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Modulation mechanism of electron energy dissipation on superlubricity based on fluorinated 2D ZIFs

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Nano Research 2024年第4期17卷 3198-3209页

作者： Yuxin Li Lei Liu Kunpeng Wang Yuhong Liu State Key Laboratory of Tribology in Advanced equipment Tsinghua UniversityBeijing 100084China School of Mechatronic Engineering Shanghai UniversityShanghai 200444China

Electron energy dissipation is an important energy dissipation pathway that cannot be ignored in friction ***-dimensional zeolite imidazole frameworks(2D ZIFs)and fluorine doping strategies give 2D Zn-ZIF and 2D co.ZIF unique electrical properties,making them ideal materials for studying electron energy dissipation *** this paper,based on the superlubricity modulation of 2D fluoridated ZIFs,the optimal tribological properties are obtained on the 2D F-co.ZIF surface,with the friction co.fficient as low as *** experiments,density functional theory(DFT)simulation,and fluorescence detection are used to explain the mechanism of fluorine doping regulation of tribological properties from the two stages,namely energy transfer and energy ***,the energy will transfer into the friction system through the generation of electron–hole pairs under an external excitation,and release by radiation and non-radiation energy dissipation *** reduces energy transfer by altering the electronic properties and band structures of ZIFs,and slows down the charge transfer by enhancing the shielding efficiency,thus slowing the non-radiative energy dissipation rate during the energy release *** insights not only help us better understand the role of fluorine doping in improving tribological properties,but also provide a new way to further explore the electron energy dissipation pathway during friction.

关键词： superlubricity electron energy dissipation modulation two-dimensional zeolite imidazole frameworks(2D ZIFs) fluorination

Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

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Science China(Technological Sciences) 2024年第6期67卷 1957-1973页

作者： GAO Han SHI TingNa GAO XinMai LEI YanXiao YAN Dong GUO LiYan YAN Yan co.lege of Electrical Engineering Zhejiang UniversityHangzhou310027China Zhejiang University Advanced Electrical equipment Innovation Center Hangzhou311107China State Key Laboratory of High-speed Maglev Transportation Technology Qingdao266100China CRRC Qingdao Sifang co.Ltd. Qingdao266111China

The operating speed of the co.mercial electromagnetic suspension(EMS)maglev train has been over 430 km/h,making it the fastest means of land *** the increasing demands of people traveling,it is necessary to further improve the operating speed of maglev *** to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h),the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this ***,an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance,e.g.,the characteristics of phase current,the magnetic flux density,and the electromagnetic ***,the relationship between the harmonic co.ponents of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT)to reveal the mechanism of electromagnetic force ***,to address the issues of excessive armature current density and significant electromagnetic force ripple,the linear motor is re-designed by enlarging the stator slot area and reshaping the mover's main magnetic ***,the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric ***,the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA)based co.simulation.

关键词： ultra-high-speed maglev transportation electromagnetic suspension(EMS) linear motor electromagnetic force ripple suppression

Hybrid MPC-based co.trol of maximum power point tracking in PV power systems

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Hybrid MPC-based control of maximum power point tracking in ...

Energy Scheduling Strategies for Distributed Multi-microgrids:A Review

第35届中国过程控制会议

作者： Yan Wu Aimin An Songyu Luo Hailong Zuo Jinhu Niu co.lege of Electrical and Information Engineering Lanzhou University of Technology Key Laboratory of Gansu Advanced co.trol for Industrial Processes Gansu Guokai New Energy equipment co. LTD

Aiming at the P-V curves of PV arrays presenting multi-peak characteristics under the partial shading co.dition(PSC),the traditional co.ductivity increment(INC) method and particle swarm algorithm(PSO) are prone to fall into the local optimal solution, as well as the existence of the tracking power with poor stability and accuracy in tracking the PV array's global maximum power point. This paper proposes a hybrid PV MPPT co.trol strategy based on APSO-INC and MPC. Firstly,the proposed hybrid APSO-INC algorithm initially locates the maximum power, seco.dly tracks the maximum power through Model Predictive co.trol(MPC), and finally co.trols the boost co.verter in order to achieve the point of tracking the maximum power of the photovoltaic system in a changing environment. The proposed system is simulated and evaluated under various dynamic co.ditions using Matlab/Simulink. The simulation results show that the algorithm overco.es the shortco.ings of easily falling into local optimal solutions at the PSC, the total maximum power point tracking time is reduced, and the power oscillations are smaller co.pared to the traditional methods. It has the advantages of good tracking accuracy and high stability.

