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3DT-CM: A Low-complexity Cross-matching Algorithm for Large astronomical Catalogues Using 3d-tree Approach

Research in Astronomy and Astrophysics 2023年第10期23卷 324-334页

作者： Yifei Mu Ce Yu Chao Sun Kun Li Yajie Zhang Jizeng Wei Jian Xiao Jie Wang College of Intelligence and Computing Tianjin UniversityTianjin 300350China Technical R&D Innovation center National Astronomical Data CenterTianjin 300350China Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

Location-based cross-matching is a preprocessing step in astronomy that aims to identify records belonging to the same celestial body based on the angular distance formula. The traditional approach involves comparing each record in one catalog with every record in the other catalog, resulting in a one-to-one comparison with high computational complexity. To reduce the computational time, index partitioning methods are used to divide the sky into regions and perform local cross-matching. In addition, cross-matching algorithms have been adopted on highperformance architectures to improve their efficiency. But the index partitioning methods and computation architectures only increase the degree of parallelism, and cannot decrease the complexity of pairwise-based crossmatching algorithm itself. A better algorithm is needed to further improve the performance of cross-matching algorithm. In this paper, we propose a 3d-tree-based cross-matching algorithm that converts the angular distance formula into an equivalent 3dEuclidean distance and uses 3d-tree method to reduce the overall computational complexity and to avoid boundary issues. Furthermore, we demonstrate the superiority of the 3d-tree approach over the 2d-tree method and implement it using a multi-threading technique during both the construction and querying phases. We have experimentally evaluated the proposed 3d-tree cross-matching algorithm using publicly available catalog data. The results show that our algorithm applied on two 32-core CPUs achieves equivalent performance than previous experiments conducted on a six-node CPU-GPU cluster.

关键词： methods:data analysis catalogs techniques:miscellaneous

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The research objectives and observational possibilities for fast moving near-Earth asteroids

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Research in Astronomy and Astrophysics 2021年第7期21卷 199-208页

作者： Anton Pomazan Zheng-Hong Tang Nadiia Maigurova Kai Tang Yong Yu Yin-Dun Mao Shanghai astronomical Observatory Chinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Research Institute“Mykolaiv astronomical Observatory” Mykolaiv 54030Ukraine

The paper describes observations of fast-moving near-Earth asteroids(NEAs) made with the small ground-based telescopes of national Time Service center of Chinese Academy of Science(NTSC of CAS) and Research Institute "Mykolaiv astronomical Observatory"(RI MAO) by the rotating-drift-scan CCD(RDS CCD) technique. This technique is used to obtain the point images of both the studied objects and reference stars. The results of ongoing follow-up observations of NEAs are discussed. The residual differences(O-C) between the observed and calculated positions from JPL ephemeris were generally small for these asteroids. The standard deviations of these differences were typically ±(0.2′′-0.3′′) in both coordinates for objects with apparent velocity which substantially exceed FWHM for the given exposure time. The results of comparative statistics for such observations from the MPC database show that this is a good level of precision for NEAs. Moreover, the telescopes with the RDS CCD technique implemented can observe the NEAs that closely approach the Earth and with enough observations can improve the precision of determining their orbital elements and impact predictions.

关键词： astronomical databases:miscellaneous surveys methods:observational techniques:miscellaneous astrometry minor planets asteroids:general

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Simulation analysis of a method to improve data-transmission performance of Nanshan 26 m Radio Telescope based on Software-Defined Networks

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Research in Astronomy and Astrophysics 2021年第11期21卷 79-88页

作者： Jie Wang Hai-Long Zhang Na Wang Xin-Chen Ye Wan-Qiong Wang Jia Li Meng Zhang Ya-Zhou Zhang Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China national astronomical data center Beijing 100101China

data center of Xinjiang astronomical Observatory(XAO-DC)commenced operating in 2015,and provides services including archiving,releasing and retrieving precious astronomical data collected by the Nanshan 26 m Radio Telescope(NSRT)over the years,and realises the open sharing of astronomical observation *** observation data from NSRT are transmitted to XAO-DC 100 km away through dedicated fiber for long-term *** the continuous increase of data,the static architecture of the current network cannot meet NSRT data-transmission requirements due to limited network *** get high-speed data-transmission using the existing static network architecture,a method for reconstruction data-transmission network using Software-Defined Networks(SDN)is *** from the SDN’s data and control plane separation,and open programmable,combined with the Mininet simulation platform for experiments,the TCP throughput(of single thread)was improved by~24.7%,the TCP throughput(of multi threads)was improved by~9.8%,~40.9%,~35.5%and~11.7%.Compared with the current network architecture,the Latency was reduced by~63.2%.

