant colony optimization - Artificial intelligence - Behavioral research - Climate change - Computer simulation - Computer software - Decision support systems - Ecology - Economics - Geographic information systems - Java programming language - Lakes - Models - Natural resources - Pollution - Water pollution - Water quality - Watersheds - Wetlands
Uncontrolled terms:Ant Colony Optimization (ACO) - Ant-agents behavior - Artificial intelligence algorithms - Calibration and verification - Dynamic changes - Ecological environment protections - Non-point source pollution - Resistance coefficients
Classification code:403 Urban and Regional Planning and Development - 442.2 Land Reclamation - 444 Water Resources - 444.1 Surface Water - 451 Air Pollution - 453 Water Pollution - 453.2 Water Pollution Control - 454.2 Environmental Impact and Protection - 454.3 Ecology and Ecosystems - 501 Exploration and Prospecting - 512 Petroleum and Related Deposits - 723 Computer Software, Data Handling and Applications - 803 Chemical Agents and Basic Industrial Chemicals - 902.1 Engineering Graphics - 921.5 Optimization Techniques - 971 Social Sciences
DOI:10.3969/j.issn.1002-6819.2014.19.035
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 26>
Accession number:201446200443
Title:Effects of plastic mulching on surface of no-till straw mulching on soil water and temperature
Authors:Yin, Tao (1); He, Wenqing (1); Yan, Changrong (1); Liu, Shuang (1); Liu, Enke (1)
Author affiliation:(1) Key Laboratory of Dryland Agriculture of Ministry of Agriculture, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing , China
Corresponding author:He, Wenqing
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:78-87
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Concerning the decline of crop yield caused low temperature under no-till with straw mulching in dry farmlands of north China, field experiments were conducted to investigate the effects of plastic mulching on the surface of no-till with straw mulching on soil water and temperature at the Ministry of Agriculture Shouyang Dryland Agriculture Key Field Scientific Observation and Experiment Station. The field management practices including conventional tillage (CT), no-till with straw mulching (NTSM) and plastic mulching on the surface of no-till with straw mulching (NTSMP) were designed to study their effects on soil water and temperature, water use efficiency (WUE) and crop yield. The results showed that the maize (Zea mays) was able to take a good advantage of soil water in the deep layers in the treatment of NTSMP than in treatments of CT and NTSM in the seeding stage under less rainfall condition. In the early growth stage of maize at the topsoil (0-20 cm), the soil water content in the treatment of NTSMP was 20.2% and 21.5% higher (p<0.05) than that of NTSM and CT, respectively. However, the water content in NTSMP treatment was 8.8% to 14.0% and 12.7% to 18.8% lower (p<0.05) than that in the treatments of NTSM and CT, respectively. The soil water storage declined in the treatment of NTSMP at the end of growing season, but it was not significant (p>0.05) compared with the treatment of CT. This might attribute to the good water conservation capacity of the soil interface in NTSMP that allowed the use of water from deeper soil layers. The treatment of NTSMP had significant (p<0.05) effects on soil temperature mostly in the seeding stage and in the decline stage when the crop area covering the soil was smaller than in any other stages. However, the effects soil temperature on the growth of crops was more important in the earlier stages than in middle and late stages. The average soil temperature in NTSMP treatment in the 0~10 cm deep soil layer in the early growth stage of maize (April, May) was 3.2 and 1.9, higher than that of NTSM and CT, respectively. The yield of maize in the treatment of NTSMP was 50.3% and 36.8% higher than that in treatments of NTSM and CT (p<0.05). The water use efficiency increased by 42.5% and 30.4%, respectively, compared with the treatments of NTSM and CT. Therefore, it can be concluded that the treatment of NTSMP increased the soil surface temperature and water use by maize in the early growth stage. The NTSMP treatment provided a better water and temperature condition for maize growth. Thus, the method can improve maize yield and the water use efficiency.
Number of references:30
Main heading:Water treatment
Controlled terms:Agricultural machinery - Agriculture - Atmospheric temperature - Crops - Efficiency - Experiments - Geophysical prospecting - Grain (agricultural product) - Moisture - Soil conservation - Soil moisture - Soils - Temperature - Water conservation
Uncontrolled terms:Conventional tillage - End of growing seasons - No tillage - Scientific observations - Soil surface temperatures - Straw mulching - Temperature conditions - Water use efficiency
Classification code:443.1 Atmospheric Properties - 444 Water Resources - 445.1 Water Treatment Techniques - 483.1 Soils and Soil Mechanics - 501 Exploration and Prospecting - 512 Petroleum and Related Deposits - 641.1 Thermodynamics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901.3 Engineering Research - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2014.19.010
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 27>
Accession number:201446200469
Title:Pilot-plant-scale test of cold-pressed oil extraction with twin-screw pressing for camellia seeds
Authors:Li, Shilong (1); Liu, Xiefang (1); Zhang, Yonglin (1); Liu, Qianggao (2)
Author affiliation:(1) School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan , China; (2) Wuhan New Concept Agriculture Machine Manufacture Co. Ltd, Wuhan , China
Corresponding author:Li, Shilong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:300-308
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:The oil camellia (Camellia oleifera Abel., Theaceae) is notable as an important source of edible oil (known as tea oil or camellia oil) obtained from its seeds in China. Camellia oil with high oleic acid content is coming more into the focus of interest in recent years since the fatty acid composition is more comparable to olive oil. Another important aspect is that the high content of oleic acid results in a high oxidative stability, making this oil interesting for a wide range of applications. Traditional processing of camellia oil extraction is carried out by seed preparation, cooking, hot pressing, solvent extraction, and refining. This results in the loss of some nutritional component and peculiar flavor due to high temperature. A cold-pressed production process for camellia seeds oil was developed for high-quality, tasty, and natural camellia oil, including storage of raw materials, dehulling, twin-screw pressing, and the purification of crude oil.
