Berry curvature describes the intrinsic geometric property of electronic band structure,crucial for governing emergent transport phenomena.As a typical Berry-curvature-related property,the anomalous Nernst effect prob...Berry curvature describes the intrinsic geometric property of electronic band structure,crucial for governing emergent transport phenomena.As a typical Berry-curvature-related property,the anomalous Nernst effect probes local Berry curvature near the Fermi surface,whereas the anomalous Hall effect integrates contributions across all occupied states.Thus,the anomalous Nernst effect is a superior probe for detecting subtle evolution of Berry curvature near the Fermi level;however,their relation remains elusive.Here,we demonstrate giant anomalous Nernst angles induced by Berry curvature in layered itinerant ferromagnets Fe_(3)GaTe_(2)and Fe_(5)GeTe_(2).Their maximum values(≈0.33 for Fe_(3)GaTe_(2)and≈0.41 for Fe_(5)GeTe_(2))are one order of magnitude larger than those of traditional ferromagnets(θ_(AN)^(max)<0.02).Scaling analysis of anomalous Hall effect in these two systems further suggests these giant angles originate from intrinsic Berry curvature.These findings indicate Berrycurvature-dominated regimes,and establish these materials for high-performance spin-caloritronic devices.展开更多
Altermagnetism,a recently identified class of collinear magnetism,combines key features of antiferromagnets and ferromagnets.Despite having zero net magnetization,altermagnetic materials exhibit anomalous transport ef...Altermagnetism,a recently identified class of collinear magnetism,combines key features of antiferromagnets and ferromagnets.Despite having zero net magnetization,altermagnetic materials exhibit anomalous transport effects,including the anomalous Hall,Nernst,and thermal Hall effects,as well as magneto-optical Kerr and Faraday effects.These phenomena,previously thought unique to ferromagnets,are dictated by symmetry,as confirmed by density functional theory(DFT)calculations.However,an effective model-based approach to verify these symmetry constraints remains unavailable.In this Letter,we construct a k·ρ model for d-wave altermagnets CuX_(2)(X=F,Cl)using spin space group representations and apply it to calculate the anomalous Hall effect.The symmetry-imposed transport properties predicted by the model are in agreement with the DFT results,providing a foundation for further investigation into symmetry-restricted transport phenomena in altermagnetic materials.展开更多
Kagome magnets Tb Mn_(6)Sn_(6-x)In_(x)(x=0-1.2)exhibit a robust anomalous Hall effect(AHE)that persists above room temperature,demonstrating significant potential for high-temperature spintronics applications.At eleva...Kagome magnets Tb Mn_(6)Sn_(6-x)In_(x)(x=0-1.2)exhibit a robust anomalous Hall effect(AHE)that persists above room temperature,demonstrating significant potential for high-temperature spintronics applications.At elevated temperatures,a spin-reorientation transition induces a ferrimagnetic state(FIM1)with in-plane magnetic moments,accompanied by a nonmonotonic Hall response that differs markedly from the low-temperature behavior.Upon indium doping,the long-range ferrimagnetic transition is progressively suppressed to lower temperatures,along with a noticeable reduction in magnetic anisotropy.Interestingly,at a doping level of x=1.2,the FIM1 state observed in the parent compound is completely eliminated.These systematic changes in magnetic ordering and transport properties underscore a coherent evolution of the electronic and magnetic states with doping,offering critical insights into the interplay among lattice structure,magnetism,and electronic behavior in kagome lattices.展开更多
The emergent metagrating,with its unique and flexible beam shaping capabilities,offers new paths to efficient modulation of acoustic waves.In this work,an acoustic metagrating is demonstrated for high-efficiency and w...The emergent metagrating,with its unique and flexible beam shaping capabilities,offers new paths to efficient modulation of acoustic waves.In this work,an acoustic metagrating is demonstrated for high-efficiency and wide-angle anomalous refraction.It is shown that the normal reflection and transmission can be totally suppressed by properly modulating the amplitude and phase characteristics of the metagrating supercells for high-efficiency anomalous refraction.The anomalous refraction behavior is achieved in the wide range of incident angles from 28°to 78°,and the efficiency of-1st order diffraction is higher than 90%by finely designing the metagrating structure.The anomalous refraction behaviors are verified experimentally at incidence angle of 28°,45°,and 78°,respectively.The demonstrated metagrating is anticipated to possess efficient wide-angle composite wavefront engineering applications in such fields as communications.展开更多
FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses(MGs)systems.However,the glass-forming ability(GFA)of FeNi-based MGs is much lower than that of...FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses(MGs)systems.However,the glass-forming ability(GFA)of FeNi-based MGs is much lower than that of their counterparts.Thus,uncovering the solidification and anomalous nano-crystallization behavior of FeNi-based MGs is crucial to the development of FeNibased bulk metallic glasses with larger plasticity and critical size concurrently.Regarding this,a combination of complementary in situ synchrotron radiation high-energy X-ray diffraction,small-angle neutron scattering(SANS),and 3-dimentional atom probe tomography(3-D APT)is used to study solidification and nano-crystallization behavior of Fe_(48)Ni_(30)Mo_(3)B_(19)liquid and MG.The time–temperature–transformation diagram was successfully depicted via melting spun,in situ solidification,and isothermal annealing methods.We found that the Fe_(48)Ni_(30)Mo_(3)B_(19)MG can only be prepared via the meltspinning method to obtain amorphous ribbons,which could contribute to the low activation energy for the nano-crystallization growth E_(p).Moreover,during isothermal annealing,the anomalous slow growth behavior in kinetic of theγ-FeNi phase embedded in the amorphous matrix is caused by the Fe and Ni partitioning,and the Mo-enriched region around the nanosizedγ-FeNi phase,which is revealed by 3-D APT.These results exhibit a new perspective for understanding the relationship between GFA and nano-crystallization behavior and provide feasible guidance for the development of newγ-FeNi-containing Fe-based BMG composites with desired mechanical properties and GFA.展开更多
