This paper reviews a strategic scientific proposal to dig and construct three navigable sea lanes linking isolated inland seas and blocked side bays and linking it with the open seas, to facilitate the movement of fre...This paper reviews a strategic scientific proposal to dig and construct three navigable sea lanes linking isolated inland seas and blocked side bays and linking it with the open seas, to facilitate the movement of free trade and international navigation, and to break the captivity of geographically isolated environments, and to give a strategic advantage to some areas and sectors that are neglected politically, socially, economically and environmentally, and to adopt the strategy of establishing a marine channel between the “Caspian Sea” and the “Black Sea” through the “lands belonging to Russia”. On digging a navigational canal at the lowest cost in a plain area within the territory of Russia, with a length of approximately 600 kilometers (616 km), starting from the nearest bay in the Caspian Sea, passing near the city of “Pyatigorsk” to the city of “Sochi” on the Black Sea, while it comes: -The strategy of the waterway and the sea channel between the “Caspian Sea” and the “Arabian Gulf” through the “lands belonging to Iran” by digging and cutting a path in the rocks with a width of 100 meters and a length of about 700 kilometers, and at a time rate of less than 10 years, and this project will liberate all countries in the Caspian Sea, and the study concludes with the strategy of the navigational channel between the “Arabian Gulf” and the “Mediterranean Sea” through the two countries of “Iraq-Syria”, with a length of about 1350 km, and the world will benefit in the security, commercial and political fields.展开更多
It is difficult to rescue people from outside, and emergency evacuation is still a main measure to decrease casualties in high-rise building fires. To improve evacuation efficiency, a valid and easily manipulated grou...It is difficult to rescue people from outside, and emergency evacuation is still a main measure to decrease casualties in high-rise building fires. To improve evacuation efficiency, a valid and easily manipulated grouping evacuation strategy is proposed. Occupants escape in groups according to the shortest evacuation route is determined by graph theory. In order to evaluate and find the optimal grouping, computational experiments are performed to design and simulate the evacuation processes. A case study shown the application in detail and quantitative research conclusions is obtained. The thoughts and approaches of this study can be used to guide actual high-rise building evacuation processes in future.展开更多
Purpose–Revenue management(RM)is a significant technique to improve revenue with limited resources.With the macro environment of dramatically increasing transit capacity and rapid railway transport development in Chi...Purpose–Revenue management(RM)is a significant technique to improve revenue with limited resources.With the macro environment of dramatically increasing transit capacity and rapid railway transport development in China,it is necessary to involve the theory of RM into the operation and decision of railway passenger transport.Design/methodology/approach–This paper proposes the theory and framework of generalized RM of railway passenger transport(RMRPT),and the thoughts and methods of the main techniques in RMRPT,involving demand forecasting,line planning,inventory control,pricing strategies and information systems,are all studied and elaborated.The involved methods and techniques provide a sequential process to help with the decision-making for each stage of RMRPT.The corresponding techniques are integrated into the information system to support practical businesses in railway passenger transport.Findings–The combination of the whole techniques devotes to railway benefit improvement and transit resource utilization and has been applied into the practical operation and organization of railway passenger transport.Originality/value–The development of RMRPT would provide theoretical and technical support for the improvement of service quality as well as railway benefits and efficiency.展开更多
The target of integrated construction of comprehensive transportation hub is to integrate the traffic resources,achieve butt joint of pan-regional transportation mode,and finally realize the"seamless connection&q...The target of integrated construction of comprehensive transportation hub is to integrate the traffic resources,achieve butt joint of pan-regional transportation mode,and finally realize the"seamless connection"of the goods and"zero transfer"of the passenger traffic.Relying on the particularity of the geographical location and the convenience of the Yangtze River channel,Luzhou puts forth effort to build a comprehensive transport hub in Southern Sichuan and has made great efforts in traffic infrastructure construction.However,there are still some problems.Combining practice of Luzhou,using the advanced experience of foreign and domestic cities for reference,the paper pointed out that for the sake of constructing a comprehensive transportation hub,we need to build the traffic integration on the basis of the efficiency.Besides,the paper proposed the strategies for construction.展开更多
To enhance the management level and quality of the automobile transportation logistics supply chain and promote innovation and development in automobile transportation logistics enterprises,it is essential to strength...To enhance the management level and quality of the automobile transportation logistics supply chain and promote innovation and development in automobile transportation logistics enterprises,it is essential to strengthen the construction of the automobile transportation logistics supply chain management model.This can be achieved through the gradual improvement of the automobile transportation logistics management process,ensuring that the management of the automobile transportation logistics supply chain proceeds in an orderly manner.The aim is to improve automobile transportation and logistics service levels while meeting the changing market supply needs.This will enable automobile transportation and logistics enterprises to maintain steady economic benefits and enhance their core competitiveness in the market.Therefore,this paper has conducted a comprehensive exploration and research on managing the automobile transportation logistics supply chain.Corresponding management strategies are proposed as a starting point to achieve the aforementioned goals.展开更多
Firstly, the development background of Ningbo Transportation Port & Shipping Industry is analyzed on a spatial scale. Based on that, the strategic goal of Ningbo transportation port Port & Shipping Industry is...Firstly, the development background of Ningbo Transportation Port & Shipping Industry is analyzed on a spatial scale. Based on that, the strategic goal of Ningbo transportation port Port & Shipping Industry is put forward, and strategic path analysis of strategic objectives is carried out. Finally, with the dynamic resource view, the strategic integration model of Ningbo Port & Shipping Industry is proposed.展开更多
