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

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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 ${\bm~{Einstein~~Probe}}$

Assessing the corrosion protection property of coatings loaded with corrosion inhibitors using the real-time atmospheric corrosion monitoring technique

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 119-126页

作者： Xiaoxue Wang Lulu Jin Jinke Wang Rongqiao Wang Xiuchun Liu Kai Gao Jingli Sun Yong Yuan Lingwei Ma Hongchang Qian Dawei Zhang school of Energy and Power engineering Beihang UniversityBeijing 100191China Beijing institute of Space Long March Vehicle Beijing 100076China National Materials Corrosion and Protection Data Center University of Science and Technology BeijingBeijing 100083China institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China Shanghai Spaceflight Precision Machinery institute Shanghai 201600China

The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal ***,limited studies have applied ACM to the corrosion protection properties of organic *** study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over *** with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in *** the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy *** trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface *** alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic *** with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.

关键词： atmospheric corrosion monitoring technology corrosion inhibitor coating carbon steel corrosion protection

Influence of physical parameters on the collapse of a spherical bubble

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Theoretical & Applied Mechanics Letters 2022年第6期12卷 395-402页

作者： Bo-Hua Sun school of Civil engineering&institute of Mechanics and Technology Xi’an University of Architecture and TechnologyXi’an 710055China

This paper examines the influence of physical parameters on the collapse dynamics of a spherical bubble filled with diatomic gas(κ=7/5).The problem is formulated by the Rayleigh–Plesset dynamical equation,whose numerical solutions are carried out by *** studies show that each physical parameter affects the bubble collapse dynamics in different degree,which reveals that bubble collapse dynamics must considers all the parameters including liquid viscosity,surface tension,etc,else the outcome cannot be trusted.

关键词： Bubble collapse Rayleigh's modeling Physical parameters Numerical simulation Maple

First total synthesis of isoquinolinone alkaloid marinamide and its methyl ester

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Chinese Chemical Letters 2013年第8期24卷 767-769页

作者： Cheng-Liang Feng Shu-Guang Zhang Jun-Qing Chen Jin Cai Min Ji institute of pharmaceutical engineering School of Chemistry and Chemical EngineeringSoutheast University

The first total synthesis of isoquinolinone alkaloid marinamide 1 and its methyl ester 2 was described. The key steps involved a regioselective Frieclel-Crafts reaction of 1-benzyl-1H-pyrrole to form the intermediate 8.

关键词： Marinamide Methyl ester of marinamide Isoquinolinone alkaloid Total synthesis

Reactive oxygen specie-induced photodynamic therapy activation by supramolecular strategy

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Chinese Chemical Letters 2023年第5期34卷 205-208页

作者： Shuyi Wang Zizhen Zhao Jiayang Yao Siyang Jiang Zhan-Ting Li Da Ma Department of Chemistry Fudan UniversityShanghai 200438China school of pharmaceutical engineering and institute for advanced studies Taizhou UniversityTaizhou 318000China Department of Mechanics and engineering Science College of EngineeringPeking UniversityBeijing 100871China

Photodynamic therapy(PDT)agents may accumulate in skin and cause severe skin *** report a pro-guest-based supramolecular strategy to selectively activate PDT in the reactive oxygen specie(ROS)overexpressed microenvironment,which is often existing in tumor and inflammatory *** agents methylene blue(MB)and basic blue 17(BB17)are used as model *** encapsulated by acyclic cucurbit[n]uril(CB[n]),the efficacy of PDT agents is significantly *** contrast,in the presence of ROS(H_(2)O_(2))and pro-guest,PDT agents are displaced and reactivated to show a dramatically enhanced PDT efficacy in cells.

关键词： Photodynamic therapy Host-guest chemistry Cucurbit[n]uril Reactive oxygen specie

Tuning microstructure, transformation behavior, mechanical/functional properties of Ti-V-Al shape memory alloy by doping quaternary rare earth Y

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Progress in Natural Science:Materials International 2021年第2期31卷 296-302页

作者： Xiaoyang Yi Kuishan Sun Haizhen Wang Yifu Gong Xianglong Meng Zhiyong Gao Hua Zhang Wei Cai College of Nuclear Equipment and Nuclear engineering Yantai University institute for advanced studies in Precision Materials Yantai University school of Materials Science and engineering Harbin Institute of Technology

The microstructure features, martensitic transformation behavior and mechanical/functional properties of Ti–V–Al alloy were tailored by changing rare element Y content in the present investigation. The results showed that Y doping resulted in the grain refinement and formation of Y-rich phase mainly distributing along grain boundary in Ti–V–Al alloys. The martensitic transformation temperatures of Ti–V–Al alloys slightly increased due to the variation of matrix composition induced by the presence of Y-rich phase. The mechanical and functional properties of Ti–V–Al alloys doped moderate Y addition were significantly improved, which can be ascribed to grain refinement, solution strengthening and precipitation strengthening. The 1.0 at.%Y-doped Ti–V–Al alloy exhibited the highest ultimate tensile stress of 912 MPa and largest elongation of 17.68%. In addition, it was found that the maximum recoverable strain of 5.42% can be obtained in Ti–V–Al alloy with adding 1.0 at.%Y,under the pre-strain of 6% condition, which is enhanced by approximate 0.6% than that of Ti–V–Al alloy without Y addition.