关键词： data transmission observation data data center virtual machine

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X-Ray Source Classification Using Machine Learning:A Study with EP-WXT Pathfinder LEIA

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Research in Astronomy and Astrophysics 2024年第8期24卷 175-195页

作者： Xiaoxiong Zuo Yihan Tao Yuan Liu Yunfei Xu Wenda Zhang Haiwu Pan Hui Sun Zhen Zhang Chenzhou Cui Weimin Yuan national astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China national astronomical data center Beijing 100101China

X-ray observations play a crucial role in time-domain *** Einstein Probe(EP),a recently launched X-ray astronomical satellite,emerges as a forefront player in the field of time-domain astronomy and high-energy *** a focus on systematic surveys in the soft X-ray band,EP aims to discover high-energy transients and monitor variable sources in the *** achieve these objectives,a quick and reliable classification of observed sources is *** this study,we developed a machine learning classifier for autonomous source classification using data from the EP-WXT Pathfinder—Lobster Eye Imager for Astronomy(LEIA)and EP-WXT *** proposed Random Forest classifier,built on selected features derived from light curves,energy spectra,and location information,achieves an accuracy of approximately 95%on EP simulation data and 98%on LEIA observational *** classifier is integrated into the LEIA data processing pipeline,serving as a tool for manual validation and rapid classification during *** paper presents an efficient method for the classification of X-ray sources based on single observations,along with implications of most effective features for the *** work facilitates rapid source classification for the EP mission and also provides valuable insights into feature selection and classification techniques for enhancing the efficiency and accuracy of X-ray source classification that can be adapted to other X-ray telescope data.

关键词： methods data analysis-X-rays binaries-stars variables general-X-rays bursts

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Single-cell omics: experimental workflow, data analyses and applications

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Science china Life Sciences 2025年第1期68卷 5-102页

作者： Fengying Sun Haoyan Li Dongqing Sun Shaliu Fu Lei Gu Xin Shao Qinqin Wang Xin Dong Bin Duan Feiyang Xing Jun Wu Minmin Xiao Fangqing Zhao Jing-Dong J.Han Qi Liu Xiaohui Fan Chen Li Chenfei Wang Tieliu Shi Department of Clinical Laboratory the Affiliated Wuhu Hospital of East China Normal University (The Second People's Hospital of Wuhu City) Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang University Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University) Ministry of EducationOrthopaedic DepartmentTongji HospitalBioinformatics DepartmentSchool of Life Sciences and TechnologyTongji University Frontier Science center for Stem Cells School of Life Sciences and TechnologyTongji University Translational Medical center for Stem Cell Therapy and Institute for Regenerative Medicine Shanghai East HospitalBioinformatics DepartmentSchool of Life Sciences and TechnologyTongji University Research Institute of Intelligent Computing Zhejiang Lab Shanghai Research Institute for Intelligent Autonomous Systems center for Single-cell Omics School of Public HealthShanghai Jiao Tong University School of Medicine national Key Laboratory of Chinese Medicine Modernization Innovation Center of Yangtze River DeltaZhejiang University center for Bioinformatics and Computational Biology Shanghai Key Laboratory of Regulatory Biologythe Institute of Biomedical Sciences and School of Life SciencesEast China Normal University Beijing Institutes of Life Science Chinese Academy of Sciences Peking-Tsinghua center for Life Sciences Academy for Advanced Interdisciplinary StudiesCenter for Quantitative Biology (CQB)Peking University Zhejiang Key Laboratory of Precision Diagnosis and Therapy for Major Gynecological Diseases Women's HospitalZhejiang University School of Medicine Key Laboratory of Advanced Theory and Application in Statistics and data Science-MOE School of StatisticsEast China Normal University

Cells are the fundamental units of biological systems and exhibit unique development trajectories and molecular features. Our exploration of how the genomes orchestrate the formation and maintenance of each cell, and control the cellular phenotypes of various organismsis, is both captivating and intricate. Since the inception of the first single-cell RNA technology, technologies related to single-cell sequencing have experienced rapid advancements in recent years. These technologies have expanded horizontally to include single-cell genome, epigenome,proteome, and metabolome, while vertically, they have progressed to integrate multiple omics data and incorporate additional information such as spatial sc RNA-seq and CRISPR screening. Single-cell omics represent a groundbreaking advancement in the biomedical field,offering profound insights into the understanding of complex diseases, including cancers. Here, we comprehensively summarize recent advances in single-cell omics technologies, with a specific focus on the methodology section. This overview aims to guide researchers in selecting appropriate methods for single-cell sequencing and related data analysis.

