The post-embryonic development of shoot apices in higher plants progresses through three distinct phases:the juvenile phase,adult vegetative phase,and reproductive phase.The transition from vegetative to reproductive ...The post-embryonic development of shoot apices in higher plants progresses through three distinct phases:the juvenile phase,adult vegetative phase,and reproductive phase.The transition from vegetative to reproductive growth represents a critical developmental transition that affects plant adaptability(Poethig 2003;Baurle and Dean 2006).展开更多
Separation bubbles forming on airfoils significantly influence aerodynamic behavior,particularly at low Reynolds numbers,making their accurate prediction a critical challenge in transition modelling.This study investi...Separation bubbles forming on airfoils significantly influence aerodynamic behavior,particularly at low Reynolds numbers,making their accurate prediction a critical challenge in transition modelling.This study investigates numerical modeling of a separation bubble and the effects of airfoil thickness and camber variation on the formation of the bubble dynamics at low Reynolds numbers.The numerical results were compared with the experimental results obtained from surface pressure distribution measurements,oil flow visualisation,and surface shear measurements to analyse the detailed flow behavior.The combination of pressure and flow visualisation techniques provided complementary insights,enabling a detailed characterisation of bubble formation.The results reveal that both the thickness and camber of the airfoil significantly influence the location,length,and stability of the bubble.At low Reynolds number flows(Re=0.5×10^(5)),particularly for highly cambered profiles,closer to the leading edge,separation and long bubbles were observed.As the Reynolds number increased,the separation point shifted to the leading edge,and reattachment became more likely.In numerical studies,transition models can accurately model the bubble initiation point;however,they often fail to model the bubble reattachment points accurately.This is due to the inadequacy of models that use empirical expressions for turbulence modelling,particularly in low Reynolds number flows,in their viscous modelling.In this study,it was concluded that transition onset terms,which specifically affect bubble formation,should be modified for more accurate modeling.展开更多
Polyamorphous transition refers to the transformation between two distinct amorphous states with identical composition.This phenomenon is intriguing in the field of physics and offers avenues for glass material design...Polyamorphous transition refers to the transformation between two distinct amorphous states with identical composition.This phenomenon is intriguing in the field of physics and offers avenues for glass material design.Recently,polyamorphous transitions have been frequently observed in glassy materials.However,the transition pathway has yet to be established,which is essential for understanding its structural origins.Here,we present evidence from 12 different types of metallic glasses spanning 7 orders of magnitude in timescales,demonstrating that polyamorphous transitions consistently occur after the devitrification process,between two supercooled liquid phases(Ⅰ and Ⅱ).Notably,we observe a decrease in liquid fragility and heat capacity following the transition,suggesting that the polyamorphous transition is associated with the fragile-to-strong transition(FST)in liquids.These findings elucidate the detailed structural pathway of the polyamorphous transition,via glass I→devitrification→liquid I→fragile-strong transition→liquid II,and incorporate the FST into a cohesive framework for its understanding.展开更多
Based on datasets from the International Best-Track Archive for Climate Stewardship(IBTrACS)and the fifth major global reanalysis produced by ECMWF(ERA5),the authors found that 29%of tropical cyclones(TCs)in the weste...Based on datasets from the International Best-Track Archive for Climate Stewardship(IBTrACS)and the fifth major global reanalysis produced by ECMWF(ERA5),the authors found that 29%of tropical cyclones(TCs)in the western North Pacific underwent extratropical transition(ET)from 1979 to 2022,with the frequency of ET events showing a slow decreasing trend.The extratropical transition tropical cyclones(ETCs)are classified into four clusters using the k-means clustering method based on their track patterns:recurving ETCs,westward ETCs,northwestward ETCs,and abnormal track ETCs.The transition process of recurving ETCs mostly occurs after the recurvature is completed,while 63.7%of the westward ETCs complete their transition after landfall.Abnormal track ETCs undergo transition over high-latitude oceans.Northwestward ETCs have the longest duration and slowest transition speed during the ET period,resulting in a prolonged impact.The ET process occurs at the edges of the western Pacific subtropical high(WPSH),with higher frequency during westward extension and lower during eastward retreat.While westward ETCs transition through surface friction effects,others complete ET in the northwest baroclinic zone of the WPSH.展开更多
Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling pha...Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling phase transitions to form diverse heterostructures inside a single crystal remains challenging.In this study,we realize vertical/lateral polytype heterostructures in a hole-doped Mott insulator via thermal annealing-induced structural transitions.Raman spectroscopy,atomic force microscopy and scanning Kelvin probe force microscopy confirm the coexistence of T-H polytype heterostructures.Atomic-scale scanning tunneling microscopy/spectroscopy measurements reveal the transparent effect in 1H/1T vertical heterostructures,where positive bias voltage induces in a pronounced superposition of the√13×√13 CDW of the 1T-layer on the 1H-layer.By systematically comparing the 1T/1H and 1T/1T interfaces,we demonstrate that the metallic 1H-layer induces a Coulomb screening effect on the 1T-layer,suppressing the formation of CDW domain walls and forming more ordered electronic states.These results clarify the interfacial coupling between distinct quantum many-body phases and establish a controllable pathway for constructing two-dimensional polytype heterostructures with tunable electronic properties.展开更多
Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen e...Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction(HER)and the anodic oxygen evolution reaction(OER).Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts,owing to their low cost,tunable composition,and noble-metal-like catalytic activity.Nevertheless,systematic reviews on their application as bifunctional catalysts for overall water splitting(OWS)are still limited.This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers(NFs),including metals,oxides,phosphides,sulfides,and carbides.Key strategies for enhancing their catalytic performance are systematically summarized,such as heterointerface engineering,heteroatom doping,metal-nonmetal-metal bridging architectures,and single-atom site design.Finally,current challenges and future research directions are discussed,aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.展开更多
Temperature-programmed desorption(TPD)is a fundamental technique in surface science and heterogeneous catalysis for characterizing adsorption behavior,and for extracting key parameters such as adsorption energy.Howeve...Temperature-programmed desorption(TPD)is a fundamental technique in surface science and heterogeneous catalysis for characterizing adsorption behavior,and for extracting key parameters such as adsorption energy.However,the majority of existing TPD data is accessible in the form of published images,which lacks structured and quantitative datasets.This constrains its utility for rigorous quantitative analysis and computational modelling.Using carbon monoxide(CO)which is a widely adopted probe molecule,a curated and standardized dataset of CO-TPD is constructed,encompassing 14 transition-metal single-crystal surfaces,including copper(Cu)and ruthenium(Ru).By systematically extracting numerical data points from published spectra and applying normalization,essential spectral features such as peak shape are fully preserved.The dataset also documents relevant experimental parameters,including heating rates,and was developed using a standardized protocol for data collection and quality control.This resource serves as both a reference library to support the deconvolution of TPD spectra from complex catalysts and an experimental benchmark for calibrating parameters in theoretical models.By providing a reliable and accessible data function,this work advances the microscopic understanding and the rational design of catalyst active centers.展开更多
The complex aerodynamic interaction between tandem tilt-wing and multi-rotor directly affects the wing surface flow and rotor thrust,making it a critical factor during the tilt transition process of this configuration...The complex aerodynamic interaction between tandem tilt-wing and multi-rotor directly affects the wing surface flow and rotor thrust,making it a critical factor during the tilt transition process of this configuration of rotorcraft.The aerodynamic interaction of tandem tilt-wing and multi-rotor is investigated based on the CFD method.The aerodynamic effect of multi tilt-rotor is simulated as virtual disk modeling by adding source terms to the Navier-Stokes equations,effectively reducing the calculation time while maintaining the accuracy of aerodynamic interaction calculations.Aerodynamic forces and flow field characteristics of the tandem tilt-wing and multi-rotor under different tilt angles are compared between cases with and without aerodynamic interaction.Furthermore,the differences in aerodynamic forces between dynamic tilt transition and fixed-angle conditions were compared.The results show that the aerodynamic interaction of multi-rotor obviously increases the lift of front tilt-wing at different tilt angles,the wing lift under interaction is increased by more than 40%compared with isolated wing at tilt angle of 15°for the computation in this paper,which is related to the increase of wing flow velocity and the suppression of flow separation caused by multi-rotor;the wing blocking effect will increase rotor thrust,especially near the tilt angles of 30°and 45°;the increases of rear wing lift and rear rotor thrust under aerodynamic interaction are not significant because of suppression by the front wing’s downwash;the unsteady effects during dynamic tilting have a relatively minor impact on aerodynamic interaction,with the aerodynamic forces on the rotors and wings during the dynamic tilting process showing little difference from those under corresponding fixed tilt angles.展开更多
Objective Frailty is becoming increasingly common among aging adults.Frailty transitionis shaped by biological,social,psychological,and environmental factors.This study investigated combined effects of protective fact...Objective Frailty is becoming increasingly common among aging adults.Frailty transitionis shaped by biological,social,psychological,and environmental factors.This study investigated combined effects of protective factors on frailty transition by constructing a Protection Index(PI)to guide targeted interventions.Methods Data were extracted from the 4th Sample Survey of the Aged Population in Urban and Rural China,including baseline(2017)and follow-up(2019)surveys.Frailty was assessed using the Frailty Index(FI),whereas the PI measured protective factors.Frailty transitions over 2 years were analyzed prospectively.Pearson’s correlation examined the relationship between FI and PI,and logistic regression assessed the effects of PI on frailty transitions.Results This study included 9,093 older adults.FI values increased with age and were higher in women,whereas PI values decreased with age and were higher in men.Over 2 years,56.2%of the participants showed a stable frailty status,14.2%improved,and 29.6%worsened.Negative transitions were more common than positive transitions,with transitions occurring most frequently between adjacent states.The PI was moderately negatively correlated with the FI(r=−0.349,P<0.001).A higher PI was associated with a lower risk of negative transitions among robust and prefrail individuals(OR=0.989,0.981,both P<0.05),but showed no significant effect among those with existing frailty.Conclusion Negative frailty transitions were more common with advancing age.Enhancing PI may help prevent negative frailty transitions among robust and pre-frail older adults,underscoring the value of early interventions.展开更多
Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face wit...Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed C–H activation has been employed for the functionalization of amino acids and peptides.Through domino C–H activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed C–H activation/annulation.展开更多
Discussions about the future of energy sources and environmental sustainability are becoming critical on a global scale.The energy sector plays a central role in the economy,as the availability and cost of energy infl...Discussions about the future of energy sources and environmental sustainability are becoming critical on a global scale.The energy sector plays a central role in the economy,as the availability and cost of energy influence the competitiveness of economies,while the level of energy consumption impacts the standard of living for individuals.This paper aims to examine environmental challenges and steps for a sustainable transition towards a hydrogen economy,focusing on its potential as an alternative to fossil fuels and the importance of developing the hydrogen paradigm.The research methodology is based on a combination of qualitative and quantitative methods,including an analysis of global and regional trends in the energy transition,the impact of various forms of hydrogen production(green,blue,gray hydrogen)on greenhouse gas emissions,and a comparison of existing policies and strategies in different countries transitioning to a sustainable hydrogen economy.Research results show that green hydrogen,produced via electrolysis using renewable energy sources,holds the greatest potential for reducing greenhouse gas emissions,while gray and blue hydrogen can serve as transitional options.The development of the hydrogen paradigm,rooted in innovative technologies,renewable energy sources,and international cooperation,is crucial for decarbonization and the creation of a sustainable global economy,despite challenges such as high costs and the need for global coordination.The hydrogen paradigm is becoming a cornerstone of these efforts,laying the foundation for a long-term,sustainable global economy.Currently,over 180 hydrogen transport projects,60 distribution projects,80 storage projects,30 terminal and port projects,and more than 220 hydrogen production projects are under development worldwide.The global momentum of the hydrogen transition helps mitigate climate change and build a sustainable future.展开更多
A novel method for the synthesis of 2,4-disubstituted thiophenes via the reactions of N,N-disubstituted enaminones and elemental sulfur is developed.By simply heating the substrates in pure water in the presence of Na...A novel method for the synthesis of 2,4-disubstituted thiophenes via the reactions of N,N-disubstituted enaminones and elemental sulfur is developed.By simply heating the substrates in pure water in the presence of NaOH,the thiophene annulation practically takes place via the generation of one C-C and two C-S bonds via cascade dual C-H functionalization and C-N bond thiolation without using any transition metal reagent.展开更多
The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them w...The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them was not a typical exhibition hall,but a building shaped like a gleaming stainless-steel cooking pot.展开更多
The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulat...The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulate the electronic structure of MoS_(2),thereby obtaining a multifunctional catalyst that serves as an efficient sulfur host.The W/V dual single-atomdoped MoS_(2)grown on carbon nanofibers(CMWVS)demonstrates a strong adsorption ability for lithium polysulfides,suppressing the shuttle effects.Additionally,the doping process also results in the phase transition from 2H-MoS_(2)to 1T-MoS_(2)and generates sufficient edge sulfur atoms,promoting the charge/electron transfer and enriching the reaction sites.All these merits contribute to the superior conversion reaction kinetics,leading to the outstanding Li-S battery performance.When fabricated as cathodes by compositing with sulfur,the CMWVS/S cathode delivers a high capacity of 1481.7 mAh g^(-1)at 0.1 C(1 C=1672 mAh g^(-1))and maintains 816.3 m Ah g^(-1)after 1000 cycles at 1.0 C,indicating outstanding cycling stability.Even under a high sulfur loading of 7.9 mg cm^(-2)and lean electrolyte conditions(E/S ratio of 9.0μL mg^(-1)),the cathode achieves a high areal capacity of 8.2 m Ah cm^(-2),showing great promise for practical Li-S battery applications.This work broadens the scope of doping strategies in transition-metal dichalcogenides by tailoring their electronic structures,providing insightful direction for the rational development of high-efficiency electrocatalysts for advanced Li-S battery applications.展开更多
Crossflow instability will be present when the vehicle has an angle of attack in hypersonic flow,and it might play a dominant role in hypersonic boundary layer transition.By far the mechanism of crossflow instability-...Crossflow instability will be present when the vehicle has an angle of attack in hypersonic flow,and it might play a dominant role in hypersonic boundary layer transition.By far the mechanism of crossflow instability-induced hypersonic boundary layer transition is still out of understanding,although the large effort has been devoted.Upon this work,the overall roughness effect on instabilities in hypersonic flow was researched experimentally.Surface flush-mounted pressure sensors and infrared camera were employed to investigate the instability waves when different rough surfaces were deployed.The results reveal that the moderate surface roughness level on cone model can suppress the growth of crossflow instabilities at certain azimuthal angles in hypersonic flow.展开更多
