全文获取类型
收费全文 | 21217篇 |
免费 | 599篇 |
国内免费 | 67篇 |
专业分类
化学 | 11570篇 |
晶体学 | 179篇 |
力学 | 444篇 |
综合类 | 1篇 |
数学 | 4572篇 |
物理学 | 5117篇 |
出版年
2022年 | 215篇 |
2021年 | 304篇 |
2020年 | 302篇 |
2019年 | 366篇 |
2018年 | 495篇 |
2017年 | 462篇 |
2016年 | 776篇 |
2015年 | 647篇 |
2014年 | 711篇 |
2013年 | 1535篇 |
2012年 | 1136篇 |
2011年 | 1441篇 |
2010年 | 923篇 |
2009年 | 790篇 |
2008年 | 1071篇 |
2007年 | 996篇 |
2006年 | 859篇 |
2005年 | 680篇 |
2004年 | 655篇 |
2003年 | 533篇 |
2002年 | 493篇 |
2001年 | 314篇 |
2000年 | 310篇 |
1999年 | 275篇 |
1998年 | 238篇 |
1997年 | 206篇 |
1996年 | 233篇 |
1995年 | 182篇 |
1994年 | 169篇 |
1993年 | 173篇 |
1992年 | 185篇 |
1991年 | 143篇 |
1990年 | 149篇 |
1989年 | 140篇 |
1988年 | 135篇 |
1987年 | 124篇 |
1986年 | 119篇 |
1985年 | 174篇 |
1984年 | 187篇 |
1983年 | 161篇 |
1982年 | 158篇 |
1981年 | 152篇 |
1980年 | 144篇 |
1979年 | 154篇 |
1978年 | 170篇 |
1977年 | 138篇 |
1976年 | 155篇 |
1975年 | 141篇 |
1974年 | 146篇 |
1973年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
Separation of 23 dansylated amino acids by micellar electrokinetic chromatography at low temperature
Summary The baseline separation of 23 dansylated amino acids (including 3 didansylated species) is reported. Lowering of the analysis
temperature and fine control of the surfactant concentration were essential in obtaining this result. Calibration graphs with
good linearity were obtained. 相似文献
24.
25.
26.
Yoel Shkolnisky Mark Tygert Vladimir Rokhlin 《Applied and Computational Harmonic Analysis》2006,21(3):413-420
Many signals encountered in science and engineering are approximated well by bandlimited functions. We provide suitable error bounds for the approximation of bandlimited functions by linear combinations of certain special functions—the prolate spheroidal wave functions of order 0. The coefficients in the approximating linear combinations are given explicitly via appropriate quadrature formulae. 相似文献
27.
Vladimir Kogan 《Tetrahedron letters》2006,47(43):7515-7518
Mild Ni-catalyzed homogeneous reductions of aryl tosylates are described for the first time. The catalytic system Ni(PPh3)2Cl2 and PCy3 is shown to be general for hydrogenolysis of a wide range of tosylates, including hindered, deactivated, heterocyclic, and bifunctional examples. 相似文献
28.
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
29.
Balázs Szendröi 《Mathematische Zeitschrift》2002,240(2):233-241
This note shows that a certain toric quotient of the quintic Calabi-Yau threefold in provides a counterexample to a recent conjecture of Cox and Katz concerning nef cones of toric hypersurfaces.
Received: 8 February 2001; in final form: 17 September 2001 / Published online: 1 February 2002 相似文献
30.