对称

But according to principle of relativity and absolutization theory, the effort of super symmetry has no end, super symmetry demands the existence of gravity-微子 with spin 2/3 except gravity-quantum.

但是根据对称的相对性与绝对性原理，超对称的工作是没有止境的。超对称要求除引力子外，还应当有自旋3/2的引力微子存在，但是实验上并没有发现它的存在。

The synthesis and characterization of asymmetric dinuclear and mononuclear vanadium complexes show that the pH value is very important for the products\' formation and isolation. In some pH range, theα-alkoxy bridge was easy to break and form asymmetric dinuclear and mononuclear vanadium structure.

三、不对称的双核钒和单核钒配合物的合成和表征显示，pH值对产物的形成和分离具有至关重要的作用。pH值在一定范围内，柠檬酸的烷氧基氧作为桥氧的化学键才容易断开，从而形成不对称的双核钒和单核钒结构。pH值不仅影响不对称双核V_2O_3钒配合物和单核钒配合物的形成，还关系到钒还原的速度。

Applying mechanics of partitioning of matrix and special structure, we have given the sufficient and necessary conditions for the matrix if it has bisymmetric and anti-bisymmetric solutions.

对于广义双对称与广义双反对称矩阵，首先结合矩阵的结构特点，应用广义逆的相关知识，给出了有解的充要条件以及有解时解的表达式，最后在一种特定的分解条件下，考虑了它的广义双反对称最小二乘解。

In this paper, we first introduce the concepts and structures of generalized per-symmetric matrix, generalized centro-symmetric matrix or generalized bisymmetric matrix.

本文介绍了广义广对称矩阵、广义中心对称矩阵以及广义双对称矩阵的概念及结构，研究了这些特殊矩阵集合中，矩阵方程AXB=C及矩阵方程组A_1XB_1=C_1，A_2XB_2=C_2的迭代解法，同时考虑了相应的最佳逼近问题。

Furthermore,the optimal approximation bisymmetric solution pair to a given bisymmetric matrix pair in Frobenius norm can be obtained by finding the least norm bisymmetric solution pair of new matrix equation ,where .

另外，给定双对称矩阵对，通过求矩阵方程的双对称解对，得到它的最佳逼近双对称解对。

A numerical algorithm and a numerical experiment are given. 2. The least norm, positive semidefinite and positive definite real solutions of bisymmetric matrix equations (A~TXA, XA — YAD)=(D, 0)are considered by applying the generalized singular value decomposition.

利用广义奇异值分解讨论了矩阵方程(A~T XA，XA-YAE)=(E，0)在对称次反对称矩阵集合中的解、极小范数解和在双对称矩阵集合中的解、极小范数解及正定解； 3。

According as the four modes in a symmetric waveguide, that one of modes is symmetric or anti-symmetric about X axes or Y axes, are X polarized or Y polarized odd mode or even mode, we calculated the polarized coupling characteristics using Cassinian curves as boundaries of the couplers.

本文还根据对称波导中对称于或反对称于x轴或y轴的四个模式分别为x偏振或y偏振的奇模或偶模的原理，用Cassinian曲线表示耦合器介质波导的边界，计算了耦合器的偏振耦合特性。

Chapter 7 focuses on the asymmetries in the categorial shift between verb and noun, pointing out that these asymmetries are rooted in the conceptualasymmetry of verb and noun.

第七章研究动名相互转化中的种种不对称现象，分析不对称现象产生的根本原因在于动词和名词之间概念上的不对称。

Furthermore, the optimal approximation centrosymmetric solution pair to a given centrosymmetric matrix pair in Frobenius norm can be obtained by finding the least norm centrosymmetric solution pair of new matrix equation ,where .

另外，给定中心对称矩阵对，通过求矩阵方程的中心对称解对，得到它的最佳逼近中心对称解对。

This work, concentrated on the asymmetric allylation of aldehydes controlled by different chiral auxiliaries prepared from rotational pure tartaric acid, can be divided into three parts.The first part aims to review the developments of chiral drugs and asymmetric synthesis, from which derived the present research topic backgrounds and works.Synthesis and applications of allylation from aldehydes are the second part of the thesis. By optimizing the reaction conditions, such as solvents, temperature, time and chiral auxiliaries like N,N\'-dibenzyl tartamide, N,N\'-p-dimethylphenyl tartamide, N,N\'-o-dimethylphenyl tartamide, N,N\'-o-dichlorophenyl tartamide, N,N\'-a-dinaphyl tartamide, N,N\'-dicyclohexyl tartamide and N,N\'-diphenyl tartamide, ideal experimenttal conditions are obtained according to HPLC monitoring, as well as the auxiliaries\' recoveries experiments. Starting from benzaldehyde and 3-bromopropaldehyde, N,N\'-dibenzyl tartamide is considered the best auxiliary in this reaction.

本文介绍了醛的不对称烯丙基化反应，以光学纯酒石酸为原料，研究了不同构型手性配体在醛的烯丙基化反应中的立体选择性，全文共分三部分十个章节：第一部分对当前手性药物和手性技术进行了概述，并由此展开了本文的研究背景和任务；第二部分为有机合成部分，对醛的不对称烯丙基化反应进行了深入探讨，以苯甲醛为原料对反应条件进行优化，在优化的反应条件下对制备的七种可回收手性酰胺配体(N-苄基酒石酸二酰胺、N-对甲苯基酒石酸二酰胺、N-邻甲苯基酒石酸二酰胺、N-邻氯苯基酒石酸二酰胺、N-a-萘基酒石酸二酰胺、N-环己基酒石酸二酰胺和N-苯基酒石酸二酰胺)进行筛选，优化配体回收实验条件，最终确定出N-苄基酒石酸二酰胺在苯甲醛的不对称烯丙基化反应中具有较大优越性，结晶回收的手性配体光学纯度保持不变。

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。