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Insight-HXMT observations of the Crab pulsar

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Research in Astronomy and Astrophysics 2019年第6期19卷 109-116页

作者： You-Li Tuo Ming-Yu Ge Li-Ming Song Lin-Li Yan qing-cui bu Jin-Lu Qu Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China University of the Chinese Academy of Sciences Beijing 100049 China School of Mathematics and Physics Anhui Jianzhu University Hefei 230601 China

We report on X-ray emission properties of the Crab pulsar(PSR B0531+21) using observations by Insight-HXMT during its first year after launch. We obtained high signal-to-noise profiles in the X-ray energy band 11–250 keV. We have confirmed an increase in the flux ratio of the second peak over the main peak with increasing energy, consistent with other missions. The separation of the two peaks shows no significant trend with increasing energy. The phase-averaged spectrum, fitted by a logpar model, and the phase-resolved spectra of the Crab pulsar, fitted by a powerlaw in the different energy bands of HXMT, are consistent with RXTE and NuSTAR in that photon indices evolve as a function of phase as well as a function of energy, contributing to a broadband modeling.

关键词： stars neutron star-pulsars individual(Crab)-X-rays

Timing and Spectral Analysis of the Black Hole X-Ray Binary MAXI J1803-298 with Insight-HXMT Data

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Research in Astronomy and Astrophysics 2024年第6期24卷 209-224页

作者： Ying-Chen Xu Jin-Lu Qu MMéndez Rui-Can Ma Long Ji Liang Zhang Yue Huang qing-cui bu Li-Ming Song 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 Kapteyn Astronomical Institute University of GroningenP.O.BOX 8009700 AV GroningenThe Netherlands Dongguan Neutron Science Center Dongguan 523808China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls UniversitätSand 1D-72076 TübingenGermany

We present a comprehensive analysis of the 2021 outburst of MAXI J1803–298 utilizing observations of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT)spanning from the low hard state to the high soft *** the Insight-HXMT data set,compared to the previous work,we identify a more prolonged presence of typeC quasi-periodic oscillations(QPOs)with centroid frequencies ranging from~0.16 to 6.3 Hz,which present correlations with the hardness ratio and the photon index of the Comptonized *** QPO frequencies less than~2 Hz,the QPO phase lags are hard(photons of 10–19 keV arrive later than those of 1–4 keV),while at higher frequencies,the lags become soft at and above~4 ***,the spectra in all Insight-HXMT observations consist of a multi-color blackbody component and a Comptonized component,as commonly observed in classical black hole X-ray *** analyze state transitions and the evolution of accretion geometry in this *** fitted inner disk radius increases abnormally during the low hard state,hypothesized to result from the corona condensing onto the inner ***,two significant drops in flux are observed during the soft intermediate state,maybe implying changes in the corona/jet and the disk,respectively.

关键词： X-rays:binaries accretion accretion disks stars:black holes

A low-latency pipeline for GRB light curve and spectrum using Fermi/GBM near real-time data

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Research in Astronomy and Astrophysics 2018年第5期18卷 99-110页

作者： Yi Zhao Bin-Bin Zhang Shao-Lin Xiong Xi Long Qiang Zhang Li-Ming Song Jian-Chao Sun Yuan-Hao Wang Han-Cheng Li qing-cui bu Min-Zi Feng Zheng-Heng Li Xing Wen Bo-Bing Wu Lai-Yu Zhang Yong-Jie Zhang Shuang-Nan Zhang Jian-Xiong Shao School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China School of Astronomy and Space Science Nanjing University Nanjing 210093 China Instituto de Astroffsica de Andaluc/a (IAA-CSIC) P.O. Box 03004 E-18080 Granada Spain University of Chinese Academy of Sciences Beijing 100049 China

Rapid response and short time latency are very important for Time Domain Astronomy, such as the observations of Gamma-ray bursts（GRBs） and electromagnetic（EM） counterparts of gravitational waves（GWs）. Based on near real-time Fermi/GBM data, we developed a low-latency pipeline to automatically calculate the temporal and spectral properties of GRBs. With this pipeline, some important parameters can be obtained, such as T_（90） and fluence, within ～ 20 min after the GRB *** ～ 90% of GRBs, T90 and fluence are consistent with the GBM catalog results within 2σ *** pipeline has been used by the Gamma-ray bursts Polarimeter（POLAR） and the Insight Hard Xray Modulation Telescope（Insight-HXMT） to follow up the bursts of interest. For GRB 170817 A, the first EM counterpart of GW events detected by Fermi/GBM and INTEGRAL/SPI-ACS, the pipeline gave T90 and spectral information 21 min after the GBM trigger, providing important information for POLAR and Insight-HXMT observations.

