1,721,228 research outputs found
On the optimized mixing of order and disorder in high-Tc ceramic superconductors
No full textCoherent excitations of localized states, represented by a selfsimilar Cayley tree, produce a gap in the density of states, which is deeper as the number of generations increases. The model can suitably describe systems in which an optimized concentration of "defects" allows self similarity of the state-tree and coherent coupling between clusters of localized states. A renormalization of the state-tree leads to a hierarchy of the energy eigenvalues
Current density and activation energy: a comparison between transport and magnetic measurements
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Vortex pinning and anisotropy in Ag/Bi(Pb)SrCaCuO-2223 tapes by means of surface columnar defects
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