全文获取类型
收费全文 | 12086篇 |
免费 | 647篇 |
国内免费 | 57篇 |
专业分类
化学 | 8859篇 |
晶体学 | 38篇 |
力学 | 297篇 |
数学 | 1864篇 |
物理学 | 1732篇 |
出版年
2023年 | 92篇 |
2022年 | 119篇 |
2021年 | 205篇 |
2020年 | 294篇 |
2019年 | 306篇 |
2018年 | 145篇 |
2017年 | 168篇 |
2016年 | 439篇 |
2015年 | 478篇 |
2014年 | 493篇 |
2013年 | 659篇 |
2012年 | 930篇 |
2011年 | 936篇 |
2010年 | 579篇 |
2009年 | 499篇 |
2008年 | 752篇 |
2007年 | 709篇 |
2006年 | 657篇 |
2005年 | 637篇 |
2004年 | 503篇 |
2003年 | 409篇 |
2002年 | 400篇 |
2001年 | 187篇 |
2000年 | 157篇 |
1999年 | 145篇 |
1998年 | 154篇 |
1997年 | 151篇 |
1996年 | 123篇 |
1995年 | 95篇 |
1994年 | 93篇 |
1993年 | 103篇 |
1992年 | 75篇 |
1991年 | 69篇 |
1990年 | 60篇 |
1989年 | 74篇 |
1988年 | 56篇 |
1987年 | 41篇 |
1986年 | 47篇 |
1985年 | 60篇 |
1984年 | 50篇 |
1983年 | 50篇 |
1982年 | 52篇 |
1981年 | 65篇 |
1980年 | 46篇 |
1979年 | 48篇 |
1978年 | 47篇 |
1977年 | 45篇 |
1976年 | 51篇 |
1975年 | 45篇 |
1973年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Claudius Gros 《Entropy (Basel, Switzerland)》2021,23(2)
Human societies are characterized by three constituent features, besides others. (A) Options, as for jobs and societal positions, differ with respect to their associated monetary and non-monetary payoffs. (B) Competition leads to reduced payoffs when individuals compete for the same option as others. (C) People care about how they are doing relatively to others. The latter trait—the propensity to compare one’s own success with that of others—expresses itself as envy. It is shown that the combination of (A)–(C) leads to spontaneous class stratification. Societies of agents split endogenously into two social classes, an upper and a lower class, when envy becomes relevant. A comprehensive analysis of the Nash equilibria characterizing a basic reference game is presented. Class separation is due to the condensation of the strategies of lower-class agents, which play an identical mixed strategy. Upper-class agents do not condense, following individualist pure strategies. The model and results are size-consistent, holding for arbitrary large numbers of agents and options. Analytic results are confirmed by extensive numerical simulations. An analogy to interacting confined classical particles is discussed. 相似文献
2.
Laurens Kooijman Dr. Matthias Schuster Christian Baumann Simon Jurt Dr. Frank Löhr Dr. Boris Fürtig Prof. Dr. Peter Güntert Prof. Dr. Oliver Zerbe 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21151-21158
To achieve efficient proton pumping in the light-driven proton pump bacteriorhodopsin (bR), the protein must be tightly coupled to the retinal to rapidly convert retinal isomerization into protein structural rearrangements. Methyl group dynamics of bR embedded in lipid nanodiscs were determined in the dark-adapted state, and were found to be mostly well ordered at the cytosolic side. Methyl groups in the M145A mutant of bR, which displays only 10 % residual proton pumping activity, are less well ordered, suggesting a link between side-chain dynamics on the cytosolic side of the bR cavity and proton pumping activity. In addition, slow conformational exchange, attributed to low frequency motions of aromatic rings, was indirectly observed for residues on the extracellular side of the bR cavity. This may be related to reorganization of the water network. These observations provide a detailed picture of previously undescribed equilibrium dynamics on different time scales for ground-state bR. 相似文献
3.
4.
5.
6.
7.
8.
9.
In 1976 S. Hawking claimed that “Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state”. 1 This was the starting point of the popular “black hole (BH) information paradox”. 相似文献
10.