The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium.Here,we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid.We ca...The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium.Here,we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid.We calculated the transmission ratios and deduced the Brillouin shift and linewidth to construct the Brillouin spectrum by extracting the Brillouin edge signal through filtered double-edge data.We built a detection system to test the performance of this method and measured the Brillouin spectrum for distilled water at different temperatures and compared it with the theoretical prediction.The observed difference between the experimental and theoretical values for Brillouin shift and linewidth is less than 4.3 MHz and 3.2 MHz,respectively.Moreover,based on the double-edge technique,the accuracy of the extracted temperatures and salinity is approximately 0.1°C and 0.5‰,respectively,indicating significant potential for application in water detection and oceanography.展开更多
The universality of improved CO2 fixing upon the addition of mixed electron donors（MEDs）composed of Na2 S,NO2-,and S2O32-to non-photosynthetic microbial communities（NPMCs）obtained from 12 locations in four oceans ...The universality of improved CO2 fixing upon the addition of mixed electron donors（MEDs）composed of Na2 S,NO2-,and S2O32-to non-photosynthetic microbial communities（NPMCs）obtained from 12 locations in four oceans of the world was validated. The CO2 fixing efficiencies of NPMCs were universally enhanced by MED compared with those obtained using H2 alone as electron donor,with average increase of about 276%. An increase in microbial inoculation concentration could increase the net amount of CO2 fixing to853.34 mg/L in the presence of MED. NO2-and S2O32-may play the roles of both electron acceptor and electron donor under aerobic conditions,which may improve the energy utilization efficiency of NPMC and enhance the CO2 fixation efficiency. The sequence determination of 16 S ribosomal deoxyribonucleic acid（rDNA） from 150 bacteria of NPMC showed that more than 50% of the bacteria were symbiotic and there were many heterotrophic bacteria such as Vibrio natriegens. These results indicate that NPMC acts as a symbiotic CO2 fixing system. The interaction between autotrophic and heterotrophic bacteria may be a crucial factor supporting ladder utilization and recycling of energy/carbon source.展开更多
<div style="text-align:justify;"> Gansu Province is a large province in Western China, and its geographical location and economic status are very important. With the state’s attention to the western d...<div style="text-align:justify;"> Gansu Province is a large province in Western China, and its geographical location and economic status are very important. With the state’s attention to the western development, the economy of the western region represented by Gansu Province has developed rapidly, and the construction of roads and other infrastructure has also been developed. Taking Gansu Province as an example, this paper studies and discusses the application of highway maintenance platform based on GIS + BIM Technology. Firstly, this paper expounds the advantages of GIS + BIM Technology in highway construction and maintenance, and analyzes the development status of GIS + BIM Technology;Secondly, it expounds how to solve the problem of highway maintenance from the aspects of GIS + BIM system and its advantages and difficulties in highway maintenance, and briefly explains the difficulties existing in highway maintenance in Gansu Province. Then, starting from the path of GIS + BIM Technology to solve highway maintenance in Gansu Province, this paper analyzes the expected effect of GIS + BIM Technology in highway maintenance in Gansu Province. </div>展开更多
This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an ...This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.展开更多
Adaptive dwell scheduling is essential to achieve full performance for a simultaneous multi-beam radar system.The dwell scheduling for such a radar system considering desired execution time criterion is studied in thi...Adaptive dwell scheduling is essential to achieve full performance for a simultaneous multi-beam radar system.The dwell scheduling for such a radar system considering desired execution time criterion is studied in this paper.The primary objective of this model is to achieve maximum scheduling gain and minimum scheduling cost while adhering to not only time,aperture,and frequency constraints,but also electromagnetic compatibility(EMC)constraint.The dwell scheduling algorithm is proposed to solve the above optimization problem,where several separation points are set on the timeline,so that each separator divides the scheduling interval into two sides.For the two sides,the dual-side time pointers are introduced,which move from the separator to both ends of the scheduling interval.The dwell tasks are analyzed in sequence at each analysis point based on their two-level synthetical priority.These tasks are then executed simultaneously by sharing the whole aperture under various constraints to accomplish multiple tasks concurrently.The above process is respectively conducted at each separator,and the final scheduling result is the one with the minimal cost among all.Simulation results prove that the proposed algorithm can achieve real-time dwell scheduling and outperform the existing algorithms in terms of scheduling performance.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering usin...The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants.This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angleθ_(23).The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory(TAO)detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site,local and global nuclear reactors,JUNO and TAO detector responses,expected event rates and spectra of signals and backgrounds,and systematic uncertainties of analysis inputs.We find that a 3σmedian sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years×26.6 GW thermal power.展开更多
