Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pr...Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.展开更多
By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this pape...By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this paper is derived from differential equation and based on the theory of non-imaging focusing heliostat proposed by Chen et al. in 2001. The comparison of the derivative form of fixed aberration correction surface has been made with that of integral form surface as well as that of spherical surface in concentrating the solar ray.展开更多
Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study invest...Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.展开更多
Negative Poisson’s ratio materials and structures exhibit lateral expansion under tensile loading,demonstrating significant mechanical advantages over conventional materials.This study systematically investigated thr...Negative Poisson’s ratio materials and structures exhibit lateral expansion under tensile loading,demonstrating significant mechanical advantages over conventional materials.This study systematically investigated three typical two-dimensional negative Poisson’s ratio metamaterial structures(Concave honeycomb,Anti-chiral,and Anti-chiral concave honeycomb hybrid structures)through both experimental tests and numerical analysis.The test specimens were fabricated using selective laser melting(SLM)additive manufacturing technology,and the experimental test was conducted with the use of a DIC strain measurement system.The numerical studies were performed considering both static tensile loading and dynamic impact loading with different strain rates.The deformation behaviors,failure process,negative Poisson’s ratio effects,and energy absorption capacity of the three different metamaterial structures are systematically investigated,and the associated mechanical mechanisms are thoroughly revealed.Results and findings of this work could provide valuable guidance for the engineering design and application of negative Poisson’s ratio metamaterials and structures.展开更多
As the prevalence of obesity increases dramatically,obesity-associated cardiac dysfunction constitutes a considerable challenge to human health.This study aimed to identify more useful lipid/inflammatory markers to pr...As the prevalence of obesity increases dramatically,obesity-associated cardiac dysfunction constitutes a considerable challenge to human health.This study aimed to identify more useful lipid/inflammatory markers to predict the risk of obesity-associated cardiac dysfunction.By retrospectively analyzing the clinical characteristics of 5648 cardiac disease patients,we found that both the plasma level of high-density lipoprotein cholesterol(HDLC)and the blood monocyte count were significantly associated with impairment of the left ventricular ejection fraction(LVEF).Univariate and multivariate regression analyses revealed that the monocyte to HDL-C ratio(MHR)was a more powerful predictor of the risk of LVEF decline than either HDL-C or monocyte alone.Mediation analysis further revealed a mediating effect of a high MHR on the decline in obesity-associated cardiac systolic function.Collectively,our results demonstrate a superior role of MHR in predicting the risk of an obesityassociated decline in cardiac systolic function among routine metabolic/inflammatory markers.展开更多
In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extens...In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extensive knowledge regarding its macroscopic properties,there is a wide knowledge gap in understanding the influence of microscale parameters like aggregate porosity and volume ratio on the mechanical response of LWAC.This study aims to bridge this knowledge gap,spurred by the need to enhance the predictability and applicability of LWAC in various construction environments.With the help of advanced numerical methods,including the finite element method and a random circular aggregate model,this study critically evaluates the role played by these microscale factors.We found that an increase in the aggregate porosity from 23.5%to 48.5%leads to a drastic change of weakness from the bonding interface to the aggregate,reducing compressive strength by up to 24.2%and tensile strength by 27.8%.Similarly,the increase in the volume ratio of lightweight aggregate from 25%to 40%leads to a reduction in compressive strength by 13.0%and tensile strength by 9.23%.These results highlight the imperative role of microscale properties on the mechanical properties of LWAC.By supplying precise quantitative details on the effect of porosity and aggregate volume ratio,this research makes significant contributions to construction materials science by providing useful recommendations for the creation and optimization of LWAC with improved performance and sustainability in construction.展开更多
Background:The long-term outcomes of robotic-assisted surgery and the prognostic significance of the pretreatment neutrophil-to-lymphocyte ratio(NLR)in locally advanced rectal cancer(LARC)remain uncertain.This study a...Background:The long-term outcomes of robotic-assisted surgery and the prognostic significance of the pretreatment neutrophil-to-lymphocyte ratio(NLR)in locally advanced rectal cancer(LARC)remain uncertain.This study aimed to assess the long-term outcomes of patients with LARC undergoing robotic-assisted surgery and to determine the prognostic value of pretreatment NLR.Methods:We retrospectively reviewed 252 patients with LARC who were treated at a single medical center in Taiwan between January 2012 and January 2023.All patients underwent neoadjuvant concurrent chemoradiotherapy(CRT)followed by robotic-assisted surgery with total mesorectal excision(TME).Patients were stratified into four groups on the basis of pretreatment NLRs and carcinoembryonic antigen(CEA)levels.Univariate and multivariate analyses were conducted to identify prognostic indicators for overall survival(OS)and disease-free survival(DFS).Results:Patients with a pretreatment NLR of≥3.2 exhibited significantly worse OS and DFS compared with those with an NLR of<3.2(OS:94.4 vs.116.5 months,p=0.001;DFS:78.8 vs.101.7 months,p=0.003).Group A exhibited the poorest prognosis,whereas Group D had the most favorable outcomes.Multivariate analysis revealed NLR≥3.2 as an independent predictor of poor OS(hazard ratio[HR]=2.306,95%CI:1.149-3.747;p=0.001)and DFS(HR=2.055,95%CI:1.341-3.148;p=0.001).Conclusion:Neoadjuvant concurrent CRT followed by robotic-assisted TME is an effective treatment strategy for LARC.A higher pretreatment NLR(≥3.2)independently predicted worse OS and DFS.Stratification using the NLR in combination with CEA levels may enhance prognostic accuracy for patients undergoing robotic-assisted surgery for LARC.展开更多