The interactions between clouds and aerosols represent one of the largest uncertainties in assessing the Earth's radiation budget, highlighting the importance of research on the transition zone(TZ) within the clou...The interactions between clouds and aerosols represent one of the largest uncertainties in assessing the Earth's radiation budget, highlighting the importance of research on the transition zone(TZ) within the cloud-aerosol continuum.This study assesses the global distribution of TZ conditions, analyzes its optical characteristics, and determines the cloud or aerosol types most commonly associated with them, using the cloud-aerosol discrimination(CAD) score of the CloudAerosol Lidar with Orthogonal Polarization(CALIOP) instrument on the CALIPSO satellite. The CAD score classifies clouds and aerosols by the probability density functions of attenuated backscatter, total color ratio, volume depolarization ratio, altitude, and latitude. After applying several filters to avoid artifacts, the TZ was identified as those atmospheric layers that cannot be clearly classified as clouds or aerosols, layers within the no-confidence range(NCR) of the CAD score, and cirrus fringes. The optical characteristics of NCR layers exhibit two main clusters: Cluster 1, with properties between high-altitude ice clouds and aerosols(e.g., wispy cloud fragments), and Cluster 2, with properties between water clouds and aerosols at lower altitudes(e.g., large hydrated aerosols). Our results highlight the significant ubiquity of TZ conditions, which appear in 9.5% of all profiles and comprise 6.4% of the detected layers. Cluster 1 and cirrus-fringe layers predominate near the ITCZ and in mid-latitudes, whereas Cluster 2 layers are more frequent over the oceans along the central West African and East Asian coasts, where elevated smoke and dusty marine aerosols are common.展开更多
In Chin.Phys.B 34114704(2025),Eq.(7)and the associated unit notation were incorrect.The correct ones are present here.Since Eq.(7)is an in-built expression in the simulation package,the correction is purely typographi...In Chin.Phys.B 34114704(2025),Eq.(7)and the associated unit notation were incorrect.The correct ones are present here.Since Eq.(7)is an in-built expression in the simulation package,the correction is purely typographical and does not affect the simulation procedure,numerical results,or the conclusions.展开更多
Oncology Research Editorial Office Published:23 March 2026 The published article titled“TRAF4 Regulates Migration,Invasion,and Epithelial-Mesenchymal Transition via PI3K/AKT Signaling in Hepatocellular Carcinoma”has...Oncology Research Editorial Office Published:23 March 2026 The published article titled“TRAF4 Regulates Migration,Invasion,and Epithelial-Mesenchymal Transition via PI3K/AKT Signaling in Hepatocellular Carcinoma”has been retracted from Oncology Research,Vol.25,No.8,2017,pp.1329-1340.DOI:10.3727/096504017X14876227286564 URL:https://www.techscience.com/or/v25n8/56917.展开更多
Transition metal phosphides exhibit excellent efficiency in the oxygen evolution reaction under alkaline conditions,and they have garnered widespread recognition.Currently,most studies have focused on the evolution an...Transition metal phosphides exhibit excellent efficiency in the oxygen evolution reaction under alkaline conditions,and they have garnered widespread recognition.Currently,most studies have focused on the evolution and role of metal cations in the oxygen evolution reaction process,while attention to phosphorus elements is relatively scarce.Actually,phosphides possess unique properties that distinguish them from other metal compounds,and the role of phosphorus in them cannot be ignored.This study used nickel phosphide(Ni_(2)P)as a model catalyst to reveal the reconstruction and dynamic behavior of anions under alkaline conditions through cyclic voltammetry.The results indicate that as the cycle progresses,surface phosphides are converted into active oxyhydroxides.It is worth noting that the presence of the P element accelerates the rapid completion of the reconstruction process but also exhibits triple synergistic functions.First,the internal phosphorus nuclei of the active layer act as conductive scaffolds,effectively enhancing the efficiency of electron conduction.Second,the oxygen-containing anions formed in situ on metal hydroxides optimize the adsorption of reaction intermediates.Finally,the phosphorus atoms dissolved in the electrolyte suppress nickel loss,improve stability,and increase the electrochemical activity specific surface area,exposing more active sites.This study elucidates the oxygen evolution reaction mechanism of phosphides from a novel perspective,enhancing comprehension of surface reconstruction phenomena and the characteristics of active sites,guiding the rational design of phosphide pre-catalysts.展开更多
Fe_(3)Sn_(2),a ferromagnetic metal with a kagome lattice,serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure.However,systematic reports on the t...Fe_(3)Sn_(2),a ferromagnetic metal with a kagome lattice,serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure.However,systematic reports on the transport properties of Fe_(3)Sn_(2)nanosheets remain scarce.We present temperature-dependent transport property measurements of Fe_(3)Sn_(2)nanosheets synthesized via chemical vapor deposition on Si/SiO_(2)substrates.The samples exhibit a robust anomalous Hall effect from 40 K to 300 K,along with a magnetoresistance sign reversal at 40 K at high magnetic fields,indicating a spin reorientation from in-plane to out-of-plane.Notably,a sharp crossover in the dominant transport contribution from electrons to holes near 200 K is observed,accompanied by distinct anomalous Hall behaviors in the two regimes,indicating a temperature-induced Lifshitz transition within the multi-band system.This divergence is potentially linked to a topological reconstruction of the Fermi surface across the transition.Our findings highlight the tunability of topological transport in two-dimensional kagome magnets and provide new insights into the interplay between band topology,dimensionality and magnetic order.展开更多
基金supported by grants from Biological Breeding-National Science and Technology Major Project(2023ZD04076)the National Key Research and Development Program of Hubei Province(2022BBA154)the Foundation of Hubei Hongshan Laboratory(2021hszd010).
文摘The post-embryonic development of shoot apices in higher plants progresses through three distinct phases:the juvenile phase,adult vegetative phase,and reproductive phase.The transition from vegetative to reproductive growth represents a critical developmental transition that affects plant adaptability(Poethig 2003;Baurle and Dean 2006).
基金the Scientific and Technological Research Council of Turkey(TÜB˙ITAK)for support under project number:122M826to the Scientific Research Projects Unit of Erciyes University under contract No.:FYL-2023-13162 and FYL-2024-13701.
