A reformed numerical model based on the 'one-line theory' for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined ...A reformed numerical model based on the 'one-line theory' for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined with wave refraction, diffraction and reflection is used to simulate wave climate to increase numerical accuracy.The results show that the numerical model has a good precision based on the adequate field data. The results can be applied to practical engineering.展开更多
A novel self-healing coating with photothermal and pH dual-responsive properties has been designed to protect carbon steel against corrosion by loading the stimuli-responsive microcapsules into a shape memory epoxy co...A novel self-healing coating with photothermal and pH dual-responsive properties has been designed to protect carbon steel against corrosion by loading the stimuli-responsive microcapsules into a shape memory epoxy coating. The sandwich-like microcapsules were based on reduced graphene oxide/mesoporous silica(r GO@MS) assembled with a p H-responsive poly(N,N-dimethylaminoethyl methacrylate)(PDMAEMA) layer, and were loaded with benzotriazole(BTA) inhibitors(abbreviated as rGO@MS-P-BTA). Under near-infrared(NIR) light irradiation, the prominent photothermal effect of rGO could not only elevate the coating temperature to activate the shape memory effect and close the coating scratch, but also facilitate the release of corrosion inhibitors to suppress the corrosion activity. Moreover,the PDMAEMA as a p H-driven “gatekeeper” realized the controlled release of BTA from microcapsules at acid conditions. The surface morphology analysis, electrochemical impedance spectroscopy(EIS), and scanning electrochemical microscopy(SECM) were performed to evaluate the self-healing performance of the composite coatings. The results showed that the combination of NIR light and p H-responsive selfhealing effects endowed the coating with short healing time and prominent healing efficiency.展开更多
Measurements of the total radiated power and its spatial distribution are crucial for fusion research.On the experimental advanced superconducting tokamak(EAST),both the metal foil resistive bolometer and the absolute...Measurements of the total radiated power and its spatial distribution are crucial for fusion research.On the experimental advanced superconducting tokamak(EAST),both the metal foil resistive bolometer and the absolute extreme ultraviolet(AXUV)photodiodes have been used to quantify the radiated power.This article introduces the latest improvement of the bolometer diagnostic system on EAST.It also details the successful design and installation of new divertor AXUV cameras,which are dedicated to the investigation of divertor physics.The shielding components of the bolometer detector have been refined,and the article provides a detailed exposition of the double shielding structures that have been verified as effective in microwave shielding.Additionally,the changes in the radiated power distribution in the divertor region during the plasma detachment process are measured using the divertor AXUV camera.Finally,the radiated power measured by the AXUV detector and metal foil resistive bolometer are compared,and different detector performances are presented.展开更多
Software-Defined Networking(SDN)represents a significant paradigm shift in network architecture,separating network logic from the underlying forwarding devices to enhance flexibility and centralize deployment.Concur-r...Software-Defined Networking(SDN)represents a significant paradigm shift in network architecture,separating network logic from the underlying forwarding devices to enhance flexibility and centralize deployment.Concur-rently,the Internet of Things(IoT)connects numerous devices to the Internet,enabling autonomous interactions with minimal human intervention.However,implementing and managing an SDN-IoT system is inherently complex,particularly for those with limited resources,as the dynamic and distributed nature of IoT infrastructures creates security and privacy challenges during SDN integration.The findings of this study underscore the primary security and privacy challenges across application,control,and data planes.A comprehensive review evaluates the root causes of these challenges and the defense techniques employed in prior works to establish sufficient secrecy and privacy protection.Recent investigations have explored cutting-edge methods,such as leveraging blockchain for transaction recording to enhance security and privacy,along with applying machine learning and deep learning approaches to identify and mitigate the impacts of Denial of Service(DoS)and Distributed DoS(DDoS)attacks.Moreover,the analysis indicates that encryption and hashing techniques are prevalent in the data plane,whereas access control and certificate authorization are prominently considered in the control plane,and authentication is commonly employed within the application plane.Additionally,this paper outlines future directions,offering insights into potential strategies and technological advancements aimed at fostering a more secure and privacy-conscious SDN-based IoT ecosystem.展开更多
