全文获取类型
收费全文 | 267393篇 |
免费 | 2375篇 |
国内免费 | 623篇 |
专业分类
化学 | 141986篇 |
晶体学 | 4162篇 |
力学 | 11922篇 |
综合类 | 9篇 |
数学 | 29481篇 |
物理学 | 82831篇 |
出版年
2019年 | 2289篇 |
2018年 | 3114篇 |
2017年 | 3110篇 |
2016年 | 4482篇 |
2015年 | 2656篇 |
2014年 | 4280篇 |
2013年 | 10671篇 |
2012年 | 8067篇 |
2011年 | 9893篇 |
2010年 | 7081篇 |
2009年 | 6874篇 |
2008年 | 9308篇 |
2007年 | 9509篇 |
2006年 | 8878篇 |
2005年 | 8069篇 |
2004年 | 7420篇 |
2003年 | 6732篇 |
2002年 | 6657篇 |
2001年 | 7325篇 |
2000年 | 5659篇 |
1999年 | 4359篇 |
1998年 | 3859篇 |
1997年 | 3844篇 |
1996年 | 3584篇 |
1995年 | 3332篇 |
1994年 | 3490篇 |
1993年 | 3189篇 |
1992年 | 3663篇 |
1991年 | 3666篇 |
1990年 | 3599篇 |
1989年 | 3457篇 |
1988年 | 3568篇 |
1987年 | 3463篇 |
1986年 | 3285篇 |
1985年 | 4361篇 |
1984年 | 4631篇 |
1983年 | 3872篇 |
1982年 | 4007篇 |
1981年 | 3931篇 |
1980年 | 3908篇 |
1979年 | 3876篇 |
1978年 | 4190篇 |
1977年 | 4107篇 |
1976年 | 4173篇 |
1975年 | 3849篇 |
1974年 | 3893篇 |
1973年 | 4050篇 |
1972年 | 2851篇 |
1971年 | 2378篇 |
1970年 | 2177篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
123.
124.
125.
S. A. Gurevich T. A. Zaraiskaya S. G. Konnikov V. M. Mikushkin S. Yu. Nikonov A. A. Sitnikova S. E. Sysoev V. V. Khorenko V. V. Shnitov Yu. S. Gordeev 《Physics of the Solid State》1997,39(10):1691-1695
The concentration and chemical state of copper in the subsurface region of Cu/SiO2 composite films obtained by simultaneous magnetron sputtering from two sources (Cu and SiO2) are determined by x-ray photoelectron spectroscopy (XPS). It is established that copper in the as-grown film is primarily in the form of unoxidized atoms dispersed in a SiO2 matrix. Annealing of the film results in practically no oxidation, but about 70% of the copper atoms condense into metallic clusters with sizes below 10 Å in the subsurface region and about 50 Å in the bulk of the film. The changes in the binding energy of core electrons, and especially in the energies of Auger electrons, are so large in this situation that photoelectron and Auger spectroscopy are efficient methods for monitoring the chemical state of this composite material. 相似文献
126.
The changes in the magnetization of yttrium iron garnet (YIG) when irradiated by a pulsed neodymium laser beam with wavelength
λ=1.06 μm are investigated. Measurements are performed in the temperature range from 100 K to 600 K in various external magnetic
fields. YIG single crystals grown along the crystallographic (100), (110), and (111) directions are chosen so that the external
anisotropy of the indicated processes can be determined. Characteristic temperature intervals dominated by different mechanisms
of variation of the magnetization under the influence of a laser pulse are discussed.
Fiz. Tverd. Tela (St. Petersburg) 39, 1263–1266 (July 1997) 相似文献
127.
The temporal evolution of a long-pulse high-density electron beam in a high-power traveling-wave tube with a periodic magnetic
focusing system is investigated. The relation between the variation of the characteristics of the electron beam and ionization
of the residual gas and particles desorbed from the electrode surfaces is shown. A strong influence of the formation of the
collector plasma and the flux of ions from its surface on the beam dynamics is revealed. The effect of microwave fields in
the transport channel on the characteristics of the beam during its evolution is studied.
Zh. Tekh. Fiz. 67, 54–58 (December 1997) 相似文献
128.
129.
A simple method is proposed for increasing the accuracy of computation of the eigenvalues of elliptic operators, which does not require high-order accurate schemes.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 63, pp. 63–68, 1987. 相似文献
130.
I. V. Ukrainets S. G. Taran O. V. Gorokhova P. A. Bezuglyi A. V. Turov 《Chemistry of Heterocyclic Compounds》1994,30(2):204-207
In a solution of DMF, 2-carbethoxymethyl-4H-3,1-benzoxazin-4-one reacts with primarily aromatic amines basically with the formation of the corresponding 2-carbethoxymetlzyl-3-arylquinazolin-4(3H)-ones. Possible mechanisms of these chemical transformations are reported and discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 225–228, February, 1994. Original article submitted June 28, 1993. 相似文献