Carbon dioxide(CO_(2))emissions from the road sector have attracted increasing attention in current years.This paper attempted to provide a systematic review of the existing research efforts on road life-cycle CO_(2)e...Carbon dioxide(CO_(2))emissions from the road sector have attracted increasing attention in current years.This paper attempted to provide a systematic review of the existing research efforts on road life-cycle CO_(2)emissions by analyzing the system’s boundary division,identifying the CO_(2)emission contributions of each life-cycle phase,listing major emission contributors,exploring related emission reduction technologies,and giving directions for future development.The research showed that the road life cycle is usually divided into five phases:material production,construction,use,maintenance and end-of-life(EOL)phases.The use phase and the initial construction stage(including material production and construction phases)contributed the most CO_(2)emissions during the road life cycle.In detail,the production of cement,asphalt and steel were the three main emission contributors in the material production phase.The pavement roughness,albedo,and concrete carbonation were the main factors affecting emissions in the use phase.In addition,emission reduction technologies such as using recycled materials and recycling techniques,lowering mixing temperature,and equipment energy substitution were commonly used to reduce emissions from material production and construction phases.The application of emerging technologies such as carbon capture and storage,carbon sink,and the use of hydrogen,solar and photovoltaic in the road sector may have emission reduction potentials and should be highlighted more in future studies.展开更多
The purpose of this paper is to provide a summary of a quick overview of the latest developments and unprecedented opportunities for scholars who want to set foot in the field of traditional taxi and online car-hailin...The purpose of this paper is to provide a summary of a quick overview of the latest developments and unprecedented opportunities for scholars who want to set foot in the field of traditional taxi and online car-hailing(TTOC).From the perspectives of peoples(e.g.,passenger,driver,and policymaker),vehicle,road,and environment,this paper describes the current research status of TTOC's big data in six hot topics,including the ridership factor,spatio-temporal distribution and travel behavior,cruising strategy and passenger service market partition,route planning,transportation emission and new-energy,and TTOC's data extensional application.These topics were included in five mainstreams as follows:(1)abundant studies often focus only on determinant analysis on given transportation(taxi,transit,online car-hailing);the exploration of ridership patterns for a multimodal transportation mode is rare;furthermore,multiple aspects of factors were not considered synchronously in a wide time span;(2)travel behavior research mainly concentrates on the commuting trips and distribution patterns of various travel indices(e.g.,distance,displacement,time);(3)the taxi driver-searching strategy can be divided into autopsychic cruising and system dispatching;(4)the spatio-temporal distribution character of TTOC's fuel consumption(FC)and greenhouse gas(GHG)emissions has become a hotspot recently,and there has been a recommendation for electric taxi(ET)in urban cities to decrease transportation congestion is proposed;and(5)based on TTOC and point of interest(POI)multi-source data,many machine learning algorithms were used to predict travel condition indices,land use,and travel behavior.Then,the main bottlenecks and research directions that can be explored in the future are discussed.We hope this result can provide an overview of current fundamental aspects of TTOC's utilization in the urban area.展开更多
The Paleogene is the first period after the Mesozoic Mass Extinction. Mammals become the dominant group in the terrestrial ecosystem with a rapid radiation, and Asia has been considered to be the origin place of sever...The Paleogene is the first period after the Mesozoic Mass Extinction. Mammals become the dominant group in the terrestrial ecosystem with a rapid radiation, and Asia has been considered to be the origin place of several mammalian groups.The Paleogene System consists mostly of terrestrial deposits in Asia, especially in East Asia. A well-established regional chronostratigraphic framework is the foundation for understanding both the Paleogene geologic history and evolutionary history of Asia and their relationships. The Paleogene is subdivided into the Paleocene, Eocene and Oligocene in the International Chronostratigraphic Chart. Based on the land mammal ages, the Chinese terrestrial Paleogene can be subdivided into 11 stages:the Shanghuan, Nongshanian and Bayanulanian stages of the Paleocene, the Lingchan, Arshantan, Irdinmanhan, Sharamurunian,Ulangochuian and Baiyinian stages of the Eocene, and the Ulantatalian and Tabenbulukian stages of the Oligocene. These stages have distinctive paleontological characters, with special significance of fossil mammals, which provide a reliable practical basis.The bases of the Shanghuan, Lingchan, and Ulantatalian stages are coincident respectively with those of the Paleocene, Eocene and Oligocene. The ages for their bases are determined as 66.0, 56.0 and 33.9 Ma, respectively, following that for the corresponding series in the International Chronostratigraphic Chart. For other stages, estimated ages are provided based on available paleomagnetic results.展开更多
