Single crystals and thin film growth in Bi(Pb)-SrCaCuO system by the flux method

We present ab initio calculations for Si ad-atom kinetics on surfactant (As, Sb) covered Si(111) considering the structures experimentally found during homoepitaxy. On As-covered Si(111), one exclusively finds islands with double-step height which always show the equilibrium (1 2 1)-structure. On the other hand, on Sb-covered Si(111) large Si islands with single-step height appear with (1 2 1)-structure, on which smaller islands nucleate which show the ( $ \sqrt{3} \times \sqrt{3} $ )-structure of the Sb-covered terraces. The competition between diffusion of ad-atoms on top of the surfactant layer and incorporation into the layer by exchange with a surfactant atom, and the consequences for the island development on the different structures are discussed.     

Tokamak DEMO-FNS: Concept of magnet system and vacuum chamber

The level of knowledge accumulated to date in the physics and technologies of controlled thermonuclear fusion (CTF) makes it possible to begin designing fusion—fission hybrid systems that would involve a fusion neutron source (FNS) and which would admit employment for the production of fissile materials and for the transmutation of spent nuclear fuel. Modern Russian strategies for CTF development plan the construction to 2023 of tokamak-based demonstration hybrid FNS for implementing steady-state plasma burning, testing hybrid blankets, and evolving nuclear technologies. Work on designing the DEMO-FNS facility is still in its infancy. The Efremov Institute began designing its magnet system and vacuum chamber, while the Kurchatov Institute developed plasma-physics design aspects and determined basic parameters of the facility. The major radius of the plasma in the DEMO-FNS facility is R = 2.75 m, while its minor radius is a = 1 m; the plasma elongation is k ₉₅ = 2. The fusion power is P _FUS = 40 MW. The toroidal magnetic field on the plasma-filament axis is B _t0 = 5 T. The plasma current is I _p = 5 MA. The application of superconductors in the magnet system permits drastically reducing the power consumed by its magnets but requires arranging a thick radiation shield between the plasma and magnet system. The central solenoid, toroidal-field coils, and poloidal-field coils are manufactured from, respectively, Nb₃Sn, NbTi and Nb₃Sn, and NbTi. The vacuum chamber is a double-wall vessel. The space between the walls manufactured from 316L austenitic steel is filled with an iron—water radiation shield (70% of stainless steel and 30% of water).     

Closedness and Adjoints of Products of Operators, and Compressions

We reprove and slightly improve theorems of Nudelman and Stenger about compressions of maximal dissipative and self-adjoint operators to subspaces of finite codimension and discuss related results concerning the closedness and the adjoint of a product of two operators on a Hilbert space.     

On one direct method for the approximate solution of a periodic boundary-value problem

We propose a direct method for the approximate solution of integral equations that arise in the course of approximate solution of a periodic boundary-value problem for linear differential equations by the method of boundary conditions. We show that the proposed direct method is optimal in order.     

Mass-spectrometric study of esters of marmesin and saturated acids

Summary From a methanolic extract of the roots ofPrangos biebersteinii Karjag., in addition to substances found previously, two other components — (I) and (II) — of the coumarin series have been isolated.The results of a study of their IR, NMR, and mass spectra, and also their chemical properties have enabled (I) to be identified as the known coumarin umbelliferone and the structure of 5-(1,2-dihydroxy-isopropyl)-4,5-dihydrofuro-2,3:7,6-coumarin to be proposed for (II), which has been named prandiol.Leningrad Sanitary-Hygenic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 574–577, September–October, 1974.     

Catalytic properties of cobalt and manganese complexes with macromolecular ligands in the liquid-phase oxidation of ethylbenzene

The selective catalytic effect of transition metal complexes (in particular cobalt and manganese) with polymeric ligands is shown on the example of the liquid-phase oxidation of ethylbenzene. The catalytic activity depends on both the structure of the polymeric matrix and the nature of metal.

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