Nonlinear inverse problem of reconstructing transport coefficients

The inverse coefficient problem for the quasilinear heat-conduction equation is solved numerically.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 6, pp. 909–915, December, 1985.     

Joint scientific council on the complex problem of mechanical engineering of the Russian Academy of Sciences in 2010

Mechanical engineering is the material base of scientific and technical progress of a country, its economy, and national security. This makes it necessary to ensure the transfer of industry to a new technological base, providing a decrease in the material intensity and energy consumption of industry and growth in labor productivity and competitiveness of produced goods.     

Hydrogen sorption by carbon nanomaterials

Hydrogen sorption by carbon nanomaterials has been investigated at a temperature of 298 K and pressure of 10 MPa by single and multiwalled nanotubes, graphitic nanofibers, and split graphite. The measurement error is calculated for the presented method. The obtained results are analyzed on the base of the physical-chemical foundation of sorption.     

Plastic relaxation of GeSi/Si(001) films grown by molecular-beam epitaxy in the presence of the Sb surfactant

Plastically relaxed GeSi films with the Ge fraction equal to 0.29–0.42 and thickness as large as 0.5 μm were grown on Si (001) substrates using the low-temperature (350°C) buffer Si layer and Sb as a surfactant. It is shown that introduction of Sb that smoothens the film surface at the stage of pseudomorphic growth lowers the density of threading dislocations in the plastically relaxed heterostructure by 1–1.5 orders of magnitude and also reduces the final roughness of the surface. The root-mean-square value of roughness smaller than 1 nm was obtained for a film with the Ge content of 0.29 and the density of threading dislocations of about 10⁶ cm^?2. It is assumed that the effect of surfactant is based on the fact that the activity of surface sources of dislocations is reduced in the presence of Sb.     

Simultaneous TE<Subscript>1</Subscript> and TE<Subscript>2</Subscript> mode lasing yielding dual-wavelength oscillation in a semiconductor laser with a tunnel junction

Dual-frequency oscillation is obtained and investigated in a new type of injection heterolaser, an interband two-stage cascade laser with a tunneling p-n junction separating two active regions with quantum wells located in a common waveguide. The laser design provides for simultaneous oscillation at the first-order TE mode of wavelength λ = 1.086 μm and the second-order TE mode of wavelength λ = 0.96 μm in the continuous-wave regime at room temperature.     

Production of Powdered α-Fe2O3 with Multilevel Gradient Porosity

Russian Journal of Non-Ferrous Metals - This article discusses methods for producing a material with gradient multilevel porosity by sintering layer-by-layer distributed α-Fe2O3 nanopowders...