The Imaging Science Subsystem(ISS)mounted on the Cassini spacecraft has taken a lot of images,which provides an important source of high-precision astrometry of some planets and satellites.However,some of these images...The Imaging Science Subsystem(ISS)mounted on the Cassini spacecraft has taken a lot of images,which provides an important source of high-precision astrometry of some planets and satellites.However,some of these images are degraded by trailed stars.Previously,these degraded images cannot be used for astrometry.In this paper,a new method is proposed to detect and compute the centers of these trailed stars automatically.The method is then performed on the astrometry of ISS images with trailed stars.Finally,we provided 658 astrometric positions between 2004 and 2017 of several satellites that include Enceladus,Dione,Tethys,Mimas and Rhea.Compared with the JPL ephemeris SAT427,the mean residuals of these measurements are 0.11 km and 0.26 km in R.A.and decl.,respectively.Their standard deviations are 1.08 km and 1.37 km,respectively.The results show that the proposed method performs astrometric measurements of Cassini ISS images with trailed stars effectively.展开更多
Cell|低糖饮食通过外泌体TRAIL介导形成免疫抑制微环境促进肿瘤肺转移 葡萄糖代谢重编程是肿瘤恶性特征之一。有临床前证据提示,低碳水化合物饮食或糖酵解抑制剂在缩小原发灶的同时,可能意外播下肿瘤远处转移的“种子”。2025年7月15日...Cell|低糖饮食通过外泌体TRAIL介导形成免疫抑制微环境促进肿瘤肺转移 葡萄糖代谢重编程是肿瘤恶性特征之一。有临床前证据提示,低碳水化合物饮食或糖酵解抑制剂在缩小原发灶的同时,可能意外播下肿瘤远处转移的“种子”。2025年7月15日,中山大学邝栋明、魏瑗团队在Cell在线发表了题为“Glucose restriction shapes pre-metastatic innate immune landscapes in the lung through exosomal TRAIL”的研究论文(doi:10.1016/j.cell.2025.06.027),破除了这一矛盾。展开更多
主题语境:旅游探险,篇幅:330词,建议用时:6分钟,For thrill-seekers and nature lovers,Kyrgyzstan just got a whole lot more exciting!The Kyrgyz Nomad Trail(KNT)is an incredible 2,000⁃kilometer hiking route that stretches ac...主题语境:旅游探险,篇幅:330词,建议用时:6分钟,For thrill-seekers and nature lovers,Kyrgyzstan just got a whole lot more exciting!The Kyrgyz Nomad Trail(KNT)is an incredible 2,000⁃kilometer hiking route that stretches across northern and eastern Kyrgyzstan,making it Central Asias longest trail network.Launched in June 2024,this adventure trail weaves through breathtaking landscapes,passing through regions like Jalal-Abad,Naryn and Issyk-Kul.展开更多
A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of fr...A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of freedom of the Trailing Edge Flap(TEF)is analyzed by employing an inverse nested overset grid method.Simulation of non-rotational and rotational modes of blade motion are carried out to investigate the formation and development of TEF shedding vortex with high-frequency deflection of TEF.Moreover,the mechanism of TEF deflection interference with blade tip vortex and overall rotor aerodynamics is also explored.In nonrotational mode,two bundles of vortices form at the gap ends of TEF and the main blade and merge into a single TEF vortex.Dynamic deflection of the TEF significantly interferes with the blade tip vortex.The position of the blade tip vortex consistently changes,and its frequency is directly related to the frequency of TEF deflection.In rotational mode,the tip vortex forms a helical structure.The end vortices at the gap sides co-swirl and subsequently merge into the concentrated beam of tip vortices,causing fluctuations in the vorticity and axial position of the tip vortex under the rotor.This research concludes with the investigation on suppression of Blade Vortex Interaction(BVI),showing an increase in miss distance and reduction in the vorticity of tip vortex through TEF phase control at a particular control frequency.Through this mechanism,a designed TEF deflection law increases the miss distance by 34.7%and reduces vorticity by 11.9%at the target position,demonstrating the effectiveness of AFC in mitigating BVI.展开更多
This study focuses on the application of dynamic route planning and augmented reality(AR)technology within interactive theme trail platforms.Taking the“Dongpo Travelogue”digital guide mini-program as a case study,it...This study focuses on the application of dynamic route planning and augmented reality(AR)technology within interactive theme trail platforms.Taking the“Dongpo Travelogue”digital guide mini-program as a case study,it employs empirical analysis to explore its impact on enhancing visitor engagement and cultural identification.Employing a combined quantitative and qualitative methodology,the study analyses the platform’s functional implementation in route planning,cultural narration,interactive games,and their impact on visitor experience.Findings indicate that the integration of dynamic route planning and AR technology significantly enhances visitor engagement and cultural identity,offering novel insights for the digital transformation of the cultural tourism industry.展开更多