关键词： single-cell sequencing genome epigenome proteomics metabolomics multimodal spatial transcriptomics CRISPR screening

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Research on a Coherent Dedispersion Algorithm for Pulsar Baseband data

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Research in Astronomy and Astrophysics 2023年第1期23卷 285-295页

作者： Hai-Long Zhang Ya-Zhou Zhang Meng Zhang Jie Wang Ting Zhang Shuang-Qiang Wang Jian-ping Yuan Xin-Chen Ye Jian Li Xinjiang astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China national astronomical data center Beijing 100101China College of Physics and Astronomy China West Normal UniversityNanchong 637002China

When the pulsar signal propagates in the interstellar medium(ISM),the high frequency and low frequency components of the signal reach the radio telescope with a certain ***,the pulsar signal will appear energy dispersion,which will broaden the pulse profile,decrease the signal to noise ratio,and even lead to the disappearance of the pulse *** this paper,we analyze the sampling,polarization and arrangement of baseband data based on the coherent dedispersion algorithm for the problem of pulsar baseband data *** systematically study the coherent dedispersion data processing procedure,and test the pulse profile changes under different FFT block *** optimal selection strategy of FFT block sizes is proposed for reducing the operation time and obtaining a better pulse *** propose two methods,one is the generation of ISM transfer function,the other is the pulsar period and phase prediction method at a certain time,and discuss integral and folding *** test the algorithm based on the baseband data of CASPSR and Medusa terminals observed by the Parkes 64 m radio telescope,and analyze the reading and processing methods of baseband data of different *** experimental results show that the phase and amplitude information of the pulse profile processed by our algorithm is basically consistent with the results obtained by DSPSR.

关键词： pulsar -coherent dedispersion -baseband data -pulse profile

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Cross-section measurements for the^(58,60,61)Ni(n,α)^(55,57,58)Fe reactions at 8.50,9.50 and 10.50 MeV neutron energies

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Chinese Physics C 2022年第2期46卷 70-78页

作者： Haoyu Jiang Zengqi Cui Yiwei Hu Jie Liu Haofan Bai Jinxiang Chen Guohui Zhang Yu.M.Gledenov E.Sansarbayar G.Khuukhenkhuu L.Krupa I.Chuprakov Xichao Ruan Hanxiong Huang Jie Ren Qiwen Fan State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion PhysicsSchool of PhysicsPeking UniversityBeijing 100871China Frank Laboratory of Neutron Physics Joint Institute for Nuclear ResearchDubna 141980Russia Nuclear Research Centre National University of MongoliaUlaanbaatarMongolia Flerov Laboratory of Nuclear Reactions Joint Institute for Nuclear ResearchDubna 141980Russia Institute of Experimental and Applied Physics Czech Technical University in PragueHorska 3a/22Prague 212800Czech Republic L.N.Gumilyov Eurasian national University Nur-sultan 010000Kazakhstan The Institute of Nuclear Physics Ministry of Energy of the Republic of KazakhstanAlmaty 050032Kazakhsta china Institute of Atomic Energy Beijing 102413China

Cross sections of the^(58,60,61)Ni(n,α)^(55,57,58)Fe reactions were measured at 8.50,9.50 and 10.50 MeV neutron energies based on the HI-13 tandem accelerator of china Institute of Atomic Energy(CIAE)with enriched^(58)Ni,^(60)Ni,and^(61)Ni foil samples with backings.A twin gridded ionization chamber(GIC)was used as the charged particle detector,and an EJ-309 liquid scintillator was used to obtain the neutron energy *** relative and absolute neutron fluxes were determined via three highly enriched^(238)U_(3)O_(8)samples inside the *** uncertainty of the present data of the^(58)Ni(n,α)^(55)Fe reaction is smaller than most existing *** present data of^(60)Ni(n,α)^(57)Fe and^(61)Ni(n,α)^(58)Fe reactions are the first measurement results above 8 *** present experimental data could be reasonably reproduced by calculations with TALYS-1.9 by adjusting several default values of theoretical model parameters.

