Electric-field control of electron interference effects in 2D semiconductor nanostructures with parabolic quantum wells

The possibility of the influence of a constant electric field on spatial reproduction effects for quantum-mechanical current density, which arise during interference of electron waves in 2D semiconductor nanostructures, is studied theoretically. It is found that, in structures comprising a narrow rectangular quantum well and a wide parabolic quantum well placed successively in the direction of propagation of an electron wave, the transverse current density distribution existing at the input of the wide quantum well is reproduced in this well with a certain accuracy in periodically repeated cross sections. The inhomogeneous current density distribution arises because of the interference of electron waves propagating in the wide quantum well simultaneously in different quantum-dimensional subbands. It is shown that it is possible to control these effects via the use of a constant electric field perpendicular to the axis of the structure in the region of the wide quantum well.     

Electrodynamic Theory of Sagnac Effect

Using the strict solution of the problem on the possibility that there exists an electric-type wave in rotating cylindrical waveguide analysis of electromagnetic phenomena is performed. Dependence effects of wavelength, phase and group velocity of propagating partial harmonics and independence effects of phase and group velocities of re-reflecting in the cross section partial harmonics on the waveguide’s rotation speed are revealed.Astrictly applicable formula for estimating experimental results in Sagnac effect for partial harmonics’ phase difference (phase difference due to path length difference) is obtained     

Specific features of kinetics of molecular beam epitaxy of compounds in the GaN-AlN system

The effect of growth conditions (V/III ratio, substrate temperature) on the properties of materials in AlN-GaN systems is discussed. A concept of the growth of the AlN/AlGaN/GaN multilayer heterostructure, which provides the improvement of crystal quality and surface morphology of the layers, is suggested and realized. The improvement of the properties of GaN in the AlN/AlGaN/GaN/AlGaN multilayer heterostructure is confirmed by a considerable increase in electron mobility in the two-dimensional electron gas formed at the upper heterointerface GaN/Al_0.3Ga_0.7N.     

Spectral Reflectivity of Ceramics of Cubic Zirconium Oxide on the Wavelength of 0.63 μm under Intense Surface Heating above the Melting Point and Subsequent Cooling

The experimental data on the normally hemispherical reflectivity of zirconium oxide ceramics are obtained for the wavelength of 0.63 m in the course of the first cycle of heating by concentrated laser radiation up to temperatures above the melting point and free cooling in ambient air. The obtained data are compared with analogous results of the second and subsequent cycles of heating and cooling. Analysis is made of the effect of the temperature field in the heated layer on the reflectivity and on the effective temperature measured by a pyrometer.     

Reinforcing properties of ethanol in neonatal rats: Involvement of the opioid system.

Toward understanding why infant rats ingest high levels of ethanol without initiation procedures, the authors tested effects of mu and kappa receptor antagonists on ethanol reinforcement in neonatal rats. After an intracisternal injection of CTOP (mu antagonist), nor-Binaltorphimine (kappa antagonist), or saline, newborn (3-hr-old) rats were given conditioning pairings of an odor with intraorally infused ethanol or a surrogate nipple with ethanol administered intraperitoneally (to minimize ethanol's gustatory attributes). In each case, these opioid antagonists reduced or eliminated ethanol's reinforcement effect. The same effects occurred with saccharin as the reinforcer in olfactory conditioning. The results imply that activation of mu and kappa receptors, apparently acting jointly, is necessary for reinforcement or that antagonists of this activity impair basic conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Calibration-free method to determine the size and hemoglobin concentration of individual red blood cells from light scattering

At present, hemoglobin concentration and the volume of an erythrocyte can be determined from the intensities of light scattered by an individual cell at fixed angular intervals. This method is used in modern hemoglobin analyzers, but it requires calibration of optical and electronic units by certified particles of known size and refractive index. We describe a method that is based on the parametric solution of an inverse light-scattering problem and does not require a calibration procedure. The method is based on the use of parameters of the entire angular light-scattering pattern, called an indicatrix here. These parameters do not depend on the absolute intensity of light scattering. The indicatrix parameters form approximating equations that relate these parameters to the size and the phase-shift parameters of the particle. The applicability of the method is demonstrated by measurement of the indicatrices of individual sphered erythrocytes. The indicatrices of the individual erythrocytes were measured with a scanning flow cytometer at an angular range of from 15 to 55 deg. The volume and the hemoglobin concentration have been calculated by use of the developed method and by fitting of the experimental indicatrices to the indicatrices calculated from the Mie theory.     

Sum-Frequency Generation of Femtosecond Pulses in CsLiB(6)O(10) Down to 175 nm

Using a 150-mum-thick CsLiB(6)O(10) crystal, we produced 100-fs, >200-nJ light pulses tunable between 175 and 180 nm by sum-frequency generation at a 1-kHz repetition rate with an all-solid-state laser system mixing the fourth harmonic of a femtosecond Ti:sapphire regenerative amplifier and the idler pulse from a traveling-wave optical parametric amplifier.     

Organization of monitoring the safety of hydraulic structures of the Volga-Lenin hydroelectric station

Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 23–25, January, 1994.     

Reverse adaptation studied by recording short-latency auditory evoked potentials

Difficulties of diagnosis of pleural neoplasms in biopsies are discussed. The short history of serous tumors as entity, their classification, methodological approaches to their morphological diagnosis are outlined. It is concluded that the problem of neoplastic pleural diseases verification can be solved by clinical and morphological correlations. Histochemistry, immunomorphology, and electron microscopy should be combined with conventional morphologic methods used in biopsy investigations.