This paper analyzed the distribution of thermohaline and circulation characteristics of Zhejiang and Fujian waters,based on the cross-sectional thermohaline data and on current data （up to 30 d duration） at fixed-po...This paper analyzed the distribution of thermohaline and circulation characteristics of Zhejiang and Fujian waters,based on the cross-sectional thermohaline data and on current data （up to 30 d duration） at fixed-point moorings,collected in the summer of 2006.We also performed low-pass filtering and spectrum analysis on the mooring submersible buoy data.Based on that analysis,we discussed the characteristics of low frequency currents and time-variations in these waters.The main conclusions are as follows.（1） There is a low salinity pinnate area near the Hangzhou Bay in summer,and outside the low salinity area,an obvious salinity front is present from surface to bottom near 123 E.There is also a temperature front below the surface at a corresponding position.（2） Bottom water of the Taiwan Warm Current comes from the subsurface of Kuroshio.（3） The direction of low frequency current at fixed anchor stations is N-NE or S,which mainly depends on the interaction of control currents in this waters.（4） Significant spectral peaks at all mooring stations are typically semidiurnal and diurnal tides.Semidiurnal tidal waves are the main ones in these waters,and have more energy closer to the shore.（5） Significant energy spectral peaks of middle period （3 to 8 d） of currents are responses to weather frequency.（6） Significant energy spectral peaks of long periods at the surface or bottom are probably responses to seasonal wind or bottom friction,while,the long period peaks of other depths can reflect cyclical changes of interactions between currents.We conclude that the pulsation period of the Taiwan Warm Current in these waters is 10-17 d.展开更多
Power spectrum and cross-wavelet transform analysis was adopted to study the time-frequency characteristics and multiscale correlations between runoff,tidal range and salinity in the Changjiang Estuary based on the ru...Power spectrum and cross-wavelet transform analysis was adopted to study the time-frequency characteristics and multiscale correlations between runoff,tidal range and salinity in the Changjiang Estuary based on the runoff data collected at the Datong Station,the tidal range measured at the Baozhen Station,and the salinity at the Baogang Station from 2008 to 2009.The variations of the salinity showed significant periodicity at scales of 2-3,7-8,14-15 and 26-30 d.The correlation between the salinity and the runoff and the tidal range were found to be significantly related to shock at scales of 5-7,14-15,26-30 d and 0.5 a.The correlation between the runoff and the salinity was mainly in the same phase,while the correlation between the tidal range and the salinity was in the antiphase.Different frequency bands were related to different degrees,and their relevance increased as the resonance frequency decreased.In addition,changes of the seasonal runoff were obvious.Specifically,a point of discontinuity was reached in early June with a cycle of 7-8 d,which coincided with the periodicity of plum rains in the Changjiang-Huaihe region.High-frequency changes （8-16 d period） of the salinity corresponded to the time domain in January-April 2008,February-April 2009 and October-December 2009 and exhibited an approximately 0.5 a （184 d） long frequency oscillation.Short-period changes were found to be stronger than long-period changes.Cross-wavelet transforms for the salinity,the runoff and the tidal range revealed local features in the time domain,while the significant levels of different periodic oscillations were observed in the frequency domain.The correlation characteristics of the salinity and the runoff were significant in the 80-90 d frequency domain,indicating that the major impact of the runoff on the salinity was reflected in seasonal changes.The tidal range on the small scale of 14-15 and 30-32 d was more obvious than the runoff.展开更多
The value of application of three-dimensional visualization and animation technique in dynamic simulation of geographical landscape formation is analyzed and, in particular, how to simulate the formation and evolvemen...The value of application of three-dimensional visualization and animation technique in dynamic simulation of geographical landscape formation is analyzed and, in particular, how to simulate the formation and evolvement of geographical landscape in temporal dimension is discussed thoroughly. Based on various modeling tools in 3DS MAX and original DEM data of the study area acquired from topographic map, real three-dimensional terrain model is generated by using the method of three-dimensional mesh approximation through DEM interpolating and surface modeling, which leads to the realization of the dynamic visualization and simulation of volcanic landscape, formation and evolvement. Furthermore, the dynamic three-dimensional visual virtual scenery of the formation and evolvement of the volcano in the Changbai Mountains of Jilin, China, is constructed. The applicability, potential, and corresponding technique of using 3DS MAX to dynamically simulate the formation of geographical landscape are expatiated.展开更多