关键词： cross-section measurements ^(58 60 61)Ni(n α)^(55 57 58) GIC CIAE

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Cross-section measurements for 58,60,61Ni(n,α)55,57,58Fe reactions in the 4.50-5.50 MeV neutron energy region

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Chinese Physics C 2020年第11期44卷 138-149页

作者： Haoyu Jiang Zengqi Cui Yiwei Hu Jie Liu Jinxiang Chen Guohui Zhang Yu.M.Gledenov E.Sansarbayar G.Khuukhenkhuu L.Krupa I.Chuprakov State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion PhysicsPeking UniversityBeijing 100871China Frank Laboratory of Neutron Physics Joint Institute for Nuclear ResearchDubna 141980Russia Nuclear Research Centre National University of MongoliaUlaanbaatar 210646Mongolia Flerov Laboratory of Nuclear Reactions Joint Institute for Nuclear ResearchDubna 141980Russia Institute of Experimental and Applied Physics Czech Technical University in PragueHorska 3a/22Prague 212800Czech Republic

The cross sections at 5 energy points of the 58Ni(n,α)55Fe reaction were measured in the 4.50 MeV≤En≤5.50 MeV region while those for the 60Ni(n,α)57Fe and 61Ni(n,α)58Fe reactions were measured at En=5.00 and 5.50 MeV using the 4.5 MV Van de Graaff accelerator at Peking University.A gridded twin ionization chamber(GIC)was used as the detector,and enriched 58Ni,60Ni,and 61Ni foil samples were prepared and mounted at the sample changer of the *** highly enriched 238U3O8 samples inside the GIC were used to determine the relative and absolute neutron *** neutron energy spectra were obtained through unfolding the pulse height spectra measured by the EJ-309 liquid *** interference from the low-energy neutrons and impurities in the samples has been *** present data of the 60Ni(n,α)57Fe reaction are the first measurement results below 6.0 MeV,and those of the 61Ni(n,α)58Fe reactions are the first measurement results in the MeV *** present results have been compared with existing measurements,evaluations,and TALYS-1.9 calculations.

关键词： 58,60,61Ni(n,α)55,57,58Fe reactions cross sections GIC

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Chemical abundances of three new Ba stars from the Keck/HIRES spectra

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Research in Astronomy and Astrophysics 2021年第11期21卷 67-78页

作者： Shuai Liu Liang Wang Jian-Rong Shi Zhen-Yu Wu Hong-Liang Yan Qi Gao Chun-Qian Li CAS 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 national astronomical Observatories/Nanjing Institute of astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyChinese Academy of SciencesNanjing 210042China

Based on high resolution,high signal-to-noise(S/N)ratio spectra from Keck/HIRES,we have determined abundances of 20 elements for 18 Ba *** parameter space of these stars is in the range of 4880≤Teff≤6050 K,2.56≤log g≤4.53 dex and-0.27≤[Fe/H]≤0.09 *** is found that four of them can be identified as Ba stars with[s/Fe]>0.25 dex(s:Sr,Y,Zr,Ba,La,Ce and Nd),and three of them are newly discovered,which include two Ba giants(HD 16178 and HD 22233)and one Ba subgiant(HD 2946).Our results show that the abundances ofα,odd and iron-peak elements(O,Na,Mg,Al,Si,Ca,Sc,Ti,Mn,Ni and Cu)for our program stars are similar to those of the thin disk,while the distribution of[hs/ls](hs:Ba,La,Ce and Nd,ls:Sr,Y and Zr)ratios of our Ba stars is similar to those of the known Ba *** of the four Ba stars show clear enhancement in carbon including the known CH subgiant HD *** is found that three of the Ba stars present clear evidence of hosting stellar or sub-stellar companions from the radial velocity data.

关键词： Galaxy Ba stars Chemical abundances Binary

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A thin film ^(10)B sample for measuring the atom number

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Nuclear Science and Techniques 2010年第2期21卷 114-117页

作者： ZHANG Jiaguo WU Hao ZHANG Guohui State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion Physics Peking University Beo＇ing 100871 China

In order to measure differential cross sections of the 10B(n,α)7Li reaction induced by MeV neutrons using the forward-backward coincidence method, a thin film 10B sample was designed and the 10B atom number was determined with a reference 10B film sample. Alpha counts of the 10B(nth,α)7Li reaction from the 10B thin film and the reference sample were measured using a gridded ionization chamber and thermal neutrons, which were moderated and thermalized by paraffin from fast neutrons produced in D(d,n)3He reaction on a 4.5 MV Van de Graaff. The neutron flux was normalized by measuring the fission yield of a small 238U fission chamber.

关键词：样品测量薄膜样品原子数屏栅电离室核反应微分截面中子通量热中子

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