Structure of three-loop contributions to the β-function of <Emphasis Type="Italic">N</Emphasis> = 1 supersymmetric QED with <Emphasis Type="Italic">N</Emphasis><Subscript>f</Subscript> flavors regularized by the dimensional reduction

In the case of using the higher derivative regularization for N = 1 supersymmetric quantum electrodynamics (SQED) with N _f flavors, the loop integrals giving the β-function are integrals of double total derivatives in themomentum space. This feature allows reducing one of the loop integrals to an integral of the δ-function and deriving the Novikov–Shifman–Vainshtein–Zakharov relation for the renormalization group functions defined in terms of the bare coupling constant. We consider N = 1 SQED with N _f flavors regularized by the dimensional reduction in the \(\overline {DR} \)-scheme. Evaluating the scheme-dependent three-loop contribution to the β-function proportional to (N _f)² we find the structures analogous to integrals of the δ-singularities. After adding the schemeindependent terms proportional to (N _f)¹, we obtain the known result for the three-loop β-function.     

Structure characterization of MHEMT heterostructure elements with In<Subscript>0.4</Subscript>Ga<Subscript>0.6</Subscript>As quantum well grown by molecular beam epitaxy on GaAs substrate using reciprocal space mapping

The crystallographic parameters of elements of a metamorphic high-electron-mobility transistor (MHEMT) heterostructure with In_0.4Ga_0.6As quantum well are determined using reciprocal space mapping. The heterostructure has been grown by molecular-beam epitaxy (MBE) on the vicinal surface of a GaAs substrate with a deviation angle of 2° from the (001) plane. The structure consists of a metamorphic step-graded buffer (composed of six layers, including an inverse step), a high-temperature buffer of constant composition, and active high-electron-mobility transistor (HEMT) layers. The InAs content in the metamorphic buffer layers varies from 0.1 to 0.48. Reciprocal space mapping has been performed for the 004 and 224 reflections (the latter in glancing exit geometry). Based on map processing, the lateral and vertical lattice parameters of In_xGa_1–xAs ternary solid solutions of variable composition have been determined. The degree of layer lattice relaxation and the compressive stress are found within the linear elasticity theory. The high-temperature buffer layer of constant composition (on which active MHEMT layers are directly formed) is shown to have the highest (close to 100%) degree of relaxation in comparison with all other heterostructure layers and a minimum compressive stress.     

Phase composition,microstructure, and thermophysical and dielectric properties of multiferroic Bi<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Dy<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>FeO<Subscript>3</Subscript>

An extensive study was performed to establish correlations between the crystal structure, the grain composition, and the dielectric and thermophysical properties of high-temperature multiferroics of the Bi_1?x Dy_x FeO₃ type (x = = 0.05–0.20). It is shown that a trade-off between the macroresponses in the materials is achieved at x = 0.10; this circumstance permits recommendation of the materials for practical use.     

Self-propagating synthesis of chromium acetylacetonate

After preliminary mechanical activation a mixture of solid chromium(III) chloride and sodium acetylacetonate becomes capable of reacting to form chromium acetylacetonate. The reaction may be carried out in the mode of a self-propagating process.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1150–1152, June, 1995.The work was carried out as a part of the Project No. 1-164 Mechanochemical Synthesis of Complex Compounds of State Scientific and Technical Program Ecologically Safe Processes in Chemistry and Chemical Technology under financial support of The Ministry of Science of the Russian Federation and of the Russian Foundation for Basic Research (Project No. 95-03-08244a).     

Automata in algebra

In this paper, some algebraic problems are considered. Several aspects of automaton theory and algebraic structures needed to obtain solutions of the problems are discussed.     

Investigation of interaction between reflected shocks and growing perturbation on an interface

This paper reports the result of investigation into Richtmyer–Meshkov instability (RMI) resulting from multiple interactions of shock waves with the interface between two media of different densities. The instability growth rates were measured after the interactions of the mixing zone with the refracted shock and the first and the second shocks reflected from the endwall. It was shown that for the contribution of separate shock–interface interactions to the instability growth rate, the condition of additivity is not realized. The values of the factor , accounting for the decrease in the RMI growth rate due to the thickening of the mixing zone, have been determined for a continuous interface and for a turbulent mixing zone. Received 27 January 1998 / Accepted 10 June 1998     

Experiment neutrino-4 on searching for a sterile neutrino with multisection detector model

Technical Physics - A laboratory for searching for oscillations of reactor antineutrinos has been created based on the SM-3 reactor in order to approach the problem of the possible existence of a...     

Prototropic equilibrium in 1(11)<Emphasis Type="Italic">H</Emphasis>-2, 3, 4, 5-tetrahydro[1, 3]diazepino[1, 2-<Emphasis Type="Italic">a</Emphasis>]benzimidazole,synthesis and pharmacological properties of its <Emphasis Type="Italic">N</Emphasis>-substituted derivatives

Based on the X-ray crystallography and ¹H NMR spectroscopy data and quantum chemical studies, it was found that 1(11)H-2, 3, 4, 5-tetrahydro[1, 3]diazepino[1, 2-a]benzimidazole (1) exists almost exclusively in the 1H-prototropic form. To prepare the fixed 11H-diazepinobenzimidazole forms of 1, 1-R-2-(4-chlorobutylamino)benzimidazoles (R = Me, N=CHAr) were synthesized, which underwent thermal cyclization with the formation of a mixture of 11-Rsubstituted diazepine 1 and 1-R-2-(pyrrolidin-1-yl)benzimidazole. Alkylation of diazepine 1 in a neutral medium regioselectively gave 11-R-diazepinobenzimidazoles in high yield. Their 1-substituted isomers were obtained by carrying out this reaction in the system NaH—THF. The N(11)-derivatives of diazepinobenzimidazole 1 were found to inhibit dipeptidyl peptidase 4 (DPP-4), but less actively than a comparator drug sitagliptin. The compounds under study did not exhibit antiglycation action in vitro and virtually did not affect activity of α-glucosidase and glycogen phosphorylase. However, they are characterized by a strong antiaggregant effect, making these derivatives promising for further studies.     

Experimental investigation of Richtmayer-Meshkov instability development on a contact discontinuity with three-dimensional disturbances

The results of an experimental investigation of Richtmayer-Meshkov instability on a contact discontinuity with three-dimensional disturbances are presented and compared with previously obtained results for contact discontinuities with two-dimensional disturbances.Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 111–117, November–December, 1995.