Growing private vehicle use and a limited supply of parking resources have increased competition for parking spaces.Ineffective searching for parking spaces is a significant barrier to smooth traffic flow.Smart techno...Growing private vehicle use and a limited supply of parking resources have increased competition for parking spaces.Ineffective searching for parking spaces is a significant barrier to smooth traffic flow.Smart technology-generated parking reservations are regarded as an excellent way to increase parking efficiency and lessen traffic.Although there is increased attention on smart parking research and parking reservation optimization,a scoping review is currently lacking.Therefore,the purpose of this paper is to provide a comprehensive review of the research literature related to parking reservations.Out of the original 438 publications identified in this search,99 were eventually chosen for analysis.The review categorized parking reservations into four research topics:inventory control,allocation decisions,pricing strategies,and performance evaluation.The elements considered in these research themes,modeling techniques,and evaluation criteria are explored in detail.In addition,the challenges and further enhancements of parking reservation optimization are discussed.It is believed that the findings from this study will be beneficial in further research on parking reservations.展开更多
In data-driven materials design where the target materials have limited data,the transfer machine learning from large known source materials,becomes a demanding strategy especially across different crystal structures....In data-driven materials design where the target materials have limited data,the transfer machine learning from large known source materials,becomes a demanding strategy especially across different crystal structures.In this work,we proposed a deep transfer learning approach to predict thermodynamically stable perovskite oxides based on a large computational dataset of spinel oxides.The deep neural network(DNN)source domain model with“Center-Environment”(CE)features was first developed using the formation energy of 5329 spinel oxide structures and then was fine-tuned by learning a small dataset of 855 perovskite oxide structures,leading to a transfer learning model with good transferability in the target domain of perovskite oxides.Based on the transferred model,we further predicted the formation energy of potential 5329 perovskite structures with combination of 73 elements.Combining the criteria of formation energy and structure factors including tolerance factor(0.7<t≤1.1)and octahedron factor(0.45<μ<0.7),we predicted 1314 thermodynamically stable perovskite oxides,among which 144 oxides were reported to be synthesized experimentally,10 oxides were predicted computationally by other literatures,301 oxides were recorded in the Materials Project database,and 859 oxides have been first reported.Combing with the structure-informed features the transfer machine learning approach in this work takes the advantage of existing data to predict new structures at a lower cost,providing an effective acceleration strategy for the expensive high-throughput computational screening in materials design.The predicted stable novel perovskite oxides serve as a rich platform for exploring potential renewable energy and electronic materials applications.展开更多
With the increasing international consensus concerning the negative effects of climate change,reducing greenhouse gases has become a higher priority in government policies and research committees.The transportation se...With the increasing international consensus concerning the negative effects of climate change,reducing greenhouse gases has become a higher priority in government policies and research committees.The transportation sector generates approximately 29%of the total greenhouse gas emissions and 25%of the global energy related carbon dioxide(CO2)emissions.Thus,it is essential to understand the influencing factors of vehicle emissions and establish a corresponding evaluation model for the emission estimation of operating vehicles.This paper reviews different methods of measuring vehicle emissions,including laboratory measurements,on-road measurements,and tunnel measurements.Then,we summarize the factors affecting the emission evaluation of operating vehicles based on the vehicle operating features and road environment.Finally,the applications of vehicle emission evaluation models are analyzed,including the emission assessment of the vehicles operating at road segments and intersections.Based on this review,one can conclude that selecting different measurements will significantly impact the assessment of the vehicle emission results and the applicable scope of the measurements.Considering the different influencing factors of the operating vehicle emissions will have an impact on the model application of the vehicle emission evaluation.Moreover,several analysis methods for new technology vehicles can compensate for the potential lack in connectedness with the rapid development of new energy vehicle technology and the improvement of intelligent transportation systems(ITS).展开更多
A fairly well-preserved specimen of a new primitive mammal, Repenomamus robustus gen. et sp. nov., has been described from the Yixian Formation (Lower Cretaceous), western Liaoning, China. This animal has several deri...A fairly well-preserved specimen of a new primitive mammal, Repenomamus robustus gen. et sp. nov., has been described from the Yixian Formation (Lower Cretaceous), western Liaoning, China. This animal has several derived characteristics, such as well-developed den-tary/squamosal articulation, reduced number of tooth, differentiation of premolars and molars in postcanine teeth, presence of a dorsal process of the premaxilla that is not in contact with the nasal, closed medial wall of the orbit, and presence of fingerlike promontorium on the petrosal. It also retains some primitive reptile-like features. It is the most primitive taxon among the three mammals known from the Jehol Biota, and also represents the largest mammal of Mesozoic age over the world.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK...The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.展开更多
