9,926 research outputs found
Ab initio calculation of the dynamical properties of PPP and PPV
In this work, we have calculated the vibrational modes and frequencies of the
crystalline PPP (in both the Pbam and Pnnm symmetries) and PPV (in the P21/c
symmetry). Our results are in good agreement with the available experimental
data. Also, we have calculated the temperature dependence of their specific
heats at constant volume, and of their vibrational entropies. Based on our
results, at high temperatures, the PPP is more stable in the Pnnm structure
than in the Pbam one.Comment: 5 pages, 7 figures, accepted for publication in Braz. J. Phys.,
special number, Proceedings of BWSP-12, 12th Brazilian Workshop on
Semiconductor Physic
Observation of the dielectric-waveguide mode of light propagation in p-n junctions
Theoretical considerations of the propagation of electromagnetic energy near a p-n junction (1) show that the āsandwichā formed by having a depletion layer bounded by the p and n regions can act as a dielectric waveguide. (1,2
CaracterizaĆ§Ć£o da variabilidade genĆ©tica de populaƧƵes locais de pimenta dedo-de-moƧa, utilizando marcadores RAPD.
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