查询词典 developable surface

In addition, some modifications on several computational methods are also presented. Using LMTO method the electronic structure of several systems are studied, and some results are obtained. They are: The ideal Nb (100) surface has three surface states, the multi-layer relaxed surface has two surface states. The surface energy of the ideal surface is higher than that of the relaxed surface, that means that the multi-layer relaxed surface is more stable than the former one, which supports the LEED results. The mono-layer relaxed Ag (111) surface is the most stable one among several" stable surface models"presented by several researchers. The surface energy of Ag (111) surface is higher than that of surface Ag (001), which supports some experimental results such as different reaction rate at different surface orientations for the same material. The surafce states of Si (111) surface not only locate near the Fermi level, but also in the valence band, which agrees well with Cohen's conclusion. Si (111)-H is an effective model for analysing the surface states and H adsorbed on the back surface is a good method for improving the convincingness of the results obtained on thinner slab models. The surface stability depends on three different kinds of MoSi〓(001) surfaces, the surface with mono-layer Si is the most stable one, and the surface with Mo at the first layer is the most unstable one among them. These are consistant with the Kemoda's experimental results. The valence bands of clean or K adsorbed CdTe (111) surface agrees well with the synchrotron radiation studies. The surface of CdTe (111) consists of four kinds of surface models which show different surface electronic structures and different surface structure stabilities. The conclusion agrees well with Wu's experimental work. The different absorbed alkali metals on the CdTe (111) surface give different adsorption characteristics which have relations not only with the valence electrons, but also with the core ones of the alkali metals. The electonic structures of Si-C alloys are different from that of Si-Ge alloys, and the energy band gaps of Si-C alloys do not increase linearly with Carbon concentration, our conclusion supports Alexander's results, but conflicts with Soref's one.

现分述如下： LMTO方法及其应用方面：1）通过对Nb（100）表面电子态分析发现清洁理想表面有三个表面态，多层弛豫表面有两个表面态；表面能大小说明多层弛豫表面更稳定，支持了LEED结果。2）通过对采用不同方法获得的几种不同Ag（111）表面稳定结构的表面能计算分析，给出了单层弛豫表面为Ag（111）表面的最稳定结构；从Ag（111）单层弛豫表面和Ag（001）表面的表面能比较，发现了Ag（001）表面表面能要比Ag（111）小的，表明了同种物质不同表面取向将表现出不同物理、化学性质，这是与实验中得出的结论是吻合的，3）通过对Si（111）表面态分析，不仅发现了Si（111）表面不仅具有居于费米能级附近的悬挂键所对应的表面态，而且还有很多表面态位于价带能量范围内，与Cohen等结果一致，H饱和slab模型背表面相当于增加了slab层的厚度，是一有效的变相增加slab层厚的方法，弛豫表面较清洁理想表面价带谱们低能端的少许移动，预示着总能降低，说明弛豫表面较清洁理想表面稳定。4）MoSi〓具有三种表面，从费米能级上态密度值大小得到单层Si表面最稳定，Mo原子为表层原子的表面最不稳定，双层Si原子表面居中的结论，这与Kemoda等人实验结果是一致的。5）通过对CdTe（111）表面表面电子态、表面结构稳定性及表面H、碱金属吸附的电子结构系列研究，不仅得出了CdTe（111）清洁及碱金属K吸附价带谱与同步辐射光电子谱相吻合的结果，而且发现了CdTe（111）表面具有四类不同原子近邻特征，表现出四类不同的表面结构及电子结构特征：不同表面态分布、不同的表面结构稳定性（表层原子与次层原子成三键有一悬挂键的表面要比表层原子与次层原子成一键有三悬挂键稳定（与Wu等人实验结果一致））、不同的H吸附特性。

In the particular ease where a and γ are equal to 1, the developable CE-Bézier surface is a developable Bézier surface. Finally, some applications in developable surfaces design are discussed, The modeling examples illustrate that the developable CE-Bézier surfaces provide two valuable ways for the design of developable surfaces.