A statistical analysis of the twinning behavior in a basal-textured Mg sheet under hard orientation loading was performed at strain rates of 1×10^(-5) and 1×10^(-1) s^(-1) with grain sizes of 70 and 20µ...A statistical analysis of the twinning behavior in a basal-textured Mg sheet under hard orientation loading was performed at strain rates of 1×10^(-5) and 1×10^(-1) s^(-1) with grain sizes of 70 and 20µm.There were 1609 tension twins identified including adequate(51%)anomalous twins(Schmid factor m<0).Twin variant selection exhibited almost no grain size or strain rate effects.Most twin variants(74%)correlated well with the proposed normalized Schmid factor(mnor).The Luster-Morris parameter(m′)values failed to correlate with the twin transmission,while 96%of transmitted pairs exhibited large mnor or normalized m′(m′nor)values.Twin transmission occurred more frequently at lower grain boundary misorientation angles(10°-30°).The active anomalous twins correlated well with m of the prismatic slip.The present work provided a statistical perspective that,the mnor and m′nor can correlate the anomalous twinning rather than m and m′.The local condition also played a critical role in anomalous twinning behavior.展开更多
While the deformation behavior of rare-earth magnesium alloys at high temperatures has been extensively studied,the deformation mechanisms under moderate-to-low temperatures and high strain rates remain insufficiently...While the deformation behavior of rare-earth magnesium alloys at high temperatures has been extensively studied,the deformation mechanisms under moderate-to-low temperatures and high strain rates remain insufficiently understood.To address this gap,hot compression tests were conducted on a Mg-11Gd-3Y-0.5Zr(wt.%)alloy over a temperature range of 150℃–450℃under strain rates of 10^(-3) s^(-1)(low strain rate(LSR))and 10 s^(-1)(high strain rate(HSR))to explore the strain rate-temperature coupling effects during hot deformation.The results revealed an anomalous increase in peak stress at 150℃–250℃as the strain rate decreased,attributed to the combined effects of nano-precipitates,dislocation cell structures,and serrated flow induced by dynamic strain aging.At higher temperatures,strain rate influences softening pathways:under HSR at 450℃,the effect of twinning shifts from strengthening to facilitating dynamic recrystallization(DRX),resulting in substantial grain refinement(-4 μm,81%area fraction at a strain of 0.6).In contrast,at LSR,softening is dominated by dynamic recovery at 350℃,with limited DRX(-4 μm grains,10%area fraction at a strain of 0.6)occurs at 400℃.These findings clarify the dual role of twinning and its interaction with rate-temperature conditions,providing valuable insights into optimizing the hot processing of rare-earth magnesium alloys.展开更多
This study investigates the mechanism of ^(6)Li+^(7)Li anomalous large-angle scattering.First,elastic scattering is analyzed using an optical model with the São Paulo potential,and inelastic scattering to the fir...This study investigates the mechanism of ^(6)Li+^(7)Li anomalous large-angle scattering.First,elastic scattering is analyzed using an optical model with the São Paulo potential,and inelastic scattering to the first excited state of ^(7)Li is analyzed by distorted wave born approximation method.The experimental data of the elastic scattering angular distributions could be described reasonably well by the optical model at forward angles;however,anomalous large-angle scattering is observed in the angular distributions of both the elastic and inelastic channels for all measured energies.Elastic and inelastic scatterings are investigated using the coupled reaction channel method.The elastic and inelastic scattering,transfer reactions for the ground and excited states,and their coupling effects are considered in the coupled reaction channel scheme.In addition,the influence of the breakup effects of the weakly bound ^(6)Li and ^(7)Li is investigated by including three resonance states of ^(6)Li and two resonance states of ^(7)Li in the coupled reaction channel framework.The observed anomalous large-angle scattering is explained using the transfer reaction mechanism and breakup effect,and the calculated results reproduce the experimental data reasonably well.展开更多
Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodi...Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodicity.Here,we provide both numerical and analytical evidence that a depth gradient metasurface can achieve discrete ultra-broadband perfect anomalous reflection in the microwave range in the absence of geometric periodicity.Remarkably,by adjusting the operating frequency of the incident wave,the same effect can be steadily obtained via a physically equivalent phase periodicity in the PGM.Based on this mechanism,a perfect retroreflector with a broadband response ranging from 1 GHz to 40 GHz is realized.Our work has promising applications in communication,source tracking,and military satellites.展开更多
Dear Editor,We describe a case diagnosed with exudative perifoveal vascular anomalous complex(ePVAC)successfully treated with focal laser photocoagulation(577 nm),achieving a favorable prognosis with best-corrected vi...Dear Editor,We describe a case diagnosed with exudative perifoveal vascular anomalous complex(ePVAC)successfully treated with focal laser photocoagulation(577 nm),achieving a favorable prognosis with best-corrected visual acuity(BCVA)of 20/20.Additionally,we discussed the identification of a possible early-onset non-ePVAC.The ePVAC is characterized as an isolated,aneurysmal abnormity near the macula and usually accompanied by cystic macular edema(ME)[1-2].展开更多
Spin-orbit interaction(SOI)can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures.In this work,we stack trilayer WSe_(2) on Bernal tetralayer graphene to inv...Spin-orbit interaction(SOI)can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures.In this work,we stack trilayer WSe_(2) on Bernal tetralayer graphene to investigate the influence of SOI on the anomalous Hall effect(AHE).In this structurally asymmetric device,by comparing the magnitude of AHE at positive and negative displacement fields,we find that AHE is strongly enhanced by bringing electrons in proximity to the WSe_(2) layer.Meanwhile,the enhanced AHE signal persists up to 80 K,providing important routes for topological device applications at high temperatures.展开更多
