A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized ...A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized along the thickness direction. The generalized displacements are expressed as the sum of the gradient of a scalar (dilatation wave) and the curl of a vector (shear wave). With the help of dynamic equilibrium equations and geometric equations, we can obtain dynamic equations of the dilatation wave and the shear wave. The conclusion that the types of the dilatation waves and the shear waves remain unchanged after being reflected by the boundary can be obtained through the analysis of these kinetic equations. The dispersion properties and phase velocity surface of the dilatation and shear wave can be obtained by solutions of dynamic equilibrium equations. Influences of the piezoelectric and piezomagnetic parameters on wave characteristics are discussed.展开更多
This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies on environmental stimuli such as temperature,vibration,and shock.A novel stress-isolation system is use...This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies on environmental stimuli such as temperature,vibration,and shock.A novel stress-isolation system is used to effectively decouple an axis-symmetric bulk-acoustic wave(BAW)vibratory gyro from its substrate,minimizing the effect that external sources of error have on the offset and scale factor of the device.Substrate-decoupled(SD)BAW gyros with a resonance frequency of 4.3 MHz and Q values near 60000 were implemented using the high aspect ratio poly and single-crystal silicon(HARPSS)process to achieve ultra-narrow capacitive gaps.Wafer-level packaged sensors were interfaced with a customized application-specific integrated circuit(ASIC)to achieve low variations in the offset across temperature(±26°s^(−1) from−40 to 85℃),supreme random-vibration immunity(0.012°s^(−1) gRMS−1)and excellent shock rejection.With a scale factor of 800μV(°s^(−1))^(−1),the SD-BAW gyro system attains a large full-scale range(±1250°s^(−1))with a non-linearity of less than 0.07%.A measured angle-random walk(ARW)of 0.39°/√h and a bias instability of 10.5°h^(−1) are dominated by the thermal and flicker noise of the integrated circuit(IC),respectively.Additional measurements using external electronics show bias-instability values as low as 3.5°h−1,which are limited by feed-through signals coupled from the drive loop to the sense channel,which can be further reduced through proper re-routing of the gyroscope pin-out configuration.展开更多
Shear-wave velocity is a key parameter for calibrating monitoring time-lapse 4D seismic data during CO2-EOR （Enhanced Oil Recovery） and CO2 sequestration. However, actual S-wave velocity data are lacking, especially...Shear-wave velocity is a key parameter for calibrating monitoring time-lapse 4D seismic data during CO2-EOR （Enhanced Oil Recovery） and CO2 sequestration. However, actual S-wave velocity data are lacking, especially in 4D data for CO2 sequestration because wells are closed after the CO2 injection and seismic monitoring is continued but no well log data are acquired. When CO2 is injected into a reservoir, the pressure and saturation of the reservoirs change as well as the elastic parameters of the reservoir rocks. We propose a method to predict the S-wave velocity in reservoirs at different pressures and porosities based on the Hertz-Mindlin and Gassmann equations. Because the coordination number is unknown in the Hertz Mindlin equation, we propose a new method to predict it. Thus, we use data at different CO2 injection stages in the Gao89 well block, Shengli Oilfield. First, the sand and mud beds are separated based on the structural characteristics of the thin sand beds and then the S-wave velocity as a function of reservoir pressure and porosity is calculated. Finally, synthetic seismic seismograms are generated based on the predicted P- and S-wave velocities at different stages of CO2 injection.展开更多
Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets,making it universally applicabl...Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets,making it universally applicable to almost all biological systems.Thin-film bulk acoustic wave(BAW)resonators operating at gigahertz(GHz)frequencies have been demonstrated to generate localized high-speed microvortices through acoustic streaming effects.Benefitting from the strong drag forces of the high-speed vortices,BAW-enabled GHz acoustic streaming tweezers(AST)have been applied to the trapping and enrichment of particles ranging in size from micrometers to less than 100 nm.However,the behavior of particles in such 3D microvortex systems is still largely unknown.In this work,the particle behavior(trapping,enrichment,and separation)in GHz AST is studied by theoretical analyses,3D simulations,and microparticle tracking experiments.It is found that the particle motion in the vortices is determined mainly by the balance between the acoustic streaming drag force and the acoustic radiation force.This work can provide basic design principles for AST-based lab-on-a-chip systems for a variety of applications.展开更多
Experiments on silt incipient motion under wave action were carried out. Under wave action, for different wave periods, water depths and bulk densities of silt, the shear stress or height of waves for incipient motion...Experiments on silt incipient motion under wave action were carried out. Under wave action, for different wave periods, water depths and bulk densities of silt, the shear stress or height of waves for incipient motion was determined, and a relation between the shear stress and bulk density of silt was established. Results indicate that the critical shear stress depends on the structure of the silt itself, related to the tightness between the grains （or bulk density）. Exterior condition is only an external cause of silt incipient motion, and the critical shear stress for the incipient motion is the token of exterior condition.展开更多
