Identification of low-energy light nuclei recorded by means of an ionizational mass spectrometer

A method of identifying low-energy nuclei from the readings of an ionizational mass spectrometer is considered. The identification principles for particles recorded by a multilayer detector are discussed, together with the fundamentals of a probabilistic approach to the solution of this problem. The method permits correct analysis of the experimental data obtained. The determination of the charge and isotopic composition of radiation consisting of a mixture of different nuclei is considered. The results of calculations by the given method which permit the determination of the optimal detector parameters for the solution of the specific physical problem are outlined. This approach is also applicable for the analysis of data from other types of measuring apparatus.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 84–88, July, 1991.     

Modulation of Particle Concentrations in the Interference Laser Radiation Field

Spatial redistribution of microparticles in a suspension on exposure to the interference laser field depending on the parameters of the particles and the field characteristics has been analyzed theoretically. Results of experimental investigations are presented that illustrate the capture of an ensemble of polymeric small spheres and also of the lymphocytes of human blood and other microparticles in a liquid in the interference radiation bands of the He–Ne laser.     

Synthesis of indoles from pyridinium salts. 1. Recyclization of 4-alkyl-2,6-dimethyl-3-nitropyridine methiodides in the presence of ketones

A method for the synthesis of 4-alkylpolymethylindoles by recyclization of 4-alkyl-2,6-dimethyl-3-nitropyridine methiodides in the presence of ketones was developed. A method for establishing the structures of the polyalkylindoles on the basis of data from the PMR spectra and the proton-coupled ¹³C NMR spectra is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 509–518, April, 1985.     

Reaction of alkyl-3-nitropyridinium salts with dimethylformamide diethylacetal

Alkyl-3-nitropyridinium salts react with DMF diethylacetal to give -aminovinyl derivatives under considerably milder conditions than with the corresponding bases. The regioselectivity of this process has been studied in dependence on the structure and positions of the alkyl substituents in the initial salt.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1488–1494, November, 1993.This work was carried out with a grant from the Russian Fund for Fundamental Research (project # 93-03-4593).     

Synthesis of indoles from pyridinium salts. 7. Sterically hindered alkyl-3-nitropyridinium salts in the synthesis of indoles

The introduction of bulky alkyl substituents (iso-Pr,tert-Bu) into any positions of the starting 3-nitropyridinium salt only increases the reaction time and decreases the yields of the corresponding alkylindoles somewhat.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 805–810, June, 1989.     

Synthesis of indoles from pyridinium salts 5. Secondary amines in the reaction of 3-nitropyridinium salts with acetone

The use of secondary amines in the reaction of 3-nitropyridinium salts with acetone makes it possible to isolate stable intermediates in the formation of indoles — (o-N,N-dialkylaminobenzyl)ketones — and to observe new reaction pathways — the formation of bisindolylpropanes and p-nitroanilines.See [1] for Communication 4.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1213–1221, September, 1988.     

Direct synthesis of molecular self-complexes in the indole series

A method for the alkylation of 3-unsubstituted indoles by means of 1-(-haloalkyl)-pyridinium salts via the Friedel-Crafts reaction with the aid of complex catalysts, viz., complexes of zinc, tin, and titanium chlorides with pyridine, was developed. On the basis of a study of the electronic spectra of the resulting 1-(3-indolyl-alkyl)pyridinium salts it was shown that they are molecular self-complexes. The stabilities of the molecular self-complexes were investigated as a function of the length of the alkyl chain and the character of the substituents in the indole ring.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1222–1226, September, 1980.     

Rückstreung schneller Elektronen

The inelastic reflection of fast electrons is investigated on base of invariant imbedding method. The non-linear term in the integral equation is neglegted by means of the strong anisotropical elastic cross section of fast electrons. Using the small-angle approximation and the Laplace transformation a simple analytical formula is found expanding the backscattering coefficient into a series of Legendre polynomials. It has shown that the results from the model are in good quantitative agreement with experimental data.

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Rückstreung schneller Elektronen

Zusammenfassung Die Rückdiffusion schneller Elektronen wird mit Hilfe der Einschließungsmethode beschrieben, wobei das nichtlinere Glied in der erhaltenen Integralgleichung auf Grund der starken Anisotropie des elastischen Streuquerschnitts vernachlässigt wird. Eine einfache analytische Lösung, als Reihenentwicklung nach den Legendreschen Polynomen dargestellt, wurde im Modell kleiner Winkelstreuung und mit Hilfe der Laplace-Transformation gefunden. Es wird gezeigt, daß die erhaltenen Ergebnisse gut mit experimentellen Werten übereinstimmen.