Water electrolyzers play a crucial role in green hydrogen production.However,their efficiency and scalability are often compromised by bubble dynamics across various scales,from nanoscale to macroscale components.This...Water electrolyzers play a crucial role in green hydrogen production.However,their efficiency and scalability are often compromised by bubble dynamics across various scales,from nanoscale to macroscale components.This review explores multi-scale modeling as a tool to visualize multi-phase flow and improve mass transport in water electrolyzers.At the nanoscale,molecular dynamics(MD)simulations reveal how electrode surface features and wettability influence nanobubble nucleation and stability.Moving to the mesoscale,models such as volume of fluid(VOF)and lattice Boltzmann method(LBM)shed light on bubble transport in porous transport layers(PTLs).These insights inform innovative designs,including gradient porosity and hydrophilic-hydrophobic patterning,aimed at minimizing gas saturation.At the macroscale,VOF simulations elucidate two-phase flow regimes within channels,showing how flow field geometry and wettability affect bubble discharging.Moreover,artificial intelligence(AI)-driven surrogate models expedite the optimization process,allowing for rapid exploration of structural parameters in channel-rib flow fields and porous flow field designs.By integrating these approaches,we can bridge theoretical insights with experimental validation,ultimately enhancing water electrolyzer performance,reducing costs,and advancing affordable,high-efficiency hydrogen production.展开更多
A thermodynamically complete multi-phase equation of state(EOS)applicable to both dense and porous metals at wide ranges of temperature and pressure is constructed.A standard three-term decomposition of the Helmholtz ...A thermodynamically complete multi-phase equation of state(EOS)applicable to both dense and porous metals at wide ranges of temperature and pressure is constructed.A standard three-term decomposition of the Helmholtz free energy as a function of specific volume and temperature is presented,where the cold component models both compression and expansion states,the thermal ion component introduces the Debye approximation and melting entropy,and the thermal electron component employs the Thomas-Fermi-Kirzhnits(TFK)model.The porosity of materials is considered by introducing the dynamic porosity coefficientαand the constitutive P-αrelation,connecting the thermodynamic properties between dense and porous systems,allowing for an accurate description of the volume decrease caused by void collapse while maintaining the quasi-static thermodynamic properties of porous systems identical to the dense ones.These models enable the EOS applicable and robust at wide ranges of temperature,pressure and porosity.A systematic evaluation of the new EOS is conducted with aluminum(Al)as an example.300 K isotherm,shock Hugoniot,as well as melting curves of both dense and porous Al are calculated,which shows great agreements with experimental data and validates the effectiveness of the models and the accuracy of parameterizations.Notably,it is for the first time Hugoniot P-σcurves up to 10~6 GPa and shock melting behaviors of porous Al are derived from analytical EOS models,which predict much lower compression limit and shock melting temperatures than those of dense Al.展开更多
Based on the theory of superimposed deformation and the regional tectonic background,the multi-phase non-coaxial superimposed structures in Junggar Basin were systematically analyzed using seismic interpretation,field...Based on the theory of superimposed deformation and the regional tectonic background,the multi-phase non-coaxial superimposed structures in Junggar Basin were systematically analyzed using seismic interpretation,field outcrop observation,and paleo-stress field recovery methods according to the characteristics of the current tectonic framework.Moreover,the tectonic evolution process of the basin was reconstructed using sandbox analogue modelling technology.The results showed that the study area has experienced five phases of non-coaxial deformation with superimposition:The first phase of deformation(D1)is characterized by NNE-SSW extension during late Carboniferous to early Permian,which formed large graben,half graben and other extensional structure style around the basin.The second phase of deformation(D2)is represented by NE-SW compression during the middle to late Permian,and it comprised numerous contraction structures that developed based on D1.The basic form of the entire basin is alternating uplift and depression.The third phase of deformation(D3)is the NW-SE transpressional strike-slip in the Triassic-Jurassic,which produced numerous strike-slip structural styles in the middle part of the basin.The fourth phase of deformation(D4)is the uniform sedimentation during Cretaceous,and the fifth phase(D5)is the compression along NNE-SSW due to the North Tianshan northward thrust,which produced three rows of fold thrust belts and tear faults in the front of the mountain in the southern margin of the basin.The newly established three-dimensional tectonic evolution model shows that,based on the large number of NW-trending grabens and half grabens in the Carboniferous basement of Junggar Basin,multiple level NE trending uplifts have formed with the joint superposition of the late structural inversion and multiple stress fields.This has resulted in the current tectonic units of alternating uplifts and depressions in different directions in the study area.展开更多
A parametrization of density matrices of ddimensions in terms of the raising J+and lowering J−angular momentum operators is established together with an implicit connection with the generalized Bloch-GellMann paramete...A parametrization of density matrices of ddimensions in terms of the raising J+and lowering J−angular momentum operators is established together with an implicit connection with the generalized Bloch-GellMann parameters. A general expression for the density matrix of the composite system of angular momenta j1and j2is obtained. In this matrix representation violations of the Bell-Clauser-Horne-Shimony-Holt inequalities are established for the X-states of a qubit-qubit, pure and mixed, composite system, as well as for a qubit-qutrit density matrix. In both cases maximal violation of the Bell inequalities can be reached, i.e., the Cirel’son limit. A correlation between the entanglement measure and a strong violation of the Bell factor is also given. For the qubit-qutrit composite system a time-dependent convex combination of the density matrix of the eigenstates of a two-particle Hamiltonian system is used to determine periodic maximal violations of the Bell’s inequality.展开更多
