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DESIGN AND ANALYSIS OF A CYLINDRICAL STANDING WAVE ULTRASONIC MOTOR USING CANTILEVER AND SANDWICH TYPE TRANSDUCERS

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DESIGN AND ANALYSIS OF A CYLINDRICAL STANDING WAVE ULTRASONI...

A rotary ultrasonic motor using radial bending mode of ring with nested PZT excitation

第三届全国压电和声波理论及器件技术研讨会

作者： ying-xiang liu,wei-shan chen,jun-kao liu,Sheng-jun SHI State Key Laboratory of Robotics and System,Harbin Institute of Technology, 92 West Dazhi Street,Harbin,Heilongjiang Province,China

A cylindrical standing wave ultrasonic motor using cantilever and sandwich type transducers was proposed in this paper. There are four pairs of cantilevers outside the cylindrical stator,and four PZT ceramics are set between each pair of *** PZT ceramics together with a pair of cantilevers compose a longitudinal *** bending mode of cylindrical stator is excited by the longitudinal vibration of PZT ***,linear simple harmonic motions are achieved at the particle on the *** the frictional force between rotor and stator is the driving force to realize the rotational motion of *** PZT ceramics work with d mode,which have high electromechanical coupling efficiency and could improve the output *** working principle of proposed motor was *** cylinder and longitudinal transducer were designed with *** sensitive parameters of resonant frequency of transducers and cylinder were gained with modal *** longitudinal resonant frequency of transducers and bending resonant frequency of cylinder were degenerated,and the motion trajectories of nodes on the teeth were *** results of this study could be useful in the development of this new type of ultrasonic motor.

关键词： Ultrasonic motor cylindrical cantilever type longitudinal transducer FEM

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第3期13卷 189-196页

作者： ying-xiang liu jun-kao liu wei-shan chen Xiao-hui YANG State Key Laboratory of Robotics and System Harbin Institute of Technology Horbin 150001 China

This study presents and verifies a new idea for constructing a rotary traveling wave ultrasonic motor （USM） that uses the radial bending mode of a ring. In the new design, 20 trapezoid cross section slots are cut symmetrically in the outer surface of a thick duralumin alloy ring, where 20 PZT stacks are nested. In each slot, two wedging blocks are set between the PZT stack and the two sides of the slot respectively to apply preloading on the PZT ceramics. Two radial bending modes of the stator that have a phase difference of a quarter wavelength on space are generated by using the d33 operating mode of the PZT elements, and then a flexural traveling wave is formed by the superimposing of two standing waves whose amplitudes are equal and phases are different by 90~ temporally. Two conical rotors are pressed to each end of the ring type stator by a coiled spring. The finite element method （FEM） simulation is developed to validate the feasibility of the proposed motor. The maximal speed and torque of the prototype are tested to be 126 r/rain and 0.8 N＇m, respectively.

关键词： Rotary ultrasonic motor Radial bending mode Traveling wave Wedging block clamped structure

Using spanwise flexibility of caudal fin to improve swimming performance for small fishlike robots

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Journal of Hydrodynamics 2018年第5期30卷 859-871页

作者： Dan Xia wei-shan chen jun-kao liu xiang Luo School of Mechanical Engineering Southeast UniversityNanjing 211189China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This paper examines the beneficial effects of the spanwise flexibility of the caudal fin for the improvement of the swimming performance for small fishlike robots. A virtual swimmer is adopted for controlled numerical experiments by varying the spanwise flexible trajectories and the spanwise flexible size of the caudal fin while keeping the body kinematics fixed. 3-D Navier-Stokes equations are used to compute the viscous flow over the robot. Elliptical, parabolic and hyperbola trajectories are chosen to describe the spanwise flexible profile of the caudal fin. According to the sign（positive or negative） of the phase difference of the swinging motion, the spanwise flexibility can be divided into the fin surface of ＂bow＂ and the fin surface of ＂scoop＂. It is observed that for both the fin surface of ＂bow＂ and the fin surface of ＂scoop＂, the spanwise elliptical trajectory has the optimal swimming velocity, thrust, lateral force, and efficiency. With comparisons, using the flexible caudal fin with the fin surface of ＂bow＂, the lateral force and the power consumption can be reduced effectively and the swimming stability can be increased while reducing little the swimming velocity and thrust. Meanwhile, using the flexible caudal fin with the fin surface of ＂scoop＂ can greatly improve the swimming velocity, thrust, and efficiency while increasing part of the lateral force and the power consumption. Three-dimensional flow structures clearly indicate the evolution process around the swimming robot. It is suggested that the fish, the dolphin, and other aquatic animals may benefit their hydrodynamic performance by the spanwise flexibility of the caudal fin.

