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Electronic and phononic properties of the chalcopyrite CuGaS2
The availability of ab initio electronic calculations and the concomitant
techniques for deriving the corresponding lattice dynamics have been profusely
used for calculating thermodynamic and vibrational properties of
semiconductors, as well as their dependence on isotopic masses. The latter have
been compared with experimental data for elemental and binary semiconductors
with different isotopic compositions. Here we present theoretical and
experimental data for several vibronic and thermodynamic properties of CuGa2, a
canonical ternary semiconductor of the chalcopyrite family. Among these
properties are the lattice parameters, the phonon dispersion relations and
densities of states (projected on the Cu, Ga, and S constituents), the specific
heat and the volume thermal expansion coefficient. The calculations were
performed with the ABINIT and VASP codes within the LDA approximation for
exchange and correlation and the results are compared with data obtained on
samples with the natural isotope composition for Cu, Ga and S, as well as for
isotope enriched samples.Comment: 9 pages, 8 Figures, submitted to Phys. Rev
Identification and localization of calcium-dependent protease II in Neurospora crassa and Uromyces appendiculatus
Summary: The existence of Ca2+-dependent protease II in crude extracts ofNeurospora crassa andUromyces appendiculatus was demonstrated by immunoblotting using specific antibodies. In both extracts two immunoreacting bands were observed. The molecular mass of the major band inN. crassa corresponded to 37 kDa, while that inU. appendiculatus was 43 kDa, similar to that previously reported forAllomyces arbuscula. Immunofluorescence of the enzyme was predominantly localized in the apical regions of germlings and growing hyphae, suggesting a functional role for the enzyme in hyphal growt
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