Cascading faults have been identified as the primary cause of multiple power outages in recent years.With the emergence of integrated energy systems(IES),the conventional approach to analyzing power grid cascading fau...Cascading faults have been identified as the primary cause of multiple power outages in recent years.With the emergence of integrated energy systems(IES),the conventional approach to analyzing power grid cascading faults is no longer appropriate.A cascading fault analysis method considering multi-energy coupling characteristics is of vital importance.In this study,an innovative analysis method for cascading faults in integrated heat and electricity systems(IHES)is proposed.It considers the degradation characteristics of transmission and energy supply com-ponents in the system to address the impact of component aging on cascading faults.Firstly,degradation models for the current carrying capacity of transmission lines,the water carrying capacity and insulation performance of thermal pipelines,as well as the performance of energy supply equipment during aging,are developed.Secondly,a simulation process for cascading faults in the IHES is proposed.It utilizes an overload-dominated development model to predict the propagation path of cascading faults while also considering network islanding,electric-heating rescheduling,and load shedding.The propagation of cascading faults is reflected in the form of fault chains.Finally,the results of cascading faults under different aging levels are analyzed through numerical examples,thereby verifying the effectiveness and rationality of the proposed model and method.展开更多
β-Ga_(2)O_(3)is a promising candidate for solarblind ultraviolet photodetection owing to its suitable bandgap of approximately 4.9 eV,excellent photoresponse characteristics,and high stability.However,the lack of a s...β-Ga_(2)O_(3)is a promising candidate for solarblind ultraviolet photodetection owing to its suitable bandgap of approximately 4.9 eV,excellent photoresponse characteristics,and high stability.However,the lack of a sufficient driving force within the material leads to extensive bulk charge recombination,limiting its photocurrent and thus posing significant challenges in designing high-performance Ga_(2)O_(3)-based photodetection.In this study,we propose a gradient doping strategy to achieve a Sn-doping concentration gradient along theβ-Ga_(2)O_(3)film thickness.By combining sol-gel synthesis with rapid thermal annealing,a spatially graded band structure with a full-space built-in electric field is constructed,which increases the width of band bending over a large region and is crucial for significantly enhancing carrier separation and transport in the bulk.The resulting gradient Sn-dopedβ-Ga_(2)O_(3)enables exceptional photoelectric performance without an external bias under 254 nm irradiation,including a superior responsivity of 66.88 mA W^(-1),a high detectivity of 8.12×10^(11)Jones,and a fast rise/decay time of 79/65 ms,outstanding most existing similar reported photoelectrochemical(PEC)type optoelectronic devices.Additionally,the device exhibits excellent long-term stability and enables high-resolution underwater ultraviolet imaging.This study demonstrates that the gradient doping strategy provides a feasible approach for enhancing the PEC performance ofβ-Ga_(2)O_(3)photoelectrodes.展开更多
With the advancement in autonomous driving techniques,autonomous demand-responsive transit(ADRT)is a newly emerging sustainable transport mode for the future,which will provide more flexible services to public users.A...With the advancement in autonomous driving techniques,autonomous demand-responsive transit(ADRT)is a newly emerging sustainable transport mode for the future,which will provide more flexible services to public users.ADRT offers benefits such as flex-ible stops and routes and comfortable seats,but it also involves risks due to the vehicles being driverless.This paper particularly investigates users’preferences and attitudes towards ADRT,and mode choice behavior between ADRT buses and traditional buses.A survey with Likert scale statements and stated preference(SP)choice scenarios is designed and conducted to explore users’attitudes towards the safety risks of autonomous vehicles(AVs),social concerns,service flexibility concerns when using AVs,interest in new things,and shuttle mode choices.An integrated choice and latent variable(ICLV)model is adopted to explore users’psychological factors through latent variables and to integrate them into mode choice behavioral modeling.Estimated results indicate that users’attitudes towards AV safety risks,their social concerns,and their flexibility concerns with ADRT strongly influence their mode choices and are strongly related to sociodemographic and travel-related factors such as age,gender,income,education,number of family members.In gen-eral,a young age,a high education level,a higher income,private car ownership,and better knowledge of AVs are positively related to attitudes towards ADRT.Females,users from large families,and users with driving licenses or long commuting times are less willing to adopt ADRT.The study’s outcomes highlight significant heterogeneities among users and can be highly valuable for policymakers,such as government authorities,in providing social support and designing policies targeting specific population groups.This will be ben-eficial in attracting more users to this emerging mobility service and contributing to sus-tainable urban development.展开更多
