Results 121 to 130 of about 35,458 (292)

A Cool, Nutrient‐Enriched Eastern Equatorial Pacific During the Mid‐Pleistocene Transition

open access: yesGeophysical Research Letters, 2019
The emergence of high‐amplitude, low‐frequency glacial‐interglacial cycles during the mid‐Pleistocene climate transition (MPT; 800–1,200 ka) is associated with global cooling.
Rebecca S. Robinson   +5 more
doaj   +1 more source

Cobalt Single‐Atom Catalysts for Ultrafast Sulfamethoxazole Degradation: Unveiling the Chloride‐Ion‐Enhanced Formation of Co(IV)=O

open access: yesAdvanced Science, EarlyView.
An atomically dispersed Co–N4 single‐atom catalyst rapidly activates peroxymonosulfate to remove the antibiotic sulfamethoxazole from water. Common ions have little impact, but chloride dramatically speeds degradation by promoting a high‐valent Co(IV) = O oxidant via in situ HOCl–catalyst electron transfer.
Anting Ding   +6 more
wiley   +1 more source

Multi-isotope analysis and the reconstruction of prey species palaeomigrations and palaeoecology [PDF]

open access: yes, 2010
This thesis explores the use of multi-element isotope analysis and intra-tooth sampling to reconstruct prey species ecology and biogeography. Modern caribou (Rangifer tarandus ssp.) and bison (Bison bison) from North America are used to assess the ...
BRITTON, KATE,HELENA
core  

W‐N‐C Tandem Catalytic Centers Mediating Efficient Charge Transfer for the Enhanced Radical‐Path U(VI) Photoreduction

open access: yesAdvanced Science, EarlyView.
This work constructed a tandem W−N−C center to simultaneously achieve the regulation of reaction pathways and optimization of charge separation efficiency. The Lewis‐acidic W6+ sites activated O2 to generate O2−$O_2^ - $, with enhanced charge separation via electronic modulation, steering U(VI) reduction down an efficient radical pathway.
Zhiyao Wu   +11 more
wiley   +1 more source

Dual-Isotope (δ2H, δ18O) and Bioelement (δ13C, δ15N) Fingerprints Reveal Atmospheric and Edaphic Drought Controls in Sauvignon Blanc (Orlești, Romania)

open access: yesPlants
Grapevine water relations are increasingly influenced by drought under climate change, with significant implications for yield, fruit composition and wine quality.
Marius Gheorghe Miricioiu   +4 more
doaj   +1 more source

Physiological Nitrogen Isotopic Responses in Paracoccus denitrificans [PDF]

open access: yes, 2006
The natural abundances of stable isotopes in our environment serve as intrinsic tracers that are incorporated into biological compounds and create unique isotopic signatures that record molecular history.
Pan, Bruce
core  

Enhancing Biogenic Formic Acid Production in the Modified OxFA Process by Acetonitrile Addition

open access: yesAdvanced Science, EarlyView.
In this study, the beneficial effect of using acetonitrile as a co‐solvent in the modified OxFA process is shown, outperforming methanol, demonstrating improved reaction kinetics combined with high selectivity for the HPA‐2 (H5PV2Mo10O40) catalyzed oxidation of xylose to FA.
Jan‐Dominik H. Krueger   +7 more
wiley   +1 more source

Research on Production of 15N Isotope with N2 by Gas Diffusion Method

open access: yesYuanzineng kexue jishu
There are two natural stable isotopes of nitrogen, 14N and 15N, with isotopic abundances of 99.636% and 0.364%. 15N is widely used in research and analysis in atmospheric tracing, agricultural and forestry research, and origin tracing.
HAN Yilun, ZHOU Mingsheng, WANG Fei
doaj   +1 more source

Tracing nitrate sources with dual isotopes and long term monitoring of nitrogen species in the Yellow River, China

open access: yesScientific Reports, 2017
A heavy load of nitrogenous compounds reflects nutrient loss and influences water quality in large rivers. Nitrogenous concentrations and dual isotopes of nitrate were measured to ascertain the spatial and temporal distributions of nitrate transformation
Fu-Jun Yue   +4 more
doaj   +1 more source

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