A scheme for probabilistic teleporting an unknown two-particle state of general formation by partly pure entangled four-particle state is proposed. It is shown that after performing two Bell state measurements, proper...A scheme for probabilistic teleporting an unknown two-particle state of general formation by partly pure entangled four-particle state is proposed. It is shown that after performing two Bell state measurements, proper unitary transformation and the measurement on an auxiliary qubit, the unknown two-particle state of general formation, which was destroyed at one place, can be reconstructed at another place with certain probability.展开更多
Embedded clusters are ideal laboratories for understanding the early phase of the dynamical evolution of clusters as well as massive star formation. An interesting observational phenomenon is that some of the embedded...Embedded clusters are ideal laboratories for understanding the early phase of the dynamical evolution of clusters as well as massive star formation. An interesting observational phenomenon is that some of the embedded clusters show mass segregation, i.e., the most massive stars are preferentially found near the cluster center. We develop a new approach to describe mass segregation. Using this approach and the Two Micron All Sky Survey Point Source Catalog （2MASS PSC）, we analyze 18 embedded clusters in the Galaxy. We find that 11 of them are mass-segregated and that the others are not mass-segregated. No inversely mass-segregated cluster is found.展开更多
Spectra are fundamental observation data used for astronomical research,but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations.Different models giv...Spectra are fundamental observation data used for astronomical research,but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations.Different models give different insights for understanding a specific object.Hence,laboratory benchmarks for these theoretical models become necessary.An electron beam ion trap is an ideal facility for spectroscopic benchmarks due to its similar conditions of electron density and temperature compared to astrophysical plasmas in stellar coronae,supernova remnants and so on.In this paper,we will describe the performance of a small electron beam ion trap/source facility installed at National Astronomical Observatories,Chinese Academy of Sciences.We present some preliminary experimental results on X-ray emission,ion production,the ionization process of trapped ions as well as the effects of charge exchange on the ionization.展开更多
With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we sum- marize the major statistical results that have been revealed ...With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we sum- marize the major statistical results that have been revealed mainly by radial velocity and transiting observations, and try to interpret them within the scope of the classical core-accretion scenario of planet formation, especially in the formation of different orbital architectures for planetary systems around main sequence stars. Based on the different possible formation routes for different planet systems, we tentatively classify them into three major catalogs： hot Jupiter systems, standard systems and distant giant planet systems. The standard systems can be further categorized into three sub-types under different circumstances： solar-like systems, hot Super-Earth systems, and sub- giant planet systems. We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.展开更多
We re-examine the properties of the star cluster population in the circumnuclear starburst ring in the face-on spiral galaxy NGC 7742, whose young cluster mass function has been reported to exhibit significant deviati...We re-examine the properties of the star cluster population in the circumnuclear starburst ring in the face-on spiral galaxy NGC 7742, whose young cluster mass function has been reported to exhibit significant deviations from the canonical power law. We base our reassessment on the clusters＇ luminosi- ties （an observational quantity） rather than their masses （a derived quantity）, and confirm conclusively that the galaxy＇s starburst-ring clusters--and particularly the youngest subsample, log（t yr-1） ≤7.2- show evidence of a turnover in the cluster luminosity function well above the 90% completeness limit adopted to ensure the reliability of our results. This confirmation emphasizes the unique conundrum posed by this unusual cluster population.展开更多
Stellar populations contain the most important information about star cluster formation and evo- lution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar po...Stellar populations contain the most important information about star cluster formation and evo- lution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations （SSPs）. However, discoveries of multiple stellar populations in Galactic globular clus- ters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar popu- lations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ages. We present the history and progress of research in this active field, as well as some of the most recent improvements, including ob- servational results and scenarios that have been proposed to explain the observations. Although our current ability to determine the origin of multiple stellar populations in star clusters is unsatisfactory, we propose a number of promising projects that may contribute to a significantly improved understanding of this subject.展开更多
文摘A scheme for probabilistic teleporting an unknown two-particle state of general formation by partly pure entangled four-particle state is proposed. It is shown that after performing two Bell state measurements, proper unitary transformation and the measurement on an auxiliary qubit, the unknown two-particle state of general formation, which was destroyed at one place, can be reconstructed at another place with certain probability.
