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Microphysical Characteristics of Rainfall Based on Long-Term Observations with a 2DVD in Yangbajain,Tibet

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Advances in Atmospheric Sciences 2024年第9期41卷 1721-1734页

作者： Ming LI Yongheng BI Yonghai SHEN Yinan WANG Ciren Nima Tianlu CHEN Daren LYU key laboratory for cosmic rays of the ministry of education Tibet UniversityLhasa 850000China key laboratory of Middle Atmosphere and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChinese Academy of ScienceBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Raindrop size distribution(DSD)plays a crucial role in enhancing the accuracy of radar quantitative precipitation estimates in the Tibetan Plateau(TP).However,there is a notable scarcity of long-term,high-resolution observations in this *** address this issue,long-term observations from a two-dimensional video disdrometer(2DVD)were leveraged to refine the radar and satellite-based algorithms for quantifying precipitation in the hinterland of the *** was observed that weak precipitation(R<1,mm h-1)accounts for 86%of the total precipitation time,while small raindrops(D<2 mm)comprise 99%of the total raindrop ***,the average spectral width of the DSD increases with increasing rain *** DSD characteristics of convective and stratiform precipitation were discussed across five different rain rates,revealing that convective precipitation in Yangbajain(YBJ)exhibits characteristics similar to maritime-like *** constrained relationships between the slopeΛand shapeμ,D_(m)and N_(w)of gamma DSDs were ***,we established a correlation between the equivalent diameter and drop axis ratio and found that raindrops on the TP attain a nearly spherical ***,the application of the rainfall retrieval algorithms of the dual-frequency precipitation radar in the TP is improved based on the statistical results of the DSD.

关键词： Tibetan Plateau raindrop size distribution 2DVD dual frequency radar microphysical features

Mid-infrared Period–Luminosity Relations of Gaia DR3 Long Period Variables

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Research in Astronomy and Astrophysics 2024年第7期24卷 59-73页

作者： Xiaohan Chen Xiaodian Chen Licai Deng Shu Wang Tianlu Chen Department of Physics College of ScienceTibet University key laboratory of cosmic rays (Tibet University) Ministry of Education CAS key laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences School of Astronomy and Space Science University of the Chinese Academy of Sciences Department of Astronomy China West Normal University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University

Long period variable（LPV） stars are very promising distance indicators in the infrared bands. We selected asymptotic giant branch（AGB） stars in the Large and Small Magellanic Cloud（LMC and SMC） from the Gaia Data Release 3 LPV catalog, and classified them into oxygen-rich（O-rich） and carbon-rich（C-rich） AGB *** the Wide-field Infrared Survey Explorer database, we determined the W1-and W2-band period–luminosity relations（PLRs） for each pulsation-mode sequence of AGB stars. The dispersion of the PLRs of O-rich AGB stars in sequences C' and C is relatively small, around 0.14 mag. The PLRs of LMC and SMC are consistent in each sequence. In the W2 band, the PLR of large-amplitude C-rich AGB stars is steeper than that of small-amplitude C-rich AGB stars, due to their more circumstellar dust. By two methods, we find that some PLR sequences of O-rich AGB stars in the LMC are dependent on metallicity. The coefficients of the metallicity effect are β = –0.533 ± 0.213 mag dex1and β = –0.767 ± 0.158 mag dex1for sequence C in W1 and W2 bands, respectively. The significance of the metallicity effect in W1 band for the four sequences is 2.2-3.5σ. Both of these imply that distance measurements using O-rich Mira may need to take the metallicity effect into account.

