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We report the results of theoretical studies of radiative processes involving heteronuclear rare gas ions formed in low-temperature plasmas of noble gas mixtures. The continuous absorption of light by such molecular and quasimolecular ions occurs as a result of a number of nonadiabatic bound–bound, bound–free, free–free, and free–bound transitions between their ground and excited electronic terms. The main emphasis in the work is put on the development of a self-consistent semiclassical theory of such processes, taking into account the contributions of all rovibrational levels and continuum states of such ions. Our approach is based on the theory of nonadiabatic transitions between potential energy curves of diatomic molecules combined with the approximation of a quasicontinuum for their rovibrational levels. Nonadiabatic free–free and free–bound transitions in asymmetric collisions of heavy rare gas atomic ions with atoms of a buffer rare gas are described in a similar way. We use analytical formulas derived in this work to carry out calculations of the continuous absorption processes involving ArXe+ and KrXe+ ions with sufficiently low and moderate dissociation energies ( D 0 ArXe + = 184 meV and D 0 KrXe + = 396 meV). The competition of different reaction channels in the total absorption coefficient is discussed. The results obtained demonstrate importance of studied radiative processes in the formation of continuous absorption of electromagnetic radiation in plasmas of noble gas mixtures. [ABSTRACT FROM AUTHOR]

We investigate a new modeling way for describing the continuous absorption of electromagnetic radiation in a dense partially ionized hydrogen plasma with electron densities 5·1018-1.5·1019 cm-3 and temperatures 16 000–25 000 K, in the wavelength range 300–500 nm. The results can be applied to the plasma of partially ionized layers of stellar atmospheres.

The complexation of Li+ and Na+ cations by three bis(oxaalkyl) sulphates(IV) was studied by FTIR and NMR on 1H, 13C, 7Li and 23Na nuclei. The NMR results have proved the formation of complexes and the fluctuation of Li+ and Na+ cations in respective circular arrangements. In the FTIR spectra of protonated sulphates intense continuous absorptions were observed indicating fast fluctuation of the protons in the respective multiminima potentials. The continuous absorptions in the far infrared region of the FTIR spectra of Li+ or Na+ complexes with three bis(oxaalkyl) sulphates(IV) indicate fast fluctuations of Li+ or Na+ cations between O-atoms of the oxaalkyl chains. The independence of the shape of the continua on the length of the oxaalkyl chains, i. e. the number of minima in the multiminima potential, demonstrates that the fluctuation of cations occurs in the respective circular arrangements. [Copyright &y& Elsevier]