全文获取类型
收费全文 | 17637篇 |
免费 | 802篇 |
国内免费 | 281篇 |
专业分类
化学 | 11472篇 |
晶体学 | 91篇 |
力学 | 399篇 |
综合类 | 13篇 |
数学 | 3183篇 |
物理学 | 3562篇 |
出版年
2023年 | 165篇 |
2022年 | 338篇 |
2021年 | 379篇 |
2020年 | 467篇 |
2019年 | 542篇 |
2018年 | 417篇 |
2017年 | 334篇 |
2016年 | 677篇 |
2015年 | 612篇 |
2014年 | 633篇 |
2013年 | 1028篇 |
2012年 | 1225篇 |
2011年 | 1420篇 |
2010年 | 762篇 |
2009年 | 645篇 |
2008年 | 1013篇 |
2007年 | 951篇 |
2006年 | 938篇 |
2005年 | 874篇 |
2004年 | 675篇 |
2003年 | 529篇 |
2002年 | 498篇 |
2001年 | 288篇 |
2000年 | 223篇 |
1999年 | 220篇 |
1998年 | 177篇 |
1997年 | 201篇 |
1996年 | 210篇 |
1995年 | 173篇 |
1994年 | 144篇 |
1993年 | 126篇 |
1992年 | 114篇 |
1991年 | 93篇 |
1990年 | 83篇 |
1989年 | 58篇 |
1988年 | 58篇 |
1987年 | 62篇 |
1986年 | 68篇 |
1985年 | 86篇 |
1984年 | 63篇 |
1983年 | 50篇 |
1982年 | 75篇 |
1981年 | 59篇 |
1980年 | 59篇 |
1979年 | 56篇 |
1978年 | 55篇 |
1977年 | 64篇 |
1976年 | 60篇 |
1975年 | 45篇 |
1974年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Let a selfadjoint operator-valued functionL() be given on the interval [a,b] such thatL(a)0,L(b)0,L()0 (ab), andL() has a certain smoothness (for instance, it satisfies Hölder's condition). It turns out that the spectral theory of the operator-valued functionL() can be reduced to the spectral theory of one operatorZ, the spectrum of which lies on (a, b) and which is similar to a selfadjoint operator. In particular, the factorization takes place:L()=M()(I–Z), where the operator-valued functionM() is invertible on [a, b]. Earlier similar results were known only for analytic operator-valued functions. The authors had to use new methods for the proof of the described theorem. The key moment is the decomposition ofL
–1() into the sume of its principal and regular parts. 相似文献
132.
133.
Schumm BA Koetke DS Adolphsen CE Alexander JP Averill D Barish BC Barklow T Barnett BA Blockus D Boyarski A Brabson B Breakstone A Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Cords D Coupal DP Dauncey P DeStaebler HC Dorfan JM Drell PS Drewer DC Durrett D Elia R Feldman GJ Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gero E Gidal G Glanzman T Goldhaber G Gomez Cadenas JJ Gratta G Hanson G Harr R Harral B Harris FA Hayes K Hearty C Heusch CA Hildreth MD Himel T Hinshaw DA 《Physical review D: Particles and fields》1992,46(1):453-456
134.
D. M. Moltz J. C. Batchelder T. F. Lang T. J. Ognibene Joseph Cerny P. E. Haustein P. L. Reeder 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(3):273-276
The beta-delayed two-proton decay of theT
z
=–5/2 nuclide39Ti has been observed. The39Sc isobaric analog state has been calculated to lie at 8.82 MeV using the measured two-proton sum energy of 4750±40 keV for its decay to the37K ground state. Combining this excitation energy with a Coulomb displacement energy calculation has lowered the energy available for ground state two-proton emission of39Ti from 760 to 530 keV.This work was supported by Director, Office of Energy Research, Division of Nuclear Physics of the Office of High Energy and Nuclear Physics of the U.S. Depeartment of Energy under Contracts DE-AC03-76SF00098 with Lawrence Berkeley Laboratory, DE-AC02-76CH00016 with Brookhaven National Laboratory and DE-AC06-76RL0 1830 with Pacific Northwest Laboratories. 相似文献
135.
A. Lang B. Blättel W. Cassing V. Koch U. Mosel K. Weber 《Zeitschrift für Physik A Hadrons and Nuclei》1991,340(3):287-295
Within a covariant BUU-approach we simulate heavyion collisions at various bombarding energies from 400 MeV/u to 1 GeV/u. We evaluate locally the energymomentum tensorT
v
(x), and extract pressures, energydensities and temperatures. The connection of these thermodynamical quantities to experimental observables and their sensitivity to the equation of state is discussed. Furthermore, we investigate the question of local equilibration and evaluate the entropy produced in these reactions.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday. Work supported by BMFT and GSI Darmstadt 相似文献
136.
Fulton R Jensen T Johnson DR Kagan H Kass R Morrow F Whitmore J Wilson P Bortoletto D Chen W Dominick J McIlwain RL Miller DH Ng CR Schaffner SF Shibata EI Shipsey IP Yao W Battle M Sparks K Thorndike EH Wang C Alam MS Kim IJ Li WC Romero V Sun CR Wang P Zoeller MM Goldberg M Haupt T Horwitz N Jain V Mestayer MD Moneti GC Rozen Y Rubin P Sharma V Skwarnicki T Thulasidas M Zhu G Csorna SE Letson T Alexander J Artuso M Bebek C Berkelman K Browder T Cassel DG Cheu E Coffman DM Crawford G DeWire JW 《Physical review D: Particles and fields》1991,43(3):651-663
137.
Kubota Y Nelson JK Perticone D Poling R Schrenk S Crawford G Fulton R Jensen T Johnson DR Kagan H Kass R Malchow R Morrow F Whitmore J Wilson P Bortoletto D Brown D Dominick J McIlwain RL Miller DH Modesitt M Ng CR Schaffner SF Shibata EI Shipsey IP Battle M Kroha H Sparks K Thorndike EH Wang C Alam MS Kim IJ Li WC Nemati B Romero V Sun CR Wang P Zoeller MM Goldberg M Haupt T Horwitz N Jain V Mestayer MD Moneti GC Rozen Y Rubin P Skwarnicki T Stone S Thusalidas M Yao W Zhu G Barnes AV Bartelt J 《Physical review D: Particles and fields》1991,44(3):593-600
138.
139.
Alexander Pott 《Combinatorica》1992,12(1):89-93
In this paper we develop a new method to obtain identities in a group algebraGF(p)G if an abelian difference set of ordern0 (modp) exists inG. We give an explicit formula ifp
2 orp
3 is the exactp-power dividingn. This generalizes the approach of Wilbrink, Arasu and the author. The proof presented here uses some knowledge about field extensions of thep-adic numbers. 相似文献
140.
On abelian difference set codes 总被引:1,自引:0,他引:1
Alexander Pott 《Designs, Codes and Cryptography》1992,2(3):263-271
In this paper we determine the ranks of the incidence matrices that belong to the following types of difference sets: Twin prime power difference sets, biquadratic residues and biquadratic residues with 0. We also prove a conjecture of Assmus and Key on the code generated by the hyperovals of PG(2, q). 相似文献