An autostereoscopic display system with a bicylindrical lens based on temporal-spatial multiplexing technique is introduced in this paper.The system comprises a directional scanning backlight,a liquid crystal display ...An autostereoscopic display system with a bicylindrical lens based on temporal-spatial multiplexing technique is introduced in this paper.The system comprises a directional scanning backlight,a liquid crystal display panel with high refreshing rate,and an eye tracking device.The directional scanning backlight consists of an LED board,two lenticular lens arrays with matching periods,a parallax barrier film,and other optical films.One of the lenticular lenses is a bicylindrical lens designed to reduce aberration,hence achieving better image quality.A prototype is set up based on the proposed structure.A series of experiments are conducted,and the overall performance of the prototype is evaluated.The LEDs are divided into 10 groups that form 10 view zones.On the one hand,it achieves full resolution in both 2D and 3D display modes.On the other hand,the viewing angle is increased to t26 deg.Most importantly,the crosstalk is low.The minimum crosstalk is 6%,and the maximum crosstalk is 8.8%at a viewing angle of ±22 deg.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neut...The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.展开更多
Horizontal strengthened storeys are widely used in super high-rise steel structures to improve the lateral structural rigidity.This use has great effects on the seismic properties of the entire structure.The seismic p...Horizontal strengthened storeys are widely used in super high-rise steel structures to improve the lateral structural rigidity.This use has great effects on the seismic properties of the entire structure.The seismic properties of the Wuhan International Securities Building (a 68-storey super high-rise steel structure with three horizontal strengthened storeys) were evaluated in this study.Two approaches,i.e.,mode-superposition response spectrum analysis and time-history analysis,were employed to calculate the seismic response of the structure.The response spectrum analysis indicated that transition parts near the three strengthened storeys were weak zones of the structure because of the abrupt change in rigidity.In the response spectrum analysis approach,the Square Root of Sum of Square (SRSS) method was recommended when the vertical seismic effects could be ignored.However,the complete quadratic combination (CQC) method was superior to SRSS method when the vertical seismic effects should be considered.With the aid of time-history analysis,the seismic responses of the structure were obtained.The whiplash effect that spectrum analysis cannot reveal was observed through time-history analysis.This study provides references for the seismic design of super high-rise steel structures with horizontal strengthened storeys.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 62175072, No. 62175072 and No. 12074209)the Open Project of State Key Laboratory of Low-Dimensional Quantum Physics (Grant No. KF202008)support from International Postdoctoral Exchange Fellowship Program (Talent-Introduction Program)。
文摘The Brillouin scattering spectrum has been used to investigate the properties of a liquid medium.Here,we propose an improved method based on the double-edge technique to obtain the Brillouin spectrum of a liquid.We calculated the transmission ratios and deduced the Brillouin shift and linewidth to construct the Brillouin spectrum by extracting the Brillouin edge signal through filtered double-edge data.We built a detection system to test the performance of this method and measured the Brillouin spectrum for distilled water at different temperatures and compared it with the theoretical prediction.The observed difference between the experimental and theoretical values for Brillouin shift and linewidth is less than 4.3 MHz and 3.2 MHz,respectively.Moreover,based on the double-edge technique,the accuracy of the extracted temperatures and salinity is approximately 0.1°C and 0.5‰,respectively,indicating significant potential for application in water detection and oceanography.
基金supported by the National Natural Science Foundation of China (Nos.21177093,21307093)the National High Technology Research and Development Program of China (No.2012AA050101)+3 种基金the Research Fund for the Doctoral Program of Higher Education of China (No.20130072110025)China Postdoctoral Science Foundation (Nos.2013M531220,121656)the State Key Laboratory of Pollution Control and Resource Reuse Foundation (No.PCRRY12002)the Collaborative Innovation Center for Regional Environmental Quality
文摘The universality of improved CO2 fixing upon the addition of mixed electron donors（MEDs）composed of Na2 S,NO2-,and S2O32-to non-photosynthetic microbial communities（NPMCs）obtained from 12 locations in four oceans of the world was validated. The CO2 fixing efficiencies of NPMCs were universally enhanced by MED compared with those obtained using H2 alone as electron donor,with average increase of about 276%. An increase in microbial inoculation concentration could increase the net amount of CO2 fixing to853.34 mg/L in the presence of MED. NO2-and S2O32-may play the roles of both electron acceptor and electron donor under aerobic conditions,which may improve the energy utilization efficiency of NPMC and enhance the CO2 fixation efficiency. The sequence determination of 16 S ribosomal deoxyribonucleic acid（rDNA） from 150 bacteria of NPMC showed that more than 50% of the bacteria were symbiotic and there were many heterotrophic bacteria such as Vibrio natriegens. These results indicate that NPMC acts as a symbiotic CO2 fixing system. The interaction between autotrophic and heterotrophic bacteria may be a crucial factor supporting ladder utilization and recycling of energy/carbon source.
