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Exploring Antarctic subglacial lakes with RECoverable Autonomous Sonde(RECAS):Design and first field tests

Science China(Technological Sciences) 2024年第6期67卷 1866-1878页

作者： SUN YouHong PAVEL Talalay LI YuanSheng YU HaiBin WANG DongLiang LI GuoPing XU LiPing GONG Da WANG JiXin WANG JianHua WANG Ting ZHANG Nan WANG ZhiGang CHEN YanJi LIU YunChen LI YaZhou PENG ShiLin SHI JianGuang AN ChunLei GE Qun XU Jing NI XiaoKang CUI QiFeng JIANG Qiang MIKHAIL Sysoev Yang Yang WANG RuSheng WEI XianZhe WANG Yu ZHU TianXin DENG ZhiPeng ALEXEY Markov LI Bing FAN XiaoPeng Polar research center Jilin UniversityChangchun130000China School of Engineering and Technology China University of GeosciencesBeijing100083China Polar research Institute of China Shanghai200120China College of Electronics and Information Hangzhou Dianzi UniversityHangzhou310018China Aerospace System Engineering Shanghai Shanghai201109China Nanjing Institute of astronomical Optics&Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing210000China National Ocean Technology center Tianjin300000China

Conducting scientific drilling on subglacial lakes and obtaining samples of subglacial lake water holds great significance in unraveling the formation and evolution of Antarctic subglacial lakes and early Earth's life *** various approaches to access and directly sample subglacial water and sediments,clean access and exploration of subglacial lakes remain *** address this concern,Jilin University has developed the RECoverable Autonomous Sonde(RECAS)*** technology enables sampling and in-situ detection of subglacial lake water while being isolated from the surface,thus minimizing the risk of *** tests,including downward and upward drilling,long-running,remote-control,and cold-environment assessments,were conducted to validate the sonde's principle and *** the 38th Chinese National Antarctic research Expedition,CHINARE(2021–2022 season),the RECAS prototype underwent testing on the flank region of Dalk glacier,10 km from Zhongshan Station in *** boreholes with depths of 200.3,183.2,and 133.5 m were successfully drilled,with the refrozen meltwater sealing the boreholes during the *** 600 mL of melted water samples were collected from each *** the drilling tests,all systems of the RECAS prototype performed within the expected ranges.

关键词： subglacial lake thermal drilling water sampling Antarctic autonomous sonde

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UWLPIPE: Ultra-wide Bandwidth Low-frequency Pulsar Data Processing Pipeline

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research in Astronomy and Astrophysics 2024年第7期24卷 148-160页

作者： Ya-Zhou Zhang Hai-Long Zhang Jie Wang Jian Li Xin-Chen Ye Shuang-Qiang Wang Xu Du Han Wu Ting Zhang Shao-Cong Guo Xinjiang astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences National astronomical Data center Southeast University

For real-time processing of ultra-wide bandwidth low-frequency pulsar baseband data, we designed and implemented an ultra-wide bandwidth low-frequency pulsar data processing pipeline(UWLPIPE) based on the shared ringbuffer and GPU parallel technology. UWLPIPE runs on the GPU cluster and can simultaneously receive multiple 128 MHz dual-polarization VDIF data packets preprocessed by the front-end FPGA. After aligning the dual-polarization data, multiple 128M subband data are packaged into PSRDADA baseband data or multi-channel coherent dispersion filterbank data, and multiple subband filterbank data can be spliced into wideband data after time alignment. We used the Nanshan 26 m radio telescope with the L-band receiver at964 ～ 1732 MHz to observe multiple pulsars. Finally, we processed the data using DSPSR software, and the results showed that each subband could correctly fold out the pulse profile, and the wideband pulse profile accumulated by multiple subbands could be correctly aligned.

关键词： (stars:) pulsars: general methods: data analysis techniques: miscellaneous

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Spectral Fittings of Warm Coronal Radiation with High Seed Photon Temperature: Apparent Low-temperature and Flat Soft Excess in AGNs

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research in Astronomy and Astrophysics 2024年第7期24卷 138-147页

作者： Ze-Yuan Tang Jun-Jie Feng Jun-Hui Fan School of Mathematics and Information Science Guangzhou University center for Astrophysics Guangzhou University Astronomy Science and Technology research Laboratory of Department of Education of Guangdong Province Key Laboratory for astronomical Observation and Technology of Guangzhou

A warm corona has been widely proposed to explain the soft excess （SE） in X-ray above the 2–10 ke V power law extrapolation in Active Galactic Nuclei （AGNs）.In actual spectral fittings,the warm coronal seed photon temperature（Ts） is usually assumed to be far away from the soft X-ray,but kTscan reach close to 0.1 ke V in the standard accretion disk *** this study,we used Monte Carlo simulations to obtain radiation spectra from a slab-like warm corona and fitted the spectra using the spherical-geometry-based routine THCOMP or a thermal *** findings reveal tha high Tscan influence the fitting results.A moderately high kTs（around 0.03 ke V） can result in an apparent low-temperature and flat SE,while an extremely high kTs（around 0.07 ke V） can even produce an unobserved blackbody-like *** conclusions indicate that,for spectral fittings of the warm coronal radiation （SE in AGNs）,kTsshould be treated as a free parameter with an upper limit,and an accurate coronal geometry is necessary when kTs>0.01 ke V.

