High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission ph...High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission phase and identifying the HHG mechanism.However,achieving this feature by applying traditional two-beam far-field interferometry to solid materials remains challenging.In this study,we present a novel interferometric approach that utilizes a single laser beam to excite two ZnO microwires(MWs)simultaneously,thereby generating coherent high-harmonic sources that form interference fringes in the far-field region.We leverage the diameter-dependent field-enhancement effect in MWs to measure the intensity-dependent fringe shift,revealing that the intraband current mechanism dominates the below-bandgap harmonic,whereas the interband polarization mechanism dominates the above-bandgap harmonic.This study offers a robust method for measuring the dipole phase of solid-state HHG and inspires intensity-modulated high-harmonic applications in coherent imaging and microdevice design.展开更多
The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets ...The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.展开更多
For collisional merging fleld-reversed conflgurations(FRCs),it is desired to have both FRCs tuned to be approximately the same,as well as to optimize each FRC to have high temperature and high translation speed so as ...For collisional merging fleld-reversed conflgurations(FRCs),it is desired to have both FRCs tuned to be approximately the same,as well as to optimize each FRC to have high temperature and high translation speed so as to retain most of the equilibrium flux after traveling a distance to the middle plane for merging.The present study reports the experimental study of a single-translated FRC in the KMAX-FRC device with various diagnostics,including a triple probe,a bolometer,several magnetic probe arrays,and a novel 2 D internal magnetic probe array.According to the measurements conducted in the present study,a maximum toroidal magnetic fleld equal to~1/3 of the external magnetic fleld inside the FRC separatrix radius is observed,and the typical parameters of a single-translated FRC near the device’s mid-plane are ne~(2–4)×10^(19)m^(-3),T_(e)~8e V,T_(i)~5 e V,r_(s)~0.2 m,l_(s)~0.6 m andφ_(()p(RR))~0.2 m Wb.The 2 D magnetic topology measurement revealed,for the flrst time,the time evolution of the overall internal magnetic flelds of a single-translated FRC,and an optimized operation regime is given in the paper.展开更多
This paper presents results of hydrodynamic and heat transfer investigations in liquid metal flow affected by a longitudinal magnetic field in an inclined tube with respect to tokamak cooling problem.Experimental stud...This paper presents results of hydrodynamic and heat transfer investigations in liquid metal flow affected by a longitudinal magnetic field in an inclined tube with respect to tokamak cooling problem.Experimental study has been conducted for the tube with slope 1\5 to the horizon which corresponds to the conditions oflTER project in case the LM flow faced longitudinal MF.The results obtained in the regimes without the MF,may be interesting for the design of nuclear reactors cooled by LM and metallurgical processes.展开更多
Background The construction of China Spallation Neutron Source(CSNS)was started in 2011 and will be completed in 2018.The phase I CSNS facility consists of an 80MeV HLinac,a 1.6GeV Proton Rapid Cycling Synchrotron(RCS...Background The construction of China Spallation Neutron Source(CSNS)was started in 2011 and will be completed in 2018.The phase I CSNS facility consists of an 80MeV HLinac,a 1.6GeV Proton Rapid Cycling Synchrotron(RCS),two beam transport lines and a target station.Magnets in the RCS and transport lines should be measured before being installed in the tunnel.Method In this paper,a new hall probe measurement system is described.The design and performance of the hall probe measurement system is presented.Conclusions The measurement results meet the design requirements.Some key issues were solved in the process.展开更多
Skyrmions—topological spin/pseudospin textures—are natural charge excitations of quantum Hall(QH)ferromagnets.In a WSe_(2)-encapsulated bilayer graphene(BLG)heterostructure,we tune the valley-only Landau level(LL)cr...Skyrmions—topological spin/pseudospin textures—are natural charge excitations of quantum Hall(QH)ferromagnets.In a WSe_(2)-encapsulated bilayer graphene(BLG)heterostructure,we tune the valley-only Landau level(LL)crossings atν=±3 with an out-of-plane displacement field(D field)and use them as a platform to probe valley excitations.Activation gap measurements reveal a finite gap at degeneracy that rises sharply with D field near the crossing and exceeds the single-particle valley susceptibility,suggesting valley-skyrmion charge excitations.We quantify the skyrmion size and elucidate the mechanism governing its magnetic-field dependence.Similar behavior appears at valley-orbital and valley-spin entangled crossings(ν=±2 andν=±1,respectively).These results suggest controlled valley-skyrmion formation in BLG and open a route to engineering interacting multicomponent QH ferromagnets with tunable spin/pseudospin textures.展开更多
Supercritical water(SCW)fluidized bed reactors convert biomass to fuels without pollutants emission.In this work,experimental studies were carried out to investigate voidage distribution in an SCW fu-idized bed by cap...Supercritical water(SCW)fluidized bed reactors convert biomass to fuels without pollutants emission.In this work,experimental studies were carried out to investigate voidage distribution in an SCW fu-idized bed by capacitance probes.Quartz sands with different particle sizes were fluidized by SCW under system pressure of 20-27 MPa and temperature of 410-570℃.The effect of operation conditions on voidage distributions of the emulsion phase(e.g.averaged voidage and probability density)is discussed.A predicting correlation between voidage and superficial velocity in emulsion phase is proposed.The relative error of the correlation is within+25%.These research results provide useful guidance for the optimization of supercritical water gasification technology.展开更多
基金supported by the National Key R&D Program of China (Grant Nos.2023YFA1406801 and 2022YFA1604301)the National Natural Science Foundation of China (Grant Nos.12434013,12595343,12404393,and 12174011)。
文摘High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission phase and identifying the HHG mechanism.However,achieving this feature by applying traditional two-beam far-field interferometry to solid materials remains challenging.In this study,we present a novel interferometric approach that utilizes a single laser beam to excite two ZnO microwires(MWs)simultaneously,thereby generating coherent high-harmonic sources that form interference fringes in the far-field region.We leverage the diameter-dependent field-enhancement effect in MWs to measure the intensity-dependent fringe shift,revealing that the intraband current mechanism dominates the below-bandgap harmonic,whereas the interband polarization mechanism dominates the above-bandgap harmonic.This study offers a robust method for measuring the dipole phase of solid-state HHG and inspires intensity-modulated high-harmonic applications in coherent imaging and microdevice design.