Number of references:29
Main heading:Petroleum refining
Controlled terms:Cost benefit analysis - Economic analysis - Extraction - Fatty acids - Hot pressing - Metabolites - Nutrition - Oil shale - Oil wells - Oils and fats - Oleic acid - Pilot plants - Presses (machine tools) - Profitability - Refining - Screws - Seed - Solvent extraction - Technology - Thermal processing (foods) - Unsaturated fatty acids
Uncontrolled terms:Benefit to cost ratios - Cold-pressed oil - Economic feasibility analysis - Fatty acid composition - Oil quality - Processing capacities - Screw pressings - Traditional processing
Classification code:402.1 Industrial and Agricultural Buildings - 461.2 Biological Materials and Tissue Engineering - 512.1 Petroleum Deposits - 512.1.1 Oil Fields - 513.1 Petroleum Refining, General - 603.1 Machine Tools, General - 605 Small Tools and Hardware - 802.3 Chemical Operations - 804.1 Organic Compounds - 812.1 Ceramics - 821.4 Agricultural Products - 822.2 Food Processing Operations - 822.3 Food Products - 901 Engineering Profession - 911 Cost and Value Engineering; Industrial Economics - 911.2 Industrial Economics
DOI:10.3969/j.issn.1002-6819.2014.19.036
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 28>
Accession number:201446200467
Title:Spatial-temporal change and analysis of land consolidation's newly increased cultivated land in China
Authors:Zhou, Jian (1); Zhang, Fengrong (1); Wang, Xiuli (1); Zhang, Bailin (1)
Author affiliation:(1) College of Resources and Environmental Sciences, China Agricultural University, Beijing , China
Corresponding author:Zhang, Fengrong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:282-289
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Land consolidation is of significance in the construction of ecological civilization put forward by Chinese Government and to be carried out in the future development. So studying spatial-temporal change and future development of land consolidation's newly increased cultivated land is important to investigate the role of land consolidation in ecological construction of China. This paper analyzed spatial-temporal changes of newly increased cultivated land from land arrangement, land exploitation, and land reclamation from 2001 to 2011, using the method of weighted gravity center model, which displayed moved direction and moved distance of land consolidation's newly increased cultivated land. The results showed that the newly increased cultivated land of land consolidation was 3.2×10<sup>6</sup> hm<sup>2</sup> from 2001 to 2011. The majority of newly increased cultivated land, accounting for 63.2% was derived from land exploitation. The newly increased cultivated land area from land arrangement and land reclamation accounted for 21.8% and 15.0% of the total newly increased cultivated land, respectively. The zone analysis of newly increased cultivated land of land consolidation was conducted based on the classification of China into 4 regions of East zone, West zone, Middle zone and North-east zone. The newly increased cultivated land from land arrangement was mainly distributed in East zone with 53.8% of the total from 2001 to 2008. East zone and west zone were the main distribution zones of newly increased cultivated land from land exploitation. They were 37.9% and 33.0% of the total from 2001 to 2008. Land discarded by factories and damaged mines, which was the object of land reclamation, had uncertainty in distribution and happening, so the proportion of newly increased cultivated land from land reclamation changed significantly among inter-zones and inter-annuals. The weighted gravity center of newly increased cultivated land area from land arrangement moved to west from 2001 to 2011. Comparing with 2001-2006 and 2007-2009, the moved average distance of 2010-2011 to the west were 769.59 and 603.44 km, respectively. The weighted gravity centers of newly increased cultivated land area from land exploitation during 2001 to 2006 were located in north and west of our country's geographic gravity center, with the tendency of moving to north from west, and it showed a trend of moving to west from east from 2007 to 2011. There were uncertainties in the moved direction of weighted gravity center of newly increased cultivated land area from land reclamation from 2001 to 2011. Based on the analysis above, we reckon that, at the background of ecological construction and relatively stable cultivated land quantity in China, the proportion of newly increased cultivated land from land exploitation should be decreased by the means of reducing land exploitation projects in land consolidation plan, and the related actions, for example, the reasonable layouts of land exploitation projects should be considered to prevent that weighted gravity center of newly increased cultivated land from land exploitation moves to west of China; the improvement of land quality and construction of fertilized farmland should be strengthened through land arrangement, which will be the main direction of land consolidation; and, land reclamation should play a more important role in repairing the damaged ecological environment with increasing cultivated land area.
Number of references:26
Main heading:Land reclamation
Controlled terms:Cultivation - Ecology - Land use - Natural resources exploration - Quality control - Reclamation - Repair
Uncontrolled terms:Average Distance - China - Chinese Government - Ecological construction - Ecological environments - Exploitation projects - Land consolidations - Spatial-temporal changes
Classification code:442.2 Land Reclamation - 444 Water Resources - 452.4 Industrial Wastes Treatment and Disposal - 454.3 Ecology and Ecosystems - 501 Exploration and Prospecting - 512 Petroleum and Related Deposits - 821.3 Agricultural Methods - 913.3 Quality Assurance and Control - 913.5 Maintenance
DOI:10.3969/j.issn.1002-6819.2014.19.034
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 29>
Accession number:201446200460
Title:Recognition of honey pomelo leaf diseases based on optimal binary tree support vector machine
Authors:Zhang, Jianhua (1); Kong, Fantao (1); Li, Zhemin (1); Wu, Jianzhai (1); Chen, Wei (1); Wang, Shengwei (1); Zhu, Mengshuai (1)
Author affiliation:(1) Agricultural Information Institute of Chinese Academy of Agricultural Sciences, Beijing , China
Corresponding author:Li, Zhemin
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:222-231
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Honey pomelo, one of the most important fruits in China, always suffers a variety of diseases during the whole process of planting, such as maculopathy, anthracnose, scab and dark mildew, which seriously affects the fruit quality and yield. The accurate recognition of honey pomelo leaf diseases is the premise of the treatment of honey pomelo diseases, and the precision directly affects the efficiency in controlling diseases. However, most of the current researches on disease recognition aimed at the global information of the study objects, but ignored the disease's local feature extraction in multi-scale and multi-direction; in addition, the present researches generally used the method of "one to one" or "one to many" when building many types of support vector machine (SVM) in the disease classification model, few researches used the method about SVM based on directed acyclic decision tree. So, leaf diseases recognition of honey pomelo based on SVM of directed acyclic decision tree was put forward in this paper. At first, statistical analysis on components of color characteristics of collected honey pomelo leaf diseases was carried on, and the conclusion was drawn according to the statistics of component B, component 2G-R-B, component (G R B)/3 and component Q in YIQ color model, which were easily distinguished among the 4 diseases, and so the 4 color components were used as disease color features. Secondly, honey pomelo leaf disease images were converted into 4 grayscale images of component B, component 2G-R-B, component (G R B)/3 and component Q in YIQ color model. Gabor wavelet with 5 dimensions and 8 directions was used for convolution calculation with 4 grayscale component images, and 16-dimension energy sub-band was got, the mean value of which was used as eigenvector. Disease recognition model of three-level directed acyclic decision tree SVM was constructed by 6 SVM classifiers, in order to recognize 4 honey pomelo diseases, i.e. maculopathy, anthracnose, scab and dark mildew. According to the test results of cross validation method, the recognition accuracies of maculopathy, anthracnose, scab and dark mildew respectively reached 90%, 96.66%, 93.33% and 96.66%, and the average recognition rate of the 4 diseases was 94.16%, showing that the method could effectively recognize the 4 honey pomelo leaf diseases. Optimal binary tree SVM proposed in this paper was compared with BP neural network, one-to-one SVM and one-to-many SVM in different characteristic dimensions, and the results showed that the training time of the proposed method in this paper and other 3 methods was respectively 740 ms, 420 ms, 450 ms and 370 ms, and the disease recognition accuracy of the 4 methods was respectively 86%, 91.5%, 90% and 94.16%. The method proposed in this paper is superior to the other 3 algorithms in training time and recognition precision. So the proposed method can provide technical support for the accurate recognition of honey pomelo leaf diseases, in favor of the prevention and treatment of pomelo diseases, and also provide references for the prevention and cure of other plant's leaf diseases.
