十面体

Based on mathematical mechanization method and computer symbolic processing technique this paper carried out a solution by symbolic method for position analysis of robot with octahedral and decahedral variable greometry truss.

基于数学机械化方法和计算机符号处理技术，对八面体及十面体变几何桁架机器人的位置分析进行了符号法求解，成功地将非线性位置约束方程组化简为等价的三角化方程组，分别导出了单变量的16次和48次代数方程，并给出一个数字实例说明这种方法。

The displacement analysis of octahedral, decahedron and dodecahedral variable geometry truss manipulators are studied systematically.

提出了八面体和十面体变几何桁架机器人直接位置分析的符号解法，并得到了符号化的封闭解。

This method has been used to calculate electronic structures of the icosahedral,tetrahedral and dihedral fullerenes and some stability rules are obtained.

这种方法已经用于系统地研究具有二十面体群、四面体群和二面体群对称性的各富勒烯同系列，并且得到规律性的结果。

Plato conjectured each of these elements to be made up of a certain Platonic solid: the element of earth would be a cube, of air an octahedron, of water an icosahedron, and of fire a tetrahedron .

柏拉图推测每一种元素都是由某些理想立方体组成：地元素是由立方体组成，风元素是一个八面体，水元素是二十面体，火元素是四面体。

At each penton, a hole (φ=20〓) can be seen connecting the inside and the outside of the capsid, and there is a hole (φ=12〓) at each hexton and the center of 2-fold axis, so there are 132 holes in total at the surface of CSBV.

应用冷冻电镜技术和计算机三维结构重构的方法，我们测定了CSBV核衣壳的三维结构，分辩率为25 〓，病毒的核衣壳是按T=1（P=3）的对称结构排列二十面体，病毒表面比较光滑，有12个五邻体、60个六邻体的结构，每个五邻体的中央有孔洞，六邻体的中央也有孔洞，另外在2次轴的位置上也有孔洞，这样病毒共有132个孔洞，五邻体的孔洞的直径为20 〓，而六邻体和二次轴的孔洞的直径月为12 〓。

There are three forms of symmetry in virus capsids: icosahedral , helical and complex forms.

壳粒排列的方式使病毒的结构呈几何对称，病毒衣壳有三种对称形式：二十面体立体对称、螺旋对称、复合对称，螺旋结构呈杆状，而二十面体由对称的亚单位组成近似的球状，非对称的衣壳是较复杂的形式，往往与细菌病毒有关。

A virus is a unit of infectious genetic material smaller than any bacteria and embodying properties placing it on the borderline between life and non-life. The vast majority of the virus capsid protein assembled into icosahedral symmetry of the structure. Caspar-Klug Theory has become a fundamental concept for the classification of icosahedral viral capsids based on the principle of quasi-equivalence.

二：病毒是比任何细菌都小的感染性遗传物质，介于生命与非生命之间的一类无细胞结构的生物，绝大多数病毒的衣壳蛋白装配成二十面体对称的结构，&准等价&原理是解决严格遵从二十面体对称性的病毒衣壳几何特征的有效而成熟的方法。

The continuing of the process produces icosahedra of even higher orders (a2, a3,…,an).

实质上，这一模型可以看成正二十面体与正十二面体共轭生成的结果。

The growth of truncated icosahedra could be induced and maintained through interplay of following processes:the～50 nm multiple twinned seeds were generated; shape and size focused by Ostwald ripening,then oxidativly etched and preferentially grew on the {100} face.Oxidative etching plays an important role in the formation of gold nanocrystals on hydrothermal condition.

对二十面体金纳米粒子及截角二十面体的生长机理进行了探讨，考察了不同刻蚀程度对金纳米粒子的形态影响，研究结果表明，增强体系刻蚀程度有利于单晶的生长，减弱刻蚀程度有利于孪晶的生长。

On the basis of the frame of dodecahedron, we apply the method of "spherical stretching" to the frame, we can obtain a novel polyhedron with I_h symmetry, which contains 72 pentagons.

我们在十二面体框架的基础上，利用&球面拉伸&的方法，得到新的具有二十面体对称性，72个五边形构造的的多面体结构。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