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Luminosity of a radio pulsar and its new emission death line

Research in Astronomy and Astrophysics 2020年第11期20卷 325-332页

作者： qing-Dong Wu Qi-Jun Zhi Cheng-Min Zhang De-Hua Wang chang-qing ye School of Physics and Electronic Sciences Guizhou Normal UniversityGuiyang 550001China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guiyang 550001China University of Chinese Academy of Sciences Beijing 100049China

We investigated the pulsar radio luminosity(L),emission efficiency(ratio of radio luminosity to its spin-down powerE),and death line in the magnetic field(B)versus spin period(P)*** found that the dependence of pulsar radio luminosity on its spin-down power(L-E)is very weak,shown as L^E0.06,which deduces an equivalent inverse correlation between emission efficiency and spin-down power asξ~***,we examined the distributions of radio luminosity of millisecond and normal pulsars and found that for the similar spin-down powers,the radio luminosity of millisecond pulsars is about one order of magnitude lower than that of the normal *** analysis of pulsar radio flux suggests that these correlations are not due to a selective effect but are intrinsic to the pulsar radio emission *** radio radiations may be dominated by the different radiation *** cutoff phenomenon of currently observed radio pulsars in B-P diagram is usually referred as the"pulsar death line",which corresponds toE≈1030 erg s-1 and is obtained by the cut-off voltage of electron acceleration gap in the polar cap model of pulsar proposed by Ruderman and ***,this death line can be inferred by the actual observed pulsar flux S≥1 mJy and 1 kpc distance,together with the maximum radio emission efficiency of 1%.However,the observation data show that the 37 pulsars pass over the death line,including the recently observed two pulsars with long periods of 23.5 s and 12.1 s,which violate the prediction of the polar cap *** present,the actual observed pulsar flux can reach0.01 mJy by FAST *** will arise the observational limit of spin-down power of pulsars as low as E˙≈1028 erg *** means that the new death line is downward shifted two orders of magnitude,which might be favorably referred as the"observational limit–line".Accordingly,the pulsar theoretical model for the cut-off voltage of gap should be heavily modified.

关键词： stars neutron pulsars general stars fundamental parameters

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Detection of astrophysical gravitational wave sources by TianQin and LISA

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 123-163页

作者： Alejandro Torres-Orjuela Shun-Jia Huang Zheng-Cheng Liang Shuai Liu Hai-Tian Wang chang-qing ye Yi-Ming Hu Jianwei Mei MOE Key Laboratory of Tian Qin Mission Tian Qin Research Center for Gravitational PhysicsSchool of Physics and AstronomyFrontiers Science Center for Tian QinGravitational Wave Research Center of CNSASun Yat-Sen University(Zhuhai Campus)Zhuhai 519082China Department of Physics The University of Hong KongHong Kong 999077China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing100871China

TianQin and LISA are space-based laser interferometer gravitational wave(GW)detectors planned to be launched in the *** detectors will detect low-frequency GWs around 10^(-2)Hz;however,Tian Qin is more sensitive to frequencies above this common sweet-spot while LISA is more sensitive to frequencies below 10^(-2)***,Tian Qin and LISA will be able to detect the same sources but with different accuracy depending on the source and its *** consider some of the most important astrophysical sources—massive black hole binaries,stellar-mass black hole binaries,double white dwarfs,extreme mass ratio inspirals,light and heavy intermediate mass ratio inspirals,as well as the stochastic gravitational background of astrophysical origin—that Tian Qin and LISA will be able to *** each of these sources,we analyze how far they can be detected(detection distance)and how well their parameters can be measured(detection accuracy)using a Fisher Matrix *** compare the results obtained by the three detection scenarios(Tian Qin alone,LISA alone,and joint detection by LISA and Tian Qin)highlighting the gains from joint detection as well as the contribution of Tian Qin and LISA to a combined study of astrophysical *** particular,we consider the different orientations,lifetimes,and duty cycles of the two detectors to explore how they can give a more complete picture when working together.

关键词： wave extreme stochastic

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Molecular Conformational Isomerization:An Efficient Way to Design Novel Emitters with Dual-Thermally Activated Delayed Fluorescence Characteristics and Their Optoelectronic and Bioimaging Applications

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CCS Chemistry 2024年第4期6卷 912-922页

作者： Yi-Zhong Shi Ya-Fang Xiao Hao Wu Shao-Li Zhang Xiao-Chun Fan ye Tian chang-qing ye Kai Wang Jia Yu Chun-Sing Lee Xiao-Hong Zhang School of Materials Science and Engineering Suzhou University of Science and TechnologySuzhou 215009 Institute of Functional Nano and Soft Materials(FUNSOM) Joint International Research Laboratory of Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhou 215123Jiangsu Center of Super-Diamond and Advanced Films(COSDAF) Department of ChemistryCity University of Hong KongHong Kong SAR School of Biomedical Engineering The Second Affiliated HospitalGuangzhou Medical UniversityGuangzhou 510260 Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices Soochow UniversitySuzhou 215123Jiangsu Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123Jiangsu

