查询词典 descent method

This project studies the scale-dependent deformation behavior of the metal matrix composite, the void nucleation and void growth mechanisms at the micron/submicron scale. The main results are:(1) In prophase, growth and coalescence of the void embedded in the graded matrix are analyzed in detailed;(2) Based on the infinite solid model containing a micro-void, coupling effects of the void shape and the void size on the void growth are studied carefully, the results show that it seems to exist a critical equivalent void radius, which is associated with the material length. When radius of a microvoid is close to or smaller than the critical void radius, the micro-void growth rate is essentially eliminated;(3) The coupling effects of the particle shape and size on the mesoscopic stress fields within the particle and matrix are also investigated by introducing the conception of inclusion/matrix interfacial energy. The results show that the stress concentration factors within the particle and on the matrix/particle interface are also strongly size-dependent,so the void nucleation mechanism is size-dependent.(4) By employing a specific orthogonal curve coordinate frame and a 'kernel function' conception, a 'unified method'solving the spheriodal and spherical void problems is suggested; by this unified method, size-dependent plastic potentials of the porous materials containing the spheriodal or spherical voids are obtained, which extend the traditional Gurson model for the spherical void and GLD model for the spheriodal voids to the micron scale.(5) Based on the RVE model containing the spheriodal or spherical particles, the influences of the particle shape and size on the size-dependent mechanical behavior of metal matrix composite are studied.

中文摘要：本项目对金属基复合材料在微细观尺度下的尺度相关变形行为、孔洞形核及长大的机理和模型进行了研究，取得了如下主要结果：1）在前期研究中，探讨了基体的梯度分布对孔洞长大和聚合的影响；2）基于含孔洞的无限大体模型，探讨了孔洞形状和孔洞尺寸对其长大的耦合作用，结果表明：可能存在一个与材料特征长度相关的临界孔洞尺寸，当椭球孔洞的等效半径小于临界孔洞半径时，孔洞的长大受到明显抑制；3）通过引入基体/夹杂界面能的概念，分析了夹杂尺寸、夹杂形状对材料细观应力场的耦合影响，结果表明：颗粒内部和界面上的应力集中因子强烈地依赖于夹杂的尺寸和形状，因此，孔洞的形核机理是尺寸相关的；4）采用一种特殊的正交曲线坐标系和引入"核函数"的概念，"统一"地得到了含椭球和球形孔洞的材料的尺寸相关塑性势，它将传统的Gurson球形孔洞模型和GLD椭球孔洞模型推广到微尺度范围；5）基于含椭球和球形夹杂的体胞模型，初步研究了夹杂形状、夹杂尺寸对金属基复合材料尺寸相关力学行为的影响。

Based on the establishment of an evaluation index system, this paper evaluates the intensive land use of Wuhu City from 1990 to 2005 with method of global principal components analysis, and predicts the level of intensive land use of the city in 2010 using the time series method, revealing in a quantitative manner the potential of intensive land use.

在构建城市土地集约利用评价指标体系的基础上，运用全局主成分法评价了1990-2005年芜湖市土地集约利用水平，同时通过时间序列法预测2010年土地集约利用水平，定量揭示其土地集约利用潜力。

The third part—Chapter 6, in view of economy sustainable development pattern and tactics, this part used the method of Entropy-value, Principal Components Analysis and Hierarchical Clustering Method to analysis economic criterion of 25 energy type cities in our country and concluded five typical types of all of energy type cities and their corresponding developing tactics.

本章运用前文的综合分析方法及结论对平顶山及选择性典型能源城市可持续发展水平进行了深入的比较研究。把平项山市可持续发展状态同集团内部城市、第一集团城市以及全部能源城市的可持续发展状态进行比较，从不同角度来研究了平顶山市可持续发展的水平。

Pattern Recognition of Remote Sensing FTIR Spectrum The method of PCA-LDA (principal components analysis-linear discriminantanalysis) is introduced creatively in the analysis of remote sensing FTIR spectrumin this dissertation and the method of pattern recognition of PLS-LDA andPCA-LDA are built to recognize VOCs in the atmosphere.

遥感FTIR谱图的模式识别本文创造性地将主成分提取与线性判别分析(Linear Discriminant Analysis，LDA)相结合的方法，引入到遥感FTIR光谱的分析中，建立了PLS-LDA、PCA-LDA对VOCs的模式识别方法。

An applied method was put forward to select regularization parameters in the iterative process of gradient regularization method.

并给出了该方法在计算过程中求正则解时一种实用正则参数选取方法。

L-curve method is the inverse problem regularization method of parameter selection in an important way, this procedure is given on how to properly select one of the parameters!

L-曲线法是反问题正则化方法中的参数选取中的重要方法，本程序给出了如何恰当选取其中的参数！

Then by using the method of half-uadratic regularization, a new method combining texture extraction with edge detection is derived based on the new decomposition model.

接着运用半二次规整化方法推广这个分解模型，提出了一种联合纹理特征提取和边缘检测的变分模型。

On the basis of that, the article gives a regularization filter and builds up a quite new method of regularization. It also discusses the calculation of regularization resolutions enor and the choice of regularization parameter, and proves that this method is the best to make the resolution have order optimality.

文中以此为依据给出了一个正则化滤子函数，从而建立一种新的正则化方法，并讨论了正则解的误差估计及正则参数的选取问题，证明了这种方法使正则解的误差具有渐进最优阶。

Simulation results for the images with different structure and contrast show that TTLS method can yield high quality image and its application field is larger than that of Tikhonov regularization method.

对不同结构以及不同对比度图像的数值仿真结果显示，截断完全最小二乘正则化方法，较只考虑数据项存在误差的Tikhonov正则化方法成像质量高，且适用范围广。

At the condition of high spacial frequency, the principle and methods of image blind deconvolution has been studied, and the method of regularization image blind deconvolution based total variation has been used in the restoration problem of the 1-D bar code signals. The problem of blurring and interaction of bar signals under convolution with the SPF was solved with the method.

研究了图像盲目反降晰的基本原理与方法，并将基于总变分的正则化盲目图像反降晰方法应用到我们的一维条码信号的复原问题中，很好地解决了高空间频率条件下因光学系统点扩散函数带来的信号降晰及边缘混叠问题。

However it can often be frust ating for a child when people are unable to pronounce their name.

但它往往可以令人沮丧的一个孩子当人们无法断言他们的名字。

All these compounds were obtained from this genus for the first time. Compound, 4-cumylphenol, was a new nature product.

所有化合物均为首次从本属海藻中分离得到，其中4cumylphenol为新天然产物。