关键词： gamma-ray bursts general - polarization - radiation mechanisms non-thermal

Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring

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Research in Astronomy and Astrophysics 2021年第3期21卷 193-204页

作者： He-Xin Liu Yue Huang Guang-Cheng Xiao qing-cui bu Jin-Lu Qu Shu Zhang Shuang-Nan Zhang Shu-Mei Jia Fang-Jun Lu Xiang Ma Lian Tao Wei Zhang Li Chen Li-Ming Song Ti-Pei Li Yu-Peng Xu Xue-Lei Cao Yong Chen Cong-Zhan Liu Ce Cai Zhi Chang Gang Chen Tian-Xiang Chen Yi-Bao Chen Yu-Peng Chen Wei cui Wei-Wei cui Jing-Kang Deng Yong-Wei Dong Yuan-Yuan Du Min-Xue Fu Guan-Hua Gao He Gao Min Gao Ming-Yu Ge Yu-Dong Gu Ju Guan Cheng-Cheng Guo Da-Wei Han Jia Huo Lu-Hua Jiang Wei-Chun Jiang Jing Jin Yong-Jie Jin Ling-Da Kong Bing Li Cheng-Kui Li Gang Li Mao-Shun Li Wei Li Xian Li Xiao-Bo Li Xu-Fang Li Yang-Guo Li Zheng-Wei Li Xiao-Hua Liang Jing-Yuan Liao Bai-Sheng Liu Guo-qing Liu Hong-Wei Liu Xiao-Jing Liu Yi-Nong Liu Bo Lu Xue-Feng Lu Qi Luo Tao Luo Bin Meng Yi Nang Jian-Yin Nie Ge Ou Na Sai Ren-Cheng Shang Xin-Ying Song Liang Sun Ying Tan You-Li Tuo Chen Wang Guo-Feng Wang Juan Wang Ling-Jun Wang Weng-Shuai Wang Yu-Sa Wang Xiang-Yang Wen Bai-Yang Wu Bo-Bing Wu Mei Wu Shuo Xiao Shao-Lin Xiong He Xu Jia-Wei Yang Sheng Yang Yan-Ji Yang Yi-Jung Yang Qi-Bin Yi Qian-qing Yin Yuan You Ai-Mei Zhang Cheng-Mo Zhang Fan Zhang Hong-Mei Zhang Juan Zhang Tong Zhang Wan-Chang Zhang Wen-Zhao Zhang Yi Zhang Yi-Fei Zhang Yong-Jie Zhang Yuan-Hang Zhang Yue Zhang Zhao Zhang Zhi Zhang Zi-Liang Zhang Hai-Sheng Zhao Xiao-Fan Zhao Shi-Jie Zheng Yao-Guang Zheng Deng-Ke Zhou Jian-Feng Zhou Yu-Xuan Zhu Ren-Lin Zhuang Yue Zhu 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 Institut fur Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls Universität72076 TubingenGermany Department of Astronomy Beijing Normal UniversityBeijing 100088China Department of Astronomy Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China College of Physics Sciences&Technology Hebei UniversityBaoding 071002Hebei ProvinceChina

We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and *** outburst can be classified roughly into four different ***-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this ***,we study various physical quantities related to QPO *** QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain *** relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.

关键词： X-ray binaries black hole candidate QPO EXO 1846–031

Event-Triggered Asymmetric Bipartite Consensus Tracking for Nonlinear Multi-Agent Systems Based on Model-Free Adaptive Control

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 662-672页

作者： Jiaqi Liang Xuhui bu Lizhi cui Zhongsheng Hou School of Electrical Engineering and Automation Henan Polytechnic UniversityJiaozuo 454003China School of Automation Qingdao UniversityQingdao 266071China IEEE

In this paper,an asymmetric bipartite consensus problem for the nonlinear multi-agent systems with cooperative and antagonistic interactions is studied under the event-triggered *** the agents described by a structurally balanced signed digraph,the asymmetric bipartite consensus objective is firstly defined,assigning the agents'output to different signs and module *** with the completely unknown dynamics of the agents,a novel event-triggered model-free adaptive bipartite control protocol is designed based on the agents'triggered outputs and an equivalent compact form data *** utilizing the Lyapunov analysis method,the threshold of the triggering condition is ***,the asymptotic convergence of the tracking error is deduced and a sufficient condition is obtained based on the contraction mapping ***,the simulation example further demonstrates the effectiveness of the protocol.

关键词： Asymmetric bipartite consensus tracking eventtriggered model-free adaptive control(MFAC) nonlinear systems signed digraph

Some Properties of the Injective Tensor Product of Banach Spaces

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Acta Mathematica Sinica,English Series 2007年第9期23卷 1697-1706页

作者： Xiao Ping XUE Yong Jin LI qing Ying bu(qingying bu) Department of Mathematics Harbin Institute of Technology Harbin 150001 P. R. China Department of Mathematics Sun Yat-sen University Guangzhou 510275 P. R. China Department of Mathematics University of Mississippi University MS 38677 USA

Let X and Y be Banach spaces such that X has an unconditional basis. Then X Y, the injective tensor product of X and Y, has the Radon-Nikodym property （respectively, the analytic Radon-Nikodym property, the near Radon-Nikodym property, non-containment of a copy of co, weakly sequential completeness） if and only if both X and Y have the same property and each continuous linear operator from the predual of X to Y is compact.

