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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.{3. 2.{2. for the History of Natural Science, Chinese Academy of Sciences, beijing 100010,{3. 3.National Time Service center, Chinese Academy of Sciences, Xi’an 710600,{3. 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 2.00 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

A modeling study of relation between cloud amount and SST over Western Tropical Pacific cloudy regions during TOGA COARE

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Progress in Natural Science:Materials International 2009年第2期19卷 187-193页

作者： Shouting Gaoa,Xiaopeng Cui a,Xiaofan Li b a Laboratory of Cloud-Precipitation physics and Severe Storms (LACS),institute of Atmospheric physics,Chinese Academy of Sciences,{3. 10002.,china b Joint center for Satellite Data Assimilation and NOAA/NESDIS/center for Satellite Applications and Research,Camp Springs,MD,USA Laboratory of Cloud-Precipitation physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Joint center for Satellite Data Assimilation and NOAA/NESDIS/center for Satellite Applications and Research Camp Springs MD USA

The relationship between cloud amount and sea surface temperature (SST) over Western Tropical Pacific cloudy regions during TOGA COARE is investigated based on hourly grid simulation data from a two-dimensional coupled ocean-cloud resolving atmosphere model. The model is forced by the large-scale vertical velocity and zonal wind observed and derived from TOGA COARE for a 50-day period. The cloud amount becomes smaller when the ocean surface gets warmer,which is similar to previous relations obtained from observational analyses. As SST increases,the atmospheric temperature increases whereas the surface sensible heat flux decreases. The atmospheric water vapor is not sensitive to SST whereas the surface evaporation flux decreases as SST increases. These indicate that the oceanic effects do not play an important role in determining atmospheric heat and water vapor budgets. The cold atmosphere pro-duces a larger amount of ice clouds that cover a larger area than the warm atmosphere does. The large amounts of ice clouds lead to cooling of the ocean surface through reflecting large amount of solar radiation back to the space. Thus,the negative correlation between the cloud amount and SST only accounts for the important atmospheric effects on the ocean.

关键词： Cloud amount Sea surface temperature Coupled ocean-cloud resolving atmosphere model TOGA COARE

在Si(111)-(7×7)表面自组织生长二维Ge团簇超晶格

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物理学报 2002年第5期51卷 1017-1021页

作者：闫隆张永平彭毅萍庞世谨高鸿钧中国科学院物理研究所和凝聚态物理中心北京真空物理开放实验室北京100080

利用超高真空扫描隧道显微镜研究了室温条件下亚单层Ge在Si(111) (7× 7)表面上的自组织生长 .通过控制Ge的沉积量 ,在Si(111) (7× 7)表面上自组织生长成一种具有六重对称性的二维Ge团簇超晶格 .构成超晶格的Ge团簇均位于 (7× 7)亚... 详细信息

利用超高真空扫描隧道显微镜研究了室温条件下亚单层Ge在Si(111) (7× 7)表面上的自组织生长 .通过控制Ge的沉积量 ,在Si(111) (7× 7)表面上自组织生长成一种具有六重对称性的二维Ge团簇超晶格 .构成超晶格的Ge团簇均位于 (7× 7)亚单胞的位置上 ,而且它们的形状和大小基本保持一致 .

关键词：扫描隧道显微镜 STM Si(111)-(7×7)表面二维Ge团簇超晶格自组织结构半导体外延生长自组织生长硅衬底

Progress in multi-waveband observations of supernova remnants

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Progress in Natural Science:Materials International 2008年第9期18卷 1057-1062页

作者： Xuejuan Yang a,b, Fangjun Lua, Wenwu Tian c,d,* a Particle Astrophysics center, {2. of High Energy physics, Chinese Academy of Sciences, beijing 100049, china b Department of Astronomy, beijing Normal University, beijing 100875, china c National Astronomical Observatories, Chinese Academy of Sciences, 2.A Datun Road, Chaoyang District, CAS, beijing 100012. china d Department of physics & Astronomy, University of Calgary, Alberta, Canada T2. 1N4 Particle Astrophysics center Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Department of Astronomy Beijing Normal University Beijing 100875 China National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Chaoyang District CAS Beijing 100012 China Department of physics & Astronomy University of Calgary Alberta Canada T2N 1N4

The development of observational techniques has enriched our knowledge of supernova remnants. In this paper, we review the main progresses in the last decade, including new discoveries of supernova remnants and the associated (rare type of) pulsars, nucleosynthesis, the interaction between supernova remnants and molecular clouds, dust in the supernova remnants, shock physics, and cosmic ray accelerations.

关键词： Supernova remnant Observations

HIGH-ENERGY PROTON IRRADIATION EFFECTS ON GaAs/Ge SPACE SOLAR CELLS

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 463-466页

作者： R. Wang (The Key Laboratory of Beam Technology and Materials Modification of Ministry of Education, institute of Low Energy Nuclear physics, {2. Normal University {2. Radiation center, {2. 100875, china) S.D. Yao (Department of Technical Phys Inst. of Energy Nucl. Phys. Beijing Normal Univ. Beijing 100875 China

This paper reports the high-energy proton irradiation effects on GaAs/Ge space solar cells. The solar cells were irradiated by protons with energy of 5-2. MeV at fluence ranging from 1×109 to 7×1013.cm-2. and then their electric parameters were measured at AM0. It was shown that the Isc, Voc and Pmax decrease as the proton energy increasing, and the degradation is relative to proton irradiation-induced defect with a level of Ec-0.41 eV in irradiated GaAs/Ge cells.

