A large magnitude-9.0 earthquake struck northeast Japan on March 11, 2011. Thirty minutes later, a tsunami reached Tokyo Electric Power Corporation （TEPCO）＇s Fukushima Daiichi nuclear power station, and the emergen...A large magnitude-9.0 earthquake struck northeast Japan on March 11, 2011. Thirty minutes later, a tsunami reached Tokyo Electric Power Corporation （TEPCO）＇s Fukushima Daiichi nuclear power station, and the emergency diesel generators submerged under water. Three units of the reactor experienced meltdown, and hydrogen explosions occurred at reactor houses. The RIKEN Nishina Center （RNC） contributed to the radiation screening effort by providing human resources, instruments, and transportation. The RNC also carried out extraction work and sample tests for soil contamination. Last summer, RIKEN was legally required to save 15% （equivalent to 3.3 MW） of its allocated electricity in its contract, making it extremely difficult to conduct experiments using accelerators. Accelerator operation was thus reduced to a minimum during the first half of the year. The RNC has a gas-turbine-based co-generation system （CGS） with an electrical capacity of 6.5 MW. The CGS was operated non-stop until the end of the year. RIKEN is constructing two sets of CGSs, each with a capacity of 1.5 MW to be commissioned this autumn.展开更多
Superconducting magnet system for a 28GHz ECR ion source has been designed.The maximum axial magnetic fields are 4T at the rf injection side and 2T at the beam extraction side,respectively.The hexapole magnetic field ...Superconducting magnet system for a 28GHz ECR ion source has been designed.The maximum axial magnetic fields are 4T at the rf injection side and 2T at the beam extraction side,respectively.The hexapole magnetic field is about 2T on the inner surface of the plasma chamber.The superconducting coils consist of six solenoids and six racetrack windings for a hexapole field.Two kinds of coil arrangements were investigated:one is an arrangement in which the hexpole coil is located in the bore of the solenoids,and another is the reverse of it.The coils use NbTi-Copper conductor and are bath-cooled in liquid helium.The six solenoids are excited with individual power supplies to search for the optimal axial field distribution.The current leads use high Tc material and the cryogenic system is operated in LHe re-condensation mode using small refrigerators.The thermal insulated supports of the cold mass have also been designed based on the calculated results of the magnetic force.The heat loads to 70K and LHe stages were estimated from the design of the supports,the current leads and so on.展开更多
We measured the main plasma parameters(density of electron,temperature of electron and ion confinement time)and beam intensity of various heavy ions as a function of B_(min).The B_(min) strongly affects the field grad...We measured the main plasma parameters(density of electron,temperature of electron and ion confinement time)and beam intensity of various heavy ions as a function of B_(min).The B_(min) strongly affects the field gradient at the resonance zone,consequently the plasma parameters and beam intensity are changed. Based on these experimental results,we started to construct new 18GHz ECRIS and make a detailed design of the 28GHz SC-ECRIS for RIKEN RI beam factory project.展开更多
At RIKEN,three ECR ion sources(10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS) are operated as external ion sources of heavy ion accelerators.In the last year,multi-charged uranium ion beam was produced from 18GH...At RIKEN,three ECR ion sources(10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS) are operated as external ion sources of heavy ion accelerators.In the last year,multi-charged uranium ion beam was produced from 18GHz ECRIS by using UF_6 and the ^(238)U ion was successfully accelerated by the accelerator complex which consists of the RFQ linear accelerator,RIKEN heavy ion linear accelerator(RILAC)and RIKEN ring cyclotron accelerator(RRC).The typical beam intensity of^(238)U^(14+) was about 2pμA on faraday cup after analysing magnet.^(70)Zn beam was still supplied for the new super-heavy element search experiment with insertion method.Intense beam of^(70)Zn^(16+) was produced for long term(～43 days)without vacuum break and remarkably low material consumption rate(～100μgr/h).We already supplied Zn beam longer than 200 days for this experiment.^(48)Ca ion was also produced by insertion method using^(48)CaO rod for the nuclear physics experiment.In this contribution,we will present ion source parameter and techniques for production of each of the metal ions.展开更多
