In this paper, applying Parseval’s formula, we prove a Gθ – summability analogue of Avadhani’s theorem for the Riesz–summability of the eigenfunction expansion. A crucial step in our proof of this theorem was to find a function g(x) that would lead us to the kernel of the Gθ –summability, which is more complex than the kernel of the Riesz – summability.
In this paper, microwave processing of nanostructured ZnO powder as well as preparation of nanostructured ZnO/PEO composite were described. As a fast processing method which introduces a large amount of energy in the reaction system, the role of microwave processing was to modify ZnO crystal structure, while the role of PEO was to additionally sensitivize surface of ZnO particles; both of the approaches were used in the aim to improve optical properties of zinc oxide in comparison with bulk one. The synthesized powders were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and photoluminescence (PL). It was found that point defects (oxygen vacancies and zinc interstitials) were created in the crystal structure of zinc oxide. However, PEO has two-fold role, it passivate surface of the ZnO particles, but also introduce oxygen interstitials on the surface. The influence of the point defects on optical properties of ZnO was studied; it was found that oxygen vacancies, zinc interstitials and oxygen interstitials improved percent of thevisible light absorption, also shift band gap energy toward visible range of the spectrum.
Nema pronađenih rezultata, molimo da izmjenite uslove pretrage i pokušate ponovo!
Ova stranica koristi kolačiće da bi vam pružila najbolje iskustvo
Saznaj više