四面体

TPR characterization shows that there are two kinds of Mo coordination species, namely octahedral molybdenumMo(O and tetrahedron molybdenumMo

TPR表征显示，催化剂表面的钼物种有2种结构，即八面体的MoO(下标 h和四面体的MoT

The main structure unit of clay minerals contains silicon-oxygen tetrahedron and aluminium-oxygen octahedron.

其主要结构单元是硅—氧四面体和铝—氧八面体。

Applying the triangular element to the stationary Stokes equation, we obtain error analysis and optimal convergent order of approximation solution.

对于各向异性三角形元和各向异性四面体元，我们分别讨论了它们的各向异性插值，将它们应用于定常Stokes方程，我们研究了有限元空间不满足散度条件的各向异性非协调有限元解法，同样得到了逼近解的误差分析和最优收敛阶。

The calcination of the catalysts at high temperature may easily result in theformation of tetrahedral structure Mo species before sulfidation,and decrease theamount of octahedral coordination Mo species.The sinter and loss of the activecomponents would take place during the calcination at overhigh temperature. Meanwhile,the active component could react with support,thus made the activecomponents entered into support bulk phase.

7催化剂在硫化前进行高温焙烧，容易形成四面体结构的钼物种，而八面体配位钼物种减少，且过高的焙烧温度易使活性组分发生烧结，同时可能发生活性组分的流失或与载体发生反应进入载体体相。

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。

A parallelepiped bounded by six similar faces (either rhombuses or parallelograms).

有六个面的平行四面体（或是棱形的或是平行四边形的）。

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。

As the tetrahedral grids exist in the majority area, the pentahedral prism grids are adopted near the boundary, which meets the SST model's requirement of mesh in the boundary layer. Pressure recovery factors under different number of grids are calculated so as to decrease the error from coarse mesh, then the suitable number of grids is obtained.

流场大部分区域为四面体网格，在边界附近采用加密的五面体棱柱型网格，满足了SST模型对边界层网格的要求；为了减少网格过粗引起的汁算误差，还通过计算不同网格数下尾水管的压力恢复系数来优选出合适的网格数目。

The author presents the auto-generation mesh super-elements models of pentahedron and tetrahedron. The computer program for auto-generation of FEM mesh developed by the author can be used to mesh generation of every kind of block structure.

由于作者提出了五面体和四面体超单元自动生成网格的模式，使得所编制的自动剖分程序适用于各种块体结构的网格离散。

Effects of the number of cells and relative density on the elastic properties of closed-cell foam model are investigated by the finite element method and periodic boundary conditions.

建立十四面体的单胞模型和多胞模型，采用有限元方法和周期性边界条件，研究胞体数目和相对密度对闭孔泡沫模型弹性性能的影响。

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