全文获取类型
收费全文 | 14261篇 |
免费 | 582篇 |
国内免费 | 3篇 |
专业分类
化学 | 7970篇 |
晶体学 | 42篇 |
力学 | 266篇 |
数学 | 1919篇 |
物理学 | 4649篇 |
出版年
2023年 | 115篇 |
2021年 | 122篇 |
2020年 | 174篇 |
2019年 | 108篇 |
2018年 | 154篇 |
2017年 | 155篇 |
2016年 | 356篇 |
2015年 | 343篇 |
2014年 | 325篇 |
2013年 | 635篇 |
2012年 | 610篇 |
2011年 | 791篇 |
2010年 | 318篇 |
2009年 | 286篇 |
2008年 | 693篇 |
2007年 | 674篇 |
2006年 | 649篇 |
2005年 | 534篇 |
2004年 | 411篇 |
2003年 | 402篇 |
2002年 | 364篇 |
2001年 | 341篇 |
2000年 | 271篇 |
1999年 | 221篇 |
1998年 | 187篇 |
1997年 | 199篇 |
1996年 | 198篇 |
1995年 | 189篇 |
1994年 | 168篇 |
1993年 | 197篇 |
1992年 | 195篇 |
1991年 | 156篇 |
1990年 | 132篇 |
1989年 | 126篇 |
1988年 | 115篇 |
1987年 | 128篇 |
1986年 | 137篇 |
1985年 | 153篇 |
1984年 | 190篇 |
1983年 | 160篇 |
1982年 | 178篇 |
1981年 | 188篇 |
1980年 | 164篇 |
1979年 | 158篇 |
1978年 | 171篇 |
1977年 | 163篇 |
1976年 | 142篇 |
1975年 | 137篇 |
1974年 | 126篇 |
1973年 | 112篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
141.
Summary The problem is considered of orthogonal 1 fitting of discrete data. Local best approximations are characterized and the question of the robustness of these solutions is considered. An algorithm for the problem is presented, along with numerical results of its application to some data sets. 相似文献
142.
Karl Oelschläger 《Probability Theory and Related Fields》1987,74(4):591-616
Summary We study the asymptotic behaviour of the fluctuations of the empirical processes of the second example of moderately interacting diffusion processes of [3] and show that in the limit, as the number of different processes tends to infinity, these fluctuations behave gaussian.This work has been supported by the Deutsche Forschungsgemeinschaft 相似文献
143.
Summary The question of the existence of good Markov [good stationary] policies is studied for a general class of Borel [stationary] dynamic programming models. It is shown, for example, that Markov [stationary] policies are uniformly adequate if every transition law is absolutely continuous with respect to a fixed measure [and the reward function is positive or the model satisfies certain compactness and continuity conditions].Research supported by Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 72Research supported by National Science Foundation Grant MCS 8100789 相似文献
144.
145.
146.
H. Prade J. Döring W. Enghardt L. Funke L. Käubler 《Zeitschrift für Physik A Hadrons and Nuclei》1987,328(4):501-502
An (α, 2nγ) in-beam study of excited states in 142Nd revealed 27 new levels on top of the 6+ isomer. Nanosecond lifetimes were found for two levels. The measured excitation energies were compared with spherical shell-model predictions obtained from suitably truncated model spaces. 相似文献
147.
S. Barlag H. Becker T. Böhringer M. Bosman V. Castillo V. Chabaud D. Buchholz C. Damerell C. Daum H. Dietl H. Fawcett S. Gill A. Gillman R. Gilmore T. Gooch L. Görlich P. Gras Z. Hajduk E. Higon B. D. Hyams D. P. Kelsey J. Kemmer R. Klanner U. Kötz S. Kwan B. Lücking G. Lütiens G. Lutz J. Malos W. Männer E. Neugebauer H. Palka M. Pepé J. Richardson G. De Rijk K. Rybicki H. J. Seebrunner U. Stierlin H. G. Tiecke M. Turala G. Waltermann S. Watts P. Weilhammer F. Wickens L. W. Wiggers A. Wylie T. Zeludziewicz ACCMOR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1987,37(1):17-23
We have measured the lifetimes of hadronically produced charged and neutralD mesons using silicon microstrip detectors and an active silicon target in the NA32 spectrometer at the CERN SPS. We obtainτ D± = (10.9± 1.5 1.9 )·10?13s andτ D (?)10 = (4.2±0.5)·10?13s based on 59 and 90 fully reconstructed decays respectively, giving a ratioτ D±/τ D (?)10 of 2.6 ±0.5. 相似文献
148.
Wagner F Gruber O Lackner K Murmann HD Speth E Becker G Bosch HS Brocken H Cattanei G Dorst D Eberhagen A Elsner A Erckmann V Fussmann G Gehre O Gernhardt J Gierke Gv Glock E Grieger G Grigull P Haas G Hacker H Hartfuss HJ Jäckel H Jaenicke R Janeschitz G Junker J Karger F Kasparek W Keilhacker M Kick M Klüber O Kornherr M Kroiss H Kuehner M Lenoci M Lisitano G Maassberg M Mahn C Marlier S Mayer HM McCormick K Meisel D Mertens V Müller ER Müller Müller G Niedermeyer H Ohlendorf W 《Physical review letters》1986,56(20):2187-2190
149.
H. Dijkstra R. Bailey E. Belau T. Böhringer M. Bosman V. Chabaud C. Damerell C. Daum G. de Rijk S. Gill A. Gillman R. Gilmore Z. Hajduk C. Hardwick W. Hoogland B. D. Hyams R. Klanner S. Kwan U. Kötz G. Lütjens G. Lutz J. Malos W. Männer E. Neugebauer H. Palka M. Pepé J. Richardson K. Rybicki H. J. Seebrunner U. Stierlin R. J. Tapper H. G. Tiecke M. Turala G. Waltermann S. Watts P. Weilhammer F. Wickens L. W. Wiggers A. Wylie T. Zeludziewicz ACCMOR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1986,32(3):353-358
The joint production of ? mesons andπ ±,π 0,p, \(\bar p\) ,K s 0 andK ± is investigated using a sample of 600,000 inclusive ? meson events obtained in hadron Be interactions with incidentπ ±,p, \(\bar p\) andK ± beams. Evidence is presented for the joint production of ? mesons and strange particles produced with non-strange incident beams. With incidentK ± beam the number of additional strange particles is suppressed. The results are found to be in agreement with the qualitative predictions of a parton fusion model. The comparison with the Lund model for lowp T processes is fair. 相似文献
150.
The Mössbauer spectra of the solid solution Fe[FexV2–x]O4 within 1.0×2.0 consist of two sets of sextets corresponding to A- and B-sites. From the superimposed sextets of the B-site pattern result typical values of isomer shift and internal magnetic field strength due to different environments of the B-site iron. It is shown that V ions both enhance the conduction electron density at the neighbouring Fe ions and diminish the strength of the magnetic interactions. 相似文献