Synthesis and transformation of 2-methyl-3-acetyl-1,6-dioxaspiro[4,4]-2-nonene

Conclusions 2-Methyl-3-acetyl-1,6-dioxaspiro[4,4]-2-nonene is formed when tetrahydrofurfurole is reacted with acetylactone, from which some new furan, cyclopentenone, pyrrole and pyrazole derivatives were obtained.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 908–910, April, 1984.     

Synthesis of N-substituted pyrrole-3-carbaldehydes by hydroformamination of 2,5-dimethoxy-2,5-dihydrofuran

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, p. 1285, September, 1990.     

Distribution of radiant heat fluxes over the surface of three-dimensional and axisymmetric bodies in a supersonic ideal-gas flow

Numerous studies have been devoted to the calculation of supersonic radiating flow past bodies (see the bibliography in [1, 2]). In almost all these studies the gas flows investigated are plane or axisymmetric. Three-dimensional flows, however, have received little attention. The flow of air past three-dimensional bodies was considered in [3], where the chief object was to investigate the accuracy with which a real radiating volume can be simulated by the widely used plane-layer approximation. In [4] the flow of a hydrogen-helium mixture past three-dimensional bodies was investigated in the hypersonic approximation in the neighborhood of the stagnation point and in two planes of symmetry with allowance for the screening of the radiation of vaporized material.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1, pp. 92–97, January–February, 1986.The authors wish to thank V. V. Lunev for his useful observations and advice.     

Reversible relaxation of the shape of metal nanoparticles and its light-induced acceleration

A reversible change in the shape of metal nanoparticles with a variation of the temperature of a dielectric substrate has been revealed. It has been shown that illumination increases the rate of the relaxation of the shape of the nanoparticles. The observed phenomena have been interpreted in the framework of the light-induced diffusion of metal atoms on the surface of a metal nanoparticle.     

Femtosecond optical second harmonic generation by metal clusters: The influence of inhomogeneous line broadening on the dephasing time of surface plasmon excitation

Received: 4 December 1998     

Method for preparation of methyl 3-(2,2-dimethyl-4-tetrahydropyranyl)-3-oxopropionate

A method is proposed for the synthesis of methyl 3-(2,2-dimethyl-4-tetrahydropyranyl)-3-oxopropionate on the basis of 2,2-dimethyl-4-ethynyltetrahydro-4-pyranol.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 466–469, April, 1979.     

Fabrication and laser-assisted modification of the Ag particles ensembles supporting quadrupole plasmon oscillations

Optical and Quantum Electronics - In this paper, a theoretical analysis of figure of merit (FOM) of a surface plasmon resonance (SPR) sensor with a buffer layer of magnesium fluoride has been...     

Chemical interface damping of surface plasmon excitation in metal nanoparticles: a study by persistent spectral hole burning

As demonstrated recently, persistent spectral hole burning in the optical spectra of metal nanoparticles makes possible the determination of the ultrafast dephasing time T₂ of surface plasmon excitation. Here, the influence of the chemical environment on the dephasing process is investigated under ultrahigh vacuum conditions by depositing an adsorbate on the nanoparticles. By comparing the optical spectra and the widths of the generated holes of the nanoparticles with and without adsorbate coverage, the influence of chemical interface damping on the dephasing process is examined. The potential of the novel procedure is demonstrated for silver nanoparticles on sapphire and quartz substrates using SO₂ as the adsorbate. A drastic decrease of T₂ for the adsorbate-covered nanoparticles is observed and explained by dynamic charge transfer of electrons from the particles into and out of adsorbate states of the SO₂ molecules. PACS 78.67.Bf; 61.46.+w; 71.45.Gm; 73.22.Lp; 68.43.-h