n-余挠模和n-平坦模（英文）  

n-cotorsion Modules and n-fiat Modules

作　　者：张树林[1] 刘万利 ZHANG Shulin;LIU Wanli(Xuzhou Vocational Technology Academy of Finance and Economics,Xuzhou,Jiangsu,221008,P.R.China;Department of Mathematics,Xuzhou University of Technology,Xuzhou,Jiangsu,221018,P.R.China)

机构地区：[1]江苏省徐州财经高等职业技术学校,徐州江苏221008 [2]徐州工程学院数学系,徐州江苏221018

出　　处：《数学进展》2018年第5期667-675,共9页Advances in Mathematics（China）

基　　金：Supported by NSFC(No.41504032)

摘　　要：本文引入n-余挠模并给出一些性质,证明了右n-凝聚环上一类n-凝聚左R-模是包络的,证明了一类n-平坦左R-模是覆盖的和预包络的,研究了由n-平坦预覆盖和预包络诱导的n-平坦维数.In this paper, we introduce n-cotorsion modules and study some properties of them. Over right n-coherent rings, we prove that the class of n-cotorsion left R-modules is enveloping. Furthermore, we prove the class of n-flat left R-modules is covering and preenveloping and investigate the n-flat dimensions induced by n-flat precovers and preenvelopes.

关 键 词：N-平坦模 n-余挠模 n-平坦维数 

分 类 号：O154.2[理学—数学]