R e g u l a r p a p e r s

Moscow University Physics Bulletin 1983. **38**. N 3. P. 1

An analysis of temperature deformations of the EPR spectrum of alcohol solutions of benzocarboline is used to prove the necessity of taking into account solvation of solute molecules in the calculation of the diffusion coefficient. We suggest a method for estimating the energy of interaction of the solute and solvent molecules based on an analysis of radiospectroscopic data.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 7

We estimate the energy transmission coefficient of a layered medium and its rate of change in terms of parameters of the layered medium: its thickness, permissible limits of change of its wave impedance, etc. With application to the synthesis of multi-layered optical coverings, we discuss the use of a priori estimates in the specification of the synthesis, and in concrete calculations using synthesis programs to determine the useful regions of the parameters.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 12

We study the variability of the thermal structure in a coastal zone of the sea as a result of the entrainment mechanism. We estimate the magnitude of terms in the equation for the energy balance, and the empirical coefficient in the relation $E=kRi^{-n}$.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 18

In the observation of classical force from the response of a quantum test system, the generalized coordinate operator of the quantum system does not commute with the operator whose measurement corresponds to the optimal observation procedure. According to the uncertainty relations, the sensitivity of the test system therefore increases with increasing level of fluctuations of its coordinate.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 22

It is shown that for $E_{\gamma}\le 50$ MeV, the $T_{\gamma N}$ matrix of the reaction $(\gamma,N)$ can be expressed in terms of the vector vertex $\tau [n+1]$: $\tau_{\gamma}[n+1]=V_{\gamma}GG\Gamma_{2,n+1}$ where $V_{\gamma}$ is the vertex of noninteracting nucleons with respect to the field of the gamma quantum, and $\Gamma_{2,n+1}$ is the full vertex part (total interaction amplitude). We obtain the renormalized equations for $\Gamma_{2,n+1}$, which contain the products of polar single-particle Green's functions G and the effective interactions amplitudes $\Gamma_{2,n+1}$. The T matrix of the reaction $(\gamma,N)$ can be decomposed into two parts. One part describes a direct multistep nuclear photoeffect (without formation of the compound nucleus), and the other part describes a resonant multistep nuclear photoeffect (via intermediate states of the compound nucleus). After statistical averaging, we obtain expressions for $|T_N|^2$ which describe a $(\gamma,N)$ reaction for the energies of the gamma quanta $E \le 50$ MeV.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 28

We consider in a general form, the methods of assignment of NMR spectra of an arbitrary type $A_iB_kC_lD_n$... It is shown that, under specific conditions, the method of repeating intervals and the double-resonance method make it possible to make a unambiguous assignment of the spectrum. We consider an optimum method of assignment with a combined application of the rule of repeating interval and the double resonance.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 34

The method of molecular orbitals is used to show that a change in the oxygen parameter of a ferrite with the spinel structure affects considerably its Curie point. This factor must be taken into account in the search for improvement of the magnetic properties of spinel ferrites, together with such factors as the number of exchange bonds and the electron configuration of cations which participate in the exchange interactions.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 38

It is shown that the Dirac forms of relativistic dynamics can be obtained from the covariant formulation of relativistic mechanics. The formulation of the problem in terms of various forms of relativistic dynamics is made more rigorous, and we give an interpretation of the physical equivalence of these forms.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 44

It is shown that the presence of an impurity in semiconductor can lead to a resonant structure of the coefficient of nonlinear polarizability.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 48

For the general theory of relativity with asymptotically flat metric, we construct a space of states Г which satisfy the following requirements: a) solutions of the constraint equations exist in Г; b) Г is invariant with respect to transformations of the Poincare group; c) the symplectic form in Г is finite. Using the symplectic form, we construct the generators of the equations of motion (Poincare transformations).

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 55

Using a standard model of the weak electric interactions, we calculate the contribution of weak neutral currents to the shift of energy levels of hydrogen-like atoms. The Logunov-Takhvelidze quasipotential method is used to obtain the weak-interaction potential between particles in the nonrelativistic approximation. We calculate the contribution of the P-even part of this potential to the hyperfine splitting of levels of muonium and muonic hydrogen.

Show AbstractB r i e f r e p o r t s

Moscow University Physics Bulletin 1983. **38**. N 3. P. 59

We show the existence of quantization of a one-dimensional Hamiltonian system in which the classical and quantum Kubo-Martin-Schwinger states coincide on the classical observable and on its quantum analog.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 63

We study the temperature dependence of the absorption spectra of rhodamine dyes in polar solutions. It is shown that when volume expansion of the solvent is taken into account, the absorptivity of molecules of rhodamine dyes remains constant in a wide range of temperatures. This is in a good agreement with the phonon mechanism of broadening of the absorption spectra.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 66

Electron-beam irradiation of the i region of an i-n structure based on zinc-doped gallium nitride is observed to increase the intensity of the cathodoluminescence band with maximum at $\hbar \omega=2,87$ eV. The emission intensity increases by 1.5-2 orders of magnitude in comparison with the intensity at the initial period of the irradiation. Irradiation beyond the broad maximum caused the intensity to decrease. The experiments were carried out with electron-beam energy 20 keV, current density up to 200 A/cm$^2$, and sample temperature 300°K.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 70

It is shown that estimates of anisotropy of the inertial mass $\Delta m/m<10^{-22}$ and $\Delta m/m<5\cdot 10^{-23}$, which were obtained in experiments testing the Mach prinriple, are incorrect. A generalized Klein-Gordon equation is developed using a relativistic theory of locally anisotropic space-time which is consistent with the Mach principle. This equation makes it possible to take into account correctly the effect of anisotropy on the nuclear potential.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 73

