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Thermal analysis of the baffle structure of the Solar Space Telescope

Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1755-1764页

作者： LI Rong1,2,3 & WANG Sen1,3 1 national astronomical observatories,chinese academy of sciences,beijing 100012,china 2 Graduate University of chinese academy of sciences,beijing 100049,china 3 Key Laboratory of Solar Activity,national astronomical observatories of chinese academy of sciences,beijing 100012,china chinese academy of sciences National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) Graduate University of chinese academy of sciences Beijing China (GRID:grid.458514.9) national astronomical observatories of chinese academy of sciences Key Laboratory of Solar Activity Beijing China (GRID:grid.450302.0) (ISNI:***) chinese academy of sciences National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) national astronomical observatories of chinese academy of sciences Key Laboratory of Solar Activity Beijing China (GRID:grid.450302.0) (ISNI:***)

The SST(Space Solar Telescope) is an astronomical telescope with a primary mirror of 1 m in *** observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray *** baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control *** this study,the compatibility analysis of the thermal effect of baffle structures in SST is *** GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are *** objective and method of the compatibility analysis are *** the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3' tilt angle and 16' tilt angle,and different tilt angles of the outer baffle with a 200 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray *** design of the baffle structure of SST is achieved:the main baffle of length 4100 mm,the internal shield of radius 494 mm,the outer baffle of length 200 mm,and the outer baffle of tilt angle 3' are successfully *** paper presents the relationship between the thermal control design and stray light elimination plan in the *** aims of the optimal design of the baffle structure of SST are *** thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

关键词： baffle the main baffle the outer baffle GCF BRDF

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Simulations for terrestrial planets formation

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Science china(Physics,Mechanics & Astronomy) 2009年第5期52卷 794-803页

作者： ZHANG Niu 1,2 &JI JiangHui 2,3 1Graduate University of chinese academy of sciences,beijing 100049,china 2Purple Mountain Observatory,chinese academy of sciences,Nanjing 210008,china 3 national astronomical observatories,chinese academy of sciences,beijing 100012,china Graduate University of chinese academy of sciences Beijing China Purple Mountain Observatory Chinese Academy of Sciences Nanjing China national astronomical observatories Chinese Academy of Sciences Beijing China

In this paper,the formation of terrestrial planets in the late stage of planetary formation is investigated using the two-planet *** that time,the protostar formed for about 3 Ma and the gas disk *** the model,the perturbations from Jupiter and Saturn are *** of the mass of outer planet,and the initial eccentricities and inclinations of embryos and planetesimals are also *** results show that,terrestrial planets are formed in 50 Ma,and the accretion rate is about 60%-80%.In each simulation,3-4 terrestrial planets are formed inside"Jupiter"with masses of 0.15 -3.6M⊕.In the 0.5-4 AU,when the eccentricities of planetesimals are excited,planetesimals are able to accrete material from wide radial *** plenty of water material of the terrestrial planet in the Habitable Zone may be transferred from the farther places by this *** could also happen a few times between two major planets only if the outer planet has a moderate mass and the small terrestrial planet could survive at some resonances over time scale of 10 8 *** one of our simulations,commensurability of the orbital periods of planets is very ***,a librating-circulating 3:2 configuration of mean motion resonance is found.

关键词： astrophysics exoplanet planetary formation n-body simulation

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astronomical function and date of the Taosi observatory

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Science china(Physics,Mechanics & Astronomy) 2009年第1期52卷 151-158页

作者： WU JiaBi1, CHEN MeiDong2 & LIU CiYuan3 1 national astronomical observatories, chinese academy of sciences, beijing 100012, china 2 Institute for the History of Natural Science, chinese academy of sciences, beijing 100010, china 3 national Time Service Center, chinese academy of sciences, Xi’an 710600, china national astronomical observatories Chinese Academy of Sciences Beijing China Institute for the History of Natural Science Chinese Academy of Sciences Beijing China national Time Service Center Chinese Academy of Sciences Xi’an China

