利用卫星进行双向时间传递

介绍了利用卫星进行双向时间传递方法的原理（TWSTT），包括了电离层延时误差、卫星转发时延、接收机和发射机时延和相对论效应修正误差。作者使用昆明站和临潼站的观测数据进行处理。得到高精度的时间比对。     

利用光纤进行高精度时间传递

介绍了一种利用光纤电视信道传递时间和频率的初步方案,对闭环时延的测定作了阐述,还讨论了采用扩频技术的副载波复用系统进行双向时间传递的方法.     

计算机互联网上时间传递的一种设计方案

目前,国内外时间传递方式主要有长波授时、短波地、电话授时、双星比对、ＧＰＳ时间信息等。信息产业的不断发展,使得互联网络已成为一种新的信息传递手段和资源共享方式 。通过计算机网络传输标准时间、频率将是授时领域的新课题,也是时间同步的新手段。讨论了计算机互联网上时间传递的一种设计方案,给出利用计算机网络系统实现标准时间的传递的具体方法,并介绍一种计算机互联网时间传递软件的使用方法等。     

利用微波通讯系统进行高精度时间传递--国家授时中心的微波时间传递系统

介绍了国家授时中心时间基准实验室与时频监控实验室之间的微波时间传递系统的特点和运行状态,分析了时间比对结果随时间的变化,并提出了改进该系统的建议。     

利用同步卫星进行中日双向时间传递

时间同步是高精度授时不可缺少的环节。利用同步卫星进行双向时间传递可最大限度地消除路径因素对时间同步的影响,并且可准确,适时地得到高精度的比对结果。国际计量局（ＢＩＰＭ）为改善世界范围内时间同步,提出了全球双向卫星时间传递（ＴＷＳＴＴ）计划。由中国科学院陕西天文台（ＣＳＡＯ）和日本邮政省通信综合研究所（ＧＲＬ）所进行的双向卫星时间传递经过一年的工作,已经得到了较好结果,进一步的分析正在进行中。     

光纤时间传递系统中时钟驯服模块的设计和实现

提出了一种基于光纤时间传递系统的时钟驯服模块设计方案。介绍了系统硬件的组成。在对信道特性和压控晶振进行理论和实验分析的基础上,设计实现了适用于光纤信道特性的卡尔曼滤波算法以及驯服流程控制程序。实验测试表明：该模块能结合恒温晶振短期稳定度好和光纤时间传递系统秒脉冲长期稳定度好的优点,时间传递的精度优于0．25ns（1σ）,输出的秒脉冲的长期稳定度优于10^-14。     

新型原子钟发展现状

结合我国全球卫星导航定位系统的建设和发展需求,介绍了不同类型的新型原子钟研究现状与发展趋势,并简要给出了发展我国原子钟研究的讨论性意见。     

基于轨道改正的卫星电视时间传递

利用在模拟卫星电视信号中插入的时间信息可实现时间传递,但由于它常采用固定的卫星位置,限制了时间传递精度。为此,研究了基于轨道改正的卫星电视时间传递方法,并给出了在轨道改正的基础上实现单向和共视时间传递的计算公式。将该方法应用于我国的模拟卫星电视时间传递中,计算了从中央电视台到国家授时中心的单向时间传递结果。     

Flows in clumpy planetary nebulae

The dynamics of clumps observed in planetary nebulae are considered. The possibility that SiO maser spots in evolved stars and the planetary nebula clumps are formed by the Parker instability behind shocks in pulsating stars' atmospheres is raised. Molecular observations of the clumps are suggested. The effects of the ablation of clumps on the global flow structure of a more tenuous plasma in which they are embedded are reviewed.     

Variable stars in the globular cluster NGC 6362

We report the results of a CCD search for short-period variables in the field of a southern globular cluster NGC 6362. We identified 19 new candidate variables, five of which are cluster RR Lyraes, four are probable SX Phe-type stars and eight are eclipsing binaries. Of the discovered binaries, three are EA-type systems, two of which are located on the cluster CMD in the turn-off region and the third 1 mag above the turn-off point, in the yellow straggler region. Five other systems are of W UMa type, three of which are foreground objects and two are likely cluster members. The remaining two candidates exhibit a modulation of the brightness level with an amplitude of 0.1–0.2 mag; further observations are needed to reveal the nature of their variability. Phased VI light curves for 20 variables (18 RR Lyrae stars and two blue stragglers) located in the central region of the cluster are presented.     