During a residential settlement evacuation, a large number of individuals do not have access to any private means of transport in order to be evacuated;these people are assembled at Evacuation Assembly Points (E.A.P.s...During a residential settlement evacuation, a large number of individuals do not have access to any private means of transport in order to be evacuated;these people are assembled at Evacuation Assembly Points (E.A.P.s), so as to be picked up, gathered and evacuated by the competent authorities. The present study aims to evaluate whether some pedestrian assembly points are adequate for these people’s fastest assembly, taking into account the demographic characteristics of the studied population and the incline of the studied area’s ground. In order for said fastest assembly and evacuation to be achieved Geographical Information Systems (G.I.S.) and GPS measurements have been employed. The suggested method has led to the creation of the households’ classification maps based upon their inhabitants’ response time in order to improve the pre-existent Intervention Teams’ contingency plans. First, in order to identify the demographic characteristics of the studied population, we have employed the field survey method;second, we have determined the fastest and ergo optimal evacuation routes using the Dijkstra algorithm. What is more, the results hereof prove that it is feasible that the time it takes to gather the pedestrians be optimized by way of choosing the best evacuation point, whilst a method of large crowds’ evacuation in groups has been developed. The latter could constitute a useful tool for Civil Protection Agents and responders.展开更多
In this paper, a cellular automaton model considering game strategy update is proposed to study the pedestrian evac- uation in a hall. Pedestrians are classified into two categories, i.e., cooperators and defectors, a...In this paper, a cellular automaton model considering game strategy update is proposed to study the pedestrian evac- uation in a hall. Pedestrians are classified into two categories, i.e., cooperators and defectors, and they walk to an exit according to their own strategy change. The conflicts that two or three pedestrians try to occupy the same site at the same time are investigated in the Game theory model. Based on it, the relationship between the pedestrian flow rate and the evacuation time as well as the variation of cooperative proportion against evacuation time is investigated from the different initial cooperative proportions under the influence of noise. The critical value of the noise is found when there is a small number of defectors in the initial time. Moreover, the influences of the initial cooperative proportion and strength of noise on evacuation are discussed. The results show that the lower the initial cooperative proportion as well as the bigger the strength of noise, the longer the time it takes for evacuation.展开更多
The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different fac...The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different factors on the aerodynamic drag of a train running at subsonic speed in an evacuated tube. Firstly, we present the assumption of a steady state, two dimensional, incompressible viscous flow with lubricity wall conditions. Subsequently, based on the Navier-Stokes equation and the k-c turbulent models, we calculate the aerodynamic drag imposed on the column train with a 3-meter diameter running under different pressure and blockage ratio conditions in an evacuated tube transporta- tion (ETT) system. The simulation is performed with FLUENT 6.3 software package. An analyses of the simulation re- sults suggest that the blockage ratio for ETT should be in the range of 0.25-0.7, and the tube internal diameter in the range of 2-4 m, with the feasible vacuum pressure in the range of 1-10 000 Pa for the future subsonic ETT trains.展开更多
With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention a...With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention and control in China.The stereoscopic monitoring of regional PM_(2.5) and O_(3) and their precursors is crucial to achieve coordinated control.However,current monitoring networks are currently inadequate for monitoring the vertical profiles of both PM_(2.5) and O_(3) simultaneously and support air quality control.The University of Science and Technology of China(USTC)has established a nationwide ground-based hyperspectral stereoscopic remote sensing network based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)since 2015.This monitoring network provides a significant opportunity for the regional coordinated control of PM_(2.5) and O_(3) in China.One-year vertical profiles of aerosol,NO_(2) and HCHO monitored from four MAX-DOAS stations installed in four megacities(Beijing,Shanghai,Shenzhen,and Chongqing)were used to characterize their vertical distribution differences in four key regions,Jing–Jin–Ji(JJJ),Yangtze River Delta(YRD),Pearl River Delta(PRD),and Sichuan Basin(SB),respectively.The normalized and yearly averaged aerosol vertical profiles below 400 m in JJJ and PRD exhibit a box shape and a Gaussian shape,respectively,and both show exponential shapes in YRD and SB.The NO_(2) vertical profiles in four regions all exhibit exponential shapes because of vehicle emissions.The shape of the HCHO vertical profile in JJJ and PRD was Gaussian,whereas an exponential shape was shown in YRD and SB.Moreover,a regional transport event occurred at an altitude of 600–1000 m was monitored in the southwest–northeast pathway of the North China Plain(NCP)by five MAX-DOAS stations(Shijiazhuang(SJZ),Wangdu(WD),Nancheng(NC),Chinese Academy of Meteorological Sciences(CAMS),and University of Chinese Academy of Sciences(UCAS))belonging to the above network.The aerosol optical depths(AOD)in these five stations decreased in the order of SJZ>WD>NC>CAMS>UCAS.The short-distance regional transport of NO2 in the 700–900 m layer was monitored between WD and NC.As an important precursor of secondary aerosol,the peak of NO_(2) air mass in WD and NC all occurred 1 h earlier than that of aerosol.This was also observed for the short-distance regional transport of HCHO in the 700–900 m layer between NC and CAMS,which potentially affected the O_(3) concentration in Beijing.Finally,CAMS was selected as a typical site to determine the O_(3)–NO_(x)–volatile organic compounds(VOCs)sensitivities in vertical space.We found the production of O_(3) changed from predominantly VOCs-limited conditions to mainly mixed VOCs–NO_(x)-limited condition from the 0–100 m layer to the 200–300 m layer.In addition,the downward transport of O_(3) could contribute to the increase of ground surface O_(3) concentration.This ground-based hyperspectral stereoscopic remote sensing network provide a promising strategy to support management of PM_(2.5) and O_(3) and their precursors and conduct attribution of sources.展开更多
