Simulation of time-resolved vibronic spectra and the possibility of analyzing molecules with similar spectral properties

The possibility of using time-resolved vibronic spectroscopy for spectral analysis of mixtures of chemical compounds with similar optical properties, when traditional methods (based on stedy-state spectra) are inefficient, is demonstrated by using the method of computer simulation. The analysis is carried out by the example of molecules of a series of polyenes (butadiene, hexadiene, octatetraene, decapentaene, and decatetraene), their various cis-and trans-rotational isomers, and phenyl-substituted polyenes. Ranges of relative concentrations of molecules similar in their spectral properties, where reliable interpretation of time-resolved spectra of mixtures and both qualitative and quantitative analyses are possible, are determined. The use of computer simulation methods for optimizing full-scale experiments in femtosecond spectroscopy is shown to hold much promise.     

Diffraction of Elastic Waves from a Cylindrical Infinite Cavity with Circular Cross Section Filled by a Liquid

Based on the equations of elasticity theory and hydroacoustics, we calculated the field structures arising when a plane wave is incident on an infinite cylindrical cavity with circular cross section filled by a liquid. The variable pressure component on the cavity axis for longitudinal and shear incident waves is determined.     

Technical Stability of Nonlinear Spatial Dynamic States of Continuous Systems in the Case of Their Interaction with a Flow of a Liquid

Nonlinear Oscillations -     

Liquid chromatographic analysis of prednisolone, prednisone and their 20-reduced metabolites in perfusion media

A reversed-phase liquid chromatographic assay was developed to quantitate prednisolone, prednisone and the 20 alpha-dihydro and 20 beta-dihydro reduced metabolites of both parent compounds in tissue culture media from in vitro perfusions of the human placental lobule. Steroids were extracted from perfusate, using reversed-phase cartridges, with average recoveries of 95.2% or greater. The internal standard for the analyses was 6 alpha-methylprednisolone. In this assay cortisol coelutes with prednisolone, however, no other significant interferences were found. Assay of each steroid was linear in the range 0-1 microgram/ml. Intra-assay coefficients of variation were measured at 10 and 750 ng/ml with ranges of 3.4% (20 alpha-dihydroprednisone) to 8.8% (20 beta-dihydroprednisolone) and 4.1% (20 beta-dihydroprednisone) to 8.8% (prednisone). The corresponding inter-assay coefficients of variation were 3.3% (20 alpha-dihydroprednisone) to 9.1% (20 beta-dihydroprednisolone) and 1.9% (prednisolone) to 3.5% (prednisone). The analyses utilized two C18 columns which were linked together and maintained at 40 degrees C.     

UniversalR-matrix for quantized (super)algebras

For quantum deformations of finite-dimensional contragredient Lie (super)algebras we give an explicit formula for the universalR-matrix. This formula generalizes the analogous formulae for quantized semisimple Lie algebras obtained by M. Rosso, A. N. Kirillov, and N. Reshetikhin, Ya. S. Soibelman, and S. Z. Levendorskii. Our approach is based on careful analysis of quantized rank 1 and 2 (super)algebras, a combinatorial structure of the root systems and algebraic properties ofq-exponential functions. We don't use quantum Weyl group.     

Luminescence of heterogeneous dimers of certain polymethine dyes in dichloroethane

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 5, pp. 881–884, November, 1991.