Extraction of Iridium(IV) from Hydrochloric Acid Solution with Bis(piperidinoethylthioethyl)-1-phenyl-1-ethanone

A bidentate organic compound containing nitrogen and sulfur donor atoms was tested as a reagent for extraction of iridium(IV) from aqueous solutions. The composition of the extractable Ir(IV) complex was determined by ¹H NMR, UV, and IR spectroscopy and elemental analysis.     

Inverse problems of the nonlinear electrodynamics of high-T c superconductors

A method is developed for reconstructing the dependence of the surface impedance of Z _s (H) of high-T _c superconductors (HTSCs) on the amplitude of an ac magnetic field from measurements of the nonlinear radiophysical characteristics of microwave HTSC resonators. It is shown that the nonuniformity of the structure of the electromagnetic field in a resonator lead to integral equations for Z _s (H). The corresponding integral equations are obtained for certain types of resonators. The errors of the conventional methods employing algebraic relations for Z _s (H) are analyzed. The Tikhonov regularization method, developed in the theory of ill-posed inverse problems, is used to reconstruct the functions Z _s (H) from the integral equations. Numerical experiments on the reconstruction of Z _s (H) were performed, and the requirements for the accuracies and other characteristics of the experimental data were determined from them. Zh. Tekh. Fiz. 68, 78–86 (August 1998)     

Resonant excitation and nonlinear evolution of waves in the equatorial waveguide in the presence of the mean current

We study interactions of planetary waves propagating across the equator with trapped Rossby or Yanai modes, and the mean flow. The equatorial waveguide with a mean current acts as a resonator and responds to planetary waves with certain wave numbers by making the trapped modes grow. Thus excited waves reach amplitudes greatly exceeding the amplitude of the incoming wave. Nonlinear saturation of the excited waves is described by an amplitude equation with one or two attracting equilibrium solutions. In the latter case spatial modulation leads to formation of characteristic defects in the wave field. The evolution of the envelopes of long trapped Rossby waves is governed by the driven complex Ginzburg-Landau equation, and by the damped-driven nonlinear Schr?dinger equation for short waves. The envelopes of the Yanai waves obey a simple wave equation with cubic nonlinearity.     

Synthesis and properties of N-[ω-(p-toluenesulfonoxyl)alkyl]uracils

Conclusions The possibility of N-(-hydroxyalkyl)uracil tosylates undergoing intramolecular cyclization to give bicyclic pyrimidinium salts was studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2349–2356, October, 1980.     

Approximations of exchange-correlation energy by functionals with kernels depends on difference of coordinates

An area has been found containing for any given electron density all possible values of exchange-correlation energy approximated by nonlocal expressions with kernels depends on the difference of coordinates. It is assumed that such functionals satisfy but a few evident physical restrictions.Subsystem of valent electrons of germanium has been considered for sake of illustration. The details of kernels behaviour have been shown to weakly affect the total exchange-correlation energy.     

Reactions of pyrimidinols and pyrimidinethiols with 2-chloroethanol and with 2-chloro-1-propanol

Conclusions In the reactions of pyrimidinethiols and pyrimidinols with 2-chloroethanol and 2-chloro-1-propanol 2-(pyrimidinylthio)alkanols and N-(hydroxyalkyl)pyrimidinones are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1613–1617, September.