A finite equilibrium current density arises in the anomalous Hall effect(AHE)as a result of time-reversal symmetry breaking,affecting both the differential current density and total current.In this paper,we illustrate...A finite equilibrium current density arises in the anomalous Hall effect(AHE)as a result of time-reversal symmetry breaking,affecting both the differential current density and total current.In this paper,we illustrate the equilibrium current density in a ribbon-shaped system within the AHE regime,consisting of two sets of counterpropagating channels arranged in a zebra stripes pattern.While the middle channels are susceptible to scattering,the edge channels remain relatively robust.Despite this difference,all channels exhibit the same differential current density when subjected to a differential voltage across the two ends of the ribbon.When a differential voltage is applied to both sides of the ribbon,it results in a snaking pattern of differential current density forming across it.Furthermore,in a four-terminal device comprising the ribbon and two normal leads,it is found that Hall conductance is independent of ribbon width within certain scattering strengths due to the differences in robustness between middle and edge channels.These findings disclose the details of the AHE transport in a finite-sized system under weak scattering.展开更多
Recent advancements in two-dimensional van der Waals moir´e materials have unveiled the captivating landscape of moir´e physics.In twisted bilayer graphene(TBG)at‘magic angles’,strong electronic correlatio...Recent advancements in two-dimensional van der Waals moir´e materials have unveiled the captivating landscape of moir´e physics.In twisted bilayer graphene(TBG)at‘magic angles’,strong electronic correlations give rise to a diverse array of exotic physical phenomena,including correlated insulating states,superconductivity,magnetism,topological phases,and the quantum anomalous Hall(QAH)effect.Notably,the QAH effect demonstrates substantial promise for applications in electronic and quantum computing devices with low power consumption.This article focuses on the latest developments surrounding the QAH effect in magic-angle TBG.It provides a comprehensive analysis of magnetism and topology—two crucial factors in engineering the QAH effect within magic-angle TBG.Additionally,it offers a detailed overview of the experimental realization of the QAH effect in moir´e superlattices.Furthermore,this review highlights the underlying mechanisms driving these exotic phases in moir´e materials,contributing to a deeper understanding of strongly interacting quantum systems and facilitating the manipulation of new material properties to achieve novel quantum states.展开更多
MoS_(2) monolayer, as a highly promising two-dimensional semiconducting material for electronic and optoelectronic applications, exhibits deep-ultraviolet(DUV) laser-induced anomalous lattice dynamics as revealed by R...MoS_(2) monolayer, as a highly promising two-dimensional semiconducting material for electronic and optoelectronic applications, exhibits deep-ultraviolet(DUV) laser-induced anomalous lattice dynamics as revealed by Raman spectroscopy. Remarkably, not only the Raman intensity of many second-order Raman peaks but also the intensity ratio between the first-order modes E′and A′_1 exhibits a non-monotonic behavior that depends on laser energy. Moreover, there are significant inconsistencies in the literature regarding the assignments of these second-order Raman modes. In this work, we perform a thorough exploration of the anomalous lattice dynamics and conduct a renewed assignment of the numerous double resonant Raman modes of MoS_(2) monolayer. At three laser energies(E_L= 2.33, 3.50, and 4.66 e V) spanning from the visible to the ultraviolet and further into the DUV region, the calculated double-resonance Raman spectra correlate reasonably well with the experimental ones in terms of both peak positions and relative intensities. We confirm that the P_1 peak at ~450 cm^(-1) represents the second-order longitudinal acoustic(2LA) overtone mode. Each of the P_i(i = 1, 2,..., 7) peaks has multiple contributions from two phonons with distinct q wavevectors. Our calculations further reveal that the DUV laser-induced anomalous lattice dynamics stems from the quantum interference effect among different Raman scattering channels.展开更多
Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in...Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in June followed by floods in July.The 2024 event was the most severe since 1981.This study demonstrates that such compound extreme events are closely linked to anomalous subseasonal evolution of large-scale atmospheric circulation.During the drought phase,the East Asian subtropical westerly jet(EAJ)shifts southward,and the western Pacific subtropical high(WPSH)exhibits anomalous strengthening with its western ridge line displaced southward.The flood phase is characterized by acceleration of the EAJ,westward extension of the WPSH,and enhanced southwestern moisture transport from the western Pacific.Beyond these typical features,the 2024 early summer circulation exhibited unique characteristics:Anomalous northeastward intensification of the WPSH facilitated merged moisture influx from both the Indian Ocean and the western Pacific along the southeast pathway into the HHHRB in July,resulting in the highest net moisture inflow at the southern boundary of the HHHRB since 1981.The synergistic effects of multiple factors primarily explain the exceptionally intense DFAA event in 2024.展开更多
Vanadium-based transition metal chalcogenides VmXn(X=S,Se,Te)with their distinctive quantum effects,tunable magnetism,spin-orbit coupling,and high carrier mobility are a valuable platform to explore the interplay betw...Vanadium-based transition metal chalcogenides VmXn(X=S,Se,Te)with their distinctive quantum effects,tunable magnetism,spin-orbit coupling,and high carrier mobility are a valuable platform to explore the interplay between magnetism and electronic correlations,especially with tunable structural phases and magnetic properties through stoichiometric variations,making them ideal candidates for advanced device applications.Here,we report the synthesis of high-quality V_(5+x)S_(8)single crystals with different concentrations of self-intercalated vanadium.V_(5+x)S_(8)crystals show an antiferromagnetic behavior and a spin-flop-like transition below TN of 30.6 K.The high-quality V_(5+x)S_(8)single crystals exhibit a large negative magnetoresistance of 12.3%at 2 K.Interestingly,V_(5+x)S_(8)crystals show an obvious low-temperature resistance upturn that gradually levels off with the increasing magnetic field,attributed to the Kondo effect arising from the interaction between conduction electrons and embedded vanadium magnetic impurities.With increasing V doping,the antiferromagnetic interactions intensify,weakening the coupling between the local moments and conduction electrons,which in turn lowers the Kondo temperature(TK).Furthermore,the anomalous Hall effect is observed in V5.73S8,with an anomalous Hall conductivity(AHC)of 50.46 W^(-1)·cm^(-1)and anomalous Hall angle of 0.73%at 2 K.Our findings offer valuable insights into the mechanisms of the Kondo effect and anomalous Hall effect in self-intercalated transition metal chalcogenides with complex magnetism and electronic correlation effects.展开更多
