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Panel positioning error and support mechanism for a 30-m THz radio telescope

Research in Astronomy and Astrophysics 2011年第6期11卷 725-736页

作者： De-Hua Yang Daniel Okoh Guo-Hua Zhou Ai-Hua li Guo-Ping Jing-Quan Cheng national astronomical Observatories /Nanjing Institute of astronomical Optics ＆ Technology Chinese Academy of SciencesNanjing 210042China key Laboratory of astronomical Optics ＆ Technology Nanjing Institute of Astronomical Optics ＆ TechnologyChinese Academy of SciencesNanjing 210042China Centre for Basic Space Science National Space Research and Development AgencyUniversity of NigeriaNsukka 410002Nigeria national Radio Astronomy observatory CharlottesvilleVA 22903USA

A 30-m TeraHertz（THz） radio telescope is proposed to operate at 2.0 μm with an active primary *** paper presents sensitivity analysis of active surface panel positioning errors with optical performance in terms of the Strehl *** on Ruze＇s surface error theory and using a Monte Carlo simulation,the effects of six rigid panel positioning errors,such as piston,tip,tilt,radial,azimuthal and twist displacements,were directly *** optical performance of the telescope was then evaluated using the standard Strehl *** graphically illustrated the various panel error effects by presenting simulations of complete ensembles of full reflector surface errors for the six different rigid panel positioning *** of the panel error sensitivity analysis revealed that the piston error and tilt/tip errors are dominant while the other rigid errors are much less ***,as indicated by the results,we conceived of an alternative Master-Slave Concept-based（MSC-based） active surface by implementating a special Series-Parallel Concept-based（SPC-based） hexapod as the active panel support mechanism.A new 30-m active reflector based on the two concepts was demonstrated to achieve correction for all the six rigid panel positioning errors in an economically feasible way.

关键词： telescopes-methods:data analysis-methods:statistical-techniques:miscellaneous

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The Network and Its Application for the Solar Radio SpectralTelescope at yunnan {2.

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天文研究与技术 1999年第S1期 143-146页

作者： Chen Jingying, Xia Zhiguo, Cao Ying, Wang Shuhao, Jin Zhenyu, Wang Min (national astronomical Observatories, CAS) (Beijing {2., The chinese academy of sciences) (yunnan {2., The chinese academy of sciences, kunming 650011, china)

A “star shaped topology” network for solar radio dynamic spectrograph large scale data acquisition, storage and processing system (meterwave band 2.0 ～ 300MHz and decimeter band 700 ～ 1 4 GHz) and auto control system for the 10meter antenna has been set up at the yunnan observatory. Resource sharing among the optical disk drive, laser printer, MODEM and other devices is rea{2.zed. And a way to large scale data processing and storage for the solar radio observations of high time and frequency resolutions is found. A homepage is made on the Internet and the test of remote control of the telescope is successful.

关键词： computer network LAN application Internet dynamic spectrograph

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A Check on the Cardassian Expansion Model with Type-la Supernovae Data

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chinese Journal of Astronomy and Astrophysics 2003年第4期3卷 341-346页

作者： li Caonational {2. Observatories, chinese academy of sciences, Beijing 100012

We use the magnitude-redshift relation for the type Ia supernova datacompiled by Riess et al. to analyze the Cardassian expansion scenario. This scenario assumes theuniverse to be flat, matter dominated, and accelerating, but contains no vacuum contribution. Thebest fitting model parameters are H_0 = 65.3 km s^(-1) Mpc^(-1), n = 0.35 and Ω_m = 0.05. When thehighest redshift supernova, SN 1997ck, is excluded, H_0 remains the same, but n becomes 0.2. andΩ_m, 0.15, and the matter density remains unreasonably low. Our result shows that this particularscenario is strongly disfavoured by the SNeIa data.

关键词： supernovae: general cosmology: theory distances and redshifts

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k-Nearest Neighbors for automated classification of celestial objects

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Science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 916-922页

作者： li li{2.,2.3, ZHANG YanXia1 & ZHAO YongHeng1 1 national astronomical Observatories, chinese academy of sciences, Beijing 100012. china 2.Department of Physics, Hebei Normal University, Shijiazhuang 050016, china 3 Weishanlu Middle School, Tianjin 3002.2. china national astronomical Observatories Chinese Academy of Sciences Beijing China Department of Physics Hebei Normal University Shijiazhuang China Weishanlu Middle School Tianjin China

The nearest neighbors (NNs) classifiers, especially the k-Nearest Neighbors (kNNs) algorithm, are among the simplest and yet most efficient classification rules and widely used in practice. It is a nonparametric method of pattern recognition. In this paper, k-Nearest Neighbors, one of the most commonly used machine learning methods, work in automatic classification of multi-wavelength astronomical objects. Through the experiment, we conclude that the running speed of the kNN classier is rather fast and the classification accuracy is up to 97.73%. As a result, it is efficient and applicable to discriminate active objects from stars and normal galaxies with this method. The classifiers trained by the kNN method can be used to solve the automated classification problem faced by astronomy and the virtual {2. (VO).

