两对称

Two different Fabry-Perot cavities have been adopted: plane mirror cavity and confocal concave spherical mirror cavity.

采用了两种不同的Fabry-Perot腔体结构：平面腔镜结构和对称共焦球面腔镜结构；首先进行了理论分析，得出两种结构中折射率变化与干涉条纹变化的关系，然后分别对两种腔体结构下的测量系统进行实验研究，都可以探测到10-5量级的折射率变化量，结果基本令人满意。

The main idea is tolift the band degeneracy at high symmetry points in the Brillouin zone of crystals bylowering the structure symmetry of crystal.One way is introducing nonspherical atomconfigurations,another is introducing anisotropy in atom dielectricity.

设计的核心思想是通过降低光子晶体结构的对称性，消除光子能带在晶体的布里渊区高对称点上的本征简并，以获得完全的带稀我们采用两种方法，一种是将晶体的原子做成非球对称，另一种用各向异性的颗粒球做晶体原子。

For very long time, many research groups focus on using more than a stoichiometric amount of a chiral auxiliaries to obtain high enantioselectivity. There were mainly two sorts of processes reported on highly catalytic asymmetric addition of Grignard reagents to aldehydes. The former case was to transform Grignard reagent RMgX into other organometal reagents such as R_2Zn and R-Ti derivatives via complicated procedures at extremely low temperature. The later case was to link a chiral ligand to Mg in the form of organomagnesium amides or use chiral amine ligand catalyzing the alkylation of aldehydes.

格氏试剂对醛的不对称加成的报道大多需要大量的手性助剂以获得高的光学活性，而高度催化的格氏试剂对醛的不对称加成主要通过两种途径进行：一种是把格氏试剂转化成其他的有机金属试剂如R_2Zn和R-Ti化合物再对醛进行加成，反应通常在低温下进行；另一种是利用手性镁胺作为中间体或直接用手性胺催化来完成此反应。

In the fifth chapter,we study dipolarizations in some quadratic Lie algebras.Inthe first section,we obtain some results on the classification of dipolarizations in gen-eral quadratic Lie algebras,and prove that there exist dipolarizations in the solvablequadratic Lie algebras whose Cartan subalgebras consist of semisimple elements.

第五章讨论了某些二次李代数的双极化，在第一节中，我们给出了二次李代数的双极化的一些分类结果；特别证明Cartan子代数是由半单元组成的二次李代数上存在双极化，第二节确定了四维扩张Heisenberg代数的所有双极化，在第三节中，我们构造了2n+2维扩张Heisenberg代数的六类双极化，我们发现两个不同于半单李代数情形的有趣事实：（1）在扩张Heisenberg代数上同时存在对称和非对称双极化；（2）对应于扩张Heisenberg代数的双极化的特征元有的是半单的有的是幂零的。

The crystal consists of two similar but independent molecules in the asymmetric unit and the Ce ion coordinated toward ten donor atoms, six of which belong to the nitrogen atoms of two tridentate ligands and four oxygen atoms from two bidentate picrates.

晶体中一个不对称单元内有两个结晶学上独立的分子，这两个分子的构型基本相同，中心Ce3＋均与两个三齿配位的配体及两个双齿配位的苦味酸根配位，配位数为10。

Its main features are: algae body as a single cell or even into a variety of groups; cell walls composed of silica and pectin, but also by the structure of the shell and the shell under the combined set of the Cheng, vertical section view was "soap-box"-shaped; in the upper and lower shell surface of the shell are patterns arranged in patterns on both sides of the main mode of symmetry and radial symmetry is divided into two categories, for the classification of the most important basis; be able to campaign Type in the shell has a shell side seam, can not be changed no shell seam types; pigment body sheet or ribbon, 1 or 2, or for multiple small discoid, yellow green or brown, containing chlorophyll a, c, also contains fucoxanthin and silicon A flavin and other photosynthetic pigments; storage material mainly for oil droplets; reproduction mainly for cell division and cell division in diatoms obvious features are: each cell division, resulting from two sub-cells,, only one and the mother cell and so big, the other one is smaller.

其主要特征是：藻体为单细胞或连成各式群体；细胞壁由硅质和果胶质组成，而且在结构上都是由上壳和下壳套合而成，纵断面观呈&肥皂盒&形；在上下壳的壳面上有花纹，花纹排列的方式主要分为两侧对称和辐射对称两大类，为分类上的最重要依据；能运动的种类在壳面都有壳缝，不能动的种类均无壳缝；色素体片状或带状，1个或2个，或为多个小盘状，黄绿色或黄褐色，含叶绿素a、c，还含有墨角藻黄素和硅甲黄素等光合色素；贮藏物质主要为油滴；繁殖方式主要为细胞分裂，硅藻的细胞分裂的明显特点是：每次细胞分裂所产生的2个子细胞中，仅有1个和母细胞等大，另1个则稍小。

Aiming to characteristic of 3-phase to 2-phase power supply based on balance transformer, a new current balance compensation method utilizing inverter is proposed, which is mainly used to compensate negative sequence current .

从而使平衡变压器两相侧的输出电流对称，消除平衡变压器三相侧产生负序电流的条件，达到三相电流对称的目的。

In view of the development about the certain airborne radar antenna array,considering the structural features of antenna array,analyse the cruces in manufacturing of feed cavity and radiant plate,and present the corresponding solution by mainly dealing with precise positioning style,delicate clamp design,error distribution and compensation method,high speed machining technology design,machining simulation and program optimizing.

某机载雷达平面裂缝阵列天线的单面阵如图1所示。该面阵布置多路裂缝线源，共分布384处长度各不相同的辐射裂缝，每一路线源均由脊型波导口单独馈电。面阵由辐射板和馈电腔两个零件组成，采用整体钎焊成形。线源结构为非对称单脊共线形式，即在普通单脊波导的两侧与辐射裂缝相对应的位置上布置不对称的凹台。

The first one is the system for the two-armed hard-flexible manipulators moving in a certain channel. The dynamic model of that is proposed based on the D'AlembertLagrange principle.

第一个模型研究了由两支对称的刚性-柔性机器臂构成一个双臂机器人的定轨道水平移物问题，利用D'Alembert-Lagrange原理建立了双臂钢性-柔性机器人系统的双臂机器人定轨道移动的非线性对称组合模型。

The detailed works are as follows: 1. Realization of numerical simulation for rotationally asymmetric sound absorbent structures by finite element method.

具体工作在如下两方面：(1)具有旋转对称腔体和非对称基材单元的水下吸声结构声学特性在数值仿真的实现。

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。