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Plumb line variation at Tangshan during 1987―1998 and its relation with the earthquakes around

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Science china Earth Sciences 2009年第1期52卷 101-107页

作者： LI ZhengXin1,2 & LI Hui3 1 Shanghai observatory,Chinese Academy of Sciences,Shanghai 200030,china 2 Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuchang 430077,china 3 Institute of Seismology,china Earthquake Administration,Wuchang 430071,china Shanghai observatory Chinese Academy of Sciences Shanghai China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuchang China Institute of Seismology China Earthquake Administration Wuchang China

Plumb line variations(PLV) at Tangshan during the years of 1987―1998 are determined by using the 46 batch repeated gravity observations of the Beijing-Tangshan *** has been found that PLV at Tangshan are related with the 38 earthquakes in this *** appears that the time of an earthquake around Tangshan is usually quite the same when PLV at Tangshan begins moving in opposite direction.

关键词： plumb line variations network in northern china variations of local gravity field earthquakes

CO observations of massive star forming regions at different evolutionary phases

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 626-640页

作者： CHEN Xi1,2, XU Ye1,3, SHEN Zhiqiang1,3 & LI Jingjing1,2 1. Shanghai Astronomical observatory, Chinese Academy of Sciences, Shanghai 200030, china 2. Graduate School of the Chinese Academy of Sciences, Beijing 100034, china 3. Joint Institute for Galaxy and Cosmology, Shanghai Astronomical observatory and the University of Science and Technology of china, Shanghai 200030, china Shanghai Astronomical observatory Chinese Academy of Sciences Shanghai 200030 China

The 12CO (J=1-0), 13CO (J=1-0) and C18O (J=1-0) emissions in 9 massive star forming regions, which are believed to be at different stages of massive star formation, were mapped with the 13.7 m millimeter wave telescope at Qinghai Station of Purple Mountain observatory. Of the observed 9 sources, 13CO cores were detected in seven of them, and C18O cores in five of them. And only two sources associated with C18O cores and H2O masers showed the extended structures and strong outflows. This is the first detection of outflow associated with IRAS 22566+5828 in the observing field of S152/S153. The physical parameters of cores and outflows for these sources, derived from Local Thermal Equilibrium (LTE) analysis, are presented. These observing results suggest that the C18O cores will only appear when the gas density is high enough and the probability to have an outflow is very high when the clumps show the C18O and H2O maser simulta- neously.

关键词： star formation cloud core outflow H2O maser

The radio structure of BL Lac object S5 2007+777

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 187-190页

作者： WU ZhongZu1,3,GU MinFeng2 & CHEN YongJun2 1 College of Science,Guizhou University,Guiyang 550025,china 2 Key Laboratory for Research in Galaxies and Cosmology,Shanghai Astronomical observatory,Chinese Academy of Sciences,Shanghai 200030,china 3 naoc-GZU Sponsored Center for Astronomy,Guizhou University,Guiyang 550025,china College of Science Guizhou University Guiyang China naoc-GZU Sponsored Center for Astronomy Guizhou University Guiyang China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China

BL Lac object S5 2007+777 has been classified as a HYMOR(Hybrid Morphology radio source) for its hybrid FR I and FR II radio *** is one of four BL Lac objects with a kpc scale extended X-ray *** this paper,we searched the unpublished European VLBI Network(EVN) archived high resolution data for this source,and present the high resolution radio *** EVN images all show a core-jet structure in 1.6,5 and 8 *** combination with the VLA data in the literature,we found position angle differences(△PA) of about 10°-20° between pc and kpc scale jet *** brightness temperature estimated from multi-band EVN images are around 1011.2-1011.8 K,from which the Doppler factor ranges from 3.2 to *** found significant flux variations of the radio core in 1.6 and 5 GHz,from which we derived the variability in brightness temperature Tvar to be 1013.6 K and 1014.0 K,corresponding to the Doppler factors of 9.3 and 12.4,respectively.

