A technique developed to accurately simulate the amplification of back-reflected light through a multi-petawatt laser system is presented.Using the Frantz–Nodvik equation,we developed an iterative algorithm to simula...A technique developed to accurately simulate the amplification of back-reflected light through a multi-petawatt laser system is presented.Using the Frantz–Nodvik equation,we developed an iterative algorithm to simulate the amplification of the main beam as it propagates through solid-state multipass amplifiers,while also accounting for back-reflections from experimental targets and the residual gain within the crystals.Our technique builds on the theoretical model by estimating the energy levels after multiple passes through all amplifiers and refining the simulated data using a brute-force optimization algorithm.We also demonstrate an application of this tool aimed at evaluating machine safety:optimizing the laser system to minimize crystal gain in the post-pulse regime and,consequently,the amplification of back-reflections,while taking advantage of the B-integral.展开更多
The Hengduan Mountains are susceptible to hydrological disasters,with precipitation representing a significant risk factor.For effective disaster mitigation strategies,accurate rainfall simulation is essential,typical...The Hengduan Mountains are susceptible to hydrological disasters,with precipitation representing a significant risk factor.For effective disaster mitigation strategies,accurate rainfall simulation is essential,typically achieved through the use of numerical models.Some research has indicated that using a convection-permitting model(CPM)at high resolution(<4 km)could provide more precise rainfall estimates than traditional cumulus parameterization schemes(CPs)at lower resolutions,but CPM demands substantial computational resources.Therefore,to assess whether CPM maintains superior simulation accuracy,this study employed the Weather Research and Forecasting(WRF)model to simulate summer precipitation over the Hengduan Mountains in 2009,comparing CPM(4 km)and CPs(10 km)resolutions.The simulations were evaluated against satellite observations to quantify their performance differences.The results showed that all simulations overestimated amounts and frequency.The CPM outperformed most CPs,except the Tiedtke scheme,which exhibited Root Mean Square Errors(RMSEs)of 2.51 mm·day^(-1) for amount and 5.63%for frequency.The CPM had slightly higher RMSEs of 2.80 mm·day^(-1) and 6.98%,respectively.Both CPM and Tiedtke captured the spatial distribution of precipitation,but overestimations occurred in central and southern regions and underestimations in river valleys.While Tiedtke demonstrated superiority in various aspects,CPM provided more detail.Additionally,the study noted significant differences in diurnal variation at intermediate altitudes and found correlations between rainfall amounts and convective available potential energy(CAPE),frequency,and outgoing longwave radiation(OLR),respectively.Consequently,the Tiedtke scheme is suggested as a more resource-efficient alternative to CPM for simulating precipitation in the Hengduan Mountains.展开更多
The deep potential(DP)is an innovative approach based on deep learning that uses ab initio calculation data derived from density functional theory(DFT),to create high-accuracy potential functions for various materials...The deep potential(DP)is an innovative approach based on deep learning that uses ab initio calculation data derived from density functional theory(DFT),to create high-accuracy potential functions for various materials.Platinum(Pt)is a rare metal with significant potential in energy and catalytic applications,However,there are challenges in accurately capturing its physical properties due to high experimental costs and the limitations of traditional empirical methods.This study employs deep learning methods to construct high-precision potential models for single-element systems of Pt and validates their predictive performance in complex environments.The newly developed DP is highly consistent with DFT results in predicting the stable phases,lattice constants,surface energies,and phonons dispersion relations of Pt,demonstrating outstanding quantum-level accuracy.Additionally,the complex phase transitions and domain formations of Pt are extensively and quantitatively analyzed.Molecular dynamic simulations utilizing the DP approach show that Pt’s face-centered cubic(FCC)structure undergoes a phase transition from solid to liquid at its melting point of 1986 K,this is in close agreement with the experimental value of 2041.5 K.Increased temperature enhances the diffusion of Pt atoms,with a self-diffusion coefficient of 1.17×10-11 m2/s at the melting point,comparable to that of other FCC metals.This result can be utilized for the precise analysis of the fundamental properties of the rare metal Pt at the microscopic scale,and it facilitates the development of binary or multi-component deep potential models that include Pt.展开更多
Researching and comprehending the characteristics of destructive seismic motions is essential for the seismic design of critical infrastructure.This study employs historical data from the M 7.5 earthquake that occurre...Researching and comprehending the characteristics of destructive seismic motions is essential for the seismic design of critical infrastructure.This study employs historical data from the M 7.5 earthquake that occurred in 1850 to simulate the impacts of a M 7.5 event on hydropower stations located in proximity to Xichang.Key factors taken into account in the simulation of seismic motion encompass uncertainties,mixed-source models,and the placement of asperities.Through these simulations,we acquired the peak ground acceleration(PGA),acceleration time histories,and acceleration response spectra for the hydropower facilities affected by the earthquake.To perform a comprehensive analysis,we utilized a multi-scenario stochastic finite fault simulation method to estimate parameters including the minimum,average,and maximum values of PGA and pseudo-spectral acceleration(PSA)response spectra.Additionally,we assessed the 50^(th),84^(th),and 95^(th)percentiles values of the peak ground acceleration and pseudo-spectral acceleration response spectra.The simulation results also include peak ground acceleration field maps and peak ground velocity(PGV)field maps and intensity distribution maps pertaining to the earthquake.The findings demonstrate that the intensity maps produced through the stochastic finite fault method closely correspond with the intensity contour maps published of historical seismic records.These findings offer significant insights for the seismic safety evaluation and design of the specified hydropower stations.Moreover,this multi-scenario methodology can be effectively utilized for other critical infrastructure projects to derive dependable seismic motion parameters.展开更多
