全文获取类型
收费全文 | 8193篇 |
免费 | 183篇 |
国内免费 | 60篇 |
专业分类
化学 | 350篇 |
晶体学 | 16篇 |
力学 | 67篇 |
综合类 | 12篇 |
数学 | 7217篇 |
物理学 | 774篇 |
出版年
2023年 | 10篇 |
2022年 | 14篇 |
2021年 | 19篇 |
2020年 | 40篇 |
2019年 | 214篇 |
2018年 | 220篇 |
2017年 | 117篇 |
2016年 | 77篇 |
2015年 | 100篇 |
2014年 | 236篇 |
2013年 | 433篇 |
2012年 | 295篇 |
2011年 | 459篇 |
2010年 | 461篇 |
2009年 | 640篇 |
2008年 | 625篇 |
2007年 | 633篇 |
2006年 | 482篇 |
2005年 | 300篇 |
2004年 | 248篇 |
2003年 | 256篇 |
2002年 | 188篇 |
2001年 | 190篇 |
2000年 | 195篇 |
1999年 | 227篇 |
1998年 | 191篇 |
1997年 | 138篇 |
1996年 | 186篇 |
1995年 | 247篇 |
1994年 | 203篇 |
1993年 | 160篇 |
1992年 | 112篇 |
1991年 | 52篇 |
1990年 | 43篇 |
1989年 | 53篇 |
1988年 | 36篇 |
1987年 | 25篇 |
1986年 | 26篇 |
1985年 | 41篇 |
1984年 | 43篇 |
1983年 | 25篇 |
1982年 | 30篇 |
1981年 | 27篇 |
1980年 | 13篇 |
1979年 | 26篇 |
1978年 | 22篇 |
1977年 | 21篇 |
1975年 | 10篇 |
1974年 | 9篇 |
1973年 | 9篇 |
排序方式: 共有8436条查询结果,搜索用时 15 毫秒
11.
12.
Franz-Viktor Kuhlmann 《Advances in Mathematics》2004,188(2):399-424
We consider the Zariski space of all places of an algebraic function field F|K of arbitrary characteristic and investigate its structure by means of its patch topology. We show that certain sets of places with nice properties (e.g., prime divisors, places of maximal rank, zero-dimensional discrete places) lie dense in this topology. Further, we give several equivalent characterizations of fields that are large, in the sense of F. Pop's Annals paper Embedding problems over large fields. We also study the question whether a field K is existentially closed in an extension field L if L admits a K-rational place. In the appendix, we prove the fact that the Zariski space with the Zariski topology is quasi-compact and that it is a spectral space. 相似文献
13.
Paulo D. Cordaro 《Advances in Mathematics》2004,184(1):89-118
Taking as a start point the recent article of Meziani [7], we present several results concerning the normalization of a class of complex vector fields in the plane which degenerate along a real curve. We mainly deal with operators with finite regularity and analyze both the local situation as well as the case of normalization near a circle. Some related questions (e.g., on semi-global solvability and on the normalization of a class of generalized Mizohata operators) are also discussed. 相似文献
14.
Reduced rank regression assumes that the coefficient matrix in a multivariate regression model is not of full rank. The unknown rank is traditionally estimated under the assumption of normal responses. We derive an asymptotic test for the rank that only requires the response vector have finite second moments. The test is extended to the nonconstant covariance case. Linear combinations of the components of the predictor vector that are estimated to be significant for modelling the responses are obtained. 相似文献
15.
Abstract. We propose a general approach to deal with nonlinear, nonconvex variational problems based on a reformulation of the problem
resulting in an optimization problem with linear cost functional and convex constraints. As a first step we explicitly explore
these ideas to some one-dimensional variational problems and obtain specific conclusions of an analytical and numerical nature. 相似文献
16.
The existence of an attractor for a 2D-Navier-Stokes system with delay is proved. The theory of pullback attractors is successfully applied to obtain the results since the abstract functional framework considered turns out to be nonautonomous. However, on some occasions, the attractors may attract not only in the pullback sense but in the forward one as well. Also, this formulation allows to treat, in a unified way, terms containing various classes of delay features (constant, variable, distributed delays, etc.). As a consequence, some results for the autonomous model are deduced as particular cases of our general formulation. 相似文献
17.
Marco Biroli Silvia Mataloni Michele Matzeu 《NoDEA : Nonlinear Differential Equations and Applications》2005,12(3):295-321
Some stability results for Mountain Pass and Linking type solutions of semilinear problems involving a very general class
of Dirichlet forms are stated. The non linear terms are supposed to have a suitable superlinear growth and the family of Dirichlet
forms is required to be dominated from below and from above by a fixed diffusion type form. Some concrete examples are also
given. 相似文献
18.
Michael T. Anderson 《Advances in Mathematics》2003,179(2):205-249
This paper studies several aspects of asymptotically hyperbolic (AH) Einstein metrics, mostly on 4-manifolds. We prove boundary regularity (at infinity) for such metrics and establish uniqueness under natural conditions on the boundary data. By examination of explicit black hole metrics, it is shown that neither uniqueness nor finiteness holds in general for AH Einstein metrics with a prescribed conformal infinity. We then describe natural conditions which are sufficient to ensure finiteness. 相似文献
19.
Operators on manifolds with corners that have base configurations with geometric singularities can be analysed in the frame of a conormal symbolic structure which is in spirit similar to the one for conical singularities of Kondrat'ev's work. Solvability of elliptic equations and asymptotics of solutions are determined by meromorphic conormal symbols. We study the case when the base has edge singularities which is a natural assumption in a number of applications. There are new phenomena, caused by a specific kind of higher degeneracy of the underlying symbols. We introduce an algebra of meromorphic edge operators that depend on complex parameters and investigate meromorphic inverses in the parameter-dependent elliptic case. Among the examples are resolvents of elliptic differential operators on manifolds with edges. 相似文献
20.
Zhaoyang Yin 《Monatshefte für Mathematik》2004,141(4):337-344
We prove under quite general assumptions the existence of a bounded positive solution to the semilinear Schrödinger equation in a two-dimensional exterior domain. 相似文献