Compressor surge is a major aerodynamic instability that constrains the performance and reliability of industrial gas turbines.To address this challenge,this paper provides a comprehensive review of recent progress in...Compressor surge is a major aerodynamic instability that constrains the performance and reliability of industrial gas turbines.To address this challenge,this paper provides a comprehensive review of recent progress in surge monitoring,modeling,and control strategies.Key difficulties in early surge detection are identified,including ambiguous precursor signals,strongly coupled system dynamics,and sensor-actuator time delays.The review categorizes existing modeling approaches into high-fidelity computational fluid dynamics(CFD),reducedorder physical models,and data-driven techniques,evaluating each in terms of accuracy,adaptability,and realtime feasibility.In terms of control strategies,both passive and active methods are analyzed,with a particular focus on closed-loop feedback,model predictive control,robust control,and intelligent data-driven approaches.The review concludes by outlining future directions that prioritize model integration,control reliability,and systemlevel coordination for enhanced compressor stability.展开更多
Surge-type glaciers are widely developed in mountainous areas around the world.Understanding the trigger mechanism of glacier surge is a prerequisite for addressing their impacts on hydrological assessments,disentangl...Surge-type glaciers are widely developed in mountainous areas around the world.Understanding the trigger mechanism of glacier surge is a prerequisite for addressing their impacts on hydrological assessments,disentangling climate-glacier linkages,and mitigating downstream hazards.Most glacier surges occur in the compound glaciers;however,attention paid to the trigger mechanisms of such surges is minimal.This study confirmed two surges in the northern and southern branches of the Aru-4 glacier,respectively,in the Western Tibetan Plateau,using multisource remote sensing data.The northern branch of the Aru-4 glacier entered the active phase in 1999 and the active phase lasted for 6 years.The southern branch of the Aru-4 glacier entered the active phase in 2007 and the active phase lasted for 9 years.The southern branch of the Aru-4 glacier experienced a long period of retreat before the northern branch surged and their tongues were in a detached state.The northern branch surge carried a large amount of ice to the frontal area,blocking the downward transport of ice from the southern branch and initiated surge.Through the analysis of two surge processes of Aru-4 glacier,we found a new surge mechanism for compound glaciers.It was revealed that surges in such glaciers are not only triggered by the reduction in basal sliding resistance caused by the internal factors.These surges initiated in the upper part of the glacier then propagated to down glacier by intense compression force.Furthermore,surges can also be triggered by external intervention of blocking by other branches.This external trigger initiates the surge in the lower part of the glacier then propagated to the upper part by longitudinal traction force.In addition,comparing with the surge triggered by the internal factors,the surge triggered by the external intervention may have a more dramatic process.展开更多
Timely and accurate forecasting of storm surges can effectively prevent typhoon storm surges from causing large economic losses and casualties in coastal areas.At present,numerical model forecasting consumes too many ...Timely and accurate forecasting of storm surges can effectively prevent typhoon storm surges from causing large economic losses and casualties in coastal areas.At present,numerical model forecasting consumes too many resources and takes too long to compute,while neural network forecasting lacks regional data to train regional forecasting models.In this study,we used the DUAL wind model to build typhoon wind fields,and constructed a typhoon database of 75 processes in the northern South China Sea using the coupled Advanced Circulation-Simulating Waves Nearshore(ADCIRC-SWAN)model.Then,a neural network with a Res-U-Net structure was trained using the typhoon database to forecast the typhoon processes in the validation dataset,and an excellent storm surge forecasting effect was achieved in the Pearl River Estuary region.The storm surge forecasting effect of stronger typhoons was improved by adding a branch structure and transfer learning.展开更多
Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These su...Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales.展开更多
Lianfa Textile(002394) was founded in 1955. After decades of hard work, it has gradually grown into a large-scale textile enterprise with operations ranging from cotton processing to garment production. Its business c...Lianfa Textile(002394) was founded in 1955. After decades of hard work, it has gradually grown into a large-scale textile enterprise with operations ranging from cotton processing to garment production. Its business covers cotton spinning, yarndyed weaving, printing and dyeing, home textiles, knitting, clothing, brands, trade, logistics and new energy, among others. The company's main products include six series: yarn, yarn-dyed fabrics, printed and dyed fabrics, home textile fabrics and clothing.展开更多
To investigate the effect of typhoon path translation on storm surge augmentation,the storm surge during Typhoon 1909 Lekima in the East China Sea is simulated using Delft 3D.The model sets up three scenarios to analy...To investigate the effect of typhoon path translation on storm surge augmentation,the storm surge during Typhoon 1909 Lekima in the East China Sea is simulated using Delft 3D.The model sets up three scenarios to analyze the path’s effect on storm surge in the Shandong Peninsula Sea by shifting the typhoon path to the east and west.Results show that the areas of maximum storm surge in each scenario are located on both sides of the typhoon path and shift along with its movement.When the typhoon path shifts eastward,the maximum storm surge intensifies at Zhifu Island station 8 hours earlier.Conversely,a westward shift in the typhoon track leads to a maximum storm surge increase at Shidao Island station 12 hours earlier.Other scenarios exhibit minimal deviation from the original route.Typhoons penetrating deep inland can induce substantial storm surges,with the most extensive surge area situated in the western part of the Shandong Peninsula.展开更多
Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard a...Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard assessment of SSEs,this study introduced the concept of the storm surge event seawater-atmosphere system(SSE-SAS)and proposed the system energy equivalence(SEE)model from a systemic energy perspective.SEE was obtained by employing a parameterization approach,and the hazard index(HI)and the concept of most significant hazard(MSH)were adopted to evaluate the severity of SSE-SAS.SEE at five stations in the Shandong Peninsula was calculated from 2005 to 2019,and probability analysis and hazard assessment were further conducted.Results show that the SEE of SSE-SAS ranges from 0.029×10^(3) to 30.418×10^(3) J/m^(2),and it exhibits an insignificant decreasing trend from 2005 to 2019.The SEE of SSE-SAS in the west of the Shandong Peninsula is greater than that in the east.Moreover,storm waves,storm surges,and storm rainfall are the major contributors to SEE,which exhibit different spatial patterns and characters in different SSE-SAS types.The HI of SSE-SAS at five stations is no more than medium hazard level,with MSH at return periods of 2-to 4-year level.This study provides a new approach for quantifying multi-hazard SSEs,which offers scientific insights for regional multi-hazard risk reduction and mitigation efforts.展开更多
Previous studies have demonstrated that the surge in jacking force during the Guanjingkou project is caused by the contact conditions of the debris bentonite slurry outside the pipe.Therefore,this paper further system...Previous studies have demonstrated that the surge in jacking force during the Guanjingkou project is caused by the contact conditions of the debris bentonite slurry outside the pipe.Therefore,this paper further systematically investigates the influence of different debris slurry mass ratios(SLRs)and different particle size distributions(PSDs)on the pipe-rock friction characteristics using friction tests.The test results reveal that under the same PSD,an adequate amount of slurry(with an SLR of 1:4)consistently yields the lowest friction coefficient.When the SLR is between 1:2 and 1:3,the viscosity of the slurry reaches its peak,resulting in the highest friction coefficient.Additionally,when the PSD is 1:1:5 and 1:1:15,the friction coefficient is primarily governed by the plowing effect at the contact surface.When the PSD is 5:1:1 and 15:1:1,the friction coefficient is mainly controlled by the void ratio(VR)of debris.In the case of PSDs 1:5:1 and 1:15:1,the friction coefficient is jointly controlled by the adhesion effect of high-viscosity slurry and the plowing effect at the contact surface,and it gradually shifts towards being dominated by the VR as the amount of debris increases.Regardless of the SLRs and PSDs,the continuous deposition of debris and the injection of slurry incessantly exacerbate both the plowing and adhesion effects,creating a vicious cycle.This is the reason why the high-pressure water flushing method can not only fail to resolve the issue but also accelerate the occurrence of the surge in jacking force.展开更多
The local time-stepping(LTS)algorithm is an adaptive method that adjusts the time step by selecting suitable intervals for different regions based on the spatial scale of each cell and water depth and flow velocity be...The local time-stepping(LTS)algorithm is an adaptive method that adjusts the time step by selecting suitable intervals for different regions based on the spatial scale of each cell and water depth and flow velocity between cells.The method can be optimized by calculating the maximum power of two of the global time step increments in the domain,allowing the optimal time step to be approached throughout the grid.To verify the acceleration and accuracy of LTS in storm surge simulations,we developed a model to simulate astronomical storm surges along the southern coast of China.This model employs the shallow water equations as governing equations,numerical discretization using the finite volume method,and fluxes calculated by the Roe solver.By comparing the simulation results of the traditional global time-stepping algorithm with those of the LTS algorithm,we find that the latter fit the measured data better.Taking the calculation results of Typhoon Sally in 1996 as an example,we show that compared with the traditional global time-stepping algorithm,the LTS algorithm reduces computation time by 2.05 h and increases computation efficiency by 2.64 times while maintaining good accuracy.展开更多
A coupled tide-surge-wave model was established to analyze the impacts of radial sand ridges on storm surges in the South Yellow Sea.Numerical topography experiments were designed on the basis of multiple well-verifie...A coupled tide-surge-wave model was established to analyze the impacts of radial sand ridges on storm surges in the South Yellow Sea.Numerical topography experiments were designed on the basis of multiple well-verified types of extreme weather events.The findings demonstrated that the radial sand ridges(RSRs)generally enhanced tidal levels,current velocities,and significant wave heights in the affected area.The nonlinear effects of shallow water in the radial sand ridge area can induce large tide ranges.A unique seabed can cause an increase in current speed from the open sea to the nearshore.Another impact is that subaqueous ridges can result in shallow water conditions,and the degree of depth-induced wave breaking significantly varies.Compared with those in the northern and southern radial sand ridge areas,the tidal levels,current speeds,and wave heights in the middle radial sand ridge area were the highest,which can cause more severe storm surge disasters.Additionally,the wave radiation stress varied obviously under the action of fan-shaped sand ridges.Thus,it is necessary to consider wave-current interactions when modeling storm surges in sand ridges.展开更多
