全文获取类型
收费全文 | 1764篇 |
免费 | 131篇 |
国内免费 | 202篇 |
专业分类
化学 | 23篇 |
力学 | 48篇 |
综合类 | 27篇 |
数学 | 1724篇 |
物理学 | 275篇 |
出版年
2024年 | 3篇 |
2023年 | 26篇 |
2022年 | 28篇 |
2021年 | 38篇 |
2020年 | 43篇 |
2019年 | 50篇 |
2018年 | 41篇 |
2017年 | 47篇 |
2016年 | 51篇 |
2015年 | 58篇 |
2014年 | 80篇 |
2013年 | 103篇 |
2012年 | 79篇 |
2011年 | 79篇 |
2010年 | 70篇 |
2009年 | 111篇 |
2008年 | 160篇 |
2007年 | 113篇 |
2006年 | 104篇 |
2005年 | 99篇 |
2004年 | 65篇 |
2003年 | 87篇 |
2002年 | 81篇 |
2001年 | 50篇 |
2000年 | 71篇 |
1999年 | 53篇 |
1998年 | 51篇 |
1997年 | 49篇 |
1996年 | 45篇 |
1995年 | 23篇 |
1994年 | 26篇 |
1993年 | 20篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 9篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1936年 | 3篇 |
排序方式: 共有2097条查询结果,搜索用时 15 毫秒
101.
We build examples of Norden metrics on × S
1, where R
2 n
n
is either a pseudosphere or a pseudohyperbolic space. These turn out to be locally conformal to flat anti-Kählerian metrics, strongly non anti-Kählerian, and with a parallel Lee form. Conversely, any connected complete anti-Hermitian manifold possessing these properties is shown to be locally analytically homothetic to × S
1. 相似文献
102.
Densely Continuous Forms in Vietoris Hyperspaces 总被引:2,自引:0,他引:2
R. A. McCoy 《Set-Valued Analysis》2000,8(3):267-271
For countably paracompact normal spaces X and locally compact separable metric spaces Y, a characterization is given for the closure of the set of densely continuous forms from X to Y in the hyperspace of nonempty closed subsets of X × Y under the Vietoris topology. This shows that for such X having no isolated points, every closed subset of X × R that is dense over X can be Vietoris approximated by a semicontinuous function on X. 相似文献
103.
L. Rodrí guez-Piazza M. C. Romero-Moreno 《Transactions of the American Mathematical Society》2000,352(1):379-395
Let be a real number such that and its conjugate exponent . We prove that for an operator defined on with values in a Banach space, the image of the unit ball determines whether belongs to any operator ideal and its operator ideal norm. We also show that this result fails to be true in the remaining cases of . Finally we prove that when the result holds in finite dimension, the map which associates to the image of the unit ball the operator ideal norm is continuous with respect to the Hausdorff metric.
104.
105.
Paul Francis Bracken 《International Journal of Theoretical Physics》2007,46(1):116-129
The problem of studying the quantum Hall effect on manifolds with non constant metric is addressed. The Hamiltonian on a space
with hyperbolic metric is determined, and the spectrum and eigenfunctions are calculated in closed form. The hyperbolic disk
is also considered and some other applications of this approach are discussed as well.
PACS numbers: 73.43.-f, 02.30.Jr. 相似文献
106.
Beniamino Cappelletti Montano Antonio De Nicola 《Journal of Geometry and Physics》2007,57(12):2509-2520
We present a compared analysis of some properties of 3-Sasakian and 3-cosymplectic manifolds. We construct a canonical connection on an almost 3-contact metric manifold which generalises the Tanaka–Webster connection of a contact metric manifold and we use this connection to show that a 3-Sasakian manifold does not admit any Darboux-like coordinate system. Moreover, we prove that any 3-cosymplectic manifold is Ricci-flat and admits a Darboux coordinate system if and only if it is flat. 相似文献
107.
D.H. Delphenich 《Annalen der Physik》2007,16(9):615-639
An alternative to the representation of complex relativity by self‐dual complex 2‐forms on the spacetime manifold is presented by assuming that the bundle of real 2‐forms is given an almost‐complex structure. From this, one can define a complex orthogonal structure on the bundle of 2‐forms, which results in a more direct representation of the complex orthogonal group in three complex dimensions. The geometrical foundations of general relativity are then presented in terms of the bundle of oriented complex orthogonal 3‐frames on the bundle of 2‐forms in a manner that essentially parallels their construction in terms of self‐dual complex 2‐forms. It is shown that one can still discuss the Debever‐Penrose classification of the Riemannian curvature tensor in terms of the representation presented here. 相似文献
108.
In the present paper we answer two questions raised by Barbilian in 1960. First, we study how far can the hypothesis of Barbilian’s
metrization procedure can be relaxed. Then, we prove that Barbilian’s metrization procedure in the plane generates either
Riemannian metrics or Lagrance generalized metrics not reducible to Finslerian or Langrangian metrics. 相似文献
109.
In this paper we introduce a contractive condition, called ϕ-pair, for two mappings in the framework of cone metric spaces and we prove a theorem which assures existence and uniqueness of
common fixed points for ϕ-pairs. Also we obtain a result on points of coincidence. These results extend and generalize well-known comparable results in the
literature.
The authors are supported by Università degli Studi di Palermo, R. S. ex 60%. 相似文献
110.
In this paper we describe the general forms of surjective isometries of the space of all probability distribution functions on R with respect to the Kolmogorov-Smirnov metric. 相似文献