This study presents a framework involving statistical modeling and machine learning to accurately predict and optimize the mechanical and damping properties of hybrid granite-epoxy(G-E)composites reinforced with cast ...This study presents a framework involving statistical modeling and machine learning to accurately predict and optimize the mechanical and damping properties of hybrid granite-epoxy(G-E)composites reinforced with cast iron(CI)filler particles.Hybrid G-E composite with added cast iron(CI)filler particles enhances stiffness,strength,and vibration damping,offering enhanced performance for vibration-sensitive engineering applications.Unlike conventional approaches,this work simultaneously employs Artificial Neural Networks(ANN)for highaccuracy property prediction and Response Surface Methodology(RSM)for in-depth analysis of factor interactions and optimization.A total of 24 experimental test data sets of varying input factors(granite weight%,epoxy weight%,and CI filler weight%)were utilized to train and test the prediction models using an ANN approach and further analyze the interaction effects using RSM.Mechanical properties,including tensile,compressive,and flexural strength,elastic modulus,density and damping properties measured under various testing conditions,were set as output parameters for prediction.This study analyzed and optimized the performance of the ANN model using Bayesian Regularization and Levenberg-Marquardt algorithms to identify the best performing number of neurons in the hidden layer for achieving the highest prediction accuracy.The proposed ANN framework achieved an exceptional average determination coefficient(R2)exceeding 99%,with Bayesian Regularization demonstrating remarkable stability in the 22-neuron range and minimal variation across all properties.RSM and ANN form a powerful framework for predicting and optimizing hybrid G-E composite properties,enabling efficient design for vibration-critical applications with reduced experimental effort and performance optimization.展开更多
This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-fiel...This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.展开更多
Background:Panacis Quinquefolii Radix(PQR)is known for its ability to nourish“Qi”(it serves as the driving force for the functional activities of the body’s organs and meridians,promoting and regulating various phy...Background:Panacis Quinquefolii Radix(PQR)is known for its ability to nourish“Qi”(it serves as the driving force for the functional activities of the body’s organs and meridians,promoting and regulating various physiological functions)and“Yin”(it represents the material foundation of the human body.It plays a role in nourishing,moistening,and cooling the body).Notoginseng Radix et Rhizoma(NRR)is recognized for its properties of resolving blood stasis(it refers to a pathological condition characterized by impaired or stagnant blood circulation within the body).Changes in the compatibility ratio of these herbs often lead to variations in their chemical composition and efficacy.However,the specific alterations in chemical composition and efficacy resulting from compatibility adjustments remain unclear.We aimed to compare the material basis and their effects of different compatibility ratios of PQR and NRR on“Qi”deficiency and blood stasis syndrome(QBS).Methods:This study employed UPLC-Q/TOF-MS to identify effective compounds in the compatibility of PQR and NRR and utilized UPLC-TQ-MS/MS to analyze the dissolution of 16 saponins in PQR and NRR at 9 different ratios.A rat model of QBS was established,and the efficacy of PQR and NRR in treating this syndrome was assessed using hemorheology and coagulation analyses.Results:The study results show that PQR and NRR exhibit significant efficacy,effectively reducing blood viscosity induced by platelet aggregation and lowering inflammatory markers such as IL-6,IL-10,TXB2 and ET associated with vascular injury.Moreover,this combination regulates ATP and ADP levels,enhances energy metabolism,and promotes overall health.A total of 104 compounds in the compatibility of PQR and NRR were identified.The ratios of 1:2 and 1:3 showed the highest total saponin content,but the ratio of 1:1 demonstrated a superior pharmacological effect for the treatment of QBS.Conclusion:In summary,the compatibility of PQR and NRR not only shows the complex interactions between traditional Chinese medicinal materials,but also provides a new idea and method for the treatment of QBS.展开更多
The propagation properties of the off-axis superposition of partially coherent beams through atmospheric turbulence and their beam quality in terms of the mean-squared beam width w（z） and the power in the bucket （...The propagation properties of the off-axis superposition of partially coherent beams through atmospheric turbulence and their beam quality in terms of the mean-squared beam width w（z） and the power in the bucket （PIB） are studied in detail, where the effects of partial coherence, off-axis beam superposition and atmospheric turbulence are considered. The analytical expressions for the intensity, the beam width and the PIB are derived, and illustrative examples are given numerically. It is shown that the maximum intensity/max and the PIB decrease and w（z） increases as the refraction index structure constant Cn^2 increases. Therefore, the turbulence results in a degradation of the beam quality. However, the resulting partially coherent beam with a smaller value of spatial correlation parameter γ and larger values of separate distance Xd and beam number M is less affected by the turbulence than that with a larger value of y and smaller values of Xd and M. The main results obtained in this paper are explained physically.展开更多
Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex...Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex and needs to trade off other aberration in traditional ways.Although metasurface offers an effective method to overcome these limits and results in well-engineered dispersion,off-axis dispersion control is still a challenging topic.In this paper,we design a single-layer metalens which is capable of focusing at three wavelengths(473 nm,532 nm,and 632 nm)with different incident angles(0°,-17°and 17°)into the same point.We also demonstrate that this metalens can provide an alternative for the bulky color synthetic prism in a 3-chips digital micromirror device(DMD)laser projection system.Through this approach,various off-axis dispersion controlling optical devices could be realized.展开更多
Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-d...Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-diffraction properties of an offaxis parabolic mirror in the presence of misalignments of the incoming beam. The physical origin of these effects is also explored. The results show that the far-field intensity profile is altered by the distortion-, coma-, and astigmatism-like aberrations, which are caused by oblique incidence rather than inherent aberrations for the off-axis configuration. The radius of 90% encircled energy also increases but does not change monotonically with incident beam size increasing, or rather,it first decreases and then increases. The focal shift strongly depends on the effective focal length and oblique incidence angle, but it is almost independent of the beam size, which affects the focusing spot patterns. The intensity distribution produces a higher astigmatic image with off-axis angle increasing. Coma-like aberration starts to become dominant with beam size increasing and results in larger curved propagation trajectory. The incident polarization also affects the intensity distribution. The variation in the Strehl ratio with oblique incidence angle strongly depends on the misalignment direction and beam size as well. In addition, we find that the difference in locus between the catacaustic and the diffraction focus in the meridian is small. But the locus of the sagittal foci is obviously different from the locus of the meridian foci and the catacaustic focus. Moreover, the peak intensity of the sagittal focus is maximum, and the ratio of the peak intensity to that in the meridian plane is approximately 1.5. Understanding these effects is valuable for assessing a practical focused intensity and describing the motion of charged particles under a strong electric field in ultraintense laser–matter interaction.展开更多
As the scaling down of semiconductor devices, it would be necessary to discover the structure-property relationship of semiconductor nanomaterials at nanometer scale. In this review, the quantitative characterization ...As the scaling down of semiconductor devices, it would be necessary to discover the structure-property relationship of semiconductor nanomaterials at nanometer scale. In this review, the quantitative characterization technique off-axis electron holography is introduced in details, followed by its applications in various semiconductor nanomaterials including group IV, compound and two-dimensional semiconductor nanostructures in static states as well as under various stimuli. The advantages and disadvantages of off-axis electron holography in material analysis are discussed, the challenges facing in-situ electron holographic study of semiconductor devices at working conditions are presented, and all the possible influencing factors need to be considered to achieve the final goal of fulfilling quantitative characterization of the structure-property relationship of semiconductor devices at their working conditions.展开更多
As a kind of special acoustic field, the helical wavefront of an acoustic vortex（AV） beam is demonstrated to have a pressure zero with phase singularity at the center in the transverse plane. The orbital angular mom...As a kind of special acoustic field, the helical wavefront of an acoustic vortex（AV） beam is demonstrated to have a pressure zero with phase singularity at the center in the transverse plane. The orbital angular momentum of AVs can be applied to the field of particle manipulation, which attracts more and more attention in acoustic researches. In this paper,by using the simplified circular array of point sources, dual coaxial AV beams are excited by the even-and odd-numbered sources with the topological charges of l_E and l_O based on the phase-coded approach, and the composite acoustic field with an on-axis center-AV and multiple off-axis sub-AVs can be generated by the superimposition of the AV beams for｜l_E｜ ≠ ｜l_O｜. The generation of edge phase dislocation is theoretically derived and numerically analyzed for l_E=-l_O. The numbers and the topological charges as well as the locations of the center-AV and sub-AVs are demonstrated, which are proved to be determined by the topological charges of the coaxial AV beams. The proposed approach breaks through the limit of only one on-axis AV with a single topological charge along the beam axis, and also provides the feasibility of off-axis particle trapping with multiple AVs in object manipulation.展开更多
Reflective optics with wide field of view has been applied more and more widely in EUVL or space optics, and also plays an important role in promoting scientific and technological research. Among the reflective optics...Reflective optics with wide field of view has been applied more and more widely in EUVL or space optics, and also plays an important role in promoting scientific and technological research. Among the reflective optics, the off-axis reflective optics is the most hopeful solution to the ever-highest demands of these applications. This paper gives the requirements of both the above mentioned applications and the similarities and differences between these two kinds of optical systems. Finally, a design example of off-axis reflective optics with wide field of view is presented and described.展开更多
