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Radiation force and torque on a two-dimensional circular cross-section of a non-viscous eccentric layered compressible cylinder in acoustical standing waves
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作者 F G Mitri 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期355-366,共12页
The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic... The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic standing waves having an arbitrary angle of incidence in the polar(transverse)plane.The host medium of wave propagation and the eccentric liquid-like cylinder are non-viscous.Numerical computations illustrate the theoretical analysis with particular emphases on the eccentricity of the cylinder,the angle of incidence and the dimensionless size parameters of the inner and coating cylindrical fluid materials.The method to derive the acoustical scattering,and radiation force and torque components conjointly uses modal matching with the addition theorem,which adequately account for the multiple wave interaction effects between the layer and core fluid materials.The results demonstrate that longitudinal and lateral radiation force components arise.Moreover,an axial radiation torque component is quantified and computed for the non-absorptive compound cylinder,arising from geometrical asymmetry considerations as the eccentricity increases.The computational results reveal the emergence of neutral,positive,and negative radiation force and torque depending on the size parameter of the cylinder,the eccentricity,and the angle of incidence of the insonifying field.Moreover,based on the law of energy conservation applied to scattering,numerical verification is accomplished by computing the extinction/scattering energy efficiency.The results may find some related applications in fluid dynamics,particle trapping,mixing and manipulation using acoustical standing waves. 展开更多
关键词 radiation force radiation torque liquid compound cylinder multiple scattering acoustical standing waves
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The viscous strip approach to simplify the calculation of the surface acoustic wave generated streaming
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作者 F.JAZINI DORCHEH M.GHASSEMI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第4期711-724,共14页
In recent decades,the importance of surface acoustic waves,as a biocompatible tool to integrate with microfluidics,has been proven in various medical and biological applications.The numerical modeling of acoustic stre... In recent decades,the importance of surface acoustic waves,as a biocompatible tool to integrate with microfluidics,has been proven in various medical and biological applications.The numerical modeling of acoustic streaming caused by surface acoustic waves in microchannels requires the effect of viscosity to be considered in the equations which complicates the solution.In this paper,it is shown that the major contribution of viscosity and the horizontal component of actuation is concentrated in a narrow region alongside the actuation boundary.Since the inviscid equations are considerably easier to solve,a division into the viscous and inviscid domains would alleviate the computational load significantly.The particles'traces calculated by this approximation are excellently alongside their counterparts from the completely viscous model.It is also shown that the optimum thickness for the viscous strip is about 9-fold the acoustic boundary layer thickness for various flow patterns and amplitudes of actuation. 展开更多
关键词 surface acoustic wave MICROFLUIDICS numerical simulation particle tracing acoustic streaming
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Ion acoustic solitary waves in an adiabatic dusty plasma:Roles of superthermal electrons,ion loss and ionization
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作者 饶强华 陈辉 +1 位作者 刘三秋 陈小昌 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期337-342,共6页
We investigate propagation of dust ion acoustic solitary wave(DIASW)in a multicomponent dusty plasma with adiabatic ions,superthermal electrons,and stationary dust.The reductive perturbation method is employed to deri... We investigate propagation of dust ion acoustic solitary wave(DIASW)in a multicomponent dusty plasma with adiabatic ions,superthermal electrons,and stationary dust.The reductive perturbation method is employed to derive the damped Korteweg-de Vries(DKdV)equation which describes DIASW.The result reveals that the adiabaticity of ions significantly modifies the basic features of the DIASW.The ionization effect makes the solitary wave grow,while collisions reduce the growth rate and even lead to the damping.With the increases in ionization cross sectionΔσ/σ_(0),ion-to-electron density ratioδ_(ie)and superthermal electrons parameterκ,the effect of ionization on DIASW enhances. 展开更多
关键词 dust ion acoustic wave solitary wave IONIZATION adiabatic process
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Effect of gas saturation on P-wave velocity in tight sandstone
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作者 Pan Bao-Zhi Zhou Wei-Yi +2 位作者 Guo Yu-Hang Fang Chun-Hui Zhang Li-Hua 《Applied Geophysics》 SCIE CSCD 2024年第3期487-495,617,共10页
