分布式无线通信系统(Distributed Wireless Communication System,DWCS)是近几年提出的一种新型无线通信体系结构,系统采用网络无线电技术,信号处理和控制模块均在PC工作站中完成。本文结合软件无线电相关技术,研究PC工作站在DWCS基站...分布式无线通信系统(Distributed Wireless Communication System,DWCS)是近几年提出的一种新型无线通信体系结构,系统采用网络无线电技术,信号处理和控制模块均在PC工作站中完成。本文结合软件无线电相关技术,研究PC工作站在DWCS基站中的应用。本文将详细分析软基站设计及实现的关键问题,并给出软基站系统的实测性能。展开更多
Understanding the mechanical response of Q2 loess subjected to dry-wet cycles(DWCs)is the premise for the rational design of a hydraulic tunnel.Taking the Hanjiang-to-Weihe south line project in China as the research ...Understanding the mechanical response of Q2 loess subjected to dry-wet cycles(DWCs)is the premise for the rational design of a hydraulic tunnel.Taking the Hanjiang-to-Weihe south line project in China as the research background,the microstructure evolution,strength degradation and compression characteristics of Q2 loess under different DWCs were investigated,and the fluid-solid coupling analysis of the hydraulic tunnel was carried out using the FLAC3D software.The amplification effect of tunnel surrounding soil pressure(SSP)and its influence on the long-term stability of the tunnel under different DWCs were obtained.The results showed that the pore microstructure parameters of the undisturbed and remolded loess basically tend to be stable after the number of DWCs exceeds 3.The porosity of Q2 loess is increased by 26%.The internal friction angle and cohesion of Q2 loess are decreased by 35%and 31%,respectively.The vertical strain of Q2 loess is increased by 55%after considering the DWCs.After the DWCs stabilized,the SSP ratio is increased between 10%and 25%.With the increase in buried depth of the tunnel,the SSP ratio is increased by 8%e10%.The SSP is reduced from 8%to 16%by the rise in groundwater level.As the number of DWCs increases and the burial depth of the tunnel decreases,the distribution of SSP becomes progressively more non-uniform.Based on the amplification factor and the modified compressive arch theory,the SSP distribution model of loess tunnel was proposed,which can be preliminarily applied to the design of supporting structures considering DWCs.展开更多
The future wireless communication system requires higher data transmission rates and better QoS. Therefore, the system capacity should be greatly improved, which can be fulfilled only by great improvements in the spec...The future wireless communication system requires higher data transmission rates and better QoS. Therefore, the system capacity should be greatly improved, which can be fulfilled only by great improvements in the spectrum efficiency due to limited radio frequency resources. The Multiple Input Multiple Output (MIMO) technology is a good choice for future wireless communications. The most study of MIMO focuses on the MIMO channel, MIMO transceiver, distributed MIMO and application of MIMO. The MIMO technology is a great technological breakthrough in the field of wireless communications. It is expected to become a key technology for the future broadband mobile communication system and wireless broadband access system.展开更多
The development trend of Fischer–Tropsch(F–T)technology is to develop high value-added products.The separation of linearα-olefns with low cost is an efective method.Nevertheless,the lack of thermodynamic data and t...The development trend of Fischer–Tropsch(F–T)technology is to develop high value-added products.The separation of linearα-olefns with low cost is an efective method.Nevertheless,the lack of thermodynamic data and the huge energy consumption are the two main problems restricting the development of the separation process.The thermodynamic data of the key components(1-dodecene and n-dodecane)in the F–T product were measured.The Wilson binary interaction parameters of the key components were obtained.Next,one traditional distillation column sequence and two dividing wall column(DWC)sequences were designed to separate the F–T heavy oil to obtain narrow fractions with diferent carbon numbers.Then,the obtained fractions of C10 and C12 were simulated to obtain 1-decene and 1-dodecene,respectively.There was a traditional distillation and a diferential pressure thermal coupling distillation process.When separating 95.0%purity 1-decene and 1-octene,the direct DWC process and diferential pressure thermal coupled distillation are an excellent combination,which can reduce the energy by 33.1%(i.e.,11,286 kW)and total annual cost by 15.9%(i.e.,3.96×10^(6)$)compared with traditional distillation.展开更多
