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FAST ultra-wideband observation of abnormal emission-shift events of PSR B0919+06

science china(Physics,Mechanics & astronomy) 2019年第5期62卷 32-37页

作者： Ye-zhao yu Bo Peng Kuo liu ChengMin Zhang lin Wang FeiFei Kou JiGuang Lu Meng yu FAST Collaboration CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China school of astronomy and space sciences University of Chinese Academy of SciencesBeijing 100049China Max-Planck-Institut fur Radioastronomie Auf dem Hugel 69Bonn 53121Gennany 不详

PSR B0919+06 is known for its abnormal emission phenomenon, where the pulse emission window occasionally shifts progressively in longitude and returns afterwards. The physical mechanism behind this phenomenon is still under investigation. In this paper, we present our ultra-wideband observation of this pulsar using the Five-hundred-meter Aperture Spherical radio Telescope(FAST), with simultaneous measurements in the frequency ranges 280-780 and 1250-1550 MHz. We have identified three abnormal events, each of which becomes less apparent as the frequency decreases. At 1400 MHz, the averaged profile slightly shifted after the first and third abnormal events, implying a relationship between abnormal event and profile variation. We also found a linear trend in the left-edge position of the averaged profiles between the first and third events as well as after the third event, suggesting the existence of a slow-drifting mode between the two major events. The second event has a comparatively small shift in phase and is thus categorized as a "small flare state". During the third event, a sequence of approximately nine pulses was seen to significantly weaken in all frequency bands, likely associated with the pseudo-nulling observed at 150 MHz.A three-component de-composition analysis of the normal averaged profiles shows that the trailing component is dominant at our observing frequencies, while the centre component has a comparatively steeper spectrum. We found the overall flux density in an abnormal event to slightly differ from that in an ordinary state, and the difference shows a frequency dependence. A comparison of the normal, abnormal and dimmed averaged profile indicates that the leading component is likely to be stable in all states.

关键词： pulsar B0919+06 radio

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Searching for exoplanets with HEPS:*** probability of Earth-like planets in multiple systems

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Research in astronomy and Astrophysics 2019年第1期19卷 35-46页

作者： Zhou-Yi yu hui-Gen liu Ji-lin Zhou Dong-Hong Wu Ming Yang Songhu Wang hui Zhang Zi Zhu Jia-Cheng liu school of astronomy and space science Key Laboratory of Modern Astronomy and Astrophysics in Ministry of EducationNanjing University Department of astronomy Yale University

The astrometry method has great advantages in searching for exoplanets in the habitable zone around solar-like stars. However, the presence of multiple planets may cause a problem with degeneracy when trying to compute accurate planet parameters from observation data and reduce detectability. The degeneracy problem is extremely critical, especially in a space mission which has limited observation time and cadence. In this series of papers, we study the detectability of habitable Earth-mass planets in different types of multi-planet systems, aiming to find the most favorable targets for the potential space mission–Habitable ExoPlanet Survey(HEPS). In the first paper, we present an algorithm to find planets in the habitable zone around solar-like stars using astrometry. We find the detectability can be well described by planets' signal-to-noise ratio(SNR) and a defined parameter S = M2/(T1-T2)2, where M2 and T2are the mass and period of the second planet, respectively. T1 is the period of the planet in the habitable zone. The parameter S represents the influence of planetary architectures. We fit the detectability as a function of both the SNR of the planet in the habitable zone and the parameter S. An Earth-like planet in a habitable zone is harder to detect(with detectability PHP< 80%) in a system with a hot Jupiter or warm Jupiter(within2 AU), in which the parameter S is large. These results can be used in target selections and to determine the priority of target stars for HEPS, especially when we select and rank nearby planet hosts with a single planet.