By measuring the variation of the P-and S-wave velocities of tight sandstone samples under water saturation,it was confirmed that with the decrease in water saturation,the P-wave velocity first decreased and then incr... By measuring the variation of the P-and S-wave velocities of tight sandstone samples under water saturation,it was confirmed that with the decrease in water saturation,the P-wave velocity first decreased and then increased.The variation in velocity was influenced by the sandstone’s porosity.The commonly used Gassmann equation based on fluid substitution theory was studied.Comparing the calculated results with the measured data,it was found that the Gassmann equation agreed well with the measured data at high water saturation,but it could not explain the bending phenomenon of P-wave velocity at low saturation.This indicated that these equations could not accurately describe the relationship between fluid content and rock acoustic velocity.The reasons for this phenomenon were discussed through Taylor’s expansion.The coefficients of the fitting formula were calculated and verified by fitting the measured acoustic velocity changes of the cores.The relationship between P-wave velocity and saturation was discussed,which provides experimental support for calculating saturation using seismic and acoustic logging data. 展开更多
关键词 Tight sandstone Saturation model Reservoir parameters Acoustic wave measurement
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Numerical Simulation and Parallel Computing of Acoustic Wave Equation in Isotropic-Heterogeneous Media
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作者 Arshyn Altybay Niyaz Tokmagambetov 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第11期1867-1881,共15页
In this paper,we consider the numerical implementation of the 2D wave equation in isotropic-heterogeneous media.The stability analysis of the scheme using the von Neumann stability method has been studied.We conducted... In this paper,we consider the numerical implementation of the 2D wave equation in isotropic-heterogeneous media.The stability analysis of the scheme using the von Neumann stability method has been studied.We conducted a study on modeling the propagation of acoustic waves in a heterogeneous medium and performed numerical simulations in various heterogeneous media at different time steps.Developed parallel code using Compute Unified Device Architecture(CUDA)technology and tested on domains of various sizes.Performance analysis showed that our parallel approach showed significant speedup compared to sequential code on the Central Processing Unit(CPU).The proposed parallel visualization simulator can be an important tool for numerous wave control systems in engineering practice. 展开更多
关键词 Acoustic wave simulation numerical simulation isotropic-heterogeneous media graphics processing unit(GPU) von Neumann stability analysis
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Derivation of Cylindrical Internal-Surface Acoustic Waves and Their Small Gravity Effect
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作者 Philipp G. Kornreich 《Journal of Modern Physics》 2024年第12期2193-2219,共27页
The properties of Cylindrical Internal-Surface Acoustic Waves (CISAW) propagating on the inside surface of a high purity fused quartz tubular fiber are derived from basic principles using a variational method. The CIS... The properties of Cylindrical Internal-Surface Acoustic Waves (CISAW) propagating on the inside surface of a high purity fused quartz tubular fiber are derived from basic principles using a variational method. The CISAW consist of Energy Momentum Packets (EMP) moving in a looping motion. The EMP have mass and are affected by gravity similar to a pendulum bob. The effect of gravity on CISAW is much larger than the effect of gravity in a light wave. Therefore, one can build much smaller CISAW Interferometer Gravity wave Observatories (CIGO) than the present km size Light Interferometer Gravity wave Observatories (LIGO). An array of CIGO can be used to detect gravity wave images. Since the wavelength of gravity waves is much larger than the expected spacing between CIGO array elements this would result in sub-wavelength images. It would be interesting to determine what new discoveries could be made using such an array. 展开更多
关键词 Elastic Constant Tensor Continuum Mechanics LAGRANGIAN wave Equation Surface Acoustic waves Newtonian Gravity
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Three-dimensional acoustic wave equation modeling based on the optimal finite-difference scheme 被引量:4
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作者 蔡晓慧 刘洋 +4 位作者 任志明 王建民 陈志德 陈可洋 王成 《Applied Geophysics》 SCIE CSCD 2015年第3期409-420,469,共13页
