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Synthesis and Electric Properties of Polyethylene Grlycol-modified Fly Ash Floating Bead/polyaniline Composites

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Journal of Wuhan University of Technology(Materials Science) 2017年第1期32卷 197-204页

作者：雷西萍 HAN Ding WANG Yue song xuefeng LIN Yanmei Functional Materials Laboratory College of Materials&Mineral ResourcesXi'an University of Architecture and TechnologyXi'an 710055China

Fly ash floating bead（FAFB） was modified by the nonionic surfactant polyethylene glycol（PEG） under various concentrations to improve its hydrophobility,and then PEG modified FAFB composited with polyaniline（FAFB-PEG/PAn） by emulsion polymerization method using different feed ratios of *** chemical structure,phase structure,microstructure,conductivity,and dielectric properties were studied by FT-IR,XRD,SEM,four-probe technique,and LCR digital bridge,*** was demonstrated that the optimal concentration of PEG was 1 mol/L and the corresponding grafting ratio was 1.42%.The phase structure of FAFB was not destroyed after modification by PEG,while the surface became smoother and could be coated by PAn successfully according to SEM *** to that of dodecylbenzenesulfonic acid doped PAn（PAn-DBSA）,the conductivity of FAFB-PEG/PAn was decreased by 10-100 times after introduction of various amounts of FAFB-PEG,especially the value could be decreased to 0.01 S cm^-1 if 50 wt%of FAFBPEG was ***,the dielectric constant and loss factor of FAFB-PEG/PAn composites gradually decreased with increasing amount of FAFB-PEG in the frequency range of 100 KHz-2 MHz,namely,the dielectric constant could be still kept at 500 and correspondingly the loss factor decreased to 4.7 at 100 KHz if50 wt%of FAFB-PEG was *** leaking current phenomenon derived from PAn-DBSA could also be weakened by FAFB-PEG.

关键词： fly ash floating bead polyaniline electric conductivity dielectric property

Fluoride Ion Adsorption Effect and Adsorption Mechanism of Self-Supported Adsorbent Materials Based on Desulfurization Gypsum-Aluminate Cement

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Journal of Renewable Materials 2023年第12期11卷 4079-4095页

作者： xuefeng song Minjuan Sun Juan He Lei Wang College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

The adsorption method has the advantages of low cost,high efficiency,and environmental friendliness in treating fluorinated wastewater,and the adsorbent material is the *** study combines the inherent anion-exchange adsorption properties of layered double hydroxides(LDHs).Self-supported porous adsorbent materials loaded with AFm and AFt were prepared from a composite cementitious system consisting of calcium aluminate cement(CAC)and flue gas desulfurization gypsum(FGDG)by chemical foaming *** mineral composition of the adsorbent material was characterized by X-ray diffraction(XRD)and Scanning electron microscopy(SEM).Through the static adsorption experiment,the adsorption effect of the mineral composition of the adsorbent on fluoride ions was deeply analyzed,and the adsorption mechanism was *** and SEM showed that the main hydration phases of the composite cementitious system consisting of CAC and FGDG are AFm,AFt,AH_(3),and CaSO_(4)·2H_(2)*** accelerates the hydration process of CAC and inhibits the transformation of AFt to *** AFt content increased,and the AFm content decreased or even disappeared as the amount of FGDG *** adsorption experiment results showed that AFm and AFt in adsorbent materials could significantly enhance the adsorption of fluoride *** adsorption of F^(−)in aqueous solution by PAG tends more towards monolayer adsorption with a theoretical maximum capacity of 108.70 mg/g and is similar to the measured value of 112.77 mg/g.

关键词： Flue gas desulfurization gypsum(FGDG) Calcium aluminate cement(CAC) AFm AFt Fluoride ions adsorption

Motion simulation and test on threshed grains in tapered threshing and transmission device for plot wheat breeding based on CFD-DEM

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International Journal of Agricultural and Biological Engineering 2019年第1期12卷 66-73页

作者： Fei Dai xuefeng song Wuyun Zhao Zhengsheng Han Fengwei Zhang Shilin Zhang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China

Mechanization of field experiments is the only way to improve crop breeding and seed propagation *** order to further clarify and improve the working performance of tapered threshing device for plot breeding,and reduce the remaining seeds in the device,the numerical simulation was carried out on the motion process of materials in the longitudinal-axial tapered cylinder threshing and transmission device of the plot wheat breeding combine harvester based on CFD-DEM *** results showed that,threshing and transmission of particles and short stalks at axial direction could be realized under the influence of air ***,the material transference and distribution rule and stream field distribution rule of air flow in the threshing and transmission device were obtained,the variations of velocity and displacement of particles and short stalks with time were obtained;the motion trajectories and forms of particles in different types of retention were also *** rotating speed of 1300-1600 r/min for the tapered threshing cylinder in the verification test,the particle retention rate in the enclosure was 0-0.13%,while in the simulation the particle retention rate in the enclosure was 0-0.11%,only a 0.02%difference between *** results proved a favorable feasibility to simulate the working performance of the tapered threshing and transmission device for plot breeding through gas-solid coupling method.

