全文获取类型
收费全文 | 165篇 |
免费 | 2篇 |
专业分类
化学 | 161篇 |
数学 | 1篇 |
物理学 | 5篇 |
出版年
2021年 | 3篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 14篇 |
2012年 | 3篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 2篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 3篇 |
2001年 | 9篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1983年 | 1篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有167条查询结果,搜索用时 0 毫秒
161.
4,4',4' '-(1,3,5-Benzenetriyl)tris(2,6-di-tert-butylphenol) was prepared by the cross-coupling of 1,3,5-tribromobenzene and [4-(trimethylsiloxy)phenyl]magnesium bromide. X-ray analysis of the single crystal showed a propeller-like structure with a mean dihedral angle of 39 degrees between the hydroxyphenyl and the core benzene. The phenoxyl mono-, di-, and triradicals were generated by the electrochemical oxidation of the trianion. A stepwise radical formation was revealed by a differential pulse voltammogram, electrolytic ESR spectroscopy, and a comproportionation reaction between the radicals, which was discussed as an effect of the pi-conjugated but non-Kekulé-type coupler. The quartet and triplet ground state for the tri- and diradical, respectively, were confirmed by a SQUID measurement. 相似文献
162.
Anodic oxidation of 2,6-disubstituted phenols gave poly(2,6-disubstituted-1,4-phenyleneoxide)s quantitatively by using dichloromethane and tetraethyl ammonium bromide as the solvent and the supporting electrolyte respectively. Phenol was also electro-oxidatively polymerized to yield oligo(1,4-phenyleneoxide) with molecular weight of 1200~2500. The 2-step polymerization and the polymerization in the presence of bisphenol were carried out to increase the molecular weight of the oligo(phenyleneoxide). The mechanism of the electro-oxidative polymerization was discussed by electrochemical and ESR measurements. 相似文献
163.
Hiroyuki Nishide Eiichi Soda Hiroyuki Mizuma Eishun Tsuchida 《Macromolecular Symposia》1996,105(1):191-197
A polymer membrane containing N,N-disalicylidenethylenediaminocobalt (Co(salen)) was prepared. The Co(salen) supported in the polymer not only worked as a reversible and specific oxygen-adsorbent but discontinuously bound oxygen at the atmospheric oxygen partial pressure of ca. 15 cmHg to give an on-off-like oxygen-binding curve. Oxygen permeation through the Co(salen) membrane was also augmented in the higher upstream oxygen pressure region, which was caused by the specific oxygen-binding to the Co(salen) fixed in the membrane. 相似文献
164.
165.
5-(4-Trimethylsilyethynylphenyl)-10,15,20-triphenylplatinumporphyrin was synthesized and copolymerized with trimethylsilylpropyne to give a new high-molecular-weight porphyrin polymer. The polymer formed a smooth and tough coating on many types of surfaces. The coating showed a strong blue luminescence from the platinumporphyrin residue which was quenched in the presence of oxygen. The relationship of the luminescence intensity vs oxygen pressure displayed a remarkably high pressure sensitivity in the low oxygen pressure area, which was ascribed to the high oxygen permeability of the polymer. 相似文献
166.
Reversible oxygen-binding was observed at low temperature for the poly(vinylimidazole-co-octyl methacrylate) complexes of the simple or planar cobaltporphyrins (CoP) such as cobalt-tetraphenylporphyrin and cobalt-octaethylporphyrin. The oxygen-binding affinity and rate constants were compared with those for the cobalt-picketfence porphyrin, a typical oxygen-carrier. The low oxygen-binding affinity for the CoP complexes was attributed to the enormously large oxygen-releasing rate constant. 相似文献
167.
Summary: The water-insoluble, thermostable and homogeneous polymer complex membrane formation of polysulfonic acids was examined by modifying the preparation conditions of the layer-by-layer adsorption method of the acid and base polymers. The complexation of poly(4-styrenesulfonic acid) in the 0.15 unit mM solution with poly(allylamine) gave a polymer complex membrane on a gold substrate in which one polymer layer was formed with a thickness of 1 nm. Properties including the proton conductivity of the membrane suggested possible applications of the polymer complex membrane. 相似文献