Molecular structure of thin layers of pentameric polyorganocyclosiloxane

Birefringence in thin layers of a star-shaped pentameric polyorganocyclosiloxane has been studied by the oblique polarized beam method. The coefficient of birefringence is measured in relation to temperature and thickness of the surface layer. On the basis of these data, the melting temperature of the compound concerned is determined and the orientational-order parameter is estimated as ?0.27. The anisotropy of polarizabilities of pentameric polyorganocyclosiloxane molecules is theoretically estimated. A model of supramolecular structures that treats the formation of domains as stacks of pentameric polyorganocyclosiloxane molecules is advanced.     

Investigation into the correlation factor of substrate and multilayer film surfaces by atomic force microscopy

A method for studying the correlations between substrate and film-coating profiles by atomic force microscopy, which makes it possible to calculate the correlation factor (a function of spatial frequency), has been developed. The spatial-frequency range in which the correlation factor can be reliably calculated is established. The method proposed is used to calculate the dependence of the correlation factor on spatial frequency for multilayer interference mirror elements.     

Magnetic activity of nanostructured biopolymeric nanomagnets

The magnetic properties of arabinogalactan-stabilized iron-containing nanobiocomposites, which include magnetite nanoparticles, were studied. The magnetic characteristics of samples were measured on a SQUID magnetometer in the temperature range of 5–320 K and magnetic fields of up to 1.5·10⁴ G. The coercive force and the residual magnetization of ferroarabinogalactan nanocomposites are inversely dependent on the magnetite nanoparticle size.     

Dynamics of a pendulum with a quasiperiodic perturbation

The dynamics of a damped pendulum with a quasiperiodic external perturbation is investigated. It is shown that in contrast to a pendulum with a periodic perturbation, a quasiperiodic perturbation leads to chaos in the weakly nonlinear limit when the peak-to-peak amplitude of the oscillations of the pendulum is small. This effect is attributed to the appearance of saddle states induced by the external perturbation. The analytical conditions for the appearance of chaotic oscillations are obtained by the method of running Lyapunov exponents and by the repeated-averaging technique. Zh. Tekh. Fiz. 67, 1–7 (October 1997)     

A Class of Numerical Algorithms, Conservative at Stabilization, for Modeling Transport Processes

We consider a class of effective two-step symmetrized algorithms for numerical modeling of processes defined by boundary-value problems for transport equations with boundary conditions of the third kind in cases of various approximations of the convection terms of the equation and different ways of writing the difference schemes with respect to time. We prove that the algorithms are unconditionally stable and show that they are economical. We find an approximation for physical conservation laws on grid sets and prove that the difference algorithms are conservative when the process stabilizes.     

6-Hydroxyindole derivatives from benzoquinonimines

The reaction of N-arylsulfonyl-2,6-dichloro-1,4-benzoquinonimines with 3-alkylamino-erotonates proceeds with displacement of the arylsulfonyl group and formation of a substituted 6-hydroxyindole.Translated from Khimiya Geterosiklicheskikh Soedinenii, No. 4, pp. 490–492, April, 1976.     

Gold-Catalyzed Nucleophilic Addition of Imidazole to Arabinogalactan Propargyl Ether

Nucleophilic addition of imidazole to arabinogalactan propargyl ether has been accomplished for the first time in the presence of hydrogen tetrachloroaurate(III) tetrahydrate with the goal of obtaining new pharmacologically promising polysaccharides.     

Poly(ester urethane acrylates) and holographic properties of formulations on their basis

Poly(ester urethane acrylates) with unsaturated bonds in stiff blocks have been synthesized from oligo(ester acrylates) containing functional groups. The structure and mechanical properties of the block copolymers thus prepared have been studied before and after UV cure. On the basis of the said poly(ester urethane acrylates), light-sensitive formulations for holographic recording have been designed. The formation of holographic gratings under illumination by an Ar laser light has been investigated. The formations under study offer promise as photostructuring media for holography.