Background:Anomalous origin of the left coronary artery from the pulmonary artery(ALCAPA)is a rare congenital anomalous coronary artery origin disorder.Objective:We sought to summarize the clinical experience and prog...Background:Anomalous origin of the left coronary artery from the pulmonary artery(ALCAPA)is a rare congenital anomalous coronary artery origin disorder.Objective:We sought to summarize the clinical experience and prognostic characteristics of surgical treatment of ALCAPA.Methods:We retrospectively analyzed clinical information on patients who had ALCAPA and underwent surgery at our center from February 2016 to October 2023.Results:This comparative study of 23 ALCAPA patients(9 infants<1 year;14 children>1 year)demonstrated significant age-dependent outcomes.Infant patients exhibited markedly prolonged mechanical ventilation(183±105.6 vs.48.5±62.2 min,p=0.001)and hospitalization(30.8±8.2 vs.19.5±6.2 days,p=0.001),despite comparable operative times(p>0.05).The perioperative mortality rate was 8.7%(2/23).Early postoperative mortality showed a non-significant trend in infants(22.2%vs.0%,p=0.11).Serial follow-up revealed substantial functional improvement,with abnormal left ventricular ejection fractions decreasing from 56.5%preoperatively to 14.3%at 1-month(p<0.01),and severe mitral regurgitation declining from 34.7%to 14.3%.However,persistent left ventricular enlargement(81%at follow-up)and moderate mitral regurgitation(52.4%)were frequently observed.Conclusion:Surgical correction of ALCPA effectively restores coronary perfusion and reduces severe mitral regurgitation,though residual ventricular dilation and moderate valvular dysfunction persist in the short-term postoperative period.Nevertheless,the overall prognosis remains favorable when timely intervention is performed.展开更多
A nickel-based superalloy with good corrosion resistance was fabricated by directional solidification, and its microstructure and tensile properties at elevated temperatures were investigated. Microstructure observati...A nickel-based superalloy with good corrosion resistance was fabricated by directional solidification, and its microstructure and tensile properties at elevated temperatures were investigated. Microstructure observations reveal that the γ＇ precipitates are arrayed in the y matrix regularly with some MC, Ni5Hf and M3B2 particles distributed along the grain boundary. The tensile tests exhibit that the tensile properties depend on temperature significantly and demonstrate obvious anomalous yield and intermediate-temperature brittleness （ITB） behavior. Below 650℃, the yield strength decreases slightly but the ultimate tensile strength almost has no change. When the temperature is between 650 ℃ and 750 ℃, the yield and ultimate tensile strengths rise rapidly, and after then they both decrease gradually with temperature increasing further. The elongation has its minimum value at about 700 ℃. The TEM examination exhibits that sharing of the γ＇ by dislocation is almost the main deformation mechanism at low temperatures, but the γ＇ by-pass dominates the deformation at high temperatures. The transition temperature from shearing to by-pass should be around 800 ℃. The anomalous yield and intermediate-temperature brittleness behaviors should be attributed to the high content of γ＇. In addition, the carbides and eutectic structure also contribute some to the ITB behaviors of the alloy.展开更多
Making use of the temperature data from 53 stations in Liaoning Province in April from 1961 to 2010 and the data of 500 hPa height field and sea surface temperature issued by National Climate Center,the characteristic...Making use of the temperature data from 53 stations in Liaoning Province in April from 1961 to 2010 and the data of 500 hPa height field and sea surface temperature issued by National Climate Center,the characteristics of temperature,sea surface temperature(SST) and 500 hPa height field in April in 2010 were analyzed.The results showed that the anomalously lower temperature in April in 2010 was mainly caused by the anomalous Arctic Oscillation(AO),so as to provide scientific basis for short-term climate prediction.展开更多
Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed a...Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed as a fundamental equation of statistical physics. This equation reflects that the law of motion of particles obeying reversible, deterministic laws in dynamics becomes irreversible and stochastic in thermodynamics. From this the fundamental equations of nonequilibrium thermodynamics, the principle of entropy increase and the theorem of minimum entropy production have been derived. The hydrodynamic equations, such as the generalized Navier-Stokes equation and the mass drift-diffusion equation etc. have been derived rigorously from the kinetic kinetic equation which is reduced from the anomalous Langevin equation in Liouville space. All these are unified and self consistent. But it is difficult to prove that entropy production density σ can never be negative everywhere for all the isolated inhomogeneous systems far from equilibrium.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1408104,2021YFA1202901,and 2022YFA1204001)the National Natural Science Foundation of China(Grant Nos.92365203,U24A6002,52302180,and U21A2086)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20243011)the Hebei Natural Science Foundation No.E2023203002).
文摘Berry curvature describes the intrinsic geometric property of electronic band structure,crucial for governing emergent transport phenomena.As a typical Berry-curvature-related property,the anomalous Nernst effect probes local Berry curvature near the Fermi surface,whereas the anomalous Hall effect integrates contributions across all occupied states.Thus,the anomalous Nernst effect is a superior probe for detecting subtle evolution of Berry curvature near the Fermi level;however,their relation remains elusive.Here,we demonstrate giant anomalous Nernst angles induced by Berry curvature in layered itinerant ferromagnets Fe_(3)GaTe_(2)and Fe_(5)GeTe_(2).Their maximum values(≈0.33 for Fe_(3)GaTe_(2)and≈0.41 for Fe_(5)GeTe_(2))are one order of magnitude larger than those of traditional ferromagnets(θ_(AN)^(max)<0.02).Scaling analysis of anomalous Hall effect in these two systems further suggests these giant angles originate from intrinsic Berry curvature.These findings indicate Berrycurvature-dominated regimes,and establish these materials for high-performance spin-caloritronic devices.
