A certain class of non-self-conjugate boundary-value problems in electrodynamics may be solved by a projection method, which is a generalization of Galerkin's incomplete method to a complex space having a pseudoscalar product.
Show AbstractA model is considered for the interaction of a single-mode boson field with a system of electrons placed at the nodes of an N-node lattice. Bogolyubov's approximating-Hamiltonian method is used to obtain an expression exact in the thermodynamic limit for the free-energy density in the system for the case of an arbitrary electron concentration ($0 < \bar{n} < 2$). The conditions for the existence of a superradiative state are derived.
Show AbstractExact solutions have been obtained to Dirac's equation for a pseudoscalar wave whose wave vector $k_{\mu}$ is arbitrary.
Show AbstractSome one-dimensional inverse problems in electric borehole logging are considered, particularly those important to prospecting for oil and gas deposits. It is shown that the solutions to these inverse problems are unique for certain particular cases of the conductivity distribution. A numerical algorithm is derived for solving the direct problem in electric logging for a certain class of models, and another algorithm is described for solving the inverse problem for a layered model. Results are given from numerical experiments.
Show AbstractA method is proposed for eliminating the multiple values arising in quantizing a classical system having a finite number of fermion degrees of freedom.
Show AbstractIt is shown that in the decay of a set of neutrons, as a whole unpolarized in a magnetic field, produces a negative mean value for the projection of the antineutrino momentum on the field direction as calculated per nucleon if the magnetic field is weak or if the initial neutron distribution over the spin states is restored more rapidly than the decay occurs, while it becomes positive in a strong field if the recovery of the initial spin-state distribution is much slower than the decay. An analogous situation occurs in the reaction $e^-+p \to n+\nu_e$.
Show AbstractAn oscillatory system with delayed feedback is considered in relation to three possible ways of transition from periodic oscillations to stochastic ones: 1) via an infinite sequence of bifurcations involving period doubling, 2) by merging of an unstable limit cycle with a stable singular point, and 3) by the formation and disruption of an almost periodic state.
Show AbstractElectromagnetic-wave propagation is considered for a nonequilibrium anisotropic medium with planar stratification. A combined fitting algorithm is used to examine the scope for the excitation in the magnetosphere of electron fluxes related to the Earth's kilometer radiation known from geophysics. The results agree with experimental data.
Show AbstractA numerical experiment is reported on recovering the input to a gravitational antenna. It is shown to be desirable to use a parametric transducer as the recording component. An additional increase in the recovery accuracy is provided by using dynamic damping for the sensor noise.
Show AbstractExperimental results are presented on the effects of plasma density inhomogeneity on the perturbations arising from an external pulsed voltage source. It is found that the inhomogeneity damps the waves arising from the leading or trailing edges of the pulse because of additional charged-particle loss.
Show AbstractA description is given of a two-frequency Raman spectrometer for examining organic compounds, which has been automated with a D3-28 minicomputer.
Show AbstractMeasurements have been made on the absorption spectra in acetonitrile for 2,6-diarylpyrylium salts. It is found that the addition of various radicals to the 2,6-diphenylpyrylium cation influences the excited-state lifetimes and the oscillator strengths for the various absorption bands. The largest increase in the sum of the oscillator screngths for all the absorption bands occurs when phenyl or oxalkyl radicals are attached to the cation.
Show AbstractAn aberration-free description is given of dynamic wave-front control designed to improve the concentration at a moving detector. Focusing and wave-front inclination laws have been derived for a continuous control algorithm. Aspects of speed and efficiency in flexible-mirror control are examined with and without constraints on their profiles.
Show AbstractMeasurements have been made on the luminescence of adsorbed erythrosine on the surfaces of $Ge-GeO_2$ and $Ge-GeO_2$-transition-metal oxide structures, as well as charge transfers in electron and hole surface traps on illumination in the dye absorption band. It has been found that the trap photodepletion in such systems is due to excitation-energy transfer from the adsorbed molecules; there is a correlation between the structure of the surface oxide layers and the performance in that process.
Show AbstractA method is proposed for determining the amplitudes and widths of the components in a compound spectral line by the use of even derivatives. The parameters are calculated from the relative amplitudes of the peaks in the various derivatives corresponding to a given component. The method allows one to use derivative spectrophotometry to describe all the components of a compound spectral line.