关键词： astrometry stars:planetary systems planets and satellites:detection methods:numerical

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CEPC Technical Design Report

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Radiation Detection Technology and Methods 2024年第1期8卷 I0003-I0016,1-1091页

作者： Waleed Abdallah Tiago Carlos Adorno de Freitas Konstantin Afanaciev Shakeel Ahmad Ijaz Ahmed xiaocong Ai Abid Aleem Wolfgang Altmannshofer Fabio Alves Weiming An Rui An Daniele Paolo Anderle Stefan Antusch Yasuo Arai Andrej Arbuzov Abdesslam Arhrib Mustafa Ashry Sha Bai yu Bai Yang Bai Vipul Bairathi Csaba Balazs Philip Bambade Yong Ban Tripamo Bandyopadhyay Shou-Shan Bao Desmond P.Barber Ayse Bat Varvara Batozskaya Subash Chandra Behera Alexander Belyaev Michele Bertucci xiao-Jun Bi yuanjie Bi Tianjian Bian Fabrizio Bianchi Thomas Biekotter Michela Biglietti Shalva Bilanishvili Deng Binglin Denis Bodrov Anton Bogomyagkov Serge Bondarenko Stewart Boogert Maarten Boonekamp Marcello Borri Angelo Bosotti Vincent Boudry Mohammed Boukidi Igor Boyko Ivanka Bozovic Giuseppe Bozzi Jean-Claude Brient Anastasiia Budzinskaya Masroor Bukhari Vladimir Bytev Giacomo Cacciapaglia Hua Cai Wenyong Cai Wujun Cai Yijian Cai Yizhou Cai yuchen Cai Haiying Cai Huacheng Cai Lorenzo Calibbi Junsong Cang Guofu Cao Jianshe Cao Antoine Chance Xuejun Chang yue Chang Zhe Chang xinyuan Chang Wei Chao Auttakit Chatrabhuti Yimin Che yuzhi Che Bin Chen Danping Chen Fuqing Chen Fusan Chen Gang Chen Guoming Chen Hua-xing Chen huirun Chen Jinhui Chen Ji-yuan Chen Kai Chen Mali Chen Mingjun Chen Mingshui Chen Ning Chen Shanhong Chen Shanzhen Chen Shao-Long Chen Shaomin Chen Shiqiang Chen Tianlu Chen Wei Chen xiang Chen xiaoyu Chen xin Chen Xun Chen Xurong Chen Ye Chen Ying Chen yukai Chen Zelin Chen Zilin Chen Gang Chen Boping Chen Chunhui Chen Hok Chuen Cheng Huajie Cheng Shan Cheng Tongguang Cheng yunlong Chi Pietro Chimenti Wen Han Chiu Guk Cho Ming-Chung Chu xiaotong Chu Ziliang Chu Guglielmo Coloretti Andreas Crivellin Hanhua Cui xiaohao Cui zhaoyuan Cui Brunella D'Anzi ling-yun Dai xinchen Dai Xuwen Dai Antonio De Maria Nicola De Filippis Christophe De La Taille Francesca De Mori Chiara De Sio Elisa Del Core Shuangxue Deng Wei-Tian Deng Zhi Deng Ziyan Deng Bhupal Dev Tang Dewen Biagio Di Micco Ran Ding Siqin Dingl Yadong Ding Haiyi Dong Jianin AGH university of science and Technology Faculty of Physics and Applied Computer ScienceKrakow Anhui university HefeiAnhui Applied Physics Department Federal Urdu University of ArtsScience and TechnologyIslamabad Banaras Hindu university Institute of ScienceVaranasi Bandirma Onyedi Eylul university Bandirma Beihang university Beijing Beijing Computational science Research Center Beijing Beijing Conveyi LTD Beijing Beijing Glass Research Institute Co. LtdBeijing Beijing Institute of Technology Beijing Beijing Normal university Beijing Brown university ProvidenceRI Budker Institute of Nuclear Physics Novosibirsk Cadi Ayyad university Laboratory of Fundamental and Applied PhysicsPolydisciplinary FacultyMarrakech Cairo university Giza Center for Theory and Computation National Tsing Hua UniversityHsinchu Central china Normal university WuhanHubei Central South university ChangshaHunan Centro de Fisica Teorica de Particulas Universidade Tecnica de LisboaLisboa Chengdu KaitengSifang Digital Radio&TV Equipment Co. LtdChengduSichuan china academy of engineering physics MianyangSichuan china building materials academy Beijing china Center of Advanced science and Technology Beijing china Institute of Atomic Energy Beijing china Jiliang university HangzhouZhejiang china Nuclear Instrument CO. LTDBeijing china university of Geosciences Beijing china university of Geosciences WuhanHubei china university of Mining and Technology XuzhouJiangsu china West Normal university NanchongSichuan Chongqing university Department of PhysicsChongqing Chulalongkorn university Bangkok City university of Hong Kong Department of PhysicsHong Kong Cockcroft Institute Daresbury Cornell university IthacaNY CPPM(AMU/IPhU&CNRS/INP) Marseille Dalian Minzu university DalianLiaoning Dalian university of Technology Department of PhysicsDalian Deutsches Elektronen-Synchrotron DESY Hamburg Dzhelepov Laboratory of Nuclear Problems of Joint Institute for Nuclear Research(DLNP JINR) Dubna East china university Of science And Technol