基金supported by the National Natural Science Foundation of China(Grant No.12274117)the Natural Science Foundation of Henan(Grant No.242300421214)+4 种基金the Program for Innovative Research Team(in Science and Technology)in the University of Henan Province(Grant No.24IRTSTHN025)the Open Fund of Guangdong Provincial Key Laboratory of Nanophotonic Manipulation(No.202502)Guangdong S&T Program(No.2023B1212010008)the High-Performance Computing Center of Henan Normal Universitysupported by the U.S.DOE,Office of Science(Grant No.DE-FG02-05ER46237)。
文摘Altermagnetism,a recently identified class of collinear magnetism,combines key features of antiferromagnets and ferromagnets.Despite having zero net magnetization,altermagnetic materials exhibit anomalous transport effects,including the anomalous Hall,Nernst,and thermal Hall effects,as well as magneto-optical Kerr and Faraday effects.These phenomena,previously thought unique to ferromagnets,are dictated by symmetry,as confirmed by density functional theory(DFT)calculations.However,an effective model-based approach to verify these symmetry constraints remains unavailable.In this Letter,we construct a k·ρ model for d-wave altermagnets CuX_(2)(X=F,Cl)using spin space group representations and apply it to calculate the anomalous Hall effect.The symmetry-imposed transport properties predicted by the model are in agreement with the DFT results,providing a foundation for further investigation into symmetry-restricted transport phenomena in altermagnetic materials.
基金supported by Guangzhou Basic and Applied Basic Research Foundation(Grant No.2023B151520013)the National Natural Sciences Foundation of China(Grant No.92165204)+2 种基金the National Key Research and Development Program of China(Grant Nos.2023YFF0718400 and 2022YFA1403301)the Fund from the Research Center for Magnetoelectric Physics of Guangdong Province,China(Grant No.2024B0303390001)the Independent Fund of the State Key Laboratory of Optoelectronic&Materials and Technologies(Sun Yat-sen University)(Grant No.OEMT-2023-ZTS-01)。
文摘Kagome magnets Tb Mn_(6)Sn_(6-x)In_(x)(x=0-1.2)exhibit a robust anomalous Hall effect(AHE)that persists above room temperature,demonstrating significant potential for high-temperature spintronics applications.At elevated temperatures,a spin-reorientation transition induces a ferrimagnetic state(FIM1)with in-plane magnetic moments,accompanied by a nonmonotonic Hall response that differs markedly from the low-temperature behavior.Upon indium doping,the long-range ferrimagnetic transition is progressively suppressed to lower temperatures,along with a noticeable reduction in magnetic anisotropy.Interestingly,at a doping level of x=1.2,the FIM1 state observed in the parent compound is completely eliminated.These systematic changes in magnetic ordering and transport properties underscore a coherent evolution of the electronic and magnetic states with doping,offering critical insights into the interplay among lattice structure,magnetism,and electronic behavior in kagome lattices.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2023YFB3811400 and 2022YFB3806000)the National Natural Science Foundation of China(Grant No.12074314)+1 种基金the Science and Technology New Star Program of Shaanxi Province,China(Grant No.2023KJXX-148)the Fundamental Research Funds for the Central Universities。
文摘The emergent metagrating,with its unique and flexible beam shaping capabilities,offers new paths to efficient modulation of acoustic waves.In this work,an acoustic metagrating is demonstrated for high-efficiency and wide-angle anomalous refraction.It is shown that the normal reflection and transmission can be totally suppressed by properly modulating the amplitude and phase characteristics of the metagrating supercells for high-efficiency anomalous refraction.The anomalous refraction behavior is achieved in the wide range of incident angles from 28°to 78°,and the efficiency of-1st order diffraction is higher than 90%by finely designing the metagrating structure.The anomalous refraction behaviors are verified experimentally at incidence angle of 28°,45°,and 78°,respectively.The demonstrated metagrating is anticipated to possess efficient wide-angle composite wavefront engineering applications in such fields as communications.
基金financially supported by the National Key R&D Program of China(No.2022YFA1603801)the Open Fund of the Science and Technology on Metrology and Calibration Laboratory(No.JLKG2023001C004)+6 种基金the National Natural Science Foundation of China(Nos.52130108,52301213,52071024,52271003,and 52101188)Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515110805,2021B1515140028,and 2021CX02C087)the Open Fund of the China Spallation Neutron Source Songshan Lake Science City(No.KFKT2023B11)Construction of a Coordination Network for Science and Technology Assistance to Latin American Countries(Science and Technology Partnership Program,Ministry of Science and Technology of China,No.KY202401006)the Youth Innovation Promotion Association,CAS(No.2020010)the State Key Lab of Advanced Metals and Materials(No.2022-ZD01)the SSRF proposal(No.2024-SSRF-PT-506766)
文摘FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses(MGs)systems.However,the glass-forming ability(GFA)of FeNi-based MGs is much lower than that of their counterparts.Thus,uncovering the solidification and anomalous nano-crystallization behavior of FeNi-based MGs is crucial to the development of FeNibased bulk metallic glasses with larger plasticity and critical size concurrently.Regarding this,a combination of complementary in situ synchrotron radiation high-energy X-ray diffraction,small-angle neutron scattering(SANS),and 3-dimentional atom probe tomography(3-D APT)is used to study solidification and nano-crystallization behavior of Fe_(48)Ni_(30)Mo_(3)B_(19)liquid and MG.The time–temperature–transformation diagram was successfully depicted via melting spun,in situ solidification,and isothermal annealing methods.We found that the Fe_(48)Ni_(30)Mo_(3)B_(19)MG can only be prepared via the meltspinning method to obtain amorphous ribbons,which could contribute to the low activation energy for the nano-crystallization growth E_(p).Moreover,during isothermal annealing,the anomalous slow growth behavior in kinetic of theγ-FeNi phase embedded in the amorphous matrix is caused by the Fe and Ni partitioning,and the Mo-enriched region around the nanosizedγ-FeNi phase,which is revealed by 3-D APT.These results exhibit a new perspective for understanding the relationship between GFA and nano-crystallization behavior and provide feasible guidance for the development of newγ-FeNi-containing Fe-based BMG composites with desired mechanical properties and GFA.
