State Field Observation and Research Station of Debris Flow in Dongchuan,Yunnan is also named Dongchuan Debris Flow Observation and Research Station,Chinese Academy of Sciences.The study area,Jiangjia Ravine,is about ...State Field Observation and Research Station of Debris Flow in Dongchuan,Yunnan is also named Dongchuan Debris Flow Observation and Research Station,Chinese Academy of Sciences.The study area,Jiangjia Ravine,is about 48.6 km2 and characterized by intense tectonism.Accumulated clastic detritus is the main source of the materials in the debris flows when an intense rainfall occurs.The recorded highest density and sediment transport are 2370 kg/m^(3) and 6.079×10^(6) kg/s,respectively.The ravine is now called the“debris flow museum”in China and supplies advantageous research conditions.展开更多
This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the compl...This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the complexities,simulation time cost and convergence problems of detailed PV power station models.First,the amplitude–frequency curves of different filter parameters are analyzed.Based on the results,a grouping parameter set for characterizing the external filter characteristics is established.These parameters are further defined as clustering parameters.A single PV inverter model is then established as a prerequisite foundation.The proposed equivalent method combines the global search capability of PSO with the rapid convergence of KMC,effectively overcoming the tendency of KMC to become trapped in local optima.This approach enhances both clustering accuracy and numerical stability when determining equivalence for PV inverter units.Using the proposed clustering method,both a detailed PV power station model and an equivalent model are developed and compared.Simulation and hardwarein-loop(HIL)results based on the equivalent model verify that the equivalent method accurately represents the dynamic characteristics of PVpower stations and adapts well to different operating conditions.The proposed equivalent modeling method provides an effective analysis tool for future renewable energy integration research.展开更多
As renewable energy penetration continues to rise,enhancing power system flexibility has become a critical requirement.Photovoltaic–storage–charging stations(PSCSs)are key components for enhancing local regulation c...As renewable energy penetration continues to rise,enhancing power system flexibility has become a critical requirement.Photovoltaic–storage–charging stations(PSCSs)are key components for enhancing local regulation capability and promoting renewable integration.However,evaluating the adjustable capability of such hybrid stations while considering security constraints remains a major challenge.This paper first analyzes the adjustable capabilities of all the resources within such a station based on the power-energy boundary(PEB)model.Then,an optimal formulation is proposed to obtain the adjusted parameters of the aggregate feasible region(AFR)model,which embeds low-dimensional linear models within high-dimensional linear models to improve the accuracy.To solve this formulation,it is transformed using duality theory and an alternating optimization algorithm is designed to obtain the solution.Finally,a multi-station adjustable capability aggregation method considering security constraints is introduced.Simulation results verify that the proposed method effectively reduces infeasible regions and improves smoothness of aggregated boundaries,providing an accurate and practical tool for flexibility evaluation in PSCSs and offering guidance for aggregators and system planners.展开更多
Due to the centralization of charging stations(CSs),CSs are organized as charging station alliances(CSAs)in the commercial competition.Under this situation,this paper studies the profit-oriented dynamic pricing strate...Due to the centralization of charging stations(CSs),CSs are organized as charging station alliances(CSAs)in the commercial competition.Under this situation,this paper studies the profit-oriented dynamic pricing strategy of CSAs.As the practicability basis,a privacy-protected bidirectional real-time information interaction framework is designed,under which the status of EVs is utilized as the reference for pricing,and the prices of CSs are the reference for charging decisions.Based on this framework,the decision-making models of EVs and CSs are established,in which the uncertainty caused by the information asymmetry between EVs and CSs and the bounded rationality of EV users are integrated.To solve the pricing decision model,the evolutionary game theory is adopted to describe the dynamic pricing game among CSAs,the equilibrium of which gives the optimal pricing strategy.Finally,the case study conducted in an urban area of Shanghai,China,validates the practicability of the framework and the effectiveness of the dynamic pricing strategy.展开更多
With the large-scale integration of new energy sources,various resources such as energy storage,electric vehicles(EVs),and photovoltaics(PV) have participated in the scheduling of active distribution networks(ADNs),po...With the large-scale integration of new energy sources,various resources such as energy storage,electric vehicles(EVs),and photovoltaics(PV) have participated in the scheduling of active distribution networks(ADNs),posing new challenges to the operation and scheduling of distribution networks.Aiming at the uncertainty of PV and EV,an optimal scheduling model for ADNs based on multi-scenario fuzzy set based charging station resource forecasting is constructed.To address the scheduling uncertainties caused by PV and load forecasting errors,a day-ahead optimal scheduling model based on conditional value at risk(CVaR) for cost assessment is established,with the optimization objectives of minimizing the operation cost of distribution networks and the risk cost caused by forecasting errors.An improved subtractive optimizer algorithm is proposed to solve the model and formulate day-ahead optimization schemes.Secondly,a forecasting model for dispatchable resources in charging stations is constructed based on event-based fuzzy set theory.On this basis,an intraday scheduling model is built to comprehensively utilize the dispatchable resources of charging stations to coordinate with the output of distributed power sources,achieving optimal scheduling with the goal of minimizing operation costs.Finally,an experimental scenario based on the IEEE-33 node system is designed for simulation verification.The comparison of optimal scheduling results shows that the proposed method can fully exploit the potential scheduling resources of charging stations,improving the operation stability of ADNs and the accommodution capacity of new energy.展开更多
