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High Spatial Resolution X-Ray Spectroscopy of Cas A with Chandra

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Chinese Journal of Astronomy and Astrophysics 2008年第4期8卷 439-450页

作者： xue-juan yang Fang-Jun Lu Li Chen Particle Astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Department of Astronomy Beijing Normal University Beijing 100875 China

We present high spatial resolution X-ray spectroscopy of the supernova remnant Cassiopeia A with the Chandra observations. The X-ray emitting region of this remnant was divided into 38 × 34 pixels of 10″× 10″ each. Spectra of 960 pixels were created and fitted with an absorbed two component non-equilibrium ionization model. From the results of the spectral analysis we obtained maps of absorbing column density, temperatures, ionization ages, and the abundances of Ne, Mg, Si, S, Ca and Fe. The Si, S and possibly Ca abundance maps show obvious jet structures, while Fe does not follow the jet but seems to be distributed perpendicular to it. The abundances of Si, S and Ca show tight correlations between one another over a range of about two dex. This suggests that they are ejecta from explosive O- burning and incomplete Si-burning. Meanwhile, the Ne abundance is well correlated with that of Mg, indicating them to be the ashes of explosive C/Ne burning. The Fe abundance is positively correlated with that of Si when the latter is lower than 3 times the solar value, and is negatively correlated when higher. We suggest that such a two phase correlation is due to the different ways in which Fe was synthesized.

关键词： ISM supernova remnants -ISM individual Cassiopeia A

The In-Flight Realtime Trigger and Localization Software of GECAM

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Research in Astronomy and Astrophysics 2024年第10期24卷 11-24页

作者： Xiao-Yun Zhao Shao-Lin Xiong Xiang-yang Wen Xin-Qiao Li Ce Cai Shuo Xiao Qi Luo Wen-Xi Peng Dong-Ya Guo Zheng-Hua An Ke Gong Jin-Yuan Liao Yan-Qiu Zhang Yue Huang Lu Li Xing Wen Fei Zhang Jing Duan Chen-Wei Wang Dong-Li Shi Peng Zhang Qi-Bin Yi Chao-yang Li Yan-Bing Xu Xiao-Hua Liang Ya-Qing Liu Da-Li Zhang Xi-Lei Sun Fan Zhang Gang Chen Huan-Yu Wang Sheng yang Xiao-Jing Liu Min Gao Mao-Shun Li Jin-Zhou Wang Xing Zhou Yi Zhao Wang-Chen xue Chao Zheng Jia-Cong Liu Xing-Bo Han Jin-Ling Qi Jia Huang Ke-Ke Zhang Can Chen Xiong-Tao yang Dong-Jie Hou Yu-Sa Wang Rui Qiao Xiang Ma Xiao-Bo Li Ping Wang Xin-Ying Song Li-Ming Song Shi-Jie Zheng Bing Li Hong-Mei Zhang Yue Zhu Wei Chen Jian-Jian He Zhen Zhang Jin Hou Hong-Jun Wang Yan-Chao Hao Xiang-Yu Wang Zong-Yuan yang Zhi-Long Wen Zhi Chang Yuan-Yuan Du Rui Gao Xiao-Fei Lan Yan-Guo Li Gang Li Xu-Fang Li Fang-Jun Lu Hong Lu Bin Meng Feng Shi Hui Wang Hui-Zhen Wang Yu-Peng Xu Jia-Wei yang xue-juan yang Shuang-Nan Zhang Chao-Yue Zhang Cheng-Mo Zhang Zhi-Cheng Tang Cheng Cheng Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China School of Information Science and Technology Southwest Jiaotong UniversityChengdu 611756China Key Laboratory of Stellar and Interstellar Physics and Department of Physics Xiangtan UniversityXiangtan 411105China Physics and Space Science College China West Normal UniversityNanchong 637002China Department of Astronomy Beijing Normal UniversityBeijing 100875China Innovation Academy for Microsatellites of CAS Shanghai 201203China Changchun University of Science and Technology Changchun 130022China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesCASBeijing 100101China

