Analytical Model for Atomic-Layer Deposition of Thin Films on the Walls of Cylindrical Holes with a Relatively High Aspect Ratio

A theoretical model that predicts the thickness of a film grown on the walls of high-aspect-ratio cylindrical hole using the atomic-layer deposition is proposed. The model can be used to calculate the critical time of precursor supply needed for conformal coating of the walls. An analytical model is derived to estimate the minimum time of precursor supply versus parameters of the technological process.

     

Generation of terahertz radiation by the optical breakdown induced by a bichromatic laser pulse

Experimental results are presented on generation of terahertz radiation by the air breakdown induced by a high-intensity laser pulse having not only a fundamental component, but also a second-harmonic one. A theoretical explanation of the experimental data is proposed, based on a model of field ionization of a gas by a bichromatic laser.     

Development of a compact hardware/software package for noninvasive diagnostics of skin diseases in the THz frequency range

The key elements of a mobile hardware/software package for noninvasive diagnostics of skin diseases in the THz frequency range have been designed, produced, and approved in model experiments. These elements are a compact THz oscillator based on an all-fiber femtosecond laser system and a unit for recovering electrodynamic characteristics of layered objects from scattered THz radiation spectra. Generation of 250-fs optical pulses at a wavelength of 1.03 µm with energy of 0.3 µJ and a repetition frequency of 1MHz is demonstrated and the efficiency of optical-THz conversion is found to be 5×10^?6. The proposed algorithm is constructed based on an iterative procedure and can be used for dispersive and absorbing media. It has higher operating speed in comparison with the algorithms for solving inverse problems, which are based on functional minimization methods.     

Peculiarities of the nitration of secondary polynitroalkanes

Conclusions In the interaction of salts of 1,1,1,3,5,5,5-heptanitro- or 1,5-difluoro-1,1,3,5,5-pentanitropentanes with nitrating systems based on HNO₃, 1,1,1,3,3,5,5,5-octanitro- or 1,5-difluoro-1,1,3,3,5,5-hexanitropentanes, 1,1,1,5,5,5-hexanitro- or 1,5-difluoro-1,1,5,5-tetranitropentan-3-ones, the O-bis-(2,2,2-trinitroethyl)nitromethyl ether of bis(2,2,2-trinitroethyl)carboxime or the O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl ether of bis(2-fluoro-2,2-dinitroethyl)carboxime are formed. The ratio of the reaction products depends on the composition of the nitrating system. The data obtained permit us to consider that the nitrating reagent is a nonionized form of HONO₂ or AcONO₂.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1357–1361, June 1986.     

Synthesis and structure of o-bis(2-fluoro-2,2-dinitroethyl)-nitromethyl ester of 2′-fluoro-2′, 2′-dinitroethyl-2″-fluoro-2″-nitroethylenecarboxime

Conclusions The product of conversion of O-bis(2-fluoro-2,2-dinitroethyl)nitromethylbis(2-fluoro-2,2-dinitroethyl)carboxime in methanol or ether is O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl-2-fluoro-2,2-dinitroethyl-2'-fluoro-2-nitroethylenecarboxinie, the structure of which has been established by x-ray diffraction analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2019–2021, September, 1987.     

New antimetastatic preparations based on chlorodinitromethyl-1,3,5-triazines

An approach to the synthesis of water-soluble chlorodinitromethyl-1,3,5-triazines was developed. For this purpose, a diamine bound to the 1,3,5-triazine cycle and capable to form hydrochloride salts on chlorination is introduced in a molecule.     

Curing of aqueous epoxy dispersions in the presence of a cycloaliphatic amine

The possibility of using a cycloaliphatic amine NC-558 as a curing agent for water-based epoxy compounds was examined. The effect of the component concentrations and temperature on the properties of the films obtained was studied.