In this paper, we consider the two-dimensional complex Ginzburg–Landau equation(CGLE) as the spatiotemporal model, and an expression of energy eigenvalue is derived by using the phase-amplitude representation and the...In this paper, we consider the two-dimensional complex Ginzburg–Landau equation(CGLE) as the spatiotemporal model, and an expression of energy eigenvalue is derived by using the phase-amplitude representation and the basic ideas from quantum mechanics. By numerical simulation, we find the energy eigenvalue in the CGLE system can be divided into two parts, corresponding to spiral wave and bulk oscillation. The energy eigenvalue of spiral wave is positive, which shows that it propagates outwardly; while the energy eigenvalue of spiral wave is negative, which shows that it propagates inwardly. There is a necessary condition for generating a spiral wave that the energy eigenvalue of spiral wave is greater than bulk oscillation. A wave with larger energy eigenvalue dominates when it competes with another wave with smaller energy eigenvalue in the space of the CGLE system. At the end of this study, a tentative discussion of the relationship between wave propagation and energy transmission is given.展开更多
It is well known that the undistorted transmission of pulses is impossible in bulk dispersive linear media with the transverse effects not being considered. The compressing or broadening of optical pulses during trans...It is well known that the undistorted transmission of pulses is impossible in bulk dispersive linear media with the transverse effects not being considered. The compressing or broadening of optical pulses during transmission depends on the incident pulse states. In order to achieve ultrahigh data rates of transmission in optical communication systems, several possible ways of overcoming dispersion effects have been employed. Among them the most significant and practial one was suggested by Hasegawa et al. , in which the nonlinear dependence of the refractive index on pulse intensity was utilized. This展开更多
In this paper, a mathematical relation was found between interatomic Hooke’s force constant and both the bulk modulus and interatomic distance in solid crystals, considering that the forces which have effect on an at...In this paper, a mathematical relation was found between interatomic Hooke’s force constant and both the bulk modulus and interatomic distance in solid crystals, considering that the forces which have effect on an atom are only those resulted from the neighboring atoms, and the forces are subject to Hooke’s law as the deflections of atoms from their equilibrium positions are very small. This work has been applied on some solid semiconducting crystals of diatomic primitive cell, including crystals of mono-atomic primitive cell automatically, by using linear statistical fitting with computer programming and, then, using mathematical analysis, proceeding from the vibrational dispersion relation of solid linear lattice, these two methods have been used in the process in order to support each other and for the result to be satisfying and reasonable. This is a contribution to the process of using computer programming in physics to facilitate mathematical analyses and obtain the required relations and functions by designing and developing appropriate computer programs in line with the macro and micro natures of materials. The importance of this is in enhancing our understanding of the interatomic actions in cells and of the crystal structure of materials in general and semiconductors in particular, as it is a step of the initial steps to facilitate the process of calculating energies and extracting mathematical relations between correlation energy and temperature as well as between sub-fusion and fusion energies with temperature.展开更多
Bulk acoustic wave resonators with piezoelectric films have been widely explored for the small size and high quality factor （Q） at GHz. This paper describes a high overtone bulk acoustic resonator （HBAR） based on ...Bulk acoustic wave resonators with piezoelectric films have been widely explored for the small size and high quality factor （Q） at GHz. This paper describes a high overtone bulk acoustic resonator （HBAR） based on AI/ZnO/AI sandwich layers and c-axis sapphire substrate. ZnO film with high quality c-axis orientation has been obtained using DC magnetron sputtering. The fabricated HBAR presents high Q at the multiple resonances from a 0.5-4.0 GHz wide band with a total size （including the contact pads） of 0.6 mm×0.3 mm×0.4 mm, The device exhibits the best acoustic coupling at around 2.4 GHz, which agrees with the simulation results based on the one-dimensional Mason equivalent circuit model. The HBAR also demonstrates Q values of 30 000, 25 000, and 6500 at 1.49, 2.43, and 3.40 GHz, respectively. It is indicated that the HBAR has potential applications for the low phase noise high frequency oscillator or microwave signal source.展开更多
文摘A dynamic solution is presented for the propagation of waves in an electric-magneto-elastic plate composed of piezoelectric, piezomagnetic materials and elastic matrix. The electric-magneto-elastic plate is polarized along the thickness direction. The generalized displacements are expressed as the sum of the gradient of a scalar (dilatation wave) and the curl of a vector (shear wave). With the help of dynamic equilibrium equations and geometric equations, we can obtain dynamic equations of the dilatation wave and the shear wave. The conclusion that the types of the dilatation waves and the shear waves remain unchanged after being reflected by the boundary can be obtained through the analysis of these kinetic equations. The dispersion properties and phase velocity surface of the dilatation and shear wave can be obtained by solutions of dynamic equilibrium equations. Influences of the piezoelectric and piezomagnetic parameters on wave characteristics are discussed.
