全文获取类型
收费全文 | 61234篇 |
免费 | 1832篇 |
国内免费 | 164篇 |
专业分类
化学 | 37800篇 |
晶体学 | 376篇 |
力学 | 995篇 |
综合类 | 5篇 |
数学 | 11227篇 |
物理学 | 12827篇 |
出版年
2023年 | 394篇 |
2022年 | 604篇 |
2021年 | 828篇 |
2020年 | 885篇 |
2019年 | 910篇 |
2018年 | 1138篇 |
2017年 | 1076篇 |
2016年 | 2047篇 |
2015年 | 1714篇 |
2014年 | 1740篇 |
2013年 | 3774篇 |
2012年 | 3659篇 |
2011年 | 3672篇 |
2010年 | 2453篇 |
2009年 | 2182篇 |
2008年 | 3234篇 |
2007年 | 3041篇 |
2006年 | 2740篇 |
2005年 | 2676篇 |
2004年 | 2258篇 |
2003年 | 1918篇 |
2002年 | 1655篇 |
2001年 | 1285篇 |
2000年 | 1234篇 |
1999年 | 893篇 |
1998年 | 699篇 |
1997年 | 642篇 |
1996年 | 813篇 |
1995年 | 581篇 |
1994年 | 667篇 |
1993年 | 615篇 |
1992年 | 623篇 |
1991年 | 525篇 |
1990年 | 565篇 |
1989年 | 461篇 |
1988年 | 456篇 |
1987年 | 441篇 |
1986年 | 413篇 |
1985年 | 547篇 |
1984年 | 525篇 |
1983年 | 404篇 |
1982年 | 407篇 |
1981年 | 414篇 |
1980年 | 364篇 |
1979年 | 334篇 |
1978年 | 314篇 |
1977年 | 314篇 |
1976年 | 324篇 |
1974年 | 284篇 |
1973年 | 305篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Zoltá n M. Balogh Marianna Csö rnyei 《Proceedings of the American Mathematical Society》2006,134(9):2667-2675
We give sufficient conditions for Sobolev and Lipschitz functions in terms of their lower scaled-oscillation. The sharpness of these conditions is shown by examples. Our examples also show that a Stepanov-type differentiability theorem does not hold under the boundedness assumption of the lower scaled-oscillation.
32.
33.
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
34.
35.
Lubomír Kubáček 《Applications of Mathematics》2006,51(6):565-582
Some remarks to problems of point and interval estimation, testing and problems of outliers are presented in the case of multivariate
regression model.
This work was supported by the Council of Czech Government J14/98:153100011. 相似文献
36.
37.
Possible Loss and Recovery of Gibbsianness¶During the Stochastic Evolution of Gibbs Measures 总被引:1,自引:1,他引:0
A.C.D. van Enter R. Fernández F. den Hollander F. Redig 《Communications in Mathematical Physics》2002,226(1):101-130
We consider Ising-spin systems starting from an initial Gibbs measure ν and evolving under a spin-flip dynamics towards a
reversible Gibbs measure μ≠ν. Both ν and μ are assumed to have a translation-invariant finite-range interaction. We study
the Gibbsian character of the measure νS(t) at time t and show the following:
(1) For all ν and μ, νS(t) is Gibbs for small t.
(2) If both ν and μ have a high or infinite temperature, then νS(t) is Gibbs for all t > 0.
(3) If ν has a low non-zero temperature and a zero magnetic field and μ has a high or infinite temperature, then νS(t) is Gibbs for small t and non-Gibbs for large t.
(4) If ν has a low non-zero temperature and a non-zero magnetic field and μ has a high or infinite temperature, then νS(t) is Gibbs for small t, non-Gibbs for intermediate t, and Gibbs for large t.
The regime where μ has a low or zero temperature and t is not small remains open. This regime presumably allows for many different scenarios.
Received: 26 April 2001 / Accepted: 10 October 2001 相似文献
38.
Lithium (10–150 ng ml?1) in wine is determined by atomic absorption spectrometry by direct nebulization and after digestion with mixed acids. The results of methods are similar. Thirty-four wines from various Spanish provinces are analysed. 相似文献
39.
Gábor Dörnyei Marietta Bárczai-Beke Gábor Blaskó Péter Péchy Csaba Szántay 《Tetrahedron letters》1982,23(28):2913-2916
Regioselective demethylation of 3,4-dihydropapaveraldine (a) at 7 and 3' positions affords a properly substituted diphenolic key intermidiate (d) for the synthesis of reticuline and N-norreticuline. 相似文献
40.
V. Čápek 《Czechoslovak Journal of Physics》1991,41(10):975-989
A review of ideas leading to full rejection of any finite or partially-infinite order kinetic equation linearized in external field is given on grounds of the time-convolution Generalized Master Equations (GME). By two examples (two-level and band conduction problem), it is shown how standard kinetic equations result from GME in the lowest order approximations which obscure, however, a direct correspondence with the Kubo linear response theory. Without approximations, on the other hand, the rigorous approach is shown to be fully equivalent with the Kubo results. It is argued and illustrated that usual technical simplicity and seeming physical lucidity of standard theories (connected with the presence of field-independent transfer or scattering rates in the fielddependent linearized theory) are just owing to structural features which are solely due to the lowest order approximations involved. These features (i.e. also the possibility of standard physical interpretation of kinetic phenomena) are proved to disappear completely as far as the theory goes properly to higher orders. 相似文献