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941.
本文采用简化一般价力场对Fe(C5Me4H)2,Ru(C5Me4H)2的振动光谱作了简正坐标分析计算,得到了一套合理的力常数,并对振动频率进行了指认。 相似文献
942.
The study of the radiative and electrical properties of granular materials coated with polypyrrole (PPy) a conducting polymer, shows the influence of the processing conditions concerning the nature of the substrate and the deposition parameters. Binary mixtures with varying compositions of mono and bidisperse particles, coated with or without PPy (which are conductive and insulating, respectively) present electrical percolation thresholds which can also be found when the radiative aspect is considered. The principal component analysis carried out on the spectral values allows us to corroborate the experimental factors and to distinguish the mixtures according to their compositions. 相似文献
943.
J. Borkowska-Burnecka W. ?yrnicki E.H. Fink 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,86(1):87-95
Rotational and vibrational temperatures of the Bi2 dimer have been measured in a chemiluminescent flame. Emission spectra of the Bi2 a3Σu+(a11u)→X1Σg+(X0g+) transition in the near-infrared region were recorded with a FTIR spectrometer. High-resolution spectra of the 0-3, 0-8, 0-9, 2-3, 4-1, 6-0, 6-1, and 7-1 bands served for the determination of the rotational temperature. It was observed that both rotational and vibrational levels are described well by Boltzmann distributions. The average rotational temperature was found to be consistent with the vibrational temperature . The study has shown that such a very heavy molecule as Bi2 can serve for temperature measurements by optical emission as reported so far only for light molecules. 相似文献
944.
Nevena Todorova 《Surface science》2007,601(3):665-671
Density functional theory was employed to examine the interactions of atomic sulfur with the Fe(1 0 0) and Fe(1 1 0) surfaces. Vibrational frequency calculations were performed to determine the nature of stationary points at the high symmetry atop, bridge and hollow adsorption sites and to indicate the direction the adsorbate would move across the surface. The values were also used in the determination of the rate constant for hopping of S from one energy minimum site to another. Ab initio molecular dynamics (MD) simulations were then performed to monitor the mobility of the S atom on the (1 0 0) surface at different temperatures up to the melting point of Fe (1808 K) and were compared to our previously obtained ab initio MD results for S/Fe(1 1 0) [N. Todorova, M.J.S. Spencer, I. Yarovsky, Australian Institute of Physics 16th Biennial Congress, 2005, Canberra, Australia, ISBN 0-9598064-8-2]. 相似文献
945.
Aidan J. Quinn 《Surface science》2007,601(13):2740-2745
We review our recent progress on probing the electronic properties of self-assembled arrays of ligand-stabilized gold nanocrystals via charge transport measurements on both laterally- and vertically-contacted arrays. We show that the electronic properties of these assemblies can be manipulated through experimental control of the nanocrystal diameter, the array formation conditions and the nature of the protecting ligand. 相似文献
946.
We report on scanning tunneling microscopy (STM) studies of submonolayer growth of cobalt on the close-packed (1 1 1) surfaces of Au and Ag. Both substrates belong to the category of noble metals, and they both exhibit a lattice misfit of ∼13% with respect to the (0 0 0 1) plane of Co. However, whereas the Au(1 1 1) surface reconstructs into the rather complex herringbone structure that disperses the cobalt into nanoclusters, the Ag(1 1 1) surface does not reconstruct in its clean state, and the surface dispersion of Co on this surface is therefore different. For Ag(1 1 1) at temperatures ranging from 160 to 200 K and for Au(1 1 1) at room temperature, the Co growth is three-dimensional starting with double layer islands followed by additional single layers. For both the Co/Au(1 1 1) and the Co/Ag(1 1 1) system, a Moiré pattern develops in the first bilayer of the Co islands, indicating an epitaxial but not commensurate growth. For Co islands with more than two layers, the subsequent layers are commensurate with the lower Co layers in the islands, but exhibit a decreasing corrugation of the Moiré pattern as observed in STM images. Despite a difference in the Moiré lattice constant and rotational angle, we show that the cobalt lattice constant is the same on both surfaces. We furthermore relate defect nucleation on the herringbone reconstruction on Au(1 1 1) to defect nucleation on steps on Ag(1 1 1). 相似文献
947.
应用分子动力学模拟方法研究了液相水中水分子O-H弯曲振动能量弛豫的机理. 采用刚性和柔性溶剂模型来探讨振动能量弛豫的不同通道. 研究发现,刚性溶剂中O?H弯曲振动泛频的弛豫时间为174 fs而柔性溶剂中为115 fs. O-H 弯曲振动泛频振动能量弛豫的主要途径是跃迁O?H 弯曲振动基频. O-H弯曲振动基频的弛豫时间为204 fs,与实验值170 fs符合得较好. 相似文献
948.
Martin P. Barnes 《Journal of Molecular Spectroscopy》2007,241(2):200-219
The long wavelength end of the electronic spectrum of CuCl2, between 636 and 660 nm, has been recorded in the gas phase by laser-excitation spectroscopy using a sample prepared at low temperatures (ca. 10 K) in a free-jet expansion. Under these conditions, it is possible to resolve vibrational, rotational, and even Cu hyperfine structure. The (0, 0) band of the E2Πu-X2Πg transition has been identified with an origin at 15546.286(3) cm−1 for 63Cu35Cl2. The observation and analysis of bands involving vibrationally excited levels has allowed the determination of all three vibrational intervals for the E2Πu state (ν1 = 335.88 cm−1, ν2 = 112.42 cm−1, and ν3 = 482.17 cm−1, 63Cu35Cl2). In addition, two other, unrelated transitions have been identified in the same narrow wavelength region. This, combined with the observation of local perturbations of the rotational structure in various bands, reveals the presence of other closely lying electronic states in the same energy region. 相似文献
949.
The ammonia ν1 + 2ν4 perpendicular stretch-bend combination band has been investigated in spectra of 14NH3 and 15NH3 recorded in the 6400-6800 cm−1 region with an external cavity tunable diode laser (ECTDL) spectrometer. For 14NH3, new assignments were determined initially by extrapolating from published low-J jet-cooled beam results up to transitions of higher J and K. Corresponding ν1 + 2ν4 transitions for the 15NH3 species were then found by identifying similar patterns of lines with a characteristic downshift of approximately 9.7 cm−1. Assignments were confirmed employing ground-state combination differences. Term values, a-s inversion splittings, l-doubling energies and parameter estimates from simple single-state fits are reported for the two ammonia species. 相似文献
950.
Y. Pavlyukh W. Hübner 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(2):239-246
We present a method for the numerical investigation of the electron dynamics in small metallic clusters in intense laser fields.
We obtain information about collective excitations and relaxation processes in the Na
9
+
and Pt3 clusters analyzing the power spectrum of the dipole moment within a mean-field approach. The power spectrum is computed for
various laser pulse parameters as well as for the limit of an infinitely short laser pulse. Due to the basis set expansion
of the wave function our method is capable to follow the dynamics not only of the whole electron cloud, but of any particular
molecular orbital.
Received 28 March 2002 / Received in final form 31 May 2002 Published online 24 September 2002
RID="a"
ID="a"e-mail: pavlyukh@mpi-halle.de 相似文献