Scale height determination of spiral galaxies

The method adopted here is based on the rigorous solution of Poisson’s equation for logarithmic disturbance density within finite thickness galaxies. After their spiral arms are fitted directly with logarithmic spirals, the morphological parameters, scale heights and their relative errors for 32 spiral galaxies, such as NGC4814, are obtained.     

THE (U K)-ORBITS OF ESSENTIALLY NORMAL OPERATORS AND THEIR STRONG IRREDUCIBILITY

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Synthesis and Characterization of Ferrocene-terminated Ruthenium Phenylacetylide COmplexes with Alligator Clips

Ferrocene-terminated trans-Ru(dppm)2 (dppm=Ph2PCH2pph2)-containing molecular wires with alligator clips were prepared.They are suitable for self-assembly on gold electrode to investigate the influence of metal incorporation on the electron transportation property of the molecular wires.     

Theoretical investigation of the Au/Si(1 1 1)-(5 × 2) surface structure

The atomic structure of the Au/Si(1 1 1)-(5 × 2) surface has been studied by density-functional theory calculations. Two structure models, proposed experimentally by Marks et al. and Hasegawa et al., have been examined on an equal ground. In our total-energy calculations, both models are found to be locally stable and energetically comparable. In our electronic-structure analyses, however, both models fail to reproduce the key features of angle-resolved photoemission spectra and scanning-tunneling-microscopy images, indicating that the considered models need to be modified. Suggestions for the modification are given based on the present calculations.     

Mechanism of proton anisotropic velocity distribution in the solar wind

Although it has been long that spacecraft observed the anisotropy of velocity protons in the solar wind, there is still not a reasonable explanation. In this paper we try to give an explanation from the diffusion plateau of protoncyclotron resonance predicted by the quasi-linear theory for the resonance between the protons and the parallel propagating waves. We consider the effect of dispersion relation on diffusion plateau and notice that the diffusion plateau we have got by using cold plasma dispersion relation accords with the density contours in the velocity phase space detected at 0.3 AU in fast solar wind. For explaining proton distributions obtained in the fast solar wind from 0.7 AU to 1 AU hot plasma dispersion relation should be considered. We also give a theoretical relation of proton thermal anisotropy A and plasma parameter β.     

Synthesis,structure and electrochemical properties of two new unsymmetrical tetrathiafulvalene derivatives

Two new unsymmetrical tetrathiafulvalene (TTF) derivatives, 2,3‐bis(cyanoethylthio)‐6,7‐(methyl‐ethylenedithio)tetrathiafulvalene ( 6a ) and 2,3‐bis(cyanoethylthio)‐6,7‐(cyclopentodithio)tetrathiafulvalene ( 6b ), have been prepared and characterized by NMR, MS, IR and Elemental analyses. The molecular structures have been determined by X‐ray crystallography. Their redox properties have been investigated by cyclic voltammetry in dichloromethane solution and each compound shows two reversible single‐electron redox couples.     

Ferrocenylimidazoline palladacycles as efficient catalysts for the aza‐Claisen rearrangement reaction of allylic imidates

Chloride‐bridged palladacycle dimers 1 have been evaluated as catalysts for the aza‐Claisen rearrangement of allylic imidates 2 to the corresponding allyl amides 3 . Cyclopalladated complexes 1b–e bearing electron‐donating substituents on imidazoline ring were identified as being superior catalysts because excellent yields were obtained without using silver salts for activation. In addition, a correlation between substituents on the imidazoline ring and catalytic activity of palladacycles was established. The electron‐deficient ligands and good solubility of catalysts in the reaction solution increase the catalytic activity. Copyright © 2008 John Wiley & Sons, Ltd.     

Hitting time of large subsets of the hypercube

We study the simple random walk on the n‐dimensional hypercube, in particular its hitting times of large (possibly random) sets. We give simple conditions on these sets ensuring that the properly rescaled hitting time is asymptotically exponentially distributed, uniformly in the starting position of the walk. These conditions are then verified for percolation clouds with densities that are much smaller than (n log n)^‐1. A main motivation behind this article is the study of the so‐called aging phenomenon in the Random Energy Model, the simplest model of a mean‐field spin glass. Our results allow us to prove aging in the REM for all temperatures, thereby extending earlier results to their optimal temperature domain. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008     

catena‐Poly[[[bis(μ‐4,5‐dihydrothiazole‐2‐thiolato)‐tetrahedro‐tetracopper(I)]‐di‐μ‐4,5‐dihydrothiazole‐2‐thiolato] dihydrate]

The title compound, {[Cu₄(C₃H₄NS₂)₄]·2H₂O}_n, was produced by diffusing a solution of 2‐mercapto­thia­zoline in tetra­hydro­furan into a solution of CuCl in CH₃CN at room temperature. The structure is characterized by self‐assembled one‐dimensional chains that are condensed from butterfly‐like [Cu(C₃H₄NS₂)]₄ tetrameric units via double S‐bridging at opposite ends. The Cu—Cu distances within the Cu₄ butterfly cluster are in the range 2.7103 (10)–2.9764 (10) Å, while the shortest Cu?Cu intercluster distance is 3.468 (1) Å, much longer than the sum of the van der Waals radii.     

无源红外方位标研究

提出在现有条件下利用激光实现无源红外方位标的思路，并通过详细计算与分析，论述了无源红外方位标的可行性。