全文获取类型
收费全文 | 313728篇 |
免费 | 2416篇 |
国内免费 | 953篇 |
专业分类
化学 | 173027篇 |
晶体学 | 5201篇 |
力学 | 12652篇 |
综合类 | 6篇 |
数学 | 32755篇 |
物理学 | 93456篇 |
出版年
2019年 | 2904篇 |
2018年 | 3472篇 |
2017年 | 3372篇 |
2016年 | 5111篇 |
2015年 | 3118篇 |
2014年 | 4854篇 |
2013年 | 13204篇 |
2012年 | 9309篇 |
2011年 | 11605篇 |
2010年 | 8122篇 |
2009年 | 7988篇 |
2008年 | 10802篇 |
2007年 | 10955篇 |
2006年 | 10320篇 |
2005年 | 9364篇 |
2004年 | 8437篇 |
2003年 | 7660篇 |
2002年 | 7480篇 |
2001年 | 8812篇 |
2000年 | 6900篇 |
1999年 | 5236篇 |
1998年 | 4322篇 |
1997年 | 4386篇 |
1996年 | 4235篇 |
1995年 | 3632篇 |
1994年 | 3722篇 |
1993年 | 3677篇 |
1992年 | 4045篇 |
1991年 | 4003篇 |
1990年 | 3854篇 |
1989年 | 3999篇 |
1988年 | 3835篇 |
1987年 | 3825篇 |
1986年 | 3613篇 |
1985年 | 4810篇 |
1984年 | 4917篇 |
1983年 | 4020篇 |
1982年 | 4308篇 |
1981年 | 4198篇 |
1980年 | 3965篇 |
1979年 | 4258篇 |
1978年 | 4538篇 |
1977年 | 4391篇 |
1976年 | 4319篇 |
1975年 | 4127篇 |
1974年 | 4099篇 |
1973年 | 4220篇 |
1972年 | 2798篇 |
1968年 | 2712篇 |
1967年 | 3034篇 |
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
71.
72.
73.
74.
Inside Back Cover: On the Resolution Limit of Femtosecond Stimulated Raman Spectroscopy: Modelling Fifth‐Order Signals with Overlapping Pulses (ChemPhysChem 16/2015)
下载免费PDF全文
![点击此处可从《Chemphyschem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
75.
M.M. Elseweidy N.N. Younis S.E. Elswefy F.R. Abdallah S.I. El-Dahmy G. Elnagar 《Natural product research》2015,29(10):961-965
The anti-atherogenic potentials of total ginger (Zingiber officinale) extract (TGE) or curcuminoids extracted from turmeric (Curcuma longa), members of family Zingiberaceae, were compared in hypercholesterolaemia. Rabbits were fed either normal or atherogenic diet. The rabbits on atherogenic diet received treatments with TGE or curcumenoids and placebo concurrently for 6 weeks (n = 6). The anti-atherogenic effects of curcuminoids and ginger are mediated via multiple mechanisms. This effect was correlated with their ability to lower cholesteryl ester transfer protein activity. Ginger extract exerted preferential effects on plasma lipids, reverse cholesterol transport, cholesterol synthesis and inflammatory status. Curcuminoids, however, showed superior antioxidant activity. 相似文献
76.
Automated solvent system screening for the preparative countercurrent chromatography of pharmaceutical discovery compounds
下载免费PDF全文
![点击此处可从《Journal of separation science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
James Bradow Frank Riley Laurence Philippe Qi Yan Brandon Schuff Guy H. Harris 《Journal of separation science》2015,38(23):3983-3991
A fully automated countercurrent chromatography system has been constructed to rapidly screen the commonly used heptane/ethyl acetate/methanol/water solvent system series and translate the results to preparative scale separations. The system utilizes “on‐demand” preparation of the heptane/ethyl acetate/methanol/water solvent system upper and lower phases. Elution‐extrusion countercurrent chromatography was combined with non‐dynamic equilibrium injection reducing the screening time for each heptane/ethyl acetate/methanol/water system to 17 min. The result enabled solvent system development to be reduced to under 2 h. The countercurrent chromatography system was interfaced with a mass spectrometer to allow selective detection of target components in crude medicinal chemistry reaction mixtures. Mass‐directed preparative countercurrent chromatography purification was demonstrated for the first time using a synthetic tetrazole epoxide derived from a routine medicinal chemistry support workflow. 相似文献
77.
Iron(III)‐Selective Chelation‐Enhanced Fluorescence Sensing for In Vivo Imaging Applications
下载免费PDF全文
![点击此处可从《化学:亚洲杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lin E. Guo Xin Yi Liu Huan Wang Qiu Ling Chen Guang Ke Wang Prof. Kaijun Luo Qi Li Mi Prof. Ying Zhou Jun Feng Zhang 《化学:亚洲杂志》2015,10(9):1898-1902
A “turn‐on” pattern Fe3+‐selective fluorescent sensor was synthesized and characterized that showed high fluorescence discrimination of Fe3+ over Fe2+ and other tested ions. With a 62‐fold fluorescence enhancement towards Fe3+, the probe was employed to detect Fe3+ in vivo in HeLa cells and Caenorhabditis elegans, and it was also successfully used to elucidate Fe3+ enrichment and exchange infected by innexin3 (Inx3) in hemichannel‐closed Sf9 cells. 相似文献
78.
79.
80.