The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-...The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.展开更多
Compared with traditional rain gauges and weather radars,hydrogel flexible electronic sensor capable of responding directly to rainfall events with promptness and authenticity,shows great prospects in real-time rainfa...Compared with traditional rain gauges and weather radars,hydrogel flexible electronic sensor capable of responding directly to rainfall events with promptness and authenticity,shows great prospects in real-time rainfall monitoring.Aluminum coordination hydrogel(Al-HG),one of the most qualified sensors suitable for rainfall monitoring,however,is currently impeded from widespread application by its weak mechanical properties due to the low binding strength between Al^(3+)and functional ligands.Herein,inspired by the antifreeze proteins(AFPs)that protect those Patagonian toothfishes by strongly binding to ice crystals at freezing temperatures,a low temperature-induced strategy is introduced to promote more and stronger ligand carboxyls firm combination with Al^(3+),thus forming a high-coordinated structure to deal with this challenge.Expectedly,the whole mechanical performance of the product Al-HG_(F1/F2) obtained by the low temperature-induced strategy is improved.For example,the tensile fracture toughness and the maximum compressive stress of Al-HG_(F1/F2) are 1.66 MJ·m^(-3) and 12.01 MPa,approximately twice those of the sample Al-HGF3/F0 obtained by traditional soaking method(0.86 MJ·m^(-3) and 7.38 MPa,respectively).Coupled with its good biocompatibility,ionic conductivity,and sensing ability,Al-HG_(F1/F2) demonstrates promising application for real-time rainfall monitoring in discrepant rainfall intensities,different zones,and even under extreme environments.This work aims to offer a stride toward mechanically robust aluminum coordination hydrogel sensors for real-time rainfall monitoring as well as provide insights into flood prevention and disaster mitigation.展开更多
With the same level of measurement accuracy,more portable and miniaturized measurement systems will have greater advantages,providing users with more flexible and convenient measurement solutions.Here,we introduce a n...With the same level of measurement accuracy,more portable and miniaturized measurement systems will have greater advantages,providing users with more flexible and convenient measurement solutions.Here,we introduce a new type of digital image correlation(DIC)system that incorporates a binocular meta-lens,featuring a simple and compact configuration.Meta-lens is one of the promising flat optical imaging devices that are ultra-thin,customizable,and well-suited for use in confined spaces.We evaluated this binocular meta-lens based DIC(BM-DIC)system through classic in-plane and out-of-plane translation tests,followed by a bending test on a helicopter wing model to capture 3D displacement and deformation fields.For in-plane translations,the system achieved high precision with a standard deviation(σ)below 2μm.Despite a small baseline of 4 mm,the system maintained aσof approximately 32μm for out-of-plane translations.Comparative analysis with conventional dual-camera stereo DIC systems showed that the BM-DIC system maintains an acceptable relative error margin of about 1%in measured strain fields despite a 75-fold reduction in baseline length.This research demonstrates the integration of DIC techniques with advanced meta-lens technology,indicating substantial potential to enhance the capabilities of DIC technology in experimental solid mechanics.展开更多