关键词： infrared: stars stars: distances stars: variables: general

Ultrafast pulse-dilation framing camera and its application for time-resolved X-ray diagnostic

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Nuclear Science and Techniques 2024年第7期35卷 101-114页

作者： Hou-Zhi Cai Qiu-Yan Luo Kai-Xuan Lin Xuan Deng Jun-Kai Liu Kai-Zhi Yang Dong Wang Jia-Jie Chen Jia-Heng Wang Jing-Hua Long Li-Hong Niu Yun-Fei Lei Jin-Yuan Liu key laboratory of Optoelectronic Devices and Systems of ministry of education and Guangdong Province Shenzhen Key Laboratory of Photonics and BiophotonicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China

An ultrafast framing camera with a pulse-dilation device,a microchannel plate(MCP)imager,and an electronic imaging system were *** camera achieved a temporal resolution of 10 ps by using a pulse-dilation device and gated MCP imager,and a spatial resolution of 100μm by using an electronic imaging system comprising combined magnetic *** spatial resolution characteristics of the camera were studied both theoretically and *** results showed that the camera with combined magnetic lenses reduced the field curvature and acquired a larger working area.A working area with a diameter of 53 mm was created by applying four magnetic lenses to the ***,the camera was used to detect the X-rays produced by the laser-targeting *** diagnostic results indicated that the width of the X-ray pulse was approximately 18 ps.

关键词： Inertial confinement fusion Plasma diagnostics Framing camera Combined lenses Pulse-dilation

Research on the knee region of cosmic ray by using a novel type of electron-neutron detector array

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Frontiers of physics 2024年第4期19卷 13-24页

作者： Bing-Bing Li Xin-Hua Ma Shu-Wang Cui Hao-Kun Chen Tian-Lu Chen Danzengluobu Wei Gao Hai-Bing Hu Denis Kuleshov Kirill Kurinov Hu Liu Mao-Yuan Liu Ye Liu Da-Yu Peng Yao-Hui Qi Oleg Shchegolev Yuri Stenkin Li-Qiao Yin Heng-Yu Zhang Liang-Wei Zhang College of Physics Hebei Normal UniversityShijiazhuang 050024China key laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China TIANFU cosmic Ray Research Center Chengdu 610000China College of Science Tibet UniversityLhasa 850000China key laboratory of Comic rays Ministry of EducationTibet UniversityLhasa 850000China Institute for Nuclear Research of the Russian Academy of Sciences Moscow 117312Russia School of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610031China School of Management Science and Engineering Hebei University of Economics and BusinessShijiazhuang 050061China Moscow Institute of Physics and Technology Moscow 141700Russia

By accurately measuring composition and energy spectrum of cosmic ray,the origin problem of so called“knee”region(energy>one PeV)can be ***,up to the present,the results of the spectrum in the knee region obtained by several previous experiments have shown obvious differences,so they cannot give effective evidence for judging the theoretical models on the origin of the ***,the Large High Altitude Air Shower Observatory(LHAASO)has reported several major breakthroughs and important results in astro-particle physics *** on its advantages of wide-sky survey,high altitude location and large area detector arrays,the research content of LHAASO experiment mainly includes ultra high-energy gamma-ray astronomy,measurement of cosmic ray spectra in the knee region,searching for dark matter and new phenomena of particle physics at higher *** electron and thermal neutron detector(EN-Detector)is a new scintillator detector which applies thermal neutron detection technology to measure cosmic ray extensive air shower(EAS).This technology is an extension of *** EN-Detector Array(ENDA)can highly efficiently measure thermal neutrons generated by secondary hadrons so called“skeleton”of *** this paper,we perform the optimization of ENDA configuration,and obtain expectations on the ENDA results,including thermal neutron distribution,trigger efficiency and capability of cosmic ray composition *** obtained real data results are consistent with those by the Monte Carlo simulation.

