Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challe...Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.展开更多
Based on the first-order correlation function of light,we propose analogous optical coherent states(AOCSs)sourced by partially coherent beams,which can nondiffractively propagate with sinusoidal oscillation in the har...Based on the first-order correlation function of light,we propose analogous optical coherent states(AOCSs)sourced by partially coherent beams,which can nondiffractively propagate with sinusoidal oscillation in the harmonic potential when the nondiffraction propagation matching condition(NPMC)is met.Unlike the traditional quantum coherent state,the minimum uncertainty of AOCS is related to the coherence of light,and only when the NPMC is met,its uncertainty is the least.Furthermore,based on the mathematical similarity between the Schrödinger and the Helmholtz equations,we find that our proposed AOCSs correspond to the partially coherent steady states of the harmonic oscillator.Our research not only increases the understanding of the coherence of light and enriches the types of nondiffraction beams but also increases the understanding of the quantum coherence regulating the evolution of probability waves.展开更多
Public-key encryption is essential for secure communications,eliminating the need for pre-shared keys.However,traditional schemes such as RSA(Rivest-Shamir-Adleman)and elliptic curve cryptography rely on computational...Public-key encryption is essential for secure communications,eliminating the need for pre-shared keys.However,traditional schemes such as RSA(Rivest-Shamir-Adleman)and elliptic curve cryptography rely on computational complexity,making them increasingly susceptible to advances in computing power and algorithms.Physical-layer encryption,which leverages the intrinsic properties of physical systems,offers a promising alternative with security rooted in physics.Despite progress in this field,public-key encryption at the optical layer remains largely unexplored.Here,we propose a novel optical public-key encryption scheme based on partially coherent light sources.The cryptographic keys are encoded in the incoherent optical transmission matrix of an on-chip Mach-Zehnder interferometer mesh,providing high complexity and resilience to computational attacks.We experimentally demonstrate encrypted image transmission over 40 km of optical fiber with high decryption fidelity and achieve a 10 Gbit/s optical encryption rate using a lithium niobate photonic chip.This represents the first implementation of public-key encryption at the physical optical layer.The approach offers key advantages in security,cost,energy efficiency,and compatibility with commercial optical communication systems.By integrating public-key encryption into photonic hardware,this work opens a new direction for secure and high-speed optical communications in next-generation networks.展开更多
Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid ...Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid route and the solid-solid route.However,the formation of DCN structures in steel requires long processes and complex steps.So far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain unavoidable.Here,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field.Ti-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 s.These small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel matrix.Our findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.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
Single negatively charged nitrogen vacancy(NV-)centers in diamond have emerged as promising platforms for quantum information science,where long coherence times are essential for advancing quantum technologies.However...Single negatively charged nitrogen vacancy(NV-)centers in diamond have emerged as promising platforms for quantum information science,where long coherence times are essential for advancing quantum technologies.However,traditional fabrication methods often introduce lattice damage during the irradiation process used to create vacancies,significantly impairing the spin coherence properties of NV-centers.展开更多
Deconvolution methods are commonly used to improve the performance of phased array beamforming for sound source localization. However, for coherent sources localization, existing deconvolution methods are either highl...Deconvolution methods are commonly used to improve the performance of phased array beamforming for sound source localization. However, for coherent sources localization, existing deconvolution methods are either highly computationally demanding or sensitive to parameters.A deconvolution method, based on modifications of Clean based on Source Coherence(CLEAN-SC), is proposed for coherent sources localization. This method is called Coherence CLEAN-SC(C–CLEAN-SC). C–CLEAN-SC is able to locate coherent and incoherent sources in simulation and experimental cases. It has a high computational efficiency and does not require pre-set parameters.展开更多
