The determination of the populations of vibrational levels of molecules from electron diffraction data

The application of modern gas-phase electron diffraction for directly determining the populations of vibrational levels is demonstrated for the molecule I₂. It is concluded that, under the conditions of the conventional electron diffraction experiment, a thermal equilibrium can reliably be assumed for a gas jet but at a temperature which can be markedly lower than that of the nozzle. The diffraction results favour a Boltzmann distribution of molecules over the vibrational states.     

Percolation of the boundary layer of a newtonian fluid through a perforated obstacle

We study the behavior of an inhomogeneous conducting fluid percolating through a porous obstacle. For a family of boundary value problems with micro-inhomogeneities on the boundary and nontrivial internal microstructure we construct the homogenized problem and prove the convergence of solutions to the initial problem to the solution of the homogenized problem. Bibliography: 7 titles. Illustrations: 2 figures.     

Homogenization of a stratified magnetic fluid problem with microinhomogeneous magnetic field and boundary data

We consider a planar magnetohydrodynamic boundary layer of a stratified fluid with microinhomogeneous magnetic field and boundary data. The asymptotic behavior of the solutions to the Prandtl equations is studied in the case of rapidly oscillating magnetic field and boundary data. The convergence of these solutions to the solution of the homogenized problem is established. Bibliography: 6 titles. Illustrations: 1 figure.     

Water-Soluble Magnetic Nanocomposites Based on Carboxymethyl Cellulose and Iron(III) Oxide

The one-step synthesis of water-soluble composites from maghemite (γ-Fe₂O₃) nanoparticles with a diameter of 12 ± 4 nm and a biocompatible polysaccharide, namely, sodium salt of carboxymethyl cellulose, is described. The role of the polymer matrix consists in stabilization of the resulting nanoparticles by the electrostatic interaction of polymer carboxyl groups with the surface atoms of iron in the (3+) oxidation state. The dissolution of the composites in water affords aggregatively stable dispersions responding to the external magnetic field. The content of the magnetic phase (iron oxide) in the formulation of the maghemite–carboxymethyl cellulose composite is defined by the ratio of components during the synthesis.