Issue 1, 1985
Simulating charged-particle fluxes along the paths of space probes in the Earth's radiation belts
Simulating charged-particle fluxes along the paths of space probes in the Earth's radiation belts
O.I. Savun, B.Yu. Yushkov
A method is considered for using a computer to derive the omnidirectional electron and proton fluxes from the initial data set for a wide class of space-probe paths in the Earth's radiation belts over the energy range from 0.1 to 400 MeV for protons and from 40 keV to 4 MeV for electrons; allowance is made for the phase of the solar cycle. Integral proton and electron spectra may be derived for the days of flight, which can be used in calculating absorbed radiation doses behind various forms of shielding in a given orbit. Data are given on the electron fluxes at low levels.
Show AbstractEffects of adsorption on the absorption spectra of solutions of polyatomic organic compounds
Effects of adsorption on the absorption spectra of solutions of polyatomic organic compounds
L.Yu. Gorbunova, B.D. Ryzhikov, N.R. Senatorova
Aqueous solutions of rnodamine 6G have been used to show that one can determine the spectra of dyes and other polyatomic organic compounds correctly only if allowance is made for adsorption at the surface of the solution. The criterion is given for making the corresponding corrections and a method for compensating for surface effects.
Show AbstractSynthesis of multilayer optical coatings with allowance for dispersion and absorption
Synthesis of multilayer optical coatings with allowance for dispersion and absorption
N.V. Grishina, A.V. Tikhonravov
A variational formula is used in the synthesis of multilayer optical coatings with allowance for dispersion and absorption. A study is made of the influence of these factors on the synthesis and on the spectral parameters of the synthesized systems.
Show AbstractThe selective action of xenon on the violet cyan system spectrum
The selective action of xenon on the violet cyan system spectrum
I.S. Lakoba, P.M. Lozovskii, S.P. Chernov, P.B. Essel'bakh
Emission spectra have been recorded from a plasma produced by a fast discharge in the vapors of $CH_3CN$, $BrCN$, and $C_2N_2$ and mixtures of these with He, Ne, Kr, and Xe. It is found that the xenon produces a substantial change in the intensity distribution in the violet cyan bands, which are altered in structure. The effect is interpreted on the assumption of the formation of (XeCN)* complexes, which are formed because of intersection between the bound and repulsive potential surfaces in the Xe-C-N system.
Show AbstractSeparating the Earth's shell into mineral fractions
Separating the Earth's shell into mineral fractions
M.V. Avdulov
A physical model is examined for the separation of the Earth's shell into mineral fractions at a temperature below the rock solidus temperature. The model is based on concepts of approach between crystals pulsating during polymorphic transitions during periodic temperature changes. Equations are given for the kinetics of the crystal motion under Bjorknes forces. The physical nature of the periodic temperature changes is considered.
Show AbstractNumerical solution of free-boundary problems in Josephson-junction theory
Numerical solution of free-boundary problems in Josephson-junction theory
P.N. Babishchevich, S.A. Vasenko, V.K. Semenov
A numerical method has oeen devised for solving nonlinear problems involving free boundaries that occur in the theoretical consideration of large Josephson junctions. The effective numerical algorithm has been based on the penalty method. The numerical solution to the initial nonlinear problem is compared with the exact solution for the case of axial symmetry, where the analytic solution is known.
Show AbstractQuantum statistics and temperature effects in the theory of the interactions of fermions with torsion
Quantum statistics and temperature effects in the theory of the interactions of fermions with torsion
A.A. Gvozdev, P.I. Pronin
An immediate extension of Einstein's theory (the Einstein-Cartan theory) is used for the case of only spinor torsion-field sources to examine finite-temperature effects in the interaction of torsion with fermions.
Show AbstractParametric spin-wave excitation in a fine-grained polycrystalline garnet
Parametric spin-wave excitation in a fine-grained polycrystalline garnet
E.V. Lebedeva, M.K. Rodionova, N.S. Sedletskaya, M.A. Kharinskaya
A study has been made of the effects of the inherent losses $\Delta H_{k_{in}}$ in the anisotropy field and of the pumping frequency on the dependence of the spin-wave excitation threshold on the grain size $l$ for substituted yttrium-aluminum garnets. It is shown that the minimum threshold is proportional to $\sqrt{\Delta H_{k_{in}}^2+(A/l)^2}$ where A is the parameter dependent on the material and pumping frequency. The effects of the grain size on the threshold increase as the pumping frequency decreases. As the anisotropy field decreases, one finds an appreciable effect of the grain size on the threshold only for $l\le 2$ $\mu$m.