Taking the planning practice of green transportation in Sino-Singapore Tianjin Eco-city as an example,the key factors and design strategies for its healthy development were summarized from the aspects of the coordinat...Taking the planning practice of green transportation in Sino-Singapore Tianjin Eco-city as an example,the key factors and design strategies for its healthy development were summarized from the aspects of the coordination of land use and traffic development,the development of the public transport plus slow traffic model,and the development of reasonable and humanized traffic management measures,through analyzing the connotation and scale of green cluster.In addition,the design strategies of the green transportation concept suitable for the development of urban clusters represented by Guangming New District in Shenzhen were proposed,so as to provide a reference for promoting better the coordinated development of green traffic and cities,and maximizing the economic,social and environmental benefits of green transportation development.展开更多
The present study is focused on the development of a methodology pertaining to the evacuation plans improvement in a scenario where infrastructures are located in residential settlements that might be threatened by fi...The present study is focused on the development of a methodology pertaining to the evacuation plans improvement in a scenario where infrastructures are located in residential settlements that might be threatened by fires;the aforesaid settlements are oftentimes found to be resided by vulnerable population groups, namely elderly people, handicapped people and children. The study pinpoints Evacuation Assembly Points (E.A.P.s) on the outskirts of their settlement and examines the evacuation routes accessibility and safety by way of utilizing Geographic Information Systems (GISs). What is more, our meticulously planned methodology combining quantitative analysis, as well as participatory planning, allows for improve strategies targeted on how to effectively ensure the vulnerable population groups evacuation. The study’s results exhibit how vital it is to integrate technological tools in combination with each community’s partaking in the process of preparing and implementing evacuation plans. The study’s findings furthermore suggest the need to further research the evolution of dynamic evacuation models, which would take the ever-changing and ever-evolving needs of vulnerable population groups into account.展开更多
The limited energy density of lithium-ion capacitors poses a significant obstacle to their widespread application,primarily stemming from the inability of the electrodes to simultaneously fulfill both high energy dens...The limited energy density of lithium-ion capacitors poses a significant obstacle to their widespread application,primarily stemming from the inability of the electrodes to simultaneously fulfill both high energy density and rapid charging requirements.Experimental data demonstrate that a directional particle configuration can enhance charging speed while maintaining high-capacity density,but it is rarely discussed.Here,we have developed a particle-level electrochemical model capable of reconstructing an electrode with a directional particle configuration.By employing this method,an investigation was conducted to explore how the spatial morphology characteristics of particle configuration impact the energy storage characteristics of electrodes.Results demonstrate that rational particle configuration can effectively enhance the transport of lithium ions and create additional space for lithium-ion storage.With the same particle size distribution,the best electrode can increase the discharge capacity by up to132.4% and increase the charging SOC by 11.3% compared to the ordinary electrode under the condition of 6 C.These findings provide a further understanding of the energy storage mechanism inside the anisotropic particle distribution electrode,which is important for developing high-performance lithium-ion capacitors.展开更多
Since Maglev vehicles will run in a closed vacuum tube,the layout of the terminal stations of evacuated tube transportation(ETT) will differ from the traditional railway stations.This paper deals with some possible ...Since Maglev vehicles will run in a closed vacuum tube,the layout of the terminal stations of evacuated tube transportation(ETT) will differ from the traditional railway stations.This paper deals with some possible station layouts of ETT,e.g.,a station with an airlock,a station without an airlock,above ground and underground stations,and stations with either level arrayed or rotation platforms.Then different station layouts are compared,and characteristics of each are analyzed.Finally,a more secure mode for ETT station layouts is suggested,which can be the basis for future ETT station layout and designs.展开更多
Facing increasing passenger and cargo transport demand and limited re-source in the 13th Five-Year period, how to make a breakthrough and substantial progress has become a key issue on planning and the Top-level Desig...Facing increasing passenger and cargo transport demand and limited re-source in the 13th Five-Year period, how to make a breakthrough and substantial progress has become a key issue on planning and the Top-level Design. In this paper we judged and analyzed the current development and potential demand of the energy saving and emission reduction in Beijing traffic industry. Through application of energy and emission prediction model which based on the vehicle activity data, the development goals of “one drop, double control, and triple upgrade” have been put forward. In order to achieve the goal, “5 + 1” development strategies should be implemented, and we also proposed the thinking and recommendations on sustainable development of transportation.展开更多
Evacuated Tube Transport Technologies (ET3) offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to susta...Evacuated Tube Transport Technologies (ET3) offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to sustainably displace most global transportation by car, ship, truck, train, and jet aircraft. To do this, ET3 standards should adhere to certain key principals: maximum value through efficiency, reliability, and simplicity; equal consideration for passenger and cargo loads; optimum size; high speed/high frequency operation; demand oriented; random accessibility; scalability; high granularity; automated control; full speed passive switching; open standards of implementation; and maximum use of existing capacities, materials, and processes.展开更多
