Affichage de 142 résultats

Description archivistique
Sergio Porto
BR SPSIARQ SP · Collection · 1938-1992

Em geral, a documentação está diretamente relacionada aos estudos e pesquisas sobre as diversas aplicabilidade do raio laser. O acervo é composto por livros, revistas, artigos científicos, teses, material didático e cartas, além do processo de vida funcional.

Sans titre
BR SPSIARQ SP_Pi_AS_001 · Pièce
Fait partie de Sergio Porto

'The infrared spectrum of three diethyl benzenes has been observed in the region from two to forty microns. Different infrared spectrographs were used and absorption curves are given for the different regions. A Tentaive semi-emprirical, assigment of the observed frequences to the molecular vibrations is given."

BR SPSIARQ SP_Pi_ASC_019 · Pièce · 1973
Fait partie de Sergio Porto

" The behavior of the low frequency dieletric constant of NaNO2 as function of frenquency and temperature is consistently correlated to the temperature behavior of the frequencies and linewidths of the phonons of B1 summetry in the crytal. The frequency of the librational 'soft' mode closely related to the ferroelectric - paraelectric phase transition does not go to zero but tends to a hard core value at the transition temperature and frequency is explained by assumig a dielectric relaxation mechanism proposed by Mason and not by Cochran´s soft phonon model".

Sans titre