Raman light scattering in [(NH$_{4}$)$_{1-x}$K$_{x}$]$_{2}$SO$_{4}$, [(NH$_{4}$)$_{1-x}$Rb$_{x}$]$_{2}$SO$_{4}$, [(NH$_{4}$)$_{1-x}$Cs$_{x}$]$_{2}$SO$_{4}$ crystals
Raman light scattering in [(NH$_{4}$)$_{1-x}$K$_{x}$]$_{2}$SO$_{4}$, [(NH$_{4}$)$_{1-x}$Rb$_{x}$]$_{2}$SO$_{4}$, [(NH$_{4}$)$_{1-x}$Cs$_{x}$]$_{2}$SO$_{4}$ crystals
L.P. Avakyants, V.P. Burtseva, D.F. Kiselev, E.D. Obraztsova
The Raman scattering spectra in crystals of the ammonium-sulfate family are investigated. In the external-vibration spectra of the [(NH$_{4}$)$_{1-x}$Rb$_x$]$_{2}$SO$_{4}$ and (NH$_4$)$_2$SO$_4$ at room temperature, two vibrations of symmetry A are seen; their frequency depends linearly on the ionic radius of the cation and monotonically on its mass ($\approx$1/$\sqrt{M}$). A dependence of the internal vibration frequency $\nu _{1}$ of the SO$_{4}^{-2}$ group on the type of cation is observed.
Show AbstractQuenching of excited states of fluorescein dye molecules by external heavy atoms
Quenching of excited states of fluorescein dye molecules by external heavy atoms
L.V. Levshin, L.K. Sokolova, G.A. Ketsle, V.V. Bryukhanov
The deactivation of triplet states of the dyes eosin and erythrosine in the presence of external heavy atoms (EHA) of iodine (the salt KI) is studied by the method of pulsed lamp excitation of the luminescence and triplet-triplet absorption of aqueous solutions of these dyes. It is found that, in conditions of constant concentration of the triplet dye molecules, the influence of EHA results in ignition of slow fluorescence of type E due to intensification of the rate of intercombinational transition of the molecules to the singlet excited state.
Show AbstractPropagation of a light pulse in a semiconductor
Propagation of a light pulse in a semiconductor
T.M. Il'inova, T.V. Ishchenko, I.M. Sorokina
The self-consistent problem of incoherent photoexcitation of a straight-band nondegenerate intrinsic self-conductor is considered in the limiting cases of slow and fast electron-electron relaxation. A dependence of the concentration of free charge carriers on the pumping energy is obtained. The absorption of the pulse propagating in the semiconductor is studied.
Show AbstractTime-of-flight effects in crystals of reduced titanium dioxide in the presence of space-charge-limited currents
Time-of-flight effects in crystals of reduced titanium dioxide in the presence of space-charge-limited currents
V.L. Kashintseva, G.I. Ovchinnikova, A.B. Snedkov
Effects associated with the time of flight of charge carriers through the crystal volume in rutile-based materials in the presence of carrier injection from the contacts and of space-charge-limited currents are observed. Measuring the time of flight of injected charge carriers allows the microscopic mobility of the charge carriers in single crystals of reduced rutile to be determined.
Show AbstractAccuracy of the moments of the angular distribution of electron-photon cascades
Accuracy of the moments of the angular distribution of electron-photon cascades
I.P. Ivanenko, V.V. Sizov
For the example of angular moments, the sensitivity of the angular characteristics of electron-photon cascades to details of the description of elementary interactions is investigated. The physical accuracy of models widely used to describe Rutherford scattering is studied: the Landau and small-angle approximations, and the case when screening and the finite nuclear dimensions are taken approximately into account. Specific calculations are made for the mean cosine and the mean-square angle for electrons and photons in air and lead.
Show AbstractExperiment on the nuclear composition and energy spectra of solar cosmic rays on the Prognoz-9 spacecraft
Experiment on the nuclear composition and energy spectra of solar cosmic rays on the Prognoz-9 spacecraft
S.A. Belyakov, Ju.P. Gordeev, Yu.I. Denisov, G.Ya. Kolesov, A.N. Podorol'skii, B.A. Nikitin
An instrument with semiconductor telescopes is described; the basic factors determining its resolving power are considered; experimental data characterizing the operation of the instrument on a spacecraft are given.
Show AbstractSolution of the Helmholtz equation in a strip with piecewise-constant non-self-conjugate boundary conditions
Solution of the Helmholtz equation in a strip with piecewise-constant non-self-conjugate boundary conditions
V.P. Modenov
A scheme for the orthogonal Galerkin method is constructed on the basis of generalization of the partial-region method to a complex space with a pseudoscalar product. This scheme is applicable to the solution of the boundary problem for the Helmholtz equation in a strip with piecewise-constant non-self-conjugate boundary conditions of impedance type.
Show AbstractAccuracy and reliability of experimental interpretation
Accuracy and reliability of experimental interpretation
Yu.P. Pyt'ev
The accuracy of experimental interpretation is determined by the model of the measurement scheme adopted and so does not allow the experimental results to be fully characterized if the reliability of the model is unknown. The concept of the reliability of the model is defined and analyzed in the present work as the minimum probability of erroneous rejection of the model on the basis of measurement results in some set of alternatives.
Show AbstractAsymptotic investigation of the rapid growth in the second moment of a magnetic field in a mirror-symmetric flow
Asymptotic investigation of the rapid growth in the second moment of a magnetic field in a mirror-symmetric flow
O.V. Artamonova, D.D. Sokolov
An asymptotic solution of the Kazantsev equation is constructed in the limit of high magnetic Reynolds numbers; the rate of growth in the energy, the excitation threshold, and the structure of the magnetic-field correlation function are calculated, and compared with the results of numerical integration of the Kazantsev equation.
Show AbstractRelativistic spectrum of a two-meson bound state in scalar electrodynamics
Relativistic spectrum of a two-meson bound state in scalar electrodynamics
A.P. Martynenko, R.N. Faustov
Within the framework of scalar electrodynamics, the construction of an interaction operator of two scalar particles is considered for the local quasi-potential equation obtained by the "rationalization" method from the Logunov-Tavkhelidze equation. The relativistic spectrum of a two-meson bound state is calculated with an accuracy of $\alpha^{4}$.
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