文摘Separation bubbles forming on airfoils significantly influence aerodynamic behavior,particularly at low Reynolds numbers,making their accurate prediction a critical challenge in transition modelling.This study investigates numerical modeling of a separation bubble and the effects of airfoil thickness and camber variation on the formation of the bubble dynamics at low Reynolds numbers.The numerical results were compared with the experimental results obtained from surface pressure distribution measurements,oil flow visualisation,and surface shear measurements to analyse the detailed flow behavior.The combination of pressure and flow visualisation techniques provided complementary insights,enabling a detailed characterisation of bubble formation.The results reveal that both the thickness and camber of the airfoil significantly influence the location,length,and stability of the bubble.At low Reynolds number flows(Re=0.5×10^(5)),particularly for highly cambered profiles,closer to the leading edge,separation and long bubbles were observed.As the Reynolds number increased,the separation point shifted to the leading edge,and reattachment became more likely.In numerical studies,transition models can accurately model the bubble initiation point;however,they often fail to model the bubble reattachment points accurately.This is due to the inadequacy of models that use empirical expressions for turbulence modelling,particularly in low Reynolds number flows,in their viscous modelling.In this study,it was concluded that transition onset terms,which specifically affect bubble formation,should be modified for more accurate modeling.
基金supported by the National Science Foundation of China(NSFC 52571185,52201180 and 52371148)the China Postdoctoral Science Foundation(2023T160241 and 2023M731176)+2 种基金the Natural Science Foundation of Chongqing(CSTB2025NSCQ-GPX1026)the Science and Technology Research Program of Chongqing Municipal Education Commission of China(KJQN202500526)the Foundation of Chongqing Normal University(No.24XLB019).
文摘Polyamorphous transition refers to the transformation between two distinct amorphous states with identical composition.This phenomenon is intriguing in the field of physics and offers avenues for glass material design.Recently,polyamorphous transitions have been frequently observed in glassy materials.However,the transition pathway has yet to be established,which is essential for understanding its structural origins.Here,we present evidence from 12 different types of metallic glasses spanning 7 orders of magnitude in timescales,demonstrating that polyamorphous transitions consistently occur after the devitrification process,between two supercooled liquid phases(Ⅰ and Ⅱ).Notably,we observe a decrease in liquid fragility and heat capacity following the transition,suggesting that the polyamorphous transition is associated with the fragile-to-strong transition(FST)in liquids.These findings elucidate the detailed structural pathway of the polyamorphous transition,via glass I→devitrification→liquid I→fragile-strong transition→liquid II,and incorporate the FST into a cohesive framework for its understanding.
基金supported by the National Key Research and Development Program of China [grant number 2023YFF0807000]。
文摘Based on datasets from the International Best-Track Archive for Climate Stewardship(IBTrACS)and the fifth major global reanalysis produced by ECMWF(ERA5),the authors found that 29%of tropical cyclones(TCs)in the western North Pacific underwent extratropical transition(ET)from 1979 to 2022,with the frequency of ET events showing a slow decreasing trend.The extratropical transition tropical cyclones(ETCs)are classified into four clusters using the k-means clustering method based on their track patterns:recurving ETCs,westward ETCs,northwestward ETCs,and abnormal track ETCs.The transition process of recurving ETCs mostly occurs after the recurvature is completed,while 63.7%of the westward ETCs complete their transition after landfall.Abnormal track ETCs undergo transition over high-latitude oceans.Northwestward ETCs have the longest duration and slowest transition speed during the ET period,resulting in a prolonged impact.The ET process occurs at the edges of the western Pacific subtropical high(WPSH),with higher frequency during westward extension and lower during eastward retreat.While westward ETCs transition through surface friction effects,others complete ET in the northwest baroclinic zone of the WPSH.
基金supported by the National Natural Science Foundation of China (Grant Nos.92477128,92580137,92477205,12374200,11604063,11974422,and 12104504)the National Key R&D Program of China (MOST) (Grant No.2023YFA1406500)+3 种基金the Strategic Priority Research Program (Chinese Academy of Sciences,CAS) (Grant No.XDB30000000)the Fundamental Research Funds for the Central Universities and Research Funds of Renmin University of China (Grant No.21XNLG27)supported by the Outstanding Innovative Talents Cultivation Funded Programs 2023 of the Renmin University of Chinaan outcome of “Two-dimensional anisotropic series of materials FePd2+xTe2:a structural modulation study from the atomic scale to the mesoscopic scale” (RUC25QSDL128),funded by the “Qiushi Academic-Dongliang” Talent Cultivation Project at Renmin University of China in 2025。
文摘Transition-metal dichalcogenides hosting multiple competing structural and electronic phases are thus ideal platforms for constructing polytype heterostructures with emergent quantum properties.However,controlling phase transitions to form diverse heterostructures inside a single crystal remains challenging.In this study,we realize vertical/lateral polytype heterostructures in a hole-doped Mott insulator via thermal annealing-induced structural transitions.Raman spectroscopy,atomic force microscopy and scanning Kelvin probe force microscopy confirm the coexistence of T-H polytype heterostructures.Atomic-scale scanning tunneling microscopy/spectroscopy measurements reveal the transparent effect in 1H/1T vertical heterostructures,where positive bias voltage induces in a pronounced superposition of the√13×√13 CDW of the 1T-layer on the 1H-layer.By systematically comparing the 1T/1H and 1T/1T interfaces,we demonstrate that the metallic 1H-layer induces a Coulomb screening effect on the 1T-layer,suppressing the formation of CDW domain walls and forming more ordered electronic states.These results clarify the interfacial coupling between distinct quantum many-body phases and establish a controllable pathway for constructing two-dimensional polytype heterostructures with tunable electronic properties.