The analytical expression of off-axis hollow Gaussian–Schell model vortex beam(HGSMVB)generated by anisotropic Gaussian–Schell model source is first introduced.The evolution properties of off-axis HGSMVB propagating...The analytical expression of off-axis hollow Gaussian–Schell model vortex beam(HGSMVB)generated by anisotropic Gaussian–Schell model source is first introduced.The evolution properties of off-axis HGSMVB propagating in turbulent atmosphere are analyzed.The results show that the off-axis HGSMVB with smaller coherence length or propagating in stronger turbulent atmosphere will evolve from dark hollow beam into Gaussian-like beam with a larger beam spot faster.The beams with different values of integer order N or the position for hollow and vortex factor R will have almost the same Gaussian-like spot distribution at the longer propagation distance.展开更多
Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the tra...Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the transmitter and receiver must be parallel and coaxial;otherwise,the accuracy of mode detection at the receiver can be seriously influenced.In this paper,we design an OAM millimeter-wave communication system for overcoming the above limitation.Specifically,the first contribution is that the power distribution between different OAM modes and the capacity of the system with different mode sets are analytically derived for performance analysis.The second contribution lies in that a novel mode selection scheme is proposed to reduce the total interference between different modes.Numerical results show that system performance is less affected by the offset when the mode set with smaller modes or larger intervals is selected.展开更多
The effects of trapped electrons on off-axis lower hybrid current drive （LHCD） in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The co...The effects of trapped electrons on off-axis lower hybrid current drive （LHCD） in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The code is suitable for various auxiliary heating and current drive schemes in tokamak plasmas. The influence of the resonance regime on the current drive efficiency as well as the influence of trapped particle fraction on the current drive efficiency are emphasized. It is shown that, as an electrostatic force, the lower hybrid wave causes some of the trapped electrons to be untrapped and lose their energy, which can cut the LHCD efficiency by about 30%. The ITER scaling law is also used to estimate the trapped electron effects.展开更多
This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circ...This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.展开更多
基金funded by the National Nature Science Foundation of China(11934009,12174198,and 12227808)the Natural Science Foundation of Jiangsu Province,China(BE2022814)+2 种基金the Universal Technology for Primary and Secondary Schoolsthe National Research Institute for Teaching Materialsthe Qing Lan Project of Jiangsu Province,China。
文摘Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.
文摘By using the derivative method, we obtained the same result with that of the previous work of Chen et al. in 2006. Different from the integral form, the derivative form of the surface expression published in this paper is derived from differential equation and based on the theory of non-imaging focusing heliostat proposed by Chen et al. in 2001. The comparison of the derivative form of fixed aberration correction surface has been made with that of integral form surface as well as that of spherical surface in concentrating the solar ray.
基金funded by the Natural Science Foundation of China(Grants No 42277127)。
文摘Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.
基金supported by the National Natural Science Foundation of China(No.12472136)Innovation Fund of Marine Defense Technology Innovation Center(No.25GFC-JJ16-3608).
文摘Negative Poisson’s ratio materials and structures exhibit lateral expansion under tensile loading,demonstrating significant mechanical advantages over conventional materials.This study systematically investigated three typical two-dimensional negative Poisson’s ratio metamaterial structures(Concave honeycomb,Anti-chiral,and Anti-chiral concave honeycomb hybrid structures)through both experimental tests and numerical analysis.The test specimens were fabricated using selective laser melting(SLM)additive manufacturing technology,and the experimental test was conducted with the use of a DIC strain measurement system.The numerical studies were performed considering both static tensile loading and dynamic impact loading with different strain rates.The deformation behaviors,failure process,negative Poisson’s ratio effects,and energy absorption capacity of the three different metamaterial structures are systematically investigated,and the associated mechanical mechanisms are thoroughly revealed.Results and findings of this work could provide valuable guidance for the engineering design and application of negative Poisson’s ratio metamaterials and structures.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.82430018 to Q.C.,82270361 and 82570402 to H.Z.)the Nanjing Medical University Undergraduate Innovation and Entrepreneurship Training Program Fund(Grant No.202410312138Y to C.Z.)the Basic Sciences of Jiangsu Higher Education Institutions(Grant No.22KJA310002 to H.Z.)。
文摘As the prevalence of obesity increases dramatically,obesity-associated cardiac dysfunction constitutes a considerable challenge to human health.This study aimed to identify more useful lipid/inflammatory markers to predict the risk of obesity-associated cardiac dysfunction.By retrospectively analyzing the clinical characteristics of 5648 cardiac disease patients,we found that both the plasma level of high-density lipoprotein cholesterol(HDLC)and the blood monocyte count were significantly associated with impairment of the left ventricular ejection fraction(LVEF).Univariate and multivariate regression analyses revealed that the monocyte to HDL-C ratio(MHR)was a more powerful predictor of the risk of LVEF decline than either HDL-C or monocyte alone.Mediation analysis further revealed a mediating effect of a high MHR on the decline in obesity-associated cardiac systolic function.Collectively,our results demonstrate a superior role of MHR in predicting the risk of an obesityassociated decline in cardiac systolic function among routine metabolic/inflammatory markers.
