数环

Suppose G is a finite group, then QG is a semisimple Q-algera, obviously ZG is a Z-order of QG,we denote the maximal Z-order by ?.If G is not abelian, it is not an easy thing to determine г; if G is an abelian group, then QG is isomorphic to the direct sum of a finite number of number fields, and r is the direct sum of these rings of algebraic integers of those number fields, but which elements of QG belong to r is not clear.

设G是一个有限群，那么QG是一个半单代数，ZG是QG的一个Z-序，设Γ是QG的一个极大Z-序，当G是一个非交换群时，Γ的求解是困难的问题；当G是一个交换群时，QG同构于有限多个数域的直和，Γ相应的就是各数域代数整数环的直和，但Γ具体是QG中那些元素不清楚。

HPLC was coupled with both mass spectroscopy and ultraviolet absorption spectroscopy for simultaneous separation and characterization of the products from glow plasma reaction of chloroform.(3) Phosphorus pentachloride has been used to perchlorinate acenaphthene under moderate pressure and temperature in sealed reaction vessels.

在此基础上，以反相C〓柱为固定相，甲醇/乙醇/环己烷为流动相，采用梯度洗脱的方法，对氯仿辉光放电合成产物进行高效液相色谱-紫外光谱-质谱联用分离分析，成功的分离得到包括富勒烯C〓和全氯代碳簇在内的数十种产物，并得到了相应的质谱和光谱数据。

The experimental results show that the algorithm based on directed acyclic graph by the spacial relation among changing data can improve computing performance of an extraction of graphical data.

结果表明，基于有向无环图表示的数据抽取算法利用变化数据的空间关系能够提高计算性能，且算法的计算时间与变化数呈线性关系。

We discuss the relation between elementary maps and ring isomorphisms, andwe give a characterization of elementary maps on stndard operator algebras on Banachspaces, JSL-algebras and nest algebras. For Jordan-triple elementeary maps, we provetheir additivity on a class of ring and show a relation of them with Jordan isomorphisms. Furthermore. we describe the Jordan elementary maps on standard operator algebrasand nest algebras. We also study the semi-Jordan elementary maps on effect algebrasand the space of self adjoint operators.

研究了算子代数上的初等映射和环同构的关系，完全刻画了Banach空间上标准算子代数，JSL代数和套代数上的初等映射；讨论了Jordan-triple初等映射的可加性以及它和Jordan同构的关系，进而完全刻画了Banach空间上标准算子代数和套代数上的Jordan-triple初等映射；刻画了效应代数和自伴算子空间上的semi-Jordan初等映射。

In the thesis , firstly the problem of static output feedback H∞control was explored for discrete time singular systems. Based on the generalized Riccati inequality and linear matrix inequality, necessary and sufficient conditions were obtained for the existence of static output feedback H∞controllers, which guarantees that the resulting closed-loop system is admissible with its transfer function matrix satisfying H∞norm constraint.

本文首先利用线性矩阵不等式和广义Riccati不等式，给出离散广义系统中存在静态输出反馈H∞控制器，使得闭环系统是容许的且其传递函数矩阵满足H∞范数约束的充要条件。

Write the structural formulas for a cyclic alkyne hydrocarbon with the fewest number of C's which has a meso stereoisomers.

答：写出有内消旋体的且含有碳原子数最少的环炔烃，给出内消旋体的结构式，并命名这些化合物

With a soluble carbohydrate this appears as a ring if the the sulphuric acid is gently poured into form a layer below the aqueous solution.

Molish试验：生药水浸液，加a -萘酚试剂数滴，摇匀后沿管壁滴加浓硫酸，若有糖类成分与甙类存在，则在二液面交界处出现紫红色环。

By choosing suitable design parameters, all the signals in the resulting closed-loop system are uniformly bounded and the norm of the tracking error vector converges to an arbitrarily small neighborhood around zero by using the presented control approach.

通过选择适当的设计参数，提出的控制方法使得闭环系统的所有信号是一致有界的和跟踪误差向量的范数收敛到小的零邻域内。

By means of generalized Lyapunov function and linear matrix inequality,the asymptotical stability with zero solution is studied for the system,and a sufficient condition is given such that the system is asymptotically stable with zero solution and also a H∞ norm constraint .

针对非线性离散广义系统研究了状态反馈H∞控制器的设计问题，利用广义Lyapunov函数和线性矩阵不等式，首先对系统的零解渐近稳定问题进行了研究，并在此基础上给出了系统的零解渐近稳定且具有H∞范数约束的充分条件，之后设计了状态反馈H∞控制器，使闭环系统具有同样的性能，最后给出了数值算例说明本文结论的有效性和可行性

In chapter 2 we use harmonic 1-forms and discuss the relationship between an almost nonnegatively Ricci curved n-manifold with the first Betti number equal to n and a flat n-torus.

在第二章中我们利用调和1-形式研究了第一贝蒂数等于n且Ricci曲率几乎非负的n维黎曼流形和n维平坦环面之间的关系。

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。