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Issue 6, 2008

Theoretical and mathematical physics

Latitudinal baromagnetic asymmetry on planets and stars

Latitudinal baromagnetic asymmetry on planets and stars

V.I. Grigor’ev, V.S. Rostovskii

Moscow University Physics Bulletin 2008. 63. N 6. P. 371

It is shown how the latitudinal magnetic asymmetry of celestial bodies can be explained on the basis of baroelectric effect theory

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Geometric interpretation of the tensor of an electromagnetic field with orthogonal components $E$ and $B$

Geometric interpretation of the tensor of an electromagnetic field with orthogonal components $E$ and $B$

M.D. Malykh

Moscow University Physics Bulletin 2008. 63. N 6. P. 374

An electromagnetic field with $(\vec{B},\vec{E})=0$ is interpreted geometrically as associating with each point $(x,y,z,t)$ of the projective line $\mathbb{P}^3$. For this field, the general solution to the first four Maxwell equations, ${\mathop{\mathfrak{Rot}}\nolimits F=0}$, is obtained. The remaining four equations are reduced, in a field with no charges and currents, to a problem which is bound up with the scalar wave equation.

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Physics of nuclei and elementary particles

Resonances of stretched states in open shell nuclei

Resonances of stretched states in open shell nuclei

N.G. Goncharova, V.A. Erokhova, N.D. Pronkina

Moscow University Physics Bulletin 2008. 63. N 6. P. 378

Form factors of $1\hbar\omega$ maximal spin resonances are obtained in the version “particle core coupling” of multiparticle shell model for the nuclei $^{24}$Mg, $^{26}$Mg, $^{28}$Si, $^{40}$Ca, $^{42}$Ca, $^{44}$Ca. Wave functions of excited states are calculated using information on the spectroscopy of direct reactions. Comparison with a cross section of $(e,e')$ reactions showed that the theoretical calculation is in good agreement with existing experimental data. Fragmentation of M6 resonance force in 40Ca into 22 peaks is shown.

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Optics and spectroscopy. Laser physics

Damping mechanism of the relaxation oscillations in a gas mixture fast flow laser

Damping mechanism of the relaxation oscillations in a gas mixture fast flow laser

L.S. Kuz’minskii, Yu.V. Luzhinskaya, A.I. Odintsov, A.I. Fedoseev

Moscow University Physics Bulletin 2008. 63. N 6. P. 383

It is shown that the exchange of perturbations of moving active medium components, such as a CO2-N2 laser working mixture, results in the damping of relaxation oscillations and stabilization of stationary lasing. Analytical expressions for frequencies and increments of relaxation oscillations and their self-excitation threshold are obtained using the characteristics of stationary lasing.

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Broadening of vibrational spectra of carbon dioxide upon absorption and condensation in nanopores

Broadening of vibrational spectra of carbon dioxide upon absorption and condensation in nanopores

V.G. Arakcheev$^1$, V.N. Bagratashvili$^2$, A.A. Valeev$^1$, V.B. Morozov$^1$, A.N. Olenin$^1$, V.K. Popov$^2$, V G. Tunkin$^1$

Moscow University Physics Bulletin 2008. 63. N 6. P. 388

Coherent anti-Stokes Raman Spectroscopy (CARS) has been used to study the vibrational Q-branch with the frequency of 1388 cm$^{-1}$ of the $\nu_{1}$ mode of carbon dioxide molecules filling a sample made of nanopore glass at room temperature (20.5$^о$C). The measurements were carried out in a gas cell at pressures approaching saturation $P_\textbf{sat}$. When pressure was increased above $0.8P_\textbf{sat}$, in addition to the spectral component due to the gaseous phase molecules, the CARS spectra featured a component due to the molecules adsorbed on the pore walls. Simulation of spectra taking the interference of these two contributions into account enabled the estimation of the broadening of the vibrational molecular spectra in the adsorbed layer. The spectral width of the component due to the adsorbed molecules was nearly a factor of two times larger than that of molecules in the bulk liquid phase. At pressures above $0.94P_\textbf{sat}$, the spectral width of the component due to the adsorbed molecules decreased to values close to those measured in the bulk liquid phase, which corresponds to the condensation of molecules in nanopores.