关键词： k-Nearest Neighbors data analysis classification astronomical catalogues

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Searching for Variable Stars in and around Open Clusters

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chinese Journal of Astronomy and Astrophysics 2002年第6期2卷 481-486页

作者： Yu Xin, Xiao-Bin Zhang and li-Cai Dengnational {2. Observatories, chinese academy of sciences, Beijing 100012 national astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

We present a snapshot-of our recent results of a variable star survey in 1 degree fields around three open clusters: NGC 188, NGC 7789 and M67. A total number of 39 variable stars are newly discovered, including 2. W ... 详细信息

关键词： open clusters : individual : NGC 188, NGC 7789 and M67 stars : variables

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天体物理学讲座第一讲恒星的演化

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物理 2001年第9期30卷 560-570页

作者：黄润乾中国科学院国家天文台云南天文台

恒星结构和演化理论是研究恒星内部的物理过程、结构和恒星如何演化的科学 .文章介绍了恒星结构和演化模型的计算方法 ,恒星在赫罗图中的分布规律 ,恒星的形成和早期演化特性 ,质量不同的各类恒星从主序开始的演化进程 ,恒星演化的晚期... 详细信息

恒星结构和演化理论是研究恒星内部的物理过程、结构和恒星如何演化的科学 .文章介绍了恒星结构和演化模型的计算方法 ,恒星在赫罗图中的分布规律 ,恒星的形成和早期演化特性 ,质量不同的各类恒星从主序开始的演化进程 ,恒星演化的晚期阶段和产物 :白矮星、超新星和中子星 .

关键词：恒星演化恒星纳部结构计算方法赫罗图形成白矮星超新星

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Study of the primordial lithium abundance

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Science china(Physics,Mechanics & Astronomy) 2011年第S1期54卷 67-72页

作者： li ZhiHong1, li ErTao1, SU {2.1, li YunJu1, BAI XiXiang1, GUO Bing1, WANG YouBao1, CHEN YongShou1, HOU SuQing1, ZENG Sheng1, liAN Gang1, SHI JianRong2.& liU WeiPing1 1 china Institute of Atomic Energy, Beijing 102.13, china 2.9} astronomical Observatories, chinese academy of sciences, Beijing 100012. china china Institute of Atomic Energy Beijing China national astronomical Observatories Chinese Academy of Sciences Beijing China

lithium isotopes have attracted an intense interest because the abundance of both 6li and 6li from big bang nucleosynthesis (BBN) is one of the puzzles in nuclear astrophysics. Many investigations of both astrophysical observation and nucleosynthesis calculation have been carried out to solve the puzzle, but it is not solved yet. Several nuclear reactions involving lithium have been indirectly measured at china Institute of Atomic Energy, Beijing. The Standard BBN (SBBN) network calculations are then performed to investigate the primordial lithium abundance. The result shows that these nuclear reactions have minimal effect on the SBBN abundances of 6li and 7li.

关键词： big bang nucleosynthesis element abundance nuclear reaction network

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On the Evolution of the Lower Energy Cutoff of Nonthermal Electrons in Solar Flares

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chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 103-105页

作者： Wei－QunGan You－Pingli 等 PurpleMountainobservatory ChineseAcademyofSciencesNanjing210008 nationalastronomicalObservatories ChineseAcademyofSciencesBeijing100012

Using the method recently developed by Can et al. (2.01a, 2.02., We investigate the time variation of the lower energy cutoff (Ec) of nonthermal electrons for three BATSE/CGRO hard X-ray events. The result shows that Ec changes with time, from smaller before the peak flux, to larger at the peak, and then back to smaller after the peak. Such a variation of Ec, being a preliminary conclusion for the first time, should be checked in the future by using data with a higher energy resolution.

关键词： Sun: hard X-rays─Sun: gamma-rays─Sun: flares─Sun: particles

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New species and new records of diatoms from Lake Fuxian,china

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Journal of Systematics and Evolution 2010年第1期48卷 65-72页

作者： 1 Yan-ling li 1 Zhi-{2. GONG 2.Chun-Chao WANG 1 Ji SHEN 1(State key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and limnology,chinese academy of sciences,Nanjing 2.0008,china) 2.Nanjing Institute of Geology and Palaeontology,chinese academy of sciences,Nanjing 2.0008,china) (State key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China) (Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China)

One new species,four newly recorded genera,and two newly recorded species of diatoms are described from *** are Sellaphora fuxianensis ***,Sellaphora Mereschkowsky,Karayevia Round & Bukhtiyarova,Placoneis Mereschkowsky,Fallacia Stickle & Mann,Placoneis prespanensis Levkov,Krstic & Nakov,and Fallacia lucinensis(Hustedt) *** taxa were collected from Lake Fuxian in yunnan Province,*** species were observed with {2.ght and scanning electron microscopes,and their taxonomic characters are discussed.

关键词： china diatom new records new species.

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BL Lac Objects and Unified Model

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天文研究与技术 1999年第S1期 210-212页

作者： Fan J.H. (yunnan observatory, The {2., kunming 650011, china) (national astronomical Observatories, The {2.) (Center for Astrophysics, Guangzhou Normal University, Guangzhou 510400, china e mail: jhfan@g

In this paper: 1. The assumption of the dependence of Doppler factor on the emission frequency (δ v≈δ 0 18logvv o , Fan et al. 1993, ApJ., 415, 113) is used to explain the observational differences between the radio selected BL Lac objects (RBLs) and the X Ray Selected BL lac objects (XBLs): a) Hubble relation; b) different multiwavelength correlations; c) different regions in the effective spectral index (α RO - α OX ) diagram; d) different polarization. The results suggest that RBLs and XBLs are the same. 2. From the analysis of the relation between infrared magnitude and redshift, it is proposed that the parent population of BL Lac objects should be FRI radio galaxies and FRII(G) radio galaxies showing the optical spectra of a galaxy. 3. From the superluminal motion, the assumption (δ v≈δ 0 18+logvv 0 ) is confirmed. 4. Based on the relation between polarization and Doppler factor (Fan et al. 1997a), it is proposed that the f, ratio of the beamed luminosity to the unbeamed luminosity in the source frame of OVVs/HPQs is smaller than that of BL Lac objects: f RBLs ～ 6f FSRQs .

关键词： BL Lac Objects and Unified Model

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