对称

METHODS: A total of 36 patients from the Affiliated Hospital of Guilin Medical College between September 2003 and August 2006 were treated with OPAK system of 0.022 inch straight wire appliance to pull out four permanent teeth of first bicuspid in symmetrical order.

选择2003-09/2006-08在桂林医学院附属医院进行口腔正畸治疗，双侧对称拔除四颗第一双尖牙的恒牙牙合患者36例。

In this paper, by supposing the currents on the two lines are equal but opposite and with the application of bifilar transmission-line theory, the current-voltage relationships of the asymmetrical bifilar even transmission line are obtained.

该文在假设双线传输线两线上电流大小相等、方向相反的条件下，运用双线传输线理论思想，推得不对称双线均匀传输线的电压、电流关系。

with the development of satellite navigation communication,antenna is a very important unit,performance of the satellite navigation communication system is affected by it partly.a new type of bifilar helix for satellite navigation communication system is introduced,and the traving-wave bifilar helix is analyzed briefly.meanwhile,the design and the test results are given.the results show that the antenna possesses excellent circular hemispherical beam with wide angle circular polarization and better impedance match,and has a compact structure and high integration.it can be applied in caps systems successful.

小 摘要：随着卫星导航通信技术的迅速发展，天线作为卫星导航通信系统中的重要部分，在一定程度上决定着卫星导航通信系统的性能。介绍一种用于卫星导航通信系统的双臂螺旋天线，讲述爬行波式螺旋天线的设计过程，并给出最终测试结果。结果表明，该天线具有优良的圆对称半球波束，良好的广角圆极化特性和优良的阻抗匹配特性，其结构简单、紧凑，为通信入站回传提供了一种优良的选择。

Based on the boundary integral formula and natural boundary integral equation for the boundary value problems of biharmonic equation , the non-symmetrical banding solutions to the circular plate under thermal boundary conditions are gained by the Fourier series and convolution formulae.

根据双调和方程边值问题的边界积分公式和自然边界积分方程，利用傅立叶级数及卷积的几个公式，求得了相应变温边界条件下非对称载荷圆板的弯曲解，从实践上证明了此方法的可行性。

His face was described as bilaterally asymmetrical, and various other signs of degeneration were described.

他的脸被描写成两面不对称，还涂上了些别的堕落迹象。

We have classified all types of the solvable Lie algebras with nondegenerate invariant bilinear form.

我们给出了带有非退化不变对称双线性型的可解李代数的完全分类。

So if 2 is invertible in ''R''(when ''R'' is a field this is the same as having characteristic not 2), then we can recover the quadratic form from the symmetric bilinear form ''B'' by

所以如果 2 在''R''中是可逆的(在''R''是一个域的时候这同于有不是 2 的特征)，则我们可以从对称双线性形式''B''恢复二次形式，通过

In section 3 ,we will introduce bilinear form B on Lie colour algebra L. is called quadratic if B is color symmetric .non-degenerate and invariant .In this case ,B is called an invariant scalar product on L .

第三部分介绍了具有双线性型B的李color代数L，如果B是color对称的，非退化的和color不变的，则称是二次李color代数，B则称为不变数量积，给出了理想非退化的定义。

Chapter 3 introduces some methods seeking exact solutions for the nonlinear evolution equation, such as inverse scattering method, symmetry reduction method, Backlund transformation, Darboux transformation , Hirota bilinear method, Painleve analysis method, AC = BD model, and so on.

第三章简要介绍了非线性发展方程的若干求解方法，如反散射方法，对称与微分方程约化，Backlund变换和Darboux变换方法，Hirota双线性方法，Painleve奇性分析法，AC=BD框架下的精确求解等。

Matrix to determine whether it is reflexive and symmetric, Discrete Mathematics in the binary relation.

判断矩阵是否是自反的，对称的，离散数学中的二元关系。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。