基金supported by the National Natural Science Foundation of China(Nos.52171125,52071178)。
文摘A statistical analysis of the twinning behavior in a basal-textured Mg sheet under hard orientation loading was performed at strain rates of 1×10^(-5) and 1×10^(-1) s^(-1) with grain sizes of 70 and 20µm.There were 1609 tension twins identified including adequate(51%)anomalous twins(Schmid factor m<0).Twin variant selection exhibited almost no grain size or strain rate effects.Most twin variants(74%)correlated well with the proposed normalized Schmid factor(mnor).The Luster-Morris parameter(m′)values failed to correlate with the twin transmission,while 96%of transmitted pairs exhibited large mnor or normalized m′(m′nor)values.Twin transmission occurred more frequently at lower grain boundary misorientation angles(10°-30°).The active anomalous twins correlated well with m of the prismatic slip.The present work provided a statistical perspective that,the mnor and m′nor can correlate the anomalous twinning rather than m and m′.The local condition also played a critical role in anomalous twinning behavior.
基金financially supported by the National Natural Science Foundation of China (grants 52301146 and 52275308)the Fundamental Research Funds for the Central Universities (grant 2023JG007)China Postdoctoral Science Foundation (grant 8206300226)。
文摘While the deformation behavior of rare-earth magnesium alloys at high temperatures has been extensively studied,the deformation mechanisms under moderate-to-low temperatures and high strain rates remain insufficiently understood.To address this gap,hot compression tests were conducted on a Mg-11Gd-3Y-0.5Zr(wt.%)alloy over a temperature range of 150℃–450℃under strain rates of 10^(-3) s^(-1)(low strain rate(LSR))and 10 s^(-1)(high strain rate(HSR))to explore the strain rate-temperature coupling effects during hot deformation.The results revealed an anomalous increase in peak stress at 150℃–250℃as the strain rate decreased,attributed to the combined effects of nano-precipitates,dislocation cell structures,and serrated flow induced by dynamic strain aging.At higher temperatures,strain rate influences softening pathways:under HSR at 450℃,the effect of twinning shifts from strengthening to facilitating dynamic recrystallization(DRX),resulting in substantial grain refinement(-4 μm,81%area fraction at a strain of 0.6).In contrast,at LSR,softening is dominated by dynamic recovery at 350℃,with limited DRX(-4 μm grains,10%area fraction at a strain of 0.6)occurs at 400℃.These findings clarify the dual role of twinning and its interaction with rate-temperature conditions,providing valuable insights into optimizing the hot processing of rare-earth magnesium alloys.
基金supported by the President’s Fund of China Academy of Engineering Physics(No.YZJJZQ2023022)Nature Science Foundation of Shanxi Province,China(Nos.202103021224309 and 201901D111317).
文摘This study investigates the mechanism of ^(6)Li+^(7)Li anomalous large-angle scattering.First,elastic scattering is analyzed using an optical model with the São Paulo potential,and inelastic scattering to the first excited state of ^(7)Li is analyzed by distorted wave born approximation method.The experimental data of the elastic scattering angular distributions could be described reasonably well by the optical model at forward angles;however,anomalous large-angle scattering is observed in the angular distributions of both the elastic and inelastic channels for all measured energies.Elastic and inelastic scatterings are investigated using the coupled reaction channel method.The elastic and inelastic scattering,transfer reactions for the ground and excited states,and their coupling effects are considered in the coupled reaction channel scheme.In addition,the influence of the breakup effects of the weakly bound ^(6)Li and ^(7)Li is investigated by including three resonance states of ^(6)Li and two resonance states of ^(7)Li in the coupled reaction channel framework.The observed anomalous large-angle scattering is explained using the transfer reaction mechanism and breakup effect,and the calculated results reproduce the experimental data reasonably well.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274313,62275184,and 62411540033)Collaborative Innovation Center of Suzhou Nano Science and Technology,Suzhou Basic Research Project(Grant No.SJC2023003)+1 种基金the Gusu Leading Talent Plan for Scientific and Technological Innovation and Entrepreneurship(Grant No.ZXL2024400)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Perfect anomalous reflections have been demonstrated in optical phase gradient metasurfaces(PGMs),but they suffer from single-frequency(narrow-band)response due to the intrinsic limitation of natural geometric periodicity.Here,we provide both numerical and analytical evidence that a depth gradient metasurface can achieve discrete ultra-broadband perfect anomalous reflection in the microwave range in the absence of geometric periodicity.Remarkably,by adjusting the operating frequency of the incident wave,the same effect can be steadily obtained via a physically equivalent phase periodicity in the PGM.Based on this mechanism,a perfect retroreflector with a broadband response ranging from 1 GHz to 40 GHz is realized.Our work has promising applications in communication,source tracking,and military satellites.
基金Supported by the 1.3.5 Project of West China Hospital of Sichuan University(No.2023HXFH043)Sichuan Natural Science Foundation(No.24NSFSC1718).
文摘Dear Editor,We describe a case diagnosed with exudative perifoveal vascular anomalous complex(ePVAC)successfully treated with focal laser photocoagulation(577 nm),achieving a favorable prognosis with best-corrected visual acuity(BCVA)of 20/20.Additionally,we discussed the identification of a possible early-onset non-ePVAC.The ePVAC is characterized as an isolated,aneurysmal abnormity near the macula and usually accompanied by cystic macular edema(ME)[1-2].