Show AbstractEffects of reverse transfer from traps on luminescence quantum yields
Effects of reverse transfer from traps on luminescence quantum yields
P.V. Elyutin, M.L. Isakova
Energy migration is examined in a disordered system of donor and acceptor molecules with allowance for the probability of reverse transfer from the acceptor to the donor. It is shown that this transfer may lead to a nonmonotone dependence of the quantum yield on the donor concentration.
Show AbstractA method of simulating nonlinear flow incorporating velocity shear and compressibility
A method of simulating nonlinear flow incorporating velocity shear and compressibility
V.N. Kozhevnikov, L.E. Rontu (Finland)
A new method is given for transforming the initial nonlinear equations for the two-dimensional stationary case of altitude stratification in the atmosphere, where a slight simplification in the equation of continuity enables one to derive interesting particular cases where the flow treatment amounts exactly to solving a linear equation for the streamline function. A study is made to see how well one can incorporate the altitude profiles for the stability and velocity. The approach is compared with previous ones.
Show AbstractChoice of molecular center in calculating the thermodynamic parameters of liquids and gases
Choice of molecular center in calculating the thermodynamic parameters of liquids and gases
A.D. Okhotsimskii, V.G. Gryaznov
The center of an unsymmetrical rigid molecule may be taken as the point in it at which the molecular interaction potential is closest to being of central type. A simple method has been devised for calculating the coordinates of this center. This method has been used in calculating liquid critical volumes.
Show AbstractStochastic oscillations in a two-temperature electron-hole plasma in a semiconductor
Stochastic oscillations in a two-temperature electron-hole plasma in a semiconductor
V.L. Bonch-Bruevich, Le Vu Ki (Vietnam)
A study is made of nonstationary states in an electron-hole plasma produced by optical absorption in a semiconductor with direct transitions. Allowance is made for recombination mechanisms involving phonon and/or radiative transitions as well as collisional ones (interband ones); the adiabatic approximation (slow recombination) is not used. Explicit conditions are derived for self-excited oscillations in the carrier concentration and in the electron and hole temperatures.
Show AbstractShock-wave propagation in a gas mixture
Shock-wave propagation in a gas mixture
F.V. Shugaev, A.E. Kondrashov, E.N. Fomenko
A study is made on the spatial interaction of an initially planar shock wave with acoustic and entropy perturbations in a perfect gas thermodynamically in equilibrium. Experiments nave been performed on shock-wave transmission by a gas mixture having a concentration gradient in a shock tube. It is observed that a vortex is formed behind the reflected wave.
Show AbstractRight-left asymmetry in the elastic scattering of polarized electrons at nuclei with allowance for the second Born approximation
Right-left asymmetry in the elastic scattering of polarized electrons at nuclei with allowance for the second Born approximation
B.K. Kerimov, V.N. Alizade, M.Ya. Safin
A study has been made on the second Born approximation for the cross section and the right-left asymmetry $A_{RL}$ for elastic scattering of longitudinally polarized electrons by zero-spin nuclei. An analytic expression is obtained for this correction in the case of the $lp$-shell nuclei, whose form factors are described by the harmonic-oscillator model. A simple expression has also been found for $A_{RL}$ on the basis of the second Born approximation in the case of point nuclei. The angle dependence of $A_{RL}$ has been studied by reference to $^{12}C$.
Show AbstractPolarized luminescence in polydisperse system analysis
Polarized luminescence in polydisperse system analysis
R.Z. Syunyaev, L.V. Levshin, B.D. Ryzhikov
The Levshin-Perrin formula has been modified for the case of a polydisperse system in which the particles of the dispersed phase can luminesce. The size distribution is considered as a Volmer one, which contains an unknown parameter n. A formula is derived, from which calculations are made on the accessory quantity S for various n. Comparison with the S derived from experiment enables one to determine n in the distribution.
Show AbstractThe electronic absorption spectra of polyatomic molecules in liquid solvents
The electronic absorption spectra of polyatomic molecules in liquid solvents
V.M. Boitsov, V.I. Yuzhakov
A description is given of the vibronic absorption spectra of liquid solutions of polyatomic compounds, which enables one to determine the dependence of the half-width for the homogeneous (relaxation) Lorentz component $\Gamma (\nu_s)$ on the transition frequency and the same for the square of the electronic matrix element for the transition dipole moment $|\mu (\nu_s)|^2$. It is shown that these functions are solutions to the proposed equation system; they have been determined for the absorption spectra of acetone in various solvents at T = 297 K.
