The notorious shuttle effect has long been obstructing lithium-sulfur(Li-S) batteries from yielding the expected high energy density and long lifespan.Herein,we develop a multifunctional polysulfide barrier reinforced...The notorious shuttle effect has long been obstructing lithium-sulfur(Li-S) batteries from yielding the expected high energy density and long lifespan.Herein,we develop a multifunctional polysulfide barrier reinforced by the graphitic carbon nitride/carbon nanotube(g-C_3 N_4/CNT) composite toward inhibited shuttling behavior and improved battery performance.The obtained g-C_3 N_4 delivers a unique spongelike architecture with massive ion transfer pathways and fully exposed active interfaces,while the abundant C-N heteroatomic structures impose strong chemical immobilization toward lithium polysulfides.Combined with the highly conductive agent,the g-C_3 N_4/CNT reinforced separator is endowed with great capability of confining and reutilizing the active sulfur within the cathode,thus contributing to an efficient and stable sulfur electrochemistry.Benefiting from these synergistic attributes,Li-S cells based on g-C_3 N_4/CNT separator exhibit an excellent cyclability with a minimum decay rate of 0.03% per cycle over 500 cycles and decent rate capability up to 2 C.Moreover,a high areal capacity of 7.69 mAh cm^(-2)can be achieved under a raised sulfur loading up to 10.1 mg cm^(-2).demonstrating a facile and efficient pathway toward superior Li-S batteries.展开更多
AIDS has spread throughout the world for decades.Men who have sex with men(MSM)is the harder-hit sector of sexually transmitted diseases due to their physiological characteristics.However,because homosexuals suffer di...AIDS has spread throughout the world for decades.Men who have sex with men(MSM)is the harder-hit sector of sexually transmitted diseases due to their physiological characteristics.However,because homosexuals suffer discrimination and exclusion in many aspects,the relevant data about the spread of HIV in this group are scarce.Therefore,building a network model to study and analyze this problem can provide valuable reference for the prevention of HIV.Complex network can establish fixed edges between vertices,and ignores the spatial characteristics of the network.These two aspects are exactly what cellular automata are good at,but cellular automata are rarely used in the problem of HIV propagation among MSM populations.Therefore,we combined the advantages of these two methods,and got a new hybrid model.It may provide us with some theoretical factors that affect the spread of HIV and provide guidance for the actual prevention work.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21978110 and 51772126)the Natural Science Foundation of Beijing (No. L182062)+8 种基金the Organization Department of Beijing Talents Project (2018000021223ZK21)the Yue Qi Young Scholar Project of China University of Mining & Technology (Beijing) (No. 2017QN17)the Fundamental Research Funds for the Central Universities (No. 2014QJ02)the Jilin Province Science and Technology Department Program (Nos. 20200201187JC, 20190201309JC, and 20190101009JH)the ‘‘13th five-year” Science and Technology Project of Jilin Provincial Education Department (No. JJKH20200407KJ)the Jilin Province Development and Reform Commission Program (Nos. 2020C026-3 and 2019C042-1)the Jilin Province Fund for Talent Development Program (No. [2019] 874)the supports from Natural Sciences and Engineering Research Council of Canada (NSERC), the University of Waterloothe Waterloo Institute for Nanotechnology。
文摘The notorious shuttle effect has long been obstructing lithium-sulfur(Li-S) batteries from yielding the expected high energy density and long lifespan.Herein,we develop a multifunctional polysulfide barrier reinforced by the graphitic carbon nitride/carbon nanotube(g-C_3 N_4/CNT) composite toward inhibited shuttling behavior and improved battery performance.The obtained g-C_3 N_4 delivers a unique spongelike architecture with massive ion transfer pathways and fully exposed active interfaces,while the abundant C-N heteroatomic structures impose strong chemical immobilization toward lithium polysulfides.Combined with the highly conductive agent,the g-C_3 N_4/CNT reinforced separator is endowed with great capability of confining and reutilizing the active sulfur within the cathode,thus contributing to an efficient and stable sulfur electrochemistry.Benefiting from these synergistic attributes,Li-S cells based on g-C_3 N_4/CNT separator exhibit an excellent cyclability with a minimum decay rate of 0.03% per cycle over 500 cycles and decent rate capability up to 2 C.Moreover,a high areal capacity of 7.69 mAh cm^(-2)can be achieved under a raised sulfur loading up to 10.1 mg cm^(-2).demonstrating a facile and efficient pathway toward superior Li-S batteries.
基金This work was supported by IDRC104519-010 and Shanghai Key Laboratory of acupuncture mechanism and acupoint function(14DZ2260500).
文摘AIDS has spread throughout the world for decades.Men who have sex with men(MSM)is the harder-hit sector of sexually transmitted diseases due to their physiological characteristics.However,because homosexuals suffer discrimination and exclusion in many aspects,the relevant data about the spread of HIV in this group are scarce.Therefore,building a network model to study and analyze this problem can provide valuable reference for the prevention of HIV.Complex network can establish fixed edges between vertices,and ignores the spatial characteristics of the network.These two aspects are exactly what cellular automata are good at,but cellular automata are rarely used in the problem of HIV propagation among MSM populations.Therefore,we combined the advantages of these two methods,and got a new hybrid model.It may provide us with some theoretical factors that affect the spread of HIV and provide guidance for the actual prevention work.