The search for the chiral magnetic effect(CME) in relativistic heavy-ion collisions(HICs) is challenged by significant background contamination. We present a novel deep learning approach based on a U-Net architecture ...The search for the chiral magnetic effect(CME) in relativistic heavy-ion collisions(HICs) is challenged by significant background contamination. We present a novel deep learning approach based on a U-Net architecture to time-reversely unfold the dynamics of CME-related charge separation, enabling the reconstruction of the physics signal across the entire evolution of HICs. Trained on the events simulated by a multi-phase transport model with different cases of CME settings, our model learns to recover the charge separation based on final-state transverse momentum distributions at either the quark–gloun plasma freeze-out or hadronic freeze-out. This devises a methodological tool for the study of CME and underscores the promise of deep learning approaches in retrieving physics signals in HICs.展开更多
Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible ap...Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible application in ultraviolet(UV)materials.Herein the systematic synthesis approach was adopted,which enhances the optical and electrical properties of the grown wide band-gap composite nanomaterial.Structural characterization of the grown materials was attempted using X-ray diffraction(XRD)and scanning electron microscopy(SEM).Most importantly the electrochemical analysis of the grown samples was carried out by employing a glassy carbon electrode and 3 mol/L KOH electrolyte,which demonstrates significant improvements in a specific capacitance of approximately360 F/g,an energy density of approximately 18 Wh/kg,and a maximum power density of approximately 257 W/kg,respectively.Moreover,NdCrO_(3)/GO nanocomposite maintains a cyclic stability of 97.6%after4000 cycles.Photoluminescence(PL)spectroscopy confirms the wide bandgap nature of the NdCrO_(3)and NdCrO_(3)/GO nanocomposite,indicating its potential application in UVC devices.These findings emphasize the potential of the NdCrO_(3)/GO nanocomposite in advancing efficient energy storage solutions and the possibility of being used in UVC technology.展开更多
The electron-doped cuprate superconductor exhibits a unique electronic structure,where both electron and hole Fermi surface(FS)pockets coexist in the optimally doped(OP)region,while in the overdoped(OD)region there ex...The electron-doped cuprate superconductor exhibits a unique electronic structure,where both electron and hole Fermi surface(FS)pockets coexist in the optimally doped(OP)region,while in the overdoped(OD)region there exists only a large hole FS pocket.It is therefore an intriguing question whether or not a p-n junction arises if the OD electron-doped cuprate interfaces with the OP compound.Here,we construct such an in-plane junction by selectively modulating the doping levels in thin films of La_(2-x)Ce_(x)CuO_(4)(LCCO)—a typical electron-doped cuprate.We find that the junction exhibits non-linear,asymmetricⅠ-Ⅴcharacteristics,which are consistent with those of a p-n semiconductor junction,across a wide temperature range from 250 K to 10 K,regardless of the Hall coefficient sign change or the superconducting transition.We attribute these features to a potential barrier formed at the junction,which is set by the band bending in both OD and OP LCCO.展开更多