关键词： cosmic ray EAS knee region LHAASO ENDA

Muon energy reconstruction in the high-energy neutrino observations

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Astronomical Techniques and Instruments 2024年第3期1卷 197-202页

作者： Ying Qi Jiali Liu Maoyuan Liu Mingjun Chen Zike Wang Tianqi Huang Peiyuan Chu College of Science Tibet UniversityLhasa 850000China key laboratory of cosmic rays Ministry of EducationTibet UniversityLhasa 850000China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Tianfu cosmic Ray Research Center Chengdu 610000China University of Chinese Academy of Sciences Beijing 100049China

The reconstruction of muon energies is crucial for the data analysis of neutrino experiments using large water Cherenkov detectors,but the resolution for muon energy reconstruction using traditional methods is ***,we propose a revised approach to remove noisy optical modules along the track produced by the propagation of muons through *** number of photons on the optical modules is first corrected by the attenuation properties of light in *** the difference in time between the observed optical modules and the expected ones is determined based on the geometry of the triggered optical ***,the standard of correction is measured by the ratio of photon number before and after *** modules selection conditions were optimized according to these parameters,with most noisy optical modules successfully removed,improving the resolution of muon energy reconstruction.

关键词： dE/dx detectors Neutrino detectors Data processing

Application of deep learning methods combined with physical background in wide field of view imaging atmospheric Cherenkov telescopes

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Nuclear Science and Techniques 2024年第4期35卷 208-220页

作者： Ao-Yan Cheng Hao Cai Shi Chen Tian-Lu Chen Xiang Dong You-Liang Feng Qi Gao Quan-Bu Gou Yi-Qing Guo Hong-Bo Hu Ming-Ming Kang Hai-Jin Li Chen Liu Mao-Yuan Liu Wei Liu Fang-Sheng Min Chu-Cheng Pan Bing-Qiang Qiao Xiang-Li Qian Hui-Ying Sun Yu-Chang Sun Ao-Bo Wang Xu Wang Zhen Wang Guang-Guang Xin Yu-Hua Yao Qiang Yuan Yi Zhang School of Physics and Technology Wuhan UniversityWuhan 430072China School of Physics and Astronomy Yunnan UniversityKunming 650091China ministry of education The Key Laboratory of Cosmic Rays(Tibet University)Lhasa 850000China key laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences 19 A Yuquan RoadShijingshan DistrictBeijing 100049China College of Physics Sichuan UniversityChengdu 610064China School of Intelligent Engineering Shandong Management UniversityJinan 250357China Tsung‑Dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China Suzhou Aerospace Information Research Institute Suzhou 215123China College of Physics Chongqing UniversityNo.55 Daxuecheng South RoadHigh‑tech DistrictChongqing 401331China key laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210008China

The High Altitude Detection of Astronomical Radiation(HADAR)experiment,which was constructed in Tibet,China,combines the wide-angle advantages of traditional EAS array detectors with the high-sensitivity advantages of focused Cherenkov *** objective is to observe transient sources such as gamma-ray bursts and the counterparts of gravitational *** study aims to utilize the latest AI technology to enhance the sensitivity of HADAR *** datasets and models with distinctive creativity were constructed by incorporating the relevant physical theories for various *** models can determine the type,energy,and direction of the incident particles after careful *** obtained a background identification accuracy of 98.6%,a relative energy reconstruction error of 10.0%,and an angular resolution of 0.22°in a test dataset at 10 *** findings demonstrate the significant potential for enhancing the precision and dependability of detector data analysis in astrophysical *** using deep learning techniques,the HADAR experiment’s observational sensitivity to the Crab Nebula has surpassed that of MAGIC and *** energies below 0.5 TeV and remains competitive with conventional narrow-field Cherenkov telescopes at higher *** addition,our experiment offers a new approach for dealing with strongly connected,scattered data.

