全文获取类型
收费全文 | 517篇 |
免费 | 10篇 |
国内免费 | 2篇 |
专业分类
化学 | 370篇 |
晶体学 | 2篇 |
力学 | 15篇 |
数学 | 45篇 |
物理学 | 70篇 |
无线电 | 27篇 |
出版年
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 39篇 |
2012年 | 37篇 |
2011年 | 52篇 |
2010年 | 27篇 |
2009年 | 19篇 |
2008年 | 34篇 |
2007年 | 27篇 |
2006年 | 28篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 27篇 |
2002年 | 23篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1975年 | 1篇 |
1939年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 15 毫秒
221.
Eliane Pottier Roger Dubest Robert Guglielmetti Pascale Tardieu Arlette Kellmann Francis Tfibel Patrick Levoir Jean Aubard 《Helvetica chimica acta》1990,73(2):303-315
Substituent, Heteroatom, and Solvent Effects on the Thermal-Bleaching Kinetics and Absorption Spectra of Photomerocyanines Issued from Spiro[indoline-oxazines] Quantitative information useful for the development of new photochromic systems is obtained from the study of heteroatom and substituent effects on the thermal-bleaching kinetics and the absorption spectra of the photomerocyanines issued from spiro[indoline-oxazines]. The effect on photochromic properties of the presence of N-atoms either in the dimethine bridge or in the aromatic rings has been investigated through the comparison of spiro[indoline-naphthopyrans] C with spiro[indoline-naphthoxazines] A and with spiro[indoline-quinolinoxazines] B . Besides the occurrence of biexponential thermal-bleaching kinetics in non-polar solvents is observed: a tentative explanation for this observation is given which involves the formation, in either sequential or parallel steps, of energetically distinct stereoisomers of the opened form. 相似文献
222.
223.
224.
225.
226.
227.
Pascale Chenevier Laurent Mugherli Sunita Darbe Léa Darchy Sylvain DiManno Phong D. Tran Fabrice Valentino Marina Iannello Anne Volbeda Christine Cavazza Vincent Artero 《Comptes Rendus Chimie》2013,16(5):491-505
While hydrogen is often considered as a promising energy vector and an alternative to fossil fuels, the rise of the hydrogen economy is ever and ever postponed. This is mainly due to the high costs of the materials required for the elaboration of fuel cells, these wonderful systems that release the energy contained in the H2 molecule in the form of electrical power. Indeed, scarce and precious platinum is required as a catalyst at both electrodes of fuel cells. A solution may be found in nature with metalloenzymes involved in hydrogen metabolism, called hydrogenases. These natural catalysts can be used directly in biofuel cells or serve as an inspiration to chemists for the elaboration of bio-inspired electrocatalytic materials. 相似文献
228.
Pujol AM Cuillel M Renaudet O Lebrun C Charbonnier P Cassio D Gateau C Dumy P Mintz E Delangle P 《Journal of the American Chemical Society》2011,133(2):286-296
Metal overload plays an important role in several diseases or intoxications, like in Wilson's disease, a major genetic disorder of copper metabolism in humans. To efficiently and selectively decrease copper concentration in the liver that is highly damaged, chelators should be targeted at the hepatocytes. In the present work, we synthesized a molecule able to both lower intracellular copper, namely Cu(I), and target hepatocytes, combining within the same structure a chelating unit and a carbohydrate recognition element. A cyclodecapeptide scaffold displaying a controlled conformation with two independent faces was chosen to introduce both units. One face displays a cluster of carbohydrates to ensure an efficient recognition of the asialoglycoprotein receptors, expressed on the surface of hepatocytes. The second face is devoted to metal ion complexation thanks to the thiolate functions of two cysteine side-chains. To obtain a chelator that is active only once inside the cells, the two thiol functions were oxidized in a disulfide bridge to afford the glycopeptide P(3). Two simple cyclodecapeptides modeling the reduced and complexing form of P(3) in cells proved a high affinity for Cu(I) and a high selectivity with respect to Zn(II). As expected, P(3) becomes an efficient Cu(I) chelator in the presence of glutathione that mimics the intracellular reducing environment. Finally, cellular uptake and ability to lower intracellular copper were demonstrated in hepatic cell lines, in particular in WIF-B9, making P(3) a good candidate to fight copper overload in the liver. 相似文献
229.