全文获取类型
收费全文 | 106篇 |
免费 | 0篇 |
专业分类
化学 | 63篇 |
力学 | 3篇 |
数学 | 10篇 |
物理学 | 30篇 |
出版年
2022年 | 3篇 |
2017年 | 1篇 |
2013年 | 3篇 |
2012年 | 6篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有106条查询结果,搜索用时 5 毫秒
101.
Bis(4,4′-benzoyl chloride) dimethylsilane (SiCO) and 2,2-bis(4,4′-benzoyl chloride) propane (CCO) were synthesized and polymerized with butanediol, resorcinol, or hydroquinone. The polymers of SiCO–hydroquinone (SiCO–Hyd) and SiCO–resorcinol (SiCO–Res) possess glass transition temperatures 25°C lower than their carbon analogs but the less aromatic SiCO–butanediol (SiCO–BDO) and CCO–butanediol (CCO–BDO) polymers have similar glass transitions. Silicon containing polymers are superior to their carbon counterparts in thermal stability. Furthermore, polyarylates of excellent thermal stability and solubility were synthesized from SiCO/terephthaloyl chloride and hydroquinone. © 1993 John Wiley & Sons, Inc. 相似文献
102.
Boyd DR Sharma ND Loke PL Malone JF McRoberts WC Hamilton JT 《Organic & biomolecular chemistry》2007,5(18):2983-2991
A range of seventeen quinoline alkaloids, involving several types of oxidations during their biosynthetic pathways, have been isolated from leaves of Choisya ternata. In addition to the nine known quinoline alkaloids, eight new members of the furoquinoline family, derived mainly from prenylation at C-5 (including two novel hydroperoxides), have been identified. The absolute configurations and enantiopurity values of all chiral quinoline alkaloids have been determined. One of the isolated alkaloids, 7-isopentenyloxy-gamma-fagarine, has been used as a precursor for the chemical asymmetric synthesis of the enantiopure alkaloids: evoxine, anhydroevoxine and evodine. The possible roles of oxygenase and other oxygen-atom-transfer enzymes, in the biosynthetic pathways of the C. ternata alkaloids, have been discussed. 相似文献
103.
Boyd DR Sharma ND Sbircea L Murphy D Belhocine T Malone JF James SL Allen CC Hamilton JT 《Chemical communications (Cambridge, England)》2008,(43):5535-5537
Biphenyl dioxygenase-catalysed cis-dihydroxylation of 2-chloroquinoline, 2-chloro-3-methylquinoline and 2-chloro-6-phenylpyridine substrates yielded the corresponding enantiopure cis-dihydrodiols; enantiopure 2,2'-bipyridines, synthesised in four steps from 2-chloroquinoline, proved to be efficient chiral ligands in catalytic asymmetric allylic oxidation and cyclopropanation reactions of alkenes. 相似文献
104.
Boyd DR Sharma ND Malone JF McIntyre PB Stevenson PJ Allen CC Kwit M Gawronski J 《Organic & biomolecular chemistry》2012,10(30):6217-6229
Biotransformation of 3-substituted and 2,5-disubstituted phenols, using whole cells of P. putida UV4, yielded cyclohexenone cis-diols as single enantiomers; their structures and absolute configurations have been determined by NMR and ECD spectroscopy, X-ray crystallography, and stereochemical correlation involving a four step chemoenzymatic synthesis from the corresponding cis-dihydrodiol metabolites. An active site model has been proposed, to account for the formation of enantiopure cyclohexenone cis-diols with opposite absolute configurations. 相似文献
105.
The nuclear quadrupole resonance signals from both a single crystal and a powder sample of spin-1 nuclei under a Carr?CPurcell?CMeiboom?CGill are modeled numerically. While the single crystal clearly shows the effects of dipolar coupling for on-resonant pulses, the powder does not. However, for certain off-resonant conditions, the powder sample exhibits the same response as the single crystal. Experimentally, this corresponds to the observation of a rapid decay at these conditions. Using a powder sample of NaNO2, the functional form of the echo train, when the dipolar coupling is not refocused, is clearly different than the decay for an on-resonance sequence, and can be used to characterize the dipolar coupling. 相似文献
106.