The kagome lattice,naturally encompassing Dirac fermions,flat bands,and van Hove singularities,tends to intertwine exotic electronic states.Revealing the characteristics of its Fermi surface will help clarify the natu...The kagome lattice,naturally encompassing Dirac fermions,flat bands,and van Hove singularities,tends to intertwine exotic electronic states.Revealing the characteristics of its Fermi surface will help clarify the nature of the complex quantum phenomena in kagome material.Here we report the Fermi surface properties of the novel kagome metal CsTi_(3)Bi_(5)by the de Haas-van Alphen oscillations.The observed oscillations are clear and consist of six principal frequencies ranging from 214 T to 1013 T.The angular dependence of the frequency implies a quasi-two-dimensional electronic structure.In addition,the geometry phase corresponding to 281 T,determined by direct Lifshitz-Kosevich formula fitting,yields a value close toπ,which may indicate a band structure with nontrivial topological property.These results underscore the potential of CsTi_(3)Bi_(5)as a promising platform to explore the interplay between topological order,electronic nematicity,and superconductivity.展开更多
Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental tech...Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.展开更多
采用900 e V能量的电子对直玻璃管进行了穿透实验,测量了玻璃管在倾角为–0.15°,–0.4°和–1.15°时充电过程角分布的时间演化,以及平衡态下出射电子能谱.发现穿透率随时间先下降后上升最后趋于平稳,下降的时间随倾角的...采用900 e V能量的电子对直玻璃管进行了穿透实验,测量了玻璃管在倾角为–0.15°,–0.4°和–1.15°时充电过程角分布的时间演化,以及平衡态下出射电子能谱.发现穿透率随时间先下降后上升最后趋于平稳,下降的时间随倾角的增大而减小.当倾角为–0.4°和–1.15°时,电子穿透率下降到最低点时几乎看不到穿透电子(穿透率小于3‰),这种穿透率最低点状态保持时间随倾角增大而增大.穿透电子的角分布中心随着时间变化.在平稳状态时,发现穿透电子的能量损失随倾角增大而增大.采用蒙特卡罗方法模拟了电子经过管壁不同次数反射后的能谱,与测量能谱进行对比,发现–0.15°,–0.4°和–1.15°倾角下,穿透电子分别经历了管壁的一次、两次和三次与表面的反射过程.基于此,本文对电子穿越玻璃管的充电过程动力学给出了物理解释.实验结果和理论分析表明,在小倾角下玻璃管内能形成宏观负电荷累积,排斥后续电子形成反射,增加电子出射概率,这对应用绝缘体微结构,例如玻璃锥管产生稳定的电子微束具有重要的参考意义.展开更多
文摘A large magnitude-9.0 earthquake struck northeast Japan on March 11, 2011. Thirty minutes later, a tsunami reached Tokyo Electric Power Corporation （TEPCO）＇s Fukushima Daiichi nuclear power station, and the emergency diesel generators submerged under water. Three units of the reactor experienced meltdown, and hydrogen explosions occurred at reactor houses. The RIKEN Nishina Center （RNC） contributed to the radiation screening effort by providing human resources, instruments, and transportation. The RNC also carried out extraction work and sample tests for soil contamination. Last summer, RIKEN was legally required to save 15% （equivalent to 3.3 MW） of its allocated electricity in its contract, making it extremely difficult to conduct experiments using accelerators. Accelerator operation was thus reduced to a minimum during the first half of the year. The RNC has a gas-turbine-based co-generation system （CGS） with an electrical capacity of 6.5 MW. The CGS was operated non-stop until the end of the year. RIKEN is constructing two sets of CGSs, each with a capacity of 1.5 MW to be commissioned this autumn.
文摘Superconducting magnet system for a 28GHz ECR ion source has been designed.The maximum axial magnetic fields are 4T at the rf injection side and 2T at the beam extraction side,respectively.The hexapole magnetic field is about 2T on the inner surface of the plasma chamber.The superconducting coils consist of six solenoids and six racetrack windings for a hexapole field.Two kinds of coil arrangements were investigated:one is an arrangement in which the hexpole coil is located in the bore of the solenoids,and another is the reverse of it.The coils use NbTi-Copper conductor and are bath-cooled in liquid helium.The six solenoids are excited with individual power supplies to search for the optimal axial field distribution.The current leads use high Tc material and the cryogenic system is operated in LHe re-condensation mode using small refrigerators.The thermal insulated supports of the cold mass have also been designed based on the calculated results of the magnetic force.The heat loads to 70K and LHe stages were estimated from the design of the supports,the current leads and so on.
文摘We measured the main plasma parameters(density of electron,temperature of electron and ion confinement time)and beam intensity of various heavy ions as a function of B_(min).The B_(min) strongly affects the field gradient at the resonance zone,consequently the plasma parameters and beam intensity are changed. Based on these experimental results,we started to construct new 18GHz ECRIS and make a detailed design of the 28GHz SC-ECRIS for RIKEN RI beam factory project.
