检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 873-890页

作者： Jinghu TANG Chaofeng LI Jin ZHOU Zhiwei WU School of Mechanical Engineering&Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion Systems of Ministry of Education of China Northeastern UniversityShenyang 110819China School of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The modeling and self-excited vibration mechanism in the magnetic levitation-collision interface coupling system are *** effects of the control and interface parameters on the system's stability are *** frequency range of self-excited vibrations is investigated from the energy point of *** phenomenon of self-excited vibrations is elaborated with the phase *** corresponding control strategies are briefly analyzed with respect to the vibration *** results show that when the levitation objects collide with the mechanical interface,the system's vibration frequency becomes larger with the decrease in the collision gap;when the vibration frequency exceeds the critical frequency,the electromagnetic system continues to provide energy to the system,and the collision interface continuously dissipates energy so that the system enters the self-excited vibration state.

关键词： magnetic levitation coupling system self-excited vibration mechanical interface vibration frequency

magnetic levitation using diamagnetism:Mechanism,applications and prospects

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第1期64卷 44-58页

作者： GAO QiuHua YAN Han ZOU HongXiang LI WenBo PENG ZhiKe MENG Guang ZHANG WenMing State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

As a typical contact-free manipulation technique that removes friction and contamination risk,levitation has gradually become a preferred candidate for various *** levitation using diamagnetism,beyond Earnshaw’s theorem,is a kind of passive stable levitation that can be achieved at normal temperatures with no energy ***,most seemingly nonmagnetic materials can be levitated in a magnetic field and can stabilize free levitation of magnetic *** review focuses on the fundamental principles of magnetic levitation using diamagnetism,with emphasis on its burgeoning *** theoretical basis associated with the magnetic levitation using diamagnetism is discussed by elucidating the characteristics of diamagnetic materials,and the key levitation mechanisms are ***,state-of-the-art applications in various aspects,including sensing and measurement,actuating and micromanipulation,energy harvesting and magnetic gravity compensation,are summarized and ***,the review concludes with a brief outlook on future perspectives.

关键词： magnetic levitation diamagnetism sensors actuators energy harvesters

Design and Implementation of Digital Fractional Order PID Controller Using Optimal Pole-Zero Approximation Method for magnetic levitation System

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2018年第5期5卷 977-989页

作者： Amit S.Chopade Swapnil W.Khubalkar A.S.Junghare M.V.Aware Shantanu Das IEEE the Department of Electrical Engineering Visvesvaraya National Institute of TechnologyNagpur India-440010India Reactor Control Division Bhabha Atomic Research CentreIndia

The aim of this paper is to employ fractional order proportional integral derivative(FO-PID)controller and integer order PID controller to control the position of the levitated object in a magnetic levitation system(MLS),which is inherently nonlinear and unstable *** proposal is to deploy discrete optimal pole-zero approximation method for realization of digital fractional order *** approach of phase shaping by slope cancellation of asymptotic phase plots for zeros and poles within given bandwidth is *** controller parameters are tuned using dynamic particle swarm optimization(d PSO)*** of the proposed control scheme is verified by simulation and experimental *** performance of realized digital FO-PID controller has been compared with that of the integer order PID *** is observed that effort required in fractional order control is smaller as compared with its integer counterpart for obtaining the same system performance.

关键词： Approximation methods digital control dis-cretization fractional calculus fractional order PID controller(FO-PID) magnetic levitation particle swarm optimization(PSO) position control.

A novel superconducting magnetic levitation method to support the laser fusion capsule by using permanent magnets

在线全文

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2018年第3期3卷 104-109页

作者： Xiaojia Li Tingting Xiao Fengwei Chen Yingjuan Zhang Xiaofei Li Weidong Wu Laser Fusion Research Center China Academy of Engineering PhysicsMianyang 621900China Science and Technology on Plasma Physics Laboratory Mianyang 621900China IFSA Collaborative Innovation Center Shanghai Jiao Tong UniversityShanghai 200240China Institute of Applied Electromagnetic Engineering Huazhong University of Science and TechnologyWuhan 430074China

A novel magnetic levitation support method is proposed, which can relieve the perturbation caused by traditional support methods andprovide more accurate position control of the capsule. This method can keep the perfect symmetry of the octahedral spherical hohlraum and hasthe characteristics in stability, tunability and simplicity. It is also favorable that all the results, such as supporting forces acting on the super-conducting capsule, are calculated analytically, and numerical simulations are performed to verify these results. A typical realistic design isproposed and discussed in detail. The superconducting coating material is suggested, and the required superconducting properties are *** oscillation of the floating capsule in thin helium gas is discussed, and the restoring time is estimated.