Number of references:32
Main heading:Diseases
Controlled terms:Binary trees - Classification (of information) - Color - Color codes - Decision trees - Feature extraction - Food products - Fruits - Fungi - Identification (control systems) - Image processing - Neural networks - Support vector machines
Uncontrolled terms:Color characteristics - Cross-validation methods - Disease classification - Gabor wavelets - Global informations - Local feature extraction - Pomelo leaf - Recognition accuracy
Classification code:461.7 Health Care - 461.9 Biology - 706.2 Electric Power Lines and Equipment - 716.1 Information Theory and Signal Processing - 723 Computer Software, Data Handling and Applications - 731.1 Control Systems - 741 Light, Optics and Optical Devices - 741.1 Light/Optics - 821.4 Agricultural Products - 822.3 Food Products - 922 Statistical Methods - 961 Systems Science
DOI:10.3969/j.issn.1002-6819.2014.19.027
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 30>
Accession number:201446200444
Title:Suitability evaluation of precipitation data using SWAT model
Authors:Zhang, Xiaoli (1); Peng, Yong (1); Wang, Bende (1); Wang, Haixia (1)
Author affiliation:(1) Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian , China
Corresponding author:Peng, Yong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:88-96
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Precipitation is the important forcing data for hydrological models. However, the precision of hydrological modeling in many regions of the world is limited by the lack of precipitation data. To overcome such limitation, some available globally gridded high resolution precipitation datasets have been used to simulate runoff. Although these precipitation products have been proved to have certain accuracy and good potential for hydrologic simulation, selecting the most optimal precipitation product for certain regions is still important because the accuracy and hydrological utility of precipitation dataset vary in different regions. In this study, the suitability of three precipitation products: GLDAS, TMPA and ERA-Interim for hydrological modeling are evaluated using the multi-objective fuzzy optimum model and the Soil and Water Assessment Tool (SWAT) model during the period of 2001-2012 in the Huanren reservoir catchment, located in Hunjiang River of China. SWAT is a physical-based hydrological model, which takes precipitation series from gauged stations as input to simulate runoff. First, in order to obtain the rainfall time series for SWAT model, three interpolation methods, including inverse distance-weighted method, bilinear interpolation method and the nearest point method, were used to compute the station data from the three precipitation products. Then, the quantitative accuracy of these time series were assessed by statistical indices of mean error (ME), root mean square error (RMSE), correlation coefficient (CC) and relative bias (Bias). The multi-objective optimum fuzzy model aiming to identify the appropriate interpolation method and justify the precipitation products alternative to the gauged values was established, which used ME, RMSE, CC and Bias as characteristic indices. The results revealed that the precipitation of GLDAS cannot serve as an alternative due to its underestimation for the whole basin, which can increase the risk of flood control operation. Moreover, the bilinear interpolation was more appropriate to interpolate the grid precipitation to rain gauge compared with the inverse distance-weighted method and the nearest point method. In addition the precipitation of TMPA and ERA-Interim obtained with the bilinear interpolation method were proved to have perfect fitting with the gauge values at daily and monthly scale, thus they both were alternative to the gauge values as the forcing data to the hydrological model. The two precipitation series were then used as the input to the SWAT model that has been calibrated with rain gauge inputs to get the simulated stream flow and their Bias. Correlation coefficient and Nash-Sutcliffe efficiency coefficient (NSE) were calculated against the observed stream flow. Based on the criteria of the statistical indices specified in the present study, it can be concluded that the performances of these simulations were acceptable at daily and monthly scale. With Bias, CC and NSE as characteristic indices, the multi-objective optimum fuzzy model was developed to evaluation the suitability of TMPA and ERA-Interim for hydrological simulation. The results revealed that TMPA was more suitable for hydrological runoff modelling at the basin scale. The methodologies and approaches developed in the present study will be a reference for hydrological modelling of similar watersheds.
Number of references:40
Main heading:Precipitation (meteorology)
Controlled terms:Catchments - Climate models - Computer simulation - Flood control - Floods - Gages - Hydrology - Interpolation - Mean square error - Models - Rain - Rain gages - Reservoirs (water) - Runoff - Statistical methods - Stream flow - Time series
Uncontrolled terms:Bilinear interpolation method - Correlation coefficient - Flood control operations - Hydrological simulations - Simulation - Soil and water assessment tool - Suitability - SWAT
Classification code:441.2 Reservoirs - 443 Meteorology - 443.3 Precipitation - 444 Water Resources - 444.1 Surface Water - 454.1 Environmental Engineering, General - 631.1 Fluid Flow, General - 723.5 Computer Applications - 902.1 Engineering Graphics - 914.1 Accidents and Accident Prevention - 921 Mathematics - 921.6 Numerical Methods - 922.2 Mathematical Statistics - 943.3 Special Purpose Instruments
DOI:10.3969/j.issn.1002-6819.2014.19.011
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 31>
Accession number:201446200466
Title:Material balance of anaerobic-poor oxygen-aerobiotic biological contact oxidation process treating sewage with low carbon/nitrogen ratio
Authors:Wang, Cong (1); Wang, Shuying (1); Zhang, Miao (1); Tang, Yufang (1); Zeng, Wei (1); Peng, Yongzhen (1)
Author affiliation:(1) Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing , China
Corresponding author:Wang, Shuying
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:273-281
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Increasingly stringent discharge standards make it necessary to research and develop a new processes that have the advantages of relatively high efficiency, less land occupation, investigated savings, easy management, and maintenance for nutrient removal from the domestic sewage. An enhanced denitrifying phosphorus removal system was developed to treat domestic sewage, especially for the sewage with comparatively low carbon source and high nitrogen and phosphorus concentration. The system included an integrating anaerobic/anoxic/oxic (A<sup>2</sup>/O) reactor and a biological contact oxidation (BCO) (A<sup>2</sup>/O - BCO for short). The A<sup>2</sup>/O unit consisted of four compartments in sequence with a working volume of 40L. It was mainly used for the removal of organic compounds and nutrients without ammonium oxidation, while the BCO unit was mainly responsible for nitrification. The BCO unit, with 24L working volume, consisted of three compartments in sequence, where suspended carriers were filled in it, with packing rates of 45% in each zone. The removal of biological nitrogen (N) and phosphorus (P) were investigated in an A<sup>2</sup>/O - BCO nitrogen and phosphorus removal process when treating domestic sewage. The experiment was carried out with the influent flow at a rate of 5L/h, total hydraulic retention time (HRT) of A<sup>2</sup>O about 8 h, sludge reflux ratio of 100%, sludge retention time (SRT) of 12d, MLSS maintained at 3500 mg/L, total HRT of BCO about 1.9 h, DO should be controlled within a reasonable range, and nitrate recycling ratios were set as 100%, 200%, 300%, and 400% respectively. Based on the experimental data under steady state operating conditions of different nitrate recycling ratios, the equations for calculating material balances of COD, nitrogen, and phosphate were established. These three material distributions in the system were also evaluated. The result indicated that the process has an advantage of making full use of the raw water carbon and removing biological nitrogen and phosphorus deeply. With the nitrate recycling ratios of 100%, 200%, 300%, and 400% conditions, the system COD was mainly utilized in the anaerobic stage in A<sup>2</sup>/O reactor, and removal percentages of total COD were 78.5%, 71.8%, 57.9%, and 71.1% respsectively. Nitrogen removal was mainly achieved by denitrifying in the phosphorus removal process by denitrifying phosphorus bacteria. The denitrification removal ratios of the total amount were 28.0%, 35.7%, 48.5%, and 33.9%, respectively. Phosphorus removal was mainly achieved by the discharge of excess sludge, where the amount of phosphorus percentages of total were 78.0%, 88.4%, 84.3%, and 85.4% respectively. Under the different nitrate recycling ratios, COD balance ratios were 96.4%, 99.6%, 98.7%, and 98.3%, nitrogen balance ratios were 99.7%, 98.2%, 99.2%, and 96.5%, and phosphorus balance ratios were 92.0%, 98.1%, 93.3%, and 90.4%. Fluorescence in situ hybridization showed that the anammox bacteria existed in the biofilm of BCO, and its proportion of the total bacterial number was 0.6~2.7%. The nitrogen loss may be due to the occurrence of the anammox reaction. The amount of denitrifying phosphorus increased slightly with the nitrate recycling ratio improved. But it is essential to control nitrate recycling ratio in the appropriate range to ensure nitrogen removal efficiency. The system achieved the best removal efficiencies of nitrogen and phosphorus when the nitrate recycling ratio was set as 300%, in which the average concentrations of TN and TP were 14.96 mg/L and 0.49 mg/L respectively in the effluent, which met the class of a limit (GB18918-2002) of the discharge standards. This study not only contributes to a better understanding and analysis of distribution and changes about organics, nitrogen and phosphorus in process systems, but also provides a theoretical basis and guidance for the reliability evaluation of the of the experimental data by building a mathematical model. The combined A<sup>2</sup>/O - BCO process will get a better promotion in treating domestic wastewater, especially the rural domestic wastewater with the universal features of small quantity, scattered distribution, and water fluctuation.