The Taosi site in Xiangfen County,Shanxi Province,may be the capital of the King Yao. Archeologists recently discovered a large semi-circular stamped-earth platform, II FJT1,which has a clear and definite pounded-earth central core together with a curved wall perforated by twelve gaps. The platform is said to be an ancient observatory used to determine the seasons by watching the sunrise. Each feature of II FJT1 was precisely measured and the data are reproduced in this paper. An astronomical analysis of slots E2 and E12 was carried out using the azimuths of the slots' centerlines and the vertical angle of the mountain ridge opposite, above which the sun rises. The results show that at present the sun is close to the two slots but does not exactly enter them at summer and winter solstice sunrise. Using 14C analysis archeologists dated the site to about 2100 BC. Because of the secular change in the obliquity of the ecliptic,at that date on the summer solstice the half-risen sun would have appeared inside slot E12 just to the right of the centerline,and on the winter solstice the sun would have been exactly on the centerline of slot E2. This result provides compelling proof that II FJT1 is an ancient observatory.

关键词： astro-archeology astro-chronology Taosi culture ancient observatory time service

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A new method of ionospheric-free hybrid differential positioning based on a double-antenna CAPS receiver

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Science china(Physics,Mechanics & Astronomy) 2009年第3期52卷 368-375页

作者： GUO JinYun1,2, HAN YanBen1 & CHANG XiaoTao3 1 national astronomical observatories, chinese academy of sciences, beijing 100012, china 2 College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266510, china 3 chinese academy of Surveying and Mapping, beijing 100039, china national astronomical observatories Chinese Academy of Sciences Beijing China College of Geodesy and Geomatics Shandong University of Science and Technology Qingdao China chinese academy of Surveying and Mapping Beijing China

chinese Area Positioning System (CAPS) is a transmitted satellite navigation system moved by the chinese academy of sciences. Three basic modes of navigation and positioning with CAPS are given, and then a comparative analysis is made in this paper. In terms of the principle that the ionospheric delay is at an inverse ratio to the frequency square, a new ionospheric-free positioning method based on a double-antenna CAPS receiver is put forward. Then the hybrid differential observations and the solving equations and algorithms for one epoch and multi epochs are deduced according to the basic principle of the method. The method may remove the global errors in signal emission, propagation, transmission and receiving (e.g., ionospheric delay, hardware delay, and clock error). So it is very convenient for the single-epoch solution and multi-epoch navigation and positioning, and may efficiently improve the precision of real time CAPS navigation. Furthermore, the method can be used not only for the geometric orbit determination of CAPS GEO and IGSO satellites and the navigation and positioning, but also for the estimation of the tropospheric zenith delay, which is useful for the study of water vapor changes in the atmosphere. Polynomials are used in this method to express the tropospheric zenith delay and CAPS satellite orbits within the limited time interval, which reduces the num- ber of unknown parameters and thus speeds the computation.

关键词： chinese Area Positioning System (CAPS) ionospheric-free linear combination double-antenna receiver hybrid differential positioning method

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Automated detection of lunar craters based on object-oriented approach

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chinese Science Bulletin 2008年第23期53卷 3699-3704页

作者： YUE ZongYu1,2,3,4, LIU JianZhong3 & WU GanGuo2 1 Institute of Remote Sensing Application, chinese academy of sciences, beijing 100101, china 2 china University of Geosciences (beijing), beijing 100083, china 3 national astronomical observatories of chinese academy of sciences, beijing 100012, china 4 Department of Geological sciences, The University of Texas at San Antonio, San Antonio, TX 78249, U.S.A Institute of Remote Sensing Application Chinese Academy of Sciences Beijing 100101 China china University of Geosciences (beijing) Beijing 100083 China national astronomical observatories of chinese academy of sciences Beijing 100012 China Department of Geological sciences The University of Texas at San Antonio San Antonio TX 78249 U.S.A

