Based on elastic wave propagation theory, the dispersion equation for a thin anisotropic plate (such as commonly used Zinc okide in micro-transducers) bordered with liquid layers is derived. Higher symmetry crystals, ...Based on elastic wave propagation theory, the dispersion equation for a thin anisotropic plate (such as commonly used Zinc okide in micro-transducers) bordered with liquid layers is derived. Higher symmetry crystals, such as orthorhombic, tetragonal, cubic, isotropic, are included in this analysis as well. For the case of one liquid layer loading, numerical calcu- lations show that the phase velocity changes periodically with the thickness of the liquld layer. When the thickness 2d of the anisotropic plate is very small, mass sensing application of Ao mode Lamb wave is also discussed.展开更多
In this article,a novel and normalized Ztransform finite-difference time-domain(ZTFDTD)method is presented.This method uses a more general form of Maxwell’s equations using the E,H,D fields.The iterative model of D-E...In this article,a novel and normalized Ztransform finite-difference time-domain(ZTFDTD)method is presented.This method uses a more general form of Maxwell’s equations using the E,H,D fields.The iterative model of D-E-H-D can be obtained by using the Z-transform resulted frequency-dependent formula between D and E.The advantages of the ZTFDTD consist in that the discrete equations are simple,the results are precise,easy to program and capable of dealing with the key technologies of finite-difference time-domain(FDTD),such as absorbing boundary conditions(uniaxial anisotropic perfectly matched layer,UPML)and near-to-farfield transformation.The ZTFDTD method is then used to simulate the interaction of electromagnetic wave with plasma.Using a simplified two-dimensional model,the stealth effect of inhomogeneous,unmagnetized plasma is studied both in different electron densities of plasma,different electromagnetic wave frequencies and different plasma collision frequencies.The numerical results indicate that plasma stealth is effective in theory and a reasonable selection with the plasma parameters that can greatly enhance the effectiveness of plasma stealth.展开更多
基金supported by the National Natural Science Foundation of China.
文摘Based on elastic wave propagation theory, the dispersion equation for a thin anisotropic plate (such as commonly used Zinc okide in micro-transducers) bordered with liquid layers is derived. Higher symmetry crystals, such as orthorhombic, tetragonal, cubic, isotropic, are included in this analysis as well. For the case of one liquid layer loading, numerical calcu- lations show that the phase velocity changes periodically with the thickness of the liquld layer. When the thickness 2d of the anisotropic plate is very small, mass sensing application of Ao mode Lamb wave is also discussed.
基金supported by the Key Research Plan of National Natural Science Foundation of China (Grant No.90405004)the Specialized Research Fund for the Doctoral Program (SRFDP) (No.20060487041)。
文摘In this article,a novel and normalized Ztransform finite-difference time-domain(ZTFDTD)method is presented.This method uses a more general form of Maxwell’s equations using the E,H,D fields.The iterative model of D-E-H-D can be obtained by using the Z-transform resulted frequency-dependent formula between D and E.The advantages of the ZTFDTD consist in that the discrete equations are simple,the results are precise,easy to program and capable of dealing with the key technologies of finite-difference time-domain(FDTD),such as absorbing boundary conditions(uniaxial anisotropic perfectly matched layer,UPML)and near-to-farfield transformation.The ZTFDTD method is then used to simulate the interaction of electromagnetic wave with plasma.Using a simplified two-dimensional model,the stealth effect of inhomogeneous,unmagnetized plasma is studied both in different electron densities of plasma,different electromagnetic wave frequencies and different plasma collision frequencies.The numerical results indicate that plasma stealth is effective in theory and a reasonable selection with the plasma parameters that can greatly enhance the effectiveness of plasma stealth.