This paper reports some researches on distribution of large volume image data using techniques of the Mixed Mode of Java Servlet and COM on Web. The architecture and key technologies are discussed in detail. The web d...This paper reports some researches on distribution of large volume image data using techniques of the Mixed Mode of Java Servlet and COM on Web. The architecture and key technologies are discussed in detail. The web distribution system of image is implemented and the system is tested by the application instances. At last, the advantages and disadvantages for this web image distribution mode are analyzed.展开更多
BACKGROUND： Bone marrow-derived mesenchymal stem cells （BMSCs） are a potentially useful source for cell replacement therapy following spinal cord injury. However, the homing characteristics of BMSCs in vivo remain ...BACKGROUND： Bone marrow-derived mesenchymal stem cells （BMSCs） are a potentially useful source for cell replacement therapy following spinal cord injury. However, the homing characteristics of BMSCs in vivo remain unclear. Low-dose radiation has been shown to promote homing of BMSCs to exposed sites. OBJECTIVE： To investigate the effects of low-dose local radiation to non-injured areas on the ability of human BMSCs to home to the injured mouse spinal cord, as well as recovery of spinal cord injury. DESIGN, TIME AND SE＇I-FING： A randomized, controlled, animal experiment was performed at the Central Laboratory, Second Affiliated Hospital of Soochow University between October 2007 and October 2008. MATERIALS： BMSCs were isolated from four adult, human donors. METHODS： Fifty adult, female, Balb/c mice were subjected to adjusted weight-drop impact resulting in complete paraplegia. Three days later, mice were randomly assigned to a radiation ＋ transplantation group （n = 23） and a transplantation group （n = 20）. In total, 2 x 106 carboxyfluorescein diacetate succinimidyl ester-labeled BMSCs were injected into each mouse via the caudal vein. Mice in the radiation ＋ transplantation group received 2.5 Gy local X-ray irradiation 2 hours before BMSCs injection. MAIN OUTCOME MEASURES： The homing of BMSCs to injured cord and irradiated skin after transplantation was observed by fluorescence microscope; the structure recovery of injured cord was assessed by magnetic resonance imaging. RESULTS： Compared with the transplantation group, at 24 hours after transplantation, the number of BMSCs was significantly increased in the injured area and the exposed site （P 〈 0.05）, and inflammation and edema were significantly alleviated in the injured cord in the radiation ＋ transplantation group. CONCLUSION： Local low-dose radiation has the potential to promote homing of BMSCs and recovery of spinal cord injury, although the radiated region was not injured area.展开更多
Sediment transport in the Hangzhou Bay is extremely complicated due to its bathymetry and hydrodynamic conditions. The ECOMSED model is employed to simulate three-dimensional （3-D） cohesive sediment transport in Han...Sediment transport in the Hangzhou Bay is extremely complicated due to its bathymetry and hydrodynamic conditions. The ECOMSED model is employed to simulate three-dimensional （3-D） cohesive sediment transport in Hangzhou Bay. Dynamical factors such as Coriolis force, tides, salinity, river discharges, and waves are considered in the model. The wave parameters, including the significant wave height, period, and direction, are calculated with the SWAN model. The Grant-Madsen model is introduced for the bed shear stress due to the combined effect of waves and currents. The formulation of bed shear stress used to calculate the sink/source terms is modified based on previous research that sufficiently validated the formulation with measurement data. The integrated model of the above-mentioned models is applied to simulate sediment transport in Hangzhou Bay. The results of the simulation agree well with field observations concerning the distribution of suspended sediment, indicating that the sediments are remarkably suspended in Hangzhou Bay under the action of waves and currents.展开更多
文摘A reformed numerical model based on the 'one-line theory' for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined with wave refraction, diffraction and reflection is used to simulate wave climate to increase numerical accuracy.The results show that the numerical model has a good precision based on the adequate field data. The results can be applied to practical engineering.