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by china,fostered through extensive collaboration with international *** complex comprises four accelerators:a 30 GeV linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs *** its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs *** the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of *** Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering ***,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection *** is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 *** commencement of experiments and data collection could potentially be initiated in the mid-2030s.

关键词： initiated exceeding precise

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Research on actuator distribution and panels for a radio telescope

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Research in astronomy and Astrophysics 2021年第7期21卷 31-36页

作者： Jin-Qing Wang Zheng-xiong Sun Li Fu Jin-ling Li lin-Feng yu Yong-Chen Jiang Yong-Bin Jiang Wei Gou Wei Hu Rong-Bin zhao Qin-hui liu Zhi-Qiang Shen Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Key Laboratory of Radio astronomy Chinese Academy of SciencesNanjing 210008China Shanghai Key Laboratory of space Navigation and Positioning Techniques Shanghai 430074China university of Shanghai for science and Technology Shanghai 200093China

Trying to achieve the best surface accuracy control with the fewest actuators, this article mainly studies the distribution of actuators and the method of panel design. The influence of the number of faulty actuators on the accuracy of the surface shape is demonstrated. In addition, the method incorporating a triangular panel, node index and the fitting solution method of a single panel is also given. This method provides a reference for the design and realization of an active surface or a deformable sub-reflector for high performance large aperture radio telescopes.

关键词： radio telescope triangle panel method design

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Probing primordial gravitational waves: Ali CMB Polarization Telescope

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National science Review 2019年第1期6卷 145-154页

作者： Hong Li Si-yu Li Yang liu Yong-Ping Li Yifu Cai Mingzhe Li Gong-Bo zhao Cong-Zhan liu Zheng-Wei Li He Xu Di Wu Yong-Jie Zhang Zu-hui Fan Yong-Qiang Yao Chao-lin Kuo Fang-Jun Lu xinmin Zhang Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Theoretical Physics Division Institute of High Energy PhysicsChinese Academy of Sciences university of Chinese Academy of sciences CAS Key Laboratory for Researches in Galaxies and Cosmology Department of AstronomyUniversity of Scienceand Technology of China Interdisciplinary Center for Theoretical Study University of Science and Technology of China National Astronomical Observatories Chinese Academy of Sciences Institute of Cosmology& Gravitation University of Portsmouth Key Laboratory of Particle Astrophysics Institute of High EnergyPhysics Chinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy Physics ChineseAcademy of Sciences Department of astronomy School of Physics Peking University Physics Department Stanford University

In this paper, we will give a general introduction to the Ali CMB Polarization Telescope(Ali CPT) project,which is a Sino–US joint project led by the Institute of High Energy Physics and involves many different institutes in china. It is the first ground-based Cosmic Microwave Background(CMB) polarization experiment in china and an integral part of china’s Gravitational-wave Program. The main scientific goal of the Ali CPT project is to probe the primordial gravitational waves(PGWs) originating from the very early Universe. The AliCPT project includes two stages. The first stage, referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet at an altitude of 5250 meters. Once completed, it will be the highest ground-based CMB observatory in the world and will open a new window for probing PGWs in the northern hemisphere. The AliCPT-1 telescope is designed to have about 7000 transition-edge sensor detectors at 95 GHz and 150 GHz. The second stage is to have a more sensitive telescope(Ali CPT-2) with more than 20 000 detectors. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio r by one order of magnitude with three years’ observation. Besides the PGWs, Ali CPT will also enable a precise measurement of the CMB rotation angle and provide a precise test of the CPT symmetry. We show that three years’ observation will improve the current limit by two orders of magnitude.