By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integra...By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integral. The effect of noncanonical strength, off-axis distance and vortex sign on spatial correlation singularities in far field is stressed. Furthermore, far-field OAM spectra and densities are also investigated, and the OAM detection and crosstalk probabilities are discussed. The results show that the number of dislocations of SCS always equals the sum of absolute values of topological charges for canonical or noncanonical vortex pairs. Although the sum of the product of each OAM mode and its power weight equals the algebraic sum of topological charges for canonical vortex pairs, the relationship no longer holds in the noncanonical case except for opposite-charge vortex pairs. The changes of off-axis distance, noncanonical strength or coherence length can lead to a more dominant power in adjacent mode than that in center detection mode, which also indicates that crosstalk probabilities of adjacent modes exceed the center detection probability. This work may provide potential applications in OAM-based optical communication, imaging, sensing and computing.展开更多
We present the first theoretical study on heavy-flavor jet angularities(λ_(α)^(κ))in Pb+Pb collisions at√SNN=5.02 Te V.The initial production of heavy-flavor jets was carried out using the POWHEG+PYTHIA8 prescript...We present the first theoretical study on heavy-flavor jet angularities(λ_(α)^(κ))in Pb+Pb collisions at√SNN=5.02 Te V.The initial production of heavy-flavor jets was carried out using the POWHEG+PYTHIA8 prescription.In contrast,the SHELL transport model describes jet evolution in the quark-gluon plasma(QGP).In p+p collisions,we observed narrower angularity distributions for D ^(0)-tagged jets than for inclusive jets,consistent with the ALICE preliminary results.We then demonstrate that jet quenching in the QGP slightly widens the angularity distribution of D ^(0)-tagged jets in Pb+Pb collisions relative to that in p+p collisions for a jet transverse momentum of 10<pch/T,jet<20 Ge V/c.In contrast,the angularity distributions of the inclusive and D ^(0)-tagged jets become narrower in Pb+Pb collisions relative to p+p atpch/T,jet>20 Ge V/c because of the strong influence of selection bias.Additionally,by comparing the average angularities<λ_(α)^(κ)>of the inclusive,D ^(0)-tagged,and B ^(0)-tagged jets with varyingαandκ,we show that the larger the quark mass,the lower the jet’s<λ_(α)^(κ)>values are.As a result of the slenderer initial distribution,we predict that compared with inclusive jets,heavy-flavor jets,especially B~0-tagged ones,will suffer stronger modifications of<λ_(α)^(κ)>in Pb+Pb relative to p+p at 10<pch/T,jet<20 Ge V/c.For a larger jet radius,a more significant broadening of the jet angularities was predicted because of the enhanced contribution of the wide-angle particles.展开更多
In the burgeoning field of light-matter interactions,angular momentum has emerged as a pivotal factor,driving innovative research directions.This study delves into the interaction dynamics between vortex lights and an...In the burgeoning field of light-matter interactions,angular momentum has emerged as a pivotal factor,driving innovative research directions.This study delves into the interaction dynamics between vortex lights and an electromagnetically induced transparency(EIT)medium,with a primary focus on elucidating the underlying mechanism of angular momentum transfer.Through comprehensive theoretical analysis and numerical simulations,it is demonstrated that when the probe field carries orbital angular momentum(OAM),the dispersion and absorption characteristics of the EIT medium undergo periodic modulation.This modulation is intricately determined by the azimuthal phase and topological charge of the beam.Notably,the OAM in the driving field exerts no such influence on the medium’s properties.Leveraging vortex phase plates(VPPs)or spatial light modulators(SLMs)to manipulate the tunable OAM enables dynamic control over the EIT effect.This breakthrough not only deepens our understanding of light-matter interactions at the quantum level but also unlocks new avenues for high-dimensional quantum information processing and advanced optical communication technologies.展开更多
The experimental realization of observable phonon angular momentum(PAM)in feasible systems using relatively simple methods remains a critical challenge.Motivated by the chiral-induced spin selectivity effect,this stud...The experimental realization of observable phonon angular momentum(PAM)in feasible systems using relatively simple methods remains a critical challenge.Motivated by the chiral-induced spin selectivity effect,this study explores the generation of PAM during the transport of electrically driven polarons along a singlestranded helix structure.We demonstrate that the motion of a polaron under an applied electric field inherently induces a finite PAM,exhibiting drift-locked behavior between the PAM and the polaron.By analyzing the time evolution of PAM distribution at each site,we identify the observed PAM as a natural consequence of coherent superposition between lattice waves,in which the chiral structure selectively determines the direction of induced PAM.Furthermore,we examine the roles of two types of electron-phonon interactions and structural periodicity in modulating PAM.These findings highlight the potential of chiral molecules as platforms for PAM generation and offer new insights into developing phonon-spin-based devices for information processing and transmission.展开更多
The low ductility and strong mechanical anisotropy of wrought magnesium alloys have hindered their further processing and application.In this study,AZ31 magnesium alloy sheet was prepared by a new asymmetrical angular...The low ductility and strong mechanical anisotropy of wrought magnesium alloys have hindered their further processing and application.In this study,AZ31 magnesium alloy sheet was prepared by a new asymmetrical angular rolling(AAR)process,compared with conventional symmetrical rolling(SR)process and asymmetrical rolling(ASR)process.The effects of three rolling processes on the microstructure,texture and mechanical properties of the alloy sheets were systematically studied.The results show that the AAR sheet exhibits excellent mechanical properties compared to other two rolling processes.It not only achieves the highest ductility of 17.9%,17.9%,and 18.5% in the three directions,but also has the lowest mechanical anisotropy values for yield strength,ultimate tensile strength and elongation.The AAR process significantly reduces the anisotropy of the material by achieving the smallest average grain size of 4.93μm and the most homogeneous grain size distribution.Introduced bi-directional asymmetric shear stresses randomizes grain orientation and activates the non-basal slip system,which also significantly reduces the anisotropy.In addition,the tensile twinning mechanism dominates during the AAR process,which contributes to texture weakening and the activation of the non-basal slip system.Through the synergy of these mechanisms,the AAR sheet is characterized by high ductility and low anisotropy.展开更多
