To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of...To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of a three-layer ultra-high-performance pavement(UHPP).The high-temperature rutting resistance and wet-weather skid resistance of UHPP were evaluated through composite structure tests.The internal temperature distribution within the pavement under typical high-temperature conditions was analyzed using a temperature field model.Additionally,a temperature-stress coupling model was employed to investigate the key load positions and stress response characteristics of the UHPP.The results indicate that compared with the traditional guss asphalt+stone mastic asphalt structure,the dynamic stability of the UHPP composite structure can be improved by up to 20.4%.Even under cyclic loading,UHPP still exhibits superior surface skid resistance compared to two traditional SBDPs.The thickness composition of UHPP significantly impacts its rutting resistance and skid resistance.UHPP exhibits relatively low tensile stress but higher shear stress levels,with the highest shear stress occurring between the UHPP and the steel plate.This suggests that the potential risk of damage for UHPP primarily lies within the interlayer of the pavement.Based on engineering examples,introducing interlayer gravel and optimizing the amount of bonding layer are advised to ensure that UHPP possesses sufficient interlayer shear resistance.展开更多
The consequences of ship collisions with an oil rig, offshore installation or platform can be far more expensive in relation to safety, environment and costs of damage. The damage due to a single incident of an Oil Ri...The consequences of ship collisions with an oil rig, offshore installation or platform can be far more expensive in relation to safety, environment and costs of damage. The damage due to a single incident of an Oil Rig Collision can be catastrophic due to the number of people on board and the added risk of explosion. However, the existing rules and regulations of collisions prevention are insufficient. The purpose of this article is to critically evaluate the risk of ships collisions with offshore platforms and installations and therefore propose an international regulation for the preventions of this type of collisions.展开更多
This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/...This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.展开更多
Wind power has made rapid progress and should gain significance as an energy resource,given growing interest in renewable energy and clean energy.Offshore wind energy resources have attracted significant attention,as,...Wind power has made rapid progress and should gain significance as an energy resource,given growing interest in renewable energy and clean energy.Offshore wind energy resources have attracted significant attention,as,compared with land-based wind energy resources,offshore wind energy resources are more promising candidates for development.Sea winds are generally stronger and more reliable and with improvements in technology,the sea has become a hot spot for new designs and installation methods for wind turbines.In the present paper,based on experience building offshore wind farms,recommended foundation styles have been examined.Furthermore,wave effects have been investigated.The split installation and overall installation have been illustrated.Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed.This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.展开更多
The objective of this paper is to illustrate behavioural aspects and a collaborative Delphi-based planning approach in the maritime transport chain. Therefore, this paper analyses changes in behavioural routines and g...The objective of this paper is to illustrate behavioural aspects and a collaborative Delphi-based planning approach in the maritime transport chain. Therefore, this paper analyses changes in behavioural routines and governance structures in the maritime transport chain using a case study that depicts mutual projections of expected container transhipment moderated by a neutral third for reducing the uncertainty in planning within the whole maritime transport chain. The actors＇ different views on container transport are collected and directly confronted to an expert panel showing bounded rationality and thus asymmetric information can be circumvented The planning approach shows how actors＇ different internal planning can be improved and evident to the market. The whole maritime transport chain expects the future development in container transport which can be given by using collaborative Delphi-based planning. As a result, an overall picture for planning issues can be constituted, improving both individual planning of the actors and expected market growth.展开更多
In order to study the effect of agitation on the characteristics of air dense medium fluidization, we designed and constructed an agitation device. Analyses were then conducted on the fluidization characteristics curv...In order to study the effect of agitation on the characteristics of air dense medium fluidization, we designed and constructed an agitation device. Analyses were then conducted on the fluidization characteristics curves, the bed density stability and the average bubble rise velocity Uaunder different agitation conditions. The results indicated that a lower bed pressure drop(without considering lower gas velocity in a fixed bed stage) and higher minimum fluidized velocity are achieved with increasing agitation speed.The height d(distance between the lower blades and air distribution plate) at which the agitation paddle was located had a considerable effect on the stability of the bed density at 9.36 cm/s < U < 10.70 cm/s. The higher the value of d, the better the stability, and the standard deviation of the bed density fluctuation r dropped to 0.0364 g/cm^3 at the ideal condition of d = 40 mm. The agitation speed also had a significant influence on the fluidization performance, and r was only 0.0286 g/cm^3 at an agitation speed of N = 75 r/min. The average bubble rise velocity decreased significantly with increasing agitation speed under the operating condition of 1.50 cm/s < U–U_(mf)< 3.50 cm/s. This shows that appropriate agitation contributes to a significant improvement in the fluidization quality in a fluidized bed, and enhances the separation performance of a fluidized bed.展开更多
基金The National Natural Science Foundation of China(No.51878167)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(No.KYCX23_0300).
