全文获取类型
收费全文 | 8653篇 |
免费 | 368篇 |
国内免费 | 700篇 |
专业分类
化学 | 977篇 |
晶体学 | 10篇 |
力学 | 509篇 |
综合类 | 54篇 |
数学 | 6867篇 |
物理学 | 1304篇 |
出版年
2023年 | 92篇 |
2022年 | 80篇 |
2021年 | 86篇 |
2020年 | 176篇 |
2019年 | 170篇 |
2018年 | 205篇 |
2017年 | 224篇 |
2016年 | 255篇 |
2015年 | 170篇 |
2014年 | 339篇 |
2013年 | 591篇 |
2012年 | 336篇 |
2011年 | 399篇 |
2010年 | 367篇 |
2009年 | 543篇 |
2008年 | 617篇 |
2007年 | 550篇 |
2006年 | 516篇 |
2005年 | 445篇 |
2004年 | 325篇 |
2003年 | 385篇 |
2002年 | 356篇 |
2001年 | 261篇 |
2000年 | 271篇 |
1999年 | 272篇 |
1998年 | 228篇 |
1997年 | 240篇 |
1996年 | 132篇 |
1995年 | 124篇 |
1994年 | 102篇 |
1993年 | 70篇 |
1992年 | 62篇 |
1991年 | 64篇 |
1990年 | 68篇 |
1989年 | 51篇 |
1988年 | 54篇 |
1987年 | 41篇 |
1986年 | 39篇 |
1985年 | 51篇 |
1984年 | 56篇 |
1983年 | 18篇 |
1982年 | 36篇 |
1981年 | 33篇 |
1980年 | 33篇 |
1979年 | 26篇 |
1978年 | 30篇 |
1977年 | 38篇 |
1976年 | 25篇 |
1974年 | 16篇 |
1973年 | 16篇 |
排序方式: 共有9721条查询结果,搜索用时 78 毫秒
1.
《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2021,38(5):1337-1371
In this paper we consider minimizers of the functional where is a bounded open set and where are the first k eigenvalues on Ω of an operator in divergence form with Dirichlet boundary condition and with Hölder continuous coefficients. We prove that the optimal sets have finite perimeter and that their free boundary is composed of a regular part, which is locally the graph of a -regular function, and a singular part, which is empty if , discrete if and of Hausdorff dimension at most if , for some . 相似文献
2.
《Wave Motion》2018
The evolution of surface gravity waves is driven by nonlinear interactions that trigger an energy cascade similarly to the one observed in hydrodynamic turbulence. This process, known as wave turbulence, has been found to display anomalous scaling with deviation from classical turbulent predictions due to the emergence of coherent and intermittent structures on the water surface. In the ocean, waves are spread over a wide range of directions, with a consequent attenuation of the nonlinear properties. A laboratory experiment in a large wave facility is presented to discuss the sensitivity of wave turbulence on the directional properties of model wave spectra. Results show that the occurrence of coherent and intermittent structures become less likely with the broadening of the wave directional spreading. There is no evidence, however, that intermittency completely vanishes. 相似文献
3.
This work is concerned with the extension of the Jacobi spectral Galerkin method to a class of nonlinear fractional pantograph differential equations. First, the fractional differential equation is converted to a nonlinear Volterra integral equation with weakly singular kernel. Second, we analyze the existence and uniqueness of solutions for the obtained integral equation. Then, the Galerkin method is used for solving the equivalent integral equation. The error estimates for the proposed method are also investigated. Finally, illustrative examples are presented to confirm our theoretical analysis. 相似文献
5.
In this paper, the authors studied certain properties of the estimate of Liang and Krishnaiah (1985, J. Multivariate Anal. 16, 162–172) for multivariate binary density. An alternative shrinkage estimate is also obtained. The above results are generalized to general orthonormal systems. 相似文献
6.
Abstract
In this note, we consider a Frémond model of shape memory alloys. Let us imagine a piece of a shape memory alloy which is
fixed on one part of its boundary, and assume that forcing terms, e.g., heat sources and external stress on the remaining
part of its boundary, converge to some time-independent functions, in appropriate senses, as time goes to infinity. Under
the above assumption, we shall discuss the asymptotic stability for the dynamical system from the viewpoint of the global
attractor. More precisely, we generalize the paper [12] dealing with the one-dimensional case. First, we show the existence
of the global attractor for the limiting autonomous dynamical system; then we characterize the asymptotic stability for the
non-autonomous case by the limiting global attractor.
* Project supported by the MIUR-COFIN 2004 research program on “Mathematical Modelling and Analysis of Free Boundary Problems”. 相似文献
7.
Yoel Shkolnisky Mark Tygert Vladimir Rokhlin 《Applied and Computational Harmonic Analysis》2006,21(3):413-420
Many signals encountered in science and engineering are approximated well by bandlimited functions. We provide suitable error bounds for the approximation of bandlimited functions by linear combinations of certain special functions—the prolate spheroidal wave functions of order 0. The coefficients in the approximating linear combinations are given explicitly via appropriate quadrature formulae. 相似文献
8.
Well-Posedness by Perturbations of Variational Problems 总被引:3,自引:0,他引:3
Lemaire B. Ould Ahmed Salem C. Revalski J. P. 《Journal of Optimization Theory and Applications》2002,115(2):345-368
In this paper, we consider the extension of the notion of well-posedness by perturbations, introduced by Zolezzi for optimization problems, to other related variational problems like inclusion problems and fixed-point problems. Then, we study the conditions under which there is equivalence of the well-posedness in the above sense between different problems. Relations with the so-called diagonal well-posedness are also given. Finally, an application to staircase iteration methods is presented. 相似文献
9.
G. Dattoli 《Journal of Mathematical Analysis and Applications》2002,269(2):716-725
Bilateral generating functions are those involving products of different types of polynomials. We show that operational methods offer a powerful tool to derive these families of generating functions. We study cases relevant to products of Hermite polynomials with Laguerre, Legendre and other polynomials. We also propose further extensions of the method which we develop here. 相似文献
10.
Filippo Bracci Roberto Tauraso Fabio Vlacci 《Journal of Mathematical Analysis and Applications》2002,270(2):1131-473
Let f,g be two commuting holomorphic self-maps of the unit disc. If f and g agree at the common Wolff point up to a certain order of derivatives (no more than 3 if the Wolff point is on the unit circle), then f≡g. 相似文献