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Einstein Probe discovery of EP240408a: A peculiar X-ray transient with an intermediate timescale

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： Wenda Zhang Weimin Yuan Zhixing Ling Yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue Li Paul O’Brien Rongfeng shen Xinwen Shu shengli Sun Xiaojin Sun Xiaofeng Wang Lei Yang Bing Zhang Chen Zhang Shuang-Nan Zhang Yonghe Zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier Liming Dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan P.U.Fynbo Lluis Galbany Saurabh W.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang Liu Mingjun Liu Xing Liu Yuan Liu Zhu Liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao Junfeng Wang Song Wang Tinggui Wang Zhongxiang Wang Qingwen Wu xuefeng Wu Dong xu Yanjun xu Suijian xue Yongquan xue Zijian Zhang Zipei Zhu Hu Zou Congying bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui Yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Laidan Luo Jia Ma xuan Mao Haiwu Pan Xin Pan Liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao Wang Juan Wang Lei Wang Wenxin Wang Yilong Wang Yusa Wang Qinyu Wu Haitao xu Jingjing xu Xinpeng xu Yunfei xu Zhao xu Changbin xue Yulong xue Ailiang Yan Haonan Yang Xiongtao Yang Yanji Yang Juan Zhang Mo Zhang Wenjie Zhang Zhen Zhang Zhen Zhang Ziliang Zhang Donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Institute of Space Sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation Academy for Microsatellites Chinese Academy of Sciences Department of Physics University of Hong Kong School of Physics and Astronomy University of Leicester School of Physics and Astronomy Sun Yat-sen University Department of Physics Anhui Normal University Shanghai Institute of Technical Physics Chinese Academy of Sciences Physics Department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas Department of Physics and Astronomy University of Nevada Las Vegas South African Astronomical Observatory Department of Astronomy University of Cape Town Department of Physics University of the Free State Université Paris Cité CNRS Astroparticule et Cosmologie Université Paris Cité CEA Paris-Saclay IRFU/DAp-AIM Department of Astronomy Guangzhou University Cosmic Dawn Center (DAWN) Niels Bohr Institute University of Copenhagen Department of Physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research The University of Tokyo ESA/ESTEC Department of Astronomy School of Physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics The University of Sydney Department of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Department of Astronomy University of Science and Technology School of Astronomy and Space Sciences University of Science and Technology of China Institute of Deep Space Sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chi

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~Probe}}$

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New approach to eliminate structural redundancy in case resource pools using α mutual information

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Journal of Systems Engineering and Electronics 2013年第4期24卷 625-633页

作者： Man xu Haiyan Yu Jiang shen Department of Industrial Engineering Nankai University College of Management and Economics Tianjin University

Structural redundancy elimination in case resource pools （CRP） is critical for avoiding performance bottlenecks and maintaining robust decision capabilities in cloud computing services. For these purposes, this paper proposes a novel approach to ensure redundancy elimination of a reasoning system in CRP. By using α entropy and mutual information, functional measures to eliminate redundancy of a system are developed with respect to a set of outputs. These measures help to distinguish both the optimal feature and the relations among the nodes in reasoning networks from the redundant ones with the elimination criterion. Based on the optimal feature and its harmonic weight, a model for knowledge reasoning in CRP （CRPKR） is built to complete the task of query matching, and the missing values are estimated with Bayesian networks. Moreover, the robustness of decisions is verified through parameter analyses. This approach is validated by the simulation with benchmark data sets using cloud SQL. Compared with several state-of-the-art techniques, the results show that the proposed approach has a good performance and boosts the robustness of decisions.

关键词： case resource pool (CRP) knowledge reasoning redundancy elimination α mutual information robust decision.

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Aortic aneurysm and chronic disseminated intravascular coagulation： a retrospective study of 235 patients

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Frontiers of Medicine 2017年第1期11卷 62-67页

作者： Yun Zhang Chen Li Min shen bao Liu xuejun Zeng Ti shen Department of General Internal Medicine Peking Union Medical College Hospital Chinese Academy of Meclical Sciences and Peking Union Medical College Beijing 100730 China Department of Rheumatology Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100730 China Department of Vascular Surgery Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100730 China Department of Internal Medicine Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100730 China

Chronic disseminated intravascular coagulation （DIC） is a rare but devastating complication of aortic aneurysm （AA）. This study investigated the clinical manifestations, laboratory findings, and treatment of patients with AA-associated chronic DIC （AA-DIC） and explored the mechanisms, duration, and therapeutic response of AA-DIC. We retrospectively reviewed the medical records of 235 AA patients admitted at the Peking Union Medical College Hospital between September 2009 and January 2015. The patients were classified as those with DIC （AA-DIC） and those without DIC （non-DIC）. The AA-DIC group showed a significantly higher proportion of female patients and a significantly longer AA disease course than the non-DIC group did. The AA-DIC patients presented mural thrombi, dissecting aneurysms, a family history of AA, and diabetes significantly more frequently than the non-DIC patients did. Furthermore, multiple regression analyses revealed that sex, mural thrombus, aneurysm type, diabetes, and stent surgery are possible independent risk factors for AA-DIC patients. Fifty-two （22.1%） patients presented AA-DIC. Among these patients, 43 had non-typical DIC and 9 had typical DIC; the mortality rate of the latter was 22.2%. The mean age of the patients with typical DIC was significantly higher than of that of patients with non-typical DIC. The non-typical DIC patients also presented abnormal coagulation disorders of varying degrees. Furthermore, heparin or low-molecular-weight heparin improved the clinical symptoms and laboratory parameters in patients with AA and typical DIC. Thus, chronic DIC should be considered in patients with AA.

