Influence of additives of Al2O3 on properties of aluminum nitride-based ceramic

The properties of AlN-based materials with additives of 5–50 mass% Al₂O₃ are investigated. It is established that addition of Al₂O₃ to AlN increases the oxidation resistance of the materials as well as their mechanical strength and thermal resistance while preserving their electroinsulating properties and corrosion resistance to molten metals. AlN-Al₂O₃ composites may be used in high-temperature technology as refractory materials, electrical insulators, as well as radio-transparent materials.     

Influence of the intensity of gg irradiation on the photoluminescence of GaAs:Te

The influence of gg irradiation (⁶⁰Co) of various intensities (P _γ≈1.7−7.5kGR/h) on the photoluminescence of GaAs:Te single crystals [n ₀=(1.2–2.3×10¹⁸ cm⁻³] is investigated. Together with the known photoluminescence impurity bands (hν _max≈1.2 eV and/or hν _max≈1.35 eV) and edge band (hν _max≈1.51 eV), new bands are also observed in the spectra at hν _max≈1.3 eV and hν _max≈1.48 eV. The observed effects are attributed to radiation-stimulated ordering of the donor impurity and deep impurity centers. Fiz. Tekh. Poluprovodn. 32, 38–39 (January 1998)     

Effects of initial powder vibrogrinding on the properties of AlN - BN composites

A study has been made on the effects of initial vibroground powders with various grain sizes on the properties of AlN - BN composites. As the specific surface of these powders increases, so do the density, mechanical strength, and thermal resistance of the composites.     

Nonstationary Dynamics of Vortex-Like Domain Walls in Magnetic Films with In-Plane Anisotropy

The dynamic rearrangement of the structure of vortex domain walls (DWs) in films with uniaxial in-plane anisotropy has been examined based on two-dimensional micromagnetic model simulation. The optimum computational region has been chosen; grids with up to 270 × 75 cells 3 nm in size have been used. The scenarios of dynamic rearrangement of the DW structure in strong fields (up to 450 Oe) and in films with thicknesses exceeding 100 nm have been revealed for the first time. The emergence of multivortex instantaneous distributions of magnetization upon an increase in the film thickness and the external field intensity have been established. The dependence of the critical field on the film thickness has been refined.     

Methane Adsorption on Microporous Carbon Adsorbent Prepared from Thermochemically Activated Wood

Protection of Metals and Physical Chemistry of Surfaces - An EC-103 microporous carbon adsorbent was synthesized from wood using thermochemically activation with Н3РО4 as an...     

Novel initiating system based on AlCl3 etherate for quasiliving cationic polymerization of styrene

Summary Quasiliving cationic polymerization of styrene was obtained in the system 2-phenyl-2-propano-/AlCl₃·OBu₂/Bu₂O in a mixture of 1,2-dichloroethane and n-hexane (55:45 viv) at -15 °C. The molecular weights of the polymers (M_n) increased in direct proportion to the monomer conversion. However, the experimental M_ns are essentially higher than theoretical ones, indicating that slow initiation relative to propagation takes place. The molecular weight distributions were broad (M_w/M_n2.5), probably due to the slow initiation and slow exchange between reversibly terminated and propagating species.