全文获取类型
收费全文 | 2741篇 |
免费 | 335篇 |
国内免费 | 300篇 |
专业分类
化学 | 611篇 |
晶体学 | 12篇 |
力学 | 282篇 |
综合类 | 56篇 |
数学 | 1641篇 |
物理学 | 774篇 |
出版年
2024年 | 3篇 |
2023年 | 21篇 |
2022年 | 54篇 |
2021年 | 62篇 |
2020年 | 78篇 |
2019年 | 65篇 |
2018年 | 75篇 |
2017年 | 87篇 |
2016年 | 101篇 |
2015年 | 59篇 |
2014年 | 126篇 |
2013年 | 239篇 |
2012年 | 116篇 |
2011年 | 121篇 |
2010年 | 116篇 |
2009年 | 161篇 |
2008年 | 176篇 |
2007年 | 152篇 |
2006年 | 170篇 |
2005年 | 161篇 |
2004年 | 118篇 |
2003年 | 110篇 |
2002年 | 102篇 |
2001年 | 105篇 |
2000年 | 114篇 |
1999年 | 96篇 |
1998年 | 80篇 |
1997年 | 83篇 |
1996年 | 58篇 |
1995年 | 47篇 |
1994年 | 46篇 |
1993年 | 21篇 |
1992年 | 15篇 |
1991年 | 21篇 |
1990年 | 12篇 |
1989年 | 17篇 |
1988年 | 24篇 |
1987年 | 15篇 |
1986年 | 12篇 |
1985年 | 20篇 |
1984年 | 23篇 |
1983年 | 10篇 |
1982年 | 18篇 |
1981年 | 18篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 6篇 |
1973年 | 3篇 |
排序方式: 共有3376条查询结果,搜索用时 0 毫秒
1.
The finite-size corrections, central chargesc, and scaling dimensionsx of tricritical hard squares and critical hard hexagons are calculated analytically. This is achieved by solving the special functional equation or inversion identity satisfied by the commuting row transfer matrices of these lattice models at criticality. The results are expressed in terms of Rogers dilogarithms. For tricritical hard squares we obtainc=7/10,x=3/40, 1/5, 7/8, 6/5 and for hard hexagons we obtainc=4/5,x=2/15, 4/5, 17/15, 4/3, 9/5, in accord with the predictions of conformal and modular invariance. 相似文献
2.
3.
A localH-theorem is derived for a recently proposed extension of Enskog kinetic theory to a dense model fluid composed of particles with interactions extending beyond a hard core.On leave from: Katedra Fizyki, Uniwersytetu Szczecinskiego, 70-451 Szczecin, Poland. 相似文献
4.
本文考察了包括平面上的各种广义 Cantor集 ,Sierpinski集和包括某些连续不可微曲线在内的广义 Sierpinski集 .由相似变换 ,导出了它们的级数表达式 ,并利用它和字符串空间的对应关系 ,计算出它们的Hausdorff维数 相似文献
5.
6.
Continuous dependence on a modelling parameter is established for solutions of a problem for a complex Ginzburg–Landau equation. A homogenizing boundary condition is also used to discuss the continuous dependence results. We derive a priori estimates that indicate that solutions depend continuously on a parameter in the governing differential equation. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
7.
A complete study of the spectrum of a finite-dimensional Bose operator is carried out in the paper. The cases in which the
spectrum is discrete or continuous are studied.
Translated fromMatematicheskie Zametki, Vol. 61, No. 6, pp. 835–854, June, 1997.
Translated by A. M. Chebotarev 相似文献
8.
L. E. Payne G. A. Philippin V. Proytcheva 《Mathematical Methods in the Applied Sciences》2007,30(15):1885-1898
In this paper, we investigate the continuous dependence on the geometry and the initial time for solutions u( x , t) of a class of nonlinear parabolic initial‐boundary value problems. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
9.
《Journal of Chemical Sciences》2005,117(5):525-531
The silicon atom may increase its coordination number to values greater than four, to form pentacoordinated compounds. It
has been observed experimentally that, in general, pentacoordinated compounds show greater reactivity than tetracoordinated
compounds. In this work, density functional theory is used to calculate the global softness and the condensed softness of
the silicon atom for SiH
n
F4−n
and SiH
n
F
5−n
1−
. The values obtained show that the global and condensed softness are greater in the pentacoordinated compounds than in the
tetracoordinated compounds, a result that explains the enhanced reactivity. If the results are analysed through a local version
of the hard and soft acids and bases principle, it is possible to suggest that in nucleophilic substitution reactions, soft
nucleophiles preferably react with SiH
n
F
5−n
1−
, and hard nucleophiles with SiH
n
F4−n
. 相似文献
10.
In this paper, we consider questions related to the structure of inverse matrices of linear bounded operators acting in infinite-dimensional complex Banach spaces. We obtain specific estimates of elements of inverse matrices for bounded operators whose matrices have a special structure. Matrices are introduced as special operator-valued functions on an index set. The matrix structure is described by the behavior of the given function on elements of a special partition of the index set. The method used for deriving the estimates is based on an analysis of Fourier series of strongly continuous periodic functions. 相似文献