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排序方式: 共有121条查询结果,搜索用时 62 毫秒
61.
62.
Dye ST Annis J Becker-Szendy R Bratton CB Casper D Claus R Crouch M Errede S Gajewski W Goldhaber M Haines TJ Jones TW Kielczewska D Kropp WR Learned JG LoSecco JM McGrew C Matthews J Mudan MS Price LR Reines F Schultz J Seidel S Sinclair D Sobel HW Stone JL Sulak LR Svoboda R Thornton G van der Velde JC 《Physical review letters》1989,62(18):2069-2072
63.
Blue and Green Phosphorescent Liquid‐Crystalline Iridium Complexes with High Hole Mobility
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Dr. Yafei Wang Christopher P. Cabry ManJun Xiao Dr. Louise Male Dr. Stephen J. Cowling Prof. Dr. Duncan W. Bruce Junwei Shi Prof. Weiguo Zhu Dr. Etienne Baranoff 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(5):1618-1621
Blue‐ and green‐emitting cyclometalated liquid‐crystalline iridium complexes are realized by using a modular strategy based on strongly mesogenic groups attached to an acetylacetonate ancillary ligand. The cyclometalated ligand dictates the photophysical properties of the materials, which are identical to those of the parent complexes. High hole mobilities, up to 0.004 cm2 V?1 s?1, were achieved after thermal annealing, while amorphous materials show hole mobilities of only approximately 10?7–10?6 cm2 V?1 s?1, similar to simple iridium complexes. The design strategy allows the facile preparation of phosphorescent liquid‐crystalline complexes with fine‐tuned photophysical properties. 相似文献
64.
Abstract The composition and the stability constant of Eu(III)-rutin complex were determined by suitable spectrophotometric methods and pH-metric measurements. The formation of a (Eu(C27H26O16H3)2)+ complex whose concentration stability constant β2 ranged from 10.59 at pH=5.0 to 7.21 at pH=8.0, was established. Spectrophotometric determination of Eu(III) by means of the reaction of complex formation with rutin, was investigated. It was found that Eu(III) can be determined in the range from 5×10?6 to 7.5×10?5M. All investigations were carried out with 70% ethanolic solutions at room temperature (20°C), whereas spectrophotometric investigations were performed in the presence of a buffer, at constant pH values and ionic strength (0.015). The determination of the complex composition was done at pH=5.6, and that of Eu(III) at pH=6.3. 相似文献
65.
Defaut B Parsons TB Spencer N Male L Kariuki BM Grainger RS 《Organic & biomolecular chemistry》2012,10(25):4926-4932
A concise, stereoselective synthesis of the trans-hydrindane core of the marine natural product dictyoxetane is reported, starting from a Robinson annelation derived bicyclic enone. A phosphorane-mediated, pinacol-like rearrangement of a cis-diol, via a formal 1,2-hydride shift, is used to establish the requisite trans ring junction. (31)P NMR supports the formation of the intermediate phosphorane, generated in situ from the reaction of a diol with Ph(3)PCl(2). 相似文献
66.
67.
JC Wolff S Monte N Haskins D Bell 《Rapid communications in mass spectrometry : RCM》1999,13(18):1797-1802
Structural analysis of minor components in mixtures is a vital requirement in the development of any pharmaceutical compound. Mass spectrometry is uniquely able to give this kind of information on the trace amounts of material present as minor impurities in a drug substance. In this study we show that a combination of mass spectrometric analysers with different characteristics is an even more powerful approach with a higher chance of establishing a potential structure. In particular the advent of analysers capable of accurate mass measurement on small amounts of material has enabled structures to be proposed in situations where previously no real conclusions could be made. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
68.
In this paper the exact solution of the non-symmetric matrixRiccati equation with analytic coefficients is approximatedby a rational matrix function with a prefixed accuracy. Thisrational matrix function is locally defined as the exact solutionof a Riccati problem with matrix polynomial coefficients obtainedby truncation of the Taylor expansions of the matrix coefficientsof the original problem. 相似文献
69.
This paper presents a numerical method for solving the two‐dimensional unsteady incompressible Navier–Stokes equations in a vorticity–velocity formulation. The method is applicable for simulating the nonlinear wave interaction in a two‐dimensional boundary layer flow. It is based on combined compact difference schemes of up to 12th order for discretization of the spatial derivatives on equidistant grids and a fourth‐order five‐ to six‐alternating‐stage Runge–Kutta method for temporal integration. The spatial and temporal schemes are optimized together for the first derivative in a downstream direction to achieve a better spectral resolution. In this method, the dispersion and dissipation errors have been minimized to simulate physical waves accurately. At the same time, the schemes can efficiently suppress numerical grid‐mesh oscillations. The results of test calculations on coarse grids are in good agreement with the linear stability theory and comparable with other works. The accuracy and the efficiency of the current code indicate its potential to be extended to three‐dimensional cases in which full boundary layer transition happens. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
70.
Branko Malešević Dragana Todorić Ivana Jovović Sonja Telebaković 《Applied Mathematics Letters》2010,23(11):1367-1371
This paper deals with the reduction of non-homogeneous linear systems of first order operator equations with constant coefficients. An equivalent reduced system, consisting of higher order linear operator equations having only one variable and first order linear operator equations in two variables, is obtained by using the rational canonical form. 相似文献