关键词： ICF capsule support magnetic levitation Symmetry

Research on magnetic levitation absolute vibration measurement method in vehicles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Instrumentation 2014年第2期1卷 38-49页

作者： JIANG Dong SHAN Yi WANG Deyu YANG Jiaxiang College of Electrical&Electronic Engineering Harbin University of Science and TechnologyHarbin 150080C仇加a

This paper presents a design for a magnetic levitation absolute- vibration test system which can be used by vehicles to measure the road surface roughness. The relationship between the vibration test system output voltage and measured speed of the object was obtained through testing,the power spectrum of the measured signal was obtained by virtual instrument analysis,the vibration waveforms of the vehicle over gentle and steep slopes were measured respectively and the road surface roughness was obtained by waveform analysis. Data was saved where the waveforms exceeded threshold. Finally,the steep slope was located using a GPS system. Experimental results show that the magnetic levitation absolute- vibration measurement method has characteristics of high sensitivity and a wide frequency range. This lays the foundation for research into multi- dimensional vibration measurements through magnetic levitation vibration test systems in vehicles.

关键词： magnetic levitation speed sensor flatness power spectrum analysis

A Hybrid High-Tc Superconducting magnetic levitation Sculpture Model

在线全文

学校读者我要写书评

暂无评论

A Hybrid High-Tc Superconducting Magnetic Levitation Sculptu...

RESPONSE’S ANALYSIS OF NONLINEAR magnetic levitation CONTROL SYSTEM TO RANDOM VIBRATION

中国材料大会2012

作者： Jun Zheng Hailian Jing Xinglin Liao Dabo He Jifu Chen Suyu Wang Applied Superconductivity Laboratory (ASCLab) Southwest Jiaotong University (SWJTU) Traction Power State Key Laboratory (TPL) Southwest Jiaotong University (SWJTU)

ISBN: (纸本)9783037856079

Different from other applications, this paper explores how to use the stable high-Tc superconducting （HTS） magnetic levitation （maglev） to lift the sculpture art to a high levitation position for satisfying the artist’s requirement for the light artistic concept. With a combination of the permanent magnet （PM） levitation and HTS maglev technologies, a sculpture model was built to sustain a stable levitation with a levitation height of over 80 mm. In this hybrid HTS maglev sculpture model, three PM rings are arranged as upper, middle, and bottom as a double-layer axial levitation structure;six rectangular YBaCuO bulks are fixed along the side of the PM rings’ upper-layer as a stabilizer component along the radial direction. When the bottom PM ring was driven up by the lifting bolt, the upper PM ring, which was fixed with the art, can be lifted much higher. Then the required artistic effect will be enhanced. After the model was designed and optimized by finite element method, it was experimentally validated by the HTS maglev measurement system. This levitation design is helpful to the realization of a real-scale levitation sculpture art, and can also provide references to superconducting radial magnetic bearing systems.

关键词： High-temperature superconductor magnetic levitation Permanent magnet YBaCuO bulk.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

RESPONSE’S ANALYSIS OF NONLINEAR MAGNETIC LEVITATION CONTRO...

Lateral magnetic stiffness under different parameters in a high-temperature superconductor levitation system

The Second International Conference on Dynamics Vibration and Control

作者： Hong Yao Xueren Li and Guangjun Zhang Math and Physics Department Science College of Air Force Engineering University Xi ’an 710049 China

＜正＞Based on the theory of nonlinear control system, there is much phenomenon in the nonlinear control system that will never appear in the linear system, that is so called essential nonlinear phenomenon, such as leap, self-oscillation, sub resonance and high resonance, chaos and so on. In this case, if linear system were used to predict random response of nonlinear system, usually, incorrect conclusions will be educed. I have to note, although there are many methods to predict random response of nonlinear control system

