Direct luminescence (DL) spectra of 4H Cd12 in the spectral region 1.8-3.4 eV at temperatures between 9.3 and 215 K and thermally stimulated luminescence (TSL) spectra are reported. The DL spectra consist of several overlapping broad emission bands. These bands are due to radiative recombination of localized (trapped) electrons with localized (trapped) holes. With a simple theory, which takes i...

A quantitative analysis is presented for the site-selective Fe K-edge absorption spectra of Prussian Blue: Fe(4)[Fe(CN)(6)](3) x xH(2)O (x = 14-16). The site-selective spectra were recorded using high-resolution fluorescence detection of the K beta emission from a polycrystalline sample. The K beta fluorescence lines arising from the high-spin and low-spin sites are shifted in energy. Since the...

IR emission spectra are calculated for dust heated by starlight, formixtures of amorphous silicate and graphitic grains, including varying amounts of PAH particles. The models are constrained to reproduce the average Milky Way extinction curve. The calculations include the effects of single-photon heating. Updated IR absorption properties for the PAHs are presented that are consistent with obse...

The absorption, excitation and emission spectra of methotrexate (MTX) solutions in natural saline water and sodium hydroxide at 10(-4)-10(-5) MpH=8.4 were measured, while they were exposed to coherent and uncoherent visible and near ultraviolet (UV) light. Xe and Hg lamp and also a nitrogen pulsed laser radiation were used. The absorption spectra exhibited spectral bands between 225 nm and 450 ...

This research was performed with the objective of evaluating the accuracy of spectral angle mapper (SAM) classification using different reference spectra. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital images were applied in the SAM classification in order to map the distribution of hydrothermally altered rocks in the Kerman Cenozoic magmatic arc (KCMA), Iran...

Lu3+/Yb3+ and Lu3+/Er3+ Co-doped Sb2Se3 nanomaterials were synthesized by a Co-reduction method in hydrothermal condition. Powder XRD patterns indicate that the LnxLn′xSb2-2xSe3 Ln: Lu3+/Yb3+ and Lu3+/Er3+ crystals (x= 0.00-0.04) are isostructural with Sb2Se3. The cell parameters were increased for compounds upon increasing the dopant content (x). SEM and TEM images show that Co-doping of Lu3+/...

We fabricated the black silicon (BS) structures by using nanosecond pulsed laser (ns-laser) in vacuum or in oxygen environment. It is interesting that the enhanced visible emission occurs in the photoluminescence (PL) spectra measured at room temperature and at lower temperature on the BS surface after annealing, in which lasing near 600 nm is observed on the BS surface with Purcell cavity stru...

We present the first medium-resolution (R ∼ 600) mid-infrared (8-13.3µm) spectra of 11 Be stars. A large number of lines are observed and identified in these spectra, including, as an example, 39 hydrogen recombination lines in the spectrum of γ Cas. In the majority of our spectra, all of the observed lines are attributable to hydrogen recombination. Two of the sources, β Lyr and MWC 349 also s...

Low spectral resolution (∆λ/λ ∼50) mid-infrared observations with high angular resolution (0.3–0.5 ′′) using the Long Wavelength Spectrometer on the Keck I Telescope are reported of the nuclei of five highly luminous infrared bright galaxies. Spectra of eight distinct nuclei, ranging in luminosity from ∼ 10 11 L ⊙ to > 10 12 L ⊙ have been obtained. Four of the nuclei show the characteristic PAH...