全文获取类型
收费全文 | 206847篇 |
免费 | 1634篇 |
国内免费 | 454篇 |
专业分类
化学 | 106870篇 |
晶体学 | 3434篇 |
力学 | 10443篇 |
综合类 | 10篇 |
数学 | 22938篇 |
物理学 | 65240篇 |
出版年
2021年 | 2097篇 |
2020年 | 2129篇 |
2019年 | 2711篇 |
2018年 | 3796篇 |
2017年 | 3794篇 |
2016年 | 4989篇 |
2015年 | 2477篇 |
2014年 | 4494篇 |
2013年 | 8900篇 |
2012年 | 7123篇 |
2011年 | 8335篇 |
2010年 | 6626篇 |
2009年 | 6820篇 |
2008年 | 7845篇 |
2007年 | 7777篇 |
2006年 | 6832篇 |
2005年 | 6025篇 |
2004年 | 5758篇 |
2003年 | 5250篇 |
2002年 | 5237篇 |
2001年 | 5669篇 |
2000年 | 4188篇 |
1999年 | 3169篇 |
1998年 | 2727篇 |
1997年 | 2794篇 |
1996年 | 2589篇 |
1995年 | 2251篇 |
1994年 | 2357篇 |
1993年 | 2265篇 |
1992年 | 2555篇 |
1991年 | 2680篇 |
1990年 | 2582篇 |
1989年 | 2641篇 |
1988年 | 2557篇 |
1987年 | 2583篇 |
1986年 | 2447篇 |
1985年 | 3065篇 |
1984年 | 3123篇 |
1983年 | 2617篇 |
1982年 | 2590篇 |
1981年 | 2555篇 |
1980年 | 2354篇 |
1979年 | 2744篇 |
1978年 | 2697篇 |
1977年 | 2888篇 |
1976年 | 2891篇 |
1975年 | 2679篇 |
1974年 | 2614篇 |
1973年 | 2723篇 |
1972年 | 2088篇 |
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
1.
JETP Letters - A new approach to search for axions in the storage ring experiments, applicable at a short coherence time of the in-plane polarization as is the case for protons is discussed. The... 相似文献
2.
Gaineev A. M. Galkina I. V. Davletshin R. R. Davletshina N. V. Kuznetsov N. O. Grishaev D. Yu. Shulayeva M. P. Pozdeev O. K. 《Russian Journal of General Chemistry》2022,92(7):1208-1213
Russian Journal of General Chemistry - Aminophosphabetaines, i.e., isobutyl {[alkyl(dimethyl)ammonio]methyl}phosphonates with higher alkyl substituents at the nitrogen atom, were obtained by a... 相似文献
3.
Mamatkulova N. M. Mukarramov N. I. Sasmakov S. A. Khidirova N. K. 《Chemistry of Natural Compounds》2022,58(4):726-727
Chemistry of Natural Compounds - 相似文献
4.
Petrov P. A. Filippova E. A. Kompankov N. B. Sukhikh T. S. Sokolov M. N. 《Journal of Structural Chemistry》2022,63(3):470-475
Journal of Structural Chemistry - A new polymorph of the [ReCl3(MeCN)(PPh3)2] complex is synthesized and characterized by single crystal X-ray diffraction (XRD). Its recrystallization from the... 相似文献
5.
Giang Truong Nguyen Prof. Dr. Liviu Ungur 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(30):e202200227
Employing radical bridges between anisotropic metal ions has been a viable route to achieve high-performance single-molecule magnets (SMMs). While the bridges have been mainly considered for their ability to promote exchange interactions, the crystal-field effect arising from them has not been taken into account explicitly. This lack of consideration may distort the understanding and limit the development of the entire family. To shed light on this aspect, herein we report a theoretical investigation of a series of N -radical-bridged diterbium complexes. It is found that while promoting strong exchange coupling between the terbium ions, the N -radical induces a crystal field that interferes destructively with that of the outer ligands, and thus reduces the overall SMM behavior. Based on the theoretical results, we conclude that the SMM behavior in this series could be further maximized if the crystal field of the outer ligands is designed to be collinear with that of the radical bridge. This conclusion can be generalized to all exchange-coupled SMMs. 相似文献
6.
Russian Chemical Bulletin - New representatives of (O-Si)-chelate compounds, N-(fluorosilyl)methyl derivatives of N-methylacetamide, N-methylbenzamide, N-phenylacetamide, and N-phenylbenzamide,... 相似文献
7.
Russian Journal of General Chemistry - A mechanochemical method was developed for the synthesis of ferromagnetic Pd–Fe–Co–Ni composites based on the natural biopolymer chitosan,... 相似文献
8.
Yuki Shintani Taku Ohtomi Dr. Aya Shibata Dr. Yoshiaki Kitamura Koichiro M. Hirosawa Prof. Kenichi G. N. Suzuki Prof. Masato Ikeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202104421
Aqueous self-assembly of short peptides has attracted growing attention for the construction of supramolecular materials for various bioapplications. Herein, we describe how the thermolysin-assisted biocatalytic construction of a dipeptide hydrazide from an N-protected amino acid and an amino acid hydrazide leads to the formation of thermally stable supramolecular hydrogels. In addition, we demonstrate the post-assembly modification of the supramolecular architectures constructed in situ tethering hydrazide groups as a chemical handle by means of fluorescence imaging. 相似文献
9.
Journal of Structural Chemistry - Atomic and electronic structures of cyclic organosilicon compound 9,9,10,10-tetraethynyl-9,10-dihydrodisilaanthracene are studied by the density functional theory.... 相似文献
10.
Tsyganova S. I. Fetisova O. Yu. Mazurova E. N. Taran O. P. Kuznetsov B. N. 《Russian Journal of Applied Chemistry》2022,95(3):408-416
Russian Journal of Applied Chemistry - A method for the disposal of hydrolysis lignin waste based on its modification with ZnCl2 and FeCl3 and subsequent carbonization at 800°C was proposed.... 相似文献