Optical phased arrays(OPAs)are crucial in beam-steering applications,particularly as transmitters in light detection and ranging and free-space communication systems.In this paper,we demonstrate a on-chip OPA that emi...Optical phased arrays(OPAs)are crucial in beam-steering applications,particularly as transmitters in light detection and ranging and free-space communication systems.In this paper,we demonstrate a on-chip OPA that emits multiple orbital angular momentum(OAM)beams in different directions,each carrying unique topological charges.By superimposing a forked 1×3 Dammann grating on the grating array,six OAM beams with topological charges of ±3,±4,and±5 can be radiated from the OPA region.The OPA chip was fabricated on a silicon-on-insulator platform,and the simultaneous generation of multiple OAM beams was realized experimentally.The directions of these vortices can be steered by adjusting the wavelength of the input light and the bias voltages of the phase shifters,enabling a remarkable field of view(FOV)of 140 deg×40 deg within a 120-nm wavelength range.We pave the way for developing systems with ultrawide FOVs,improving the resolution of remote sensing and broadening the possibilities of free-space communications.展开更多
We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite ...We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite OAM state.By calculating the difference between the petal rotation angle without/with the object,the thickness information of the object,and then the flatness information,can be evaluated.Furthermore,the direction of the object’s flatness can be determined by the petal’s clockwise/counterclockwise rotation.We theoretically analyze the relationship between the object’s thickness and petal rotation angle,and verify the proposed method by experiment.The experimental results show that the proposed method is a high precision flatness measurement and can obtain the convex/concave property of the flatness.For the 1.02 mm glass sample,the mean deviation of the flatness is 1.357×10^(-8) and the variance is 0.242×10^(-16).For the 0.50 mm glass sample,the mean deviation of the flatness is 1.931×10^(-8) and the variance is 2.405×10^(-16).Two different topological charges are adopted for the 2.00 mm glass sample,and their flatness deviations are 0.239×10^(-8)(ℓ=1)and 0.246×10^(-8)(ℓ=2),where their variances are 0.799×10^(-18)(ℓ=1)and 0.775×10^(-18)(ℓ=2),respectively.It is shown that the flatness measured by the proposed method is the same for the same sample when different topological charges are used.All results indicate that the proposed method may provide a high flatness measurement,and will be a promising way to measure the flatness.展开更多
The decoherence of high-dimensional orbital angular momentum(OAM)entanglement in the weak scintillation regime has been investigated.In this study,we simulate atmospheric turbulence by utilizing a multiple-phase scree...The decoherence of high-dimensional orbital angular momentum(OAM)entanglement in the weak scintillation regime has been investigated.In this study,we simulate atmospheric turbulence by utilizing a multiple-phase screen imprinted with anisotropic non-Kolmogorov turbulence.The entanglement negativity and fidelity are introduced to quantify the entanglement of a high-dimensional OAM state.The numerical evaluation results indicate that entanglement negativity and fidelity last longer for a high-dimensional OAM state when the azimuthal mode has a lower value.Additionally,the evolution of higher-dimensional OAM entanglement is significantly influenced by OAM beam parameters and turbulence parameters.Compared to isotropic atmospheric turbulence,anisotropic turbulence has a lesser influence on highdimensional OAM entanglement.展开更多
Quantum secure direct communication(QSDC) is a communication method based on quantum mechanics and it is used to transmit secret messages. Unlike quantum key distribution, secret messages can be transmitted directly o...Quantum secure direct communication(QSDC) is a communication method based on quantum mechanics and it is used to transmit secret messages. Unlike quantum key distribution, secret messages can be transmitted directly on a quantum channel with QSDC. Higher channel capacity and noise suppression capabilities are key to achieving longdistance quantum communication. Here, we report a continuous-variable QSDC scheme based on mask-coding and orbital angular momentum, in which the mask-coding is employed to protect the security of the transmitting messages and to suppress the influence of excess noise. The combination of orbital angular momentum and information block transmission effectively improves the secrecy capacity. In the 800 information blocks ×1310 bits length 10-km experiment, the results show a statistical average bit error rate of 0.38%, a system excess noise value of 0.0184 SNU, and a final secrecy capacity of 6.319×10~6 bps. Therefore, this scheme reduces error bits while increasing secrecy capacity, providing a solution for long-distance large-scale quantum communication, which is capable of transmitting text, images and other information of reasonable size.展开更多
In this study,the interaction between deformation and precipitates during multiple equal channel angular pressing(ECAP)deformations and inter-pass aging combination and its effect on the mechanical properties of 7050 ...In this study,the interaction between deformation and precipitates during multiple equal channel angular pressing(ECAP)deformations and inter-pass aging combination and its effect on the mechanical properties of 7050 aluminum alloy are studied.The result show that ECAP induces numerous substructures and dislocations,effectively promoting the precipitation of theηʹphase exhibiting a bimodal structure during inter-pass aging.Following inter-pass aging and subsequent ECAP,the decrease in grain size(4.8μm)is together with the increase in dislocation density(1.24×10^(15) m^(−2))due to the pinning effect of the precipitated phase.Simultaneously,the dislocation motion causes the second phase particles to become even finer and more diffuse.The synergistic effects of precipitation strengthening,fine grain strengthening,and dislocation strengthening collectively enhance the high strength of aluminum alloys,with ultimate tensile strength and yield strength reaching approximately 610 and 565 MPa,respectively.Meanwhile,ductility remains largely unchanged,primarily due to coordinated grain boundary sliding and the uniform and fine dispersion of second phase particles.展开更多