In modern industrial design trends featuring with integration,miniaturization,and versatility,there is a growing demand on the utilization of microstructural array devices.The measurement of such microstructural array...In modern industrial design trends featuring with integration,miniaturization,and versatility,there is a growing demand on the utilization of microstructural array devices.The measurement of such microstructural array components often encounters challenges due to the reduced scale and complex structures,either by contact or noncontact optical approaches.Among these microstructural arrays,there are still no optical measurement methods for micro corner-cube reflector arrays.To solve this problem,this study introduces a method for effectively eliminating coherent noise and achieving surface profile reconstruction in interference measurements of microstructural arrays.The proposed denoising method allows the calibration and inverse solving of system errors in the frequency domain by employing standard components with known surface types.This enables the effective compensation of the complex amplitude of non-sample coherent light within the interferometer optical path.The proposed surface reconstruction method enables the profile calculation within the situation that there is complex multi-reflection during the propagation of rays in microstructural arrays.Based on the measurement results,two novel metrics are defined to estimate diffraction errors at array junctions and comprehensive errors across multiple array elements,offering insights into other types of microstructure devices.This research not only addresses challenges of the coherent noise and multi-reflection,but also makes a breakthrough for quantitively optical interference measurement of microstructural array devices.展开更多
Centrifugal Pumps(CPs)are critical machine components in many industries,and their efficient operation and reliable Fault Diagnosis(FD)are essential for minimizing downtime and maintenance costs.This paper introduces ...Centrifugal Pumps(CPs)are critical machine components in many industries,and their efficient operation and reliable Fault Diagnosis(FD)are essential for minimizing downtime and maintenance costs.This paper introduces a novel FD method to improve both the accuracy and reliability of detecting potential faults in such pumps.Theproposed method combinesWaveletCoherent Analysis(WCA)and Stockwell Transform(S-transform)scalograms with Sobel and non-local means filters,effectively capturing complex fault signatures from vibration signals.Using Convolutional Neural Network(CNN)for feature extraction,the method transforms these scalograms into image inputs,enabling the recognition of patterns that span both time and frequency domains.The CNN extracts essential discriminative features,which are then merged and passed into a Kolmogorov-Arnold Network(KAN)classifier,ensuring precise fault identification.The proposed approach was experimentally validated on diverse datasets collected under varying conditions,demonstrating its robustness and generalizability.Achieving classification accuracy of 100%,99.86%,and 99.92%across the datasets,this method significantly outperforms traditional fault detection approaches.These results underscore the potential to enhance CP FD,providing an effective solution for predictive maintenance and improving overall system reliability.展开更多
We theoretically investigate a cooling scheme assisted by a quantum well(QW)and coherent feedback within a hybrid optomechanical system.Although the exciton mode in the QW and the mechanical resonator(MR)are initially...We theoretically investigate a cooling scheme assisted by a quantum well(QW)and coherent feedback within a hybrid optomechanical system.Although the exciton mode in the QW and the mechanical resonator(MR)are initially uncoupled,their interaction via the microcavity field leads to an indirect exciton-mode–mechanical-mode coupling.The coherent feedback loop is applied by feeding back a fraction of the output field of the cavity through a controllable beam splitter to the cavity’s input mirror.It is shown that the cooling capability is enhanced by effectively suppressing the Stokes process through coupling with the QW.Furthermore,the effect of the anti-Stokes process is enhanced through the application of the coherent feedback loop.This particular system configuration enables cooling of the mechanical resonator even in the unresolved sideband regime(USR).This study has some important guiding significance in the field of quantum information processing.展开更多
The purpose of this paper is to show that by using a certain type of discrete-continuous limit, a series of integral entities can be defined(Mittag-Leffler multi-index functions, associated coherent states and their p...The purpose of this paper is to show that by using a certain type of discrete-continuous limit, a series of integral entities can be defined(Mittag-Leffler multi-index functions, associated coherent states and their properties), which are counterparts of the corresponding discrete entities. We built and examine the properties of a new aspect of generalized integral multi-index Mittag-Leffler functions and we constructed and examined the properties of coherent states associated with this new function. This approach is motivated through the fact that these functions can be connected with the coherent states of the continuous spectrum, as well as with so-called nu-function.展开更多
The photocatalytic reduction of CO_(2)presents a promising avenue for carbon fuel conversion.However,the efficiency of charge utilization remains a critical barrier to industrial applications.In this study,we introduc...The photocatalytic reduction of CO_(2)presents a promising avenue for carbon fuel conversion.However,the efficiency of charge utilization remains a critical barrier to industrial applications.In this study,we introduce a tandem design of Bi_(2)WO_(6)-BiOCl with an atomically matched interface,achieving highly efficient photoreduction of CO_(2)to CO.By incorporating WO_(4)^(2-)ions and tuning coordination environment,the(110)facet of BiOCl was in-situ grown on the(200)facet of Bi_(2)WO_(6).Compared to single phases and ball-milling samples,Bi_(2)WO_(6)-BiOCl exhibits a remarkable CO yield of 68.03μmol g^(-1)h^(-1)with a selectivity of 98%.Atomic visualization and coordination analysis confirm the formation of a coherent interface that facilitates charge migration for efficient electron transport.Density functional theory(DFT)calculations and in-situ Fourier transform infrared(FTIR)spectroscopy provide insights into the intrinsic active sites and reaction mechanisms.The proposed lattice engineering strategies offer a new paradigm for the rational design of heterostructures beyond traditional band alignment at the atomic scale.展开更多