关键词： Light weight shape memory alloy Ti–V–Al alloy Microstructure Phase transformation Mechanical properties

Protective effect of tannins from Ficus racemosa in hypercholesterolemia and diabetes induced vascular tissue damage in rats

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Asian Pacific Journal of Tropical Medicine 2012年第5期5卷 367-373页

作者： Velayutham Ravichandiran Sankaradoss Nirmala KFH Nazeer Ahamed Department of Pharmacognosy School of Pharmaceutical SciencesVels Institute of Science Technology and Advanced Studies(VISTAS)Vels UniversityPallavaramChennai 600 117India Department of Pharmacology School of Pharmaceutical Sciences.Vels Institute of Science Technology and Advanced Studies(VISTAS)Vels UniversityPallavaramChennai 600 117India

Objective:To evaluate the protective effect of tannins from Ficus racemosa(***) on the lipid profile and antioxidant parameters in high fat meal and streptozotocin induced hypercholestremia associated diabetes model in ***:The crude tannin fraction was separated from the acetone(70%v/v) bark extract of *** administratipn of tannin fraction(TF)(100 & 200 mg/kg body weight) to rats fed with high fat meal for 30 days (4%cholesterol,1%cholic acid,0.5%egg albumin) and injected with streptozotocin(35 mg/ kg *** citrate buffer on 14th day).Results:The administration of TF significantly reverse the increased blood glucose,total cholesterol,triglycerides,low density lipoprotein and also significandy restored the insulin and high density lipoprotein in the *** addition tannins significantly restored the activity of antioxidant enzymes such as superoxide dismutase,catalase and decreased the,glutathione peroxidase,and glutathione,thereby restoring the antioxidant status of the organs to almost normal ***:The results of this study show that two different doses of tannin supplementation had a favorable effect on plasma glucose and lipid profile *** also had an influence on attenuating oxidative stress in diabetic tats.

关键词： Diabetes Vascular tissue damage Streptozotocin Tannins Rat

Structural analysis by Rietveld refinement of calcium and lanthanum phosphosilicate apatites

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Journal of Rare Earths 2013年第9期31卷 897-904页

作者： Hela Njema Khaled Boughzala Habib Boughzala Khaled Bouzouita Laboratory of Industrial Chemistry National School of Engineering of Sfax Preparatory institute for engineering studies of Monastir Laboratory of Materials and Crystallochemistry Preparatory Institute for Engineering Studies of Nabeul

Britholites with the general formula Ca10-xLnx（PO4）6-x（SiO4）xF2, （0≤x≤6） are considered to be promising matrices for the confinement of the by-products in the nuclear industry. A thermodynamic study showed that the stability of these compounds de-creased as the substitution rate increased. The present work was an attempt to gain more information about the structural changes in-duced by the substitution, in order to understand the observed stability decrease. The samples were successfully synthesized as a sin-gle-phase apatite by a solid-state reaction between 1200 and 1400 °C. The structural refinement indicated that the La3＋ions preferen-tially occupied the 6（h） sites. A progressive shift of F-along the c-axis outside its ideal position occurred as a result of the substitution increase. This might be the cause of the observed stability decrease, especially as the energies of the La-O, La-F and Si-O bonds are higher than those of Ca-O, Ca-F and P-O. The distribution of La3＋ between the two non-equivalent sites was confirmed by the charge distribution method.

关键词： britholites Rietveld refinement infrared spectroscopy charge distribution method rare earths

Impacts of PI3K/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions

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Neural Regeneration Research 2025年第4期20卷 1031-1041页

作者： Ramón Pérez-Núñez María Fernanda González Ana María Avalos Lisette Leyton Cellular Communication Laboratory Programa de Biología Celular y MolecularCenter for Studies on ExerciseMetabolism and Cancer(CEMC)Instituto de Ciencias Biomédicas(ICBM)Facultad de MedicinaUniversidad de ChileSantiagoChile advanced Center for Chronic Diseases(ACCDiS) Faculty of Chemical and Pharmaceutical Sciences&Faculty of MedicineUniversidad de ChileSantiagoChile Instituto de Ciencias Biomédicas Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile

Astrocytes are the most abundant type of glial cell in the central nervous *** injury and inflammation,astrocytes become reactive and undergo morphological and functional *** on their phenotypic classification as A1 or A2,reactive astrocytes contribute to both neurotoxic and neuroprotective responses,***,this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and *** analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles,which emphasizes the heterogeneous nature of their *** actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types,releasing cytokines,and influencing the immune *** phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior,as evidenced by in silico,in vitro,and in vivo *** astrocytes,inflammatory cues trigger a cascade of molecular events,where nuclear factor-κB serves as a central mediator of the pro-inflammatory ***,we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their *** highlight the involvement of various signaling pathways that regulate astrocyte reactivity,including the PI3K/AKT/mammalian target of rapamycin(mTOR),αvβ3 integrin/PI3K/AKT/connexin 43,and Notch/PI3K/AKT *** targeting the inactivation of the PI3K/AKT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage,evidence suggests that activating this pathway could also yield beneficial *** dual function of the PI3K/AKT pathway underscores its complexity in astrocyte reactivity and brain function *** review emphasizes the importance of employing astrocyte-exclusive models to underst

关键词： inflammation integrins neuroprotective neurotoxic phosphatidylinositol 3-kinase reactive astrocytes signal transduction Thy-1(CD90)