W－理想与W－软代数

本文给出了Ｗ－理想与Ｗ－软代数的定义，主要结果有（Ⅰ）：（ｄ］，（ｄ＿１］分别是软代数Ｆ的同余理想，ｄ＿１≥ｄ，若（ｄ］是Ｗ－理想，则（ｄ＿１］是Ｗ－理想。（Ⅱ）：分别给出了软代数Ｆ，商软代数Ｆ／θ、软代数的直积Ｆ＝ПＦ＿ｉ是Ｗ－软代数的充分必要条件。     

软代数（Fuzzy格）的中理想及同余关系

本文主要研究软代数（Ｆｕｚｚｙ格）的内部构造．本文首次引入了反映软代数（Ｆｕｚｚｙ格）基本特性的所谓理想（Ｍ－理想）的概念．证明了任一软代数的全体中理想组成一分配格．其次讨论了软代数（Ｆｕｚｚｙ格）的同余关系，证明了全体同余关系组成一具有０，１元素的完备分配格和Ｂｒｏｕｗｅｒ格．给出了极大同余关系的存在性，讨论了软代数中“理想”跟“同余”的关系．证明了每个理想及每个元素、每个中理想都以一种确定的方式定义一同余关系．文中有趣地发现跟一般格论显著不同，在软代数（Ｆｕｚｚｙ格）里，一个理想产生的同余关系在自然映射之下，其核一般不再等于原来的理想．文中给出了使之等于原理想的充分必要条件．从而为探索同余理想（即与核相等的理想），开避了道路．本文在我们软代数讨论班上散发之后，已有四、五名学者在此基础上写出了新的论文．     

关于余模代数的Hopf—Jacobson根的一些结果

设Ｈ是Ｈｏｐｆ代数，Ａ是右Ｈ－余模代数，若（，）满射，则Ｊ（Ａ＾ｃｏＨ）＝Ｌ＾Ｈ（Ａ）∩＾ｃｏＨ，而且，若Ｊ（Ａ）是余模理想，则Ｊ（Ａ＾ｃｏＨ）＝Ｊ＾Ｈ（Ａ）∩Ａ＾ｃｏＨ。     

关于单BCI－代数的一些结果

本文讨论了单ＢＣＩ－代数．证明了一个ＢＣＩ－代数是单的当且仅当它的子代数都是单的；给出了单ｐ－半单ＢＣＩ－代数的一种表示式；证明了一个ｐ－半单ＢＣＩ－代数是单的当且仅当它的阶是素数；这样得到了一批（无限多个）单ＢＣＩ－代数；证明了商ＢＣＫ－代数Ｘ／Ａ是单的当且仅当Ａ是Ｘ的极大理想．     

关于BZ—代数中的群逆理想

证明了如下结果：如果Ａ是ＢＺ－代数Ｘ的一个理想，则Ｚ（Ａ）必是Ｘ的一个群逆理想，这里ＡＺ（Ａ）＝｛ｘ∈Ｘ｜０＊（０＊ｘ）∈Ａ｝．     

sl_2(R)上Harish-Chandra模及其应用

将ｓｌ２（Ｒ）上不可约Ｈａｒｉｓｈ－Ｃｈａｎｄｒａ模及ｓｌ２（Ｒ）上不可分解的Ｈａｒｉｓｈ－Ｃｈａｎｄｒａ模进行了完全分类，得到了与ｓｌ２（Ｃ）上模分类的不同形式．作为应用，又构造了实Ｖｉｒａｓｏｒｏ代数的一类新的不可约表示．     

BCI-代数的Fuzzy a-理想

本文的目的是引进PCI－代数的fuzzy α-理想的概念与探讨它的性质，给出了fuzzy α-理想的特征与Meng‘s扩张定理，讨论了BCI－代数中fuzzy α-理想，fuzzy q-理想与fuzzy p-理想之间的关系，从而得到一个BCI－代数的fuzzy子集是fuzzy α-理想当且仅当它是fuzzy q-理想与fuzzy p-理想。利用fuzzy α-理想与fuzzy p-理想分别刻画了结合BCI－代数与p-半单BCI－代数。此外，亦给出了fuzzy α-理想的其他性质。     

软代数的素M—理想与同余关系

在文〔１〕中，裴礼文教授引入了软代数的Ｍ－理想的概念。本文在此基础上，定义了对偶Ｍ－理想、素Ｍ－理想、素对偶Ｍ－理想等概念。并讨论了它们的若干性质及相互关系。证明了由一素Ｍ－理想，可确定软代数Ｌ的一个同余关系，这时Ｌ可同态于一个四元软代数或一三元软代数。     

