全文获取类型
收费全文 | 848篇 |
免费 | 38篇 |
国内免费 | 38篇 |
专业分类
化学 | 110篇 |
晶体学 | 1篇 |
力学 | 115篇 |
综合类 | 2篇 |
数学 | 498篇 |
物理学 | 198篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 1篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 15篇 |
2016年 | 18篇 |
2015年 | 12篇 |
2014年 | 32篇 |
2013年 | 61篇 |
2012年 | 32篇 |
2011年 | 63篇 |
2010年 | 42篇 |
2009年 | 55篇 |
2008年 | 55篇 |
2007年 | 47篇 |
2006年 | 46篇 |
2005年 | 50篇 |
2004年 | 28篇 |
2003年 | 27篇 |
2002年 | 30篇 |
2001年 | 21篇 |
2000年 | 24篇 |
1999年 | 31篇 |
1998年 | 20篇 |
1997年 | 17篇 |
1996年 | 25篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 13篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有924条查询结果,搜索用时 965 毫秒
91.
Walter D. van Suijlekom 《Journal of Functional Analysis》2011,260(8):2483-2496
We study the spectral functional for a suitable function f, a self-adjoint operator D having compact resolvent, and a certain class of bounded self-adjoint operators A. Such functionals were introduce by Chamseddine and Connes in the context of noncommutative geometry. Motivated by the physical applications of these functionals, we derive a Taylor expansion of them in terms of Gâteaux derivatives. This involves divided differences of f evaluated on the spectrum of D, as well as the matrix coefficients of A in an eigenbasis of D. This generalizes earlier results to infinite dimensions and to any number of derivatives. 相似文献
92.
Rubén Figueroa 《Applied mathematics and computation》2011,217(18):7448-7454
In this paper we obtain a result on existence of extremal quasisolutions and solutions for second-order functional differential equations with functional boundary conditions and past, present and future dependence. In order to do that, we develop a generalized monotone method in presence of lower and upper solutions. Some examples of application are provided too. 相似文献
93.
Robert A. Van Gorder 《Applied mathematics and computation》2011,217(20):8068-8079
We study a coupled nonlinear boundary value problem which has been shown to have applications to fluid flow and heat transfer in a fluid film over a stretching surface for set values of the model parameters (one of which determines the size of the problem domain). For arbitrary values of these parameters we are able to establish the existence and uniqueness of a class of monotone solutions. Perturbation solutions are then constructed and used to approximate certain invariants for the solutions. We then study a related boundary value problem formed by imposing an additional boundary condition on one of the governing equations (which results in an ill-posed problem), and we arrive at conditions allowing for solutions to this four-parameter problem to agree with the solutions to the three-parameter problem. 相似文献
94.
The primary goal of this paper is to present a comprehensive study of the nonlinear Schr?dinger equations with combined nonlinearities of the power-type and Hartree-type. Under certain structural conditions, the authors are able to provide a complete picture of how the nonlinear Schr?dinger equations with combined nonlinearities interact in the given energy space. The method used in the paper is based upon the Morawetz estimates and perturbation principles. 相似文献
95.
96.
《Indagationes Mathematicae》2021,32(2):442-455
We give a sufficient condition for the essential self-adjointness of a perturbation of the square of the magnetic Laplacian on an infinite weighted graph. The main result is applicable to graphs whose degree function is not necessarily bounded. The result allows perturbations that are not necessarily bounded from below by a constant. 相似文献
97.
双原子分子非谐振转波函数和能级 总被引:7,自引:3,他引:4
余春日 《原子与分子物理学报》2005,22(2):276-280
从双原子分子简谐势近似波函数出发,运用微扰理论计算出了双原子分子在非谐振转相互作用下的一级、二级近似能级和一级近似波函数. 相似文献
98.
99.
This paper presents a perturbation theory for the double sine-Gordon equation. We obtain a system of differential equations that shows the soliton parameters modification under the influence of the perturbation. For the particular case λ=0 the results transform into the well-known perturbation theory for the sine-Gordon equation. 相似文献
100.
Jacek Wojtkiewicz 《Journal of statistical physics》2006,123(3):585-600
The ground-state phase diagram of the two-dimensional Falicov-Kimball model with nearest-neighbour and next-nearest-neighbour hoppings has been studied in the perturbative regime where hoppings are small compared with the on-site Coulomb interaction. The phase diagram at fourth-order exhibits a richer structure than the one of the ordinary Falicov-Kimball model.
PACS numbers: 71.10.Fd, 71.21.+a, 75.10.Hk, 75.30.Kz 相似文献