首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12篇
  免费   2篇
  国内免费   7篇
数学   17篇
物理学   4篇
  2020年   1篇
  2019年   1篇
  2017年   1篇
  2014年   1篇
  2010年   5篇
  2008年   2篇
  2007年   2篇
  2006年   4篇
  2004年   1篇
  2002年   1篇
  1997年   1篇
  1981年   1篇
排序方式: 共有21条查询结果,搜索用时 15 毫秒
1.
A semigroup S with a sub-band B is called a good B-quasi-Ehresmann semigroup if it is a Bsemiabundant semigroup satisfying the congruence condition such that B((ab)+)abB((ab)*)aB(a*)B(b+)b for all a,b ∈S.We show that every good B-quasi-Ehresmann semigroup has a global representation and a standard representation.As a special case,the structure of good quasi-adequate semigroups is described.  相似文献   
2.
关于子群的两种广义正规性的注记   总被引:16,自引:0,他引:16  
群G的一个子群H称为在G中具有半覆盖远离性,如果存在G的一个主群列1=Go<G1<…<Gl=G,使得对每一i=1,…,l或者H覆盖Gj/Gj-1或者H远离Gj/Gj-1.本文证明了子群的半覆盖远离性是子群C-正规性和子群的覆盖远离性之推广.进一步应用极大子群和Sylow子群给出了有限群为可解群的一些特征.  相似文献   
3.
超模的同构定理   总被引:1,自引:1,他引:0  
本文利用模论导出超模的三个同构定理,同时,给出超模的Jordan-Holder定理,最后,探讨了超模的基本关系∈~*,并研究其性质.  相似文献   
4.
A U-abundant semigroup S in which every H-class of S contains an element in the set of projections U of S is said to be a U-superabundant semigroup.This is an analogue of regular semigroups which are unions of groups and an analogue of abundant semigroups which are superabundant.In 1941,Clifford proved that a semigroup is a union of groups if and only if it is a semilattice of completely simple semigroups.Several years later,Fountain generalized this result to the class of superabundant semigroups.In this p...  相似文献   
5.
In this paper we introduce the notion of a group ideal in a semigroup. We shall prove that all group ideals of a compact affine semigroup are convex and dense. This generalizes many results in the literature concerning ideals in semigroups.  相似文献   
6.
We theoretically discuss 40 Gb/s semiconductor optical amplifier (SOA)-based wavelength conversion (WC) using a detuning optical bandpass Jilter based on ultrafast dynamic characteristics of SOA. Both the inverted and noninverted WCs are obtained by shifting the filter central wavelength with respect to the probe wavelength when input data signal is in return-to-zero (RZ) format. However, we can obtain format conversion from nonreturn- to-zero (NRZ) to pseudo-return-to-zero (PRZ) and inverted WC when the input signal is in NRZ format.  相似文献   
7.
We introduce the notions of implicative ideals and fuzzy implicative ideals of a distributive implication groupoid. Some properties of these ideals will be investigated. In particular, the necessary and sufficient conditions for an ideal (fuzzy ideal) to be an implicative ideal (fuzzy implicative ideal) is given. By using the concept of level sets, we will characterize the fuzzy implicative ideals of a distributive implication groupoid. Finally, an extension property for fuzzy implicative ideals is given.  相似文献   
8.
Fuzzy graph theory is used for solving real-world problems in different fields, including theoretical computer science, engineering, physics, combinatorics and medical sciences. In this paper, we present conepts of bipolar neutrosophic multigraphs, bipolar neutrosophic planar graphs, bipolar neutrosophic dual graphs, and study some of their related properties. We also describe applications of bipolar neutrosophic graphs in road network and electrical connections.  相似文献   
9.
Employing the Mueller matrix method with polar decomposition, we analyse the polarization rotation (PR) effects in semiconductor optical amplifiers (SOAs) and demonstrate that the PR angle is linear to the birefringence dependent gain while the average PR coefficient is about 0.625 for the employed SOA. It is further evident that the current and optical intensity dependent PRs rotate reversely around the same axis. Thus we propose an optical-electric synchronous control scheme to obtain orthogonal polarization states with power-equalization, and implement it by a polarization-sensitive SOA. The polarization duration time is about 10 ns which is applicable to high-speed polarization state generation.  相似文献   
10.
The concepts of L*-inverse semigroups and left wreath products of semigroups are introduced. It is shown that the L*-inverse semigroup can be described as the left wreath product of a type A semigroupΓand a left regular band B together with a mapping which maps the semigroupΓinto the endomorphism semigroup End(B). This result generalizes the structure theorem of Yamada for the left inverse semigroups in the class of regular semigroups. We shall also provide a constructed example for the L*-inverse semigroups by using the left wreath products.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号