Characteristic Features of Photoluminescence of the Opal–Tellurite Glass–Er3+ Nanocomposite

We carried out a comparative investigation of the photoluminescence of Er³⁺ ions in tellurite glasses on melted quartz substrates and when introduced into the matrices of artificial opal. We have discovered an increase in the photoluminescence of the opal–tellurite glass–Er³⁺ nanocomposite in comparison with the specimens of the same glass on melted quartz substrates.     

On two-sided estimates of the particle scattering amplitude by a potential and the amplitudes of multichannel processes

Functions permitting two-sided estimates to be obtained for the real and imaginary parts of the particle scattering amplitude by a nonspherical potential and for the amplitudes of multichannel processes are considered. To diminish the interval between the two estimates it is proposed to use Schwinger iteration of the test functions, whose multiparticle generalization permits estimation of the error in the approximation of P-coupled channels and the approximate assignment of the wave functions and the energy of the internal motion.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 16, No. 7, pp. 78–83, July, 1973.The author is deeply grateful to his colleagues m the Theoretical Physics Laboratory of the Joint Institute of Nuclear Research, Lkhagva Oido-Vyn' and Doctor B. N. Zakhar'ev, for formulating the problem and for useful comments which made this research realizable.     

Mathematical analogies in the theory of flat spherical shells and plates with allowance for transverse shears

The refined equations for flat spherical monotropic shells and plates are solved with the aid of mathematical analogies in the case of local loads and local heating. The analogous equations are solved for problems of stability, vibration and stress concentration in the presence of a circular opening.Chebotarev Scientific-Research Institute of Mathematics and Mechanics, Ul'yanov-Lenin Kazan State University. Translated from Mekhanika Polimerov, No. 2, pp. 338–345, March–April, 1972.     

Adsorption and mobility of molecules of water and organic compounds in carbon adsorbents

The mobility of molecules of water and fluorine-containing organic compounds adsorbed in a mixture on active carbons has been studied by the NMR pulsed field gradient technique (¹H and¹⁹F resonances). Samples with various H₂O/C₆F₆ and H₂O/C₂Cl₃F₃ ratios have been examined. The mobility of components at total fill factors > 0.8 has been shown to decrease in comparison with the adsorption of pure substances while the diffusion activation energy increases. The results are interpreted on the basis of adsorption mechanisms of water and organic compounds on active carbons.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 56–61, January, 1993.In conclusion the authors would like to express their thanks to the German Research Society for the financial support of this work.     

Adsorption on nonporous and supermicroporous adsorbents

The mean values of the characteristic energy of C₆H₆ adsorption in large micropores were calculated from the adsorption isotherms of benzene vapor on carbon blacks. The supermicropores are characterized by the significant dispersion of the adsorption potential resulted from the pore-size distribution, which imparts the polymolecular character to adsorption. The effect of enhancement of the characteristic energy of adsorption was analyzed, which was caused by the overlap of the force fields of the opposite pore walls and the reduction of the adsorption film surface with micropore volume filling. The both factors are comparable by magnitude and depend on the micropore sizes.