Number of references:22
Main heading:Biological water treatment
Controlled terms:Bacteria - Biological materials - Biological sewage treatment - Carbon - Chemical oxygen demand - Denitrification - Efficiency - Effluents - Fluorescence microscopy - Mathematical models - Nitrates - Nitrogen - Nitrogen removal - Nutrients - Oxidation - Phosphorus - Recycling - Reliability analysis - Removal - Sewage - Sewage treatment - Wastewater treatment
Uncontrolled terms:Biological contact oxidation - Contact oxidation - Denitrifying phosphorus removal - Fluorescence in situ hybridization - Material balance - Nitrogen and phosphorus removal - Recycling ratio - Steady-state operating conditions
Classification code:445.1 Water Treatment Techniques - 452 Municipal and Industrial Wastes; Waste Treatment and Disposal - 461 Bioengineering and Biology - 802.2 Chemical Reactions - 802.3 Chemical Operations - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 913 Production Planning and Control; Manufacturing - 913.1 Production Engineering - 921 Mathematics
DOI:10.3969/j.issn.1002-6819.2014.19.033
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 32>
Accession number:201446200434
Title:Development and experiment of movable pond aquaculture water quality regulation machine based on solar energy
Authors:Liu, Xingguo (1); Xu, Hao (1); Zhang, Yongjun (1); Zou, Haisheng (1); Tian, Changfeng (1); Cheng, Guofeng (1); Wu, Zongfan (1); Liu, Shijing (1)
Author affiliation:(1) Key Laboratory of Fishery Equipment and Engineering, Fishery Machinery and Instrument Institute, Chinese Academy of Fishery Science, Shanghai , China
Corresponding author:Liu, Xingguo
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:1-10
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Pond aquaculture plays a very important role in China's aquaculture industry and is the main source of aquatic product supply. For the regulation and control of pond aquaculture water quality, a movable pond aquaculture water quality regulation machine based on solar energy (SMWM) was designed and the prototype had been manufactured. This machine is solar-powered and can move upon the water, mainly consisted of solar power device, sediment lifting device, water walking device and working control system. The solar power device provides power for the entire machine, while the water walking device drives the whole equipment moving on the water. The sediment lifting device orbits around the main part of the equipment (the solar power device, water walking device and working control system), affecting large area of pond. Tests on the mechanical properties revealed that the minimum illumination of SMWM becoming working was 13 000 lx; The no-load running noise was 68 dB; The moving speed upon the water was 0.02-0.03 m/s. In the illumination intensity of 13 000-52 500 lx, the running speed of the sediment lifting device orbiting around the main part was 0.13-0.35 m/s, the capacity of water delivery was 110-208 m<sup>3</sup>/h. Illumination intensity was an important factor influencing the moving speed and capacity of water delivery of the sediment lifting device. The stronger of illumination intensity was, the values of moving speed and water delivery capacity higher. The sediment lifting device was foldaway and the angle of suction chamber can be adjusted. By adjusting the angle, the machine can work well in ponds with different water depthes from 0.5 m to 2 m. The sucking sediment performance of sediment lifting device was related to the distance of suction mouth of lifting device to pond bottom. The smaller of the distance was, the more sediment being sucked to the surface water. In aquaculture pond, the most suitable distance was 10-15 cm. Moreover, by adjusting the length of connecting rod and the direction of traction rope, the working area of the machine can be more than 80%. For the water quality, the using of SMWM in pond aquaculture caused decreased TN, NH<inf>3</inf><sup> </sup>-N and NO<inf>2</inf><sup>-</sup>-N concentrations and increased TP concentration in water. The content of TN and available phosphorus in sediment was reduced. These findings implied that the SMWM could promote the transformation of nitrogen and phosphorus nutrients in water. In addition, results from fish production showed that the SMWM caused the yields of feed-eating fish and filter-feeding fish enhanced by more than 30% and 25%, respectively. The feed coefficient of the feed-eating fish was decreased by more than 24%. In an entire aquaculture period, the machine saved the electrical power by more than 2 400 kW. These results indicated that the SMWM might be suitable for pond aquaculture in China. Its structure and working performance had met the design requirement. The SMWM possesses the advantages of stable operation, large working area, good water quality regulation effect and notable yield-increasing effect. Applying this machine in pond aquaculture for the regulation and control of water quality is feasible.
Number of references:16
Main heading:Quality control
Controlled terms:Aquaculture - Control systems - Fish - Fish ponds - Lakes - Mechanical properties - Phosphorus - Ponding - Sediments - Solar energy - Water quality
Uncontrolled terms:Aquaculture industry - Available phosphorus - Illumination intensity - Movable way - Nitrogen and phosphorus - Regulation and control - Solar power devices - Working performance
Classification code:402 Buildings and Towers - 407 Maritime and Port Structures; Rivers and Other Waterways - 453.2 Water Pollution Control - 461 Bioengineering and Biology - 471 Marine Science and Oceanography - 471.5 Sea as Source of Minerals and Food - 483 Soil Mechanics and Foundations - 615.2 Solar Power - 731.1 Control Systems - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.3 Agricultural Methods - 822 Food Technology - 913.3 Quality Assurance and Control - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.001
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 33>
Accession number:201446200453
Title:Effect of biochar on mineral nitrogen content in soils with different pH values
Authors:Luo, Yu (1); Zhao, Xiaorong (2); Li, Guitong (2); Zhao, Lixin (1); Meng, Haibo (3); Lin, Qimei (2)
Author affiliation:(1) Chinese Academy of Agricultural Engineering, Key Laboratory of Energy Resource Utilization from Agriculture Residue, Ministry of Agriculture, Beijing , China; (2) College of Resources and Environmental Sciences, China Agricultural University, Beijing , China; (3) Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences, Beijing , China
Corresponding author:Lin, Qimei
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:166-173
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Biochar is the charred byproduct of biomass pyrolysis, the heating of plant-derived material in the absence of oxygen in order to capture combustible gases. Key chemical and physical properties of biochar are greatly affected both by the choice of feedstock (crop waste, energy crop, etc.) and the process conditions (mainly temperature and time). The effect of temperature on biochar properties shows that biochar created at low temperature may be suitable for controlling the release of nutrients, whilst high temperature biochars may be more suitable for use as activated carbon. The other key aspect of biochar is related to carbon sequestration and improvement of soil productivity. Soils amended with biochar in many centuries ago by pre-Colombian peoples in the Amazon Basin still retain higher plant-available nutrients than the adjacent unamended soils. Additions of biochar to soil have shown definite increases in the availability of major cations and phosphorus as well as total nitrogen concentration. The causes for high fertility of these soils are multiple, but the source of the large amounts of organic matter and their high nutrient retention has been attributed to the extraordinarily high proportions of black carbon. Besides, the high available nitrogen (N) is from both direct nutrient addition by the biochar and greater nutrient retention. It is also reported biochar can influence soil N concentrations via affecting soil process, such as N transformation. However, it remains largely unknown how biochar affect N transformations.In this study, biochars were produced at 350 (BC350) and 700 (BC700) by using Miscanthus giganteus, and applied with and without ryegrass into soils with low (pH = 3.8) and high pH values (pH = 7.6) incubated for 180 days. Our results showed that the addition of biochar to soils had an average increase of total N content of 22% and 17%, respectively in acid and alkaline soils. Biochars had obvious effect on NH<inf>4</inf><sup> </sup>-N in acid soil. After 87 days of incubation, NH<inf>4</inf><sup> </sup>-N was declined to very low concentration. BC350 had a slight increase of NO<inf>3</inf><sup>-</sup>-N in acid soil. Compared with BC350, soils with BC700 significantly (p<0.05) decreased the concentration of NO<inf>3</inf><sup>-</sup>-N. For BC700, NO<inf>3</inf><sup>-</sup>-N in acid soil declined from 96.23 mg/kg to 4.39 mg/kg. Results also showed that biochars had high adsorption on NH<inf>4</inf><sup> </sup>-N. but no NO<inf>3</inf><sup>-</sup>-N was adsorpted, showing different impact of biochar on NH<inf>4</inf><sup> </sup>-N and NO<inf>3</inf><sup>-</sup>-N. This can partly explain why NH<inf>4</inf><sup> </sup>-N was not detected within all biochar addition treatments while NO<inf>3</inf><sup>-</sup>-N differed between soils and biochar. In addition, the increased soil microbial biomass via pH changes and better micro-environment, which affect biochar N transformation, thus possibly benefit N use of plant. No significant difference (p>0.05) was observed in treatments with and without ryegrass, neither between day 87 and 180, suggesting mineralization was largely occurred at the early incubation time in the soil with biochar added. The effects of biochar on the form and content of soil mineral nitrogen were closely related to the biochar's abilities including ammonium adsorption, enhancing soil pH value, enhancing ammonia volatilization, and microbial biomass nitrogen formation. In the practical application, using biochar as coating materials in producing the slow-release fertilizer to improve nitrogen use efficiency seems to be very promised, and more research is needed in this area in the near future.