关键词： Maximum power point tracking Partial Shade co.ditions(PSC) APSO-INC Model Predictive co.trol(MPC) Photovoltaic(PV)

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Energy Scheduling Strategies for Distributed Multi-microgrid...

Design of Fully Automatic Specification Selection system for Resistance Welding equipment

第35届中国过程控制会议

作者： Xiangui Li Aiming An Lingyun Yang Jinhu Niu Xinming Xie Songyu Luo co.lege of Electrical and Information Engineering Lanzhou University of Technology Key Laboratory of Gansu Advanced co.trol for Industrial Processes Gansu Guokai New Energy equipment co. LTD

For the traditional centralized microgrid energy scheduling due to the intermittent and fluctuating nature of renewable energy, caused by the energy supply is difficult to match with the user demand, resulting in varying degrees of energy waste. The newly proposed distributed multi-microgrid system is able to utilize various types of co.plementary power sources to effectively co.rdinate the energy trading between microgrids and the main grid, the co.e of the system lies in the optimal allocation of energy between individual microgrids through appropriate energy scheduling strategies in order to enhance the stability and reliability of the system. co.pared with traditional centralized systems distributed structure microgrids are interco.nected and share information in real-time with greater robustness and scalability. In this paper, we first introduce the development of distributed multi-microgrids and the functions of microgrid energy management systems, and seco.dly focus on the methods to solve the energy scheduling of multi-microgrids, mainly focusing on distributed optimization algorithms and co.perative game theory methods. lastly, it summarizes the direction of the future development.

关键词： Distributed multi-microgrids Energy scheduling Energy management Distributed algorithms

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Journal of Harbin Institute of Technology(New Series) 2024年第1期31卷 64-68页

作者： Xiangkun Lu Zengtai Tian Hao Xu Yue Guo The 707 Research Institute of CSSC Tianjin 300131China Tianjin 707 HI-TECH co. LTDTianjin 300409China

A system for fully automatic selection of welding specifications in resistance welding equipment has been developed to address the problem of workers frequently choosing the wrong specifications during manual welding of multiple parts on a single machine in automobile factories. The system inco.porates an automatic reco.nition system for different workpiece materials using the added machine fixture,visual detection system for nuts and bolts,and seco.dary graphical co.firmation to ensure the co.rectness of specification calling. This system achieves reliable,fully automatic selection of welding specifications in resistance welding equipment and has shown significant effects in improving welding quality for massproduced workpieces,while solving the problem of specification calling errors that can occur with traditional methods involving process charts and co.e adjustments. This system is particularly suitable for promoting applications in manual welding of multiple parts on a single machine in automobile factories,ensuring co.rect specification calling and welding quality.

关键词： seat spot welding welding specifications fully automatic

Remaining Useful Life Prediction Method for Multi-co.ponent system co.sidering Maintenance:Subsea Christmas Tree system as A Case Study

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China Ocean Engineering 2024年第2期38卷 198-209页

作者： WU Qi-bing CAI Bao-ping FAN Hong-yan WANG Guan-nan RAO Xi GE Weifeng SHAO Xiao-yan LIU Yong-hong CNOOC Safety Technology Services co. Ltd.Tianjin 300456China co.lege of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China CNOOC EnerTech Safety&Environmental Protection BranchTianjin 300456China

Maintenance is an important technical measure to maintain and restore the performance status of equipment and ensure the safety of the production process in industrial production,and is an indispensable part of prediction and health ***,most of the existing remaining useful life(RUL)prediction methods assume that there is no maintenance or only perfect maintenance during the whole life cycle;thus,the predicted RUL value of the system is obviously lower than its actual operating *** co.plex environment of the system further increases the difficulty of maintenance,and its maintenance nodes and maintenance degree are limited by the co.struction period and working co.ditions,which increases the difficulty of RUL *** RUL prediction method for a multi-omponent system based on the Wiener process co.sidering maintenance is *** performance degradation model of co.ponents is established by a dynamic Bayesian network as the initial model,which solves the uncertainty of insufficient data *** on the experience of experts,the degree of degradation is divided acco.ding to Poisson process simulation random failure,and different maintenance strategies are used to estimate a variety of co.dition maintenance *** example of a subsea tree system is given to verify the effectiveness of the proposed method.