关键词： primordial gravitational waves cosmic microwave background Ali CMB Polarization Telescope

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Compact CubeSat Gamma-ray detector for GRID mission

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Nuclear science and Techniques 2021年第9期32卷 105-115页

作者： Jia-xing Wen Xu-Tao Zheng Jian-Dong yu yue-Peng Che Dong-xin Yang Huai-Zhong Gao Yi-Fei Jin xiang-yun Long Yi-hui liu Da-Cheng Xu yu-Chong Zhang Ming Zeng Yang Tian Hua Feng Zhi Zeng Ji-Rong Cang Qiong Wu Zong-Qing zhao Bin-Bin Zhang Peng An GRID collaboration Key Laboratory of Particle and Radiation Imaging(Tsinghua university) Ministry of EducationBeijing 100084China Department of Engineering Physics Tsinghua UniversityBeijing 100084China science and Technology on Plasma Physics Laboratory Laser Fusion Research CenterCAEPMianyang 621900China school of Electronic and Information Engineering Ningbo University of TechnologyNingbo 315201China Department of astronomy Tsinghua UniversityBeijing 100084China Department of Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Modern astronomy and Astrophysics(nanjing university) Ministry of EducationNanjing 210093China nanjing university School of Astronomy and Space SciencesNanjing 210093China

Gamma-Ray Integrated Detectors(GRID)mis-sion is a student project designed to use multiple gamma-ray detectors carried by nanosatellites(CubeSats),forming a full-time all-sky gamma-ray detection network that monitors the transient gamma-ray sky in the multi-mes-senger astronomy era.A compact CubeSat gamma-ray detector,including its hardware and firmware,was designed and implemented for the *** detector employs four Gd 2 Al 2 Ga 3 O 12:Ce(GAGG:Ce)scintillators coupled with four silicon photomultiplier(SiPM)arrays to achieve a high gamma-ray detection efficiency between 10 keV and 2 MeV with low power and small *** first detector designed by the undergraduate student team onboard a commercial CubeSat was launched into a Sun-synchronous orbit on October 29,*** detector was in a normal observation state and accumulated data for approximately one month after on-orbit functional and performance tests,which were conducted in 2019.

关键词： Gamma-ray bursts Scintillation detectors SiPM CubeSat

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Detecting and Monitoring Tidal Dissipation of Hot Jupiters in the Era of SiTian

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Research in astronomy and Astrophysics 2022年第5期22卷 36-46页

作者： Fan Yang Wei Wang xing Wei hui Zhang Ji-lin Zhou Su-Su Shan Jie Zheng Wei-Kai Zong Ming Yang yu Bai Song Wang Jia-Chen Zheng yu-Ru Xu yu-Feng Li You-Jun Lu Ji-Feng liu Department of astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Optical astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China school of astronomy and space science University of Chinese Academy of SciencesBeijing 100049China school of astronomy and space science Nanjing UniversityNanjing 210023China

Transit Timing Variation(TTV)of hot Jupiters provides direct observational evidence of planet tidal *** tidal dissipation through TTV needs high precision transit timings and long timing *** this work,we predict and discuss the potential scientific contribution of the SiTian Survey in detecting and analyzing exoplanet *** develop a tidal dissipation detection pipeline for the SiTian Survey that aims at time-domain astronomy with 721 m optical *** pipeline includes the modules of light curve deblending,transit timing acquisition and TTV *** is capable of detecting more than 25,000 exoplanets among which we expect~50 sources to show evidence of tidal *** present detection and analysis of tidal dissipating targets,based on simulated SiTian light curves of XO-3b and WASP-161 *** transit light curve modeling gives consistent results within 1σto input values of simulated light ***,the parameter uncertainties predicted by Markov Chain Monte Carlo are consistent with the distribution obtained from simulating and modeling the light curve 1000 *** timing precision of SiTian observations is~0.5 minutes with one transit *** show that differences between TTV origins,e.g.,tidal dissipation,apsidal precession and multiple planets,would be significant,considering the timing precision and *** detection rate of tidal dissipating hot Jupiters would answer a crucial question of whether the planet migrates at an early formation stage or random stages due to perturbations,e.g.,planet scattering or secular *** identified targets would be constructive given that the sample would extend tenfold.