Number of references:31
Main heading:Soils
Controlled terms:Activated carbon - Adsorption - Alkalinity - Biomass - Carbon - Crops - Forestry - Minerals - Nitrogen - Nitrogen fertilizers - Nutrients - Particulate emissions - pH - pH effects - Temperature
Uncontrolled terms:Ammonia volatilization - Chemical and physical properties - Mineral nitrogen - Mineral nitrogen content - Miscanthus - Nitrogen-use efficiency - pH value - Slow release fertilizers
Classification code:451.1 Air Pollution Sources - 482.2 Minerals - 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 801.1 Chemistry, General - 802.3 Chemical Operations - 804 Chemical Products Generally - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2014.17.020
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 34>
Accession number:201446200437
Title:Design and experiment of self-propelled grass silage combined bagging machine
Authors:Wan, Qihao (1); Wang, Decheng (1); Wang, Guanghui (1); Gong, Zeqi (1); Bai, Yang (1)
Author affiliation:(1) College of Engineering, China Agricultural University, Beijing , China; (2) Key Laboratory of Grassland Resource & Ecology Ministry of Agriculture, Grassland Research Institute Chinese Academy of Agriculture Science, Huhhot, China
Corresponding author:Wang, Decheng
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:30-37
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Silaging nutrient-rich phase grass with bags in the field can reduce nutrient loss, maintain green feed nutrients, and facilitate long-term preservation; thus promotes the growth of good livestock. To facilitate direct storage of forage harvested in the field, one self-propelled grass silage combined bagging machine was developed.. It integrated the cutting device, a conveyor feeding device, a crushing and throwing device, vertical auger conveyor equipment, grass bagging density control device. And their key device parameters were calculated. The self-propelled grass silage combined bagging machine used disc cutter to cut grass, the blade root diameter and top diameter were 500 and 620 mm, and the critical forward speed of the machine was 17.9 km/h so that leakage could be prevented and repeat cutting could be reduced. The designed grinding hob diameter and the width were 550 and 480 mm. it's rated rotating speed was 1600 r/min and the linear velocity of the feed roller was from 2.1-17.1 m/s when the length of the cutting grass was 5-40 mm. The diameters of the front and intermediate feed roller were 300 and 260 mm, and the calculated rear feeding roller diameter was 90 mm. In order to minimize forage accumulation, the designed throwing roller diameter was 300 mm, the width was 510 mm, the angular velocity was 2 600 r/min, the leaf number was 4, and the angle of thrown pieces of angle was 20°. The displacement and velocity equations at any moment from the start. Grass compressed by screw auger before output from the silo. The compression ratio of the screw mechanism can be adjusted for achieving the desired output squeeze effect. The three different of compression ratio screw auger were designed for different types of forage, and spirals can be changed by the exchange of connecting flange. According to squeeze theory, the designed spiral inner diameter was 100 mm and screw conveyor segment pitch was 345 mm at the beginning of variable pitch segments, meanwhile the surface of screw extruder was polished and longitudinal grooves in the barrel were built for increasing the extrusion effect. The crushed forage was loose and easy to squeeze, and had a large volume gradient. Then the volume gradient became small, and pitch gradually becomes small, so rational compression ratio made compression effect better. Finally, the critical rotation speed was calculated and was 99 r/min. In the self-propelled silage harvester, this innovative design combined automatic pneumatic tying device could greatly reduce labor intensity. Working performance test of the developed prototype was conducted with forage whose moisture content is 78%. Results showed a stubble height was 5-15 mm, cutting leakage loss was 0.85%, average bagging density was 320 kg/m<sup>3</sup>, average bagging time was 30 s per bag, tying rate was 100%.With average forward speed at 2.3 m/s, operation capability of the machine can achieve 0.53-0.67 hm<sup>2</sup>/h without clogging. The presented study provides a new approach for the harvest and storage of silage grass.
