Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sam...Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sample, but narrower mass distribution from CuO sample. We suggest that this is caused by collisionally stabilization. Small gas molecules CO2 and NO2, generated by laser ablation of CuCO3 and Cu(NO3)2, act as bther gas in supersonic molecular bearns, and they are helpful for the production of high mass clusters.展开更多
A critical safe distance(CSD)model in V2V(vehicle-to-vehicle)communication systems was proposed to primarily enhance driving safety by disseminating warning notifications to vehicles when they approach calculated CSD....A critical safe distance(CSD)model in V2V(vehicle-to-vehicle)communication systems was proposed to primarily enhance driving safety by disseminating warning notifications to vehicles when they approach calculated CSD.By elaborately analyzing the vehicular movement features especially when braking,our CSD definition was introduced and its configuration method was given through dividing radio range into different communication zones.Based on our definition,the needed message propagation delay was also derived which could be used to control the beacon frequency or duration.Next,the detailed CSD expressions were proposed in different mobility scenarios by fully considering the relative movement status between the front and rear vehicles.Numerical results show that our proposed model could provide reasonable CSD under different movement scenarios which eliminates the unnecessary reserved inter-vehicle distance and guarantee the safety at the same time.The compared time-headway model always shows a smaller CSD due to focusing on traffic efficiency whereas the traditional braking model generally outputs a larger CSD because it assumes that the following car drives with a constant speed and did not discuss the scenario when the leading car suddenly stops.Different from these two models,our proposed model could well balances the requirements between driving safety and traffic throughput efficiency by generating a CSD in between the values of the two models in most cases.展开更多
文摘Copper oxide cluster ions CunOm n=1-22, m=1-12 are generated by 523 nm laser ablation of CuCO3 solid sample with Time of Flight Mass Spectrometer detection.By changing precursor, we get sbolar TOF MS from Cu(NO3)2 sample, but narrower mass distribution from CuO sample. We suggest that this is caused by collisionally stabilization. Small gas molecules CO2 and NO2, generated by laser ablation of CuCO3 and Cu(NO3)2, act as bther gas in supersonic molecular bearns, and they are helpful for the production of high mass clusters.
基金Project(20100481323) supported by China Postdoctoral Science FoundationProjects(61201133,61172055,61072067,51278058)supported by the National Natural Science Foundation of China+4 种基金Project(NCET-11-0691) supported by the Program for New Century Excellent Talents in UniversityProject(11105) supported by the Foundation of Guangxi Key Lab of Wireless Wideband Communication & Signal Processing,ChinaProject(B08038) supported by the "111" Project,ChinaProject(K5051301011) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(CX12178(6)) supported by the Xian Municipal Technology Transfer Promotion funds,China
文摘A critical safe distance(CSD)model in V2V(vehicle-to-vehicle)communication systems was proposed to primarily enhance driving safety by disseminating warning notifications to vehicles when they approach calculated CSD.By elaborately analyzing the vehicular movement features especially when braking,our CSD definition was introduced and its configuration method was given through dividing radio range into different communication zones.Based on our definition,the needed message propagation delay was also derived which could be used to control the beacon frequency or duration.Next,the detailed CSD expressions were proposed in different mobility scenarios by fully considering the relative movement status between the front and rear vehicles.Numerical results show that our proposed model could provide reasonable CSD under different movement scenarios which eliminates the unnecessary reserved inter-vehicle distance and guarantee the safety at the same time.The compared time-headway model always shows a smaller CSD due to focusing on traffic efficiency whereas the traditional braking model generally outputs a larger CSD because it assumes that the following car drives with a constant speed and did not discuss the scenario when the leading car suddenly stops.Different from these two models,our proposed model could well balances the requirements between driving safety and traffic throughput efficiency by generating a CSD in between the values of the two models in most cases.
