三棱

For the application of Mathematica in the differential geometry,this paper introduces how to processe the curve curvature and the torsion questions,the graphic expression of the curvature and the torsions,and draw curves by the curvature and the torsions. Curvature ; torsion ; solution curve ; osculating plane ; natural parameter ; natural equation

利用Mathematica，只要输入有关系统命令就可以得到期望的结果。1曲率和挠率及其图形意义假设R3上的曲线一般参数表示为r=r它的曲率和挠率计算公式是：κ=‖r′×r"‖‖r′‖3τ=‖r′×r‖我们知道，空间曲线r=r在一点(s=s0)邻近的近似方程为ξ=sη=120κs2ζ=160κ0τs3通过近似方程可以确定曲线在其基本三棱形的三个平面(即密切平面，法平面，从切平面)上的投

By means of estimates for three-dimensional discrete derivative Green's function , the theory of the interpolation operator of projection type and the technique of cancellation of elements, for several usual elements in the three-dimensional setting, including rectangular parallelepiped elements, tetrahedr.

借助三维离散导数Green函数的估计，投影型插值算子理论和单元合并技术，本文详细讨论了几种常用三维单元(包括长方体元，四面体元和三棱柱元)的有限元解梯度的最大模超逼近，均获得了高精度的超逼近结果。

The Trefoil knot, a main exhibit in the middle of the hall, is 10 meters wide, 12 meters high, with bandwidth of 1.65 meters. It is made from triangular prism band.

三叶纽结整体宽度10米，高12米，带宽1.65米，是由一条三棱柱带经过三次盘绕，将其中一端旋转120度后首尾相接，由此构成三面连通的单侧单边三叶纽结造型。

There are six orthographic views. Please imagine the different posture of triangular prism in space.

三、下面有六个三视图，请你想象一下各三视图中三棱柱在空间的姿态。

On the base of other researcher, the *** from the basic equations of stable current field to derived the expressions of boundary problems under 3-D condition. Without considering the EM effect and using the generalized variation principle, we can get the corresponding variation equation. Thronging subdivide the 3-D model, interpolation, analysis, and general synthesis with the triangular prism element, we can carry out the simulation on frequency-domain IP\'s parameters under level and undulate topography.

在前人工作的基础上，在忽略电磁效应的情况下，从稳定电流场的基本方程出发，推导了三维区域满足的边值题目，用广义变分原理得到相应的变分题目，通过用三棱柱单元对大地模型进行剖分、插值、总体集成，最后解方程，得到每个节点上的复电位值，最后实现了水平和起伏地形等条件下的激电参数的数值模拟。2。

The trigonal prism yields three isomers also, but there are only two octahedral arrangements for this formulation.

三棱柱也有三个异构体，而对于这个分子式，仅有两种八面体排布。

Each metal is nine-coordinated and formed tricapped trigonal prism geometry.

每个金属离子都是9配位形成三冠三棱柱的几何构型。

Built on breakthrough technology from Holland(refer to the manual for details)and featuring a computerized control system as well as triple protective device,our product is next to none in quality.

"精致三面翻"以荷兰高新技术为依托，其特有的技术特点，微电脑智能控制系统和三重安全保护装置（三棱柱弹性保护、传动轴扭力过载保护、电机电流过载保护）在产品质量上独占鳌头。

The crystal structures have been determined by single-crystal X-ray diffraction.Cadmium atoms in compounds 1 and 2 show an eight-coordinated distorted square-antiprismatic geometry and a seven-coordinated distorted pentagonal bipyramidal geometryrespectively. Copper atoms in compounds 3 and 4 show a six-coordinated distorted threeprismatic geometry and a four-coordinated distorted tetrahedral geometry respectively.

所有配合物的晶体结构都通过单晶X-射线衍射确定：配合物1中的镉离子周围显示八配位的扭曲四方反棱柱构型；而配合物2中的镉离子周围显示七配位的扭曲五角双锥构型；配合物3中的铜离子周围显示六配位的扭曲三棱柱构型；配合物4中的铜离子周围显示四配位的扭曲四面体构型；配合物5中的锌离子周围显示六配位的扭曲八面体构型。

It was 7.25% in saline algae zone, 31.25% in Scirpus marqueter/Scirpus triqueter zone and 47.06% in reed zone;(3) The avian density undergoes declination with the development of wetland vegetation succession.

对全年不同演替阶段鸟类群落进行相似性比较，芦苇带与海三棱藨草带／藨草带的相似性系数S_1=0.5442，海三棱藨草带／藨草带与盐渍藻类带S_3=0.6182，芦苇带与盐渍藻类带S_2=0.2585。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。