On the output function in a Ginsburg’s machine

We give the form of the output function in Ginsburg’s machine in which the input and output dictionaries are abelian groups and the transition function is of a special form.     

Sur des solutions maximales de l'équation de translation

Sans résumé

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Dédié à la mémoire de Alexander M. Ostrowski à l'occasion de l'anniversaire de sa naissance     

Investigation of preheating of laser thermonuclear targets

The preheating level of the thermonuclear fuel and of the gas-compressing shell is the main criterion of the target-compression efficiency in experiments on laserdriven thermonuclear fusion. This paper contains the result of investigations of electronic, radiative, and impact preheating in experiments on compression and heating of hlgh-aspect shell targets in the Del'fin-l laser-derived thermonuclear facility. A procedure, based on analysis of the epithermal emission of the plasma, is considered for measuring the target preheating by fast electrons. The radiative and impact preheating of compressing shells in DD gas are estimated. The results of the investigation demonstrate the high degree of adiabaticity of the compression of the thermonuclear fuel in experiments with the Del'fin-l facility.Nuclear Plasma Laboratory of the Lebedev Physics Institute. Translated from Preprint No. 3, Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow, 1990.     

General characteristics of the copper-based mercury film electrode

The optimum conditions for the preparation, storage, conditioning and renewal of copper-based mercury film electrodes (CBMFEs) are given. The voltammetric results obtained at these electrodes are compared with the predictions of the theory of cyclic and stripping voltammetry at the mercury film electrode, as well as with the results obtained at the silver-based and the platinum-based mercury film electrodes. The advantage of a CBMFE is prolonged life-time, whereas the disadvantages ar the decreased range of usable positive potentials and the possibility of interfering reactions of the electrodeposited metals with the copper substrate or copper dissolved in the mercury phase. The presence of copper has no essential influence on the behaviour of lead and thallium; it affects the behaviour of zinc markedly and that of cadmium and indium slightly. The conditions allowing the minimization of the harmful action of copper on the behaviour of cadmium and indium have been found.     

Investigations of Imidazoles. 101. Synthesis of 2,3-Dihydroimidazo[1,2-a]pyrimidine from 2-Aminopyrimidine

Two novel preparative methods have been developed for the synthesis of 2,3-dihydroimidazo[1,2-a]pyrimidine from 2-aminopyrimidine. These are the reaction with 1,2-dibromoethane and also the reaction with ethylene chloro(bromo)hydrin, subsequent treatment of 1--hydroxyethyl-2-imino-1,2-dihydropyrimidine with thionyl chloride, and cyclization of the intermediate 1--chloroethyl-2-imino-1,2-dihydropyrimidine in the presence of sodium hydroxide.     

Linear dichroism study of retinoids

Linear dichroism spectra of several retinoids and related polyenes incorporated in stretched polyethylene films were determined. It is suggested that the retinoids are oriented with the plane of the ring parallel to the stretching direction of the film, the long polyene chain being displaced from that direction.     

Novel methyl helianthrones as photosensitizers: synthesis and biological evaluation

A combination of light, oxygen and a photosensitizer is used to induce death of cancer cells by photodynamic therapy. In this study, we have synthesized several new methyl helianthrone derivatives and compared their phototoxicity with that of hypericin. In contrast to hypericin, methyl helianthrones are soluble in aqueous solutions and have a broad range of light absorbance, which allows the use of polychromatic light. Structural modifications of methyl helianthrone demonstrated that substitution of hydrogen atoms of methyl helianthrone at Positions 2 and 5 with Br atoms or methylation of its phenolic hydroxyls, significantly increases the corresponding singlet oxygen quantum yield and their phototoxicity toward alphaT3-1, M2R and LNCaP cells. The phototoxicity of some of these compounds was similar to that of hypericin. Methyl helianthrones, like hypericin, accumulated mainly in the perinuclear region as evident by confocal microscopy. Irradiation of cells pretreated with methyl helianthrone derivatives generates intracellular reactive oxygen species and lipid free radicals, as shown by a fluorescentic probe and electron paramagnetic resonance methods, respectively. The phototoxicity of these methyl helianthrones as well as their ability to oxidize membrane lipids were significantly decreased on addition of specific Type-II inhibitors, suggesting the involvement of singlet oxygen as the main oxidant.     

Determination of thallium and lead in cadmium salts by anodic stripping voltammetry with addition of surfactants to suppress the cadmium peaks

Conditions have been found which make possible the determination of thallium and/or lead in cadmium and its salts without preliminary separation. The electrochemical activity of the cadmium, which usually interferes in the determination of thallium, is inhibited by the addition of 0.01% of polyethylene glycol of M.W. 4000. Thallium is determined by electrolysis at ?0.74 V vs. SCE, in 0.1M EDTA solution: 10^?1M thallium can be determined in the presence of 0.1M cadmium, while copper and lead at 10^?2M and 10^?5M respectively do not interfere. Lead is determined in 0.1M acetic acid containing 0.1% cetyltrimethylammonium bromide (CTAB). The addition of CTAB shifts the cadmium peak, as well as the optimum deposition potential for cadmium, to more negative values, making it possible to determine lead in the presence of cadmium as long as the deposition potential lies in the range between ?0.50 and ?0.56 V vs. SCE. Lead can be determined in the presence of ten times as much thallium.     

Effect of Substituents and of Wavelength of Irradiation on the Photo-Fries-Rearrangement of Enol-Esters Preliminary Communication

Enol-esters 1a-1e undergo clean Photo-Fries-rearrangements without side reactions. With anthroyl derivatives the reaction is observed only at 254 nm, not at 366 nm.