In organic photovoltaics(OPVs),theπ-orbital D18-Cl coherent stack ofπ-conjugated polymers in the active layer exerts a profound influence on exciton dissociation and charge transport.Nevertheless,the structural flex...In organic photovoltaics(OPVs),theπ-orbital D18-Cl coherent stack ofπ-conjugated polymers in the active layer exerts a profound influence on exciton dissociation and charge transport.Nevertheless,the structural flexibility intrinsic ofπ-conjugated polymers fundamentally restricts orderedπ-orbital coherent stack,thereby establishing persistent performance limitations in OPVs.Here,we demonstrate a universal crystalinduced polymericπ-orbital coherent stack reinforcement strategy by incorporating nano-monolayer nickel phosphorus trisulfide(NiPS_(3))crystal as a multifunctional additive,to modulates tighterπ–πstacking and extended crystallite coherence length.These structural improvements synergistically extend exciton lifetime,suppress carrier recombination,and optimize charge transport.Consequently,OPVs based on D18-Cl:L8-BO system achieves an impressive power conversion efficiency(PCE)of 20.83%with concurrent improvements in short-circuit current density and fill factor.The universality of this approach is further confirmed in PM6:L8-BO(PCE boosts from 17.41%±0.21%to 18.08%±0.11%)and D18:L8-BO(PCE improves from 19.20%±0.27%to 20.19%±0.20%)systems,where nano-monolayer NiPS_(3) crystal universally mediates the formation of tightlyπ-orbital coherent stack ofπ-conjugated polymers with enhanced crystallite coherence length.This work establishes nano-monolayer NiPS_(3) crystal as powerful tools for modulatesπ-orbital coherent stack of conjugated polymers,offering a materials-agnostic pathway toward high-efficiency OPVs.展开更多
Phonon coherence can reflect electron‒phonon coupling information and has been proven to modulate electronic states and charge transport.The manipulation of phonon coherence through spacer cation engineering in organi...Phonon coherence can reflect electron‒phonon coupling information and has been proven to modulate electronic states and charge transport.The manipulation of phonon coherence through spacer cation engineering in organic‒inorganic hybrid perovskites(OIHPs)has been extensively demonstrated;however,the underlying structural origin remains elusive at the molecular level.Herein,we present molecular structure and temperature-dependent coherent phonon studies via a combination of sum frequency generation vibrational spectroscopy(SFG-VS)and transient absorption spectroscopy(TAS).The conformational order of spacer cations dictates the coherent phonon oscillations in 2D OIHPs.Our study further analyzes the static order and dynamic disorder in 2D perovskites.This work provides molecular-level insights into the role of spacer cations in tuning structural order and may provide valuable guidance for advancing emergent optoelecltronics development.展开更多
The linear transmission impairments,such as the timing offset(TO),frequency offset(FO),and chromatic dispersion(CD),are major factors of signal degradations in coherent optical fiber communication systems.The estimati...The linear transmission impairments,such as the timing offset(TO),frequency offset(FO),and chromatic dispersion(CD),are major factors of signal degradations in coherent optical fiber communication systems.The estimation and compensation of such impairments play significant roles in the receiver side digital signal processing(DSP)unit.In this paper,we propose to combat the linear impairments systematically(including TO,FO and CD)with a joint timefrequency signal processing by taking the advantage of fractional Fourier transform(FrFT).In view of geometrical analysis,TO/FO induces a shift in time/frequency coordinate and the CD leads to the rotation in the fractional domain.Both mathematical derivations and geometrical interpretations have been established to unveil the relationships between impairments and linear frequency modulated(LFM)training symbols(TSs).By considering a typical coherent optical orthogonal frequency-division multiplexing(COOFDM)transmission system,three kinds of linear impairments have been jointly estimated by simple geometric calculations using appropriately designed TS based on FrFTs.Simulation and experimental results confirmed the feasibility of time-frequency techniques with better accuracy,less complexity,and improved spectral efficiency.展开更多
We propose a compact scheme to modulate a relativistic electron beam(REB)into three-dimensional(3D)nanoscale bunches by injecting a rarefied REB into an underdense plasma.This scheme self-consistently integrates the l...We propose a compact scheme to modulate a relativistic electron beam(REB)into three-dimensional(3D)nanoscale bunches by injecting a rarefied REB into an underdense plasma.This scheme self-consistently integrates the lateral focusing and axial modulation of the REB in its self-driven plasma wakefield.The REB first expels the plasma electrons in its path to form a wake,where the lateral force of the chargeseparation field compresses it to higher density,so that more plasma electrons are expelled as it propagates.The positive feedback loop is repeated until the REB becomes a thin electron filament of density a hundred times that of the original.As it continues to propagate in the elongated electron-free wake bubble,the axial electric field induces an energy chirp on the electron filament,and longitudinally modulates it into 3D nanoscale bunches by asynchronous envelope oscillations.The excitation conditions of this scheme with respect to the beam and plasma parameters,as well as the spatial scale of the obtained electron bunches,are analyzed analytically and agree well with particle-in-cell simulations.In addition,our radiation simulations show that coherent extreme ultraviolet radiation can be generated with such 3D nanoscale bunches.展开更多
