四面体的

And then adjust the position of apex adjacent to boundary point so as to satisfy the requirement of boundary normal.

DNA序列与正四面体中的映象点具有对应关系。

The coordinate transformation and numerical integration was executed on the discretized tetrahedral elements based on which the 3-D MT vector-finite element method was implemented. A whole computation framework for 3-D vector-finite element method with unstructured mesh was given. Based on this some typical models were tested which has demonstrated that our algorithm could distinctively avoid problems caused by the fake solution and both the accuracy and efficiency were enhanced which made our algorithm has a bright future for further application.3. According to theory of Sobolev vector space and the discretization of Helmholtz space, the error estimate which was suitable for 3-D MT vector-finite element modeling was deduced by which the procedure of adaptive technique was guaranteed.4. Based on the fully unstructured tetrahedralization and optical strategy, the 3-D magnetotelluric h-adaptive vector-finite element method was presented through combining the error estimate. With this work, the accuracy and creditableness for 3-D MT complicatedly modeling was guaranteed.5. The 3-D magnetotelluric h-adaptive vector-finite element algorithm with unstructured mesh was implemented.

针对非结构化的四面体单元，采用坐标变换和数值积分方法，实现了MT三维矢量有限单元分析，建立起基于非结构化网格的三维MT矢量有限元计算流程，并对典型模型和国际标准电磁模型进行了数值模拟，结果对比和分析表明，基于非结构化网格的三维MT矢量有限元不仅消除了节点型有限元的伪解，而且具有很高的计算精度和速度，有广阔的应用前景。3、根据Sobolev函数的向量空间和Hemlholtz空间的分解，推导出基于残差的三维大地电磁矢量有限元后验误差估计公式，为三维大地电磁自适应矢量有限元数值模拟的实现奠定了基础。4、在完全非结构化四面体单元剖分及优化基础上，结合三维大地电磁矢量有限元后验误差估计公式，提出了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算策略，保证了对复杂大地电磁模型数值计算的精度和可靠性。5、实现了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算流程，对典型模型和国际标准电磁模型进行了数值模拟。

A hybrid hexahedral/tetrahedral mesh of nearly 900,000 elements was used for the rotor and stators in three adjacent fluid zones.

混合六面体/四面体网格近900000要素被用于转子和定子在三个邻近的流体区。

All faces are mappable or submappable, but the vertex types are specified such that the volume cannot be divided into mappable subvolumes

TGrid/主要采用四面体单元，但是在恰当的地方也用六面体或者，锥体，楔体等单元

Calculated results show that the position of ions in the interlayers of montmorillonite was related with tetrahedral and octahedral charge sites and ion size.

计算结果表明蒙脱石层间阳离子位置与四面体和八面体电荷位置及离子的大小有关。

Basing on the concepts and algorithms, some traditional algorithms, e.g. Delaunay triangulation for planar polygonal domain, constrained Delaunay triangulation for planar points and Delaunay tetrahedralization for spatial points, are improved.

通过上述概念和算法，改进了多边形Delaunay三角剖分、平面散乱点集约束Delaunay三角剖分和空间散乱点集Delaunay四面体剖分等基于生长算法的传统数据生成方法。

This can greatly decrease intersecting judge amount of ray and cells. This method can be generalized in polyhedron volume data.

此方法并不局限于四面体元数据的体绘制，还可以被广泛地应用在一般多面体元上。

The research results are as follows:1. EpNPV is a kind of nuclear polyhedrosis virus.

结果表明： 1.EpNPV为核型多角体病毒，多角体为不规则的三角四面体，大小为0.95～2.69μm，平均1.72±0.07μm。

Additionally,the method to determine position coordinate and trajectory vector of the shooting point with detection array is also studied in this paper.

另外还研究了利用正四面体探测基阵确定射击点空间位置坐标和弹道矢量的计算方法。

For comp ound 7, the cage is consisted by six MoO〓 and four PO〓. The six MoO〓 octahedrons have consisted to the loop structure, the there PO〓 tetra hedron become triangle and the other one lies the centre. The one oxygen of two MoO〓 octahedron is coordinated to Mn atom which linked the other cage like this cag e and this Mn have six ligands.

在化合物7中，每一个笼由6个MoO〓八面体和4个PO〓四面体构成，6个MoO〓八面体构成环，四个PO〓四面体形成一个三角形在其上面，4个P和6个Mo具有C〓的对称性，每二个MoO〓八面体提供一个O原子与Mn原子配位，这个Mn原子再与相同的这样的笼相连，形成一个中间细两端粗的形状，这个Mn原子是6配位的，每一个这样的笼再通过一个Mn原子连接起来，形成二维的网状结构，而这个Mn原子是五配位的。

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