This study introduces the lattice spring model(LSM)to investigate the incline angle of a non-uniform three-segment towed array under steady-state conditions.A numerical model was established,and parametric analysis wa...This study introduces the lattice spring model(LSM)to investigate the incline angle of a non-uniform three-segment towed array under steady-state conditions.A numerical model was established,and parametric analysis was conducted to examine the effects of towing speed and cable density on the incline angle.The numerical simulations demonstrate that for a conventional three-segment towed array with heavy vibration-isolation cable and density exceeding that of seawater,the towing speed must exceed 4 kn to maintain the acoustic cable's average incline angle below 10°.To validate the proposed LSM,a 100-meter-long towed array with variable densities was fabricated and tested through lake trials.The experimental results align closely with simulations,confirming LSM as a reliable model for predicting towed array position and posture.The study concludes by analyzing the parallel computing capabilities of LSM and its application in Fluid-Structure Interaction(FSI)problems.The model's precision and parallel computing capabilities make LSM an efficient,reliable tool for analyzing the steady-state behavior of towed systems.展开更多
This paper aims to design a morphing wing with both Flexible Leading Edge(FLE)and Flexible Trailing Edge(FTE)by using cellular structures,which can help the wing boost the deformation to a greater extent on the premis...This paper aims to design a morphing wing with both Flexible Leading Edge(FLE)and Flexible Trailing Edge(FTE)by using cellular structures,which can help the wing boost the deformation to a greater extent on the premise that the weight is not changed,so as to play a greater role in aerodynamic control such as gust interference.First,as for structural design,based on NACA0012,a morphing wing model constructed by 3 forms of cell structures is proposed.Then,the aerodynamic characteristics under the interference of FLE and FTE are calculated by the Computational Fluid Dynamic(CFD)method.After the surrogate model is established to predict the lift coefficient of the wing effectively,the sensitivity analysis reveals that the main sensitivity index of FTE deflection angle β is 0.565,which has the greatest influence on the lift coefficient.And the total sensitivity index of FLE deflection angle γ is increased by 78.9%,which reveals a strong coupling relationship between FLE and FTE.Finally,using Finite Element Analysis(FEA)method and experiment,the deformation capability of the model under certain static loads are obtained.The results reveal that the maximum deflection angle of the morphing wing model can be±22°at FLE and±64°at FTE,indicating strong structural stiffness and resistance to bending breakage of the model.The presented results can be useful in the design of the cellular morphing wing with multiple flexible systems.展开更多
Vortex-induced vibration of hydrofoils is concerned with structural safety and noise level in hydraulic machinery and marine engineering.The research on vibration characteristics under different operating conditions i...Vortex-induced vibration of hydrofoils is concerned with structural safety and noise level in hydraulic machinery and marine engineering.The research on vibration characteristics under different operating conditions is significant.In this study,numerical simulations are conducted to investigate the vortex-induced vibration responses of an elastically suspended hydrofoil with blunt trailing edge in pitch direction.The work studies the effects of four parameters,namely the structural natural frequency,mass ratio,initial attack angle,and Reynolds number on vibration characteristics,with special emphasis on frequency lock-in.Results indicate that as the structural natural frequency changes,the vibration amplitude may increase substantially within a certain frequency range,in which the vortex shedding frequency locks into the structural natural frequency,and frequency lock-in occurs.In addition,with increasing the mass ratio,the frequency range of lock-in becomes narrower,and both the upper and lower thresholds decrease.As the initial attack angle increases from 0◦to 6◦,the lock-in range gets reduced.Over the three Reynolds numbers(6×10^(5),9×10^(5),and 12×10^(5)),the lock-in range remains virtually unchanged.Moreover,for a certain structural natural frequency,modifying the mass ratio,initial attack angle,and Reynolds number could effectively suppress the vibration amplitude.展开更多
