Proton affinity or transfer is crucial in determining the activity and selectivity of the electroreduction of CO_(2).However,optimizing proton supply during CO_(2) reduction while simultaneously enhancing the activity...Proton affinity or transfer is crucial in determining the activity and selectivity of the electroreduction of CO_(2).However,optimizing proton supply during CO_(2) reduction while simultaneously enhancing the activity of catalytic sites and inhibiting hydrogen evolution poses a significant challenge.In this work,we report a rapid strategy for preparing Cl^(-) modified Bi nanosheets by decorating the defective sites of Bi nanosheets with abundant Cl^(-),permitting systematical study on how Cl^(-) impact on the catalytic activity of defective Bi sites and the proton transfer during CO_(2) reduction process.It is demonstrated that rich Cl^(-) sites around defective Bi sites could form Cl-H species during catalytic process(as confirmed by operando spectroscopy)and function as unique proton relay stations for the reaction intermediate,significantly accelerating the conversion of CO_(2)-to-formate.The resulting Cl^(-) modified Bi nanosheets achieve nearly 100%formate Faradaic efficiency(FE)at 400 mA/cm^(2) and high formate FEs(>90%)across 100 to 700 mA/cm^(2),as well as a long-term stability over 130 h in acidic electrolyte,much superior than those of Bi catalysts without Cl^(-) modification.This work provides new guidance for designing advanced electrocatalysts for CO_(2) electroreduction.展开更多
This paper details on the uplink scheduling algorithm for long term evolution advanced （LTE-A） system with relays. While emulating quality of service （QoS）-aware services with different bit-rate and delay budget r...This paper details on the uplink scheduling algorithm for long term evolution advanced （LTE-A） system with relays. While emulating quality of service （QoS）-aware services with different bit-rate and delay budget requirements for the upstream direction, a new QoS-aware scheduling algorithm for in-band relays is proposed. In this work, an improved scheduling metric calculation method and bit-rate guarantee scheme is applied. Moreover, this algorithm proposes an efficient scheme for the backhaul link allocation which allows information of the most backlogged users to be transmitted first. Finally, this paper concludes with simulation results to demonstrate how the proposed resource allocation strategy improves the performance of the system.展开更多
To fully exploit the performance benefits of relay station （RS）, in the two-hop cellular networks covering hotspots, when the number of RSs is predetermined, both RS deployment and frequency reuse scheme are jointly...To fully exploit the performance benefits of relay station （RS）, in the two-hop cellular networks covering hotspots, when the number of RSs is predetermined, both RS deployment and frequency reuse scheme are jointly optimized for the purpose of maximizing the system capacity based on the constraints of system demand of capacity and the maximum number of outage demand nodes （MNDN）. Further, considering the overhead of increasing RSs, it is desired to use minimum number of RSs. The joint RS deployment and frequency reuse scheme （JRDFR） problem is formulated into a mixed integer nonlinear programming, which is non-deterministic polynomial-time hard in general. A heuristic approach based on genetic algorithm is proposed to tackle the JRDFR problem. The computational experiment of the heuristic approach is achieved and optimized RS deployment and frequency reuse scheme is obtained. Finally, we discuss the impacts of MNDN and the number of RSs on the system performance.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21931007 and 21805207)the National Key R&D Program of China(No.2022YFA1502902)+1 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions(No.23KJA430001)Natural Science Foundation of Tianjin City(No.23JCQNJC00570).
文摘Proton affinity or transfer is crucial in determining the activity and selectivity of the electroreduction of CO_(2).However,optimizing proton supply during CO_(2) reduction while simultaneously enhancing the activity of catalytic sites and inhibiting hydrogen evolution poses a significant challenge.In this work,we report a rapid strategy for preparing Cl^(-) modified Bi nanosheets by decorating the defective sites of Bi nanosheets with abundant Cl^(-),permitting systematical study on how Cl^(-) impact on the catalytic activity of defective Bi sites and the proton transfer during CO_(2) reduction process.It is demonstrated that rich Cl^(-) sites around defective Bi sites could form Cl-H species during catalytic process(as confirmed by operando spectroscopy)and function as unique proton relay stations for the reaction intermediate,significantly accelerating the conversion of CO_(2)-to-formate.The resulting Cl^(-) modified Bi nanosheets achieve nearly 100%formate Faradaic efficiency(FE)at 400 mA/cm^(2) and high formate FEs(>90%)across 100 to 700 mA/cm^(2),as well as a long-term stability over 130 h in acidic electrolyte,much superior than those of Bi catalysts without Cl^(-) modification.This work provides new guidance for designing advanced electrocatalysts for CO_(2) electroreduction.
基金supported by the Major National Science & Technology Specific Project of China (2010ZX03002-002-03)
文摘This paper details on the uplink scheduling algorithm for long term evolution advanced （LTE-A） system with relays. While emulating quality of service （QoS）-aware services with different bit-rate and delay budget requirements for the upstream direction, a new QoS-aware scheduling algorithm for in-band relays is proposed. In this work, an improved scheduling metric calculation method and bit-rate guarantee scheme is applied. Moreover, this algorithm proposes an efficient scheme for the backhaul link allocation which allows information of the most backlogged users to be transmitted first. Finally, this paper concludes with simulation results to demonstrate how the proposed resource allocation strategy improves the performance of the system.
文摘To fully exploit the performance benefits of relay station （RS）, in the two-hop cellular networks covering hotspots, when the number of RSs is predetermined, both RS deployment and frequency reuse scheme are jointly optimized for the purpose of maximizing the system capacity based on the constraints of system demand of capacity and the maximum number of outage demand nodes （MNDN）. Further, considering the overhead of increasing RSs, it is desired to use minimum number of RSs. The joint RS deployment and frequency reuse scheme （JRDFR） problem is formulated into a mixed integer nonlinear programming, which is non-deterministic polynomial-time hard in general. A heuristic approach based on genetic algorithm is proposed to tackle the JRDFR problem. The computational experiment of the heuristic approach is achieved and optimized RS deployment and frequency reuse scheme is obtained. Finally, we discuss the impacts of MNDN and the number of RSs on the system performance.
