查询词典 phase boundary

Part II, the artificial boundary condition and its numerical methods based on natural boundary reduction for a hyperbolic initial boundary value problem in an infinite domain with a concave angle is investigated.

第二部分，研究一类具有凹角的无界外区域的双曲型初边值问题基于自然边界归化的人工边界条件及其数值方法。

Based on the correlation of the Guadalupian and Lopingian conodont zones of the Salt Range, Pakistan with those of South China, the Amb Formation and the lower part of the Wargal Formation in the Salt Range, Pakistan are Late Guadalupian in age. The Guadalupian/Lopingian boundary is in the lower part of the Wargal Formation, and the Wuchi-apingian/Changhsingian boundary is in the lower part of the Chhidru Formation. The Permian/Triassic boundary is in the Kathwai Member of the Mianwali Formation.

根据华南与盐岭地区瓜达鲁普统和乐平统的牙形类化石带对比，可以确定Amb组和Wargal组底部的时代为瓜达鲁普世晚期，瓜达鲁普统与乐平统的界线位于Wargal组下部，吴家坪阶与长兴阶的界线位于Chhidru组的下部，而二叠与三叠系的界线位于Mianwali组下部的Kathwai段之内。

Take the method of "subarea" and "conjunction" to segment the whole request model to three parts. Making use of boundary continuousness between medium and lining structure at stress and displacement, construct a wave function that can satisfy the stress boundary condition at horizontal surface by the scattering of SH-waves in circular part. And then, availing of the wave function, conjoin the circular part into the semi-circular hollow space at common boundary. The problem can be reduced to solve the question that can only meet the condition of "conjunction". Finally, the solution of the problem can be summarized to a series of algebraic equations and solved numerically by truncating the finite terms of the infinite algebraic equations.

采用"分区"与"契合"的方法，将整个求解区域分割成三部分，利用介质与衬砌结构在边界上的应力、位移的连续性，构造一个可以自动满足水平界面上应力边界条件的圆域对SH波散射的波函数；再利用这一波函数将圆域与半圆形凹陷半空间的"公共边界"进行"契合"，将问题简化成对一个只需满足'契合'边界条件的散射问题的求解；最终归结为对一组无穷代数方程组的求解问题，利用截断有限项的方法对其进行计算。

In this thesis, we apply Coulomb's law and propose an external force to overcome the problem of traditional ACM that can not capture the cavities of an object. Assume that each node of a snake has its own electric charge, and the object boundary has opposite electric charge. Then object boundary will attract the nodes of the snake. This helps the contour easily to move to the object boundary.

本论文中，我们运用库仑定律的观念，提出了一个运用局部引力作为外力的方法，用以克服传统主动性轮廓模型在凹面处收敛不佳的缺点；假设物件边界带电，而主动性轮廓模型的结点带与物件边界相异之电荷，则物件边界会吸引著主动性轮廓模型各结点，使得模型曲线更容易靠近物件边界。

Compared with the known results,the nonlinearity is allowed to change sign and is involved with the first-order derivative explicitly.In particular,the boundary condition includes the Dirichlet boundary condition and Robin boundary condition.

与现有工作相比，我们所考虑的动力方程不但非线性项可变号，而且包含一阶导数项，所考虑的边值条件更具一般性，比如可以包含Dirichlet及Robin边值条件等。

In order to bypass the difficulty of discretizing the boundary r or the Lebesgue discontinuous set Su in the Mumford-Shah model, we use an edge-detector function and a threshold value to induce a thin-belt where the image boundary lie in and displace the length of the boundary by the area of the thin-belt approximatively.

为避免在离散化Mumford-Shah模型中的边界Γ或Lebesgue不连续集S_u的困难，我们借助边界检测算子和门限值，确定图像边界所在的窄带区域，用窄带区域面积近似边界的长度。

Initial boundary value problem of two dimensional unsteady diffusion equations is solved in this paper. By using time-dependent fundamental solution of two dimensional diffusion equations and the extension of double layer potential, we establish virtual boundary integral expression of diffusion equations. Then virtual boundary element method is used to implement the numerical computation.

本文在求解二维非定常扩散方程的初边值问题时，利用二维扩散方程与时间有关的基本解，基于双层位势的延拓，建立二维扩散方程的虚边界积分表达式，然后利用虚边界元法进行数值计算。

This is a kind of evolutionary elliptic free boundary problems, in which the free boundary changes with time and at each fixed time the unknown function satisfies a boundary value problem for an equation of elliptic type.

详细本文分两部分。第一部分讨论拟定常电加工问题。这是一类发展型的椭圆自由边界问题，其自由边界依赖于时间的变化而不断演化，在每一固定时间，未知函数满足椭圆型方程的边值问题。

Using the method of blow up lower and upper solutions, the existence and boundary behavior of positive boundary blow up solutions for some elliptic systems of competitive type with singular weight functions are obtained, here the singular weight functions are permitted to be bounded in some parts of the boundary, and to go to infinity or even oscillate in other parts.

利用爆破上、下解方法，本文建立了带奇异权函数的竞争型椭圆方程组正的边界爆破解的存在性和边界行为，这里奇异权函数可以在边界的某一部分有界，而在其他的部分趋于无穷或者震荡。

The modal tests of PCB and PCB assembly (free boundary condition and fixed boundary condition) were carried out. The equivalent elastic modulus and damping parameters of PCB can be gained, and the fixed boundary condition of finite element model was also determined. These will help to the following work.Second, drop impact tests of three different heights were carried out. Strains and acceleration responses of PCB were measured. Failed BGA packages of different test conditions were dyeing, and cross section analysis of failed solder joints was conducted.

针对JEDEC标准试件的局限性，提出了设计便于统计学研究焊点可靠性的试验试件的构想，利用有限元模态分析方法确定并验证了用圆形PCB组件替代JEDEC标准试件的可行性；通过一系列模态试验和有限元模态分析，确定了圆形PCB组件的相关试验参数，这不仅为跌落碰撞下PCB组件有限元模拟确定了较为合理准确的有限元模型，而且为正确地评价跌落碰撞下PCB组件的可靠性问题奠定了基础。2。

Diabetes is a social disease that affects several million people worldwide.

糖尿病是一个社会性疾病，全世界有数百万人罹患此病。

I'll call you on Friday to see if we can reschedule our luncheon meeting at your convenience.

我星期五会给您打电话在您方便的时候我们重新安排我们的午餐约会。