Generally, FD coefficients can be obtained by using Taylor series expansion (TE) or optimization methods to minimize the dispersion error. However, the TE-based FD method only achieves high modeling precision over a... Generally, FD coefficients can be obtained by using Taylor series expansion (TE) or optimization methods to minimize the dispersion error. However, the TE-based FD method only achieves high modeling precision over a limited range of wavenumbers, and produces large numerical dispersion beyond this range. The optimal FD scheme based on least squares (LS) can guarantee high precision over a larger range of wavenumbers and obtain the best optimization solution at small computational cost. We extend the LS-based optimal FD scheme from two-dimensional (2D) forward modeling to three-dimensional (3D) and develop a 3D acoustic optimal FD method with high efficiency, wide range of high accuracy and adaptability to parallel computing. Dispersion analysis and forward modeling demonstrate that the developed FD method suppresses numerical dispersion. Finally, we use the developed FD method to source wavefield extrapolation and receiver wavefield extrapolation in 3D RTM. To decrease the computation time and storage requirements, the 3D RTM is implemented by combining the efficient boundary storage with checkpointing strategies on GPU. 3D RTM imaging results suggest that the 3D optimal FD method has higher precision than conventional methods. 展开更多
关键词 3D acoustic wave equation optimal finite-difference forward modeling reversetime migration
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A normalized wavefield separation cross-correlation imaging condition for reverse time migration based on Poynting vector 被引量:16
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作者 陈婷 何兵寿 《Applied Geophysics》 SCIE CSCD 2014年第2期158-166,253,共10页
Prestack reverse time migration(PSTM) is a common imaging method; however low-frequency noises reduce the structural imaging precision. Thus, the suppression of migration noises must be considered. The generation me... Prestack reverse time migration(PSTM) is a common imaging method; however low-frequency noises reduce the structural imaging precision. Thus, the suppression of migration noises must be considered. The generation mechanism of low-frequency noises is analyzed and the up-, down-, left-, and right-going waves are separated using the Poynting vector of the acoustic wave equation. The computational complexity and memory capacitance of the proposed method are far smaller than that required when using the conventional separation algorithm of 2D Fourier transform. The normalized wavefield separation crosscorrelation imaging condition is used to suppress low-frequency noises in reverse time migration and improve the imaging precision. Numerical experiments using the Marmousi model are performed and the results show that the up-, down-, left-, and right-going waves are well separated in the continuation of the wavefield using the Poynting vector. We compared the imaging results with the conventional method, Laplacian filtering, and wavefield separation with the 2D Fourier transform. The comparison shows that the migration noises are well suppressed using the normalized wavefield separation cross-correlation imaging condition and higher precision imaging results are obtained. 展开更多
关键词 acoustic wave equation Poynting vector wavefield separation normalized crosscorrelation migration noises
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WAVELET METHOD FOR CALCULATING THE DEFECT STATES OF TWO-DIMENSIONAL PHONONIC CRYSTALS 被引量:16
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作者 Zhizhong Yah Yuesheng Wang Chuanzeng Zhang 《Acta Mechanica Solida Sinica》 SCIE EI 2008年第2期104-109,共6页
Based on the variational theory, a wavelet-based numerical method is developed to calculate the defect states of acoustic waves in two-dimensional phononic crystals with point and line defects. The supercell technique... Based on the variational theory, a wavelet-based numerical method is developed to calculate the defect states of acoustic waves in two-dimensional phononic crystals with point and line defects. The supercell technique is applied. By expanding the displacement field and the material constants (mass density and elastic stiffness) in periodic wavelets, the explicit formulations of an eigenvalue problem for the plane harmonic bulk waves in such a phononic structure are derived. The point and line defect states in solid-liquid and solid-solid systems are calculated. Comparisons of the present results with those measured experimentally or those from the plane wave expansion method show that the present method can yield accurate results with faster convergence and less computing time. 展开更多
关键词 acoustic wave phononic crystal defect state waveLET band structure
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3-D acoustic wave equation forward modeling with topography 被引量:6
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作者 Wang Xiangchun Liu Xuewei 《Applied Geophysics》 SCIE CSCD 2007年第1期8-15,共8页
In order to model the seismic wave field with surface topography, we present a method of transforming curved grids into rectangular grids in two different coordinate systems. Then the 3D wave equation in the transform... In order to model the seismic wave field with surface topography, we present a method of transforming curved grids into rectangular grids in two different coordinate systems. Then the 3D wave equation in the transformed coordinate system is derived. The wave field is modeled using the finite-difference method in the transformed coordinate system. The model calculation shows that this method is able to model the seismic wave field with fluctuating surface topography and achieve good results. Finally, the energy curves of the direct and reflected waves are analyzed to show that surface topography has a great influence on the seismic wave's dynamic properties. 展开更多
关键词 acoustic wave equation surface topography FINITE-DIFFERENCE numerical modeling.
