RESUMEN
Resonant excited state absorption (ESA) and relaxation processes in Tb(3+)-doped aluminosilicate glasses are quantitatively evaluated. A model describing the excitation steps and upconversion emission is developed and applied to interpret the results from laser-induced surface deformation using thermal mirror spectroscopy. The fluorescence quantum efficiency of level (5)D(4) was found to be close to unity and concentration independent while, for the level (5)D(3), it decreases with Tb(3+) concentration. Emission spectroscopy measurements supported these results. ESA cross sections are found to be more than three orders of magnitude higher than the ground state absorption cross section.
Asunto(s)
Silicatos de Aluminio/química , Calcio/química , Lentes , Microscopía Fluorescente/instrumentación , Resonancia por Plasmón de Superficie/métodos , Terbio/química , Termografía/instrumentación , Absorción , Diseño de Equipo , Análisis de Falla de Equipo , Vidrio/química , Luz , Ensayo de Materiales/instrumentación , Dispersión de RadiaciónRESUMEN
The present study was designed to investigate the effects of nickel chloride on dietary iron deficiency in rats. The degree of iron deficiency was relatively moderate, but a more generalized anemia occurred in iron deficiency, in absence of nickel chloride. Moderate iron deficiency anemia induced increased lactate-dehydrogenase activity of serum and bone marrow, perhaps related to the decreased production of energy by oxidative means. Nickel chloride, perhaps for its ability to change iron absorption, for the maintenance of bone marrow metabolism and for to increase ceruloplasmin activity, inhibited the alteration on hemoglobin synthesis. Furthermore, nickel chloride possibly for its action on copper content and Cu-Zn superoxide-dismutase activity, inhibits the shortening of the red cell life span, caused by superoxide radicals.