关键词： magnetic levitation random vibration response control system

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第7期30卷 515-525页

作者： Yong Yang Yun-Yi Wu School of Mechano-Electronic Engineering Xidian UniversityXi'an 710071China China Three Gorges Science and Technology Research Institute Beijing 100036China Physikalisches Institute B RWTH AachenAachen 52056Germany

magnetic stiffness determines the stability of a high-temperature superconductor(HTS)magnetic levitation *** quantitative properties of the physical and geometrical parameters that affect the stiffness of HTS levitation systems should be identified for improving the stiffness by some effective *** magnetic stiffness is directly related to the first-order derivative of the magnetic force with respect to the corresponding displacement,which indicates that the effects of the parameters on the stiffness should be different from the relationships between the forces and the same *** this paper,we study the influences of some physical and geometrical parameters,including the strength of the external magnetic field(B0)produced by a rectangular permanent magnet(PM),critical current density(Jc),the PM-to-HTS area ratio(α),and thickness ratio(β),on the lateral stiffness by using a numerical approach under zero-field cooling(ZFC)and field cooling(FC)*** the first and second passes of the PM,the lateral stiffness at most of lateral positions essentially increases with B0 increasing and decreases withβincreasing in ZFC and *** largest lateral stiffness at every lateral position is almost produced by the minimum value of Jc,which is obviously different from the lateral force–Jc ***α-dependent lateral stiffness changes with some parameters,which include the cooling conditions of the bulk HTS,lateral displacement,and movement history of the *** findings can provide some suggestions for improving the lateral stiffness of the HTS levitation system.

关键词： high-temperature superconductor magnetic levitation lateral stiffness lateral force

Flexible multilayer MEMS coils and their application in energy harvesters

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第4期67卷 1282-1293页

作者： ZHANG Jie HOU XiaoJuan QIAN Shuo BI XiaoXue HU DongXu LIU JianJun GENG WenPing MU JiLiang HE Jian CHOU XiuJian Science and Technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan 030051China School of Software North University of ChinaTaiyuan 030051China

Electromagnetic vibration energy harvesters are promising for the power supply of wireless sensor nodes,small electronic devices,and wearable *** electromagnetic harvesters usually increase output by increasing the size of coils and magnets,limiting the improvement of energy conversion efficiency and power *** this study,multilayer microelectromechanical system(MEMS)coils were prepared using flexible electronics,and their high integration performance in arbitrary space was utilized to greatly improve the utilization of the space magnetic field by the electromagnetic *** core magnet of the generator was magnetically balanced to achieve levitation,which improved the sensitivity and reduced fatigue damage compared with traditional spring *** wound coils on the top and bottom of the magnet and the flexible coils on the sides worked together to improve the energy efficiency and output of the *** output performance of the device with different number distributions was simulated using mathematical models to obtain the optimal structural *** results show that by introducing flexible multilayer MEMS coils on the side surface of the energy harvester,the open-circuit voltage of the energy generators increased from 7 to 10 V by more than 43%.Flexible multilayer MEMS coils can enhance energy conversion rates and possess compact dimensions,making them suitable for integration onto complex *** the vibration energy harvesting system testing,the maximum peak power of the harvester was 7.1 m W at an acceleration of1 g and a resonant frequency of 11 Hz with a resistor of 3.5 kΩinternal ***,a 470μF capacitor can be charged to 3.5 V within 10 s to drive a hygrothermograph to work for more than 80 s and can supply a light bulb *** strategy shows the great potential of vibration-energy-driven electromagnetic generators for powering small electronics in limited spaces.

关键词： electromagnetic harvester mechanical energy harvesting multilayer MEMS coils magnetic levitation overall space magnetic field flexible planar coils

Efficient loading of cesium atoms in a magnetic levitated dimple trap

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 324-328页

作者：张国庆冯国胜李玉清武寄洲马杰 State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyCollege of Physics and Electronics EngineeringShanxi UniversityTaiyuan 030006China Department of magnetic Resonance Imaging The First Hospital of Shanxi Medical UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

We report a detailed study of magnetically levitated loading of ultracold ^(133)Cs atoms in a dimple *** atomic sample was produced in a combined red-detuned optical dipole trap and dimple trap formed by two small waist beams crossing a horizontal *** magnetic levitation for the ^(133)Cs atoms forms an effective potential for a large number of atoms in a high spatial *** of the number of atoms loaded and trapped in the dimple trap on the magnetic field gradient and bias field is in good agreement with the theoretical *** method has been widely used to obtain the Bose–Einstein condensation atoms for many atomic species.

关键词： ultracold atom magnetic levitation dimple trap