基金Supported by the National Natural Science Foundation of China(No.52273056)the Science and Technology Development Program of Jilin Province,China(No.YDZJ202501ZYTS305)。
文摘Electrochemical water splitting represents a sustainable technology for hydrogen(H_(2))production.However,its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction(HER)and the anodic oxygen evolution reaction(OER).Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts,owing to their low cost,tunable composition,and noble-metal-like catalytic activity.Nevertheless,systematic reviews on their application as bifunctional catalysts for overall water splitting(OWS)are still limited.This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers(NFs),including metals,oxides,phosphides,sulfides,and carbides.Key strategies for enhancing their catalytic performance are systematically summarized,such as heterointerface engineering,heteroatom doping,metal-nonmetal-metal bridging architectures,and single-atom site design.Finally,current challenges and future research directions are discussed,aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.
基金Supported by the Robotic AI-Scientist Platform of Chinese Academy of SciencesNational Natural Science Foundation of China(22372185)+2 种基金Youth Talent Development Program of SKLCC(2025BWZ009)Natural Science Foundation of Shanxi Province(202203021221219)Research on the Construction of Scientific and Technological Innovation Think Tank of Shanxi Association for Science and Technology(KXKT202542)。
文摘Temperature-programmed desorption(TPD)is a fundamental technique in surface science and heterogeneous catalysis for characterizing adsorption behavior,and for extracting key parameters such as adsorption energy.However,the majority of existing TPD data is accessible in the form of published images,which lacks structured and quantitative datasets.This constrains its utility for rigorous quantitative analysis and computational modelling.Using carbon monoxide(CO)which is a widely adopted probe molecule,a curated and standardized dataset of CO-TPD is constructed,encompassing 14 transition-metal single-crystal surfaces,including copper(Cu)and ruthenium(Ru).By systematically extracting numerical data points from published spectra and applying normalization,essential spectral features such as peak shape are fully preserved.The dataset also documents relevant experimental parameters,including heating rates,and was developed using a standardized protocol for data collection and quality control.This resource serves as both a reference library to support the deconvolution of TPD spectra from complex catalysts and an experimental benchmark for calibrating parameters in theoretical models.By providing a reliable and accessible data function,this work advances the microscopic understanding and the rational design of catalyst active centers.
基金supported by the National Key Laboratory of Helicopter Aeromechanics Fund(No.2024-CXPT-GF-JJ-093-05).
文摘The complex aerodynamic interaction between tandem tilt-wing and multi-rotor directly affects the wing surface flow and rotor thrust,making it a critical factor during the tilt transition process of this configuration of rotorcraft.The aerodynamic interaction of tandem tilt-wing and multi-rotor is investigated based on the CFD method.The aerodynamic effect of multi tilt-rotor is simulated as virtual disk modeling by adding source terms to the Navier-Stokes equations,effectively reducing the calculation time while maintaining the accuracy of aerodynamic interaction calculations.Aerodynamic forces and flow field characteristics of the tandem tilt-wing and multi-rotor under different tilt angles are compared between cases with and without aerodynamic interaction.Furthermore,the differences in aerodynamic forces between dynamic tilt transition and fixed-angle conditions were compared.The results show that the aerodynamic interaction of multi-rotor obviously increases the lift of front tilt-wing at different tilt angles,the wing lift under interaction is increased by more than 40%compared with isolated wing at tilt angle of 15°for the computation in this paper,which is related to the increase of wing flow velocity and the suppression of flow separation caused by multi-rotor;the wing blocking effect will increase rotor thrust,especially near the tilt angles of 30°and 45°;the increases of rear wing lift and rear rotor thrust under aerodynamic interaction are not significant because of suppression by the front wing’s downwash;the unsteady effects during dynamic tilting have a relatively minor impact on aerodynamic interaction,with the aerodynamic forces on the rotors and wings during the dynamic tilting process showing little difference from those under corresponding fixed tilt angles.
基金supported by grants from the National Key R&D Program of China[Grant Nos.2020YFC2003000 and 2020YFC2003001]the National High Level Hospital Clinical Research Funding(BJ-2023-074 and BJ-2023-018)+1 种基金Beijing Municipal Science&Technology Commission“AI+Health Collaborative Innovation Cultivation”Project(Z221100003522015)the Non-Profit Central Research Institute Fund of the Chinese Academy of Medical Sciences(2021-JKCS-024).