关键词： Spanwise flexibility caudal fin fishlike robot swimming performance flow structures

The energy-saving advantages of burst-and-glide mode for thunniform swimming

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Journal of Hydrodynamics 2018年第6期30卷 1072-1082页

作者： Dan Xia wei-shan chen jun-kao liu xiang Luo School of Mechanical Engineering Southeast University State Key Laboratory of Robotics and System Harbin Institute of Technology

This paper explores the energy-saving advantages of the burst-and-glide swimming and compares it with the normal self-swimming for a thunniform swimmer. The virtual swimmer allows us to perform controlled numerical experiments by varying the swinging tail number and the duty cycle while keeping the other parameters fixed. 3-D Navier-Stokes equations are used to compute the viscous flow over the swimmer. The user-defined functions and the dynamic mesh technology are used to simulate the burst-and-glide swimming. The results show that with the increase of the swinging tail number or the duty cycle, the swimming velocity, the power and the efficiency all increase, but the velocity-power ratio decreases somewhat. Therefore, choosing smaller swinging tail number and duty cycle is beneficial in reducing the power and increasing the velocity-power ratio, and thus to obtain the same velocity, less power is consumed. And to swim the same distance, the energy can significantly be saved. The power consumption, the efficiency and the velocity-power ratio in the burst-and-glide case are 43.9%, 40.6% and 1.15 times of those in the normal swimming case, respectively. The flow structures clearly show the evolution process around the fish in the burst-and-glide swimming. The findings can be used to reasonably plan the swimming action and to take the advantage of the external flow field energy for the fishlike robot, to be more efficient and energy-saving.

关键词： Energy-saving advantages burst-and-glide mode normal self-swimming thunniform swimmer

Engineering a high-barrier d-f single-molecule magnet centered with hexagonal bipyramidal Dy(Ⅲ)unit

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Science China Chemistry 2024年第10期67卷 3291-3298页

作者： wei Deng Chan-ying Yao Yan-Cong chen ying-Qian Zhou shan-Nan Du jun-Liang liu Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of ChemistryInstitute of Green Chemistry and Molecular EngineeringGuangdong Basic Research Center of Excellence for Functional Molecular EngineeringSun Yat-sen UniversityGuangzhou 510006China

In the pursuit of high-performance single-molecule magnets(SMMs),incorporating intramolecular magnetic coupling emerges as a pivotal *** these,d-f SMMs have garnered significant attention due to their remarkable versatility,which lies in their ability to tune coordination environments and facilely substitute metal ***,achieving performance-centric d-f SMMs through the synergistic interplay between highly anisotropic f ions and d-f magnetic interactions remains a formidable *** mononuclear hexagonal bipyramidal(D_(6h))Dy^(Ⅲ)SMMs have been successfully isolated,the exploration of d-f SMMs featuring D_(6h)-lanthanide metal centers remains uncharted *** this study,we employed planar bipodal ligands in conjunction with“staple-like”axial phenoxide ligands to synthesize the first hexagonal bipyramidal d-f ***,this compound exhibits alternating-current magnetic susceptibilities peaking up to 68 K with an energy barrier surpassing 1,200 K,thus establishing a new benchmark within the heterometallic d-f SMM landscape inclusive of complexes with diamagnetic d metals and paramagnetic f ***,the ferromagnetic interaction at the d-f sites engenders oscillating relaxation times contingent on the magnetic field—a characteristic distinct from mononuclear *** findings shed light on a deliberate design approach for d-f SMMs,emphasizing the cooperative utilization of high-barrier lanthanide modules alongside d ions through magnetic *** synergy significantly enhances and diversifies the magnetic dynamics of these intriguing molecular systems.