Floods and storm surges pose significant threats to coastal regions worldwide,demanding timely and accurate early warning systems(EWS)for disaster preparedness.Traditional numerical and statistical methods often fall ...Floods and storm surges pose significant threats to coastal regions worldwide,demanding timely and accurate early warning systems(EWS)for disaster preparedness.Traditional numerical and statistical methods often fall short in capturing complex,nonlinear,and real-time environmental dynamics.In recent years,machine learning(ML)and deep learning(DL)techniques have emerged as promising alternatives for enhancing the accuracy,speed,and scalability of EWS.This review critically evaluates the evolution of ML models—such as Artificial Neural Networks(ANN),Convolutional Neural Networks(CNN),and Long Short-Term Memory(LSTM)—in coastal flood prediction,highlighting their architectures,data requirements,performance metrics,and implementation challenges.A unique contribution of this work is the synthesis of real-time deployment challenges including latency,edge-cloud tradeoffs,and policy-level integration,areas often overlooked in prior literature.Furthermore,the review presents a comparative framework of model performance across different geographic and hydrologic settings,offering actionable insights for researchers and practitioners.Limitations of current AI-driven models,such as interpretability,data scarcity,and generalization across regions,are discussed in detail.Finally,the paper outlines future research directions including hybrid modelling,transfer learning,explainable AI,and policy-aware alert systems.By bridging technical performance and operational feasibility,this review aims to guide the development of next-generation intelligent EWS for resilient and adaptive coastal management.展开更多
Cold-surge events can lead to temperature drops and strong winds,which then leads to upper-ocean cooling and deepening of the mixed-layer depth,as illustrated in previous studies.In this study,based on the temperature...Cold-surge events can lead to temperature drops and strong winds,which then leads to upper-ocean cooling and deepening of the mixed-layer depth,as illustrated in previous studies.In this study,based on the temperature drop of Shanwei meteorological station,two extreme cold surges and five weak cold invasions in the South China Sea are simulated using an ocean-atmosphere coupled model to investigate their different impacts on the upper-ocean temperature.The diffusion term contributes to the difference in temperature tendency of the upper 20 m,while the advection term contributes to the positive difference from 20 to 80 m of the offshore region and negative difference from 80 to 160 m.In addition,the significant differences are attributed primarily to the influence of the upper-ocean temperature gradient,which subsequently impacts the advection term and results in notable differences in temperature tendency at depths from 80 to 160 m.展开更多
In this paper, ECOMSED （Estuarine Coastal Ocean Model with sediment transport） model is employed to simulate storm surge process caused by typhoon passing across East China Sea in nearly years. Capability of ECOMSED...In this paper, ECOMSED （Estuarine Coastal Ocean Model with sediment transport） model is employed to simulate storm surge process caused by typhoon passing across East China Sea in nearly years. Capability of ECOMSED to simulate storm surge is validated by comparing model result with observed data. Sensitivity experiments are designed to study the influence of sea level rise on typhoon storm surge. Numerical experiment shows that influence of mean sea level rise on typhoon storm surge is non-uniform spatially and changes as typhoon process differs. Maybe fixed boundary method would weaken the influence of mean sea level rise on storm surge, and free boundary method is suggested for the succeeding study.展开更多
Because of the special topography and large tidal range in the South Yellow Sea,the dynamic process of tide and storm surge is very complicated.The shallow water circulation model Advanced Circulation(ADCIRC)was used ...Because of the special topography and large tidal range in the South Yellow Sea,the dynamic process of tide and storm surge is very complicated.The shallow water circulation model Advanced Circulation(ADCIRC)was used to simulate the storm surge process during typhoon Winnie,Prapiroon,and Damrey,which represents three types of tracks attacking the South Yellow Sea,which are,moving northward after landing,no landing but active in offshore areas,and landing straightly to the coastline.Numerical experiments were carried out to investigate the effects of tidal phase on the tide-surge interaction as well as storm surge.The results show that the peak surge caused by Winnie and Prapiroon occurs 2-5 h before the high tide and its occurring time relative to high tide has little change with tidal phase variations.On the contrary,under the action of Damrey,the occurring time of the peak surge relative to high tide varies with tidal phase.The variation of tide-surge interaction is about 0.06-0.37 m,and the amplitude variations of interaction are smooth when tidal phase changes for Typhoon Winnie and Prapiroon.While the interaction is about 0.07-0.69 m,and great differences exists among the stations for Typhoon Damrey.It can be concluded that the tide-surge interaction of the former is dominated by the tidal phase modulation,and the time of surge peak is insensitive to the tidal phase variation.While the interaction of the latter is dominated by storm surge modulation due to the water depth varying with tide,the time of surge peak is significantly affected by tidal phase.Therefore,influence of tidal phase on storm surge is related to typhoon tracks which may provide very useful information at the design stage of coastal protection systems.展开更多