文摘Objective Frailty is becoming increasingly common among aging adults.Frailty transitionis shaped by biological,social,psychological,and environmental factors.This study investigated combined effects of protective factors on frailty transition by constructing a Protection Index(PI)to guide targeted interventions.Methods Data were extracted from the 4th Sample Survey of the Aged Population in Urban and Rural China,including baseline(2017)and follow-up(2019)surveys.Frailty was assessed using the Frailty Index(FI),whereas the PI measured protective factors.Frailty transitions over 2 years were analyzed prospectively.Pearson’s correlation examined the relationship between FI and PI,and logistic regression assessed the effects of PI on frailty transitions.Results This study included 9,093 older adults.FI values increased with age and were higher in women,whereas PI values decreased with age and were higher in men.Over 2 years,56.2%of the participants showed a stable frailty status,14.2%improved,and 29.6%worsened.Negative transitions were more common than positive transitions,with transitions occurring most frequently between adjacent states.The PI was moderately negatively correlated with the FI(r=−0.349,P<0.001).A higher PI was associated with a lower risk of negative transitions among robust and prefrail individuals(OR=0.989,0.981,both P<0.05),but showed no significant effect among those with existing frailty.Conclusion Negative frailty transitions were more common with advancing age.Enhancing PI may help prevent negative frailty transitions among robust and pre-frail older adults,underscoring the value of early interventions.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20220409)the National Natural Science Foundation of China(No.22401153)+2 种基金the FWO[Fund for Scientific Research-Flanders(Belgium)]for financial support(recipient Erik V.Van der Eycken)the Research Council of the KU Leuven(recipient Erik V.Van der Eycken)the support of the"RUDN University Strategic Academic Leadership Program"(recipient Erik V.Van der Eycken).
文摘Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed C–H activation has been employed for the functionalization of amino acids and peptides.Through domino C–H activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed C–H activation/annulation.
文摘Discussions about the future of energy sources and environmental sustainability are becoming critical on a global scale.The energy sector plays a central role in the economy,as the availability and cost of energy influence the competitiveness of economies,while the level of energy consumption impacts the standard of living for individuals.This paper aims to examine environmental challenges and steps for a sustainable transition towards a hydrogen economy,focusing on its potential as an alternative to fossil fuels and the importance of developing the hydrogen paradigm.The research methodology is based on a combination of qualitative and quantitative methods,including an analysis of global and regional trends in the energy transition,the impact of various forms of hydrogen production(green,blue,gray hydrogen)on greenhouse gas emissions,and a comparison of existing policies and strategies in different countries transitioning to a sustainable hydrogen economy.Research results show that green hydrogen,produced via electrolysis using renewable energy sources,holds the greatest potential for reducing greenhouse gas emissions,while gray and blue hydrogen can serve as transitional options.The development of the hydrogen paradigm,rooted in innovative technologies,renewable energy sources,and international cooperation,is crucial for decarbonization and the creation of a sustainable global economy,despite challenges such as high costs and the need for global coordination.The hydrogen paradigm is becoming a cornerstone of these efforts,laying the foundation for a long-term,sustainable global economy.Currently,over 180 hydrogen transport projects,60 distribution projects,80 storage projects,30 terminal and port projects,and more than 220 hydrogen production projects are under development worldwide.The global momentum of the hydrogen transition helps mitigate climate change and build a sustainable future.
基金supported by the National Natural Science Foundation of China(No.22261026).
文摘A novel method for the synthesis of 2,4-disubstituted thiophenes via the reactions of N,N-disubstituted enaminones and elemental sulfur is developed.By simply heating the substrates in pure water in the presence of NaOH,the thiophene annulation practically takes place via the generation of one C-C and two C-S bonds via cascade dual C-H functionalization and C-N bond thiolation without using any transition metal reagent.
文摘The moment a media delegation from the Republic of the Congo arrived at the Othello Kitchenware Museum on 18 November 2025,they were greeted with a vivid show of Guangdong’s industrial strength.Standing before them was not a typical exhibition hall,but a building shaped like a gleaming stainless-steel cooking pot.
基金supported by the National Natural Science Foundation of China(52402166)the Science and Technology Development Fund+2 种基金Macao SAR(0065/2023/AFJ,0116/2022/A3)the Australian Research Council(DE220100154)the Natural Science Foundation of Guangdong Province(2025A1515011120)。
文摘The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulate the electronic structure of MoS_(2),thereby obtaining a multifunctional catalyst that serves as an efficient sulfur host.The W/V dual single-atomdoped MoS_(2)grown on carbon nanofibers(CMWVS)demonstrates a strong adsorption ability for lithium polysulfides,suppressing the shuttle effects.Additionally,the doping process also results in the phase transition from 2H-MoS_(2)to 1T-MoS_(2)and generates sufficient edge sulfur atoms,promoting the charge/electron transfer and enriching the reaction sites.All these merits contribute to the superior conversion reaction kinetics,leading to the outstanding Li-S battery performance.When fabricated as cathodes by compositing with sulfur,the CMWVS/S cathode delivers a high capacity of 1481.7 mAh g^(-1)at 0.1 C(1 C=1672 mAh g^(-1))and maintains 816.3 m Ah g^(-1)after 1000 cycles at 1.0 C,indicating outstanding cycling stability.Even under a high sulfur loading of 7.9 mg cm^(-2)and lean electrolyte conditions(E/S ratio of 9.0μL mg^(-1)),the cathode achieves a high areal capacity of 8.2 m Ah cm^(-2),showing great promise for practical Li-S battery applications.This work broadens the scope of doping strategies in transition-metal dichalcogenides by tailoring their electronic structures,providing insightful direction for the rational development of high-efficiency electrocatalysts for advanced Li-S battery applications.
基金supported by the National Natural Science Foundation of China(No.11972357)。
文摘Crossflow instability will be present when the vehicle has an angle of attack in hypersonic flow,and it might play a dominant role in hypersonic boundary layer transition.By far the mechanism of crossflow instability-induced hypersonic boundary layer transition is still out of understanding,although the large effort has been devoted.Upon this work,the overall roughness effect on instabilities in hypersonic flow was researched experimentally.Surface flush-mounted pressure sensors and infrared camera were employed to investigate the instability waves when different rough surfaces were deployed.The results reveal that the moderate surface roughness level on cone model can suppress the growth of crossflow instabilities at certain azimuthal angles in hypersonic flow.
