Studying permeability of nanostructures obtained from polyethylene threads

The paper studies process of interaction of a moving molecule with structure atoms. The mathematical description is based on application of Hamiltonian systems model and numerical methods for solving the basic problem of molecular dynamics. The interaction between individual atoms and the simplest molecules is cared out using the classical Lennard-Jones potential. Polyethylene nanostructures are considered as filtering elements for selective separation of natural gas mixtures, in particular, their light components: hydrogen and helium. The influence of geometric dimensions and geometric features of a nanostructure on selectivity of gas mixtures separation is studied

The interaction potential of an open nanotube and its permeability: molecular dynamics simulation

The integration of the modified LJ-potential allowed revealing the universal effect of the open carbon tube on the molecular objects moving within or proximate to the tube. There has been established that there are modes of the molecule motion without the energy exchange with the atoms of the carbon framing, under which the moving molecules are subjected to the considerable activation in the tube. The potential holes being the sorption zones in fact are localized

Social and moral potential of taekwondo in the education of young people

The paper deals with the problems of moral education of students by means of physical culture. The emphasis is placed on the consideration of martial arts with great educational potential. Using the example of taekwondo, the beneficial effect of this type of sports activity on the development of socio-moral personal characteristics of young people is shownВ работе рассматриваются проблемы нравственного воспитания учащейся молодёжи средствами физической культуры. Акцент сделан на рассмотрении единоборств, обладающих большим воспитательным потенциалом. На примере тхэквондо показано благотворное влияние данного вида спортивной деятельности на развитие социально-нравственных личностных характеристик молодёж

From self-similar groups to self-similar sets and spectra

The survey presents developments in the theory of self-similar groups leading to applications to the study of fractal sets and graphs, and their associated spectra

``Smoke Rings'' in Ferromagnets

It is shown that bulk ferromagnets support propagating non-linear modes that are analogous to the vortex rings, or ``smoke rings'', of fluid dynamics. These are circular loops of {\it magnetic} vorticity which travel at constant velocity parallel to their axis of symmetry. The topological structure of the continuum theory has important consequences for the properties of these magnetic vortex rings. One finds that there exists a sequence of magnetic vortex rings that are distinguished by a topological invariant (the Hopf invariant). We present analytical and numerical results for the energies, velocities and structures of propagating magnetic vortex rings in ferromagnetic materials.Comment: 4 pages, 3 eps-figures, revtex with epsf.tex and multicol.sty. To appear in Physical Review Letters. (Postscript problem fixed.