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Petroleum Science 2021年第5期18卷 1543-1550页

作者： Xin-Ge Fu Ke Shi Jian-Liang Xue Chuan Chen Yu Bai Yan-Lu Qiao Yi-Xuan Liu Xiang-Ming Hu Yu Gao Hao Yu college of Safety and Environmental Engineering Shandong University of Science and TechnologyQingdaoShandong266590China School of Environment Harbin Institute of TechnologyHaerbinHeilongjiang150001China chinaunicom system integration co LtdNo.131Xidan North RoadBeijing100085China college of Chemical and Biological Engineering Shandong University of Science and TechnologyQingdaoShandong266590China

In order to effectively control petroleum hydrocarbon pollution by immobilisation technology,it is necessary to understanding the degradation pathways of petroleum hydrocarbon in immobilised petroleum-degradation bacteria ***,the adsorption in degradation process is rarely *** this study,adsorption process of petroleum hydrocarbon was synergistically studied by means of the surface properties,adsorption thermodynamics and molecular *** results indicate that the immobilised petroleum-degradation bacteria have many holes for the bacteria to *** diesel adsorption by immobilised petroleum-degradation bacteria is a spontaneous,entropy-increasing and endothermic *** is first adsorbed to the surface of immobilised petroleum-degradation bacteria through hydrogen bonding,and then is *** study provided substantial knowledge of immobilised technology in controlling petroleum hydrocarbon pollution.

关键词： Petroleum hydrocarbon pollution Immobilisation Adsorption-biodegradation Molecular simulation Bioremediation

MEMS development focusing on collaboration using common facilities:a retrospective view and future directions

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Microsystems & Nanoengineering 2021年第4期7卷 25-33页

作者： Masayoshi Esashi MEMS coRE co.Ltd.(CTO) Sendai 981-3206Japan Micro system integration Center(pSIC)(senior research fellow) Tohoku UniversitySendai 980-0845Japan

I have been developing MEMS(microelectromechanical systems)technology and supporting the industry through collaboration.A facility was built in house on a 20 mm square wafer for use in prototyping MEMS and ICs(integrated circuits).The constructed MEMS devices include commercialized integrated capacitive pressure sensors,electrostatically levitated rotational gyroscopes,and two-axis optical *** integration,which is a MEMS on an LSI(large-scale integration),was developed for sophisticated systems using LSI made in a *** technology was applied for tactile sensor networks for safe robots,multi FBAR filters on LSI,active-matrix multielectron emitter arrays,and so *** facility used to produce MEMS on 4-and 6-inch wafers was developed based on an old semiconductor factory and has been used as an open hands-on access facility by many *** directions of MEMS research are discussed.

关键词： scanner directions companies

Thermo-physical Characteristics of Nickel-coated Aluminum Powder as a Function of Particle Size and Oxidant

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Chinese Journal of Mechanical Engineering 2016年第6期29卷 1244-1255页

作者： LEE Sanghyup NOH Kwanyoung LIM Jihwan YOON Woongsup Advanced Energy and Propulsion Laboratory Department of Mechanical Engineering Yonsei University Missile system integration / propulsion Center Hanwha Corp.

Aluminum particles 15-25 μm in size are widely used in fuel propellants and underwater propulsion systems in national defense research. However, these particles are covered with an aluminum oxide film, which has a high melting point, so ignition is difficult. To improve the ignitability of high-energy aluminum powder and to understand the reaction phenomenon as a function of particle size（15-25 μm, 74-105 μm, and 2.38 mm） and oxidizer（air, co2, and argon）, the natural oxide films are chemically removed. The particles are then coated with nickel using an electro-less method. The degree of nickel deposition is confirmed qualitatively and quantitatively through surface analysis using scanning electron microscopy/energy dispersive spectroscopy. To characterize the nickel coatings, elemental analysis is also conducted by using X-ray diffraction. Thermogravimetric analysis/differential scanning calorimetry （TGA/DSC） enable comparisons between the uncoated and coated aluminum, and the reaction process are investigated through fine structural analysis of the particle surfaces and cross sections. There are little difference in reactivity as a function of oxidant type. However, a strong exothermic reaction in the smaller nickel-coated aluminum particles near the melting point of aluminum accelerates the reaction of the smaller particles. Explanation of the reactivity of the nickel-coated aluminum depending on the particle sizes is attempted.

