全文获取类型
收费全文 | 6432篇 |
免费 | 178篇 |
国内免费 | 15篇 |
专业分类
化学 | 4478篇 |
晶体学 | 38篇 |
力学 | 129篇 |
数学 | 802篇 |
物理学 | 1178篇 |
出版年
2021年 | 53篇 |
2020年 | 55篇 |
2019年 | 57篇 |
2016年 | 133篇 |
2015年 | 117篇 |
2014年 | 116篇 |
2013年 | 250篇 |
2012年 | 192篇 |
2011年 | 213篇 |
2010年 | 162篇 |
2009年 | 141篇 |
2008年 | 205篇 |
2007年 | 226篇 |
2006年 | 242篇 |
2005年 | 202篇 |
2004年 | 185篇 |
2003年 | 176篇 |
2002年 | 181篇 |
2001年 | 147篇 |
2000年 | 115篇 |
1999年 | 113篇 |
1998年 | 93篇 |
1997年 | 83篇 |
1996年 | 110篇 |
1995年 | 92篇 |
1994年 | 91篇 |
1993年 | 96篇 |
1992年 | 130篇 |
1991年 | 106篇 |
1990年 | 103篇 |
1989年 | 112篇 |
1988年 | 107篇 |
1987年 | 103篇 |
1986年 | 103篇 |
1985年 | 139篇 |
1984年 | 134篇 |
1983年 | 88篇 |
1982年 | 121篇 |
1981年 | 107篇 |
1980年 | 118篇 |
1979年 | 126篇 |
1978年 | 95篇 |
1977年 | 119篇 |
1976年 | 88篇 |
1975年 | 84篇 |
1974年 | 95篇 |
1973年 | 68篇 |
1972年 | 37篇 |
1971年 | 64篇 |
1967年 | 41篇 |
排序方式: 共有6625条查询结果,搜索用时 15 毫秒
41.
H. Fawcett S. Barlag H. Becker E. Belau T. Böhringer M. Bosman V. Castillo V. Chabaud D. Bucholz C. Damerell C. Daum G. De Rijk H. Dietl S. Gill A. Gillman R. Gilmore T. Gooch P. Gras Z. Hajduk E. Higon B. Hyams D. Kelsey J. Kemmer R. Klanner U. Kötz S. Kwan B. Lücking G. Lütjens G. Lutz J. Malos W. Männer E. Neugebauer H. Palka M. Pepé G. Polok J. Richardson M. Rozanska K. Rybicki H. Seebrunner U. Stierlin R. Tapper H. Tiecke M. Turala G. Waltermann S. Watts P. Weilhammer F. Wickens L. Wiggers A. Wylie T. Zeludziewicz ACCMOR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,46(4):513-519
The production of the neutralK ? (892) resonances by 200 GeVK ? andπ ? has been studied over the kinematic range 0.0<x f<1.0 andp t 2 <5.0 GeV2. Longitudinal and transverse momentum distributions are presented. In addition the decay angular distributions inK ? fragmentation to \(\bar K^{0*} \) have been investigated. 相似文献
42.
43.
The dispersion relation for the coherent propagation of a hole moving in a two-dimensional quantum antiferromagnet is discussed. The system is described by two model Hamiltonians, thet-J model and thet-t-J model, which have been used frequently to discuss strong electron-correlation effects present in high-T
c
superconductors. The calculations are based on the introduction of a new wave function which is constructed by use of equations derived by Shraiman and Siggia. The different mechanisms for the coherent propagation, which are due to the spin fluctuation and the hopping terms of the Hamiltonian, are treated on the same footing. As a result of the inclusion of an effective hopping mechanism along spiral paths-first discussed by Trugman-the minimum of the band is somewhat changed compared to results recently obtained in the literature. For large values of the ratiot/J an inversion of the whole dispersion relation occurs. The overall shapes of the dispersion within both models are found to agree quite well, though for small values oft/J the bandwidth within thet-J model becomes significantly smaller than that of thet-t-J model. 相似文献
44.
Manfred Droste 《Order》1988,5(3):261-273
We show that any lattice-ordered group (l-group) G can be l-embedded into continuously many l-groups H
i
which are pairwise elementarily inequivalent both as groups and as lattices with constant e. Our groups H
i
can be distinguished by group-theoretical first-order properties which are induced by lattice-theoretically nice properties of their normal subgroup lattices. Moreover, they can be taken to be 2-transitive automorphism groups A(S
i
) of infinite linearly ordered sets (S
i
, ) such that each group A(S
i
) has only inner automorphisms. We also show that any countable l-group G can be l-embedded into a countable l-group H whose normal subgroup lattice is isomorphic to the lattice of all ideals of the countable dense Boolean algebra B. 相似文献
45.
R. Suntz H. Becker P. Monkhouse J. Wolfrum 《Applied physics. B, Lasers and optics》1988,47(4):287-293
Two-dimensional laser-induced fluorescence (2D-LIF) imaging of OH radicals, excited at 308 nm, has been employed to visualize the flame front in an internal combustion engine burning air/propane mixtures. Light sheet thicknesses down to 70 m have been attained for excitation. Hydroxyl radicals were detected up to pressures of 7.5 bar at engine speeds of 500 rpm. An upper limit of 300 m for the flame front thickness was obtained from line intensity profiles. 相似文献
46.
Adler J Becker JJ Blaylock GT Bolton T Brient J Browder T Brown JS Bunnell KO Burchell M Burnett TH Cassell RE Coffman D Cook V Coward DH DeJongh F Dorfan DE Drinkard J Dubois GP Eigen G Einsweiler KF Eisenstein BI Freese T Gatto C Gladding G Grab C Hamilton RP Hauser J Heusch CA Hitlin DG Izen JM Kim PC Köpke L Li A Lockman WS Mallik U Matthews CG Mincer AI Mir R Mockett PM Mozley RF Nemati B Odian A Parrish L Partridge R Pitman D Plaetzer SA Richman JD Sadrozinski HF Scarlatella M Schalk TL 《Physical review letters》1989,62(16):1821-1824
47.
The association constant K of mono-acetato complex of Tb3+ has been determined at normal p and T conditions by measurement of its luminescence lifetime in aqueous solution containing increasing concentrations of acetate. Two experimental arrangements used for the measurement are described. 相似文献
48.
49.
50.