正多面体

In order to solvepiecewise algebraic varieties, we propose a new method to compute an algebraic varietyon a convex polyhedron by adding hyperplanes with the method of Groebner bases. Thus,the algebraic variety on the convex polyhedron is transformed to the positive solutionsof a system of polynomials. Besides, the minimal decomposition is also obtained.

通过添加超平面技巧将Groebner基方法应用到凸多面体内任意维代数簇的计算上，从而把凸多面体内的代数簇转化为另外一组多项式方程组的正解，并且得到了该代数簇在凸多面体内的极小分解。

Necessary and sufficient conditions of the robust positively invariant sets are established for the linear discrete-time system family specified by matrix convex polyhedron and additive interval disturbances.

对由矩阵凸多面体和加性区间扰动描述的线性时变离散系统族，得到了鲁棒正不变集的充分必要条件；对非线性系统族则得到有关充分条件。

Its occurrence in regular pentagons and decagons was duly observed, as well as in the dodecahedron (a regular polyhedron whose twelve faces are regular pentagons).

它出现在正五边形和正十边形以及正12面体（一种规则多面体，它的每个面都是正五边形）中是易于观察到的。

Goldberg got a class of polyhedra which are icosahedral symmetry by appending hexagons on regular dodecahedron by rule in 1937. They are called Goldberg polyhedra which provides a new approach for polyhedral molecule design.

1937年，数学家Goldberg通过在正十二面体上有规律地添加六边形面得到一类具有二十面体对称性的多面体，即Goldberg多面体。

We obtain three classes of polyhedra which have high symmetry. they are regular tetrahedral class belonging to tetrahedral group , regular hexahedral class and regular octahedral class belonging to octahedral group.

本文将Goldberg在正十二面体上构筑多面体的方法推广到其它柏拉图多面体上，分别得到了三类具有较高对称性的多面体：属于四面体群的正四面体类和属于八面体群的正六面体类、正八面体类。

Using the divisible theory of the integer,the underside conclusion is proved:for all the vertex-coloring formulas of the regular polyhedron ,let be any integer,the result of these formulas is still the integer.

利用整数的整除理论，证明了以下结论：在所有正多面体顶点着色公式中，当颜色数取任何一个整数时，这些公式的计算结果仍然是整数。

The designed photoelectric sensors of regular polyhedron rotation realized to adjust the

本研究对该传感器的性能进行了测试，结果表明光电式正多面体转速传感器误差小于3%，测量精度的一致性比较好，基本上达到了设计要求。

The reconstructed stable structures, through either the melt-recrystallization or surface migration, are polyhedrons consisting of {111} and {100} surfaces, with only the relative ratio of the areas of the two types of surfaces differing from case to case. The critical size increases linearly with raising temperature.

两 种情况下形成的稳定结构均为由{111}和{100}面组成的正多面体纳米岛，只是两种面的相对面积比有所不同；该临界尺寸随温度升高而呈近线性增大。

So the body-centred cubic structure of Li9 has the greatest binding energy for per atom among body-centered regular polyhedral structures of Lin (n= 5 ,7,9,13), which may be a reason for alkali metal crystal adopting the body-centred cubic structure as its unit cell.

故在体心正多面体结构Lin (n= 5 ，7，9，13)中，Li9的体心立方结构有最大的原子平均结合能，这也许是碱金属晶体的晶胞取体心立方结构的一个原因。

We obtain three classes of polyhedra which have high symmetry.

本文将Goldberg在正十二面体上构筑多面体的方法推广到其它柏拉图多面体上，分别得到了三类具有较高对称性的多面体：属于四面体群的正四面体类和属于八面体群的正六面体类、正八面体类。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。