We present a theoretical study of four-wave mixing(FWM)in a degenerate two-level atomic system subject to a magnetic field whose Zeeman sublevels constitute a tripod-type atomic system,which is driven by a linearly po...We present a theoretical study of four-wave mixing(FWM)in a degenerate two-level atomic system subject to a magnetic field whose Zeeman sublevels constitute a tripod-type atomic system,which is driven by a linearly polarized field,and coupled and probed by two sets of left and right circularly polarized fields.The optical effects of coherent hole burning(CHB)and electromagnetically induced transparency(EIT)are involved in the coherent system,among which the CHB has much larger response for the FWM than the EITs.Three situations of CHB are involved,and they are the solitary CHB,overlapped CHBs,and an overlap between CHB and EIT.The overlapped CHBs have the greatest magnitude of FWM signal among the three situations.Whereas,for the overlapped CHB and EIT,it has the smallest FWM magnitude,which is no more than one tenth of the former.While for the single CHB,the FWM magnitude is half of that of the overlapped CHBs.It is noted that,in the overlap between CHB and EIT,dual EIAs can be obtained,whose FWM signal also has an enhancement in comparison to no EIA.展开更多
Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing.Here we provide a complete picture for the frequency estimation precision of three...Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing.Here we provide a complete picture for the frequency estimation precision of three important states(the Greenberger-Horne-Zeilinger(GHZ)state,the maximal spin squeezed state,and the spin coherent state)of a spin-S under both individual dephasing and collective dephasing by general Gaussian noise,ranging from the Markovian limit to the extreme non-Markovian limit.Whether or not the noise is Markovian,the spin coherent state is always worse than the classical scheme under collective dephasing although it is equivalent to the classical scheme under individual dephasing.Moreover,the maximal spin squeezed state always give the best sensing precision(and outperforms the widely studied GHZ state)in all cases.This establishes the general advantage of the spin squeezed state for noisy frequency estimation in many quantum sensing platforms.展开更多
Non-oriented silicon steels with both excellent magnetic properties and high strength are essential for the drive motors of new energy vehicles.However,achieving a balance between strength and magnetic properties is a...Non-oriented silicon steels with both excellent magnetic properties and high strength are essential for the drive motors of new energy vehicles.However,achieving a balance between strength and magnetic properties is a challenging task.This study successfully developed non-oriented silicon steel that met these demanding requirements by utilizing the coherent nano-Cu-rich phases precipitated during aging.In the current investigation,the evolution of precipitation during the aging process of Cu-alloyed non-oriented silicon steel is revealed as:BCC Cu-rich cluster(Fe:Cu>1)→B2 FeCu cluster(Fe:Cu approaches 1)→BCC Cu cluster(Fe:Cu<1)→Twinned 9R Cu→Detwinned 9R Cu.Notably,the 9R Cu precipitated in the later stage of aging was coarse and incoherent with the matrix,offering minimal strengthening benefits while considerably deteriorated the magnetic properties.Conversely,the other three phases that formed in the early stage of aging were fine,dispersed,and coherent with the matrix,effectively enhancing the yield strength of the steel with minimal negative impact on its magnetic properties.The total increment of yield strength attributed to BCC Cu-rich clusters,B2 FeCu clusters,and BCC Cu clusters were 207,304,and 374 MPa,respectively.The strengthening mechanism operated primarily through the cutting mechanism,which was dominated by the modulus difference strengthening and coherent strain strengthening.Moreover,a unique ordered strengthening of approximately 207 MPa arose from the ordered B2 FeCu clusters.Thus,the steel aged for 3–30 min with the precipitation of B2 FeCu clusters and BCC Cu clusters exhibited the most favorable overall performance with a yield strength of 750–800 MPa,P1.0/400 of 16.3–18.3 W kg^(−1),and B5000 of 1.641–1.656 T.展开更多
In this paper,we introduce a new generalization of coherent rings using the Auslander class.A ring R is called an A-coherent ring in case every nitely generated submodule of a free R-module in AC(R)is nitely presented...In this paper,we introduce a new generalization of coherent rings using the Auslander class.A ring R is called an A-coherent ring in case every nitely generated submodule of a free R-module in AC(R)is nitely presented,where C is a semidualizing module.Firstly,A-injective and A-at modules are introduced and their properties are studied.Further,we characterize A-coherent rings in various ways,using A-injective,A-at modules,and cotorsion theories.展开更多
基金supported by the Guangdong High Level Innovation Research Institute(Grant No.2021B0909050006)the National Grand Instrument Project(Grant No.2019YFF01014402)+1 种基金the National Natural Science Foundation of China(Grant No.12205008)support from the National Science Fund for Distinguished Young Scholars(Grant No.12225501)。
文摘Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.
基金supported by the Ministry of Science and Technology of the People’s Republic of China(Grant No.2022YFC2808203)the National Natural Science Foundation of China(Grant Nos.11474254 and 11804298).