文摘This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies on environmental stimuli such as temperature,vibration,and shock.A novel stress-isolation system is used to effectively decouple an axis-symmetric bulk-acoustic wave(BAW)vibratory gyro from its substrate,minimizing the effect that external sources of error have on the offset and scale factor of the device.Substrate-decoupled(SD)BAW gyros with a resonance frequency of 4.3 MHz and Q values near 60000 were implemented using the high aspect ratio poly and single-crystal silicon(HARPSS)process to achieve ultra-narrow capacitive gaps.Wafer-level packaged sensors were interfaced with a customized application-specific integrated circuit(ASIC)to achieve low variations in the offset across temperature(±26°s^(−1) from−40 to 85℃),supreme random-vibration immunity(0.012°s^(−1) gRMS−1)and excellent shock rejection.With a scale factor of 800μV(°s^(−1))^(−1),the SD-BAW gyro system attains a large full-scale range(±1250°s^(−1))with a non-linearity of less than 0.07%.A measured angle-random walk(ARW)of 0.39°/√h and a bias instability of 10.5°h^(−1) are dominated by the thermal and flicker noise of the integrated circuit(IC),respectively.Additional measurements using external electronics show bias-instability values as low as 3.5°h−1,which are limited by feed-through signals coupled from the drive loop to the sense channel,which can be further reduced through proper re-routing of the gyroscope pin-out configuration.
基金supported by the National High Techology Research and Development Program(No.2012AA050103)
文摘Shear-wave velocity is a key parameter for calibrating monitoring time-lapse 4D seismic data during CO2-EOR （Enhanced Oil Recovery） and CO2 sequestration. However, actual S-wave velocity data are lacking, especially in 4D data for CO2 sequestration because wells are closed after the CO2 injection and seismic monitoring is continued but no well log data are acquired. When CO2 is injected into a reservoir, the pressure and saturation of the reservoirs change as well as the elastic parameters of the reservoir rocks. We propose a method to predict the S-wave velocity in reservoirs at different pressures and porosities based on the Hertz-Mindlin and Gassmann equations. Because the coordination number is unknown in the Hertz Mindlin equation, we propose a new method to predict it. Thus, we use data at different CO2 injection stages in the Gao89 well block, Shengli Oilfield. First, the sand and mud beds are separated based on the structural characteristics of the thin sand beds and then the S-wave velocity as a function of reservoir pressure and porosity is calculated. Finally, synthetic seismic seismograms are generated based on the predicted P- and S-wave velocities at different stages of CO2 injection.
基金The authors gratefully acknowledge financial support from the National Key R&D Program of China(2018YFE0118700)the Natural Science Foundation of China(NSFC No.62174119)+1 种基金Tianjin Applied Basic Research and Advanced Technology(17JCJQJC43600)the 111 Project(B07014).
文摘Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets,making it universally applicable to almost all biological systems.Thin-film bulk acoustic wave(BAW)resonators operating at gigahertz(GHz)frequencies have been demonstrated to generate localized high-speed microvortices through acoustic streaming effects.Benefitting from the strong drag forces of the high-speed vortices,BAW-enabled GHz acoustic streaming tweezers(AST)have been applied to the trapping and enrichment of particles ranging in size from micrometers to less than 100 nm.However,the behavior of particles in such 3D microvortex systems is still largely unknown.In this work,the particle behavior(trapping,enrichment,and separation)in GHz AST is studied by theoretical analyses,3D simulations,and microparticle tracking experiments.It is found that the particle motion in the vortices is determined mainly by the balance between the acoustic streaming drag force and the acoustic radiation force.This work can provide basic design principles for AST-based lab-on-a-chip systems for a variety of applications.