A new vapor distributor based on the Coanda effect is added to the Dividing Wall column(DWC),and the multiphase flow simulation is performed using ANSYS Fluent by this model.The results show that with the addition of ...A new vapor distributor based on the Coanda effect is added to the Dividing Wall column(DWC),and the multiphase flow simulation is performed using ANSYS Fluent by this model.The results show that with the addition of the liquid phase,the new vapor distributor still follows the Coanda effect.Hereby,the vapor is ejected from the slits of the distributor to take away the surrounding vapor,and a negative pressure is formed under the distributor,so as to achieve the purpose of regulating Rv.Analogously to the working principle of vapor distributor,a certain amount of vapor is drawn out from a position of prefractionator,which is equivalent to the vapor ejected by the distributor.The same amount of vapor is fed into the main column,which corresponds to the gas phase at the inlet of the distributor.The Rv is adjusted by changing the speed of the input or output vapor.Simulation results show that adding this control mechanism on the basis of temperature or concentration control structure can better achieve the effect of vapor distribution.展开更多
The compensation circuit plays a crucial role in the framework of Capacitive Power Transfer(CPT)in wireless Electric Vehicle(EV)charging schemes.Various wireless charging factors such as power transfer capacity,effici...The compensation circuit plays a crucial role in the framework of Capacitive Power Transfer(CPT)in wireless Electric Vehicle(EV)charging schemes.Various wireless charging factors such as power transfer capacity,efficiency,and frequency depend on the design of compensation circuit topology.In CPT,power is transferred between the two capacitor plates(one transmitter plate embedded on the track and the other plate which is inserted in the wireless EV chassis operates as a receiver).The transmitter plate is excited by a high frequency source and power is transferred between the plates through an electric field.This review paper introduced an experimental prototype of the Corbin Sparrow(CS),featuring an onboard battery charger and an off-board DC charging port.Additionally,it presented a novel conformal bumper-based approach,highlighting its distinct advantages compared to alternative charging methods.The major challenges to employing capacitive technology in transferring power up to kW level are-the greater air gap between the capacitor of vehicle chassis&ground and the high value of electric field strength in the contour of plates.Also,due to the lowvalue of coupling capacitance,there is the requirement for suitable gain and compensated network which is a major area of concern.This review paper proposed various designs of compensation circuit topologies to achieve the effectiveness of the CPT scheme for Wireless Power Transfer(WPT)systems.展开更多
As the adoption of Electric Vehicles(EVs)intensifies,two primary challenges emerge:limited range due to battery constraints and extended charging times.The traditional charging stations,particularly those near highway...As the adoption of Electric Vehicles(EVs)intensifies,two primary challenges emerge:limited range due to battery constraints and extended charging times.The traditional charging stations,particularly those near highways,exacerbate these issues with necessary detours,inconsistent service levels,and unpredictable waiting durations.The emerging technology of dynamic wireless charging lanes(DWCLs)may alleviate range anxiety and eliminate long charging stops;however,the driving speed on DWCL significantly affects charging efficiency and effective charging time.Meanwhile,the existing research has addressed load balancing optimization on Dynamic Wireless Charging(DWC)systems to a limited extent.To address this critical issue,this study introduces an innovative eco-driving speed control strategy,providing a novel solution to the multi-objective optimization problem of speed control on DWCL.We utilize mathematical programming methods and incorporate the longitudinal dynamics of vehicles to provide an accurate physical model of EVs.Three objective functions are formulated to tackle the challenges at hand:reducing travel time,increasing charging efficiency,and achieving load balancing on DWCL,which corresponds to four control strategies.The results of numerical tests indicate that a comprehensive control strategy,which considers all objectives,achieves a minor sacrifice in travel time reduction while significantly improving energy efficiency and load balancing.Furthermore,by defining the energy demand and speed range through an upper operation limit,a relatively superior speed control strategy can be selected.This work contributes to the discourse on DWCL integration into modern transportation systems,enhancing the EV driving experience on major roads.展开更多
文摘分布式无线通信系统(Distributed Wireless Communication System,DWCS)是近几年提出的一种新型无线通信体系结构,系统采用网络无线电技术,信号处理和控制模块均在PC工作站中完成。本文结合软件无线电相关技术,研究PC工作站在DWCS基站中的应用。本文将详细分析软基站设计及实现的关键问题,并给出软基站系统的实测性能。
基金the National Natural Science Foundation of China(Grant Nos.52279110,52178355 and 52108339).