文摘At RIKEN,three ECR ion sources(10GHz ECRIS,18GHz ECRIS and liquid He-free SC-ECRIS) are operated as external ion sources of heavy ion accelerators.In the last year,multi-charged uranium ion beam was produced from 18GHz ECRIS by using UF_6 and the ^(238)U ion was successfully accelerated by the accelerator complex which consists of the RFQ linear accelerator,RIKEN heavy ion linear accelerator(RILAC)and RIKEN ring cyclotron accelerator(RRC).The typical beam intensity of^(238)U^(14+) was about 2pμA on faraday cup after analysing magnet.^(70)Zn beam was still supplied for the new super-heavy element search experiment with insertion method.Intense beam of^(70)Zn^(16+) was produced for long term(～43 days)without vacuum break and remarkably low material consumption rate(～100μgr/h).We already supplied Zn beam longer than 200 days for this experiment.^(48)Ca ion was also produced by insertion method using^(48)CaO rod for the nuclear physics experiment.In this contribution,we will present ion source parameter and techniques for production of each of the metal ions.
基金sponsored by the National Natural Science Foundation of China(Nos.5210125 and 52375422)the Science Research Project of Hebei Education Department(No.BJK2023058)the Natural Science Foundation of Hebei Province(Nos.E2020208069,B2020208083 and E202320801).
文摘The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.
基金supported by the National Natural Science Foundation of China(22308210)the Young Talent Fund of the Association for Science and Technology in Shaanxi of China(20240412)+1 种基金the RIKEN-MOST Project between the Ministry of Science and Technology of the People’s Republic of China(MOST)and RIKEN,the China Scholarship Council(202108610127)the Natural Science Foundation of Shaanxi University of Science&Technology(2019BT-44).
文摘Compared with traditional rain gauges and weather radars,hydrogel flexible electronic sensor capable of responding directly to rainfall events with promptness and authenticity,shows great prospects in real-time rainfall monitoring.Aluminum coordination hydrogel(Al-HG),one of the most qualified sensors suitable for rainfall monitoring,however,is currently impeded from widespread application by its weak mechanical properties due to the low binding strength between Al^(3+)and functional ligands.Herein,inspired by the antifreeze proteins(AFPs)that protect those Patagonian toothfishes by strongly binding to ice crystals at freezing temperatures,a low temperature-induced strategy is introduced to promote more and stronger ligand carboxyls firm combination with Al^(3+),thus forming a high-coordinated structure to deal with this challenge.Expectedly,the whole mechanical performance of the product Al-HG_(F1/F2) obtained by the low temperature-induced strategy is improved.For example,the tensile fracture toughness and the maximum compressive stress of Al-HG_(F1/F2) are 1.66 MJ·m^(-3) and 12.01 MPa,approximately twice those of the sample Al-HGF3/F0 obtained by traditional soaking method(0.86 MJ·m^(-3) and 7.38 MPa,respectively).Coupled with its good biocompatibility,ionic conductivity,and sensing ability,Al-HG_(F1/F2) demonstrates promising application for real-time rainfall monitoring in discrepant rainfall intensities,different zones,and even under extreme environments.This work aims to offer a stride toward mechanically robust aluminum coordination hydrogel sensors for real-time rainfall monitoring as well as provide insights into flood prevention and disaster mitigation.
基金financial support from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.C5031-22G,CityU11310522,CityU11300123)City University of Hong Kong(Project No.9610628)+5 种基金National Natural Science Foundation of China(NSFC)(12172222,12302368,22227901)National Science and Technology Major Project of China(J2019-V-0004-0095)Science Center for Gas Turbine Project(2023-B-V-002-001)Aeronautical Science Foundation of China(20230046057018)China Postdoctoral Science Foundation(2023M742231)Postdoctoral Fellowship Program of CPSF(GZC20231561。
文摘With the same level of measurement accuracy,more portable and miniaturized measurement systems will have greater advantages,providing users with more flexible and convenient measurement solutions.Here,we introduce a new type of digital image correlation(DIC)system that incorporates a binocular meta-lens,featuring a simple and compact configuration.Meta-lens is one of the promising flat optical imaging devices that are ultra-thin,customizable,and well-suited for use in confined spaces.We evaluated this binocular meta-lens based DIC(BM-DIC)system through classic in-plane and out-of-plane translation tests,followed by a bending test on a helicopter wing model to capture 3D displacement and deformation fields.For in-plane translations,the system achieved high precision with a standard deviation(σ)below 2μm.Despite a small baseline of 4 mm,the system maintained aσof approximately 32μm for out-of-plane translations.Comparative analysis with conventional dual-camera stereo DIC systems showed that the BM-DIC system maintains an acceptable relative error margin of about 1%in measured strain fields despite a 75-fold reduction in baseline length.This research demonstrates the integration of DIC techniques with advanced meta-lens technology,indicating substantial potential to enhance the capabilities of DIC technology in experimental solid mechanics.
