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Analysis of multiple scattering from two-dimensional dielectric sea surface with iterative Kirchhoff approximation 下载免费PDF全文
<正>An iterative method in the Kirchhoff approximation is proposed for high frequency multiple electromagnetic scattering from two-dimensional dielectric sea surface.The multiple interaction of the scattering field is characterized with the corrected electromagnetic currents of the wind-driven sea surface.The actual surface currents are approximated with the iterative solution of the corrected currents.A newly developed sea spectrum,Elfouhaily spectrum,is utilized to build the sea surface model.The shadowing correction is improved by the Depth-Buffer algorithm.The validity of the iterative Kirchhoff approximation is verified by the agreement of backscattering coefficients with the measured data. 相似文献
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Method of Fundamental Solution for Composite Electromagnetic Scattering from Two-Dimensional Object Located on a Rough Surface 下载免费PDF全文
Numerical modeling on the composite electromagnetic (EM) scattering from a two-dimensional (2-D) object located on a rough surface is presented by using the efficient method of fundamental solution (MFS). The proposed special choice of the MFS is an interesting alternative to the onerous mesh generation in the traditional numerical methods, particularly for the method of moment (MoM). There is no mesh scheme and singularity analysis, the field to be solved can be obtained directly in terms of the fundamental solutions of the appropriate wave equations. The numerical results are obtained and compared with the traditional MoM results, to demonstrate the accuracy and effectiveness of this technique. 相似文献
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经含有羟基的二胺单体HAB与二酐单体 4 ,4′ (六氟异丙基 ) 双邻苯二甲酸酐 ( 6FDA)的缩聚反应 ,制备了含有羟基的先驱聚合物PI OH ,通过PI OH上羟基与肉桂酰氯的酯化反应 ,制备了侧链带有肉桂酸酯基团的光敏聚酰亚胺PI CI.用氢核磁共振 ( 1H NMR)分析、傅立叶红外光谱 (FTIR)分析等表征了上述聚合物的结构与感光性能 .用紫外 可见光谱 (UV Vis)等方法研究了PI CI的光交联反应 .聚合物PI CI旋镀膜经线性偏振光聚合技术 (LPP)处理并装配得到的液晶盒可使液晶分子很好地定向沿面排列 .上述实验表明 ,本文所合成的聚酰亚胺定向层材料是一种新的液晶光定向层材料 相似文献
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Based on the double superimposition model, a sea slope model is obtained on the basis of the generated oceanic surface instead of being assumed as a Gaussian distribution model. Then, a summation formula of the backscattering coefficient is derived from the Bass Fuks two-scale model and its application is extended to the non-Gaussian oceanic surface with the help of simulated sea slopes, which can adequately reflect the non-Gaussian configuration of the sea surface. Finally, this scattering model is employed to describe the baekscattering configuration of sea surfaces in different sea states and wind directions, and is confirmed by several numerical examples. 相似文献
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Time-Domain Techniques for Transient Scattering from Dielectric Bodies and Sea Surface Governed by Jonswap~s Sea Spectra * 下载免费PDF全文
A time-domain surface integral equation (TDCFIE) approach is utilized to calculate the transient scattering from arbitrarily shaped, three-dimensional dielectric bodies. In conjunction with the marching-on-in-time (MOT) method, the TDCFIE-MOT method is used to derive explicit expressions for the present-time current as a function of the incident field. Sample results showing various geometries are presented and are compared with other numerical techniques. Finally, by an incident Gaussian plane tapered wave, transient scattering from the sea surface governed by Jonswap's sea spectra is computed. 相似文献
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An angular cutoff composite model for investigation on electromagnetic scattering from two-dimensional rough sea surfaces 下载免费PDF全文
Based on the local configuration angle division to select the corresponding method for electromagnetic scattering calculation from rough sea surface,this paper presents an angular cutoff composite model:when the local scattered angle is in the specular region that is given by an approximately 20 degrees cone around the specular direction,the Kirchhoff approximation is applied to evaluate the specular reflection,which dominates the total scattering in this region;the small perturbation method is employed to handle the diffuse reflection which is predominant as the local scattered angle is situated out of the specular region.Numerical results are compared with those of experimental and theoretical models in several configurations as a function of incident angle,wind speed,wind direction.The comparison of numerical results of other experimental and theoretical models in several configurations shows that the new composite model is robust to give accurate numerical evaluations for the sea surface scattering. 相似文献
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