文摘Based on the first-order correlation function of light,we propose analogous optical coherent states(AOCSs)sourced by partially coherent beams,which can nondiffractively propagate with sinusoidal oscillation in the harmonic potential when the nondiffraction propagation matching condition(NPMC)is met.Unlike the traditional quantum coherent state,the minimum uncertainty of AOCS is related to the coherence of light,and only when the NPMC is met,its uncertainty is the least.Furthermore,based on the mathematical similarity between the Schrödinger and the Helmholtz equations,we find that our proposed AOCSs correspond to the partially coherent steady states of the harmonic oscillator.Our research not only increases the understanding of the coherence of light and enriches the types of nondiffraction beams but also increases the understanding of the quantum coherence regulating the evolution of probability waves.
基金supported by the Fundamental Research Funds for the Central Universities.National Natural Science Foundation of China(62425504,U21A20511,62275088).
文摘Public-key encryption is essential for secure communications,eliminating the need for pre-shared keys.However,traditional schemes such as RSA(Rivest-Shamir-Adleman)and elliptic curve cryptography rely on computational complexity,making them increasingly susceptible to advances in computing power and algorithms.Physical-layer encryption,which leverages the intrinsic properties of physical systems,offers a promising alternative with security rooted in physics.Despite progress in this field,public-key encryption at the optical layer remains largely unexplored.Here,we propose a novel optical public-key encryption scheme based on partially coherent light sources.The cryptographic keys are encoded in the incoherent optical transmission matrix of an on-chip Mach-Zehnder interferometer mesh,providing high complexity and resilience to computational attacks.We experimentally demonstrate encrypted image transmission over 40 km of optical fiber with high decryption fidelity and achieve a 10 Gbit/s optical encryption rate using a lithium niobate photonic chip.This represents the first implementation of public-key encryption at the physical optical layer.The approach offers key advantages in security,cost,energy efficiency,and compatibility with commercial optical communication systems.By integrating public-key encryption into photonic hardware,this work opens a new direction for secure and high-speed optical communications in next-generation networks.
基金financially supported by the National Natural Science Foundation of China(No.51771125)the Sichuan Province Science and Technology Support Program(No.2020YFG0102)。
文摘Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid route and the solid-solid route.However,the formation of DCN structures in steel requires long processes and complex steps.So far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain unavoidable.Here,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field.Ti-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 s.These small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel matrix.Our findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.
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 National Natural Science Foundation of China(Grant Nos.112374012 and 11974208)Shandong Provincial Natural Science Foundation(Grant Nos.ZR2023JQ001 and tsqn202211128)。
文摘Single negatively charged nitrogen vacancy(NV-)centers in diamond have emerged as promising platforms for quantum information science,where long coherence times are essential for advancing quantum technologies.However,traditional fabrication methods often introduce lattice damage during the irradiation process used to create vacancies,significantly impairing the spin coherence properties of NV-centers.
基金supported by the National Science and Technology Major Project of China (No. 2017-II-003–0015)。
文摘Deconvolution methods are commonly used to improve the performance of phased array beamforming for sound source localization. However, for coherent sources localization, existing deconvolution methods are either highly computationally demanding or sensitive to parameters.A deconvolution method, based on modifications of Clean based on Source Coherence(CLEAN-SC), is proposed for coherent sources localization. This method is called Coherence CLEAN-SC(C–CLEAN-SC). C–CLEAN-SC is able to locate coherent and incoherent sources in simulation and experimental cases. It has a high computational efficiency and does not require pre-set parameters.
基金Supported by National Natural Science Foundation of China(Grant Nos.52375414,52075100)Shanghai Science and Technology Committee Innovation Grant of China(Grant No.23ZR1404200).
文摘In modern industrial design trends featuring with integration,miniaturization,and versatility,there is a growing demand on the utilization of microstructural array devices.The measurement of such microstructural array components often encounters challenges due to the reduced scale and complex structures,either by contact or noncontact optical approaches.Among these microstructural arrays,there are still no optical measurement methods for micro corner-cube reflector arrays.To solve this problem,this study introduces a method for effectively eliminating coherent noise and achieving surface profile reconstruction in interference measurements of microstructural arrays.The proposed denoising method allows the calibration and inverse solving of system errors in the frequency domain by employing standard components with known surface types.This enables the effective compensation of the complex amplitude of non-sample coherent light within the interferometer optical path.The proposed surface reconstruction method enables the profile calculation within the situation that there is complex multi-reflection during the propagation of rays in microstructural arrays.Based on the measurement results,two novel metrics are defined to estimate diffraction errors at array junctions and comprehensive errors across multiple array elements,offering insights into other types of microstructure devices.This research not only addresses challenges of the coherent noise and multi-reflection,but also makes a breakthrough for quantitively optical interference measurement of microstructural array devices.
