全文获取类型
收费全文 | 1210篇 |
免费 | 45篇 |
国内免费 | 8篇 |
专业分类
化学 | 669篇 |
晶体学 | 32篇 |
力学 | 15篇 |
数学 | 200篇 |
物理学 | 347篇 |
出版年
2021年 | 14篇 |
2020年 | 18篇 |
2019年 | 31篇 |
2018年 | 20篇 |
2017年 | 14篇 |
2016年 | 33篇 |
2015年 | 26篇 |
2014年 | 26篇 |
2013年 | 47篇 |
2012年 | 62篇 |
2011年 | 39篇 |
2010年 | 31篇 |
2009年 | 28篇 |
2008年 | 47篇 |
2007年 | 48篇 |
2006年 | 36篇 |
2005年 | 26篇 |
2004年 | 21篇 |
2003年 | 32篇 |
2002年 | 17篇 |
2001年 | 18篇 |
2000年 | 20篇 |
1999年 | 29篇 |
1998年 | 18篇 |
1997年 | 22篇 |
1996年 | 14篇 |
1995年 | 18篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 30篇 |
1991年 | 16篇 |
1990年 | 17篇 |
1989年 | 12篇 |
1988年 | 11篇 |
1987年 | 17篇 |
1986年 | 19篇 |
1985年 | 16篇 |
1984年 | 12篇 |
1981年 | 20篇 |
1980年 | 12篇 |
1979年 | 14篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1975年 | 10篇 |
1971年 | 9篇 |
1970年 | 10篇 |
1969年 | 10篇 |
1968年 | 11篇 |
1967年 | 9篇 |
1966年 | 14篇 |
排序方式: 共有1263条查询结果,搜索用时 0 毫秒
1.
Positivity - We prove new characterisations of exponential stability for positive linear discrete-time systems in ordered Banach spaces, in terms of small-gain conditions. Such conditions have... 相似文献
2.
3.
We study a small quantum system (e.g., a simplified model for an atom or molecule) interacting with two bosonic or fermionic
reservoirs (say, photon or phonon fields). We show that the combined system has a family of stationary states parametrized
by two numbers, T
1 and T
2 (‘reservoir temperatures’). If T
1 ≠ T
2, then these states are non-equilibrium stationary states (NESS). In the latter case we show that they have nonvanishing heat
fluxes and positive entropy production and are dynamically asymptotically stable. The latter means that the evolution with
an initial condition, normal with respect to any state where the reservoirs are in equilibria at temperatures T
1 and T
2, converges to the corresponding NESS. Our results are valid for the temperatures satisfying the bound min (T
1,T
2) > g
2 + α, where g is the coupling constant and 0 < α < 1 is a power related to the infra-red behaviour of the coupling functions.
Submitted: March 20, 2006. Revised: March 19, 2007. Accepted: May 11, 2007.
Marco Merkli: Partly supported by an NSERC PDF, the Institute of Theoretical Physics of ETH Zürich, Switzerland, the Departments
of Mathematics of McGill University and the University of Toronto, Canada.
Matthias Mück: Supported by DAAD under grant HSP III.
Israel Michael Sigal: Supported by NSERC under grant NA7901. 相似文献
4.
5.
6.
7.
We introduce triplet spaces for symmetric relations with defect index (1, 1) in a Pontryagin space. Representations of Pontryagin spaces by spaces of vector-valued analytic functions are investigated. These concepts are used to study 2×2-matrix valued analytic functions which satisfy a certain kernel condition. 相似文献
8.
9.
10.
The parton distributions of the nucleon are evaluated dynamically using the assumption that at some low resolution scale the nucleon consists entirely of valence quarks. A simple parametrization of the resulting gluon distribution is presented, forx? 10?5 up toQ 2?106 GeV2. This gluon distribution is predicted dicted to be much steeper and larger in the very smallx region (x<10?2) than usually assumed. Applications to deep inelastic scaling violations and heavy quark (c, b, t) contribution are discussed and presented as well as hadronic heavy quark production at SSC/LHC energies. For example, the \(b\bar b\) production rate at 40 TeV is predicted to be about an order of magnitude larger than that estimated with other gluon distributions so far. 相似文献