全文获取类型
收费全文 | 16667篇 |
免费 | 354篇 |
国内免费 | 210篇 |
专业分类
化学 | 980篇 |
晶体学 | 68篇 |
力学 | 165篇 |
综合类 | 22篇 |
数学 | 14832篇 |
物理学 | 1164篇 |
出版年
2023年 | 27篇 |
2022年 | 90篇 |
2021年 | 61篇 |
2020年 | 64篇 |
2019年 | 372篇 |
2018年 | 418篇 |
2017年 | 186篇 |
2016年 | 171篇 |
2015年 | 185篇 |
2014年 | 400篇 |
2013年 | 1000篇 |
2012年 | 475篇 |
2011年 | 978篇 |
2010年 | 805篇 |
2009年 | 1026篇 |
2008年 | 1231篇 |
2007年 | 1221篇 |
2006年 | 911篇 |
2005年 | 658篇 |
2004年 | 536篇 |
2003年 | 438篇 |
2002年 | 357篇 |
2001年 | 297篇 |
2000年 | 293篇 |
1999年 | 415篇 |
1998年 | 374篇 |
1997年 | 297篇 |
1996年 | 396篇 |
1995年 | 373篇 |
1994年 | 354篇 |
1993年 | 329篇 |
1992年 | 287篇 |
1991年 | 216篇 |
1990年 | 175篇 |
1989年 | 190篇 |
1988年 | 124篇 |
1987年 | 141篇 |
1986年 | 112篇 |
1985年 | 191篇 |
1984年 | 179篇 |
1983年 | 97篇 |
1982年 | 164篇 |
1981年 | 150篇 |
1980年 | 98篇 |
1979年 | 68篇 |
1978年 | 96篇 |
1977年 | 76篇 |
1976年 | 56篇 |
1975年 | 23篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Liang Zhao 《Journal of Differential Equations》2019,266(9):5615-5624
In this paper, let be n-dimensional noncompact metric measure space which satisfies Poincaré inequality with some Ricci curvature condition. We obtain a Liouville theorem for positive weak solutions to weighted p-Lichnerowicz equation where are real constants. 相似文献
2.
The growth-fragmentation equation describes a system of growing and dividing particles, and arises in models of cell division, protein polymerisation and even telecommunications protocols. Several important questions about the equation concern the asymptotic behaviour of solutions at large times: at what rate do they converge to zero or infinity, and what does the asymptotic profile of the solutions look like? Does the rescaled solution converge to its asymptotic profile at an exponential speed? These questions have traditionally been studied using analytic techniques such as entropy methods or splitting of operators. In this work, we present a probabilistic approach: we use a Feynman–Kac formula to relate the solution of the growth-fragmentation equation to the semigroup of a Markov process, and characterise the rate of decay or growth in terms of this process. We then identify the Malthus exponent and the asymptotic profile in terms of a related Markov process, and give a spectral interpretation in terms of the growth-fragmentation operator and its dual. 相似文献
3.
4.
Alessandro Morando Paola Trebeschi Tao Wang 《Journal of Differential Equations》2019,266(9):5397-5430
We show the short-time existence and nonlinear stability of vortex sheets for the nonisentropic compressible Euler equations in two spatial dimensions, based on the weakly linear stability result of Morando and Trebeschi (2008) [20]. The missing normal derivatives are compensated through the equations of the linearized vorticity and entropy when deriving higher-order energy estimates. The proof of the resolution for this nonlinear problem follows from certain a priori tame estimates on the effective linear problem in the usual Sobolev spaces and a suitable Nash–Moser iteration scheme. 相似文献
5.
This paper deals with the Cauchy–Dirichlet problem for the fractional Cahn–Hilliard equation. The main results consist of global (in time) existence of weak solutions, characterization of parabolic smoothing effects (implying under proper condition eventual boundedness of trajectories), and convergence of each solution to a (single) equilibrium. In particular, to prove the convergence result, a variant of the so-called ?ojasiewicz–Simon inequality is provided for the fractional Dirichlet Laplacian and (possibly) non-analytic (but ) nonlinearities. 相似文献
6.
7.
Andrea Blunck 《Monatshefte für Mathematik》1997,123(2):93-107
In this note we show that the chain space belonging to a quadric can be embedded into the chain geometry over a Clifford algebra via a generalized stereographic projection. 相似文献
8.
9.
Summary In the analysis of discretization methods for stiff intial value problems, stability questions have received most part of the attention in the past.B-stability and the equivalent criterion algebraic stability are well known concepts for Runge-Kutta methods applied to dissipative problems. However, for the derivation ofB-convergence results — error bounds which are not affected by stiffness — it is not sufficient in many cases to requireB-stability alone. In this paper, necessary and sufficient conditions forB-convergence are determined.This paper was written while J. Schneid was visiting the Centre for Mathematics and Computer Science with an Erwin-Schrödinger stipend from the Fonds zur Förderung der wissenschaftlichen Forschung 相似文献
10.
Summary We present an approximation method of a space-homogeneous transport equation which we prove is convergent. The method is very promising for numerical computation. Comparison of a numerical computation with an exact solution is given for the Master equation. 相似文献