关键词： aortic aneurysm disseminated intravascular coagulation anticoagulation therapy

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Modified smoothed particle hydrodynamics approach for modelling dynamic contact angle hysteresis

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Acta Mechanica Sinica 2019年第3期35卷 472-485页

作者： Yanyao bao Ling Li Luming shen Chengwang Lei Yixiang Gan School of Civil Engineering University of SydneySydneyNSW 2006Australia

Dynamic wetting plays an important role in the physics of multiphase flow, and has a significant influence on many industrial and geotechnical applications. In this work, a modified smoothed particle hydrodynamics (SPH) model is employed to simulate surface tension, contact angle and dynamic wetting effects at meso-scale. The wetting and dewetting phenomena are simulated in a capillary tube, where the liquid particles are raised or withdrawn by a shifting substrate. The SPH model is modified by introducing a newly developed viscous force formulation at the liquid-solid interface to reproduce the rate-dependent behaviour of the moving contact line. Dynamic contact angle simulations with the interfacial viscous force are conducted to verify the effectiveness and accuracy of this new formulation. In addition, the influence of interfacial viscous forces with different magnitude on the contact angle dynamics is examined by empirical power-law correlations;the derived constants suggest that the dynamic contact angle changes monotonically with the interfacial viscous force. The simulation results are consistent with experimental observations and theoretical predictions, implying that the interfacial viscous force can be associated with the slip length of flow and the microscopic surface roughness. This work demonstrates that the modified SPH model can successfully account for the rate-dependent effects of a moving contact line, and can be used for realistic multiphase flow simulations under dynamic conditions.

关键词： Smoothed particle hydrodynamics Contact angle dynamics Capillary number Interfacial viscous force

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Hotspots of Photocatalytic Materials in 2020 Based on Big Data

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Chinese Journal of Structural Chemistry 2021年第10期40卷 1317-1327页

作者： CHEN bao-Guo YING Qiu-Yang shen Jin-Ni Institute of Science and Technology and Social Research Fuzhou UniversityFuzhou 350100China International College Krirk UniversityBangkok 10220Thailand State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China School of Chemistry Fuzhou UniversityFuzhou 350100China

Based on Cite Space software,big data bibliometrics analysis was carried out on the keywords of papers of photocatalytic materials published in *** the hotspots and directions can help young scholars to understand the latest *** the Web of Sciences,4147 related papers were searched with"photocatalytic materials"as the main *** analysis showed that the hotspots were g-C_(3)N_(4),Mxene and metal-organic frameworks (MOF) and titanium dioxide (TiO_(2)).

关键词： Cite Space visual analysis photocatalytic materials big data analysis

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An Evaluation on the Ratio of Plant to Animal Protein in the Diet of Juvenile Sea Cucumber(Apostichopus japonicus):Growth,Nutrient Digestibility and Nonspecific Immunity

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Journal of Ocean University of China 2018年第6期17卷 1479-1486页

作者： bao Pengyun LI Xiaoyu xu Yongping School of Life Sciences and Biotechnology Dalian University of TechnologyDalian 116024China School of Fisheries and Life Sciences Dalian Ocean UniversityDalian 116023China Ministry of Education Center for Food Safety of Animal Origin Dalian 116620China Liaoning Food Safety of Animal Origin Innovation Team Dalian 116024China

This study was conducted to evaluate the effects of plant/animal(P/A) protein ratios(viz.1:4, 1:3, 1:2, 1:1,2:1, 3:1, 4:1) on growth performance, body composition, apparent digestibility of diets, and nonspecific immunity of juvenile sea cucumber(Apostichopus japonicus). Sea cucumbers were divided into 21 plastic tanks, and each tank was stocked with 15 individuals(initial weight: about 23.73 g). Each feed was allocated to three replicates of sea cucumbers. The feeding experiment lasted for 50 days. Results indicated that weight gain rate(WGR) and body wall weight(BWW) significantly increased as dietary ratio of P/A increased from 1:4 to 3:1, and then decreased significantly with further increase of this ratio(P 0.05). The apparent digestibility of dry matter, protein and lipid increased with ratio of P/A increasing from 1:4 to 2:1(P < 0.05), and then decreased with further increase of this ratio. Correspondingly, activities of trypsin and amylase were significantly increased as P/A increased from 1:4 to 2:1(P < 0.05). The activities of SOD and CAT showed a similar trend with WGR, with the highest value observed in the ratio of 1:2 and 1:1, respectively. Results above showed that moderate or relatively higher ratio of P/A protein(1:1-3:1) significantly increased the growth performance, apparent digestibility, and nonspecific immunity of sea cucumber. This will contribute to improving the feed formulation for juvenile cucumbers.