文摘<div style="text-align:justify;"> Gansu Province is a large province in Western China, and its geographical location and economic status are very important. With the state’s attention to the western development, the economy of the western region represented by Gansu Province has developed rapidly, and the construction of roads and other infrastructure has also been developed. Taking Gansu Province as an example, this paper studies and discusses the application of highway maintenance platform based on GIS + BIM Technology. Firstly, this paper expounds the advantages of GIS + BIM Technology in highway construction and maintenance, and analyzes the development status of GIS + BIM Technology;Secondly, it expounds how to solve the problem of highway maintenance from the aspects of GIS + BIM system and its advantages and difficulties in highway maintenance, and briefly explains the difficulties existing in highway maintenance in Gansu Province. Then, starting from the path of GIS + BIM Technology to solve highway maintenance in Gansu Province, this paper analyzes the expected effect of GIS + BIM Technology in highway maintenance in Gansu Province. </div>
基金Supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+20 种基金the CAS Center for Excellence in Particle Physics,Wuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique(F.R.S-FNRS)FWO under the"Excellence of Science-EOS"in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo and ANID Millennium Science Initiative Program—ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+in Germanythe Joint Institute of Nuclear Research(JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation(RSF)National Natural Science Foundation of China(NSFC)research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn University and Suranaree University of Technology in Thailandthe University of California at Irvinethe National Science Foundation in USA。
文摘This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.
基金supported in part by the National Natural Science Foundation of China(Nos.61771095 and 62031007).
文摘Adaptive dwell scheduling is essential to achieve full performance for a simultaneous multi-beam radar system.The dwell scheduling for such a radar system considering desired execution time criterion is studied in this paper.The primary objective of this model is to achieve maximum scheduling gain and minimum scheduling cost while adhering to not only time,aperture,and frequency constraints,but also electromagnetic compatibility(EMC)constraint.The dwell scheduling algorithm is proposed to solve the above optimization problem,where several separation points are set on the timeline,so that each separator divides the scheduling interval into two sides.For the two sides,the dual-side time pointers are introduced,which move from the separator to both ends of the scheduling interval.The dwell tasks are analyzed in sequence at each analysis point based on their two-level synthetical priority.These tasks are then executed simultaneously by sharing the whole aperture under various constraints to accomplish multiple tasks concurrently.The above process is respectively conducted at each separator,and the final scheduling result is the one with the minimal cost among all.Simulation results prove that the proposed algorithm can achieve real-time dwell scheduling and outperform the existing algorithms in terms of scheduling performance.
基金Supported by the Chinese Academy of Sciences,the National Key R&D Program of Chinathe CAS Center for Excellence in Particle Physics,Wuyi University,and the TsungDao Lee Institute of Shanghai Jiao Tong University in China+3 种基金the Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Italian-Chinese collaborative research program MAECI-NSFC,the Fond de la Recherche Scientifique(F.R.S-FNRS)and FWO under the“Excellence of Science–EOS”in Belgium,the Conselho Nacional de Desenvolvimento Cient´ıfico e Tecnol`ogico in Brazil,the Agencia Nacional de Investigacion y Desarrollo and ANID-Millennium Science Initiative Program-ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Association,and the Cluster of Excellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR)and Lomonosov Moscow State University in Russia,the joint Russian Science Foundation(RSF)and National Natural Science Foundation of China(NSFC)research program,the MOST and MOE in Taiwan,China,the Chulalongkorn University and Suranaree University of Technology in Thailand,University of California at Irvine and the National Science Foundation in the US。
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants.This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angleθ_(23).The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory(TAO)detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site,local and global nuclear reactors,JUNO and TAO detector responses,expected event rates and spectra of signals and backgrounds,and systematic uncertainties of analysis inputs.We find that a 3σmedian sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years×26.6 GW thermal power.
