四面体

Elliptic orbit ; Tetrahedron configuration ; Formation flying ; J2 perturbation ; Orbit optimization design

椭圆轨道；四面体构形；编队飞行； J2项摄动力；轨道优化设计

The relationship between the orientation of tetrahedral [SO4]2- in sulfate crystals such as barite,anhydrite, epsomite and jarosite and their morphology was studied from the standpoint of crystal chemistry,and the formation inechanisin of their morphology was analysed according to the structural orientation of tetrahedral [SO4]2- and the bonding energy between [SO4]2- and metal ions [M2+] during growth.

本文从硫酸盐类晶体中负离子配位多面体的结晶方位和相互联结的稳定性出发，探讨了硫酸盐类晶体中[SO4]2-结晶方位与晶体结晶形貌之间的关系；认为[SO4]2-四面体与金属阳离子（Ba2+、Ca2+、Mg2+…）结合时，由于晶体结构和生长条件的不同，在晶体各族晶面上的叠合速率和取向不同；晶体的结晶形貌迥然有别。

Experiment results show that using this new algorithm for tetrahedron, finite element model can provide well visual result.

实验表明，研究的新算法用于四面体单元的有限元模型，具有良好的切割处理效果。

The tetrahedron mesh-cut algorithm is an important part of finite element method. The mesh-cut result determines the speed and the precision of stiff matrix regeneration.

四面体网格切割算法是有限元仿真中的重要组成部分，切剖的结果决定了刚度矩阵的更新速度和精度。

The geometry of the crop circle ship is an octahedron at the core of a large tetrahedron.

麦田圈船的几何是一个在大型四面体的核心的八面体。

Gynophore free end rising above nutlets as thick tetrahedral mucro with short style at apex.

Gynophore 免费末端上升到小坚果以上作为厚的四面体的短尖头用短花柱在先端。

Then loading the models in both feet standing body posture, gain stress distribution figures of the models, record stress numerus of weight bearing dome, anterior wall and posterior wall in condition of different areas posterior wall fractures. Results 1、Normal 3D finite element model of acetabulum Obtain 3D visible model of pelvic by restituting CT fault images with Mimics10.01; gain 3D visible model of haunch bone by splitting the pelvic model with FreeForm software.

结果 1、正常髋臼三维有限元模型通过Mimics10.01软件对骨盆断层CT图像进行三维重建，获得骨盆三维可视模型；然后在FreeForm软件系统中对模型进行修饰，平滑模型表面，设定各受力面与界线；并成功截取出髋骨三维可视模型；再将模型导入Ansys8.0中进行各部分材料赋值及网格划分，建立了正常髋臼三维有限元模型，共含节点69440个，三维四面体单元45209个。

In this dissertation, Lanthanum is used to substitute part of Phosphorus or Aluminium in the framework and enter into the tetrahedron structure unit of oxygen negative ion for obtaining a kind of heteroatom molecular sieve with acidity.

本论文中，用镧原子同晶取代SAPO-n分子筛骨架中的部分铝或磷，进入骨架中的氧负离子四面体结构单元，得到具有一定酸性的杂原子硅磷酸铝分子筛。

A hybrid hexahedral/tetrahedral mesh of nearly 900,000 elements was used for the rotor and stators in three adjacent fluid zones.

混合六面体/四面体网格近900000要素被用于转子和定子在三个邻近的流体区。

Hybrid meshes, consisting of mixed element types, allow you to combine the ease of tetrahedral meshing on complex geometries with the advantages of traditional hexahedral cells in regions of less geometric complexity.

混合网格组成的混合元素类型，让您的难易程度相结合的四面体网格的复杂外形的优势与传统的六面体细胞较少地区的几何复杂性。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。