Structure and superconducting properties of Bi2Ba2−xMxCuO6+δ

The effect of oxygen nonstoichiometry and barium cation substitution on the structure and superconducting properties of Bi₂Ba_2−xM_xCuO_{6 +δ}(M = Sr, Ru, Rh, Pd, In, Sb or Pb;xchanged from 0 to 0.2) were studied. The cation-substituted samples annealed in oxygen flow contain a superconducting phase withT_c^initnear 95 K.     

Reconstruction of a Source from Observational Data

A procedure is described for determining the strength, position, and startup time of a surface force source acting on an elastic half-space from recorded data on the vertical displacements (seismograms) of a linear oscillator (seismograph). The algorithm is based on a previously published analytical solution of the Lamb problem. Special attention is given to the role of the Rayleigh wavefront as a generator of displacements much larger than in the approach of P waves and SV waves to the seismograph, revealing the Rayleigh wave as the primary indicator of a source's space–time position.     

Photoinduced reversible changes in local bonding configuration of amorphous Ge-S thin films

Reversible changes of the Raman spectra by the cycle of band-gap laser irradiation and annealing (storing in the dark) have been observed for amorphous Ge₂₀S₈₀ thin films for the first time.

The observed changes in the region of stretch vibrations of the chalcogenide atoms is direct evidence for the occurrence of gross structural changes in local bonding configuration caused by optical irradiation. It has been shown that under the laser irradiation the bonding tendency of the chalcogenide atoms is to form rings rather than chains, i.e. the cis-conformation is preferred over the trans-conformation.     

Reaction of 2 -methyl-2-cinnamoyloxiranes with benzylamine and thioacetic acid

Reaction of 2-methyl-2-cinnamoyloxiranes with benzylamine gave stereoisomeric 3-hydroxy-3-methyl-1-benzyl-6-aryl-4-piperidones, which were converted to 3-hydroxy-1,3-dimethyl-6-aryl-4-piperidones by debenzylation and subsequent methylation. 3-Hydroxy-3-methyl-6-phenyltetrahydro-4-thiopyrone acetate was obtained by reaction of 2-methyl-2-cinnamoyloxirane with thioacetic acid. The three-dimensional configurations of the synthesized compounds were established by means of their IR and PMR spectra.