Widespread deployment of proton exchange membrane water electrolyzers(PEMWE)relies on acid-stable oxygen evolution reaction(OER)catalysts capable of operating at high current densities.Inspired by the robust chemistry...Widespread deployment of proton exchange membrane water electrolyzers(PEMWE)relies on acid-stable oxygen evolution reaction(OER)catalysts capable of operating at high current densities.Inspired by the robust chemistry of lead-acid batteries,we introduce lead(Pb)into ruthenium-iridium mixed oxide(RuIrO_(x))through a facile sol-gel method.The as-prepared RuIrPbO_(x)nanoparticulate catalysts with the optimal composition(Ru_(0.5)Ir_(0.4)Pb_(0.1)O_(x))achieve an overpotential of 241 mV at 10 mA cm^(-2)and exceptional stability of 1000 h at a high current density of 100 mA cm^(-2)without degradation.In situ differential electrochemical mass spectrometry indicates that doping RuIrO_(x)with an appropriate amount of Pb helps to suppress the participation of lattice oxygen during OER,contributing to structural preservation and long-term stability.Density functional theory calculations reveal that Pb doping effectively regulates the electronic structure of the Ru sites,reducing Ru-O covalency,which in turn increases the Ru dissolution energy and therefore prevents Ru leaching—a key degradation pathway for Ru-containing OER catalysts.When integrated into a membrane electrode assembly,the PEMWE cell can operate at a large current density of 3.0 A cm^(-2)under 1.96 V(at 60℃)for 400 h with minimal performance degradation,demonstrating the significant potential of the Ru_(0.5)Ir_(0.4)Pb_(0.1)O_(x)as an efficient and durable OER catalyst for practical applications under demanding conditions.展开更多
基金supported by Shanghai Rising-Star Program(No.22QA1403900)the National Natural Science Foundation of China(No.71804106)the Noncarbon Energy Conversion and Utilization Institute under the Shanghai Class IV Peak Disciplinary Development Program.
文摘Cascading faults have been identified as the primary cause of multiple power outages in recent years.With the emergence of integrated energy systems(IES),the conventional approach to analyzing power grid cascading faults is no longer appropriate.A cascading fault analysis method considering multi-energy coupling characteristics is of vital importance.In this study,an innovative analysis method for cascading faults in integrated heat and electricity systems(IHES)is proposed.It considers the degradation characteristics of transmission and energy supply com-ponents in the system to address the impact of component aging on cascading faults.Firstly,degradation models for the current carrying capacity of transmission lines,the water carrying capacity and insulation performance of thermal pipelines,as well as the performance of energy supply equipment during aging,are developed.Secondly,a simulation process for cascading faults in the IHES is proposed.It utilizes an overload-dominated development model to predict the propagation path of cascading faults while also considering network islanding,electric-heating rescheduling,and load shedding.The propagation of cascading faults is reflected in the form of fault chains.Finally,the results of cascading faults under different aging levels are analyzed through numerical examples,thereby verifying the effectiveness and rationality of the proposed model and method.
基金supported by the National Natural Science Foundation of China(12304102,62574029)Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0479)+1 种基金Science and Technology Research Project of Chongqing Education Committee(KJQN202400558)Doctoral Scientific Research Fund of Chongqing Normal University(23XLB029)。
文摘β-Ga_(2)O_(3)is a promising candidate for solarblind ultraviolet photodetection owing to its suitable bandgap of approximately 4.9 eV,excellent photoresponse characteristics,and high stability.However,the lack of a sufficient driving force within the material leads to extensive bulk charge recombination,limiting its photocurrent and thus posing significant challenges in designing high-performance Ga_(2)O_(3)-based photodetection.In this study,we propose a gradient doping strategy to achieve a Sn-doping concentration gradient along theβ-Ga_(2)O_(3)film thickness.By combining sol-gel synthesis with rapid thermal annealing,a spatially graded band structure with a full-space built-in electric field is constructed,which increases the width of band bending over a large region and is crucial for significantly enhancing carrier separation and transport in the bulk.The resulting gradient Sn-dopedβ-Ga_(2)O_(3)enables exceptional photoelectric performance without an external bias under 254 nm irradiation,including a superior responsivity of 66.88 mA W^(-1),a high detectivity of 8.12×10^(11)Jones,and a fast rise/decay time of 79/65 ms,outstanding most existing similar reported photoelectrochemical(PEC)type optoelectronic devices.Additionally,the device exhibits excellent long-term stability and enables high-resolution underwater ultraviolet imaging.This study demonstrates that the gradient doping strategy provides a feasible approach for enhancing the PEC performance ofβ-Ga_(2)O_(3)photoelectrodes.
