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Statistical characteristics and classification of ionospheric mid-latitude trough as revealed by the observations of DMSP-F18

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earth and Planetary Physics 2025年第1期9卷 137-147页

作者： Yi Liu JiuHou Lei FuQing Huang Su Zhou school of earth and Space sciences University of Science and Technology of ChinaHefei 230026China school of science Guiyang UniversityGuiyang 550005China

Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)*** data was obtained at an altitude of around 860 km in near polar orbit,throughout *** study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude *** differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron *** our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic *** was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct ***,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in *** ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E ***,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in *** addition,the troughs related to ion velocity(Vi)maximums could be observed in all *** troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both *** implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.

关键词： topside ionosphere mid-latitude trough ionospheric main trough auroral oval boundary temperature maximum

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Solar flare forecasting based on a Fusion Model

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earth and Planetary Physics 2025年第1期9卷 171-181页

作者： YiYang Li ShiYong Huang SiBo Xu ZhiGang Yuan Kui Jiang QiYang Xiong RenTong Lin school of earth and Space science Technology Hubei Luojia LaboratoryWuhan UniversityWuhan 430072China

Solar flare prediction is an important subject in the field of space *** learning technology has greatly promoted the development of this *** this study,we propose a novel solar flare forecasting model integrating Deep Residual Network(ResNet)and Support Vector Machine(SVM)for both≥C-class(C,M,and X classes)and≥M-class(M and X classes)*** collected samples of magnetograms from May 1,2010 to September 13,2018 from Space-weather Helioseismic and Magnetic Imager(HMI)Active Region Patches and then used a cross-validation method to obtain seven independent data *** then utilized five metrics to evaluate our fusion model,based on intermediate-output extracted by ResNet and SVM using the Gaussian kernel *** results show that the primary metric true skill statistics(TSS)achieves a value of 0.708±0.027 for≥C-class prediction,and of 0.758±0.042 for≥M-class prediction;these values indicate that our approach performs significantly better than those of previous *** metrics of our fusion model’s performance on the seven datasets indicate that the model is quite stable and robust,suggesting that fusion models that integrate an excellent baseline network with SVM can achieve improved performance in solar flare ***,we also discuss the performance impact of architectural innovation in our fusion model.

关键词： solar flare pace weather deep learning Fusion Model

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Rise of β-furanosyl ribonucleosides as the extant RNA component facilitated by simple divalent transition-metal minerals

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science China Chemistry 2025年

作者： Qianqian Chen Haoxing Xu Bingyue Zhao Yeersen Patehebieke Zerun Zhao Xiao Wang school of Chemistry and Chemical Engineering Nanjing University Frontiers science Center for Critical earth Material Cycling Nanjing University

The selective nucleoside synthesis through direct condensation between nucleobase and unactivated sugar in aqueous media has long been a formidable obstacle for the early chemical transformations hypothesized to construct the RNAWorld, due to product complexity and the low selectivity of the desired isomer. The preference of β-furanoside, the extant RNA component, has never been documented. Here we report an aqueous ribosylation mediated by divalent transition-metal ions, which unprecedentedly enhances the selectivity of furanosyl ribonucleosides as opposed to the traditionally predominating pyranosyl ones, with the furanoside/pyranoside ratio reaching up to 9/1. Furthermore, β-furanoside stands out for the first time as the most prevalent isomer in the presence of zinc and ammonium salts. The mechanism of this selectivity is elucidated with density functional theory calculations. The selectivity for β-furanoside can be further elevated via the adsorption on a zinc mineral. These findings exhibit as the first example that the selection of nucleosides with the desired, canonical configuration might be completed in the early stage of the RNA-forming process as opposed to later evolution, promoted by simple and widespread transition-metal minerals. The study may also find its value in synthetic chemistry as a guideline for developing a sustainable and selective glycosylation process.