A mixed strategy of the exit selection in a pedestrian evacuation simulation with multi-exits is constructed by fusing the distance-based and time-based strategies through a cognitive coefficient, in order to reduce t...A mixed strategy of the exit selection in a pedestrian evacuation simulation with multi-exits is constructed by fusing the distance-based and time-based strategies through a cognitive coefficient, in order to reduce the evacuation imbalance caused by the asymmetry of exits or pedestrian layout, to find a critical density to distinguish whether the strategy of exit selection takes effect or not, and to analyze the exit selection results with different cognitive coefficients. The strategy of exit selection is embedded in the computation of the shortest estimated distance in a dynamic parameter model, in which the concept of a jam area layer and the procedure of step-by-step expending are introduced. Simulation results indicate the characteristics of evacuation time gradually varying against cognitive coefficient and the effectiveness of reducing evacuation imbalance caused by the asymmetry of pedestrian or exit layout. It is found that there is a critical density to distinguish whether a pedestrian jam occurs in the evacuation and whether an exit selection strategy is in effect. It is also shown that the strategy of exit selection has no effect on the evacuation process in the no-effect phase with a low density, and that evacuation time and exit selection are dependent on the cognitive coefficient and pedestrian initial density in the in-effect phase with a high density.展开更多
Exploring highly foldable batteries with no safety hazard is a crucial task for the realization of portable,wearable,and implantable electric devices.Given these concerns,developing solid-state batteries is one of the...Exploring highly foldable batteries with no safety hazard is a crucial task for the realization of portable,wearable,and implantable electric devices.Given these concerns,developing solid-state batteries is one of the most promising routes to achieve this aspiration.Because of the excellent flexibility and processability,polyvinylidene fluoride(PVDF) based electrolytes possess great potential to pack high energy density flexible batteries,however,suffers the various intrinsic shortcomings such as inferior ionic conductivity,a high degree of crystallinity,and lack of reactive groups.Clearing the progress of the present state and concluding the specific challenges faced by PVDF based electrolytes will help to develop PVDF based polymer batteries.In this review,we summarize the recent progress of gel polymer electrolytes and all solid polymer electrolytes based on PVDF.The ion transport mechanisms and preparation methods of PVDF based electrolytes are briefly introduced.Meanwhile,the current design principle and properties of electrolytes are highlighted and systematically discussed.Some peculiar modified strategies performed in lithium-sulfur batteries and lithium-oxygen batteries are also included.Finally,this review describes the challenges and prospects of some solid-state electrolytes to provide strategies for manufacturing high-performance PVDF electrolytes aimed at practical application with flexible requirements.展开更多
Taiwan has disadvantageous conditions for sediment-related disasters such as debris flows. The construction of engineering structures is an effective strategy for reducing debris flow disasters. However, it is impossi...Taiwan has disadvantageous conditions for sediment-related disasters such as debris flows. The construction of engineering structures is an effective strategy for reducing debris flow disasters. However, it is impossible to construct engineering structures in all debris flow areas in a short period. Therefore, the government aims to gradually develop non-structural preventive strategies, including evacuation planning, debris flow disaster emergency action system, disaster resistant community program, recruitment of debris flow professional volunteers, debris flow warning systems, and land management strategies, to mitigate disasters and secure the safety of residents. This review describes the processes and effects of recent debris flow non-structural preventive strategies in Taiwan. The average number of casualties prior to the year 2000 was far higher than the corresponding number after 2000 because debris flow evacuation drills have been promoted since 2000 and the debris flow disaster emergency action system has been progressively improved since 2002. Furthermore, the changes in risks caused by debris flow disasters before and after the implementation of non-structural preventive strategies were used to explain the effectiveness of these strategies at the community level. The results showed that softwarebased non-structural preventive strategies can effectively reduce the casualties caused by debris flows at both the national and community levels.展开更多
Routing and path selection are crucial for many communication and logistic applications. We study the interaction between nodes and packets and establish a simple model for describing the attraction of the node to the...Routing and path selection are crucial for many communication and logistic applications. We study the interaction between nodes and packets and establish a simple model for describing the attraction of the node to the packet in transmission process by using the gravitational field theory, considering the real and potential congestion of the nodes. On the basis of this model, we propose a gravitational field routing strategy that considers the attractions of all of the nodes on the travel path to the packet. In order to illustrate the efficiency of proposed routing algorithm, we introduce the order parameter to measure the throughput of the network by the critical value of phase transition from a free flow phase to a congested phase,and study the distribution of betweenness centrality and traffic jam. Simulations show that, compared with the shortest path routing strategy, the gravitational field routing strategy considerably enhances the throughput of the network and balances the traffic load, and nearly all of the nodes are used efficiently.展开更多
文摘This paper reviews a strategic scientific proposal to dig and construct three navigable sea lanes linking isolated inland seas and blocked side bays and linking it with the open seas, to facilitate the movement of free trade and international navigation, and to break the captivity of geographically isolated environments, and to give a strategic advantage to some areas and sectors that are neglected politically, socially, economically and environmentally, and to adopt the strategy of establishing a marine channel between the “Caspian Sea” and the “Black Sea” through the “lands belonging to Russia”. On digging a navigational canal at the lowest cost in a plain area within the territory of Russia, with a length of approximately 600 kilometers (616 km), starting from the nearest bay in the Caspian Sea, passing near the city of “Pyatigorsk” to the city of “Sochi” on the Black Sea, while it comes: -The strategy of the waterway and the sea channel between the “Caspian Sea” and the “Arabian Gulf” through the “lands belonging to Iran” by digging and cutting a path in the rocks with a width of 100 meters and a length of about 700 kilometers, and at a time rate of less than 10 years, and this project will liberate all countries in the Caspian Sea, and the study concludes with the strategy of the navigational channel between the “Arabian Gulf” and the “Mediterranean Sea” through the two countries of “Iraq-Syria”, with a length of about 1350 km, and the world will benefit in the security, commercial and political fields.
