As the frontier of multidimensional transportation systems,urban air mobility(UAM)is receiving increasing attention from international organizations,governments,and stakeholders in industry and academia owing to its h...As the frontier of multidimensional transportation systems,urban air mobility(UAM)is receiving increasing attention from international organizations,governments,and stakeholders in industry and academia owing to its high efficiency,low carbon footprint,and operational flexibility.Vertical take-off and landing(VTOL)infrastructure is the core facility that enables UAM and is therefore essential for its safe,efficient,and large-scale commercial implementation.However,the key technologies for establishing low-altitude VTOL infrastructure are still nascent,and government,industry,and academia have yet to harmonize the corresponding construction,management,and operation standards.To address this gap,we herein systematically review the related progress and trends,comprehensively surveying the key technologies of establishing VTOL infrastructure serving unmanned aerial vehicles(UAVs)and electric VTOL aircraft from three complementary perspectives of ground-side,airspace-side,and communication,navigation,surveillance,and information services.In the light of future UAM operations characterized by diverse vehicle types and dense air traffic,we propose a conceptual design for a public multioperator VTOL site to provide constructive insights into the sustainable growth of the low-altitude economy.展开更多
为探究考虑心理因素影响下我国城市潜在MaaS(Mobility as a Service)用户的套餐选择行为与支付意愿的影响因素,综合考虑了受访者个人属性、心理属性与套餐属性3个方面,分别在北京和大连开展了RP与SP调查。在此基础上,构建了结构方程模...为探究考虑心理因素影响下我国城市潜在MaaS(Mobility as a Service)用户的套餐选择行为与支付意愿的影响因素,综合考虑了受访者个人属性、心理属性与套餐属性3个方面,分别在北京和大连开展了RP与SP调查。在此基础上,构建了结构方程模型和离散选择模型,对受访者的MaaS套餐选择行为和支付意愿进行了定性与定量研究。研究结果显示:个人属性方面,北京样本中男性和收入为1万~2万元对MaaS套餐选择行为有显著正面影响;本科教育水平和家中儿童数为2个及以上有显著负面影响;大连样本中本科及以上教育水平、家中老人数为2个及以上、收入2万元及以上、工作有弹性等因素对MaaS套餐选择行为有显著正面影响;年龄在36~60岁、家中有私家车、家中有儿童等因素有显著负面影响。心理属性方面,行为态度对MaaS套餐选择行为具有显著影响,其中北京受访者表现尤为明显;套餐属性方面,套餐价格、公共交通次数及共享单车次数对MaaS套餐选择行为均有显著影响。支付意愿方面,北京和大连受访者对出租车和网约车支付意愿均最高,每增加一公里出租车或网约车均愿为套餐多花费1元。研究结果可为我国未来MaaS套餐的设计与推广提供理论支撑。展开更多
Mobility as a service (MaaS) is a relatively new concept, which holds the promise for a paradigm shift in the provision of urban mobility. The concept of MaaS is to use a single app to access and pay for various trans...Mobility as a service (MaaS) is a relatively new concept, which holds the promise for a paradigm shift in the provision of urban mobility. The concept of MaaS is to use a single app to access and pay for various transport modes within a city or beyond;and the app will give options to allow a traveller to select the most suitable transport mode. The concept of MaaS is enabled by the current mass uptake of smartphones and social media as well ubiquitous internet connection. By studying current applications of MaaS in Europe and US conditions of operation of MaaS have been summarised. Based on the necessary conditions, a checklist has been developed for potential developers of MaaS to assess if they can implement MaaS in a city. This paper also discusses challenges of implementation of MaaS and their potential impacts on urban mobility and societal changes.展开更多
出行即服务(Mobility as a Service,MaaS)以公共交通为核心,整合多模式交通资源构建集查询、规划、预约、支付于一体的“门到门”按需响应出行服务系统。它深度契合数智化、绿色化和定制化的出行发展趋势,并驱动城市治理由“车本位”向...出行即服务(Mobility as a Service,MaaS)以公共交通为核心,整合多模式交通资源构建集查询、规划、预约、支付于一体的“门到门”按需响应出行服务系统。它深度契合数智化、绿色化和定制化的出行发展趋势,并驱动城市治理由“车本位”向“人本位”转型。针对中国交通出行供需双侧协同不足的痛点,MaaS可成为实现资源精准匹配与需求动态响应的关键路径。本文基于国内外研究与实践进展,系统解析MaaS对城市交通服务、建成环境、社会公平的多维影响;聚焦中国当前MaaS发展面临的资源整合不足、治理机制缺位、支撑体系薄弱三大瓶颈,提出涵盖引导政策设计、商业运营创新、协作机制构建、环境设施优化等方面的本土化规划治理建议,以期为MaaS的实践提供指导,同时丰富既有研究成果。展开更多