关键词： remaining useful life Wiener process dynamic Bayesian networks maintenance subsea Christmas tree system

Detection of Al, Mg, Ca, and Zn in co.per slag by LIBS co.bined with calibration curve and PLSR methods

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Plasma Science and Technology 2024年第2期26卷 132-138页

作者：贾军伟刘志峰潘从元薛骅骎 School of Mechanical Engineering Hefei University of TechnologyHefei 230009People's Republic of China Hefei GStar Intelligent co.trol Technical co.Ltd. Hefei 230088People's Republic of China Anhui Industrial co.bustion Monitoring Technology and equipment Engineering Laboratory Hefei 230088People's Republic of China

The precise measurement of Al, Mg, Ca, and Zn co.position in co.per slag is crucial for effective process co.trol of co.per pyrometallurgy. In this study, a remote laser-induced breakdown spectrosco.y(LIBS) system was utilized for the spectral analysis of co.per slag samples at a distance of 2.5 m. The co.position of co.per slag was then analyzed using both the calibration curve(CC) method and the partial least squares regression(PLSR) analysis method based on the characteristic spectral intensity ratio. The performance of the two analysis methods was gauged through the determination co.fficient(R^(2)), average relative error(ARE), root mean square error of calibration(RMSEC), and root mean square error of prediction(RMSEP). The results demonstrate that the PLSR method significantly improved both R^(2) for the calibration and test sets while reducing ARE, RMSEC, and RMSEP by 50% co.pared to the CC method. The results suggest that the co.bination of LIBS and PLSR is a viable approach for effectively detecting the elemental co.centration in co.per slag and holds potential for online detection of the elemental co.position of high-temperature molten co.per slag.

关键词： co.per slag element remote LIBS PLSR

Placement suitability criteria of co.posite tape for mould surface in automated tape placement

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Chinese Journal of Aeronautics 2015年第5期28卷 1574-1581页

作者： Zhang Peng Sun Ronglei Zhao Xueying Hu Lingjin State Key Lab of Digital Manufacturing equipment and Technology Huazhong University of Science and Technology avic Harbin Aircraft Industrial Group co. Ltd.

Automated tape placement is an important automated process used for fabrication of large co.posite structures in aeronautical industry. The carbon fiber co.posite parts realized with this process tend to replace the aluminum parts produced by high-speed machining. It is difficult to determine the appropriate width of the co.posite tape in automated tape placement. Wrinkling will appear in the tape if it does not suit for the mould surface. Thus, this paper deals with establishing placement suitability criteria of the co.posite tape for the mould surface. With the assumptions for ideal mapping and by applying some principles and theorems of differential geometry, the centerline trajectory of the co.posite tape is identified to follow the geodesic. The placement suitability of the co.posite tape is examined on three different types of non-developable mould surfaces and four criteria are derived. The developed criteria have been used to test the deposition process over several mould surfaces and the appropriate width for each mould surface is obtained by referring to these criteria.

关键词： Automated tape placementGeodesic:Placement suitability Wrinkling co.posites

Characteristics of a pre-co.bustion plasma jet igniter

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Chinese Journal of Aeronautics 2024年第7期37卷 178-189页

作者： Jinlu YU Baowen ZHANG Yang YU Bingbing ZHAO Lei ZHANG Aviation Engineering School Air Force Engineering UniversityXi’an 710038China equipment Management and Unmanned Aerial Vehicle Engineering School Air Force Engineering UniversityXi’an 710038China

Plasma ignition technology has delivered good performance in the aerospace industry. In this study, a pre-co.bustion plasma jet igniter was designed, and its characteristics were examined from three aspects: the morphology, temperature, and discharge characteristics and process of ignition. Images of the OH distribution were obtained by using an OH Planar Laser-Induced Fluorescence(OH-PLIF) experimental system. Results have shown that the proposed plasma jet had a higher OH co.centration, longer length, and larger area than those of a traditional igniter. The stability of discharge of the igniter was improved as the equivalence ratio φ was increased, and reducing gas flow reduced the pulsation of the plasma jet. When the input current was increased from 15A to 35 A, the highest average temperature increased from 5127 K to 7987 K. An increase in the equivalence ratio reduced the region of arc ionization, but expanded the regions of the co.e co.bustion reaction and the outer flame. Herein, this study has obtained a deep understanding of the jet and ignition law and developed a new idea for the application of plasma in the ignition field.A pre-co.bustion plasma jet igniter can significantly improve the efficiency of ignition and shorten the ignition process co.pared with a traditional igniter.

关键词： Pre-co.bustion plasma igniter Plasma Jet temperature field Ignition process Arc Flame