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Investigation of the density structure of the thin water-air boundary layer

Investigation of the density structure of the thin water-air boundary layer

E.P. Anisimova, A.A. Pivovarov, A.A. Speranskaya, and V.P. Sukhanov

Moscow University Physics Bulletin 1977. 32. N 4. P. 13

Findings of an experimental investigation of the heat transfer mechanism at work in the thin water - air boundary layer in the absence of advective transport are presented. Data are cited on values of the coefficient of turbulent heat transfer in the thin surface layer of air over the water and in the near - surface layer of the water, estimates are offered for the ratio of the coefficients of turbulent thermal diffusivity and turbulent diffusion of moisture, and the Bowen number is calculated.

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Investigation of a penning discharge at high-intensity magnetic fields

Investigation of a penning discharge at high-intensity magnetic fields

E.M. Reikhrudel and G.V. Smirnitskaya

Moscow University Physics Bulletin 1977. 32. N 4. P. 20

Characteristics of a Pehning discharge struck in strong magnetic fields of intensity H = 5 to 50 kOe , at anode voltages Va = 2 to 4 kV, are presented for various cell geometric dimensions. Experimental results for a specified configuration of discharge tubes are compared to theoretic a l dependences reported earlier by the authors. Conclusions are drawn on the assignment of geometrical and physical, discharge parameters in work using high - intensity magnetic fields.

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Coupling and spectral distribution of transverse modes in GaAs stripe-geometry lasers

Coupling and spectral distribution of transverse modes in GaAs stripe-geometry lasers

A.S. Logginov and V.E. Solov'ev

Moscow University Physics Bulletin 1977. 32. N 4. P. 25

An experimental investigation of the near-field pattern and integrated emission spectra of stripe-geometry injection lasers is reported. It is shown that self- Q - swltching of the stripe laser output occurs when several transverse lasing modes are excited simultaneously as they interact. Maxima on the envelopes of transverse modes of different order are separated by an interval of the order of 20 A determined by the difference in the excitation thresholds of the modes involved.

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Gruneisen constants for optical modes of α-quartz

Gruneisen constants for optical modes of α-quartz

V.G. Zubov, E.K. Zakharova, and L.P. Osipova

Moscow University Physics Bulletin 1977. 32. N 4. P. 29

Thermal expansion of the α-quartz lattice is compared to expansion induced by fast-neutron bombardment, on the basis of the relationship $∆ν_j/ν_j = = (-γ_j∆V)/V$, where $∆ν_j/ν_j$ is the change in the frequency of normal lattice vibration, ∆V/V is the crystal cubic expansion, $γ_j$ is the Gruneisen constant of the j-th normal lattice vibration (of frequency $ν_j$). It is shown that various normal vibrations introduce different contributions to expansion of the quartz lattice induced by heating or by fast-neutron bombardment.

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Correlation effects in hopping transport theory. Conductivity and thermoelectromotive force

Correlation effects in hopping transport theory. Conductivity and thermoelectromotive force

I.P. Zvyagin

Moscow University Physics Bulletin 1977. 32. N 4. P. 33

The temperature dependence of hopping conductivity and thermopower is found, with attention given to interaction between electrons arriving at the same center. It is shown that treatment of repulsive correlation leads to the appearance of Coulomb iterations in the apparent density of states figuring in the conductivity and thermopower. In the case of attraction, exponential temperature dependences are to be expected for the magnetic susceptibility, EPR signal intensity, and conductivity across singly charged centers. A nonactivated process of direct hopping of pairs competing, in the low temperature range, with the conduction mechanism is discussed.

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Screening and absorption of long electromagnetic waves in a disordered soft-gap semiconductor

Screening and absorption of long electromagnetic waves in a disordered soft-gap semiconductor

V.L. Bonch-Bruevich

Moscow University Physics Bulletin 1977. 32. N 4. P. 40

The specific features of screening of the electrostatic field in a semiconductor with an everywhere dense spectrum of discrete levels, under conditions where the density of states at the Fermi level vanishes, is studied. The temperature and frequency dependences of the absorption coefficient of electromagnetic waves are calculated for the system.

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Fluctuations in the intensity of light scattered by a liquid crystal

Fluctuations in the intensity of light scattered by a liquid crystal

S.V. Kir'yanov

Moscow University Physics Bulletin 1977. 32. N 4. P. 45

The pair correlation function of fluctuations of the intensity of the electrical component of light scattered by the isotropic phase of a liquid crystal (LXTAL) is calculated.

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Pseudosurface waves in magnetodi electrics

Pseudosurface waves in magnetodi electrics

К.V. Goncharov, T.A. Mamatova, and L.A. Ivanets

Moscow University Physics Bulletin 1977. 32. N 4. P. 50

Проведено экспериментальное исследование затухания магнитоупругих волн релеевского типа в кристаллах феррита-гранита иттрия в зависимости от величины и направления подмагничивающего поля. Использование метода «мостика» позволила провести импульсные измерения с различными срезами кристаллов на частотах 22, 30 и 60 МГц. Исходя из макроскопической теории магнитоупругих волн в приближении упругой изотропии найдены границы, спектров магнитостатического излучения волн релеевского типа в зависимости от ориентации подмагничивающего поля.

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Effect of viscosity distribution on parameters of the near-bottom density current

Effect of viscosity distribution on parameters of the near-bottom density current

V.M. Belokopytov and Yu.G. Pyrkin

Moscow University Physics Bulletin 1977. 32. N 4. P. 55

The solution of the problem of how to find the vertical distribution of the mean flowspeed of the near-bottom current propagating along a sloping bottom in a nonmoving lighter liquid is presented for the case where the viscosity is a function of the vertical coordinate, and also for the case where the viscosity remains constant throughout the depth of the liquid. It is shown that depth variation of the viscosity must be taken into account in studying near-bottom currents whose density exceeds the density of the above-lying liquid by more than 5•1О^{-3}g/cm^3, since this change exerts a pronounced effect on the shape of the velocity profile. But if the density difference is less than that figure, the viscosity can be treated as constant in calculating the flow parameters.

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The structure of weak leptonic currents and neutrino-electron scattering

The structure of weak leptonic currents and neutrino-electron scattering

В. K. Kerimov, S. Kh. Buzardan, I.M. Al - Khamis, and M. Ya. Safin

Moscow University Physics Bulletin 1977. 32. N 4. P. 60

The S,Т,Р,V,А-variants of interaction between neutral and charged leptonic currents are investigated, with attention given to polarization effects, and interference between these two modes of current interactions in elastic νe(¯νe)-scattering is also studied. It is shown that scattering with or without changes in the helicity of the neutrino (or antineutrino) is characterized, in the case of a polarized electron target, by a different dependence of cross sections on the variable y=Ee / Eν(Eqs.(lO)-(ll')). The latest experimental data are employed in developing numerical estimates of the coupling constants for antineutrino scattering (¯ν=¯ν_R), and these estimates are found at variance with those predicted in the Weinberg - Salam model.

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