基金supported by the Technology Innovation Program(20023566,‘Development and Demonstration of Industrial IoT and AI-Based Process Facility Intelligence Support System in Small and Medium Manufacturing Sites’)funded by the Ministry of Trade,Industry,&Energy(MOTIE,Republic of Korea).
文摘Centrifugal Pumps(CPs)are critical machine components in many industries,and their efficient operation and reliable Fault Diagnosis(FD)are essential for minimizing downtime and maintenance costs.This paper introduces a novel FD method to improve both the accuracy and reliability of detecting potential faults in such pumps.Theproposed method combinesWaveletCoherent Analysis(WCA)and Stockwell Transform(S-transform)scalograms with Sobel and non-local means filters,effectively capturing complex fault signatures from vibration signals.Using Convolutional Neural Network(CNN)for feature extraction,the method transforms these scalograms into image inputs,enabling the recognition of patterns that span both time and frequency domains.The CNN extracts essential discriminative features,which are then merged and passed into a Kolmogorov-Arnold Network(KAN)classifier,ensuring precise fault identification.The proposed approach was experimentally validated on diverse datasets collected under varying conditions,demonstrating its robustness and generalizability.Achieving classification accuracy of 100%,99.86%,and 99.92%across the datasets,this method significantly outperforms traditional fault detection approaches.These results underscore the potential to enhance CP FD,providing an effective solution for predictive maintenance and improving overall system reliability.
基金supported by the National Natural Science Foundation of China(Grant Nos.62061028 and 62461035)the Key Project of Natural Science Foundation of Jiangxi Province(Grant No.20232ACB202003)+2 种基金the Finance Science and Technology Special“contract system”Project of Nanchang University Jiangxi Province(Grant No.ZBG20230418015)the Natural Science Foundation of Chongqing(Grant No.CSTB2024NSCQ-MSX0412)the Opening Project of Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology(Grant No.ammt2021A-4).
文摘We theoretically investigate a cooling scheme assisted by a quantum well(QW)and coherent feedback within a hybrid optomechanical system.Although the exciton mode in the QW and the mechanical resonator(MR)are initially uncoupled,their interaction via the microcavity field leads to an indirect exciton-mode–mechanical-mode coupling.The coherent feedback loop is applied by feeding back a fraction of the output field of the cavity through a controllable beam splitter to the cavity’s input mirror.It is shown that the cooling capability is enhanced by effectively suppressing the Stokes process through coupling with the QW.Furthermore,the effect of the anti-Stokes process is enhanced through the application of the coherent feedback loop.This particular system configuration enables cooling of the mechanical resonator even in the unresolved sideband regime(USR).This study has some important guiding significance in the field of quantum information processing.
文摘The purpose of this paper is to show that by using a certain type of discrete-continuous limit, a series of integral entities can be defined(Mittag-Leffler multi-index functions, associated coherent states and their properties), which are counterparts of the corresponding discrete entities. We built and examine the properties of a new aspect of generalized integral multi-index Mittag-Leffler functions and we constructed and examined the properties of coherent states associated with this new function. This approach is motivated through the fact that these functions can be connected with the coherent states of the continuous spectrum, as well as with so-called nu-function.
基金supported by the National Key R&D Program of China(No.2021YFA1200201)the Beijing Outstanding Young Scientists Projects(No.BJJWZYJH01201910005018)+1 种基金The Basic Science Center Program for Multiphase Evolution in Hypergravity of the National Natural Science Foundation of China(No.51988101)the National Natural Science Foundation of China(Nos.52071003 and 91860202)。
文摘The photocatalytic reduction of CO_(2)presents a promising avenue for carbon fuel conversion.However,the efficiency of charge utilization remains a critical barrier to industrial applications.In this study,we introduce a tandem design of Bi_(2)WO_(6)-BiOCl with an atomically matched interface,achieving highly efficient photoreduction of CO_(2)to CO.By incorporating WO_(4)^(2-)ions and tuning coordination environment,the(110)facet of BiOCl was in-situ grown on the(200)facet of Bi_(2)WO_(6).Compared to single phases and ball-milling samples,Bi_(2)WO_(6)-BiOCl exhibits a remarkable CO yield of 68.03μmol g^(-1)h^(-1)with a selectivity of 98%.Atomic visualization and coordination analysis confirm the formation of a coherent interface that facilitates charge migration for efficient electron transport.Density functional theory(DFT)calculations and in-situ Fourier transform infrared(FTIR)spectroscopy provide insights into the intrinsic active sites and reaction mechanisms.The proposed lattice engineering strategies offer a new paradigm for the rational design of heterostructures beyond traditional band alignment at the atomic scale.
基金the National Natural Science Foundation of China(NSFC,No.62404094)the Natural Science Foundation of Hunan Province(No.2023JJ40532)+1 种基金the Fund of University of South China(Nos.210XQD018 and 5524GC017)the Fund of Hengyang Science and Technology Bureau(No.202121014588).
