The outbreak of SARS in 2003 opened the way of public health emergency management in China.COVID-19 which suddenly outbroke in 2019 is still raging all over the world,and emergency management mechanism of China is bei...The outbreak of SARS in 2003 opened the way of public health emergency management in China.COVID-19 which suddenly outbroke in 2019 is still raging all over the world,and emergency management mechanism of China is being tested.Efforts to improve the emergency management mechanism can provide effective institutional guarantee for the overall victory of anti epidemic and the prevention and control of public health emergencies.展开更多
This paper analyzed the key issues and challenges confronted in the governance of Village B in the non-epicenter area in rural areas of China during the COVID-19 pandemic.It clarified the weak points in the prevention...This paper analyzed the key issues and challenges confronted in the governance of Village B in the non-epicenter area in rural areas of China during the COVID-19 pandemic.It clarified the weak points in the prevention and control of infectious diseases in Village B.A triple emergency management mechanism of"people-materials-environment"in rural areas should be established.It came up with constructive recommendations for scientifically and effectively responding to public health emergencies in rural non-epicenter areas,which is helpful to improve the rationality,legality and scientific effectiveness of the construction of emergency response mechanisms in rural areas.展开更多
Flexible materials are essential in bionic fields such as soft robots.However,the lack of stiffness limits the mechanical performance of soft robots and makes them difficult to develop in many extreme working conditio...Flexible materials are essential in bionic fields such as soft robots.However,the lack of stiffness limits the mechanical performance of soft robots and makes them difficult to develop in many extreme working conditions,such as lifting and excavation operations.To address this issue,we prepared a stiffness-tunable composite by dispersing low-melting-point alloy into thermosetting epoxy resin.A dramatic and rapid change in stiffness was achieved by changing the state of matter at lower temperatures,and accurate control of the composite modulus was achieved by controlling the temperature.When the alloy content is at 30vol%,the tensile modulus changes 41.6 times,while the compressive modulus changes 58.9 times.By applying the composite to a flexible actuator,the initial stiffness of the actuator was improved by 124 times,reaching 332 mN/mm.In addition,the use of stiffness-tunable materials in the wheel allowed for timely changes in the grounding area to improve friction.These flexible materials with manageable mechanical properties have wide applicability in fields including bionics,robotics,and sensing.Our findings provide a new approach to designing and developing flexible materials with improved stiffness and controllability.展开更多
Cooperative jamming(CJ)is one of the important methods to solve security problems of underwater acoustic sensor networks(UASNs).In this paper,we propose a Cooperative Jamming Scheme based on Node Authentication for UA...Cooperative jamming(CJ)is one of the important methods to solve security problems of underwater acoustic sensor networks(UASNs).In this paper,we propose a Cooperative Jamming Scheme based on Node Authentication for UASNs to improve the effect of CJ by selecting suitable jamming source for found illegal nodes.In the node authentication,all nodes will be identified by their trust value(TV).TV is calculated according to three types of evidence:channel-based trust evidence,behavior-based trust evidence and energy-based trust evidence.Besides,to deal with cases where legal nodes may be suspected,the historical TV and trust redemption will be considered when calculating TV.In cooperative jamming,according to the link quality,several nodes are selected to jam illegal nodes.Both simulation and field experiment show that the proposed scheme can accurately find the illegal nodes in the time-vary channel and improve the security of the network.展开更多
文摘The outbreak of SARS in 2003 opened the way of public health emergency management in China.COVID-19 which suddenly outbroke in 2019 is still raging all over the world,and emergency management mechanism of China is being tested.Efforts to improve the emergency management mechanism can provide effective institutional guarantee for the overall victory of anti epidemic and the prevention and control of public health emergencies.
基金Humanities and Social Sciences Project of the Ministry of Education"Relationship between Haze Pollution and Socio-economic Growth:Research on Three Dimensions Spatial-temporal Feature,Decoupling effect and Collaborative Governance"(21YJCZH016).
文摘This paper analyzed the key issues and challenges confronted in the governance of Village B in the non-epicenter area in rural areas of China during the COVID-19 pandemic.It clarified the weak points in the prevention and control of infectious diseases in Village B.A triple emergency management mechanism of"people-materials-environment"in rural areas should be established.It came up with constructive recommendations for scientifically and effectively responding to public health emergencies in rural non-epicenter areas,which is helpful to improve the rationality,legality and scientific effectiveness of the construction of emergency response mechanisms in rural areas.
基金This work was supported by the Project of National Key Research and Development Program of China(2018YFA0703300)the National Natural Science Foundation of China(52105299,52175271,52021003,91948302)+1 种基金Science and technology development plan project of Jilin Province(20210509047RQ,20210508057RQ)Program for JLU Science and Technology Innovative Research Team(2017TD-04).
文摘Flexible materials are essential in bionic fields such as soft robots.However,the lack of stiffness limits the mechanical performance of soft robots and makes them difficult to develop in many extreme working conditions,such as lifting and excavation operations.To address this issue,we prepared a stiffness-tunable composite by dispersing low-melting-point alloy into thermosetting epoxy resin.A dramatic and rapid change in stiffness was achieved by changing the state of matter at lower temperatures,and accurate control of the composite modulus was achieved by controlling the temperature.When the alloy content is at 30vol%,the tensile modulus changes 41.6 times,while the compressive modulus changes 58.9 times.By applying the composite to a flexible actuator,the initial stiffness of the actuator was improved by 124 times,reaching 332 mN/mm.In addition,the use of stiffness-tunable materials in the wheel allowed for timely changes in the grounding area to improve friction.These flexible materials with manageable mechanical properties have wide applicability in fields including bionics,robotics,and sensing.Our findings provide a new approach to designing and developing flexible materials with improved stiffness and controllability.
基金Supported by the National Natural Science Foundation of China under Grant No.62171310the Marine Defense Innovation Fund JJ-2020-701-09Lanzhou Jiaotong University-Tianjin University Co-Funding under Grant No.2022064。
文摘Cooperative jamming(CJ)is one of the important methods to solve security problems of underwater acoustic sensor networks(UASNs).In this paper,we propose a Cooperative Jamming Scheme based on Node Authentication for UASNs to improve the effect of CJ by selecting suitable jamming source for found illegal nodes.In the node authentication,all nodes will be identified by their trust value(TV).TV is calculated according to three types of evidence:channel-based trust evidence,behavior-based trust evidence and energy-based trust evidence.Besides,to deal with cases where legal nodes may be suspected,the historical TV and trust redemption will be considered when calculating TV.In cooperative jamming,according to the link quality,several nodes are selected to jam illegal nodes.Both simulation and field experiment show that the proposed scheme can accurately find the illegal nodes in the time-vary channel and improve the security of the network.