文摘Understanding the mechanical response of Q2 loess subjected to dry-wet cycles(DWCs)is the premise for the rational design of a hydraulic tunnel.Taking the Hanjiang-to-Weihe south line project in China as the research background,the microstructure evolution,strength degradation and compression characteristics of Q2 loess under different DWCs were investigated,and the fluid-solid coupling analysis of the hydraulic tunnel was carried out using the FLAC3D software.The amplification effect of tunnel surrounding soil pressure(SSP)and its influence on the long-term stability of the tunnel under different DWCs were obtained.The results showed that the pore microstructure parameters of the undisturbed and remolded loess basically tend to be stable after the number of DWCs exceeds 3.The porosity of Q2 loess is increased by 26%.The internal friction angle and cohesion of Q2 loess are decreased by 35%and 31%,respectively.The vertical strain of Q2 loess is increased by 55%after considering the DWCs.After the DWCs stabilized,the SSP ratio is increased between 10%and 25%.With the increase in buried depth of the tunnel,the SSP ratio is increased by 8%e10%.The SSP is reduced from 8%to 16%by the rise in groundwater level.As the number of DWCs increases and the burial depth of the tunnel decreases,the distribution of SSP becomes progressively more non-uniform.Based on the amplification factor and the modified compressive arch theory,the SSP distribution model of loess tunnel was proposed,which can be preliminarily applied to the design of supporting structures considering DWCs.
基金Program ofNational Natural Science Foundation of China(No. 60496313) Project of National ResearchFoundation for the Doctoral Program of Ministryof Education of China (No. 20020614001)
文摘The future wireless communication system requires higher data transmission rates and better QoS. Therefore, the system capacity should be greatly improved, which can be fulfilled only by great improvements in the spectrum efficiency due to limited radio frequency resources. The Multiple Input Multiple Output (MIMO) technology is a good choice for future wireless communications. The most study of MIMO focuses on the MIMO channel, MIMO transceiver, distributed MIMO and application of MIMO. The MIMO technology is a great technological breakthrough in the field of wireless communications. It is expected to become a key technology for the future broadband mobile communication system and wireless broadband access system.
基金Acknowledgements The authors are grateful for the fnancial support from the Key Research and Development Program of Ningxia(Nos.2018BDE02057,2019NDYFLX0001)the Haihe Laboratory of Sustainable Chemical Transformations.The authors also thank the reviewers for their insightful comments and suggestions.
文摘The development trend of Fischer–Tropsch(F–T)technology is to develop high value-added products.The separation of linearα-olefns with low cost is an efective method.Nevertheless,the lack of thermodynamic data and the huge energy consumption are the two main problems restricting the development of the separation process.The thermodynamic data of the key components(1-dodecene and n-dodecane)in the F–T product were measured.The Wilson binary interaction parameters of the key components were obtained.Next,one traditional distillation column sequence and two dividing wall column(DWC)sequences were designed to separate the F–T heavy oil to obtain narrow fractions with diferent carbon numbers.Then,the obtained fractions of C10 and C12 were simulated to obtain 1-decene and 1-dodecene,respectively.There was a traditional distillation and a diferential pressure thermal coupling distillation process.When separating 95.0%purity 1-decene and 1-octene,the direct DWC process and diferential pressure thermal coupled distillation are an excellent combination,which can reduce the energy by 33.1%(i.e.,11,286 kW)and total annual cost by 15.9%(i.e.,3.96×10^(6)$)compared with traditional distillation.