基金supported by the National Natural Science Foundation of China (Nos. 51771029 and 51901015)。
文摘A novel self-healing coating with photothermal and pH dual-responsive properties has been designed to protect carbon steel against corrosion by loading the stimuli-responsive microcapsules into a shape memory epoxy coating. The sandwich-like microcapsules were based on reduced graphene oxide/mesoporous silica(r GO@MS) assembled with a p H-responsive poly(N,N-dimethylaminoethyl methacrylate)(PDMAEMA) layer, and were loaded with benzotriazole(BTA) inhibitors(abbreviated as rGO@MS-P-BTA). Under near-infrared(NIR) light irradiation, the prominent photothermal effect of rGO could not only elevate the coating temperature to activate the shape memory effect and close the coating scratch, but also facilitate the release of corrosion inhibitors to suppress the corrosion activity. Moreover,the PDMAEMA as a p H-driven “gatekeeper” realized the controlled release of BTA from microcapsules at acid conditions. The surface morphology analysis, electrochemical impedance spectroscopy(EIS), and scanning electrochemical microscopy(SECM) were performed to evaluate the self-healing performance of the composite coatings. The results showed that the combination of NIR light and p H-responsive selfhealing effects endowed the coating with short healing time and prominent healing efficiency.
基金supported by the National MCF Energy R&D Program of China(Nos.2022YFE03040003 and 2019YFE03010003).
文摘Measurements of the total radiated power and its spatial distribution are crucial for fusion research.On the experimental advanced superconducting tokamak(EAST),both the metal foil resistive bolometer and the absolute extreme ultraviolet(AXUV)photodiodes have been used to quantify the radiated power.This article introduces the latest improvement of the bolometer diagnostic system on EAST.It also details the successful design and installation of new divertor AXUV cameras,which are dedicated to the investigation of divertor physics.The shielding components of the bolometer detector have been refined,and the article provides a detailed exposition of the double shielding structures that have been verified as effective in microwave shielding.Additionally,the changes in the radiated power distribution in the divertor region during the plasma detachment process are measured using the divertor AXUV camera.Finally,the radiated power measured by the AXUV detector and metal foil resistive bolometer are compared,and different detector performances are presented.
基金This work was supported by National Natural Science Foundation of China(Grant No.62341208)Natural Science Foundation of Zhejiang Province(Grant Nos.LY23F020006 and LR23F020001)Moreover,it has been supported by Islamic Azad University with the Grant No.133713281361.
文摘Software-Defined Networking(SDN)represents a significant paradigm shift in network architecture,separating network logic from the underlying forwarding devices to enhance flexibility and centralize deployment.Concur-rently,the Internet of Things(IoT)connects numerous devices to the Internet,enabling autonomous interactions with minimal human intervention.However,implementing and managing an SDN-IoT system is inherently complex,particularly for those with limited resources,as the dynamic and distributed nature of IoT infrastructures creates security and privacy challenges during SDN integration.The findings of this study underscore the primary security and privacy challenges across application,control,and data planes.A comprehensive review evaluates the root causes of these challenges and the defense techniques employed in prior works to establish sufficient secrecy and privacy protection.Recent investigations have explored cutting-edge methods,such as leveraging blockchain for transaction recording to enhance security and privacy,along with applying machine learning and deep learning approaches to identify and mitigate the impacts of Denial of Service(DoS)and Distributed DoS(DDoS)attacks.Moreover,the analysis indicates that encryption and hashing techniques are prevalent in the data plane,whereas access control and certificate authorization are prominently considered in the control plane,and authentication is commonly employed within the application plane.Additionally,this paper outlines future directions,offering insights into potential strategies and technological advancements aimed at fostering a more secure and privacy-conscious SDN-based IoT ecosystem.
