全文获取类型
收费全文 | 6054篇 |
免费 | 452篇 |
国内免费 | 252篇 |
专业分类
化学 | 1150篇 |
晶体学 | 24篇 |
力学 | 934篇 |
综合类 | 81篇 |
数学 | 3490篇 |
物理学 | 1079篇 |
出版年
2024年 | 19篇 |
2023年 | 72篇 |
2022年 | 117篇 |
2021年 | 129篇 |
2020年 | 152篇 |
2019年 | 168篇 |
2018年 | 152篇 |
2017年 | 172篇 |
2016年 | 195篇 |
2015年 | 162篇 |
2014年 | 257篇 |
2013年 | 574篇 |
2012年 | 283篇 |
2011年 | 307篇 |
2010年 | 232篇 |
2009年 | 356篇 |
2008年 | 378篇 |
2007年 | 390篇 |
2006年 | 297篇 |
2005年 | 261篇 |
2004年 | 250篇 |
2003年 | 183篇 |
2002年 | 177篇 |
2001年 | 162篇 |
2000年 | 155篇 |
1999年 | 130篇 |
1998年 | 138篇 |
1997年 | 112篇 |
1996年 | 106篇 |
1995年 | 75篇 |
1994年 | 72篇 |
1993年 | 57篇 |
1992年 | 69篇 |
1991年 | 36篇 |
1990年 | 34篇 |
1989年 | 34篇 |
1988年 | 21篇 |
1987年 | 29篇 |
1986年 | 29篇 |
1985年 | 16篇 |
1984年 | 28篇 |
1983年 | 17篇 |
1982年 | 22篇 |
1981年 | 19篇 |
1980年 | 21篇 |
1979年 | 21篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 17篇 |
1973年 | 8篇 |
排序方式: 共有6758条查询结果,搜索用时 0 毫秒
61.
Mathematical Notes - 相似文献
62.
We first state a uniform convergence theorem for finite-part integrals which are derivatives of weighted Cauchy principal value integrals. We then give a two-stage process to modify approximating splines and optimal nodal splines in such a way that the conditions of this theorem are satisfied. Consequently, these modified splines can be used in the numerical evaluation of these finite-part integrals. 相似文献
63.
Hubert Grudzński 《Reports on Mathematical Physics》2004,53(3):331-338
New elements of the dual cone of the set of fermion N-representable 2-density operators are proposed. So far, the explicit form of the corresponding necessary conditions for N-representability is obtained for N = 3. In this case the new condition is stronger than the known B- and C-conditions for 3-representability. The results provide evidence that in the spectral decomposition of the N-representable 2-density operator there exists an intrinsic relation between the eigenvalue and the corresponding eigenfunction. 相似文献
64.
The line search method incorporating the Wolfe conditions is modified to ensure that a descent algorithm terminates in a finite number of steps at an approximate stationary point where the second-order conditions of optimality are satisfied. A simple procedure based on conjugate directions is proposed to determine directions of negative curvature. 相似文献
65.
CONE-DIRECTED CONTINGENT DERIVATIVES AND GENERALIZED PREINVEX SET-VALUED OPTIMIZATION 总被引:2,自引:0,他引:2
丘京辉 《数学物理学报(B辑英文版)》2007,27(1):211-218
By using cone-directed contingent derivatives, the unified necessary and suffi-cient optimality conditions are given for weakly and strongly minimal elements respectively in generalized preinvex set valued optimization. 相似文献
66.
We investigate which types of asymptotic distributions can be generated by the knots of convergent sequences of interpolatory integration rules. It will turn out that the class of all possible distributions can be described exactly, and it will be shown that the zeros of polynomials that are orthogonal with respect to varying weight functions are good candidates for knots of integration rules with a prescribed asymptotic distribution.Research supported by the Deutsche Forschungsgemeinschaft (AZ: Sta 299/4-2). 相似文献
67.
Mark C. Veraar 《Proceedings of the American Mathematical Society》2007,135(5):1477-1486
In this paper we prove the equivalence of decoupling inequalities for stochastic integrals and one-sided randomized versions of the UMD property of a Banach space as introduced by Garling.
68.
Contingent epiderivatives and set-valued optimization 总被引:24,自引:0,他引:24
In this paper we introduce the concept of the contingent epiderivative for a set-valued map which modifies a notion introduced by Aubin [2] as upper contingent derivative. It is shown that this kind of a derivative has important properties and is one possible generalization of directional derivatives in the single-valued convex case. For optimization problems with a set-valued objective function optimality conditions based on the concept of the contingent epiderivative are proved which are necessary and sufficient under suitable assumptions. 相似文献
69.
林支桂 《数学物理学报(B辑英文版)》1998,(3)
1IntroductionInthispaper,weconsidertheinitial-boundaryvalueproblem,where"o(x)isnon-negativesmoothfunctionsatisfying"o.(0)=0,"o.(1)=1'Whenconsideringtheblow-upofsolution,thefollowingproblemarisenaturally:Doesblow-upoccur?Howdoesthesolutionapproachtheblow-uptime'!Andwilersisthehotspotlocated(blow-upset)?WelookattheheatequationwithanonlillearboundaryconditiollHerefiisaboundeddomaininR",p>1isarealnumber.IthasbeenknownforalongtimethattheDroblelil(1.1).(1.2)withAL(~,0)--'no(x)doesnothaveaglobals… 相似文献
70.
本文讨论定义于Banach空间的多目标数学规划,得到一些ε-最优解和(弱)有效解的必要条件,充分条件和必要充分条件。 相似文献