基金supported by the National Natural Science Foundation of China(Grant Nos.51878062,52102390 and 52002032)the Natural Science Foundation of Shaanxi Province(Grant No.2022JQ-527)the Fundamental Research Funds for the Central Universities(Grant Nos.300102342501 and 300102342517)
文摘Carbon dioxide(CO_(2))emissions from the road sector have attracted increasing attention in current years.This paper attempted to provide a systematic review of the existing research efforts on road life-cycle CO_(2)emissions by analyzing the system’s boundary division,identifying the CO_(2)emission contributions of each life-cycle phase,listing major emission contributors,exploring related emission reduction technologies,and giving directions for future development.The research showed that the road life cycle is usually divided into five phases:material production,construction,use,maintenance and end-of-life(EOL)phases.The use phase and the initial construction stage(including material production and construction phases)contributed the most CO_(2)emissions during the road life cycle.In detail,the production of cement,asphalt and steel were the three main emission contributors in the material production phase.The pavement roughness,albedo,and concrete carbonation were the main factors affecting emissions in the use phase.In addition,emission reduction technologies such as using recycled materials and recycling techniques,lowering mixing temperature,and equipment energy substitution were commonly used to reduce emissions from material production and construction phases.The application of emerging technologies such as carbon capture and storage,carbon sink,and the use of hydrogen,solar and photovoltaic in the road sector may have emission reduction potentials and should be highlighted more in future studies.
基金supported by the National Natural Science Foundation of China,grant number 51878062the National Key Research and Development Program of China,grant number 2019YFB1600300the National Science Foundation of Shaanxi Province,grant number 2020JQ-387。
文摘The purpose of this paper is to provide a summary of a quick overview of the latest developments and unprecedented opportunities for scholars who want to set foot in the field of traditional taxi and online car-hailing(TTOC).From the perspectives of peoples(e.g.,passenger,driver,and policymaker),vehicle,road,and environment,this paper describes the current research status of TTOC's big data in six hot topics,including the ridership factor,spatio-temporal distribution and travel behavior,cruising strategy and passenger service market partition,route planning,transportation emission and new-energy,and TTOC's data extensional application.These topics were included in five mainstreams as follows:(1)abundant studies often focus only on determinant analysis on given transportation(taxi,transit,online car-hailing);the exploration of ridership patterns for a multimodal transportation mode is rare;furthermore,multiple aspects of factors were not considered synchronously in a wide time span;(2)travel behavior research mainly concentrates on the commuting trips and distribution patterns of various travel indices(e.g.,distance,displacement,time);(3)the taxi driver-searching strategy can be divided into autopsychic cruising and system dispatching;(4)the spatio-temporal distribution character of TTOC's fuel consumption(FC)and greenhouse gas(GHG)emissions has become a hotspot recently,and there has been a recommendation for electric taxi(ET)in urban cities to decrease transportation congestion is proposed;and(5)based on TTOC and point of interest(POI)multi-source data,many machine learning algorithms were used to predict travel condition indices,land use,and travel behavior.Then,the main bottlenecks and research directions that can be explored in the future are discussed.We hope this result can provide an overview of current fundamental aspects of TTOC's utilization in the urban area.
基金supported by the National Natural Science Foundation of China (Grant No. 41572021)the National Commission on Stratigraphy of China
文摘The Paleogene is the first period after the Mesozoic Mass Extinction. Mammals become the dominant group in the terrestrial ecosystem with a rapid radiation, and Asia has been considered to be the origin place of several mammalian groups.The Paleogene System consists mostly of terrestrial deposits in Asia, especially in East Asia. A well-established regional chronostratigraphic framework is the foundation for understanding both the Paleogene geologic history and evolutionary history of Asia and their relationships. The Paleogene is subdivided into the Paleocene, Eocene and Oligocene in the International Chronostratigraphic Chart. Based on the land mammal ages, the Chinese terrestrial Paleogene can be subdivided into 11 stages:the Shanghuan, Nongshanian and Bayanulanian stages of the Paleocene, the Lingchan, Arshantan, Irdinmanhan, Sharamurunian,Ulangochuian and Baiyinian stages of the Eocene, and the Ulantatalian and Tabenbulukian stages of the Oligocene. These stages have distinctive paleontological characters, with special significance of fossil mammals, which provide a reliable practical basis.The bases of the Shanghuan, Lingchan, and Ulantatalian stages are coincident respectively with those of the Paleocene, Eocene and Oligocene. The ages for their bases are determined as 66.0, 56.0 and 33.9 Ma, respectively, following that for the corresponding series in the International Chronostratigraphic Chart. For other stages, estimated ages are provided based on available paleomagnetic results.