An integrally coupled wave-tide-surge model was developed and then applied to the simulation of the wave-typhoon surge for the typhoon Isewan （typhoon Vera （5915））, which is the strongest typhoon that has struck J...An integrally coupled wave-tide-surge model was developed and then applied to the simulation of the wave-typhoon surge for the typhoon Isewan （typhoon Vera （5915））, which is the strongest typhoon that has struck Japan and caused incalculable damage. An integrally coupled tide-surge-wave model using identical and homogeneous meshes in an unstructured grid system was used to correctly resolve the physics of wave-circulation interaction in both models. All model components were validated independently. The storm surge and wave properties such as the surge height, the significant wave height, wave period and direction were reproduced reasonably under the meteorological forcing, which was reprocessed to be close to the observations. The resulting modeling system can be used extensively for the prediction of the storm surge and waves and the usual barotropic forecast.展开更多
Storm surge along the China＇s Zhe-Min coast is addressed using the tightly coupled surge model ofADCIRC＋SWAN. In this study, we primarily focus on the effects of surge-tide interaction and waveset-up/set-down. And t...Storm surge along the China＇s Zhe-Min coast is addressed using the tightly coupled surge model ofADCIRC＋SWAN. In this study, we primarily focus on the effects of surge-tide interaction and waveset-up/set-down. And the influences of intensity and landing moment of tropical cyclone （TC） arealso presented. The results show that： water elevation without considering tide-surge interactiontends to be underestimated/overestimated when TC lands during astronomical low/high tide;tide-surge coupling effect is more pronounced north of TC track （more than 0.7 m in our cases）;irrelevant to TC＇s intensity, wave set-up south of TC track is negligible because the depth-relatedwave breaking doesn＇t occur in water body blown towards open seas.展开更多
Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Ti...Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.展开更多
This study proposes an active surge control method based on deep reinforcement learning to ensure the stability of compressors when adhering to the pressure rise command across the wide operating range of an aeroengin...This study proposes an active surge control method based on deep reinforcement learning to ensure the stability of compressors when adhering to the pressure rise command across the wide operating range of an aeroengine.Initially,the study establishes the compressor dynamic model with uncertainties,disturbances,and Close-Coupled Valve(CCV)actuator delay.Building upon this foundation,a Partially Observable Markov Decision Process(POMDP)is defined to facilitate active surge control.To address the issue of unobservability,a nonlinear state observer is designed using a finite-time high-order sliding mode.Furthermore,an Improved Soft Actor-Critic(ISAC)algorithm is developed,incorporating prioritized experience replay and adaptive temperature parameter techniques,to strike a balance between exploration and convergence during training.In addition,reasonable observation variables,error-segmented reward functions,and random initialization of model parameters are employed to enhance the robustness and generalization capability.Finally,to assess the effectiveness of the proposed method,numerical simulations are conducted,and it is compared with the fuzzy adaptive backstepping method and Second-Order Sliding Mode Control(SOSMC)method.The simulation results demonstrate that the deep reinforcement learning based controller outperforms other methods in both tracking accuracy and robustness.Consequently,the proposed active surge controller can effectively ensure stable operation of compressors in the high-pressure-ratio and high-efficiency region.展开更多
A method to improve the surge current capability of silicon carbide(SiC)merged PiN Schottky(MPS)diodes is presented and investigated via three-dimensional electro-thermal simulations.When compared with a conventional ...A method to improve the surge current capability of silicon carbide(SiC)merged PiN Schottky(MPS)diodes is presented and investigated via three-dimensional electro-thermal simulations.When compared with a conventional MPS diode,the proposed structure has a more uniform current distribution during bipolar conduction due to the help of the continuous P+surface,which can avoid the formation of local hotspots during the surge process.The Silvaco simulation results show that the proposed structure has a 20.29%higher surge capability and a 15.06%higher surge energy compared with a conventional MPS diode.The bipolar on-state voltage of the proposed structure is 4.69 V,which is 56.29%lower than that of a conventional MPS diode,enabling the device to enter the bipolar mode earlier during the surge process.Furthermore,the proposed structure can suppress the occurrence of‘snapback'phenomena when switching from the unipolar to the bipolar operation mode.In addition,an analysis of the surge process of MPS diodes is carried out in detail.展开更多
文摘Compressor surge is a major aerodynamic instability that constrains the performance and reliability of industrial gas turbines.To address this challenge,this paper provides a comprehensive review of recent progress in surge monitoring,modeling,and control strategies.Key difficulties in early surge detection are identified,including ambiguous precursor signals,strongly coupled system dynamics,and sensor-actuator time delays.The review categorizes existing modeling approaches into high-fidelity computational fluid dynamics(CFD),reducedorder physical models,and data-driven techniques,evaluating each in terms of accuracy,adaptability,and realtime feasibility.In terms of control strategies,both passive and active methods are analyzed,with a particular focus on closed-loop feedback,model predictive control,robust control,and intelligent data-driven approaches.The review concludes by outlining future directions that prioritize model integration,control reliability,and systemlevel coordination for enhanced compressor stability.
