面对称

The influence of position of the substitution, strength and number of donors and acceptors, and their coplanarity and asymmetry is discussed. The results indicate that the molecules may have larger first hyperpolarizabilities when the molecules have stronger and more donors and acceptors, large asymmetry of HOMO and LUMO, better coplanarity and higher accentricity. This work attemps at finding out the relationship between the structure and the property, thus providing theoretical basis for designing nonlinear optical molecules.

进一步研究体系中取代基的位置，给体与受体的数量和得失电子的能力，分子的共面性和对称性对分子第一超极化率的影响，结果表明，有机分子拥有更多数量与更强得失电子能力的给体和受体，最高占据分子轨道和最低未占据分子轨道空间分布的不对称，具有较高的原子共面性和较低的分子中心对称性，都能显著增加

Direction cosine analysis based on winmeil;2. According to the directioncosine formula in hexahedron tubular hea ter,the direction cosine of energy bind in inclined and symmetry tubular heater is stuided.

分析了用蒙特卡罗法计算加热炉辐射传热时能束的发射方向和行程长度，根据六面体加热炉中能束的方向余弦公式，对斜顶对称加热炉中发射能束的方向余弦进行了研究，得到了其修正公式，对斜顶壁面相交坐标进行了修正。

The recess (13) has a bottom surface (14) transverse to the plane of symmetry and substantially parallel walls (15) along said plane.

该凹槽(13)有一个横切对称平面的底面(14)和与所述对称平面基本平行的内壁(15)。

Preformed malleable dental crowns with a side-generic external shape with a plane of symmetry in the facial-lingual direction and/or a plane of symmetry in the mesial-distal direction.

具有在颊舌方向上的对称面和/或近远中方向上的对称面的侧面通用外形的预制的可煅的牙冠。

The tooth spaces of the sprocket can be symmetric, asymmetric and the root surface can be relieved.

链轮的齿间可以是对称的、非对称的，并且齿根面可以减少。

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. The Green-Schwarz superstring theory is a covariant theory.

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。

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。

Under the direct current electric field, the expression of PDGFR were increased obviously and distributed asymmetricly on the membrane of VSMC. This receptor were mainly focused on the cathodal side of cellular membrane in electric field. The AT1R were also enhanced in the cells after exposure to the electric field, and the expression of AT2R had showed the changeless.

改进的电场干预装置作用下，血管平滑肌细胞膜血小板源生长因子受体表达增加，部分细胞内血小板源生长因子受体表达上调，呈不对称分布，在电场负极面较集中；细胞中血管紧张素Ⅱ1型受体表达亦增加，但无明显不对称分布现象；血管紧张素Ⅱ2型受体表达改变不显著。

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。

Ni6 cluster is an octahedron belonging to Oh point group. Its 3Eg orbital presents strong negative exchange coupling and has a trend of antiferromagnetic couplings. Ni5 cluster is of three-side pyramidal structure belonging to point group C3v. The magnetic moment direction of Ni atom lying on vertex of the pyramid is antiparallel to the moment direction of the Ni atoms lying on underside of the pyramid, which present the characteristic of ferrimagnetic couplings.

具有Oh点群对称的八面体原子簇Ni6的3Eg轨道上存在很强的负交换耦合，呈现反铁磁耦合趋势；具有C3v点群对称的三边金字塔结构的原子簇Ni5位于塔顶点的Ni原子与基面上的Ni原子磁矩方向相反，但大小不等，呈现出亚铁磁交换耦合特征。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。