对称中心

Evolution of Gauss beam in biased centrosymmetric photorefractive media.

高斯光束在有外电场的中心对称光折变材料中的演化。

According to the disc of the installation in the valve body, butterfly valve can be divided into the following forms:① centrosymmetric board.

根据蝶板在阀体中的安装方式，蝶阀可以分成以下几种形式：①中心对称板。

The centrosymmetric molecules are theoretically studied using VB-4CT model and the effect of broken symmetry on first hyperpolarizability is discussed.

利用VB-4CT模型作理论研究中心对称分子并讨论对称性破坏对一阶超极化率的效应。

The cation is centrosymmetric and the crystal structure is stabilized by C-H…Br hydrogen boding.

阳离子部分的结构是中心对称的，晶体由于C—H…Br氢键的存在而十分稳定。

Model updating; modal parameter; centrosymmetric; iterative method; least squares problem; quadratic constraint

模型修正；模态参数；中心对称矩阵；迭代法；最小二乘问题；二次约束

The mechanism is applied to explain the exceptional high first hyperpolarizability of furan-containing [2.2]cyclophan-diene, which has centrosymmetric chromophores.

这机制被用来解释拥有中心对称发光团的 furan-containing [2，2]-cyclophandiene 具有异常高的一阶超极化率。

Applying the conjugate gradient method, an iterative algorithm is presented to solve the constrained matrix equation AXB+CXD=F over centrosymmetric matrix X and its optimal approximation.

应用共轭梯度思想，给出了求解约束矩阵方程AXB+CXD=F的中心对称解及其最佳逼近的迭代算法。

C12A7 is basis phase, and C3A phase is central symmertrical 3-D structure with clavated antenna extending in different directions.

其中：C12A7为基底相，C3A呈中心对称的条索状三维结构，易于机械单体解离，便于选矿分离利用。

The first asymmetric total synthesis of coumarinolignoids Daphneticin and it's enantiomer was accomplished starting from 7-hydroxycoumarin and 3, 4, 5-trimethoxybenzaldehyde, in which Sharpless asymmetric dihydroxy reaction was used to construct chiral center, and Mitsunobu reaction was used to obtain desired configuration.

并以7-羟基香豆素和3，4，5-三甲氧基苯甲醛为起始原料，用Sharpless不对称双羟化反应构筑手性中心，用Mitsunobu偶联反应作为关键步骤，合成了手性的香豆素木脂素Daphneticin及其异构体。

Symmetrical six-horn nickel diselenide nanostars were firstly synthesized with selenium powder as precursor but without any external reducing agents. Each nanostar consisted of a central core and six symmetrical nanohorns.

以硒粉为硒源，在无外加还原剂的条件下首次合成了六角星状二硒化镍纳米晶，每个纳米星具有一个中心核和六个对称纳米角。

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。