基金supported by Beijing University of Civil Engineering and Architecture Nature Science(ZF16078,X18067)
文摘It is difficult to rescue people from outside, and emergency evacuation is still a main measure to decrease casualties in high-rise building fires. To improve evacuation efficiency, a valid and easily manipulated grouping evacuation strategy is proposed. Occupants escape in groups according to the shortest evacuation route is determined by graph theory. In order to evaluate and find the optimal grouping, computational experiments are performed to design and simulate the evacuation processes. A case study shown the application in detail and quantitative research conclusions is obtained. The thoughts and approaches of this study can be used to guide actual high-rise building evacuation processes in future.
基金China State Railway Group Co.,Ltd(No.K2023X030)China Academy of Railway Sciences Corporation Limited(No.2021YJ017).
文摘Purpose–Revenue management(RM)is a significant technique to improve revenue with limited resources.With the macro environment of dramatically increasing transit capacity and rapid railway transport development in China,it is necessary to involve the theory of RM into the operation and decision of railway passenger transport.Design/methodology/approach–This paper proposes the theory and framework of generalized RM of railway passenger transport(RMRPT),and the thoughts and methods of the main techniques in RMRPT,involving demand forecasting,line planning,inventory control,pricing strategies and information systems,are all studied and elaborated.The involved methods and techniques provide a sequential process to help with the decision-making for each stage of RMRPT.The corresponding techniques are integrated into the information system to support practical businesses in railway passenger transport.Findings–The combination of the whole techniques devotes to railway benefit improvement and transit resource utilization and has been applied into the practical operation and organization of railway passenger transport.Originality/value–The development of RMRPT would provide theoretical and technical support for the improvement of service quality as well as railway benefits and efficiency.
文摘The target of integrated construction of comprehensive transportation hub is to integrate the traffic resources,achieve butt joint of pan-regional transportation mode,and finally realize the"seamless connection"of the goods and"zero transfer"of the passenger traffic.Relying on the particularity of the geographical location and the convenience of the Yangtze River channel,Luzhou puts forth effort to build a comprehensive transport hub in Southern Sichuan and has made great efforts in traffic infrastructure construction.However,there are still some problems.Combining practice of Luzhou,using the advanced experience of foreign and domestic cities for reference,the paper pointed out that for the sake of constructing a comprehensive transportation hub,we need to build the traffic integration on the basis of the efficiency.Besides,the paper proposed the strategies for construction.
文摘To enhance the management level and quality of the automobile transportation logistics supply chain and promote innovation and development in automobile transportation logistics enterprises,it is essential to strengthen the construction of the automobile transportation logistics supply chain management model.This can be achieved through the gradual improvement of the automobile transportation logistics management process,ensuring that the management of the automobile transportation logistics supply chain proceeds in an orderly manner.The aim is to improve automobile transportation and logistics service levels while meeting the changing market supply needs.This will enable automobile transportation and logistics enterprises to maintain steady economic benefits and enhance their core competitiveness in the market.Therefore,this paper has conducted a comprehensive exploration and research on managing the automobile transportation logistics supply chain.Corresponding management strategies are proposed as a starting point to achieve the aforementioned goals.
文摘Firstly, the development background of Ningbo Transportation Port & Shipping Industry is analyzed on a spatial scale. Based on that, the strategic goal of Ningbo transportation port Port & Shipping Industry is put forward, and strategic path analysis of strategic objectives is carried out. Finally, with the dynamic resource view, the strategic integration model of Ningbo Port & Shipping Industry is proposed.
