Luminescent properties of anthracene-doped diphenyl crystal as a function of the electron dose

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 3, pp. 390–393, March, 1990.     

The influence of reverse excitation transfer on donor and acceptor fluorescence decay: Monte Carlo simulations

Department of Technical Physics and Applied Mathematics, Technical University of Gdańsk, Narutowicza 11/12, 80–952 Gdańsk, Poland. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 4, pp. 179–184, July–August, 1995.     

Simple synthesis of substituted 3-oxabicyclo[3.1.0]hexan-2-ones and their rearrangement in the presence of lithium iodide

2-Alkenylidenemalonic ester monoepoxides react with organolithium and organomagnesium compounds to give 1-ethoxycarbonyl-4-alkyl-6-alkenyl(alkyl, aryl, alkynyl)-3-oxabicyclo[3.1.0]hexan-2-ones in high yields. The latter, when an alkenyl fragment is present, undergo rearrangement in the presence of LiI to substituted 1-ethoxycarbonyl-3-oxabicyclo[3.3.0]-6-octen-2-ones or 3-(1,3-butadienyl)-4-butanolides.Institute of Chemistry, Bashkir Science Center, Ural Branch, Russian Academy of Sciences, Ufa 450054. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 946–954, April, 1992.     

2-(1H-Tetrazol-1-yl)­benzoic acid

In the title compound, C₈H₆N₄O₂, the tetrazole and benzene rings are planar to within 0.001 (1) and 0.007 (1) Å, respectively. These rings are not coplanar in the mol­ecule, the dihedral angle between them being 52.90 (4)°. Molecules are connected together by O—H⋯N and C—H⋯O hydrogen bonds, forming two-dimensional networks parallel to the xz plane with van der Waals interactions between them.     

Diffraction of light by ultrasound under the conditions of Fresnel reflection

The features of the Bragg diffraction of light by ultrasound under the conditions of Fresnel reflection from the boundaries of a perturbed layer have been investigated. It has been shown that layers based on acousto-optical gyrotropic crystals perturbed by ultrasound can be used as efficient light modulators. The relative intensities of diffracted waves have been found to be determined by the relation of the refractive indices of adjacent media and by the ultrasound intensity. With an increase in the thickness of the modulated layer, the reflection and transmission coefficients of the first-order diffracted waves achieve their maxima at a lower ultrasound intensity.     

Features of acousto-optic interaction in uniaxial gyrotropic crystals

The features of noncollinear acousto-optic interaction in gyrotropic crystals in the intermediate diffraction regime and the regime of Bragg diffraction were investigated. The dependence of the efficiency of diffraction in gyrotropic paratellurite, tellurium, and quartz crystals on the intensity of the ultrasonic wave, acousto-optic interaction length, and incident-light polarization was investigated. It is shown that the gyrotropy of the crystal is responsible for the appearance of a multiple-peak structure of the Bragg maximum. It has been established that in the case of propagation of incident and diffracted waves in the vicinity of the optical axis of the crystal, the diffraction efficiency is independent of the polarization state of the incident light. The results of theoretical calculations are in agreement with the experimental results obtained for uniaxial crystals. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 105–110, January–February, 2000.     

Single-step fabrication of drug-encapsulated inorganic microspheres with complex form by sonication-induced nanoparticle assembly

Sonication of nanoparticle suspensions confined within aqueous droplets of drug molecules in toluene produces drug-loaded silica or titania porous microspheres with complex morphology and storage/release properties.