关键词： VHE gamma-ray astronomy HADAR Deep learning Convolutional neural networks

Variable Stars in the 50BiN Open Cluster Survey.Ⅲ.NGC 884

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Research in Astronomy and Astrophysics 2024年第2期24卷 36-45页

作者： Lin-Hong Wang Qian-Heng Nie Kun Wang Xiao-Dian Chen Chun-Guang Zhang Li-Cai Deng Xiao-Bin Zhang Tian-Lu Chen Department of Physics College of ScienceTibet UniversityLhasa 850000China key laboratory of cosmic rays Tibet UniversityMinistry of EducationLhasa 850000China key laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Middlesex School ConcordMassachusettsUnited States of America School of Physics and Astronomy China West Normal UniversityNanchong 637002China

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky *** stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host *** most powerful tool for such studies is time-domain photometric *** paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC *** target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally *** the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were *** detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown *** new variable stars were discovered in this *** also compared the variable star content of NGC 884 with its companion NGC 869.

关键词： stars variables general-(Galaxy:)open clusters and associations individual(…,…)-(stars:)binaries general

All-sky Guide Star Catalog for CSST

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Research in Astronomy and Astrophysics 2024年第4期24卷 35-59页

作者： Hui-Mei Feng Zi-Huang Cao Man I Lam Ran Li Hao Tian Da-Yi Yin Yuan-Yu Yang Xin Zhang Dong-Wei Fan Yi-Qiao Dong Xin-Feng Li Wei Wang Long Li Hugh RAJones Yi-Han Tao Jia-Lu Nie Pei-Pei Wang Mao-Yuan Liu He-jun Yang Chao Liu key laboratory of cosmic rays(Tibet University) Ministry of EducationLhasa 850000China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of ChineseAcademy of Sciences Beijing 100049China Shanghai Institute of Technical Physics Chinese Academy of SciencesShanghai200083China Technology and Engineering Center for Space Utilization.Chinese Academy of Sciences Beijing 100094China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Centre for Astrophysics University of HertfordshireHatfieldUK Beijing University of Technology Beijing 100124China

The China Space Station Telescope(CSST)is a two-meter space telescope with multiple back-end *** Fine Guidance Sensor(FGS)is an essential subsystem of the CSST Precision Image Stability System to ensure the required absolute pointing accuracy and line-of-sight *** this study,we construct the Main Guide Star Catalog for *** accomplish this,we utilize the information about the FGS and object information from the Gaia Data Release *** provide an FGS instrument magnitude and exclude variables,binaries,and high proper motion stars from the catalog to ensure uniform FGS guidance ***,we generate a HEALPix index,which provides a hierarchical tessellation of the celestial sphere,and employ the Voronoi algorithm to achieve a homogeneous distribution of stars across the *** distribution ensures adequate coverage and sampling of the *** performance of the CSST guide star catalog was assessed by simulating the field of view of the FGS according to the CSST mock survey strategy *** analysis of the results indicates that this catalog provides adequate coverage and *** catalog's performance meets the FGS requirements,ensuring the functioning of the FGS and its guidance capabilities.

关键词： catalogs astrometry instrumentation:detectors

The Influence of the Sun and Moon on the Observation of Very High Energy Gamma-ray Sources Using EAS Arrays

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Research in Astronomy and Astrophysics 2024年第6期24卷 245-252页

作者： Tao Wen Songzhan Chen Benzhong Dai School of Physics and Astronomy Yunnan UniversityKunming 650091China key laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Tianfu cosmic Ray Research Center Chengdu 610000China

With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the ***,the Sun and Moon would have some impacts on the observation of gamma-ray sources,which have not been taken into account in previous *** this paper,the influence of the Sun and Moon on the observation of very high energy gamma-ray sources when they are near the line of sight of the Sun or Moon is *** tracks of all the known VHE sources are scanned and several VHE sources are found to be very close to the line of sight of the Sun or Moon during some *** absorption of very high energy gamma rays by sunlight is estimated with detailed method and some useful conclusions are *** main influence is the block of the Sun and Moon on gamma rays and the shadow on the cosmic ray *** influence is investigated considering the detector angular resolution and some strategies on data analysis are proposed to avoid the underestimation of the gamma-ray emission.

关键词： astroparticle physics Sun:general methods:observational Sun:UV radiation