Conducting Materials Based on Thermally Expanded Graphite

The electrical conductivity of composites produced from thermally expanded graphite, isoprene rubber, and polyvinyl chloride plastisol was studied as influenced by the process conditions.     

Basis set convergence studies of Hartree-Fock calculations of molecular properties within the resolution of the identity approximation

Within the resolution of the identity (RI) method, the convergence of the Hartree-Fock (HF) total molecular energy and the multipole moments in the course of the combined regular expansion of the molecular and auxiliary (RI) basis sets is studied. Dunning's cc-pVXZ series is used for both the molecular and the RI basis sets. The results show the calculated quantities converge to the HF limit when both the molecular and the RI basis sets are expanded from correlation-consistent polarized valence double zeta to correlation-consistent polarized valence sextuple zeta. Combinations of molecular/RI basis sets sufficient for convergence of the total energy and of the multipole moments at various accuracy levels have been determined. A measure of the RI basis set incompleteness is suggested and discussed. As it is significantly faster than the standard HF algorithm for small and midsize molecules, the RI-HF method, together with appropriate expanding series of both molecular and RI basis sets, provide an efficient tool to estimate and control the error of the Hartree-Fock calculations due to the finite basis set.     

Modified carbon nanostructures as materials for hydrogen storage

Within the framework of ab initio simulation, a number of modifications of well-known carbon nanostructures are proposed, which could form the basis for designing materials with high adsorptivity for molecular hydrogen.     

Classification of ternary forms with zero Hessian

In this paper we study the differential invariant algebra of the GL₃(ℂ)-action on the space of ternary forms with zero Hessian and classify GL₃(ℂ)-orbits of such forms.     

Nikola\overset{\lower0.5em\hbox{ Grigor’evich Bibikov (On his 60th birthday)

Chronicle

Nikola $\overset{\lower0.5em\hbox{$\overset{\lower0.5em\hbox{ Grigor’evich Bibikov (On his 60th birthday)     

Boundary-value problem for nonlinear Schrödinger equation

Leningrad State University. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 79, No. 3, pp. 334–346, June, 1989.     

Dirac operators on the quantum group SU(2) and the quantum sphere

The problem of constructing the Dirac operators on the quantum groupSU(2) and the quantum sphere S_qμ ² are discussed. In both cases, the constructions presented have the sameSU _q(2)-invariant form and are directly connected with the corresponding Laplace operators. Bibliography:16 titles. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 245, 1997, pp. 49–65. Translated by P. N. Bibikov.     

Experimental study of gasification of vacuum residue in metal melt by alternating reactor feeding with carbonaceous feedstock and oxidant

Processes occurring in a metal melt during plasma-assisted melt gasification of carbonaceous feedstock have been studied in the mode of alternating feeding the reactor with the carbonaceous feedstock and oxidant. Vacuum residue was used as an oxygen-free carbonaceous material, and air and steam were used as an oxidant. The results of the study show that by alternating the carbonaceous-feedstock pyrolysis step and the step of carbon oxidation in the metal melt, it is possible to produce synthesis gas with any desired H₂/CO ratio.     

Study of the reduction of silicon monoxide in arc plasma

The results of study aimed to reveal the existence of kinetic limitations on the reduction of silicon monoxide with methane carbon in arc plasma in relation to the potential use of this process in the proposed advanced technology for manufacturing pure silicon are reported. It was concluded that the amount of silicon monoxide should be two times its stoichiometric amount required for the complete consumption of the methane carbon and there are no kinetic constraints on the process of silicon monoxide reduction over a time of τ = 4–5 ms at atmospheric pressure and a temperature of T = 2240–2350 K.