Results 41 to 50 of about 695,127 (377)
Site-selectively generated photon emitters in monolayer MoS2 via local helium ion irradiation
Nature Communications, 2019 Quantum light sources in solid-state systems are of major interest as a basic ingredient for integrated quantum photonic technologies. The ability to tailor quantum emitters via site-selective defect engineering is essential for realizing scalable ...
J. Klein +24 more
semanticscholar +1 more source
Helium Absorption at 1083 nm from Extended Exoplanet Atmospheres: Dependence on Stellar Radiation [PDF]
Astrophysical Journal, 2019 Strong absorption signatures in the helium line at 1083 nm have recently been detected in transmission spectra of several close-in exoplanets. This absorption line originates from neutral helium atoms in an excited, metastable 23S state.
A. Oklopčić
semanticscholar +1 more source
Rb*He_n exciplexes in solid 4_He [PDF]
, 2006 We report the observation of emission spectra from Rb*He_n exciplexes in solid 4He. Two different excitation channels were experimentally identified, viz., exciplex formation via laser excitation to the atomic 5P3/2 and to the 5P1/2 levels.
Hofer, A. +4 more
core +2 more sources
Proton and Helium Spectra from the CREAM-III Flight [PDF]
, 2017 Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007–2008 Antarctic season.
Y. Yoon +24 more
semanticscholar +1 more source
Applied Sciences, 2020 Massive underground storage of hydrogen could be a way that excess energy is produced in the future, provided that the risks of leakage of this highly flammable gas are managed. The ROSTOCK-H research project plans to simulate a sudden hydrogen leak into
Stéphane Lafortune +5 more
doaj +1 more source
Proceedings of the National Academy of Sciences, 1998 The ratio 3 He/ 4 He (R) plays a central role in models of mantle evolution that propose an undegassed lower mantle, rich in the primordial isotope 3 He. A large primordial volatile-rich reservoir, a feature of recent models, is inconsistent with high-temperature ...
openaire +4 more sources
A comparative study of single-particle cryo-EM with liquid-nitrogen and liquid-helium cooling
IUCrJ, 2019 Radiation damage is the most fundamental limitation for achieving high resolution in electron cryo-microscopy (cryo-EM) of biological samples. The effects of radiation damage are reduced by liquid-helium cooling, although the use of liquid helium is more
Olivia Pfeil-Gardiner +3 more
doaj +1 more source
Helium Ionization in the Diffuse Ionized Gas surrounding UCHII regions [PDF]
, 2017 We present measurements of the singly ionized helium to hydrogen ratio ($n_{He^+}/n_{H^+}$) toward diffuse gas surrounding three Ultra-Compact HII (UCHII ) regions: G10.15-0.34, G23.46-0.20 \& G29.96-0.02.
Anderson, L. D. +2 more
core +3 more sources
The Cosmic Production of Helium [PDF]
Science, 2003 We estimate the cosmic production rate of helium relative to metals (Δ Y/ Δ Z ) using K dwarf stars in the Hipparcos catalog with accurate spectroscopic metallicities. The best fitting value is Δ Y/ Δ Z = 2.1 ± 0.4 at the 68% confidence level ...
Jimenez, Raul +3 more
openaire +5 more sources