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PROPAGATION OF SURFACE ACOUSTIC WAVES IN PRESTRESSED ANISOTROPIC LAYERED PIEZOELECTRIC STRUCTURES 被引量:5
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作者 Liu Hua Kuang Zhenbang +2 位作者 Cai Zhengming Wang Tiejun Wang Zikun 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第1期16-23,共8页
The propagation of surface acoustic waves in layered piezoelectric structureswith initial stresses is investigated. The phase velocity equations are obtained for electricallyfree and shorted cases, respectively. Effec... The propagation of surface acoustic waves in layered piezoelectric structureswith initial stresses is investigated. The phase velocity equations are obtained for electricallyfree and shorted cases, respectively. Effects of the initial stresses on the phase velocity and theelectromechanical coupling coefficient for the fundamental mode of the layered piezoelectricstructures are discussed. Numerical results for the c-axis oriented film of LiNbO_3 on a sapphiresubstrate are given. It is found that the fractional change in phase velocity is a linear functionwith the initial stresses, and the electromechanical coupling factor increases with an increase ofthe absolute values of the compressive initial stresses. The results are useful for the design ofsurface acoustic wave devices. 展开更多
关键词 surface acoustic waves layered piezoelectric structure phase velocity electromechanical coupling coefficient
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Dynamic Adaptive Finite Element Analysis of Acoustic Wave Propagation Due to Underwater Explosion for Fluid-structure Interaction Problems 被引量:4
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作者 Seyed Shahab Emamzadeh Mohammad Taghi Ahmadi +1 位作者 Soheil Mohammadi Masoud Biglarkhani 《Journal of Marine Science and Application》 CSCD 2015年第3期302-315,共14页
In this paper, an investigation into the propagation of far field explosion waves in water and their effects on nearby structures are carried out. For the far field structure, the motion of the fluid surrounding the s... In this paper, an investigation into the propagation of far field explosion waves in water and their effects on nearby structures are carried out. For the far field structure, the motion of the fluid surrounding the structure may be assumed small, allowing linearization of the governing fluid equations. A complete analysis of the problem must involve simultaneous solution of the dynamic response of the structure and the propagation of explosion wave in the surrounding fluid. In this study, a dynamic adaptive finite element procedure is proposed. Its application to the solution of a 2D fluid-structure interaction is investigated in the time domain. The research includes:a) calculation of the far-field scatter wave due to underwater explosion including solution of the time-depended acoustic wave equation, b) fluid-structure interaction analysis using coupled Euler-Lagrangian approach, and c) adaptive finite element procedures employing error estimates, and re-meshing. The temporal mesh adaptation is achieved by local regeneration of the grid using a time-dependent error indicator based on curvature of pressure function. As a result, the overall response is better predicted by a moving mesh than an equivalent uniform mesh. In addition, the cost of computation for large problems is reduced while the accuracy is improved. 展开更多
关键词 adaptive mesh fluid-structure interaction acoustic wave finite element analysis underwater explosion
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Biomedical microwave-induced thermoacoustic imaging 被引量:4
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作者 Qiang Liu Xiao Liang +3 位作者 Weizhi Qi Yubin Gong Huabei Jiang Lei Xi 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2022年第4期13-48,共36页
Microwave induced thermoacoustic imaging(MTAI)has emerged as a potential biomedical imaging modality with over 20-year growth.MTAI typically employs pulsed microwave as the pumping source,and detects the microwave-ind... Microwave induced thermoacoustic imaging(MTAI)has emerged as a potential biomedical imaging modality with over 20-year growth.MTAI typically employs pulsed microwave as the pumping source,and detects the microwave-induced ultrasound wave via acoustic transducers.Therefore,it features high acoustic resolution,rich elect romagnetic contrast,and large imaging depth.Benefiting from these unique advantages,MTAI has been extensively applied to various fields including pathology,biology,material and medicine.Till now,MTAI has been deployed for a wide range of biomedical applications,including cancer diagnosis,joint evaluation,brain in-vestigation and endoscopy.This paper provides a comprehensive review on(1)essential physics(endogenous/exogenous contrast mechanisms,penetration depth and resolution),(2)hardware configurations and software implementations(excit ation source,antenna,ultrasound detector and image recovery algorithm),(3)animal studies and clinical applications,and(4)future directions. 展开更多
关键词 Thermoacoustic imaging biomedical imaging electromagnetic radiation acoustic waves biomedical image processing
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Propagation of acoustic wave in viscoelastic medium permeated with air bubbles 被引量:3