Released in September 2024 by an oversight committee of the US National Aeronautics and Space Administration(NASA),a safety report about the International Space Station(ISS)cited,in addition to 50 other“areas of conc...Released in September 2024 by an oversight committee of the US National Aeronautics and Space Administration(NASA),a safety report about the International Space Station(ISS)cited,in addition to 50 other“areas of concern,”a troublesome leak first detected six years ago in one of the station’s modules[1].Given the persistent leak,called“a top safety risk”[2],and the fact that the space sta-tion has outlived its original life expectancy by more than 10 years,the agency’s current plans call for decommissioning the ISS in 2031 by dragging it into the Pacific Ocean[3].展开更多
The Hongyancun subway station in Chongqing,China,is 116 meters deep and the difference in air pressure often leaves users with clogged(堵塞的)ears when accessed via its elevator.When the air pressure outside the eardr...The Hongyancun subway station in Chongqing,China,is 116 meters deep and the difference in air pressure often leaves users with clogged(堵塞的)ears when accessed via its elevator.When the air pressure outside the eardrum(耳膜)becomes different than the pressure inside,you experience ear barotrauma(气压伤).It occurs most often during steep ascents and descents and is usually associated with plane take⁃offs and landings,or driving up or down mountains.Most subway stations dont usually cause ear barotrauma,because they arent deep or steep enough for your ears to register a significant enough difference in air pressure.But taking the elevator to reach Chinas deepest subway station might actually clog up your ears.Thats because it is located 116 meters below the surface,which is the equivalent of about 40 floors underground.展开更多
The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
The issues of slow traffic connection around Pingguoyuan Metro Station were studied,such as the disorderly parking of non-motorized vehicles in the entrances and exits and the difficulty in maintaining order over the ...The issues of slow traffic connection around Pingguoyuan Metro Station were studied,such as the disorderly parking of non-motorized vehicles in the entrances and exits and the difficulty in maintaining order over the long term.Through policy review,on-site observation,and analysis of public feedback,the underlying reasons such as extensive parking space configuration,the lack of coordination mechanisms,and the spatial tension caused by the overlapping of peak traffic flows were revealed.Besides,comprehensive response paths were proposed from aspects of facility optimization,the reconfiguration of the responsibility system,and the improvement of the public participation mechanism,including the construction of intelligent parking spaces,the establishment of a joint management model between the local area and the operating unit,and the transformation of the handling of public demands from passive response to proactive governance.The research results can provide a reference for the coordination of traffic organization and grassroots governance around urban railway stations.展开更多
In line with the new concept of building up a“well-connected,fullyi integrated,environment-friendlypassenger-oriented,economically-efficient,culturally-rich,intelligent and convenient”railway station and the constru...In line with the new concept of building up a“well-connected,fullyi integrated,environment-friendlypassenger-oriented,economically-efficient,culturally-rich,intelligent and convenient”railway station and the construction requirements of"elaborate,fine and exquisite construction of excellent passenger stations" put forward by China State Railway Group Co.Ltd.,design optimization and innovation are carried out in the construction of Nantongxi Railway Station and Pingtan Station in the aspects offunctional layout,decoration style,cultural enhancement,construction materials to be used,details treatment of the station buildings and the use of photoelectric technology,focusing on the consideration and research for furrther enhancing cultural confidence,deeply integrating into the regional features,inheriting historical context,innovating artistic expression,trying diversified integration,and exploring the use of science and technology in the contexl 0f the new era,and thus devoting to the construction of railway passenger stations in the new era which will meet the growing needs of the people for a better life.展开更多
