全文获取类型
收费全文 | 7887篇 |
免费 | 519篇 |
国内免费 | 731篇 |
专业分类
化学 | 150篇 |
力学 | 349篇 |
综合类 | 113篇 |
数学 | 7646篇 |
物理学 | 879篇 |
出版年
2024年 | 11篇 |
2023年 | 91篇 |
2022年 | 105篇 |
2021年 | 105篇 |
2020年 | 181篇 |
2019年 | 195篇 |
2018年 | 170篇 |
2017年 | 213篇 |
2016年 | 196篇 |
2015年 | 179篇 |
2014年 | 355篇 |
2013年 | 621篇 |
2012年 | 291篇 |
2011年 | 411篇 |
2010年 | 371篇 |
2009年 | 467篇 |
2008年 | 564篇 |
2007年 | 572篇 |
2006年 | 489篇 |
2005年 | 478篇 |
2004年 | 359篇 |
2003年 | 379篇 |
2002年 | 295篇 |
2001年 | 268篇 |
2000年 | 235篇 |
1999年 | 229篇 |
1998年 | 217篇 |
1997年 | 209篇 |
1996年 | 139篇 |
1995年 | 89篇 |
1994年 | 72篇 |
1993年 | 61篇 |
1992年 | 54篇 |
1991年 | 56篇 |
1990年 | 32篇 |
1989年 | 30篇 |
1988年 | 33篇 |
1987年 | 19篇 |
1986年 | 26篇 |
1985年 | 41篇 |
1984年 | 30篇 |
1983年 | 20篇 |
1982年 | 25篇 |
1981年 | 31篇 |
1980年 | 20篇 |
1979年 | 26篇 |
1978年 | 24篇 |
1977年 | 17篇 |
1976年 | 16篇 |
1973年 | 6篇 |
排序方式: 共有9137条查询结果,搜索用时 15 毫秒
991.
Jan Melin 《Journal of Mathematical Analysis and Applications》2005,303(1):81-89
We use the theory of distributions to extend the Poincaré-Bendixson theorem and the Bendixson criterion to piecewise Lipschitz continuous system possessing unique and continuous solutions. We demonstrate the use of these extensions by several examples that have recently appeared in the literature. 相似文献
992.
Carlo Bertoluzza Pedro Miranda Pedro Gil 《International Journal of Approximate Reasoning》2005,40(3):127-146
In this paper we propose a generalization of the concept of the local property for divergence measures. These new measures will be called g-local divergence measures, and we study some of their properties. Once this family is defined, a characterization based on Ling’s theorem is given. From this result, we obtain the general form of g-local divergence measures as a function of the divergence in each element of the reference set; this study is divided in three parts according to the cardinality of the reference set: finite, infinite countable or non-countable. Finally, we study the problem of componible divergence measures as a dual concept of g-local divergence measures. 相似文献
993.
本文基于Mellin变换法求解复杂更一般形式的对偶积分方程组.通过积分变换,由实数域化成复数域上的方程组,引入未知函数的积分变换,移动积分路径,应用Cauchy积分定理,实现退耦正则化为Cauchy奇异积分方程组,由此给出一般性解,并严格证明了对偶积分方程组退耦正则化为Cauchy奇异积分方程组与原对偶积分方程组等价性,以及对偶积分方程组解的存在性和唯一性.给出的解法和理论解,作为求解复杂对偶积分方程组一种有效解法,可供求解复杂的数学、物理、力学中的混合边值问题应用. 相似文献
994.
CHO Min-hyung 《数学季刊》2005,20(2):137-140
The classical countable summation type Hahn-Schur theorem is a famous result in summation theory and measure theory. An interesting problem is whether the theorem can be generalized to non-countable summation case? In this paper, we show that the answer is true. 相似文献
995.
Claus Müller 《Journal of Mathematical Analysis and Applications》2002,269(2):401-420
We extend the Trotter-Kato theorem on C0-semigroups to local convoluted semigroups on dual spaces and apply these results to the general Banach space setting. Compared to known results we obtain weaker convergence assumptions on the resolvent. 相似文献
996.
Michael Voit 《Journal of multivariate analysis》1996,59(2):230-248
Forn2, let (μxτ, n)τ0be the distributions of the Brownian motion on the unit sphereSn
n+1starting in some pointxSn. This paper supplements results of Saloff-Coste concerning the rate of convergence ofμxτ, nto the uniform distributionUnonSnforτ→∞ depending on the dimensionn. We show that,[formula]forτn:=(ln n+2s)/(2n), where erf denotes the error function. Our proof depends on approximations of the measuresμxτ, nby measures which are known explicitly via Poisson kernels onSn, and which tend, after suitable projections and dilatations, to normal distributions on
forn→∞. The above result as well as some further related limit results will be derived in this paper in the slightly more general context of Jacobi-type hypergroups. 相似文献
997.
The no-free-lunch theorem of optimization (NFLT) is an impossibility theorem telling us that a general-purpose, universal optimization strategy is impossible. The only way one strategy can outperform another is if it is specialized to the structure of the specific problem under consideration. Since optimization is a central human activity, an appreciation of the NFLT and its consequences is essential. In this paper, we present a framework for conceptualizing optimization that leads to a simple but rigorous explanation of the NFLT and its implications. 相似文献
998.
Brice Franke 《Journal of Theoretical Probability》2007,20(4):1087-1100
We prove a functional non-central limit theorem for jump-diffusions with periodic coefficients driven by stable Lévy-processes
with stability index α>1. The limit process turns out to be an α-stable Lévy process with an averaged jump-measure. Unlike in the situation where the diffusion is driven by Brownian motion,
there is no drift related enhancement of diffusivity. 相似文献
999.
研究利用Lie对称的生成元τ(t,q,q·)和ξs(t,q,q·)来构造广义H ojman守恒 量,并讨论三种特殊情况,研究表明:Hojman守恒量是该广义守恒量的特例,且在Lie对称 的生成元的形式为τ(t,q)和ξs(t,q)时,该广义Hojman守恒量可以导出Lu tzky守恒 量,此外,还给出一个排除平凡守恒量的条件.最后,给出两个简单例子,作为所获得结果 的说明.
关键词:
动力学系统
广义Hojman定理
Lie对称
守恒量 相似文献
1000.
Quantum information processing is at the crossroads of physics, mathematics and computer science. It is concerned with what
we can and cannot do with quantum information that goes beyond the abilities of classical information processing devices.
Communication complexity is an area of classical computer science that aims at quantifying the amount of communication necessary
to solve distributed computational problems. Quantum communication complexity uses quantum mechanics to reduce the amount
of communication that would be classically required.
Pseudo-telepathy is a surprising application of quantum information processing to communication complexity. Thanks to entanglement,
perhaps the most nonclassical manifestation of quantum mechanics, two or more quantum players can accomplish a distributed
task with no need for communication whatsoever, which would be an impossible feat for classical players. After a detailed
overview of the principle and purpose of pseudo-telepathy, we present a survey of recent and not-so-recent work on the subject.
In particular, we describe and analyse all the pseudo-telepathy games currently known to the authors.
Supported in Part by Canada’s Natural Sciences and Engineering Research Council (NSERC), the Canada Research Chair programme
and the Canadian Institute for Advanced Research (CIAR).
Supported in part by a scholarship from Canada’s NSERC.
Supported in part by Canada’s NSERC
Québec’s Fonds de recherche sur la nature et les technologies (FQRNT), the CIAR and the Mathematics of Information Technology
and Complex Systems Network (MITACS). 相似文献