基金funded by the Open Research Fund of TPESER(Grant No.TPESER202502)the National Key Research and Development Program of China(Grant No.2024YFF0810700)+3 种基金the Science and Technology Program Project of Gansu Province,China(Grant No.25JRRA138)the Hydraulic Science Experimental Research and Technology Extension Project of Gansu Province,China(Grant No.25GSLK094)the Open Foundation of MOE Key Laboratory of Western China's Environmental System,Lanzhou Universitythe Fundamental Research Funds for the Central Universities(Grant No.1zujbky-2025-jdzx02)。
文摘Surge-type glaciers are widely developed in mountainous areas around the world.Understanding the trigger mechanism of glacier surge is a prerequisite for addressing their impacts on hydrological assessments,disentangling climate-glacier linkages,and mitigating downstream hazards.Most glacier surges occur in the compound glaciers;however,attention paid to the trigger mechanisms of such surges is minimal.This study confirmed two surges in the northern and southern branches of the Aru-4 glacier,respectively,in the Western Tibetan Plateau,using multisource remote sensing data.The northern branch of the Aru-4 glacier entered the active phase in 1999 and the active phase lasted for 6 years.The southern branch of the Aru-4 glacier entered the active phase in 2007 and the active phase lasted for 9 years.The southern branch of the Aru-4 glacier experienced a long period of retreat before the northern branch surged and their tongues were in a detached state.The northern branch surge carried a large amount of ice to the frontal area,blocking the downward transport of ice from the southern branch and initiated surge.Through the analysis of two surge processes of Aru-4 glacier,we found a new surge mechanism for compound glaciers.It was revealed that surges in such glaciers are not only triggered by the reduction in basal sliding resistance caused by the internal factors.These surges initiated in the upper part of the glacier then propagated to down glacier by intense compression force.Furthermore,surges can also be triggered by external intervention of blocking by other branches.This external trigger initiates the surge in the lower part of the glacier then propagated to the upper part by longitudinal traction force.In addition,comparing with the surge triggered by the internal factors,the surge triggered by the external intervention may have a more dramatic process.
基金supported by the National Natural Science Foundation of China(Grant No.42076214)Natural Science Foundation of Shandong Province(Grant No.ZR2024QD057).
文摘Timely and accurate forecasting of storm surges can effectively prevent typhoon storm surges from causing large economic losses and casualties in coastal areas.At present,numerical model forecasting consumes too many resources and takes too long to compute,while neural network forecasting lacks regional data to train regional forecasting models.In this study,we used the DUAL wind model to build typhoon wind fields,and constructed a typhoon database of 75 processes in the northern South China Sea using the coupled Advanced Circulation-Simulating Waves Nearshore(ADCIRC-SWAN)model.Then,a neural network with a Res-U-Net structure was trained using the typhoon database to forecast the typhoon processes in the validation dataset,and an excellent storm surge forecasting effect was achieved in the Pearl River Estuary region.The storm surge forecasting effect of stronger typhoons was improved by adding a branch structure and transfer learning.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)National Natural Science Foundation of China(42475003)Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP209)。
文摘Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales.
文摘Lianfa Textile(002394) was founded in 1955. After decades of hard work, it has gradually grown into a large-scale textile enterprise with operations ranging from cotton processing to garment production. Its business covers cotton spinning, yarndyed weaving, printing and dyeing, home textiles, knitting, clothing, brands, trade, logistics and new energy, among others. The company's main products include six series: yarn, yarn-dyed fabrics, printed and dyed fabrics, home textile fabrics and clothing.