The angular deviations and influential factors of Burgers orientation relationship(BOR)in Ti-6Al-4V and Ti-6.5Al-2Zr-1Mo-1V alloys were investigated by optical microscope(OM),scanning electron microscope(SEM),electron...The angular deviations and influential factors of Burgers orientation relationship(BOR)in Ti-6Al-4V and Ti-6.5Al-2Zr-1Mo-1V alloys were investigated by optical microscope(OM),scanning electron microscope(SEM),electron backscattered diffraction(EBSD)and high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM).A spherical center angle model was introduced to calculate the angular deviations from the ideal BOR between α and β phases.The results indicate thatαand β phases in α colonies of both alloys do not follow the perfect BOR during β→α phase transformation,with angular deviation values less than 3°.Through detailed microstructure characterization,the broad face of α/β interfaces viewed along two different electron incident directions shows the atomic-scale terrace-ledge structure,and many dislocations are observed within α and β phases and near α/β interfaces.Further studies reveal that the angular deviations mainly originate from lattice distortions caused by dislocations in α and β phases and lattice mismatches at α/β interfaces.展开更多
Optical orbital angular momentum(OAM)mode multiplexing has emerged as a promising technique for boosting communication capacity.However,most existing studies have concentrated on channel(de)-multiplexing,overlooking t...Optical orbital angular momentum(OAM)mode multiplexing has emerged as a promising technique for boosting communication capacity.However,most existing studies have concentrated on channel(de)-multiplexing,overlooking the critical aspect of channel routing.This challenge involves the reallocation of multiplexed OAM modes across both spatial and temporal domains—a vital step for developing versatile communication networks.To address this gap,we introduce a novel approach based on the time evolution of OAM modes,utilizing the orthogonal conversion and diffractive modulation capabilities of unitary transformations.This approach facilitates high-dimensional orthogonal transformations of OAM mode vectors,altering both the propagation direction and the spatial location.Using Fresnel diffraction matrices as unitary operators,it manipulates the spatial locations of light beams during transmission,breaking the propagation invariance and enabling temporal evolution.As a demonstration,we have experimentally implemented the deep routing of four OAM modes within two distinct time sequences.Achieving an average diffraction efficiency above 78.31%,we have successfully deep-routed 4.69 Tbit-s^(-1)quadrature phase-shift keying(QPSK)signals carried by four multiplexed OAM channels,with a bit error rate below 10^(-6).These results underscore the efficacy of our routing strategy and its promising prospects for practical applications.展开更多
We demonstrate an effective and optimal strategy for generating spatially resolved longitudinal spin angular momentum(LSAM)in optical tweezers by tightly focusing the first-order spirally polarized vector(SPV)beams wi...We demonstrate an effective and optimal strategy for generating spatially resolved longitudinal spin angular momentum(LSAM)in optical tweezers by tightly focusing the first-order spirally polarized vector(SPV)beams with zero intrinsic angular momentum into a refractive index stratified medium.The stratified medium gives rise to a spherically aberrated intensity profile near the focal region of the optical tweezers,with off-axis intensity lobes in the radial direction possessing opposite LSAM(helicities corresponding toσ=+1 and−1)compared to the beam center.We trap mesoscopic birefringent particles in an off-axis intensity lobe as well as at the beam center by modifying the trapping plane and observe particles spinning in opposite directions depending on their location.The direction of rotation depends on the particle size with larger particles spinning either clockwise or anticlockwise depending on the direction of spirality of the polarization of the SPV beam after tight focusing,while smaller particles spin in both directions depending on their spatial locations.Numerical simulations support our experimental observations.Our results introduce new avenues in spin-orbit optomechanics to facilitate novel yet straightforward avenues for exotic and complex particle manipulation in optical tweezers.展开更多
To investigate the effect of microstructure evolution on corrosion behavior and strengthening mechanism of Mg-1Zn-1Ca(wt.%)alloys,as-cast Mg-1Zn-1Ca alloys were performed by equal channel angular pressing(ECAP)with 1 ...To investigate the effect of microstructure evolution on corrosion behavior and strengthening mechanism of Mg-1Zn-1Ca(wt.%)alloys,as-cast Mg-1Zn-1Ca alloys were performed by equal channel angular pressing(ECAP)with 1 and 4 passes.The corrosion behavior and mechanical properties of alloys were investigated by optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),electrochemical tests,immersion tests and tensile tests.The results showed that mechanical properties improved after ECAP 1 pass;however,the corrosion resistance deteriorated due to high-density dislocations and fragmented secondary phases by ECAP.In contrast,synchronous improvement in the mechanical properties and corrosion resistance was achieved though grain refinement after ECAP 4 passes;fine grains led to a significant improvement in the yield strength,ultimate tensile strength,elongation,and corrosion rate of 103 MPa,223 MPa,30.5%,and 1.5843 mm/a,respectively.The enhanced corrosion resistance was attributed to the formation of dense corrosion product films by finer grains and the barrier effect by high-density grain boundaries.These results indicated that Mg-1Zn-1Ca alloy has a promising potential for application in biomedical materials.展开更多
This letter demonstrates an experimental approach to measuring the angular-momentum-resolved population of excited states in laser-produced argon ions.By measuring the spectra of free induction decay emissions corresp...This letter demonstrates an experimental approach to measuring the angular-momentum-resolved population of excited states in laser-produced argon ions.By measuring the spectra of free induction decay emissions corresponding to the resonant transitions between Rydberg states,the relative population of the Rydberg states is obtained with known Einstein A-coefficients.This study deepens the mechanistic understanding of coherent dynamics in laser-driven ionic excited states,and establishes experimental benchmarks essential for validating and refining advanced quantum kinetic models in strong-field physics.展开更多
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.15308024)a grant from Research Centre for Carbon-Strategic Catalysis,The Hong Kong Polytechnic University(CE2X).
