四面体

In view of that conventional algorithms of collision detection spend a lot of detection time on complex polyhedrons, an algorithm to divide a convex polyhedron was presented and proved.

针对传统的碰撞检测算法对于复杂多面体之间的碰撞检测时间过长的缺陷，提出并证明了一种凸多面体的剖分算法，该算法能将复杂的凸多面体剖分为简单四面体，利用基于MPI(Mes-sagePassingInterface)并行处理的方法来提高碰撞检测的实时性。

Experimental results indicate that silicon tips of octahedron and tetrahedron are fabricated with changing mask directions. The direction of mask does not affect the rapid etched crystal planes at the fixed solution concentration and temperature.

实验结果表明：当腐蚀溶液浓度和温度一定时，正方形掩模的方向并不影响快腐蚀晶面的类型，利用正方形掩模的偏转，可以制备出八面体和四面体的硅尖。

The variable geometry truss mechanisms have been studied extensively and systematically by this project. The research plan has been completed all sidedly, and expected results have been obtained. Three new kinds of combination decahedrons and a new class of variable geometry truss mechanism, which is composed of an octahedron and three tetrahedrons connected in parallel form, are proposed. The position analyses for decahedrons, dodecahedrons, triple-octahedrons, combinations decahedron and a new type of structure of variable geometry truss mechanisms are presented by introducing additional extra linear displacement sensors and using resultant elimination and homotopy continuation algorithms. The method of kinematical analysis of variable geometry truss mechanisms is established.

课题组对变几何桁架机构进行了深入的研究，全面地完成了研究计划，取得了预期的成果；提出了三种新的十面体组合机构以及由一个八面体和三个四面体组成的新型变几何桁架机构的结构形式；应用结式消元、附加传感器和同伦方法等提出了十面体、十二面体、三重八面体、组合十面体和新型变几何桁架机构的位置分析方法；建立了变几何桁架机构运动分析的一般方法；建立了简洁的凯恩和拉格伦日动力学的模型；应用有限元和子结构方法，提出了变几何柞架机构弹性动力学模型，导出了逆动力学方程的显式形式；设计和研制了一台可折叠的八面体变几何杵架机构装置等。

This is a special state of condensed matter with long-range order that is neither three-dimensionally periodic nor quasicrystalline, but nevertheless possessing a higher degree of organization and higher symmetry than the individual crystals constituting the MTPs.

SEM-EDS分析得到所观察到的二十面体构形的颗粒的成分比B/O是6.4；另外一种四面体结构则有B/O为2，其相应的化学式是B〓O。

In this paper, the L(d,1)-labeling is studied and the upper bounds of λd of plane triangulation graph, solid tetrahedron subdivision graph, plane near quadrangle subdivision graph are derived, and as corollaries, the conjecture is proved to be true for the above several classes of graphs.

此文研究了作为L(2，1)-标号问题的推广的L(d，1)-标号问题，并得出了平面三角剖分图、立体四面体剖分图、平面近四边形剖分图的L(d，1)-标号的上界，作为推论证明了对上述几类图该猜想成立。

At the same time, the trend of Kirie simplex is also confirmed by the distribution of tetrahedron coefficient.

同时，四面体系数的分布进一步证实Kirie单纯形的变化趋势。

Our results show that the duality of self-dual tetrahedral link is "trivial", and the duality of hexahedral and octahedral link as well as dodecahedral and icosahedral link are "nontrivial".

从构型角度考虑，四面体链环的自对偶是"平凡"的，六面体链环和八面体链环，十二面体和二十面体链环的对偶是"非平凡"的。

The resulting materials were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, Nuclear magnetic resonance and Photoluminescence. Those spectra reveal that by adding SiO2 to YAG:Ce precursor, the lattice constant decreases while vacancies are generate due to the co-dopant ions (Si4+) replaces in the place of Al3+ sites of YAG:Ce system. YAG:Ce phosphors with Y3+ dodecahedral site replaced by Ce3+ and diffused effectively as an activator, as a result the photoluminescence intensity increased about ~20-30%.

研究成果显示，掺杂SiO2之YAG：Ce萤光粉经过高温热处理后，由X光绕射、红外线吸收光谱仪以及核磁共振可以得知，当SiO2添加量增加时，YAG：Ce晶格常数会因为Si4+取代Al3+的四面体晶格位置而变小，同时产生将YAG：Ce之铝离子空位缺陷，使活化中心更有效地在YAG：Ce主体中扩散取代Y3+的十二面体晶格位置，提高其发光性质约20~35%。

These growth units were absorbed and join the crystal lattice on the growth interface through collision and aggregation.The powders with better crystallinity and double cone or tetrahedron shape were obtained after amorphous ZnS was treated by solventthermal method.

采用溶剂热处理高浓度条件下制备的ZnS无定形粉末，得到晶态结构完整，形状为双锥状或四面体状的粉末。

He population analysis proved the interaction between helium atom and V was electrovalent bond. The helium had the stronger attractive to the vanadium atom which was in lattice site.

i-He(o2)体系在四种Ti-He体系(两种八面体和两种四面体)中具有最低的能量，单点能为-6481.4287eV，Ti-He(t1)次之，单点能为-6480.3876eV，在Ti-He体系中氦原子嵌入到o2位置具有更趋稳定的结构。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了