The object-oriented approach is a powerful method in making classification. With the segmentation of images to objects, many features can be calculated based on the objects so that the targets can be distinguished. However, this method has not been applied to lunar study. In this paper we attempt to apply this method to detecting lunar craters with promising results. Craters are the most obvious features on the moon and they are important for lunar geologic study. One of the important questions in lunar research is to estimate lunar surface ages by examination of crater density per unit area. Hence, proper detection of lunar craters is necessary. Manual crater identification is inefficient, and a more efficient and effective method is needed. This paper describes an object-oriented method to detect lunar craters using lunar reflectance images. In the method, many objects were first segmented from the image based on size, shape, color, and the weights to every layer. Then the feature of "contrast to neighbor objects" was selected to identify craters from the lunar image. In the next step, by merging the adjacent objects belonging to the same class, almost every crater can be taken as an independent object except several very big craters in the study area. To remove the crater rays diagnosed as craters, the feature of "length/width" was further used with suitable parameters to finish recognizing craters. Finally, the result was exported to ArcGIS for manual modification to those big craters and the number of craters was acquired.

关键词：自动化检测月球环形山地貌

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The initial and final state of SNe Ia from the single degenerate model

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1732-1738页

作者： MENG XiangCun1,YANG WuMing1 & LI ZhongMu2,3 1School of Physics and Chemistry,Henan Polytechnic University,Jiaozuo 454000,china 2Institute for Astronomy and History of Science and Technology,Dali University,Dali 671003,china 3national astronomical observatories,chinese academy of sciences,beijing 100012,china Henan Polytechnic University School of Physics and Chemistry Jiaozuo China (GRID:grid.412097.9) (ISNI:***) Dali University Institute for Astronomy and History of Science and Technology Dali China (GRID:grid.440682.c) chinese academy of sciences National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***)

Although type Ia supernovae(SNe Ia) show their importance in many astrophysical fields,the nature of the progenitors of SNe Ia is still *** present,the single degenerate(SD) model is presented to be a very likely progenitor *** the comprehensive SD model developed by Meng & Yang(2010),we show the initial and final state of the progenitor systems of SNe Ia in an orbital period—the secondary mass(log Pi,M2i) *** results may explain the location of some supersoft X-ray sources and recurrent novae in the(log Pi,M2i) plane,and be helpful to judge whether an SD system is the potential progenitor system of SNe Ia,as well as to simulate the interaction between SN ejecta and its companion.

关键词： binaries:close stars:evolution supernovae:general white dwarfs

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Population information extraction in Chaohu watershed based on RS and GIS

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chinese Science Bulletin 2003年第2期48卷 181-183页

作者： LIU Jianjun1,2 & LI Chunlai3 1. Institute of Geochemistry, chinese academy of sciences, Guiyang 550002, china 2. Graduate School, chinese academy of sciences, beijing 100039, china 3. national astronomical observatories, chinese academy of sciences, beijing 100012, china Correspondence should be addressed to Liu Jianjun (e-mail: dhsliujj@ ***) Institute of Geochemistry Chinese Academy of Sciences Guiyang China Graduate School Chinese Academy of Sciences Beijing China national astronomical observatories Chinese Academy of Sciences Beijing China

It is always difficult to extract population in-formation of small watershed during the region environment assessment. The report adopted compound areal interpola-tion to study the population in Chaohu watershed with the GIS technique and landuse interpretation data from remote sensing. The result indicated that the method is effective to extract population information of small watershed.

关键词：巢湖流域人口分布信息提取 RS GIS 小流域生态环境评价

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The emission positions of kHz QPOs and Kerr spacetime influence

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 114-116页

作者： ZHANG ChengMin1,WEI YingChun1,YIN HongXing1,ZHAO YongHeng1,LEI YaJuan2,SONG LiMing2,ZHANG Fan2 & YAN Yan3 1 national astronomical observatories,chinese academy of sciences,beijing 100012,china 2 Institute of High Energy Physics,chinese academy of sciences,19B Yuquan Road,beijing 100049,china 3 Urumqi Observatory,national astronomical observatories,CAS,Urumqi 830011,china national astronomical observatories Chinese Academy of Sciences Beijing China Institute of High Energy Physics Chinese Academy of Sciences Beijing China Urumqi Observatory National Astronomical Observatories CAS Urumqi China

