十面体

V-shape grooves exist in twinned crystal planes of fivefold twin. As for thermodynamics and kinetics, the grooves are helpful for diamond grains of fivefold twin to grow.

正二十面体和正十面体颗粒都是"五重孪晶"结构，在颗粒表面上与五重孪晶面对应的区域形成V-形槽，这种V-形槽对五重孪晶金刚石颗粒的长大有热力学和动力学的有利作用。

Gastaldi and co-workers have observed two types of contrasts in Al-Pd-Mn IQCs: black-white double-lobe and loop-shaped, by using X-ray topography, and the facetted dodecahedral pores by phase-sensitive radiography.

Gastaldi领导的小组在结合利用X射线形貌术以及相位敏感成像术研究Al-Pd-Mn二十面体准晶单晶中的缺陷时发现两种衬度，其中已知黑白双瓣衬度是由于准晶中的五角十二面体空洞引起，而对于环形衬度则除了知道退火行为不同于位错从而不太可能是位错圈外，基本上对其缺陷的几何及性质不甚了解。

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。

Regular icosahedron ; regular dodecahedron ; quasicrystal ; conjugate fractal structural model ; conjugate fractal structural model of quasicrystal ; Penrose pattern ; high resolution structural image by electron microscopy.

正十二面体；正二十面体；准晶体；共轭分数维模型；准晶共轭结构模型； Penrose拼图；高分辨电子显微结构图

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。

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。

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