Results 51 to 60 of about 5,722 (281)

The Formation of Hard Very High Energy Spectra from Gamma-ray Burst Afterglows via Two-zone Synchrotron Self-Compton Emission

open access: yesThe Astrophysical Journal, 2023
Electron Compton scattering of target photons into the gamma-ray energy band (inverse Compton scattering; IC) is commonly expected to dominate the very high energy (VHE) spectra in gamma-ray bursts (GRBs) especially during the afterglow phase.
Dmitry Khangulyan   +2 more
doaj   +1 more source

Copper‐based Materials for Photo and Electrocatalytic Process: Advancing Renewable Energy and Environmental Applications

open access: yesAdvanced Functional Materials, EarlyView.
Cu‐based catalysts as a cornerstone in advancing sustainable energy technologies are fully reviewed in this manuscript, highlighting their potential in photo‐ and electrocatalysis. It includes metallic copper, copper oxides, copper sulfides, copper halide perovskites, copper‐based metal–organic frameworks (MOFs), and covalent organic frameworks (COFs),
Jéssica C. de Almeida   +16 more
wiley   +1 more source

Fermi-LAT Detection of a Transient γ-Ray Source in the Direction of a Distant Blazar B3 1428+422 at z = 4.72 [PDF]

open access: yesThe Astrophysical Journal Letters, 2018
Abstract We report the detection of a transient γ-ray source in the direction of B3 1428+422 (z = 4.72) by analyzing the 110-month Fermi-LAT Pass 8 data. The new transient γ-ray source is far away from the Galactic plane and has a rather soft spectrum, in agreement with being a high redshift blazar.
Neng-Hui Liao, Shang Li, Yi-Zhong Fan
openaire   +2 more sources

Copper Doping Enhances the Activity and Selectivity of Atomically Precise Ag44 Nanoclusters for Photocatalytic CO2 Reduction

open access: yesAdvanced Functional Materials, EarlyView.
By a simple anti‐Galvanic reaction, up to six copper atoms could be preferably doped into the Ag2(SR)5 staple motifs and Ag20 dodecahedral shell of an atomically precise Ag44(SR)30 nanocluster. When anatase TiO2 is used as substrate, the (AgCu)44/TiO2 photocatalyst exhibited much improved activity in photocatalytic CO2 reduction compared to Ag44/TiO2 ...
Ye Liu   +5 more
wiley   +1 more source

Multi-instrument Search for Gamma-Ray Counterpart of X-Ray Transients Detected by EP/WXT

open access: yesThe Astrophysical Journal Letters
As a soft X-ray imager with an unprecedentedly large field of view, Einstein Probe (EP)/Wide-field X-ray Telescope (WXT) has detected many (fast) X-ray transients, whose nature is very intriguing.
Yan-Qiu Zhang   +27 more
doaj   +1 more source

Mechanically Tunable Bone Scaffolds: In Vivo Hardening of 3D‐Printed Calcium Phosphate/Polycaprolactone Inks

open access: yesAdvanced Functional Materials, EarlyView.
A 3D bone scaffold with osteogenic properties and capable of hardening in vivo is developed. The scaffold is implanted in a ductile state, and a phase transformation of the ceramic induces the stiffening and strengthening of the scaffold in vivo. Abstract Calcium phosphate 3D printing has revolutionized customized bone grafting.
Miguel Mateu‐Sanz   +7 more
wiley   +1 more source

Defect Analysis of the β– to γ–Ga2O3 Phase Transition

open access: yesAdvanced Functional Materials, EarlyView.
The role of defects at all the relevant stages of the β$\beta$‐ to γ$\gamma$‐Ga2O3 polymorph transition is investigated using a multi method approach. The positron annihilation spectroscopy based results show that the defect density decreases after the transition, and that changes in defect configuration within the γ phase occur with increasing ...
Umutcan Bektas   +9 more
wiley   +1 more source

EP240801a/XRF 240801B: An X-Ray Flash Detected by the Einstein Probe and the Implications of Its Multiband Afterglow

open access: yesThe Astrophysical Journal Letters
We present multiband observations and analysis of EP240801a, a low-energy, extremely soft gamma-ray burst (GRB) discovered on 2024 August 1 by the Einstein Probe (EP) satellite with a weak contemporaneous signal also detected by the Fermi Gamma-ray Burst
Shuai-Qing Jiang   +91 more
doaj   +1 more source

Fast‐Responding O2 Gas Sensor Based on Luminescent Europium Metal‐Organic Frameworks (MOF‐76)

open access: yesAdvanced Functional Materials, EarlyView.
Luminescent MOF‐76 materials based on Eu(III) and mixed Eu(III)/Y(III) show rapid and reversible changes in emission intensity in response to O2 with very short response times. The effect is based on triplet quenching of the linker ligands that act as photosensitizers. Average emission lifetimes of a few milliseconds turn out to be mostly unaffected by
Zhenyu Zhao   +5 more
wiley   +1 more source

The Nature of Optical Afterglows without Gamma-Ray Bursts: Identification of AT2023lcr and Multiwavelength Modeling

open access: yesThe Astrophysical Journal
In the past few years, the improved sensitivity and cadence of wide-field optical surveys have enabled the discovery of several afterglows without associated detected gamma-ray bursts (GRBs).
Maggie L. Li   +31 more
doaj   +1 more source

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