球面

By constructing a sphere hexagonal grid system based on the Truncated Icosahedrons Projection, this paper focuses on the study of the address coding mechanism of the sphere hexagonal grids, including the hierarchy coding schemes, the study of the positional relations among the grid units and the mutual conversion between the address codes of the grid units and the geographical coordinates.

本文通过构建基于截顶正二十面体投影的球面六边形网格系统，对球面六边形网格的地址编码机制进行了重点研究，包括网格的层次编码方案、网格单元位置关系研究和网格单元地址码与地理坐标之间的相互转换。

In thisthesis, we first extend the vanishing theorem due to Lawson, Simons and Xinto the case of compact submanifolds of a hyperbolic space. Thus, by using thenew vanishing theorem for homology groups, we prove the topological spheretheorem for complete submanifolds in a hyperbolic space. Hence we generalizethe Shiohama-Xu topological sphere theorem.

本文进一步将Lawson-Simons-Xin同调群消没定理拓广到双曲空间中紧致子流形的情形，并运用这一新的同调群消没定理证明了双曲空间中完备子流形的拓扑球面定理，从而推广了Shiohama-Xu的拓扑球面定理。

Among the three concave reflecting surfaces, namely, a spherical cap, a paraboloid and a hyperboloid of revolution, the enhancement degree of FM for a spherical reflector is the largest.

在球面、旋转抛物面和旋转双曲面三种类型的凹面反射端中，采用球面反射端通过上述方式提高悬浮力，可以获得最佳效果。

Under these coordinate systems, the algorithms that translate hexagonal grid cells from an unfolded icosahedron to a sphere were put forward.

球面离散网格模型是管理海量数据的有效途径，如何构建球面网格是这类模型的基础问题。

In order to generate spherical equal-area grid,this paper finds the corresponding relationships between unfolded icosahedron and sphere using Snyder equal-area projection.

文中利用Snyder等积多面体投影建立了平面与球面的对应关系，设计了球面等积三角形和四边形离散网格的生成算法。

On the basis of on the analysis of current spherical spatial data structure, the clew of the spherical spatial basal subdivision mode which uses Snyder equal area projection on the truncated icosahedron DGG is discussed, and then global multi-resolution overlay is obtained by subdividing hierarchically on the initial projection plane according to the hexagonal grid.

在分析当前球面空间数据结构的基础上，讨论了利用Snyder等积投影在二十面体上建立球面空间基础剖分方式的思路，然后在初始投影面上采用六边形格网进行层次细分，获得多分辨率的全球铺盖。

Such a problem need us to know whether an onto isometry between the unit spheres of Banach spaces has an linear extension to the whole space?

它是问定义在两个Banach空间单位球面到单位球面上的等距算子是否可以线性等距延拓到整个空间上？

Based on the traits of the aspherical lens, the sunlight was focused on a very small spot, and then it was transferred into a plastic fiber by an aspherical lens and a selfoc lens. A formula for calculating the optimal length of selfoc lens is presented. The optimal assembly of the aspherical lens and selfoc lens was implemented by the aid of this formula. Therefore, sunlight is coupled into a plastic fiber efficiently.

根据非球面透镜垂轴球差小的特点把太阳光会聚到很小的光点，再利用长度约为1/4节距的自聚焦透镜改变光线的数值孔径使其满足光纤的数值孔径，通过一个计算公式来计算最佳的自聚焦透镜长度，实现非球面透镜和自聚焦透镜的最佳组合，把太阳光以较高的耦合效率耦合进塑料光纤。

Instead, he suggested it was an oblate spheroid—a sphere that is squashed at its poles and swollen at the equator.

相反，他提出地球是一个扁球面——两极稍扁、中间略鼓的扁球面。

We take the spherical harmonic functions as base functions on the spherical surface and other systems of orthogonal functions as base functions in the direction of radius. However.

据此，我们可以在球面上以球面调和函数为基函数而在半径方向以其它适当的正交函数系为基函数，从而构成一种混合谱方法。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。