Show AbstractIon-sound response in pulsed plasma probing
Ion-sound response in pulsed plasma probing
Yu.V. Korpusova, A.A. Kuzovnikov, K.G. Pukalov, V.S. Sviridkina, A.K. Sukhov, V.V. Tarasova
Experiments have been performed on ion-sound instability produced by voltage pulses and the effects on the propagation from plasma density inhomogeneity. It is found that the amplitude of the perturbations increases away from the source, while the perturbations acquire an oscillatory structure. If the plasma density is reduced to the level at which the ionic Langmuir frequency becomes comparable with the ion-sound frequency, it is found that the ion sound is not transmitted.
Show AbstractDetermining free-field bounds and acoustic type for a sound source
Determining free-field bounds and acoustic type for a sound source
A.N. Ivannikov, D.I. Kravchenko
A description is given of an apparatus and of certification results on a sound chamber in relation to the sound-field phase structure. Results are also given on the phase structure of the near fields from sound sources
Show AbstractElectron-beam bifurcation in the field of an open cavity
Electron-beam bifurcation in the field of an open cavity
Yu.K. Alekseev, A.I. Kostienko
Current density modulation has been examined for a broad strip beam in the field of an open cavity. An expression has been obtained for the spectrum of the convection current at the output from the modulator with allowance for the beam bifurcation in the standing-wave field. Averaging the harmonic amplitudes over the beam cross section shows that the bifurcation only slightly reduces the mean energy stored in the beam at the modulating frequency.
Show AbstractThe ratio of the external and internal perimeters of a percolation cluster
The ratio of the external and internal perimeters of a percolation cluster
I.M. Sokolov
The topological features of percolation clusters are used with similarity arguments to derive an asymptotic dependence of the ratio of the external and internal perimeters for a very large finite cluster on the diameter.
Show AbstractReduced efficiency in induced Raman scattering excitation in a cavity under conditions of induced Mandelshtam-Brillouin mode interaction
Reduced efficiency in induced Raman scattering excitation in a cavity under conditions of induced Mandelshtam-Brillouin mode interaction
O.M. Vokhnik, I.V. Zykanova, V.I. Odintsov, L.P. Rogacheva
It has been shown from theory and experiment that induced Mandelshtam-Brillouin longitudinal-mode interaction in the cavity involved in induced Raman scattering excitation may lead to a considerable reduction in the pumping conversion factor and to increase in the Raman scattering line width.
Show AbstractEffects of radiation defects due to the $(n, \gamma)$ reaction on the hyperfine interaction of $^{181}Ta$ in $YFe_2$
Effects of radiation defects due to the $(n, \gamma)$ reaction on the hyperfine interaction of $^{181}Ta$ in $YFe_2$
M.D. Bondar'kov, M. Budzinski, A.A. Sorokin, L.G. Shpin'kova
Measurements have been made by the perturbed angular $\gamma \gamma$ correlation method, which have shown that the magnetic fields at the $^{181}Ta$ a nuclei at regular nodes in the Y sublattice differ from those at the defective positions produced by $(n, \gamma)$ reaction not only in magnitude but also in sign: $H_{reg}$ = -14,4 T, $H_{def}$ = + 62 T.
Show AbstractPicosecond laser spectroscopy applied to the unrelaxed ground states of luminescence centers with large Stokes losses
Picosecond laser spectroscopy applied to the unrelaxed ground states of luminescence centers with large Stokes losses
V.N. Salomatov, S.N. Mysovskii
A study is made of the scope for examining the unrelaxed ground state of a luminescence center with high Stokes loss on increasing the population of that state by means of amplified light pulses acting on the crystal in synchronism with test ones.
Show AbstractEffects of an electric field on the photoelectric parameters of a-Si:H
Effects of an electric field on the photoelectric parameters of a-Si:H
I.A. Kurova, N.N. Ormont
Measurements have been made on the temperature dependence of the stationary band-band photoconductivity, the lux-ampere characteristic LAC, and the voltage-current characteristic (VCC) for a-Si:H films in electric fields of up to $2\cdot 10^4 V\cdot cm^{-1}$. In weak fields, there is thermal photoconductivity quenching, and the LAC becomes superlinear in the quenching region. It is found that an electric field can suppress the thermal quenching of the stationary band-band photoconductivity and the superlinearity in the LAC.
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