基金The Public Science and Technology Research Funds Projects of Ocean under contract Nos 200905001,200905010 and 201005019the Research Programs of the Science and Technology Commission of Shanghai under contract No.09DZ1201200the Young Scientist Foundation of the State Oceanic Administration of China under contract No.2011209
文摘This paper analyzed the distribution of thermohaline and circulation characteristics of Zhejiang and Fujian waters,based on the cross-sectional thermohaline data and on current data （up to 30 d duration） at fixed-point moorings,collected in the summer of 2006.We also performed low-pass filtering and spectrum analysis on the mooring submersible buoy data.Based on that analysis,we discussed the characteristics of low frequency currents and time-variations in these waters.The main conclusions are as follows.（1） There is a low salinity pinnate area near the Hangzhou Bay in summer,and outside the low salinity area,an obvious salinity front is present from surface to bottom near 123 E.There is also a temperature front below the surface at a corresponding position.（2） Bottom water of the Taiwan Warm Current comes from the subsurface of Kuroshio.（3） The direction of low frequency current at fixed anchor stations is N-NE or S,which mainly depends on the interaction of control currents in this waters.（4） Significant spectral peaks at all mooring stations are typically semidiurnal and diurnal tides.Semidiurnal tidal waves are the main ones in these waters,and have more energy closer to the shore.（5） Significant energy spectral peaks of middle period （3 to 8 d） of currents are responses to weather frequency.（6） Significant energy spectral peaks of long periods at the surface or bottom are probably responses to seasonal wind or bottom friction,while,the long period peaks of other depths can reflect cyclical changes of interactions between currents.We conclude that the pulsation period of the Taiwan Warm Current in these waters is 10-17 d.
基金The Public Science and Technology Research Funds Projects of Ocean under contract Nos 200905001,200905010 and 201005019the Research Programs of the Science and Technology Commission of Shanghai of China under contract No.09DZ1201200Young Scientist Foundation of the State Oceanic Administration of China under contract No.2008234
文摘Power spectrum and cross-wavelet transform analysis was adopted to study the time-frequency characteristics and multiscale correlations between runoff,tidal range and salinity in the Changjiang Estuary based on the runoff data collected at the Datong Station,the tidal range measured at the Baozhen Station,and the salinity at the Baogang Station from 2008 to 2009.The variations of the salinity showed significant periodicity at scales of 2-3,7-8,14-15 and 26-30 d.The correlation between the salinity and the runoff and the tidal range were found to be significantly related to shock at scales of 5-7,14-15,26-30 d and 0.5 a.The correlation between the runoff and the salinity was mainly in the same phase,while the correlation between the tidal range and the salinity was in the antiphase.Different frequency bands were related to different degrees,and their relevance increased as the resonance frequency decreased.In addition,changes of the seasonal runoff were obvious.Specifically,a point of discontinuity was reached in early June with a cycle of 7-8 d,which coincided with the periodicity of plum rains in the Changjiang-Huaihe region.High-frequency changes （8-16 d period） of the salinity corresponded to the time domain in January-April 2008,February-April 2009 and October-December 2009 and exhibited an approximately 0.5 a （184 d） long frequency oscillation.Short-period changes were found to be stronger than long-period changes.Cross-wavelet transforms for the salinity,the runoff and the tidal range revealed local features in the time domain,while the significant levels of different periodic oscillations were observed in the frequency domain.The correlation characteristics of the salinity and the runoff were significant in the 80-90 d frequency domain,indicating that the major impact of the runoff on the salinity was reflected in seasonal changes.The tidal range on the small scale of 14-15 and 30-32 d was more obvious than the runoff.
