Formation of the Shock Pressure Regime in the Form of a Traveling Wave in Nematic Twisted Cells

Physics of the Solid State - The paper presents a numerical study, within a nonlinear generalization of the classical Ericksen–Leslie theory, of a new nonlinear mechanism for the formation of...     

Spectral study of complexation ofcis,cis-1,3,5-tri[2-(diphenylphosphinyl)ethylamino]cyclohexane with copper(ii) and cobalt(ii) ions

The complexation ofcis,cis-1,3,5-tri[2-(diphenylphosphinyl)ethylamino]cyclohexane (L¹) with Cu²⁺ and Co²⁺ cations has been studied in different solvents by means of UV-Vis, ESR, and IR spectroscopy. It has been shown that in the CuL¹ complex the metal ion is pentacoordinated by three nitrogen atoms and two phosphinyl groups of the ligand and has a tetragonal-pyramidal environment. The conformation of the coordination polyhedron for the CuL¹ complex depends on the solvent. In the CoL¹ complex, as well as in the CoL² complex, where L² is 1,4,7-tris(2-diphenylphosphinylethyl)-1,4,7-triazacyclononane, the Co²⁺ ion has an octahedral environment and is bound to all donor atoms of the ligands.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1199–1202, July, 1993.The authors are grateful to A. G. Matveeva and Yu. M. Polikarpov for the fruitful discussions.     

The complexation of (N,N-diethylcarbamoylmethyl)diphenylphosphine sulfide with silver nitrate

The crystalline complex [Ag(L ¹)NO₃]₂ (A) was isolated by the interaction of (N,N-diethylcaibamoylmethyl)diphenylphosphine sulfide Ph₂P(S)CH₂C(O)NEt₂ (L ¹) with AgNO₃ in different solvents at the ratios of metal:ligand = 11 and 12. According to the X-ray data, complexA is a center-symmetric dimer with bridge sulfur atoms. The cations of the metal are in a tetrahedral environment formed by two S atoms and the O atoms of CO and NO₃ groups. The interaction ofL ¹ with AgNO₃ was studied in solution by IR spectroscopy, and the structures of the complexes formed are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 708–713, April, 1994.The authors are grateful to B. V. Lokshin and his coworkers for help in measurement of the Raman spectra and for useful discussion.The present investigation was financially supported by the Russian Foundation for Basic Research (Project 93-03-4351).     

Electrically controlled waveguide mode in LC layer for fiber optic applications

A new electrically controlled waveguide mode for optical beams propagating in the plane of a liquid crystal (LC) layer is described. The mode is based on the total internal reflection of light beams from two parallel boundaries, which separates the regions of a liquid crystal cell with different director orientations and refractive indices. In experiments electric field was applied to the initially planar layer to produce the channel with a homeotropic orientation surrounded by the planar regions. It results in focusing and waveguide propagation of a light beam emitted by an optical fiber inserted in a liquid crystal cell. Scattering of light by thermal LC director fluctuations is used to visualize light beams propagation. The obtained waveguide mode can be used for an elaboration of electrically controlled LC switches with low operating voltages. The prototype of such device made with usage of a photolithography and a photo alignment technique is described. The possible ways of optimization of LC-switch are considered.     

Test center of the Novosibirsk Chemical Concentrate Plant

The authors of this paper, Head of the Control and Methodological Laboratory of the Central Plant Laboratory (CPL) A.I. Kamelin, Head of CPL N.P. Miroshnik, and Deputy Head of CPL V.L. Pasechnik, recollect stages of the development of plant analytics and, which is most important, the people responsible for the success achieved by the plant test center, whose core was always the Central Plant Laboratory.     

Amino-substitutedgem-diphosphonic acids: Dissociation mechanism and the structure of species in aqueous solutions

The mechanism of dissociation of amino-substitutedgem-diphosphonic acids R₂N(CH₂) _n CR'(PO₃H₂)₂ with different lengths of the alkylidene chain and different substituents at the N atom was studied by vibrational (IR, Raman) and NMR (¹H,¹⁴N,³¹P) spectroscopy using data of conformational analysis (molecular mechanical) data. The important role of intramolecular H-bonds and cyclic solvates for the stabilization of various conformations and tautomeric forms of ions was demonstrated. The spectral data that allow one to consider thegem-diphosphonate group as a single acidic center were found. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 6, pp. 1051–1064, June, 2000.