关键词： Germanium High energy physics Irradiation Protons Semiconducting gallium arsenide

CVD Synthesis of Single-Walled Boron Nitride Nanotubes

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CVD Synthesis of Single-Walled Boron Nitride Nanotubes

The correlation timescale of the X-ray flux during the outbursts of soft X-ray transients

2.11中国材料研讨会

作者： Muhong Wu 1,3.Wenlong Wang,1,Xuedong Bai,1,Yu Sui 3.and Enge Wang,1,2.1 beijing National Laboratory for condensed {2. {3.,institute of {3.,Chinese Academy of Sciences,beijing 100190,china 2.International center for Quantum Materials,School of {3.,Peking University,beijing 100871,china 3.center for condensed {2. Science and Technology (CCMSIT),Department of {3.,Harbin institute of Technology,Harbin 150001,china

＜正＞As the binary III-VI homolog of carbon nanotubes（CNTs）,the boron nitride nanotubes（BNNTs）share the most structural similarity with CNTs and can be regarded as an important

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 161-167页

作者： WU YuXiang1,2.YU WenFei1 & LI TiPei2.1 Shanghai Astronomical Observatory,Shanghai 100012.{3. 2.Department of Engineering physics & {2. for Astrophysics,Tsinghua University,beijing 100084,{3. Shanghai Astronomical Observatory Shanghai China Department of Engineering physics & center for Astrophysics Tsinghua University Beijing China

Recent studies of black hole and neutron star low mass X-ray binaries(LMXBs) show a positive correlation between the X-ray flux at which the low/hard(LH)-to-high/soft(HS) state transition occurs and the peak flux of the following HS *** analyzing the data from the All Sky Monitor(ASM) onboard the Rossi X-ray Timing Explorer(RXTE),we show that the HS state flux after the source reaches its HS flux peak still correlates with the transition flux during soft X-ray transient(SXT) *** studying large outbursts or flares of GX 3.9-4,Aql X-1 and 4U 1705-44,we have found that the correlation holds up to 2.0,40,and 50 d after the LH-to-HS state transition,*** time scales correspond to the viscous time scale in a standard accretion disk around a stellar mass black hole or a neutron star at a radius of-104-5 Rg,indicating that the mass accretion rates in the accretion flow either correlate over a large range of radii at a given time or correlate over a long period of time at a given *** the accretion geometry is a two-flow geometry composed of a sub-Keplerian inflow or outflow and a disk flow in the LH state,the disk flow with a radius up to-105 Rg would have contributed to the nearly instantaneous non-thermal radiation directly or indirectly,and therefore affects the time when the state transition occurs.

关键词： accretion disks black hole physics star:individual(Aquila X-1 GX 3.9-4 4U 1705-44)

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二维LiNbO_3.线性光子晶体

物理学报 2003年第8期52卷 1925-1928页

作者：倪培根马博琴程丙英张道中中国科学院物理研究所和凝聚态物理中心光物理实验室北京100080

制备了周期为 13.6 4 μm方形格子二维周期性极化的LiNbO3.利用二阶准相位匹配实现了波长为 1 0 6 4 μm二倍频 ,二次谐波的内部转换效率高达 4 2.% .测量了二次谐波输出功率随晶体温度及入射光入射方向的变化 ,实验值与模拟计算一致 .... 详细信息

制备了周期为 13.6 4 μm方形格子二维周期性极化的LiNbO3.利用二阶准相位匹配实现了波长为 1 0 6 4 μm二倍频 ,二次谐波的内部转换效率高达 4 2.% .测量了二次谐波输出功率随晶体温度及入射光入射方向的变化 ,实验值与模拟计算一致 .制备二阶准相位匹配掩模板 ,解决了在制备一阶准相位匹配掩模板中遇到周期尺寸太小、数据量大的难题 ,同时还降低了因周期太小造成的极化难度 .

关键词： LiNbO3.体二维非线性光子晶体铌酸锂晶体二阶准相位匹配二次谐波掩模板激光技术

SrTiO_3.片的晶体质量及表面粗糙结构的X射线研究

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物理学报 1997年第9期46卷 1758-1763页

作者：李超荣朱爱军戴道扬麦振洪中国科学院凝聚态物理中心中国科学院物理研究所中国科学院微重力实验室

用Ｘ射线双晶衍射摇摆曲线以及双晶Ｘ射线形貌对两个ＳｒＴｉＯ３基片的单晶质量进行了对比研究，并用Ｘ射线掠入射镜面反射及漫散射研究了它们的表面粗糙结构．结果表明，两个ＳｒＴｉＯ３基片中都存在镶嵌缺陷，其中一个样品的晶体质... 详细信息

用Ｘ射线双晶衍射摇摆曲线以及双晶Ｘ射线形貌对两个ＳｒＴｉＯ３基片的单晶质量进行了对比研究，并用Ｘ射线掠入射镜面反射及漫散射研究了它们的表面粗糙结构．结果表明，两个ＳｒＴｉＯ３基片中都存在镶嵌缺陷，其中一个样品的晶体质量相对较高．两个样品的表面粗糙结构相差很大，包括均方根粗糙度σ和横向相关长度ξ．σ分别为（０５±０１）和（１３±０１）ｎｍ，ξ分别为（１２００±２００）和（３００±２０）ｎｍ．样品的表面粗糙将增加Ｘ射线的漫散射强度而降低镜面反射的强度．晶体质量较高的样品，其表面也较平整，粗糙度较小。

关键词：钛酸锶基片晶体质量表面结构光电子材料