Multifrequency stimulated Raman scattering of light in liquid nitrogen infiltrated into 3D photonic crystals

Spectral characteristics of stimulated Raman scattering at least in synthetic opal matrices infiltrated with liquid nitrogen upon excitation by nanosecond laser pulses are studied. The effect of the stop band position on the generation efficiency of anti-Stokes components of stimulated Raman scattering up to the third order is demonstrated. The excitation threshold of stimulated Raman scattering in liquid nitrogen infiltrated into opals is significantly lower in comparison with the generation in bulk samples.     

Modeling the Competitive Heavy Metal Sorption onto Sediments with the Use of Multifactorial Experiment

Russian Journal of General Chemistry - A study of the competitive sorption of heavy metals onto sediments by means of a planned multifactorial experiment yielded equations describing the mutual...     

Catalytic activity of aminomethylated calix[4]resorsinolarene aggregates in hydrolysis of esters of phosphorus acids

The reaction kinetics of aminomethylated calix[4]resorcinolarenes (AMC) withp-nitrophenyl esters of phosphorus acids (EPA) in a water—DMF solution (30 vol.% DMF) was studied by spectrophotometry and³¹P NMR spectroscopy in the presence and absence of the nonionic surfactant Triton X-100. The AMC form aggregates of micellar and nonmicellar types and are the catalysts for EPA hydrolysis. The catalytic activity of the aggregates depends on their structure, pH of the medium, and the nature of the solvent. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1361–1365, August, 2000.     

Micellar effects of cation-active surfactants on the reaction of (o-aminomethyl)phenols with ethylp-nitrophenyl chloromethylphosphonate

The reaction of (o-aminomethyl)phenols with ethylp-nitrophenyl chloromethylphosphonate in aqueous micellar solutions of cation-active surfactants has been studied. The effect of the structure of the surfactant and the nucleophile, pH of the medium, and temperature on the reaction rate in the micellar phase has been investigated. The rate constants in micelles are much higher than those in water.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2065–2068, December, 1993.     

L- and R-Cross-Sections in the Brauer Semigroup

We classify all cross-sections of Green's relations L and R in the Brauer semigroup. The regular behavior of such cross-sections starts from n = 7. We show that in the regular case there are essentially two different cross-sections and all others are S_n-conjugated to one of these two. We also classify all cross-sections up to isomorphism.     

Cetylpyridinium bromide-based oil-in-water microemulsions as a medium for hydrolysis of esters of phosphorus acids in the presence of primary amines

High-resolution ¹H NMR technique with Fourier-transform and pulsed-gradient spin-echo was used to study the structure of oil-in-water microemulsions based on cetylpyridinium bromide. The sizes of microdrops and the distribution of components between the disperse and continuous phases were found. It was shown for the hydrolytic decomposition of O,O-bis-(p-nitrophenyl) methyl phosphonate in the presence of amines that the microemulsion medium can affect both the rate and mechanism of hydrolysis. The reaction rate constants depend on the structure of microdrops.