为推动城市内Mobility as a Service系统构建,并解决其票务支付一体化和换乘服务的相关问题。文章首先从MaaS系统的特性出发,分析MaaS系统框架的构成及其关键因素;其次在考虑上述关键因素的基础上,以单一类型交通方式费用、换乘费用和...为推动城市内Mobility as a Service系统构建,并解决其票务支付一体化和换乘服务的相关问题。文章首先从MaaS系统的特性出发,分析MaaS系统框架的构成及其关键因素;其次在考虑上述关键因素的基础上,以单一类型交通方式费用、换乘费用和服务费用为核心,构建了基于MaaS系统的交通费用模型;然后考虑出行时间和舒适度,构建了面向MaaS系统的交通广义费用模型,以解决票务支付一体化和换乘费用等问题;最后以成都市为例,定量分析了模型内各项参数并使用不同模型计算出行费用、时间,以出行费用和广义费用作为评价依据,分析得出基于MaaS系统的交通费用模型所具有的优势。从而为整合交通资源、建立城市MaaS交通体系提供合理依据。展开更多
The tight sandstone reservoirs in the first sub-member of Chang 7 member(Chang 71)of Triassic Yanchang Formation in the Jiyuan area,Ordos Basin,show significant variations in microscopic pore-throat structure(PTS)and ...The tight sandstone reservoirs in the first sub-member of Chang 7 member(Chang 71)of Triassic Yanchang Formation in the Jiyuan area,Ordos Basin,show significant variations in microscopic pore-throat structure(PTS)and fluid mobility due to the influences of the northeast and northwest dual provenance systems.This study performed multiple experimental analyses on nine samples from the area to determine the petrological and petrophysical properties,as well as the PTS characteristics of reservoirs in different provenance-controlled regions.On this basis,the pore-throat size distribution(PSD)obtained from high-pressure mercury injection(HPMI)was utilized to convert the NMR movable fluid T2spectrum,allowing for quantitative characterization of the full PSD and the occurrence characteristics of movable fluids.A systematic analysis was conducted on the primary controlling factors affecting fluid mobility in the reservoir.The results indicated that the lithology in the eastern and western regions is lithic arkose.The eastern sandstones,being farther from the provenance,exhibit higher contents of feldspar and lithic fragments,along with the development of more dissolution pores.The reservoir possesses good petrophysical properties,low displacement pressure,and high pore-throat connectivity and homogeneity,indicating strong fluid mobility.In contrast,the western sandstones,being nearer to the provenance,exhibit poor grain sorting,high contents of lithic fragments,strong compaction and cementation effects,resulting in poor petrophysical properties,and strong pore-throat heterogeneity,revealing weak fluid mobility.The range of full PSD in the eastern reservoir is wider than that in the western reservoir,with relatively well-developed macropores.The macropores are the primary space for occurrence of movable fluids,and controls the fluid mobility of the reservoir.The effective porosity of movable fluids(EPMF)quantitatively represents the pore space occupied by movable fluids within the reservoir and correlates well with porosity,permeability,and PTS parameters,making it a valuable parameter for evaluating fluid mobility.Under the multi-provenance system,the eastern and western reservoirs underwent different sedimentation and diagenesis processes,resulting in differential distribution of reservoir mineral components and pore types,which in turn affects the PTS heterogeneity and reservoir quality.The composition and content of reservoir minerals are intrinsic factors influencing fluid mobility,while the microscopic PTS is the primary factor controlling it.Low clay mineral content,welldeveloped macropores,and weak pore-throat heterogeneity all contribute to the storage and seepage of reservoir fluids.展开更多
Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the ...Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions.展开更多