基金supported by National Science Foundation of China(10972015,11172015)the Beijing Natural Science Foundation(8162008).
文摘In modern construction,Lightweight Aggregate Concrete(LWAC)has been recognized as a vital material of concern because of its unique properties,such as reduced density and improved thermal insulation.Despite the extensive knowledge regarding its macroscopic properties,there is a wide knowledge gap in understanding the influence of microscale parameters like aggregate porosity and volume ratio on the mechanical response of LWAC.This study aims to bridge this knowledge gap,spurred by the need to enhance the predictability and applicability of LWAC in various construction environments.With the help of advanced numerical methods,including the finite element method and a random circular aggregate model,this study critically evaluates the role played by these microscale factors.We found that an increase in the aggregate porosity from 23.5%to 48.5%leads to a drastic change of weakness from the bonding interface to the aggregate,reducing compressive strength by up to 24.2%and tensile strength by 27.8%.Similarly,the increase in the volume ratio of lightweight aggregate from 25%to 40%leads to a reduction in compressive strength by 13.0%and tensile strength by 9.23%.These results highlight the imperative role of microscale properties on the mechanical properties of LWAC.By supplying precise quantitative details on the effect of porosity and aggregate volume ratio,this research makes significant contributions to construction materials science by providing useful recommendations for the creation and optimization of LWAC with improved performance and sustainability in construction.
基金supported by grants through funding from the National Science and Technology Council(NSTC112-2314-B-037-050-MY3,NSTC114-2314-B-037-103-MY3,NSTC114-2321-B-037-003)the Ministry of Health and Welfare(MOHW113-TDU-B-222-134014)+3 种基金funded by the health and welfare surcharge of on tobacco products,and the Kaohsiung Medical University Hospital(KMUH113-3R31,KMUH113-3R32,KMUH113-3R33,KMUH113-3M58,KMUH113-3M59,KMUH-S11412,KMUH-SH11403)Kaohsiung Medical University Research Center Grant(KMU-TC113A04)National Tsing Hua University-Kaohsiung Medical University Joint Research Project(NTHU-KMU-KT114P008)supported by the Grant of Taiwan Precision Medicine Initiative and Taiwan Biobank,Academia Sinica,Taiwan.
文摘Background:The long-term outcomes of robotic-assisted surgery and the prognostic significance of the pretreatment neutrophil-to-lymphocyte ratio(NLR)in locally advanced rectal cancer(LARC)remain uncertain.This study aimed to assess the long-term outcomes of patients with LARC undergoing robotic-assisted surgery and to determine the prognostic value of pretreatment NLR.Methods:We retrospectively reviewed 252 patients with LARC who were treated at a single medical center in Taiwan between January 2012 and January 2023.All patients underwent neoadjuvant concurrent chemoradiotherapy(CRT)followed by robotic-assisted surgery with total mesorectal excision(TME).Patients were stratified into four groups on the basis of pretreatment NLRs and carcinoembryonic antigen(CEA)levels.Univariate and multivariate analyses were conducted to identify prognostic indicators for overall survival(OS)and disease-free survival(DFS).Results:Patients with a pretreatment NLR of≥3.2 exhibited significantly worse OS and DFS compared with those with an NLR of<3.2(OS:94.4 vs.116.5 months,p=0.001;DFS:78.8 vs.101.7 months,p=0.003).Group A exhibited the poorest prognosis,whereas Group D had the most favorable outcomes.Multivariate analysis revealed NLR≥3.2 as an independent predictor of poor OS(hazard ratio[HR]=2.306,95%CI:1.149-3.747;p=0.001)and DFS(HR=2.055,95%CI:1.341-3.148;p=0.001).Conclusion:Neoadjuvant concurrent CRT followed by robotic-assisted TME is an effective treatment strategy for LARC.A higher pretreatment NLR(≥3.2)independently predicted worse OS and DFS.Stratification using the NLR in combination with CEA levels may enhance prognostic accuracy for patients undergoing robotic-assisted surgery for LARC.