基金supported by the National Natural Science Foundation of China (Grant Nos.12147101 and 12325507)the National Key Research and Development Program of China (Grant No.2022YFA1604900)+4 种基金the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2020B0301030008 for S.G.and G.M.)the CUHK-Shenzhen university development fund (Grant Nos.UDF01003041 and UDF03003041)Shenzhen Peacock Fund (Grant No.2023TC0179 for K.Z.)the RIKEN TRIP initiative (RIKEN Quantum),JSPS KAKENHI (Grant No.25H01560)JST-BOOST (Grant No.JPMJBY24H9 for L.W.)。
文摘The search for the chiral magnetic effect(CME) in relativistic heavy-ion collisions(HICs) is challenged by significant background contamination. We present a novel deep learning approach based on a U-Net architecture to time-reversely unfold the dynamics of CME-related charge separation, enabling the reconstruction of the physics signal across the entire evolution of HICs. Trained on the events simulated by a multi-phase transport model with different cases of CME settings, our model learns to recover the charge separation based on final-state transverse momentum distributions at either the quark–gloun plasma freeze-out or hadronic freeze-out. This devises a methodological tool for the study of CME and underscores the promise of deep learning approaches in retrieving physics signals in HICs.
基金support from the Deanship of Scientific Research at King Khalid University,Saudi Arabia(RGP2/505/45)。
文摘Neodymium chromium oxide(NdCrO_(3))and NdCrO_(3)/graphene oxide(GO)nanocomposite were synthesized via sol-gel and co-precipitation techniques for being used in high-perfo rmance supercapacitors and for the possible application in ultraviolet(UV)materials.Herein the systematic synthesis approach was adopted,which enhances the optical and electrical properties of the grown wide band-gap composite nanomaterial.Structural characterization of the grown materials was attempted using X-ray diffraction(XRD)and scanning electron microscopy(SEM).Most importantly the electrochemical analysis of the grown samples was carried out by employing a glassy carbon electrode and 3 mol/L KOH electrolyte,which demonstrates significant improvements in a specific capacitance of approximately360 F/g,an energy density of approximately 18 Wh/kg,and a maximum power density of approximately 257 W/kg,respectively.Moreover,NdCrO_(3)/GO nanocomposite maintains a cyclic stability of 97.6%after4000 cycles.Photoluminescence(PL)spectroscopy confirms the wide bandgap nature of the NdCrO_(3)and NdCrO_(3)/GO nanocomposite,indicating its potential application in UVC devices.These findings emphasize the potential of the NdCrO_(3)/GO nanocomposite in advancing efficient energy storage solutions and the possibility of being used in UVC technology.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1403100)the National Natural Science Foundation of China(Grant Nos.52388201,12361141820,and 12274249)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302400)。
文摘The electron-doped cuprate superconductor exhibits a unique electronic structure,where both electron and hole Fermi surface(FS)pockets coexist in the optimally doped(OP)region,while in the overdoped(OD)region there exists only a large hole FS pocket.It is therefore an intriguing question whether or not a p-n junction arises if the OD electron-doped cuprate interfaces with the OP compound.Here,we construct such an in-plane junction by selectively modulating the doping levels in thin films of La_(2-x)Ce_(x)CuO_(4)(LCCO)—a typical electron-doped cuprate.We find that the junction exhibits non-linear,asymmetricⅠ-Ⅴcharacteristics,which are consistent with those of a p-n semiconductor junction,across a wide temperature range from 250 K to 10 K,regardless of the Hall coefficient sign change or the superconducting transition.We attribute these features to a potential barrier formed at the junction,which is set by the band bending in both OD and OP LCCO.