基金supported by the National Key Research and Development Program of China (2019YFB1600300)the National Natural Science Foundation of China (NSFC) (51878062)the Fundamental Research Funds for the Central Universities (300102341303)。
文摘Growing private vehicle use and a limited supply of parking resources have increased competition for parking spaces.Ineffective searching for parking spaces is a significant barrier to smooth traffic flow.Smart technology-generated parking reservations are regarded as an excellent way to increase parking efficiency and lessen traffic.Although there is increased attention on smart parking research and parking reservation optimization,a scoping review is currently lacking.Therefore,the purpose of this paper is to provide a comprehensive review of the research literature related to parking reservations.Out of the original 438 publications identified in this search,99 were eventually chosen for analysis.The review categorized parking reservations into four research topics:inventory control,allocation decisions,pricing strategies,and performance evaluation.The elements considered in these research themes,modeling techniques,and evaluation criteria are explored in detail.In addition,the challenges and further enhancements of parking reservation optimization are discussed.It is believed that the findings from this study will be beneficial in further research on parking reservations.
基金This work was supported by the National Natural Science Foundation of China[Nos.22177067]Sino-German Mobility Program[No.M-0209]+3 种基金the Shanghai Rising-Star Program[No.20QA1403400]the Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(20JC1415300)This work was also supported the Key Research Project of Zhejiang Laboratory(No.2021PE0AC02)Shanghai Technical Service Center for Advanced Ceramics Structure Design and Precision Manufacturing(No.20DZ2294000).The authors acknowledge the Beijing Super Cloud Computing Center,Hefei Advanced Computing Center,and Shanghai University for providing HPC resources.
文摘In data-driven materials design where the target materials have limited data,the transfer machine learning from large known source materials,becomes a demanding strategy especially across different crystal structures.In this work,we proposed a deep transfer learning approach to predict thermodynamically stable perovskite oxides based on a large computational dataset of spinel oxides.The deep neural network(DNN)source domain model with“Center-Environment”(CE)features was first developed using the formation energy of 5329 spinel oxide structures and then was fine-tuned by learning a small dataset of 855 perovskite oxide structures,leading to a transfer learning model with good transferability in the target domain of perovskite oxides.Based on the transferred model,we further predicted the formation energy of potential 5329 perovskite structures with combination of 73 elements.Combining the criteria of formation energy and structure factors including tolerance factor(0.7<t≤1.1)and octahedron factor(0.45<μ<0.7),we predicted 1314 thermodynamically stable perovskite oxides,among which 144 oxides were reported to be synthesized experimentally,10 oxides were predicted computationally by other literatures,301 oxides were recorded in the Materials Project database,and 859 oxides have been first reported.Combing with the structure-informed features the transfer machine learning approach in this work takes the advantage of existing data to predict new structures at a lower cost,providing an effective acceleration strategy for the expensive high-throughput computational screening in materials design.The predicted stable novel perovskite oxides serve as a rich platform for exploring potential renewable energy and electronic materials applications.
基金supported in part by the National Natural Science Foundation of China (Grant Nos. 71901035, 51878062, and 51908462)in part by the Fundamental Research Funds for the Central Universities (Grant No. 300102210113)by the Higher Education Discipline Innovation Project 111 (Grant No. B20035)
文摘With the increasing international consensus concerning the negative effects of climate change,reducing greenhouse gases has become a higher priority in government policies and research committees.The transportation sector generates approximately 29%of the total greenhouse gas emissions and 25%of the global energy related carbon dioxide(CO2)emissions.Thus,it is essential to understand the influencing factors of vehicle emissions and establish a corresponding evaluation model for the emission estimation of operating vehicles.This paper reviews different methods of measuring vehicle emissions,including laboratory measurements,on-road measurements,and tunnel measurements.Then,we summarize the factors affecting the emission evaluation of operating vehicles based on the vehicle operating features and road environment.Finally,the applications of vehicle emission evaluation models are analyzed,including the emission assessment of the vehicles operating at road segments and intersections.Based on this review,one can conclude that selecting different measurements will significantly impact the assessment of the vehicle emission results and the applicable scope of the measurements.Considering the different influencing factors of the operating vehicle emissions will have an impact on the model application of the vehicle emission evaluation.Moreover,several analysis methods for new technology vehicles can compensate for the potential lack in connectedness with the rapid development of new energy vehicle technology and the improvement of intelligent transportation systems(ITS).
