Homogeneous symplectic structures of second order on loop spaces and symplectic connections

Scientific Industrial Association, All-Union Scientific Research Institute of Physicotechnical and Radiotechnical Measurements. Translated from Funktsional'nyi Analiz i Ego Prilozheniya, Vol. 25, No. 2, pp. 65–67, April–June, 1991.     

Determination of U,Ra and Th in waters from the Danube Delta area

The methods applied for natural uranium, radium and thorium determinations in water samples are shortly presented together with some preliminary results. The measurements will be continued as part of an extended program of ecological study of the Danube Delta area.     

The inverse problem of the scatter of unguided missiles

The inverse scatter problem determines the characteristics of the perturbations of the initial conditions, design parameters, and the wind velocity from given characteristics of the scatter of the point of impact of an unguided missile. A deterministic and a probabilistic formulation of the problem are considered. Some properties of its solutions are noted and a method of computing them is proposed.     

Electrochemical reduction of 1,1-dihalo-2,2-disubstituted cyclopropanes

The electrochemical reduction of 1,1-dihalo-2-R-2-methylcyclopropanes was studied by polarography and preparative electrolysis. A mixture of stereoisomeric monoboro- and monochlorocyclopropanes was obtained with preparative yield of 60–70% in preparative electroreduction in methanol against a background of 0.1 M LiClO₄. In the case of bromine derivatives of cyclopropanes (except when R = CN) an effect was found on the part of the current density on the ratio of cis and trans isomers, which was interpreted as a change, in dependence on current density, of the contributions of the reactions of reduction of the starting compounds (S_N2 mechanism) and ionic pairs (S_N1 mechanism). The effect of the solvent (CHCl₃, DMF, DMSO, MeOH) and background salt (LiClO₄, Et₄NBr) on the ratio of stereoisomers is in agreement with this interpretation.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, Kazan. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2023–2032, September, 1992.     

Solution of the Reich-Walczak problem regarding conformality in the Belinskii-Lavrent'ev sense

A positive answer is given to the Reich-Walczak problem relative to conformality in the Belinskii-Lavrent'ev sense of quasiconformal mappings at a point in the case of an arbitrary modulus of the complex characteristic and under an appropriate selection of its argument.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 44, No. 10, pp. 1406–1411, October, 1992.     

Theoretical and experimental investigation of x-band two-cavity gyroklystron

Using self-consistent field theory, the interaction of electron flow with HF fields in a gyroklystron has been analized. Optimal parameters of its output cavity corresponding to the maximum efficiency have been found. Experimental study of dependence of the efficiency on Q-factor and length of the output cavity has been carried out. The results of simulation are in good qualitative agreement with experimental data.     

Kinetics of domain growth in systems with thermal gradient

Monte Carlo simulations have been carried out to study the growth kinetics after a rapid quench of a system with nonconserved order parameter into a steady state characterized by a thermal gradient. Both the Allen-Cahn growth law for the average domain size as well as the scaling behavior, typical for systems evolving towards equilibrium, are observed. Some aspects of different spinupdating algorithms are briefly discussed.