关键词： nickel-coated aluminum TGA/DSC aluminum ignition combustion intermetallic reaction

Numerical study on the aerodynamic performance and safe running of high-speed trains in sandstorms

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 971-978页

作者： Hong-bing XIONG Wen-guang YU Da-wei CHEN Xue-ming SHAO Department of Mechanics Zhejiang University Hangzhou 310027 China National Engineering Laboratory for system integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd. Qingdao 266111 China

The influence of sandstorms on train aerodynamic performance and safe running was studied in response to the frequent occurrence of sandstorm weather in north *** Eulerian two-phase model in the computational fluid dynamic (CFD) software FLUENT,validated with published data,was used to solve the gas-solid multiphase flow of a sandstorm around a *** train aerodynamic performance under different sandstorm levels and no sand conditions was then *** showed that in sandstorm weather,the drag,lift,side forces and overturning moment increase by variable *** on a numerical analysis of aerodynamic characteristics,an equation of train stability was also derived using the theory of moment balance from the view of dynamics.A recommended speed limit of a train under different sandstorm levels was calculated based on the stability analysis.

关键词： High-speed train Sandstorm Gas-solid multiphase Eulerian two-phase model Aerodynamic Safety Speed limit

Unsteady simulation for a high-speed train entering a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 957-963页

作者： Xin-hua LI Jian DENG Da-wei CHEN Fang-fang XIE Yao ZHENG School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China National Engineering Laboratory for system integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd Qingdao 266111 China

In order to study the unsteady aerodynamics effects in railway tunnels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulation of turbulence,while the dynamic grid technique is employed for moving *** focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface,and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel *** is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed,so are the microwave and the drag of the train.

关键词： High-speed train Aerodynamics Railway tunnel Numerical analysis

Aerodynamic modeling and stability analysis of a high-speed train under strong rain and crosswind conditions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 964-970页

作者： Xue-ming SHAO Jun WAN Da-wei CHEN Hong-bing XIONG Department of Mechanics Zhejiang University Hangzhou 310027 China National Engineering Laborat ory for System Integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd. Qingdao 266111 China

With the development of high-speed train,it is considerably concerned about the aerodynamic characteristics and operation safety issues of the high-speed train under extreme weather *** aerodynamic performance of a high-speed train under heavy rain and strong crosswind conditions are modeled using the Eulerian two-phase model in this *** impact of heavy rainfall on train aerodynamics is investigated,coupling heavy rain and a strong *** show that the lift force,side force,and rolling moment of the train increase significantly with wind speed up to 40 m/s under a rainfall rate of 60 mm/*** considering the rain and wind *** increases of the lift force,side force,and rolling moment may deteriorate the train operating safety and cause the train to overturn.A quasi-static stability analysis based on the moment balance is used to determine the limit safety speed of a train under different rain and wind *** results can provide a frame of reference for the train safe operation under strong rain and crosswind conditions.

关键词： High-speed train Aerodynamic characteristics Multiphase flow Rain Crosswind Overturning

Plasma enhanced chemical vapor deposition of excellent a-Si：H passivation layers for a-Si：H/c-Si heterojunction solar cells at high pressure and high power

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Frontiers in Energy 2017年第1期11卷 85-91页

作者： Lei ZHAO Wenbin ZHANG Jingwei CHEN Hongwei DIAO Qi WANG Wenjing WANG Key Laboratory of Solar Thermal Energy and Photovoltaic system of Chinese Academy of Sciences Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China GCL system integration Technology co. Ltd Shanghai 201406 China

The intrinsic a-Si：H passivation layer inserted between the doped a-Si：H layer and the c-Si substrate is very crucial for improving the performance of the a-Si：H/c- Si heterojunction （SHJ） solar cell. The passivation performance of the a-Si：H layer is strongly dependent on its microstructure. Usually, the compact a-Si：H deposited near the transition from the amorphous phase to the nanocrystalline phase by plasma enhanced chemical vapor deposition （PECVD） can provide excellent passivation. However, at the low deposition pressure and low deposition power, such an a-Si：H layer can be only prepared in a narrow region. The deposition condition must be controlled very carefully. In this paper, intrinsic a- Si：H layers were prepared on n-type Cz c-Si substrates by 27.12 MHz PECVD at a high deposition pressure and high deposition power. The corresponding passivation perfor- mance on c-Si was investigated by minority carrier lifetime measurement. It was found that an excellent a-Si：H passivation layer could be obtained in a very wide deposition pressure and power region. Such wide process window would be very beneficial for improving the uniformity and the yield for the solar cell fabrication. The a-Si：H layer microstructure was further investigated by Raman and Fourier transform infrared （FTIR） spectro-scopy characterization. The correlation between the microstructure and the passivation performance was revealed. According to the above findings, the a-Si：H passivation performance was optimized more elaborately. Finally, a large-area SHJ solar cell with an efficiency of 22.25% was fabricated on the commercial 156 mm pseudo-square n-type Cz c-Si substrate with the opencircuit voltage （Voc） of up to 0.732 V.

