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
One-dimensional(1D)transition-metal dichalcogenide(TMDC)nanoribbons are appealing for a plethora of emergent physics and innovative high-tech applications unattainable with their two-dimensional(_(2)D)and bulk counter...One-dimensional(1D)transition-metal dichalcogenide(TMDC)nanoribbons are appealing for a plethora of emergent physics and innovative high-tech applications unattainable with their two-dimensional(_(2)D)and bulk counterparts.Despite notable progress in synthesizing TMDC monolayer nanoribbons,the production of TMDC heterostructure nanoribbons,which can integrate the best characteristics of the constituent monolayers,remains elusive.展开更多
Dielectrophoresis(DEP)was combined with adsorption(ADS)to simultaneously and effectively remove Cd^2+ and Pb^2+ species from aqueous solution.To implement the process,bentonite particles of submicro-meter size were us...Dielectrophoresis(DEP)was combined with adsorption(ADS)to simultaneously and effectively remove Cd^2+ and Pb^2+ species from aqueous solution.To implement the process,bentonite particles of submicro-meter size were used to first adsorb the heavy metal ions.These particles were subsequently trapped and removed by DEP.The effects of the adsorbent dosage,DEP cell voltage and the capture pool numbers on the removal rate were investigated in batch processes,which allowed us to determine the optimal experimental conditions.The high removal efficiency,97.3% and 99.9% for Cd^2+ and Pb^2+,respectively,were achieved when the ions are coexisting in the system.The microstructure of bentonite particles before and after ADS/DEP was examined by scanning electron microscopy.Our results suggest that the dielectrophoresis-assisted adsorption method has a high capability to remove the heavy metals from wastewater.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)started physics data taking on 26 August 2025.JUNO consists of a 20-kton liquid scintillator central detector,surrounded by a 35 kton water pool serving as a Cherenko...The Jiangmen Underground Neutrino Observatory(JUNO)started physics data taking on 26 August 2025.JUNO consists of a 20-kton liquid scintillator central detector,surrounded by a 35 kton water pool serving as a Cherenkov veto,and almost 1000 m^(2) of plastic scintillator veto on top.The detector is located in a shallow underground laboratory with an overburden of 1800 m.w.e.This paper presents the performance results of the detector,extensively studied during the commissioning of the water phase,the subsequent liquid scintillator filling phase,and the first physics runs.The liquid scintillator achieved an attenuation length of 20.6 m at 430 nm,while the high coverage PMT system and scintillator together yielded about 1785 photoelectrons per MeV of energy deposit at the detector centre,measured using the 2.223 MeVγfrom neutron captures on hydrogen with an Am-C calibration source.The reconstructed energy resolution is 3.4%for two 0.511 MeVγat the detector centre and 2.9%for the 0.93 MeV quenched ^(214)Po alpha decays from natural radioactive sources.The energy non-linearity is calibrated to better than 1%.Intrinsic contaminations of ^(238)U and ^(232)Th in the liquid scintillator are below 10^(-16) g/g,assuming secular equilibrium.The water Cherenkov detector achieves a muon detection efficiency better than 99.9%for muons traversing the liquid scintillator volume.During the initial science runs,the data acquisition duty cycle exceeded 97.8%,demonstrating the excellent stability and readiness of JUNO for high-precision neutrino physics.展开更多
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 by the National Natural Science Foundation of China(Grant Nos.12422402,61888102,and 12274447)the National Key R&D Program of China(Grant No.2021YFA1202900)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB0470101)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2021B0301030002)。
文摘One-dimensional(1D)transition-metal dichalcogenide(TMDC)nanoribbons are appealing for a plethora of emergent physics and innovative high-tech applications unattainable with their two-dimensional(_(2)D)and bulk counterparts.Despite notable progress in synthesizing TMDC monolayer nanoribbons,the production of TMDC heterostructure nanoribbons,which can integrate the best characteristics of the constituent monolayers,remains elusive.
基金the National Major Science and Technology Program for Water Pollution Control and Treatment(No.2017ZX07101-002)the Fundamental Research Funds for the Central Universities(No.2016SHXY06)the National Natural Science Foundation of China(Grant No.51609271).
文摘Dielectrophoresis(DEP)was combined with adsorption(ADS)to simultaneously and effectively remove Cd^2+ and Pb^2+ species from aqueous solution.To implement the process,bentonite particles of submicro-meter size were used to first adsorb the heavy metal ions.These particles were subsequently trapped and removed by DEP.The effects of the adsorbent dosage,DEP cell voltage and the capture pool numbers on the removal rate were investigated in batch processes,which allowed us to determine the optimal experimental conditions.The high removal efficiency,97.3% and 99.9% for Cd^2+ and Pb^2+,respectively,were achieved when the ions are coexisting in the system.The microstructure of bentonite particles before and after ADS/DEP was examined by scanning electron microscopy.Our results suggest that the dielectrophoresis-assisted adsorption method has a high capability to remove the heavy metals from wastewater.
文摘The Jiangmen Underground Neutrino Observatory(JUNO)started physics data taking on 26 August 2025.JUNO consists of a 20-kton liquid scintillator central detector,surrounded by a 35 kton water pool serving as a Cherenkov veto,and almost 1000 m^(2) of plastic scintillator veto on top.The detector is located in a shallow underground laboratory with an overburden of 1800 m.w.e.This paper presents the performance results of the detector,extensively studied during the commissioning of the water phase,the subsequent liquid scintillator filling phase,and the first physics runs.The liquid scintillator achieved an attenuation length of 20.6 m at 430 nm,while the high coverage PMT system and scintillator together yielded about 1785 photoelectrons per MeV of energy deposit at the detector centre,measured using the 2.223 MeVγfrom neutron captures on hydrogen with an Am-C calibration source.The reconstructed energy resolution is 3.4%for two 0.511 MeVγat the detector centre and 2.9%for the 0.93 MeV quenched ^(214)Po alpha decays from natural radioactive sources.The energy non-linearity is calibrated to better than 1%.Intrinsic contaminations of ^(238)U and ^(232)Th in the liquid scintillator are below 10^(-16) g/g,assuming secular equilibrium.The water Cherenkov detector achieves a muon detection efficiency better than 99.9%for muons traversing the liquid scintillator volume.During the initial science runs,the data acquisition duty cycle exceeded 97.8%,demonstrating the excellent stability and readiness of JUNO for high-precision neutrino physics.
