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61.
The fine and hyperfine structure of 14N2+ has been observed in 31 rotational lines of the (0, 1) band of the B2Σu+-X2Σg+ system using the method of Doppler-tuned laser-induced fluorescence on a molecular ion beam. The spin-rotation constants (γ′, γ″, γ′J) are in good agreement with other experiments in which the hyperfine structure was not resolved. The Fermi-contact (b′F, b″F) and dipolar (t′, t″) hyperfine coupling constants are in reasonably good agreement with values calculated from ab initio wavefunctions. The least-squares experimental values in MHz are γ″ = 279.1(6), γ′ = 726.4(6), γ′J = ?0.0460(2), b″F = 105(4), b′F = 708(3), t″ = 49(6), and t′ = 26(5). 相似文献
62.
Neutron reflection spectroscopy has been used to characterise the composition of interfaces between liquid Sn-Ti alloys and Al2O3. The reflectivity profiles for both 1% and 3% Ti alloys are consistent with the presence of a layer approximately 2 nm thick at the liquid/solid interface, showing extensive segregation of Ti. The composition of this layer is not pure Ti but shows a greater Ti content than any known Ti oxide composition. In all interfaces exposed to liquid metals at elevated temperature (including pure Sn) there is a layer of thickness 20–100 nm on the alumina surface with slightly lower neutron scattering length density than pure alumina. This is interpreted as evidence for surface roughening of the Al2O3 surface during exposure to the liquid metal. 相似文献
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66.
The reactions have been studied by a mass-balance method involving the photolysis of small amounts of biacetyl in the presence of a large excess of isobutane containing a small proportion of the unsaturated substrate. The following Arrhenius parameters have been derived:
The results for methyl addition to ethylene are based on previous determinations by other techniques as well as the present studies. The results for methyl addition to acetylene and benzene are derived solely from the present experiments and are calculated relative to a rate constant of log k2(l./mol·sec) = 7.42 - (7.1/θ) for the reference reaction (2), ·H3 + (CH3)3CH → CH4 + ·4H9. 相似文献
Temperature | |||
---|---|---|---|
E | log A | range | |
Reaction | (kcal/mol) | (1./mol·sec) | (°K) |
?H3 + C2H4 → ?3H7 | 7.3 ± 1.0 | 8.32 ± 0.5 | 350 – 500 |
?H3 + C2H2 → ?3H5 | 7.7 ± 1.5 | 8.79 ± 0.8 | 379 – 487 |
?H3 + C6H6 → C7H9 | 7.6 ± 1.0 | 8.79 ± 0.5 | 372 – 484 |
67.
The angular dependence of the EPR linewidth in the paramagnetic region for CsMnCl3 is accurately represented by A(1+cos2θ) + B in accord with conventional exchange narrowing theory but the spin fluctuations in this material are not in the short correlation time limit. 相似文献
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A heated rhenium wire is an effective catalyst for the decomposition of methanol at low pressures, the mass-spectrometrically recorded products of decomposition being carbon monoxide and hydrogen. When newly cleaned, more than 30% of c led to decomposition, for filament temperatures between 900 and 1300 K. Under steady-state conditions, or when the filament was pre-saturated with oxygen, the temperature dependence of catalytic activity was significantly differe though the maximum efficiency was still as much as 20% at 900 K. 相似文献
70.
The single crystal spectra of pure CsNiCl3, CsNiBr3, RbNiCl3, and [(CH3)4]NiCl3, and the single crystal spectrum of CsNiCl3 diluted in CsMgCl3 have been measured to 5°K. The spectra of the magnetically concentrated materials show a number of anomalously intense maxima. These are interpreted in terms of cooperative interactions. 相似文献