On a summer morning in Boqiang Village,tucked beneath the emerald mountains of Fanshi County,Shanxi Province,the Ultra Trail Mount Wutai 2025 commenced with the sound of the starting pistol-an event that was much more...On a summer morning in Boqiang Village,tucked beneath the emerald mountains of Fanshi County,Shanxi Province,the Ultra Trail Mount Wutai 2025 commenced with the sound of the starting pistol-an event that was much more than just a competition.As soon as the colourful smoke bombs lit up the sky,some 2,000 runners from China and abroad set off to reach one of the country’s most sacred Buddhist peaks.Over the past decade,this race has become a fixture on the global running calendar and a symbol of the growing popularity of endurance sports.展开更多
Biomimetics has recently emerged as an interesting approach to enhance renewable energy technologies.In this work,bioinspired Trailing Edge Serrations(TES)were evaluated on a typical Vertical Axis Wind Turbine(VAWT)ai...Biomimetics has recently emerged as an interesting approach to enhance renewable energy technologies.In this work,bioinspired Trailing Edge Serrations(TES)were evaluated on a typical Vertical Axis Wind Turbine(VAWT)airfoil,the DU06-W200.As noise reduction benefits of these mechanisms are already well-established,this study focuses on their impact on airfoil and VAWT performance.A saw-tooth geometry was chosen based on VAWT specifications and existing research,followed by a detailed assessment through wind tunnel tests using a newly developed aerodynamic balance.For a broad spectrum of attack angles and Reynolds numbers,lift,drag,and pitching moments were carefully measured.The results show that TES enhance the lift-to-drag ratio,especially in stalled conditions,and postpone stall at negative angles,expanding the effective performance range.A notable increase in pitching moment also is also observed,relevant for blade-strut joint design.Additionally,the impact on turbine performance was estimated using an analytical model,demonstrating excellent accuracy when compared against previous experimental results.TES offer a modest 2%improve-ment in peak performance,though they slightly narrow the optimal tip-speed ratio zone.Despite this,the potential noise reduction and performance gains make TES a valuable addition to VAWT designs,especially in urban settings.展开更多
Meteor Burst Communication(MBC),a niche yet revolutionary wireless communication paradigm,exploits the transient ionized trails generated by meteors ablating in Earth’s atmosphere to enable sporadic yet resilient lon...Meteor Burst Communication(MBC),a niche yet revolutionary wireless communication paradigm,exploits the transient ionized trails generated by meteors ablating in Earth’s atmosphere to enable sporadic yet resilient long-distance radio links.Known for its exceptional resilience,robustness,and sustained connectivity,MBC holds significant promise for applications in emergency communications,remote area connectivity,military/defense systems,and environmental monitoring.However,the scientific exploration and application of MBC have long been highly challenging.In particular,under the combined influence of multiple physical field factors,the channel experiences superimposed multiple random fading effects,exhibiting bursty,highly time-varying,and strongly random characteristics.This persistent technical challenge has resulted in the absence of a practical statistical channel model for MBC to date.展开更多
基金partly supported by the Joint Research Fund in Astronomy under cooperative agreement between the National Natural Science Foundation of China and Chinese Academy of Sciences(No.U2031104)the National Natural Science Foundation of China(No.62071201)the Natural Science Foundation of Guangdong Province(No.2023A1515011340)。
文摘The Imaging Science Subsystem(ISS)mounted on the Cassini spacecraft has taken a lot of images,which provides an important source of high-precision astrometry of some planets and satellites.However,some of these images are degraded by trailed stars.Previously,these degraded images cannot be used for astrometry.In this paper,a new method is proposed to detect and compute the centers of these trailed stars automatically.The method is then performed on the astrometry of ISS images with trailed stars.Finally,we provided 658 astrometric positions between 2004 and 2017 of several satellites that include Enceladus,Dione,Tethys,Mimas and Rhea.Compared with the JPL ephemeris SAT427,the mean residuals of these measurements are 0.11 km and 0.26 km in R.A.and decl.,respectively.Their standard deviations are 1.08 km and 1.37 km,respectively.The results show that the proposed method performs astrometric measurements of Cassini ISS images with trailed stars effectively.