文摘The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.
基金supported by the National Key R&D Program of China(No.2017YFE0301802)National Natural Science Foundation of China(No.12175226)。
文摘For collisional merging fleld-reversed conflgurations(FRCs),it is desired to have both FRCs tuned to be approximately the same,as well as to optimize each FRC to have high temperature and high translation speed so as to retain most of the equilibrium flux after traveling a distance to the middle plane for merging.The present study reports the experimental study of a single-translated FRC in the KMAX-FRC device with various diagnostics,including a triple probe,a bolometer,several magnetic probe arrays,and a novel 2 D internal magnetic probe array.According to the measurements conducted in the present study,a maximum toroidal magnetic fleld equal to~1/3 of the external magnetic fleld inside the FRC separatrix radius is observed,and the typical parameters of a single-translated FRC near the device’s mid-plane are ne~(2–4)×10^(19)m^(-3),T_(e)~8e V,T_(i)~5 e V,r_(s)~0.2 m,l_(s)~0.6 m andφ_(()p(RR))~0.2 m Wb.The 2 D magnetic topology measurement revealed,for the flrst time,the time evolution of the overall internal magnetic flelds of a single-translated FRC,and an optimized operation regime is given in the paper.
基金Item Sponsored by the RF President grant[MK-4882.2012.8]financial support of Ministry of Education[No16.518.11.7078]
文摘This paper presents results of hydrodynamic and heat transfer investigations in liquid metal flow affected by a longitudinal magnetic field in an inclined tube with respect to tokamak cooling problem.Experimental study has been conducted for the tube with slope 1\5 to the horizon which corresponds to the conditions oflTER project in case the LM flow faced longitudinal MF.The results obtained in the regimes without the MF,may be interesting for the design of nuclear reactors cooled by LM and metallurgical processes.
文摘Background The construction of China Spallation Neutron Source(CSNS)was started in 2011 and will be completed in 2018.The phase I CSNS facility consists of an 80MeV HLinac,a 1.6GeV Proton Rapid Cycling Synchrotron(RCS),two beam transport lines and a target station.Magnets in the RCS and transport lines should be measured before being installed in the tunnel.Method In this paper,a new hall probe measurement system is described.The design and performance of the hall probe measurement system is presented.Conclusions The measurement results meet the design requirements.Some key issues were solved in the process.
基金Peking University was supported by the National Key Research and Development Program of China(Grant No.2021YFA1401900)the National Natural Science Foundation of China(NSFC)(Grant No.12141001)+2 种基金Zhejiang University was supported by the NSFC(Grant Nos.12374047 and U23A2076)the Fundamental Research Funds for the Central Universities(Grant No.226-2025-00118)the National Key Research and Development Program of China(Grant No.2021YFA1401902 for Z.L.)。
文摘Skyrmions—topological spin/pseudospin textures—are natural charge excitations of quantum Hall(QH)ferromagnets.In a WSe_(2)-encapsulated bilayer graphene(BLG)heterostructure,we tune the valley-only Landau level(LL)crossings atν=±3 with an out-of-plane displacement field(D field)and use them as a platform to probe valley excitations.Activation gap measurements reveal a finite gap at degeneracy that rises sharply with D field near the crossing and exceeds the single-particle valley susceptibility,suggesting valley-skyrmion charge excitations.We quantify the skyrmion size and elucidate the mechanism governing its magnetic-field dependence.Similar behavior appears at valley-orbital and valley-spin entangled crossings(ν=±2 andν=±1,respectively).These results suggest controlled valley-skyrmion formation in BLG and open a route to engineering interacting multicomponent QH ferromagnets with tunable spin/pseudospin textures.
基金This work was financially supported by the National Key R&D Program of China(No.2020YFA0714400)the China National Funds for Distinguished Young Scientists(No.51925602).
文摘Supercritical water(SCW)fluidized bed reactors convert biomass to fuels without pollutants emission.In this work,experimental studies were carried out to investigate voidage distribution in an SCW fu-idized bed by capacitance probes.Quartz sands with different particle sizes were fluidized by SCW under system pressure of 20-27 MPa and temperature of 410-570℃.The effect of operation conditions on voidage distributions of the emulsion phase(e.g.averaged voidage and probability density)is discussed.A predicting correlation between voidage and superficial velocity in emulsion phase is proposed.The relative error of the correlation is within+25%.These research results provide useful guidance for the optimization of supercritical water gasification technology.
