全文获取类型
收费全文 | 52499篇 |
免费 | 7452篇 |
国内免费 | 5416篇 |
专业分类
化学 | 37471篇 |
晶体学 | 665篇 |
力学 | 2885篇 |
综合类 | 338篇 |
数学 | 6414篇 |
物理学 | 17594篇 |
出版年
2024年 | 90篇 |
2023年 | 906篇 |
2022年 | 1401篇 |
2021年 | 1584篇 |
2020年 | 1828篇 |
2019年 | 1824篇 |
2018年 | 1534篇 |
2017年 | 1427篇 |
2016年 | 2204篇 |
2015年 | 2172篇 |
2014年 | 2576篇 |
2013年 | 3581篇 |
2012年 | 4485篇 |
2011年 | 4787篇 |
2010年 | 3272篇 |
2009年 | 3161篇 |
2008年 | 3493篇 |
2007年 | 3203篇 |
2006年 | 2873篇 |
2005年 | 2491篇 |
2004年 | 1909篇 |
2003年 | 1520篇 |
2002年 | 1464篇 |
2001年 | 1161篇 |
2000年 | 1035篇 |
1999年 | 1081篇 |
1998年 | 918篇 |
1997年 | 872篇 |
1996年 | 910篇 |
1995年 | 740篇 |
1994年 | 667篇 |
1993年 | 573篇 |
1992年 | 550篇 |
1991年 | 470篇 |
1990年 | 393篇 |
1989年 | 329篇 |
1988年 | 261篇 |
1987年 | 236篇 |
1986年 | 225篇 |
1985年 | 233篇 |
1984年 | 147篇 |
1983年 | 106篇 |
1982年 | 104篇 |
1981年 | 71篇 |
1980年 | 63篇 |
1979年 | 67篇 |
1978年 | 46篇 |
1976年 | 46篇 |
1974年 | 43篇 |
1973年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
991.
H. Sun Y. Ma J. Zhang H. Zheng S. Zhou Y. Liu S. Wen G. Li G. Yuan C. Yang 《Zeitschrift für Physik A Hadrons and Nuclei》1995,352(2):115-116
The yrast band in the doubly odd156Tm nucleus was studied through144Sm(19F,2p5n)156Tm reaction at beam energy of 105MeV. Several high-spin states of156Tm were identified and the highest spin of the band with configuration7/2–[523] v1/2+[660] could be built up to spin 25. The level structure shows the onset of a non- or weak collectivity which generally appears at neutron number of 87 in neutron-deficient rare-earth nuclei.This work was supported in part by the Fok Ying Tung Education Foundation and the Natural Science Fund of China. 相似文献
992.
X. Zhou Y. Guo X. Sun X. Lei X. Chen Z. Liu Y. Zhang H. Jin Y. Luo S. X. Wen G. J. Yuan G. S. Li C. X. Yang 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(1):3-4
The high spin states of119Te, populated in110Pd(13C,4n) and110Pd(12C,3n) reactions, have been studied through -ray spectroscopy. The level scheme has been established upto a spin of 55/2. Three-quasiparticle states, based on g2
7/2h11/2 and g7/2d5/2h11/2 configurations, have been identified. The 35/2 and 39/2 states are suggested to be the fully aligned states constituted by five valence h11/2
3, g7/2, d5/2 quasiparticles. 相似文献
993.
用原子吸收光谱法测下了“东北水三七”根、茎、叶的21种化学元素,结果表明,不同部位的元素含量有一定差别。 相似文献
994.
Assume that the probability density function for the lifetime of a newly designed product has the form: [H(t)/Q()] exp{–H(t)/Q()}. The Exponential(), Rayleigh, WeibullW(, ) and Pareto pdf's are special cases.Q() will be assumed to have an inverse Gamma prior. Assume thatm independent products are to be tested with replacement. A Bayesian Sequential Reliability Demonstration Testing plan is used to eigher accept the product and start formal production, or reject the product for reengineering. The test criterion is the intersection of two goals, a minimal goal to begin production and a mature product goal. The exact values of various risks and the distribution of total number of failures are evaluated. Based on a result about a Poisson process, the expected stopping time for the exponential failure time is also found. Included in these risks and expected stopping times are frequentist versions, thereof, so that the results also provide frequentist answers for a class of interesting stopping rules.This research was supported by NSF grants DMS-8703620 and DMS-8923071, and forms part of the Ph.D. Thesis of the first author, the development of which was supported in part by a David Ross grant at Purdue University. The authors thank the editors and a referee for insightful comments and suggestions. 相似文献
995.
Given a family of Riemann surfaces and a holomorphic vector bundle Beilinson and Schechtman construct a canonical connection on the associated determinant bundle. We prove the conjecture which states that their connection coincides with the Quillen connection. This is done by reducing to the case where
along fibers are invertible. Both connection forms become more accessible in this case.Supported in part by N.S.F. Grant No. DMS-9201022Supported in part by National Science Council of Republic of China Grant No. NSC 82-0208-M-002-125-T, and NSERC of Canada Grant No. OGP 0121883 相似文献
996.
997.
Cinabro D Henderson S Liu T Saulnier M Wilson R Yamamoto H Bergfeld T Eisenstein BI Gollin G Ong B Palmer M Selen M Thaler JJ Sadoff AJ Ammar R Ball S Baringer P Bean A Besson D Coppage D Copty N Davis R Hancock N Kelly M Kwak N Lam H Kubota Y Lattery M Nelson JK Patton S Perticone D Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Nemati B O'Neill JJ Severini H Sun CR Zoeller MM Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Malchow R Morrow F Skovpen Y 《Physical review letters》1994,72(10):1406-1410
998.
999.
Kubota Y Lattery M Nelson JK Patton S Perticone D Poling R Savinov V Schrenk S Wang R Alam MS Kim IJ Nemati B O'Neill JJ Severini H Sun CR Zoeller MM Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Malchow R Morrow F Skovpen Y Sung M White C Butler F Fu X Kalbfleisch G Ross WR Skubic P Snow J Wang PL Wood M Brown DN Fast J McIlwain RL Miao T Miller DH Modesitt M Payne D Shibata EI Shipsey IP Wang PN Battle M Ernst J Kwon Y Roberts S Thorndike EH Wang CH 《Physical review letters》1994,72(13):1972-1976
1000.