关键词： accretion accretion disks black hole physics galaxies: active

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XGCN:a library for large-scale graph neural network recommendations

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Frontiers of Computer Science 2024年第3期18卷 247-249页

作者： Xiran SONG Hong HUANG Jianxun LIAN Hai JIN National Engineering research center for Big Data Technology and System Services Computing Technology and System LabCluster and Grid Computing LabSchool of Computer Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China Microsoft research Asia Beijing 100080China

1 Introduction Graph Neural Networks(GNNs)have gained widespread adoption in recommendation systems,and nowadays there is a pressing need to effectively manage large-scale graph data[1].When it comes to large graphs,GNNs may encounter the scalability issue stemming from their multi-layer messagepassing ***,scaling GNNs has emerged as a crucial research area in recent years,with numerous scaling strategies being proposed.

关键词： scaling gained operations

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Digitization of astronomical Photographic Plates of China and Astrometric Measurement of Single-exposure Plates

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research in Astronomy and Astrophysics 2024年第5期24卷 103-116页

作者：商正君于涌王亮亮杨美婷杨静沈世银刘敏徐权峰崔辰州樊东卫唐正宏赵建海 Shanghai astronomical Observatory Chinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Key Lab for Astrophysics Shanghai200234China National astronomical Observatories Chinese Academy of SciencesBeijing 100101China National astronomical Data center Chinese Academy of SciencesBeijing 100101China

From the mid-19th century to the end of the 20th century, photographic plates served as the primary detectors for astronomical observations. astronomical photographic observations in China began in 1901, and over a century, a total of approximately 30,000 astronomical photographic plates were captured. These historical plates play an irreplaceable role in conducting long-term, time-domain astronomical research. To preserve and explore these valuable original astronomical observational data, Shanghai astronomical Observatory has organized the transportation of plates, taken during nighttime observations from various stations across the country, to the Sheshan Plate Archive for centralized preservation. For the first time, plate information statistics were calculated. On this basis, the plates were cleaned and digitally scanned, and finally digitized images were acquired for 29,314 plates. In this study, using Gaia DR2 as the reference star catalog, astrometric processing was carried out successfully on 15,696 single-exposure plates, including object extraction, stellar identification,and plate model computation. As a result, for long focal length telescopes, such as the 40 cm double-tube refractor telescope, the 1.56 m reflector telescope at Shanghai astronomical Observatory, and the 1m reflecting telescope at Yunnan astronomical Observatory, the astrometric accuracy obtained for their plates is approximately 0."1–0."3. The distribution of astrometric accuracy for medium and short focal length telescopes ranges from 0."3 to 1."0. The relevant data of this batch of plates, including digitized images and a stellar catalog of the plates, are archived and released by the National astronomical Data center. Users can access and download plate data based on keywords such as station, telescope, observation year, and observed celestial coordinates.

关键词： methods data analysis-techniques image processing-astronomical databases miscellaneous-astrometry

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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 177-197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 Sciences University of Chinese Academy of Sciences National astronomical Data center

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 stars: variables: general X-rays: binaries X-rays: bursts

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astronomical Knowledge Entity Extraction in Astrophysics Journal Articles via Large Language Models

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research in Astronomy and Astrophysics 2024年第6期24卷 140-155页

作者： Wujun Shao Rui Zhang Pengli Ji Dongwei Fan Yaohua Hu Xiaoran Yan Chenzhou Cui Yihan Tao Linying Mi Lang Chen National astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China National astronomical Data center Beijing 100101China research Institute of Artificial Intelligence Zhejiang LabHangzhou 311100China Guilin University Guangxi 541006China Xidian University Xi’an 710126China

astronomical knowledge entities,such as celestial object identifiers,are crucial for literature retrieval and knowledge graph construction,and other research and applications in the field of *** methods of extracting knowledge entities from texts face numerous challenging obstacles that are difficult to ***,there is a pressing need for improved methods to efficiently extract *** study explores the potential of pre-trained Large Language Models(LLMs)to perform astronomical knowledge entity extraction(KEE)task from astrophysical journal articles using *** propose a prompting strategy called PromptKEE,which includes five prompt elements,and design eight combination prompts based on *** select four representative LLMs(Llama-2-70B,GPT-3.5,GPT-4,and Claude 2)and attempt to extract the most typical astronomical knowledge entities,celestial object identifiers and telescope names,from astronomical journal articles using these eight combination *** accommodate their token limitations,we construct two data sets:the full texts and paragraph collections of 30 *** the eight prompts,we test on full texts with GPT-4and Claude 2,on paragraph collections with all *** experimental results demonstrate that pre-trained LLMs show significant potential in performing KEE tasks,but their performance varies on the two data ***,we analyze some important factors that influence the performance of LLMs in entity extraction and provide insights for future KEE tasks in astrophysical articles using ***,compared to other methods of KEE,LLMs exhibit strong competitiveness in multiple aspects.