基金This work was supported by the Chinese Academy of Sciences (Grant Nos. KZCX3-J-03 and KZ951-B1-410) the Major Basic Research Project of the Ministry of Science and Technology of China (Grant No. G2000077700) and the National Natural Science Foundatio
文摘A fairly well-preserved specimen of a new primitive mammal, Repenomamus robustus gen. et sp. nov., has been described from the Yixian Formation (Lower Cretaceous), western Liaoning, China. This animal has several derived characteristics, such as well-developed den-tary/squamosal articulation, reduced number of tooth, differentiation of premolars and molars in postcanine teeth, presence of a dorsal process of the premaxilla that is not in contact with the nasal, closed medial wall of the orbit, and presence of fingerlike promontorium on the petrosal. It also retains some primitive reptile-like features. It is the most primitive taxon among the three mammals known from the Jehol Biota, and also represents the largest mammal of Mesozoic age over the world.
基金supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+22 种基金the CAS Center for Excellence in Particle PhysicsWuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules (IN2P3) in Francethe Istituto Nazionale di Fisica Nucleare (INFN) in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique (F.R.S-FNRS)FWO under the "Excellence of Science-EOS" in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo in Chilethe Charles University Research Centrethe Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft (DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+ in Germanythe Joint Institute of Nuclear Research (JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation (RSF)National Natural Science Foundation of China (NSFC) research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn UniversitySuranaree University of Technology in Thailandthe University of California at Irvine in USA
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.
文摘An autostereoscopic display system with a bicylindrical lens based on temporal-spatial multiplexing technique is introduced in this paper.The system comprises a directional scanning backlight,a liquid crystal display panel with high refreshing rate,and an eye tracking device.The directional scanning backlight consists of an LED board,two lenticular lens arrays with matching periods,a parallax barrier film,and other optical films.One of the lenticular lenses is a bicylindrical lens designed to reduce aberration,hence achieving better image quality.A prototype is set up based on the proposed structure.A series of experiments are conducted,and the overall performance of the prototype is evaluated.The LEDs are divided into 10 groups that form 10 view zones.On the one hand,it achieves full resolution in both 2D and 3D display modes.On the other hand,the viewing angle is increased to t26 deg.Most importantly,the crosstalk is low.The minimum crosstalk is 6%,and the maximum crosstalk is 8.8%at a viewing angle of ±22 deg.
基金This work was supported by the Chinese Academy of Sciences,the National Key R&D Program of China,the CAS Center for Excellence in Particle Physics,the Joint Large Scale Scientific Facility Funds of the NSFC and CAS,Wuyi University,and the Tsung-Dao Lee Instiute of Shanghai Jiao Tong University in China,the In stiut National de Physique Nucleaire et de Physique de Particules(IN2P3)in France,the Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Fond de la Recherche Scintifique(F.R.S-FNRS)and FWO under the"Excellence of Science-EOS"in Belgium,the Conselho Nacional de Desenvolvimento Cientificoce Tecnologico in Brazil,the Agencia Nacional de Investigacion y Desrrollo in Chile,the Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG),the Helmholtz Association,and the Cluster of Exellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR),Lomonosov Moscow State University,and Russian Foundation for Basic Research(RFBR)in Russia,the MOST and MOE in Taiwan,the Chu-lalongkorm University and Suranaree University of Technology in Thailand,and the University of aliformia at Irvine in USA.
文摘The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.
文摘Horizontal strengthened storeys are widely used in super high-rise steel structures to improve the lateral structural rigidity.This use has great effects on the seismic properties of the entire structure.The seismic properties of the Wuhan International Securities Building (a 68-storey super high-rise steel structure with three horizontal strengthened storeys) were evaluated in this study.Two approaches,i.e.,mode-superposition response spectrum analysis and time-history analysis,were employed to calculate the seismic response of the structure.The response spectrum analysis indicated that transition parts near the three strengthened storeys were weak zones of the structure because of the abrupt change in rigidity.In the response spectrum analysis approach,the Square Root of Sum of Square (SRSS) method was recommended when the vertical seismic effects could be ignored.However,the complete quadratic combination (CQC) method was superior to SRSS method when the vertical seismic effects should be considered.With the aid of time-history analysis,the seismic responses of the structure were obtained.The whiplash effect that spectrum analysis cannot reveal was observed through time-history analysis.This study provides references for the seismic design of super high-rise steel structures with horizontal strengthened storeys.