文摘In organic photovoltaics(OPVs),theπ-orbital D18-Cl coherent stack ofπ-conjugated polymers in the active layer exerts a profound influence on exciton dissociation and charge transport.Nevertheless,the structural flexibility intrinsic ofπ-conjugated polymers fundamentally restricts orderedπ-orbital coherent stack,thereby establishing persistent performance limitations in OPVs.Here,we demonstrate a universal crystalinduced polymericπ-orbital coherent stack reinforcement strategy by incorporating nano-monolayer nickel phosphorus trisulfide(NiPS_(3))crystal as a multifunctional additive,to modulates tighterπ–πstacking and extended crystallite coherence length.These structural improvements synergistically extend exciton lifetime,suppress carrier recombination,and optimize charge transport.Consequently,OPVs based on D18-Cl:L8-BO system achieves an impressive power conversion efficiency(PCE)of 20.83%with concurrent improvements in short-circuit current density and fill factor.The universality of this approach is further confirmed in PM6:L8-BO(PCE boosts from 17.41%±0.21%to 18.08%±0.11%)and D18:L8-BO(PCE improves from 19.20%±0.27%to 20.19%±0.20%)systems,where nano-monolayer NiPS_(3) crystal universally mediates the formation of tightlyπ-orbital coherent stack ofπ-conjugated polymers with enhanced crystallite coherence length.This work establishes nano-monolayer NiPS_(3) crystal as powerful tools for modulatesπ-orbital coherent stack of conjugated polymers,offering a materials-agnostic pathway toward high-efficiency OPVs.
基金supported by the National Natural Science Foundation of China(Nos.21925302,92250306)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450202)+1 种基金the Innovation Program for Quantum Science and Technology(2021ZD0303303)the National Key Research and Development Program of China(2018YFA0208702).
文摘Phonon coherence can reflect electron‒phonon coupling information and has been proven to modulate electronic states and charge transport.The manipulation of phonon coherence through spacer cation engineering in organic‒inorganic hybrid perovskites(OIHPs)has been extensively demonstrated;however,the underlying structural origin remains elusive at the molecular level.Herein,we present molecular structure and temperature-dependent coherent phonon studies via a combination of sum frequency generation vibrational spectroscopy(SFG-VS)and transient absorption spectroscopy(TAS).The conformational order of spacer cations dictates the coherent phonon oscillations in 2D OIHPs.Our study further analyzes the static order and dynamic disorder in 2D perovskites.This work provides molecular-level insights into the role of spacer cations in tuning structural order and may provide valuable guidance for advancing emergent optoelecltronics development.
文摘The linear transmission impairments,such as the timing offset(TO),frequency offset(FO),and chromatic dispersion(CD),are major factors of signal degradations in coherent optical fiber communication systems.The estimation and compensation of such impairments play significant roles in the receiver side digital signal processing(DSP)unit.In this paper,we propose to combat the linear impairments systematically(including TO,FO and CD)with a joint timefrequency signal processing by taking the advantage of fractional Fourier transform(FrFT).In view of geometrical analysis,TO/FO induces a shift in time/frequency coordinate and the CD leads to the rotation in the fractional domain.Both mathematical derivations and geometrical interpretations have been established to unveil the relationships between impairments and linear frequency modulated(LFM)training symbols(TSs).By considering a typical coherent optical orthogonal frequency-division multiplexing(COOFDM)transmission system,three kinds of linear impairments have been jointly estimated by simple geometric calculations using appropriately designed TS based on FrFTs.Simulation and experimental results confirmed the feasibility of time-frequency techniques with better accuracy,less complexity,and improved spectral efficiency.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1613400)the National Natural Science Foundation of China(Grant Nos.12475238,12175154,12205201,and 12475248)+5 种基金the Financial Support for Outstanding Talents Training Fund in Shenzhen(Project No.202101)the Shenzhen Science and Technology Program(Grant No.RCYX20221008092851073)the Guangdong Province Key Construction Discipline Scientific Research Capacity Improvement Project(Grant No.2021ZDJS107)the Natural Science Foundation of Guangdong(Grant No.2025A1515012853)the Natural Science Foundation of Top Talent of SZTU(Grant Nos.GDRC202310 and GDRC202423)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2025A1515010791).
文摘We propose a compact scheme to modulate a relativistic electron beam(REB)into three-dimensional(3D)nanoscale bunches by injecting a rarefied REB into an underdense plasma.This scheme self-consistently integrates the lateral focusing and axial modulation of the REB in its self-driven plasma wakefield.The REB first expels the plasma electrons in its path to form a wake,where the lateral force of the chargeseparation field compresses it to higher density,so that more plasma electrons are expelled as it propagates.The positive feedback loop is repeated until the REB becomes a thin electron filament of density a hundred times that of the original.As it continues to propagate in the elongated electron-free wake bubble,the axial electric field induces an energy chirp on the electron filament,and longitudinally modulates it into 3D nanoscale bunches by asynchronous envelope oscillations.The excitation conditions of this scheme with respect to the beam and plasma parameters,as well as the spatial scale of the obtained electron bunches,are analyzed analytically and agree well with particle-in-cell simulations.In addition,our radiation simulations show that coherent extreme ultraviolet radiation can be generated with such 3D nanoscale bunches.
