Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applicatio...Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.展开更多
This paper aims to provide a decision-making method for the transportation management strategies in guiding the transformation of trip mode choice during planned special events. The Expo 2010 Shanghai is taken as an e...This paper aims to provide a decision-making method for the transportation management strategies in guiding the transformation of trip mode choice during planned special events. The Expo 2010 Shanghai is taken as an example, and a structural equation model is employed to analyze the dynamic mechanism of trip mode choice behavior and the effectiveness of the transportation management measures at different stages. Based on the difference between the objective-oriented stated preference （SP） survey results and the objectives, together with the feedback from the previous stage survey, some adjustments on the transportation management measures are made in the next stage of the planning process until the objectives are eventually achieved. The results indicate that the adjustments on transportation management measures at different stages can effectively raise the transit share to 88.6%. Nonlocal visitors are inclined to choose nonstop modes of transportation and the companion attributes have the most significant effects on the trip mode choices of visitors. The research method is proved to be an effective way to support the decision making process of transportation management measures during planned special events in the future.展开更多
In order to find the main factors that influence the urban traffic structure,a relational model between the travelers＇ characteristics and the trip mode choice is built.The data of urban residents＇ characteristics a...In order to find the main factors that influence the urban traffic structure,a relational model between the travelers＇ characteristics and the trip mode choice is built.The data of urban residents＇ characteristics are obtained from statistical data,while the trip mode split data is collected through a trip survey in Bengbu.In addition,the discrete choice model is adopted to build the functional relationship between the mode choice and the travelers＇ personal characteristics,as well as family characteristics and trip characteristics.The model shows that the relationship between the mode split and the personal,as well as family and trip characteristics is stable and changes little as the time changes.Deduced by the discrete model,the mode split result is relatively accurate and can be feasibly used for trip mode structure forecasts.Furthermore,the proposed model can also contribute to find the key influencing factors on trip mode choice,and restructure or optimize the urban trip mode structure.展开更多
A review of the current status and progress of steel arch bridges in China is presented in this paper. The existing steel arch bridges in China were analyzed in terms of steel material, span, structure type, main arch...A review of the current status and progress of steel arch bridges in China is presented in this paper. The existing steel arch bridges in China were analyzed in terms of steel material, span, structure type, main arch rib form and construction method. The comparison with CFST arch bridges and RC arch bridges is also conducted. It is shown that steel arch bridge has gain rapid development in China since 2000, characterized by long main spans. As for the span, most of the steel arch bridges have a span less than 250 m, while when the span exceeds 350 m, steel arch bridges are strongly competitive against CFST or RC arch bridges. Over 80% of the bridges are through and half-through bridge types, and the arch ribs are hingeless structures. The rise-to-span ratios of the arches are mainly between 1：4 and 1： 5. Most of the arches use solid box ribs, and a small portion of arches use truss ribs in which box sections are mostly adopted for the truss members. The cantilever method and scaffolding method are the two main construction methods used, but some other construction methods have also been developed.展开更多
Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures （VLFSs） and create additional connector loads. In this study, the combined effects of ship collision...Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures （VLFSs） and create additional connector loads. In this study, the combined effects of ship collision and wave loads are considered to establish motion differential equations for a multi-body VLFS. A time domain calculation method is proposed to calculate the connector load of the VLFS in waves. The Longuet-Higgins model is employed to simulate the stochastic wave load. Fluid force and hydrodynamic coefficient are obtained with DNV Sesam software. The motion differential equation is calculated by applying the time domain method when the frequency domain hydrodynamic coefficient is converted into the memory function of the motion differential equation of the time domain. As a result of the combined action of wave and impact loads, high-frequency oscillation is observed in the time history curve of the connector load. At wave directions of 0° and 75°, the regularities of the time history curves of the connector loads in different directions are similar and the connector loads of C1 and C2 in the X direction are the largest. The oscillation load is observed in the connector in the Y direction at a wave direction of 75° and not at 0° This paper presents a time domain calculation method of connector load to provide a certain reference function for the future development of Chinese VLFS展开更多
The content of China＇s economic transformation is not single, and this article argues that it includes three parts. The first is the reform of economic system, the second is the change in the pattern of economic grow...The content of China＇s economic transformation is not single, and this article argues that it includes three parts. The first is the reform of economic system, the second is the change in the pattern of economic growth, and the third is the adjustment of economic structure. Government is the leading force of China＇s economic transformation, and repeated reform of government institutions has brought about some changes to government functions. But problems are obvious that lag changes of government functions have become an obstacle in China＇s economic transformation. This article describes the historical evolution and the reality of China＇s economic transformation, and analyzes the main reasons of lag changes in government functions, and reveals that the transformation of government functions is the key for successful transformation of China＇s economy.展开更多
The nitrogen adsorption isotherms at 77.69 K were measured for two samples of activated carbon fibers and their microstructures were investigated. Among established isotherm equations, the Dubinin-Radushkevieh equatio...The nitrogen adsorption isotherms at 77.69 K were measured for two samples of activated carbon fibers and their microstructures were investigated. Among established isotherm equations, the Dubinin-Radushkevieh equation showed the best agreement with the experimental data, while the Langmuir equation showed a large deviation when employed at low relative pressures. The MP method, t-method and as-method were used to analyze the pore size distribution. The calculated average pore widths and BET （Brunauer-Emmett-Teller） surface areas for the sample A-13 were 0.86 nm and 1 286.60 m^2/g, while for the sample A-16, they were 0.82 nm and 1 490.64 m^2/g. The sample with larger pore width was more suitable to be used as additive in chemical heat pumps, while the other one could be used as adsorbent in adsorption refrigeration systems .展开更多
文摘Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.
