全文获取类型
收费全文 | 4699篇 |
免费 | 261篇 |
国内免费 | 570篇 |
专业分类
化学 | 44篇 |
晶体学 | 2篇 |
力学 | 47篇 |
综合类 | 68篇 |
数学 | 4945篇 |
物理学 | 424篇 |
出版年
2024年 | 7篇 |
2023年 | 88篇 |
2022年 | 42篇 |
2021年 | 67篇 |
2020年 | 89篇 |
2019年 | 126篇 |
2018年 | 134篇 |
2017年 | 136篇 |
2016年 | 144篇 |
2015年 | 101篇 |
2014年 | 188篇 |
2013年 | 365篇 |
2012年 | 156篇 |
2011年 | 224篇 |
2010年 | 219篇 |
2009年 | 340篇 |
2008年 | 379篇 |
2007年 | 353篇 |
2006年 | 326篇 |
2005年 | 280篇 |
2004年 | 218篇 |
2003年 | 204篇 |
2002年 | 197篇 |
2001年 | 155篇 |
2000年 | 158篇 |
1999年 | 155篇 |
1998年 | 127篇 |
1997年 | 132篇 |
1996年 | 84篇 |
1995年 | 46篇 |
1994年 | 39篇 |
1993年 | 18篇 |
1992年 | 19篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 21篇 |
1984年 | 18篇 |
1983年 | 11篇 |
1982年 | 20篇 |
1981年 | 9篇 |
1980年 | 23篇 |
1979年 | 12篇 |
1978年 | 15篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1936年 | 3篇 |
排序方式: 共有5530条查询结果,搜索用时 671 毫秒
101.
We prove the Cramér theorem forK-invariant Gaussian measures on irreducible symmetric spacesX=G/K withG semisimple noncompact. To do this we use a kind of Abel transform ofK-invariant measures onX.This research is supported by KBN Grant. 相似文献
102.
Alexander Koldobsky 《Journal of Theoretical Probability》1994,7(1):135-145
Let μ be a measure in a Banach spaceE, f be an even function onR. We consider the potentialg(a)=f E f(‖x?a‖)dμ(x). The question is as follows: For whichf does the potentialg determine μ uniquely? In this article we give answers in the cases whereE=l ∞ n and wheref(t)=|t| p andE is a finite dimensional Banach space with symmetric analytic norm. Calculating the Fourier transform of the functionf(‖x‖ ∞) we give a new proof of the J. Misiewicz's result that the functionf(‖x‖ ∞) is positive definite only iff is a constant function. 相似文献
103.
B. Aspacher W. Frank P. Kizler K. Maier 《Applied Physics A: Materials Science & Processing》1994,59(4):339-348
In previous Perturbed-Angular-Correlation (PAC) studies of the - emission of 111In probe nuclei in cold-worked or particle-irradiated nickel, it has been found that thermal annealing in the temperature regime of recovery stage III leads to the formation of so-called C-defects (Cubic defects). This is indicated by the occurrence of a new frequency of about 80 Mrad/s, in addition to the frequency (200 Mrad/s) that is due to 111In on substitutional sites. Obviously, the C-defects are complexes consisting of 111In and the intrinsic point-defect species that migrates freely in recovery stage III. Therefore, they have played an important rôle in the long-standing controversy on whether the recovery-stage-III defects are vacancies (one-interstitial model) or self-interstitials (two-interstitial model). The present paper reports on a novel experimental effort to reveal the nature of the C-defects by combining PAC studies on nickel samples differently pretreated in a systematic way, investigations of the Extended X-ray Absorption Fine Structure (EXAFS) on In-doped nickel, and measurements of the decay rate of 111In nuclei in the Electron-Capture-Induced Decay (ECID). On the basis of the results of these experiments it is concluded that the defects trapped by substitutional 111In atoms (Ins) in recovery stage III are self-interstitials (I), as expected according to the two-interstitial model. Moreover, there is evidence that the C-defects are In interstitials on tetrahedral sites (Ini) that form exclusively in the vicinity of the specimen surface from Ins – I pairs via the reaction Ins+I Ini. 相似文献
104.
Let and be real Banach spaces. A map between and is called an -bi-Lipschitz map if for all . In this note we show that if is an -bi-Lipschitz map with from onto , then is almost linear. We also show that if is a surjective -bi-Lipschitz map with , then there exists a linear isomorphism such that
where as and .
105.
Classical verigin problem as a limit case of verigin problem with surface tension at free boundary 总被引:1,自引:0,他引:1
TAOYOUSHAN YIFAHUAI 《高校应用数学学报(英文版)》1996,11(3):307-322
In this psper we consider Verigin problem with surface tension st free 相似文献
106.
Friedbert Prü fer Franco Tricerri Lieven Vanhecke 《Transactions of the American Mathematical Society》1996,348(11):4643-4652
We first prove that a Riemannian manifold with globally constant additive Weyl invariants is locally homogeneous. Then we use this result to show that a manifold whose Laplacian commutes with all invariant differential operators is a locally homogeneous space.
107.
Eva Matousková Charles Stegall 《Proceedings of the American Mathematical Society》1996,124(4):1083-1090
A Banach space is not reflexive if and only if there exist a closed separable subspace of and a convex closed subset of with empty interior which contains translates of all compact sets in . If, moreover, is separable, then it is possible to put .
108.
V. I. Chilin P. G. Dodds A. A. Sedaev F. A. Sukochev 《Transactions of the American Mathematical Society》1996,348(12):4895-4918
We present several characterizations of Kadec-Klee properties in symmetric function spaces on the half-line, based on the -functional of J. Peetre. In addition to the usual Kadec-Klee property, we study those symmetric spaces for which sequential convergence in measure (respectively, local convergence in measure) on the unit sphere coincides with norm convergence.
109.
Jun-ichi Tanaka 《Transactions of the American Mathematical Society》1996,348(10):4113-4129
Using the Stone-\v{C}ech compactification of integers, we introduce a free extension of an almost periodic flow. Together with some properties of outer functions, we see that, in a certain class of ergodic Hardy spaces , , the corresponding subspaces are all singly generated. This shows the existence of maximal weak- Dirichlet algebras, different from of the disc, for which the single generator problem is settled.
110.
Bolis Basit Hans Gü nzler 《Transactions of the American Mathematical Society》1996,348(11):4489-4500
Let be a semigroup and a topological space. Let be an Abelian topological group. The right differences of a function are defined by for . Let be continuous at the identity of for all in a neighbourhood of . We give conditions on or range under which is continuous for any topological space . We also seek conditions on under which we conclude that is continuous at for arbitrary . This led us to introduce new classes of semigroups containing all complete metric and locally countably compact quasitopological groups. In this paper we study these classes and explore their relation with Namioka spaces.