全文获取类型
收费全文 | 316篇 |
免费 | 13篇 |
国内免费 | 3篇 |
专业分类
化学 | 184篇 |
晶体学 | 3篇 |
力学 | 7篇 |
数学 | 55篇 |
物理学 | 83篇 |
出版年
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 15篇 |
2012年 | 26篇 |
2011年 | 18篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 12篇 |
2007年 | 16篇 |
2006年 | 6篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 10篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1985年 | 4篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1972年 | 9篇 |
1970年 | 2篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1962年 | 2篇 |
1941年 | 2篇 |
1937年 | 2篇 |
1935年 | 2篇 |
1932年 | 2篇 |
1930年 | 2篇 |
1927年 | 2篇 |
排序方式: 共有332条查询结果,搜索用时 187 毫秒
31.
Improved signal-to-noise ratio in spectral-domain compared with time-domain optical coherence tomography 总被引:1,自引:0,他引:1
A signal-to-noise ratio (SNR) analysis is presented for optical coherence tomography (OCT) signals in which time-domain performance is compared with that of the spectral domain. A significant SNR gain of several hundredfold is found for acquisition in the spectral domain. The SNR benefit is demonstrated experimentally in a hybrid time-domain-spectral-domain OCT system. 相似文献
32.
J. -E. Augustin G. Cosme F. Couchot B. Dudelzak F. Fulda B. Grelaud G. Grosdidier B. Jean-Marie S. Jullian D. Lalanne V. Lepeltier B. Louis F. Mané C. Paulot R. Riskalla Ph. Roy F. Rumpf G. Szklarz Z. Ajaltouni A. Falvard J. Jousset B. Michel J. C. Montret R. Baldini S. Calcaterra G. Capon D. Bisello G. Busetto S. Limentani M. Nigro L. Pescara M. Posocco P. Sartori L. Stanco DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1987,36(3):369-376
The radiative decayJ/ψ → γ π+ π? has been studied using the 8.6 millionJ/ψ produced in the DM2 experiment at the DCIe +e? storage rings at Orsay. The π+ π? mass spectrum shows a cleanf 2 (1270) signal, and the possible presence of two other states at thef 2 (1720) andf 4 (2030) masses. For thef 2 (1270), the branching ratio BR(J/ψ →γf)xBR(f→π+ π?) is measured to be (7.50±0.30±1.12)×10?4, and the spin analysis prefers theJ=2 assignment, with helicity parametersx=0.83±0.06 andy=0.01±0.06. The existence of higher mass states is discussed. 相似文献
33.
Wm. Lerch R. H. Bogue E. S. Shepherd G. A. Rankin F. E. Wright F. Ferrari J. Stanton Pierce W. C. Setzer F. Strumpf und R. H. H. Stanger 《Fresenius' Journal of Analytical Chemistry》1930,81(12):476-480
Ohne Zusammenfassung 相似文献
34.
35.
Chuanlei Liu Kurt Ungar Dylan Pierce Ian Hoffman Weihua Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(3):471-478
In assistance of radionuclide measurements at Canada’s Comprehensive Nuclear-Test-Ban Treaty (CTBT) laboratory, a Geant4 Monte Carlo application has been developed in simulating a broad-energy germanium detector and calculating detection efficiencies. The detector model was optimized in a reliable and non-biased manner through simultaneous tuning on gap distance and detector dimension, and was validated over various realistic measurement scenarios. All work is based on a series of experiments which covers the typical energy range of gamma radiation in environmental analysis, and considers the variety of the CTBT sample type, dimension and distance-to-detector. In all cases, the predicted efficiencies are consistent with the empirical ones within 5%, with a typical deviation of 3% in majority. 相似文献
36.
S. Pierce 《Linear and Multilinear Algebra》2013,61(3-4)
This section appears in nearly every issue. Send submissions to R. C. Thompson, at the Department of Mathematics, University of California, Stanta Barbara, CA 93106, U.S.A. 相似文献
37.
38.
Stephen Pierce 《Linear and Multilinear Algebra》1992,33(3):305-306
Topics in Matrix Analysis, Roger A. Horn and Charles R. Johnson, Cambridge University Press, New York, 1991, viii+607 pages. ISBN 0-521-30587-X 相似文献
39.
40.
We find that the topography and composition of a reactive surface can evolve during epitaxy via motion of point and line defects within the material. We observe the response of a NiAl surface to an Al atom flux with low-energy electron microscopy. Initially, new NiAl layers grow as Al atoms exchange with bulk Ni atoms. When the surface is critically enriched in Al, condensation occurs at dislocations. They dissociate, move linearly, and leave tracks of altered composition and new atomic steps. We show how these dynamics depend on the identity and quantity of point defects near the surface. 相似文献