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作者 梁彬 朱哲民 程建春 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第2期412-421,共10页
Based on the modification of the radial pulsation equation of an individual bubble, an effective medium method (EMM) is presented for studying propagation of linear and nonlinear longitudinal acoustic waves in visco... Based on the modification of the radial pulsation equation of an individual bubble, an effective medium method (EMM) is presented for studying propagation of linear and nonlinear longitudinal acoustic waves in viscoelastic medium permeated with air bubbles. A classical theory developed previously by Gaunaurd (Gaunaurd GC and UEberall H, J. Acoust, Soc, Am., 1978; 63: 1699-1711) is employed to verify the EMM under linear approximation by comparing the dynamic (i.e. frequency-dependent) effective parameters, and an excellent agreement is obtained. The propagation of longitudinal waves is hereby studied in detail, The results illustrate that the nonlinear pulsation of bubbles serves as the source of second harmonic wave and the sound energy has the tendency to be transferred to second harmonic wave, Therefore the sound attenuation and acoustic nonlinearity of the viscoelastic matrix are remarkably enhanced due to the system's resonance induced by the existence of bubbles. 展开更多
关键词 acoustic wave viscoelastic medium BUBBLE NONLINEARITY
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Transformation method and wave control 被引量:3
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作者 Zheng Chang Jin Hu Geng-Kai Hu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第6期889-898,共10页
Transformation method provides an efficient way to control wave propagation by materials.The transformed relations for field and material during a transformation are essential to fulfill this method.We propose a syste... Transformation method provides an efficient way to control wave propagation by materials.The transformed relations for field and material during a transformation are essential to fulfill this method.We propose a systematic method to derive the transformed relations for a general physic process,the constraint conditions are obtained by considering geometrical and physical constraint during a mapping. The proposed method is applied to Navier's equation for elastodynamics,Helmholtz's equation for acoustic wave and Maxwell's equation for electromagnetic wave,the corresponding transformed relations are derived,which can be used in the framework of transformation method for wave control.We show that contrary to electromagnetic wave,the transformed relations are not uniquely determined for elastic wave and acoustic wave,so we have a freedom to choose them differently.Using the obtained transformed relations,we also provide some examples for device design,a concentrator for elastic wave,devices for illusion acoustic and illusion optics are conceived and validated by numerical simulations. 展开更多
关键词 wave control Elastic wave Acoustic wave Electromagnetic wave Local affine transformation
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Propagations of Rayleigh and Love waves in ZnO films/glass substrates analyzed by three-dimensional finite element method 被引量:3
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作者 王艳 谢英才 +1 位作者 张淑仪 兰晓东 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期468-473,共6页
Propagation characteristics of surface acoustic waves(SAWs) in ZnO films/glass substrates are theoretically investigated by the three-dimensional(3D) finite element method. At first, for(11ˉ20) ZnO films/glass ... Propagation characteristics of surface acoustic waves(SAWs) in ZnO films/glass substrates are theoretically investigated by the three-dimensional(3D) finite element method. At first, for(11ˉ20) ZnO films/glass substrates, the simulation results confirm that the Rayleigh waves along the [0001] direction and Love waves along the [1ˉ100] direction are successfully excited in the multilayered structures. Next, the crystal orientations of the ZnO films are rotated, and the influences of ZnO films with different crystal orientations on SAW characterizations, including the phase velocity, electromechanical coupling coefficient, and temperature coefficient of frequency, are investigated. The results show that at appropriate h/λ, Rayleigh wave has a maximum k^2 of 2.4% in(90°, 56.5°, 0°) ZnO film/glass substrate structure; Love wave has a maximum k^2 of 3.81% in(56°, 90°, 0°) ZnO film/glass substrate structure. Meantime, for Rayleigh wave and Love wave devices, zero temperature coefficient of frequency(TCF) can be achieved at appropriate ratio of film thickness to SAW wavelength. These results show that SAW devices with higher k^2 or lower TCF can be fabricated by flexibly selecting the crystal orientations of ZnO films on glass substrates. 展开更多
关键词 surface acoustic wave ZnO films electromechanical coupling coefficient temperature coefficientof frequency 3D finite element method
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Viscoelastic Analysis of a Surface Acoustic Wave Gas Sensor Coated by a New Deposition Technique 被引量:3
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作者 Wen Wang Shi-tang He Yong Pan 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第1期47-53,共7页
