乌鲁木齐天文站25m天线18cm脉冲星脉冲到达时间观测系统

脉冲星脉冲到达时间观测系统建立在２５ｍ射电天线的１８ｃｍ波段上,消色散采用了２ｘ１２８ｘ２．５ＭＨｚ多通过滤波器和数字化器,数据采集系统由ＰＣ机完成．１９９９年５月至６月间建立了基于常温接收机的到达时间观测系统．观测到的最弱源的平均流量密度为４ｍＪｙ．     

大质量双星系统的非守恒演化

由于大质量双星系统有强大的星风物质损失,因而在研究其结构和演化时必须考虑星风物质损失,动量损失,物质交换以及由以上原因引起的轨道参量的变化,此外,天文观测又证实,一些大质量双星系统中存在星风冲击波,有Ｘ射线辐射以及有致密天体（白矮星,中子星）的存在,因此在研究大质量双星的演化时,又会遇到在星风冲击波理论及其对演化的影响,双星系统何时会演化成为公共外壳的系统,以及双星系统中如果发生超新星爆发,是否会     

X线选射电噪活动星系核的多波段性质

基于被ROSAT全天区巡天观测和射电4．85GHz巡天观测同时探测到的活动星系核的大样本,研究了X射线选的射电噪活动星系核的多波段性质．通过分析该样本中的活动星系核的宽波段能量分布,确认了来自射电、光学和X射线波段的辐射光度之间的显著相关性．这种相关性对于类星体、赛弗特、蝎虎座天体和射电星系是有区别的．同时,探讨了从光学到X射线波段之间的谱指数与红移以及5000A和4．85GHz处的单色光度的相关性．     

地理信息系统发展趋势

本文根据国内外在地理信息系统方面的进展，就地理信息系统的科学概念、基本构成和它的以下一些发展趋势作了讨论：（1）地理信息系统是构成地理学日臻完善的技术体系的重要部分；（2）空间分析功能是系统研究和应用的主要目标；（3）系统最重要的技术问题是管理和存储大量空间数据的数据结构；（4）综合性的发展特色日益明显；（5）标准化和智能型的发展方向已引起关注。     

X‐shooting Herbig Ae/Be stars: Accretion probed by near‐infrared He I emission

The Herbig Ae/Be stars are intermediate mass pre‐main sequence stars that bridge the gap between the low mass T Tauri stars and the Massive Young Stellar Objects. In this mass range, the acting star forming mechanism switches from magnetically controlled accretion to an as yet unknown mechanism, but which is likely to be direct disk accretion onto the star. We observed a large sample of Herbig Ae/Be stars with X‐shooter to address this issue from a multi‐wavelength perspective. It is the largest such study to date, not only because of the number of objects involved, but also because of the large wavelength coverage from the blue to the near‐infrared. This allows many accretion diagnostics to be studied simultaneously. By correlating the various properties with mass, temperature and age, we aim to determine where and whether the magnetically controlled mass accretion mechanism halts and the proposed direct disk accretion takes over. Here, we will give an overview of the background, present some observations and discuss our initial results. We will introduce a new accretion diagnostic for the research of Herbig Ae/Be stars, the HeI 1.083 μm line (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X-ray spectral evolution of low-mass X-ray binary GX 349+2

We present the results of a systematic investigation of spectral evolution in the Z source GX 349+2, using data obtained during 1998 with the Proportional Counter Array (PCA) on-board the RXTE satellite. The source traced a extended normal branch (NB) and flaring branch (FB) in the colour–colour diagram (CD) and the hardness-intensity diagram (HID) during these observations. The spectra at different positions of the Z-track were best fitted by a model consisting of a disc blackbody and a Comptonized spectrum. A broad (Gaussian) iron line at ∼6.7 keV is also required to improve the fit. The spectral parameters showed a systematic and significant variation with the position along the Z-track. The evolution in spectral parameters is discussed in view of the increasing mass accretion rate scenario, proposed to explain the motion of Z sources in the CD and the HID.