The semi-rigid pile-supported composite foundation is widely used in highway projects due to its effectiveness in increasing the bearing capacity and stability of foundations.It is crucial to understand the stress dis...The semi-rigid pile-supported composite foundation is widely used in highway projects due to its effectiveness in increasing the bearing capacity and stability of foundations.It is crucial to understand the stress distribution across the embankment width and the behaviour of unreinforced foundations.Thus,five centrifuge tests were conducted to examine the bearing and deformation behaviours of NPRS(Non-Connected Piled Raft Systems)and GRPS(GeosyntheticReinforced Pile-Supported systems)with varying substratum stiffness,then a comparative analysis was conducted on embankment settlement,pressures underneath the embankments,and axial forces along the piles.The results indicated that greater substratum stiffness correlates with reduced settlement and deformation at various depths.Deformation occurring 5 meters from the embankment toe includes settlement in NPRS and upward movement in GRPS.The potential sliding surface is primarily located within the embankment in NPRS,whereas it may extend through both the embankment and foundation in GRPS.The pile-soil stress ratio and efficiency in NPRS are higher than in GRPS across the embankment.The axial force borne by end-bearing piles is significantly greater than that by floating piles.As the buried depth increases,the axial force in GRPS initially rises then declines,whereas in NPRS,it remains relatively constant within a certain range before decreasing.This study aids in assessing the applicability of composite foundations in complex railway environments and provides a reference for procedural measures under similar conditions.展开更多
The bridge deck on the Yuzhong side of Zengjiayan Jialing River Bridge is close to subway lines and light rail stations.It is necessary to set up transfer stairways on both sides of the bridge.The construction technol...The bridge deck on the Yuzhong side of Zengjiayan Jialing River Bridge is close to subway lines and light rail stations.It is necessary to set up transfer stairways on both sides of the bridge.The construction technology of installing and replacing with tunnel under special conditions is discussed to provide reference for bridge construction.展开更多
This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave fo...This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave force is calculated using the full-field quadratic transfer function(QTF). The coupled effect of the horizontal motions, such as surge, sway and yaw motions, and the set-down motion are taken into consideration by the nonlinear restoring matrix. The time-domain analysis with 50-yr random sea state is performed. A comparison of the results of different case studies is made to assess the influence of second-order wave force on the motions of the platform. The analysis shows that the second-order wave force has a major impact on motions of the TLP. The second-order difference-frequency wave force has an obvious influence on the low-frequency motions of surge and sway, and also will induce a large set-down motion which is an important part of heave motion. Besides, the second-order sum-frequency force will induce a set of high-frequency motions of roll and pitch. However, little influence of second-order wave force is found on the yaw motion.展开更多
The content security requirements of a radio frequency identification （RFID） based logistics-customs clearance service platform （LCCSP） are analysed in this paper. Then, both the unified identity authentication an...The content security requirements of a radio frequency identification （RFID） based logistics-customs clearance service platform （LCCSP） are analysed in this paper. Then, both the unified identity authentication and the access control modules are designed according to those analyses. Finally, the unified identity authentication and the access control on the business level are implemented separately. In the unified identity authentication module, based on an improved Kerberos-based authentication approach, a new control transfer method is proposed to solve the sharing problem of tickets among different servers of different departments. In the access control module, the functions of access controls are divided into different granularities to make the access control management more flexible. Moreover, the access control module has significant reference value for user management in similar systems.展开更多
Based on the Bohai ocean environment characteristics, a new platform vibration distribution structure is designed to reduce the platform vibration due to flowing ice. The effect of the earthquake wave and ocean wave l...Based on the Bohai ocean environment characteristics, a new platform vibration distribution structure is designed to reduce the platform vibration due to flowing ice. The effect of the earthquake wave and ocean wave load on this vibration distribution structure is considered in the design. The principal idea of this new vibration distribution structure is dividing the platform main column into the inner tube and the outer tube. The outer tube is connected with the leg pontoon by braces, while the inner tube is used to support the platform deck. The inner tube and outer tube can be connected or disconneted in the region near the water line. For evaluating the vibration reduction effect of such a structure, tests are carried out on a steel model, and the external load of flowing ice, earthquake wave and ocean wave are simulated by concentated random load applied to different points of the model. The tests are performed in water media and air media respectively. The vibration reduction effect is evaluated by the transfer function of the vibration response at the measured points, and is presented by a dimensionless function dependent on the frequency. Test results show that this new vibration structure has an excellent vibration reduction effect.展开更多
Many cell-matrix interaction studies have proved that dynamic changes in the extracellular matrix(ECM)are crucial to maintain cellular properties and behaviors.Thus,developing materials that can recapitulate the dynam...Many cell-matrix interaction studies have proved that dynamic changes in the extracellular matrix(ECM)are crucial to maintain cellular properties and behaviors.Thus,developing materials that can recapitulate the dynamic attributes of the ECM is highly desired for threedimensional(3 D)cell culture platforms.To this end,we sought to develop a hydrogel system that would enable dynamic and reversible turning of its mechanical and biochemical properties,thus facilitating the control of cell culture to imitate the natural ECM.Herein,a hydrogel with dynamic mechanics and a biochemistry based on an addition-fragmentation chain transfer(AFCT)reaction was constructed.Thiol-modified hyaluronic acid(HA)and allyl sulfide-modifiedε-poly-L-lysine(EPL)were synthesized to form hydrogels,which were non-swellable and biocompatible.The reversible modulus of the hydrogel was first achieved through the AFCT reaction;the modulus can also be regulated stepwise by changing the dose of UVA irradiation.Dynamic patterning of fluorescent markers in the hydrogel was also realized.Therefore,this dynamically controllable hydrogel has great potential as a 3 D cell culture platform for tissue engineering applications.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51878577 and 52378463)the Natural Science Foundation of Shandong Provincial,China(No.ZR2022ME042)the School-Enterprise Cooperation Program of China Railway 14th Bureau Group Co.(QTHT-HGLCHSD-00052)。
文摘The semi-rigid pile-supported composite foundation is widely used in highway projects due to its effectiveness in increasing the bearing capacity and stability of foundations.It is crucial to understand the stress distribution across the embankment width and the behaviour of unreinforced foundations.Thus,five centrifuge tests were conducted to examine the bearing and deformation behaviours of NPRS(Non-Connected Piled Raft Systems)and GRPS(GeosyntheticReinforced Pile-Supported systems)with varying substratum stiffness,then a comparative analysis was conducted on embankment settlement,pressures underneath the embankments,and axial forces along the piles.The results indicated that greater substratum stiffness correlates with reduced settlement and deformation at various depths.Deformation occurring 5 meters from the embankment toe includes settlement in NPRS and upward movement in GRPS.The potential sliding surface is primarily located within the embankment in NPRS,whereas it may extend through both the embankment and foundation in GRPS.The pile-soil stress ratio and efficiency in NPRS are higher than in GRPS across the embankment.The axial force borne by end-bearing piles is significantly greater than that by floating piles.As the buried depth increases,the axial force in GRPS initially rises then declines,whereas in NPRS,it remains relatively constant within a certain range before decreasing.This study aids in assessing the applicability of composite foundations in complex railway environments and provides a reference for procedural measures under similar conditions.
