Shock waves in a long-period optical fiber

The possibility of forming a shock wave of the pulse envelope has been investigated in a long-period or Bragg optical fiber with a system of two unidirectional linearly coupled waves. It has been demonstrated that, in principle, the possibility exists of forming a shock wave in a nonlinear optical fiber not only at the trailing edge but also at the leading edge of the wave packet. The origin of the formation of a shock wave depends substantially on the initial conditions providing excitation of the optical fiber.     

Thermodynamics of mixtures and solutions of hydroxypropylcellulose with poly(ethylene glycol)

Differential scanning calorimetry, X-ray diffraction analysis, polarization microscopy, methods of cloud points and static sorption, and a polarization-photoelectric installation were used to make a thermodynamic analysis of systems constituted by hydroxypropylcellulose, poly(ethylene glycols), and water. The thermodynamic parameters obtained were correlated with phase diagrams of these systems.     

Sorption and Thermodynamic Characteristics of Compositions of Water-Soluble Nonionic Polymers and Nanocluster Polyoxomolybdates

Russian Journal of Physical Chemistry A - New data on the interaction between methanol vapors and compositions based on polyvinylpyrrolidone and polyvinyl alcohol that include nanocluster...     

Synthesis and study of 3-(pyrimidin-2-yl)amino-1(2)H-1,2,4-triazole derivatives

The previously unknown 3-[4(3H)-pyrimidinon-2-yl]amino-1H-1,2,4-triazoles, which were converted to 3-[4-chloro-, 3-(4-ethoxy)-, 3-(4-hydrazinopyrimidin-2-yl)]-amino-2(4)H-1,2,4-triazoles, were obtained by the reaction of 2-nitroamino-4(3H)-pyrimidinones with 3-amino-5-hexyl-1H-1,2,4-triazole. The condensation of the initial products with -diketones gave 3-[4-(1H-pyrazol-1-yl)pyrimidin-2-yl]-amino-2(4)H-1,2,4-triazoles. The IR, UV, and PMR spectra of the synthesized compounds were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1678–1681, December, 1980.     

Synthesis and properties of carbon-chain polymers with pendant 1,3,4-oxadiazole rings

Carbon-chain polymers with 1,3,4-oxadiazole rings were prepared by radical polymerization and polymer-analogous transformations. The kinetic relationships of the polymerization of vinyl-1,3,4-oxadiazole monomers and some properties of the resulting polymers were studied. The thermodynamics of interaction of poly-2-vinyl-5-methyl-1,3,4-oxadiazole, a nonionic water-soluble polymer, with water was examined.     

Interaction between Dioxane and Nanocluster Polyoxomolybdates and Their Composites Containing Water-Soluble Polymers

Russian Journal of Physical Chemistry A - New data are obtained on the thermodynamics and molecular mechanisms of the interaction between dioxane and nanocluster polyoxomolybdates of the keplerate...     

Pulse dynamics in inhomogeneous optically coupled amplifying optical fibers with high-order dispersion effects taken into account

The evolution of the envelope of a two-mode wave packet in an inhomogeneous-over-length amplifying optical fiber is analyzed with the third-order dispersion effects taken into account, the presence of which leads to modulations of one or both edges of the wave packet. High degrees of compression of the pulse and the complete suppression of oscillations of its time envelope can be attained by an appropriate choice of the type of inhomogeneity of the dispersion parameters.     

Thermodynamics of water interaction with 5-vinyltetrazole copolymers with different hydrophilic-hydrophobic balances

The thermodynamics of interaction with water and the behavior of 5-vinyltetrazole copolymers with comonomers of different chemical natures and hydrophilicities in aqueous media have been studied. It has been shown that the presence of side perfluoroalkyl and disubstituted tetrazole fragments, which ensure a strong self-association of polymer chains in copolymer macromolecules, favors a greater decrease in water affinity of polymers compared to the effect of hydrophobic alkyl substituents.     

First representative of macroheterocyclic ligands of the dibenzo-[c,m]dipyrazolo[3,4-f:4′,3′-j][1,2,5,8,912]hexaazacyclotetradecene class

The first representative of macroheterocyclic ligands of the dibenzo[c,m]dipyrazolo[3,4-f:4,3-j][1,2,5,8,9,12]hexaazacyclotetradecene class was obtained by nontemplate cyclization of 4,4-azobis(5-chloro-2,3-dimethyl-1-phenyl-1H-pyrazolium) bis(methylsulfate) with 2,2-diaminoazobenzene in an aprotic solvent in the presence of potassium carbonate or magnesium oxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 239–243, February, 1984.