Based the Alfven wave oscillation model(AWOM) and relativistic precession model(RPM) for twin kHz QPOs,we estimate the emission positions of most detected kHz QPOs to be at r=18+/-3 km(R/15 km),except Cir X-1 at r-30+/-5 km(R/15 km).For the proposed Keplerian frequency as an upper limit to kHz QPO,the spin effects in Kerr Spacetime are discussed,which have about a 5%(2%) modification for that of the Schwarzchild case for the spin frequency of 1000(400) *** application to the four typical QPO sources,Cir X-1,Sco X-1,SAX J1808.4-3658 and XTE 1807-294,is mentioned.

关键词： kHz QPO neutron star low-mass X-ray binaries

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The Chiralities of Three Filaments in AR7500

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天文研究与技术 1999年第S1期 433-437页

作者： Jiang Yunchun 1,2,3 , Luan Di 1,2 , Lin Ganghua 1,3 , Wang Jingxiu 1,3 1 (national astronomical observatories, The chinese academy of sciences, beijing 100012, china) 2 (Yunnan Observatory, The chinese academy of sciences, Kunming 65001

An analysis of structure and evolution of three filaments in AR7500 ON May, 1993 is presented. The three filaments show the following remarkable peculiarities: 1) a sinistral filament lies between two dextral filaments and meets them at two cusps. One of the cusps is rooted in positive polarity plage region while the other in a small decaying spot with negative polarity. 2) Both chromospheric plagette associated fibrils near the filaments and the transverse magnetic fields of the photosphere beneath the filaments almost parallel to the long axis of these filaments, suggesting the dominance of axial field of filaments; the spots near filament’s ends, however, do not show clearly counterclockwise or clockwise superpenumbral fibril pattern. 3) The three filaments do not merge into a single filament during 8 day observation. This can be explained by considering that the magnetic fields along their long axes are in different directions at two cusps. When one of dextral filaments and the sinistral filarment eventually dissipate into fibrils connecting the opposite polarity regions, their jointing cusps can be still clearly observed due to their opposite chiralities.

关键词： Sun: filament Sun:magnetic field

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New background quasars in the vicinity of the Andromeda Galaxy discovered with the Guoshoujing Telescope (LAMOST)

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Research in Astronomy and Astrophysics 2010年第7期10卷 612-620页

作者： Zhi-Ying Huo Xiao-Wei Liu Hai-Bo Yuan Hui-Hua Zhang Yong-Heng Zhao Jian-Jun Chen Zhong-Rui Bai Hao-Tong Zhang Hua-Wei Zhang Ruben Garcia-Benito Mao-Sheng Xiang Hong-Liang Yan Juan-Juan Ren Shi-Wei Sun Yong Zhang Ye-Ping Li Qi-Shuai Lu You Wang Ji-Jun Ni Hai Wang Department of Astronomy Peking University Beijing 100871 China Kavli Institute for Astronomy and Astrophysics Peking University Beijing 100871 China national astronomical observatories Chinese Academy of Sciences Beijing 100012 China Department of Astronomy Beijing Normal University Beijing 100875 China Nanjing Institute of astronomical Optics ＆ Technology Chinese Academy of Sciences Nanjing 210042 China

We present preliminary analyses of spectra of quasar candidates in two Guoshoujing Telescope （GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope - LAMOST） test fields near M 31 where one is close to the optical center of the disk and the other is towards the northeastern outskirts of the halo, obtained during the early stage of the GSJT commissioning in the last season of 2009. Both fields contain background low-redshift quasar candidates selected from the SDSS photometry. In total, 14 new quasars with redshifts up to 2 and i magnitudes between 16.7 and 19.2, are discovered, including 7 within the 2.5° central region of M 31. We briefly discuss the potential applications of these newly discovered bright quasars.

关键词： galaxies individual (M31) -- quasars general -- quasars emission lines

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