Results 31 to 40 of about 676 (225)

A Detailed Model Atmosphere Analysis of Hot White Dwarfs in DESI DR1

open access: yesThe Astrophysical Journal
We present a detailed model atmosphere analysis of hot white dwarfs in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. Our sample includes 19,321 unique targets with G _BP  −  G _RP ≤ 0.
Mukremin Kilic   +8 more
doaj   +1 more source

Opportunities of Semiconducting Oxide Nanostructures as Advanced Luminescent Materials in Photonics

open access: yesAdvanced Materials, EarlyView.
The review discusses the challenges of wide and ultrawide bandgap semiconducting oxides as a suitable material platform for photonics. They offer great versatility in terms of tuning microstructure, native defects, doping, anisotropy, and micro‐ and nano‐structuring. The review focuses on their light emission, light‐confinement in optical cavities, and
Ana Cremades   +7 more
wiley   +1 more source

Spectroscopic Follow-up on Potential Magnetic Cataclysmic Variables

open access: yesThe Astronomical Journal
Spectroscopic observations of nine cataclysmic variables that have been postulated to contain magnetic white dwarfs were obtained to further characterize their classifications, orbital parameters, inclinations, and/or accretion properties.
Paula Szkody   +10 more
doaj   +1 more source

Polymorph‐Specific Electronic Transduction in WO3 during Molecular Sensing

open access: yesAdvanced Materials, EarlyView.
Metal‐oxide polymorphs with similar surface chemistry can nevertheless exhibit distinct sensing properties. In γ‐ and ε‐WO3, analyte adsorption appears comparable; yet, only ε‐WO3 induces a pronounced lattice electronic perturbation that accommodates charge in sub‐conduction band minimum states.
Matteo D'Andria   +6 more
wiley   +1 more source

Hot DQ White Dwarf Stars: A New Challenge to Stellar Evolution

open access: yes, 2007
We report the discovery of a new class of hydrogen-deficient stars: white dwarfs with an atmosphere primarily composed of carbon, with little or no trace of hydrogen or helium. Our analysis shows that the atmospheric parameters found for these stars do not fit satisfactorily in any of the currently known theories of post-asymptotic giant branch (AGB ...
Dufour, Patrick   +3 more
openaire   +2 more sources

X-ray and optical observations of the ultrashort period dwarf nova SW Ursae Majoris - A likely new DQ Herculis star

open access: yesThe Astrophysical Journal, 1986
Time-resolved X-ray and optical photometric and optical spectroscopic observations of the ultrashort period cataclysmic variable SW UMa are reported. The spectroscopic observations reveal the presence of an s-wave component which is almost in phase with the extreme line wings and presumably the white dwarf. This very unusual phasing in conjunction with
A. W. Shafter   +2 more
openaire   +1 more source

Large‐Area 2D Metasurface‐Based Triboelectric E‐Skin Arrays: Contact & Proximity Tactile Mapping with Broadband Acoustic Readouts

open access: yesAdvanced Materials, EarlyView.
Metasurface‐engineered NC‐TENG arrays integrate tactile pressure mapping, non‐contact gesture sensing, and acoustic signal readouts in one ultrathin module, and outperforms pristine PDMS in terms of electrical output and real‐time spatial mapping for next‐gen wearables.
Injamamul Arief   +12 more
wiley   +1 more source

The 100 pc White Dwarf Sample in the SDSS Footprint. II. A New Look at the Spectral Evolution of White Dwarfs

open access: yesThe Astrophysical Journal
We increase the spectroscopic completeness of the 100 pc white dwarf sample in the Sloan Digital Sky Survey footprint with 840 additional spectra. Our spectroscopy is 86% complete for white dwarfs hotter than T _eff  = 5000 K, where H α remains visible ...
Mukremin Kilic   +7 more
doaj   +1 more source

Missing metals in DQ stars: a compelling clue to their origin

open access: yesMonthly Notices of the Royal Astronomical Society
ABSTRACT White dwarf stars frequently experience external pollution by heavy elements, and yet the intrinsically carbon-enriched DQ spectral class members fail to exhibit this phenomenon, representing a decades-old conundrum. This study reports a high-resolution spectroscopic search for Ca ii in classical DQ white dwarfs, finding that ...
J Farihi, P Dufour, T G Wilson
openaire   +2 more sources

Direct Synthesis of High‐Valence Protein@UiO‐66 Composites: Linking Crystallization Pathways to Protein Encapsulation

open access: yesAdvanced Materials, EarlyView.
This work reports a direct, biocompatible method to synthesize UiO‐66, enabling one‐step encapsulation of proteins without compromising crystallinity or activity. Using advanced in situ and ex situ techniques, the study reveals that proteins integrate concurrently with MOF growth, forming crystalline protein@UiO‐66 nanoparticles, and provide insight ...
Jesús Cases Díaz   +5 more
wiley   +1 more source

Home - About - Disclaimer - Privacy