In the background of the low-carbon transformation of the energy structure,the problem of operational uncertainty caused by the high proportion of renewable energy sources and diverse loads in the integrated energy sy...In the background of the low-carbon transformation of the energy structure,the problem of operational uncertainty caused by the high proportion of renewable energy sources and diverse loads in the integrated energy systems(IES)is becoming increasingly obvious.In this case,to promote the low-carbon operation of IES and renewable energy consumption,and to improve the IES anti-interference ability,this paper proposes an IES scheduling strategy that considers CCS-P2G and concentrating solar power(CSP)station.Firstly,CSP station,gas hydrogen doping mode and variable hydrogen doping ratio mode are applied to IES,and combined with CCS-P2G coupling model,the IES low-carbon economic dispatch model is established.Secondly,the stepped carbon trading mechanism is applied,and the sensitivity analysis of IES carbon trading is carried out.Finally,an IES optimal scheduling strategy based on fuzzy opportunity constraints and an IES risk assessment strategy based on CVaR theory are established.The simulation shows that the gas-hydrogen doping model proposed in this paper reduces the operating cost and carbon emission of IES by 1.32%and 7.17%,and improves the carbon benefit by 5.73%;variable hydrogen doping ratio model reduces the operating cost and carbon emission of IES by 3.75%and 1.70%,respectively;CSP stations reduce 19.64%and 38.52%of the operating costs of IES and 1.03%and 1.80%of the carbon emissions of IES respectively compared to equal-capacity photovoltaic and wind turbines;the baseline price of carbon trading of IES and its rate of change jointly affect the carbon emissions of IES;evaluating the anti-interference capability of IES through trapezoidal fuzzy number and weighting coefficients,enabling IES to guarantee operation at the lowest cost.展开更多
The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with...The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this study.The indoor model test verified the accuracy of the numerical model.The influence laws of different hard combinations,train operating speeds and modes were studied and evaluated accordingly.The results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 Hz.The vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the source.Furthermore,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the superstructure.The vibration response under the reversible operation of the train is greater than that of the unidirectional operation.The operating speed of the train is proportional to its vibration response.The vibration amplification area appears between the middle and the top of the superstructure at a higher train speed.Its vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are required.Within the scope of application,this study provides some suggestions for constructing subway stations and superstructures.展开更多
To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was introduced.Twenty-four groups of near-fault pulse-like ground motions were selected.The s...To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was introduced.Twenty-four groups of near-fault pulse-like ground motions were selected.The seismic resilience of the no-isolation railway stations(NIRS)and the isolation railway stations(IRS)were compared to provide a numerical result of the improvement in resilience.The results show that in the station isolation design,the station's functional requirements and structural characteristics should be considered and the appropriate placement of isolation bearings is under the waiting room.Under the action of a rare earthquake,the repair cost,repair time,rate of harm and death of the IRS were decreased by 8.04 million,18.30 days,6.93×10^(-3)and 1.21×10^(-3),respectively,when compared to the NIRS.The IRS received a seismic resilience grade of three-stars and the NIRS only one-star,indicating that rational isolation design improves the seismic resilience of stations.Thus,for the design of stations close to earthquake faults,it is suggested to utilize appropriate isolation techniques to improve their seismic resilience.展开更多
To investigate the response of Roadside Monitoring Stations(RSs)to traffic-related air pollution,traffic and pollutant characteristics,influencing factors,and potential source characterization in Tianjin,China were de...To investigate the response of Roadside Monitoring Stations(RSs)to traffic-related air pollution,traffic and pollutant characteristics,influencing factors,and potential source characterization in Tianjin,China were determined based on roadside monitoring of real-world data conducted at RSs in 2022.The diurnal variation trend of pollutants at RSs was consistent with that at the National Monitoring Station(NM),with notably higher pollutant fluctuations during the morning and evening peak traffic times at RSs,where the average diurnal concentration was 41.46%higher than that at the NM.The generalized additive model(GAM)for nitrogen oxides(NO_(x))and carbon monoxide(CO),responding to themultiple influencing factors,performed well at RSs,with deviance explained by 86.6%and 61.4%,respectively.The synergistic effects of wind direction and speed contributed to most of the variations in NO_(x) and CO,which were 14.74%and 12.87%,respectively.Pollutant concentrations were highest under windless conditions,with pollutants originating primarily from local vehicle emissions.The model results indicated that medium-duty truck(MDT)traffic flow predominantly contributed to the variability in NO_(x) emissions,whereas passenger car(PC)traffic flow was the primary source of CO emissions from traffic variables.MDTs should be the focus of urban NO_(x) traffic emissions control.Potential-source analysis validated the results obtained from the GAM,and both analyses showed that RSs can better characterize traffic-related air pollutants.Furthermore,more stringent emission standards have effectively mitigated the release of pollutants from motor vehicles and contributed to the modernization of vehicle fleet composition,effectively decreasing CO concentrations.展开更多