文摘This study presents a framework involving statistical modeling and machine learning to accurately predict and optimize the mechanical and damping properties of hybrid granite-epoxy(G-E)composites reinforced with cast iron(CI)filler particles.Hybrid G-E composite with added cast iron(CI)filler particles enhances stiffness,strength,and vibration damping,offering enhanced performance for vibration-sensitive engineering applications.Unlike conventional approaches,this work simultaneously employs Artificial Neural Networks(ANN)for highaccuracy property prediction and Response Surface Methodology(RSM)for in-depth analysis of factor interactions and optimization.A total of 24 experimental test data sets of varying input factors(granite weight%,epoxy weight%,and CI filler weight%)were utilized to train and test the prediction models using an ANN approach and further analyze the interaction effects using RSM.Mechanical properties,including tensile,compressive,and flexural strength,elastic modulus,density and damping properties measured under various testing conditions,were set as output parameters for prediction.This study analyzed and optimized the performance of the ANN model using Bayesian Regularization and Levenberg-Marquardt algorithms to identify the best performing number of neurons in the hidden layer for achieving the highest prediction accuracy.The proposed ANN framework achieved an exceptional average determination coefficient(R2)exceeding 99%,with Bayesian Regularization demonstrating remarkable stability in the 22-neuron range and minimal variation across all properties.RSM and ANN form a powerful framework for predicting and optimizing hybrid G-E composite properties,enabling efficient design for vibration-critical applications with reduced experimental effort and performance optimization.
基金supported by the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(Grant No.2025ZD005100)by Beijing Geolight Technology Co.,Ltd.under the project“The Impact of Strong Ground Motion on Buildings”(YF-202520).
文摘This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing,as well as from a free-field station and roof frame,during a Mw 5.5 magnitude earthquake in Pingyuan,Shandong,in 2023.The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves.The results indicate that during the earthquake,the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz,whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz,which is 4–6 times greater than that of the points below.The amplitude was suppressed by more than 70%,confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building.When the building was excited by an earthquake,a three-tier frequency gradient was formed throughout the building:“base-isolation layer(0.17 Hz)-main body(1.18 Hz)-roof frame(3.83 Hz)”,which can effectively avoid resonance of the entire building.In addition,the composite base-isolation device changed the dynamic characteristics of the structure.The resonance period was extended from 0.74 s(theoretical value without base isolation)to 5.9 s(calculated value),and the resonance frequency was reduced from 1.35 to 0.17 Hz.This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.
基金funded by the Entrusted service project of Shaanxi Administration of Traditional Chinese Medicine(ZYJXG-L23001)2023 Sanqin Talent Special Support Program Innovation and Entrepreneurship Team Project,and Sci-Tech Innovation Talent System Construction Program of Shaanxi University of Chinese Medicine(2023).
文摘Background:Panacis Quinquefolii Radix(PQR)is known for its ability to nourish“Qi”(it serves as the driving force for the functional activities of the body’s organs and meridians,promoting and regulating various physiological functions)and“Yin”(it represents the material foundation of the human body.It plays a role in nourishing,moistening,and cooling the body).Notoginseng Radix et Rhizoma(NRR)is recognized for its properties of resolving blood stasis(it refers to a pathological condition characterized by impaired or stagnant blood circulation within the body).Changes in the compatibility ratio of these herbs often lead to variations in their chemical composition and efficacy.However,the specific alterations in chemical composition and efficacy resulting from compatibility adjustments remain unclear.We aimed to compare the material basis and their effects of different compatibility ratios of PQR and NRR on“Qi”deficiency and blood stasis syndrome(QBS).Methods:This study employed UPLC-Q/TOF-MS to identify effective compounds in the compatibility of PQR and NRR and utilized UPLC-TQ-MS/MS to analyze the dissolution of 16 saponins in PQR and NRR at 9 different ratios.A rat model of QBS was established,and the efficacy of PQR and NRR in treating this syndrome was assessed using hemorheology and coagulation analyses.Results:The study results show that PQR and NRR exhibit significant efficacy,effectively reducing blood viscosity induced by platelet aggregation and lowering inflammatory markers such as IL-6,IL-10,TXB2 and ET associated with vascular injury.Moreover,this combination regulates ATP and ADP levels,enhances energy metabolism,and promotes overall health.A total of 104 compounds in the compatibility of PQR and NRR were identified.The ratios of 1:2 and 1:3 showed the highest total saponin content,but the ratio of 1:1 demonstrated a superior pharmacological effect for the treatment of QBS.Conclusion:In summary,the compatibility of PQR and NRR not only shows the complex interactions between traditional Chinese medicinal materials,but also provides a new idea and method for the treatment of QBS.