基金supported by the Yantai Science,Technology and Innovation Development Programme(Nos.2023 JCYJ094,2023JCYJ097)the Major Research Grant from the Natural Science Foundation of China(NSFC)(No.42330406)。
文摘To investigate the effect of typhoon path translation on storm surge augmentation,the storm surge during Typhoon 1909 Lekima in the East China Sea is simulated using Delft 3D.The model sets up three scenarios to analyze the path’s effect on storm surge in the Shandong Peninsula Sea by shifting the typhoon path to the east and west.Results show that the areas of maximum storm surge in each scenario are located on both sides of the typhoon path and shift along with its movement.When the typhoon path shifts eastward,the maximum storm surge intensifies at Zhifu Island station 8 hours earlier.Conversely,a westward shift in the typhoon track leads to a maximum storm surge increase at Shidao Island station 12 hours earlier.Other scenarios exhibit minimal deviation from the original route.Typhoons penetrating deep inland can induce substantial storm surges,with the most extensive surge area situated in the western part of the Shandong Peninsula.
基金supported by the Key Laboratory of Coastal Science and Integrated Management,Ministry of Natural Resources(No.2022COSIMQ002)the Shandong Provincial Social Science Planning Research Project(No.22CXSXJ15)+1 种基金the Guangxi Key Laboratory of Marine Environmental Science,Guangxi Academy of Sciences(No.GXKLHY21-04)the Hainan Province Marxism Project General Program(No.2023HNMGC03).
文摘Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard assessment of SSEs,this study introduced the concept of the storm surge event seawater-atmosphere system(SSE-SAS)and proposed the system energy equivalence(SEE)model from a systemic energy perspective.SEE was obtained by employing a parameterization approach,and the hazard index(HI)and the concept of most significant hazard(MSH)were adopted to evaluate the severity of SSE-SAS.SEE at five stations in the Shandong Peninsula was calculated from 2005 to 2019,and probability analysis and hazard assessment were further conducted.Results show that the SEE of SSE-SAS ranges from 0.029×10^(3) to 30.418×10^(3) J/m^(2),and it exhibits an insignificant decreasing trend from 2005 to 2019.The SEE of SSE-SAS in the west of the Shandong Peninsula is greater than that in the east.Moreover,storm waves,storm surges,and storm rainfall are the major contributors to SEE,which exhibit different spatial patterns and characters in different SSE-SAS types.The HI of SSE-SAS at five stations is no more than medium hazard level,with MSH at return periods of 2-to 4-year level.This study provides a new approach for quantifying multi-hazard SSEs,which offers scientific insights for regional multi-hazard risk reduction and mitigation efforts.
基金the funding support from the National Natural Science Foundations for Young Scientists of China(Grant No.52208391)Doctoral Foundation Project of Guizhou University(Grant No.2021e78).
文摘Previous studies have demonstrated that the surge in jacking force during the Guanjingkou project is caused by the contact conditions of the debris bentonite slurry outside the pipe.Therefore,this paper further systematically investigates the influence of different debris slurry mass ratios(SLRs)and different particle size distributions(PSDs)on the pipe-rock friction characteristics using friction tests.The test results reveal that under the same PSD,an adequate amount of slurry(with an SLR of 1:4)consistently yields the lowest friction coefficient.When the SLR is between 1:2 and 1:3,the viscosity of the slurry reaches its peak,resulting in the highest friction coefficient.Additionally,when the PSD is 1:1:5 and 1:1:15,the friction coefficient is primarily governed by the plowing effect at the contact surface.When the PSD is 5:1:1 and 15:1:1,the friction coefficient is mainly controlled by the void ratio(VR)of debris.In the case of PSDs 1:5:1 and 1:15:1,the friction coefficient is jointly controlled by the adhesion effect of high-viscosity slurry and the plowing effect at the contact surface,and it gradually shifts towards being dominated by the VR as the amount of debris increases.Regardless of the SLRs and PSDs,the continuous deposition of debris and the injection of slurry incessantly exacerbate both the plowing and adhesion effects,creating a vicious cycle.This is the reason why the high-pressure water flushing method can not only fail to resolve the issue but also accelerate the occurrence of the surge in jacking force.
基金National Natural Science Foundation of China(No.52071306)the Natural Science Foundation of Shandong Province(No.ZR2019MEE050)the Natural Science Foundation of Zhejiang Province(No.LZ22E090003).
文摘The local time-stepping(LTS)algorithm is an adaptive method that adjusts the time step by selecting suitable intervals for different regions based on the spatial scale of each cell and water depth and flow velocity between cells.The method can be optimized by calculating the maximum power of two of the global time step increments in the domain,allowing the optimal time step to be approached throughout the grid.To verify the acceleration and accuracy of LTS in storm surge simulations,we developed a model to simulate astronomical storm surges along the southern coast of China.This model employs the shallow water equations as governing equations,numerical discretization using the finite volume method,and fluxes calculated by the Roe solver.By comparing the simulation results of the traditional global time-stepping algorithm with those of the LTS algorithm,we find that the latter fit the measured data better.Taking the calculation results of Typhoon Sally in 1996 as an example,we show that compared with the traditional global time-stepping algorithm,the LTS algorithm reduces computation time by 2.05 h and increases computation efficiency by 2.64 times while maintaining good accuracy.
