various concentrations of copper were embedded into silica matrix to xerogel forms using copper source cu(no3)2∙3h2o. the xerogel samples were prepared by hydrolysis and condensation of tetraethyl ortho-silicate (teos) with determination of new molar ratio of the components by the sol-gel method. after ambient drying, the xerogel samples were heated from 60 to 1000˚c at a slow heating rate (50°...

Recently, convincing evidence was found for extremely large X-ray absorption by column densities > 1023 cm−2 in broad absorption line quasars. One consequence of this is that any soft X-ray emission from these QSOs would be the scattered light or leaked light from partially covering absorbing material. A detection of the unabsorbed soft X-ray and absorbed hard X-ray component will allow to dete...

Recently, convincing evidence was found for extremely large X-ray absorption by column densities > 1023 cm−2 in broad absorption line quasars. One consequence of this is that any soft X-ray emission from these QSOs would be the scattered light or leaked light from partially covering absorbing material. A detection of the unabsorbed soft X-ray and absorbed hard X-ray component will allow to dete...

Eumelanin is a ubiquitous biological pigment, and the origin of its broadband absorption spectrum has long been a topic of scientific debate. Here, we report a first-principles computational investigation to explain its broadband absorption feature. These computations are complemented by experimental results showing a broadening of the absorption spectra of dopamine solutions upon their oxidati...

   In this research Fe-TiO2 nanocomposites with different molar ratios of Fe/Ti were prepared as nano-photocatalyst using a modified Sol-Gel process at ambient temperature. Crystallographic properties of nanocomposites were characterized by X-ray Diffraction (XRD). Surface morphology and mean particle size of nanocomposites were specified by Field Emission Scann...