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Distinct MLT asymmetry of auroral kilometric radiation observed by the FAST satellite

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earth and Planetary Physics 2025年第1期9卷 188-193页

作者： JiaWen Tang Sai Zhang FuLiang Xiao HongMing Yang Si Liu YiHua He Chang Yang YuYue Jin ZhouKun Deng Ping Li Archie James Johnston school of Physics and Electronic sciences Changsha University of Science and TechnologyChangsha 410114China Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-earth Electromagnetic Environments Changsha University of Science and TechnologyChangsha 410114China school of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha 410114China

Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u *** emissions have been observed in all magnetic planet magnetospheres of the solar *** this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) *** distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic *** addition,the occurrence rate on the nightside clearly increases as the AE^(*) index *** study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.

关键词： asymmetry auroral kilometric radiation interplanetary magnetic field

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Visualizing charge transfer and nuclear quantum effects in the hydrogen bond network of water

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science China Chemistry 2025年

作者： Ying Gao Haotian Wang Bin Zhang Department of Chemistry School of Science Tianjin University

Water, one of the most common and important solvents on earth, is widely used in biology, physics, chemistry, and other fields [1]. The hydrogen bond interactions between water molecules form a highly dynamic and syne...

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Deciphering Water Oxidation Catalysts:The Dominant Role of Surface Chemistry over Reconstruction Degree in Activity Promotion

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Nano-Micro Letters 2025年第3期17卷 340-354页

作者： Li An Jianyi Li Yuanmiao Sun Jiamin Zhu Justin Zhu Yeow Seow Hong Zhang Nan Zhang Pinxian Xi * Zhichuan JXu Chun‑Hua Yan State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceFrontiers Science Center for Rare IsotopesCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000People’s Republic of China school of Materials science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Faculty of Materials science and Energy Engineering Institute of Technology for Carbon NeutralityShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Key Laboratory of Electromagnetic Materials and Devices National Center for International Research On Photoelectric and Energy MaterialsSchool of Materials and EnergyElectron Microscopy CenterYunnan UniversityKunming 650091People’s Republic of China State Key Laboratory of Baiyunobo Rare earth Resource Researches and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030People’s Republic of China Beijing National Laboratory for Molecular sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU‑HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryPeking UniversityBeijing 100871People’s Republic of China

Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution *** surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity ***,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is *** substituting Fe content influences both current change tendency and surface reconstruction ***_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)*** reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based ***,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term ***,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction *** effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface *** finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.

关键词： Oxygen evolution reaction Perovskite oxides Doping Activation and reconstruction

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Boosting hydrocarbon conversion via Cu-doping induced oxygen vacancies on CeO2 in CO2 electroreduction

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Journal of Energy Chemistry 2025年第1期100卷 66-76页

作者： Lei Xue Tong Shi Chenhui Han Heng Zhang Fenrong Liu Haorun Li Yan Wang Xiaojun Gu Shanghong Zeng Inner Mongolia Key Laboratory of Chemistry and Physics of Rare earth Materials School of Chemistry and Chemical Engineering Inner Mongolia University State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Institute of Catalysis Department of Chemistry Zhejiang University National Key Laboratory of Baiyunobo Rare earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare Earths

Conversion of CO2back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as ***,precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging,especially for Cu-based ***,we report a novel defect engineering strategy,by which Cu-doping-induced oxygen vacancies on CeO2nanorods were effectively created,with adjustable vacancy/Cu *** resulting optimum catalyst shows up to 79% catalytic current density to hydrocarbons （excluding CO）,with 49% faradaic efficiency to *** and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of*CHO and activation of H2O,which leads to the following deep hydrogenation to *** findings may spur new insights for designing and developing more controllable chemical process relevant to CO2utilization.