基金financially supported by the Fundamental Research Funds for the Central Universities(Grant No.B210202031)the National Natural Science Foundation of China(Grant No.41606042)。
文摘A coupled tide-surge-wave model was established to analyze the impacts of radial sand ridges on storm surges in the South Yellow Sea.Numerical topography experiments were designed on the basis of multiple well-verified types of extreme weather events.The findings demonstrated that the radial sand ridges(RSRs)generally enhanced tidal levels,current velocities,and significant wave heights in the affected area.The nonlinear effects of shallow water in the radial sand ridge area can induce large tide ranges.A unique seabed can cause an increase in current speed from the open sea to the nearshore.Another impact is that subaqueous ridges can result in shallow water conditions,and the degree of depth-induced wave breaking significantly varies.Compared with those in the northern and southern radial sand ridge areas,the tidal levels,current speeds,and wave heights in the middle radial sand ridge area were the highest,which can cause more severe storm surge disasters.Additionally,the wave radiation stress varied obviously under the action of fan-shaped sand ridges.Thus,it is necessary to consider wave-current interactions when modeling storm surges in sand ridges.
文摘Floods and storm surges pose significant threats to coastal regions worldwide,demanding timely and accurate early warning systems(EWS)for disaster preparedness.Traditional numerical and statistical methods often fall short in capturing complex,nonlinear,and real-time environmental dynamics.In recent years,machine learning(ML)and deep learning(DL)techniques have emerged as promising alternatives for enhancing the accuracy,speed,and scalability of EWS.This review critically evaluates the evolution of ML models—such as Artificial Neural Networks(ANN),Convolutional Neural Networks(CNN),and Long Short-Term Memory(LSTM)—in coastal flood prediction,highlighting their architectures,data requirements,performance metrics,and implementation challenges.A unique contribution of this work is the synthesis of real-time deployment challenges including latency,edge-cloud tradeoffs,and policy-level integration,areas often overlooked in prior literature.Furthermore,the review presents a comparative framework of model performance across different geographic and hydrologic settings,offering actionable insights for researchers and practitioners.Limitations of current AI-driven models,such as interpretability,data scarcity,and generalization across regions,are discussed in detail.Finally,the paper outlines future research directions including hybrid modelling,transfer learning,explainable AI,and policy-aware alert systems.By bridging technical performance and operational feasibility,this review aims to guide the development of next-generation intelligent EWS for resilient and adaptive coastal management.
基金jointly supported by the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)[grant number SML2023SP240]the National Natural Science Foundation of China[grant number 92158204]。
文摘Cold-surge events can lead to temperature drops and strong winds,which then leads to upper-ocean cooling and deepening of the mixed-layer depth,as illustrated in previous studies.In this study,based on the temperature drop of Shanwei meteorological station,two extreme cold surges and five weak cold invasions in the South China Sea are simulated using an ocean-atmosphere coupled model to investigate their different impacts on the upper-ocean temperature.The diffusion term contributes to the difference in temperature tendency of the upper 20 m,while the advection term contributes to the positive difference from 20 to 80 m of the offshore region and negative difference from 80 to 160 m.In addition,the significant differences are attributed primarily to the influence of the upper-ocean temperature gradient,which subsequently impacts the advection term and results in notable differences in temperature tendency at depths from 80 to 160 m.
文摘In this paper, ECOMSED （Estuarine Coastal Ocean Model with sediment transport） model is employed to simulate storm surge process caused by typhoon passing across East China Sea in nearly years. Capability of ECOMSED to simulate storm surge is validated by comparing model result with observed data. Sensitivity experiments are designed to study the influence of sea level rise on typhoon storm surge. Numerical experiment shows that influence of mean sea level rise on typhoon storm surge is non-uniform spatially and changes as typhoon process differs. Maybe fixed boundary method would weaken the influence of mean sea level rise on storm surge, and free boundary method is suggested for the succeeding study.
基金Supported by the National Key Research and Development Program of China(No.2016YFC1402000)
文摘Because of the special topography and large tidal range in the South Yellow Sea,the dynamic process of tide and storm surge is very complicated.The shallow water circulation model Advanced Circulation(ADCIRC)was used to simulate the storm surge process during typhoon Winnie,Prapiroon,and Damrey,which represents three types of tracks attacking the South Yellow Sea,which are,moving northward after landing,no landing but active in offshore areas,and landing straightly to the coastline.Numerical experiments were carried out to investigate the effects of tidal phase on the tide-surge interaction as well as storm surge.The results show that the peak surge caused by Winnie and Prapiroon occurs 2-5 h before the high tide and its occurring time relative to high tide has little change with tidal phase variations.On the contrary,under the action of Damrey,the occurring time of the peak surge relative to high tide varies with tidal phase.The variation of tide-surge interaction is about 0.06-0.37 m,and the amplitude variations of interaction are smooth when tidal phase changes for Typhoon Winnie and Prapiroon.While the interaction is about 0.07-0.69 m,and great differences exists among the stations for Typhoon Damrey.It can be concluded that the tide-surge interaction of the former is dominated by the tidal phase modulation,and the time of surge peak is insensitive to the tidal phase variation.While the interaction of the latter is dominated by storm surge modulation due to the water depth varying with tide,the time of surge peak is significantly affected by tidal phase.Therefore,influence of tidal phase on storm surge is related to typhoon tracks which may provide very useful information at the design stage of coastal protection systems.