Intercity mobility lays the foundation for capital flow,information flow,and knowledge flow,etc.,and is important for promoting regional integration.Although many scholars have studied intercity mobility in extensive ...Intercity mobility lays the foundation for capital flow,information flow,and knowledge flow,etc.,and is important for promoting regional integration.Although many scholars have studied intercity mobility in extensive well-developed urban agglomerations,few studies have examined the characteristics of intercity mobility at the county level and its impact on regionalization in western China.This study takes the Guanzhong Plain urban agglomeration(GPUA)as a case to study the geographical law of intercity mobility and then explore its impact on regionalization.The results obtained show that intercity mobility network exhibits a hub and spoke patterns focusing on major municipal districts at the county level.We also found a corridor effect that counties with higher travel volumes are mostly located along the trunk high speed railway(HSR)lines.Unlike previous studies,the distribution of intercity mobility is more concentrated than that of population and exhibits a super-linear behavior rule.There are the differences in gravity law for overall trips,weekday trips,weekend trips,and holiday trips.With the decrease of travel duration,the effect of attraction of destination is weakening,but the influence of distance decay is increasing.Finally,the spatial organization is still administrative-centric and is dominated by intraprefecture and intra-provincial development.Moreover,the coupled degree between network-based regionalization and attribute-based regionalization shows a decreasing trend from administrative via cultural to physical factors.These findings enrich the research on the intercity mobility and the regionalization in inland developing urban agglomerations.展开更多
本文首先深入探讨了出行即服务(Mobility as a Service,MaaS)的概念与框架,初步揭示MaaS理念的核心与重要作用;其次聚焦于当前我国在MaaS理念指导下交通智能出行的发展现状,发掘存在的技术不足,为用户提供无缝衔接、按需获取的出行体验...本文首先深入探讨了出行即服务(Mobility as a Service,MaaS)的概念与框架,初步揭示MaaS理念的核心与重要作用;其次聚焦于当前我国在MaaS理念指导下交通智能出行的发展现状,发掘存在的技术不足,为用户提供无缝衔接、按需获取的出行体验;最后结合最新技术趋势有针对性地提出基于MaaS的多模式交通智能出行发展路径,为后续的深入研究与实践应用奠定理论基础,为我国多模式交通智能出行的健康发展提供参考。展开更多
In this paper,the small-signal modeling of the Indium Phosphide High Electron Mobility Transistor(InP HEMT)based on the Transformer neural network model is investigated.The AC S-parameters of the HEMT device are train...In this paper,the small-signal modeling of the Indium Phosphide High Electron Mobility Transistor(InP HEMT)based on the Transformer neural network model is investigated.The AC S-parameters of the HEMT device are trained and validated using the Transformer model.In the proposed model,the eight-layer transformer encoders are connected in series and the encoder layer of each Transformer consists of the multi-head attention layer and the feed-forward neural network layer.The experimental results show that the measured and modeled S-parameters of the HEMT device match well in the frequency range of 0.5-40 GHz,with the errors versus frequency less than 1%.Compared with other models,good accuracy can be achieved to verify the effectiveness of the proposed model.展开更多
The 2025 Shanghai Auto Show reaffirmed its role as one of the world’s most influential automotive industry events,offering a panoramic view of the future shaped by intelligent and electrified vehicles.With over 200 n...The 2025 Shanghai Auto Show reaffirmed its role as one of the world’s most influential automotive industry events,offering a panoramic view of the future shaped by intelligent and electrified vehicles.With over 200 new models on display-85 percent of them new energy vehicles-this year’s show spotlighted how the global auto industry is pivoting rapidly towards an era of software-defined and AI-powered mobility.展开更多