关键词： PECVD high pressure and high power,a-Si:H microstructure passivation heterojunction solar cell

Simulation and experimental study of a novel bifacial structure of silicon heterojunction solar cell for high efficiency and low cost

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Chinese Physics B 2018年第3期27卷 520-525页

作者： Haibin Huang Gangyu Tian Lang Zhou Jiren Yuan Wolfgang R.Fahrner Wenbin Zhang Xingbing Li Wenhao Chen Renzhong Liu Institute of Photovoltaics Nanchang UniversityNanchang 330031China Department of Physics Nanchang UniversityNanchang 330031China GCL system integration Technology co.Ltd. Shanghai 201700China Hareon Solar co.Ltd. Taicang 215400China

A novel structure of Ag gridlSiN_(x)/n+-c-Si/n-c-Si/i-a-Si:H/p^(+)-a-Si:HlTco/Ag grid was designed to increase the ef-ficiency of bifacial amorphous/crystalline silicon-based solar cells and reduce the rear material consumption and production *** simulation results show that the new structure obtains higher efficiency compared with the typical bifa-cial amorphous/crystalline silicon-based solar cell because of an increase in the short-circuit current(J_(sc)),while retaining the advantages of a high open-circuit voltage,low temperature coefficient,and good weak-light ***,real cells composed of the novel structure with dimensions of 75 mm×75 mm were fabricated by a special fabrication recipe based on industrial *** parameter optimization,the cell efficiency reached 21.1%with the J_(sc)of 41.7 mA/cm^(2).In addition,the novel structure attained 28.55%potential conversion efficiency under an illumination of AM 1.5 G,100 mW/cm^(2).We conclude that the configuration of the Ag grid/SiN_(x)/n^(+)-c-Si/n-c-Si/i-a-Si:H/p^(+)-a-Si:H/Tco/Ag grid is a promising structure for high efficiency and low cost.

关键词： silicon solar cell a-Si:H/c-Si heterojunction short-circuit current

Management of co_(2) in a tomato greenhouse using WSN and BPNN techniques

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International Journal of Agricultural and Biological Engineering 2015年第4期8卷 43-51页

作者： Li Ting Zhang Man Ji Yuhan Sha Sha Jiang Yiqiong Li Minzan Key Laboratory of Modern Precision Agriculture system integration Research Ministry of EducationCollege of Information and Electrical EngineeringChina Agriculture UniversityBeijing 100083China

Rational management of co_(2) can improve the net photosynthetic rate of plants,thereby improving crop yield and *** order to precisely manage co_(2) in a greenhouse,a wireless sensor network(WSN)system was developed to monitor greenhouse environmental parameters in real time,including air temperature,humidity,co_(2) concentration,soil temperature,soil moisture,and light *** WSN system includes several sensor nodes,a gateway node,and remote management *** sensor nodes can collect 0-5 V and 4-20 mA analog signals and universal asynchronous receiver/transmitter(UART)*** gateway node can process and transmit the data and commands between sensor nodes and remote management *** remote management software provides a friendly interface between user and *** can inquire about real-time data,and set the parameters of the *** photosynthetic rate of tomato plants were studied in the flowering stage.A LI-6400XT portable photosynthesis analyzer was used to measure the photosynthetic rates of the tomato plants,and the environmental parameters of leaves were controlled according to the presetting *** photosynthetic rate prediction model of a single leaf was established based on a back propagation neural network(BPNN).The environmental parameters were used as input neurons after being processed by principal component analysis(PCA),and the photosynthetic rate was taken as the output *** performance of the prediction model was evaluated,and the results showed that the correlation coefficient between the simulated and observed data sets was 0.9899,and root-mean-square error(RMSE)was ***,when different co_(2) concentrations were selected as the input to predict the photosynthetic rate,the simulated and observed data showed the same *** to the above analysis,it was concluded that the model can be used for quantitative regulation of co_(2) for tomato plants in greenhouses.

关键词： WSN ZigBee greenhouse information photosynthetic rate co_(2)fertilization

Refined modeling and experimental verification of a torque motor for an electro-hydraulic servo valve

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Chinese Journal of Aeronautics 2023年第6期36卷 302-317页

作者： Zhichuang CHEN Shenghong GE Yulei JIANG Wenhao CHENG Yuchuan ZHU National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Aero Electromechanical system integration Nanjing Engineering Institute of Aircraft SystemsNanjing 210061China AVIC Nanjing Servo control system co. LtdNanjing 210032China

The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic *** on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are *** verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is *** with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA *** experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.

关键词： Calculation accuracy Electro-hydraulic servo valve Experimental verification Finite element analysis Refined model Torque motor