Single-molecule luminophores with dual-thermally activated delayed fluorescence(TADF)properties are receiving increasing ***,how to achieve these goals requires more in-depth ***,we demonstrate a novel example emitter,10-(5-(2-(pyridin-3-yl)-[4,5′-bipyrimidin]-6-yl)pyridin-2-yl)-10Hphenoxazine(PmPy-PXZ),enabling dual-TADF properties due to its key feature of conformational *** a pyridine bridge can greatly reduce the steric hindrance and facilitate dual-stable conformations in the ground state,where the quasi-axial(QA)forms ***,unlike previously reported TADF molecules with dual confirmations,both theoretical and experimental measurements show that not only the quasi-equatorial(QE)forms but also the QA forms exhibit distinct TADF characteristics,which can be attributed to an additional higher reverse intersystem crossing *** is the first time that dual-TADF properties of single molecules have been achieved based on conformational *** applications in“self-doping”organic light-emitting diode and biomedical imaging have further been *** these results show the good potential of such dual-band TADF emitters based on molecular conformational isomerization.

关键词： dual-thermally activated delayed fluorescence conformational isomerization organic light-emitting diode biomedical imaging self-doping

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负运价的财务原因与管理策略——中国海运业负运价案引发的思考

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中国流通经济 2008年第11期22卷 78-80页

作者：常叶青山东工商学院会计学院山东烟台264005

在国际海运市场上,由于竞争激烈,海运运价日益下滑。海运企业为了揽活,以不收钱甚至倒贴钱的方式,将货主的货物送达目的港口,出现了零运价和负运价现象。文章提出,负运价其实是中国海运业的一种高风险财务策略,负运价并不等于负的运费收... 详细信息

在国际海运市场上,由于竞争激烈,海运运价日益下滑。海运企业为了揽活,以不收钱甚至倒贴钱的方式,将货主的货物送达目的港口,出现了零运价和负运价现象。文章提出,负运价其实是中国海运业的一种高风险财务策略,负运价并不等于负的运费收入,负运价的实施只是削减了利润,并不意味着海运企业必然亏损,甚至有时还有利可图。负运价将导致市场无序化,带来海运企业更高程度的经营风险。因此,必须在宏观上加强法律法规约束,树立共赢的财务理念,追求卓越的服务质量,开创新的市场空间,确立战略管理思维,并实行相对谨慎的财务管理策略,以加强对海运业的管理,促进海运业稳健发展。

关键词：负运价中日航线经营杠杆财务政策战略思维

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Interest and participation are two crucial factors for bilingual teaching of pathophysiology

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中国病理生理杂志 2009年第11期25卷 2255-2255页

作者： ZHANG Li XU chang- qing TIAN ye Department of Pathophysiology Harbin Medical University Harbin 150086 China

Because the western medicine originates in western countries and those countries offer the cutting-edge technologies for current medical development,Chinese medical professionals need to learn from their foreign peers. When Chinese medical scholars go abroad,attend an international scientific conference or publish their research results,one issue they may face is the cross-culture academic English communication.

关键词：病理生理学双语教学国际学术会议利息西方国家国际竞争力尖端技术研究成果

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Statistical properties of fast radio bursts elucidate their origins:magnetars are favored over gamma-ray bursts

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Research in Astronomy and Astrophysics 2021年第8期21卷 285-292页

作者： Xiang-Han Cui Cheng-Min Zhang Shuang-Qiang Wang Jian-Wei Zhang Di Li Bo Peng Wei-Wei Zhu Richard Strom Na Wang qingdong Wu chang-qing ye De-Hua Wang Yi-Yan Yang Zhen-Qi Diao CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Department of Astronomy Beijing Normal UniversityBeijing 100875China NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa Key Laboratory of Radio Astronomy Chinese Academy of SciencesBeijing 100101China Netherlands Institute for Radio Astronomy(ASTRON) Postbus 27990 AA Dwingeloothe Netherlands Astronomical Institute ‘Anton Pannekoek’ Faculty of Science University of Amsterdam1090 GE Amsterdamthe Netherlands TianQin Research Center for Gravitational Physics Sun Yat-sen UniversityZhuhai 519082China School of Physics and Electronic Sciences Guizhou Education UniversityGuiyang 550018China

Fast radio bursts(FRBs) are extremely strong radio flares lasting several milliseconds,most of which come from unidentified objects at a cosmological *** can be apparently repeating or *** this paper,we analyzed 18 repeaters and 12 non-repeating FRBs observed in the frequency bands of 400–800 MHz from Canadian Hydrogen Intensity Mapping Experiment(CHIME).We investigated the distributions of FRB isotropic-equivalent radio luminosity,considering the K ***,the luminosity distribution can be better fitted by Gaussian form than by *** on the above results,together with the observed FRB event rate,pulse duration,and radio luminosity,FRB origin models are evaluated and constrained such that the gamma-ray bursts(GRBs) may be excluded for the non-repeaters while magnetars or neutron stars(NSs) emitting the supergiant pulses are preferred for the *** also found the necessity of a small FRB emission beaming solid angle(about 0.1 sr) from magnetars that should be considered,and/or the FRB association with soft gamma-ray repeaters(SGRs) may lie at a low probability of about 10%.Finally,we discussed the uncertainty of FRB luminosity caused by the estimation of the distance that is inferred by the simple relation between the redshift and dispersion measure(DM).

关键词： transients:fast radio bursts methods:statistical stars:magnetars

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