关键词： astronomical databases:miscellaneous virtual observatory tools methods:data analysis

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A hybrid memory architecture supporting fine-grained data migration

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Frontiers of Computer Science 2024年第2期18卷 31-41页

作者： Ye CHI Jianhui YUE Xiaofei LIAO Haikun LIU Hai JIN National Engineering research center for Big Data Technology and System Services Computing Technology and System LabCluster and Grid Computing LabSchool of Computer Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China Department of Computer Science Michigan Technological UniversityMichigan 49931USA

Hybrid memory systems composed of dynamic random access memory(DRAM)and Non-volatile memory(NVM)often exploit page migration technologies to fully take the advantages of different memory *** previous proposals usually migrate data at a granularity of 4 KB pages,and thus waste memory bandwidth and DRAM *** this paper,we propose Mocha,a non-hierarchical architecture that organizes DRAM and NVM in a flat address space physically,but manages them in a cache/memory *** the commercial NVM device-Intel Optane DC Persistent Memory Modules(DCPMM)actually access the physical media at a granularity of 256 bytes(an Optane block),we manage the DRAM cache at the 256-byte size to adapt to this feature of *** design not only enables fine-grained data migration and management for the DRAM cache,but also avoids write amplification for Intel Optane *** also create an Indirect Address Cache(IAC)in Hybrid Memory Controller(HMC)and propose a reverse address mapping table in the DRAM to speed up address translation and cache ***,we exploit a utility-based caching mechanism to filter cold blocks in the NVM,and further improve the efficiency of the DRAM *** implement Mocha in an architectural *** results show that Mocha can improve application performance by 8.2%on average(up to 24.6%),reduce 6.9%energy consumption and 25.9%data migration traffic on average,compared with a typical hybrid memory architecture-HSCC.

关键词： non-volatile memory hybrid memory system data migration fine-grained caching

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Text Difficulty Study:Do Machines Behave the Same as Humans Regarding Text Difficulty?

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Machine Intelligence research 2024年第2期21卷 283-293页

作者： Bowen Chen Xiao Ding Yi Zhao Bo Fu Tingmao Lin Bing Qin Ting Liu research center for Social computing and Information Retrieval Harbin Institute of TechnologyHarbin 150001China Fundamental Technology center China Construction Bank Financial Technology Co.Ltd.Beijing 100033China

With the emergence of pre-trained models,current neural networks are able to give task performance that is comparable to ***,we know little about the fundamental working mechanism of pre-trained models in which we do not know how they approach such performance and how the task is solved by the *** example,given a task,human learns from easy to hard,whereas the model learns ***,difficulty-insensitive learning leads to great success in natural language processing(NLP),but little attention has been paid to the effect of text difficulty in *** propose a human learning matching index(HLM Index)to investigate the effect of text *** results show:1)LSTM gives more human-like learning behavior than ***,UID-SuperLinear gives the best evaluation of text difficulty among four text difficulty *** nine tasks,some tasks’performance is related to text difficulty,whereas others are not.2)Model trained on easy data performs best in both easy and medium test data,whereas trained on hard data only performs well on hard test data.3)Train the model from easy to hard,leading to quicker convergence.

关键词： Cognition inspired natural language processing psycholinguistics explainability text difficulty curriculum learning

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Long-term Integration Ability of the Submillimeter Wave Astronomy Satellite(SWAS)Spectral Line Receivers

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research in Astronomy and Astrophysics 2024年第6期24卷 315-322页

作者： Bing-Ru Wang Di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Rudolf Schieder Gary J.Melnick National astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China research center for astronomical computing Zhejiang LaboratoryHangzhou 311100China Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China KOSMA I.Physik.InstitutUniversität zu KölnZülpicher Str.7750937 KölnGermany center for Astrophysics|Harvard&Smithsonian 60 Garden StreetMS 66CambridgeMA 02138USA

The Submillimeter Wave Astronomy Satellite(SWAS)was the first space telescope capable of high spectral resolution observations of terahertz spectral *** have investigated the integration ability of its two receivers and spectrometer during five and a half years of on-orbit *** CI,O_(2),H_(2)O,and^(13)CO spectra taken toward all observed Galactic sources were *** present results are based on spectra with a total integration time of up to 2.72×10~4hr(■10~8s).The noise in the spectra is generally consistent with that expected from the radiometer equation,without any sign of approaching a noise *** noise performance reflects the extremely stable performance of the passively cooled front end as well as other relevant components in the SWAS instrument throughout its mission lifetime.

关键词： telescopes space vehicles:instruments instrumentation:miscellaneous ISM:lines and bands

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