1.Introduction As China’s first floating production platform in ultra-deepwater,the“Deep Sea No.1”energy station is a milestone in China’s deepwater resource utilization.The energy station is located in the LS17-2...1.Introduction As China’s first floating production platform in ultra-deepwater,the“Deep Sea No.1”energy station is a milestone in China’s deepwater resource utilization.The energy station is located in the LS17-2 gas field,150 km off the southeast coast of Hainan Island,China.It is a semi-submersible platform(Fig.1)with a displacement of 101 thousand tonnes and an operational draft of 35 to 40 m.The platform is permanently moored in 1422 m water by 16 chain-polyester-chain mooring lines in a 4×4 pattern,and six steel catenary risers(SCRs)are attached to the platform.It is the world’s first and only semi-submersible platform with the function of condensate storage,so it can be regarded as a floating production storage and offloading(FPSO)unit.With the ability to produce 3 billion m3 of natural gas each year(enough for over 10 million families),the Deep Sea No.1 energy station is a key step toward China’s energy independence.The LS17-2 gas field,where the Deep Sea No.1 energy station is located,was discovered in 2014.Plans for its development were made in 2015,followed by research and a preliminary design.Deep Sea No.1 went into operation on June 25,2021,and will operate onsite continuously without dry-docking for 30 years.展开更多
The wireless signals emitted by base stations serve as a vital link connecting people in today’s society and have been occupying an increasingly important role in real life.The development of the Internet of Things(I...The wireless signals emitted by base stations serve as a vital link connecting people in today’s society and have been occupying an increasingly important role in real life.The development of the Internet of Things(IoT)relies on the support of base stations,which provide a solid foundation for achieving a more intelligent way of living.In a specific area,achieving higher signal coverage with fewer base stations has become an urgent problem.Therefore,this article focuses on the effective coverage area of base station signals and proposes a novel Evolutionary Particle Swarm Optimization(EPSO)algorithm based on collective prediction,referred to herein as ECPPSO.Introducing a new strategy called neighbor-based evolution prediction(NEP)addresses the issue of premature convergence often encountered by PSO.ECPPSO also employs a strengthening evolution(SE)strategy to enhance the algorithm’s global search capability and efficiency,ensuring enhanced robustness and a faster convergence speed when solving complex optimization problems.To better adapt to the actual communication needs of base stations,this article conducts simulation experiments by changing the number of base stations.The experimental results demonstrate thatunder the conditionof 50 ormore base stations,ECPPSOconsistently achieves the best coverage rate exceeding 95%,peaking at 99.4400%when the number of base stations reaches 80.These results validate the optimization capability of the ECPPSO algorithm,proving its feasibility and effectiveness.Further ablative experiments and comparisons with other algorithms highlight the advantages of ECPPSO.展开更多
The microwave wireless power transmission technologies for space solar power station are a crucial field in the international space sector,where various countries are competing in its development.This paper surveys th...The microwave wireless power transmission technologies for space solar power station are a crucial field in the international space sector,where various countries are competing in its development.This paper surveys the research experiments and development efforts related to space solar power stations and microwave wireless power transmission technologies worldwide.The objective is to assess the progress and current state of this technological foundation,determine the necessary focus for developing high-power microwave wireless power transmission technology,and provide clarity on the direction of future technology development in these areas.Finally,a distributed space solar power station plan that is immediately feasible is proposed.展开更多
Ground fissure,as a common geo-hazard,impairs the integrity of the site soil and affects the seismic performance of engineering structures.In this paper,a finite element(FE)model for subway stations in a ground fissur...Ground fissure,as a common geo-hazard,impairs the integrity of the site soil and affects the seismic performance of engineering structures.In this paper,a finite element(FE)model for subway stations in a ground fissure area was developed and validated by using experimental results.Numerical analyses were conducted to investigate the seismic response and failure mode of subway stations in a ground fissure area with different locations.Effects of ground fissure on deformations and internal forces of a station,soil pressures and soil plastic strains were discussed.The results showed that the seismic response of the station was significantly amplified by the ground fissure,and stations in the ground fissure area displayed obvious rocking deformation during earthquakes as compared to those in the area without fissures.It also was found that the soil yielding around the station,the dislocation occurring in the ground fissure area,and the dynamic amplification effect were more significant under vertical ground motion,which weakened the station’s ductility and accelerated its destruction process.展开更多
文摘State Field Observation and Research Station of Debris Flow in Dongchuan,Yunnan is also named Dongchuan Debris Flow Observation and Research Station,Chinese Academy of Sciences.The study area,Jiangjia Ravine,is about 48.6 km2 and characterized by intense tectonism.Accumulated clastic detritus is the main source of the materials in the debris flows when an intense rainfall occurs.The recorded highest density and sediment transport are 2370 kg/m^(3) and 6.079×10^(6) kg/s,respectively.The ravine is now called the“debris flow museum”in China and supplies advantageous research conditions.