文摘Water electrolyzers play a crucial role in green hydrogen production.However,their efficiency and scalability are often compromised by bubble dynamics across various scales,from nanoscale to macroscale components.This review explores multi-scale modeling as a tool to visualize multi-phase flow and improve mass transport in water electrolyzers.At the nanoscale,molecular dynamics(MD)simulations reveal how electrode surface features and wettability influence nanobubble nucleation and stability.Moving to the mesoscale,models such as volume of fluid(VOF)and lattice Boltzmann method(LBM)shed light on bubble transport in porous transport layers(PTLs).These insights inform innovative designs,including gradient porosity and hydrophilic-hydrophobic patterning,aimed at minimizing gas saturation.At the macroscale,VOF simulations elucidate two-phase flow regimes within channels,showing how flow field geometry and wettability affect bubble discharging.Moreover,artificial intelligence(AI)-driven surrogate models expedite the optimization process,allowing for rapid exploration of structural parameters in channel-rib flow fields and porous flow field designs.By integrating these approaches,we can bridge theoretical insights with experimental validation,ultimately enhancing water electrolyzer performance,reducing costs,and advancing affordable,high-efficiency hydrogen production.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12205023,U2230401,12374056,U23A20537,11904027)。
文摘A thermodynamically complete multi-phase equation of state(EOS)applicable to both dense and porous metals at wide ranges of temperature and pressure is constructed.A standard three-term decomposition of the Helmholtz free energy as a function of specific volume and temperature is presented,where the cold component models both compression and expansion states,the thermal ion component introduces the Debye approximation and melting entropy,and the thermal electron component employs the Thomas-Fermi-Kirzhnits(TFK)model.The porosity of materials is considered by introducing the dynamic porosity coefficientαand the constitutive P-αrelation,connecting the thermodynamic properties between dense and porous systems,allowing for an accurate description of the volume decrease caused by void collapse while maintaining the quasi-static thermodynamic properties of porous systems identical to the dense ones.These models enable the EOS applicable and robust at wide ranges of temperature,pressure and porosity.A systematic evaluation of the new EOS is conducted with aluminum(Al)as an example.300 K isotherm,shock Hugoniot,as well as melting curves of both dense and porous Al are calculated,which shows great agreements with experimental data and validates the effectiveness of the models and the accuracy of parameterizations.Notably,it is for the first time Hugoniot P-σcurves up to 10~6 GPa and shock melting behaviors of porous Al are derived from analytical EOS models,which predict much lower compression limit and shock melting temperatures than those of dense Al.
基金supported by the National Natural Science Foundation of China,(Grant No.42072144)Shengli Oilfield,SINOPEC,China(Nos.30200018-21-ZC0613-0030 and 30200018-20-ZC0613-0116)。
文摘Based on the theory of superimposed deformation and the regional tectonic background,the multi-phase non-coaxial superimposed structures in Junggar Basin were systematically analyzed using seismic interpretation,field outcrop observation,and paleo-stress field recovery methods according to the characteristics of the current tectonic framework.Moreover,the tectonic evolution process of the basin was reconstructed using sandbox analogue modelling technology.The results showed that the study area has experienced five phases of non-coaxial deformation with superimposition:The first phase of deformation(D1)is characterized by NNE-SSW extension during late Carboniferous to early Permian,which formed large graben,half graben and other extensional structure style around the basin.The second phase of deformation(D2)is represented by NE-SW compression during the middle to late Permian,and it comprised numerous contraction structures that developed based on D1.The basic form of the entire basin is alternating uplift and depression.The third phase of deformation(D3)is the NW-SE transpressional strike-slip in the Triassic-Jurassic,which produced numerous strike-slip structural styles in the middle part of the basin.The fourth phase of deformation(D4)is the uniform sedimentation during Cretaceous,and the fifth phase(D5)is the compression along NNE-SSW due to the North Tianshan northward thrust,which produced three rows of fold thrust belts and tear faults in the front of the mountain in the southern margin of the basin.The newly established three-dimensional tectonic evolution model shows that,based on the large number of NW-trending grabens and half grabens in the Carboniferous basement of Junggar Basin,multiple level NE trending uplifts have formed with the joint superposition of the late structural inversion and multiple stress fields.This has resulted in the current tectonic units of alternating uplifts and depressions in different directions in the study area.
文摘A parametrization of density matrices of ddimensions in terms of the raising J+and lowering J−angular momentum operators is established together with an implicit connection with the generalized Bloch-GellMann parameters. A general expression for the density matrix of the composite system of angular momenta j1and j2is obtained. In this matrix representation violations of the Bell-Clauser-Horne-Shimony-Holt inequalities are established for the X-states of a qubit-qubit, pure and mixed, composite system, as well as for a qubit-qutrit density matrix. In both cases maximal violation of the Bell inequalities can be reached, i.e., the Cirel’son limit. A correlation between the entanglement measure and a strong violation of the Bell factor is also given. For the qubit-qutrit composite system a time-dependent convex combination of the density matrix of the eigenstates of a two-particle Hamiltonian system is used to determine periodic maximal violations of the Bell’s inequality.