关键词： tensor products types of Radon-Nikodym properties Schauder decomposition

Biogas production from microbial-alkali pretreated corn stover by solid-state anaerobic digestion

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International Journal of Agricultural and Biological Engineering 2015年第5期8卷 96-104页

作者： Zhao Pengxiang cui Fengjie bu Lingxi Jiang Jianxin Department of Chemistry and Chemical Engineering Beijing Forestry UniversityBeijing 100083China School of Food and Biological Engineering Jiangsu UniversityZhenjiang 212013China Beijing Biomass Energy Technology Center State Grid Energy Conservation Service Ltd.Beijing 100053China

Corn stover pretreated by Ceriporiopsis subvermispora was used as substrate to enhance biogas production via solid state anaerobic digestion(SS-AD).Effects of temperature,inoculum volume and alkaline concentration on the biogas production profermance were *** results showed that pretreatment of corn stover by *** benefited the biogas *** optimal conditions were temperature 35°C,inoculum 10:1(w/w)and adding 5.0%of alkali,under which the maximum productions were obtained for daily and cumulative biogas of 14.07 L/kg VS and 211.09 L/kg *** the SS-AD process,the total solids(TS)and volatile solid(VS)were significantly *** volatile fatty acids(VFA)concentration increased to 106 mmol/L and alkalinity decreased by about 23%.The results collectively suggested that microbial-alkali pretreatment of corn stove combining mesophilic condition could be a promising way to produce biogas in SS-AD.

关键词： solid-state anaerobic digestion corn stover Ceriporiopsis subvermispora microbial-alkali pretreatment biogas production

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失效的“压舱石”:经济安全化的现实转向

国际安全研究 2025年第1期43卷 133-154,159页

作者：高程部彦君中国社会科学院拉丁美洲研究所中国社会科学院大学国际政治经济学院北京100007 同济大学政治与国际关系学院上海200092

经济安全化是国家通过安全叙述将非安全的经济议题转化为安全议题的过程。在国家认为经济合作的收益将损害其在权力竞争中的整体所得时,或者在国家间政治外交关系遇到巨大震荡或冲击时,国家安全逻辑会超越经济逻辑而生效。此时,安全与... 详细信息

经济安全化是国家通过安全叙述将非安全的经济议题转化为安全议题的过程。在国家认为经济合作的收益将损害其在权力竞争中的整体所得时,或者在国家间政治外交关系遇到巨大震荡或冲击时,国家安全逻辑会超越经济逻辑而生效。此时,安全与经济问题在刻意煽动下交织碰撞,国家间密切的经贸关系不仅难以成为管控两国矛盾与分歧的“压舱石”,反而会被国家视作现存的“安全威胁”,成为某些国家中断或破坏双边政治经济联系的借口与手段。国家间存在的经济相互依赖关系也会随之成为安全化操纵国维护与拓展权力、进行地缘政治竞争和打击、操纵他国的战略性工具。因此,文章以存在紧密经济相互依赖的中美与俄欧关系为案例,在比较中美、俄欧之间不同经济安全化动因的基础上,分析经济安全化转向背后的选择逻辑,为中国更好地应对经济安全化挑战、更有针对性地发挥“经济压舱石”作用提供一定思考。

关键词：经济安全化经济压舱石国家安全经济相互依赖

Unsupervised feature selection via joint local learning and group sparse regression

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Frontiers of Information Technology & Electronic Engineering 2019年第4期20卷 538-553页

作者： Yue WU Can WANG Yue-qing ZHANG Jia-jun bu Zhejiang Provincial Key Laboratory of Service Robot College of Computer Science and Technology Zhejiang University Alibaba-Zhejiang University Joint Institute of Frontier Technologies

Feature selection has attracted a great deal of interest over the past decades. By selecting meaningful feature subsets, the performance of learning algorithms can be effectively improved. Because label information is expensive to obtain, unsupervised feature selection methods are more widely used than the supervised ones. The key to unsupervised feature selection is to find features that effectively reflect the underlying data distribution. However,due to the inevitable redundancies and noise in a dataset, the intrinsic data distribution is not best revealed when using all features. To address this issue, we propose a novel unsupervised feature selection algorithm via joint local learning and group sparse regression(JLLGSR). JLLGSR incorporates local learning based clustering with group sparsity regularized regression in a single formulation, and seeks features that respect both the manifold structure and group sparse structure in the data space. An iterative optimization method is developed in which the weights finally converge on the important features and the selected features are able to improve the clustering results. Experiments on multiple real-world datasets(images, voices, and web pages) demonstrate the effectiveness of JLLGSR.

关键词： Unsupervised Local learning Group sparse regression Feature selection