全文获取类型
收费全文 | 641136篇 |
免费 | 5841篇 |
国内免费 | 1491篇 |
专业分类
化学 | 323477篇 |
晶体学 | 9445篇 |
力学 | 31978篇 |
综合类 | 16篇 |
数学 | 85046篇 |
物理学 | 198506篇 |
出版年
2021年 | 5796篇 |
2020年 | 6424篇 |
2019年 | 7247篇 |
2018年 | 9956篇 |
2017年 | 9900篇 |
2016年 | 14066篇 |
2015年 | 7938篇 |
2014年 | 13174篇 |
2013年 | 28529篇 |
2012年 | 22470篇 |
2011年 | 27070篇 |
2010年 | 20258篇 |
2009年 | 20334篇 |
2008年 | 25488篇 |
2007年 | 25080篇 |
2006年 | 23032篇 |
2005年 | 20367篇 |
2004年 | 19123篇 |
2003年 | 17088篇 |
2002年 | 17258篇 |
2001年 | 18524篇 |
2000年 | 14322篇 |
1999年 | 11050篇 |
1998年 | 9556篇 |
1997年 | 9212篇 |
1996年 | 8712篇 |
1995年 | 7864篇 |
1994年 | 7822篇 |
1993年 | 7602篇 |
1992年 | 8188篇 |
1991年 | 8554篇 |
1990年 | 8280篇 |
1989年 | 8119篇 |
1988年 | 7916篇 |
1987年 | 7868篇 |
1986年 | 7388篇 |
1985年 | 9288篇 |
1984年 | 9520篇 |
1983年 | 7763篇 |
1982年 | 8005篇 |
1981年 | 7710篇 |
1980年 | 7212篇 |
1979年 | 7920篇 |
1978年 | 8125篇 |
1977年 | 8129篇 |
1976年 | 8119篇 |
1975年 | 7505篇 |
1974年 | 7361篇 |
1973年 | 7474篇 |
1972年 | 5721篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
T. V. Maslova 《Russian Journal of Mathematical Physics》2006,13(4):425-430
The results obtained in V. P. Maslov’s article [1] can automatically be carried over to arbitrary semiotic systems if the
string of signs is sufficiently long. We shall show in this article, by using arguments based on the ideas of Kolmogorov complexity
and by applying the theorem of V. P. Maslov from [2], that one can obtain similar formulas for the distribution of various
semiotic objects. In order to do this, we must introduce notions generalizing the occurrence frequency of words in corpora
of texts. We also interpret a formula due to Maslov (appearing in [3]) from the point of view of the general semiotic notions
introduced here. 相似文献
152.
The Fokker–Planck-type kinetic equation is constructed with the help of the evolution equation for the transverse energy of channelized particles, which in its turn is derived beyond the framework of perturbation theory proceeding from the condition of nonconcervation of the adiabatic invariant. 相似文献
153.
V. P. Nosko 《Journal of Mathematical Sciences》1991,56(3):2489-2492
We study the asymptotics of some regression functions which occur in the study of high rejections of homogeneous Gaussian random fields.Translated from Statisticheskie Metody Otsenivaniya i Proverki Gipotez, pp. 143–148, 1988. 相似文献
154.
S. V. Ivanov V. V. Trachevskii O. S. Titova L. A. Zozulya 《Russian Journal of Applied Chemistry》2006,79(10):1712-1714
Experimental data demonstrate that a study of accelerated aging can enable prognostication of the working capacity and storage life of polymeric formulations used in aircraft components on the basis of changes in thermogravimetric constants of these polymeric formulations. 相似文献
155.
Off-the-shell anomalous factors of the two-body Coulomb transition matrices appear in the integral form of the Faddeev second-order
nuclear-electronic amplitude, for proton-hydrogen charge transfer scattering in a typical nlm → n′l′m′ transition. A symmetric-impulse approximation (SIA) is applied to eliminate these factors and an induction method is proposed
to analytically calculate the remaining integrals. The nuclear-electronic amplitude is derived for the general case, and for
totally symmetric collisions, in terms of generalized hypergeometric functions of two variables, F
4, and of one variable, 3
F
2, respectively. The angular distribution of the second-order nuclear-electronic charge transfer amplitude shows the Thomas
mechanism as a peak or a hump for symmetric and asymmetric collisions. There also exists a peak in the forward angular distribution
of the second-order nuclear-electronic amplitude, which partly cancels the kinematic peak in the angular distribution of the
charge transfer differential cross sections. 相似文献
156.
V. B. Larin 《Ukrainian Mathematical Journal》1989,41(5):532-538
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 41, No. 5, pp. 615–621, May, 1989. 相似文献
157.
158.
159.
160.
V. A. Zayats A. N. Nikolaevskii T. A. Filippenko O. P. Kniga G. A. Tikhonova 《Russian Journal of Applied Chemistry》2006,79(10):1651-1654
Specific features of the initiated oxidation of polyethylene and its low-molecular-weight analogue tridecane, associated with the occurrence of the process in the short-chain mode, were studied. 相似文献