基金supported by the Research Project of China Southern Power Grid(No.056200KK52222031).
文摘This paper proposes an equivalent modeling method for photovoltaic(PV)power stations via a particle swarm optimization(PSO)K-means clustering(KMC)algorithm with passive filter parameter clustering to address the complexities,simulation time cost and convergence problems of detailed PV power station models.First,the amplitude–frequency curves of different filter parameters are analyzed.Based on the results,a grouping parameter set for characterizing the external filter characteristics is established.These parameters are further defined as clustering parameters.A single PV inverter model is then established as a prerequisite foundation.The proposed equivalent method combines the global search capability of PSO with the rapid convergence of KMC,effectively overcoming the tendency of KMC to become trapped in local optima.This approach enhances both clustering accuracy and numerical stability when determining equivalence for PV inverter units.Using the proposed clustering method,both a detailed PV power station model and an equivalent model are developed and compared.Simulation and hardwarein-loop(HIL)results based on the equivalent model verify that the equivalent method accurately represents the dynamic characteristics of PVpower stations and adapts well to different operating conditions.The proposed equivalent modeling method provides an effective analysis tool for future renewable energy integration research.
基金supported by Science and Technology Project of China Southern Power Grid Company(036000KK52222007(GDKJXM20222121)).
文摘As renewable energy penetration continues to rise,enhancing power system flexibility has become a critical requirement.Photovoltaic–storage–charging stations(PSCSs)are key components for enhancing local regulation capability and promoting renewable integration.However,evaluating the adjustable capability of such hybrid stations while considering security constraints remains a major challenge.This paper first analyzes the adjustable capabilities of all the resources within such a station based on the power-energy boundary(PEB)model.Then,an optimal formulation is proposed to obtain the adjusted parameters of the aggregate feasible region(AFR)model,which embeds low-dimensional linear models within high-dimensional linear models to improve the accuracy.To solve this formulation,it is transformed using duality theory and an alternating optimization algorithm is designed to obtain the solution.Finally,a multi-station adjustable capability aggregation method considering security constraints is introduced.Simulation results verify that the proposed method effectively reduces infeasible regions and improves smoothness of aggregated boundaries,providing an accurate and practical tool for flexibility evaluation in PSCSs and offering guidance for aggregators and system planners.
基金sponsored in part by the National Natural Science Foundation of China(52167014)in part by the Science and Technology Commission of Shanghai Municipality(23XD1422000,23QB1400500).
文摘Due to the centralization of charging stations(CSs),CSs are organized as charging station alliances(CSAs)in the commercial competition.Under this situation,this paper studies the profit-oriented dynamic pricing strategy of CSAs.As the practicability basis,a privacy-protected bidirectional real-time information interaction framework is designed,under which the status of EVs is utilized as the reference for pricing,and the prices of CSs are the reference for charging decisions.Based on this framework,the decision-making models of EVs and CSs are established,in which the uncertainty caused by the information asymmetry between EVs and CSs and the bounded rationality of EV users are integrated.To solve the pricing decision model,the evolutionary game theory is adopted to describe the dynamic pricing game among CSAs,the equilibrium of which gives the optimal pricing strategy.Finally,the case study conducted in an urban area of Shanghai,China,validates the practicability of the framework and the effectiveness of the dynamic pricing strategy.