一般域上无限矩阵李代数的y-型李子代数

本文在无限矩阵李代数ｇｌ_∞（Ｆ）中定义了 ｙ－型李子代数ｇｌ_∞（ｙ）和 ｓｌ_∞（ｙ），刻划了它们的结构．并证明了ｙ－型李子代数 ｇｌ_∞（ｙ）是单李代数．把文［１］中 ｇｌ_∞（Ｃ）的多项式李子代数 ｇｌ_∞（ｐ（ｔ））和ｇｌ_∞（ｐ（ｔ））在ｙ－型李子代数下得到了统一，指出了 ［１］中ｇｌ_∞（ｐ（ｔ））结构刻划的不完善情形，并在本文定理３中得到了正确的刻划。     

AF C*-代数中的Lie理想

本文描述了AF C*-代数中闭Lie理想,证明了如果AF C*-代数A中的线性流形L 是A的闭Lie理想,则存在A的闭结合理想I和A的典型masa D中的闭子代数EI使得[A,I](?)L(?)I EI,并且A中每一个这种形式的闭子空间都是A的闭Lie理想.     

On the Banach space isomorphism type of AF C*-algebras and their triangular subalgebras

It is shown that all the approximately finite dimensional C^*-algebras which are not of Type I are isomorphic as Banach spaces. This generalizes the matroid case given previously by Arazy. Analogous results are obtained for various families of triangular subalgebras of AF C^*-algebras. In addition the classification of various continua of Type I AF C^*-algebras is discussed.     

PrO-C*-代数的顺从性和核性

研究了Pro—C^*-代数的顺从性和核性．主要证明了(1)顺从Pro—C^*代数的闭理想是顺从的；(2)核Pro—C^*代数类对归纳极限封闭；(3)交换σ-C^*-代数和核C^*-代数都是核，σ-C^*-代数并且核σ-C^*-代数类对于商运算、张量积运算和可数逆向极限封闭．进一步得到核，σ-C^*-代数的扩张保持核性的条件。     

Local-to-global spectral sequences for the cohomology of diagrams

We construct local-to-global spectral sequences for the cohomology of a diagram, which compute the cohomology of the full diagram in terms of smaller pieces. These are motivated by the obstruction theory of D. Blanc et al. [D. Blanc, M.W. Johnson, J.M. Turner, On realizing diagrams of Π-algebras, Algebraic Geom. Topol. 6 (2006) 763-807] for realizing a diagram of Π-algebras, but are valid in quite general algebraic settings.     

Crossed products by finite group actions with the Rokhlin property

We prove that a number of classes of separable unital C*-algebras are closed under crossed products by finite group actions with the Rokhlin property, including: (a) AI algebras, AT algebras, and related classes characterized by direct limit decompositions using semiprojective building blocks. (b) Simple unital AH algebras with slow dimension growth and real rank zero. (c) C*-algebras with real rank zero or stable rank one. (d) Simple C*-algebras for which the order on projections is determined by traces. (e) C*-algebras whose quotients all satisfy the Universal Coefficient Theorem. (f) C*-algebras with a unique tracial state. Along the way, we give a systematic treatment of the derivation of direct limit decompositions from local approximation conditions by homomorphic images which are not necessarily injective.     

On BF-algebras

In this paper we introduce the notion of BF-algebras, which is a generalization of B-algebras. We also introduce the notions of an ideal and a normal ideal in BF-algebras. We investigate the properties and characterizations of them.      

AF C~*-代数中的子代数上的保幂等映射和局部导子

证明了从AFC-代数E中的子代数A到任意赋范代数B上的范数连续保幂等映射是Jordan同态,以及从A到任意赋范E-双模M上的局部导子是导子,从而推广了Crist关于局部导子的结果．     

Description of Real AW*-Factors of Type I

In the paper, real AW*-algebras are considered, i.e., real C*-algebras which are Baer *-rings. It is proved that every real AW*-factor of type I (i.e., having a minimal projection) is isometrically *-isomorphic to the algebra B(H) of all bounded linear operators on a real or quaternionic Hilbert space H and, in particular, is a real W*-factor. In the case of complex AW*-algebras, a similar result was proved by Kaplansky.     

On Unital Full Amalgamated Free Products of Quasidiagonal C*-Algebras

In the paper, we consider the question as to whether a unital full amalgamated free product of quasidiagonal C*-algebras is itself quasidiagonal. We give a sufficient condition for a unital full amalgamated free product of quasidiagonal C*-algebras with amalgamation over a finite-dimensional C*-algebra to be quasidiagonal. By applying this result, we conclude that the unital full free product of two AF algebras with amalgamation over a finite-dimensional C*-algebra is AF if there exists a faithful tracial state on each of the two AF algebras such that the restrictions of these states to the common subalgebra coincide.     

C~*-代数的实完全等距映射

C*-代数的*-同构一定是(完全)等距映射,反之不然.本文证明了C*-代数的实完全等距映射能够完全决定C*-代数*-同构的结论.