关键词： Apostichopus japonicus plant protein animal protein growth digestibility nonspecific immunity

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Coating metals on micropowders by magnetron sputtering

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China Particuology 2007年第5期5卷 345-350页

作者： Zheng xu Xiaozheng Yu Zhigang shen National Engineering Laboratory of Biohydrometallurgy General Research Institute for Nonferrous Metals Beijing 100088 China Beijing Key Laboratory for Powder Technology R. & D. Beijing University of Aeronautics andAstronautics Beijing 100083 China

Magnetron sputtering was used to coat various metals on micropowder surfaces. By using this method, the fine particles are better dispersed and can therefore be coated more homogeneously. The micro-powders used include cenospheres from fly ash of coal-burning electric power plants （diameter 40-200 μm and particle density 0.7 ± 0.1 g/cm^3）, as well as carborundum particles of different sizes. Aluminum, silver, copper, cobalt and nickel were used as the coating metals. Tests showed that the coated metal film was compact adhering tightly on the base powders, and the coated powders possess adequate flow properties.

关键词： Micropowder magnetron sputter Metal coating

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Photoredox/palladium-cocatalyzed enantioselective alkylation of secondary benzyl carbonates with 4-alkyl-1,4-dihydropyridines

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Science China Chemistry 2020年第5期63卷 687-691页

作者： xu shen Linlin Qian Shouyun Yu State Key Laboratory of Analytical Chemistry for Life Science Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

A photoredox/palladium-cocatalyzed enantioselective alkylation of racemic secondary carbonates with 4-alkyl-1,4-dihydropyridines under visible light irradiation has been developed. The present study provides a method for the preparation of optically active diarylalkanes from racemic diarylmethyl carbonates by a dynamic kinetic asymmetric transformation(DYKAT).This photoredox/palladium dual catalysis strategy expands the scope of the asymmetric Pd-catalyzed benzylic substitution reaction and serves as its potential alternative and complement.

关键词： photoredox catalysis palladium dual catalysis photochemistry benzylic alkylation

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Blockchain for Network Slicing in 5G and Beyond:Survey and Challenges

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Journal of Communications and Information Networks 2022年第4期7卷 349-359页

作者： Shihan bao Yacong Liang Hui xu Department of CICT Mobile Communication Technology Co. Ltd.Beijing 100083China

Network slicing has gained popularity as a result of the advances in the fifth generation(5G)mobile *** slicing facilitates the support of different service types with varying requirements,which brings into light the slicing-aware next generation mobile network *** allowing resource sharing among multiple stakeholders,there is a long list of administrative negotiations among parties that have not established mutual *** ledger technology may be a solution to mitigate the above issues by taking its decentralized yet immutable and auditable ledger,which may help to ease administrative negotiations and build mutual trust among *** have been many research interests in this direction which focus on handling various problems in network *** paper aims at constructing this area of knowledge by introducing network slice from a standardization point of view to start with,and presenting security,privacy,and trust challenges of network slicing in 5G and beyond ***,this paper covers distributed ledger technologies basics and related approaches that tackle security,privacy,and trust threats in network slicing for 5G and beyond *** various proposals proposed in the literature are compared and ***,limitations of current work and open challenges are illustrated as well.

关键词： network slicing blockchain beyond 5G security privacy and trust

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Electrokinetic and permeation characterization of hydrolyzed polyacrylonitrile (PAN) hollow fiber ultrafiltration membrane

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Science China Chemistry 2009年第5期52卷 683-689页

作者： bao Wenxuan xu ZhenLiang YANG Hu Membrane Science and Engineering R&D Laboratory Chemical Engineering Research CenterEast China University of Science and TechnologyShanghai 200237China

PAN membrane and hydrolyzed PAN membranes with the same pore size were used to investigate the relationship between the electrokinetic property and permeation performance by streaming potential measurement and ion exchange technology. SEM and FT-IR/ATR spectra were employed to analyze the reaction and the presence of the amide groups. The thickness of the polyacrylic acid (PAA) layer on the membrane surface measured by ion-exchange titration technology increased with the reaction time, and that on membrane hydrolyzed for 50 min could reach 10.8 nm. Streaming potential measurement was used to study the influence of the carboxylic and nitrile group on the membrane surface on their separation property. Zeta potential measured in pure water had close relationship with the permeation property. This measurement also proved that there was a maximum zeta potential between zero and the concentration tested. For the ionization or dissociation of the carboxylic group on the membrane surface, treated membranes had a more flexible zeta potential range than that of the untreated membrane in the pH range of 3-9. They were all negative in pure water and 1 g·L-1 KCl solution, while the membranes hydrolyzed for 30 min and 50min had IEPs at pH 5.5 and 6.1 in 1 g·L-1 MgCl2 solution. Special inflection points of all the membranes were observed in AlCl3 solution for the positive colloid structure of Al(OH)3.

关键词： polyacrylonitrile (PAN) zeta potential ultrafiltration hollow fiber membrane

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