Realtime trigger and localization of bursts are the key functions of GECAM,an all-sky gamma-ray monitor launched on 2020 December *** developed a multifunctional trigger and localization software operating in the CPU of the GECAM Electronic *** onboard software has the following features:high trigger efficiency for real celestial bursts with a suppression of false triggers caused by charged particle bursts and background fluctuation,dedicated localization algorithm optimized for both short and long bursts,and low time latency of the trigger information which is downlinked through the Global Short Message Communication service of the global BeiDou navigation *** paper provides a detailed description of the design and development of the trigger and localization software system for *** covers the general design,workflow,the main functions,and the algorithms used in the *** paper also includes on-ground trigger tests using simulated gamma-ray bursts generated by a dedicated X-ray tube,as well as an overview of the performance for real celestial bursts during its in-orbit operation.

关键词： telescopes instrumentation:detectors methods:observational

Unusual infrared emission toward Sgr B2: possible planar C24

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Research in Astronomy and Astrophysics 2019年第10期19卷 35-42页

作者： Xiu-Hui Chen Fu-Yuan Xiang xue-juan yang Aigen Li Department of Physics Xiangtan University Xiangtan 411105 China Department of Physics and Astronomy University of Missouri Columbia MO 65211 USA

Interstellar graphene could be present in the interstellar medium(ISM), resulting from the photochemical processing of polycyclic aromatic hydrocarbon(PAH) molecules and/or collisional fragmentation of graphitic particles. Indeed, by comparing the observed ultraviolet(UV) extinction and infrared(IR) emission of the diffuse ISM with that predicted for graphene, as much as ~ 2% of total interstellar carbon could be locked up in graphene without violating the observational constraints. While the possible detection of planar C24, a small piece of a graphene sheet, has been reported towards several Galactic and extragalactic planetary nebulae, graphene has not yet been detected in interstellar environments. In this work, we search for the characteristic IR features of C24 at ~ 6.6, 9.8 and 20 μm toward Sgr B2, a high-mass star formation region, and find a candidate target toward R.A.(J2000)= 267.05855?and Decl.(J2000)=-28.01479?in Sgr B2 whose Spitzer/IRS spectra exhibit three bands peaking at ~ 6.637, 9.853 and 20.050 μm which appear to be coincident with those of C24. Possible features of C60 are also seen in this region. The candidate region is a warm dust environment heated by massive stars or star clusters, associated with a WISE spot(a tracer of star formation activity), close to the HII region candidate IRAS 17450–2759, and is surrounded by seven young stellar object candidates within ~ 5′, suggesting that the creation and/or excitation of C24 could be related to star formation activities.

关键词： line identification-ISM lines and bands-ISM molecules

High spatial resolution spectroscopy of G292.0+1.8 with Chandra

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Research in Astronomy and Astrophysics 2014年第10期14卷 1279-1288页

作者： xue-juan yang Xiao-Qin Liu Shun-Yu Li Fang-Jun Lu Faculty of Materials Optoelectronics and PhysicsXiangtan University Particle Astrophysics Center Institute of High Energy PhysicsChinese Academy of Sciences

We present high spatial resolution X-ray spectroscopy of supernova rem- nant G292.0＋1.8 made with Chandra observations. The X-ray emitting region of this remnant was divided into 25 × 25 pixels with a scale of 20＂ × 20＂ each. Spectra of 328 pixels were created and fitted with an absorbed one component non-equilibrium ionization model. With the spectral analysis results, we obtained maps of absorbing column density, temperature, ionization age and abundances for O, Ne, Mg, Si, S and Fe. The abundances of O, Ne and Mg show tight correlations between each other in the range of about two orders of magnitude, suggesting that they are all from explo- sive C/Ne burning. Meanwhile, the abundances of Si and S are also well correlated, indicating that they are the ashes of explosive O-burning or incomplete Si-burning. The Fe emission lines are not prominent in the whole remnant, and their abundance is significantly reduced, indicating that the reverse shock may not have propagated to the Fe-rich ejecta. Based on relative abundances of O, Ne, Mg, Si and Fe to Si, we suggest a progenitor mass of 25 - 30 M⊙ for this remnant.

