两对称

The introduction of local supersymmetry on worldsheet results in the Ramond-Neveu-Schwarz model, and global supersymmetry in the ten-dimensional spacetime directly yields the Green-Schwarz superstring.

这两种描述方式的不同点是：Ramond-Neveu-Schwarz超弦理论在超弦的世界面引入局域的超对称，Green-Schwarz超弦理论是在十维时空中直接引入超对称，它是一个协变的理论。

For example, it is possible to find a transformation and two bases, so that the matrix is symmetric with respect to one basis and not symmetric with respect to the other.

为了 例如，有可能找到一个转型和两个基地，使矩阵对称的一个方面，而不是对称的基础上对其他。

As mentioned above, this dissertation can be divided into two parts. One is devoted to study the high resolution ro-vibrational spectra of some asymmetry top molecules, such as D〓O and DOCl. Another is about studying anharmonic force field and vibrational intensities of some symmetry top molecules by quantum chemistry method, such as SiHCl〓 and AsH〓.

因此本论文的工作以此为脉络分为两个部分，第一部分以D〓O和DOCl分子为体系，研究非对称陀螺分子的高分辨振转光谱；第二部分以对称陀螺SiHCl〓和AsH〓分子为体系，用量子化学计算的方法研究了小分子的非谐性力场和振动光谱强度。

According to the anisomerous differentiation of the needle leaves, the 4 or 5 needles per bundle could be formed under compatible condition, or affected by abnormity factors, such as mechanical, traumatic and insect pest injury

依据针叶原基的不对称发育和分化，如果温湿条件较好，或受到机械创伤，不对称的两个或三个针叶原基可以进一步分化成4个或5个针叶原基而形成4、5针1束。

Crystal structural analysis reveals that, because water molecules bond to Cu atoms, the dhbd ligand can only adopt a hydroxyl oxygen atom to bridge two reversed U-shaped subunits into a novel centrosymmetric dual-U-shaped tetranuclear Cu structure. Each U-shaped frame consists of two crystallographically distinct Cu atoms, two dpphen ligands and one coordinated water molecule.

晶体结构分析表明，由于水的配位阻断， 2，3-二羟基丁二酸根仅通过单羟基氧桥联两个U形双核亚单元形成具有一个对称中心的双U形四核结构，其中U型亚单元包含晶体学上不对称的2个Cu原子、1个2，3-二羟基丁二酸根、2个4，7-二苯基-1，10-邻菲咯啉和1个配位H2O分子。

The third part of this thesis is reactive simulating calculation In this section, some well-known auxiliaries are selected to compute in density functional theory B3LYP on Gaussian 03, from which the relationship between reaction active energies of transition states and enantiomeric excess of chiral products homoallylic alcohols isobtained based on relative reactive ratio theory. Using this relationship, calculations on the reaction of more than eight auxiliaries with four other aldehydes are carried out in AMI and MNDO, proving that N,N\'-dibenzyl tartamide has higher enantioselectivity than others in this reaction.

第三部分为计算化学部分，运用密度泛函理论B3LYP方法在Gaussian03软件上对已经报道的几种手性配体参与的醛不对称烯丙基化反应过程进行模拟计算，基于相对反应速率理论找出两种构型过渡态间活化能的差异与产物光学收率之间的关系；并以此为基础，用AM1和MNDO方法对上述合成的几种配体控制的反应过程进行量化计算，从而在理论上证实了N-苄基酒石酸二酰胺配体在醛的不对称烯丙基化反应中具有较高的立体选择性。

The paper analyses the cooling process of symmetrical and dissymmetrical section profile with FEM software ANSYS, then adopt the data to guide the design of moulds cooling system.

使用有限元分析软件ANSYS分析了对称截面和不对称截面两种型材在定型模内冷却的过程，并采用分析得出的数据指导定型模冷却系统的设计。

Physical and numerical models were establishedased on NˉS c ontrol equations and RNG kˉεturbulence model, the interior flow fields of the nozzles were analyzed through num erical method, both the flow parameters change trend and thrust speciality of the asymmetry quadrate nozzle were resea rched.

文中建立了非对称方形尾喷管及传统轴对称尾喷管的物理数学模型，基于N S方程和RNG kε湍流模型，对两种尾喷管三维内流场进行了数值分析，研究了非对称方形尾喷管内部流动参数的变化趋势及其推力特性。

For both series of heteroleptic tris rare earth compounds, the characteristic phthalocyanine dianion IR bands for Pc2- and O OPc2- at ca. 1329 and 1380 cm-1 attributed to the pyrrole stretching and the symmetric C-H bending of -CH3 groups in octyloxy side chains of OOPc rings together with some small contribution from the isoindole stretching vibrations,re specteively,are simultaneously found in their IR spectra.

在这两个不对称三明治型稀土配合物系列的红外光谱中发现了这样一种特性，即酞菁阴离子Pc~(2-)和OOPc~(2-)的特征波段在1329cm~(-1)和1380cm~(-1)之间，这是因为吡咯的伸缩振动和OOPc环中八烷氧基侧链上-CH_3基团的对称C-H的弯曲振动共同作用于吲哚环的伸缩振动。

The main idea is to lift the band degeneracy at high symmetry points in the Brillouin zone of crystals by lowering the structure symmetry of crystal. One way is introducing nonspherical atom configurations, 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，以获得完全的带隙我们采用两种方法，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。

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。