Structural characteristics of different types of nanoparticles synthesised in mesomorphic metal alkanoates

The class of thermotropic ionic liquid crystals (LCs) of the metal alkanoates possesses a number of unique properties, such as intrinsic ionic conductivity, high dissolving ability and ability to form time-stable mesomorphic glasses. These ionic LCs can be used as nanoreactors for the synthesis and stabilisation of different types of nanoparticles (NPs). Thus, some semiconductors, metals and core/shell NPs were chemically synthesised in the thermotropic ionic liquid crystalline phase (smectic A) of the cadmium octanoate (CdC₈) and of the cobalt octanoate (CoC₈). By applying the scanning electron microscopy, the cadmium and cobalt octanoate composites containing CdS, Au, Ag and core/shell Au/CdS NPs have been studied. NPs’ sizes and dispersion distribution of the NPs’ size in the nanocomposites have been obtained.     

Intramolecular cyclization of 4-amino-3-alkylsulfanyl-1,2,4-triazoles as a method for annelation of thiadiazine and thiadiazole rings

4-Amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiols reacted with N-substituted isatins to give 2-oxo-3-[5-(pyridin-4-yl)-3-sulfanyl-4H-1,2,4-triazole-4-ylimino]-2,3-dihydro-1H-indoles which were treated with phenacyl bromides to obtain the corresponding S-phenacyl derivatives. The latter underwent base-catalyzed intramolecular cyclization with formation of 6,7-dihydro-5H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines spiro-fused to 2-oxo-2,3-dihydro-1H-indole fragment at C³. Analogous cyclization of 2,6-di-tert-butyl-4-[5-hetaryl-3-(2-aryl-2-oxoethylsulfanyl)-4H-1,2,4-triazole-4-ylimino]cyclohexa-2,5-dienones involved the imino nitrogen atom to produce the corresponding 6-aroyl-5-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-hetaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles.     

Effect of the shape of an approximate potential on the calculation of vibrational levels of diatomic molecules

The effect of the potential shape on the calculation of vibrational levels of diatomic molecules is investigated in terms of the molecular parameters, obtained from its Dunham, Ogilvie-Tipping, Simons-Parr-Finlan, and Takkar approximate expansions. It is established that the last two representations provide the best reconstruction of vibrational levels from an adjustable potential.     

Magnetic resonance of short-lived triplet exciton pairs detected by fluorescence modulation at room temperature

The possibility of resonant electromagnetic field modulation of the rate of reactions between paramagnetic particles in a condensed medium lasting for 10^?8–10^?10 sand shorter than the spin-lattice relaxation time has been demonstrated experimentally. The EPR spectra of triplet exciton pairs in tetracene and charge transfer crystals have been recorded at room temperature.     

Periodic Orbits and Bifurcations of the Vibrational Modes of the Ozone Molecule at High Energies

Russian Physics Journal - The study of quantum states near the dissociation threshold is necessary both to understand the formation of molecules and to explore accurately chemical reactions....     

Hybrid opto-TV image-processing system

Quantum Radiophysics Division. Translated from preprint No. 23, 1991 of the Lebedev Physics Institute, Russian Academy of Sciences, Moscow, Russia.     

Laminar heat transfer near an asymmetric stagnation point

This paper considers the laminar boundary layer at an obstacle near the stagnation point of a three-dimensional incompressible potential flow, asymmetric with respect to this point (e.g., for a jet incident at an angle on an obstacle). The effect of compressibility is investigated in the example of a plane subsonic flow. The solution in the close vicinity of the stagnation point is obtained by expanding in series with respect to the longitudinal coordinate, and for the more distant vicinity, the problem is solved by the method of local similarity. It is shown that in this case (in contrast with a symmetric flow [1, 2]) the maximum heat flux does not coincide with the stagnation point.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 140–145, November–December, 1976.The author thanks V. V. Lunev for stating the problem and for scientific guidance.     

Study of solid-surface states by RYDMR spectroscopy

A new approach for studying solid-surface states is proposed. This approach is based on the reaction-yield-detected-magnetic-resonance (RYDMR) phenomenon and on detection of magnetic resonance spectra of spin-correlated pairs of particles on solid surfaces. The approach was verified for surface particles arising as follows: (1) From the fracture of AgBr crystals and cellulose samples; (2) under high pressure on the ruby crystal surface. The depth of the surface analysis is about 0.5–1 nm.