Results 41 to 50 of about 2,410,397 (202)
Spectroscopy of the Hamburg Meteorite, Michigan H4
The Planetary Science JournalSpectroscopic studies of the Hamburg (Michigan H4) meteorite using visible–near-infrared (VNIR), mid-infrared (MIR), Raman, and Mössbauer data reproduce the results of more conventional laboratory measurements of petrology and geochemistry.
M. Darby Dyar +12 more
doaj +1 more source
Evidence for silicate dissolution on Mars from the Nakhla meteorite [PDF]
, 2013 Veins containing carbonates, hydrous silicates and sulphates that occur within and between grains of augite and olivine in the Nakhla meteorite are good evidence for the former presence of liquid water in the Martian crust.
Smith, C.L. +8 more
core +1 more source
The Anatomical Record, EarlyView.Abstract Phylogenetic comparative methods have been used in recent literature to work with laws and test for regularities (evolutionary associations of quantitative features) and evolutionary singularities (features that evolved in a single taxon). We analyzed these uses epistemologically, taking the evolution of red‐blood‐cell mean corpuscular volume (
Jorge Cubo +3 more
wiley +1 more source
IUCrJ, 2020 Icosahedral quasicrystals (i-phases) in the Al–Cu–Fe system are of great interest because of their perfect quasicrystalline structure and natural occurrences in the Khatyrka meteorite. The natural quasicrystal of composition Al62Cu31Fe7, referred to as i-
Jinping Hu +3 more
doaj +1 more source
CLASSIFICATION OF THE GEOCHEMICAL COMPOSITION OF METEORITE OF PUNGGUR (ASTOMULYO) BY k-NEAREST NEIGHBOR ALGORITHM [PDF]
, 2023 The fall of a meteorite in Astomulyo Village, Punggur, Lampung Province in early 2021 is an interesting topic for further study. This rare object has been suggested to have a unique geochemical composition and a special connection with other meteorites ...
Muliawati, Triyana
core +1 more source
Uncatalyzed Guanosine Phosphorylation under Potentially Prebiotic Conditions
Chemistry – A European Journal, EarlyView.Pyrophosphate acts as phosphorylating agent of guanosine under simple wet‐dry cycles without condensing agent and inorganic catalysts to afford cyclic guanosine monophosphate derivatives useful for oligomerization in prebiotic processes. ABSTRACT The phosphorylation of nucleosides and their subsequent polymerization are key issues in the study of the ...
Martina Proietti +5 more
wiley +1 more source
Geological Journal, EarlyView.Chemical states of Se and Br atoms in the KPg boundary sediments from Stevns Klint were studied using XAFS spectroscopy. The high concentrations of Se4+ could become an index of the degree to which the global environment was soiled with dust and ash derived from impact ejecta or volcanic eruptions.
Kei‐ichiro Murai +5 more
wiley +1 more source
The Plasma Spectroscopic Study of Dergaon Meteorite, India
Molecules, 2020 Meteorites are the recoverable portions of asteroids that reach the surface of the Earth. Meteorites are rare extraterrestrial objects studied extensively to improve our understanding of planetary evolution.
Abhishek K. Rai +7 more
doaj +1 more source
Mercury cycling during the last glacial period in Arctic Lake El'gygytgyn, NE Russia
Journal of Quaternary Science, EarlyView.ABSTRACT Tectonic processes play a key role in the global mercury (Hg) cycle on geological timescales, by mobilising Hg from deep Earth reservoirs to the surface. These natural fluxes also introduce a dynamic component to the terrestrial Hg cycle that can interact with other environmental signals and influence Hg delivery to sedimentary records.
Alice R. Paine +7 more
wiley +1 more source
Chemical composition and classification of the Caçapava do Sul Meteorite / Composição química e classificação do meteorito de Caçapava do Sul [PDF]
, 2021 The amount of material present in the interplanetary space of the Solar System is still not completely known, as well as its size. Incidentally, they can be as small as grains of dust to bodies larger than 100 m in diameter.
Soares, Daniele Martins +3 more
core +1 more source