Article
Environmental Sciences
Song Tao, Zhang Liankai, Liu Pengyu, Zou Shengzhang, Zhao Yi, Liu Xiang, Li Danyang
Summary: This study investigates the transformation of water resources in karst areas, focusing on different forms of water including precipitation, overland flow, groundwater, evapotranspiration water, and soil water. Through long-term observations and modeling, the study reveals the conversion processes and rates of these water forms under different rainfall conditions. The findings provide important insights into the complex water dynamics in karst areas.
ENVIRONMENTAL EARTH SCIENCES
(2022)
Article
Engineering, Civil
Sheng Wang, Yan Yan, Zhiyong Fu, Hongsong Chen
Summary: The study reveals the unique threshold-like runoff responses to rainfall inputs on karst slope, where epikarst seepage runoff plays a crucial role in regulating flow functions. Soil depth directly affects surface runoff, while identifying the factors controlling rainfall-induced subsurface runoff remains a challenge. Nonlinear hydrological behaviors such as the 'hockey stick', 'heaviside' function, and sigmoid function were observed, suggesting the complexity of karst hydrological systems.
JOURNAL OF HYDROLOGY
(2022)
Article
Environmental Sciences
Fan Liu, Guanghui Jiang, Guangcai Wang, Fang Guo, Jia Wang, Qigang Wang, Jie Shi, Jingyi Cai, Min Wang
Summary: This study investigated the runoff characteristics in rainwater harvesting by monitoring stable isotopes of hydrogen and oxygen in subtropic cockpit karst landforms. Different runoff types, such as surface runoff and subsurface runoff, play significant roles in water harvesting. End-member analysis proposed three mixing patterns with indicators of isotopic value and total dissolved solids, contributing to better management of cistern water resources in rural karst mountain areas.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Chemistry, Organic
Jian-Guo Gu, Cai-Xia Wang, Guang-Qi Hu, Kang Shen, Hong-Hai Zhang
Summary: This study reveals the K2CO3/18-crown-6-catalyzed H/D exchange of heretoarenes in high atom % deuterium incorporation. The use of a weak base as a catalyst demonstrates excellent site selectivity and broad functional group tolerance. Control experiments confirm the essential role of removable bromide directing group in enhancing adjacent C-H bond reactivity, and bromide conversion to other functional groups is performed to construct useful deuterated compounds.
Article
Water Resources
Francesca A. McInerney, Christoph Gerber, Emma Dangerfield, Lucas A. Cernusak, Athina Puccini, Steve Szarvas, Tanoj Singh, Nina Welti
Summary: The oxygen (delta O-18) and hydrogen (delta H-2) isotope ratios of water change as it moves from the atmosphere to the land surface, through soils and plants, and back to the atmosphere. This is due to isotopic fractionation during transpiration, which is influenced by climate. Predictions of isotopic fractionation during transpiration can be made using process-based models and climate data. These predictions can then be used to generate maps of leaf water isotope ratios, or isoscapes, which can be used in various fields including hydrology, ecology, and forensics. In this study, leaf water isoscapes for Australia, the driest vegetated continent on Earth, were generated with higher resolution and region-specific parameters, improving the accuracy of predictions.
HYDROLOGICAL PROCESSES
(2023)
Review
Chemistry, Physical
Daniel A. Kurtz, Bryan M. Hunter
Summary: Transition metal oxides/oxyhydroxides have generated much interest as electrocatalysts for water splitting due to their ability to cycle between different oxidation states. A thermodynamic model is proposed to explain the trends in first-row transition metal catalysts for oxygen evolution half-reaction. The model can provide quantitative predictions based on experimental data.
Article
Water Resources
Jose Luis Yanes Conde, Francisco Moral Martos
Summary: This study investigated the isotopic composition of precipitation and groundwater in Andalusia. The results showed that groundwater is lighter and has higher d-excess than meteoric waters. The study also revealed the effects of the Atlantic-Mediterranean divide, continentality, and altitude on the isotopic composition of spring waters.