基金The National Natural Science Foundation of China(No.51278363)
文摘This paper aims to provide a decision-making method for the transportation management strategies in guiding the transformation of trip mode choice during planned special events. The Expo 2010 Shanghai is taken as an example, and a structural equation model is employed to analyze the dynamic mechanism of trip mode choice behavior and the effectiveness of the transportation management measures at different stages. Based on the difference between the objective-oriented stated preference （SP） survey results and the objectives, together with the feedback from the previous stage survey, some adjustments on the transportation management measures are made in the next stage of the planning process until the objectives are eventually achieved. The results indicate that the adjustments on transportation management measures at different stages can effectively raise the transit share to 88.6%. Nonlocal visitors are inclined to choose nonstop modes of transportation and the companion attributes have the most significant effects on the trip mode choices of visitors. The research method is proved to be an effective way to support the decision making process of transportation management measures during planned special events in the future.
基金The National Natural Science Foundation of China (No.50738001,51078086)
文摘In order to find the main factors that influence the urban traffic structure,a relational model between the travelers＇ characteristics and the trip mode choice is built.The data of urban residents＇ characteristics are obtained from statistical data,while the trip mode split data is collected through a trip survey in Bengbu.In addition,the discrete choice model is adopted to build the functional relationship between the mode choice and the travelers＇ personal characteristics,as well as family characteristics and trip characteristics.The model shows that the relationship between the mode split and the personal,as well as family and trip characteristics is stable and changes little as the time changes.Deduced by the discrete model,the mode split result is relatively accurate and can be feasibly used for trip mode structure forecasts.Furthermore,the proposed model can also contribute to find the key influencing factors on trip mode choice,and restructure or optimize the urban trip mode structure.
文摘A review of the current status and progress of steel arch bridges in China is presented in this paper. The existing steel arch bridges in China were analyzed in terms of steel material, span, structure type, main arch rib form and construction method. The comparison with CFST arch bridges and RC arch bridges is also conducted. It is shown that steel arch bridge has gain rapid development in China since 2000, characterized by long main spans. As for the span, most of the steel arch bridges have a span less than 250 m, while when the span exceeds 350 m, steel arch bridges are strongly competitive against CFST or RC arch bridges. Over 80% of the bridges are through and half-through bridge types, and the arch ribs are hingeless structures. The rise-to-span ratios of the arches are mainly between 1：4 and 1： 5. Most of the arches use solid box ribs, and a small portion of arches use truss ribs in which box sections are mostly adopted for the truss members. The cantilever method and scaffolding method are the two main construction methods used, but some other construction methods have also been developed.
基金Foundation item： Supported by the National Natural Science Foundation of China （51309123）, National Key Basic Research and Development Plan （973 Plan, 2013CB036104）, Jiangsu Province Natural Science Research Projects in Colleges and Universities （13KJB570002）, Open Foundation of State Key Laboratory of Ocean Engineering （1407）, ＂Qing Lan Project＂ of Colleges and Universities in Jiangsu Province, Academic Program Development of Jiangsu Higher Education Institutions （PAPD）.
文摘Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures （VLFSs） and create additional connector loads. In this study, the combined effects of ship collision and wave loads are considered to establish motion differential equations for a multi-body VLFS. A time domain calculation method is proposed to calculate the connector load of the VLFS in waves. The Longuet-Higgins model is employed to simulate the stochastic wave load. Fluid force and hydrodynamic coefficient are obtained with DNV Sesam software. The motion differential equation is calculated by applying the time domain method when the frequency domain hydrodynamic coefficient is converted into the memory function of the motion differential equation of the time domain. As a result of the combined action of wave and impact loads, high-frequency oscillation is observed in the time history curve of the connector load. At wave directions of 0° and 75°, the regularities of the time history curves of the connector loads in different directions are similar and the connector loads of C1 and C2 in the X direction are the largest. The oscillation load is observed in the connector in the Y direction at a wave direction of 75° and not at 0° This paper presents a time domain calculation method of connector load to provide a certain reference function for the future development of Chinese VLFS
文摘The content of China＇s economic transformation is not single, and this article argues that it includes three parts. The first is the reform of economic system, the second is the change in the pattern of economic growth, and the third is the adjustment of economic structure. Government is the leading force of China＇s economic transformation, and repeated reform of government institutions has brought about some changes to government functions. But problems are obvious that lag changes of government functions have become an obstacle in China＇s economic transformation. This article describes the historical evolution and the reality of China＇s economic transformation, and analyzes the main reasons of lag changes in government functions, and reveals that the transformation of government functions is the key for successful transformation of China＇s economy.
基金the National Science Fund for Distinguished Young Scholars of China(No.50225621)the Shanghai Shuguang Training Program for the Talents (No.02GG03)the Natural Science Fund of Shanghai City(No.05ZR14072)
文摘The nitrogen adsorption isotherms at 77.69 K were measured for two samples of activated carbon fibers and their microstructures were investigated. Among established isotherm equations, the Dubinin-Radushkevieh equation showed the best agreement with the experimental data, while the Langmuir equation showed a large deviation when employed at low relative pressures. The MP method, t-method and as-method were used to analyze the pore size distribution. The calculated average pore widths and BET （Brunauer-Emmett-Teller） surface areas for the sample A-13 were 0.86 nm and 1 286.60 m^2/g, while for the sample A-16, they were 0.82 nm and 1 490.64 m^2/g. The sample with larger pore width was more suitable to be used as additive in chemical heat pumps, while the other one could be used as adsorbent in adsorption refrigeration systems .
