Synthesis and photochromic properties of spiroanthrooxazine

1,3,3-Trimethylspiro[indoline-2,3-3H-anthraceno[2,1-b][1,4]oxazine] was synthesized. The compound has photochromic properties in solutions and in polymeric matrices. It was found from the spectral data that the colored form of the spiroanthrooxazine exists in a quinoid form and is characterized by a positive solvatochromic effect.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1521–1525, July, 1990.     

Pseudosurface dispersion polaritons and their resonance excitation

The conditions for the transformation of surface polaritons (surface electromagnetic waves) into pseudosurface polaritons under the influence of perturbations are investigated. The transformation occurs because of the appearance of a weak energy loss flow typical of pseudosurface polaritons, which carries energy away from the surface of the solid. The dispersion polaritons existing at negative values of the dielectric constant are considered. The domain of existence of the pseudosurface polaritons is studied; their main characteristics and the parameters of the resonance excitation of these polaritons by a pumping wave are investigated.     

Plasmon Polaritons with Uniquely Long Free Path

JETP Letters - It is shown that the free path of plasmon polaritons propagating along the interface between a metal and a crystal may be greatly increased (up to several orders of magnitude) by the...     

Implications of the Marangoni effect on the onset of Rayleigh–Benard convection in a two-layer system with a deformable interface

The European Physical Journal Special Topics - The paper deals with the investigation of the implications of the Marangoni effect on the onset of Rayleigh-Benard convection in a two-layer system...     

New strategy for the synthesis of ladybird beetle azaphenalene alkaloids using a combination of allylboration and intramolecular metathesis. Total synthesis of (±)-Hippocasine and (±)-epi-Hippodamine

A new strategy for assembly a tricyclic skeleton of ladybirds azaphenalene alkaloids (coccinellides) was developed based on the combination of allylboration reaction and intramolecular metathesis. The first key step is the 1,2-organolithiation of 4-picoline with (4,4-dieth-oxybutyl)lithium with subsequent reductive allylation with triallylborane leading to trans-2-allyl-6-(4,4-diethoxybutyl)-4-methyl-1,2,3,6-tetrahydropyridine. The 4,4-diethoxybutyl substituent was further converted to 4-acetoxy-5-hexenyl in four steps, then, the product obtained was involved in the second key step, the intramolecular allylic amination upon treatment with a [Pd] or an [Ir] catalyst giving diastereomeric bicyclic terminal dienes (～1: 1), which were separated by chromatography. The stereochemistry of one of the dienes is the same as that in alkaloid Hippocasine. The third key step (the intramolecular metathesis reaction) includes the final assembly of the azaphenalene system. The tricyclic derivative obtained contains two differently substituted C=C bonds, selective hydrogenation of one of which (Pd/C) leads to (±)-Hippocasine, whereas exhaustive hydrogenation gives (±)-epi-Hippodamine.     

Non-axisymmetric oscillations of a hemispherical drop

Natural oscillations of a hemispherical drop on a solid substrate are considered. The Hocking condition is used to take into account the contact angle dynamics. The natural oscillations attenuate due to dissipation on the contact line and the degeneracy in the azimuthal number is eliminated. Forced oscillations of the drop are studied for tangential vibrations of the substrate. For the case of a fixed contact line, the amplitude of the forced oscillations grows without bound near the fundamental requency. In other cases, the amplitude is finite.Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, 2004, pp. 8–20. Original Russian Text Copyright © 2004 by Lyubimov, Lyubimova, Shklyaev.     

Investigation of the electrode potential drop at a molybdenum electrode in a flow of argon seeded with potassium

The results of an experimental investigation of the operation of an electrode in argon containing 0.15% of potassium at temperatures from 1400 to 1800 °C and a pressure of 1 atmosphere when the gas and the electrode are in thermal equilibrium are presented. The current-voltage characteristics obtained are compared with the theory of electrode processes developed previously [1, 2]. Good agreement is obtained between the theoretical and experimental data.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 132–136, July–August, 1970.