基金Project supported by the National Key R&D Program of China(Grant Nos.2021YFA1400100 and 2024YFA1409700)the National Natural Science Foudation of China(Grant Nos.12374168 and T2325026)。
文摘Spin-orbit interaction(SOI)can be introduced by the proximity effect to modulate the electronic properties of graphene-based heterostructures.In this work,we stack trilayer WSe_(2) on Bernal tetralayer graphene to investigate the influence of SOI on the anomalous Hall effect(AHE).In this structurally asymmetric device,by comparing the magnitude of AHE at positive and negative displacement fields,we find that AHE is strongly enhanced by bringing electrons in proximity to the WSe_(2) layer.Meanwhile,the enhanced AHE signal persists up to 80 K,providing important routes for topological device applications at high temperatures.
基金supported by the National Natural Science Foundation of China(Grant No.12304062)supported by the National Natural Science Foundation of China(Grant No.12074107)+1 种基金the Program of Outstanding Young and Middle-aged Scientific and Technological Innovation Teams of Colleges and Universities in Hubei Province(Grant No.T2020001)the Innovation Group Project of the Natural Science Foundation of Hubei Province of China(Grant No.2022CFA012)。
文摘A finite equilibrium current density arises in the anomalous Hall effect(AHE)as a result of time-reversal symmetry breaking,affecting both the differential current density and total current.In this paper,we illustrate the equilibrium current density in a ribbon-shaped system within the AHE regime,consisting of two sets of counterpropagating channels arranged in a zebra stripes pattern.While the middle channels are susceptible to scattering,the edge channels remain relatively robust.Despite this difference,all channels exhibit the same differential current density when subjected to a differential voltage across the two ends of the ribbon.When a differential voltage is applied to both sides of the ribbon,it results in a snaking pattern of differential current density forming across it.Furthermore,in a four-terminal device comprising the ribbon and two normal leads,it is found that Hall conductance is independent of ribbon width within certain scattering strengths due to the differences in robustness between middle and edge channels.These findings disclose the details of the AHE transport in a finite-sized system under weak scattering.
基金supported by the Science Research Project of Hebei Education Department(Grant No.BJK2024168)the National Natural Science Foundation of China(Grant No.11904076)+1 种基金the Natural Science Foundation of Hebei(Grant No.A2019205313)Science Foundation of Hebei Normal University(Grant No.L2024J02).
文摘Recent advancements in two-dimensional van der Waals moir´e materials have unveiled the captivating landscape of moir´e physics.In twisted bilayer graphene(TBG)at‘magic angles’,strong electronic correlations give rise to a diverse array of exotic physical phenomena,including correlated insulating states,superconductivity,magnetism,topological phases,and the quantum anomalous Hall(QAH)effect.Notably,the QAH effect demonstrates substantial promise for applications in electronic and quantum computing devices with low power consumption.This article focuses on the latest developments surrounding the QAH effect in magic-angle TBG.It provides a comprehensive analysis of magnetism and topology—two crucial factors in engineering the QAH effect within magic-angle TBG.Additionally,it offers a detailed overview of the experimental realization of the QAH effect in moir´e superlattices.Furthermore,this review highlights the underlying mechanisms driving these exotic phases in moir´e materials,contributing to a deeper understanding of strongly interacting quantum systems and facilitating the manipulation of new material properties to achieve novel quantum states.
基金Project supported by the Strategic Priority Research Program of CAS (Grant No. XDB0460000)the National Natural Science Foundation of China (Grant Nos. 12404213, 52031014, and 51702146)the National Key Research and Development Program of China (Grant No. 2022YFA1203900)。
文摘MoS_(2) monolayer, as a highly promising two-dimensional semiconducting material for electronic and optoelectronic applications, exhibits deep-ultraviolet(DUV) laser-induced anomalous lattice dynamics as revealed by Raman spectroscopy. Remarkably, not only the Raman intensity of many second-order Raman peaks but also the intensity ratio between the first-order modes E′and A′_1 exhibits a non-monotonic behavior that depends on laser energy. Moreover, there are significant inconsistencies in the literature regarding the assignments of these second-order Raman modes. In this work, we perform a thorough exploration of the anomalous lattice dynamics and conduct a renewed assignment of the numerous double resonant Raman modes of MoS_(2) monolayer. At three laser energies(E_L= 2.33, 3.50, and 4.66 e V) spanning from the visible to the ultraviolet and further into the DUV region, the calculated double-resonance Raman spectra correlate reasonably well with the experimental ones in terms of both peak positions and relative intensities. We confirm that the P_1 peak at ~450 cm^(-1) represents the second-order longitudinal acoustic(2LA) overtone mode. Each of the P_i(i = 1, 2,..., 7) peaks has multiple contributions from two phonons with distinct q wavevectors. Our calculations further reveal that the DUV laser-induced anomalous lattice dynamics stems from the quantum interference effect among different Raman scattering channels.
基金supported by the National Natural Science Foundation of China[grant numbers U2142207 and U2342205]the National Key R&D Program of China[grant number 2024YFC3013100]China Meteorological Administration(CMA)Youth Innovation Team[CMA2024QN06].
文摘Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in June followed by floods in July.The 2024 event was the most severe since 1981.This study demonstrates that such compound extreme events are closely linked to anomalous subseasonal evolution of large-scale atmospheric circulation.During the drought phase,the East Asian subtropical westerly jet(EAJ)shifts southward,and the western Pacific subtropical high(WPSH)exhibits anomalous strengthening with its western ridge line displaced southward.The flood phase is characterized by acceleration of the EAJ,westward extension of the WPSH,and enhanced southwestern moisture transport from the western Pacific.Beyond these typical features,the 2024 early summer circulation exhibited unique characteristics:Anomalous northeastward intensification of the WPSH facilitated merged moisture influx from both the Indian Ocean and the western Pacific along the southeast pathway into the HHHRB in July,resulting in the highest net moisture inflow at the southern boundary of the HHHRB since 1981.The synergistic effects of multiple factors primarily explain the exceptionally intense DFAA event in 2024.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1204100)the National Natural Science Foundation of China(Grant Nos.62488201 and 1240041502)+2 种基金the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-003)the Chinese Academy of Sciences(Grant No.XDB33030100)the Innovation Program of Quantum Science and Technology(Grant No.2021ZD0302700).
