梯度法

Firstly, nonlinear diffusion filter was used to wipe of noise efficiently and kept the edge information of the image. Secondly, gradient calculation of pixel diagonal direction was considered in the calculation of neighborhood gradient amplitude which further repressed the impact of noise. Thirdly, using average interclass variance, the self-adaptively double thresholds for different images were calculated.

首先采用非线性扩散滤波减少了图像噪声，同时保持图像的边缘信息；在邻域梯度幅值计算中，考虑像素对角线方向的梯度，进一步抑制了噪声的影响；最后采用平均方差阈值法选取阈值，从而提高了对不同图像的自适应性。

Two special cases are discussed: flow due to a constant pressure gradient and flow due to a periodic one; In chapter 4, on the basis of the method of fractional element proposed by Schiessel et al and of the generalized fractional element networks proposed by Xu and Tan and by the use of discretization method for solving the inverse Laplace transform, we obtain the creep compliance of Zener and Poynting-Thomson models which are composed of the generalized fractional element networks.

并讨论了如下两种特殊情形：常压力梯度下的流动和周期性压力梯度下的流动；第四章在Schiessel等提出的分数阶单元法和徐明瑜等提出的广义分数阶单元网络的基础上，应用离散求逆Laplace变换的方法，给出并讨论了广义分数阶单元网络Zener和Poynting-Thomson模型的蠕变柔量。

This study was carried out in collective-owned summer grassland in Ganchaitan, which is located at the south foot of eastern Lenglongling Mountain (a branch of north Qilian Mountain), with yak and Tibetan sheep miscellaneously grazed on it. The grassland type could be classified as alpine meadow, dominated by Potentilla froticosa shrub. This study, under grads grazing stress, focused on the community structure, composition, species diversity, above-ground biomass of PFS, by using pane net sampling based on spatial distribution in stead of temporal succession. Results showed that: Grazing stress negatively related to the distance between grazing area and resident area.

以祁连山北支冷龙岭东段南麓的甘柴滩夏季牧场集体长期混合放牧的高寒金露梅Potentilla froticosa灌丛草场为对象，利用空间分布代替时间演替的方法，采用方格网法取样分析调查，对不同放牧压力梯度下金露梅灌丛群落的结构、组成、物种多样性、地上生物量进行研究，结果表明：①放牧居住点由远到近，放牧压力梯度不断增加，金露梅株高、密度、覆盖度、地上生物量和丛间草地的地上生物量均有不同程度的降低，地上的总生物量降低幅度达84.77%。

Firstly, based on the basic theory of GRIN optics the optical effects of the spherical symmetry GRIN micro-sphere lens were analyzed systematically. Firstly, based on the basic theory of GRIN optics the optical effects of the spherical symmetry GRIN micro-sphere lens were analyzed systematically.

本工作从梯度折射率介质光学的基本理论出发，对球对称GRIN微球透镜的光学性能进行了系统的分析；研究了用球对称GRIN微球制作回归反射材料的可能；进而选择两种聚合物单体，采用悬浮扩散共聚法，研究制备了较大粒径的聚合物梯度折射率微球透镜。

It has great potentialities in such fields as micro-optics, integrated optics and optics communication.Firstly, based on the basic theory of GRIN optics the optical effects of the spherical symmetry GRIN micro-sphere lens were analyzed systematically.

本工作从梯度折射率介质光学的基本理论出发对球对称GRIN微球透镜的光学性能进行了系统分析；选择两种适当单体，采用悬浮扩散共聚法制备出聚合物梯度折射率微球透镜；测量所得透镜的折射率分布曲线和其他光学参数。

Firstly, an Iterative Closest Point algorithm is applied for coarse registration. Secondly, gradient feature is extracted from image. Based on the principle of projective transformation, the fine registration is performed by finding the maximum CT gradient projections.

首先基于一种最近点迭代法进行快速粗配准；然后提取图像的梯度特征，根据投影变换原理，采用寻找具有CT最大梯度投影位置的方法进行精配准。

So it is difficult to control the temperature gradient and the cooling parameters in forging process.

但在具体的工艺实施过程中，对大锻件在JTS法锻造中的温度梯度控制，钢锭外表面的冷却控制，以及温度梯度对内部的应力应变及组织的影响缺乏足够的认识，所以很难掌握其规律。

ZHOU Zhangjian（Laboratory of Special Ceramics and Powder Metallurgy, USTBeijing, Beijing, 100083, China）Abstract:On the basis of analysisof developing background and theory of thermoelectric graded materials, p-type (Bi1-0.85Sb0.85)2Te3and PbTe two segments thermoelectrical graded materials with different barriers werefabricated by conventional hot-pressing process.

具有不同扩散势垒的p型(Bi1-0.85Sb0.85)2Te3和PbTe二元梯度热电材料的研制徐桂英葛昌纯高艳平周张健摘要：在分析了热电材料的发展背景和研究理论的基础上，采用热压法制备出单体和双层具有不同扩散势垒的(Bi1-0.85Sb0.85)2Te3与PbTe体系二元梯度热电材料。

In this work, the homogenous Ba0.90Sr0.10ZrxTi1-xO3(x=0~0.40) and compositionally graded BSZT thin films was prepared by sol gel processing.

采用溶胶-凝胶法在Pt(111)/Ti/SiO2/Si衬底上制备了Ba0.90Sr0.10ZrxTi1-xO3(x=0~0.40)组分及其成分梯度薄膜，研究了各组分及梯度薄膜的相结构，显微结构以及在外加电场作用下的介电特性。

He correspondence between two point set surfaces was established based on the deformation gradient and the moving least square method. The deformation gradient was decomposed into a rotation and a stretching component with the matrix polar factorization. Then each component was interpolated in dividually over the time. Shape interpolation was implemented through a global quadric energy optimization.

基于该变形梯度以及移动最小二乘方法建立了源点云与目标点云之间的对应关系；将变形梯度进行矩阵极分解，对分解后的各分量分别进行插值，再通过一个全局的二次能量优化实现点云曲面的形状插值。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。