基金supported by the Open Subject of the State Key Laboratory of Quantum Optics and Quantum Optics Devices(Grant No.KF202209).
文摘We present a theoretical study of four-wave mixing(FWM)in a degenerate two-level atomic system subject to a magnetic field whose Zeeman sublevels constitute a tripod-type atomic system,which is driven by a linearly polarized field,and coupled and probed by two sets of left and right circularly polarized fields.The optical effects of coherent hole burning(CHB)and electromagnetically induced transparency(EIT)are involved in the coherent system,among which the CHB has much larger response for the FWM than the EITs.Three situations of CHB are involved,and they are the solitary CHB,overlapped CHBs,and an overlap between CHB and EIT.The overlapped CHBs have the greatest magnitude of FWM signal among the three situations.Whereas,for the overlapped CHB and EIT,it has the smallest FWM magnitude,which is no more than one tenth of the former.While for the single CHB,the FWM magnitude is half of that of the overlapped CHBs.It is noted that,in the overlap between CHB and EIT,dual EIAs can be obtained,whose FWM signal also has an enhancement in comparison to no EIA.
基金supported by the National Natural Science Foundation of China(NSFC)Grant No.12274019the NSAF grant in NSFC with Grant No.U2230402。
文摘Exploring the quantum advantages of various non-classical quantum states in noisy environments is a central subject in quantum sensing.Here we provide a complete picture for the frequency estimation precision of three important states(the Greenberger-Horne-Zeilinger(GHZ)state,the maximal spin squeezed state,and the spin coherent state)of a spin-S under both individual dephasing and collective dephasing by general Gaussian noise,ranging from the Markovian limit to the extreme non-Markovian limit.Whether or not the noise is Markovian,the spin coherent state is always worse than the classical scheme under collective dephasing although it is equivalent to the classical scheme under individual dephasing.Moreover,the maximal spin squeezed state always give the best sensing precision(and outperforms the widely studied GHZ state)in all cases.This establishes the general advantage of the spin squeezed state for noisy frequency estimation in many quantum sensing platforms.
基金supported by the National Natural Science Foundation of China(Nos.52074200,52274393,and 12102310)the Key R&D Program of Hubei Province(No.2023BAB141)the State Key Laboratory for Advanced Metals and Materials(No.2023-ZD03).
文摘Non-oriented silicon steels with both excellent magnetic properties and high strength are essential for the drive motors of new energy vehicles.However,achieving a balance between strength and magnetic properties is a challenging task.This study successfully developed non-oriented silicon steel that met these demanding requirements by utilizing the coherent nano-Cu-rich phases precipitated during aging.In the current investigation,the evolution of precipitation during the aging process of Cu-alloyed non-oriented silicon steel is revealed as:BCC Cu-rich cluster(Fe:Cu>1)→B2 FeCu cluster(Fe:Cu approaches 1)→BCC Cu cluster(Fe:Cu<1)→Twinned 9R Cu→Detwinned 9R Cu.Notably,the 9R Cu precipitated in the later stage of aging was coarse and incoherent with the matrix,offering minimal strengthening benefits while considerably deteriorated the magnetic properties.Conversely,the other three phases that formed in the early stage of aging were fine,dispersed,and coherent with the matrix,effectively enhancing the yield strength of the steel with minimal negative impact on its magnetic properties.The total increment of yield strength attributed to BCC Cu-rich clusters,B2 FeCu clusters,and BCC Cu clusters were 207,304,and 374 MPa,respectively.The strengthening mechanism operated primarily through the cutting mechanism,which was dominated by the modulus difference strengthening and coherent strain strengthening.Moreover,a unique ordered strengthening of approximately 207 MPa arose from the ordered B2 FeCu clusters.Thus,the steel aged for 3–30 min with the precipitation of B2 FeCu clusters and BCC Cu clusters exhibited the most favorable overall performance with a yield strength of 750–800 MPa,P1.0/400 of 16.3–18.3 W kg^(−1),and B5000 of 1.641–1.656 T.
文摘In this paper,we introduce a new generalization of coherent rings using the Auslander class.A ring R is called an A-coherent ring in case every nitely generated submodule of a free R-module in AC(R)is nitely presented,where C is a semidualizing module.Firstly,A-injective and A-at modules are introduced and their properties are studied.Further,we characterize A-coherent rings in various ways,using A-injective,A-at modules,and cotorsion theories.
