Results 81 to 90 of about 3,020 (234)

Secular Evolution of Mantle Sulfur Isotopes Since the Archean

Geochemistry, Geophysics, Geosystems
Sulfur isotopes in mantle plume‐derived magmas show heterogeneities attributed to recycling of material from the Earth's surface. The sedimentary sulfur isotope record exhibits dramatic temporal variations over Earth history, raising the question of ...
J. Eguchi, B. A. Black, E. G. Nisbet, Y. Moussallam, G. Georgeais   +4 more
doaj   +1 more source

An Estimate of Sulfur Isotope Fractionation Due to SO₂ Self-Shielding in the Upper Atmosphere of Venus

Atmosphere
Sulfur dioxide is a trace constituent of the upper atmosphere of Venus but plays a dominant role in the photochemistry above the cloud tops. Because SO2 undergoes indirect dissociation to a relatively long-lived excited state, it has a line-type ...
James R. Lyons
doaj   +1 more source

Insect communities of late Pleistocene steppe–tundra and Holocene boreal forest ecosystems in central Yukon Territory, Canada

Journal of Quaternary Science, EarlyView.
ABSTRACT Subfossil insect communities from the Quartz Creek site provide a detailed record of both Late Pleistocene steppe–tundra and Holocene boreal forest ecosystems in central Yukon Territory, Canada. Fifteen Pleistocene assemblages (marine isotope stages [MIS] 4 to 2) are dominated by steppe–tundra and dry‐tundra taxa, particularly the weevils ...
Scott L. Cocker, Svetlana Kuzmina, Nick Schafstall, Michael A. Monzon, Duane G. Froese   +4 more
wiley   +1 more source

Advancing isotope-enabled model for comprehensive understanding of atmospheric sulfur isotope effects: demonstrating the overlooked isotopic fractionation during combustion and flue gas desulfurization [PDF]

Atmospheric Chemistry and Physics
The isotopic composition of atmospheric species provides fundamental insights into their sources, sinks, and chemical processes. Conventional end-member mixing models, however, cannot capture progressive isotopic evolution in open systems where mixing ...
L. Wei, L. Wei, L. Wei, X. Chen, W. Yang, Z. Wang, J. Li, D. Liu, H. Du, X. Pan, Y. Cheng, P. Fu, Z. Wang, Z. Wang   +13 more
doaj   +1 more source

Qualitative Analysis of Biogas by Raman Spectroscopy: Effect of Pressure on Major Components

Journal of Raman Spectroscopy, EarlyView.
Raman spectra of major and selected minor biogas components were studied under pressures up to 100 bar. Pressure‐induced shifts and band broadening were quantified for methane, carbon dioxide, and nitrogen, while Raman spectra of ammonia and hydrogen sulfide are presented in the context of biogas quality monitoring.
Dominik Tománek, Matouš Kuneš, Tomáš Hlinčík   +2 more
wiley   +1 more source

Proteomic and Isotopic Response of Desulfovibrio vulgaris to DsrC Perturbation

Frontiers in Microbiology, 2019
Dissimilatory sulfate reduction is a microbial energy metabolism that can produce sulfur isotopic fractionations over a large range in magnitude. Calibrating sulfur isotopic fractionation in laboratory experiments allows for better interpretations of ...
William D. Leavitt, William D. Leavitt, William D. Leavitt, William D. Leavitt, Sofia S. Venceslau, Jacob Waldbauer, Derek A. Smith, Inês A. Cardoso Pereira, Alexander S. Bradley, Alexander S. Bradley   +9 more
doaj   +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

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

Ion Activation Methods for Top‐Down Proteomics

Mass Spectrometry Reviews, EarlyView.
ABSTRACT Mass spectrometry (MS) has emerged as a premier method used to characterize the sequences of proteins. Top‐down proteomics aims to capture the multiple sources of structural diversity reflected in proteins, such as those that arise from alternative RNA splicing events or the addition of post‐translational modifications. Tandem MS (i.e., MS/MS)
Jada N. Walker, Jennifer S. Brodbelt
wiley   +1 more source

Introgressed Brassica napus × Sinapis alba enhance resistance to the crucifer flea beetle (Phyllotreta cruciferae)

Pest Management Science, EarlyView.
This study demonstrates that Brassica napus lines with Sinapis alba introgressions enhanced resistance against Phyllotreta cruciferae, resulting in reduced feeding damage and improved seedling physiological performance. The introgressed lines showed strong potential as genetic resources for developing more resilient and sustainable canola varieties ...
Aziz Ullah, Altaf Hussain, Vicky Roslinsky, Sally L. Vail, Boyd A. Mori   +4 more
wiley   +1 more source