查询词典 anisotropic

As the foundation of ultrasonic testing of composite materials, this thesis is intended to explore in detail a number of features of wave propagation in anisotropic plates, and the following essential problems will be considered:(1) Propagation of plane bulk waves in homogeneous and orthotropic anisotropic media;(2) Lamb wave propagation in multilayered anisotropic plates;(3) Influence of isotropic solid or liquid loading on Lamb wave propagation in anisotropic solid media;(4) Influence of interface layers on Lamb wave propagation in layered anisotropic composite laminates;(5) Dispersion characteristic analysis of attenuation Lamb wave while existing an thin viscous layer which is used for simulating the poor curing in adhesively bonded joints.

作为复合材料超声检测的基础，本文研究了如下国际前沿性的课题：（1）平面体波在正交均匀各向异性媒质中的传播；（2）多层各向异性媒质中Lamb波的传播；（3）各向同性固体或液体负载对各向异性固体媒质中Lamb波传播的影响；（4）界面层对层状各向异性复合媒质中Lamb波传播的影响；（5）胶粘剂未固化而呈现粘弹性时粘接结构中衰减Lamb波的频散特性分析。

Moreover, the micro-pattern etching of electrodes and PZT thin films have been investigated, and the fast and successful etchings have been actualized with new etchants and original methods. The technics and mechanism of anisotropic etching of monocrystalline silicon have been studied deeply, for example the influences of the concentration and temperature of tetramethyl ammonium hydroxide on the rate and effect of the anisotropic etching.

此外，结合PZT铁电薄膜热释电单元红外探测器的设计和制备，对电极和PZT铁电薄膜的微图形刻蚀工艺进行了研究，采用新的刻蚀液配方和具有独创性的方法，实现了对PZT铁电薄膜和上下电极快速、成功的刻蚀。

With aid of techniques of analytical continuation and conformal mapping, exact solutions are obtained for three typical problems concerning Eshelby's inclusion. The three problems are1 interaction between an arbitrarily shaped Eshelby inclusion and a circular inhomogeneity in transversely isotropic piezoelectric medium; 2 interaction between an arbitraily shaped Eshelby inclusion and an interface in anisotropic piezoelectric medium, the interface in our investigation may be a perfect interface, or a frictionless slipping interface , or a compliant electrode layer is embedded along the full interface of the bimaterials; 3 interaction between an arbitraily shaped Eshelby inclusion and an elliptical hole in anisotropic piezoelectric medium.

通过采用解析延拓和共形映射技术，获得了压电复合材料中有关Eshelby夹杂三个典型问题的精确弹性解答，即横观各向同性压电介质中任意形状的Eshelby夹杂与圆柱异相夹杂间相互作用；一般各向异性压电介质中任意形状的Eshelby夹杂与双压电材料所形成界面的相互作用，我们所考虑的界面包括理想界面、滑动界面以及柔性金属电极层增强界面；一般各向异性压电介质中任意形状的Eshelby夹杂与椭圆孔洞的相互作用。

Based on the laminate theory, a laminate weakened by damage is treated as an anisotropic thin plate. Using the complex potential method in the plane theory of elasticity of an anisotropic body, the series solution of finite anisotropic thin plate containing an elliptical inclusion is proposed with the help of Faber series. A hybrid element with an elliptical inclusion for anisotropic materials is obtained by using the hybrid variable principle, and the element efficiency is verified by numerical examples. The state of the damage is modeled by an elliptical soft inclusion, and using the point stress criterion based on characteristic curve and Yamada-Sun etc. criteria, the prediction of the strength of a composite laminate with damage is set up. The effects of various parameters on the stress distribution and the residual strength of a composite laminate weakened by damage are detailedly studied.

首先基于经典层板理论，将复合材料层板的弹性问题化归为均匀各向异性板来求解；采用各向异性体平面弹性理论中的复势方法，以Faber级数为工具，给出了有限大含椭圆核各向异性板弹性问题的级数解形式；利用杂交变分原理，成功导出含椭圆核各向异性板杂交应力有限元，并用算例验证了该单元的可行性和有效性；采用含刚度折减椭圆形弹性核的冲击损伤模型，引入基于特征曲线和Yamada-Sun破坏准则的点应力判据，建立了含损伤复合材料层板剩余强度的分析方法；通过数值计算详细讨论了各种几何参数对损伤层板应力分布、剩余强度的影响，得到了一系列对工程应用具有实用价值的结论。

In this paper, we detailed analyze the anisotropic transform and give an improved anisotropic transform.

我们对三维模型各向同性预处理进行了分析，给出了改进的各向同性预处理。

Assuming that the friction angle on different slip planes varied with the angle between the slip plane and bedding plane, an anisotropic strength criterion was established based on the concept of SMP. The formulation for cross-anisotropic granular materials was then derived.

基于SMP准则，假定不同平面上的摩擦角随该平面与沉积面之间的夹角变化，提出了一般应力条件下各向异性粒状材料的强度准则，称为ASMP准则，给出了该强度准则在横观各向同性条件下的表达式。

objective to obtain the diffusion tensor maps of the normal human brain,and assess intrinstic properties of water diffusion in quantitative parameters for an anatomic analysis.methods maps of isotropic apparent diffusion coefficient and various anisotropic maps were calculated in60healthy adults from seven diffusion imagings by using single-shot echo-planar diffusion-weighted sequence.brain parenchyma anatomy was analyzed and adciso and various anisotropic index were measured.results （1）diffusion properties of different tissues and anatomic areas of normal adult human brain are different.diffusion in white matter is anisotropic;diffusion in gray matter is isotropic.

