K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of potassium.To develop advanced electrode materials for accommodating the large size and h...K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of potassium.To develop advanced electrode materials for accommodating the large size and high activity of potassium ion is of great interests.Herein,a segment-like antimony (Sb) nanorod encapsulated in hollow carbon tube electrode material (Sb@HCT) was prepared.Beneficial from the virtue of abundant nitrogen doping in carbon tube,one-dimensional and hollow structure advantages,Sb@HCT exhibits excellent potassium storage properties:in the case of potassium bis(fluorosulfonyl)imide (KFSI) electrolyte,Sb@HCT displays a reversible capacity of up to 453.4 mAh·g^-1 at a current density of 0.5 A·g^-1 and good rate performance (a capacity of 211.5 mAh·g^-1 could be achieved at an ultrahigh rate of 5 A·g^-1).Additionally,Sb@HCT demonstrates excellent long-cycle stability at a current density of 2 A·g^-1 over 120 cycles.Meanwhile,electrolyte optimization is an effective strategy for greatly improving electrochemical performance.Through ex-situ characterizations,we disclosed the potassiation of Sb anode is quite reversible and undergoes multistep processes,combining solid solution reaction and two-phase reaction.展开更多
Mobile Edge Computing (MEC) has been considered a promising solution that can address capacity and performance challenges in legacy systems such as Mobile Cloud Computing (MCC). In particular, such challenges include ...Mobile Edge Computing (MEC) has been considered a promising solution that can address capacity and performance challenges in legacy systems such as Mobile Cloud Computing (MCC). In particular, such challenges include intolerable delay, congestion in the core network, insufficient Quality of Experience (QoE), high cost of resource utility, such as energy and bandwidth. The aforementioned challenges originate from limited resources in mobile devices, the multi-hop connection between end-users and the cloud, high pressure from computation-intensive and delay-critical applications. Considering the limited resource setting at the MEC, improving the efficiency of task offloading in terms of both energy and delay in MEC applications is an important and urgent problem to be solved. In this paper, the key objective is to propose a task offloading scheme that minimizes the overall energy consumption along with satisfying capacity and delay requirements. Thus, we propose a MEC-assisted energy-efficient task offloading scheme that leverages the cooperative MEC framework. To achieve energy efficiency, we propose a novel hybrid approach established based on Particle Swarm Optimization (PSO) and Grey Wolf Optimizer (GWO) to solve the optimization problem. The proposed approach considers efficient resource allocation such as sub-carriers, power, and bandwidth for offloading to guarantee minimum energy consumption. The simulation results demonstrate that the proposed strategy is computational-efficient compared to benchmark methods. Moreover, it improves energy utilization, energy gain, response delay, and offloading utility.展开更多
基金the National Natural Science Foundation of China (No.51832004)the National Natural Science Fund for Distinguished Young Scholars (No.51425204)+2 种基金the National Key R&D Program of China (No.2016YFA0202603)the Programme of Introducing Talents of Discipline to Universities (No.B17034)the Yellow Crane Talent (Science & Technology) Program of Wuhan City.
文摘K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of potassium.To develop advanced electrode materials for accommodating the large size and high activity of potassium ion is of great interests.Herein,a segment-like antimony (Sb) nanorod encapsulated in hollow carbon tube electrode material (Sb@HCT) was prepared.Beneficial from the virtue of abundant nitrogen doping in carbon tube,one-dimensional and hollow structure advantages,Sb@HCT exhibits excellent potassium storage properties:in the case of potassium bis(fluorosulfonyl)imide (KFSI) electrolyte,Sb@HCT displays a reversible capacity of up to 453.4 mAh·g^-1 at a current density of 0.5 A·g^-1 and good rate performance (a capacity of 211.5 mAh·g^-1 could be achieved at an ultrahigh rate of 5 A·g^-1).Additionally,Sb@HCT demonstrates excellent long-cycle stability at a current density of 2 A·g^-1 over 120 cycles.Meanwhile,electrolyte optimization is an effective strategy for greatly improving electrochemical performance.Through ex-situ characterizations,we disclosed the potassiation of Sb anode is quite reversible and undergoes multistep processes,combining solid solution reaction and two-phase reaction.
基金supported by the Chinese Scholarship Council(CSC)under MOFCOM(No.2017MOC010907)any opinions,findings,and conclusions are those of the authors and do not necessarily reflect the views of the above agency.
文摘Mobile Edge Computing (MEC) has been considered a promising solution that can address capacity and performance challenges in legacy systems such as Mobile Cloud Computing (MCC). In particular, such challenges include intolerable delay, congestion in the core network, insufficient Quality of Experience (QoE), high cost of resource utility, such as energy and bandwidth. The aforementioned challenges originate from limited resources in mobile devices, the multi-hop connection between end-users and the cloud, high pressure from computation-intensive and delay-critical applications. Considering the limited resource setting at the MEC, improving the efficiency of task offloading in terms of both energy and delay in MEC applications is an important and urgent problem to be solved. In this paper, the key objective is to propose a task offloading scheme that minimizes the overall energy consumption along with satisfying capacity and delay requirements. Thus, we propose a MEC-assisted energy-efficient task offloading scheme that leverages the cooperative MEC framework. To achieve energy efficiency, we propose a novel hybrid approach established based on Particle Swarm Optimization (PSO) and Grey Wolf Optimizer (GWO) to solve the optimization problem. The proposed approach considers efficient resource allocation such as sub-carriers, power, and bandwidth for offloading to guarantee minimum energy consumption. The simulation results demonstrate that the proposed strategy is computational-efficient compared to benchmark methods. Moreover, it improves energy utilization, energy gain, response delay, and offloading utility.
