四面体的

The results of the dissertation were concluded as follows:(1) It is essential to deposit a basic additive on the Mo-based catalysts for the synthesis of CH_3SH. The potassium-doped Mo-based catalysts exhibit the highest activity than that of the catalysts doped with the otherⅠA andⅡA group basic promoters. H_2-TPR and LRS characterizations suggest that the addition of a base leads to the transformation of octahedrally coordinated Mo to tetrahedrally coordinated Mo, thus leads to the split of low temperature reduction peaks. The interaction between the basic components and Mo lead to the formation of B-Mo interface phase, which are closely correlated with the formation of CH_3SH.(2) It has been found that Fe, Co, Ni and Te have evident promoting effects for the K-Mo/SiO_2 catalysts.

主要结果归纳如下：(1)在Mo基催化剂中，必须添加碱才具有可观的合成甲硫醇活性，在IA和IIA族元素中，K是最佳的碱促进剂，当K/Mo摩尔比为2，前驱体为K_2CO_3，采用共浸法制备的K-Mo催化剂活性最高。H_2-TPR和LRS表征显示，碱的加入导致表面八面体钼氧物种向四面体转化，催化剂的低温还原峰发生分裂，碱助剂与钼之间存在强相互作用形成了B-Mo"界面相"，该物种与合成甲硫醇密切相关。

It is a common knowledge in shape optimization that second order solid tetrahedron elements give good stress results but are not so good for shape optimization.

这是一个常识的形状优化的二阶坚实的四面体分子提供良好的压力的结果，但没有那么好了形状优化。

Nearly-degenerate A1 and B1(C2y) electronic states are found with distorted trigonal bipyramid and edge-capped tetrahedral geometries together with a E'(D3h) state for Ga3P2.while a distorted structure with 2B1 symmetry and a 2a2 undistorted D3h structure are found to be nearly-degenerate for Ga2P3 .we employ the complete active space multi-configuration self-consistent field followed by multi-reference singles + doubles configuration interaction computations that included up to 2.5 million configurations.

近退化A1和B1 (C2y)电子状态找到与被变形的三角bipyramid，并且边缘加盖的四面体geometries与一个E' (D3h)状态一起为Ga3P2.while一个被变形的结构与2B1对称和2a 2未变形的D3h结构被发现近退化的为Ga2P3 。we使用自洽场被多参考跟随选拔+双配置互作用的完全活跃空间多配置计算包括2.5百万种配置。

Methods A wet hip joint's sample from corpse was scaned by CT and all images of every cross-section hip joint's layer was obtained, and an hip joint's model was contructed with Unigraphics NX 2.0 and Solid Works 2006 SP 0.0 software. The models were assembled when simulated total hip arthroplasty after total hip joint prosthetic and ischiofemoral ligament model had been constructured. Analysis was done on von Mises stress distribution and amount of total hip component when simulated seated leg-crossing manuver. The bone and metal components were meshed as rigid bodies, composed of three-dimensional, all-quadrilateral rigid body elements, and hip joint capsule ligament was fully three-dimensional, hexahedral continuum elements representations. Results The current form of this ischiofemoral ligament's reconstruction finite element model provided for multi-body contact, large displacement interfacial sliding, large deformation capsule ligament representation, and clearly reflected the real ischiofemoral ligansent's anatomy and biomechanical behavior. The maximum on Mises stresses at the joint interface was more than that fur an otherwise identical hardware-only construct.

选择成人尸体髋关节行CT成像得到髋关节每层横截面图像，提取边界坐标，利用有限元分析软件Unigraphics NX 2.0和Solid-Works 2006 SP0.0构建出髋关节三维有限元模型及人工髋关节假体，并模拟全髋置换术进行装配，将坐股韧带按其术中重建位置进行构建骨骼与金属模型采用三维十节点四面体实体单元进行网格划分，关节囊六面体连接单元划分，模拟坐位腿交叉动作载荷获取假体撞击过程的角活动度和相应的von Mises应力分布情况结果所构建的多体连接、大界面划移、大变形的坐股韧带重建有限元模型，客观反映坐股韧带真实解剖形态及生物力学行为，增加坐股韧带重建的模型其关节面的最大主应力值大于仅有金属的模型。

ABSTRACT: Silicoaluminophosphate molecular sieves are microporous crystals with the structure of SiO2、AlO2－、PO2+ tetrahedral units.The physical—chemical properties of SAPO are not only similar to silicoalumino zeolites but also similar to some aluminophosphate zeolites.SAPO is a novel class of catalytic materials which exhibit excellent shape—selectivity、thermal and hydrothermal stability.

摘 要：磷酸硅铝分子筛是由SiO2、AlO2－、PO2＋三种四面体单元构成的微孔型晶体，它的物化性质不仅类似于硅铝沸石，同时具有某些铝磷酸盐分子筛的特性，是一种具有优异的择形选择性以及热稳定性和湿热稳定性的新催化材料。

The cellular structure of porous metal-bonded diamond wheel can be modeled by tetrakaidecahedron and their elastic modulus can be calculated by the finite element method. Furthermore, diamond is acted as reinforced particle.

利用十四面体模型描述开孔金属结合剂金刚石砂轮胎体的胞体结构，并用有限元方法确定材料的弹性模量，进而将金刚石以增强颗粒的形式加入胎体材料中，形成开孔结构的金属结合剂金刚石砂轮节块的有限元模型。

In this paper, material properties of the segment of the porous metal-bonded diamond grinding wheel were researched by finite element simulation. Segments were manufactured according to the design result and their elastic modulus was measured. The key points are as follows: The influence of the porosity on the elastic modulus was analyzed through a finite element method. In the FEM model, the design variable only includes the porosity, and the tetrakaidecahedron model is applied as the microstructure model of porous metal matrix. The corresponding porosity was decided in order to meet the requirement of the elastic modulus.

本文利用有限元软件对多孔金属结合剂金刚石砂轮节块的材料性能进行了数值模拟计算，依设计结果制备了节块试样，并测试了节块的弹性模量，主要内容有： 1、充分借鉴多孔材料结构设计和分析的方法，以十四面体模型为多孔金属胎体的微观结构模型，以孔隙率为设计变量，通过有限元分析，计算出满足一定弹性模量要求的多孔金属胎体的孔隙率范围。

In a radio wave absorber (10), four hollow tetrahedrons (20) each of which has one open surface are connected such that a surface (20a) opposed to the open surface of the hollow tetrahedron (20) forms a side of a hollow pyramid (22). The radio wave absorber (10) is composed of a radio wave absorbing member shaped like a thin plate.

该电波吸收体(10)呈按照下述方式连接而形成的形状，该连接方式为将4个一面开口的中空四面体(20)以开口面相对的面(20a)作为中空棱锥(22)的侧面的方式形成。

Final R and wR are 0.0496 and 0\^1248 respectively for 1952 I≥2σ(I observed reflections. The crystal molecule consists of 〔WOS 3Ag 3Br(PPh 3) 3〕 and OPPh ...

该晶体由簇合物分子〔WOS3Ag3Br(PPh3) 3〕和以P为中心的扭曲四面体结构的中性分子OPPh3 构成，其中的簇合物分子的骨架为由1个W原子、3个S原子、3个Ag原子和 1个Br原子构成的立方烷状。W、O(1)和Br原子位于C3轴上。

They report in the latest issue of Physical Review Letters that the tetrahedra filled roughly 76% of the available space in a large container, whereas experiments with spheres typically filled only 64% of the available volume.

他们发表在最近一期的《物理评论快报》中，四面体状的骰子大约能够占据大容器76%的空间，而典型的球形实验中，只占据了64%的空间。

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