文摘During a residential settlement evacuation, a large number of individuals do not have access to any private means of transport in order to be evacuated;these people are assembled at Evacuation Assembly Points (E.A.P.s), so as to be picked up, gathered and evacuated by the competent authorities. The present study aims to evaluate whether some pedestrian assembly points are adequate for these people’s fastest assembly, taking into account the demographic characteristics of the studied population and the incline of the studied area’s ground. In order for said fastest assembly and evacuation to be achieved Geographical Information Systems (G.I.S.) and GPS measurements have been employed. The suggested method has led to the creation of the households’ classification maps based upon their inhabitants’ response time in order to improve the pre-existent Intervention Teams’ contingency plans. First, in order to identify the demographic characteristics of the studied population, we have employed the field survey method;second, we have determined the fastest and ergo optimal evacuation routes using the Dijkstra algorithm. What is more, the results hereof prove that it is feasible that the time it takes to gather the pedestrians be optimized by way of choosing the best evacuation point, whilst a method of large crowds’ evacuation in groups has been developed. The latter could constitute a useful tool for Civil Protection Agents and responders.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11262003 and 11302125)the Fund from the Shanghai Science and Technology Commission,China(Grant No.12PJ1404000)the Graduate Student Innovative Foundation of Guangxi Zhuang Autonomous Region,China(Grant No.YCSZ2012013)
文摘In this paper, a cellular automaton model considering game strategy update is proposed to study the pedestrian evac- uation in a hall. Pedestrians are classified into two categories, i.e., cooperators and defectors, and they walk to an exit according to their own strategy change. The conflicts that two or three pedestrians try to occupy the same site at the same time are investigated in the Game theory model. Based on it, the relationship between the pedestrian flow rate and the evacuation time as well as the variation of cooperative proportion against evacuation time is investigated from the different initial cooperative proportions under the influence of noise. The critical value of the noise is found when there is a small number of defectors in the initial time. Moreover, the influences of the initial cooperative proportion and strength of noise on evacuation are discussed. The results show that the lower the initial cooperative proportion as well as the bigger the strength of noise, the longer the time it takes for evacuation.
基金supported by the National Natural Science Foundation of China (No. 50678152)the Scientific Plan Fund of Shaanxi Province(No. 2009K09-24)
文摘The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different factors on the aerodynamic drag of a train running at subsonic speed in an evacuated tube. Firstly, we present the assumption of a steady state, two dimensional, incompressible viscous flow with lubricity wall conditions. Subsequently, based on the Navier-Stokes equation and the k-c turbulent models, we calculate the aerodynamic drag imposed on the column train with a 3-meter diameter running under different pressure and blockage ratio conditions in an evacuated tube transporta- tion (ETT) system. The simulation is performed with FLUENT 6.3 software package. An analyses of the simulation re- sults suggest that the blockage ratio for ETT should be in the range of 0.25-0.7, and the tube internal diameter in the range of 2-4 m, with the feasible vacuum pressure in the range of 1-10 000 Pa for the future subsonic ETT trains.
基金This research is supported by grants from the National Key Research and Development Program of China(2018YFC0213104)Project supported by the Presidential Foundation of the Hefei Institutes of Physical Science,Chinese Academy Sciences,China-“Spark”(YZJJ2021QN06)+6 种基金National Natural Science Foundation of China(41722501,91544212,51778596,41575021,41977184,and 41875043)National Key Research and Development Program of China(2017YFC0210002,2016YFC0203302,and 2017YFC0212800)Anhui Science and Technology Major Project(18030801111)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23020301)the National Key Project for Causes and Control of Heavy Air Pollution(DQGG0102 and DQGG0205)the National High-Resolution Earth Observation Project of China(05-Y30B01-9001-19/20-3)Civil Aerospace Technology Advance Research Project(Y7K00100KJ).From 0-100 and 200-300 m layers,the production of O_(3) changed from predominantly VOCs-limited condition to mainly mixed VOCs-NOx-limited condition.
文摘With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention and control in China.The stereoscopic monitoring of regional PM_(2.5) and O_(3) and their precursors is crucial to achieve coordinated control.However,current monitoring networks are currently inadequate for monitoring the vertical profiles of both PM_(2.5) and O_(3) simultaneously and support air quality control.The University of Science and Technology of China(USTC)has established a nationwide ground-based hyperspectral stereoscopic remote sensing network based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)since 2015.This monitoring network provides a significant opportunity for the regional coordinated control of PM_(2.5) and O_(3) in China.One-year vertical profiles of aerosol,NO_(2) and HCHO monitored from four MAX-DOAS stations installed in four megacities(Beijing,Shanghai,Shenzhen,and Chongqing)were used to characterize their vertical distribution differences in four key regions,Jing–Jin–Ji(JJJ),Yangtze River Delta(YRD),Pearl River Delta(PRD),and Sichuan Basin(SB),respectively.The normalized and yearly averaged aerosol vertical profiles below 400 m in JJJ and PRD exhibit a box shape and a Gaussian shape,respectively,and both show exponential shapes in YRD and SB.The NO_(2) vertical profiles in four regions all exhibit exponential shapes because of vehicle emissions.The shape of the HCHO vertical profile in JJJ and PRD was Gaussian,whereas an exponential shape was shown in YRD and SB.Moreover,a regional transport event occurred at an altitude of 600–1000 m was monitored in the southwest–northeast pathway of the North China Plain(NCP)by five MAX-DOAS stations(Shijiazhuang(SJZ),Wangdu(WD),Nancheng(NC),Chinese Academy of Meteorological Sciences(CAMS),and University of Chinese Academy of Sciences(UCAS))belonging to the above network.The aerosol optical depths(AOD)in these five stations decreased in the order of SJZ>WD>NC>CAMS>UCAS.The short-distance regional transport of NO2 in the 700–900 m layer was monitored between WD and NC.As an important precursor of secondary aerosol,the peak of NO_(2) air mass in WD and NC all occurred 1 h earlier than that of aerosol.This was also observed for the short-distance regional transport of HCHO in the 700–900 m layer between NC and CAMS,which potentially affected the O_(3) concentration in Beijing.Finally,CAMS was selected as a typical site to determine the O_(3)–NO_(x)–volatile organic compounds(VOCs)sensitivities in vertical space.We found the production of O_(3) changed from predominantly VOCs-limited conditions to mainly mixed VOCs–NO_(x)-limited condition from the 0–100 m layer to the 200–300 m layer.In addition,the downward transport of O_(3) could contribute to the increase of ground surface O_(3) concentration.This ground-based hyperspectral stereoscopic remote sensing network provide a promising strategy to support management of PM_(2.5) and O_(3) and their precursors and conduct attribution of sources.
