代数扩张

This process is actually the process of algebraic extension; also it is the basic way of algebra: organizing some objects into an operation system, and then study the relationship between elements or parts of the system.

这实际上是代数扩张的做法，也是代数的本质：将一些对象组织成一个运算体系，研究这个体系中各个个体之间以及部分与全体之间的关系。

In the second part , according to the spirit of algebraic extension , we first introduce the definition of coalgebra extension and trivial extension of a coalgebra .

在第一节，我们介绍了代数扩张，代数平凡扩张，Frobenius代数，coFrobenius余代数等概念，着重阐述了引理1.5。，即引理1.5。

Computing integral closure of a finite extension is not only an important problem in commutative algebra, but also in algebraic geometry and algebraic number theory.

计算有限扩张的整闭包不但是交换代数中的一个核心问题，也很受代数几何以及代数数论发展的推动。

Based on the methods and techniques of covering theory, the structure of module category of tame concealed algebra, one-point extension, vector space category, finite enlargement, degeneration theory, stable equivalence and combinatorial method, we will classify all of the three-point algebras with Gabriel quiver the system quiver Q according to representation type. We get the classification theorem: Let A=kQ/I be a three-point algebra given by the system quiver Q.

本文综合利用覆盖理论，tame concealed代数模范畴的结构，单点扩张，向量空间范畴，有限enlargement，退化理论，稳定等价以及组合的方法等多种方法和技巧，将所有由系统箭图Q给出的三点代数按表示型进行分类，得到如下分类定理：Q是系统箭图，I是kQ的一个admissible理想。

We give some examples of BiFrobenius algebras based on the extensions of algebras and coalgebras . Let H be a bialgebra of finite dimension . Then T= H⊕H* has an algebra structure and a coalgebra structure also . We discuss the properties of T , and get the necessary and sufficient condition for T to be a BiFrobenius algebra .

然后根据代数余代数的平凡扩张给出一类BiFrobenius代数的例子，设H是有限维双代数， T= H⊕H*既有代数结构也有余代数结构，研究T的性质，给出了T成为BiFrobenius代数的充要条件，即定理3.9。

Lastly,Using the extension theory of〓-algebras founded and developed by Brown-Douglas-Fillmore in 70s,inparticular,using the homotopy invariance of the extensions and the indexformule of Toeplitz operator matrices,the paper characterized the automorphismgroup of the continuous function symbol Toeplitz 〓-algebra in terms of thetopological degrees of the continuous mappings on the n-dimensional sphere.

最后，本文利用Brown-Douglas-Fillmore在七十年代建立并发展起来的C*-代数扩张理论，尤其是扩张的同伦不变性，以及Toeplitz算子矩阵的指标公式，通过球面上连续映射的拓扑度，刻划了高维球面Hardy空间上连续符号Toeplitz 〓代数的自同构群。

By using Jordan-Hlder type theorem of table algebras, we prove that table algebras satisfying nilpotent extension condition are nilpotent, which does not correspond to extension problems of nilpotent groups exactly.

本文研究了幂零表代数的一个有趣的性质，利用表代数的Jorda-Hlder型定理，证明了表代数满足幂零被幂零扩张仍是幂零的，但有限幂零群没有这样的扩张。

The so-called AT-algebras are inductive limits of finite direct sums of matrices over the extension algeras of circle algebra by K, where K is the C~*— algebra of all compact operators on a separable infinite dimensional Hilbert space.

若V_*与V_*同构，且保持单位元等价类；T与T仿射同胚，且同构映射与同胚映射相容，则存在E与E′的同构导出上述同构和同胚，所谓AT-代数即为圆代数通过κ的本质酉扩张的矩阵代数的有限直和的归纳极限，这里κ为可分的无限维复Hilbert空间上的紧算子全体，不变量中的V*为三变元Abel半群，T为迹态空间，[1]为单位元所在的Murray-von Neumann等价类，r_E为连接映射。

In the fifth chapter,we study dipolarizations in some quadratic Lie algebras.Inthe first section,we obtain some results on the classification of dipolarizations in gen-eral quadratic Lie algebras,and prove that there exist dipolarizations in the solvablequadratic Lie algebras whose Cartan subalgebras consist of semisimple elements.

第五章讨论了某些二次李代数的双极化，在第一节中，我们给出了二次李代数的双极化的一些分类结果；特别证明Cartan子代数是由半单元组成的二次李代数上存在双极化，第二节确定了四维扩张Heisenberg代数的所有双极化，在第三节中，我们构造了2n+2维扩张Heisenberg代数的六类双极化，我们发现两个不同于半单李代数情形的有趣事实：（1）在扩张Heisenberg代数上同时存在对称和非对称双极化；（2）对应于扩张Heisenberg代数的双极化的特征元有的是半单的有的是幂零的。

In this paper, we characterize the multiplier algebras of JC-algebras by double centralizers , and study the relationship between multiplier algebra M of complex C*-algebra A and C*-algebra C* M(Asa generated by the multiplier algebra of JC-algebra Asa, the self-adjoint part of A, Finally, we study the extension of JB-algebras.

本文用双中心子刻画了JC代数的乘子代数，并且研究了复C*－代数的自伴部分的乘子代数生成的C*－代数与原C*－代数的乘子代数之间的关系，最后研究了JB代数的扩张。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。