基金supported by the the National Key R&D Program of China(No.2019YFE0108300)the National Natural Science Foundation of China(No.71971162).
文摘With the advancement in autonomous driving techniques,autonomous demand-responsive transit(ADRT)is a newly emerging sustainable transport mode for the future,which will provide more flexible services to public users.ADRT offers benefits such as flex-ible stops and routes and comfortable seats,but it also involves risks due to the vehicles being driverless.This paper particularly investigates users’preferences and attitudes towards ADRT,and mode choice behavior between ADRT buses and traditional buses.A survey with Likert scale statements and stated preference(SP)choice scenarios is designed and conducted to explore users’attitudes towards the safety risks of autonomous vehicles(AVs),social concerns,service flexibility concerns when using AVs,interest in new things,and shuttle mode choices.An integrated choice and latent variable(ICLV)model is adopted to explore users’psychological factors through latent variables and to integrate them into mode choice behavioral modeling.Estimated results indicate that users’attitudes towards AV safety risks,their social concerns,and their flexibility concerns with ADRT strongly influence their mode choices and are strongly related to sociodemographic and travel-related factors such as age,gender,income,education,number of family members.In gen-eral,a young age,a high education level,a higher income,private car ownership,and better knowledge of AVs are positively related to attitudes towards ADRT.Females,users from large families,and users with driving licenses or long commuting times are less willing to adopt ADRT.The study’s outcomes highlight significant heterogeneities among users and can be highly valuable for policymakers,such as government authorities,in providing social support and designing policies targeting specific population groups.This will be ben-eficial in attracting more users to this emerging mobility service and contributing to sus-tainable urban development.
基金support from the Ministry of Science and Technology of China through the National Key R&D Program(Grant No.2024YFE0114900)the Talent Recruitment Program(Grant No.22J4021Z311)as well as from Songshan Lake Materials Laboratory through the startup grant(Grant No.Y2D1051Z311).
文摘Widespread deployment of proton exchange membrane water electrolyzers(PEMWE)relies on acid-stable oxygen evolution reaction(OER)catalysts capable of operating at high current densities.Inspired by the robust chemistry of lead-acid batteries,we introduce lead(Pb)into ruthenium-iridium mixed oxide(RuIrO_(x))through a facile sol-gel method.The as-prepared RuIrPbO_(x)nanoparticulate catalysts with the optimal composition(Ru_(0.5)Ir_(0.4)Pb_(0.1)O_(x))achieve an overpotential of 241 mV at 10 mA cm^(-2)and exceptional stability of 1000 h at a high current density of 100 mA cm^(-2)without degradation.In situ differential electrochemical mass spectrometry indicates that doping RuIrO_(x)with an appropriate amount of Pb helps to suppress the participation of lattice oxygen during OER,contributing to structural preservation and long-term stability.Density functional theory calculations reveal that Pb doping effectively regulates the electronic structure of the Ru sites,reducing Ru-O covalency,which in turn increases the Ru dissolution energy and therefore prevents Ru leaching—a key degradation pathway for Ru-containing OER catalysts.When integrated into a membrane electrode assembly,the PEMWE cell can operate at a large current density of 3.0 A cm^(-2)under 1.96 V(at 60℃)for 400 h with minimal performance degradation,demonstrating the significant potential of the Ru_(0.5)Ir_(0.4)Pb_(0.1)O_(x)as an efficient and durable OER catalyst for practical applications under demanding conditions.
