内射模的t－平坦性

设Ｒ为环，ｔ是左Ｒ－模范畴的一个遗传挠理论．文中证明了下述各点等价：（１）每个内射左Ｒ－模是ｔ－平坦的；（２）每个ｔ－有限表现左Ｒ－模的内射包络是ｔ－平坦的；（３）每个ｔ－有限表现左Ｒ－模是自由Ｒ－模的子模；（４）每个ｔ－有限表现左Ｒ－模是自反的且其对偶模是Ｈ－有限生成的．     

关于环上矩阵的广义逆

本文得到了一般带有对合反自同构的结合环上一类矩阵{1,…,i}-逆存在的充要条件,给出了{3}-逆,{4}-逆,{1,…,i}-逆的表式,而这类矩阵则概括了左右主理想整环,单Artin环(特别是体)上所有矩阵.     

FP—内射环和IF环的几个特征

本文给出了FP—内射环和IF环的如下几个特征:(l)R为右FP—内射环当且仅当任意左R—模正合列Kⁿ→Kⁿ→N→0 N为无挠模,当且仅当任一n阶矩阵环为右P—内射环;(2)R为左IF环当且仅当任一有限生成左R—模均可嵌入平坦模;(3)R为IF环当且仅当R为伪凝聚的上平坦环。     

Integrating multiple images in a sampled phase-only hologram

Past research has demonstrated that a sampled phase-only hologram(SPOH) is capable of representing an image without the magnitude component of the hologram. At present, an SPOH can only record and reconstruct a single source image. In this Letter, we propose, for the first time, to the best of our knowledge, a method for representing multiple images with a single integrated SPOH(ISPOH). Subsequently, each image can be retrieved from the ISPOH with a unique key parameter and displayed as a visible image on a phase-only spatial light modulator.     

I-semi-π-regular Rings

Let R be a ring and I an ideal of R. A ring R is called I-semi-π--regular if R/I is π-regular and idempotents of R can be strongly lifted modulo I. Characterizations of I-semi-π-regular rings are given and relations between semi-π-regular rings and semiregular rings are explored.     

复矩阵和的Drazin逆

1引 言设Cn×n为n×n复矩阵的集合,对A∈Cn×n,满足rank(Ak+1 )=rank( Ak)的最小非负整数k称为A的指标,记为Ind(A)=κ,则存在唯一矩阵AD∈Cn×n,满足下列矩阵方程组[1]:Ak=Ak+1AD AD=ADAAD AAD=ADAAD称为A的Drazin逆.若Ind(A)=1,则AD称为A的群逆,记为A#.显然Ind(A)=0当且仅当A非奇异,此时AD =A-1.     

相对复盖与包络

本文旨在给出相对复盖与包络的特征刻划．作为应用，证明了：若Ｒ为任意环，０ＡＢＣ０为左Ｒ 模正合列并且Ａ与Ｃ都有平坦复盖，则Ｂ有平坦复盖．     

关于环上矩阵的群逆与Drazin逆

本文给出了环上一类方阵有群逆，｛１，５｝－道的充要条件及其它们的表式，推广了体（域）上关于群逆的Ｃｌｉｎｅ定理．此外还首次得到了矩阵有Ｄｒａｚｉｎ逆的判别准则及其它的表式．     

正则环和GP-内射环

A ring R is called left Gp-injective if for any a∈R, there exists a positive integer n such that any left R-homomorphism of Raⁿ into R extends to one of R into R. In this paper, we prove that the centre of semiprime (left nonsingular) left GP- injective ring is regular ring, and improve some propositions in [3].     

关于左A—内射环

本文主要证明了：（1）适合右零化子升链条件的左A－内射环为QF环。（2）适合左零化子升链条件的左f-内射环为QF环。（3）若对环R的任意左理想A，B和右理想I满足r(A∩B）=r(A) r(B),rι(I)=I，则R为半完全环且有本质左基座，特别地，右CF的左A－内射环（或E(RR)为投射左R－模）为QF环。