六边形

Some typical structures of titanium nanowires , i.e. four-strands helical, centered pentagonal, hexagonal and the thicker hexagonal structures are chosen to study the structural and size effects of ultrathin nanowires. The angular correlation functions and vibrational properties are discussed.

我们选择不同的结构和生长序列的几个典型的超细钛纳米线，即四边形、五边形和六边形序列，以及六边形序列的两个较大体系，以分别考察结构和尺寸效应。

Experiment proved the practicability and efficiency of this algorithm. We study a class of subband coding schemes allowing perfect reconstruction for a bidimensional signal sampled on the hexagonal grid.

辨析了张量积子波变换与六边形子波变换的特性，尤其是空间取向性的差异，六边形子波变换克服了张量积子波变换在频率域上的"某些方向不确定性问题"，提供了频率域上的尖角分解准理想模式。

Carried out generalized Mises yield criterion , yield curve on the n flat face was circle curve, and different elected parameters correspond to external angular point circumcircle、 internal angular point circumcircle and incircle of Mohr-Coulomb unequiangular hexagon. According to unequiangular hexagon, circle yield curve which had the same area as hexagon can be found, and corresponding yield criterionwas equilateral circle yield curve.

3广义米赛斯准则在π平面上的屈服曲线为圆曲线，选择的参数不同对应有莫尔—库仑不等角六边形的外角点外接圆，内角点外接圆和内切圆，对于不等角六边形，还可以找到一个面积和六边形相等的圆屈服曲线，对应的屈服准则为等面圆屈服曲线。

Given a hexagon circumscribed on a conic section , the lines joining opposite polygon vertices meet in a single point

已知一个六边形外切于一条圆锥曲线，那么连接这个六边形相对顶点的三条线交于一点。

Given a hexagon inscribed in a conic section , the three pairs of the continuations of opposite sides meet on a straight line , called the Pascal line .

已知一个六边形内接于一条圆锥曲线，那么这个六边形对边的交点位于同一条直线上。

By constructing a sphere hexagonal grid system based on the Truncated Icosahedrons Projection, this paper focuses on the study of the address coding mechanism of the sphere hexagonal grids, including the hierarchy coding schemes, the study of the positional relations among the grid units and the mutual conversion between the address codes of the grid units and the geographical coordinates.

本文通过构建基于截顶正二十面体投影的球面六边形网格系统，对球面六边形网格的地址编码机制进行了重点研究，包括网格的层次编码方案、网格单元位置关系研究和网格单元地址码与地理坐标之间的相互转换。

The results are listed as follows:(1) In peneplain with plenty water-resource, hexagonal spatial structure of urban system can be formed. Due to differential competed function of central places, the hexagonal system is distorted. The result is that the area covered is decr eased and the girth is unchanged——but every border is usually unequal;(2) A pattern of pentagonal system evolves from hexagonal system controlled by a river;(3) A pattern of quadrilateral develops from hexagonal system under two parallel rivers;(4) The equal distance distribution of central places in narrow geographic space has its special reasons. The results are very important for understanding urban's formation and development and urban plan in Huang-Huai-Hai plain.

本文通过自然地理因素中水文、地形这两个重要要素对城镇体系空间结构形成的影响，分析了华北平原区在不同要素影响下的城镇体系空间结构样式：①在水源充足的准"均质"河北冲积平原上，基本满足六边形形成条件，但由于周边中心地发展竞争力不同，故使得正六边形发生畸变——覆盖面积减小而周长却保持不变；②构建了在一条河流影响下的六边形网络结构朝五边形网络演变的模型；③构建了在平行状河流作用下六边形网络向四边形网络演替的模式；④指出了在水源充足的狭长地理空间，城镇体系空间结构发育成等间距的现象与原因。

Zinc Selenide hexagonal flakes and hexagonal prism have been synthesized by solvothermal method using ethylenediamine as solvent.

以乙二胺-乙醇为溶剂采用溶剂热法成功合成了具有六方结构的六边形硒化锌薄片和六边形棱柱。

Some models were designed where the unique tetragon and hexagon grids borrowed from the wing structure were used as the basic elements, these models were analyzed numerically, it is shown that the model consisting of tetragon grids is much stiffer than that consisting of hexagon grids, while, more material is used in the first model;crinkling models based on tetragon grids or arched models consisting of hexagon grids become more stiffer than flat ones;hybrid models consisting of tetragon grids and hexagon grids can realize a proper balance between material saving and stiffness improving.

分别提取四边形、六边形的基本网格，建立结构模型，并对它们进行非线性数值分析。研究发现：四边形网格结构刚度大，六边形网格结构刚度小；而从材料利用率角度来讲，六边形网状结构更省材料；起皱对四边形网格结构刚度有加强，而起拱对六边形网格结构刚度有提高；如果将四、六边形的网格进行合理搭配，可以使结构刚度和材料利用率得到优化。

There is a holding angle at the vertex of hexagon.

当参考电压矢量位于过调制模式Ⅰ时，其轨迹位于六边形内部的部分仍保持为圆形，其幅值略大于参考电压矢量的模值，以补偿空间矢量在六边形边上的电压损失；在六边形之外的圆形轨迹变为六边形的边沿，此区域内，电压空间矢量的幅值扭曲，相位连续。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。