全文获取类型
收费全文 | 34482篇 |
免费 | 636篇 |
国内免费 | 512篇 |
专业分类
化学 | 14624篇 |
晶体学 | 318篇 |
力学 | 1547篇 |
综合类 | 20篇 |
数学 | 9755篇 |
物理学 | 9366篇 |
出版年
2023年 | 61篇 |
2022年 | 130篇 |
2021年 | 182篇 |
2020年 | 173篇 |
2019年 | 185篇 |
2018年 | 1305篇 |
2017年 | 1568篇 |
2016年 | 929篇 |
2015年 | 771篇 |
2014年 | 738篇 |
2013年 | 1053篇 |
2012年 | 3564篇 |
2011年 | 2802篇 |
2010年 | 2082篇 |
2009年 | 1818篇 |
2008年 | 944篇 |
2007年 | 974篇 |
2006年 | 885篇 |
2005年 | 4705篇 |
2004年 | 4141篇 |
2003年 | 2506篇 |
2002年 | 661篇 |
2001年 | 404篇 |
2000年 | 204篇 |
1999年 | 247篇 |
1998年 | 183篇 |
1997年 | 134篇 |
1996年 | 121篇 |
1995年 | 84篇 |
1994年 | 104篇 |
1993年 | 83篇 |
1992年 | 203篇 |
1991年 | 189篇 |
1990年 | 150篇 |
1989年 | 137篇 |
1988年 | 118篇 |
1987年 | 73篇 |
1986年 | 68篇 |
1985年 | 65篇 |
1984年 | 52篇 |
1979年 | 40篇 |
1976年 | 84篇 |
1975年 | 45篇 |
1974年 | 44篇 |
1973年 | 55篇 |
1972年 | 43篇 |
1970年 | 37篇 |
1969年 | 40篇 |
1968年 | 39篇 |
1966年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
71.
Dorota G?azowska Janusz Matkowski 《Journal of Mathematical Analysis and Applications》2007,331(2):1187-1199
The invariance of the geometric mean G with respect to the Lagrangian mean-type mapping (Lf,Lg), i.e. the equation G○(Lf,Lg)=G, is considered. We show that the functions f and g must be of high class regularity. This fact allows to reduce the problem to a differential equation and determine the second derivatives of the generators f and g. 相似文献
72.
In the paper we indicate an error made in the proof of the main result of the paper [M.A. Darwish, On quadratic integral equation of fractional orders, J. Math. Anal. Appl. 311 (2005) 112-119]. Moreover, we provide correct proof of a slightly modified version of the mentioned result. The main tool used in our proof is the technique associated with the Hausdorff measure of noncompactness. 相似文献
73.
In this paper we deal with nonlinear second-order boundary value problems with impulses. The impulsive functions depend implicitly on the different considered variables and the boundary value conditions are nonlinear. In both cases functional dependence on the solution is allowed. The existence results follow from the existence of a pair of well-ordered lower and upper solutions. 相似文献
74.
We study linear dynamical systems with multidimensional time in Banach spaces. Using Taylor functional calculus we prove that under additional assumptions hyperbolic systems have shadowing property. 相似文献
75.
S?awomir Solecki 《Topology and its Applications》2007,154(12):2462-2464
Let I0 be the σ-ideal of subsets of a Polish group generated by Borel sets which have perfectly many pairwise disjoint translates. We prove that a Fubini-type theorem holds between I0 and the σ-ideals of Haar measure zero sets and of meager sets. We use this result to give a simple proof of a generalization of a theorem of Balcerzak-Ros?anowski-Shelah stating that I0 on N2 strongly violates the countable chain condition. 相似文献
76.
We study in this Note the continuum (macroscopic) limit for some atomistic models for crystals. The purpose is to derive densities of mechanical energies from microscopic models. In contrast to the setting of a previous study, where the microscopic structure was assumed to be periodic, it is modelled here by a stochastic lattice, which enjoys some stationarity and ergodicity properties, following notions previously introduced elsewhere. To cite this article: X. Blanc et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
77.
78.
R. Knizikevi?ius 《Applied Surface Science》2006,253(3):1581-1583
The ion-beam-assisted etching of silicon in Cl2 environment is considered. The theoretically calculated dependences of silicon etching rate on the flux of Cl2 molecules at different ion current densities are compared with experimentally measured. The composition of the adsorbed layer is determined. It is found that SiCl2 molecules prevail in the adsorbed layer. The reciprocal of relative concentration of SiCl2 molecules in the adsorbed layer linearly depends on the ion-to-neutral flux ratio. 相似文献
79.
Francesc Carreras 《Discrete Applied Mathematics》2007,155(4):496-505
Different (proper as well as improper) simple games may share any nonseparating blocking family. An interesting question is whether all such proper games on one hand, and all improper ones on the other, are isomorphic. The answer is given here and the automorphisms of the blocking family help us to understand the structure and links of all such games. 相似文献
80.
We study the Helmholtz equation in the exterior of an infinite perturbed cylinder with a Dirichlet boundary condition. Existence and uniqueness of solutions are established using the variational technique introduced (SIAM J. Math. Anal. 2005; 37 (2):598–618). We also provide stability estimates with explicit dependence of the constants in terms of the frequency and the perturbed cylinder thickness. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献