Results 31 to 40 of about 142,268 (297)

The Period Distribution of Hot Jupiters Is Not Dependent on Host Star Metallicity

open access: yesThe Astrophysical Journal Letters, 2023
The probability that a Sun-like star has a close-orbiting giant planet (period ≲1 yr) increases with stellar metallicity. Previous work provided evidence that the period distribution of close-orbiting giant planets is also linked to metallicity, hinting ...
Samuel W. Yee, Joshua N. Winn
doaj   +1 more source

Core to Cosmic Edge: SIMBA-C’s New Take on Abundance Profiles in the Intragroup Medium at z = 0

open access: yesUniverse
We employ the simba-c cosmological simulation to study the impact of its upgraded chemical enrichment model (Chem5) on the distribution of metals in the intragroup medium (IGrM).
Aviv Padawer-Blatt   +11 more
doaj   +1 more source

CRITICAL METALLICITY FOR POPULATION II STARS

open access: yesOdessa Astronomical Publications, 2008
We present simple arguments about metallicity of transition from first stellar generation (population III) to the second one. We consider the efficiency of fragmentation in gas induced by thermal instability in cold gas layers and filaments (T < 104 K ...
E. O. Vasiliev, Yu. A. Shchekinov
doaj   +1 more source

Mechanochemical Synthesis and Characterization of Nanostructured ErB4 and NdB4 Rare‐Earth Tetraborides

open access: yesAdvanced Engineering Materials, Volume 27, Issue 6, March 2025.
ErB4 and NdB4 nanostructured powders are produced by mechanochemical synthesis. 5 h mechanical alloying and 4 M HCl acid leaching are used in the production. ErB4 and NdB4 powders exhibit maximum magnetization of 0.4726 emu g−1 accompanied with an antiferromagnetic‐to‐paramagnetic phase transition at about TN = 18 K and 0.132 emu g−1 with a maximum at ...
Burçak Boztemur   +5 more
wiley   +1 more source

The Star Formation History of the Milky Way’s Nuclear Star Cluster

open access: yesThe Astrophysical Journal, 2023
We report the first star formation history study of the Milky Ways nuclear star cluster (NSC), which includes observational constraints from a large sample of stellar metallicity measurements.
Zhuo Chen   +8 more
doaj   +1 more source

Revisiting Stability Criteria in Ball‐Milled High‐Entropy Alloys: Do Hume–Rothery and Thermodynamic Rules Equally Apply?

open access: yesAdvanced Engineering Materials, Volume 27, Issue 6, March 2025.
The stability criteria affecting the formation of high‐entropy alloys, particularly focusing in supersaturated solid solutions produced by mechanical alloying, are analyzed. Criteria based on Hume–Rothery rules are distinguished from those derived from thermodynamic relations. The formers are generally applicable to mechanically alloyed samples.
Javier S. Blázquez   +5 more
wiley   +1 more source

A Different Perspective on the Solid Lubrication Performance of Black Phosphorous: Friend or Foe?

open access: yesAdvanced Engineering Materials, EarlyView.
Researchers investigate black phosphorous (BP) as a standalone solid lubricant coating through ball‐on‐disc linear‐reciprocating sliding experiments in dry conditions. Testing on different metals shows BP doesn't universally reduce friction and wear. However, it achieves 33% friction reduction on rougher iron surfaces and 23% wear reduction on aluminum.
Matteo Vezzelli   +5 more
wiley   +1 more source

Bistable Mechanisms 3D Printing for Mechanically Programmable Vibration Control

open access: yesAdvanced Engineering Materials, EarlyView.
This work introduces a 3D‐printed bistable mechanism integrated into tuned mass dampers (TMDs) for mechanically adaptive passive vibration suppression. Through optimized geometry, the bistable design provides adaptable vibration reduction across a broad range of scenarios, achieving effective vibration mitigation without complex controls or external ...
Ali Zolfagharian   +4 more
wiley   +1 more source

Deformation Behavior of La2O3‐Doped Copper during Equal Channel Angular Pressing

open access: yesAdvanced Engineering Materials, EarlyView.
By additions of strengthening elements and/or structure optimization, the mechanical properties of copper can be increased while keeping favorable electric conductivity. By combining addition of La2O3 and processing by equal channel angular pressing, substructure development is achieved, leading to increase in microhardness to more than double the ...
Lenka Kunčická   +2 more
wiley   +1 more source

CO Emission, Molecular Gas, and Metallicity in Main-sequence Star-forming Galaxies at z ∼ 2.3

open access: yesThe Astrophysical Journal, 2023
We present observations of CO(3−2) in 13 main-sequence z = 2.0–2.5 star-forming galaxies at $\mathrm{log}({M}_{* }/{M}_{\odot })=10.2\mbox{--}10.6$ that span a wide range in metallicity (O/H) based on rest-optical spectroscopy. We find that ${L}_{\mathrm{
Ryan L. Sanders   +11 more
doaj   +1 more source

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