文摘By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integral. The effect of noncanonical strength, off-axis distance and vortex sign on spatial correlation singularities in far field is stressed. Furthermore, far-field OAM spectra and densities are also investigated, and the OAM detection and crosstalk probabilities are discussed. The results show that the number of dislocations of SCS always equals the sum of absolute values of topological charges for canonical or noncanonical vortex pairs. Although the sum of the product of each OAM mode and its power weight equals the algebraic sum of topological charges for canonical vortex pairs, the relationship no longer holds in the noncanonical case except for opposite-charge vortex pairs. The changes of off-axis distance, noncanonical strength or coherence length can lead to a more dominant power in adjacent mode than that in center detection mode, which also indicates that crosstalk probabilities of adjacent modes exceed the center detection probability. This work may provide potential applications in OAM-based optical communication, imaging, sensing and computing.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030008)the National Natural Science Foundation of China(Grant Nos.11935007 and 12035007)+1 种基金supported by the Open Foundation of the Key Laboratory of Quark and Lepton Physics(MOE)(Grant No.QLPL2023P01)the Talent Scientific Star-up Foundation of the China Three Gorges University(CTGU)(Grant No.2024RCKJ013)。
文摘We present the first theoretical study on heavy-flavor jet angularities(λ_(α)^(κ))in Pb+Pb collisions at√SNN=5.02 Te V.The initial production of heavy-flavor jets was carried out using the POWHEG+PYTHIA8 prescription.In contrast,the SHELL transport model describes jet evolution in the quark-gluon plasma(QGP).In p+p collisions,we observed narrower angularity distributions for D ^(0)-tagged jets than for inclusive jets,consistent with the ALICE preliminary results.We then demonstrate that jet quenching in the QGP slightly widens the angularity distribution of D ^(0)-tagged jets in Pb+Pb collisions relative to that in p+p collisions for a jet transverse momentum of 10<pch/T,jet<20 Ge V/c.In contrast,the angularity distributions of the inclusive and D ^(0)-tagged jets become narrower in Pb+Pb collisions relative to p+p atpch/T,jet>20 Ge V/c because of the strong influence of selection bias.Additionally,by comparing the average angularities<λ_(α)^(κ)>of the inclusive,D ^(0)-tagged,and B ^(0)-tagged jets with varyingαandκ,we show that the larger the quark mass,the lower the jet’s<λ_(α)^(κ)>values are.As a result of the slenderer initial distribution,we predict that compared with inclusive jets,heavy-flavor jets,especially B~0-tagged ones,will suffer stronger modifications of<λ_(α)^(κ)>in Pb+Pb relative to p+p at 10<pch/T,jet<20 Ge V/c.For a larger jet radius,a more significant broadening of the jet angularities was predicted because of the enhanced contribution of the wide-angle particles.
文摘In the burgeoning field of light-matter interactions,angular momentum has emerged as a pivotal factor,driving innovative research directions.This study delves into the interaction dynamics between vortex lights and an electromagnetically induced transparency(EIT)medium,with a primary focus on elucidating the underlying mechanism of angular momentum transfer.Through comprehensive theoretical analysis and numerical simulations,it is demonstrated that when the probe field carries orbital angular momentum(OAM),the dispersion and absorption characteristics of the EIT medium undergo periodic modulation.This modulation is intricately determined by the azimuthal phase and topological charge of the beam.Notably,the OAM in the driving field exerts no such influence on the medium’s properties.Leveraging vortex phase plates(VPPs)or spatial light modulators(SLMs)to manipulate the tunable OAM enables dynamic control over the EIT effect.This breakthrough not only deepens our understanding of light-matter interactions at the quantum level but also unlocks new avenues for high-dimensional quantum information processing and advanced optical communication technologies.
基金supported by the National Key R&D Project from Ministry of Science and Technology of China(Grant No.2022YFA1203100)the National Natural Science Foundation of China(Grant No.52350088)+1 种基金the Department of Science and Technology of Jiangsu Province(Grant No.BK20220032)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX241797)。
文摘The experimental realization of observable phonon angular momentum(PAM)in feasible systems using relatively simple methods remains a critical challenge.Motivated by the chiral-induced spin selectivity effect,this study explores the generation of PAM during the transport of electrically driven polarons along a singlestranded helix structure.We demonstrate that the motion of a polaron under an applied electric field inherently induces a finite PAM,exhibiting drift-locked behavior between the PAM and the polaron.By analyzing the time evolution of PAM distribution at each site,we identify the observed PAM as a natural consequence of coherent superposition between lattice waves,in which the chiral structure selectively determines the direction of induced PAM.Furthermore,we examine the roles of two types of electron-phonon interactions and structural periodicity in modulating PAM.These findings highlight the potential of chiral molecules as platforms for PAM generation and offer new insights into developing phonon-spin-based devices for information processing and transmission.
基金financially supported by Fund Program for Research Project Supported by Shanxi Scholarship Council of China(No.20230007)(jie bang guashuai)‘Open Competition’project:Preparation technology and product development of key new materials for 5G communication(No.20231207)+3 种基金Projects of the Patent Conversion Program in Shanxi Province(No.20241140)Research and Innovation Projects in Shanxi Province(No.2023KY633)Graduate Education Innovation Project at Taiyuan University of Science and Technology(No.BY2023003)Basic Research Plan Free Exploration of General Program in Shanxi Province(No.202303021221143).
文摘The low ductility and strong mechanical anisotropy of wrought magnesium alloys have hindered their further processing and application.In this study,AZ31 magnesium alloy sheet was prepared by a new asymmetrical angular rolling(AAR)process,compared with conventional symmetrical rolling(SR)process and asymmetrical rolling(ASR)process.The effects of three rolling processes on the microstructure,texture and mechanical properties of the alloy sheets were systematically studied.The results show that the AAR sheet exhibits excellent mechanical properties compared to other two rolling processes.It not only achieves the highest ductility of 17.9%,17.9%,and 18.5% in the three directions,but also has the lowest mechanical anisotropy values for yield strength,ultimate tensile strength and elongation.The AAR process significantly reduces the anisotropy of the material by achieving the smallest average grain size of 4.93μm and the most homogeneous grain size distribution.Introduced bi-directional asymmetric shear stresses randomizes grain orientation and activates the non-basal slip system,which also significantly reduces the anisotropy.In addition,the tensile twinning mechanism dominates during the AAR process,which contributes to texture weakening and the activation of the non-basal slip system.Through the synergy of these mechanisms,the AAR sheet is characterized by high ductility and low anisotropy.
基金supported by the National Natural Science Foundation of China(Grant Nos.62341508 and 62105203)the Shanghai Municipal Science and Technology Major Project(Grant No.BH0300071).