Number of references:17
Main heading:Agricultural machinery
Controlled terms:Agricultural runoff - Agriculture - Augers - Compression ratio (machinery) - Conveyors - Cutting - Cutting equipment - Design - Extrusion - Grinding (machining) - Harvesting - Machine design - Nutrients - Rollers (machine components) - Screw conveyors
Uncontrolled terms:Bagging - Compression effects - Connecting flanges - Conveyor equipment - Long-term preservation - Screw extrusion - Silage - Working performance
Classification code:408 Structural Design - 502.2 Mine and Quarry Equipment - 535.2.2 Metal Forming Practice - 601 Mechanical Design - 601.2 Machine Components - 604.1 Metal Cutting - 606.2 Abrasive Devices and Processes - 618.1 Compressors - 692.1 Conveyors - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.3969/j.issn.1002-6819.2014.19.004
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 35>
Accession number:201446200454
Title:Analysis on phosphorus removal in series horizontal subsurface flow constructed wetland based on hydraulic model
Authors:Zhang, Yan (1); Cui, Lijuan (1); Li, Wei (1); Zhang, Manyin (1); Zhang, Yaqiong (1)
Author affiliation:(1) Beijing Key Laboratory of Wetland Ecological Functions and Restoration, Beijing , China
Corresponding author:Cui, Lijuan
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:174-181
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to explore the internal water flow patterns of series horizontal subsurface flow constructed wetland and the treatment efficiency of wastewater from the domestically raised waterfowl, treatment performance on the waterfowl wastewater by a horizontal subsurface flow constructed wetland with three stages in series (P1, P2, P3) was monitored continuously. Changes in the removal efficiency of total phosphorus (TP) per area base by the horizontal subsurface flow constructed wetland in different months were analyzed. The effects of the influent flow rate and hydraulic retention time on the effluent concentration of TP in the horizontal subsurface flow constructed wetland were analyzed. In addition, the actual flow morphologic characteristics in the horizontal subsurface flow constructed wetland were described through the use of three different hydraulic models including the plug-flow model, the dispersed-flow model and the tanks-in-series model. Results showed that an overall decrease of the removal efficiency of TP was observed as the number of treatment ponds increased. The averaged removal efficiencies of TP were (0.11±0.09) g/(m<sup>2</sup>·d), (0.08±0.03) g/(m<sup>2</sup>·d) and (0.05±0.01) g/(m<sup>2</sup>·d) respectively for the treatment ponds P1, P2 and P3 throughout the experiment. The increase of influent flow rate was conducive to the increase of the removal efficiency of TP in the treatment pond P1 when the influent flow rates were maintained at a level lower than 55 m<sup>3</sup>/d. However, the removal efficiencies of TP in the treatment ponds P2 and P3 declined as the influent load increased when the influent flow rates were lower than 55 m3/d. While the increase of hydraulic retention time was beneficial to the increase of the removal efficiencies of TP, resulting in decrease of effluent concentrations of TP in different treatment ponds. The removal efficiencies of TP in the treatment ponds P2 and P3 appeared to be more sensitive to the changes in the hydraulic retention time conditions when the hydraulic retention time was longer than 85 d, and exhibited greater fluctuations than the removal efficiencies of TP when the hydraulic retention time was less than 85 d. The maximum removal efficiencies of TP were reached under the condition of optimal combinations of influent flow rate and hydraulic retention time: 55 m<sup>3</sup>/d and 166 d; 3.4 m<sup>3</sup>/d and 151 d and 9.5 m<sup>3</sup>/d and 176 d, respectively for the treatment ponds P1, P2 and P3. Seasonal variations in the removal efficiency of TP were observed in the horizontal subsurface flow constructed wetland. The treatment pond P1 appeared to be efficient in the removal of TP in summer as indicated by higher removal efficiencies of TP in the summer than in the autumn. While the treatment pond P3 experienced a longer time of net discharges of TP in the summer than in the autumn. The removal efficiency of TP in the treatment pond P2 exhibited a great fluctuation as the experiment proceeded and net discharges of TP occurred both in the summer and in the autumn. Compared with the treatment ponds P2 and P3, the treatment pond P1 with a more favorable physical and chemical conditions in the horizontal subsurface flow constructed wetland was more efficient in the removal of phosphorus, as indicated by the higher first-order removal coefficients ranged from 0.663 cm/d to 0.751 cm/d than treatment ponds P2 (0.641 to 0.722 cm/d) and P3 (0.429 to 0.458 cm/d). Results of the simulations demonstrated that the tanks-in-series model with higher determination coefficients of 0.567~0.883 (P < 0.05) fit the observed data better than the dispersed-flow model (R<sup>2</sup>: 0.510~0.723, P < 0.05) and the plug-flow model (R<sup>2</sup>: 0.465~0.626, P < 0.05), indicating that the actual flow morphologic characteristics in the horizontal subsurface flow constructed wetland was close to mixed flow. Results of this study were benefit in deepening the understanding of the internal flow patterns and distributions, as well as the transportation and dispersion mechanisms of phosphorus under different operating conditions of horizontal subsurface flow constructed wetlands.
Number of references:30
Main heading:Wetlands
Controlled terms:Computer simulation - Efficiency - Effluent treatment - Effluents - Experiments - Flow patterns - Flow rate - Hydraulic models - Lakes - Models - Morphology - Phosphorus - Ponds - Purification - Removal - Tanks (containers) - Wastewater treatment
Uncontrolled terms:Determination coefficients - Different operating conditions - Effluent concentrations - Horizontal subsurface flow constructed wetlands - Hydraulic retention time - Internal flow patterns - Morphologic characteristics - Tanks-in-series model
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 442.2 Land Reclamation - 452.3 Industrial Wastes - 452.4 Industrial Wastes Treatment and Disposal - 454.3 Ecology and Ecosystems - 619.2 Tanks - 631 Fluid Flow - 631.1 Fluid Flow, General - 632.1 Hydraulics - 723.5 Computer Applications - 802.3 Chemical Operations - 804 Chemical Products Generally - 901.3 Engineering Research - 902.1 Engineering Graphics - 913.1 Production Engineering - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.021
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 36>
Accession number:201446200441
Title:Fatigue analysis of pintle valve of motor with five-star radial piston under effect of hydraulic shock
Authors:Wang, Jianli (1); Liu, Jinhao (1)
Author affiliation:(1) College of technology, Beijing Forestry University, Beijing , China
Corresponding author:Liu, Jinhao
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:65-70
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Hydraulic shock often happens when valves are opened or closed suddenly, and it may cause a series of trouble for the hydraulic system. If the motor in the hydraulic system has a huge initial load, hydraulic shocks might be larger when the valve is closed. When a hydraulic motor drives a plate whose rotary inertia is as large as 17 kgm<sup>2</sup> running at a highest rotating speed of 400 r/min, if the control valve is suddenly closed, the hydraulic shock is not ignorable.
Number of references:13
Main heading:Fatigue damage
Controlled terms:Computer simulation - Electric drives - Fatigue of materials - Friction - Hose - Hydraulic equipment - Hydraulic motors - Loading - Pistons - Pressure relief valves - Safety valves - Stars
Uncontrolled terms:Experimental section - Fatigue analysis - Fatigue damage mechanism - High hydraulic pressure - Hydraulic shocks - Hydraulic system - Pressure boundary - Simulation model
Classification code:421 Strength of Building Materials; Mechanical Properties - 612.1.1 Internal Combustion Engine Components - 619.1 Pipe, Piping and Pipelines - 619.1.1 Pipe Accessories - 632.2 Hydraulic Equipment and Machinery - 657.2 Extraterrestrial Physics and Stellar Phenomena - 672 Naval Vessels - 705 Electric Generators and Motors - 723.5 Computer Applications - 931.1 Mechanics - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.008
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 37>
Accession number:201446200465
Title:Effect of lignin on recalcitrance of lignocellulose
Authors:Yan, Zhipei (1); Li, Jihong (1); Li, Shizhong (1); Cui, Ting (1); Yu, Menghui (1); Cong, Guangtao (1); Zhao, Gang (1)
Author affiliation:(1) Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing , China; (2) Beijing Engineering Research Center of Biofuels, Tsinghua University, Beijing , China
Corresponding author:Li, Shizhong
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:265-272
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:Lignin has been considered as an important factor to affect the recalcitrance of lignocellulose. Understanding the effect of lignin on the recalcitrance of lignocellulose make sense to building plants by gene modification, screening of enzymes and optimizing pretreatment conditions for biofuels production. Study on the effect of lignin on the recalcitrance of lignocellulose has been done by many researchers. This review examines the effect of lignin content and structure on the recalcitrance of lignocellulose primarily on the effect of the initial lignin content, the residual lignin content, and ratio of different constitutive units, the interconnected bond and functional group. In addition, the effect of isolated lignin on the recalcitrance of simulated lignocellulose was reviewed. General, higher initial lignin content make higher recalcitrance of lignocellulose for the same species. Relationship of them for different species was similar but the regularity is poorer. Removal of lignin from the lignocellulose can improve the enzymatic hydrolysis of biomass. The residual lignin content was negatively correlated to the recalcitrance of lignocellulose within certain limits. Beyond this limit, further removal of lignin had nonsense to the improvement of enzymatic hydrolysis of lignocellulose. The structure of the lignin effect on the recalcitrance of lignocellulose too. Firstly, the constituent of lignin, mainly the content/ proportion of syringyl units(S) / guaiacyl units (G), has influence on the inhibition of lignin to the enzymatic hydrolysis of cellulose. In addition, the content of H also affects the inhibition. Secondly, the interconnected bond between monomers of lignin impacts the recalcitrance of lignocellulose. The type of bonds may affect the complexity of lignin removal. Moreover, it may affect the contact of lignin with cellulose. Thirdly, the functional group of lignin, mainly the hydroxyl group (-OH), carboxylic group (-COOH) can affect the inhibition of lignin on the recalcitrance of lignocellulose. Lignin with high phenolic hydroxyl group was easier to be removed. On the other hand, the phenolic hydroxyl group of lignin intensifies the invalid adsorption of cellulase on the lignin. The aliphatic hydroxyl group can affect the hydrogen bond between cellulase and lignin. Carboxylic group of lignin can reduce the invalid adsorption of cellulase on the lignin. In order to suppress interference, many studiers isolated lignin from biomass, and study the impact of isolated lignin on the cellulose. Since the origin, species and methods of isolation were different, the structure of lignin was different. As a result, the effect of isolated lignin on the enzymatic hydrolysis of cellulose was different. Though many studies have been done, it is far from recognizing the exact effect of lignin on the recalcitrance of lignocellulose. Because there are various lignocellulose and lignin, the study conclusions always result from their substrate. It is difficult to summarize the law applied to all lignocellulose. Verification of lignin effect on the recalcitrance of lignocellulose need further studies and advance in the In situ detection technology.