文摘Taking the planning practice of green transportation in Sino-Singapore Tianjin Eco-city as an example,the key factors and design strategies for its healthy development were summarized from the aspects of the coordination of land use and traffic development,the development of the public transport plus slow traffic model,and the development of reasonable and humanized traffic management measures,through analyzing the connotation and scale of green cluster.In addition,the design strategies of the green transportation concept suitable for the development of urban clusters represented by Guangming New District in Shenzhen were proposed,so as to provide a reference for promoting better the coordinated development of green traffic and cities,and maximizing the economic,social and environmental benefits of green transportation development.
文摘The present study is focused on the development of a methodology pertaining to the evacuation plans improvement in a scenario where infrastructures are located in residential settlements that might be threatened by fires;the aforesaid settlements are oftentimes found to be resided by vulnerable population groups, namely elderly people, handicapped people and children. The study pinpoints Evacuation Assembly Points (E.A.P.s) on the outskirts of their settlement and examines the evacuation routes accessibility and safety by way of utilizing Geographic Information Systems (GISs). What is more, our meticulously planned methodology combining quantitative analysis, as well as participatory planning, allows for improve strategies targeted on how to effectively ensure the vulnerable population groups evacuation. The study’s results exhibit how vital it is to integrate technological tools in combination with each community’s partaking in the process of preparing and implementing evacuation plans. The study’s findings furthermore suggest the need to further research the evolution of dynamic evacuation models, which would take the ever-changing and ever-evolving needs of vulnerable population groups into account.
基金This work is supported by the National Key R&D Program of China(2021YFB2400400).
文摘The limited energy density of lithium-ion capacitors poses a significant obstacle to their widespread application,primarily stemming from the inability of the electrodes to simultaneously fulfill both high energy density and rapid charging requirements.Experimental data demonstrate that a directional particle configuration can enhance charging speed while maintaining high-capacity density,but it is rarely discussed.Here,we have developed a particle-level electrochemical model capable of reconstructing an electrode with a directional particle configuration.By employing this method,an investigation was conducted to explore how the spatial morphology characteristics of particle configuration impact the energy storage characteristics of electrodes.Results demonstrate that rational particle configuration can effectively enhance the transport of lithium ions and create additional space for lithium-ion storage.With the same particle size distribution,the best electrode can increase the discharge capacity by up to132.4% and increase the charging SOC by 11.3% compared to the ordinary electrode under the condition of 6 C.These findings provide a further understanding of the energy storage mechanism inside the anisotropic particle distribution electrode,which is important for developing high-performance lithium-ion capacitors.
基金supported by the National Natural Science Foundation of China (No.50678152)the Scientific Plan Fund of Shaanxi Province (No.2009K09-24)
文摘Since Maglev vehicles will run in a closed vacuum tube,the layout of the terminal stations of evacuated tube transportation(ETT) will differ from the traditional railway stations.This paper deals with some possible station layouts of ETT,e.g.,a station with an airlock,a station without an airlock,above ground and underground stations,and stations with either level arrayed or rotation platforms.Then different station layouts are compared,and characteristics of each are analyzed.Finally,a more secure mode for ETT station layouts is suggested,which can be the basis for future ETT station layout and designs.
文摘Facing increasing passenger and cargo transport demand and limited re-source in the 13th Five-Year period, how to make a breakthrough and substantial progress has become a key issue on planning and the Top-level Design. In this paper we judged and analyzed the current development and potential demand of the energy saving and emission reduction in Beijing traffic industry. Through application of energy and emission prediction model which based on the vehicle activity data, the development goals of “one drop, double control, and triple upgrade” have been put forward. In order to achieve the goal, “5 + 1” development strategies should be implemented, and we also proposed the thinking and recommendations on sustainable development of transportation.
