全文获取类型
收费全文 | 3661篇 |
免费 | 77篇 |
国内免费 | 25篇 |
专业分类
化学 | 2603篇 |
晶体学 | 33篇 |
力学 | 94篇 |
数学 | 506篇 |
物理学 | 527篇 |
出版年
2022年 | 18篇 |
2021年 | 27篇 |
2020年 | 33篇 |
2019年 | 37篇 |
2018年 | 28篇 |
2017年 | 30篇 |
2016年 | 64篇 |
2015年 | 58篇 |
2014年 | 63篇 |
2013年 | 186篇 |
2012年 | 175篇 |
2011年 | 216篇 |
2010年 | 103篇 |
2009年 | 82篇 |
2008年 | 212篇 |
2007年 | 218篇 |
2006年 | 191篇 |
2005年 | 179篇 |
2004年 | 185篇 |
2003年 | 146篇 |
2002年 | 138篇 |
2001年 | 43篇 |
2000年 | 40篇 |
1999年 | 39篇 |
1998年 | 39篇 |
1997年 | 46篇 |
1996年 | 61篇 |
1995年 | 55篇 |
1994年 | 56篇 |
1993年 | 43篇 |
1992年 | 34篇 |
1991年 | 34篇 |
1990年 | 43篇 |
1989年 | 34篇 |
1988年 | 46篇 |
1987年 | 46篇 |
1986年 | 41篇 |
1985年 | 77篇 |
1984年 | 54篇 |
1983年 | 54篇 |
1982年 | 66篇 |
1981年 | 56篇 |
1980年 | 61篇 |
1979年 | 41篇 |
1978年 | 36篇 |
1977年 | 40篇 |
1976年 | 25篇 |
1975年 | 27篇 |
1974年 | 34篇 |
1973年 | 32篇 |
排序方式: 共有3763条查询结果,搜索用时 31 毫秒
41.
42.
This paper investigates conditions under which a prime ideal is completely prime and conditions for which every prime ideal in a near-ring is completely prime. Various implications of these conditions are examined with respect to the associated radicals. 相似文献
43.
Gary M. Lieberman 《Annali di Matematica Pura ed Applicata》1987,148(1):77-99
Summary We study solutions of the conormal derivative problem for uniformly parabolic equations in divergence form. Under weak regularity hypotheses on the operator, the global Hölder continuity of the gradient of a weak solution is established. The method of proof is based on [5] and the results extend those in [7, Section V.7].Sponsored by the National Science Foundation under Grant DMS-8315545. 相似文献
44.
45.
Gary K. Rockswold 《BIT Numerical Mathematics》1987,27(1):123-128
The-type linear multistep formulas are a generalization of the Adams-type formulas. This paper is concerned with completely characterizing theA
0-stability of thek-step, orderk -type formulas. Specifically, all such formulas of orders 4 or less are identified and it is shown that no-type formulas of order 5 or more exist. These theorems generalize some previous results. 相似文献
46.
Peter Breitenlohner Dieter Maison Gary Gibbons 《Communications in Mathematical Physics》1988,120(2):295-333
In this paper we consider generalizations in 4 dimensions of the Einstein-Maxwell equations which typically arise from Kaluza-Klein theories. We specify conditions such that stationary solutions lead to non-linear-models for symmetric spaces. Using both this group theoretic structure and some properties of harmonic maps we are able to generalize many of the known existence and uniqueness theorems for black holes in Einstein-Maxwell theory to this more general setting. 相似文献
47.
We consider a two-body potential which has only periodic ground states and prove that it can be perturbed, by an arbitrarily small perturbation, so as to have only aperiodic ground states.Research supported in part by NSF grant MCS 78-01520-A01. 相似文献
48.
An argument is given in favor of the conjecture that an isolated system in general relativity must have nonnegative total energy. 相似文献
49.
Aihara H Alston-Garnjost M Bakken JA Barbaro-Galtieri A Barnes AV Barnett BA Bengtsson H Blumenfeld BJ Bross AD Buchanan CD Chamberlain O Chien C Clark AR Cordier A Dahl OI Day CT Derby KA Eberhard PH Fancher DL Fujii H Fujii T Gabioud B Gary JW Gorn W Hadley NJ Hauptman JM Hofmann W Huth JE Hylen J Kamae T Kaye HS Kenney RW Kerth LT Koda RI Kofler RR Kwong KK Layter JG Lindsey CS Loken SC Lu X Lynch GR Madansky L Madaras RJ Maruyama K Marx JN Matthews JA Melnikoff SO Moses W Nemethy P 《Physical review letters》1985,54(4):270-273
50.
In this paper, we propose a theory of quantum logics which is general enough to enable us to reexamine previous work on quantum logics in the context of this theory. It is then easy to assess the differences between the different systems studied. The quantum logical systems which we incorporate are divided into two groups which we call quantum propositional logics and quantum event logics. We include the work of Kochen and Specker (partial Boolean algebras), Greechie and Gudder (orthomodular partially ordered sets), Domotar (quantum mechanical systems), and Foulis and Randall (operational logics) in quantum propositional logics; and Abbott (semi-Boolean algebras) and Foulis and Randall (manuals) in quantum event logics. In this part of the paper, we develop an axiom system for quantum propositional logics and examine the above structures in the context of this system. 相似文献