查询词典 symmetry

This passage tells us that how to measure the distance of the center of two symmetry holes with the help of the tool-maker's microscope and the lying optical gage .

本文介绍如何利用卧式测长仪和万能工具显微镜间接测量对称孔中心距离。

If the screwed fastening piece and solid piece are longitudinally sectioned and the cut plane goes through the center of symmetry, these parts are represented as though they were not sectioned.

对于螺纹紧固件及实心件若按纵向剖切且剖切平面通过其对称中心时，这些零件按不剖画出。

The specimen laser cutting experiments show that it is feasible to cut thin quartz glass plates pricisely with laser cutting technique with accuracy of better than 20μm and central symmetry of less than 3m.

对石英玻璃薄板的激光精密切割进行了实验验证，实验结果表明，激光精密切割技术能够较好地运用于石英玻璃薄板的精密切割加工中，其加工精度优于20μm、中心对称度小于3μm。

The conclusion is that inductive electromotive force, gotten from sensor with the distribution regularities of weighting function, is proportional to the average flow velocity in pipe and is not relevant to the distribution of flow velocity when flow velocity is non-central symmetry with the central axis.

得出按权重函数分布规律的传感器，在流速非中心轴对称分布时，感应电势仅与平均流速呈正比，而与流速分布无关的结论，从而从原理上解决电磁流量计了高精度测量的问题。

The results are as follow:(1) In static status, the velocity of jet flow shows a symmetry distribution through central axis of enclosure.

结果表明，腔体静止时，射流速度沿腔体中心轴对称分布，腔体中心轴上的速度最大，两侧流速逐渐减小，近壁处为零；腔体转动时，在哥氏力的作用下，射流中心发生偏转，流场相对于腔体中心轴不再对称分布，腔体中各点处的流速分布随角速度而变化，压电射流角速度传感器利用这一特性敏感角速度。

Statistical characteristics include Tectonic Density, Degree of Central Symmetry, Skewness Index, Degree of Tectonic Optimal Direction, Power Spectrum Density, Cubic Entropy and so on. The former four indexes are implemented in this paper; Structural characteristics show the characteristics of spatial distribution of geological bodies. In chapter four, a quantitative method for describing geological structure by using the structure "tree" is studied and implemented, including its formalized definition and the measurement of the similarity of different "trees".

统计特征有构造密度、中心对称度、失真指数、优益度、密度功率谱、方位熵等等，本文实现了前四个参数值的提取；结构特征是反映地质体空间分布的结构特点，第四章研究和实现了用"树结构"描述地质结构的定量方法，包括结构的形式化描述和结构的相似性度量。

Based on the depth research on extension array manifold of uniform circular, for some uniform circular arrays which had subarrays with the nature of rotational invariance and had the nature of central symmetry two ESPRIT algo-rithms were presented, the first algorithm reduced one time of SVD, the second algorithm avoided parameter pairs.

在深入研究均匀圆阵扩展阵列流形的基础上，针对某些均匀圆阵的扩展阵列中含有旋转不变性的子阵列组以及中心对称性质，提出了2种基于均匀圆阵的二维ESPRIT算法，第一种算法减少了一次奇异值分解，第二种算法避免了参数配对。

Among the large number of nonlinear absorbers, the material applied most extensively is phthalocyanine reverse saturable absorption compound which is organic large molecule with central symmetry two-dimensional π-electron conjugate system. In the off-resonance condition, its absorption coefficient will raise along with the increasing of incoming light intensity, which shows its reverse saturable absorption properties.

在非线性光学材料中目前最具应用价值的是酞菁类的反饱和吸收材料，这是一类具有中心对称二维π电子共轭体系的有机大分子，在非共振激发条件下，吸收系数往往会随入射光强的增加而增加，体现反饱和吸收。

The diffraction theory of Kirchhoff is applied to the four-pinhole aperture diffraction screens, the intensity, the zero-contour of the real and imaginary parts of complex amplitude and the phase distribution in deep Fresnel diffraction region are simulated, and it is found that the bright spots in interference field show central symmetry distribution. When the observation plane close to the diffraction screen, the zero-value points of light intensity can form line segment, on which the eccentricities of the light intensity isoline are close or equal to 1, the intensity changes very fast on both sides of the zero-line of light intensity.

利用基尔霍夫衍射理论计算了四圆孔径衍射屏在菲涅尔深区形成的的干涉光场的强度、零值线和相位的分布，发现干涉光场亮斑关于中心呈对称分布，在距离衍射屏较近的观察面上，光强值为的零点组成光强零值线段，该线段上光强等值线的离心率都接近或等于1，其两侧的光强值变化非常剧烈。

The first conductivity base board comprises: a base material, a first projection, a second projection and a light spacer; the first projection and the second projection are installed on the base material with central line symmetry, the second projection is the image structure of the first projection relative to the central line.

第一导电基板包括一底材、一第一凸块、一第二凸块及一光间隔物，第一凸块及第二凸块以对称于一中心线的方式设置于底材之上，第二凸块为第一凸块对应于此中心线的镜射结构。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。