文摘Optical phased arrays(OPAs)are crucial in beam-steering applications,particularly as transmitters in light detection and ranging and free-space communication systems.In this paper,we demonstrate a on-chip OPA that emits multiple orbital angular momentum(OAM)beams in different directions,each carrying unique topological charges.By superimposing a forked 1×3 Dammann grating on the grating array,six OAM beams with topological charges of ±3,±4,and±5 can be radiated from the OPA region.The OPA chip was fabricated on a silicon-on-insulator platform,and the simultaneous generation of multiple OAM beams was realized experimentally.The directions of these vortices can be steered by adjusting the wavelength of the input light and the bias voltages of the phase shifters,enabling a remarkable field of view(FOV)of 140 deg×40 deg within a 120-nm wavelength range.We pave the way for developing systems with ultrawide FOVs,improving the resolution of remote sensing and broadening the possibilities of free-space communications.
基金supported by the National Natural Science Foundation of China(Grant No.62375140)the Open Research Fund of National Laboratory of Solid State Microstructures(Grant No.M36055).
文摘We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite OAM state.By calculating the difference between the petal rotation angle without/with the object,the thickness information of the object,and then the flatness information,can be evaluated.Furthermore,the direction of the object’s flatness can be determined by the petal’s clockwise/counterclockwise rotation.We theoretically analyze the relationship between the object’s thickness and petal rotation angle,and verify the proposed method by experiment.The experimental results show that the proposed method is a high precision flatness measurement and can obtain the convex/concave property of the flatness.For the 1.02 mm glass sample,the mean deviation of the flatness is 1.357×10^(-8) and the variance is 0.242×10^(-16).For the 0.50 mm glass sample,the mean deviation of the flatness is 1.931×10^(-8) and the variance is 2.405×10^(-16).Two different topological charges are adopted for the 2.00 mm glass sample,and their flatness deviations are 0.239×10^(-8)(ℓ=1)and 0.246×10^(-8)(ℓ=2),where their variances are 0.799×10^(-18)(ℓ=1)and 0.775×10^(-18)(ℓ=2),respectively.It is shown that the flatness measured by the proposed method is the same for the same sample when different topological charges are used.All results indicate that the proposed method may provide a high flatness measurement,and will be a promising way to measure the flatness.
基金supported by the Project of the Hubei Provincial Department of Science and Technology(Grant Nos.2022CFB957,2022CFB475)the National Natural Science Foundation of China(Grant No.11847118)。
文摘The decoherence of high-dimensional orbital angular momentum(OAM)entanglement in the weak scintillation regime has been investigated.In this study,we simulate atmospheric turbulence by utilizing a multiple-phase screen imprinted with anisotropic non-Kolmogorov turbulence.The entanglement negativity and fidelity are introduced to quantify the entanglement of a high-dimensional OAM state.The numerical evaluation results indicate that entanglement negativity and fidelity last longer for a high-dimensional OAM state when the azimuthal mode has a lower value.Additionally,the evolution of higher-dimensional OAM entanglement is significantly influenced by OAM beam parameters and turbulence parameters.Compared to isotropic atmospheric turbulence,anisotropic turbulence has a lesser influence on highdimensional OAM entanglement.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62071381 and 62301430)Shaanxi Fundamental Science Research Project for Mathematics and Physics (Grant No. 23JSY014)+1 种基金Scientific Research Plan Project of Shaanxi Education Department (Natural Science Special Project (Grant No. 23JK0680)Young Talent Fund of Xi’an Association for Science and Technology (Grant No. 959202313011)。
文摘Quantum secure direct communication(QSDC) is a communication method based on quantum mechanics and it is used to transmit secret messages. Unlike quantum key distribution, secret messages can be transmitted directly on a quantum channel with QSDC. Higher channel capacity and noise suppression capabilities are key to achieving longdistance quantum communication. Here, we report a continuous-variable QSDC scheme based on mask-coding and orbital angular momentum, in which the mask-coding is employed to protect the security of the transmitting messages and to suppress the influence of excess noise. The combination of orbital angular momentum and information block transmission effectively improves the secrecy capacity. In the 800 information blocks ×1310 bits length 10-km experiment, the results show a statistical average bit error rate of 0.38%, a system excess noise value of 0.0184 SNU, and a final secrecy capacity of 6.319×10~6 bps. Therefore, this scheme reduces error bits while increasing secrecy capacity, providing a solution for long-distance large-scale quantum communication, which is capable of transmitting text, images and other information of reasonable size.
基金Project(52275350)supported by the National Natural Science Foundation of ChinaProject(0301006)supported by the International Cooperative Scientific Research Platform of SUES,China。
文摘In this study,the interaction between deformation and precipitates during multiple equal channel angular pressing(ECAP)deformations and inter-pass aging combination and its effect on the mechanical properties of 7050 aluminum alloy are studied.The result show that ECAP induces numerous substructures and dislocations,effectively promoting the precipitation of theηʹphase exhibiting a bimodal structure during inter-pass aging.Following inter-pass aging and subsequent ECAP,the decrease in grain size(4.8μm)is together with the increase in dislocation density(1.24×10^(15) m^(−2))due to the pinning effect of the precipitated phase.Simultaneously,the dislocation motion causes the second phase particles to become even finer and more diffuse.The synergistic effects of precipitation strengthening,fine grain strengthening,and dislocation strengthening collectively enhance the high strength of aluminum alloys,with ultimate tensile strength and yield strength reaching approximately 610 and 565 MPa,respectively.Meanwhile,ductility remains largely unchanged,primarily due to coordinated grain boundary sliding and the uniform and fine dispersion of second phase particles.
基金supported by the National Natural Science Foundation of China(Nos.51971009,12002013,51831006)the Natural Science Foundation of Zhejiang Province,China(No.LZ23E010004).