基金funded through project NUBOLOSYTI (PID2023149972NB-100) of the Spanish Ministry of Science and Innovation (MICINN)supported by an IFUdG 2022 fellowship。
文摘The interactions between clouds and aerosols represent one of the largest uncertainties in assessing the Earth's radiation budget, highlighting the importance of research on the transition zone(TZ) within the cloud-aerosol continuum.This study assesses the global distribution of TZ conditions, analyzes its optical characteristics, and determines the cloud or aerosol types most commonly associated with them, using the cloud-aerosol discrimination(CAD) score of the CloudAerosol Lidar with Orthogonal Polarization(CALIOP) instrument on the CALIPSO satellite. The CAD score classifies clouds and aerosols by the probability density functions of attenuated backscatter, total color ratio, volume depolarization ratio, altitude, and latitude. After applying several filters to avoid artifacts, the TZ was identified as those atmospheric layers that cannot be clearly classified as clouds or aerosols, layers within the no-confidence range(NCR) of the CAD score, and cirrus fringes. The optical characteristics of NCR layers exhibit two main clusters: Cluster 1, with properties between high-altitude ice clouds and aerosols(e.g., wispy cloud fragments), and Cluster 2, with properties between water clouds and aerosols at lower altitudes(e.g., large hydrated aerosols). Our results highlight the significant ubiquity of TZ conditions, which appear in 9.5% of all profiles and comprise 6.4% of the detected layers. Cluster 1 and cirrus-fringe layers predominate near the ITCZ and in mid-latitudes, whereas Cluster 2 layers are more frequent over the oceans along the central West African and East Asian coasts, where elevated smoke and dusty marine aerosols are common.
文摘In Chin.Phys.B 34114704(2025),Eq.(7)and the associated unit notation were incorrect.The correct ones are present here.Since Eq.(7)is an in-built expression in the simulation package,the correction is purely typographical and does not affect the simulation procedure,numerical results,or the conclusions.
文摘Oncology Research Editorial Office Published:23 March 2026 The published article titled“TRAF4 Regulates Migration,Invasion,and Epithelial-Mesenchymal Transition via PI3K/AKT Signaling in Hepatocellular Carcinoma”has been retracted from Oncology Research,Vol.25,No.8,2017,pp.1329-1340.DOI:10.3727/096504017X14876227286564 URL:https://www.techscience.com/or/v25n8/56917.
基金support of the National Natural Science Foundation of China(22275035).
文摘Transition metal phosphides exhibit excellent efficiency in the oxygen evolution reaction under alkaline conditions,and they have garnered widespread recognition.Currently,most studies have focused on the evolution and role of metal cations in the oxygen evolution reaction process,while attention to phosphorus elements is relatively scarce.Actually,phosphides possess unique properties that distinguish them from other metal compounds,and the role of phosphorus in them cannot be ignored.This study used nickel phosphide(Ni_(2)P)as a model catalyst to reveal the reconstruction and dynamic behavior of anions under alkaline conditions through cyclic voltammetry.The results indicate that as the cycle progresses,surface phosphides are converted into active oxyhydroxides.It is worth noting that the presence of the P element accelerates the rapid completion of the reconstruction process but also exhibits triple synergistic functions.First,the internal phosphorus nuclei of the active layer act as conductive scaffolds,effectively enhancing the efficiency of electron conduction.Second,the oxygen-containing anions formed in situ on metal hydroxides optimize the adsorption of reaction intermediates.Finally,the phosphorus atoms dissolved in the electrolyte suppress nickel loss,improve stability,and increase the electrochemical activity specific surface area,exposing more active sites.This study elucidates the oxygen evolution reaction mechanism of phosphides from a novel perspective,enhancing comprehension of surface reconstruction phenomena and the characteristics of active sites,guiding the rational design of phosphide pre-catalysts.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1403503,2022YFA1602802,2023YFA1607400,and 2024YFA1613200)Beijing Natural Science Foundation(Grant No.JQ23022)supported by the Synergetic Extreme Condition User Facility and the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302600)。
文摘Fe_(3)Sn_(2),a ferromagnetic metal with a kagome lattice,serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure.However,systematic reports on the transport properties of Fe_(3)Sn_(2)nanosheets remain scarce.We present temperature-dependent transport property measurements of Fe_(3)Sn_(2)nanosheets synthesized via chemical vapor deposition on Si/SiO_(2)substrates.The samples exhibit a robust anomalous Hall effect from 40 K to 300 K,along with a magnetoresistance sign reversal at 40 K at high magnetic fields,indicating a spin reorientation from in-plane to out-of-plane.Notably,a sharp crossover in the dominant transport contribution from electrons to holes near 200 K is observed,accompanied by distinct anomalous Hall behaviors in the two regimes,indicating a temperature-induced Lifshitz transition within the multi-band system.This divergence is potentially linked to a topological reconstruction of the Fermi surface across the transition.Our findings highlight the tunability of topological transport in two-dimensional kagome magnets and provide new insights into the interplay between band topology,dimensionality and magnetic order.
