全文获取类型
收费全文 | 202605篇 |
免费 | 2823篇 |
国内免费 | 741篇 |
专业分类
化学 | 109945篇 |
晶体学 | 3263篇 |
力学 | 7958篇 |
综合类 | 3篇 |
数学 | 24824篇 |
物理学 | 60176篇 |
出版年
2021年 | 1604篇 |
2020年 | 1894篇 |
2019年 | 2008篇 |
2018年 | 2337篇 |
2017年 | 2433篇 |
2016年 | 3966篇 |
2015年 | 2590篇 |
2014年 | 3880篇 |
2013年 | 9361篇 |
2012年 | 7531篇 |
2011年 | 9125篇 |
2010年 | 6119篇 |
2009年 | 5954篇 |
2008年 | 8475篇 |
2007年 | 8369篇 |
2006年 | 7998篇 |
2005年 | 7265篇 |
2004年 | 6618篇 |
2003年 | 5901篇 |
2002年 | 5674篇 |
2001年 | 5638篇 |
2000年 | 4271篇 |
1999年 | 3330篇 |
1998年 | 2813篇 |
1997年 | 2735篇 |
1996年 | 2708篇 |
1995年 | 2452篇 |
1994年 | 2390篇 |
1993年 | 2278篇 |
1992年 | 2588篇 |
1991年 | 2495篇 |
1990年 | 2394篇 |
1989年 | 2325篇 |
1988年 | 2339篇 |
1987年 | 2318篇 |
1986年 | 2209篇 |
1985年 | 2980篇 |
1984年 | 3015篇 |
1983年 | 2628篇 |
1982年 | 2808篇 |
1981年 | 2624篇 |
1980年 | 2591篇 |
1979年 | 2702篇 |
1978年 | 2713篇 |
1977年 | 2614篇 |
1976年 | 2635篇 |
1975年 | 2566篇 |
1974年 | 2549篇 |
1973年 | 2704篇 |
1972年 | 1710篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
121.
S. O. Kolusheva B. A. Salakhutdinov T. F. Aripov L. P. Vernon 《Chemistry of Natural Compounds》1994,29(4):523-525
It has been shown by the ESR of spin probes that thionin initially interacts with with negatively charged membranes electrostatically and then passes into the membranes to a depth comparable with the length of the hydrophobic sections of the protein loops.Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Brigham Young University, Provo, Utah, USA. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 594–597, July–August, 1993. 相似文献
122.
123.
124.
125.
The evaluation of second derivatives of the electronic energy for nonvariational wave functions using an energy functional is discussed. It is shown that, in certain cases, the formation of the first-order relaxed density matrix leads to an efficient algorithm for the calculation of second-order response properties. Detailed formulas are given for second-order Møller–Plesset perturbation theory. © 1994 John Wiley & Sons, Inc. 相似文献
126.
127.
V. A. Nebol'sin B. M. Darinskii E. E. Popova A. A. Shchetinin 《Russian Physics Journal》1995,38(10):1023-1026
An estimate of the factors which influence the rate of growth of filamentary silicon crystals in a standard chloride system using a quartz reactor with hot walls is given. It is shown that a diffusion form of crystallization is observed under the conditions investigated.Voronezh State Technical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 22–26, October, 1995. 相似文献
128.
A method using capillary gel electrophoresis with laser-induced fluorescence detection is described which permits complete sequence determination of antisense DNA analogues of unknown sequence. This method, originally created as a tool to confirm the sequence of antisense oligonucleotides being developed as therapeutic drugs, utilizes data collected under a range of experimental conditions described by the Ogston model as applied to gel electrophoresis. A linear relationship independent of experimental conditions between the relative electrophoretic migration time and the oligonucleotide base number was observed and is shown to be consistent with a simplified version of this model and can be used to facilitate the sequence determination. 相似文献
129.
Philip B. Burt 《Foundations of Physics》1993,23(6):965-968
Several interesting and important quantum field theories must contain the coupling constant in the boundary conditions. The theories considered include quantum electrodynamics of spin-1/2 fermions and gauge field theories. 相似文献
130.
C. Daum L. Hertzberger W. Hoogland R. Jongerius S. Peters P. Van Deurzen V. Chabaud A. Gonzalez-Arroyo B. Hyams H. Tiecke P. Weilhammer A. Dwurazny G. Polok M. Rozanska K. Rybicki M. Turala J. Turnau G. Ascoli H. Backer G. Blanar M. Cerrada H. Dietl J. Gallivan M. Glaubmann R. Klanner E. Lorenz G. Lütjens G. Lutz W. Männer U. Stierlin I. Blakey M. Bowler R. Cashmore J. Loken W. Spalding G. Thompson B. Alper C. Damerell A. Gillman C. Hardwick M. Hotchkiss F. Wickens ACCMOR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1981,10(2):95-100
Muon electron pairs were detected in an Al multiplate spark chamber, exposed to a neutrino beam from the CERN PS. The leptons were not accompanied by other particles, except occasionally by protons. The background came mainly from muon associated π0 production, with one decay gamma lost. It was determined empirically, together with the small contribution from υ e reactions. For electron energies above 2 GeV the background is 5.7±1.5 events, whereas 18 (μe)-candidates have been observed. Hence the effect is established, with a rate of about 10?4 as compared to the muonic reactions above 3 GeV. Charm creation as the origin of this (μe)-production process is excluded; heavy neutral lepton production does not fit the kinematics observed. Instead the events are compatible with the two-body decay of an object with variable invariant mass of order 1 GeV, possibly resulting from axion interactions. 相似文献