关键词： Nanorods

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Constraints on what controls millennial-scale basin-wide denudation across mountain belts, Asia

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science China earth sciences 2025年第1期 74-93页

作者： Ye YANG Steven A.BINNIE Sheng XU Cong-Qiang LIU Tibor J.DUNAI Institute of Surface-earth System science School of Earth System Science Tianjin University Institute of Geology and Mineralogy University of Cologne

The terrestrial cosmogenic nuclide dataset consisting of 123310Be measurements of fluvial sediment samples across the Asian mountain belts is used to constrain the influence of climate,tectonics and topography on earth-surface denudation processes.10Be-derived basin-wide denudation rates were recalculated using a Monte Carlo simulation approach that relied on pixel-by-pixel production *** rates derived span four orders of magnitude,from 7.4±0.7 mm kyr-1（1σ;Central Tibetan Plateau） to 9,646744+777mm kyr-1（1σ;Southern Tibetan Plateau）,with a median of 186 mm *** our results with the traditional basin-wide production rate scaling model using a centroid coordinate and mean elevation,suggests that 96.6%of production rates will be underestimated using the latter method,especially for basins with a large *** bias between both methods reaches as large as 40%,caused by basin hypsometry and the nonlinear scaling of production rate with elevation and *** of the correlations between uniformly recalculated denudation rates and tectonics,climate,topography and rock lithology will facilitate the extrapolation of denudation rates in unknown basins using available *** the perspective of local scales,precipitation coupled with neotectonics-driven landslides is likely the most influential factor in subtropical Taiwan Island,while topography primarily constrains surface denudation rates in the eastern Tibetan Plateau within a narrow range of *** highland regions with glacier coverage,such as the Pamir,central and southern Tibetan Plateau high denudation rates are affected by glaciation,whereas lower precipitation and high erosion base level may limit river incision and evolving relief in the Central Tibetan *** contrast to local-scale findings highlighting a dominant factor constraining denudation rate,our large-scale quantitative analyses across the Asian mountain belts finds that （1） topographic metrics including

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An embedded electron current layer observed at the edge of the plasma sheet in the earth’s magnetotail

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earth and Planetary Physics 2025年第1期9卷 148-158页

作者： ChenChen Zhan RongSheng Wang QuanMing Lu San Lu XinMin Li Deep Space Exploration Laboratory/school of earth and Space sciences University of Science and Technology of ChinaHefei 230026China Chinese Academy of sciences(CAS)Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Anhui Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Astronautical science and Technology Harbin 150001China

The formation of an embedded electron current sheet within the magnetotail plasma sheet has been poorly *** this article,we present an electron current layer detected at the edge of the magnetotail plasma *** ions were demagnetized inside the electron current layer,but the electrons were still frozen in with the magnetic field ***,this decoupling of ions and electrons gave rise to a strong Hall electric field,which could be the reason for the formation of the embedded thin current *** magnetized electrons,the absence of the nongyrotropic electron distribution,and negligible energy dissipation in the layer indicate that magnetic reconnection had not been triggered within the embedded thin current *** highly asymmetric plasma on the two sides of the current layer and low magnetic shear across it could suppress magnetic *** observations indicate that the embedded electric current layer,probably generated by the Hall electric field,even down to electron scale,is not a sufficient condition for magnetic reconnection.

关键词： magnetotail plasma sheet magnetic reconnection

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Comparative analysis of empirical and deep learning models for ionospheric sporadic E layer prediction

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earth and Planetary Physics 2025年第1期9卷 10-19页

作者： BingKun Yu PengHao Tian XiangHui Xue Christopher JScott HaiLun Ye JianFei Wu Wen Yi TingDi Chen XianKang Dou Institute of Deep Space sciences Deep Space Exploration LaboratoryHefei 230088China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of Meteorology University of ReadingReading RG66BBUK

Sporadic E(Es)layers in the ionosphere are characterized by intense plasma irregularities in the E region at altitudes of 90-130 *** they can significantly influence radio communications and navigation systems,accurate forecasting of Es layers is crucial for ensuring the precision and dependability of navigation satellite *** this study,we present Es predictions made by an empirical model and by a deep learning model,and analyze their differences comprehensively by comparing the model predictions to satellite RO measurements and ground-based ionosonde *** deep learning model exhibited significantly better performance,as indicated by its high coefficient of correlation(r=0.87)with RO observations and predictions,than did the empirical model(r=0.53).This study highlights the importance of integrating artificial intelligence technology into ionosphere modelling generally,and into predicting Es layer occurrences and characteristics,in particular.

关键词： ionospheric sporadic E layer radio occultation ionosondes numerical model deep learning model artificial intelligence

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