在无单位元下体现零模

本文用Horn函子刻划阿丁环．     

Gleeble-3800热模拟试验机故障的检测及处理

介绍了Gleeble-3800热模拟试验机运行一年来陆续出现的一些故障及对故障的排查过程和解决方法.     

新一代航空发动机燃烧室

针对新一代高油气比(0.051及以上)航空发动机燃烧室,本文提出头部采用化学恰当比直接混合燃烧设计方案.对于新一代高压比(70及以上)低排放民用航空发动机燃烧室,由于其自着火延迟时间极短,因此采用贫油直接混合燃烧,而不能采用预混合预蒸发燃烧.本文提出了一种贫油直接混合低排放燃烧室方案,其燃油空气模由简单的压力雾化喷嘴和...     

Ding分次模和强Ding分次模

研究了分次环R上的Ding分次投射(内射)R-模以及强Ding分次投射(内射)R-模,证明了任意分次环上的Ding分次投射(内射)模类是投射(内射)可解的.研究了强Ding分次投射(内射)R-模与Ding分次投射(内射)R-模之间的关系,以及强Ding分次投射(内射)R-模与非分次的强Ding投射(内射)R-模之间的关系.证明了对有限群分次环R,若M是强Ding投射(内射)R-模,则F(M)是强Ding分次投射(内射)的;若N是强Ding分次投射(内射)R-模,则U(N)是强Ding投射(内射)的.     

NUMERICAL STUDY OF STEADY LAMINAR FLOW THROUGH TUBES WITH MULTIPLE CONSTRICTIONS USING CURVILINEAR CO-ORDINATES

The flow field through tubes with multiple axisymmetric constrictions in tubes was studied numerically. Two practical problem cases were considered and the numerical scheme was developed for both. In the first case there are one, two, three and four constrictions in the tube. The effects of the number of constrictions on wall shear stress, pressure drop, streamline, vorticity and velocity distributions as the flow passes through the tube were studied and the development of the periodicity characteristics was investigated. In the second case there were multiple constrictions in the tube equidistant from each other. For this case the governing equations were reformulated for a module at a sufficient distance downstream from the inlet where the entrance region effects could be ignored and flow field is assumed to repeat itself. The flow field solutions were obtained in this region. The governing equations were formulated in curvilinear co-ordinates and a finite volume discretization procedure was used to solve the problem. The computations were carried out over a range of Reynolds numbers between 50 to 250 for constrictions with 75 percent area reduction. The method is validated by comparing some of the solutions with experimental results.     

关于Kellogg定理的若干推广

本文以连续模,光滑模为工具,讨论由单位圆至光滑的若当曲线Ｌ所范单连通区的保角映射问题,对于Ｋｅｌｌｏｇｇ定理作了较大幅度的推广,得出了新的结果。     

Structure indices for multidimensional systems

The structure indices of a one-dimensional system are an importantset of invariants. In this paper we examine a generalizationof this concept to multidimensional linear systems, which correspondsto the algebraic concept of a Hilbert series. We use the standardtheory of the Hilbert series to explain some of the previousID system-theoretic results. We discuss the computation of nDstructure indices from an initial condition set, and the invariantswhich can be derived from these indices.     

对偶双代数

在文献[1]中,作者引入了扭曲积（twistingproduct）概念,并指出量子偶（Drinfel’ddouble）D（H）为张量积代数的扭曲积．本文把扭曲积加以推广为扭曲模,并给出它的基本结构定理．同时,我们引进对偶Hopf模,它是[2]中对偶Hopf模的发展．     

关于遗传环与亚遗传环

给出了左遗传环、左亚遗传环的几个等价条件,讨论了左亚遗传环的直和,还讨论了左亚遗传环与SI-环、半单环的关系。     

Modules over double crossproducts of Skew-Hopf pairs

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