查询词典 planar developable surface

The calculated NICS values show that nucleus-independent chemical shifts values of roof-shaped isomers for Sb42-, Bi42-, and22- species are all negative, consequently indicating that these roof-shaped isomers possess aromaticities. NICS values for the planar ring isomers are all positive, suggesting that these three planar ring isomers have antiaromatic characters.

计算显示Sb42-、Bi42-和22-团簇的所有屋顶型结构的核独立化学位移全部为负值，从而说明这些屋顶型结构拥有芳香性；平面环结构的核独立化学位移值全部为正值，说明这三种平面环结构具有反芳香性。

British original kemet planar face specular lapping machine, and two units for various types of supplies, professional and various light mould backlighting formwork-planar optical specular lapping and polishing.

英国原装kemet平面光学镜面研磨机组二台和各类专用耗材，专业各类导光板和背光板模仁的平面光学镜面研磨和抛光。

Therefore, the EL spectra of (Znq_2)_4 is wider than that of Znq_2. 4._2 was synthesized. The analysis of molecular spatial structure and the characterization of material performance of_2 and Liq showed that two Liq molecules and two Naq molecules were connected by Na-O-Na bond bridges to form_2. Compared with Liq,_2 exhibits stronger rigidity in planar molecular structure, larger steric hindrance and intermolecular distance, and much smaller molecular polarity, thus resulting in much longer fluorescence lifetime, much higher fluorescence quantum efficiency, wider energy bandgap and better film formability. When used as light-emitting layer in OLED,_2 shows lower formation probability of excited dimmer and exciplex formation than Liq, thus emits bluer light with higher current efficiency than Liq. When_2 ultrathin film is used as electron injection layer in OLED, it exhibits higher current density, higher luminance, lower turn-on voltage and higher current efficiency than Liq ultrathin film for the existence of sodium ions in_2 ultrathin film. 5. The summarization the relationship between molecular spatial structure and material performance of Alq_3,(Znq_2) and Liq, lead the conclusion that the molecular spatial structure of Mq_n affects its material performance in such aspects as the rigidity of planar molecular structure, intermolecular interaction, molecule stacking mode and intermolecular distance.

制备了_2，通过对_2和Liq的分子空间结构与性能进行分析与讨论，发现_2是通过两个Na-O-Na键桥将两个Liq和两个Naq连接构成的，其分子平面结构的刚性程度强于Liq，空间位阻大于Liq，分子之间的距离大于Liq，分子极性远远小于Liq；_2的荧光寿命长于Liq，荧光量子效率高于Liq，成膜性优于Liq；_2的禁带宽度比Liq大，光致发光光谱中_2的最大发射峰较Liq发生蓝移；当_2在OLED中作为发光层时，激发二聚体与激基复合物的生成几率远远小于Liq，发的光比Liq更蓝，电流效率大于Liq；_2超薄膜中有Na离子的存在，与Liq超薄膜相比，当其在OLED中作为电子注入层时，具有更大的电流密度，更高的发光强度，更低的阈值电压和更高的电流效率 5、对上述Alq_3、Znq_2和Liq的分子空间结构与材料性能之间的关系进行了归纳总结，认为Mq_n的分子空间结构主要在分子平面结构的刚性程度，相邻分子之间的相互作用，分子堆叠的方式和分子之间的距离这四个方面影响其性能。

In this paper,the B-spline curve is supposed as boundary curves,when they are in two paralled plane and two arbitrary plane,the condition about the control vertex of characteristic polygon when the ruled surface is developable are gained,solved the designing problem of degree and degree B-spline curve .Throughing (2,3) degree and (2,2) degree B-spline ,we haveproved the validity and utility of this method.

本文用两条B样条曲线作边界曲线，当它们位于两平行平面上和两任意平面上时，研究得到了由它们形成的直纹面为可展面时它们的特征多边形顶点满足的条件，解决了(n，n+1)次和次可展B样条曲面的设计问题，然后以(2，3)次和(2，2)次B样条曲面为构造实例，证明了该算法的正确性和实用性。

When designing the shapes of industrial products,we will encount with the design problem of developable surface.

在工业产品外形的设计时，经常会遇到可展面的设计问题。

A developable surface is one that can be made from a flat sheet without any in-plane strains.

可展曲面是一个可以由平板在不发生任何面内应变的条件下弯成的曲面。

In this manner, a developable surface was designed using control planes with Bézier and B-spline basis functions.

基于将可展曲面作为平面单参数族包络面的思想，给出在Bézier和B样条基下可展曲面的参数表示形式。

The programs of the above methods und algorithms are developed, which shall be used in the system of developable surface modeling for CAD/CAM.

zier曲线的情形作了分析和比较。这些方法和算法均应用于实例在计算机上得以实现。

Necessary and sufficient conditions for convexity preserving of developable surface patches are presented.

文中对计算机辅助设计技术中常用的可展面进行了保凸分析，利用该结论可以轻而易举地判别和控制可展面的形状

Based on that,the problem of reconstruction is studied according whether the axis-track surface is developable or not,and some valuable conclusions are derived.

在得出包络面、轴迹曲面、等效轴迹曲面互为等距曲面的结论的基础上，研究了轴迹曲面可展与不可展两种情况下的非等径包络重构问题，得到了一些有价值的结论。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。