目的 获取正常人脑组织扩散张力性图像（diffusion densor imaging，dti），定量分析正常人脑组织水扩散的内在特性，进一步评价脑解剖结构。方法 60例健康正常人，应用单次激发epi-dw序列，计算出adciso图及各向异性图，分析脑实质不同区域的解剖结构，测量adciso（isotropic apparent diffusion coefficient）及各向异性指数。结果（1）脑内不同组织结构弥散特性不同，脑白质弥散表现为各向异性，而脑灰质弥散表现为各向同性。

In this paper,two nonlinear anisotropic diffusion filtering methods are presented and they are based on the multispectral anisotropic diffusion models proposed by Pope and Acton.We build a couple of new diffusion coefficients in partial derivative equation based on Tukey's biweight estimator error norm by recurring to the relationship between robust statistics and anisotropic diffusion incorporated with the nonlinear time-dependent cooling technique for gradient threshold.

在Pope和Acton提出的两个多光谱图像各向异性扩散滤波模型的基础上，通过各向异性扩散和稳健统计学的联系，建立了基于B iwe ight Estim ator误差模型的扩散系数，同时利用非线性退化技术对梯度阈值的改进，提出了两个基于各向异性扩散方程的非线性滤波方法。

The UV and IR spectroscopic studies of the monomer films showed that the photoreaction ratio of monomer (about 50%) was higher than the corresponding photosensitive polymer (about 10%, PVCi). The polarized IR spectra proved that obvious anisotropic absorption was displayed in the irradiated photosensitive film. With polarizing microscopy method, we found that these kinds of photoalignment films exhibited good alignment ability, and the stability of the photoalignment film could reach about 100℃. 2 A photosensitive self-assembled monolayer was fabricated that contained photo-cycloadditable groups, such as, coumarin and cinnamate. The reaction process were detected by contact angle method because the IR absorption of monolayer was very weak. The photosensitive self-assembled monolayer promote uniform alignment of nematic liquid crystals by LPUV, and it thermal stability could reach about 130℃. 3 A cationic bolaform amphiphiles was synthesized that had two photosensitive double bonds, and can be polymerized by ultraviolet. A layer-by-layer self-assembled deposition film was prepared in aqueous solution by using this material and poly (sodium 4-styrenesulfonate). The UV-Vis. spectra proved that the multilayers film was uniform and layer-by-layer. When LPUV irradiated the film, the photopolymerizable double bond underwent [2+2] cycloaddition, and the production of the reaction distributed along the polarized direction of incident LPUV. Polarized UV-Vis. spectra indicated that the irradiated self-assembled multiplayer film was anisotropic, and the dichromic ration is about 0.09, it is higher than the spin-coating method of photosensitive polymer or monomer. We used this anisotropic film as alignment layer of nematic liquid crystals, and obtained a uniform and stability alignment result, the static contrast ratio is about 100, which is very close to application of liquid crystal device. This thesis is an instance that the photochemical material was used in the physics region of liquid crystals, the route that was from photosensitive monomer, self-assembled monolayer film to self-assembled multiplayer film was undergone, by this logical research method photoailgnment of liquid crystal was extended and consummated.

围绕上述思路开展了如下工作：1合成了三种可进行光二聚反应的光敏小分子单体，LPUV 辐照制作了光控取向膜；用紫外-可见光谱法和红外光谱法分析了薄膜中的光化学反应，发现小分子的光反应程度可达到50%以上，至少比光敏高分子高出5倍；薄膜的偏振红外光谱证实，经过LPUV 辐照后薄膜出现了明显的各向异性；将小分子光控取向膜制成液晶器件，在偏光显微镜下观察看到均匀一致的液晶取向；并且热稳定性达到100℃左右，接近实用化要求。2制备了含肉桂酸、香豆素基团的自组装单层膜；采用接触角的方法监测自组装反应的动力学过程；紫外-可见光谱证实了自组装单层膜在石英基板表面形成；自组装单层膜经LPUV 辐照后能诱导液晶均匀取向，而且热稳定性可达130℃，热稳定性进一步提高。3合成了含有光敏双键的双季铵盐，在水溶液状态下将它和聚乙烯基苯磺酸钠沉积生成layer-by-layer 自组装多层膜，紫外-可见光谱证实这是一个逐层均匀的沉积；在LPUV 照射下，自组装膜中的光敏双键按照偏振方向发生[2+2]环加成反应，形成取向膜，用二向色性值评价的分子取向度高于高分子及小分子光控取向膜的水平；实验证明用自组装多层膜制成的液晶器件亮暗态均匀，静态对比度约为100，达到实用化器件的水平。

Second, based on the spherical vector wave function in uniaxial anisotropic medium, and the first, second, third and fourth spherical Bessel functions satisfy the same differential equation and recursive formula. The scattering fields in terms of spherical vector wave function from a uniaxial anisotropic spherical shell and an anisotropic uniaxial-coated conducting sphere by a plane wave are derived. The electromagnetic fields in uniaxial anisotropic medium and free space can be expressed in terms of spherical vector wave functions in uniaxial anisotropic media and isotropic medium.

二、在建立均匀各向异性单轴介质球矢量波函数理论的基础上，利用二阶线性偏微分方程的性质和第一、第二、第三和第四类球Bessel函数满足相同的微分方程和递推关系，我们分别研究了单轴介质球壳和单轴介质涂覆导体球对平面波的电磁散射特性，首先给出了各个区域的电磁场用球矢量波函数来表示的解析表达式，进而利用电磁场在边界上满足电磁场切向连续的边界条件和球谐函数的正交性，得出了各向异性单轴介质球结构中电磁场用球矢量波函数表示的系数所满足的矩阵方程。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。