基金supported by the National Natural Science Foundation of China (Grant No 60778048)
文摘The propagation properties of the off-axis superposition of partially coherent beams through atmospheric turbulence and their beam quality in terms of the mean-squared beam width w（z） and the power in the bucket （PIB） are studied in detail, where the effects of partial coherence, off-axis beam superposition and atmospheric turbulence are considered. The analytical expressions for the intensity, the beam width and the PIB are derived, and illustrative examples are given numerically. It is shown that the maximum intensity/max and the PIB decrease and w（z） increases as the refraction index structure constant Cn^2 increases. Therefore, the turbulence results in a degradation of the beam quality. However, the resulting partially coherent beam with a smaller value of spatial correlation parameter γ and larger values of separate distance Xd and beam number M is less affected by the turbulence than that with a larger value of y and smaller values of Xd and M. The main results obtained in this paper are explained physically.
基金We acknowledge the financial support by the National Natural Science Foundation of China under contact Nos.61622508,61622509,and 61575201.
文摘Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex and needs to trade off other aberration in traditional ways.Although metasurface offers an effective method to overcome these limits and results in well-engineered dispersion,off-axis dispersion control is still a challenging topic.In this paper,we design a single-layer metalens which is capable of focusing at three wavelengths(473 nm,532 nm,and 632 nm)with different incident angles(0°,-17°and 17°)into the same point.We also demonstrate that this metalens can provide an alternative for the bulky color synthetic prism in a 3-chips digital micromirror device(DMD)laser projection system.Through this approach,various off-axis dispersion controlling optical devices could be realized.
基金Project supported by the Science Foundation for Youth Scholars of Minjiang University,China(Grant No.Mj9n201602)the National Science and Technology Major Project of the Ministry of Science and Technology of China。
文摘Based on a full vector-diffraction theory, a detailed theoretical study is carried out, aiming at providing a clear insight into the effects of different focusing and off-axis parabola parameters on far-field vector-diffraction properties of an offaxis parabolic mirror in the presence of misalignments of the incoming beam. The physical origin of these effects is also explored. The results show that the far-field intensity profile is altered by the distortion-, coma-, and astigmatism-like aberrations, which are caused by oblique incidence rather than inherent aberrations for the off-axis configuration. The radius of 90% encircled energy also increases but does not change monotonically with incident beam size increasing, or rather,it first decreases and then increases. The focal shift strongly depends on the effective focal length and oblique incidence angle, but it is almost independent of the beam size, which affects the focusing spot patterns. The intensity distribution produces a higher astigmatic image with off-axis angle increasing. Coma-like aberration starts to become dominant with beam size increasing and results in larger curved propagation trajectory. The incident polarization also affects the intensity distribution. The variation in the Strehl ratio with oblique incidence angle strongly depends on the misalignment direction and beam size as well. In addition, we find that the difference in locus between the catacaustic and the diffraction focus in the meridian is small. But the locus of the sagittal foci is obviously different from the locus of the meridian foci and the catacaustic focus. Moreover, the peak intensity of the sagittal focus is maximum, and the ratio of the peak intensity to that in the meridian plane is approximately 1.5. Understanding these effects is valuable for assessing a practical focused intensity and describing the motion of charged particles under a strong electric field in ultraintense laser–matter interaction.
基金supported by the National Natural Science Foundation of China (51871104)the Fundamental Research Funds for the Central Universities (No.2019kfy RCPY074)。
文摘As the scaling down of semiconductor devices, it would be necessary to discover the structure-property relationship of semiconductor nanomaterials at nanometer scale. In this review, the quantitative characterization technique off-axis electron holography is introduced in details, followed by its applications in various semiconductor nanomaterials including group IV, compound and two-dimensional semiconductor nanostructures in static states as well as under various stimuli. The advantages and disadvantages of off-axis electron holography in material analysis are discussed, the challenges facing in-situ electron holographic study of semiconductor devices at working conditions are presented, and all the possible influencing factors need to be considered to achieve the final goal of fulfilling quantitative characterization of the structure-property relationship of semiconductor devices at their working conditions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474166 and 11604156)the Science and Technology Cooperation Projects of People’s Republic of China–Romania(Grant No.42-23)+2 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20161013)the Postdoctoral Science Foundation of China(Grant No.2016M591874)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘As a kind of special acoustic field, the helical wavefront of an acoustic vortex（AV） beam is demonstrated to have a pressure zero with phase singularity at the center in the transverse plane. The orbital angular momentum of AVs can be applied to the field of particle manipulation, which attracts more and more attention in acoustic researches. In this paper,by using the simplified circular array of point sources, dual coaxial AV beams are excited by the even-and odd-numbered sources with the topological charges of l_E and l_O based on the phase-coded approach, and the composite acoustic field with an on-axis center-AV and multiple off-axis sub-AVs can be generated by the superimposition of the AV beams for｜l_E｜ ≠ ｜l_O｜. The generation of edge phase dislocation is theoretically derived and numerically analyzed for l_E=-l_O. The numbers and the topological charges as well as the locations of the center-AV and sub-AVs are demonstrated, which are proved to be determined by the topological charges of the coaxial AV beams. The proposed approach breaks through the limit of only one on-axis AV with a single topological charge along the beam axis, and also provides the feasibility of off-axis particle trapping with multiple AVs in object manipulation.