Number of references:43
Main heading:Lignin
Controlled terms:Adsorption - Cellulose - Degradation - Enzymatic hydrolysis - Hydrogen bonds - Hydrolysis - Structure (composition)
Uncontrolled terms:Aliphatic hydroxyl groups - Biofuels production - Content - Enzymatic hydrolysis of lignocellulose - Gene modification - In-situ detections - Phenolic hydroxyl group - Pretreatment conditions
Classification code:801.4 Physical Chemistry - 802.2 Chemical Reactions - 802.3 Chemical Operations - 815.1.1 Organic Polymers - 951 Materials Science
DOI:10.3969/j.issn.1002-6819.2014.19.032
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 38>
Accession number:201446200440
Title:Energy management and torque coordination control for plug-in 4WD hybrid electric vehicle
Authors:Qian, Lijun (1); Qiu, Lihong (1); Xin, Fulong (1); Hu, Weilong (1)
Author affiliation:(1) School of Machinery and Automotive Engineering, Hefei University of Technology, Hefei , China
Corresponding author:Qian, Lijun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:55-64
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:This paper focuses on the control strategy of a plug-in 4-wheel-drive (4WD) hybrid electric vehicle (PHEV). To overcome the defects of the traditional proportion-integration-differentiation (PID) control method, an algorithm based on an adaptive fuzzy PID control method which provides better dynamic and static performances for the vehicle was adopted and a driver model was established using this algorithm. The input of the driver model was the difference between the cycle velocity and the actual output velocity of the vehicle. The output of the driver model was the required torque coefficient which reflects the driver's intention and thus can be used to calculate the actual required torque of the driver. The PID parameters can be revised real-time according to the change of the cycle conditions, and the principle to choose theses parameters to ensure the stability of the controller was introduced as well. The domain of discourse for the inputs and outputs of the fuzzy PID controller and their membership functions were analyzed and parts of the fuzzy rules were provided. The energy management control strategy based on engine optimal torque was adopted in order to improve the fuel economy of the vehicle. Because there was little possibility that the engine could drive the vehicle alone with the optimal engine output torque control strategy, and the general efficiency for the series mode was relatively low, the drive modes of the vehicle were only classified into four modes, including EV (electric vehicle) mode, parallel mode, 4WD mode, and E_charge (engine drives and charges the battery) mode. Mode judging rules and torque distribution methods were described, and a state-flow model in the paper was used to illustrate the energy management of the vehicle. In addition, a torque coordination control strategy based on "engine speed regulation clutch fuzzy PID control engine dynamic torque lookup 2 motor compensation" was proposed. The engine dynamic torque related to the engine speed, throttle opening and its change rate were obtained by experiments, and they were fitted into a more detailed table through MATLAB programming. Aiming to have a more precise output oil pressure of the clutches, the two clutches were controlled by the combination of two fuzzy controllers and an adaptive fuzzy PID controller, and then a more reliable output of the required torque was obtained. One of the fuzzy controllers was used to calculate the oil pressure increment in the clutch, and the other was for the change rate of the original oil pressure. The fuzzy PID controller which was adaptive to different drive cycles was used to more accurately calculate the final oil pressure. The torque coordination control strategy was introduced by taking the transition between EV mode and parallel mode as an example. The detailed transition procedures were briefly introduced. The control strategy of the vehicle was simulated using hardware-in-loop(HIL) based on dSPACE with the cycle of 2*NEDC (which consists of two new European driving cycles) and the research results which include the output of the power components, SOC of the battery pack, and the velocity error which was reduced by 37.1% before and after the application of adaptive fuzzy PID indicate that the control strategy realized the basic energy management of the vehicle, and the jerk after the application of torque coordination control was reduced by 47.5% because of the coordination of the power components during mode transitions, and the adaptive fuzzy PID control of the two clutches. The control effectiveness of the control strategy was validated in this paper and it is of significance for controlling similar complicated hybrid systems.
Number of references:25
Main heading:Plug-in hybrid vehicles
Controlled terms:Clutches - Controllers - Electric batteries - Electric control equipment - Electric drives - Electric vehicles - Energy management - Engines - Fuel economy - Hardware - Hybrid systems - Hybrid vehicles - MATLAB - Membership functions - Oil shale - Proportional control systems - Secondary batteries - Speed - Three term control systems - Torque - Vehicles
Uncontrolled terms:Adaptive fuzzy pid controllers - Control effectiveness - Energy management control strategies - EV (electric vehicle) - Hardware-in-loop - Integration differentiations - New european driving cycles - Proportion integration differentiations
Classification code:421 Strength of Building Materials; Mechanical Properties - 432 Highway Transportation - 512.1 Petroleum Deposits - 521 Fuel Combustion and Flame Research - 525 Energy Management and Conversion - 602.2 Mechanical Transmissions - 605 Small Tools and Hardware - 612 Engines - 702.1 Electric Batteries - 702.1.2 Secondary Batteries - 705 Electric Generators and Motors - 731.1 Control Systems - 732.1 Control Equipment - 921 Mathematics - 931.1 Mechanics
DOI:10.3969/j.issn.1002-6819.2014.19.007
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 39>
Accession number:201446200464
Title:Effect of ethanol pre-fermentation on methane fermentation during anaerobic co-digestion of kitchen waste and vinasse
Authors:Zhang, Xiao (1); Song, Na (1); Wang, Qunhui (1); Wang, Lihong (1); Xiang, Juan (1); Chang, Qiang (1); Yu, Miao (1)
Author affiliation:(1) Department of Environmental Engineering, University of Science and Technology Beijing, Beijing , China
Corresponding author:Wang, Qunhui
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:257-264
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:To solve the inhibition issue caused by volatile fatty acids in two-stage dry anaerobic co-digestion of food waste and distillers grains, microzyme was added into the reactors in the acidification process with different pre-treated times of 12 h, 24 h and 48 h respectively. After pre-fermentation, all groups underwent anaerobic digestion under the same experimental condition. The purpose was to investigate the effects of pre-treated time on methane yield, the changes of parameters such as pH, TVFA, acetic acid, propanoic acid, and ethanol concentration in the methane fermentation process, and to compare them with the control group. The most innovative idea is that of the ethanol pre-fermentation process, food waste was converted into ethanol which decreased the other volatile fatty acids` concentration in the meantime. Since ethanol is neutral and it can convert into acetic acid, which can be directly used by methanogens, this ethanol pre-fermentation process can indeed improve digestion efficiency and methane yield in the following anaerobic system. Moreover, with less volatile fatty acids produced at the beginning of digestion, the acid accumulation issue could be well relieved in the future. This meaningful topic has been focused on by our research team since 2011. Please find more detailed information in our articles if you are interested. According to this experiment, the result showed that the ranks of ethanol concentration and pH (from high to low) of all groups were: pre-treated 48h > 24h > 12h > control. However, the ranks of acetic acid and TVFA concentration were the opposite. This phenomenon is caused by the ethanol pre-fermentation which can force more glucose to degrade into ethanol instead of other volatile fatty acids such as propanoic acid. Besides, the ethanol is neutral, and it can convert into acetic acid more easily than propanoic acid. Therefore, the pre-fermentation process can overcome the acidification issue caused by the accumulation of VFAs. As compared with the control group, the accumulated methane yields of pre-treated groups with 12h, 24h, and 48h were 9.1%, 31.6% and 19.9% higher respectively. The results indicated that the pre-treated group of 24h was the most effective. As well known, methanogens` activity is very sensitive regarding tiny changes of propanoic acid concentration. The ratio of PC/AC is also a warning indicator in anaerobic system. One relevant literature shows that a range of 0~0.08 has a positive effect on methanogens. Interestingly, we found that there was a difference in the range-width among different groups. The rank of range-width (from high to low) in this result was: pre-treated 24 h>48 h>12 h> control. This result indicated that pre-fermentation could increase the suitable range-width in order to prevent the digestion system from acid accumulation issue. The same situation happened with the relationship between methane yield and initial ethanol concentration. It deeply explained the reason why anaerobic digestion could benefit from pre-fermentation. From another point of view, both the concentration of acetic acid and ethanol, microzyme and methanogen were reaching a dynamic balance. However, this complex mechanism of biology and dynamics should be discussed in future research.