关键词： particle threshing and transmission tapered threshing and transmission device hydromechanics calculation discrete element numerical simulation test

Numerical simulation and analysis of mechanized suppression process of seedbed with whole plastic film mulching on double ridges

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International Journal of Agricultural and Biological Engineering 2021年第1期14卷 142-150页

作者： Fei Dai xuefeng song Wuyun Zhao Bugong Sun Ruijie Shi Yang Zhang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China Gansu Provincial Key Laboratory of Aridland Crop Science Gansu Agricultural UniversityLanzhou 730070China

In order to achieve the construction standard of high mechanized performance of the seedbed with whole plastic-film mulching on double ridges,in this study,the forms of suppression failure were analyzed,and the key factors influencing the suppression performance were determined based on the structure of the seedbed suppression device and its working *** discrete element method was adopted for numerical simulation on the suppression process of the seedbed with whole plastic film mulching on double ridges;the parameters during the interaction between the suppression device and seedbed soil were extracted and analyzed,such as contact area,sinkage and horizontal traction resistance trend of press wheels on big ridges and furrows of small *** the suppression load on big ridges,suppression load on furrows of small ridge,and advancing velocity of the combined operation machine as the independent variables,qualified rate of suppression as the response value,a mathematical model between the test factors and qualified rate of suppression was established,to explore the influence sequence of the factors on suppression qualified *** optimal working parameters of the suppression device were finally obtained:the suppression load on big ridges was 40 N,suppression load on furrows of small ridge was 69.8 N and the machine advancing velocity was 0.98 m/s,and the achieved mean value of suppression qualified rate was 92.6%.Field verification test showed that the mean value of suppression qualified rate was 90.3%,a mere difference of 2.3%compared with the simulation *** actual operation of the sample machine was basically consistent with the simulation process and could reveal the mechanized suppression operation mechanism of the seedbed with whole plastic film mulching on double ridges,indicating that the established DEM model and its parameter setting were relatively accurate and reasonable.

关键词： seedbed whole plastic film mulching double ridges mechanized suppression discrete element method numerical simulation parameter optimization

Mechanism analysis and performance improvement of mechanized ridge forming of whole plastic film mulched double ridges

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International Journal of Agricultural and Biological Engineering 2020年第5期13卷 107-116页

作者： Fei Dai xuefeng song Wuyun Zhao Ruijie Shi Fengwei Zhang Xuekun Zhang Gansu Provincial Key Laboratory of Aridland Crop Science Gansu Agricultural UniversityLanzhou 730070China College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China

In order to achieve high-performance and mechanization construction standard of whole plastic mulched double ridge seedbed,and to meet its forming process and corresponding agronomic requirements of the mechanized double ridge seedbed,the key working parameters such as the speed of rotary blade group,the thickness of upturned sod and the power consumption of rotary blade group under different parameters were analyzed based on related working performance in ridge ***,the test factors and their range of values were finally determined in this *** element method(DEM)simulation was applied in the numerical simulation of the mechanized ridge forming process of whole plastic mulched double ridges,and the ridge forming effect and digging resistance variation characteristics of different types of shovels were *** the forward speed of the combined machine,the penetration angle of the arc-shaped shovel and the depth of rotary tillage as independent variables,and the qualified rate of seedbed tillage as the response value,the mathematical model between the test factors and the qualified rate of the seedbed tillage was established,to explore the influence sequence of the factors on the qualified rate of seedbed tillage,and obtained the following optimal working parameters of the ridge forming device:the advancing velocity of the combined machine of 0.50 m/s,penetration angle of the arc-shaped shovel of 31°,rotary tillage depth of 140 mm,and average qualified rate 95.20%of seedbed tillage in corresponding simulation verification *** test showed that the average qualified rate of seedbed tillage in ridge forming device was 93.60%,which was close to that of the simulation *** actual working condition of the sample machine was basically in line with the simulation process and could relatively precisely reflect the mechanized ridge forming mechanism of whole plastic double *** results showed that the established DEM model and its

关键词： whole plastic film mulched double ridges mechanized ridge forming DEM numerical simulation parameter optimization

Design and field test of crosswise belt type whole plastic-film ridging-mulching corn seeder on double ridges

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International Journal of Agricultural and Biological Engineering 2019年第4期12卷 88-96页

作者： Fei Dai Wenjuan Guo xuefeng song Ruijie Shi Wuyun Zhao Fengwei Zhang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China

In order to realize seedbed mechanization of whole plastic-film mulching on double ridges and to overcome the difficulty in crosswise belt type soil covering by whole plastic-film,a kind of crosswise belt type whole plastic-film ridging-mulching corn seeder on double ridges was designed in this *** key components of the sample machine was designed and its working parameters of seedbed soil covering device,crosswise-belt soil covering mechanism and profiling sowing depth adjustment device were *** numerical simulation on the film edge and crosswise soil covering by whole plastic-film on double ridges by discrete element method,the velocity and displacement of the oscillating plate,and the variation rule of amount of covered soil with time were *** test results show that,when the advancing velocity of the machine was 0.50 m/s,the qualified rate of soil width covered on film edge of the seedbed reached 96.1%,qualified rate of crosswise soil belt width was 94.5%,qualified rate of soil thickness on seedbed was 95.3%,qualified rate of sowing depth was 89.3%,qualified rate of spacing between crosswise soil belts reached 93.6%,which all met related standards in China and satisfied design requirements,and could realize seedbed mechanization of whole plastic-film mulching on double *** tests on working performances of practical soil covering show a basic consistence with the seedbed soil covering simulation,and verified the effectiveness of the soil covering model built by using discrete element method.

