全文获取类型
收费全文 | 1225篇 |
免费 | 37篇 |
国内免费 | 1篇 |
专业分类
化学 | 817篇 |
晶体学 | 8篇 |
力学 | 21篇 |
数学 | 171篇 |
物理学 | 246篇 |
出版年
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 23篇 |
2020年 | 12篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2016年 | 20篇 |
2015年 | 22篇 |
2014年 | 19篇 |
2013年 | 54篇 |
2012年 | 72篇 |
2011年 | 79篇 |
2010年 | 46篇 |
2009年 | 28篇 |
2008年 | 74篇 |
2007年 | 83篇 |
2006年 | 48篇 |
2005年 | 80篇 |
2004年 | 54篇 |
2003年 | 39篇 |
2002年 | 39篇 |
2001年 | 25篇 |
2000年 | 21篇 |
1999年 | 12篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 15篇 |
1981年 | 14篇 |
1980年 | 13篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1974年 | 9篇 |
1973年 | 15篇 |
1972年 | 7篇 |
排序方式: 共有1263条查询结果,搜索用时 15 毫秒
1.
In the following we find all of the three-dimensional flat spacetimes which are static and rotationally symmetric. 相似文献
2.
We derive and analyse four algorithms for computing the current induced on a thin straight wire by a transient electric field.
They all involve solving the thin wire electric field integral equations (EFIEs) and consist of a very accurate differential
equations solver together with various schemes to approximate the vector potential integral equation. We carry out a rigorous
numerical stability analysis of each of these methods. This has not previously been done for solution schemes for the thin
wire EFIEs. Each scheme is shown to be stable and convergent provided the radius of the wire is small enough for the thin
wire equations to be a valid model. 相似文献
3.
Multiple-zero multiple-pole optical filter transfer functions may be implemented more efficiently in an integrated optics architecture if higher order N × M optical couplers are utilized. For example, a coherent ring resonator made from two 3×3 couplers offers some advantages over the three mirror Fabry-Perot etalon, which is its analog. To this end we develop the formalism for obtaining the transfer functions and scattering matrices of ring resonators made from two N × M couplers. We then present a methodology for analyzing serial and parallel systems of N × M optical coupler ring resonators. 相似文献
4.
5.
Edwards KW Ogg M Bellerive A Britton DI Hyatt ER MacFarlane DB Patel PM Spaan B Sadoff AJ Ammar R Baringer P Bean A Besson D Coppage D Copty N Davis R Hancock N Kelly M Kotov S Kravchenko I Kwak N Lam H Kubota Y Lattery M Momayezi M Nelson JK Patton S Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Ling Z Mahmood AH O'Neill JJ Severini H Sun CR Wappler F Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Sung M White C Wolf A Zoeller MM Butler F Fu X Nemati B 《Physical review letters》1995,74(17):3331-3335
6.
Battle M Ernst J Kwon Y Roberts S Thorndike EH Wang CH Dominick J Lambrecht M Sanghera S Shelkov V Skwarnicki T Stroynowski R Volobouev I Wei G Zadorozhny P Artuso M Goldberg M He D Horwitz N Kennett R Mountain R Moneti GC Muheim F Mukhin Y Playfer S Rozen Y Stone S Thulasidas M Vasseur G Zhu G Bartelt J Csorna SE Egyed Z Jain V Kinoshita K Edwards KW Ogg M Britton DI Hyatt ER MacFarlane DB Patel PM Akerib DS Barish B Chadha M Chan S Cowen DF Eigen G Miller JS O'Grady C Urheim J Weinstein AJ 《Physical review letters》1994,73(8):1079-1083
7.
R. F. Kiefl J. Sonier D. A. Bonn J. H. Brewer J. F. Carolan K. H. Chow P. Dosanjh W. N. Hardy Ruixing Liang W. A. MacFarlane P. Mendels G. D. Morris T. M. Riseman J. W. Schneider 《Hyperfine Interactions》1994,86(1):537-542
We report precision transverse fieldSR measurements of the internal field distribution in the vortex state of crystalline YBa2Cu3O6.95. A novel low background apparatus was used to study a mosaic sample of three high quality single crystals (Tc=93.3K). The observed frequency spectra in magnetic fields of 5kG and 15 kG applied along the c-axis have the characteristic features expected for a regular vortex lattice with some additional broadening. From a preliminary analysis we find that [(0)/(T)]2 has a linear temperature coefficient forT<30 K. Such a term is inconsistent with simple s-wave pairing in the superconducting state. These results support recent microwave measurements of(T) on similar crystals in zero applied field but differ significantly from previousSR reports on sintered powders and crystals with lower Tc.This research was supported by the Natural Sciences and Engineering Research Council of Canada. 相似文献
8.
9.
10.