全文获取类型
收费全文 | 423002篇 |
免费 | 2554篇 |
国内免费 | 715篇 |
专业分类
化学 | 201285篇 |
晶体学 | 6510篇 |
力学 | 22936篇 |
综合类 | 5篇 |
数学 | 56189篇 |
物理学 | 139346篇 |
出版年
2021年 | 3826篇 |
2020年 | 4222篇 |
2019年 | 5024篇 |
2018年 | 7695篇 |
2017年 | 8027篇 |
2016年 | 9954篇 |
2015年 | 4918篇 |
2014年 | 8675篇 |
2013年 | 17109篇 |
2012年 | 14481篇 |
2011年 | 16714篇 |
2010年 | 13263篇 |
2009年 | 13493篇 |
2008年 | 15808篇 |
2007年 | 15478篇 |
2006年 | 14195篇 |
2005年 | 14974篇 |
2004年 | 14351篇 |
2003年 | 12342篇 |
2002年 | 11147篇 |
2001年 | 12257篇 |
2000年 | 9393篇 |
1999年 | 7094篇 |
1998年 | 6001篇 |
1997年 | 5946篇 |
1996年 | 5417篇 |
1995年 | 4896篇 |
1994年 | 4916篇 |
1993年 | 4781篇 |
1992年 | 5276篇 |
1991年 | 5674篇 |
1990年 | 5511篇 |
1989年 | 5459篇 |
1988年 | 5224篇 |
1987年 | 5310篇 |
1986年 | 4817篇 |
1985年 | 5816篇 |
1984年 | 6062篇 |
1983年 | 5034篇 |
1982年 | 5211篇 |
1981年 | 4768篇 |
1980年 | 4556篇 |
1979年 | 5277篇 |
1978年 | 5419篇 |
1977年 | 5508篇 |
1976年 | 5541篇 |
1975年 | 5189篇 |
1974年 | 5025篇 |
1973年 | 5169篇 |
1972年 | 4134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Generic polynomials for the symmetric group S4, the Klein group V4, the cyclic group of order 4, the dihedral group D4, and the alternating group A4 over fields of characteristic 2 are described explicitly. Bibliography: 5 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 330, 2006, pp. 247–258. 相似文献
993.
V. A. Sadovnichy V. V. Alexandrov E. Soto T. B. Alexandrova T. G. Astakhova R. Vega N. V. Kulikovskaya V. I. Kurilov S. S. Migunov N. E. Shulenina 《Journal of Mathematical Sciences》2007,146(3):5938-5947
A mathematical model of the system composed of two sensors, the semicircular canal and the sacculus, is suggested. The model
is described by three lines of blocks, each line of which has the following structure: a biomechanical block, a mechanoelectrical
transduction mechanism, and a block describing the hair cell ionic currents and membrane potential dynamics. The response
of this system to various stimuli (head rotation under gravity and falling) is investigated. Identification of the model parameters
was done with the experimental data obtained for the axolotl (Ambystoma tigrinum) at the Institute of Physiology, Autonomous
University of Puebla, Mexico. Comparative analysis of the semicircular canal and sacculus membrane potentials is presented.
__________
Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 11, No. 7, pp. 207–220, 2005. 相似文献
994.
Testing exponentiality against a class of alternatives which includes the RNBUE distributions based on the empirical laplace transform 总被引:1,自引:0,他引:1
S. G. Meintanis Ya. Yu. Nikitin A. V. Tchirina 《Journal of Mathematical Sciences》2007,145(2):4871-4879
A scale-free test for exponentiality is proposed which is consistent within an extended set of models, including, but not
limited to, the “renewal new better than used in expectation” (RNBUE) class of life distributions. The limiting null distribution of the test statistics is derived, and the approximate local
Bahadur efficiency is calculated for several families of alternatives. Finite-sample properties of the proposed procedures
are investigated via simulation. Bibliography: 24 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 339, 2006, pp. 63–77. 相似文献
995.
996.
V. V. Bilykh 《Journal of Experimental and Theoretical Physics》2007,104(5):814-818
The polarition linewidth is calculated as a function of magnetic field applied perpendicular to the microcavity plane for microcavity excition-polaritons scattered by free electrons in a quantum well. The calculated function exhibits oscillatory behavior; i.e., the scattering rate either increases or decreases with magnetic induction. Possible applications of this effect are discussed. 相似文献
997.
998.
We present a study of the temporal compression of nanosecond laser pulses resulting from the coherent control peculiarities of the propagation dynamics in a regime of electromagnetically induced transparency. We describe the general theoretical framework and discuss the crucial conditions required in order to experimentally realize such a temporal compression scheme. A proof-of-concept experimental realization of a scheme of this type in a sample of hot sodium vapors is currently being implemented: we describe in detail the experimental setup designed for this purpose. 相似文献
999.
T. M. Tovstik 《Vestnik St. Petersburg University: Mathematics》2007,40(3):250-252
An algorithm for calculating the discrepancy of finitely many points in the unit n-cube [0, 1]n is suggested. This algorithm is easy to program. For 2 ≤ n ≤ 4, the suggested algorithm is significantly faster than Bundschuh and Zhu’s algorithm. For larger n, whether this algorithm is faster depends on the number of points. 相似文献
1000.
Yu. V. Kaletina V. M. Schastlivtsev E. A. Fokina 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(12):1667-1673
The effect of magnetic treatment on the isothermal martensitic transformation in the Fe-24% Ni-4% Mn alloy has been investigated. The martensitic transformation in a dc magnetic field at liquid-helium temperature has been analyzed. 相似文献