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Condensed matter physics

Crystallographic patterns of the shape memory effect in non-ordered solid solutions

Crystallographic patterns of the shape memory effect in non-ordered solid solutions

A.G. Hundjua, E.A. Brovkina, A.G. Pticyn

Moscow University Physics Bulletin 2008. 63. N 6. P. 393

A method is proposed to estimate the possibility of achieving shape memory effects in martensite alloys with disordered lattices. The analysis of orientational relationships between the lattices of austenite and martensite allows one to detect those which are able to form self-accommodation complexes, an important part of the memory effect mechanism. This method has been applied to the Ti$_{48}$Zr$_{48}$Nb$_{4}$ alloy in which two martensite phases are formed: hexagonal $\alpha'$ and orthorhombic $\alpha''$ martensites.

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Investigation of the frustration between ferroelectricity and antiferroelectricity in smectics

Investigation of the frustration between ferroelectricity and antiferroelectricity in smectics

A.V. Emelyanenko

Moscow University Physics Bulletin 2008. 63. N 6. P. 396

A molecular-statistical theory that describes the smectic phases with frustration between the ferroelectric and antiferroelectric ones has been developed. The molecular model is used to estimate the mean-field parameters responsible for the formation of complex smectic phases with long periods. A general phase diagram is constructed and the helix pitch is estimated in all phases. The results obtained are compared with the experimental ones.

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Biophysics and medical physics

Aspects of the biological effects of low intensity electromagnetic radiation (population aspects)

Aspects of the biological effects of low intensity electromagnetic radiation (population aspects)

M.G. Gapochka

Moscow University Physics Bulletin 2008. 63. N 6. P. 401

The responses of unicellular organisms to the effects of toxic agents and EHF-irradiation exhibit both fundamental differences and similarities. The difference is that the resistance of microalgae to the effects of toxic agents during culture growth and population establishment increases, while resistance to the effects of irradiation decreases. The similarity lies in the fact that the resistance of microalgae to both factors depends on the growth phase and the stage of population development.

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Construction of a molecular model of a fragment of a lipid membrane in the gel and liquid crystalline states

Construction of a molecular model of a fragment of a lipid membrane in the gel and liquid crystalline states

D.V. Zlenko, P.M. Krasil’nikov

Moscow University Physics Bulletin 2008. 63. N 6. P. 405

A model of a lipid membrane in the liquid crystalline and gel states is constructed. The model of the membrane in the liquid crystalline state adequately reproduces the geometric parameters of the membrane, lipid packing, and the mobility parameters of molecules. The model of the membrane in the gel state of the bilayer reproduces the geometric parameters of the real membrane and lipid packing. New methods for calculation of the mobility parameters of phospholipid molecules in the plane of the bilayer are presented.

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Interaction of polymer matrix and bound water in poly(N-vinylcaprolaktam) films

Interaction of polymer matrix and bound water in poly(N-vinylcaprolaktam) films

G.V. Markin, I.A. Malyshkina, N.D. Gavrilova, E.E. Makhaeva, T.E. Grigor’ev

Moscow University Physics Bulletin 2008. 63. N 6. P. 410

Interaction of water molecules and the polymer matrix of poly(N-vinylcaprolaktam) (PVCL), depending on temperature (−100 and 50°C) and water concentration (less than 1, 5 and 24 wt %), was investigated using the dielectric spectroscopy method (at $10^{-1}$-$10^{7}$ Hz). The presence of characteristic temperature points of changes of system properties, whose values depend on the quantity of water molecules in the polymer, was identified. It was found that the mechanism of temperature influence and water concentrations changes the characteristics of hydrogen bonds.