Imagine a city that seems to hum rather than roar-a place where innovation moves at the pace of everyday life instead of like the flashy glamor of high-end tech hubs.This is Liuzhou,a city in southern China that is qu...Imagine a city that seems to hum rather than roar-a place where innovation moves at the pace of everyday life instead of like the flashy glamor of high-end tech hubs.This is Liuzhou,a city in southern China that is quietly shaping the future of electric vehicles(EVs).It has become an unlikely yet powerful engine of change in the world of clean mobility.展开更多
High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the ex...High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.展开更多
This paper discusses the influence of Sb/In ratio on the transport properties and crystal quality of the 200 nm InAs_(x)Sb_(1-x)thin film.The Sb content of InAs_(x)Sb_(1-x)thin film in all samples was verified by HRXR...This paper discusses the influence of Sb/In ratio on the transport properties and crystal quality of the 200 nm InAs_(x)Sb_(1-x)thin film.The Sb content of InAs_(x)Sb_(1-x)thin film in all samples was verified by HRXRD of the symmetrical 004 reflections and asymmetrical 115 reflections.The calculation results show that the Sb component was 0.6 in the InAs_(x)Sb_(1-x)thin film grown under the conditions of Sb/In ratio of 6 and As/In ratio of 3,which has the highest electron mobility(28560 cm^(2)/V·s)at 300 K.At the same time,the influence ofⅤ/Ⅲratio on the transport properties and crystal quality of Al_(0.2)In_(0.8)Sb/InAs_(x)Sb_(1-x)quantum well heterostructures also has been investigated.As a result,the Al_(0.2)In_(0.8)Sb/InAs_(0.4)Sb_(0.6)quantum well heterostructure with a channel thickness of 30 nm grown under the conditions of Sb/In ratio of 6 and As/In ratio of 3 has a maximum electron mobility of 28300 cm^(2)/V·s and a minimum RMS roughness of 0.68 nm.Through optimizing the growth conditions,our samples have higher electron mobility and smoother surface morphology.展开更多
We report the epitaxial growth of high-quality Al_(0.8)Ga_(0.2)Sb/InAs/Al_(0.8)Ga_(0.2)Sb quantum well films characterized by high carrier mobility and strong spin-orbit coupling.By appropriately optimizing the Al-to-...We report the epitaxial growth of high-quality Al_(0.8)Ga_(0.2)Sb/InAs/Al_(0.8)Ga_(0.2)Sb quantum well films characterized by high carrier mobility and strong spin-orbit coupling.By appropriately optimizing the Al-to-Ga ratio in the AlGaSb barrier layer,the quantum confinement of the heterostructure is significantly enhanced.Alongside a giant magnetoresistance ratio of 3.65×10^(5)%,the two-carrier transport model from Hall measurements reveals an ultra-high electron mobility of 7.18×10^(5)cm^(2)·V^(-1)·s^(-1)at low temperatures.Meanwhile,pronounced Shubnikov-de Haas(SdH)quantum oscillations persist up to 30 K,and their single-frequency feature indicates a well-defined Fermi surface without subband mixing in the two-dimensional electron gas channel.Moreover,the large effective g-factor and tilted-field-induced orbital effect lead to the observation of split SdH peaks at large magnetic fields.Our results validate that AlGaSb/InAs quantum well heterostructures are suitable candidates for constructing energy-efficient topological spintronic devices.展开更多
基金supported by the National Natural Science Foundation of China(No.U2333214).
