Detection of Anomalous Measurements When Analyzing Transient Processes

The present article is devoted to processing the results of measurements represented by a single realization of a transient random process with a limited volume of a priori information. The procedure is based on the highly efficient method of the multiplication of estimates.     

A phase-locked loop system for 7–18 and 37.5–78-GHz commercial microwave generators

A phase-locked loop system for widespread Γ4–84, Γ4–111, Γ4–141, and Γ4–142 microwave generators, whose operating ranges cover a frequency range of 7–78 GHz, is described. The phase-locked loop uses a rubidium frequency standard.     

Refractory Clays of the Southern Berlinskoe Deposit Studied for Technological Application

Clays sampled from three core sites of the southern area of the Berlinskoe deposit (Chelyabinsk District, Russia) are analyzed for potential technological application. The clays containing 30.9 – 35.73% Al₂O₃ have a refractoriness of 1670 – 1690°C. The clays can be used as a binder for fabricating chamotte refractories (sample 1) and as a material component for building structures (samples 2 and 3).     

Nonohmic conductance and mechanisms of energy relaxation in 2D electron gas in GaAs/InGaAs/GaAs heterostructures

The effects of heating 2D electron gas in GaAs/InGaAs/GaAs structures at temperatures of 0.4–4 K and electron densities of (1.5–6) × 10¹⁵ m^?2 are studied. For the entire range of temperatures and densities studied, the rate of energy relaxation agrees well with theoretical predictions of the energy relaxation via electron scattering at the piezoelectric and deformation potential of acoustic phonons. It is shown that the widely used analytical expressions for energy relaxation rate, which were obtained in low-and high-temperature limits, are applicable only when the relations between the Fermi quasi-momentum and the momentum of thermal phonons are strictly observed. It is shown that the dependence of the energy relaxation rate on the electron density is a nonmonotonic function. For example, at the lattice temperature of 1.4 K, it initially increases as the electron density decreases to n = 2.5 × 10¹⁵ m^?2, but then starts to decrease as the density decreases further.     

Binding of phosphoorganic cholinesterase inhibitors in rat brain tissue

Hydrophobity (coefficient in distribution in the hexane water system) and the content of cholinesterase organophosphorous inhibitors (OPI) of the structure Ro (CH3) P (O) SC2H4 SC2H5 were studied in the rat brain. When the O-alkyl radical is increased hydrophobity rises and the relative content of free OPI in the brain extracted by chloroform decreases. With an increase in R from the ethyl to butyl one the ability to the additional inhibition of the brain own cholinesterase lowers due to incubation of homogenate at 37 degrees C, that evidences for an essential drop in the studied series of the free OPI fraction relative to the free OPI extracted by chloroform.     

A quantum digital ac-voltage synthesizer based on pulse-width modulation of the Josephson junction bias current

The theory and preliminary results of the experimental tests of a method for synthesizing ac-voltage signals through the use of pulse-width modulation of the microwave power biasing a Josephson junction are presented. It is shown that it is possible to synthesize sinusoidal ac-voltage signals with an amplitude of 1 V and a nonlinear distortion factor of <0.003%.     

On a Mechanism of Wear of the Periclase-Carbon Lining for Oxygen Converters

Effects associated with the capillary impregnation of the refractory materials with melted slag, the chemical interaction of graphite carbon with slag, and the dissolution of periclase in slag are considered. The time needed for melted slag to penetrate to the hot-layer depth of the refractory lining is a matter of several seconds. The carbon component on its contact with melted slag is reduced with FeO to yield CO. The partial pressure of carbon monoxide p _CO is calculated as a function of temperature (1500 – 1700°C) and FeO activity (0.1 – 0.5) in melted slag. The pressure p _CO is shown to exceed the capillary pressure of melted slag in pores, which prevents the easy penetration (because of the CO bubbles formed) of the slag into the periclase-carbon lining. The lining-wear effects due to the MgO concentration in the slag and to the size of periclase crystals are considered.     

Electron transport effects in the IR photoconductivity of InGaAs/GaAs structures with quantum dots

We have studied the temperature dependence of the Hall effects in multilayer selectively doped InGaAs/GaAs heterostructures with quantum dots (QDs). It was found that structures possessing photoconductivity in the IR range exhibit a sharp (nearly exponential) growth of the conductivity and Hall mobility in the temperature interval from 8 to 30 K at a virtually constant Hall coefficient and electron density. A new mechanism of the lateral photoconductivity in the structures with QDs is proposed which is related to the change in the electron mobility in the two-dimensional channel as a result of a decrease in the Coulomb scattering on charged QDs.     

The VÉT-13-13–01 Josephson Secondary Volt Standard

The operating principle and metrological characteristics of a secondary volt standard developed at VNIIFTRI are discussed and the standard is described.     

Low-field anomaly of the hall effect in disordered two-dimensional systems

This study is devoted to investigation of the nonlinear behavior of the Hall resistance in low magnetic fields. When investigating two-dimensional electron gas in single GaAs/In _x Ga_{1 − x} As/GaAs quantum wells, it is shown that the anomaly of the Hall effect in disordered systems can be described taking into account the second-order quantum corrections to conductivity.