Authors:M. Popa, J. Calderon-Moreno, D. Crisan and M. Zaharescu
This work introduces results obtained during the preparation of a Bi-based material with superconducting properties by oxalate
The influence of Fe presence on the precursors thermal stability and on the superconducting phases formation mechanism are
presented. The thermal decomposition and the stability in air of FeC2O42H2O and also of the components mixture were studied by DTA/TG. It was evidenced that iron oxalate decomposes at the lowest temperature
compared to the decomposition temperatures of the individual oxalates.
XRD, IR and TEM/ED studies were approached to investigate the individual oxalates and the mixture coprecipitates for the high-Tc superconducting material synthesis.
Authors:L. Bernal-gonzález, M. Calderón-Moreno and J. Prado-Bassas
We characterize various kinds of cyclicity of sequences of coefficient multipliers, which are operators defined on spaces
of holomorphic functions. In the case of a single coefficient multiplier we characterize its cyclicity, which contrasts with
the fact that such operators are never supercyclic. Moreover, it is proved that for each cyclic function there is a dense
part of the linear span of its orbit all of whose vectors are cyclic.