群射

Proves by matrix technique and ways that affine Unitary groups have double transition on the affine maximal and deseribes the total isotropic subspaces over affine Unitary geometry and their orbits and the use of affine maximal and total isotropic subspaces to construct several classes association scheme and PBIB designs, and the calculation of all parameters as well.

利用矩阵的技巧和方法，证明了仿射酉群双可迁地作用在仿射酉几何中的仿射极大全迷向子空间上，并且给出了轨道的明确表示。作为该理论的一个应用，利用仿射酉几何中的极大全迷向子空间的全体作为处理集构作了一个多个结合类的结合方案和PBIB设计，并计算了所有的参数。

Symplectic group research is enlarged in the fi nite field to the affine Symplectic group by studying the transition of affine Symplectic group.

把有限域上的辛群的研究推广到仿射辛群并对仿射辛群的可迁性进行了研究。

It is proved that the least squareestimators of linear estimable functions of regression coefficients areadmissible under matrix loss and minimax. The necessary and sufficientexistence conditions are derived for the uniformly minimum riskequivariant estimators of linear estimable functions ofregression coefficients under an affine group and a transitive group oftransformations respectively. It is also proved that there are no UMREestimators ofthe covariance matrix and variance under an affine groupof transformations and quadratic loss functions.

本文证明了回归系数的线性可估函数的最小二乘估计是极小极大的且在矩阵损失函数下是可容许的；还分别在仿射变换群和平移群下导出了存在回归系数的线性可估函数的一致最小风险同变估计的充要条件，并证明了在仿射变换和二次损失下不存在协方差阵和方差的 UMRE 估计。

Thismethod adopted affine transformation model and a Lie derivative-based analytical algorithm.We introduced the process and characters in extracting information of biological visionsystem, studied the feasibility of the generalized Gabor function used as receptive fieldfunction in extracting information and analyzed affine transformation group and Liederivatives. Finally, we deduced the mathematical denotation for Lie derivatives, i.e. theinfinitesimal generator of the geometric distortion in affine transformation.

对生物视觉信息提取的过程及特点进行了介绍，其中主要研究了广义Gabor函数作为感受野函数提取初级视觉信息的可行性；对仿射变换作为外界图像信息在视觉成像系统上的投影模型的原理进行了初步讨论；对Lie变换群微分算子用于提取仿射变换不变量的分析方法作了剖析，并推导了该方法中关键部分——仿射变换Lie微分算子的具体表达式，也就是几何变形无限小微分算子的计算表达式，使下一步编程实现该方法成为可能。

The injectivity of a Clifford semigroup and its ideals is investigated,and the homological classification of a Clifford semigroup by the injective properties over its ideals is gained.

研究了Clifford半群及其理想的内射性质，得到了Clifford半群关于理想的内射性同调分类，并对自内射的Clifford半群给出了刻画。

This article proves that in the homomorphism of G onto ■,the inverse image of a maximal normal subgroup in ■ is also a maximal normal subgroup in G.

本文得到了在同态满射下，极大正规子群的逆象也是极大正规子群，并给出了极大正规子群的象也是极大正规子群的一些等价条件。

In addition, molecular orientation behaviors induced by shearing, electric field and magnetic field were investigated. The space group of the monomers A3EO7 and A9EO7 were determined as P2〓2〓2 and P112/m by means of electron diffraction and X-ray diffraction. Liquid crystalline properties of the monomer and the polymer were studied using DSC, variable X-ray diffraction, TEM and polarized optical microscope. Both monomers exhibit monotropic liquid crystalline behavior, and they also give a metastable phase on the cooling process. The polymer PA9EO7 shows enantiotropic liquid crystalline properties. Thus the rigid polymer backbone is not a fatal defect that completely distorts the packing arrangement of the mesogenic moiety in the side chain liquid crystalline polyacetylene.

结合电子衍射倾转方法和粉末X射线衍射技术，确定了两个液晶小分子A3EO7和A9EO7的晶胞参数和空间群，采用Cerius〓模拟软件，运用分子模拟的方法给出了小分子在晶胞中的排列方式；利用DSC、变温X射线衍射技术和透射电子显微镜研究了小分子和聚合物的液晶态，单体A3EO7和A9EO7表现出单向液晶性质，并且在降温过程中都表现出一个亚稳液晶相或亚稳结晶相，聚合物PA9EO7具有双向液晶性；采用偏光显微镜和X射线平板照相技术，研究了剪切和电场对聚合物分子取向的影响，在不同的液晶态，剪切作用对聚合物PA9EO7具有不同的诱导取向结果，直流电场可以诱导聚合物联苯液晶基元沿施加电场方向取向。

A BRACKET is a succession of two salvos, one over and one short, or one right and one left, with no straddles.

夹叉 包夹前后接连两群齐射，一群较远一群较近，或一群偏左一群偏右，但没有发生跨射。

Much of the terminology of morphisms, as well as the intuition underlying them, comes from concrete categories, where the objects are simply sets with some additional structure, and morphisms are functions preserving this structure.

例如，在集合论中，态射就是函数，在群论中，它们是群同态，而在拓扑学中，它们是连续函数。在泛代数的范围，态射通常就是同态。

On the basis of the dynamical model of aero-defence rocket launcher by volley firing,the optimization aim of firing order was set up,and possible orders were built according to some influence factors.

在建立群射防空火箭炮动力学模型的基础上，确立了射序优化的目标，考虑到其影响因素，编排了可能发射顺序。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。