基金This work was supported by the National Natural Science Foundation of China(21878066).
文摘A new vapor distributor based on the Coanda effect is added to the Dividing Wall column(DWC),and the multiphase flow simulation is performed using ANSYS Fluent by this model.The results show that with the addition of the liquid phase,the new vapor distributor still follows the Coanda effect.Hereby,the vapor is ejected from the slits of the distributor to take away the surrounding vapor,and a negative pressure is formed under the distributor,so as to achieve the purpose of regulating Rv.Analogously to the working principle of vapor distributor,a certain amount of vapor is drawn out from a position of prefractionator,which is equivalent to the vapor ejected by the distributor.The same amount of vapor is fed into the main column,which corresponds to the gas phase at the inlet of the distributor.The Rv is adjusted by changing the speed of the input or output vapor.Simulation results show that adding this control mechanism on the basis of temperature or concentration control structure can better achieve the effect of vapor distribution.
文摘The compensation circuit plays a crucial role in the framework of Capacitive Power Transfer(CPT)in wireless Electric Vehicle(EV)charging schemes.Various wireless charging factors such as power transfer capacity,efficiency,and frequency depend on the design of compensation circuit topology.In CPT,power is transferred between the two capacitor plates(one transmitter plate embedded on the track and the other plate which is inserted in the wireless EV chassis operates as a receiver).The transmitter plate is excited by a high frequency source and power is transferred between the plates through an electric field.This review paper introduced an experimental prototype of the Corbin Sparrow(CS),featuring an onboard battery charger and an off-board DC charging port.Additionally,it presented a novel conformal bumper-based approach,highlighting its distinct advantages compared to alternative charging methods.The major challenges to employing capacitive technology in transferring power up to kW level are-the greater air gap between the capacitor of vehicle chassis&ground and the high value of electric field strength in the contour of plates.Also,due to the lowvalue of coupling capacitance,there is the requirement for suitable gain and compensated network which is a major area of concern.This review paper proposed various designs of compensation circuit topologies to achieve the effectiveness of the CPT scheme for Wireless Power Transfer(WPT)systems.
基金funded by the National Natural Science Foundation of China(72201149)Xinjiang Key Laboratory of Green Mining of Coal resources,Ministry of Education(KLXGY-KB2420)Guangzhou Basic and Applied Basic Research(SL2023A04J00802).
文摘As the adoption of Electric Vehicles(EVs)intensifies,two primary challenges emerge:limited range due to battery constraints and extended charging times.The traditional charging stations,particularly those near highways,exacerbate these issues with necessary detours,inconsistent service levels,and unpredictable waiting durations.The emerging technology of dynamic wireless charging lanes(DWCLs)may alleviate range anxiety and eliminate long charging stops;however,the driving speed on DWCL significantly affects charging efficiency and effective charging time.Meanwhile,the existing research has addressed load balancing optimization on Dynamic Wireless Charging(DWC)systems to a limited extent.To address this critical issue,this study introduces an innovative eco-driving speed control strategy,providing a novel solution to the multi-objective optimization problem of speed control on DWCL.We utilize mathematical programming methods and incorporate the longitudinal dynamics of vehicles to provide an accurate physical model of EVs.Three objective functions are formulated to tackle the challenges at hand:reducing travel time,increasing charging efficiency,and achieving load balancing on DWCL,which corresponds to four control strategies.The results of numerical tests indicate that a comprehensive control strategy,which considers all objectives,achieves a minor sacrifice in travel time reduction while significantly improving energy efficiency and load balancing.Furthermore,by defining the energy demand and speed range through an upper operation limit,a relatively superior speed control strategy can be selected.This work contributes to the discourse on DWCL integration into modern transportation systems,enhancing the EV driving experience on major roads.
