A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip ...A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the niicrostrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results.展开更多
This paper deals with the determination of the thermo-elastic displacements and stresses in a multi-layered body set up in different layers of different thickness having different elastic properties due to the applica...This paper deals with the determination of the thermo-elastic displacements and stresses in a multi-layered body set up in different layers of different thickness having different elastic properties due to the application of heat and a concentrated load in the uppermost surface of the medium. Each layer is assumed to be made of homogeneous and isotropic elastic material. The relevant displacement components for each layer are taken to be axisymmetric about a line, which is perpendicular to the plane surfaces of all layers. The stress function for each layer, therefore, satisfies a single equation in absence of any body forces. The equation is then solved by integral transform technique. Analytical expressions for thermo-elastic displacements and stresses in the underlying mass and the corresponding numerical codes are constructed for any number of layers. However, the numerical comparison is made for three and four layers.展开更多
There exist the complicated waveguide modes as well as the surface waves in the electromagnetic field induced by a horizontal electric dipole in layered lossless dielectrics between two ground planes. In spectral doma...There exist the complicated waveguide modes as well as the surface waves in the electromagnetic field induced by a horizontal electric dipole in layered lossless dielectrics between two ground planes. In spectral domain, all these modes can be characterized by the rational parts with the real poles of the vector and scalar potentials. The accurate extraction of these modes plays an important role in the evaluation of the Green's function in spatial domain. In this paper, a new algorithm based on rational approximation is presented, which can accurately extract all the real poles and the residues of each pole simultaneously. Thus, we can get all the surface wave modes and waveguide modes, which is of great help to the calculation of the spatial domain Green's function. The numerical results demonstrated the accuracy and efficiency of the proposed method.展开更多
A method of analysis of experimental kinetic dependences of isothermal depolarization currents in metal-oxide varistor ceramics composed of ZnO–Bi_(2)O_(3)–CoO–Sb_(2)O_(3)–SnO_(2)–MnO–B_(2)O_(3) has been propose...A method of analysis of experimental kinetic dependences of isothermal depolarization currents in metal-oxide varistor ceramics composed of ZnO–Bi_(2)O_(3)–CoO–Sb_(2)O_(3)–SnO_(2)–MnO–B_(2)O_(3) has been proposed and tested.The method is based on reconstruction of dependences with the use of the Kohlrausch–Williams–Watt function.Expansion of the distribution and reduction of the average time of dielectric relaxation of the depolarization were found as the magnitude of the polarizing electric field increased.These findings have been interpreted in the framework of the notion of participation in the recharge of localized states more distant from the Fermi level in the crystallites of zinc-oxide ceramics under increased polarizing fields.展开更多
基金Partly supported by the Research Item B96(56) of the Ministry of Railways of China
文摘A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the niicrostrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results.
文摘This paper deals with the determination of the thermo-elastic displacements and stresses in a multi-layered body set up in different layers of different thickness having different elastic properties due to the application of heat and a concentrated load in the uppermost surface of the medium. Each layer is assumed to be made of homogeneous and isotropic elastic material. The relevant displacement components for each layer are taken to be axisymmetric about a line, which is perpendicular to the plane surfaces of all layers. The stress function for each layer, therefore, satisfies a single equation in absence of any body forces. The equation is then solved by integral transform technique. Analytical expressions for thermo-elastic displacements and stresses in the underlying mass and the corresponding numerical codes are constructed for any number of layers. However, the numerical comparison is made for three and four layers.
文摘There exist the complicated waveguide modes as well as the surface waves in the electromagnetic field induced by a horizontal electric dipole in layered lossless dielectrics between two ground planes. In spectral domain, all these modes can be characterized by the rational parts with the real poles of the vector and scalar potentials. The accurate extraction of these modes plays an important role in the evaluation of the Green's function in spatial domain. In this paper, a new algorithm based on rational approximation is presented, which can accurately extract all the real poles and the residues of each pole simultaneously. Thus, we can get all the surface wave modes and waveguide modes, which is of great help to the calculation of the spatial domain Green's function. The numerical results demonstrated the accuracy and efficiency of the proposed method.
文摘A method of analysis of experimental kinetic dependences of isothermal depolarization currents in metal-oxide varistor ceramics composed of ZnO–Bi_(2)O_(3)–CoO–Sb_(2)O_(3)–SnO_(2)–MnO–B_(2)O_(3) has been proposed and tested.The method is based on reconstruction of dependences with the use of the Kohlrausch–Williams–Watt function.Expansion of the distribution and reduction of the average time of dielectric relaxation of the depolarization were found as the magnitude of the polarizing electric field increased.These findings have been interpreted in the framework of the notion of participation in the recharge of localized states more distant from the Fermi level in the crystallites of zinc-oxide ceramics under increased polarizing fields.