Number of references:29
Main heading:Volatile fatty acids
Controlled terms:Acetic acid - Acidification - Anaerobic digestion - Ethanol - Fatty acids - Fermentation - Methane - Methanogens - pH - Process control - Propionic acid - Saturated fatty acids
Uncontrolled terms:Anaerobic co-digestion - Concentration of acetic acid - Distillers' grains - Ethanol concentrations - Ethanol fermentation - Experimental conditions - Food waste - Methane fermentation
Classification code:452.4 Industrial Wastes Treatment and Disposal - 731 Automatic Control Principles and Applications - 801.1 Chemistry, General - 801.2 Biochemistry - 804.1 Organic Compounds - 822.2 Food Processing Operations
DOI:10.3969/j.issn.1002-6819.2014.19.031
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.
<RECORD 40>
Accession number:201446200461
Title:Experiment effect of application to new assembly type solar double effect greenhouse
Authors:Qiu, Zhonghua (1); Song, Mingjun (2); Wang, Jiqing (1); Zhang, Xuebin (3); Liu, Hua (3); Meng, Tienan (1); Song, Yuanning (1)
Author affiliation:(1) The Branch of Agri. Sci. and Technol. of Gansu Science and Technol. Association with Retired Experts, Lanzhou , China; (2) Vegetable Research Institute, Gansu Academy of Agricultural Sciences, Lanzhou , China; (3) Gansu Province Economic Crop Technology Exten-sion Station, Lanzhou , China
Corresponding author:Song, Mingjun
Source title:Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering
Abbreviated source title:Nongye Gongcheng Xuebao
Volume:30
Issue:19
Issue date:October 1, 2014
Publication year:2014
Pages:232-239
Language:Chinese
ISSN:10026819
CODEN:NGOXEO
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Engineering
Abstract:In order to solve the common problems in existing solar greenhouses such as simple equipment, poor environmental regulation and cold prevention ability, as well as low land utilization rate and labor productivity, a new type of greenhouse, the assembly type solar double effect greenhouse was built and researched. There are two kinds of structures for the assembly type of the solar double effect greenhouse: internal insulation greenhouse and external insulation greenhouse. Internal insulation warehouse has two layer frames with single layer film covering each layer frame, in addition, one layer of heat preservation quilt is placed between the two layer frames to insulate and preserve heat energy during the night. The external insulation greenhouse has a structure of transparent Polycarbonate sandwich plate as its back half roof and back wall. In winter time, thermal insulation material is filled in the interlayer to preserve heat, in the meantime, the heat preservation quilt is covered on the front half roof, it changed the old way of an opaque back wall and an opaque back half roof in the previous greenhouse. Both the internal and the external insulation greenhouses are fully transparent greenhouses with galvanizing steel structures as framework. A solar energy source heat pump system is assembled in the greenhouse, it includes a solar heat collector, thermal storage pool and the heat pump, with water as its medium, it uses the solar heat collector to convert solar energy into heat energy and it is stored in thermal storage pool. When it is cold, the solar heat collector converts the heat energy stored in the heated water to the greenhouse. When the stored heated water is too cold to provide heat energy, the heat pump is started to convert the low grade heat energy to high grade heat energy, to provide heat energy to the greenhouse. The heat pump can also convert the steam and redundant heat energy in the air into heated water and it is stored in the thermal storage pool, so as to adjust the air temperature and moisture in the greenhouse automatically thus achieving double effects. In this paper, insulation moisture performance and the yield increasing effect are mainly researched for the assembly type of the solar double effect greenhouse. The test was processed from Dec. 2012 to Jan. 2013. The main test indexes are, air minimum temperature, daily average temperature, light intensity, relative air humidity, crops yield per plant and yield per unit area. The test results show: For the internal insulation greenhouse, the minimum temperature of the testing greenhouse was always over 9. Compared to the reference greenhouse, during Jan. 2013, the average temperature increased 3.4, the monthly average minimum temperature increased 4.0, and the monthly average relative air humidity was below 80%, thus achieved a 70% reduction in the incidence of vegetables. For the external insulation greenhouse, the average minimum temperature of the testing greenhouse was 12.5, the relative air humidity was below 80%, and the average temperature increased 3.8 compare to the reference greenhouse. The temperature was 27.7 higher than outside of the greenhouse (-15.2), the yield of the planting vegetables increased 19% - 55%. The conclusion is, the assembly type of the solar double effect greenhouse improved environmental conditions greatly, and improved the capacity of both cold and disease prevention, and increased both production and income. The research and application of this new type of greenhouse are referenced for similar areas in northern China.
Number of references:26
Main heading:Greenhouse effect
Controlled terms:Assembly - Environmental regulations - Greenhouses - Heat pump systems - Heat storage - Insulation - Lakes - Moisture - Productivity - Pumps - Roofs - Solar energy - Solar heating - Storage (materials) - Thermal insulation - Vegetables - Walls (structural partitions)
Uncontrolled terms:Double effects - Dual heat sources - Environmental conditions - Heat collectors - Relative air humidities - Research and application - Thermal insulation materials - Thermal storage
Classification code:402 Buildings and Towers - 402.1 Industrial and Agricultural Buildings - 407 Maritime and Port Structures; Rivers and Other Waterways - 413 Insulating Materials - 413.2 Heat Insulating Materials - 451 Air Pollution - 454.2 Environmental Impact and Protection - 615.2 Solar Power - 618.2 Pumps - 641.2 Heat Transfer - 643.1 Space Heating - 694.4 Storage - 801.4 Physical Chemistry - 821.4 Agricultural Products - 821.6 Farm Buildings and Other Structures - 913.1 Production Engineering
DOI:10.3969/j.issn.1002-6819.2014.19.028
Database:Compendex
Compilation and indexing terms, Copyright 2014 Elsevier Inc.