Results 1 to 10 of about 237,790 (259)
Frontiers in Marine Science, 2022 We investigated the pore fluid and methane-derived authigenic carbonate (MDAC) chemistry from the ARAON Mounds in the Chukchi Sea to reveal how methane (CH4) seepage impacts their compositional and isotopic properties.
Ji-Hoon Kim +15 more
doaj +1 more source
A pain-causing and paralytic ant venom glycopeptide
iScience, 2021 Summary: Ants (Hymenoptera: Formicidae) are familiar inhabitants of most terrestrial environments. Although we are aware of the ability of many species to sting, knowledge of ant venom chemistry remains limited.
Samuel D. Robinson +14 more
doaj +1 more source
Dissociation chemistry of hydrogen halides in water [PDF]
The Journal of Chemical Physics, 2004 To understand the mechanism of aqueous acid dissociation, which plays a fundamental role in aqueous chemistry, the ionic dissociation of HX acids (X=F, Cl, Br, and I) in water clusters up to hexamer is examined using density functional theory and Møller–Plesset second-order perturbation methods (MP2).
Odde, S +4 more
openaire +3 more sources
Migration of Salt Ions in Frozen Hydrate-Saturated Sediments: Temperature and Chemistry Constraints
Geosciences, 2022 Migration of dissolved salts from natural (cryopeg brines, seawater, etc.), or artificial sources can destabilize intrapermafrost gas hydrates. Salt transport patterns vary as a function of gas pressure, temperature, salinity, etc. The sensitivity of the
Evgeny Chuvilin +5 more
doaj +1 more source
On basis set optimisation in quantum chemistry [PDF]
ESAIM: Proceedings and Surveys, 2023 In this article, we propose general criteria to construct optimal atomic centered basis sets in quantum chemistry. We focus in particular on two criteria, one based on the ground-state one-body density matrix of the system and the other based on the ...
Cancès Eric +3 more
doaj +1 more source
Dissociation Chemistry of Hydrogen-Deficient Radical Peptide Anions [PDF]
Journal of the American Society for Mass Spectrometry, 2011 The fragmentation chemistry of anionic deprotonated hydrogen-deficient radical peptides is investigated. Homolytic photodissociation of carbon-iodine bonds with 266 nm light is used to generate the radical species, which are subsequently subjected to collisional activation to induce further dissociation.
Moore, Benjamin +6 more
openaire +3 more sources
MODELLING OF ACIDS AND BASES REVISITED
Studia Universitatis Babes-Bolyai Chemia, 2022 Models for dissociation and mixing of acids and bases are the main subject of many analytical chemistry textbooks. Preparing the solutions for any titration generally involves diluting acids and bases. The mathematics behind precise calculation of pH and
Lorentz JÄNTSCHI
doaj +1 more source
Liquids, 2023 This work focuses on determining the dissociation constants (pKa) of eight amines, namely, 3-(Diethylamino) propylamine, 1,3-Diaminopentane, 3-Butoxypropylamine, 2-(Methylamino) ethanol, Bis(2-methoxyethyl) amine, α-Methylbenzylamine, 2-Aminoheptane, and
Venkata Sai Priyatham Varma Alluri +2 more
doaj +1 more source
Cosmic Ray Dissociation of Molecular Hydrogen and Dense Cloud Chemistry [PDF]
Research Notes of the AAS, 2020 Abstract Dissociation of molecular hydrogen by secondary electrons produced by cosmic ray or X-ray ionization plays a crucial role in the chemistry of the densest part of molecular clouds. Here we study the effect of the mean kinetic energy of secondary electrons on this process. We compare predictions using a range of secondary electron
Gargi Shaw +2 more
openaire +3 more sources
ANALISIS MISKONSEPSI ASAM BASA CALON GURU KIMIA DENGAN METODE THREE-TIER TEST
Jurnal Pendidikan Sains Universitas Muhammadiyah Semarang, 2020 This study aims to identify the misconceptions of a prospective chemistry teacher. The study population was all students of the Chemistry Study Program at the University of Riau, while the sample was 66 students at the Chemistry Study Program at the ...
Abdullah Abdullah
doaj +1 more source