全文获取类型
收费全文 | 54433篇 |
免费 | 1701篇 |
国内免费 | 117篇 |
专业分类
化学 | 34040篇 |
晶体学 | 369篇 |
力学 | 1347篇 |
综合类 | 9篇 |
数学 | 7621篇 |
物理学 | 12865篇 |
出版年
2023年 | 349篇 |
2022年 | 353篇 |
2021年 | 740篇 |
2020年 | 846篇 |
2019年 | 777篇 |
2018年 | 1044篇 |
2017年 | 974篇 |
2016年 | 1787篇 |
2015年 | 1418篇 |
2014年 | 1533篇 |
2013年 | 2923篇 |
2012年 | 3404篇 |
2011年 | 3715篇 |
2010年 | 2127篇 |
2009年 | 1856篇 |
2008年 | 3115篇 |
2007年 | 3072篇 |
2006年 | 2731篇 |
2005年 | 2973篇 |
2004年 | 2724篇 |
2003年 | 1973篇 |
2002年 | 1555篇 |
2001年 | 1231篇 |
2000年 | 1081篇 |
1999年 | 754篇 |
1998年 | 580篇 |
1997年 | 497篇 |
1996年 | 682篇 |
1995年 | 526篇 |
1994年 | 526篇 |
1993年 | 591篇 |
1992年 | 551篇 |
1991年 | 423篇 |
1990年 | 351篇 |
1989年 | 327篇 |
1988年 | 302篇 |
1987年 | 292篇 |
1986年 | 285篇 |
1985年 | 406篇 |
1984年 | 357篇 |
1983年 | 300篇 |
1982年 | 292篇 |
1981年 | 285篇 |
1980年 | 248篇 |
1979年 | 244篇 |
1978年 | 253篇 |
1977年 | 216篇 |
1976年 | 217篇 |
1974年 | 188篇 |
1973年 | 203篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Abe F Albrow MG Amendolia SR Amidei D Antos J Anway-Wiese C Apollinari G Areti H Atac M Auchincloss P Azfar F Azzi P Bacchetta N Badgett W Bailey MW Bao J de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Bartalini P Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Benton D Beretvas A Berge JP Bertolucci S Bhatti A Biery K Binkley M Bird F Bisello D Blair RE Blocker C Bodek A Bokhari W Bolognesi V Bortoletto D Boswell C Boulos T 《Physical review D: Particles and fields》1995,52(5):2624-2655
992.
993.
994.
995.
996.
997.
González-Díaz PF 《Physical review D: Particles and fields》1995,51(10):5698-5706
998.
C. T. Zhang M. Sferrazza R. H. Mayer Z. W. Grabowski P. Bhattacharyya P. J. Daly R. Broda B. Fornal W. Królas T. Pawłat G. de Angelis D. Bazzacco S. Lunardi C. Rossi-Alvarez 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(1):11-12
Using an 11.4MeV/u136Xe beam of the UNILAC accelerator of GSI and anatW target, A=184 isobars were produced and separated by using an on-line mass separator. A new isomeric state was found in184Hf. This state decays with a half-life of 48(10) s and emits three -rays of 73, 482, and 555 keV as well as lower-lying cascade transitions. The hindrance of the 73 keV-E1 transition with K=8 is compared with those of other even-even hafnium isotopes. The half-life of184Lu was estimated to be between 15 and 25s. 相似文献
999.
A. Costela J. M. Figuera F. Florido I. García-Moreno E. P. Collar R. Sastre 《Applied Physics A: Materials Science & Processing》1995,60(3):261-270
Data on the ablation of Poly(Methyl MetAcylate) (PMMA) and Poly(2-Hydroxyethyl MetAcylate) (PHEMA) with 0%, 1% and 20% of Ethylene Glycol DiMethAcrylate (EGDMA) as crosslinking monomer by 193, 222 and 308 nm laser radiation are presented. Direct photoetching of PMMA at 308 nm is demonstrated for laser fluences ranging from 2 to 18 J/cm2. The ablation rate of PHEMA is lower than the corresponding to PMMA and decreases when the amount of EGDMA increases. The determination of the absorbed energy density required to initiate significant ablation suggests that the photoetching mechanism is similar for all the polymers studied and is a function of the irradiation wavelength. The Beer-Lambert law, the Srinivasan, Smrtic and Babu (SSB) theory and the kinetic model of the moving interface are used to analyze the experimental results. It is shown that only the moving interface theory fits well the etch rate for all the selected polymers at the three radiation wavelengths. 相似文献
1000.
The kinetic behaviors of Cr(VI) and W(VI), which catalyze a common indicator reaction between H(2)O(2) and I(-), were studied. A new concept, 'Rate Spectrum', is proposed. The two catalysts can be determined simultaneously by analyzing the rate spectra of their mixtures as the rate spectra of each catalyst are linearly independent. Principal Component Regression (PCR) was used to analyze the rate spectra of the mixtures of Cr and W, and in this way the two ions were determined simultaneously through a single kinetic run. 相似文献