Enhancing molecular oxygen activation by nitrogen-doped carbon encapsulating FeNi alloys with ultra-low Pt loading.

Modulating the electronic structure of noble metals via electronic metal-support interaction (EMSI) has been proven effectively for facilitating molecular oxygen activation and catalytic oxidation reactions. Nevertheless, the investigation of the fundamental mechanisms underlying activity enhancement has primarily focused on metal oxides as supports, especially in the catalytic degradation of volatile organic compounds. In this study, a novel Pt catalyst supported on nitrogen-doped carbon encapsulating FeNi alloy, featuring ultrafine Pt nanoparticles, was synthesized.

Rapid Iron-Mediated Aqueous-Phase Reactions of Organic Peroxides from Monoterpene-Derived Criegee Intermediates and Implications for Aerosol and Cloud Chemistry.

Fenton-like reactions between organic peroxides and transition-metal ions in the atmospheric aqueous phase have profound impacts on the chemistry, composition, and health effects of aerosols. However, the kinetics, mechanisms, and key influencing factors of such reactions remain poorly understood. In this study, we synthesized a series of monoterpene-derived α-acyloxyalkyl hydroperoxides (AAHPs), an important class of organic peroxides formed from Criegee intermediates during the ozonolysis of alkenes, and investigated their Fenton-like reactions with iron ions in the aqueous phase.

Unlocking Mechanisms for Soil Organic Matter Accumulation: Carbon Use Efficiency and Microbial Necromass as the Keys.

Soil microorganisms transform plant-derived C (carbon) into particulate organic C (POC) and mineral-associated C (MAOC) pools. While microbial carbon use efficiency (CUE) is widely recognized in current biogeochemical models as a key predictor of soil organic carbon (SOC) storage, large-scale empirical evidence is limited. In this study, we proposed and experimentally tested two predictors of POC and MAOC pool formation: microbial necromass (using amino sugars as a proxy) and CUE (by O-HO approach).

Wet deposition of atmospheric Hg in a typical inland city in North China: Sources, influencing factors, and health risk assessment.

Understanding the composition of mercury (Hg) in the atmosphere is important for confirming its sources and to preventing and reduce the production. To explore the morphological distribution characteristics of wet Hg concentrations in Xi'an Shaanxi Province, China, total Hg (THg), dissolved Hg (DTHg), reactive Hg (RTHg) and particulate-bound Hg (PTHg) (Hg insoluble in water) were measured at 72 precipitation in Xi'an from September 2020 to July 2022, and their average concentrations were 3.035 ± 3.

The transport, distribution, and budget of anthropogenic I in the Bohai and North Yellow Seas, China.

The potential release of radionuclides threatens marine ecosystems with the rapid development of coastal nuclear power plants in China. However, transport, dispersion, and final budget of anthropogenic radionuclides remain unclear, especially in the Bohai and North Yellow Seas, which are semi-enclosed marginal seas with poor water exchange. This study analyzed anthropogenic I concentration (a typical product of nuclear power plant operations) in seawater samples from this area.

Insights into plutonium in marine biota along the coast of China.

Radiation risk through seafood consumption is a big public concern under the discharge of nuclear contaminated water. Plutonium is an important radionuclide in view of radiation risk due to its high radiological and chemical toxicity, as well as consistent presence in the environment. The distribution and level of plutonium isotopes (Pu, Pu) in marine biota collected along the coast of China in 2022-2023 were investigated.

Impact of PM, relative humidity, and temperature on sleep quality: a cross-sectional study in Taipei.

Introduction: TWe investigated impacts of particulate matter with an aerodynamic diameter of less than 2.5 μm (PM), relative humidity (RH), and temperature on sleep stages and arousal.

Materials And Methods: A cross-sectional analysis involving 8,611 participants was conducted at a sleep center in Taipei.

Plutonium Marker for the Great Acceleration by Intensified Human Activities.

There has been a sharp rise in the extent and scale of human activities since the mid-20th century, termed the "Great Acceleration", and nuclear activities are one of the defining technological processes for this period. Pu released by atmospheric nuclear weapons tests provides an ideal chronostratigraphic marker for labeling this change due to its global fallout feature, temporal mutation, and long half-lives. However, the accumulation dynamics of plutonium from atmospheric deposition to preservation in the sediment is still controversial.

Novel insights into seasonal airborne bacterial interactions and potential threats to human health in a northwest city, China.

Bioaerosols significantly influence air quality and human health. This study investigated the diversity, structure, and interaction of bacterial communities in particulate matter (PM) across four seasons in Xi'an. The results revealed that operational taxonomic units (OTUs) were the highest in autumn, reaching levels comparable to those in winter, but were 3.

Transition from multi-year La Niña to strong El Niño rare but increased under global warming.

El Niño-Southern Oscillation (ENSO) exhibits a strong asymmetry between warm El Niño and cold La Niña in amplitude and temporal evolution. An El Niño often leads to a heat discharge in the equatorial Pacific conducive to its rapid termination and transition to a La Niña, whereas a La Niña persists and recharges the equatorial Pacific for consecutive years preconditioning development of a subsequent El Niño, as occurred in 2020-2023. Whether the multiyear-long heat recharge increases the likelihood of a transition to a strong El Niño remains unknown.

Asynchronicity of deglacial permafrost thawing controlled by millennial-scale climate variability.

Permafrost is a potentially important source of deglacial carbon release alongside deep-sea carbon outgassing. However, limited proxies have restricted our understanding in circumarctic regions and the last deglaciation. Tibetan Plateau (TP), the Earth's largest low-latitude and alpine permafrost region, remains underexplored.