文摘Reflective optics with wide field of view has been applied more and more widely in EUVL or space optics, and also plays an important role in promoting scientific and technological research. Among the reflective optics, the off-axis reflective optics is the most hopeful solution to the ever-highest demands of these applications. This paper gives the requirements of both the above mentioned applications and the similarities and differences between these two kinds of optical systems. Finally, a design example of off-axis reflective optics with wide field of view is presented and described.
基金Natural Science Foundation of Jilin Province,China(Grant No.20180101031JC)the Jilin Provincial Science Foundation for Basic Research,China(Grant No.2019C040-7).
文摘The analytical expression of off-axis hollow Gaussian–Schell model vortex beam(HGSMVB)generated by anisotropic Gaussian–Schell model source is first introduced.The evolution properties of off-axis HGSMVB propagating in turbulent atmosphere are analyzed.The results show that the off-axis HGSMVB with smaller coherence length or propagating in stronger turbulent atmosphere will evolve from dark hollow beam into Gaussian-like beam with a larger beam spot faster.The beams with different values of integer order N or the position for hollow and vortex factor R will have almost the same Gaussian-like spot distribution at the longer propagation distance.
基金supported in part by The National Natural Science Foundation of China(62071255,62171232,61771257)The Major Projects of the Natural Science Foundation of the Jiangsu Higher Education Institutions(20KJA510009)+3 种基金The Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications),Ministry of Education(JZNY201914)The open research fund of National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology,Nanjing University of Posts and Telecommunications(KFJJ20170305)The Research Fund of Nanjing University of Posts and Telecommunications(NY218012)Henan province science and technology research projects High and new technology(No.182102210106).
文摘Millimeter-wave transmission combined with Orbital Angular Momentum(OAM)has the advantage of reducing the loss of beam power and increasing the system capacity.However,to fulfill this advantage,the antennas at the transmitter and receiver must be parallel and coaxial;otherwise,the accuracy of mode detection at the receiver can be seriously influenced.In this paper,we design an OAM millimeter-wave communication system for overcoming the above limitation.Specifically,the first contribution is that the power distribution between different OAM modes and the capacity of the system with different mode sets are analytically derived for performance analysis.The second contribution lies in that a novel mode selection scheme is proposed to reduce the total interference between different modes.Numerical results show that system performance is less affected by the offset when the mode set with smaller modes or larger intervals is selected.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10675043, 10575031 and 10675042）.
文摘The effects of trapped electrons on off-axis lower hybrid current drive （LHCD） in tokamaks are studied, A computer code for solving the Fokker-Planck equation in a toroidal geometry is developed and employed. The code is suitable for various auxiliary heating and current drive schemes in tokamak plasmas. The influence of the resonance regime on the current drive efficiency as well as the influence of trapped particle fraction on the current drive efficiency are emphasized. It is shown that, as an electrostatic force, the lower hybrid wave causes some of the trapped electrons to be untrapped and lose their energy, which can cut the LHCD efficiency by about 30%. The ITER scaling law is also used to estimate the trapped electron effects.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10947170/A05 and 11104291)the Natural Science Fund for Colleges and Universities in Jiangsu Province (Grant No.10KJB140006)+2 种基金the Natural Sciences Foundation of Shanghai (Grant No.11ZR1441300)the Natural Science Foundation of Nanjing University of Posts and Telecommunications (Grant No.NY221098)the Jiangsu Qing Lan Project for their sponsorship。
文摘This paper presents a novel view of the impact of electron collision off-axis positions on the dynamic properties and relativistic nonlinear Thomson inverse scattering of excited electrons within tightly focused, circularly polarized laser pulses of varying intensities. We examine the effects of the transverse ponderomotive force, specifically how the deviation angle and speed of electron motion are affected by the initial off-axis position of the electron and the peak amplitude of the laser pulse. When the laser pulse intensity is low, an increase in the electron's initial off-axis distance results in reduced spatial radiation power, improved collimation, super-continuum phenomena generation, red-shifting of the spectrum's harmonic peak, and significant symmetry in the radiation radial direction. However, in contradiction to conventional understandings,when the laser pulse intensity is relatively high, the properties of the relativistic nonlinear Thomson inverse scattering of the electron deviate from the central axis, changing direction in opposition to the aforementioned effects. After reaching a peak, these properties then shift again, aligning with the previous direction. The complex interplay of these effects suggests a greater nuance and intricacy in the relationship between laser pulse intensity, electron position, and scattering properties than previously thought.
