Edge computing devices are widely deployed.An important issue that arises is in that these devices suffer from security attacks.To deal with it,we turn to the blockchain technologies.The note in the alliance chain nee...Edge computing devices are widely deployed.An important issue that arises is in that these devices suffer from security attacks.To deal with it,we turn to the blockchain technologies.The note in the alliance chain need rules to limit write permissions.Alliance chain can provide security management functions,using these functions to meet the management between the members,certification,authorization,monitoring and auditing.This article mainly analyzes some requirements realization which applies to the alliance chain,and introduces a new consensus algorithm,generalized Legendre sequence(GLS)consensus algorithm,for alliance chain.GLS algorithms inherit the recognition and verification efficiency of binary sequence ciphers in computer communication and can solve a large number of nodes verification of key distribution issues.In the alliance chain,GLS consensus algorithm can complete node address hiding,automatic task sorting,task automatic grouping,task node scope confirmation,task address binding and stamp timestamp.Moreover,the GLS consensus algorithm increases the difficulty of network malicious attack.展开更多
Based on the LOM(Laminated Object Manufacturing)process,an inert gas-assisted laser method for wood cutting was proposed.The carbonization degree of wood surface was improved by the introduction of helium(He)gas,and t...Based on the LOM(Laminated Object Manufacturing)process,an inert gas-assisted laser method for wood cutting was proposed.The carbonization degree of wood surface was improved by the introduction of helium(He)gas,and the influence of process parameters on the carbonization layer of wood surface was solved,it was significance to reduce the post-processing of LOM and improve the quality of forming workpiece.The cherry wood veneer was used as the experimental material,under the condition of the same process parameters,the wood was cut with or without inert gas-assisted,and the influence factors of kerf quality were studied by variance analysis.The results showed that under the same condition,compared with traditional laser processing,the kerf width was obviously reduced in the inert gas-assisted cutting.Because the He gas had oxygen-isolation and flame retardant effect,which prevented heat accumulation and conduction.The micro morphology of the kerf surface showed that the flatness was better in the inert gas-assisted cutting.As the excess heat was blown out by the cooling and purging of the gas,the phenomenon of oxidation and burning was reduced,the range of HAZ(heat affected zone)was reduced,and the carbonization phenomenon was obviously improved.The surface quality of kerf was improved effectively.According to the analysis of variance,in addition to the effect of laser power,cutting speed and inert gas flow on the cutting width,the interaction between inert gas flow and laser power,laser power and cutting speed were also the main factors which affected the cutting width.The feasibility of the combined inert gas and laser processing to improve wood cutting quality has been verified through experimental research,which provided a certain reference for the followup research on improving the wood processing quality.展开更多
Dear Editor,Coxsackievirus A16(CA16)is one of the major viral pathogens associated with hand,foot,and mouth disease.CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded po...Dear Editor,Coxsackievirus A16(CA16)is one of the major viral pathogens associated with hand,foot,and mouth disease.CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded positivesense RNA genome(Mao et al.,2014).Reverse genetics is an important tool for CA16 research.Previously,a reverse genetics T7 polymerase-based system was de-展开更多
Surface plasmon devices mounted at the end-facets of optical fibers are appealing candidates for rapid and point-of-care sensing applications,by offering a special dip-and-read operation mode.At present,these devices...Surface plasmon devices mounted at the end-facets of optical fibers are appealing candidates for rapid and point-of-care sensing applications,by offering a special dip-and-read operation mode.At present,these devices’noise-equivalent limits-of-detection lag far behind the free-space counterparts,leaving them incapable of most biosensing applications.Here we report a quasi-3D Fano resonance cavity and its fabrication method to fundamentally improve the quality factor and coupling efficiency for fiber-coupled surface plasmon resonance.In this device,the Fano resonance combines the high coupling efficiency of a Fabry-Pérot etalon and the high quality factor resonance of a plasmonic crystal cavity.The quasi-3D device was fabricated on a planar substrate and transferred to a single-mode fiber end-facet,which requires a low-adhesion yet surface-plasmon-tunneling interface between the device and the planar substrate.Such an interface was realized with a nanocap-slit unit structure,of which the plasmonic crystal was consisted.A noise-equivalent limit of detection of~10-7 RIU was experimentally obtained,allowing bovine serum albumin physical adsorption to be distinguished at ng mL-1 level concentrations.Therefore,breaking through the long-standing signal-to-noise ratio bottleneck,this work makes fiber end-facet surface plasmon devices into one of high sensitivity label-free sensing technologies.At the same time,it provides an enabling top-down fabrication technology for making 3D plasmonic structures on fiber end-facets at the nanometer scale.展开更多
基金We gratefully acknowledge anonymous reviewers who read drafts and made many helpful suggestions.This work is supported by the National Key Research and Development Program No.2018YFC0807002.
