全文获取类型
收费全文 | 14528篇 |
免费 | 1143篇 |
国内免费 | 1232篇 |
专业分类
化学 | 1835篇 |
晶体学 | 56篇 |
力学 | 572篇 |
综合类 | 245篇 |
数学 | 10698篇 |
物理学 | 3497篇 |
出版年
2024年 | 29篇 |
2023年 | 148篇 |
2022年 | 244篇 |
2021年 | 230篇 |
2020年 | 315篇 |
2019年 | 341篇 |
2018年 | 330篇 |
2017年 | 389篇 |
2016年 | 400篇 |
2015年 | 348篇 |
2014年 | 727篇 |
2013年 | 1175篇 |
2012年 | 647篇 |
2011年 | 825篇 |
2010年 | 712篇 |
2009年 | 924篇 |
2008年 | 1027篇 |
2007年 | 1045篇 |
2006年 | 866篇 |
2005年 | 797篇 |
2004年 | 658篇 |
2003年 | 696篇 |
2002年 | 537篇 |
2001年 | 449篇 |
2000年 | 425篇 |
1999年 | 396篇 |
1998年 | 361篇 |
1997年 | 347篇 |
1996年 | 272篇 |
1995年 | 174篇 |
1994年 | 132篇 |
1993年 | 108篇 |
1992年 | 94篇 |
1991年 | 90篇 |
1990年 | 59篇 |
1989年 | 46篇 |
1988年 | 55篇 |
1987年 | 36篇 |
1986年 | 47篇 |
1985年 | 61篇 |
1984年 | 52篇 |
1983年 | 30篇 |
1982年 | 49篇 |
1981年 | 46篇 |
1980年 | 27篇 |
1979年 | 42篇 |
1978年 | 37篇 |
1977年 | 19篇 |
1976年 | 17篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 42 毫秒
991.
Jong Soo Jung 《Applied mathematics and computation》2009,213(2):498-505
We introduce a new composite iterative scheme by viscosity approximation method for finding a common point of the set of solutions of an equilibrium problem and the set of fixed points of a nonexpansive mapping in a Hilbert space. It is proved that the sequence generated by the iterative scheme converges strongly to a common point of the set of solutions of an equilibrium problem and the set of fixed points of a nonexpansive mapping. Our results substantially improve the corresponding results of Takahashi and Takahashi [A. Takahashi, W. Takahashi, Viscosity approximation methods for equilibrium problems and fixed point problems in Hilbert spaces, J. Math. Anal. Appl. 331 (2007) 506-515]. Essentially a new approach for finding solutions of equilibrium problems and the fixed points of nonexpansive mappings is provided. 相似文献
992.
Weak and strong convergence theorems for the approximation of common fixed points of a finite family of asymptotically strictly pseudocontractive mappings are proved in Hilbert spaces using an explicit averaging cyclic algorithm. 相似文献
993.
Konrad J. Swanepoel 《Discrete and Computational Geometry》2009,41(1):1-27
We show that the maximum number of unit distances or of diameters in a set of n points in d-dimensional Euclidean space is attained only by specific types of Lenz constructions, for all d≥4 and n sufficiently large depending on d. As a corollary, we determine the exact maximum number of unit distances for all even d≥6 and the exact maximum number of diameters for all d≥4 and all n sufficiently large depending on d.
This material is based upon work supported by the South African National Research Foundation. 相似文献
994.
We introduce the bimodal logic , which is the extension of Bennett’s bimodal logic by Grzegorczyk’s axiom □(□(p→□p)→p)→p and show that the lattice of normal extensions of the intuitionistic modal logic WS5 is isomorphic to the lattice of normal extensions of , thus generalizing the Blok–Esakia theorem. We also introduce the intuitionistic modal logic WS5.C, which is the extension of WS5 by the axiom (p¬p)→(p→p), and the bimodal logic , which is the extension of Shehtman’s bimodal logic by Grzegorczyk’s axiom, and show that the lattice of normal extensions of WS5.C is isomorphic to the lattice of normal extensions of . 相似文献
995.
Weerayuth Nilsrakoo Satit Saejung 《Journal of Computational and Applied Mathematics》2009,230(2):451-462
This paper is concerned with convergence of an approximating common fixed point sequence of countable Lipschitzian mappings in a uniformly convex Banach space. We also establish weak convergence theorems for finding a common element of the set of fixed points, the set of solutions of an equilibrium problem, and the set of solutions of a variational inequality. With an appropriate setting, we obtain and improve the corresponding results recently proved by Moudafi [A. Moudafi, Weak convergence theorems for nonexpansive mappings and equilibrium problems. J. Nonlinear Convex Anal. 9 (2008) 37–43], Tada–Takahashi [A. Tada and W. Takahashi, Weak and strong convergence theorems for a nonexpansive mapping and an equilibrium problem. J. Optim. Theory Appl. 133 (2007) 359–370], and Plubtieng–Kumam [S. Plubtieng and P. Kumam, Weak convergence theorem for monotone mappings and a countable family of nonexpansive mappings. J. Comput. Appl. Math. (2008) doi:10.1016/j.cam.2008.05.045]. Some of our results are established with weaker assumptions. 相似文献
996.
Rather mild sufficient conditions are provided for the existence of positive solutions of a boundary value problem of the formwhich unify several cases discussed in the literature. In order to formulate these conditions one needs to know only properties of the homeomorphism and have information about the level of growth of the response operator F. No metric information concerning the linear operators L0,L1 in the boundary conditions is used, except that they are positive and continuous and such that Lj(1)<1 j{0,1}. 相似文献
997.
998.
Let {Sn, n ≥ 1} be partial sums of independent identically distributed random variables. The almost sure version of CLT is generalized on the case of randomly indexed sums {SNn, n ≥ 1}, where {Nn, n ≥ 1} is a sequence of positive integer‐valued random variables independent of {Sn, n ≥ 1}. The affects of nonrandom centering and norming are considered too (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
999.
A Hilbert space operator S is called (p, k)‐quasihyponormal if S *k ((S *S)p – (SS *)p )Sk ≥ 0 for an integer k ≥ 1 and 0 < p ≤ 1. In the present note, we consider (p, k)‐quasihyponormal operator S ∈ B (H) such that SX = XT for some X ∈ B (K,H) and prove the Fuglede–Putnam type theorems when the adjoint of T ∈ B (K) is either (p, k)‐quasihyponormal or dominant or a spectral operator (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
1000.
Sh. A. Alimov 《Mathematical Notes》2006,79(1-2):165-177
For piecewise smooth functions, we indicate their domains of convergence and Riecz summarizability of their spectral expansions related to the Laplace operator in ? n , depending on the geometry of points of discontinuity of the function being expanded. 相似文献