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101.
The Raman spectra of intercalated 1TTaS2 and 2HTaSe2 have been measured for the first time. Normal symmetry allowed optic phonons and charge density wave induced modes are observed in both systems. The spectra of the ethylenediamine intercalated compounds are qualitatively similar to those of the pure materials with small quantitative shifts in frequency and changes in the relative intensities of the CDW induced modes. The qualitative similarities in the spectra of the pure and the intercalated compounds reflect the two dimensional character of these materials and show that the dynamic properties of the charge density wave states are largely determined by intralayer effects. 相似文献
102.
103.
E. Tsang K. Baberschke J. Kästner B. J. Beaudry 《Zeitschrift für Physik B Condensed Matter》1980,38(3):235-242
A logarithmical decrease in the resistivity below 10 K has been observed for 200 to 5,000 ppm Gd in Y and Sc. The decrease scales with the Gd concentration. The results are in line with previously published data forLu: Gd and LaAl2: Gd, they are discussed in terms of a ferromagnetic (J>0) Kondoeffect. The scaling parameterT
K
, and the extracted effective change interactionJ
eff
are compared with other experimental results. In addition the negative magnetoresistance (the freezing out of spin-disorder scattering) has been measured up to 50 kG. Possible interference of potential and exchange scattering may have been observed in the magnetoresistance.Supported by special research fund Sfb 161 of the Deutsche Forschungsgemeinschaft 相似文献
104.
Wing Tsang 《国际化学动力学杂志》1978,10(7):687-711
4-Methylhexyne-1, 5-methylhexyne-1, hexyne-1, and 6-methylheptyne-2 have been decomposed in comparative-rate single-pulse shock-tube experiments. Rate expressions for the initial decomposition reactions at 1100°K and from 2 to 6 atm pressure are In combination with previous results, rate expressions for propargyl C? C bond cleavage are related to that for the alkanes by the expression These results yield a propargyl resonance energy of D(nC3H7-H) – D(C3H3-H) = 36 ± 2 kJ, in excellent agreement with a previous shock-tube study. They also lead to D(CH3C≡CCH2-H) – D(C3H3-H) = 0.6 ± 3 kJ, D(sC4H9-H) – D(iC3H7-H) = 0 ± 3 kJ, D(iC4H9-H) – D(nC3H7-H) = 2 ± 3 kJ, and D(nC3H7-H) – D(iC3H7-H) = 13.9 ± 3 kJ (all values are for 300°K). The systematics of the molecular decomposition process are explored. 相似文献
105.
T. Tsang 《Physica A》1979,96(3):359-368
The relative motions of particles in a simple liquid may be described as one-dimensional radial diffusion in an effective potential of the mean force. This effective potential may be obtained by an iteration procedure with the Vineyard approximation as the initial step. Using a harmonic approximation for the potential, the “distinct” part of the Van Hove time-dependent correlation function is then the convolution of a modified radial distribution function with a modified self-correlation function. The former describes the average positions of particles whereas the latter describes the density profile around the average position. For liquid argon, this modified convolution procedure appears to give results in satisfactory agreement with molecular dynamics. 相似文献
106.
We have made a series of Al-Al2O3-benzoic acid-Pb inelastic electron tunneling spectroscopy (IETS) junctions on substrates roughened by varying thicknesses of CaF2. The vibrational peaks due to the molecular monolayer of benzoic acid disappear as the substrates are made rougher. We speculate on the cause of this disappearance. 相似文献
107.
G.J. Coyle T. Tsang I. Adler L. Yin 《Journal of Electron Spectroscopy and Related Phenomena》1980,20(2):169-182
Radiation damage to the surface of transition metal sulfides under ~1-keV ion bombardment has been investigated by photoelectron spectroscopy. Under 相似文献
108.
R. Stan Brown Zhong‐Lin Lu C. Tony Liu Wing Yin Tsang David R. Edwards Alexei A. Neverov 《Journal of Physical Organic Chemistry》2010,23(1):1-15
Phosphodiesters are notoriously hydrolytically inert compounds that are demonstrated to have large accelerations of P‐OR cleavage promoted by transition and lanthanide metal ions in methanol and ethanol media. This review commentary describes recent findings of how a simple mononuclear and a dinuclear Zn(II) complex promote the cleavage of a series of RNA models and DNA models in alcohol media. The discussion centers on the analysis of the mechanisms of cleavage, energetics of the catalytic process, on recent findings of electrophilic assistance of leaving group departure, and the observation of a rapid hydrolytic reaction of a DNA model promoted by the dinuclear Zn(II) complex in ethanol containing less than 2% water. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
109.
A critical advance in the technique of low-energy electron diffraction is presented and shown to enable determining detailed structures of nanomaterials, based on experimental methods that already exist or have been proposed. Our new cluster approach speeds up the computation to scale as n logn, rather than the current n3 or n2, with n the number of atoms, for example. Applications are illustrated for C60 molecules adsorbed on a Cu(111) surface, with and without coadsorbed metal atoms, exhibiting sensitivity to important structural features such as buckyball size and deformation. 相似文献
110.
Famiano MA Liu T Lynch WG Mocko M Rogers AM Tsang MB Wallace MS Charity RJ Komarov S Sarantites DG Sobotka LG Verde G 《Physical review letters》2006,97(5):052701
Recent measurements of preequilibrium neutron and proton transverse emission from (112,124)Sn+(112,124)Sn reactions at 50 MeV/A have been completed at the National Superconducting Cyclotron Laboratory. Free nucleon transverse emission ratios are compared to those of A=3 mirror nuclei. Comparisons are made to Boltzmann-Uehling-Uhlenbeck (BUU) transport calculations and conclusions concerning the density dependence of the asymmetry term of the nuclear equation of state at subnuclear densities are made. Comparison to BUU model predictions indicate a density dependence of the asymmetry energy that is closer to a form in which the asymmetry energy increases as the square root of the density for the density region studied. A coalescent-invariant analysis is introduced as a means of reducing suggested difficulties with cluster emission in total nucleon emission. 相似文献