关键词： whole plastic-film on double ridges crosswise belt soil covering combined machine discrete element numerical simulation field test

Measurement and simulation of the suspension velocity of flax threshing material using CFD-DEM

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International Journal of Agricultural and Biological Engineering 2021年第5期14卷 230-237页

作者： Fei Dai Wenjuan Guo xuefeng song Ruijie Shi Jiangfei Qu Wuyun Zhao College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China

In order to explore the aerodynamics characteristics of flax threshing material,and accurately obtain the movement trajectory of the material of each component in air-screen cleaning,the suspension velocities of flax grains,capsules,short stalks and capsule husks at different stages were measured by means of the suspension velocity *** experimental results showed that the suspension velocity range was 4.55-8.64 m/s for flax grains,6.46-10.90 m/s for flax capsules,3.23-7.75 m/s for flax short stalks,and 1.06-4.21 m/s for flax capsule *** on the experimental results,the overall interval distribution of each component of flax threshing material and the separation characteristics were discussed and the discrete element model of each component of the flax threshing material was *** simulation measurement of angle of repose of the material and the sliding friction angle with steel,the reliability of the established model was *** gas-solid coupling method was used to simulate the suspension velocity of each component of the flax threshing material,and the suspension velocity of the four components of flax threshing material was *** simulation measurement results were within the actual measurement range,showing that the test results were basically in line with the simulation *** simulation on the suspension velocity of different components of flax threshing material based on gas-solid coupling had high precision ***,the feasibility of the suspension velocity of the flax threshing material measured in the simulation test based on CFD-DEM coupling was verified.

关键词： flax threshing material suspension velocity CFD-DEM numerical simulation

Simulation and test on separating cleaning process of flax threshing material based on gas-solid coupling theory

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International Journal of Agricultural and Biological Engineering 2020年第1期13卷 73-81,I0001页

作者： Fei Dai xuefeng song Wenjuan Guo Wuyun Zhao Fengwei Zhang Shilin Zhang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu Institute of Political Science and LawLanzhou 730070China

In order to further clarify and improve the working performance of separating cleaning device of flax threshing material,and study the motion law and characteristics of components of flax threshing material,in this paper,numerical simulation was carried out on the separating cleaning process of flax threshing material based on CFD-DEM *** results showed that the components of flax threshing material were separated and cleaned under the influence of airflow field,meanwhile,variation curves of quantity and mean velocity of flax seeds in the separating cleaning system were *** referring to streamline distribution of gas-solid coupling,the quantity variation law of components of flax threshing material with time was explored and their motion curves and variation tendency of average velocity were *** test results showed that the cleaning rate of separating cleaning device for flax threshing material was 92.66%with 1.58%of total separation *** with simulation results,the test results were 1.34%and 0.93%lower,showing that it is feasible to apply the gas-solid coupling theory and method to simulate the separating and cleaning operation of flax threshing material.

关键词： flax threshing material separating cleaning device hydromechanics calculation discrete element numerical simulation test

Migration law of flax threshing materials in double channel air-and-screen separating cleaner

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International Journal of Agricultural and Biological Engineering 2021年第3期14卷 92-102页

作者： Fei Dai xuefeng song Ruijie Shi Wuyun Zhao Wenjuan Guo Yang Zhang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China

In order to further clarify and improve the working performance of separating cleaner for flax threshing materials,and study the migration law and characteristics of components of flax threshing materials during separating and cleaning,in this paper,a gas-solid coupling simulation model was established on the separation cleaner for flax threshing materials and a numerical simulation was carried out on the separating and cleaning *** results showed that,the separating and cleaning effect of the components of flax threshing materials was good under the air-and-screen gas-solid coupling flow ***,the form distribution and the vector distribution of air volume and velocity of flax threshing materials in the air-and-screen devices were *** referring to the migration trajectories of the flax threshing materials in the vibration sieve device,double channel residue collection device and dust absorber,the volume variation,motion trajectories and variation of migration velocity of the components of flax threshing materials over time in different regions were *** test results showed that,the content impurity rate of the separation cleaner for flax threshing materials was 2.06%,and loss rate in cleaning was 3.08%.Compared with simulation results,the verification test results were 1.23%and 0.42%higher,showing that the established discrete element model on the flax threshing materials and parameter setting were basically *** verification test also verified the correctness of the simulation results of the separating and cleaning process of the flax threshing materials based on gas-solid coupling theory and the feasibility of the research method.

关键词： flax threshing materials separation cleaner air-and-screen gas-solid coupling discrete element model numerical simulation