全文获取类型
收费全文 | 434266篇 |
免费 | 5284篇 |
国内免费 | 1011篇 |
专业分类
化学 | 236265篇 |
晶体学 | 6321篇 |
力学 | 18036篇 |
综合类 | 13篇 |
数学 | 51750篇 |
物理学 | 128176篇 |
出版年
2020年 | 3748篇 |
2019年 | 4008篇 |
2018年 | 5416篇 |
2017年 | 5338篇 |
2016年 | 8324篇 |
2015年 | 5403篇 |
2014年 | 7618篇 |
2013年 | 18979篇 |
2012年 | 14878篇 |
2011年 | 17428篇 |
2010年 | 12305篇 |
2009年 | 11921篇 |
2008年 | 16419篇 |
2007年 | 16207篇 |
2006年 | 15281篇 |
2005年 | 13939篇 |
2004年 | 12727篇 |
2003年 | 11465篇 |
2002年 | 11175篇 |
2001年 | 12695篇 |
2000年 | 9813篇 |
1999年 | 7572篇 |
1998年 | 6067篇 |
1997年 | 6061篇 |
1996年 | 5929篇 |
1995年 | 5342篇 |
1994年 | 5592篇 |
1993年 | 5082篇 |
1992年 | 5975篇 |
1991年 | 5965篇 |
1990年 | 5794篇 |
1989年 | 5571篇 |
1988年 | 5645篇 |
1987年 | 5477篇 |
1986年 | 5157篇 |
1985年 | 6782篇 |
1984年 | 6997篇 |
1983年 | 5750篇 |
1982年 | 5851篇 |
1981年 | 5689篇 |
1980年 | 5631篇 |
1979年 | 5802篇 |
1978年 | 6171篇 |
1977年 | 6064篇 |
1976年 | 6037篇 |
1975年 | 5604篇 |
1974年 | 5664篇 |
1973年 | 5831篇 |
1972年 | 4026篇 |
1971年 | 3319篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Hassan E. A. M. Elabid A. E. A. Bashier E. O. Elagib T. H. H. 《Mechanics of Composite Materials》2022,58(2):261-270
Mechanics of Composite Materials - Carbon fiber (CF)/ polyamide (PA6) composites are one of the most promising thermoplastic materials for automobile applications. However, the interfacial... 相似文献
12.
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
13.
Dominik Vítek Prof. Aleš Růžička Lise Vermeersch Dr. Libor Dostál Dr. Jan Turek Prof. Roman Jambor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(70):e202202639
Reactivity studies of the GeII→B complex L(Cl)Ge⋅BH3 ( 1 ; L=2-Et2NCH2-4,6-tBu2-C6H2) were performed to determine the effect on the GeII→B donation. N-coordinated compounds L(OtBu)Ge⋅BH3 ( 2 ) and [LGe⋅BH3]2 ( 3 ) were prepared. The possible tuning of the GeII→B interaction was proved experimentally, yielding compounds 1-PPh2-8-(LGe)-C10H6 ( 4 ) and L(Cl)Ge⋅GaCl3 ( 5 ) without a GeII→B interaction. In 5 , an unprecedented GeII→Ga coordination was revealed. The experimental results were complemented by a theoretical study focusing on the bonding in 1 − 5 . The different strength of the GeII→E (E=B, Ga) donation was evaluated by using energy decomposition analysis. The basicity of different L(X)Ge groups through proton affinity is also assessed. 相似文献
14.
Peralta Cecilia Mariana Acosta Gimena Henestrosa Cecilia Gil Raúl Andrés Fernández Liliana Patricia 《Journal of Analytical Chemistry》2022,77(3):308-317
Journal of Analytical Chemistry - The present development involved a flow injection strategy using a mini-column of multiwalled carbon nanotubes and fluorescent detection (λex of 283 nm,... 相似文献
15.
Bazarra Noelia Castejón Alberto Fernández José R. Quintanilla Ramón 《Meccanica》2021,56(12):3025-3037
Meccanica - In this work we study, from the numerical point of view, a one-dimensional thermoelastic problem where the thermal law is of type III. Quasi-static microvoids are also assumed within... 相似文献
16.
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
17.
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
18.
Gürbüzbalaban Mert Ruszczyński Andrzej Zhu Landi 《Journal of Optimization Theory and Applications》2022,194(3):1014-1041
Journal of Optimization Theory and Applications - We consider a distributionally robust formulation of stochastic optimization problems arising in statistical learning, where robustness is with... 相似文献
19.
Russian Journal of Applied Chemistry - In September 1975, the head of Russian electrochemists, Academician A.N. Frumkin (1895–1976), in his report at the XI Mendeleev Congress on General and... 相似文献
20.
Filatova S. M. Guseva M. K. Bodrova T. G. Parshina D. V. Budanova U. A. Sebyakin Yu. L. 《Russian Journal of General Chemistry》2022,91(1):S13-S23
Russian Journal of General Chemistry - The review article traces the main trends of the synthetic approach to the solution of the problem of overcoming the resistance of pathogenic bacterial... 相似文献