基金project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technologyfunded by the National Aeronautics and Space Administration and the National Science Foundationsupported by the National Natural Science Foundation of China(Grant Nos.10873037,10921063,10733030 and 10833001)
文摘Embedded clusters are ideal laboratories for understanding the early phase of the dynamical evolution of clusters as well as massive star formation. An interesting observational phenomenon is that some of the embedded clusters show mass segregation, i.e., the most massive stars are preferentially found near the cluster center. We develop a new approach to describe mass segregation. Using this approach and the Two Micron All Sky Survey Point Source Catalog （2MASS PSC）, we analyze 18 embedded clusters in the Galaxy. We find that 11 of them are mass-segregated and that the others are not mass-segregated. No inversely mass-segregated cluster is found.
基金supported by the National Key R&D Program of China(No.2017YFA0402401)the National Natural Science Foundation of China(Grant No.11522326)+1 种基金the National Basic Research Program of China(973 Program,Grant 2013CBA01503)support by the Science Challenge Project(No.TZ2016005)
文摘Spectra are fundamental observation data used for astronomical research,but understanding them strongly depends on theoretical models with many fundamental parameters from theoretical calculations.Different models give different insights for understanding a specific object.Hence,laboratory benchmarks for these theoretical models become necessary.An electron beam ion trap is an ideal facility for spectroscopic benchmarks due to its similar conditions of electron density and temperature compared to astrophysical plasmas in stellar coronae,supernova remnants and so on.In this paper,we will describe the performance of a small electron beam ion trap/source facility installed at National Astronomical Observatories,Chinese Academy of Sciences.We present some preliminary experimental results on X-ray emission,ion production,the ionization process of trapped ions as well as the effects of charge exchange on the ionization.
基金supported by the National Natural Science Foundation of China (Nos. 10833001, 10925313, 11078001 and 11003010)Fundamental Research Funds for the Central Universities (No. 1112020102)the Research Fund for the Doctoral Program of Higher Education of China (Nos. 20090091110002 and 20090091120025)
文摘With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we sum- marize the major statistical results that have been revealed mainly by radial velocity and transiting observations, and try to interpret them within the scope of the classical core-accretion scenario of planet formation, especially in the formation of different orbital architectures for planetary systems around main sequence stars. Based on the different possible formation routes for different planet systems, we tentatively classify them into three major catalogs： hot Jupiter systems, standard systems and distant giant planet systems. The standard systems can be further categorized into three sub-types under different circumstances： solar-like systems, hot Super-Earth systems, and sub- giant planet systems. We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.
基金supported by the National Key Research and Development Program of China(Grant 2017YFA0402702)the National Natural Science Foundation of China(Grant Nos.U1631102,11373010and 11633005)
文摘We re-examine the properties of the star cluster population in the circumnuclear starburst ring in the face-on spiral galaxy NGC 7742, whose young cluster mass function has been reported to exhibit significant deviations from the canonical power law. We base our reassessment on the clusters＇ luminosi- ties （an observational quantity） rather than their masses （a derived quantity）, and confirm conclusively that the galaxy＇s starburst-ring clusters--and particularly the youngest subsample, log（t yr-1） ≤7.2- show evidence of a turnover in the cluster luminosity function well above the 90% completeness limit adopted to ensure the reliability of our results. This confirmation emphasizes the unique conundrum posed by this unusual cluster population.
基金supported by a Macquarie Research Fellowship and by Strategic Priority Program ‘The Emergence of Cosmological Structures’ of the Chinese Academy of Sciences(Grant XDB09000000)support from the National Natural Science Foundation of China(Grant Nos.11073001,11373010 and 11473037)
文摘Stellar populations contain the most important information about star cluster formation and evo- lution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations （SSPs）. However, discoveries of multiple stellar populations in Galactic globular clus- ters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar popu- lations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ages. We present the history and progress of research in this active field, as well as some of the most recent improvements, including ob- servational results and scenarios that have been proposed to explain the observations. Although our current ability to determine the origin of multiple stellar populations in star clusters is unsatisfactory, we propose a number of promising projects that may contribute to a significantly improved understanding of this subject.
