相关论文: Atomic transitions for adaptive optics

Altair is an A-type star known to have an appreciably oblate shape owing to its very fast rotation (~300 km/s). Despite of numerous publications on this star, its chemical abundances have been scarcely investigated so far, presumably…

We present an abundance analysis of the far-ultraviolet (905--1187 A) spectrum of the subdwarf B star PG0749+658, obtained by the Far Ultraviolet Spectroscopic Explorer (FUSE). The data have a resolution of about R = lambda / Delta lambda =…

We perform calculations of electronic structure of Cm$^{15+}$ and Bk$^{16+}$ ions and demonstrate that they have transitions which combine the features of atomic optical clocks with the enhanced sensitivity to the variations of the fine…

Geometrical frustration of the Fe ions in LuFe2O4 leads to intricate charge and magnetic order and a strong magnetoelectric coupling. Using resonant x-ray diffraction at the Fe K edge, the anomalous scattering factors of both Fe sites are…

Systematic exploration of amorphous ABC heterostructures revealed that nanoscale morphological modifications markedly improved their artificial bulk second-order susceptibility. These amorphous birefringent heterostructures were fabricated…

Structural transformation between metallic (1T) and semiconducting (2H) phases of single-layered MoS2 was systematically investigated by an in situ STEM with atomic precision. The 1T/2H phase transition is comprised of S and/or Mo…

We present high resolution imaging observations of a sample of previously unidentified far-infrared galaxies at z < 0.3. The objects were selected by cross-correlating the IRAS Faint Source Catalog with the VLA FIRST catalog and the HST…

Adaptive Optics (AO) is an innovative technique that substantially improves the optical performance of ground-based telescopes. The SOAR Adaptive Module (SAM) is a laser-assisted AO instrument, designed to compensate ground-layer…

We examine energy level-crossings of fine-structure (FS) levels in the heavier highly charged ions (HCIs) with $d^6$ and $d^8$ configurations. From the analysis, we find that some of these HCIs are tailor-made for atomic clocks with quality…

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The…

The key component of nanoplasmonics is metals. For a long time, gold and silver have been the metals of choice for constructing plasmonic nanodevices because of their excellent optical properties. However, these metals possess a common…

Stellar parameters and abundances of Na, Mg, Al, K, Ca, Sr, Ba, and Eu are determined for four very metal-poor stars (-2.66 < [Fe/H] < -2.15) based on non-LTE line formation and analysis of high-resolution (R ~60000 and 90000) high…

Plasmonics applications have been extending into the ultraviolet region of the electromagnetic spectrum. Unfortunately the commonly used noble metals have intrinsic optical properties that limit their use above 350 nm. Aluminum is probably…

We calculate the mean evolution of the iron-peak abundance ratios [(Cr,Mn,Co,Zn)/Fe] in the Galaxy, using modern supernova and hypernova chemical yields and a Galactic Chemical Evolution code that assumes homogeneous chemical evolution. We…

Using archival Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope (HST) data, we have assembled a survey of eight sightlines through high-velocity cloud Complex C. Abundances of the observed ion species vary…

In this paper, we present a first comparison of different Adaptive Optics (AO) concepts to reach a given scientific specification for 3D spectroscopy on Extremely Large Telescope (ELT). We consider that a range of 30%-50% of Ensquarred…

Superpositions of paraxial laser beam modes to generate atom-optical lenses based on the optical dipole force are investigated theoretically. Thin, wide, parabolic, cylindrical and circular atom lenses with numerical apertures much greater…

We report here the observation of a surprising phenomenon consisting in a oscillating phase transition which appears in a binary mixture, PMMA/3-octanone, when this is enlightened by a strongly focused infrared laser beam. PMMA/3-octanone…

The chemi-ionization (CI) processes in atom-Rydberg-atom collisions are investigated in this contribution. The rate coefficients for CI processes in $\textrm{Li}^{*}(n) + \textrm{Na}$, $\textrm{Li}^{*}(n) + \textrm{Li}$, $\textrm{Na}^{*}(n)…

Photospheric abundances of C, N, O, and Na were determined by applying the synthetic spectrum-fitting technique to 34 snap-shot high-dispersion spectra of 22 RR Lyr stars covering a metallicity range of -1.8 <[Fe/H] < 0.0, with an aim of…