An analysis of the response of surface acoustic wave sensors coated with polymer film based on new coating deposition (self-assemble and molecularly imprinted technology) is described and the response formulas are h... An analysis of the response of surface acoustic wave sensors coated with polymer film based on new coating deposition (self-assemble and molecularly imprinted technology) is described and the response formulas are hence deduced. Using the real part of shear modulus, the polymer can be classified into three types: glassy film, glassy-rubbery film and rubbery film, Experimental results show that the attenuation response is in better consistence with the simulation than in Martin's theory, but the velocity response does not accord with the calculation exactly. Maybe it is influenced by the experimental methods and environment. In addition, simulations of gas sorption for polymer films are performed. As for glassy film, the SAW sensor response increases with increasing fihn thickness, and the relationship between the sensor response and the concentration of gas is pretty linear, while as for glassy-rubbery flint and rubbery film, the relationship between the sensor sensitivity anti concentration of gas is very complicated. The ultimately calculated results indicate that the relationship between the sensor response and frequency is not always linear due to the viscoelastic prooerties of the polymer. 展开更多
关键词 Surface acoustic wave Gas sensor POLYMER Viscoelastic property
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Influence of adhesive layer properties on laser-generated ultrasonic waves in thin bonded plates 被引量:3
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作者 孙宏祥 许伯强 +2 位作者 张华 高倩 张淑仪 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期410-418,共9页
This paper studies quantitatively the generation of Lamb waves in thin bonded plates subjected to laser illumination, after considering the viscoelasticity of the adhesive layer. The displacements of such plates have ... This paper studies quantitatively the generation of Lamb waves in thin bonded plates subjected to laser illumination, after considering the viscoelasticity of the adhesive layer. The displacements of such plates have been calculated in the frequency domain by using the finite element method, and the time domain response has been reconstructed by applying an inverse fast Fourier transform. Numerical results are presented showing the normal surface displacement for several configurations: a single aluminum plate, a three-layer bonded plate, and a two-layer plate. The characteristics of the laser-generated Lamb waves for each particular case have been investigated. In addition, the sensitivity of the transient responses to variations of material properties (elastic modulus, viscoelastic modulus, and thickness) of the adhesive layer has been studied in detail. 展开更多
关键词 laser applications surface acoustic waves adhesive bonds finite element method
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Realization of Wavelet Transform Using SAW Devices 被引量:5
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作者 WEI Pei-yong ZHU Chang-chun LIU Jun-hua 《Semiconductor Photonics and Technology》 CAS 2001年第2期104-108,共5页
Based on the characteristics of surface acoustic wave(SAW) devices, the theory for realizing wavelet transform (WT) by SAW is deduced. Simulated experiment shows that the method of implementing WT using SAW devices ha... Based on the characteristics of surface acoustic wave(SAW) devices, the theory for realizing wavelet transform (WT) by SAW is deduced. Simulated experiment shows that the method of implementing WT using SAW devices has virtues of high speed and utility and is compatible with digital technique. It is important to implement wavelet transform. 展开更多
关键词 wavelet transform Surface acoustic wave Signal processing
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Surface Acoustic Wave Humidity Sensors Based on(1120) ZnO Piezoelectric Films Sputtered on R-Sapphire Substrates 被引量:3
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作者 王艳 张淑仪 +2 位作者 范理 水修基 杨跃涛 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第8期123-126,共4页
ZnO films on R-sapphire substrates are prepared and characterized by x-ray diffraction and scanning electron microscopy, which indicate that the thin films are well crystallized with (1120) texture. Love wave and Ra... ZnO films on R-sapphire substrates are prepared and characterized by x-ray diffraction and scanning electron microscopy, which indicate that the thin films are well crystallized with (1120) texture. Love wave and Rayleigh wave are used for fabrications of humidity sensors, which are excited in [1100] and [0001] directions of the (1120) ZnO piezoelectric films, respectively. The experimental results show that both kinds of sensors have good humidity response and repeatability, and the performances of the Love wave sensors are better than those of the Rayleigh wave sensors at room temperature. Moreover, the theoretical calculations of the mass sensitivity of the sensors are a/so carried out and the calculated results are in good agreement with the experimental measurements. 展开更多
关键词 ZnO Piezoelectric Films Sputtered on R-Sapphire Substrates Surface Acoustic wave Humidity Sensors Based on
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