基金Supported by the Technology Project of State Grid Corporation Headquarters(No.5100-202322029A-1-1-ZN)the 2024 Youth Science Foundation Project of China (No.62303006)。
文摘With the large-scale integration of new energy sources,various resources such as energy storage,electric vehicles(EVs),and photovoltaics(PV) have participated in the scheduling of active distribution networks(ADNs),posing new challenges to the operation and scheduling of distribution networks.Aiming at the uncertainty of PV and EV,an optimal scheduling model for ADNs based on multi-scenario fuzzy set based charging station resource forecasting is constructed.To address the scheduling uncertainties caused by PV and load forecasting errors,a day-ahead optimal scheduling model based on conditional value at risk(CVaR) for cost assessment is established,with the optimization objectives of minimizing the operation cost of distribution networks and the risk cost caused by forecasting errors.An improved subtractive optimizer algorithm is proposed to solve the model and formulate day-ahead optimization schemes.Secondly,a forecasting model for dispatchable resources in charging stations is constructed based on event-based fuzzy set theory.On this basis,an intraday scheduling model is built to comprehensively utilize the dispatchable resources of charging stations to coordinate with the output of distributed power sources,achieving optimal scheduling with the goal of minimizing operation costs.Finally,an experimental scenario based on the IEEE-33 node system is designed for simulation verification.The comparison of optimal scheduling results shows that the proposed method can fully exploit the potential scheduling resources of charging stations,improving the operation stability of ADNs and the accommodution capacity of new energy.
文摘Released in September 2024 by an oversight committee of the US National Aeronautics and Space Administration(NASA),a safety report about the International Space Station(ISS)cited,in addition to 50 other“areas of concern,”a troublesome leak first detected six years ago in one of the station’s modules[1].Given the persistent leak,called“a top safety risk”[2],and the fact that the space sta-tion has outlived its original life expectancy by more than 10 years,the agency’s current plans call for decommissioning the ISS in 2031 by dragging it into the Pacific Ocean[3].
文摘The Hongyancun subway station in Chongqing,China,is 116 meters deep and the difference in air pressure often leaves users with clogged(堵塞的)ears when accessed via its elevator.When the air pressure outside the eardrum(耳膜)becomes different than the pressure inside,you experience ear barotrauma(气压伤).It occurs most often during steep ascents and descents and is usually associated with plane take⁃offs and landings,or driving up or down mountains.Most subway stations dont usually cause ear barotrauma,because they arent deep or steep enough for your ears to register a significant enough difference in air pressure.But taking the elevator to reach Chinas deepest subway station might actually clog up your ears.Thats because it is located 116 meters below the surface,which is the equivalent of about 40 floors underground.
文摘The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
基金Sponsored by the Innovation and Entrepreneurship Training Planning Project for University Students in 2025:High-quality Undergraduate Teaching Plan of Beijing Universities(108051360024XN094).
文摘The issues of slow traffic connection around Pingguoyuan Metro Station were studied,such as the disorderly parking of non-motorized vehicles in the entrances and exits and the difficulty in maintaining order over the long term.Through policy review,on-site observation,and analysis of public feedback,the underlying reasons such as extensive parking space configuration,the lack of coordination mechanisms,and the spatial tension caused by the overlapping of peak traffic flows were revealed.Besides,comprehensive response paths were proposed from aspects of facility optimization,the reconfiguration of the responsibility system,and the improvement of the public participation mechanism,including the construction of intelligent parking spaces,the establishment of a joint management model between the local area and the operating unit,and the transformation of the handling of public demands from passive response to proactive governance.The research results can provide a reference for the coordination of traffic organization and grassroots governance around urban railway stations.
文摘In line with the new concept of building up a“well-connected,fullyi integrated,environment-friendlypassenger-oriented,economically-efficient,culturally-rich,intelligent and convenient”railway station and the construction requirements of"elaborate,fine and exquisite construction of excellent passenger stations" put forward by China State Railway Group Co.Ltd.,design optimization and innovation are carried out in the construction of Nantongxi Railway Station and Pingtan Station in the aspects offunctional layout,decoration style,cultural enhancement,construction materials to be used,details treatment of the station buildings and the use of photoelectric technology,focusing on the consideration and research for furrther enhancing cultural confidence,deeply integrating into the regional features,inheriting historical context,innovating artistic expression,trying diversified integration,and exploring the use of science and technology in the contexl 0f the new era,and thus devoting to the construction of railway passenger stations in the new era which will meet the growing needs of the people for a better life.
基金State Grid Gansu Electric Power Company Science and Technology Program(Grant No.W24FZ2730008)National Natural Science Foundation of China(Grant No.51767017).