文摘The value of application of three-dimensional visualization and animation technique in dynamic simulation of geographical landscape formation is analyzed and, in particular, how to simulate the formation and evolvement of geographical landscape in temporal dimension is discussed thoroughly. Based on various modeling tools in 3DS MAX and original DEM data of the study area acquired from topographic map, real three-dimensional terrain model is generated by using the method of three-dimensional mesh approximation through DEM interpolating and surface modeling, which leads to the realization of the dynamic visualization and simulation of volcanic landscape, formation and evolvement. Furthermore, the dynamic three-dimensional visual virtual scenery of the formation and evolvement of the volcano in the Changbai Mountains of Jilin, China, is constructed. The applicability, potential, and corresponding technique of using 3DS MAX to dynamically simulate the formation of geographical landscape are expatiated.
文摘This paper reports some researches on distribution of large volume image data using techniques of the Mixed Mode of Java Servlet and COM on Web. The architecture and key technologies are discussed in detail. The web distribution system of image is implemented and the system is tested by the application instances. At last, the advantages and disadvantages for this web image distribution mode are analyzed.
基金a Project for Nuclear Military Personal Health Assessment and Radiation Damage Treat-ment, No. 616010305
文摘BACKGROUND： Bone marrow-derived mesenchymal stem cells （BMSCs） are a potentially useful source for cell replacement therapy following spinal cord injury. However, the homing characteristics of BMSCs in vivo remain unclear. Low-dose radiation has been shown to promote homing of BMSCs to exposed sites. OBJECTIVE： To investigate the effects of low-dose local radiation to non-injured areas on the ability of human BMSCs to home to the injured mouse spinal cord, as well as recovery of spinal cord injury. DESIGN, TIME AND SE＇I-FING： A randomized, controlled, animal experiment was performed at the Central Laboratory, Second Affiliated Hospital of Soochow University between October 2007 and October 2008. MATERIALS： BMSCs were isolated from four adult, human donors. METHODS： Fifty adult, female, Balb/c mice were subjected to adjusted weight-drop impact resulting in complete paraplegia. Three days later, mice were randomly assigned to a radiation ＋ transplantation group （n = 23） and a transplantation group （n = 20）. In total, 2 x 106 carboxyfluorescein diacetate succinimidyl ester-labeled BMSCs were injected into each mouse via the caudal vein. Mice in the radiation ＋ transplantation group received 2.5 Gy local X-ray irradiation 2 hours before BMSCs injection. MAIN OUTCOME MEASURES： The homing of BMSCs to injured cord and irradiated skin after transplantation was observed by fluorescence microscope; the structure recovery of injured cord was assessed by magnetic resonance imaging. RESULTS： Compared with the transplantation group, at 24 hours after transplantation, the number of BMSCs was significantly increased in the injured area and the exposed site （P 〈 0.05）, and inflammation and edema were significantly alleviated in the injured cord in the radiation ＋ transplantation group. CONCLUSION： Local low-dose radiation has the potential to promote homing of BMSCs and recovery of spinal cord injury, although the radiated region was not injured area.
基金the Funds for Creative Research Groups of China under contract No. 40721004the Sino-Dutch Program for Strategic Scientific Alliance Project under contract No. 2008DFB90240
文摘Sediment transport in the Hangzhou Bay is extremely complicated due to its bathymetry and hydrodynamic conditions. The ECOMSED model is employed to simulate three-dimensional （3-D） cohesive sediment transport in Hangzhou Bay. Dynamical factors such as Coriolis force, tides, salinity, river discharges, and waves are considered in the model. The wave parameters, including the significant wave height, period, and direction, are calculated with the SWAN model. The Grant-Madsen model is introduced for the bed shear stress due to the combined effect of waves and currents. The formulation of bed shear stress used to calculate the sink/source terms is modified based on previous research that sufficiently validated the formulation with measurement data. The integrated model of the above-mentioned models is applied to simulate sediment transport in Hangzhou Bay. The results of the simulation agree well with field observations concerning the distribution of suspended sediment, indicating that the sediments are remarkably suspended in Hangzhou Bay under the action of waves and currents.
