Spectroscopy of millimeter and submillimeter ranges
Spectroscopy of millimeter and submillimeter ranges
V.V. Meriakri
The specific features of spectroscopy for the millimeter and submillimeter ranges of electromagnetic waves, the mechanisms of interaction with various media, and the peculiarities of the convenient spectroscopic techniques are considered. Examples are given of the application of millimeter and submillimeter wavelength spectroscopy in science and national economy.
Show AbstractOscillators for microwave radiometers
Oscillators for microwave radiometers
V.V. Gladun, V.V. Gruzdev, Yu.A. Pirogov
Oscillator devices employed in microwave radiometers are discussed. In order to stabilize the frequency and reduce the noise of the Gunn-effect oscillator, it is proposed to employ trapped-mode waveguide dielectric resonators, which are diffraction-excited in a rectangular waveguide either on a step-shaped H-inhomogeneity or on an E-inhomogeneity in the form of a parallelepiped with a gap along the wide wall of the waveguide. For calibration of the radiometers: wide-range noise sources have been developed, based on impact avalanche-and-transit time diodes (IMPATTD) and Shottky barrier diodes (SBD), which are highly stable with respect to the level of generation power. These sources employ the detected effects of the output signal self-modulation and self-thermostabilization.
Show AbstractSolid-state oscillators of millimeter waves with quasi-optical dielectric resonators
Solid-state oscillators of millimeter waves with quasi-optical dielectric resonators
A.Ya. Kirichenko, V.A. Solodovnik, S.N. Khar'kovskii
The experience in designing and fabrication of new types of solid-state millimeter band oscillators with quasi-optical dielectric resonators are summarized, and the underlying physical and engineering principles are considered. The authors describe the results of the experimental studies, and outline trends for further development.
Show AbstractApplication of millimeter-wave devices in the national economy
Application of millimeter-wave devices in the national economy
R.A. Amiryan
The application of millimeter-wave devices in transport, communications, and in equipment for radiometer sounding of the surface of land and ocean is discussed. The main engineering characteristics of the developed devices are generalized.
Show AbstractVibronic effects in surface phases and molecular electronics
Vibronic effects in surface phases and molecular electronics
V.B. Zaitsev, A.V. Zoteev, V.F. Kiselev, G.S. Plotnikov
In view of the fast progress in molecular electronics, much attention is being paid during recent years to systems combining the advantages of well studied basic elements of inorganic planar electronics and of elements of purely organic origin. In this work, experimental data are presented that point to the important role of vibronic effects in such structures. Considered are: (1) the role of vibronic effects in the events of trapping and recombination of charge carriers in the structures of semiconductor-insulator-adsorbed molecules, and also in photochemical transformations at the surface; (2) vibronic effects in the systems of semiconductor-insulator-dye molecules and semiconductor-insulator-Langmuir/Blodgett film; (3) some prospects for the utilization of vibronic effects in elements of molecular electronics.
Show AbstractSpace-time topology as a consequence of the dynamics of closed superstrings
Space-time topology as a consequence of the dynamics of closed superstrings
N.F. Nelipa, M.Yu. Pekar
The results obtained in the previous papers for a closed boson string are generalized to the case of a closed superstring.
Show AbstractIsometric immersions of rotation metrics on a sphere into $E^4$ in the form of surfaces of revolution
Isometric immersions of rotation metrics on a sphere into $E^4$ in the form of surfaces of revolution
A.V. Bad'in
In this paper, under investigation is the problem of immersion of a metric on $S^2$, which has the form $ds^2=g(r) (dr^2+r^2d\phi^2)$ in a certain stereographic projection, into $Е^4$ in the form of a surface of revolution with a pole. Denote the poles as $О_1$ and $O_2$. It is established that there exists an immersion in the class $C^1(S^2) \cap C^2(S^2\setminus (O_1\cup O_2))$. Some necessary and sufficient conditions are given for an immersion in the class $C^2(S^2)$. The deformability of the resulting surfaces in the same class is proved.
Show AbstractDephasing parameters (time, decrement, and angle) and their dependence on pressure; dephasing deceleration and acceleration effects
Dephasing parameters (time, decrement, and angle) and their dependence on pressure; dephasing deceleration and acceleration effects
Yu.E. D'yakov
A detailed mathematical description is developed for the dephasing time $\tau_{ph}$ as a function of pressure in different particle velocity correlation models. New polarization damping parameters (the dephasing decrement $m_{ph}$ and angle $\phi$ are introduced and their dependence on pressure is considered. The thresholds of the appearance of characteristic extrema (the Dicke dip, the peak of the function $\tau_{ph}$ etc.) are calculated for different substances. A "spectron" method is suggested for measuring the polarization damping spectrum using a single laser shot.
Show AbstractThe mechanism of origination of anomalous features in the structure of short-wavelength spectra of fluoride matrices doped with rare-earth ions
The mechanism of origination of anomalous features in the structure of short-wavelength spectra of fluoride matrices doped with rare-earth ions
K.M. Devyatkova, 0.N. lvanova, V.V. Mikhailin, S.P. Chernov
A comparative study of the optical and structural parameters was performed for $BaY_2F_8$ and $KY_3F_{10}$ single crystals doped with $Er^{3+}$, $Но^{3+}$, $Yb^{2+,3+}$, and $Тm^{2+,3+}$ ions. An interrelation was established between the occurrence of regular structure imperfections in single crystals and the anomalies in their VUV spectra, which may be utilized to improve the luminescence parameters of the materials studied.
Show AbstractModern methods of perturbation theory for calculating hydroacoustic fields
Modern methods of perturbation theory for calculating hydroacoustic fields
V.A. Burov, S.N. Sergeev
The perturbation theory methods for approximate solution of the Helmholtz equation governing the waveguide ocean model are discussed. Nonlinear perturbation theory, or the delinearization method, is introduced in addition to the standard perturbation theory modified in accord with the specificity of the acoustic problems. The new theory does not require the knowledge of the whole eigenvalue spectrum of the unperturbed problem and, besides, all the corrections are written explicitly in quadratures. Unlike the existing theories the approach suggested allows one to avoid nonremovable singularities in basic formulae for any waveguide types by choosing appropriate wavefunction representation in the form of polynomials.
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