文摘As the frontier of multidimensional transportation systems,urban air mobility(UAM)is receiving increasing attention from international organizations,governments,and stakeholders in industry and academia owing to its high efficiency,low carbon footprint,and operational flexibility.Vertical take-off and landing(VTOL)infrastructure is the core facility that enables UAM and is therefore essential for its safe,efficient,and large-scale commercial implementation.However,the key technologies for establishing low-altitude VTOL infrastructure are still nascent,and government,industry,and academia have yet to harmonize the corresponding construction,management,and operation standards.To address this gap,we herein systematically review the related progress and trends,comprehensively surveying the key technologies of establishing VTOL infrastructure serving unmanned aerial vehicles(UAVs)and electric VTOL aircraft from three complementary perspectives of ground-side,airspace-side,and communication,navigation,surveillance,and information services.In the light of future UAM operations characterized by diverse vehicle types and dense air traffic,we propose a conceptual design for a public multioperator VTOL site to provide constructive insights into the sustainable growth of the low-altitude economy.
文摘为探究考虑心理因素影响下我国城市潜在MaaS(Mobility as a Service)用户的套餐选择行为与支付意愿的影响因素,综合考虑了受访者个人属性、心理属性与套餐属性3个方面,分别在北京和大连开展了RP与SP调查。在此基础上,构建了结构方程模型和离散选择模型,对受访者的MaaS套餐选择行为和支付意愿进行了定性与定量研究。研究结果显示:个人属性方面,北京样本中男性和收入为1万~2万元对MaaS套餐选择行为有显著正面影响;本科教育水平和家中儿童数为2个及以上有显著负面影响;大连样本中本科及以上教育水平、家中老人数为2个及以上、收入2万元及以上、工作有弹性等因素对MaaS套餐选择行为有显著正面影响;年龄在36~60岁、家中有私家车、家中有儿童等因素有显著负面影响。心理属性方面,行为态度对MaaS套餐选择行为具有显著影响,其中北京受访者表现尤为明显;套餐属性方面,套餐价格、公共交通次数及共享单车次数对MaaS套餐选择行为均有显著影响。支付意愿方面,北京和大连受访者对出租车和网约车支付意愿均最高,每增加一公里出租车或网约车均愿为套餐多花费1元。研究结果可为我国未来MaaS套餐的设计与推广提供理论支撑。
文摘Mobility as a service (MaaS) is a relatively new concept, which holds the promise for a paradigm shift in the provision of urban mobility. The concept of MaaS is to use a single app to access and pay for various transport modes within a city or beyond;and the app will give options to allow a traveller to select the most suitable transport mode. The concept of MaaS is enabled by the current mass uptake of smartphones and social media as well ubiquitous internet connection. By studying current applications of MaaS in Europe and US conditions of operation of MaaS have been summarised. Based on the necessary conditions, a checklist has been developed for potential developers of MaaS to assess if they can implement MaaS in a city. This paper also discusses challenges of implementation of MaaS and their potential impacts on urban mobility and societal changes.
