查看更多>>摘要：The conventional Hall effect is linearly proportional to the field component or magnetization component perpendicular to a film.Despite the increasing theoretical proposals on the Hall effect to the in-plane field or magnetization in various special systems induced by the Berry curvature,such an unconventional Hall effect has only been experimentally reported in Weyl semimetals and in a heterodimensional superlat-tice.Here,we report an unambiguous experimental observation of the antisymmetric planar Hall effect(APHE)with respect to the in-plane magnetic field in centrosymmetric rutile RuO2 and IrO2 single-crystal films.The measured Hall resistivity is found to be linearly proportional to the component of the applied in-plane magnetic field along a particular crystal axis and to be independent of the current direction or temperature.Both the experimental observations and theoretical calculations confirm that the APHE in rutile oxide films is induced by the Lorentz force.Our findings can be generalized to ferromagnetic mate-rials for the discovery of anomalous Hall effects and quantum anomalous Hall effects induced by in-plane magnetization.In addition to significantly expanding knowledge of the Hall effect,this work opens the door to explore new members in the Hall effect family.
查看更多>>摘要：The big data explosion demands novel data storage technology.Among many different approaches,soli-tonic racetrack memory devices hold great promise for accommodating nonvolatile and low-power func-tionalities.As representative topological solitons,magnetic skyrmions are envisioned as potential information carriers for efficient information processing.While their advantages as memory and logic elements have been vastly exploited from theoretical perspectives,the corresponding experimental efforts are rather limited.These challenges,which are key to versatile skyrmionic devices,will be studied in this work.Through patterning concaved surface topography with designed arrays of indentations on standard Si/SiO2 substrates,we demonstrate that the resultant non-flat energy landscape could lead to the formation of hexagonal and square skyrmion lattices in Ta/CoFeB/MgO multilayers.Based on these films,one-dimensional racetrack devices are subsequently fabricated,in which a long-distance determin-istic shifting of skyrmions between neighboring indentations is achieved at room temperature.Through separating the word line and the bit line,a prototype shift register device,which can sequentially gener-ate and precisely shift complex skyrmionic data strings,is presented.The deterministic writing and long-distance shifting of skyrmionic bits can find potential applications in transformative skyrmionic memory,logic as well as the in-memory computing devices.
查看更多>>摘要：The mitigation of environmental and energy crises could be advanced by reclaiming platinum group pre-cious metals(PGMs)from decommissioned air purification catalysts.However,the complexity of catalyst composition and the high chemical inertness of PGMs significantly impede this process.Consequently,recovering PGMs from used industrial catalysts is crucial and challenging.This study delves into an envi-ronmentally friendly approach to selectively recover PGMs from commercial air purifiers using photocat-alytic redox technology.Our investigation focuses on devising a comprehensive strategy for treating three-way catalysts employed in automotive exhaust treatment.By meticulously pretreating and modi-fying reaction conditions,we achieved noteworthy results,completely dissolving and separating rhodium(Rh),palladium(Pd),and platinum(Pt)within a 12-h time frame.Importantly,the solubility selectivity persists despite the remarkably similar physicochemical properties of Rh,Pd,and Pt.To bolster the envi-ronmental sustainability of our method,we harness sunlight as the energy source to activate the photo-catalysts,facilitating the complete dissolution of precious metals under natural light irradiation.This eco-friendly recovery approach demonstrated on commercial air purifiers,exhibits promise for broader appli-cation to a diverse range of deactivated air purification catalysts,potentially enabling implementation on a large scale.
查看更多>>摘要：The anodic oxygen evolution reaction is a well-acknowledged side reaction in traditional aqueous electrochemiluminescence(ECL)systems due to the generation and surface aggregation of oxygen at the electrode,which detrimentally impacts the stability and efficiency of ECL emission.However,the effect of reactive oxygen species generated during water oxidation on ECL luminophores has been largely overlooked.Taking the typical luminol emitter as an example,herein,we employed NiIr single-atom alloy aerogels possessing efficient water oxidation activity as a prototype co-reaction accelerator to elucidate the relationship between ECL behavior and water oxidation reaction kinetics for the first time.By regu-lating the concentration of hydroxide ions in the electrolyte,the electrochemical oxidation processes of both luminol and water are finely tuned.When the concentration of hydroxide ions in electrolyte is low,the kinetics of water oxidation is attenuated,which limits the generation of oxygen,effectively mitigates the influence of oxygen accumulation on the ECL strength,and offers a novel perspective for harnessing side reactions in ECL systems.Finally,a sensitive and stable sensor for antioxidant detection was constructed and applied to the practical sample detection.