文摘In the background of the low-carbon transformation of the energy structure,the problem of operational uncertainty caused by the high proportion of renewable energy sources and diverse loads in the integrated energy systems(IES)is becoming increasingly obvious.In this case,to promote the low-carbon operation of IES and renewable energy consumption,and to improve the IES anti-interference ability,this paper proposes an IES scheduling strategy that considers CCS-P2G and concentrating solar power(CSP)station.Firstly,CSP station,gas hydrogen doping mode and variable hydrogen doping ratio mode are applied to IES,and combined with CCS-P2G coupling model,the IES low-carbon economic dispatch model is established.Secondly,the stepped carbon trading mechanism is applied,and the sensitivity analysis of IES carbon trading is carried out.Finally,an IES optimal scheduling strategy based on fuzzy opportunity constraints and an IES risk assessment strategy based on CVaR theory are established.The simulation shows that the gas-hydrogen doping model proposed in this paper reduces the operating cost and carbon emission of IES by 1.32%and 7.17%,and improves the carbon benefit by 5.73%;variable hydrogen doping ratio model reduces the operating cost and carbon emission of IES by 3.75%and 1.70%,respectively;CSP stations reduce 19.64%and 38.52%of the operating costs of IES and 1.03%and 1.80%of the carbon emissions of IES respectively compared to equal-capacity photovoltaic and wind turbines;the baseline price of carbon trading of IES and its rate of change jointly affect the carbon emissions of IES;evaluating the anti-interference capability of IES through trapezoidal fuzzy number and weighting coefficients,enabling IES to guarantee operation at the lowest cost.
基金National Natural Science Foundation of China under Grant No.51578463。
文摘The vibration response and noise caused by subway trains can affect the safety and comfort of superstructures.To study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this study.The indoor model test verified the accuracy of the numerical model.The influence laws of different hard combinations,train operating speeds and modes were studied and evaluated accordingly.The results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 Hz.The vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the source.Furthermore,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the superstructure.The vibration response under the reversible operation of the train is greater than that of the unidirectional operation.The operating speed of the train is proportional to its vibration response.The vibration amplification area appears between the middle and the top of the superstructure at a higher train speed.Its vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are required.Within the scope of application,this study provides some suggestions for constructing subway stations and superstructures.
基金National Natural Science Foundation of China under Grant No.52278534Sichuan Provincial Natural Science Foundation of China under Grant No.2022NSFSC0423。
文摘To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was introduced.Twenty-four groups of near-fault pulse-like ground motions were selected.The seismic resilience of the no-isolation railway stations(NIRS)and the isolation railway stations(IRS)were compared to provide a numerical result of the improvement in resilience.The results show that in the station isolation design,the station's functional requirements and structural characteristics should be considered and the appropriate placement of isolation bearings is under the waiting room.Under the action of a rare earthquake,the repair cost,repair time,rate of harm and death of the IRS were decreased by 8.04 million,18.30 days,6.93×10^(-3)and 1.21×10^(-3),respectively,when compared to the NIRS.The IRS received a seismic resilience grade of three-stars and the NIRS only one-star,indicating that rational isolation design improves the seismic resilience of stations.Thus,for the design of stations close to earthquake faults,it is suggested to utilize appropriate isolation techniques to improve their seismic resilience.
基金supported by the National Key Research and Development Program of China(Nos.2023YFC3707301 and 2023YFC3705400)the Fundamental Research Funds for the Central Universities(Nos.ZB23003425 and 63211075)。
文摘To investigate the response of Roadside Monitoring Stations(RSs)to traffic-related air pollution,traffic and pollutant characteristics,influencing factors,and potential source characterization in Tianjin,China were determined based on roadside monitoring of real-world data conducted at RSs in 2022.The diurnal variation trend of pollutants at RSs was consistent with that at the National Monitoring Station(NM),with notably higher pollutant fluctuations during the morning and evening peak traffic times at RSs,where the average diurnal concentration was 41.46%higher than that at the NM.The generalized additive model(GAM)for nitrogen oxides(NO_(x))and carbon monoxide(CO),responding to themultiple influencing factors,performed well at RSs,with deviance explained by 86.6%and 61.4%,respectively.The synergistic effects of wind direction and speed contributed to most of the variations in NO_(x) and CO,which were 14.74%and 12.87%,respectively.Pollutant concentrations were highest under windless conditions,with pollutants originating primarily from local vehicle emissions.The model results indicated that medium-duty truck(MDT)traffic flow predominantly contributed to the variability in NO_(x) emissions,whereas passenger car(PC)traffic flow was the primary source of CO emissions from traffic variables.MDTs should be the focus of urban NO_(x) traffic emissions control.Potential-source analysis validated the results obtained from the GAM,and both analyses showed that RSs can better characterize traffic-related air pollutants.Furthermore,more stringent emission standards have effectively mitigated the release of pollutants from motor vehicles and contributed to the modernization of vehicle fleet composition,effectively decreasing CO concentrations.
