Use of sodium pyrophosphate in the ion-exchange chromatography of oligonucleotides

All-Union Scientific-Research Institute of Molecular Biology. Vektor Scientific-Production Association, Ministry of the Medical Industry, Koltsova, Novosibirsk. Novosibirsk Institute of Bioorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 148–149, January–February, 1992.     

Modeling of carbonaceous feedstock pyrolysis in a multichannel reactor

A mathematical model of unsteady-state carbonaceous feedstock pyrolysis in a multichannel tubular reactor was proposed. It was shown that the conversion of feedstock being heated at periodically varying temperature can exceed the conversion on heating at constant temperature. The main design parameters of the multichannel reactor were determined.     

Fractal-cluster kinetics in phase transformations in the relaxor ceramic PLZT

Fractal formalism has been used to study the evolution of a heterophase state (consisting of polar nanoregions in a nonpolar matrix) subjected to polarization in an electric field within the diffuse phase transition in the transparent relaxor ferroelectric ceramic PLZT 8/65/35. The time dependences of the fractal dimensions of polar clusters under polarization switching and spontaneous backswitching at different temperatures have been derived from measurements of the elastic scattering of transmitted light. Various scenarios for the evolution of the heterophase and nanodomain states in relaxors with variation of the temperature and electric field are proposed. Fiz. Tverd. Tela (St. Petersburg) 41, 505–509 (March 1999)     

Oxygen-induced free-radical reactions in phenylone nitrated by nitroxide dioxide

The conversion of phenylone polymer (poly-m-phenylene isophthalamide) at 293 K under the action of a nitrogen dioxide?oxygen gaseous mixture and nitrogen dioxide and oxygen individually is studied by the ESR method. In the first case, aryliminooxyl and arylacylaminoxyl free radicals are recorded, whereas in the second, diarylaminoxyl and phenoxy free radicals. The presence of phenolic and phenyl benzoate polymeric products in nitrated phenylone is detected by IR spectroscopy. The mechanisms of reactions occurring in both the oxidation modes are considered.     

Heterogeneous and homogeneous hydrogenation of styrene and stilbene chromium tricarbonyl complexes

Heterogeneous hydrogenation of the styrene and stilbene chromium tricarbonyl complexes by molecular hydrogen on skeletal nickel and palladium on carbon as catalysts was studied. As compared to styrene and stilbene, their arene chromium tricarbonyl analogs are hydrogenated considerably more slowly, which is related, most likely, to strong adsorption of the π-complexes on the catalyst surface. For the homogeneous hydrogenation of these complexes using a H₂PtCl₆-SnCl₂-LiBr system, styrene and η⁶-styrene chromium tricarbonyl are reduced with a high rate, whereas stilbene and its chromium tricarbonyl complex are hydrogenated very slowly. A possibility of reduction of the unsaturated arene chromium tricarbonyl complexes by sodium borohydride in the presence of cobalt(II) chloride as a catalyst was shown. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 44–47, January, 2007.     

High amplitude dislocation damping in superconducting Pb and In

The amplitude dependence of ultrasound absorption due to dislocations, α, has been studied for single crystals of pure lead and indium as well as for lead doped with Tl, Sn or Bi, both in the superconducting and normal state and for a wide range of ultrasound amplitudes, ε₀. Pure and Tl-doped superconducting lead at large ε₀ displayed a maximum on the α(ε₀) dependence which became a plateau upon transition to the n-state. This is direct evidence for a change from static to dynamic dislocation hysteresis as a result of the increase in the electron drag constant. Limit values for the dislocation loop lengths have been estimated, viz. 2.4 × 10⁻⁴ cm < L_N < 10.4 × 10⁻⁴ cm. In other single crystals the dynamic hysteresis occurred both in the n- and s-state. In all the single crystals, α increased with the increase of ε₀ above the maximum amplitude and onset of the plateau which was observed in both states. The effect is associated with non-linear phenomena arising at significant loop flexures. The amplitude dependence of the losses due to this effect has been analysed, the results of the analysis being in good agreement with the experimental data.     

Simulation of the deformation processes of nonlinear viscoelastic media

Questions of the similarity and the possibility of simulating the deformation processes of nonlinear viscoelastic medía are investigated. Systems of characteristic parameters are given. It is established that simulation based on the same material is possible only if the characteristic time of the process is the same and the stresses and strains at similar points of the model and the simulated object are equal. The characterstic time for a model made of different material is different from that for the simulated object.Mekhanika Polimerov, Vol. 3, No. 2, pp. 221–226, 1967     

Development of inhomogeneous fields under postcritical deformation of steel specimens in extension

The paper deals with experimental studies of inhomogeneous strain fields in the “neck” region in extension of plane and cylindrical specimens at the postcritical stage, which directly precedes the fracture, by using a video system and a digital image correlation method. We consider the problems of interpretation of extension diagrams obtained for specimens of various length with strain inhomogeneity in the working section of the specimen with a “neck.”We obtain experimental data about the distribution of longitudinal, transverse, and shear strain fields and the displacement fields in the region of the plane specimen localization by using the digital image correlation method.     

On the Generalized Heat Conduction Laws in the Reversible Thermodynamics of a Continuous Medium

Doklady Physics - A general covariance variational model of reversible thermodynamics is developed in which the kinematic and force variables are the components of unified tensor objects in the...     

The Influence of Submicron Particles of Coal Concentrate on the Conditions of Aerosol Synthesis of Carbon Nanotubes

Russian Physics Journal -