关键词： planets and satellites gaseous planets-planets and satellites physical evolution-planets and satellites dynamical evolutionand stability-planetsandsatellites detection

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Preliminary study on road-region ecosystem stability evaluation

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Journal of Environmental science and Engineering 2008年第5期2卷 48-54页

作者： QIN Zhi-bin liu zhao-hui LI yu-zhi Changsha university of science and Technology School of Highway Engineering Changsha 410076 China

A scientific and rational evaluation on road-region ecosystem stability is the premise to properly deal with the relationship between highway constructing and ecological environment protecting to a sustainable development. Based on the connotative meaning and the procedure of evaluation on road-region ecosystem stability, this paper studied the principles and the method on determining the evaluation index system on road-region ecosystem stability. It put forward an index system for assessing road-region ecosystem stability as a reference. On the basis of detailed analyze of the multidimensional space of road-region ecosystem, a new multi-objective comprehensive evaluation method for road-region ecosystem stability is presented and a calculation tormula for multi-objective comprehensive level of road-region ecosystem stability. This method was used to evaluate road-region ecosystem stability of lin-Chang highway. This method possessed definite theoretical value and reliability in practice.

关键词： road-region ecosystem evaluation of stability multi-objective multidimensional space

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Cryo-EM structure and transport mechanism of a wall teichoic acid ABC transporter

Cryo-EM structure and transport mechanism of a wall teichoic...

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第六届全国冷冻电子显微学与结构生物学专题研讨会

作者： Li CHEN Wen-tao hou Tao FAN yu-hui LI Bang-hui liu Yong-liang JIANG Wen WEN lin-feng SUN yu-xing CHEN Cong-zhao Zhou Hefei National Laboratory for Physical sciences at the Microscale and school of Life sciences CAS Centre for Excellence in Molecular Cell science University of Science and Technology of China

＜正＞The wall teichoic acid （WTA） is a major component of pathogenic factor in methicillinresistant Staphylococcus aureus （MRSA）, and a common cause of fatal clinical infections to human. TarGH, an ABC transporter that flips WTA from cytoplasm to extracellular space, is a promising target of anti-MRSA drugs. Here we report the 3.9?cryo-EM structure of a 50%sequence-identical homolog of TarGH from Alicyclobacillus herbarius at an ATP-free and inward-facing conformation. Structural comparison and analysis enable us to propose a

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The Study of Unusual Emission from PSR B1859+07 using FAST

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Research in astronomy and Astrophysics 2022年第4期22卷 1-10页

作者： lin Wang Ye-zhao yu Feifei Kou Kuo liu xinxin Wang Bo Peng CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing100101China Qiannan Normal university for Nationalities Duyun558000China school of astronomy and space science University of Chinese Academy of SciencesBeijing100049China Max-Plank-Institut für Radioastronomie Auf dem Hügel 69BonnD-53121Germany xinjiang Astronomical Observatories Chinese Academy of SciencesUrumqi830011China United World College of Changshu china Changshu215500China

We present simultaneous broad-band radio observations on the abnormal emission mode from PSR B1859+07using the Five-hundred-meter Aperture Spherical radio Telescope(FAST).This pulsar shows peculiar emission,which takes the form of occasional shifts of emission to an early rotational phase and mode change of emission at the normal *** confirm all these three emission modes with our data sets,including the B(burst)and Q(quiet)modes of the non-shifted pulses and the emission shift mode with a quasi-periodicity of 155 *** also identify a new type of emission shift event,which has emission at the normal phase during the *** studied polarization properties of these emission modes in detail,and found that they all have similar polarization angle curve,indicating the emissions of all these three modes are from the same emission height.

关键词： pulsars:general pulsars:individual(B1859+07) methods:observational

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