Results 41 to 50 of about 7,604,095 (315)
Chemical evolution of elliptical galaxies with a variable IMF [PDF]
Astronomy & Astrophysics, 2019 Growing evidence in recent years suggests a systematic variation of the stellar initial mass function (IMF), being top-heavy for starburst galaxies and possibly bottom-heavy for massive ellipticals.
Zhiqiang Yan +3 more
semanticscholar +1 more source
Chemical Evolution of the Juvenile Universe [PDF]
, 2009 Only massive stars contribute to the chemical evolution of the juvenile universe corresponding to [Fe/H]
Barklem +9 more
core +2 more sources
Abundance gradients along the Galactic disc from chemical evolution models [PDF]
Monthly notices of the Royal Astronomical Society, 2018 In this paper, we study the formation and chemical evolution of the Milky Way disc with particular focus on the abundance patterns ([$\alpha$/Fe] vs. [Fe/H]) at different Galactocentric distances, the present-time abundance gradients along the disc and ...
V. Grisoni, E. Spitoni, F. Matteucci
semanticscholar +1 more source
Biology Direct, 2012 Background Our current understanding of evolution is so tightly linked to template-dependent replication of DNA and RNA molecules that the old idea from Oparin of a self-reproducing 'garbage bag' ('coacervate') of chemicals that predated fully-fledged ...
Vasas Vera +4 more
doaj +1 more source
Origin of Life: The Point of No Return
Life, 2020 Origin of life research is one of the greatest scientific frontiers of mankind. Many hypotheses have been proposed to explain how life began. Although different hypotheses emphasize different initial phenomena, all of them agree around one important ...
Dimiter Kunnev
doaj +1 more source
Molecules, 2018 Chiral and molecular recognition through protonation was investigated through the collision-activated dissociation (CAD) of protonated noncovalent complexes of aromatic amino acid enantiomers with l-alanine- and l-serine-containing tripeptides using a ...
Akimasa Fujihara +4 more
doaj +1 more source
Refueling the Magic Furnace: Kilonova 2017 Rewrites the Story of Element Origins
Journal of Big History, 2018 For more than half a century, we have understood element creation in the stars—described in Marcus Chown’s colorful image as “the magic furnace.” From 1958 until 2017, supernova explosions were thought to be the primary site of element creation above ...
Barry Woods
doaj +1 more source
Reactions of Graphene Nano-Flakes in Materials Chemistry and Astrophysics
Physchem, 2022 The elucidation of the mechanism of the chemical evolution of the universe is one of the most important themes in astrophysics. Polycyclic aromatic hydrocarbons (PAHs) provide a two-dimensional reaction field in a three-dimensional interstellar space ...
Hiroto Tachikawa, Tetsuji Iyama
doaj +1 more source
THE PROTOBIOLOGICAL THEORY OF CEILINGS AND FLOORS, OR CHEMICAL EVOLUTION AS A PLANETARY PROCESS [PDF]
Filozofia i NaukaThe article presents a modern protobiological theory based on the classical archetype. It connects the issues of origins of life with the theory of the hierarchy of matter and recognizes that error correction occurs within hierarchical and dynamic living
Alicja Kubica
doaj +1 more source
Life, 2022 The RNA world hypothesis suggests that chemical networks consisting of functional RNA molecules could have constructed a primitive life-like system leading a first living system.
Kunio Kawamura +8 more
doaj +1 more source