关键词： ISM supernova remnants -- ISM individual G292.0+1.8

Thermodynamic property of sandwich cylindrical shell structure with metallic wire mesh:Numerical modeling and experimental analysis

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Chinese Journal of Aeronautics 2024年第1期37卷 138-152页

作者： Xin xue Guojian SHEN juan LIAO Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Fujian Shuikou Power Generation Group Co. LTDFuzhou 350000China

As a new addition to lightweight composite structures,the sandwich cylindrical shell with a metallic wire mesh core has emerged as a promising solution for thermodynamic performance analysis at elevated *** intricate interwoven cellular formations within the metallic wire mesh pose difficulties for thermo-mechanical modeling and property ***,the constitutive models employed to characterize hysteresis phenomena were presented,comprising isotropic elasticity,Bergstrom-Boyce model,Ogden hyper-elasticity,and parameter identification through mechanical examinations at varying ***,the finite element modeling of cylindrical shell structures was determined for modal and steady-state dynamic ***,the experimental procedures were carried out,including the preparation of the sandwich cylindrical shell and the dynamic testing *** first-order natural frequency of the cylindrical shell structure is close to the resonance frequency of the dynamic test results,with a maximum error of 6.5%,demonstrating the accuracy of the simulation *** compared to the solid-core cylindrical shell,the average insertion loss of the sandwich cylindrical shell structure within the frequency range of 10–1000 Hz at room temperature is up to 11.09 ***,at elevated temperatures,the average insertion loss of the sandwich cylindrical shell decreases but fluctuates as the temperature changes.

关键词： Energy dissipation Metallic matrix composites Numerical analysis Sandwich structure Thermodynamic properties

Interface property of dissimilar Ti-6Al-4V/AA1050 composite laminate made by non-equal channel lateral co-extrusion and heat treatment

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Defence Technology（防务技术） 2024年第3期33卷 197-208页

作者： juan Liao Mengmeng Tian Xin xue School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350116China

The purpose of this paper is to examine the effect of processing parameters and subsequent heat treatments on the microstructures and bonding strengths of Ti-6Al-4V/AA1050 laminations formed via a non-equal channel lateral co-extrusion *** microstructural evolution and growth mechanism in the diffusion layer were discussed further to optimize the bonding quality by appropriately adjusting process *** electron microscopes(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD)were used to characterize interfacial diffusion *** shear test was used to determine the mechanical properties of the interfacial diffusion *** experimental results indicate that it is possible to co-extrusion Ti-6Al-4V/AA1050 compound profiles using non-equal channel lateral *** heat treatment processes affect the thickness of the diffusion *** the temperature and time of heat treatment increase,the thickness of the reaction layers increases ***,the shear strength of the Ti-6Al-4V/AA1050 composite interface is proportional to the diffusion layer *** is observed that a medium interface thickness results in superior mechanical performance when compared to neither a greater nor a lesser interface *** characterization of all heat treatments reveals that the only intermetallic compound observed in the diffusion layers is TiAl_(3).Due to the inter-diffusion of Ti and Al atoms,the TiAl_(3) layer grows primarily at AA1050/TiAl_(3) interfaces.

关键词： Shear strength Co-extrusion Heat treatment Microstructure Intermetallic compounds

Lattice-distorted Pt wrinkled nanoparticles for highly effective hydrogen electrocatalysis

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Nano Research 2024年第5期17卷 3819-3826页

作者： xue Li Xiang Han Zhenrui yang Shun Wang Yun yang juan Wang Jiadong Chen Zhongwei Chen Huile Jin Wenzhou Key Lab of Advanced Energy Storage and Conversion Zhejiang Province Key Lab of Leather EngineeringCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Institute of New Materials and Industry Technology College of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Department of Chemical Engineering Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooOntario N2L 3G1Canada

