全文获取类型
收费全文 | 2528篇 |
免费 | 275篇 |
国内免费 | 328篇 |
专业分类
化学 | 54篇 |
晶体学 | 1篇 |
力学 | 215篇 |
综合类 | 34篇 |
数学 | 2185篇 |
物理学 | 642篇 |
出版年
2023年 | 27篇 |
2022年 | 26篇 |
2021年 | 30篇 |
2020年 | 51篇 |
2019年 | 58篇 |
2018年 | 69篇 |
2017年 | 67篇 |
2016年 | 75篇 |
2015年 | 69篇 |
2014年 | 115篇 |
2013年 | 193篇 |
2012年 | 66篇 |
2011年 | 135篇 |
2010年 | 95篇 |
2009年 | 155篇 |
2008年 | 193篇 |
2007年 | 158篇 |
2006年 | 169篇 |
2005年 | 134篇 |
2004年 | 131篇 |
2003年 | 148篇 |
2002年 | 162篇 |
2001年 | 120篇 |
2000年 | 106篇 |
1999年 | 97篇 |
1998年 | 88篇 |
1997年 | 81篇 |
1996年 | 63篇 |
1995年 | 31篇 |
1994年 | 37篇 |
1993年 | 22篇 |
1992年 | 19篇 |
1991年 | 19篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有3131条查询结果,搜索用时 140 毫秒
61.
Dao-sheng Zheng 《计算数学(英文版)》1998,(2)
1.IntroductionSince1984,severalchinesemathematicianshaveobtailledmanyresultsboutmatrixoperatornormcondition.umbe.[ll'12'18].Twokindsmatrixconditionnllmbers[9]are:(1)IfAECoxsisnonsingular,thellunlberK.(A)~IIAll.llA--'if.iscalledtheor--normconditionnumberof… 相似文献
62.
63.
S. Fumeron P. Ben-Abdallah 《Journal of Quantitative Spectroscopy & Radiative Transfer》2006,97(2):195-208
The aim of this paper is to present several features of the couplings occurring between radiative transfer and the kinetics of a moving dielectric. After determining how the velocity field affects the apparent thermo-optical properties of matter, the energy transport problem is investigated in instationary regime and the general form of transient radiative transfer equation inside a moving medium is built. Then, the model is applied to the particular case of turbulent flows: a system of two equations for mean and fluctuating radiative energies is presented, and the resolution of this system is finally carried out. 相似文献
64.
设x:M→Sn 1(n≥3)是n 1-维单位球中的无脐点超曲面, Mobius不变量G,Φ,A和B分别表示x的Mobius度量, Mobius形式, Blaschke形式和Mobius第二基本形式.本文证明了如果x的Mobius形式Φ平行,并且A λG μB=0,其中λ,μ分别是定义在M上的光滑函数,那么Φ=0,由此及李海中、王长平(2003年)文献中的分类定理给出了Sn 1中具有平行的Mobius形式及满足A λG μB=0的超曲面的分类.此结果推广了他们及张廷枋(2003年)文献中的结果. 相似文献
65.
We consider a four-dimensional generalization of Hess–Appel’rot system and costruct its Lax pair. Both classical and algebro-geometric integration procedure are proceeded. The algebro-geometric integration is based on deep facts from geometry of Prym varieties such as the Mumford relation and Mumford-Dalalyan theory. The integration is similar to the integration of Lagrange bitop which has recetly been performed by the authors. 相似文献
66.
Ali Ghaffari 《Proceedings Mathematical Sciences》2007,117(2):177-183
In this paper, among other things, we state and prove the mean ergodic theorem for amenable semigroup algebras. 相似文献
67.
Cheikh Birahim Ndiaye 《Journal of Functional Analysis》2007,251(1):1-58
Working in a given conformal class, we prove existence of constant Q-curvature metrics on compact manifolds of arbitrary dimension under generic assumptions. The problem is equivalent to solving a nth-order non-linear elliptic differential (or integral) equation with variational structure, where n is the dimension of the manifold. Since the corresponding Euler functional is in general unbounded from above and below, we use critical point theory, jointly with a compactness result for the above equation. 相似文献
68.
We define nontempered (exponential growth) function spaces on the Lie group ax+b which are stable under some left-invariant (convergent) star product. The techniques used to achieved the latter come from symmetric spaces geometry and star representation theory. 相似文献
69.
A. DowJ. Vermeer 《Topology and its Applications》1993,50(3):263-282
A characterization of compact subspaces of extremally disconnected spaces is given which is similar to Gleason's characterization that the extremally disconnected spaces are projective for the class of compact spaces. An equivalence is established between the questions of whether every basically disconnected space is embeddable into an extremally disconnected space and the Borel lifting problems for the category algebras of generalized Cantor cubes. We study an inductive method of strengthening the product topology on the Cantor cubes to extremally disconnected topologies and use this to establish, from CH, that every compact F-space of weight c+ embeds into an extremally disconnected space. 相似文献
70.
Carlo Cercignani 《Journal of statistical physics》1990,58(5-6):817-823
The problem of finding the summational collision invariants for the Boltzmann equation is tackled with the aim of proving that the most general solution of the problem is not different from the standard one even when the equation defining a collision invariant is only satisfied almost everywhere inR
3×R
3×S
2. The collision invariant is assumed to be in the Hilbert spaceH
of the functions which are square integrable with respect to a Maxwellian weight. 相似文献