查询词典 boundary condition

The technique of boundary-fitted coordinate system is used to overcome the difficulties resulting from the complicated shapes of natural river boundaries;the method of alternating direction implicit finite difference scheme is used to solve the partial differential equations in the transformed plane;and the technique of moving boundary is used to deal with the river bed exposed to water surface.

用适体坐标技术克服天然河道复杂的几何边界给有限差分法所带来的困难；用交替方向隐式有限差分格式求解变换平面上的偏微分方程；用动边界技术处理河床的淹露。

An adaptive grid scheme controlling cell area is used to generated grids in the divergent section of symmetric annular nozzle, and the generated grids are used in the flowfield calculation through the uncoupled way. The elliptic equations are used to generate grids in three dimensional regions of FDN divergent section, the source terms used in the equations employ a mathematical form which is independent of the boundary shape and of the boundary grid point distribution, the free parameters contained in the source terms are determined by the two restraint conditions, the intersection angle of transverse grid lines with boundaries and the local curvature of the transverse grid lines at the boundaries, and the interior grid distribution controlled directly by the grid point distribution assigned on the boundaries is realized, it makes the grid more clustering near the nozzle wall. For the generated grids in the whole computational regions have a good smoothness and orthogonality, the accuracy of calculation in the flowfield is ensured.

对轴对称的环形喷管采用控制网格面积的自适应网格方法对扩散段部分进行了网格生成，并通过非耦合方式应用于喷管的流场计算中；对强制偏流喷管扩散段内的三维区域采用椭圆型方程进行网格生成，方程中的源项采用了与边界形状和边界网格点分布无关的数学形式，源项内的自由参数由横向网格线与边界的交角及横向网格线在边界处的局部曲率两个约束条件来确定，实现了由边界上的网格分布直接控制内部的网格点，使壁面附近具有较密集的网格，并且在整个计算区域内的网格都具有良好的光滑性和正交性，从而保证了流场计算的准确性。

In region of columnar grain, preferred orientation growth is obvious. Obviously preferred orientation on 〈001〉 was confirmed by the antipole figure. Besides, the CSL grain boundary such as ∑3,∑5 and so on are observed. Among these kinds of boundaries, the ∑3 boundary has the highest frequency.

测试结果表明：CVDW生长组织具有三个生长区，分别是等轴晶区、混合生长晶区和柱状晶区；柱状晶区的晶粒具有显著的〈001〉择优生长；低∑CSL晶界占据较大比例，其中以∑3、∑5为主要结构，∑3的出现频率最大。

The basic idea is to set a continuous solution of the region with a finite number of discrete points instead of a grid consisting of, these discrete points called grid nodes the solution of a continuous area on a given function of continuous variables used in the definition of discrete grid variable function approximation the original equation and boundary conditions in the micro-business operators to approximate differential, integral with the points and to approximate, so the original differential equations and boundary conditions are replaced by algebraic equations near Side, that is, finite difference equations , solve this equation group can get the original problem in discrete points on the approximate solution.

基本思想是把连续的定解区域用有限个离散点构成的网格来代替，这些离散点称作网格的节点；把连续定解区域上的连续变量的函数用在网格上定义的离散变量函数来近似；把原方程和定解条件中的微商用差商来近似，积分用积分和来近似，于是原微分方程和定解条件就近似地代之以代数方程组，即有限差分方程组，解此方程组就可以得到原问题在离散点上的近似解。

The concentration of D-phenylalanine in the external phase and the separation factorαcan be expressed as: The diffusion of boundary layer in outer aqueous phase is the controlled process while the concentration of D-phenylalanine in the external phase far less than the concentration of chiral carrier in the emulsion liquid membrane phase, then the diffusion coefficient k_e of boundary layer in outer aqueous phase can be achieved by data fitting.

外水相苯丙氨酸对映体的浓度以及分离因子α表示为：当外相对映体浓度远小于液膜相手性载体浓度时，该手性传质过程中外相边界层的扩散为控制步骤，利用数据拟合得到了外水相与液膜相界面边界层扩散的传质系数k_e。

By the historical and methodological pondering over the development process of modern physics,based on the research work done by Arndt,Zurek,Brune,Myatt and so on,the problem of the wave-particle duality,the boundary between classic physicsand quantum physicsand the quantum decoherence of object particles is extended to the boundary of electromagnetic fields between classic and quantum in this paper.

本文通过对现代物理学发展过程的历史学与方法论反思，在阿恩特、哲瑞克、布鲁尼、莫雅特等人工作的基础上把实物粒子的波粒二象性、经典物理与量子物理的界限以及量子退相干问题推进到了电磁场的经典与量子界面上，并就反康普顿散射的经典理论与量子理论进行了比较研究，发现了洛仑兹-康普顿佯谬并设计了一个敏感而可行的双胜判决性实验。

In this paper the defect of the traditionary boundary layer methods (including the method of matched asymptotic expansions and the method of Visik-Lyusternik) is noted, from those methods we cannot construct the asymptotic expansion of boundary layer term really.

本文指出传统的边界层方法包括匹配法和Vi(？ik—Lyusternik方法的不足：不能作出边界层项的渐近展开式。提出多重尺度构造边界层项的方法，得到符合实情的结果。

In this paper,the author discusses the multi-layer solution with two special limits in boundary layer of the singularly perturly boundary value problem and obtains uniformly valid zero order asymptotic expansion by using the matching asymptotic expanding method.

利用匹配渐近展开法，讨论了奇摄动边值问题中边界层内存在有两个特异极限的多层解，得出了奇摄动边值问题的一致有效的零次渐近展开

In Chapter 1, two solutions to the elliptical boundary value problem have been constructed through a monotone iterative process, and they might be identical. In Chapter 2, the author expresses the local solution to the parabolic initial boundary value problem taking advantage of Green function. In Chapter 3, the asymptotic solution to the initial value problem of Duffing equation is obtained and the method for finding the approximate solution to the inverse problem is put forward.This paper is planned with a view to the author's research means.

从研究结果看：第一章通过单调迭代过程构造出椭圆型方程的边值问题的两个解，并且指出二者可能是同一个解；第二章利用格林函数给出了抛物型方程的初边值问题的局部解的解析表达式；第三章中，先对Duffing方程的初值问题写出解的渐近展开式，再对其反问题提出一种求近似解的方法。

In this thesis, we provide a simpler form of the axisymmetric boundary integral equation, and modify some aspects of the direct boundary integral method.

本论文给出了轴对称情形下边界积分方程的一个更简单的形式，并在若干方面改进了直接的边界积分算法。

Objective To investigate the relationship between ovum fertilization rate and sperm morphology, acrosome reaction in IVF and to explore the influence of parameters of sperm on fertilization rate.

目的 研究体外受精(in vitro fertilization，IVF)中精子形态、顶体反应与卵子受精率之间的关系，分析精子各参数在IVF受精率方面的参考意义。

A: I hear Mr. White wants to run for the Presidency!

我听说怀特先生要参加总统竞选！