文摘Edge computing devices are widely deployed.An important issue that arises is in that these devices suffer from security attacks.To deal with it,we turn to the blockchain technologies.The note in the alliance chain need rules to limit write permissions.Alliance chain can provide security management functions,using these functions to meet the management between the members,certification,authorization,monitoring and auditing.This article mainly analyzes some requirements realization which applies to the alliance chain,and introduces a new consensus algorithm,generalized Legendre sequence(GLS)consensus algorithm,for alliance chain.GLS algorithms inherit the recognition and verification efficiency of binary sequence ciphers in computer communication and can solve a large number of nodes verification of key distribution issues.In the alliance chain,GLS consensus algorithm can complete node address hiding,automatic task sorting,task automatic grouping,task node scope confirmation,task address binding and stamp timestamp.Moreover,the GLS consensus algorithm increases the difficulty of network malicious attack.
基金The research was supported by Significant special research and development project of Guangdong province(2020B020216001)Fundamental Research Funds for the Central Universities(2572018CG06).
文摘Based on the LOM(Laminated Object Manufacturing)process,an inert gas-assisted laser method for wood cutting was proposed.The carbonization degree of wood surface was improved by the introduction of helium(He)gas,and the influence of process parameters on the carbonization layer of wood surface was solved,it was significance to reduce the post-processing of LOM and improve the quality of forming workpiece.The cherry wood veneer was used as the experimental material,under the condition of the same process parameters,the wood was cut with or without inert gas-assisted,and the influence factors of kerf quality were studied by variance analysis.The results showed that under the same condition,compared with traditional laser processing,the kerf width was obviously reduced in the inert gas-assisted cutting.Because the He gas had oxygen-isolation and flame retardant effect,which prevented heat accumulation and conduction.The micro morphology of the kerf surface showed that the flatness was better in the inert gas-assisted cutting.As the excess heat was blown out by the cooling and purging of the gas,the phenomenon of oxidation and burning was reduced,the range of HAZ(heat affected zone)was reduced,and the carbonization phenomenon was obviously improved.The surface quality of kerf was improved effectively.According to the analysis of variance,in addition to the effect of laser power,cutting speed and inert gas flow on the cutting width,the interaction between inert gas flow and laser power,laser power and cutting speed were also the main factors which affected the cutting width.The feasibility of the combined inert gas and laser processing to improve wood cutting quality has been verified through experimental research,which provided a certain reference for the followup research on improving the wood processing quality.
基金supported by grants from the Science and Technology Commission of Shanghai Municipality (13ZR1462900)the Shanghai Institutes for Biological Science (SIBS),Chinese Academy of Science (CAS) (2013KIP317)+1 种基金the support of the SA-SIBS scholarship programYouth Innovation Promotion Association of CAS (2016249)
文摘Dear Editor,Coxsackievirus A16(CA16)is one of the major viral pathogens associated with hand,foot,and mouth disease.CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded positivesense RNA genome(Mao et al.,2014).Reverse genetics is an important tool for CA16 research.Previously,a reverse genetics T7 polymerase-based system was de-
基金supported by the National Natural Science Foundation of China(grant 61975253)the Science and Technology Commission of Shanghai Municipality(grant 21N31900200)the National Infrastructures for Translational Medicine(Shanghai) and the Lumieres(Xu Yuan)Biotechnology Company.
文摘Surface plasmon devices mounted at the end-facets of optical fibers are appealing candidates for rapid and point-of-care sensing applications,by offering a special dip-and-read operation mode.At present,these devices’noise-equivalent limits-of-detection lag far behind the free-space counterparts,leaving them incapable of most biosensing applications.Here we report a quasi-3D Fano resonance cavity and its fabrication method to fundamentally improve the quality factor and coupling efficiency for fiber-coupled surface plasmon resonance.In this device,the Fano resonance combines the high coupling efficiency of a Fabry-Pérot etalon and the high quality factor resonance of a plasmonic crystal cavity.The quasi-3D device was fabricated on a planar substrate and transferred to a single-mode fiber end-facet,which requires a low-adhesion yet surface-plasmon-tunneling interface between the device and the planar substrate.Such an interface was realized with a nanocap-slit unit structure,of which the plasmonic crystal was consisted.A noise-equivalent limit of detection of~10-7 RIU was experimentally obtained,allowing bovine serum albumin physical adsorption to be distinguished at ng mL-1 level concentrations.Therefore,breaking through the long-standing signal-to-noise ratio bottleneck,this work makes fiber end-facet surface plasmon devices into one of high sensitivity label-free sensing technologies.At the same time,it provides an enabling top-down fabrication technology for making 3D plasmonic structures on fiber end-facets at the nanometer scale.