排序方式: 共有15条查询结果,搜索用时 15 毫秒
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Ae. de Groot M.P. Broekhuysen L.L. Doddema M.C. Vollering J.M.M. Westerbeek 《Tetrahedron letters》1982,23(46):4831-4834
The total synthesis of (±)-colorata-4(13),8-dienolide (), a sesquiterpene with a rearranged drimane skieleton, is described using 6β, 8aβ-dimethyl-5-methylene-3,4,4aα, 5,6,7,8,8a-octahydro-1(2H)-naphtalenone () as a key intermediate. A new annelation method for butenolides via hydrolysis of a thiohenyl furan is reported. 相似文献
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Aljaž Zalar 《Integral Equations and Operator Theory》2014,79(2):219-242
Regular normalized W-valued spectral measures on a compact Hausdorff space X are in one-to-one correspondence with unital *-representations ${\rho : C(X, \mathbb{C}) \to W}$ , where W stands for a von Neumann algebra. In this paper we show that for every compact Hausdorff space X and every von Neumann algebras W 1, W 2 there is a one-to-one correspondence between unital *-representations ${\rho : C(X, W_1) \to W_2}$ and special B(W 1, W 2)-valued measures on X that we call non-negative spectral measures. Such measures are special cases of non-negative measures that we introduced in our previous paper (Cimpri? and Zalar, J Math Anal Appl 401:307–316, 2013) in connection with moment problems for operator polynomials. 相似文献
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Ukmar T Godec A Planinšek O Kaučič V Mali G Gaberšček M 《Physical chemistry chemical physics : PCCP》2011,13(35):16046-16054
Compounds embedded into mesoporous or even microporous matrices are interesting for many emerging applications, such as novel catalysts, sensors, batteries, hydrogen storage materials or modern drug delivery devices. We report on two unexpected phenomena regarding the structural and dynamic properties of a model drug substance (indomethacin) when confined in mesoscopic matrices. Firstly, we show that the confinement directs the crystallization of the drug into a stable polymorph that is not otherwise formed at all; its relative amount depends on the pore size. This phenomenon is also explained theoretically using a modified classical heterogeneous nucleation theory. Secondly, we demonstrate that--even at relatively low volume fractions--the confined drug forms a condensed phase in a way that obstructs the passage of the pore channels. This may have far-reaching consequences for understanding the mechanisms of drug release from porous matrices. 相似文献
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