Effect of nature of organic solvent on the absorption spectrum of C60 fullerene

Absorption spectrums of C₆₀ fullerene in 10 various organic solvents in the range of 300–620 nm was studied. In all the solvents the C₆₀ fullerene has four absorption maxima in the range under study. When an aromatic solvent has an ionization potential of 8.1 eV or lower a new additional absorption band appears in the absorption spectrum of C₆₀ fullerene, caused by the formation of a charge-transfer complex (CTC) of the solvent and C₆₀ fullerene.     

Synthesis of polyfunctional β-Ketosulfides and their reactions with m-chloroperbenzoic acid and chlorine dioxide

The reaction of bromoacetophenone with various thiols furnished β-ketosulfides: 2-(1-methyl-1H-imidazol-2-ylsulfanyl)-1-phenylethanone, 2-(1H-imidazol-2-ylsulfanyl)-1-phenylethanone, 2-(2-hydroxyethylsulfanyl)-1-phenylethanone. β-Ketosulfoxides were obtained by the oxidation of β-ketosulfi des with m-chloroperbenzoic acid and chlorine dioxide.     

Simulation of oxygen diffusion in pores in the case of catalytic oxidation reactions of coal

The oxygen diffusion equation is solved analytically for the case of the coal combustion in a steady-state regime. It is shown that the oxygen concentration essentially depends on the pore geometry.     

On the possibility of transverse size oscillations in a domain with a high free-electron concentration under the action of a short light pulse on a semiconductor

Computer simulation is used to demonstrate the possibility of transverse size oscillations in a domain with a high concentration of free electrons under the action of a light pulse on a nonlinearly absorbing semiconductor. The results of computer simulation are confirmed analytically by testing the system stability.     

Short range order in powder of amorphous anodic yttrium oxide

The characteristics of the short-range order in a powder of amorphous yttrium oxide obtained by anodic oxidation are determined by the Finbak-Warren method. It is established that the first coordination number equals seven. Amorphous oxide is built by irregular coordination polyhedra characteristic of the hexagonal and monoclinic modifications of yttrium oxide.     

Investigation of the contact area of a rigid spherical indenter and a polymeric surface at various pressures,temperatures, and contact times

The effect of temperature and normal load on the variation with time of the indentation depth of a rigid spherical indenter in polymeric materials has been investigated with the object of obtaining the dependence of the contact area on the principal parameters of the process. Plexiglas, PVC and polyformaldehyde were selected for study. It is shown that at a given temperature the ratio _m/(a/R)^n–2=A is a function of time only and almost independent of the applied load. It is established that the time-temperature superposition principle can be used for investigating metal-thermoplastic contact phenomena. An expression is obtained for calculating the contact area at various temperatures and loading times.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 3, pp. 457–464, May–June, 1971.     

Friction of polymeric materials

The case of contact of polymer and metallic surface has been examined. A formula is proposed for calculating the contact area as a function of time of holding the compression surface under load and for calculating the coefficient of friction, the dependence of Young's modulus and shear strength on temperature, deformation rate, and average force on the contact surface being taken into account. The nature of deformation of irregularities on the surfaces of polymeric materials under the action of normal and tangential loading has been examined.See [1] for Communication 1.Institute for Polymer Mechanics, Academy of Sciences of the Latvian SSSR, Riga. Translated from Mekhanika Polimerov, No. 5, pp. 809–815, September–October, 1972.