全文获取类型
收费全文 | 2405篇 |
免费 | 320篇 |
国内免费 | 117篇 |
专业分类
化学 | 84篇 |
力学 | 84篇 |
综合类 | 41篇 |
数学 | 831篇 |
物理学 | 351篇 |
无线电 | 1451篇 |
出版年
2024年 | 5篇 |
2023年 | 29篇 |
2022年 | 30篇 |
2021年 | 35篇 |
2020年 | 78篇 |
2019年 | 70篇 |
2018年 | 85篇 |
2017年 | 106篇 |
2016年 | 93篇 |
2015年 | 99篇 |
2014年 | 169篇 |
2013年 | 192篇 |
2012年 | 142篇 |
2011年 | 170篇 |
2010年 | 135篇 |
2009年 | 156篇 |
2008年 | 185篇 |
2007年 | 134篇 |
2006年 | 146篇 |
2005年 | 111篇 |
2004年 | 116篇 |
2003年 | 105篇 |
2002年 | 87篇 |
2001年 | 64篇 |
2000年 | 54篇 |
1999年 | 54篇 |
1998年 | 60篇 |
1997年 | 42篇 |
1996年 | 25篇 |
1995年 | 20篇 |
1994年 | 7篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1957年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有2842条查询结果,搜索用时 656 毫秒
131.
132.
This paper continues the study of quantised function algebrasO[G] of a semisimple group G at an lth root of unity . Thesealgebras were introduced by De Concini and Lyubashenko in 1994,and studied further by De Concini and Procesi and by Gordon,amongst others. Our main purpose here is to increase understandingof the finite-dimensional factor algebras O[G](g), for g G.We determine the representation type and block structure ofthese factors, and (for many g) describe them up to isomorphism.A series of parallel results is obtained for the quantised Borelalgebras and . 2000 Mathematical Subject Classification: 16W35,17B37. 相似文献
133.
Krishnaswami Alladi Alexander Berkovich 《Transactions of the American Mathematical Society》2002,354(7):2557-2577
This paper has a two-fold purpose. First, by considering a reformulation of a deep theorem of Göllnitz, we obtain a new weighted partition identity involving the Rogers-Ramanujan partitions, namely, partitions into parts differing by at least two. Consequences of this include Jacobi's celebrated triple product identity for theta functions, Sylvester's famous refinement of Euler's theorem, as well as certain weighted partition identities. Next, by studying partitions with prescribed bounds on successive ranks and replacing these with weighted Rogers-Ramanujan partitions, we obtain two new sets of theorems - a set of three theorems involving partitions into parts (mod 6), and a set of three theorems involving partitions into parts (mod 7), .
134.
Zhi-Guo Liu 《The Ramanujan Journal》2002,6(4):429-447
In this paper the author proves a q-expansion formula which utilizes the Leibniz formula for the q-differential operator. This expansion leads to new proofs of the Rogers–Fine identity, the nonterminating 65 summation formula, and Watson's q-analog of Whipple's theorem. Andrews' identities for sums of three squares and sums of three triangular numbers are also derived. Other identities of Andrews and new identities for Hecke type series are also discussed. 相似文献
135.
Moharram A. Khan 《Czechoslovak Mathematical Journal》2002,52(2):401-413
Let p, q and r be fixed non-negative integers. In this note, it is shown that if R is left (right) s-unital ring satisfying
, respectively) where
, then R is commutative. Moreover, commutativity of R is also obtained under different sets of constraints on integral exponents. Also, we provide some counterexamples which show that the hypotheses are not altogether superfluous. Thus, many well-known commutativity theorems become corollaries of our results. 相似文献
136.
匿名无线认证协议的匿名性缺陷和改进 总被引:9,自引:1,他引:9
分析了朱建明,马建峰提出的匿名无线认证协议的匿名性安全缺陷,提出了一种改进的匿名无线认证协议(IWAA),并用对其匿名性进行了形式化的安全分析。分析表明改进后的协议不仅实现了身份认证,而且具有很强的匿名性,满足无线网络环境匿名性的安全需求。 相似文献
137.
138.
基于Harn签名方案的远距离通行字认证方案 总被引:20,自引:3,他引:17
本文首先利用Shamir的秘密共享方法将Chang-Liao通行字认证方案转变成(t,n)共享认证方案,从而使n个认证者中任意t个人能够认证通行字的正确性。其次提出了一个基于Harn数字签名方案的远距离通行字认证方案。 相似文献
139.
Salvatore?AntociEmail author Dierck-Ekkehard?Liebscher Luigi?Mihich 《General Relativity and Gravitation》2005,37(7):1191-1203
When sources are added at their right-hand sides, and g(ik) is a priori assumed to be the metric, the equations of Einstein’s Hermitian theory of relativity were shown to allow for an exact solution that describes the general electrostatic field of n point charges. Moreover, the injunction of spherical symmetry of g(ik) in the infinitesimal neighbourhood of each of the charges was proved to yield the equilibrium conditions of the n charges in keeping with ordinary electrostatics. The tensor g(ik), however, cannot be the metric of the theory, since it enters neither the eikonal equation nor the equation of motion of uncharged test particles. A physically correct metric that rules both the behaviour of wave fronts and of uncharged matter is the one indicated by Hély.In the present paper it is shown how the electrostatic solution predicts the structure of the n charged particles and their mutual positions of electrostatic equilibrium when Hély’s physically correct metric is adopted. 相似文献
140.