We develop a method for estimating the width of spectral lines, which makes it possible to obtain the result in an analytical form at any gas pressure. The method is based on the fact that the Doppler broadening of spectral lines in gases is determ1ned by the mean velocity with which the molecules move to distances of the order of a wavelength of the light wave, rather than by the instantaneous velocity of molecules. The calculated line-width agrees well with the experimental data for hydrogen in a wide range of pressures, including the Dicke narrowing region.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 78

We study experimentally the anomalous Hall effect in a system of monocrystalline Ni-Pd alloys at room temperature. The character of the observed anisotropy of the anomalous Hall effect makes it possible to draw the conclusion that the magnitude of the effect and its anisotropy are affected considerably by the spin-orbit splitting of degenerate levels.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 81

We present a system of equations which relate the characteristics of an element of the rectenna, in particular, the efficiency, with the parameters of the Schottky diode. These equations are intended for the determination of the proper ohmic losses in the element of the rectenna. We develop a method for the minimization of proper losses for various levels of the input microwave power. We calculate the losses in Au-GaAs diode. The calculations show that this type of diode can ensure higher than 90% conversion efficiency in a wide range of the input power (from 0.1 to 5W).

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 85

We study the internal effect field $H_e$ to gain a better understanding of the applicability of the model of growth of the reverse-magnetization nuclei to the case of pulse magnetization reversal of polycrystalline ferrites in weak fields. It is shown that the dependence of the field $H_e$ on the induction of the magnetized sample, calculated using this model, is in good agreement with experiment.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 88

We consider the blocking effect of regular surface waves by inhomogeneous flow. In a laboratory channel, we observe the stopping and reflection of waves with frequencies 1.5, 1.7 and 2 Hz on a parallel flow or counterflow, which changes slowly along the direction of propagation of the waves. The results agree with the ideas of the linear wave theory.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 93

We study the kinetics of slow relaxation of the charge on silicon surface in water-vapor atmosphere in a wide time range ($10^{- 2}\le t \le 10^5$ sec). It is shown that the experimental data agree fully with the ideas of the electronic-vibrational model for the charge exchange of the slow states. The form of kinetic curves corresponds to the Gaussian distribution over the energies of the O-H vibrational modes of the adsorbed complexes, which include rigidly adsorbed water molecules.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 97

The measured absolute and relative intensities of spectral lines are used to study the characteristics of a strongly nonequilibrium high-frequency discharge plasma at intermediate pressure in helium, in which the electron distribution function over energies contains groups of "slow" and "fast" electrons. It is established that the effective temperature of "slow" electrons $T_e{}^M$ is 0.15-0.25 eV, and the contribution by their ionization to the total electron concentration is of the order of $10^{12}-10^{13} cm^{-3}$. We determine the population of the highly-excited energy levels of He atoms for the principal quantum number $n=4-14$. The obtained low values of $T_e{}^M$ are explained by the presence of electron beams in the discharge.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 99

We consider the transition radiation of transversely polarized electrons which intersect the boundary of a perfectly conducting medium. We obtain the spectral-angular distribution of the radiation. It is shown that the polarization matrix of the transition radiation has spatial asymmetry due to the correlation between the pseudovector of transverse polarization of the electron, and the pseudovector of electron spin.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 102

We calculate the characteristics of the state $2p^{-2}(^3P)3s3p^1P$ in the resonant photoionization cross section of the neon atom, using the diagonalization approximation on the basis of Hartree-Fock functions. The direct coupling of the "particle-hole" state and "two particles - two holes" states is taken into account by introducing an empirical parameter. The results are compared with experiment and with the results of calculations by the method of strong coupling between channels.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 107

The solutions of the stochastic Helmholtz equation are expressed in the form of "integral over trajectories", with a subsequent averaging and evaluation by the method of stationary phase. By way of example, we consider a point source in a spherically-layered medium with small-scale inhomogeneities.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 110

We calculate theoretically the resonance curves of a circuit with metal-dielectric-semiconductor structure illuminated from the dielectric side by continuous gas laser. The change of average capacitance of the structure in the region of inversion is due to the difference between the equilibrium and pulsed voltage-capacitance characteristics. We present experimental results in the region 1-2 MHz.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 114

We discuss the possibility of applying the phase-quantization method for the reception of low-frequency and very-low-frequency radiosignals. A weak signal of frequency 1 kHz is detected experimentally using parametric quantization of phase with frequency preconversion of the frequency of the signal by 1 MHZ in a ring modulator.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 118

The Hartree-Fock approximation is used to study the 3d photoabsorption in the near-threshold region for the following atoms and ions: $I^-, Хе, Cs^+, Ва^{2+}, La^{3+}$. We discuss the hypothesis of 4f-state collapse in the isoelectronic series of Xe. It is shown that the features of the absorption cross section in $Cs^+$ can be explained without invoking the hypothesis of 4f-state collapse.

Show AbstractMoscow University Physics Bulletin 1983. **38**. N 3. P. 121

We consider the problem of construction of the resolvent of the operator which is a contraction of a given operator to a subspace generated by an orthogonal projection. We establish the equivalence of various methods of construction of these resolvents, and also the connection of this problem with the Vainshtein-Aronshain degenerate-perturbation theory. We show how these problems can be applied to the analysis of spectral properties of the Hamiltonian of a system of several quantum-mechanical particles.

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