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1403903,2023YFA1406100,2018YFA0305800,and 2022YFA1204100)the National Natural Science Foundation of China(Grant Nos.12304075,11834014,61888102,and 12447101)+2 种基金Chinese Academy of Sciences(Grant Nos.XDB33010200 and 2022YSBR-048)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB28000000)the National Science and Technology Major Project(Grant No.2024ZD0300500)。
文摘The kagome lattice,naturally encompassing Dirac fermions,flat bands,and van Hove singularities,tends to intertwine exotic electronic states.Revealing the characteristics of its Fermi surface will help clarify the nature of the complex quantum phenomena in kagome material.Here we report the Fermi surface properties of the novel kagome metal CsTi_(3)Bi_(5)by the de Haas-van Alphen oscillations.The observed oscillations are clear and consist of six principal frequencies ranging from 214 T to 1013 T.The angular dependence of the frequency implies a quasi-two-dimensional electronic structure.In addition,the geometry phase corresponding to 281 T,determined by direct Lifshitz-Kosevich formula fitting,yields a value close toπ,which may indicate a band structure with nontrivial topological property.These results underscore the potential of CsTi_(3)Bi_(5)as a promising platform to explore the interplay between topological order,electronic nematicity,and superconductivity.
基金supported by the the National Key R&D Program of China(Grant Nos.2022YFA1604900 and 2023YFA1606703)the National Natural Science Foundation of China(Grant Nos.12025501,12435007,12405133,and 12347180)+1 种基金China Postdoctoral Science Foundation(Grant No.2023M740189)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233381).
文摘Hypernuclei,nuclei containing one or more hyperons,serve as unique laboratories for probing the non-perturbative quantum chromodynamics(QCD).Recent progress in hypernuclear physics,driven by advanced experimental techniques and theoretical innovations,is briefly reviewed with a focus on key findings and unresolved challenges,such as the precise determination of the hypertriton binding energy,investigations of charge symmetry breaking in mirror hypernuclei,and the search for exotic systems,including the neutral nnΛstate.Experimental breakthroughs,including invariant-mass analyses and femtoscopy studies in heavy-ion collisions,as well as high-resolutionγ-spectroscopy,have enabled precise studies of light hypernuclei and offered critical insights into the hyperon–nucleon interaction.Theoretical progress,including ab initio calculations based on chiral effective field theory and lattice QCD,has further enhanced our understanding of hyperon–nucleon and hyperon–hyperon interactions.
文摘采用900 e V能量的电子对直玻璃管进行了穿透实验,测量了玻璃管在倾角为–0.15°,–0.4°和–1.15°时充电过程角分布的时间演化,以及平衡态下出射电子能谱.发现穿透率随时间先下降后上升最后趋于平稳,下降的时间随倾角的增大而减小.当倾角为–0.4°和–1.15°时,电子穿透率下降到最低点时几乎看不到穿透电子(穿透率小于3‰),这种穿透率最低点状态保持时间随倾角增大而增大.穿透电子的角分布中心随着时间变化.在平稳状态时,发现穿透电子的能量损失随倾角增大而增大.采用蒙特卡罗方法模拟了电子经过管壁不同次数反射后的能谱,与测量能谱进行对比,发现–0.15°,–0.4°和–1.15°倾角下,穿透电子分别经历了管壁的一次、两次和三次与表面的反射过程.基于此,本文对电子穿越玻璃管的充电过程动力学给出了物理解释.实验结果和理论分析表明,在小倾角下玻璃管内能形成宏观负电荷累积,排斥后续电子形成反射,增加电子出射概率,这对应用绝缘体微结构,例如玻璃锥管产生稳定的电子微束具有重要的参考意义.