关键词： single-molecule magnets magnetic coupling crystal engineering hexagonal bipyramid energy barrier

A 2.5-dimensional Analytical Model of Cold Leveling for Plates with Transverse Wave Defects

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Journal of Iron and Steel Research International 2015年第8期22卷 664-671页

作者： wei-hua chen Juan liu Zhen-shan CUI ying-jie WANG ying-rui WANG National Die & Mold CAD Engineering Research Center Shanghai Jiaotong University Baosteel Co. Ltd.

Waves occurring in cold-rolled plates or sheets can be divided into longitudinal and transverse waves. Classical leveling theories merely solve the problem of longitudinal waves, while no well accepted method can be employed for transverse waves. In order to investigate the essential deformation law of leveling for plates with transverse waves, a 2.5-dimensional （2.5- D） analytical approach was proposed. In this model, the plate was transversely divided into some strips with equal width; the strips are considered to be in the state of plane strain and each group of adjacent strips are assumed to be deformation compatible under stress. After calculation, the bending deformation of each strip and the leveling effect of overall plate were obtained by comprehensNe consideration of various strips along with the width. Bending of roller is a main approach to eliminate the transverse waves, which is widely accepted by the industry, but the essential effect of bending of roller on the deformation of plates and the calculation of bending of roller are unknown. According to the 2.5-D analytical model, it can be found that, for plates, it is neutral plane offsetting and middle plane elongation or contraction under inner stress that can effectively improve plate shape. Taking double side waves as an example, the appropriate values of bending of roller were obtained by the 2.5-D analytical model related to different initial unevenness, which was applicable to the current on-line adjusting of bending of roller in rolling industry.

关键词： plate leveling 2.5-dimensional analytical model transverse wave middle plane deformation

High-resolution ARPES endstation for in situ electronic structure investigations at SSRF

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Nuclear Science and Techniques 2021年第3期32卷 94-106页

作者： Yi-chen Yang Zheng-Tai liu Ji-shan liu Zhong-Hao liu Wan-Ling liu xiang-Le Lu Hong-Ping Mei Ang Li Mao Ye shan Qiao Da-wei Shen State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China University of Chinese Academy of Sciences Beijing 100049China

Angle-resolved photoemission spectroscopy(ARPES)is one of the most powerful experimental techniques in condensed matter *** ARPES,which uses photons with high flux and continuously tunable energy,has become particularly ***,an excellent synchrotron ARPES system must have features such as a small beam spot,super-high energy resolution,and a user-friendly operation interface.A synchrotron beamline and an endstation(BL03 U)were designed and constructed at the shanghai Synchrotron Radiation *** beam spot size at the sample position is 7.5(V)μm×67(H)μm,and the fundamental photon range is 7-165 eV;the ARPES system enables photoemission with an energy resolution of 2.67 meV at21.2 *** addition,the ARPES system of this endstation is equipped with a six-axis cryogenic sample manipulator(the lowest temperature is 7 K)and is integrated with an oxide molecular beam epitaxy system and a scanning tunneling microscope,which can provide an advanced platform for in situ characterization of the fine electronic structure of condensed matter.

