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61.
Jinying XuXiangdong Zhang 《Physics letters. A》2011,375(13):1524-1527
We present a rigorous multiple-scattering method to calculate the interaction energies due to electromagnetic field fluctuations in a cluster of parallel cylinders. Various kinds of cluster structure with both isotropic and anisotropic materials are considered. It is shown that Casimir interactions are sensitive to the positions of the cylinders in the cluster or the structure of the system. The sign of the interaction energy cannot only be changed by tuning the parameters of anisotropic materials, it can also be caused by changing the cylinders configuration of the system. 相似文献
62.
F. Gonzlez G. Videen P. J. Valle J. M. Saiz J. L. de la Pea F. Moreno 《Journal of Quantitative Spectroscopy & Radiative Transfer》2001,70(4-6):383-393
Four theoretical and computational methods to describe the scattering from simple particles on substrates are presented and discussed. These methods are based on the extinction theorem, image theory, the double-interaction model, and geometrical optics (ray-tracing). We compare the four methods with measurements of scattered light from gold metallic cylinders resting on a gold metallic substrate. In particular, we analyze the co-polarized (s and p polarization) full-scan and back-scattering intensities in the far field within the plane of incidence. Advantages and disadvantages of each method as a computational and reliable tool are discussed. 相似文献
63.
Lijun Jia Huaiwu Zhang Jun Luo Yingli Liu Qiye Wen 《Journal of magnetism and magnetic materials》2010,322(14):1934-1938
MgO was introduced into low-temperature sintered Z-type hexaferrites in order to improve their high-frequency electromagnetic properties. In the doped samples the major Z-type phase coexists with a small amount of W-type magnetoplumbite phase. The addition of MgO causes a decrease of the average grain size and an increase of the magnetocrystalline anisotropy (K1) and the saturation magnetization (Ms) with the increment of K1 being larger than that of Ms. These factors result in a reduce of the initial permeability. Also, the samples with MgO additive exhibit higher Q-factor and dc resistivity. Furthermore, the introduction of MgO can decrease the dielectric constant and improve the dielectric loss tangent of the samples by reducing the electronic transition in octahedral site (B-site) between Fe2+ and Fe3+ ions. 相似文献
64.
65.
Two-dimensional equations for electromagnetic fields in a multi-layered thin dielectric film are derived from the three-dimensional equations of electrodynamics by expanding the vector potential of the electromagnetic fields into trigonometric series expansions of the film thickness coordinate. The lower order equations are examined. It is shown that they can describe certain long waves in the film. The equations are useful for modeling thin film devices. 相似文献
66.
W. Melnitchouk 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):223-234
We explore the relationship between exclusive and inclusive electromagnetic scattering from the pion, focusing on the transition
region at intermediate Q2. Combining Drell-Yan data on the leading twist quark distribution in the pion with a model for the resonance region at large
x, we calculate QCD moments of the pion structure function over a range of Q2, and quantify the role of higher twist corrections. Using a parameterization of the pion elastic form factor and phenomenological
models for the π↦ρ transition form factor, we further test the extent to which local duality may be valid for the pion.
Received: 10 February 2003 / Accepted: 12 March 2003 / Published online: 27 May 2003 相似文献
67.
Akhlesh Lakhtakia 《Optik》2006,117(4):188-192
When a (frequency-domain) boundary-value problem involving a homogeneous linear material is solved to assess the validity of the Post constraint, a conflict arises between the fundamental differential equations of electromagnetism in the chosen material and a naïve application of the usual boundary conditions. It is shown here that the conflict vanishes when the boundary conditions are properly derived from the fundamental equations, and the validity of the Post constraint in modern macroscopic electromagnetism is thereby reaffirmed. 相似文献
68.
The electromagnetic surface impedance of single crystal high-Tc superconductors has been examined within the framework of the two-fluid model and the hypothesis that the e m field modulates the partial concentrations of both normal and condensate fluids. A comparison with experimental data is reported. 相似文献
69.
Nadaniela Egidi Romina Gobbi Pierluigi Maponi 《Journal of Computational and Applied Mathematics》2007,210(1-2):175-182
We consider an electromagnetic scattering problem for inhomogeneous media. In particular, we focus on the numerical computation of the electromagnetic scattered wave generated by the interaction of an electromagnetic plane wave and an inhomogeneity in the corresponding propagation medium. This problem is studied in the VV polarization case, where some special symmetry requirements for the incident wave and for the inhomogeneity are assumed. This problem is reformulated as a Fredholm integral equation of second kind, which is discretized by a linear system having a special form. This allows to compute efficiently an approximate solution of the scattering problem by using iterative techniques for linear systems. Some numerical examples are reported. 相似文献
70.