基金This research was financially supported by the High Technology Research and Development Programof China(863 Program,Grant No.2002AA601011)
文摘Experiments on silt incipient motion under wave action were carried out. Under wave action, for different wave periods, water depths and bulk densities of silt, the shear stress or height of waves for incipient motion was determined, and a relation between the shear stress and bulk density of silt was established. Results indicate that the critical shear stress depends on the structure of the silt itself, related to the tightness between the grains （or bulk density）. Exterior condition is only an external cause of silt incipient motion, and the critical shear stress for the incipient motion is the token of exterior condition.
基金Supported by the Basic Research Project of Shenzhen,China under Grant Nos.JCYJ 20140418181958489 and 20160422144751573
文摘In this paper, we consider the two-dimensional complex Ginzburg–Landau equation(CGLE) as the spatiotemporal model, and an expression of energy eigenvalue is derived by using the phase-amplitude representation and the basic ideas from quantum mechanics. By numerical simulation, we find the energy eigenvalue in the CGLE system can be divided into two parts, corresponding to spiral wave and bulk oscillation. The energy eigenvalue of spiral wave is positive, which shows that it propagates outwardly; while the energy eigenvalue of spiral wave is negative, which shows that it propagates inwardly. There is a necessary condition for generating a spiral wave that the energy eigenvalue of spiral wave is greater than bulk oscillation. A wave with larger energy eigenvalue dominates when it competes with another wave with smaller energy eigenvalue in the space of the CGLE system. At the end of this study, a tentative discussion of the relationship between wave propagation and energy transmission is given.
基金Project supported by the National Natural Science Foundation of Chinathe Provincial Natural Science Foundation of Shanxi
文摘It is well known that the undistorted transmission of pulses is impossible in bulk dispersive linear media with the transverse effects not being considered. The compressing or broadening of optical pulses during transmission depends on the incident pulse states. In order to achieve ultrahigh data rates of transmission in optical communication systems, several possible ways of overcoming dispersion effects have been employed. Among them the most significant and practial one was suggested by Hasegawa et al. , in which the nonlinear dependence of the refractive index on pulse intensity was utilized. This
文摘In this paper, a mathematical relation was found between interatomic Hooke’s force constant and both the bulk modulus and interatomic distance in solid crystals, considering that the forces which have effect on an atom are only those resulted from the neighboring atoms, and the forces are subject to Hooke’s law as the deflections of atoms from their equilibrium positions are very small. This work has been applied on some solid semiconducting crystals of diatomic primitive cell, including crystals of mono-atomic primitive cell automatically, by using linear statistical fitting with computer programming and, then, using mathematical analysis, proceeding from the vibrational dispersion relation of solid linear lattice, these two methods have been used in the process in order to support each other and for the result to be satisfying and reasonable. This is a contribution to the process of using computer programming in physics to facilitate mathematical analyses and obtain the required relations and functions by designing and developing appropriate computer programs in line with the macro and micro natures of materials. The importance of this is in enhancing our understanding of the interatomic actions in cells and of the crystal structure of materials in general and semiconductors in particular, as it is a step of the initial steps to facilitate the process of calculating energies and extracting mathematical relations between correlation energy and temperature as well as between sub-fusion and fusion energies with temperature.
基金Project (Nos. 11074274 and 11174319) supported by the National Natural Science Foundation of China
文摘Bulk acoustic wave resonators with piezoelectric films have been widely explored for the small size and high quality factor （Q） at GHz. This paper describes a high overtone bulk acoustic resonator （HBAR） based on AI/ZnO/AI sandwich layers and c-axis sapphire substrate. ZnO film with high quality c-axis orientation has been obtained using DC magnetron sputtering. The fabricated HBAR presents high Q at the multiple resonances from a 0.5-4.0 GHz wide band with a total size （including the contact pads） of 0.6 mm×0.3 mm×0.4 mm, The device exhibits the best acoustic coupling at around 2.4 GHz, which agrees with the simulation results based on the one-dimensional Mason equivalent circuit model. The HBAR also demonstrates Q values of 30 000, 25 000, and 6500 at 1.49, 2.43, and 3.40 GHz, respectively. It is indicated that the HBAR has potential applications for the low phase noise high frequency oscillator or microwave signal source.