文摘出行即服务(Mobility as a Service,MaaS)以公共交通为核心,整合多模式交通资源构建集查询、规划、预约、支付于一体的“门到门”按需响应出行服务系统。它深度契合数智化、绿色化和定制化的出行发展趋势,并驱动城市治理由“车本位”向“人本位”转型。针对中国交通出行供需双侧协同不足的痛点,MaaS可成为实现资源精准匹配与需求动态响应的关键路径。本文基于国内外研究与实践进展,系统解析MaaS对城市交通服务、建成环境、社会公平的多维影响;聚焦中国当前MaaS发展面临的资源整合不足、治理机制缺位、支撑体系薄弱三大瓶颈,提出涵盖引导政策设计、商业运营创新、协作机制构建、环境设施优化等方面的本土化规划治理建议,以期为MaaS的实践提供指导,同时丰富既有研究成果。
文摘为推动城市内Mobility as a Service系统构建,并解决其票务支付一体化和换乘服务的相关问题。文章首先从MaaS系统的特性出发,分析MaaS系统框架的构成及其关键因素;其次在考虑上述关键因素的基础上,以单一类型交通方式费用、换乘费用和服务费用为核心,构建了基于MaaS系统的交通费用模型;然后考虑出行时间和舒适度,构建了面向MaaS系统的交通广义费用模型,以解决票务支付一体化和换乘费用等问题;最后以成都市为例,定量分析了模型内各项参数并使用不同模型计算出行费用、时间,以出行费用和广义费用作为评价依据,分析得出基于MaaS系统的交通费用模型所具有的优势。从而为整合交通资源、建立城市MaaS交通体系提供合理依据。
文摘The tight sandstone reservoirs in the first sub-member of Chang 7 member(Chang 71)of Triassic Yanchang Formation in the Jiyuan area,Ordos Basin,show significant variations in microscopic pore-throat structure(PTS)and fluid mobility due to the influences of the northeast and northwest dual provenance systems.This study performed multiple experimental analyses on nine samples from the area to determine the petrological and petrophysical properties,as well as the PTS characteristics of reservoirs in different provenance-controlled regions.On this basis,the pore-throat size distribution(PSD)obtained from high-pressure mercury injection(HPMI)was utilized to convert the NMR movable fluid T2spectrum,allowing for quantitative characterization of the full PSD and the occurrence characteristics of movable fluids.A systematic analysis was conducted on the primary controlling factors affecting fluid mobility in the reservoir.The results indicated that the lithology in the eastern and western regions is lithic arkose.The eastern sandstones,being farther from the provenance,exhibit higher contents of feldspar and lithic fragments,along with the development of more dissolution pores.The reservoir possesses good petrophysical properties,low displacement pressure,and high pore-throat connectivity and homogeneity,indicating strong fluid mobility.In contrast,the western sandstones,being nearer to the provenance,exhibit poor grain sorting,high contents of lithic fragments,strong compaction and cementation effects,resulting in poor petrophysical properties,and strong pore-throat heterogeneity,revealing weak fluid mobility.The range of full PSD in the eastern reservoir is wider than that in the western reservoir,with relatively well-developed macropores.The macropores are the primary space for occurrence of movable fluids,and controls the fluid mobility of the reservoir.The effective porosity of movable fluids(EPMF)quantitatively represents the pore space occupied by movable fluids within the reservoir and correlates well with porosity,permeability,and PTS parameters,making it a valuable parameter for evaluating fluid mobility.Under the multi-provenance system,the eastern and western reservoirs underwent different sedimentation and diagenesis processes,resulting in differential distribution of reservoir mineral components and pore types,which in turn affects the PTS heterogeneity and reservoir quality.The composition and content of reservoir minerals are intrinsic factors influencing fluid mobility,while the microscopic PTS is the primary factor controlling it.Low clay mineral content,welldeveloped macropores,and weak pore-throat heterogeneity all contribute to the storage and seepage of reservoir fluids.
基金Supported by Leading Talent Program of Autonomous Region(2022TSYCLJ0070)PetroChina Prospective and Basic Technological Project(2021DJ0108)Natural Science Foundation for Outstanding Young People in Shandong Province(ZR2022YQ30).