This study examines the structural responses of a novel articulated foundation wind turbine with compliant structural design under offshore winds,waves,and seismic events.A numerical simulation analysis framework,ADRT...This study examines the structural responses of a novel articulated foundation wind turbine with compliant structural design under offshore winds,waves,and seismic events.A numerical simulation analysis framework,ADRT(Articulated Foundation Offshore Wind Turbine Dynamic Analysis and Response Prediction Tool),has been developed and validated through benchmark studies with established numerical tools,demonstrating strong correlation.The research conducts dynamic response analysis of the Articulated Foundation Offshore Wind Turbine(AFOWT)system under various seismic scenarios.Analysis reveals that response amplitude increases proportionally with seismic intensity.When wind and seismic forces act simultaneously,the system's response amplitude perpendicular to the rotor plane decreases compared with isolated seismic action,attributed to aerodynamic damping effects,except for blade deformation response.During emergency braking shutdown operations triggered by seismic excitation,the structural seismic response exceeds design safety thresholds during the shutdown feathering process,indicating that emergency shutdown procedures do not effectively mitigate the system's structural response.展开更多
1.Introduction Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)is a powerful tool for simulating dense gas-solid reacting flows,which is essential in combustion,metallurgy,and waste management.Traditional...1.Introduction Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)is a powerful tool for simulating dense gas-solid reacting flows,which is essential in combustion,metallurgy,and waste management.Traditional methods face challenges in CFD-DEM modeling of dense gas-solid flows due to multi-scale characteristics,limiting resolution and creating simulation bottlenecks.By integrating fluid dynamics and particle behavior,it optimizes industrial processes.This review highlights advancements,applications,and challenges,emphasizing its role in sustainable engineering.展开更多
基金supported by contract PN 23210105 sponsored by the Romanian Ministry of Research,Innovation and Digitalizationthe IOSIN Funds for Research Infrastructures of National Interest+1 种基金the IMPULSE project funded by the EU’s Horizon 2020 research and innovation program under grant agreement No.871161project ELI-RO-19‘HighProtonPLas’,funded by IFA and through Project ELI-RO/DFG/2023-001 ARNPhot funded by the Institute of Atomic Physics Romania。
文摘A technique developed to accurately simulate the amplification of back-reflected light through a multi-petawatt laser system is presented.Using the Frantz–Nodvik equation,we developed an iterative algorithm to simulate the amplification of the main beam as it propagates through solid-state multipass amplifiers,while also accounting for back-reflections from experimental targets and the residual gain within the crystals.Our technique builds on the theoretical model by estimating the energy levels after multiple passes through all amplifiers and refining the simulated data using a brute-force optimization algorithm.We also demonstrate an application of this tool aimed at evaluating machine safety:optimizing the laser system to minimize crystal gain in the post-pulse regime and,consequently,the amplification of back-reflections,while taking advantage of the B-integral.
基金supported by the National Natural Science Foundation of China(No.42475101)Open Research Fund of Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province(No.SZKT202303)+1 种基金the Science and Technology Research Program of Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(No.IMHE-ZDRW-06)support by the National Key Scientific and Technological Infrastructure project“Earth System Numerical Simulation Facility”(EarthLab)。
文摘The Hengduan Mountains are susceptible to hydrological disasters,with precipitation representing a significant risk factor.For effective disaster mitigation strategies,accurate rainfall simulation is essential,typically achieved through the use of numerical models.Some research has indicated that using a convection-permitting model(CPM)at high resolution(<4 km)could provide more precise rainfall estimates than traditional cumulus parameterization schemes(CPs)at lower resolutions,but CPM demands substantial computational resources.Therefore,to assess whether CPM maintains superior simulation accuracy,this study employed the Weather Research and Forecasting(WRF)model to simulate summer precipitation over the Hengduan Mountains in 2009,comparing CPM(4 km)and CPs(10 km)resolutions.The simulations were evaluated against satellite observations to quantify their performance differences.The results showed that all simulations overestimated amounts and frequency.The CPM outperformed most CPs,except the Tiedtke scheme,which exhibited Root Mean Square Errors(RMSEs)of 2.51 mm·day^(-1) for amount and 5.63%for frequency.The CPM had slightly higher RMSEs of 2.80 mm·day^(-1) and 6.98%,respectively.Both CPM and Tiedtke captured the spatial distribution of precipitation,but overestimations occurred in central and southern regions and underestimations in river valleys.While Tiedtke demonstrated superiority in various aspects,CPM provided more detail.Additionally,the study noted significant differences in diurnal variation at intermediate altitudes and found correlations between rainfall amounts and convective available potential energy(CAPE),frequency,and outgoing longwave radiation(OLR),respectively.Consequently,the Tiedtke scheme is suggested as a more resource-efficient alternative to CPM for simulating precipitation in the Hengduan Mountains.