Show AbstractParametric frequency conversion can be used to examine dye fluorescence kinetics. Measurements have been made on the decay time for the first excited electronic state and the dipole reorientation time in solution for the dyes RB and Nile blue.
Show AbstractA calculation has been performed on the absorption spectrum in the region of the second overtone of the CH vibration in $(CF_3)_3СН$ and on the fifth overtone of the CH vibration in $CHCl_2F$, where allowance is made for the inhomogeneous rotational broadening. Comparison with the observed spectrum provices the homogeneous contribution to the total spectrum width, which is 20 $cm^{-1}$ for both spectra.
Show AbstractTheoretical and experimental results are given on the acoustic field of two omnidirectional sound sources in an unbounded medium. It is shown that the particles move in a stationary harmonic sound field always along elliptic paths, whose planes and shapes are completely determined by the magnitudes and directions of the vectors for the active and reactive intensities and by the acoustic pressure in the relevant region.
Show AbstractExperiments are reported on a new method of displaying IR images, which is based on the interaction between light and ultrasound. This method has been used at a wavelength of 10.6 μm to display two-dimensional images with the resolution of 2.7 lines per mm.
Show AbstractResults are reported on the propagation of planar and spherical shock waves through the low-temperature plasma produced by a laser. It is found that the shock-wave front in the plasma splits up and vanishes.
Show AbstractMeasurements have been made over the range 4.2-400 K in fields up to 130 kOe. Chromium-cobalt alloys containing up to 12 at.% cobalt have been used. It is found that a cobalt concentration of $\simeq 4$ at.% is critical: there are differences in the dependence of the physical parameters of temperature and magnetic field in the regions below and above this value.
Show AbstractThe determinant of the secular equation for calculating the band structure by the method due to Korringa, Kohn, and Rostoker (KKR) has poles at $E= |k+G_n|^2$, where $G_n$ are the reciprocal-lattice vectors. It is shown that one can obtain an equation having a matrix whose elements and determinant are continuous functions of the energy over a particular range. This eliminates the difficulties in calculating the spectrum near the poles and enables one to alternate the calculation throughout the energy range for a given wave vector $k$.
Show AbstractIt is possible to excite surface X-ray waves in three-wave diffraction. It is shown that these waves can arise not only under the conditions of total external reflection but also in the region of the Bragg maximum when the incident wave propagates at a large angle to the surface. The form of the dispersion surface has been determined. The behavior of the wave intensities has been examined.
Show AbstractMeasurements have been made on the voltage-current characteristics and resistance transient in $Hg_{1-x}Cd_xTe$ semiconducting alloys having x = 0.20 and 0.22 at 4.2 and 77 K in the absence of a magnetic field, and also in longitudinal and transverse magnetic fields of strength up to 2 kOe. The results confirm that there is a z pinch in the electronhole plasma formed on electrical breakdown in that the magnetic-concentration effect occurs in this plasma in a transverse magnetic field.
Show AbstractMeasurements have been made on the resistivity $\rho$, thermo-EMF coefficient $\alpha$, magnetization $\sigma$, magnetoresistance ($\Delta \rho/\rho$ effect), and even thermomagnetic effect $\Delta \alpha$ for an $La_{0,6}Pb_{0,4}Ni_{0,18}Mn_{0,82}O_3$ single crystal in magnetic fields up to 14 kOe at temperatures from 80 to 600 K. There are marked anomalies in these physical parameters in the region of the Curie point.
Show AbstractLux-ampere and temperature curves have been derived for the photoresponse under conditions of high-intensity illumination and relaxation conditions.
Show AbstractKarachentsev's catalog of isolated pairs in the northern sky has been used to examine the features of a sample of double galaxies of EE type. If the members of the pairs are elliptical or lens-shaped galaxies, one can determine the average values for the kinematic and dynamic characteristics. For systems having components of EE and E-SO types one can calculate the parameters of the limiting zero-velocity surfaces within the framework of a restricted three-body problem for the spherically symmetrical case of the density distribution in the companions. The results are presented as preliminary.
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