全文获取类型
收费全文 | 2413篇 |
免费 | 62篇 |
国内免费 | 8篇 |
专业分类
化学 | 1577篇 |
晶体学 | 42篇 |
力学 | 86篇 |
数学 | 567篇 |
物理学 | 211篇 |
出版年
2023年 | 12篇 |
2022年 | 44篇 |
2021年 | 61篇 |
2020年 | 40篇 |
2019年 | 43篇 |
2018年 | 30篇 |
2017年 | 21篇 |
2016年 | 62篇 |
2015年 | 66篇 |
2014年 | 51篇 |
2013年 | 118篇 |
2012年 | 106篇 |
2011年 | 145篇 |
2010年 | 91篇 |
2009年 | 81篇 |
2008年 | 123篇 |
2007年 | 102篇 |
2006年 | 131篇 |
2005年 | 122篇 |
2004年 | 109篇 |
2003年 | 89篇 |
2002年 | 78篇 |
2001年 | 29篇 |
2000年 | 15篇 |
1999年 | 25篇 |
1998年 | 20篇 |
1997年 | 20篇 |
1996年 | 42篇 |
1995年 | 25篇 |
1994年 | 30篇 |
1993年 | 25篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 21篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 25篇 |
1984年 | 15篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 20篇 |
1980年 | 31篇 |
1979年 | 26篇 |
1978年 | 17篇 |
1976年 | 15篇 |
1975年 | 12篇 |
1915年 | 9篇 |
1906年 | 7篇 |
排序方式: 共有2483条查询结果,搜索用时 46 毫秒
101.
Giancarlo De Santis Luigi Fabbrizzi Maurizio Licchelli Piersandro Pallavicini Angelo Perotti Antonio Poggi 《Supramolecular chemistry》2013,25(2):115-125
Abstract The new ferrocene-containing water-soluble ligands 1 and 2 were synthesized and their protonation and complexation properties toward NiII and CuII studied as a function of pH, by means of potentiometric titration experiments. Electrochemical measurements were performed in aqueous solution on pure 1 and 2 and in the presence of NiII and CuII cations, in the pH range 2–12, allowing us to determine the redox potential values relative to the ferrocene oxidation in the free ligands and in their NiII and CuII complexes. 1 and 2 behave as redox switchable ligands, the former enhancing, the latter decreasing its binding ability upon oxidation of the appended ferrocene function. Besides, the CuII complex of ligand 1 and the NiII complex of ligand 2 behave as two-centre two-electron redox systems, the complexed metal cation being subject to further oxidation to MIII. 相似文献
102.
Dr. Emilio M. Pellegrino Prof. Luigi Cerruti Prof. Elena M. Ghibaudi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4330-4335
The present reflection on the development of research on carbon nanotubes (CNTs) stems from the publication of the report “Realizing the Promise of Carbon Nanotubes” by the US National Nanotechnology Initiative in 2015. The report is a critical assessment of the state‐of‐art of CNT research and highlights some unresolved issues related with this field. Starting from the results of this assessment, we carried out an analysis of the publications’ pool in CNTs and related domains, by exploiting bibliometric tools. We focused on the item of competition/collaboration between disciplines and nations, with the purpose of evaluating the position of chemistry (as a discipline) as well as the position of the main European countries and the European Union (EU) as a whole in the context of CNT research. The results of such analysis outline very clearly the interdisciplinary landscape wherein CNT research is situated and show the highly competitive place occupied by EU in the field. 相似文献
103.
104.
105.
Dr. Valerie H. L. Wong Dr. Sai V. C. Vummaleti Prof. Luigi Cavallo Dr. Andrew J. P. White Prof. Steven P. Nolan Dr. King Kuok Hii 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13320-13327
A general synthetic route was used to prepare 15 new N‐heterocyclic carbene (NHC)–AgI complexes bearing anionic carboxylate ligands [Ag(NHC)(O2CR)], including a homologous series of complexes of sterically flexible ITent ligands, which permit a systematic spectroscopic and theoretical study of the structural and electronic features of these compounds. The complexes displayed a significant ligand‐accelerated effect in the intramolecular cyclisation of propargylic amides to oxazolidines. The substrate scope is highly complementary to that previously achieved by NHC–Au and pyridyl–AgI complexes. 相似文献
106.
107.
Luigi Mondello 《Analytical and bioanalytical chemistry》2013,405(13):4589-4590
108.
109.
110.