全文获取类型
收费全文 | 372305篇 |
免费 | 4244篇 |
国内免费 | 929篇 |
专业分类
化学 | 186434篇 |
晶体学 | 4878篇 |
力学 | 16569篇 |
综合类 | 15篇 |
数学 | 58874篇 |
物理学 | 110708篇 |
出版年
2021年 | 2615篇 |
2020年 | 2966篇 |
2019年 | 3219篇 |
2018年 | 11896篇 |
2017年 | 12556篇 |
2016年 | 10085篇 |
2015年 | 4840篇 |
2014年 | 5835篇 |
2013年 | 13265篇 |
2012年 | 14553篇 |
2011年 | 23607篇 |
2010年 | 15003篇 |
2009年 | 14767篇 |
2008年 | 21241篇 |
2007年 | 24392篇 |
2006年 | 11073篇 |
2005年 | 15917篇 |
2004年 | 11791篇 |
2003年 | 10856篇 |
2002年 | 8587篇 |
2001年 | 7474篇 |
2000年 | 6172篇 |
1999年 | 4411篇 |
1998年 | 3824篇 |
1997年 | 3786篇 |
1996年 | 3907篇 |
1995年 | 3193篇 |
1994年 | 3330篇 |
1993年 | 3337篇 |
1992年 | 3499篇 |
1991年 | 3350篇 |
1990年 | 3232篇 |
1989年 | 3152篇 |
1988年 | 3053篇 |
1987年 | 3043篇 |
1986年 | 2922篇 |
1985年 | 3849篇 |
1984年 | 4013篇 |
1983年 | 3188篇 |
1982年 | 3493篇 |
1981年 | 3359篇 |
1980年 | 3163篇 |
1979年 | 3311篇 |
1978年 | 3427篇 |
1977年 | 3371篇 |
1976年 | 3316篇 |
1975年 | 3160篇 |
1974年 | 3085篇 |
1973年 | 3251篇 |
1972年 | 2100篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
101.
102.
Ivanov K. A. Gubaidullin A. R. Morozov K. M. Sasin M. E. Kaliteevskii M. A. 《Optics and Spectroscopy》2019,126(6):787-787
Optics and Spectroscopy - 10.1134/S0030400X17050095 相似文献
103.
Kaplunov I. A. Kolesnikov A. I. Kropotov G. I. Rogalin V. E. 《Optics and Spectroscopy》2019,126(3):191-194
Optics and Spectroscopy - The transmission of intrinsic, antimony-doped, and gallium-doped Ge single crystals in the THz spectral range have been experimentally investigated. It is shown that the... 相似文献
104.
Dr. Sebastian Lars Müller Xinglong Zhou Dr. Peter Leonard Oxana Korzhenko Dr. Constantin Daniliuc Prof. Dr. Frank Seela 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(12):3077-3090
Silver-mediated α-dC–Ag+–β-dC hybrid base pairs decorated with 5-iodo- or 5-octadiynyl residues are well accommodated in duplex DNA. A strong Tm increase and favorable thermodynamic data for duplex DNA were observed after addition of silver ions. The phenomenon is particularly obvious when both nucleobases of the base pairs are functionalized. Neither the position of the base pair, nor the type of 5-substituent had a negative influence. On the contrary, functionalization of conventional silver-mediated β-dC–Ag+–β-dC homo base pairs showed a negative impact induced by the bulky substituents. To this end, cytosine modified 12-mer oligodeoxynucleotides were prepared by solid-phase synthesis employing new α-anomeric 2′-deoxycytidine phosphoramidites. A multigram scale synthesis was developed for 5-iodo-α-d -2′-deoxycytidine ( 1 ) employing the direct glycosylation of cytosine with Hoffer's α-d -halogenose followed by separation of anomeric DMT nucleosides. Regarding base-pair stability and functionalization silver-mediated α/β-dC hybrid base pairs were found to be superior to β/β-dC homo pairs. According to their extraordinary properties, they might find applications in DNA diagnostics, material science, or nanotechnology. 相似文献
105.
106.
107.
J. Conrad J. Cohen-Tanugi L. E. Strigari 《Journal of Experimental and Theoretical Physics》2015,121(6):1104-1135
The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT) started a pivotal period in indirect detection of dark matter. By outperforming expectations, for the first time a robust and stringent test of the paradigm of weakly interacting massive particles (WIMPs) is within reach. In this paper, we discuss astrophysical targets for WIMP detection and the challenges they present, review the analysis tools which have been employed to tackle these challenges, and summarize the status of constraints on and the claimed detections in the WIMP parameter space. Methods and results will be discussed in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook on short term and longer term developments. 相似文献
108.
109.
S. V. Panin I. V. Vlasov V. P. Sergeev B. B. Ovechkin P. O. Marushchak Sunder Ramasubbu P. S. Lyubutin V. V. Titkov 《Physical Mesomechanics》2015,18(3):261-272
The structure and properties of 12Cr1MoV steel irradiated with a zirconium ion beam were studied by optical microscopy, scanning electron microscopy, and micro- and nanoindentation. It is shown that the modification covers the entire cross-section of the irradiated specimens to a depth of 1 mm. The data on irradiation-induced structural changes are used to interpret the changes in mechanical properties of the irradiated specimens under static and cyclic loading. Particular attention is given to analysis of strain estimation by the digital image correlation method. 相似文献
110.