On a Modification of the Scintillation Method

We solve the problem of diffraction of fluctuating radiation by an optically thin irregular layer (phase screen) with developed turbulent structure. It is shown that in the case of diffraction of radiation with saturated fluctuations and a narrow-band frequency spectrum by a weakly turbulent moving phase screen, the measured frequency spectrum of intensity fluctuations in the observation plane allows one to obtain information on the form of the spectrum of irregularities of an optically thin irregular layer in a wide size range significantly exceeding the size of the first Fresnel zone. Similarly to the well-known phase method of diagnostics of randomly irregular media, the conventional scintillation method modified in such a way yields undistorted information on the form of the irregularity spectrum. However, in contrast to the phase method, it also allows one to obtain data on the drift velocity of irregularities in the studied irregular layer.     

Analysis of appearance of moving ionospheric disturbances of the “sickle” type at middle latitudes

We present the results of analysis of the data of vertical ionospheric sounding at the Zimenki test site (Nizhny Novgorod). The January and July ionograms are used to plot the dependences of the number of “sickle” type disturbances on the time of the day for the period from 1996 to 1992. A comparison with the scattering in an ionospheric F-layer for the same period is performed. A trend in the time series of the phenomenon observed is recorded. Radiophysical Research Institute, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 40, No. 12, pp. 1455–1462, December, 1997.     

Thermodynamic modeling of the behavior of silicon oxide and nitride precursors in the preparation of dielectric layers

The thermodynamic properties of several silicon-containing derivatives of asymmetric dimethylhydrazine were estimated by comparative methods. The CVD diagrams of the deposition of silicon nitride and dioxide from gas media containing these reagents were constructed.     

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.     

Plasma-Enhanced Chemical Vapor Deposition of Silicon Carbonitride Films from Volatile Silyl Derivatives of 1,1-Dimethylhydrazine

Silicon carbonitride films were synthesized from new volatile precursors by plasma-enhanced chemical vapor deposition. Based on a detailed study of the morphology of film surfaces, it was found that the layer material was an amorphous matrix with inclusions of nanosized crystals. Calculation of the structure of the crystalline phase from synchrotron X-ray diffraction patterns demonstrated that the entire set of the diffraction peaks detected is indexed by a tetragonal structure with the lattice parameters a = 9.6 Å and c = 6.4 Å. This is consistent with the fact that the carbon 1s and nitrogen 1s core level X-ray photoelectron spectra exhibited only sp ³ bonding, which was expected for superhard carbon nitride phases.     

Hydrosilylation of Methylhydrosilyl Derivatives of 1,1-Dimethylhydrazine

Heating of dimethyl(2,2-dimethylhydrazino)silane and methylbis(2,2-dimethylhydrazino)silane with 1-hexene or styrene in the presence of a catalytic amount of rhodium dicarbonylacetylacetonate gives rise to adducts by the terminal carbon atom (yields 45-84%). The same reactions with phenylacetylene give complex mixtures of products formed primarily by disproportionation of the starting organosilicon reagents.     

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.     

Homolytic addition of polyhaloalkanes to α-vinyloxy-ω-trialkylstannoxy-alkanes as a new route to 2-perhaloalkylmethyl-substituted 1,3-dioxacyclanes

Photoinduced reactions of -vinyloxy--trialkylstannoxyalkanes, CH₂=CHO(CH₂) _n OSnEt₃ (n = 2 to 4), with polyhaloalkanes result in 2-perhaloalkylmethyl-substituted 1,3-dioxacyclanes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1824–1826, September, 1995.     

Hydrosilylation,hydrogermylation and hydrostannylation of 1-alkenylsilatranes

Conclusions The hydrosilylation and hydrogermylation of 1-vinyl- and 1-allylsilatranes in the presence of Rhacac(CO)₂ and the hdyrostannylation of these silatranes in the absence of catalyst leads to the formation of the corresponding terminal adducts in high yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 488–489, February, 1986.