文摘The bridge deck on the Yuzhong side of Zengjiayan Jialing River Bridge is close to subway lines and light rail stations.It is necessary to set up transfer stairways on both sides of the bridge.The construction technology of installing and replacing with tunnel under special conditions is discussed to provide reference for bridge construction.
基金supported by the National Natural Science Foundation of China(Nos.51239008 and 51279130)
文摘This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave force is calculated using the full-field quadratic transfer function(QTF). The coupled effect of the horizontal motions, such as surge, sway and yaw motions, and the set-down motion are taken into consideration by the nonlinear restoring matrix. The time-domain analysis with 50-yr random sea state is performed. A comparison of the results of different case studies is made to assess the influence of second-order wave force on the motions of the platform. The analysis shows that the second-order wave force has a major impact on motions of the TLP. The second-order difference-frequency wave force has an obvious influence on the low-frequency motions of surge and sway, and also will induce a large set-down motion which is an important part of heave motion. Besides, the second-order sum-frequency force will induce a set of high-frequency motions of roll and pitch. However, little influence of second-order wave force is found on the yaw motion.
基金supported by Department of Science & Technology of Guangdong Province (No.2006A15006003)National High Technology Research and Development Program of China (863 Program)(No.2006AA04A120)
文摘The content security requirements of a radio frequency identification （RFID） based logistics-customs clearance service platform （LCCSP） are analysed in this paper. Then, both the unified identity authentication and the access control modules are designed according to those analyses. Finally, the unified identity authentication and the access control on the business level are implemented separately. In the unified identity authentication module, based on an improved Kerberos-based authentication approach, a new control transfer method is proposed to solve the sharing problem of tickets among different servers of different departments. In the access control module, the functions of access controls are divided into different granularities to make the access control management more flexible. Moreover, the access control module has significant reference value for user management in similar systems.
文摘Based on the Bohai ocean environment characteristics, a new platform vibration distribution structure is designed to reduce the platform vibration due to flowing ice. The effect of the earthquake wave and ocean wave load on this vibration distribution structure is considered in the design. The principal idea of this new vibration distribution structure is dividing the platform main column into the inner tube and the outer tube. The outer tube is connected with the leg pontoon by braces, while the inner tube is used to support the platform deck. The inner tube and outer tube can be connected or disconneted in the region near the water line. For evaluating the vibration reduction effect of such a structure, tests are carried out on a steel model, and the external load of flowing ice, earthquake wave and ocean wave are simulated by concentated random load applied to different points of the model. The tests are performed in water media and air media respectively. The vibration reduction effect is evaluated by the transfer function of the vibration response at the measured points, and is presented by a dimensionless function dependent on the frequency. Test results show that this new vibration structure has an excellent vibration reduction effect.
基金financially supported by the National Natural Science Foundation of China(Nos.21803069 and 21975249)。
文摘Many cell-matrix interaction studies have proved that dynamic changes in the extracellular matrix(ECM)are crucial to maintain cellular properties and behaviors.Thus,developing materials that can recapitulate the dynamic attributes of the ECM is highly desired for threedimensional(3 D)cell culture platforms.To this end,we sought to develop a hydrogel system that would enable dynamic and reversible turning of its mechanical and biochemical properties,thus facilitating the control of cell culture to imitate the natural ECM.Herein,a hydrogel with dynamic mechanics and a biochemistry based on an addition-fragmentation chain transfer(AFCT)reaction was constructed.Thiol-modified hyaluronic acid(HA)and allyl sulfide-modifiedε-poly-L-lysine(EPL)were synthesized to form hydrogels,which were non-swellable and biocompatible.The reversible modulus of the hydrogel was first achieved through the AFCT reaction;the modulus can also be regulated stepwise by changing the dose of UVA irradiation.Dynamic patterning of fluorescent markers in the hydrogel was also realized.Therefore,this dynamically controllable hydrogel has great potential as a 3 D cell culture platform for tissue engineering applications.
