全文获取类型
收费全文 | 4100篇 |
免费 | 296篇 |
国内免费 | 284篇 |
专业分类
化学 | 27篇 |
力学 | 137篇 |
综合类 | 46篇 |
数学 | 4071篇 |
物理学 | 399篇 |
出版年
2024年 | 4篇 |
2023年 | 46篇 |
2022年 | 29篇 |
2021年 | 62篇 |
2020年 | 69篇 |
2019年 | 88篇 |
2018年 | 102篇 |
2017年 | 111篇 |
2016年 | 79篇 |
2015年 | 98篇 |
2014年 | 143篇 |
2013年 | 384篇 |
2012年 | 149篇 |
2011年 | 162篇 |
2010年 | 157篇 |
2009年 | 220篇 |
2008年 | 284篇 |
2007年 | 296篇 |
2006年 | 226篇 |
2005年 | 237篇 |
2004年 | 166篇 |
2003年 | 193篇 |
2002年 | 204篇 |
2001年 | 139篇 |
2000年 | 146篇 |
1999年 | 133篇 |
1998年 | 125篇 |
1997年 | 115篇 |
1996年 | 68篇 |
1995年 | 69篇 |
1994年 | 46篇 |
1993年 | 36篇 |
1992年 | 31篇 |
1991年 | 26篇 |
1990年 | 33篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 19篇 |
1986年 | 10篇 |
1985年 | 23篇 |
1984年 | 17篇 |
1983年 | 13篇 |
1982年 | 21篇 |
1981年 | 20篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 3篇 |
1975年 | 3篇 |
排序方式: 共有4680条查询结果,搜索用时 15 毫秒
31.
32.
In this paper, we discuss the viscosity solutions of the weakly coupled systems of fully nonlinear second-order degenerate parabolic equations and their Cauchy-Dirichlet problem. We prove the existence, uniqueness and continuity of viscosity solution by combining Perron's method with the technique of coupled solutions. The results here generalize those in Proc. London Math. Soc. 63 (1991) 212-240 and Comm. Partial Differential Equations 16 (1991) 1095-1128. 相似文献
33.
Young Ja Park 《Proceedings of the American Mathematical Society》2004,132(7):2075-2083
A logarithmic Sobolev trace inequality is derived. Bounds on the best constant for this inequality from above and below are investigated using the sharp Sobolev inequality and the sharp logarithmic Sobolev inequality.
34.
In this paper, we exhibit a unified treatment of the mixed initial boundary value problem for second order (in time) parabolic linear differential equations in Banach spaces, whose boundary conditions are of a dynamical nature. Results regarding existence, uniqueness, continuous dependence (on initial data) and regularity of classical and strict solutions are established. Moreover, several examples are given as samples for possible applications.
35.
不等式组与变分不等式的极大熵函数方法 总被引:1,自引:1,他引:0
利用极大熵函数方法将不等式组及变分不等式的求解问题转化为近似可微优化问题,给出了不等式组及变分不等式问题近似解的可微优化方法,得到了不等式组和变分不等式问题的解集合的示性函数. 相似文献
36.
37.
Ansgar Jüngel 《Mathematische Nachrichten》1997,185(1):85-110
A multi-dimensional transient drift-diffusion model for (at most) three charged particles, consisting of the continuity equations for the concentrations of the species and the Poisson equation for the electric potential, is considered. The diffusion terms depend on the concentrations. Such a system arises in electrophoretic modeling of three species (neutrally, positively and negatively charged) and in semiconductor theory for two species (positively charged holes and negatively charged electrons). Diffusion terms of degenerate type are also possible in semiconductor modeling. For the initial boundary value problem with mixed Dirichlet - Neumann boundary conditions and general reaction rates, a global existence result is proved. Uniqueness of solutions follows in the Dirichlet boundary case if the diffusion terms are uniformly parabolic or if the initial and boundary densities are strictly positive. Finally, we prove that solutions exist which are positive uniformly in time and globally bounded if the reaction rates satisfy appropriate growth conditions. 相似文献
38.
We show by general considerations that it is not possible to test violation of the existing versions of Bell’s inequality
in entangled neutral kaons system using experimentally accessible thin regenerators. We point out the loophole in the recent
argument (A Bramon and M Nowakowski, Phys. Rev. Lett.
83, 1 (1999)) that claimed such a test to be possible. 相似文献
39.
We provide some inequalities and integral inequalities connected to the Jensen-Hadamard inequalities for convex functions.
In particular, we give some refinements to these inequalities. Some natural applications and further extensions are given.
Sunto Forniamo alcune diseguaglianze e diseguaglianze integrali connesse alle dise-gueglianze di Jensen-Hadamard per funzioni convesse. In particolare, diamo qualche miglioramento di queste diseguaglianze. Alcune applicazioni naturali ed ulteriori estensioni sono date.相似文献
40.
In this paper we prove the existence of a solution of a coupled system involving a two phase incompressible flow in the ground and the mechanical deformation of the porous medium where the porosity is a function of the global pressure. The model is strongly coupled and involves a nonlinear degenerate parabolic equation. In order to show the existence of a weak solution, we consider a sequence of related uniformly parabolic problems and apply the Schauder fixed point theorem to show that they possess a classical solution. We then prove the relative compactness of sequences of solutions by means of the Fréchet-Kolmogorov theorem; this yields the convergence of a subsequence to a weak solution of the parabolic system. 相似文献