Luminescence properties of nanoparticles synthesized in electric discharge in liquid under ultrasonic cavitation

The differences in the luminescence intensity of metal oxide nanoparticles synthesized in electric discharges in liquidmedia under intense ultrasonic vibrations in the absence and presence of cavitation are studied.     

Two Electron States in a Quantum Ring on a Sphere

Two electron states in a quantum ring on a spherical surface are discussed. The problem is discussed within the frameworks of Russell–Saunders coupling scheme, that is, the spin–orbit coupling is neglected. Treating Coulomb interaction as a perturbation, the energy correction for different states is calculated. The dependence of the Coulomb interaction energy on external polar boundary angle of quantum ring is obtained. In analogue with the helium atom the concept of states exchange time is introduced, and its dependence on geometrical parameters of the ring is shown.     

Spin magnetic moment current of impurity electron in a spherical quantum dot

Current of the spin magnetic moment of an electron coupled with hydrogen-like impurity, placed in the center of a spherical quantum dot, is studied. Confinement potential of the quantum dot is approximated by rectangular infinitely high walls. S-states of electron for both positive and negative values of total energy are considered. Dependences of spin magnetic moment current of electron on the radial variable for different values of dot radius are obtained. It is shown that for quantum dots with large radius, due to weakening of size-quantization effect, corresponding curves approach each other.     

Optical transitions in parabolic quantum dot

Direct optical absorption of light is theoretically investigated in a spherical quantum dot from GaAs. The confinement potential of the dot is approximated as parabolic. Three regimes of size quantization are discussed: weak, strong, and intermediate. The corresponding threshold frequencies of absorption are determined. A comparison with the case of a spherical quantum dot with rectangular infinitely high confinement potential is performed.     

Investigations in the area of functionally substituted azines. 5.* Reactions of azines with nucleophiles and hydrogen chloride

It was shown that oxazolopyrimidinium and sym-triazinium chlorides give N₍₃₎-(2-Y-ethyl)-substituted azines with nucleophiles. Oxazolo-sym-triazine also reacts analogously, being converted by hydrogen chloride to the N₍₃₎-(2-chloroethyl) derivative.Armenian Agricultural Academy, Yerevan, 375009. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1417–1420, October, 1996. Original article submitted April 15, 1996.     

Electron and hole states in a narrow-band semiconductor InSb film in the presence of uniform electrostatic field

The states of charge carriers in a narrow-gap semiconductor InSb film, placed in a uniform electrostatic field, are considered theoretically. We consider the case when the heavy holes are described by the standard dispersion, and Kane’s dispersion law takes place for electrons and for light holes within the framework of two-band mirror model. For a certain range of values of the external field, explicit expressions for the energy spectrum and the envelope wave functions of charge carriers are obtained. Corresponding numerical estimations of allowed range of the external field are derived, for which the proposed approach allows exact analytical solutions.     

Magnetoexcitonic states in a quantum ring with the Winternitz-Smorodinsky confinement potential

We investigate magnetoexcitonic states in the Ga_{1−x 1}Al_{x 1}As/GaAs/Ga_{1−x 2}Al_{x 2} As quantum ring with the Winternitz-Smorodinsky confinement potential. A homogeneous magnetic field is directed perpendicularly to the ring plane. The Coulomb interaction between the electron and hole is assumed as weak and is considered in the framework of perturbation theory. Obtained results show that the more realistic Winternitz-Smorodinsky confinement potential, which takes into account a peculiar smoothing of the confinement potential profile, leads to raising of the electron energy levels as compared to the case of a finite-height rectangular confinement potential.