查看更多>>摘要：Highly selective production of value-added multicarbon(C2+)products via electrochemical CO2 reduction reaction(eCO2RR)on polycrystalline copper(Cu)remains challenging.Herein,the facile surface modifi-cation using poly(α-ethyl cyanoacrylate)(PECA)is presented to greatly enhance the C2+selectivity for eCO2RR over polycrystalline Cu,with Faradaic efficiency(FE)towards C2+products increased from 30.1％for the Cu electrode to 72.6％for the obtained Cu-PECA electrode at-1.1 V vs.reversible hydrogen electrode(RHE).Given the well-determined FEs towards C2+products,the partial current densities for C2+production could be estimated to be-145.4 mA cm-2 for the Cu-PECA electrode at-0.9 V vs.RHE in a homemade flow cell.In-situ spectral characterizations and theoretical calculations reveal that PECA fea-tured with electron-accepting-C≡N and-COOR groups decorated onto the Cu electrode could inhibit the adsorption of*H intermediates and stabilize the*CO intermediates,given the redistributed interfacial electron density and the raised energy level of d-band center(Ed)of Cu active sites,thus facilitating the C-C coupling and then the C2+selective production.This study is believed to be guidable to the modifi-cation of electrocatalysts and electrodes with polymers to steer the surface adsorption behaviors of reac-tion intermediates to realize practical eCO2RR towards value-added C2+products with high activity and selectivity.
查看更多>>摘要：Excitatory amino acid transporters(EAATs)are responsible for excitatory amino acid transportation and are associated with auto-immune diseases in the central nervous system and peripheral tissues.However,the subcellular location and function of EAAT2 in macrophages are still obscure.In this study,we demonstrated that LPS stimulation increases expression of EAAT2(coded by Slc1a2)via NF-κB signal-ing.EAAT2 is necessary for inflammatory macrophage polarization through sustaining mTORC1 activa-tion.Mechanistically,lysosomal EAAT2 mediates lysosomal glutamate and aspartate efflux to maintain V-ATPase activation,which sustains macropinocytosis and mTORC1.We also found that mice with mye-loid depletion of Slc1a2 show alleviated inflammatory responses in LPS-induced systemic inflammation and high-fat diet induced obesity.Notably,patients with type Ⅱ diabetes(T2D)have a higher level of expression of lysosomal EAAT2 and activation of mTORC1 in blood macrophages.Taken together,our study links the subcellular location of amino acid transporters with the fate decision of immune cells,which provides potential therapeutic targets for the treatment of inflammatory diseases.
查看更多>>摘要：The term"Holocene temperature conundrum"refers to the inconsistencies between proxy-based recon-structions and transient model simulations,and it challenges our understanding of global temperature evolution during the Holocene.Climate reconstructions indicate a cooling trend following the Holocene Thermal Maximum,while model simulations indicate a consistent warming trend due to ice-sheet retreat and rising greenhouse gas concentrations.Various factors,such as seasonal biases and over-looked feedback processes,have been proposed as potential causes for this discrepancy.In this study,we examined the impact of vegetation-climate feedback on the temperature anomaly patterns in East Asia during the mid-Holocene(～6 ka).By utilizing the fully coupled Earth system model EC-Earth and per-forming simulations with and without coupled dynamic vegetation,our objective was to isolate the influ-ence of vegetation changes on regional temperature patterns.Our findings reveal that vegetation-climate feedback contributed to warming across most of East Asia,resulting in spatially diverse temperature changes during the mid-Holocene and significantly improved model-data agreement.These results high-light the crucial role of vegetation-climate feedback in addressing the Holocene temperature conundrum and emphasize its importance for simulating accurate climate scenarios.
查看更多>>摘要：Wildfires over permafrost put perennially frozen carbon at risk.However,wildfire emissions from bio-mass burning over the diverse range of permafrost regions and their share in global wildfire emissions have not been revealed.The results showed a dramatic increase in wildfire carbon emissions from per-mafrost regions over the period 1997-2021.The share of permafrost in global wildfire CO2 emissions increased from 2.42％in 1997 to 20.86％in 2021.Accelerating wildfire emissions from continuous per-mafrost region is the single largest contributor to increased emissions in northern permafrost regions.Fire-induced emissions from 2019 to 2021 alone accounted for approximately 40％of the 25-year total CO2 emissions from continuous permafrost regions.The rise in wildfire emissions from continuous per-mafrost regions is explained by desiccation within a 5-10 cm soil depth,where wildfires combust below-ground fuel.These findings highlight the acceleration of fire-induced carbon emissions from continuous permafrost regions,which disturb the organic carbon stock and accelerate the positive feedback between permafrost degradation and climate warming,thus stimulating permafrost towards a climatic tipping point.
NETL
NSTL
万方数据