各向异性

The anisotropism degree can be expressed by an anisotropism index which is the ratio between the point load strength indexes in the strongest and weakest directions.

岩石的各向异性程度可以用各向异性指数等于最强和最弱方向的点荷载强度指数之比，比值越大，岩石的各向异性愈明显。

A second-order symmetric fabric tensor is introduced to the model, such as the stiffness of the contact planes, the hardening parameter, the dilatant/ contractant coefficient are made dependent of the orientation of the contact plane in order to capture the inherent and stress induced anisotropic behavior of clay.

在上述考虑微结构的饱和软粘土的弹塑性本构模型的基础上将考虑组构的各向异性的二阶组构张量引入接触面上的刚度、硬化参数、剪胀系数等参数中，由此反映材料引起的各向异性和应力引起的各向异性。

Second, transient flow for vertical well and fractural well in porous media with arealanisotropy has been researched in this paper. The analytic solution for vertical well andsemi-analytic solution for vertical fractural well is developed by using image inversion,superposition principle, Laplace transformation, Fourier transformation, as well as theirinverse transforms, and storage and skin are taken into account. For vertical fractural well,influence of pressure and productivity is studied when the orientation of artificial fractureisn't in accordance with the direction of major permeability, it is fundamental to evaluatepotential and analyze well test data.

文中研究了平面各向异性储层不定常渗流问题，建立了平面各向异性储层交叉直线边界中一口直井渗流的数学模型，利用镜像反演、Laplace变换、Fouier变换及其反变换推导了不同边界条件下直井的Laplace空间解析解，考虑井储和表皮的影响，分析了曲线特征及影响因素的敏感性曲线；并运用影响椭圆及Duhamel叠加原理，推导了平面各向异性储层中垂直裂缝井的压力分布方程，考虑了水力裂缝与主渗透率轴成一定角度对压力及产能的影响，为垂直裂缝井的产能评价及试井分析提供依据。

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。

Based on the method of matrix transformation used in the compound material mechanics, the anisotropic flexibility matrix of the anisotropic sand with a certain stress state is transformed to be an isotopic one of a certain isotropic reference material with the corresponding stress state, and a corresponding stress matrix is obtained simultaneously.

借鉴复合材料力学中矩阵转换的数学方法，将各向异性砂样的柔度矩阵转化为各向同性等效参考砂的柔度矩阵，同时导出与其相当的应力状态的表达式，以使对各向异性岩土材料的分析可转换为对各向同性状态进行分析，由此可将以前基于各向同性假设的强度条件能够用于各向异性土体。

Optically anisotropic PDLC films can be acted as scattering polarizers with optimal electro-optical properties. The optical anisotropy characters of oriented PDLC films are analyzed.

对PDLC的光学各向异性进行了研究，并给出了要获得低阈值电压、高各向异性的聚合物分散液晶各向异性膜的盒厚、摩擦强度以及光照强度等条件。

The process includes dry etching the protecting layer of AMR film; wet etching the permalloy layer of the AMR film; and dry etching the transition layer of the AMR film.

一种多层膜的干湿结合蚀刻方法，包括：干法刻蚀各向异性磁电阻效应薄膜的保护层；湿法腐蚀各向异性磁电阻效应薄膜的坡莫合金层；干法刻蚀各向异性磁电阻效应薄膜的过渡层。

Considering the effect of the stress Lode angle or the third stress invariant, the author presents a new yield function and develops the Ohta-Sekiguchi's elasto-plastic model and Sekiguchi-Ohta's elasto-viscoplastic model to be a true three-dimensional model. This new model can take account of the effects of anisotropy induced by initial anisotropically consolidated state and the rotation of principal stress axes.

在太田-关口弹塑性模型及关口-太田弹粘塑性模型基础上，考虑应力劳台角的影响，提出软土真正三维应力空间的各向异性弹塑性及弹粘塑性本构方程（模型中各向异性主要指初始各向不等压应力状态所诱发的各向异性），这是对太田-关口弹塑性模型及关口-太田弹粘塑性模型的进一步发展。

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 results of 3-D numerical modeling of the transversely isotropic media with horizontal symmetry axis and the orthorhombic symmetry media showed that quasi P wave,quasi-SV wave and quasi-SH wave occurred during elastic wave propagation in 3-D anisotropic media. Meanwhile, the special phenomena such as the S wave splitting, the blind zone of S wave splitting and quasi-SV wave-front triplication were clearly observed. In addition, the elastic wave-fronts are spatially changed, and the coupled relations among the quasi-P wave,quasi-SV wave and quasiSH wave in 3-D anisotropic media are very complex.

对方位各向异性介质模型和正交各向异性介质模型中弹性波的传播进行的三维数值模拟结果表明，弹性波在三维各向异性介质中传播时存在拟P波、拟SV波和拟SH波，并出现横波分裂、横波分裂盲区、波面三分叉等特殊现象，另外，性波场在空间是变化的，其拟P波、拟SV波和拟SH波的耦合关系比较复杂。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。