Parametric frequency conversion in research on dye fluorescence characteristics
Parametric frequency conversion in research on dye fluorescence characteristics
S.A. Pleshanov, V.V. Shuvalov
Parametric 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 AbstractHigh-overtone spectroscopy of quasilocal CH vibrations in polyatomic molecules: allowance for vibrational-rotational transitions
High-overtone spectroscopy of quasilocal CH vibrations in polyatomic molecules: allowance for vibrational-rotational transitions
O. Stengel, N.I. Koroteev
A 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 AbstractMotion of the particles of the medium in a complex acoustic field
Motion of the particles of the medium in a complex acoustic field
A.N. Zhukov, A.N. Ivannikov, B.N. Nyunin, O.S. Tonakanov
Theoretical 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 AbstractAn acoustic device for displaying IR images
An acoustic device for displaying IR images
V.I. Balakshii, A.M. Bogomolov, M.I. Zusman, L.N. Magdich, V.N. Parygin, M.Yu. Sharonov
Experiments 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 AbstractShock-wave propagation in a low-temperature carbon plasma
Shock-wave propagation in a low-temperature carbon plasma
A.M. Galkin, N.N. Sysoev, F.V. Shugaev
Results 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 AbstractEffects of cobalt on the magnetic, magnetoelastic, kinetic, and galvanomagnetic properties of antiferromagnetic chromium
Effects of cobalt on the magnetic, magnetoelastic, kinetic, and galvanomagnetic properties of antiferromagnetic chromium
E.I. Kondorskii, T.I. Kostina, N.V. Trubitsina
Measurements 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 AbstractEliminating poles in the KKR determinant in band-structure calculations
Eliminating poles in the KKR determinant in band-structure calculations
A.F. Tatarchenko, A.A. Katsnel'son, L.I. Yastrebov
The 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 AbstractSurface X-ray waves under conditions of three-wave diffraction
Surface X-ray waves under conditions of three-wave diffraction
A.V. Andreev, V.E. Gorshkov, Yu.A. Il'inskii
It 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 AbstractElectron-hole plasma instability in $Hg_{1-x}Cd_xTe$ semiconductors
Electron-hole plasma instability in $Hg_{1-x}Cd_xTe$ semiconductors
E.V. Bogdanov, L.S. Fleishman
Measurements 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 AbstractKinetic effects in manganites
Kinetic effects in manganites
K.P. Belov, E.P. Svirina, L.P. Shlyakhina, M.M. Lukina, V. Ntakhomvukiie
Measurements 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.
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