文摘To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of a three-layer ultra-high-performance pavement(UHPP).The high-temperature rutting resistance and wet-weather skid resistance of UHPP were evaluated through composite structure tests.The internal temperature distribution within the pavement under typical high-temperature conditions was analyzed using a temperature field model.Additionally,a temperature-stress coupling model was employed to investigate the key load positions and stress response characteristics of the UHPP.The results indicate that compared with the traditional guss asphalt+stone mastic asphalt structure,the dynamic stability of the UHPP composite structure can be improved by up to 20.4%.Even under cyclic loading,UHPP still exhibits superior surface skid resistance compared to two traditional SBDPs.The thickness composition of UHPP significantly impacts its rutting resistance and skid resistance.UHPP exhibits relatively low tensile stress but higher shear stress levels,with the highest shear stress occurring between the UHPP and the steel plate.This suggests that the potential risk of damage for UHPP primarily lies within the interlayer of the pavement.Based on engineering examples,introducing interlayer gravel and optimizing the amount of bonding layer are advised to ensure that UHPP possesses sufficient interlayer shear resistance.
文摘The consequences of ship collisions with an oil rig, offshore installation or platform can be far more expensive in relation to safety, environment and costs of damage. The damage due to a single incident of an Oil Rig Collision can be catastrophic due to the number of people on board and the added risk of explosion. However, the existing rules and regulations of collisions prevention are insufficient. The purpose of this article is to critically evaluate the risk of ships collisions with offshore platforms and installations and therefore propose an international regulation for the preventions of this type of collisions.
文摘This paper prescribes a movable voltage-variable and frequency-variable on-shore power supply system which successfully provides on-shore power for container vessel on port. The high voltage power supply (10 kV/50 Hz/2 000 kVA) for the quay cranes is used for the power input of the system, after frequency and voltage converting (450 V/60 Hz), then putting out and supplying to vessel. This system is flexible with positive effect on energy-saving and emission reduction; besides, there's no requirement of civil reconstruction to container terminals, which is suitable for the busy ports in China.
基金Supported by 111 Project Foundation under Grant No.B07019the National Natural Science Foundation of China under Grand No.50979020
文摘Wind power has made rapid progress and should gain significance as an energy resource,given growing interest in renewable energy and clean energy.Offshore wind energy resources have attracted significant attention,as,compared with land-based wind energy resources,offshore wind energy resources are more promising candidates for development.Sea winds are generally stronger and more reliable and with improvements in technology,the sea has become a hot spot for new designs and installation methods for wind turbines.In the present paper,based on experience building offshore wind farms,recommended foundation styles have been examined.Furthermore,wave effects have been investigated.The split installation and overall installation have been illustrated.Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed.This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.
文摘The objective of this paper is to illustrate behavioural aspects and a collaborative Delphi-based planning approach in the maritime transport chain. Therefore, this paper analyses changes in behavioural routines and governance structures in the maritime transport chain using a case study that depicts mutual projections of expected container transhipment moderated by a neutral third for reducing the uncertainty in planning within the whole maritime transport chain. The actors＇ different views on container transport are collected and directly confronted to an expert panel showing bounded rationality and thus asymmetric information can be circumvented The planning approach shows how actors＇ different internal planning can be improved and evident to the market. The whole maritime transport chain expects the future development in container transport which can be given by using collaborative Delphi-based planning. As a result, an overall picture for planning issues can be constituted, improving both individual planning of the actors and expected market growth.
基金financial support by the National Key Programs for Fundamental Research and Development of China(No.2012CB214904)the National Natural Science Foundation of China(Nos.51174203,51134022)
文摘In order to study the effect of agitation on the characteristics of air dense medium fluidization, we designed and constructed an agitation device. Analyses were then conducted on the fluidization characteristics curves, the bed density stability and the average bubble rise velocity Uaunder different agitation conditions. The results indicated that a lower bed pressure drop(without considering lower gas velocity in a fixed bed stage) and higher minimum fluidized velocity are achieved with increasing agitation speed.The height d(distance between the lower blades and air distribution plate) at which the agitation paddle was located had a considerable effect on the stability of the bed density at 9.36 cm/s < U < 10.70 cm/s. The higher the value of d, the better the stability, and the standard deviation of the bed density fluctuation r dropped to 0.0364 g/cm^3 at the ideal condition of d = 40 mm. The agitation speed also had a significant influence on the fluidization performance, and r was only 0.0286 g/cm^3 at an agitation speed of N = 75 r/min. The average bubble rise velocity decreased significantly with increasing agitation speed under the operating condition of 1.50 cm/s < U–U_(mf)< 3.50 cm/s. This shows that appropriate agitation contributes to a significant improvement in the fluidization quality in a fluidized bed, and enhances the separation performance of a fluidized bed.