文摘Evacuated Tube Transport Technologies (ET3) offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to sustainably displace most global transportation by car, ship, truck, train, and jet aircraft. To do this, ET3 standards should adhere to certain key principals: maximum value through efficiency, reliability, and simplicity; equal consideration for passenger and cargo loads; optimum size; high speed/high frequency operation; demand oriented; random accessibility; scalability; high granularity; automated control; full speed passive switching; open standards of implementation; and maximum use of existing capacities, materials, and processes.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB725400)the National Natural Science Foundation of China(Grant No.11172035)+2 种基金the Fundamental Research Funds for the Central Universities of China(Grant No.2013JBM046)the China Postdoctoral Science Foundation(Grant Nos.20090460184 and 201003036)the Talent Foundation of Beijing Jiaotong University,China(Grant No.2012RC026)
文摘A mixed strategy of the exit selection in a pedestrian evacuation simulation with multi-exits is constructed by fusing the distance-based and time-based strategies through a cognitive coefficient, in order to reduce the evacuation imbalance caused by the asymmetry of exits or pedestrian layout, to find a critical density to distinguish whether the strategy of exit selection takes effect or not, and to analyze the exit selection results with different cognitive coefficients. The strategy of exit selection is embedded in the computation of the shortest estimated distance in a dynamic parameter model, in which the concept of a jam area layer and the procedure of step-by-step expending are introduced. Simulation results indicate the characteristics of evacuation time gradually varying against cognitive coefficient and the effectiveness of reducing evacuation imbalance caused by the asymmetry of pedestrian or exit layout. It is found that there is a critical density to distinguish whether a pedestrian jam occurs in the evacuation and whether an exit selection strategy is in effect. It is also shown that the strategy of exit selection has no effect on the evacuation process in the no-effect phase with a low density, and that evacuation time and exit selection are dependent on the cognitive coefficient and pedestrian initial density in the in-effect phase with a high density.
基金supported by the National Natural Science Foundation of China(Grant No.51502063)the Project for guiding local Science and Technology Development by Central Government of Chin(ZY18C04)+1 种基金the Fundamental Research Foundation for Universities of Heilongjiang Province(LGYC2018JQ006)the Science Funds for Young Innovative Talents of HUST(No.201505).
文摘Exploring highly foldable batteries with no safety hazard is a crucial task for the realization of portable,wearable,and implantable electric devices.Given these concerns,developing solid-state batteries is one of the most promising routes to achieve this aspiration.Because of the excellent flexibility and processability,polyvinylidene fluoride(PVDF) based electrolytes possess great potential to pack high energy density flexible batteries,however,suffers the various intrinsic shortcomings such as inferior ionic conductivity,a high degree of crystallinity,and lack of reactive groups.Clearing the progress of the present state and concluding the specific challenges faced by PVDF based electrolytes will help to develop PVDF based polymer batteries.In this review,we summarize the recent progress of gel polymer electrolytes and all solid polymer electrolytes based on PVDF.The ion transport mechanisms and preparation methods of PVDF based electrolytes are briefly introduced.Meanwhile,the current design principle and properties of electrolytes are highlighted and systematically discussed.Some peculiar modified strategies performed in lithium-sulfur batteries and lithium-oxygen batteries are also included.Finally,this review describes the challenges and prospects of some solid-state electrolytes to provide strategies for manufacturing high-performance PVDF electrolytes aimed at practical application with flexible requirements.
基金the National Science Council of Taiwan (NSC 102-2811-B-005022) for financially supporting
文摘Taiwan has disadvantageous conditions for sediment-related disasters such as debris flows. The construction of engineering structures is an effective strategy for reducing debris flow disasters. However, it is impossible to construct engineering structures in all debris flow areas in a short period. Therefore, the government aims to gradually develop non-structural preventive strategies, including evacuation planning, debris flow disaster emergency action system, disaster resistant community program, recruitment of debris flow professional volunteers, debris flow warning systems, and land management strategies, to mitigate disasters and secure the safety of residents. This review describes the processes and effects of recent debris flow non-structural preventive strategies in Taiwan. The average number of casualties prior to the year 2000 was far higher than the corresponding number after 2000 because debris flow evacuation drills have been promoted since 2000 and the debris flow disaster emergency action system has been progressively improved since 2002. Furthermore, the changes in risks caused by debris flow disasters before and after the implementation of non-structural preventive strategies were used to explain the effectiveness of these strategies at the community level. The results showed that softwarebased non-structural preventive strategies can effectively reduce the casualties caused by debris flows at both the national and community levels.
基金Project supported by the Technology and Development Research Project of China Railway Corporation(Grant No.2012X007-D)the Key Program of Technology and Development Research Foundation of China Railway Corporation(Grant No.2012X003-A)
文摘Routing and path selection are crucial for many communication and logistic applications. We study the interaction between nodes and packets and establish a simple model for describing the attraction of the node to the packet in transmission process by using the gravitational field theory, considering the real and potential congestion of the nodes. On the basis of this model, we propose a gravitational field routing strategy that considers the attractions of all of the nodes on the travel path to the packet. In order to illustrate the efficiency of proposed routing algorithm, we introduce the order parameter to measure the throughput of the network by the critical value of phase transition from a free flow phase to a congested phase,and study the distribution of betweenness centrality and traffic jam. Simulations show that, compared with the shortest path routing strategy, the gravitational field routing strategy considerably enhances the throughput of the network and balances the traffic load, and nearly all of the nodes are used efficiently.