Synthesis and Polar and Electrooptical Properties of a Butylamine Derivative of Fullerene C<Subscript>60</Subscript>

A butylamine derivative of fullerene was prepared by the reaction of butylamine with fullerene C₆₀. The experimental electrooptical and dipole characteristics of the derivative were compared with the corresponding calculated PM3 data. The reaction product proved to be inhomogeneous in the number of the amine molecules added; it contains polar multiadducts of C₆₀ with noncentrosymmetric distribution of covalently bound amino groups over the fullerene core.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 795–802.Original Russian Text Copyright © 2005 by Evlampieva, Yakimanskii, Dobrodumov, Nazarova, Pashkov, Panarin, Ryumtsev.     

Modern state of the catalytic reforming of petrol fractions. Experience of manufacture and industrial exploitation of reforming catalysts of the PR series

Analysis of the modern state of catalytic reforming is performed. Comparative assessment of the efficiency of various technologies of the process is given and their distribution in Russia and abroad is shown. Experience of the modernization of reforming installations with periodic catalyst regeneration is summarized. The state of manufacture of reforming catalysts in our country and accumulated experience of the development of catalysts of the PR series are presented. Results of industrial exploitation of new domestic reforming catalysts are shown. On this basis comparative assessment of Russian and imported catalysts is given. Original Russian Text D.I. Kiryanov, M.D. Smolikov, V.V. Pashkov, A.G. Proskura, E.V. Zatolokina, I.E. Udras, A.S. Belyi, 2007, published in Russkii Khimicheskii Zhurnal, 2007, Vol. 51, No. 4, pp. 60–68.     

On a game of optimal pursuit of an object by two others

A game problem of the simple pursuit of one object by two others, the former having a speed advantage, is analyzed. The duration of the game is fixed. The payoff functional is the distance between the object being pursued and the pursuer closest to it when the game terminates. Similar problems were examined in /1–7/.     

Long-lived localized magnetic polarons in ZnMnSe/ZnSSe type-II superlattices

The kinetics and polarized spectra of low-temperature photoluminescence in semiconductor type-II superlattices based on ZnMnSe/ZnSSe structures have been studied in detail. Processes responsible for the formation of short-lived (about 1 ns) and long-lived (above 10 ns) localized exciton-type magnetic polarons (EMPs) in these systems are determined, and the relative contributions due to magnetic and nonmagnetic localization of heavy holes to the formation of such polarons are evaluated. A phenomenological model is constructed that takes into account the energy distribution of charge-carrier traps with respect to their level depths and employs the EMP parameters determined for ZnMnSe quantum wells. Within the proposed model, all spectral, temporal, and temperature-dependent features in the behavior of magnetophotoluminescence observed for the system under consideration can be consistently and quantitatively described.     

The eigenmode expansion method for oscillations of an elastic body with internal and external friction

A method is proposed for solving dynamical problems for a viscoelastic body (the Kelvin-Voigt model) in a massless viscous medium. Interaction with the external medium produces on the boundary of the body stresses proportional to the rate of displacement. The model of external friction is that used for modelling dynamical processes in elastic media filling an infinite domain [1, 2]. The implementation of numerical methods of solution requires an equivalent restatement of the problem in a finite domain, using external viscous friction to allow for the radiation of energy at infinity.     

Trimethylaminedichlorogailane (Cl2Ga · NMe3)2 with the Ga-Ga intermetallic bond

The reaction of GaH₃ · NMe₃ with ClPBu^t ₂ in ether occurs through the exchange of ligands followed by reduction of Ga³⁺ to Gaz+ to yield (GaCl₂ · NMe₃)₂. X-ray structural analysis demonstrated that gallium atoms in this compound form a direct metal-metal bond with the length of 2.421 Å.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 2078–2081, August, 1996.     

Synthesis of electrolytic manganese dioxide on a heated anode

Synthesis of electrolytic manganese dioxide on a heated anode was studied. The specific energy of chemical power cells fabricated using this dioxide in the Zn-Mn system is as high as 100 W h kg^?1.     

Adsorption of water molecules on yttrium barium cuprate superconductors

Gravimetry and thermogravimetric analysis were used to study the adsorption of water molecules on the high temperature superconductor YBa₂Cu₃O₇ at room temperature. It was found that water adsorption subdivides into surface adsorption and bulk adsorption, which starts after the formation at the surface of a physically bound water layer no less than 65–100 Å thick. During bulk adsorption, H₂O molecules diffuse from this surface layer to the lattice, where they form four bound states with desorption temperatures of ～208, 330, 370, and 775°C and heats of formation of 38, 99, 72, and 68 kJ/mol, respectively, and mainly occupy interstitial sites of the intermediate layers. The presence of molecules in the lattice does not affect either the superconducting transition temperature or resistance to direct current; however, it results in an increase in the surface resistance. The resistance to direct current increases due to the formation of dielectric inclusions of other phases.