基金supported by the Kunming University of Science and Technology“Double First-Class”Joint Special Project(Grant No.202101BE070001-011)Yunnan Fundamental Research Projects(202201BE070001-008,202201AT070192)+5 种基金National Natural Science Foundation of China(52402077)Shaanxi Province Key R&D Program(2021ZDLGY11-08)Open Project of Shaanxi Laboratory(2021SXsyS01-05)Open Project of Yunnan Precious Metals Laboratory(YPML-2023050240)National Natural Science Foundation of China(Grant No.52462009)Yunnan Fundamental Research Projects(Grant Nos.202201AT070192,202101BE070001-011).
文摘The deep potential(DP)is an innovative approach based on deep learning that uses ab initio calculation data derived from density functional theory(DFT),to create high-accuracy potential functions for various materials.Platinum(Pt)is a rare metal with significant potential in energy and catalytic applications,However,there are challenges in accurately capturing its physical properties due to high experimental costs and the limitations of traditional empirical methods.This study employs deep learning methods to construct high-precision potential models for single-element systems of Pt and validates their predictive performance in complex environments.The newly developed DP is highly consistent with DFT results in predicting the stable phases,lattice constants,surface energies,and phonons dispersion relations of Pt,demonstrating outstanding quantum-level accuracy.Additionally,the complex phase transitions and domain formations of Pt are extensively and quantitatively analyzed.Molecular dynamic simulations utilizing the DP approach show that Pt’s face-centered cubic(FCC)structure undergoes a phase transition from solid to liquid at its melting point of 1986 K,this is in close agreement with the experimental value of 2041.5 K.Increased temperature enhances the diffusion of Pt atoms,with a self-diffusion coefficient of 1.17×10-11 m2/s at the melting point,comparable to that of other FCC metals.This result can be utilized for the precise analysis of the fundamental properties of the rare metal Pt at the microscopic scale,and it facilitates the development of binary or multi-component deep potential models that include Pt.
基金the support of National Natural Science Foundation of China(Grant Numbers 52192675 and 52378541)。
文摘Researching and comprehending the characteristics of destructive seismic motions is essential for the seismic design of critical infrastructure.This study employs historical data from the M 7.5 earthquake that occurred in 1850 to simulate the impacts of a M 7.5 event on hydropower stations located in proximity to Xichang.Key factors taken into account in the simulation of seismic motion encompass uncertainties,mixed-source models,and the placement of asperities.Through these simulations,we acquired the peak ground acceleration(PGA),acceleration time histories,and acceleration response spectra for the hydropower facilities affected by the earthquake.To perform a comprehensive analysis,we utilized a multi-scenario stochastic finite fault simulation method to estimate parameters including the minimum,average,and maximum values of PGA and pseudo-spectral acceleration(PSA)response spectra.Additionally,we assessed the 50^(th),84^(th),and 95^(th)percentiles values of the peak ground acceleration and pseudo-spectral acceleration response spectra.The simulation results also include peak ground acceleration field maps and peak ground velocity(PGV)field maps and intensity distribution maps pertaining to the earthquake.The findings demonstrate that the intensity maps produced through the stochastic finite fault method closely correspond with the intensity contour maps published of historical seismic records.These findings offer significant insights for the seismic safety evaluation and design of the specified hydropower stations.Moreover,this multi-scenario methodology can be effectively utilized for other critical infrastructure projects to derive dependable seismic motion parameters.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.42506226 and 52301321)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20251032,BK20230669 and BK20231255)。
文摘This study examines the structural responses of a novel articulated foundation wind turbine with compliant structural design under offshore winds,waves,and seismic events.A numerical simulation analysis framework,ADRT(Articulated Foundation Offshore Wind Turbine Dynamic Analysis and Response Prediction Tool),has been developed and validated through benchmark studies with established numerical tools,demonstrating strong correlation.The research conducts dynamic response analysis of the Articulated Foundation Offshore Wind Turbine(AFOWT)system under various seismic scenarios.Analysis reveals that response amplitude increases proportionally with seismic intensity.When wind and seismic forces act simultaneously,the system's response amplitude perpendicular to the rotor plane decreases compared with isolated seismic action,attributed to aerodynamic damping effects,except for blade deformation response.During emergency braking shutdown operations triggered by seismic excitation,the structural seismic response exceeds design safety thresholds during the shutdown feathering process,indicating that emergency shutdown procedures do not effectively mitigate the system's structural response.
文摘1.Introduction Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)is a powerful tool for simulating dense gas-solid reacting flows,which is essential in combustion,metallurgy,and waste management.Traditional methods face challenges in CFD-DEM modeling of dense gas-solid flows due to multi-scale characteristics,limiting resolution and creating simulation bottlenecks.By integrating fluid dynamics and particle behavior,it optimizes industrial processes.This review highlights advancements,applications,and challenges,emphasizing its role in sustainable engineering.