文摘The angular deviations and influential factors of Burgers orientation relationship(BOR)in Ti-6Al-4V and Ti-6.5Al-2Zr-1Mo-1V alloys were investigated by optical microscope(OM),scanning electron microscope(SEM),electron backscattered diffraction(EBSD)and high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM).A spherical center angle model was introduced to calculate the angular deviations from the ideal BOR between α and β phases.The results indicate thatαand β phases in α colonies of both alloys do not follow the perfect BOR during β→α phase transformation,with angular deviation values less than 3°.Through detailed microstructure characterization,the broad face of α/β interfaces viewed along two different electron incident directions shows the atomic-scale terrace-ledge structure,and many dislocations are observed within α and β phases and near α/β interfaces.Further studies reveal that the angular deviations mainly originate from lattice distortions caused by dislocations in α and β phases and lattice mismatches at α/β interfaces.
基金the National Natural Science Foundation of China(62271322)the Guangdong Basic and Applied Basic Research Foundation(2022A1515011003 and 2023A1515030152)the Shenzhen Science and Technology Program(JCYJ20210324095610027 and JCYJ20210324095611030).
文摘Optical orbital angular momentum(OAM)mode multiplexing has emerged as a promising technique for boosting communication capacity.However,most existing studies have concentrated on channel(de)-multiplexing,overlooking the critical aspect of channel routing.This challenge involves the reallocation of multiplexed OAM modes across both spatial and temporal domains—a vital step for developing versatile communication networks.To address this gap,we introduce a novel approach based on the time evolution of OAM modes,utilizing the orthogonal conversion and diffractive modulation capabilities of unitary transformations.This approach facilitates high-dimensional orthogonal transformations of OAM mode vectors,altering both the propagation direction and the spatial location.Using Fresnel diffraction matrices as unitary operators,it manipulates the spatial locations of light beams during transmission,breaking the propagation invariance and enabling temporal evolution.As a demonstration,we have experimentally implemented the deep routing of four OAM modes within two distinct time sequences.Achieving an average diffraction efficiency above 78.31%,we have successfully deep-routed 4.69 Tbit-s^(-1)quadrature phase-shift keying(QPSK)signals carried by four multiplexed OAM channels,with a bit error rate below 10^(-6).These results underscore the efficacy of our routing strategy and its promising prospects for practical applications.
基金the SERB,Department of Science and Technology,Government of India(Project No.EMR/2017/001456)aIISER Kolkata IPh.D fellowship for research.
文摘We demonstrate an effective and optimal strategy for generating spatially resolved longitudinal spin angular momentum(LSAM)in optical tweezers by tightly focusing the first-order spirally polarized vector(SPV)beams with zero intrinsic angular momentum into a refractive index stratified medium.The stratified medium gives rise to a spherically aberrated intensity profile near the focal region of the optical tweezers,with off-axis intensity lobes in the radial direction possessing opposite LSAM(helicities corresponding toσ=+1 and−1)compared to the beam center.We trap mesoscopic birefringent particles in an off-axis intensity lobe as well as at the beam center by modifying the trapping plane and observe particles spinning in opposite directions depending on their location.The direction of rotation depends on the particle size with larger particles spinning either clockwise or anticlockwise depending on the direction of spirality of the polarization of the SPV beam after tight focusing,while smaller particles spin in both directions depending on their spatial locations.Numerical simulations support our experimental observations.Our results introduce new avenues in spin-orbit optomechanics to facilitate novel yet straightforward avenues for exotic and complex particle manipulation in optical tweezers.
基金financially supported by the National Natural Science Foundation of China(No.52374395)the Natural Science Foundation of Shanxi Province,China(Nos.20210302123135,202303021221143)+5 种基金the Scientific and Technological Achievements Transformation Guidance Special Project of Shanxi Province,China(Nos.202104021301022,202204021301009)the Central Government Guided Local Science and Technology Development Projects,China(No.YDZJSX20231B003)the Ministry of Science and Higher Education of the Russian Federation for financial support under the Megagrant(No.075-15-2022-1133)the National Research Foundation(NRF)grant funded by the Ministry of Science and ICT of Korea through the Research Institute of Advanced Materials(No.2015R1A2A1A01006795)the China Postdoctoral Science Foundation(No.2022M710541)the Research Project supported by Shanxi Scholarship Council of China(No.2022-038)。
文摘To investigate the effect of microstructure evolution on corrosion behavior and strengthening mechanism of Mg-1Zn-1Ca(wt.%)alloys,as-cast Mg-1Zn-1Ca alloys were performed by equal channel angular pressing(ECAP)with 1 and 4 passes.The corrosion behavior and mechanical properties of alloys were investigated by optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),electrochemical tests,immersion tests and tensile tests.The results showed that mechanical properties improved after ECAP 1 pass;however,the corrosion resistance deteriorated due to high-density dislocations and fragmented secondary phases by ECAP.In contrast,synchronous improvement in the mechanical properties and corrosion resistance was achieved though grain refinement after ECAP 4 passes;fine grains led to a significant improvement in the yield strength,ultimate tensile strength,elongation,and corrosion rate of 103 MPa,223 MPa,30.5%,and 1.5843 mm/a,respectively.The enhanced corrosion resistance was attributed to the formation of dense corrosion product films by finer grains and the barrier effect by high-density grain boundaries.These results indicated that Mg-1Zn-1Ca alloy has a promising potential for application in biomedical materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.12234020,12474281,12450403,and 12274461)the Science and Technology Innovation Program of Hunan Province(Grant No.2022RC1193)。
文摘This letter demonstrates an experimental approach to measuring the angular-momentum-resolved population of excited states in laser-produced argon ions.By measuring the spectra of free induction decay emissions corresponding to the resonant transitions between Rydberg states,the relative population of the Rydberg states is obtained with known Einstein A-coefficients.This study deepens the mechanistic understanding of coherent dynamics in laser-driven ionic excited states,and establishes experimental benchmarks essential for validating and refining advanced quantum kinetic models in strong-field physics.