关键词： active galactic nuclei VLBI BL Lac objects

The OH Maser Line Receiving System for the urumqi 25m Radio Telescope

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Chinese Journal of Astronomy and Astrophysics 2005年第5期5卷 557-562页

作者： Hong-Bo Zhang Jarken Esimbek Jian-Jun Zhou Xing-Wu Zhen Xi-Zhen Zhang Wen-Jie Yang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 urumqi Astronomical observatory National Astronomical Observatories Chinese Academyof Sciences Urumqi 830011 Department of Astronomy Nanjing University 210093 Beijing Institute of Tracking and Telecommunication Technology Beijing 100094

A maser spectral line system is newly implemented on the urumqi 25m Radio Telescope. The system consists mainly of a cooling receiver and a 4096 channels digital correlation spectrometer. The frequency resolution of the spectrometer at the maximum signal bandwidth of 80MHz is 19.5kHz. After careful calibrations observation at the 1665 MHz OH maser emission was made towards a number of sources, including W49N and W75N. The observed results demonstrate that the digital correlation spectrometer is suitable for astronomical spectral line observations.

关键词： instrumentation: spectrometer - OH maser

The simulation of GCRs at near earth interplanetary locations for radioprotection

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1739-1745页

作者： BAO Gang Purple Mountain observatory,Chinese Academy of Sciences,Nanjing 210008,china Chinese Academy of Sciences Purple Mountain Observatory Nanjing China (GRID:grid.9227.e) (ISNI:***)

The interplanetary radiation environment is detrimental to space missions,giving rise to cumulative damage to both astronauts and payloads and enhanced background levels in ***,there is a pressing need for a reliable simulation of these harmful effects for risk assessment and shielding optimization in manned space *** have modeled the interaction processes of the two most abundant galactic cosmic ray particle fluxes(protons and helium nuclei) using the Geant4 toolkit for a given space vehicle *** total energy deposited due to protons and helium nuclei is calculated in this work,and the energy deposited due to the secondary particles generated by this radiation is also estimated.

关键词： radioprotection simulation Geant4 cosmic rays

Arabian Peninsula-North Pacific Oscillation and its association with the Asian summer monsoon

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Science china Earth Sciences 2008年第7期51卷 1001-1012页

作者： SUN JianQi1, YUAN Wei2 & GAO YuZhong3 1 Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, china 2 china Meteorological Administration Training Centre, Beijing 100081, china 3 Heilongjiang Meteorological observatory, Harbin 150030, china Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China china Meteorological Administration Training Centre Beijing China Heilongjiang Meteorological observatory Harbin China

Using correlation and EOF analyses on sea level pressure from 57-year NCEP-NCAR reanalysis data, the Arabian Peninsula-North Pacific Oscillation (APNPO) is identified. The APNPO reflects the co-variability between the North Pacific high and South Asian summer monsoon low. This teleconnec- tion pattern is closely related to the Asian summer monsoon. On interannual timescale, it co-varies with both the East Asian summer monsoon (EASM) and South Asian summer monsoon (SASM); on decadal timescale, it co-varies with the EASM: both exhibit two abrupt climate changes in the middle 1960s and the late 1970s respectively. The possible physical process for the connections between the APNPO and Asian summer monsoon is then explored by analyzing the APNPO-related atmospheric circulations. The results show that with a strong APNPO, the Somali Jet, SASM flow, EASM flow, and South Asian high are all enhanced, and an anomalous anticyclone is produced at the upper level over northeast china via a zonal wave train. Meanwhile, the moisture transportation to the Asian monsoon regions is also strengthened in a strong APNPO year, leading to a strong moisture convergence over India and northern china. All these changes of circulations and moisture conditions finally result in an anoma- lous Asian summer monsoon and monsoon rainfall over India and northern china. In addition, the APNPO has a good persistence from spring to summer. The spring APNPO is also significantly corre- lated with Asian summer monsoon variability. The spring APNPO might therefore provide valuable in- formation for the prediction of Asian summer monsoon.

关键词： Arabian Peninsula-North Pacific Oscillation East Asian summer monsoon South Asian summer monsoon wave train abrupt climate change

Improved formula of coronal magnetic field strength diagnostic

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Chinese Science Bulletin 1997年第3期42卷 234-236页

作者： ZHOU AihuaPurple Mountian observatory, Chinese Academy of Sciences, Nanjing 210008, china Purple Mountian observatory Chinese Academy of Sciences Nanjing 210008 China

CORONAL magnetic field is one of the most important physical quantities in the solar coronal atmosphere, and it is the key to an understanding of the origin and energy release of solar flares too. In most cases, microwave (MW) bursts are caused by reactions between mildly relativistic electrons and the coronal magnetic fields. So MW burst spectrum should embody the infor-

关键词： microwave burst spectrum coronal magnetic field.

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

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