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Astronomy, astrophysics, and cosmology

Classification of celestial bodies within planetary systems

Classification of celestial bodies within planetary systems

I.D. Kotliarov

Moscow University Physics Bulletin 2008. 63. N 6. P. 416

This paper suggests a set of general criteria for classifying celestial bodies that are elements of planetary systems. An additional criterion based on the phenomenological formula of the distribution of planets in the Solar system is suggested for the Solar system for ascertaining whether celestial bodies belong to the category of planets or dwarf planets.

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Theoretical and mathematical physics

Spin-phonon interactions in cuprates

Spin-phonon interactions in cuprates

A.M. Savchenko, M.B. Sadovnikova, O.G. Karchev

Moscow University Physics Bulletin 2008. 63. N 6. P. 420

The parameter $\zeta$ of spin-phonon coupling is obtained through the analysis of the spin-wave dynamics of magnetic systems. It is shown that the parameter of spin-phonon coupling is greater, the greater the relative electron-ion potential $g_1$, the smaller the exchange correlation radius $r_c$, and the smaller the mass $M$ of ions that form a crystalline lattice.

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Exact analytical expression for magnetic field induction of rectangular shape sample

Exact analytical expression for magnetic field induction of rectangular shape sample

D.V. Vagin, T.N. Gerasimenko, P.A. Polyakov

Moscow University Physics Bulletin 2008. 63. N 6. P. 422

An analytical expression for the magnetic field inside and outside of a magnetized rectangular-shaped sample without unphysical singularities on its boundaries is derived.

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Physics of nuclei and elementary particles

The light nuclei energy spectrum of primary cosmic rays using EAS MSU array data

The light nuclei energy spectrum of primary cosmic rays using EAS MSU array data

N.N. Kalmykov, V.N. Kalmykov, G.V. Kulikov, P.V. Sulakov, Yu.A. Fomin

Moscow University Physics Bulletin 2008. 63. N 6. P. 425

The change in the energy spectrum index Δγ in the knee region was determined by means of analysis of extensive air showers (EAS) spectra using the number of the particles measured by the EAS MSU array. The value was equal to $\Delta\gamma=1.00\pm0.12$. A comparison of lightweight nuclei energy spectra collected with different installations was carried out.

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Radiophysics, electronics, acoustics

Disposition density of waveguides on printed circuits

Disposition density of waveguides on printed circuits

O.E. Nanii, E.G. Pavlova

Moscow University Physics Bulletin 2008. 63. N 6. P. 428

The dependencies of the maximum permissible disposition density of waveguides on printed circuits on the contrast value of $\Delta n$ of refractive indices are computed. It has been shown that minimum cross coupling between adjacent waveguides are observed when the dimension of the core is optimal for providing the maximum fundamental mode confinement within the core.

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Optics and spectroscopy. Laser physics

Discrete diffraction in a cascade-induced anisotropic lattice

Discrete diffraction in a cascade-induced anisotropic lattice

O.V. Borovkova, V.E. Lobanov, A.K. Sukhorukova, D.A. Chuprakov, A.P. Sukhorukov

Moscow University Physics Bulletin 2008. 63. N 6. P. 430

The features of anisotropic discrete diffraction in a cascade-induced lattice formed by two crossed pump waves in a quadratically nonlinear medium have been studied. The transition from the diffraction of a signal beam in free space to discrete diffraction with the further capture in a waveguide in a defocusing lattice by the increasing of the pump wave intensity has been traced.

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Chemical physics, physical kinetics, and plasma physics

Ignition of hydrocarbon films under the conditions of surface microwave discharge

Ignition of hydrocarbon films under the conditions of surface microwave discharge

A.F. Aleksandrov, V.M. Shibkov, L.V. Shibkova

Moscow University Physics Bulletin 2008. 63. N 6. P. 433

In the present work, rapid plasma-stimulated ignition of liquid hydrocarbons was carried out in still air under conditions of surface microwave discharge. It was shown that, depending on the microwave input power, the breakdown time changed in a range from 5 to 30μs, ignition occurred on an antenna in the area of the surface microwave discharge at a temperature not exceeding 1000 K, and the speed of the front boundary propagation of the intense ignition region near the antenna was 300 m s$^{−1}$.

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