scholarly journals Exploring the origins of a new, apparently metal-free gas cloud atz = 4.4

2018 ◽  
Vol 483 (2) ◽  
pp. 2736-2747 ◽  
Author(s):  
P Frédéric Robert ◽  
Michael T Murphy ◽  
John M O’Meara ◽  
Neil H M Crighton ◽  
Michele Fumagalli
Keyword(s):  
Free Gas ◽  
Metal Free ◽  
Gas Cloud

Lyman-Werner radiation delayed collapse of metal-free gas in the first galaxies

2012 ◽  
Author(s):  
Chalence Safranek-Shrader ◽  
Meghann Agarwal ◽  
Christoph Federrath ◽  
Anshu Dubey ◽  
Milos Milosavljevic ◽  
...  
Keyword(s):  
Free Gas ◽  
Metal Free ◽  
First Galaxies

Cataluminescence Coupled with Photoassisted Technology: A Highly Efficient Metal-Free Gas Sensor for Carbon Monoxide

2019 ◽  
Vol 91 (20) ◽  
pp. 13158-13164 ◽  
Author(s):  
Li Li ◽  
Chudong Wei ◽  
Hongjie Song ◽  
Yongsheng Yang ◽  
Ying Xue ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Gas Sensor ◽  
Free Gas ◽  
Metal Free ◽  
Highly Efficient

scholarly journals Kinematical and chemical evolution of the Galactic disk

1985 ◽  
Vol 106 ◽  
pp. 597-600 ◽  
Author(s):  
Cedric G. Lacey ◽  
S. Michael Fall
Keyword(s):  
Observational Data ◽  
Chemical Evolution ◽  
Galactic Disk ◽  
Stochastic Acceleration ◽  
Free Gas ◽  
Metal Free ◽  
Astronomical Society ◽  
Royal Astronomical Society

We have calculated models for the kinematical and chemical evolution of the Galactic disk that include the infall of metal-free gas and the stochastic acceleration of disk stars. Our models are similar in some respects to those of Chiosi (1980) and Vader & de Jong (1981), but the results are compared with a greater variety of observational data. A complete description of this work will appear shortly in Monthly Notices of the Royal Astronomical Society.

scholarly journals METAL-FREE GAS SUPPLY AT THE EDGE OF REIONIZATION: LATE-EPOCH POPULATION III STAR FORMATION

2009 ◽  
Vol 700 (2) ◽  
pp. 1672-1679 ◽  
Author(s):  
Michele Trenti ◽  
Massimo Stiavelli ◽  
J. Michael Shull
Keyword(s):  
Star Formation ◽  
Free Gas ◽  
Metal Free ◽  
Gas Supply ◽  
Population Iii

scholarly journals Evolution of zero-metallicity massive stars

2003 ◽  
Vol 212 ◽  
pp. 334-340
Author(s):  
Paola Marigo ◽  
Cesare Chiosi ◽  
Léo Girardi ◽  
Rolf-Peter Kudritzki
Keyword(s):  
Mass Loss ◽  
Large Range ◽  
Massive Stars ◽  
Stellar Winds ◽  
Constant Mass ◽  
Helium Burning ◽  
Free Gas ◽  
Metal Free ◽  
Massive Models ◽  
Carbon Burning

We discuss the evolutionary properties of primordial massive and very massive stars, supposed to have formed from metal-free gas. Stellar models are presented over a large range of initial masses (8 M⊙ ≲ Mi ≲ 1000 M⊙), covering the hydrogen- and helium-burning phases up to the onset of carbon burning. In most cases the evolution is followed at constant mass. To estimate the possible effect of mass loss via stellar winds, recent analytic formalisms for the mass-loss rates are applied to the very massive models (Mi ≥ 120 M⊙).

The Shadow Widths of Very Small Particles are Formed Independently of the Metal Cap Build Up on the Particle

1981 ◽  
Vol 39 ◽  
pp. 568-569
Author(s):  
George C. Ruben
Keyword(s):  
Gold Particle ◽  
Film Surface ◽  
Small Particles ◽  
Geometric Process ◽  
Metal Free ◽  
Shadow Area

The formation of shadows behind small particles has been thought to be a geometric process (GP) where the metal cap build up on the particle creates a shadow width the same size as or larger than the particle. This GP cannot explain why gold particle shadow widths are generally larger than the gold particle and may have no appreciable metal cap build up (fig. 1). Ruben and Telford have suggested that particle shadow widths are formed by the width dependent deflection of shadow metal (SM) lateral to and infront of the particle. The trajectory of the deflected SM is determined by the incoming shadow angle (45°). Since there can be up to 1.4 times (at 45°) more SM directly striking the particle than the film surface, a ridge of metal nuclei lateral to and infront of the particle can be formed. This ridge in turn can prevent some SM from directly landing in the metal free shadow area. However, the SM that does land in the shadow area (not blocked by the particle or its ridge) does not stick and apparently surface migrates into the SM film behind the particle.

Recent advancement in the electrocatalytic synthesis of ammonia

Nanoscale ◽  
2020 ◽  
Vol 12 (15) ◽  
pp. 8065-8094 ◽  
Author(s):  
Xudong Wen ◽  
Jingqi Guan
Keyword(s):  
Metal Oxide ◽  
Oxide Catalysts ◽  
Single Atom ◽  
Metal Oxide Catalysts ◽  
Metal Free ◽  
Recent Advancement ◽  
Nanocomposite Catalysts

Different kinds of electrocatalysts used in NRR electrocatalysis (including single atom catalysts, metal oxide catalysts, nanocomposite catalysts, and metal free catalysts) are introduced.

Transition-metal-free catalytic hydroboration reduction of amides to amines

2020 ◽  
Vol 7 (21) ◽  
pp. 3515-3520
Author(s):  
Wubing Yao ◽  
Jiali Wang ◽  
Aiguo Zhong ◽  
Shiliang Wang ◽  
Yinlin Shao
Keyword(s):  
Transition Metal ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Value Added ◽  
Metal Free

The selective catalytic reduction of amides to value-added amine products is a desirable but challenging transformation.

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