Results 21 to 30 of about 693 (229)

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

Monthly 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

Double White Dwarf Binaries in SDSS-V DR19: The Discovery of a Rare DA+DQ White Dwarf Binary with a 31 hr Orbital Period

The Astrophysical Journal
Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that help us reconstruct the complex processes involved in stellar evolution and are theorized to lead to Type Ia supernovae.
Gautham Adamane Pallathadka, Vedant Chandra, Boris T. Gänsicke, Nadia L. Zakamska, Detlev Koester, Yossef Zenati, Nicole R. Crumpler, Stefan M. Arseneau, J. J. Hermes, Matthias R. Schreiber, Keivan G. Stassun, Axel Schwope, Kareem El-Badry, Gagik Tovmassian, Tim Cunningham, Sean Morrison   +15 more
doaj   +1 more source

Current Status and Challenges in Data Collection for Aerospace Coatings Deposited by Plasma Spraying

Advanced Engineering Materials, EarlyView.
An innovative approach has been integrated into the GRENAT project to optimize plasma spraying and coating performance. Raw materials are accelerated and melted in the plasma generated by torches, creating coatings. Monitoring sensors collect process data which are combined with ex situ characterization data.
Lila Randriamananjara, Vincent Rat, Quentin Dubreuil, Patrice Valorge, Simon Goutier, Alain Denoirjean, Olivier Messe, Céline Ruelle, Jean‐Philippe Poli   +8 more
wiley   +1 more source

A New Window for Studying Intermediate Polars and Tilted Accretion Disk Precession

The Astrophysical Journal
TV Col is a long-period eclipsing intermediate polar (IP) prototype star for the negative superhump (NSH) system. We investigate the eclipse minima, eclipse depth, and NSH amplitude based on TESS photometry.
Qi-Bin Sun, Sheng-Bang Qian, Li-Ying Zhu, Wen-Ping Liao, Er-Gang Zhao, Fu-Xing Li, Xiang-Dong Shi, Min-Yu Li   +7 more
doaj   +1 more source

Extraordinary n‐type Tellurium‐Free Thermoelectric Performance of Y‐Doped BiSe via Synergistic Effect of Vacancies and Band Engineering

Advanced Functional Materials, EarlyView.
Yttrium doping in Sb‐alloyed BiSe synergistically induces Bi vacancies and flattens conduction bands, simultaneously slashing lattice thermal conductivity by 50% and boosting the power factor. The optimized n‐type Bi0.64Sb0.3Y0.06Se delivers a peak zT of 0.91 at 393 K (average zT 0.76, 300–523 K) and an 8‐pair module with 4.6% conversion efficiency ...
Wenhao Xie, Fang Lyu, Xiaolong Sun, Chang Li, Xiaolu Zhu, Liangwei Hu, Qianfeng Ding, Wenjie Zhou, Muyang Huang, Yineng Gou, Yi Zhao, Han Tang, Wei Cao, Yue Hou, Yun Zheng, Ady Suwardi, Ziyu Wang   +16 more
wiley   +1 more source

An All-sky Survey of White Dwarf Merger Remnants: Far-Ultraviolet Is the Key

The Astrophysical Journal
The majority of merging white dwarfs leave behind a white dwarf remnant. Hot/warm DQ white dwarfs with carbon-rich atmospheres have high masses and unusual kinematics. All evidence points to a merger origin.
Mukremin Kilic, Pierre Bergeron, Warren R. Brown, Simon Blouin, Gracyn Jewett, Adam Moss, Patrick Dufour, Olivier Vincent   +7 more
doaj   +1 more source

Biomimetic Microfractals Based Flexible Triboelectric Nanogenerators

Advanced Functional Materials, EarlyView.
A leaf‐skeleton‐based microfractal architecture is integrated with guided CuNW networks and biomimetic triboelectric polymer layers, enabling breathable, flexible, and material‐efficient triboelectric nanogenerators. The resulting system combines enhanced charge generation and charge transport, offering potential for next‐generation self‐powered ...
Amit Barua, Mislav Matić, Ana‐Marija Pitner, Rituporn Gogoi, Aman Kumar, Mirko Poljak, Anastasia Koivikko, Vipul Sharma   +7 more
wiley   +1 more source

TESS Light Curves of Cataclysmic Variables. VI. Intermediate Polars

The Astrophysical Journal Supplement Series
The long and (almost) continuous high-cadence light curves provided by the TESS space mission are ideally suited to study in detail brightness variations in stellar sources on the broad range of timescales between minutes and months.
Albert Bruch
doaj   +1 more source

Functionalizing Micro‐to‐Mesoscopic Electrode Architectures for Regulating Electron Transfer Behaviors in Electrocatalysis

Advanced Functional Materials, EarlyView.
A systematic review is conducted to assess the influence of electrode architecture across micro‐ to mesoscopic length scales on electron‐transfer pathways in electrocatalysis. We discuss the structure‐activity relationships in electrocatalytic applications, including resource recovery and environmental remediation, and provide cost‐effective, efficient
Manshu Zhao, Jiaojiao Zhang, Shideng Yuan, Xinmeng Yu, Keming Wan, Xiaoguang Duan, Zhining Wang   +6 more
wiley   +1 more source

TESS Light Curves of Two New Magnetic Cataclysmic Variables: An Asynchronous Polar at the Period Minimum and an Eclipsing System with a Large Spin-to-orbit Ratio

The Astrophysical Journal
A recent development in the study of magnetic cataclysmic variable stars (mCVs) has been the identification of asynchronously spinning mCVs with orbital periods
Colin Littlefield, Krystian Iłkiewicz, Paul A. Mason, Peter Garnavich, Simone Scaringi   +4 more
doaj   +1 more source