Results 131 to 140 of about 15,552 (245)

Chemical Kinetics of 2‐, 4‐, and 2,4‐Seleno‐Uracils at Low Temperatures: Tautomerizations and Rotamerizations on Inert Matrices

International Journal of Chemical Kinetics, EarlyView.
ABSTRACT In the interstellar medium, chemical reactions proceed under conditions vastly different to those on Earth; these include extremely low temperatures and densities and take place in the gas phase and on water–ice grains. Understanding the energetics and more importantly the kinetics of such reactions is of relevance to the consequences on how ...
Judith Wurmel, John M. Simmie
wiley   +1 more source

Extreme shifts in pyrite sulfur isotope compositions reveal the path to bonanza gold. [PDF]

Proc Natl Acad Sci U S A
McLeish DF, Williams-Jones AE, Clark JR, Stern RA.   +3 more
europepmc   +1 more source

Size Matters: Barrier Heights and Widths in the Kinetics Of Tautomerisation and Rotamerisation of Thiotropolone and Its Five‐ and Three‐Membered Cyclic Analogues

International Journal of Chemical Kinetics, EarlyView.
ABSTRACT Recent experiments by Nunes et al. have demonstrated that unprecedented control of chemical reactions is possible by narrowband infrared vibrational photo‐excitation at low temperatures in inert matrices. The generated higher energy level conformers may then undergo rotamerisation and tautomerisation reactions which provide extremely useful ...
Judith Wurmel, John M. Simmie
wiley   +1 more source

Continuous-Flow Stable Sulfur Isotope Analysis of Organic and Inorganic Compounds by EA-MC-ICPMS. [PDF]

Anal Chem
Horst A, Gehre M, Fahle M, Kümmel S.
europepmc   +1 more source

Cis–Trans Rotational Isomerism of Formic Acid, Sulfur, and Selenium Analogues and Their Dimers: Chemical Kinetics Under Interstellar Conditions

International Journal of Chemical Kinetics, EarlyView.
ABSTRACT We present chemical kinetic rate constants for the cis to trans isomerisation or rotamerization of monomeric seleno‐, thio‐, and formic acids and that of three of their dimeric species, based on variational transition state theory and multidimensional tunneling calculations in the gas‐phase, from 10 K to 300 K. These provide, firstly, reliable
Judith Wurmel, John M. Simmie
wiley   +1 more source

Role of APS reductase in biogeochemical sulfur isotope fractionation. [PDF]

Nat Commun, 2019
Sim MS, Ogata H, Lubitz W, Adkins JF, Sessions AL, Orphan VJ, McGlynn SE.   +6 more
europepmc   +1 more source

Effects of preservatives and poisons on the elemental and isotopic composition of freshwater particulate organic matter

Limnology and Oceanography: Methods, EarlyView.
Abstract Sediment traps, often used in tandem with preservatives or poisons, are widely used for the collection of particulate organic matter (POM), providing insight into the source to sink mechanisms that shape major biogeochemical cycles and sedimentary carbon sequestration.
Diana Velazquez, Nathan D. Sheldon, Jenan J. Kharbush   +2 more
wiley   +1 more source

Sulfur isotope analysis for representative regional background atmospheric aerosols collected at Mt. Lulin, Taiwan. [PDF]

Sci Rep, 2019
Chung CH, You CF, Hsu SC, Liang MC.
europepmc   +1 more source

Chemical Ionization Mass Spectrometry: Fundamental Principles, Diverse Applications, and the Latest Technological Frontiers

Mass Spectrometry Reviews, EarlyView.
ABSTRACT The review examines the evolution of chemical ionization mass spectrometry (CI‐MS), a technique developed in 1966 by Field and Munson. CI is a soft‐ionization method that produces more intense molecular ions with less fragmentation than electron ionization (EI).
Malvika Dutt, Adriana Arigò, Giorgio Famiglini, Pierangela Palma, Achille Cappiello   +4 more
wiley   +1 more source

Unusual sulfur isotope effect and extremely high critical temperature in H₃S superconductor. [PDF]

Sci Rep, 2018
Szczęśniak R, Durajski AP.
europepmc   +1 more source