Platinum(Pt)-based noble metal catalysts(PGMs)are the most widely used commercial catalysts,but they have the problems of high cost,low reserves,and susceptibility to small-molecule toxicity.Transition metal oxides(TM...Platinum(Pt)-based noble metal catalysts(PGMs)are the most widely used commercial catalysts,but they have the problems of high cost,low reserves,and susceptibility to small-molecule toxicity.Transition metal oxides(TMOs)are regarded as potential substitutes for PGMs because of their stability in oxidizing environments and excellent catalytic performance.In this study,comprehensive investigation into the influence of elastic strains on the adsorption energies of carbon(C),hydrogen(H)and oxygen(O)on TMOs was conducted.Based on density functional theory(DFT)calculations,these effects in both tetragonal structures(PtO_(2),PdO_(2))and hexagonal structures(ZnO,CdO),along with their respective transition metals were systematically explored.It was identified that the optimal adsorption sites on metal oxides pinpointed the top of oxygen or the top of metal atom,while face-centered cubic(FCC)and hexagonal close-packed(HCP)holes were preferred for the transition metals.Furthermore,under the influence of elastic strains,the results demonstrated significant disparities in the adsorption energies of H and O between oxides and transition metals.Despite these differences,the effect of elastic strains on the adsorption energies of C,H and O on TMOs mirrored those on transition metals:adsorption energies increased under compressive strains,indicating weaker adsorption,and decreased under tension strains,indicating stronger adsorption.This behavior was rationalized based on the d-band model for adsorption atop a metallic atom or the p-band model for adsorption atop an oxygen atom.Consequently,elastic strains present a promising avenue for tailoring the catalytic properties of TMOs.展开更多
智能网联技术的不断发展为实现公交信号优先提供了技术支持,也将助力智能网联公交向“精准公交”“安全公交”方向发展。本文从不同相位间的冲突博弈关系出发,构建智能网联环境下基于斗鸡博弈的公交信号优先引导策略。首先,利用斗鸡博弈...智能网联技术的不断发展为实现公交信号优先提供了技术支持,也将助力智能网联公交向“精准公交”“安全公交”方向发展。本文从不同相位间的冲突博弈关系出发,构建智能网联环境下基于斗鸡博弈的公交信号优先引导策略。首先,利用斗鸡博弈,分析以公交优先相位与非优先相位作为博弈双方的博弈行为,建立以加权延误为收益矩阵的博弈模型;其次,考虑优先公交车的准时性、最小绿灯时长限制、优先相位及非优先相位延误等因素,结合建立的博弈模型,采取主动优先与车速引导相结合的方法,提出智能网联环境下公交优先引导策略及优化流程;最后,利用SUMO(Simulation of Urban Mobility)和采集的交叉口数据对提出的优先引导策略进行仿真。结果表明:与初始配时相比,本文提出的公交信号优先策略可有效提高公交优先相位的通行效益,减少对非优先相位的负面影响;50%渗透率条件下,对比未实施策略,20%的优先公交车准点情况优化显著,平均排队长度、平均停车次数、延误等通行效益指标至少降低33.27%,油耗及CO_(2)排放至少降低12.20%;非优先相位各指标的劣化程度均低于8%。展开更多
Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of...Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of passengers from the dominant mode to the connecting mode was achieved. A GI/M K/1 bulk service queuing system was constituted by putting the passengers' reaching time distribution as the input and the connecting mode as the service institution. Through queuing theory, the relationship between average queuing length under steady-state and headway of the connecting mode was achieved. By putting the minimum total cost of system as optimization objective, the headway as decision variable, a coordinated scheduling model of multimode in intermodal transit hubs was established. At last, a dynamic scheduling strategy was generated to cope with the unexpected changes of the dominant mode. The instance analysis indicates that this model can significantly reduce passengers' queuing time by approximately 17% with no apparently increase in departure frequency, which provides a useful solution for the coordinated scheduling of different transport modes in hubs.展开更多
基金Science and Technology Commission of Shanghai Municipality(21ZR1472900,22ZR1471600)。
文摘Platinum(Pt)-based noble metal catalysts(PGMs)are the most widely used commercial catalysts,but they have the problems of high cost,low reserves,and susceptibility to small-molecule toxicity.Transition metal oxides(TMOs)are regarded as potential substitutes for PGMs because of their stability in oxidizing environments and excellent catalytic performance.In this study,comprehensive investigation into the influence of elastic strains on the adsorption energies of carbon(C),hydrogen(H)and oxygen(O)on TMOs was conducted.Based on density functional theory(DFT)calculations,these effects in both tetragonal structures(PtO_(2),PdO_(2))and hexagonal structures(ZnO,CdO),along with their respective transition metals were systematically explored.It was identified that the optimal adsorption sites on metal oxides pinpointed the top of oxygen or the top of metal atom,while face-centered cubic(FCC)and hexagonal close-packed(HCP)holes were preferred for the transition metals.Furthermore,under the influence of elastic strains,the results demonstrated significant disparities in the adsorption energies of H and O between oxides and transition metals.Despite these differences,the effect of elastic strains on the adsorption energies of C,H and O on TMOs mirrored those on transition metals:adsorption energies increased under compressive strains,indicating weaker adsorption,and decreased under tension strains,indicating stronger adsorption.This behavior was rationalized based on the d-band model for adsorption atop a metallic atom or the p-band model for adsorption atop an oxygen atom.Consequently,elastic strains present a promising avenue for tailoring the catalytic properties of TMOs.
文摘智能网联技术的不断发展为实现公交信号优先提供了技术支持,也将助力智能网联公交向“精准公交”“安全公交”方向发展。本文从不同相位间的冲突博弈关系出发,构建智能网联环境下基于斗鸡博弈的公交信号优先引导策略。首先,利用斗鸡博弈,分析以公交优先相位与非优先相位作为博弈双方的博弈行为,建立以加权延误为收益矩阵的博弈模型;其次,考虑优先公交车的准时性、最小绿灯时长限制、优先相位及非优先相位延误等因素,结合建立的博弈模型,采取主动优先与车速引导相结合的方法,提出智能网联环境下公交优先引导策略及优化流程;最后,利用SUMO(Simulation of Urban Mobility)和采集的交叉口数据对提出的优先引导策略进行仿真。结果表明:与初始配时相比,本文提出的公交信号优先策略可有效提高公交优先相位的通行效益,减少对非优先相位的负面影响;50%渗透率条件下,对比未实施策略,20%的优先公交车准点情况优化显著,平均排队长度、平均停车次数、延误等通行效益指标至少降低33.27%,油耗及CO_(2)排放至少降低12.20%;非优先相位各指标的劣化程度均低于8%。
基金Projects(51278221,51378076)supported by the National Natural Science Foundation of China
文摘Coordinated scheduling of multimode plays a pivotal role in the rapid gathering and dissipating of passengers in transport hubs. Based on the survey data, the whole-day reaching time distribution at transfer points of passengers from the dominant mode to the connecting mode was achieved. A GI/M K/1 bulk service queuing system was constituted by putting the passengers' reaching time distribution as the input and the connecting mode as the service institution. Through queuing theory, the relationship between average queuing length under steady-state and headway of the connecting mode was achieved. By putting the minimum total cost of system as optimization objective, the headway as decision variable, a coordinated scheduling model of multimode in intermodal transit hubs was established. At last, a dynamic scheduling strategy was generated to cope with the unexpected changes of the dominant mode. The instance analysis indicates that this model can significantly reduce passengers' queuing time by approximately 17% with no apparently increase in departure frequency, which provides a useful solution for the coordinated scheduling of different transport modes in hubs.