Intensification of future subsurface marine heatwaves in an eddy-resolving model.

A shift in depth range enables marine organisms to adapt to marine heatwaves (MHWs). Subsurface MHWs could limit this pathway, yet their response to climate warming remains unclear. Here, using an eddy-resolving Earth system model forced under a high emission scenario, we project a robust global increase in subsurface MHWs driven by rising subsurface mean temperatures and enhanced temperature variability.

Carbon sinks associated with biological carbon pump in karst surface waters: progress, challenges, and prospects.

The biological carbon pump (BCP) associated with aquatic photosynthesis in karst surface waters converts dissolved inorganic carbon (DIC) into organic carbon. In the context of global climate change, BCP could be an important carbon sink mechanism, ultimately regulating atmospheric carbon dioxide (CO) and mitigating climate change. Because of the high DIC and pH, and low dissolved CO [CO (aq)], the hydrochemical characteristics of karst surface water bodies cause C limitation in BCP efficiency.

Nitrate-Photolysis Shortens the Lifetimes of Brown Carbon Tracers from Biomass Burning.

Biomass burning is an important source of brown carbon (BrC) aerosols, which influence climate by affecting the Earth's radiative balance. However, the transformation pathways of BrC chromophores, especially in the presence of photochemically active species, such as nitrate, are not well understood. In this study, the nitrate-mediated aqueous-phase photooxidation of three typical BrC chromophores from biomass burning was investigated, including 4-nitrocatechol, 3-nitrosalicylic acid, and 3,4-dinitrophenol.

Aerosol light absorption alleviates particulate pollution during wintertime haze events.

Aerosol light absorption has been widely considered as a contributing factor to the worsening of particulate pollution in large urban areas, primarily through its role in stabilizing the planetary boundary layer (PBL). Here, we report that absorption-dominated aerosol-radiation interaction can decrease near-surface fine particulate matter concentrations ([PM]) at a large-scale during wintertime haze events. A "warm bubble" effect by the significant heating rate of absorbing aerosols above the PBL top generates a secondary circulation, enhancing the upward motion (downward motion) and the convergence (divergence) in polluted (relatively clean) areas, with a net effect of lowering near-surface [PM].

Modeling the Global Impact of Chlorine Chemistry on Secondary Organic Aerosols.

Simulation of secondary organic aerosol (SOA) in models has been an uncertain component in determining the impacts of atmospheric aerosols on air quality and climate. Recent studies have shown that reactive chlorine can rapidly oxidize volatile organic compounds (VOCs), trigger SOA formation, and alter other oxidants, thus having a potentially significant effect on SOA, which has not been thoroughly investigated at the global scale. Here, we developed a chlorine-SOA simulation within a global chemical transport model along with updated anthropogenic continental chlorine emissions.

Unraveling Reactive Nitrogen Emissions in Heavy-Duty Diesel Vehicles across Evolving Standards and Cheating Tactics.

Reactive nitrogen (Nr) emissions significantly affect air quality and the nitrogen cycle in ecosystems. Heavy-duty diesel vehicles (HDDVs), as major sources of these emissions, exhibit complex emission characteristics because of the combined effects of different driving conditions and aftertreatment technologies. This study first investigated the emission factors (EFs) of Nr species, including NO, NO, HONO, NO, and NH, from HDDVs under different emission standards (China IV/V/VI) and cheating strategies, with a particular focus on the impact of selective catalytic reduction (SCR) systems.

Deep learning for cross-region streamflow and flood forecasting at a global scale.

Streamflow and flood forecasting remains one of the long-standing challenges in hydrology. Traditional physically based models are hampered by sparse parameters and complex calibration procedures particularly in ungauged catchments. We propose a novel hybrid deep learning model termed encoder-decoder double-layer long short-term memory (ED-DLSTM) to address streamflow forecasting at global scale for all (gauged and ungauged) catchments.

Soil Organic Carbon Increases With Decreasing Microbial Carbon Use Efficiency During Vegetation Restoration.

Microbial carbon (C) use efficiency (CUE) describes the proportion of organic C used by microorganisms for anabolic processes, which increases with soil organic C (SOC) content on a global scale. However, it is unclear whether a similar relationship exists during natural vegetation restoration in terrestrial ecosystems. Here, we investigated the patterns of CUE along a 160-year vegetation restoration chronosequence (from farmland to climax forest) estimated by stoichiometric modeling; additionally, we examined the relationship between CUE and SOC content and combined these results with a meta-analysis.

Optimizing cover crop practices as a sustainable solution for global agroecosystem services.

The practice of cover crops has gained popularity as a strategy to improve agricultural sustainability, but its full potential is often limited by environmental trade-offs. Using meta-analytic and data-driven quantifications of 2302 observations, we optimized cover crop practices and evaluated their benefits for global agroecosystems. Cover crops have historically boosted crop yields, soil carbon storage, and stability, but also stimulated greenhouse gas emissions.

Chemical and boron isotope characteristics of snow in the qiyi glacier, Qinghai-Tibet Plateau.

Snow is a valuable carrier for recording atmospheric information and snowmelt constitutes a crucial hydrological resource for ecosystem sustainability and human activities. The agriculture, industry, livelihoods and ecological security in the Hexi Corridor are dependent on the support of glacier snowmelt in Qilian Mountains of Qinghai-Tibet Plateau. We investigated the main water-soluble ions, trace elements and boron isotopes composition of snow at different altitudes in the Qiyi Glacier of the Qilian Mountains from 12 to 23, Aug.