Conservation laws for a charged particle moving in gravitational and electromagnetic fields. I. Conserved quantities

Kazan State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 112–118, November, 1994.     

Investigations in the dipiperidyl series

The reduction of 2-(2-piperidyl)pyridine gives diastereomers of 2,2-dipiperidyl (III and IIIa). The action of phosgene on III gave tricyclo[1.6.7.12]-1,12-diaza-13-tridecanone and 1-chlorocarbonyl-2,2-dipiperidyl. The latter reacts with sodium ethoxide to give 1-ethoxycarbonyl-2,2-dipiperidyl, which is also obtained by alternative synthesis from III and ethyl chlorocarbonate.See [1] for communication X.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 954–956, July, 1972.     

Spectral‐Luminescent Properties of 1,1‐Dioctadecyl‐3,3,3'3'‐Tetramethylindodicarbocyanineperchlorate in Binary Solutions

On the basis of investigation of the absorption and luminescence spectra of 1,1dioctadecyl3,3,3'3'tetramethylindodicarbocyanineperchlorate (D307) molecules and their nonamphiphilic analog in binary solutions of dimethylformamide and water of different composition, a mechanism underlying the quenching luminescence of the D307 molecules has been established which is related to the formation of nonluminescent associates. It is shown that the formation of the micelles of sodium dodecylsulfate (SDS) in a binary solution with 99% content of water destroys the associates, the D307 molecules are captured by the micelles, and their mobility in the micelles is limited.     

Birefringence and anisotropic optical absorption in porous silicon

The refractive indices and the coefficients of optical absorption by free charge carriers and local vibrations in porous silicon (por-Si) films, comprising nanometer-sized silicon residues (nanocrystals) separated by nanometer-sized pores (nanopores) formed in the course of electrochemical etching of the initial single crystal silicon, have been studied by polarization-resolved IR absorption spectroscopy techniques. It is shown that the birefringence observed in por-Si is related to the anisotropic shapes of nanocrystals and nanopores, while the anisotropy (dichroism) of absorption by the local vibrational modes is determined predominantly by the microrelief of the surface of nanocrystals. It is demonstrated that silicon-hydrogen surface bonds in nanocrystals can be restored by means of selective hydrogen thermodesorption with the formation of a considerable number of H-terminated surface Si-Si dimers.     

Complexation of polycations to anionic liposomes: composition and structure of the interfacial complexes

Poly(N-ethyl-4-vinylpyridinium bromide) (a polycation with a degree of polymerization of 1100) was adsorbed onto liposomes composed of egg lecithin with a 0.05-0.20 molar fraction (nu) of anionic headgroups provided by cardiolipin (a doubly anionic lipid). According to electrophoretic mobility data, this led to total charge neutralization of the liposomes, whereupon the liposomes adopted a positive charge as additional polymer continued to adsorb. Although the liposomes aggregated at the charge-neutralization point, they disassembled into individual liposomes after becoming positively charged. The degree of polymer adsorption was shown to reach a limit. Thus, by measuring the free polymer content in a liposome suspension, it was possible to determine the polymer concentration at which the liposome surface became saturated with polymer. Beyond this point, an electrostatic/steric barrier at the surface suppressed further adsorption. Dynamic light scattering studies of liposomes with and without adsorbed polymer allowed calculation of the polymer film thickness which ranged from 22 to 35 nm as the molar fraction of cardiolipin (nu) increased from 0.05 to 0.20. The greater the content on the anionic lipid in the bilayer, the thicker the polymer film. The maximum number of polymer molecules adsorbed onto the liposomes was estimated: 1-2 molecules for nu = 0.05; 3 molecules for nu = 0.1; 4- molecules for nu = 0.15; and 6 molecules for nu = 0.2. The polymer appears to lie on the liposome surface, rather than embedding into the bilayer, because addition of NaCl easily dislodges the polymer from the liposome into the bulk water.     

Metal complexes of tetra(6-tert-butyl-2,3-quinolino)porphyrazine: I. Synthesis

Complexes of tetra(6-tert-butyl-2,3-quinolino)porphyrazine with Cu, Co, Zn, and Ni soluble in hydrophobic liquids were synthesized for the first time by template tetramerization of derivatives of 6-tert-butylquinoline-2,3-dicarboxylic acid formed from the corresponding acid in the course of carbamide synthesis in presence of the bivalent metal ions.     

Metal complexes of tetra(6-<Emphasis Type="Italic">tert</Emphasis>-butyl-2,3-quinolino)porphyrazine: II. Spectral properties

Quanitative spectral characteristics of Cu, Co, Zn, and Ni tetra(6-tert-butyl-2,3-quinolino)porphyrazine complexes prepared for the first time and soluble in hydrophobic liquids were measaured. Analogous spectral data of the protonated forms of complexes dissolved in sulfuric acids were also evaluated.     

On the investigation of free vibrations of nonthin cylindrical shells of variable thickness by the spline-collocation method

For determining the dynamic characteristics of free vibrations of circular unclosed cylindrical shells of variable thickness in two coordinate directions, we have used the spline-collocation method together with the method of discrete orthogonalization. The problem has been solved within the framework of the refined Timoshenko–Mindlin theory. We have also investigated the influence of different laws of change in the shell thickness on the character of its natural vibrations. Our calculations have been carried out for different geometrical and elastic parameters of the shell under study and different boundary conditions.