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   114篇
  免费   4篇
  国内免费   12篇
化学   2篇
力学   2篇
综合类   5篇
数学   111篇
物理学   10篇
  2023年   2篇
  2022年   2篇
  2021年   2篇
  2020年   2篇
  2019年   5篇
  2018年   1篇
  2017年   1篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   1篇
  2012年   1篇
  2011年   4篇
  2010年   4篇
  2009年   7篇
  2008年   4篇
  2007年   3篇
  2006年   5篇
  2005年   7篇
  2004年   7篇
  2003年   6篇
  2002年   12篇
  2001年   6篇
  2000年   5篇
  1999年   4篇
  1998年   4篇
  1997年   7篇
  1996年   5篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   4篇
  1990年   3篇
  1989年   2篇
  1984年   2篇
  1982年   2篇
  1978年   1篇
排序方式: 共有130条查询结果,搜索用时 15 毫秒
51.
冯良贵 《数学研究》2000,33(1):27-30
对于可换环R,本通过考察SpecR和H0R,得到了关于广义素环和广义半素环的一些结果,另一方面,本还得到了有关连通性与道路连通性的几个结果。  相似文献   
52.
This paper studies the connectedness of the cone superefficient point set in locally convex topological vector spaces. First, we prove a scalarization theorem for a cone superefficient point set. From this result, we obtain the connectedness of a cone superefficient point set under the conditions that the set is cone convex and cone weakly compact.  相似文献   
53.
研究了赋予Vietoris拓扑的超空间2X的连通性及其相关性质.这改进了Micheal[1]的一个定理的结论.  相似文献   
54.
We present a topological minimax theorem (Theorem 2.2). The topological assumptions on the spaces involved are somewhat weaker than those usually found in the literature. Even when reinterpreted in the convex setting of topological vector spaces, our theorem yields nonnegligible improvements, for example, of the Passy–Prisman theorem and consequently of the Sion theorem, contrary to most results on topological minimax. This work is part of our ongoing effort to elaborate a coherent theory of minimax.  相似文献   
55.
The aim of the present paper is to describe all connected monounary algebras for which there exists a representation by means of connected monounary algebras which are retract irreducible in the class c (or in ). This work was supported by the Slovak Grant VEGA 1/0423/03.  相似文献   
56.
The sporadic simple group F 2 known as Fischer's Baby Monster acts flag-transitively on a rank 5 P-geometry . P-geometries are geometries with string diagrams, all of whose nonempty edges except one are projective planes of order 2 and one terminal edge is the geometry of the Petersen graph. Let be a flag-transitive P-geometry of rank 5. Suppose that each proper residue of is isomorphic to the corresponding residue in . We show that in this case is isomorphic to . This result realizes a step in classification of the flag-transitive P-geometries and also plays an important role in the characterization of the Fischer–Griess Monster in terms of its 2-local parabolic geometry.  相似文献   
57.
This article shows that in Aharonov-Bohm (AB) effect arrangements, the electron wave propagation space is doubly connected for two real coherent sources, and simply connected under certain condition for two virtual coherent sources, and all known AB experiments belong to the latter case. By the Feynman path integral method, we show that in the former case there is no AB effect, whereas in the latter case there is.  相似文献   
58.
We introduce and study the concepts of connectedness and local connectedness in σ-frames. We also consider the local connectedness of the Stone-Čech compactification of a regular σ-frame.   相似文献   
59.
利用代数的方法研究了粗糙有限状态机的可恢复性与连通性,通过前驱与后继的关系,给出了粗糙有限状态机的可恢复性、连通性与可分离性的一些刻画,讨论了粗糙有限状态机的一些基本性质.  相似文献   
60.
The affine synthesis operator is shown to map the coefficient space p (ℤ+×ℤ d ) surjectively onto L p (ℝ d ), for p∈(0,1]. Here ψ j,k (x)=|det a j |1/p ψ(a j xk) for dilation matrices a j that expand, and the synthesizer ψL p (ℝ d ) need satisfy only mild restrictions, for example, ψL 1(ℝ d ) with nonzero integral or else with periodization that is real-valued, nontrivial and bounded below. An affine atomic decomposition of L p follows immediately:
Tools include an analysis operator that is nonlinear on L p . Laugesen’s travel was supported by the NSF under Award DMS–0140481.  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