四面体的

Introduced the makeup and analysis procedure of ANSYS software, and the calculating precision difference between tetrahedron element and hexahedron element are discussed, and thorough research are made to the hexahedron mesh method.

介绍了ANSYS程序结构及其分析的基本过程，重点讨论了ANSYS的模型建立和网格划分，初步分析了四面体和六面体单元对计算精度的影响，并对六面体网格划分方法进行了深入的研究。

This is a special state of condensed matter with long-range order that is neither three-dimensionally periodic nor quasicrystalline, but nevertheless possessing a higher degree of organization and higher symmetry than the individual crystals constituting the MTPs.

SEM-EDS分析得到所观察到的二十面体构形的颗粒的成分比B/O是6.4；另外一种四面体结构则有B/O为2，其相应的化学式是B〓O。

In this paper, the L(d,1)-labeling is studied and the upper bounds of λd of plane triangulation graph, solid tetrahedron subdivision graph, plane near quadrangle subdivision graph are derived, and as corollaries, the conjecture is proved to be true for the above several classes of graphs.

此文研究了作为L(2，1)-标号问题的推广的L(d，1)-标号问题，并得出了平面三角剖分图、立体四面体剖分图、平面近四边形剖分图的L(d，1)-标号的上界，作为推论证明了对上述几类图该猜想成立。

Our results show that the duality of self-dual tetrahedral link is "trivial", and the duality of hexahedral and octahedral link as well as dodecahedral and icosahedral link are "nontrivial".

从构型角度考虑，四面体链环的自对偶是"平凡"的，六面体链环和八面体链环，十二面体和二十面体链环的对偶是"非平凡"的。

The main contributions of the dissertation are as follow:(1) The possibility of generation hexahedron mesh through tetrahedron conversion method was studied,and a set of feasible method to deal with the boundary condition of constraint and loads has been brought forward.

本文的主要工作包括如下几个方面：(1)研究了在紫瑞CAE基础上采用四面体转换法进行六面体网格全自动剖分的可行性并对约束和载荷的处理提出了一套可行的方案。

Firstly, the three-dimension boundary question and its corresponding variation question concerning the point-source electrical field on a 3-D structure are presented. Secondly, the finite element method is used to solve the variational equation. The study area is divided into many tetrahedral elements. Then, we interpolate with a tri-linear function in each element. So, the variational equation is converted into a linear equation system. Finally, taking into account saving of time, we make use of symmetric successive overrelaxation preconditioned conjugate gradient algorithm to solve large linear system, and obtain the potential value of each node, resulting in the calculation of the apparent resistivity values on the ground surface.

首先给出了三维构造中点源电场的边值问题以及相应的变分问题；然后利用有限单元法求解变分问题，采用四面体单元对研究区域进行剖分，在单元中进行三线性函数插值，将变分方程化为线性代数方程组；最后，考虑到节约计算时间，利用对称超松弛预条件共轭梯度迭代算法求解大型线性方程组，得到了各节点的电位值，进而计算出地表的视电阻率。

By means of estimates for three-dimensional discrete derivative Green's function , the theory of the interpolation operator of projection type and the technique of cancellation of elements, for several usual elements in the three-dimensional setting, including rectangular parallelepiped elements, tetrahedr.

借助三维离散导数Green函数的估计，投影型插值算子理论和单元合并技术，本文详细讨论了几种常用三维单元(包括长方体元，四面体元和三棱柱元)的有限元解梯度的最大模超逼近，均获得了高精度的超逼近结果。

On the basis of investigating the sound field of a plane piston transducer and the relations between sound field and radiation force, by settling four plane piston transducers driven at the same frequency at each corner of a regular triangular pyramid with their sound-beam axes crossing at the center of the pyramid, this technique uses ultrasonic wave synthetic theory to acquire a three-dimensional ultrasonic standing wave field. The micro-component can be captured, transported, released in the range of space by adjusting the phase of the transducers.

在研究单个圆形平面活塞换能器声场分布以及声场和辐射力关系的基础上，将以相同频率驱动的4个平面活塞换能器呈正四面体放置，利用声波合成原理获得三维超声驻波场，通过调整各个换能器发射信号相位之间的关系实现对微构件在空间范围内的俘获、移动、释放等操纵。

The result of numeric computation demonstrates that the approximate directional algorithm is robust, the result of Monte Carlo simulation shows that the performance of the optimum four-element array structure is better than the common one or the regular tetrahedron one.

数值计算结果表明，提出的近似定向算法是可靠的；计算机蒙特卡罗仿真结果表明，导出的最佳四元阵列性能优于普通的四元阵和正四面体阵。

It is interesting that one month before I went to Sedona - I bought a smoky quartz Herkimer diamond - in the shape of a star tetrahedron.

在我去Sedona一个月之前，有趣的是-我买了一个烟状的石英 Herkimer 钻石--具有星星状的四面体形状。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了