文摘Cell|低糖饮食通过外泌体TRAIL介导形成免疫抑制微环境促进肿瘤肺转移 葡萄糖代谢重编程是肿瘤恶性特征之一。有临床前证据提示,低碳水化合物饮食或糖酵解抑制剂在缩小原发灶的同时,可能意外播下肿瘤远处转移的“种子”。2025年7月15日,中山大学邝栋明、魏瑗团队在Cell在线发表了题为“Glucose restriction shapes pre-metastatic innate immune landscapes in the lung through exosomal TRAIL”的研究论文(doi:10.1016/j.cell.2025.06.027),破除了这一矛盾。
文摘主题语境:旅游探险,篇幅:330词,建议用时:6分钟,For thrill-seekers and nature lovers,Kyrgyzstan just got a whole lot more exciting!The Kyrgyz Nomad Trail(KNT)is an incredible 2,000⁃kilometer hiking route that stretches across northern and eastern Kyrgyzstan,making it Central Asias longest trail network.Launched in June 2024,this adventure trail weaves through breathtaking landscapes,passing through regions like Jalal-Abad,Naryn and Issyk-Kul.
基金supported by the National Natural Science Foundation of China(No.11972190)。
文摘A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of freedom of the Trailing Edge Flap(TEF)is analyzed by employing an inverse nested overset grid method.Simulation of non-rotational and rotational modes of blade motion are carried out to investigate the formation and development of TEF shedding vortex with high-frequency deflection of TEF.Moreover,the mechanism of TEF deflection interference with blade tip vortex and overall rotor aerodynamics is also explored.In nonrotational mode,two bundles of vortices form at the gap ends of TEF and the main blade and merge into a single TEF vortex.Dynamic deflection of the TEF significantly interferes with the blade tip vortex.The position of the blade tip vortex consistently changes,and its frequency is directly related to the frequency of TEF deflection.In rotational mode,the tip vortex forms a helical structure.The end vortices at the gap sides co-swirl and subsequently merge into the concentrated beam of tip vortices,causing fluctuations in the vorticity and axial position of the tip vortex under the rotor.This research concludes with the investigation on suppression of Blade Vortex Interaction(BVI),showing an increase in miss distance and reduction in the vorticity of tip vortex through TEF phase control at a particular control frequency.Through this mechanism,a designed TEF deflection law increases the miss distance by 34.7%and reduces vorticity by 11.9%at the target position,demonstrating the effectiveness of AFC in mitigating BVI.
文摘This study focuses on the application of dynamic route planning and augmented reality(AR)technology within interactive theme trail platforms.Taking the“Dongpo Travelogue”digital guide mini-program as a case study,it employs empirical analysis to explore its impact on enhancing visitor engagement and cultural identification.Employing a combined quantitative and qualitative methodology,the study analyses the platform’s functional implementation in route planning,cultural narration,interactive games,and their impact on visitor experience.Findings indicate that the integration of dynamic route planning and AR technology significantly enhances visitor engagement and cultural identity,offering novel insights for the digital transformation of the cultural tourism industry.
基金supported by the Key Research Project of Zhejiang Lab(Grant No.K2022MEOAC01)。
文摘This study introduces the lattice spring model(LSM)to investigate the incline angle of a non-uniform three-segment towed array under steady-state conditions.A numerical model was established,and parametric analysis was conducted to examine the effects of towing speed and cable density on the incline angle.The numerical simulations demonstrate that for a conventional three-segment towed array with heavy vibration-isolation cable and density exceeding that of seawater,the towing speed must exceed 4 kn to maintain the acoustic cable's average incline angle below 10°.To validate the proposed LSM,a 100-meter-long towed array with variable densities was fabricated and tested through lake trials.The experimental results align closely with simulations,confirming LSM as a reliable model for predicting towed array position and posture.The study concludes by analyzing the parallel computing capabilities of LSM and its application in Fluid-Structure Interaction(FSI)problems.The model's precision and parallel computing capabilities make LSM an efficient,reliable tool for analyzing the steady-state behavior of towed systems.
基金co-supported by the National Natural Science Foundation of China(No.52402460)project funded by the China Postdoctoral Science Foundation(No.2024T171113)supported by the Fundamental Research Funds for the Central Universities,China。
文摘This paper aims to design a morphing wing with both Flexible Leading Edge(FLE)and Flexible Trailing Edge(FTE)by using cellular structures,which can help the wing boost the deformation to a greater extent on the premise that the weight is not changed,so as to play a greater role in aerodynamic control such as gust interference.First,as for structural design,based on NACA0012,a morphing wing model constructed by 3 forms of cell structures is proposed.Then,the aerodynamic characteristics under the interference of FLE and FTE are calculated by the Computational Fluid Dynamic(CFD)method.After the surrogate model is established to predict the lift coefficient of the wing effectively,the sensitivity analysis reveals that the main sensitivity index of FTE deflection angle β is 0.565,which has the greatest influence on the lift coefficient.And the total sensitivity index of FLE deflection angle γ is increased by 78.9%,which reveals a strong coupling relationship between FLE and FTE.Finally,using Finite Element Analysis(FEA)method and experiment,the deformation capability of the model under certain static loads are obtained.The results reveal that the maximum deflection angle of the morphing wing model can be±22°at FLE and±64°at FTE,indicating strong structural stiffness and resistance to bending breakage of the model.The presented results can be useful in the design of the cellular morphing wing with multiple flexible systems.