Modulating Pt surfaces through the introduction of lattice distortion emerges as immensely effective strategy that enhances the kinetics of alkaline hydrogen evolution and oxidation *** this study,we fabricated lattice-distorted Pt wrinkled nanoparticles(LD-Pt WNPs)for efficient hydrogen *** LD-Pt WNPs not only outperform the Pt/C benchmark in hydrogen oxidation reaction,achieving an excellent mass-specific current of 968.5 mA·mg_(Pt)^(-1)(9 times that of Pt/C),but also demonstrate outstanding hydrogen evolution reaction activity with a small overpotential of 58.0 *** experiments and density functional theory calculations reveal that lattice defects introduce an abundance of unsaturated coordination atoms while modifying the d-band center of *** dual effect optimizes the binding strength of crucial H and OH intermediates,leading to a significant reduction in the energy barrier of the reaction bottleneck,commonly known as the Volmer *** work unveils a fresh viewpoint on projecting and developing high efficiency electrocatalysts through defect engineering.

关键词： distortion nanoparticle hydrogen evolution reaction defect engineering hydrogen oxidation reaction

Advanced Materials for NH_(3)Capture:Interaction Sites and Transport Pathways

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Nano-Micro Letters 2024年第11期16卷 119-155页

作者： Hai‑Yan Jiang Zao‑Ming Wang xue‑Qi Sun Shao‑juan Zeng yang‑yang Guo Lu Bai Ming‑Shui Yao Xiang‑Ping Zhang Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190People’s Republic of China School of Future Technology University of Chinese Academy of SciencesBeijing 100049People’s Republic of China China University of Petroleum Beijing 102249People’s Republic of China Institute for Integrated Cell‑Material Sciences(iCeMS) Kyoto UniversitySakyo‑KuYoshidaKyoto 606‑8501Japan

Ammonia(NH3)is a carbon-free,hydrogen-rich chemical related to global food safety,clean energy,and environmental *** an essential technology for meeting the requirements raised by such issues,NH3 capture has been intensively explored by researchers in both fundamental and applied *** four typical methods used are(1)solvent absorption by ionic liquids and their derivatives,(2)adsorption by porous solids,(3)abadsorption by porous liquids,and(4)membrane *** in the development of advanced materials for NH3 capture,we conducted a coherent review of the design of different materials,mainly in the past 5 years,their interactions with NH3 molecules and construction of transport pathways,as well as the structure–property relationship,with specific examples ***,the challenges in current research and future worthwhile directions for NH3 capture materials are proposed.

关键词： Ammonia capture Solvents Porous solids Porous liquids Membranes

XMM-Newton observation of the eclipsing binary Algol

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Research in Astronomy and Astrophysics 2011年第4期11卷 457-470页

作者： xue-juan yang Fang-Jun Lu Bemd Aschenbach Li Chen Faculty of Materials Optoelectronics and Physics Xiangtan University Xiangtan 411105China Particle Astrophysics Center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Max-Planck-Institut fur Extraterrestrische Physik 85741 Garching Germany Department of Astronomy Beijing Normal University Beijing 100875 China

We present an XMM-Newton observation of the eclipsing binary Algol which contains an X-ray dark B8V primary and an X-ray bright K2IV secondary. The observation covered the optical secondary eclipse and captured an X-ray flare that was eclipsed by the B star. The XMM-Newton European Photon Imaging Camera and Reflection Grating Spectrometer spectra of Algol in its quiescent state are described by a two-temperature plasma model. The cool component has a temperature around 6.4× 106 K while that of the hot component ranges from 2 to 4.0× 107 K. Coronal abundances of C, N, O, Ne, Mg, Si and Fe were obtained for each component for both the quiescent and the flare phases, generally with upper limits for S and Ar, and upper limits for C, N, and O from the hot component. F-tests show that the abundances do not need to be different between the cool and the hot component and between the quiescent and the flare phase with the exception of Fe. Although the Fe abundance of the cool component remains constant at -0.14, the hot component shows an Fe abundance of -0.28, which increases to -0.44 during the flare. This increase is expected from the chromospheric evaporation model. The absorbing column density NH of the quiescent emission is 2.5 - 1020 cm-2, while that of the flare-only emission is significantly lower and consistent with the column density of the interstellar medium. This observation substantiates earlier suggestions of the presence of X-ray absorbing material in the Algol system.

关键词： stars abundance -- star binaries eclipsing -- stars flare -- stars indi-vidual Algol