How much of Earth's compositional variation dates to processes that occurred during planet formation remains an unanswered question. High-precision tungsten isotopic data from rocks from two large igneous provinces, the North Atlantic Igneous Province and the Ontong Java Plateau, reveal preservation to the Phanerozoic of tungsten isotopic heterogeneities in the mantle. These heterogeneities, caused by the decay of hafnium-182 in mantle domains with high hafnium/tungsten ratios, were created during the first ~50 million years of solar system history, indicating that portions of the mantle that formed during Earth's primary accretionary period have survived to the present.
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http://dx.doi.org/10.1126/science.aad8563 | DOI Listing |
Talanta
December 2024
Savannah River National Laboratory, Aiken, SC, 29808, USA. Electronic address:
Intentional nuclear forensics is a concept wherein the deliberate addition of benign and persistent material signatures to nuclear material can be used to reduce the time between the discovery of material outside of regulatory control and determination of its original provenance. One concept within intentional nuclear forensics involves the use of perturbed stable isotopes to generate unique isotope ratio "barcodes" to encode information (e.g.
View Article and Find Full Text PDFMolecules
December 2024
Department of Chemistry, Faculty of Science, University of Maragheh, Maragheh P.O. Box 55181-83111, Iran.
Improving the photogenerated carrier separation efficiency of individual semiconductor materials has always been a key challenge in photocatalysis. In this study, we synthesized a novel photocatalytic material, N-CQDs/UBWO, in situ by combining nitrogen-doped carbon quantum dots (N-CQDs) derived from discarded corn stover with ultrathin BiWO nanosheets (UBWO). Detailed characterization indicates that the random distribution of N-CQDs on the UBWO surface increases the specific surface area of UBWO, which is beneficial for the adsorption and degradation of oxytetracycline (OTC).
View Article and Find Full Text PDFBiomed Phys Eng Express
December 2024
Department of Radiation Oncology, Northwest Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, United States of America.
. Electron beam treatment often requires bolus to augment surface dose to nearly 100%. There are no optimum bolus materials and hence a high-Z based clothlike material is investigated to reduce air column in treatment that provides optimum surface dose.
View Article and Find Full Text PDFRev Sci Instrum
December 2024
Max-Planck-Insitut für Plasmaphysik, Boltzmannstrasse 2, Garching D-85748, Germany.
The Testbed for Analysis of Permeation of Atoms in Samples (TAPAS) is an experimental setup for ion-driven permeation studies with a focus on investigating wall materials for nuclear fusion devices. A monoenergetic, mass-filtered high-intensity keV ion beam is focused and directed onto the permeation sample by electrostatic ion optics and decelerated to the desired ion energy by a dedicated set of apertures close to the sample. We were able to obtain ion energies as low as 170 eV/D with a D3+ ion beam with an ion flux density of the order of 1020 D/m2s on a beam-wetted area of ∼33 mm2.
View Article and Find Full Text PDFEnviron Pollut
December 2024
School of Resources and Environment, Wuhan Textile University, Wuhan, 430200, PR China.
Enhancing adsorption ability of photocatalyst by vacancy is a fascinating strategy. Thus, BiWO/BiOCl with millefeuille-like was successfully prepared via multi-pots method. Experimental results discern that BOW-10 can degraded 75.
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