文摘1.Introduction As China’s first floating production platform in ultra-deepwater,the“Deep Sea No.1”energy station is a milestone in China’s deepwater resource utilization.The energy station is located in the LS17-2 gas field,150 km off the southeast coast of Hainan Island,China.It is a semi-submersible platform(Fig.1)with a displacement of 101 thousand tonnes and an operational draft of 35 to 40 m.The platform is permanently moored in 1422 m water by 16 chain-polyester-chain mooring lines in a 4×4 pattern,and six steel catenary risers(SCRs)are attached to the platform.It is the world’s first and only semi-submersible platform with the function of condensate storage,so it can be regarded as a floating production storage and offloading(FPSO)unit.With the ability to produce 3 billion m3 of natural gas each year(enough for over 10 million families),the Deep Sea No.1 energy station is a key step toward China’s energy independence.The LS17-2 gas field,where the Deep Sea No.1 energy station is located,was discovered in 2014.Plans for its development were made in 2015,followed by research and a preliminary design.Deep Sea No.1 went into operation on June 25,2021,and will operate onsite continuously without dry-docking for 30 years.
基金supported by the National Natural Science Foundation of China(Nos.62272418,62102058)Basic Public Welfare Research Program of Zhejiang Province(No.LGG18E050011)the Major Open Project of Key Laboratory for Advanced Design and Intelligent Computing of the Ministry of Education under Grant ADIC2023ZD001,National Undergraduate Training Program on Innovation and Entrepreneurship(No.202410345054).
文摘The wireless signals emitted by base stations serve as a vital link connecting people in today’s society and have been occupying an increasingly important role in real life.The development of the Internet of Things(IoT)relies on the support of base stations,which provide a solid foundation for achieving a more intelligent way of living.In a specific area,achieving higher signal coverage with fewer base stations has become an urgent problem.Therefore,this article focuses on the effective coverage area of base station signals and proposes a novel Evolutionary Particle Swarm Optimization(EPSO)algorithm based on collective prediction,referred to herein as ECPPSO.Introducing a new strategy called neighbor-based evolution prediction(NEP)addresses the issue of premature convergence often encountered by PSO.ECPPSO also employs a strengthening evolution(SE)strategy to enhance the algorithm’s global search capability and efficiency,ensuring enhanced robustness and a faster convergence speed when solving complex optimization problems.To better adapt to the actual communication needs of base stations,this article conducts simulation experiments by changing the number of base stations.The experimental results demonstrate thatunder the conditionof 50 ormore base stations,ECPPSOconsistently achieves the best coverage rate exceeding 95%,peaking at 99.4400%when the number of base stations reaches 80.These results validate the optimization capability of the ECPPSO algorithm,proving its feasibility and effectiveness.Further ablative experiments and comparisons with other algorithms highlight the advantages of ECPPSO.
基金Entrusted Fund of National Institute of Information and Communications Technology(NICT),Japan(JPJ012368C02401)。
文摘The microwave wireless power transmission technologies for space solar power station are a crucial field in the international space sector,where various countries are competing in its development.This paper surveys the research experiments and development efforts related to space solar power stations and microwave wireless power transmission technologies worldwide.The objective is to assess the progress and current state of this technological foundation,determine the necessary focus for developing high-power microwave wireless power transmission technology,and provide clarity on the direction of future technology development in these areas.Finally,a distributed space solar power station plan that is immediately feasible is proposed.
基金National Natural Science Foundation of China under Grant No.52108473Project of Shaanxi Engineering Technology Research Center for Urban Geology and Underground Space under Grant No.2025KT-03Key Project of Education Department of Shaanxi Province under Grant No.23JY042。
文摘Ground fissure,as a common geo-hazard,impairs the integrity of the site soil and affects the seismic performance of engineering structures.In this paper,a finite element(FE)model for subway stations in a ground fissure area was developed and validated by using experimental results.Numerical analyses were conducted to investigate the seismic response and failure mode of subway stations in a ground fissure area with different locations.Effects of ground fissure on deformations and internal forces of a station,soil pressures and soil plastic strains were discussed.The results showed that the seismic response of the station was significantly amplified by the ground fissure,and stations in the ground fissure area displayed obvious rocking deformation during earthquakes as compared to those in the area without fissures.It also was found that the soil yielding around the station,the dislocation occurring in the ground fissure area,and the dynamic amplification effect were more significant under vertical ground motion,which weakened the station’s ductility and accelerated its destruction process.
