全文获取类型
收费全文 | 86946篇 |
免费 | 3142篇 |
国内免费 | 35篇 |
专业分类
化学 | 53549篇 |
晶体学 | 430篇 |
力学 | 2241篇 |
综合类 | 1篇 |
数学 | 15149篇 |
物理学 | 18753篇 |
出版年
2023年 | 632篇 |
2022年 | 539篇 |
2021年 | 883篇 |
2020年 | 1191篇 |
2019年 | 1123篇 |
2018年 | 1746篇 |
2017年 | 1502篇 |
2016年 | 2877篇 |
2015年 | 2475篇 |
2014年 | 2476篇 |
2013年 | 5428篇 |
2012年 | 5650篇 |
2011年 | 5559篇 |
2010年 | 3491篇 |
2009年 | 2918篇 |
2008年 | 4841篇 |
2007年 | 4692篇 |
2006年 | 4195篇 |
2005年 | 4060篇 |
2004年 | 3551篇 |
2003年 | 2865篇 |
2002年 | 2521篇 |
2001年 | 1716篇 |
2000年 | 1591篇 |
1999年 | 1111篇 |
1998年 | 870篇 |
1997年 | 747篇 |
1996年 | 968篇 |
1995年 | 663篇 |
1994年 | 778篇 |
1993年 | 739篇 |
1992年 | 794篇 |
1991年 | 672篇 |
1990年 | 696篇 |
1989年 | 625篇 |
1988年 | 584篇 |
1987年 | 548篇 |
1986年 | 509篇 |
1985年 | 771篇 |
1984年 | 709篇 |
1983年 | 530篇 |
1982年 | 615篇 |
1981年 | 618篇 |
1980年 | 520篇 |
1979年 | 513篇 |
1978年 | 503篇 |
1976年 | 520篇 |
1975年 | 451篇 |
1974年 | 477篇 |
1973年 | 475篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
A set of exact conditions is compiled for the purpose of developing and testing approximations for the exchange-correlation energy as a functional of the electron density. Special emphasis is placed upon recently developed density-scaling relationships. Commonly used generalized gradient approximations are compared against several of these conditions. A direct tabular comparison of these functionals (not of calculated properties) with one another is also made. © 1994 John Wiley & Sons, Inc. 相似文献
85.
The capability of gated saturable absorbers for single-pulse selection is studied theoretically using the classical space-time-dependent rate-equation model. The dynamics of operation is followed experimentally by the well-known pump—probe technique. Comparing the theoretical and experimental results, it is found that gated saturable absorbers can efficiently be used for pulse forming and pulse selection of pulses longer than picosecond. 相似文献
86.
87.
88.
89.
90.
This paper attempts to develop a theory of sufficiency in the setting of non-commutative algebras parallel to the ideas in
classical mathematical statistics. Sufficiency of a coarse-graining means that all information is extracted about the mutual
relation of a given family of states. In the paper sufficient coarse-grainings are characterized in several equivalent ways
and the non-commutative analogue of the factorization theorem is obtained. As an application we discuss exponential families.
Our factorization theorem also implies two further important results, previously known only in finite Hilbert space dimension,
but proved here in generality: the Koashi-Imoto theorem on maps leaving a family of states invariant, and the characterization
of the general form of states in the equality case of strong subadditivity.
Supported by the EU Research Training Network Quantum Probability with Applications to Physics, Information Theory and Biology
and Center of Excellence SAS Physics of Information I/2/2005.
Supported by the Hungarian grant OTKA T032662 相似文献