A New Radar-Signal Parameter for Recognition of Wind-Related Weather Hazards

Radiophysics and Quantum Electronics - Wind-related weather hazards remain difficult to recognize targets for weather radars. Methods that use estimates of the width of the reflected-signal...     

The effect of simple electrolytes on coagulation of hydrosols of monodisperse negatively charged detonation nanodiamond

The influence of the concentration of potassium and barium chlorides on the aggregation stability of a hydrosol of monodisperse negatively charged detonation nanodiamond with particle sizes of 4?5 nm obtained by annealing of its agglomerates in air has been studied by turbidimetry. The experimental results have been discussed within the classical and generalized Derjaguin?Landau?Verwey?Overbeek theories. The analysis of the pair interaction potentials calculated for ultradispersed particles of detonation nanodiamond has led to the conclusion that the coagulation occurs by the barrier mechanism in the primary potential minimum. It has been assumed that the structural component of the interparticle interaction energy contributes to the total balance of the surface forces.     

Parametric instability of the m = 1 mode in the dynamic stabilization of a plasma filament

We consider the parametric excitation of long-wave magnetohydrodynamic oscillations of the m = 1 type in a cylindrical plasma conductor with an alternating, longitudinal, high-frequency current. The plasma cylinder is placed in a constant longitudinal magnetic field and is enclosed in a conducting case. The problem is solved on the basis of the flexible filament model under the assumption of ideal conductivity of the plasma and the case. Hill's method is used to study the stability of the equation with periodic coefficients that describe the oscillations of the filament. Results of computer calculations of the stability increments of oscillations in the first four resonance zones for various values of the parameters of the system are given.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 42–46, July–August, 1972.In conclusion the authors thank M. L. Levin for helpful discussions of the work.     

Study of the technological limitations of photolithography for the relief surface of a SOI wafer during formation of the three-dimensional micromechanical structure of an integral tensoconverter

The results of studying the formation of the three-dimensional micromechanical structure of an integral tensoconverter are presented. The technological restrictions on contact photolithography over the relief structure formed on the device layer of the silicon-on-insulator wafer are analyzed. The effect of the design parameters (the frame height and the width of the frame slit) are described.     

Evaluation of the morphology of particles produced by plasma-chemical synthesis of ceramic powders

A physicomathematical model of thermal and diffusion processes in a drop of a dilute metal salt solution during its heating in a plasma-chemical reactor for synthesizing metal oxide powders is presented. The results of numerical calculations are analyzed to assess the possible influence of the operation parameters of the reactor and the characteristics of the initial solution (precursor) on the morphology of the particles formed.     

The necessity of introducing a geometric control subsystem into the composite attitude control systems of spacecraft and aircraft with modern precision

We propose to introduce a geometric control subsystem into the attitude control systems of space-craft that would allow the current system sensor configuration to be determined in real time.     

Activity and selectivity of iron–molybdenum catalysts in synthesis of formaldehyde in an industrial installation

The results of operation of F-1 and F-2 iron–molybdenum formaldehyde synthesis catalysts in an industrial installation consisting of two series-connected tubular reactor are analyzed. The physicochemical properties of the catalysts were studied, and the relationship between the characteristics of acid–base sites, on the one hand, and the activity and selectivity, on the other hand, was determined. The formation of hydrogen on the industrial catalysts is improbable.     

Luminescence Excitation Spectroscopy of InAs/InGaAs/GaAs Quantum-Dot Arrays in the Temperature Range between 20 and 300 K

Optics and Spectroscopy - Evolution of photoluminescence (PL) and PL excitation spectra in structures containing InAs/InGaAs/GaAs quantum-dot (QD) arrays is investigated in detail as a function of...     

Influence of Alumina Nanoparticles on the Structure and Physical and Mechanical Properties of Pure Aluminum

Russian Physics Journal -