文摘Based on the experimental results of casting thin section,low temperature nitrogen adsorption,high pressure mercury injection,nuclear magnetic resonance T2 spectrum,contact angle and oil-water interfacial tension,the relationship between pore throat structure and crude oil mobility characteristics of full particle sequence reservoirs in the Lower Permian Fengcheng Formation of Mahu Sag,Junggar Basin,are revealed.(1)With the decrease of reservoir particle size,the volume of pores connected by large throats and the volume of large pores show a decreasing trend,and the distribution and peak ranges of throat and pore radius shift to smaller size in an orderly manner.The upper limits of throat radius,porosity and permeability of unconventional reservoirs in Fengcheng Formation are approximately 0.7μm,8%and 0.1×10^(−3)μm^(2),respectively.(2)As the reservoir particle size decreases,the distribution and peak ranges of pores hosting retained oil and movable oil are shifted to a smaller size in an orderly manner.With the increase of driving pressure,the amount of retained and movable oil of the larger particle reservoir samples shows a more obvious trend of decreasing and increasing,respectively.(3)With the increase of throat radius,the driving pressure of reservoir with different particle levels presents three stages,namely rapid decrease,slow decrease and stabilization.The oil driving pressures of various reservoirs and the differences of them decrease with the increase of temperature and obviously decrease with the increase of throat radius.According to the above experimental analysis,it is concluded that the deep shale oil of Fengcheng Formation in Mahu Sag has great potential for production under geological conditions.
基金Under the auspices of National Natural Science Foundation of China(No.42371189)Central University Basic Research Fund of China(No.24ZYYB017)。
文摘Intercity mobility lays the foundation for capital flow,information flow,and knowledge flow,etc.,and is important for promoting regional integration.Although many scholars have studied intercity mobility in extensive well-developed urban agglomerations,few studies have examined the characteristics of intercity mobility at the county level and its impact on regionalization in western China.This study takes the Guanzhong Plain urban agglomeration(GPUA)as a case to study the geographical law of intercity mobility and then explore its impact on regionalization.The results obtained show that intercity mobility network exhibits a hub and spoke patterns focusing on major municipal districts at the county level.We also found a corridor effect that counties with higher travel volumes are mostly located along the trunk high speed railway(HSR)lines.Unlike previous studies,the distribution of intercity mobility is more concentrated than that of population and exhibits a super-linear behavior rule.There are the differences in gravity law for overall trips,weekday trips,weekend trips,and holiday trips.With the decrease of travel duration,the effect of attraction of destination is weakening,but the influence of distance decay is increasing.Finally,the spatial organization is still administrative-centric and is dominated by intraprefecture and intra-provincial development.Moreover,the coupled degree between network-based regionalization and attribute-based regionalization shows a decreasing trend from administrative via cultural to physical factors.These findings enrich the research on the intercity mobility and the regionalization in inland developing urban agglomerations.
文摘本文首先深入探讨了出行即服务(Mobility as a Service,MaaS)的概念与框架,初步揭示MaaS理念的核心与重要作用;其次聚焦于当前我国在MaaS理念指导下交通智能出行的发展现状,发掘存在的技术不足,为用户提供无缝衔接、按需获取的出行体验;最后结合最新技术趋势有针对性地提出基于MaaS的多模式交通智能出行发展路径,为后续的深入研究与实践应用奠定理论基础,为我国多模式交通智能出行的健康发展提供参考。
基金Supported by the National Natural Science Foundation of China(62201293,62034003)the Open-Foundation of State Key Laboratory of Millimeter-Waves(K202313)the Jiangsu Province Youth Science and Technology Talent Support Project(JSTJ-2024-040)。
文摘In this paper,the small-signal modeling of the Indium Phosphide High Electron Mobility Transistor(InP HEMT)based on the Transformer neural network model is investigated.The AC S-parameters of the HEMT device are trained and validated using the Transformer model.In the proposed model,the eight-layer transformer encoders are connected in series and the encoder layer of each Transformer consists of the multi-head attention layer and the feed-forward neural network layer.The experimental results show that the measured and modeled S-parameters of the HEMT device match well in the frequency range of 0.5-40 GHz,with the errors versus frequency less than 1%.Compared with other models,good accuracy can be achieved to verify the effectiveness of the proposed model.