文摘Vanadium-based transition metal chalcogenides VmXn(X=S,Se,Te)with their distinctive quantum effects,tunable magnetism,spin-orbit coupling,and high carrier mobility are a valuable platform to explore the interplay between magnetism and electronic correlations,especially with tunable structural phases and magnetic properties through stoichiometric variations,making them ideal candidates for advanced device applications.Here,we report the synthesis of high-quality V_(5+x)S_(8)single crystals with different concentrations of self-intercalated vanadium.V_(5+x)S_(8)crystals show an antiferromagnetic behavior and a spin-flop-like transition below TN of 30.6 K.The high-quality V_(5+x)S_(8)single crystals exhibit a large negative magnetoresistance of 12.3%at 2 K.Interestingly,V_(5+x)S_(8)crystals show an obvious low-temperature resistance upturn that gradually levels off with the increasing magnetic field,attributed to the Kondo effect arising from the interaction between conduction electrons and embedded vanadium magnetic impurities.With increasing V doping,the antiferromagnetic interactions intensify,weakening the coupling between the local moments and conduction electrons,which in turn lowers the Kondo temperature(TK).Furthermore,the anomalous Hall effect is observed in V5.73S8,with an anomalous Hall conductivity(AHC)of 50.46 W^(-1)·cm^(-1)and anomalous Hall angle of 0.73%at 2 K.Our findings offer valuable insights into the mechanisms of the Kondo effect and anomalous Hall effect in self-intercalated transition metal chalcogenides with complex magnetism and electronic correlation effects.
文摘Background:Anomalous origin of the left coronary artery from the pulmonary artery(ALCAPA)is a rare congenital anomalous coronary artery origin disorder.Objective:We sought to summarize the clinical experience and prognostic characteristics of surgical treatment of ALCAPA.Methods:We retrospectively analyzed clinical information on patients who had ALCAPA and underwent surgery at our center from February 2016 to October 2023.Results:This comparative study of 23 ALCAPA patients(9 infants<1 year;14 children>1 year)demonstrated significant age-dependent outcomes.Infant patients exhibited markedly prolonged mechanical ventilation(183±105.6 vs.48.5±62.2 min,p=0.001)and hospitalization(30.8±8.2 vs.19.5±6.2 days,p=0.001),despite comparable operative times(p>0.05).The perioperative mortality rate was 8.7%(2/23).Early postoperative mortality showed a non-significant trend in infants(22.2%vs.0%,p=0.11).Serial follow-up revealed substantial functional improvement,with abnormal left ventricular ejection fractions decreasing from 56.5%preoperatively to 14.3%at 1-month(p<0.01),and severe mitral regurgitation declining from 34.7%to 14.3%.However,persistent left ventricular enlargement(81%at follow-up)and moderate mitral regurgitation(52.4%)were frequently observed.Conclusion:Surgical correction of ALCPA effectively restores coronary perfusion and reduces severe mitral regurgitation,though residual ventricular dilation and moderate valvular dysfunction persist in the short-term postoperative period.Nevertheless,the overall prognosis remains favorable when timely intervention is performed.
基金Projects(2012BAI18B05,2012BAI18B01)supported by the Twelfth Five-Year National Science&Technology Support Program of ChinaProject(2009CB93004)supported by the National Basic Researh Program of China
文摘A nickel-based superalloy with good corrosion resistance was fabricated by directional solidification, and its microstructure and tensile properties at elevated temperatures were investigated. Microstructure observations reveal that the γ＇ precipitates are arrayed in the y matrix regularly with some MC, Ni5Hf and M3B2 particles distributed along the grain boundary. The tensile tests exhibit that the tensile properties depend on temperature significantly and demonstrate obvious anomalous yield and intermediate-temperature brittleness （ITB） behavior. Below 650℃, the yield strength decreases slightly but the ultimate tensile strength almost has no change. When the temperature is between 650 ℃ and 750 ℃, the yield and ultimate tensile strengths rise rapidly, and after then they both decrease gradually with temperature increasing further. The elongation has its minimum value at about 700 ℃. The TEM examination exhibits that sharing of the γ＇ by dislocation is almost the main deformation mechanism at low temperatures, but the γ＇ by-pass dominates the deformation at high temperatures. The transition temperature from shearing to by-pass should be around 800 ℃. The anomalous yield and intermediate-temperature brittleness behaviors should be attributed to the high content of γ＇. In addition, the carbides and eutectic structure also contribute some to the ITB behaviors of the alloy.
文摘Making use of the temperature data from 53 stations in Liaoning Province in April from 1961 to 2010 and the data of 500 hPa height field and sea surface temperature issued by National Climate Center,the characteristics of temperature,sea surface temperature(SST) and 500 hPa height field in April in 2010 were analyzed.The results showed that the anomalously lower temperature in April in 2010 was mainly caused by the anomalous Arctic Oscillation(AO),so as to provide scientific basis for short-term climate prediction.
文摘Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed as a fundamental equation of statistical physics. This equation reflects that the law of motion of particles obeying reversible, deterministic laws in dynamics becomes irreversible and stochastic in thermodynamics. From this the fundamental equations of nonequilibrium thermodynamics, the principle of entropy increase and the theorem of minimum entropy production have been derived. The hydrodynamic equations, such as the generalized Navier-Stokes equation and the mass drift-diffusion equation etc. have been derived rigorously from the kinetic kinetic equation which is reduced from the anomalous Langevin equation in Liouville space. All these are unified and self consistent. But it is difficult to prove that entropy production density σ can never be negative everywhere for all the isolated inhomogeneous systems far from equilibrium.
