十二面体的

The morphologies of diamond include cube, cuboid, octahedron, cuboctahedron, twinned cuboctahedron, decahedron and icosahedron and ball-like diamond using SEM observation. The formation condition of the grains is discussed.

用SEM观察CVD金刚石晶粒形态主要有立方体、长方体、八面体、立方八面体、李晶八面体、十面体和二十面体颗粒以及球形金刚石，讨论了晶粒的形成条件。

The structures and stabilities of the ground-states for Cu13-nAgn clusters have been studied by Gupta model potential based on tight binding second moment approximation in combination with a genetic algorithm. It is found that the lowest energy structures of the pure clusters (n=0,13) are perfect icosahedron, and the structures for the bimetallic clusters (n=1～10) have stable structure which are slightly deformed with respect to the perfect icosahedron, The Cu atom prefers to occupy the center of the clusters with higher coordination numbers.

在混合团簇基态结构优化的遗传算法方案中增加了交换算子，结合Gupta紧束缚模型势研究了Cu13-nAgn团簇的最低能量结构，选择合适的交换和杂交概率，可有效地提高优化效率，优化结果表明，Cu13和Ag13是全对称的二十面体，n=1～10的混合团簇能形成稳定结构，其构型是在二十面体基础上发生畸变，Cu原子趋于处在团簇中心，随着Ag原子数目的增加，原子间的平均距离单调增加，团簇的结合能单调减小，Cu2Ag12和CuAg12只存在亚稳结构。

In addition to the black-white double-lobe caused by the displacement field around pores, we demonstrate that LSC should correspond to a novel, peculiar class of anti-phase domain, of which the interior is a local isomorphism with a non-zero phason-type displacement ε〓w〓 i.e.

利用这个结果，我们发现黑白双瓣衬度是二十面体准晶中的多面体微孔引起，而环形衬度则对应于一种二十面体准晶中新奇的反相畴界，其两侧是由相位子型位移ε〓w〓＝B〓联系着的局域同晶类。

Icosehedral quasicrystal, showing icosahedral point group symmetry and quasi-periodic order along three directions, has been intensively studied.

二十面体准晶是目前研究最广泛的准晶之，它具有二十面体点群对称性，属于三维准晶，就是说其原子在三维上都是准周期分布的。

Interestingly, in liquid Fe75B25 the situation is reversed. About 35% of 1441, 1431, 1421 and 1422 pairs are found, indicating that tetrahedral local order is preponderant.

一个比较有趣的结果是，在Fe20B80中，代表二十面体和扭曲二十面体微观局域结构的1551和1541占主导地位，大约占键对总数的43%。

This fact disproves an assumption that λ-phase is an approximant of the IQC.

但是我们研究发现λ相与在其基础上生成的二十面体相之间没有固定的取向关系，这反驳了λ相是二十面体相的近似相的假设。

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 truncated icosahedra have been prepared for the first time by prolonging the reaction time to 4 h.The XRD,SEM,TEM and Uv-vis technologies confirm the high shape difference between icosahedral gold nanocrystals and their truncated forms.

通过延长反应时间合成了一种类似足球的新型金纳米粒子—截角二十面体，研究结果表明，该粒子由二十个六边形和十二个五边形组成，截角面是{100}面。

A systematic analysis of the icosahedral hierarchic structure in the 3D icosahedral quasicrystal and its approximants have been made. There is an icosahedron at the center surrounded by 12 icosahedra. If two neighboring icosahedra are vertex-sharing, the multi-shell Mackay cluster consisting of 127 atoms will form. If two neighboring icosahedra penetrate into each other, the multi-shell Samson-Bergman-Pauling cluster consisting of 137 atoms will form.

系统地分析了三维二十面体准晶的近似晶体相中具有二十面体对称的等级结构，中心1个二十面体，周边12个二十面体，如两个相邻二十面体共顶点连接，得出的是由127个原子构成的Mackay球形原子簇；如两个二十面体互相穿插，得出的是由137个原子构成的Samson-Bergman-Pauling球形原子簇。

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