Investigation of clustering in light nuclei by means of relativistic-multifragmentation processes

New results concerning the topology of the fragmentation of relativistic nuclei ⁷Li and ¹⁰B are presented. A program is proposed for studying the cluster structure of stable and radioactive nuclei. The use of emulsions in the investigation of nuclear clustering in the fragmentation of light nuclei at energies are in excess of 1 GeV per nucleon is discussed.     

Hydrosilylation reactions of hydrosilatrane and 2-methyl-6-ethyl-1,3-dioxa-6-aza-2-silacyclooctane

Conclusions 1-Hydrosilatrane does not react with monosubstituted ethylenes (or acetylenes) either in the presence of platinum or rhodium complexes or upon initiation of the reactions using organic peroxides, UV irradiation, or thermal methods. By contrast, 2-methyl-6-ethyl-1,3-dioxa-6-aza-2-silacyclooctane readily takes part in hydrosilylation of the indicated unsaturated compounds when Rhacac (CO)₂ is present.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khirnicheskaya, No. 4, pp. 899–901, April, 1986.     

3-Aminopropylsilatrane and Its Derivatives: A Variety of Applications

Silatranes arouse much research interest owing to their unique structure, unusual physical–chemical properties, and diverse biological activity. The application of some silatranes and their analogues has been discussed in several works. Meanwhile, a comprehensive review of the wide practical usage of silatranes is still absent in the literature. The ability of silatranes to mildly control hydrolysis allows them to form extremely stable and smooth siloxane monolayers almost on any surface. The high physiological activity of silatranes makes them prospective drug candidates. In the present review, based on the results of numerous previous studies, using the commercially available 3-aminopropylsilatrane and its hybrid derivatives, we have demonstrated the high potential of 1-organylsilatranes in various fields, including chemistry, biology, pharmaceuticals, medicine, agriculture, and industry. For example, these compounds can be employed as plant growth biostimulants, drugs, optical, catalytic, sorption, and special polymeric materials, as well as modern high-tech devices.     

New atranes and similar ionic complexes. Synthesis,structure, properties

This review article summarizes the data on the synthesis, physicochemical properties, structure, reactivity and actual or potential pharmacological activity novel atranes and their analogs synthesized based on biogenic 2‐hydroxyethylamines (and other amines containing the NCH₂CH₂OH structural unit), biologically active (het)arylchalcogenylacetic acids, and essential metals.     

Plasmochemical synthesis of thin layers of the sulfur doped silicon dioxide

Plasmochemical synthesis of thin layers of the sulfur atoms doped SiO₂ on the basis of volatile Siorganoelement compounds containing the Si-S fragments was studied. Highly pure trimethyl-ethylthiosilane Me₃SiSEt was used as a precursor for deposition of the sulfur-silicate glass. SiO₂ layers with designated composition and properties required for construction of modern microelectronic devices were obtained.     

Directed synthesis and immunoactive properties of (2-hydroxyethyl)ammonium salts of 1-R-indol-3-ylsulfanyl(sulfonyl)alkanecarboxylic acids

A general method for the synthesis of 1-alkyl(allyl)(benzyl)-substituted (indol-3-yl)-sulfanylalkanecarboxylic acids and hexane-1,6-diyl(1,4-phenylenemethylene)bisindol-3-ylsulfanylalkanecarboxylic acids from the corresponding N-substituted indoles and bisindoles, thiourea, iodine, and halogencarboxylic acids was developed. The oxidation of substituted (indol-3-yl)sulfanylalkanecarboxylic acids for the first time afforded their analogs containing the sulfonyl group. New (2-hydroxyethyl)ammonium salts of 1-R-indol-3-ylsulfanyl(sulfonyl)-alkanecarboxylic acids, which are structural analogs of highly active immunomodulators of indacetamin and VILIM, were synthesized. Among the studied (2-hydroxyethyl)ammonium salts of 1-R-indol-3-ylsulfanylacetic and -sulfonylalkanecarboxylic acids, the compounds exhibiting high dose-dependent antiproliferative activity by the ability to affect the spontaneous and mitogen-stimulated splenocyte proliferation of mice in vitro were found.     

1,3-Dioxa-6-chalcogena-2-silacyclooctanes

Conclusions Transetherification of methylvinyldialkoxyslianes by diols (HOCH₂CH₂)₂M (M=O, S, Se, and Te) gave 2-methyl-2-vinyl-1,3-dioxa-6-chalcogena-2-silacyclooctanes CH₃ (CH₂=CH)Si(OCH₂· CH₂)₂M. The IR, NMR, and mass spectra of these compounds were studied.²⁹Si NMR spectroscopy indicated that there is a transannular interaction in such heterocycles only in the case of M=Te.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1859–1861, August, 1987.     

Problems in the prediction of the long-term strength of polymer materials. A review

Conclusions As in the case of the selection of the simplified equations used in the theory of nonlinear viscoelasticity, variants of the equations of the temperature-time dependence of the strength of polymer materials are constructed on the basis of some similarity condition of the experimental lifetime curves. Principles according to which it would be possible to make a prior assignment of a material to some class on the basis of similarity criteria only using, for example, information on chemical composition and structure without testing for long-term strength are lacking. The equations presented in this review may be used for predicting the lifetime only when the nature of the resistance to long-term destruction over time in a given temperature range exactly corresponds to the assumptions inherent in some equation. Thus, the selection of the boundaries of the temperature ranges, in which we may assume uniformity for the deformation and destruction mechanisms leading in the final analysis to identical types of destruction, becomes most significant. Hence, the parametrical methods have a series of advantages since they do not place rigid limitations on the nature of the long-term strength curves at a given temperature.The temperature-time analogy method is the most favored method for predicting long-term strength since this method, without negating other approaches, is their generalization. The use of this method is most promising for cases of a complex stressed state and complex stress pathways. In this case, the temperature -time shift function is most conveniently introduced into the surface strength functionals.Translated from Mekhanika Kompozitnykh Materialov, No. 4, pp. 694–704, July–August, 1979.