HYDROLOGICAL PROCESSES
(2022)
Article
Engineering, Environmental
Bilal Cemek, Hakan Arslan, Erdem Kucuktopcu, Halis Simsek
Summary: Isotope techniques are often used to determine groundwater origin and quality. In this study, different models were compared to estimate isotopes in groundwater, and the multilayer perceptron model performed the best. This suggests that data-driven methods, such as the multilayer perceptron, can be used when laboratory isotope analysis is unavailable or costly.
STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT
(2022)
Article
Geosciences, Multidisciplinary
Zhengyu Xia, Jakub Surma, Matthew J. Winnick
Summary: The new excess term, Delta ' 17O, of the triple oxygen isotope composition is proposed as a tracer for kinetic fractionation in the water cycle. The objective is to compare and analyze the variations in Delta ' 17O and dexcess resulting from isotopic fractionation in each step of the water cycle, and explore their different responses and sensitivities to hydroclimate processes.
EARTH-SCIENCE REVIEWS
(2023)
Article
Environmental Sciences
David Dominguez-Villar, Kristina Krklec, Ian Boomer, Ian J. Fairchild
Summary: The isotope signature of cave waters was studied using the ISODRIP model based on data from Eagle Cave in central Spain. The results indicate that various factors, including flow routes, influence the isotopic signals of cave waters significantly.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Geosciences, Multidisciplinary
Zhengyu Xia
Summary: By using a new atmospheric moisture flow dataset, this study diagnoses the OMS regions and conditions globally and finds that OMS temperature and relative humidity together explain 41% of the variability in monthly mean precipitation d-excess in low- and mid-latitudes. The study also shows the distinguishable sensitivity between d-excess and Delta ' O-17 to OMS temperature, as predicted by theory, based on a few sites with paired data. This research contributes to understanding the complex controls on precipitation d-excess and Delta ' O-17 by quantifying the crucial role of OMS dynamics.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Biodiversity Conservation
Natasa Ravbar, Metka Petric, Matej Blatnik, Astrid Svara
Summary: Karst water sources play a significant role in meeting global drinking water needs, but require appropriate protection measures due to the complexity of water flow in carbonate aquifers. This study addressed the lack of analytical evidence in current legislative frameworks and provided optimized indicators for karst water source protection by developing an advanced, multi-methodological approach.
ECOLOGICAL INDICATORS
(2021)
Article
Geosciences, Multidisciplinary
Tunde Olarinoye, Tom Gleeson, Andreas Hartmann
Summary: The analysis of karst spring recession hydrographs is crucial for understanding the dynamic nature of karst aquifer systems. Traditional manual procedures introduce subjectivity and errors, therefore an automated and objective alternative approach is developed. The modified extraction and parameter optimization methods are capable of accurately identifying different recession components and representing the karst systems.
HYDROLOGY AND EARTH SYSTEM SCIENCES
(2022)
Article
Geochemistry & Geophysics
Joshua Munro, Chris Harris
Summary: The 2060 +/- 2 Ma Phalaborwa Complex is a pipe-like intrusion formed from multiple magma pulses. It is composed of a main pipe made up of various rock types, surrounded by smaller plugs. The delta O-18 values for most minerals are consistent with magmatic equilibrium, while alkali feldspar and phlogopite show more variability. The high-delta O-18 values suggest a mantle source for the magmas.
JOURNAL OF PETROLOGY
(2023)
Article
Chemistry, Applied
Aoqian Qiu, Jun Li, Xiaofeng Zhang, Pan Ran, Weijie Ding, Xu Cheng, Mengning Ding
Summary: In this study, an electrochemical reductive deuteration strategy from phthalimide to phthalimidine-d(2), using D2O as a deuterium source, was successfully achieved in common solvents. This approach showed broad compatibility with various functional groups. Mechanistic investigations revealed a 4-electron reduction pathway, and the coupled anodic oxygen evolution maintained neutral to mild basic conditions for the electrochemical reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2023)