In the era of big data,sensor networks have been pervasively deployed,producing a large amount of data for various applications.However,because sensor networks are usually placed in hostile environments,managing the h...In the era of big data,sensor networks have been pervasively deployed,producing a large amount of data for various applications.However,because sensor networks are usually placed in hostile environments,managing the huge volume of data is a very challenging issue.In this study,we mainly focus on the data storage reliability problem in heterogeneous wireless sensor networks where robust storage nodes are deployed in sensor networks and data redundancy is utilized through coding techniques.To minimize data delivery and data storage costs,we design an algorithm to jointly optimize data routing and storage node deployment.The problem can be formulated as a binary nonlinear combinatorial optimization problem,and due to its NP-hardness,designing approximation algorithms is highly nontrivial.By leveraging the Markov approximation framework,we elaborately design an efficient algorithm driven by a continuous-time Markov chain to schedule the deployment of the storage node and corresponding routing strategy.We also perform extensive simulations to verify the efficacy of our algorithm.展开更多
We report the simple synthesis of zinc sulfide nanoparticles(ZnS NPs)by a co-precipitation method using Schiff base,(2-[(4-methoxy-phenylimino)-methyl]-4-nitrophenol)as a capping agent.The formation of ZnS NPs and the...We report the simple synthesis of zinc sulfide nanoparticles(ZnS NPs)by a co-precipitation method using Schiff base,(2-[(4-methoxy-phenylimino)-methyl]-4-nitrophenol)as a capping agent.The formation of ZnS NPs and their optical,structural,thermal properties and morphologies were studied by means of UVevis DRS,PL,FTIR,XRD,SEM,TEM,and TGA.The optical properties and quantum confinement effect of the products were confirmed by means of spectroscopic measurements.We have accessed the photocatalytic ability of the prepared ZnS and Schiff base capped ZnS NPs in the degradation of chlorpyrifos under UV light irradiation for the prevention of environmental pollution.The prepared ZnS NPs exhibited a selective probe detection of Fe^(3+),Cr^(2+) and Cd^(2+) ions by fluorometrically and the emission band which disappears in the presence of increasing concentrations of Fe^(3+),Cr^(2+) and Cd^(2+) ions.Our work suggested that the synthesized Schiff base capped ZnS NPs could be a potential selective photocatalyst for the degradation of toxic pollutants and a selective probe sensor for the detection of heavy metal ions.展开更多
基金partially supported by the Shandong Provincial Natural Science Foundation(No.ZR2017QF005)the National Natural Science Foundation of China(Nos.61702304,61971269,61832012,61602195,61672321,61771289,and 61602269)the China Postdoctoral Science Foundation(No.2017M622136)。
文摘In the era of big data,sensor networks have been pervasively deployed,producing a large amount of data for various applications.However,because sensor networks are usually placed in hostile environments,managing the huge volume of data is a very challenging issue.In this study,we mainly focus on the data storage reliability problem in heterogeneous wireless sensor networks where robust storage nodes are deployed in sensor networks and data redundancy is utilized through coding techniques.To minimize data delivery and data storage costs,we design an algorithm to jointly optimize data routing and storage node deployment.The problem can be formulated as a binary nonlinear combinatorial optimization problem,and due to its NP-hardness,designing approximation algorithms is highly nontrivial.By leveraging the Markov approximation framework,we elaborately design an efficient algorithm driven by a continuous-time Markov chain to schedule the deployment of the storage node and corresponding routing strategy.We also perform extensive simulations to verify the efficacy of our algorithm.
文摘We report the simple synthesis of zinc sulfide nanoparticles(ZnS NPs)by a co-precipitation method using Schiff base,(2-[(4-methoxy-phenylimino)-methyl]-4-nitrophenol)as a capping agent.The formation of ZnS NPs and their optical,structural,thermal properties and morphologies were studied by means of UVevis DRS,PL,FTIR,XRD,SEM,TEM,and TGA.The optical properties and quantum confinement effect of the products were confirmed by means of spectroscopic measurements.We have accessed the photocatalytic ability of the prepared ZnS and Schiff base capped ZnS NPs in the degradation of chlorpyrifos under UV light irradiation for the prevention of environmental pollution.The prepared ZnS NPs exhibited a selective probe detection of Fe^(3+),Cr^(2+) and Cd^(2+) ions by fluorometrically and the emission band which disappears in the presence of increasing concentrations of Fe^(3+),Cr^(2+) and Cd^(2+) ions.Our work suggested that the synthesized Schiff base capped ZnS NPs could be a potential selective photocatalyst for the degradation of toxic pollutants and a selective probe sensor for the detection of heavy metal ions.