由新方法生成的可展曲面不仅具有灵活的局部形状可调性和更强的描述能力，而且保留了CE-Bézier曲面的特性，特别是当α、γ都取值为1时，所生成的可展曲面即为CE-Bézier可展曲面。2种可展曲面设计方法的应用实例表明，该设计方法不仅简单、有效，而且易于控制曲面形状，从而为可展曲面的设计提供了一种新途径。

By the definition of Darboux type vector and rectifying Darboux type vector ,we constructed the rectifying type developable surfaces and Darboux type developable surfaces and tangential Darboux type developable surfaces ,and study these three developable surfaces relationship with Minkowski slant helices and Minkowski conical geodesic curves. Bying applying the singularity theoerical knowledge, We give a classification of special developable surfaces under the condition of the existence of such a special curve as geodesic.

通过定义三维Minkowski空间中的达布型向量以及修正达布型向量，构造出三维Minkowski空间中的三类可展曲面，即修正型可展曲面、达布型可展曲面和切达布型可展曲面，研究Minkowski斜螺线和Minkowski锥面测地线这两种特殊曲线和这些曲面的关系，并研究Minkowski斜螺线和Minkowski锥面测地线作为这些曲面的测地线的条件下，运用奇点理论的知识，对这三种可展曲面进行奇点分类。

The paper deals with curvature line and curvature characteristic of developable surface based on differential invariant of developable surface and it details curvature line and curvature characteristic of cone and tangent surface .

本文通过可展曲面的微分不变量，导出可展面的曲率线与曲率特征，并以锥面和切线曲面为例阐明这些特性的几何意义。

The given geometric model of garment basic pattern surface is composed of the integrally smooth and continue developable surface, which breakthroughs traditional model of intersected joining by a lot of little developable surface.

所给出的服装原型曲面的几何模型由整体上光滑连续的组合式可展面构成，突破了用小块可展面相交拼接的传统模式，更加符合服装设计的要求，具有良好的可操作性。

We proved that the necessary and sufficient condition that the developable surfaces touch the second focal surface along the orthogonal trajectories was that the base surface S was a developable surface.

证明了线汇中的两系可展曲面交第二叶焦曲面于正交轨线族的充要条件是原曲面是可展曲面，并给出了两叶焦曲面在同一条光线上两焦点相互对应下，保持渐近曲线相互对应的充要条件。

Furthermore,we present the method for designing quadratic Bezier developable surface:give four corner points of developable surface and two free designing parameters,the other two control vertexes are on the line connecting the linear interpolation point between the first two control vertexes and the linear interpolation point between the last two control vertexes,and they are the linear interpolation points between these two linear interpolation points respectively,namely,these four linear interpolation points are colinear.

提出了二次Bézier可展曲面的设计方法：给定可展曲面的4个角点a0、b0、a2、b2和两个自由设计参数？姿、？滋，则待求的2个控制顶点a1、b1是在前2个控制顶点a0、b0的线性插值点a*与后2个控制顶点a2、b2的线性插值点b*的连线上，并且也是a*、b*这2个线性插值点的线性插值，即这4点a*、a1、b1、b*共线。

This method presented in this paper can save a lot of time in drawing the developable surface, increase the productive efficiency and the accuracy of blanking , and can be applied to all dinds of expansion of developable surface, zoom the dimension.

该方法可大大缩短可展曲面展开图的绘制时间，提高生产效率及展开下料精度，适用于各种类型可展曲面的展开，并可进行尺寸缩放等相关操作，具有较好的实用性和经济价值

Furthermore, by the design method that a developable surface is an envelope surface, we give detail analysis of examples about using the same control planes to design developable surfaces.

讨论了所设计可展曲面的特点和几何构造，研究结果表明，所提出的设计方法具有现有曲线设计方法的特征，现有的对于曲线的一些几何构造技术可延伸到可展曲面的设计。

Based on the important idea of duality between plane and point geometries,two direct explicit methods of computer-aided design for developable surface s were proposed,the developable surface s were represented using control planes with appropriate basis functions.

为了克服传统方法在可展曲面设计上的缺陷，方便地解决工程中经常遇到的可展曲面位置和形状难以调整和控制的问题，基于3D射影空间中点和平面间的对偶性这一重要思想，提出了两种直接、简单的可展曲面设计方法。

Metrorrhagia is also gynaecological problems of common diseases.

崩漏是妇科常见病也是疑难症。

WordFTP gives you the convenience and timesaving you need.

wordftp让您的方便和省时您所需要的。