A low order nonconforming anisotropic finite element approximation to parabolic problem

A low order nonconforming finite element is applied to the parabolic problem with anisotropic meshes. Both the semidiscrete and fully discrete forms are studied. Some superclose properties and superconvergence are obtained through some novel approaches and techniques. This research was supported by the National Natural Science Foundation of China under Grant No. 10671184.     

ANISOTROPIC BIQUADRATIC ELEMENT WITH SUPERCLOSE RESULT

The main aim of this paper is to study the convergence of biquadratic finite element forthe second order problem on anisotropic meshes.By using some novel approaches and techniques,theoptimal error estimates are obtained.At the same time,the anisotropic superclose results are alsoachieved.Furthermore,the numerical results are given to demonstrate our theoretical analysis.     

PO Solution for Scattering by the Complex Object Coated with Anisotropic Materials

1 .INTRODUCTIONItisknownthatphysicaloptics(PO)hasbeenwidelyusedinfastpredictionofradarcrosssection (RCS)ofacomplexconductingorcoatedobject.POisadoptedwithoutexceptionamongtheissuedfamouscomputa tionalsoftwareofhigh frequencyEMscatteringbyacomplexobjectsuchasRECOTA[1 ] ,GRECO[2 ,3] ,X PATCH[4] ,whereonlytheisotropiccoatingisconcerned .However,theanisotropiccoatingencoun teredinsomepracticalapplicationsimpelsonetofindthesuitablesolutionforhigh frequencyscatteringbytheobjectcoatedwi…     

地下水在渐变各向异性介质中的渗流速度方程的改进

Darcy定律是地下水动力学的基础公式,也是描述地下水运动状态的基本公式。怎样应用Darcy定律全面而简单的表达地下水在渐变各向异性介质中的流速方程是本文的目的。     

基于灰度值数学形态算子处理的各向异性扩散

在各向异性扩散去噪音处理中,目前的正则化方法不能阻止国像边界和角的退化介绍了在非线性扩散方程中应用灰度值侵蚀和渐进正则化尺度的新算法．它能在有效地去噪音的同时保持边界和角的局域性另外在扩散方程离散化中,用形态算于梯度代替中心差商梯度,对于图像中的单像素点的线条．前者不能增强而后者则能有效地增强最后分别给出了两种算法的增强图像的例子。     

Tuning the magnetic anisotropy in LSMO manganite films through non-magnetic nanoparticles

We report the observation of anomalous magnetic anisotropy driven by nonmagnetic ZrO2 nanoparticles in epitaxial La2/3Sr1/3MnO (LSMO) films grown on LaAlO3 (LAO) substrates. The compressive epitaxial strain imposed by the lattice mismatch of substrate and film is tuned by the density of ZrO2 nanoparticles embedded in the film matrix and affects the magnetic anisotropy as well as the magnetotransport properties. Epitaxial 54 nm thick LSMO thin films with different concentrations of ZrO2 nanoparticles demonstrate anisotropic hysteresis loops concomitant with anisotropic magnetotresistance behavior. The biaxial epitaxial strain, induced by the substrate/film lattice parameter mismatch is partially relaxed by increasing the density of precipitates and they serve as a tuning parameter for the strain state. We interpret our results by a strain-induced interplay of impurity scattering, weak localization and magnetic domain structure.     

各向异性厚板静力分析新方法

本文提出了一种各向异性厚板静力分析新方法。按照此方法,可以建立含有横向坐标Z的任意高次项的高阶方程,而不需增加基本未知函数的个数。与现有厚板理论相比,本文所述方法具有基本未知函数少、基本方程易于建立、且简单易解、计算结果精度较高等优点。     

Uniaxial compression behavior and spectroscopic properties of energetic 1,1-diamino-2,2-dinitroethylene(FOX-7) crystals from density functional theory calculations

Using dispersion-corrected density functional theory (DFT),we investigate the effect of uniaxial compression on1,1-diamino-2,2-dinitroethene (FOX-7) crystal.Principal and shear stresses along the [100],[010],and [001]orientations exhibit considerable anisotropic compressibility.Raman spectra are complemented by DFT calculations in vibrational modes.Several abnormal pressure-induced changes in selected Raman modes are observed along the [100] orientation.Combined Raman peak shifts with inter/intra-molecular hydrogen bonds and N-H/N-O covalent bonds,the results demonstrate that the spectroscopic variation are associated with the rearrangement of hydrogen-bonded networks of FOX-7 crystal.These findings imply a possible phase transformation or some minor changes in molecular conformation in the pressure regions under uniaxial compression.     

非线性湿气迁移方程Carey非协调元逼近

将非协调三角形Carey元应用于非线性Sobolev-Galpern型湿气迁移方程的有限元逼近格式,利用单元特性和误差估计技巧,在各向异性网格下得到了能量模的最优误差估计及相应的L2模的收敛结果.     

一种权重的高阶扩散图像盲复原方法

为了实现对模糊噪声图像的清晰化盲复原,提出了一种权重的高阶扩散图像盲复原方法。首先,在模糊核的估计阶段,运用一种各向异性扩散的图像结构提取策略和shock滤波器将图像中的强边缘准确地提取出来,并利用提取的图像强边缘实现对模糊核的准确估计;然后,在图像的复原阶段,利用高阶扩散模型和权重平衡参数,针对复原图像,提出了一种权重的高阶正则化约束来实现图像的清晰化复原;最后,运用了一种分裂的布雷格曼(split Bregman,SB)最优化迭代策略对提出的方法进行最优化求解。实验结果表明,较近几年的一些具有代表性的图像盲复原方法相比,不仅主观的视觉效果得到了较为明显的改进,而且客观的峰值信噪比也增加了1.0~2.7 dB。