基金supported by the China-Korea Cooperative Research Project funded by CKJORCa major project titled the development of the marine environmental impact prediction system funded by KIOSTsupported by the project of KISTI for the development of HPC-based management system against national-scale disaster
文摘An integrally coupled wave-tide-surge model was developed and then applied to the simulation of the wave-typhoon surge for the typhoon Isewan （typhoon Vera （5915））, which is the strongest typhoon that has struck Japan and caused incalculable damage. An integrally coupled tide-surge-wave model using identical and homogeneous meshes in an unstructured grid system was used to correctly resolve the physics of wave-circulation interaction in both models. All model components were validated independently. The storm surge and wave properties such as the surge height, the significant wave height, wave period and direction were reproduced reasonably under the meteorological forcing, which was reprocessed to be close to the observations. The resulting modeling system can be used extensively for the prediction of the storm surge and waves and the usual barotropic forecast.
基金the support of National Natural Science Foundation of China (11772339)the Strategic Priority Research Programs (Category B) of the Chinese Academy of Sciences (XDB22040203)
文摘Storm surge along the China＇s Zhe-Min coast is addressed using the tightly coupled surge model ofADCIRC＋SWAN. In this study, we primarily focus on the effects of surge-tide interaction and waveset-up/set-down. And the influences of intensity and landing moment of tropical cyclone （TC） arealso presented. The results show that： water elevation without considering tide-surge interactiontends to be underestimated/overestimated when TC lands during astronomical low/high tide;tide-surge coupling effect is more pronounced north of TC track （more than 0.7 m in our cases）;irrelevant to TC＇s intensity, wave set-up south of TC track is negligible because the depth-relatedwave breaking doesn＇t occur in water body blown towards open seas.
文摘Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.
基金co-supported by the National Natural Science Foundation of China(No.51976089)the Science Center for Gas Turbine Project,China(No.P2023-B-V-001-001)the China Scholarship Council(No.202306830092).
文摘This study proposes an active surge control method based on deep reinforcement learning to ensure the stability of compressors when adhering to the pressure rise command across the wide operating range of an aeroengine.Initially,the study establishes the compressor dynamic model with uncertainties,disturbances,and Close-Coupled Valve(CCV)actuator delay.Building upon this foundation,a Partially Observable Markov Decision Process(POMDP)is defined to facilitate active surge control.To address the issue of unobservability,a nonlinear state observer is designed using a finite-time high-order sliding mode.Furthermore,an Improved Soft Actor-Critic(ISAC)algorithm is developed,incorporating prioritized experience replay and adaptive temperature parameter techniques,to strike a balance between exploration and convergence during training.In addition,reasonable observation variables,error-segmented reward functions,and random initialization of model parameters are employed to enhance the robustness and generalization capability.Finally,to assess the effectiveness of the proposed method,numerical simulations are conducted,and it is compared with the fuzzy adaptive backstepping method and Second-Order Sliding Mode Control(SOSMC)method.The simulation results demonstrate that the deep reinforcement learning based controller outperforms other methods in both tracking accuracy and robustness.Consequently,the proposed active surge controller can effectively ensure stable operation of compressors in the high-pressure-ratio and high-efficiency region.
基金the National Research and Development Program for Major Research Instruments of China(Grant No.62027814)the National Natural Science Foundation of China(Grant No.61904045)Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ20F040004)。
文摘A method to improve the surge current capability of silicon carbide(SiC)merged PiN Schottky(MPS)diodes is presented and investigated via three-dimensional electro-thermal simulations.When compared with a conventional MPS diode,the proposed structure has a more uniform current distribution during bipolar conduction due to the help of the continuous P+surface,which can avoid the formation of local hotspots during the surge process.The Silvaco simulation results show that the proposed structure has a 20.29%higher surge capability and a 15.06%higher surge energy compared with a conventional MPS diode.The bipolar on-state voltage of the proposed structure is 4.69 V,which is 56.29%lower than that of a conventional MPS diode,enabling the device to enter the bipolar mode earlier during the surge process.Furthermore,the proposed structure can suppress the occurrence of‘snapback'phenomena when switching from the unipolar to the bipolar operation mode.In addition,an analysis of the surge process of MPS diodes is carried out in detail.