文摘The 2025 Shanghai Auto Show reaffirmed its role as one of the world’s most influential automotive industry events,offering a panoramic view of the future shaped by intelligent and electrified vehicles.With over 200 new models on display-85 percent of them new energy vehicles-this year’s show spotlighted how the global auto industry is pivoting rapidly towards an era of software-defined and AI-powered mobility.
文摘Imagine a city that seems to hum rather than roar-a place where innovation moves at the pace of everyday life instead of like the flashy glamor of high-end tech hubs.This is Liuzhou,a city in southern China that is quietly shaping the future of electric vehicles(EVs).It has become an unlikely yet powerful engine of change in the world of clean mobility.
基金supported by a grant of the M.D.-Ph.D./Medical Scientist Training Program through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(to HK)+3 种基金supported by National Research Foundation of Korea(NRF)grants funded by the Korean government(MSITMinistry of Science and ICT)(NRF2019R1A5A2026045 and NRF-2021R1F1A1061819)a grant from the Korean Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea(HR21C1003)New Faculty Research Fund of Ajou University School of Medicine(to JYC)。
文摘High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.
基金Supported by the Natural Science Basic Research Program of Shaanxi Province(2023-JC-QN-0758)Shaanxi University of Science and Technology Research Launch Project(2020BJ-26)Doctoral Research Initializing Fund of Hebei University of Science and Technology,China(1181476).
文摘This paper discusses the influence of Sb/In ratio on the transport properties and crystal quality of the 200 nm InAs_(x)Sb_(1-x)thin film.The Sb content of InAs_(x)Sb_(1-x)thin film in all samples was verified by HRXRD of the symmetrical 004 reflections and asymmetrical 115 reflections.The calculation results show that the Sb component was 0.6 in the InAs_(x)Sb_(1-x)thin film grown under the conditions of Sb/In ratio of 6 and As/In ratio of 3,which has the highest electron mobility(28560 cm^(2)/V·s)at 300 K.At the same time,the influence ofⅤ/Ⅲratio on the transport properties and crystal quality of Al_(0.2)In_(0.8)Sb/InAs_(x)Sb_(1-x)quantum well heterostructures also has been investigated.As a result,the Al_(0.2)In_(0.8)Sb/InAs_(0.4)Sb_(0.6)quantum well heterostructure with a channel thickness of 30 nm grown under the conditions of Sb/In ratio of 6 and As/In ratio of 3 has a maximum electron mobility of 28300 cm^(2)/V·s and a minimum RMS roughness of 0.68 nm.Through optimizing the growth conditions,our samples have higher electron mobility and smoother surface morphology.
基金supported by R&D the National Key Program of China(Grant No.2021YFA0715503)the Major Project ofShanghai Municipal Science and Technology(Grant No.2018SHZDZX02)the ShanghaiTech Mate rial Device and Soft Matter Nano-fabrication Labs(No.SMN180827).
文摘We report the epitaxial growth of high-quality Al_(0.8)Ga_(0.2)Sb/InAs/Al_(0.8)Ga_(0.2)Sb quantum well films characterized by high carrier mobility and strong spin-orbit coupling.By appropriately optimizing the Al-to-Ga ratio in the AlGaSb barrier layer,the quantum confinement of the heterostructure is significantly enhanced.Alongside a giant magnetoresistance ratio of 3.65×10^(5)%,the two-carrier transport model from Hall measurements reveals an ultra-high electron mobility of 7.18×10^(5)cm^(2)·V^(-1)·s^(-1)at low temperatures.Meanwhile,pronounced Shubnikov-de Haas(SdH)quantum oscillations persist up to 30 K,and their single-frequency feature indicates a well-defined Fermi surface without subband mixing in the two-dimensional electron gas channel.Moreover,the large effective g-factor and tilted-field-induced orbital effect lead to the observation of split SdH peaks at large magnetic fields.Our results validate that AlGaSb/InAs quantum well heterostructures are suitable candidates for constructing energy-efficient topological spintronic devices.
