全文获取类型
收费全文 | 28780篇 |
免费 | 97篇 |
国内免费 | 270篇 |
专业分类
化学 | 10446篇 |
晶体学 | 259篇 |
力学 | 1374篇 |
综合类 | 12篇 |
数学 | 8958篇 |
物理学 | 8098篇 |
出版年
2021年 | 27篇 |
2020年 | 31篇 |
2018年 | 1187篇 |
2017年 | 1445篇 |
2016年 | 703篇 |
2015年 | 556篇 |
2014年 | 467篇 |
2013年 | 653篇 |
2012年 | 3123篇 |
2011年 | 2315篇 |
2010年 | 1805篇 |
2009年 | 1542篇 |
2008年 | 555篇 |
2007年 | 600篇 |
2006年 | 597篇 |
2005年 | 4422篇 |
2004年 | 3895篇 |
2003年 | 2288篇 |
2002年 | 476篇 |
2001年 | 281篇 |
2000年 | 86篇 |
1999年 | 167篇 |
1998年 | 109篇 |
1997年 | 68篇 |
1996年 | 45篇 |
1995年 | 41篇 |
1994年 | 42篇 |
1992年 | 169篇 |
1991年 | 153篇 |
1990年 | 137篇 |
1989年 | 109篇 |
1988年 | 98篇 |
1987年 | 56篇 |
1986年 | 42篇 |
1985年 | 36篇 |
1984年 | 30篇 |
1983年 | 28篇 |
1979年 | 31篇 |
1976年 | 80篇 |
1975年 | 38篇 |
1974年 | 41篇 |
1973年 | 49篇 |
1972年 | 39篇 |
1971年 | 25篇 |
1970年 | 34篇 |
1969年 | 37篇 |
1968年 | 35篇 |
1967年 | 30篇 |
1966年 | 37篇 |
1923年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
912.
Holger?P.?PeterssonEmail author 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2002,72(1):165-186
The structure group of an alternative algebra and various canonical subgroups are defined and investigated. Using the principle
of triality, natural sets of generators for these groups in the case of octonion algebras are exhibited.
Horst Tietz zur Vollendung des achtzigsten Lebensjahres gewidmet 相似文献
913.
914.
915.
916.
This paper discusses the spectral properties and numerical simulation for the second order elliptic operators with rapidly
oscillating coefficients in the domains which may contain small cavities distributed periodically with period ε. A multiscale
asymptotic analysis formula for this problem is obtained by constructing properly the boundary layer. Finally, numerical results
are given, which provide a strong support for the analytical estimates 相似文献
917.
In this paper, we give a short proof for the existence of nontrivial choreography solution to the equal-mass three-body problem,
which is discovered by Chenciner and Montgomery recently. 相似文献
918.
邓小刚 《中国科学A辑(英文版)》2002,45(3):356-370
Based on the method deriving dissipative compact linear schemes (DCS), novel high-order dissipative weighted compact nonlinear schemes (DWCNS) are developed. By Fourier analysis,the dissipative and dispersive features of DWCNS are discussed. In view of the modified wave number, the DWCNS are equivalent to the fifth-order upwind biased explicit schemes in smooth regions and the interpolations at cell-edges dominate the accuracy of DWCNS. Boundary and near boundary schemes are developed and the asymptotic stabilities of DWCNS on both uniform and stretching grids are analyzed. The multi-dimensional implementations for Euler and Navier-Stokes equations are discussed. Several numerical inviscid and viscous results are given which show the good performances of the DWCNS for discontinuities capturing, high accuracy for boundary layer resolutions, good convergent rates (the root-mean-square of residuals approaching machine zero for solutions with strong shocks) and especially the damping effect on the spudous oscillations which were found in the solutions obtained by TVD and ENO schemes. 相似文献
919.
Starting with an initial vector λ = (λ(κ))κ∈z ∈ ep(Z), the subdivision scheme generates asequence (Snaλ)∞n=1 of vectors by the subdivision operator Saλ(κ) = ∑λ(j)a(k - 2j), k ∈ Z. j∈zSubdivision schemes play an important role in computer graphics and wavelet analysis. It is very interesting tounderstand under what conditions the sequence (Snaλ)∞n=1 converges to an Lp-function in an appropriate sense.This problem has been studied extensively. In this paper we show that the subdivision scheme converges forany initial vector in ep(Z) provided that it does for one nonzero vector in that space. Moreover, if the integertranslates of the refinable function are stable, the smoothness of the limit function corresponding to the vectorλ is also independent of λ. 相似文献
920.
In the present paper, a liquid (or melt) film of relatively high temperature ejected from a vessel and painted on the moving
solid film is analyzed by using the second-order fluid model of the non-Newtonian fluid. The thermocapillary flow driven by
the temperature gradient on the free surface of a Newtonian liquid film was discussed before. The effect of rheological fluid
on thermocapillary flow is considered in the present paper. The analysis is based on the approximations of lubrication theory
and perturbation theory. The equation of liquid height and the process of thermal hydrodynamics of the non-Newtonian liquid
film are obtained, and the case of weak effect of the rheological fluid is solved in detail. 相似文献