全文获取类型
收费全文 | 593篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
化学 | 373篇 |
晶体学 | 5篇 |
力学 | 4篇 |
数学 | 7篇 |
物理学 | 212篇 |
出版年
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2018年 | 7篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 28篇 |
2012年 | 23篇 |
2011年 | 32篇 |
2010年 | 18篇 |
2009年 | 17篇 |
2008年 | 26篇 |
2007年 | 29篇 |
2006年 | 26篇 |
2005年 | 31篇 |
2004年 | 24篇 |
2003年 | 24篇 |
2002年 | 21篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1996年 | 11篇 |
1995年 | 5篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1973年 | 10篇 |
1971年 | 3篇 |
1969年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有601条查询结果,搜索用时 15 毫秒
31.
32.
33.
Katayama H Satoh K Takeuchi M Deguchi-Tawarada M Oda Y Nagasu T 《Rapid communications in mass spectrometry : RCM》2003,17(10):1071-1078
Improvement of in-gel digestion efficiency is highly desirable for one- or two-dimensional gel electrophoretic separation and mass spectrometric (MS) analysis in proteomics, because the resultant increases in sequence coverage and MS signal intensity lead to higher confidence in protein identification. Here an optimized in-gel digestion system, in combination with thin-gel separation and negative staining in a high-throughput format using 96-well plates, is described. The combination of negative staining and protein separation on a 0.9 mm thick gel showed a clear improvement in in-gel digestion efficiency in comparison with the more typical protocols such as the combination of silver staining and a 1.0 mm gel. In addition, the use of 96-well plates to increase throughput did not decrease the efficiency of this strategy when the stirring of the gel pieces in processes such as destaining, washing, gel-shrinking and peptide extraction was performed by sonication instead of shaking the plates. This procedure was optimized and applied to identify proteins of the postsynaptic density fraction; 105 proteins were identified after SDS-PAGE separation. 相似文献
34.
Akihito Sakakibara Maki Itoh Itaru Mita 《Journal of polymer science. Part A, Polymer chemistry》1995,33(8):1293-1303
Aromatic polybenzobisoxazoles, having polydimethylsiloxane side chains (SCPBOs), were prepared using terephthaloyl chloride-terminated polydimethylsiloxane macromonomers and 3,3′-bis(trimethylsiloxy)-4,4′-bis(trimethylsilylamino)biphenyl for the purpose of dispersing rigid-rod molecules in silicone matrices for molecular reinforcement. The degree of polymerization of the side chain was varied from 7.8 to 45.4, and a small amount of (3-butenyloxy)terephthaloyl chloride was copolymerized to give the polymers a functionality that can be linked to the matrices. For all the SCPBOs, the WAXD pattern showed only diffuse reflections, suggesting limited structural regularity, although the polymers were optically anisotropic. No melting transition was observed below the side chain decomposition temperature, 350°C. A polydimethylsiloxane/polybenzobisoxazole composite elastomer was obtained first curing the polysiloxane matrix containing the prepolymer of the SCPBO, followed by in situ thermal ring closure of the prepolymer. Some reinforcement was observed, but the presence of plasticizing effect by the unbound SCPBO was suggested at the same time. © 1995 John Wiley & Sons, Inc. 相似文献
35.
The common synthetic intermediate of a potent and promising anticancer agent, fostriecin, was synthesized using a unique method that combines four catalytic asymmetric reactions as shown above. 相似文献
36.
37.
38.
39.
40.
The separation of daughter nuclides in the carrier-free state from90Sr?90Y and140Ba?140La aqueous solution systems was performed by thin-layer chromatographic methods. (1) When a silica gel adsorbent and a developer of 1N NaCl, KCl, NH4Cl, CaCl2, SrCl2 or BaCl2 solutions was employed,90Y and140La were retained at the origin, while90Sr and140Ba advanced with the developer front. Addition of gypsum as binder to the silica gel prevented the separation of the140Ba?140La system, retaining both components at the origin. (2) When the140Ba?140La system was developed with water on a silica gel adsorbent containing 5% of gypsum, which was treated with various concentrations of nitric acid, the Rf value of140La increased with the concentration of nitric acid used, reaching a maximum of 0.98 at 0.1 N. The Rf value then decreased on the further increase of the concentration of nitric acid. When the same process was applied to the90Sr?90Y system, there was no separation. The radiochemical purities of90Y and140La obtained in the above two ways were more than 99%. 相似文献