几何边界条件

The models based on geometrical cell and boundary constraints are introduced to describe free-form surfaces.

建立了以几何元胞和边界条件为特征的自由曲线曲面几何形状描述方法。

Secondly,"the Nodal Green's Function Method For Cylindrical Geometry on Neumann Boundary Condition Based on Green's Functions on slab geometry"is well improved.

论文对"基于平板几何格林函数的第二类边界条件圆柱几何格林函数节块法"做了重要改进。

The research on the improvement for the convergent quality of"the Nodal Green's Function Method For Cylindrical Geometry on Neumann Boundary Condition Based on Green's Functions on slab geometry"is an original work.

在本论文中，"基于贝塞尔函数的第二类边界条件圆柱几何格林函数节块法"在中子扩散方程求解方法研究领域中是首创的，属创新成果；关于改善"基于平板几何格林函数的第二类边界条件圆柱几何格林函数节块法"的收敛性能的研究也属创新成果。

The dynamic contact of the drop hammer with the laminate was simulated by geometric contact model provided by ABAQUS/Explicit code.

在冲击动态接触过程的处理上，则采用了ABAQUS中主从面几何接触模型，直接利用冲击物的初始速度条件和几何边界条件，将落锤冲击与复合板的变形和破坏进行联立求解。

The quasi-analytical expressions of the relative concentrations at the mobile region and the immobile region are deduced respectively by using hypergeometric equation, hypergeometric function and the method of Laplace transform under the initial concentration zero and the first or second boundary condition of a semi-infinite one-dimensional space.

并分别在初始浓度为零，半无限一维空间内第一类边界条件和第二类边界条件下，利用超几何方程、超几何函数和Laplace变换法推导出了可动区和不动区溶质相对浓度的准解析表达式。

Based on analysis of the factors affecting subgrade local scour along the river such as condition of stream,condition of bed form,geometric boundary condition of river,water depth and speed of every section,scour depth of parapet,the progress of scour and the form of stream near parapet were observed through the way of field model experiment.

在对沿河路基局部冲刷影响因素如水流条件、河床沙条件和河流几何边界条件等进行分析的基础上，通过野外模型试验，观测了河流各断面的水深、流速、护墙的冲刷深度和冲刷的发展过程及护墙附近的水流形态。

Secondly, the construction simulation were performed by the model in ANSYS. The effect were emphasized in the construction process, which induced by temperature, geometric nonlinearity, and boundary condition. The conclusions were given that the stress decreased thirty percent for temperature change 10℃, and decreased fifteen percent for considering the elasticity support.

基于单元生死法施工模拟原理，运用ANSYS有限元软件建立了体育馆屋盖模型，进行了施工过程数值模拟，重点探讨了温度效应、几何非线性及支承条件对结构受力性能的影响规律，同时指出支承柱临界截面的存在，温度效应和边界条件变化对网壳结构边桁架杆件受力影响最为显著，温度变化10℃影响达30%，考虑支承弹性的影响在15%以上。

The interpolate algorithms of three-order NURBS curve and double three-orders NURBS surface are presented. The expressions of partial derivative and normal curvature of NURBS surface are derived by the theory of differential geometry. The geometric characteristics of different curvature area of the free-form surfaces are analyzed in detail. All these work lays a theoretical foundation for constructing the cutter location calculating model of free-form surfaces NC machining. 2 On the basis of analyzing the methods of cutter path generation, the standard of evaluating the various methods of cutter path generation is presented. The method of generating cutter path with constant scallop height is presented for the first time.

本文以提高复杂曲面多坐标数控加工精度和加工效率为目的，在对国内外研究现状进行深入分析的基础上，对数控编程中各环节的关键技术问题进行了深入研究，主要内容包括以下几方面： 1 分析了复杂曲面各种造型方法的优缺点，给出了根据各种边界条件所确定自由曲面的NURBS表示方法以及三次NURBS曲线曲面反算算法；用微分几何理论推导了NURBS曲面的偏导矢及法曲率计算表达式；对曲面不同曲率特性区域的几何特征进行了深入分析，为建立复杂曲面的数控加工刀位计算模型奠定了理论基础。

In order to improve the efficiency of grid generation, a two-boundary algebraic method based on transfinite interpolation was developed to generate two-dimensional grid system within geometrically complex two-dimensional plane domain rapidly.

为提高网格生成效率，提出了一种基于超限插值的双边界代数网格生成方法，可快速生成边界正交的贴体网格，引入几何一致性条件保证物理区域不变形，同时发展一系列拉伸方程控制网格分布。

The gap element method is proposed in the paper for two kinds of problems, which include contact problem and gap joint problem. Elasticity contact problem falls into the category of unknown boundary value problems. It follows that the contact area and contact conditions or states can never be determined without special mathematical analysis, which is a very difficult work. The boundary conditions of the contact surfaces are deduced.

文中给出了间隙元法在空间可动部件接触问题中的应用，推导了其几何边界条件和力学边界条件，利用虚功原理推导了含间隙元弹性接触问题的有限元方程式，给出了其数值解法的迭代步骤，并指出了利用间隙单元进行分析的特点。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。