态射的Γ-Drazin逆和柱心-幂零分解

讨论态射的Γ-Drazin逆.给出了态射的Γ-Drazin逆的一些性质和柱心-幂零分解.     

有满单分解态射的Moore-Penrose逆

态射的Moore-Penrose逆是矩阵的Moore-Penrose逆在有对合的范畴中的推广.本文给出了满态射、单态射和有“满单分解”态射存在Moore-Penrose逆的几个充分必要条件以及计算公式.这些结论和公式包括了矩阵的Moore-Pe-nrose逆的著名结果.此外,本文对引理1中已有结论的证明作了改进.     

态射的加权Moore—Penrose逆

本给出了一般态射的加权Moore-Penrose逆存在的一些新的充要条件及态射乘积的加权Moore-Penrose逆的反序律成立的充要条件，也给出了具有泛分解的态射和有核（上核）的态射的加权Moore-Penrose逆存在的一些新的充要条件及相关表达式。     

关于态射的加权Moore-Penrose逆

研究了范畴中态射 f关于态射β和γ的加权 Moore-Penrose逆 fβ,γ+,分别给出了一般态射、有满单分解态射与有核 (上核 )的 fβ,γ+存在的充要条件及其相应的表达式 ,推广了 f关于对称态射β和γ的加权Moore-Penrose逆的相应结果 .     

具有满单泛分解态射的广义逆

态射的Moore-Penrose逆是矩阵的Moore-Penrose逆在有对合＊的范畴中的推广．本文着重给出具有满单泛分解态射f的（1，3．4）-逆和Moore-Penrose存在的充要条件，同时也推广了具有泛分解广义逆的相应结果．     

加法范畴中态射的Drazin逆

本文研究了加法范畴上态射的Drazin逆。首先给出了态射和φ η与态射φ有Drazin逆的一个关系，得到了φ η的Drazin逆的一个公式，其次证明了态射φ有Drazin逆当且仅当φ^k有群逆（k为某一正整数）。最后还证明了：如果2为可逆态射，则具有Drazin逆的态射一定为两个可逆态射之和。     

态射的加权Moore-Penrose逆

该文研究范畴中态射α关于对称态射β和γ的加权Ｍｏｏｒｅ Ｐｅｎｒｏｓｅ逆αβ,γ＋ ,分别给出了一般态射、有满单分解态射与有核（上核）态射的αβ,γ＋ 存在的充要条件及其相应的表达式．     

具有泛分解的态射的广义Moore—Penrose逆

本文给出预加范畴中具泛分解和广义分解的态射的广义Moore-Penrose逆存在的条件及其表达式,推广了具泛分解态射Moore-Penrose逆的有关结果。     

态射的Drazin逆

本文研究范畴中态射的Ｄｒａｚｉｎ逆．给出了一般范畴中态射的｛１ｍ，２，５｝逆的一个等价刻划．在Ａｂｅｌ范畴中，建立指数与Ｄｒａｚｉｎ逆的概念，证明了有Ｄｒａｚｉｎ逆的态射必有柱心－幂零分解．     

关于具有泛分解的态射的广义逆

本文给出了预加范畴中具有泛分解的态射的（１,…,ｉ）－逆存在的条件及其表达式．特别地,得到了这类态射的Ｍｏｏｒｅ－Ｐｅｎｒｏｓｅ边和群逆存在的一些新的充要条件和新的表达式．     

Triharmonic morphisms between Riemannian manifolds

Polyharmonic functions have been studied in various fields. There are maps between Riemannian manifolds called harmonic morphisms and biharmonic morphisms that preserve harmonic functions and biharmonic functions respectively. In this paper, we introduce the notion of k-polyharmonic morphisms as maps that preserves polyharmonic functions of order k. For k = 3, we obtain several characterizations of triharmonic morphisms. We also give some relationships among harmonic, biharmonic, and triharmonic morphisms, and a relationship between triharmonic morphisms and p-harmonic morphisms.     

Modular Classes of Lie Algebroid Morphisms

We study the behavior of the modular class of a Lie algebroid under general Lie algebroid morphisms by introducing the relative modular class. We investigate the modular classes of pull-back morphisms and of base-preserving morphisms associated to Lie algebroid extensions. We also define generalized morphisms, including Morita equivalences, that act on the 1-cohomology, and observe that the relative modular class is a coboundary on the category of Lie algebroids and generalized morphisms with values in the 1-cohomology.     

On p -harmonic morphisms

In this paper, we study the characterisation of p -harmonic morphisms between Riemannian manifolds, in the spirit of Fuglede-Ishihara. After a result establishing that p -harmonic morphisms are precisely horizontally weakly conformal p -harmonic maps, we compare ( 2 -)harmonic morphisms and p -harmonic morphisms ( p>2 ).     

关于正则态射的广义Moore-Penrose逆

通过态射的正则性,讨论加法范畴中态射的广义Moore-Penrose逆.给出了正则态射的广义Moore-Penrose逆存在的几个充要条件以及广义Moore-Penrose逆的表达式.     

Another Approach to Topological Descent Theory

In the category T op of topological spaces and continuous functions, we prove that surjective maps which are descent morphisms with respect to the class E of continuous bijections are exactly the descent morphisms, providing a new characterization of the latter in terms of subfibrations E(X) of the basic fibration given by T op/X which are, essentially, complete lattices. Also effective descent morphisms are characterized in terms of effective morphisms with respect to continuous bijections. For classes E satisfying suitable conditions, we show that the class of effective descent morphisms coincides with the one of effective E-descent morphisms.     

效应代数上的态射性质

In the present paper the properties of morphisms in effect algebras are discussed. The conditions for the morphisms in effect algebras to be join-preservation and meet-preservation are given. From the categorical point of view, some properties of ideals, filters and congruence relations under morphisms are obtained.     

具有核的态射广义Moore-Penrose逆

本文研究了具有核的态射广义Moore-Penrose逆.利用加边态射的可逆性,获得了态射广义Moore-Penrose逆存在的一些新的充要条件及相关表达式,推广了态射Moore-Penrose逆的相应结论.     

具有广义分解的态射的广义逆

本文给出了预加范畴中态射的广义分解的概念,并研究了具有广义分解的态射的｛１,ｉ｝－逆,Ｍｏｏｒｅ－Ｐｅｎｒｏｓｅ逆存在的条件及其表达式,得到了态射的群逆及Ｄｒａｚｉｎ逆存在的充要条件,推广了具有泛分解的态射的广义逆的相应结果．