基金the National Natural Science Foundation of China(Nos.52171316 and 51479116)。
文摘Vortex-induced vibration of hydrofoils is concerned with structural safety and noise level in hydraulic machinery and marine engineering.The research on vibration characteristics under different operating conditions is significant.In this study,numerical simulations are conducted to investigate the vortex-induced vibration responses of an elastically suspended hydrofoil with blunt trailing edge in pitch direction.The work studies the effects of four parameters,namely the structural natural frequency,mass ratio,initial attack angle,and Reynolds number on vibration characteristics,with special emphasis on frequency lock-in.Results indicate that as the structural natural frequency changes,the vibration amplitude may increase substantially within a certain frequency range,in which the vortex shedding frequency locks into the structural natural frequency,and frequency lock-in occurs.In addition,with increasing the mass ratio,the frequency range of lock-in becomes narrower,and both the upper and lower thresholds decrease.As the initial attack angle increases from 0◦to 6◦,the lock-in range gets reduced.Over the three Reynolds numbers(6×10^(5),9×10^(5),and 12×10^(5)),the lock-in range remains virtually unchanged.Moreover,for a certain structural natural frequency,modifying the mass ratio,initial attack angle,and Reynolds number could effectively suppress the vibration amplitude.
文摘On a summer morning in Boqiang Village,tucked beneath the emerald mountains of Fanshi County,Shanxi Province,the Ultra Trail Mount Wutai 2025 commenced with the sound of the starting pistol-an event that was much more than just a competition.As soon as the colourful smoke bombs lit up the sky,some 2,000 runners from China and abroad set off to reach one of the country’s most sacred Buddhist peaks.Over the past decade,this race has become a fixture on the global running calendar and a symbol of the growing popularity of endurance sports.
基金The authors wish to thank the financial support of the Spanish Ministry of Science,Innovation and Universities in reference to the Project:Efficiency improvement and noise reduction of a vertical axis wind turbine for urban environments(MERTURB)-Ref.MCINN-22-TED2021-131307B-100.
文摘Biomimetics has recently emerged as an interesting approach to enhance renewable energy technologies.In this work,bioinspired Trailing Edge Serrations(TES)were evaluated on a typical Vertical Axis Wind Turbine(VAWT)airfoil,the DU06-W200.As noise reduction benefits of these mechanisms are already well-established,this study focuses on their impact on airfoil and VAWT performance.A saw-tooth geometry was chosen based on VAWT specifications and existing research,followed by a detailed assessment through wind tunnel tests using a newly developed aerodynamic balance.For a broad spectrum of attack angles and Reynolds numbers,lift,drag,and pitching moments were carefully measured.The results show that TES enhance the lift-to-drag ratio,especially in stalled conditions,and postpone stall at negative angles,expanding the effective performance range.A notable increase in pitching moment also is also observed,relevant for blade-strut joint design.Additionally,the impact on turbine performance was estimated using an analytical model,demonstrating excellent accuracy when compared against previous experimental results.TES offer a modest 2%improve-ment in peak performance,though they slightly narrow the optimal tip-speed ratio zone.Despite this,the potential noise reduction and performance gains make TES a valuable addition to VAWT designs,especially in urban settings.
文摘Meteor Burst Communication(MBC),a niche yet revolutionary wireless communication paradigm,exploits the transient ionized trails generated by meteors ablating in Earth’s atmosphere to enable sporadic yet resilient long-distance radio links.Known for its exceptional resilience,robustness,and sustained connectivity,MBC holds significant promise for applications in emergency communications,remote area connectivity,military/defense systems,and environmental monitoring.However,the scientific exploration and application of MBC have long been highly challenging.In particular,under the combined influence of multiple physical field factors,the channel experiences superimposed multiple random fading effects,exhibiting bursty,highly time-varying,and strongly random characteristics.This persistent technical challenge has resulted in the absence of a practical statistical channel model for MBC to date.