关键词： Synchrotron ARPES In situ VUV laser Quantum materials

Functional connectivity changes during migraine treatment with electroacupuncture at Shuaigu(GB8)

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Journal of Integrative Medicine 2022年第3期20卷 237-243页

作者： xiang-yu wei Shi-lei Luo Hui chen shan-shan liu Zhi-gang Gong Song-hua Zhan Department of Radiology Shuguang HospitalShanghai University of Traditional Chinese MedicineShanghai 201203China Department of Acupuncture&Moxibustion Shuguang HospitalShanghai University of Traditional Chinese MedicineShanghai 201203China

Objective:To investigate the changes in the functional connectivity(FC)in the right insula between migraine without aura(MWoA)and healthy controls by using resting-state functional magnetic resonance imaging(rs-fMRI),and to observe the instant alteration of FC in MWoA during electroacupuncture(EA)stimulation at Shuaigu(GB8).Methods:A total of 30 patients with MWoA(PM group)and 30 healthy controls(HC group)underwent rs-fMRI *** PM group underwent a second rs-fMRI scan while receiving EA at *** right insula subregions,including the ventral anterior insula(vAI),dorsal anterior insula(dAI)and posterior insula(PI),were selected as the seed points for FC ***:Aberrant FC,including dAI with right postcentral gyrus,PI with left precuneus,was found among PM before EA(PMa),PM during EA(PMb)and ***,decreased FC between dAI and the right postcentral gyrus was found in the PMa compared to the HC and *** FC between the PI and left precuneus was found in the PMa compared to the HC and *** analysis showed that the FC value of the right postcentral gyrus in PMa was negatively correlated with the scores of Hamilton Rating Scale for Depression and Hamilton Rating Scale for *** FC value of the left precuneus in PMa was positively correlated with the visual analogue scale ***:The alteration of FC between the right insula subregions and multiple brain regions may be an important index for *** at GB8 was able to adjust the FC between the right insula subregions and parietal lobe,namely,the right dAI and right postcentral gyrus,and the right PI and left precuneus,thereby rendering an instant effect in the management of MWoA.

关键词： Functional status Migraine Electroacupuncture Shuaigu(GB8) Functional magnetic resonance imaging

Experimental and computational analysis of the structure-activity relationship of ionic gel electrolytes based on bistrifluoromethanesulfonimide salts for supercapacitors

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Journal of Materiomics 2024年第6期10卷 1222-1233页

作者： wei chen ying wei Xiuling Dong Zhong-Xia Wang Zheng Xing Qingguo Zhang xiang liu College of Chemistry and Materials Engineering Bohai UniversityJinzhou121013LiaoningChina College of Chemistry and Chemical Engineering Gannan Normal UniversityGanzhou341000JiangxiChina Institute of Medicine&Chemical Engineering Zhenjiang CollegeZhenjiang212028JiangsuChina

Ionic gel(IG)electrolytes are emerging as promising components for the development of next-generation supercapacitors(SCs),offering benefits in terms of safety,cost-effectiveness,and *** ionic conductivity,stability,and mechanical properties of the gel electrolyte are relevant factors to be considered and the key to improving the performance of the ***,the structure–activity relationship between the internal structure of IGs and their SC properties is not fully *** the current study,the intuitive and regular structure–activity relationship between the structure and properties of IGs was revealed via combining computational simulation and *** terms of conductivity,the ionic liquid(IL)([EMIM][TFSI])in the IG has a high self-diffusion coefficient calculated by molecular dynamics simulation(MDS),which is conductive to transfer and then improves the *** radial distribution function of the MDS shows that the larger the g(r)between the particles in the polymer network,the stronger the *** stability,IGs based on[EMIM][TFSI]and[EOMIM][TFSI]ILs have higher density functional theory calculated binding energy,which is reflected in the excellent thermal stability and excellent capacitor cycle *** on the internal pore size distribution and stress-strain characterization of the gel network([ME3MePy][TFSI]and[BMIM][TFSI]as additives),the highly crosslinked aggregate network significantly reduces the internal mesoporous distribution and plays a leading role in improving the mechanical properties of the *** using this strategy,it will be possible to design the ideal structure of the IG and achieve excellent performance.

关键词： Ionic gel electrolytes Density functional theory Molecular dynamics simulation Self-diffusion coefficient Mean square displacement