Two-body relaxation in cosmological simulations

It is logically possible that early two-body relaxation in simulations of cosmological clustering influences the final structure of massive clusters. Convergence studies in which mass and spatial resolution are simultaneously increased cannot eliminate this possibility. We test the importance of two-body relaxation in cosmological simulations with simulations in which there are two species of particles. The cases of two mass ratios, √2:1 and 4:1, are investigated. Simulations are run with both a spatially fixed softening length and adaptive softening using the publicly available codes gadget and mlapm , respectively.
The effects of two-body relaxation are detected in both the density profiles of haloes and the mass function of haloes. The effects are more pronounced with a fixed softening length, but even in this case they are not so large as to suggest that results obtained with one mass species are significantly affected by two-body relaxation.
The simulations that use adaptive softening are less affected by two-body relaxation and produce slightly higher central densities in the largest haloes. They run about three times faster than the simulations that use a fixed softening length.     

自适应光学技术应用于激光测月中大气波前倾斜量的探测与计算

针对云南天文台1.2米望远镜在激光测月中回波光子数太少的问题，将大气湍流效应考虑到激光测月中，研究了互相关和绝对差分两种跟踪算法的原理，并编写了算法程序，利用太阳数据验证了程序的正确性,给出了根据所采集的月面感兴趣区域的图像数据，用不同方法在不同条件下处理所得的大气波前整体倾斜信号，比较了算法的优劣。     

Quasi-periodic X-ray oscillations in the source Scorpius X-1

The RXTE observations of Scorpius X-1 in 1996–1999 are presented. The properties of its quasi-periodic X-ray oscillations are studied in detail. The results obtained are used for analysis in terms of the transition-layer model (TLM) and the relativistic-precession model (RPM) for a slowly rotating neutron star. Theoretical predictions of the two models are compared and their self-consistency is verified. The tilt of the magnetosphere to the accretion-disk plane, the neutron-star mass, and its angular momentum are determined in terms of the models.     

测定天文大气折射和建立电磁波折射延迟实测模型(Ⅰ)-观测原理和可行性

简述了天文大气折射和电磁波中性大气折射延迟的成因,以及不同观测站、不同方位的折射值存在差异的事实;根据测定瞬时天文大气折射、建立本地实测模型的观测原理和要求,分析了长期以来不能直接测定天文大气折射的几个主要障碍,介绍了现已具备的排除这些障碍的必要条件,为建立天文大气折射实测模型,和随观测站、随方位而异的电磁波折射延迟改正模型提供了保证。     

类星体吸收线

类星体光谱中有大量的吸收线 ,它们或者产生于与类星体本身有联系的气体云 ,或者产生于类星体和观测者之间的吸收系统。因此 ,类星体吸收线是强有力的宇宙探针。对类星体吸收线的研究将有助于我们了解星系的形成和演化。本文介绍了类星体吸收线的性质并评述了近年来类星体吸收研究的最新进展。     

中国历代荧惑守列宿与四星聚、五星聚考查

利用授时历法和现代天文计算方法,对中国历代天文志记录的荧惑(火星)守列宿、四星聚、五星聚进行分析研究,结果表明:65条荧惑守列宿,正误率分别为49%和51%.如果把荧惑留、留守、在某宿等运动形态也考虑为守的范围,共有95条,其正误率分别为56%和44%.12条四星聚正误率各占一半,即50%.11条五星聚正误率分别为82%和18%(其中含五星并见).并对错误记录的原因做了初步探讨.     

A Multiwavelength Study of the Jets in FR-I Radio Galaxies： I. Data and Analysis

We compile a sample of 11 Fanaroff-Riley type I Radio Galaxies(FR-I RGs)with multi-wavelength observations to address the dynamic behavior of jets in these objects.Optical images acquired by the Hubble Space Telescope(HST)are carefully analyzed.The method and reduction procedure are described in detail. Unresolved optical cores emerge after having properly removed starlight from the host galaxies in eight of the FR-I RGs,of which five are new identifications.Broad band spectral properties of these newly identified compact cores are compared with that previously found in FR-I RGs,as well as the low-energy-peaked BL Lac objects. The similarity between them argues for the same non-thermal synchrotron origin. Well-resolved optical jets with knotty morphologies are found in three FR-I RGs in our sample,namely 3C 15,3C 66B and B20755 37.The optical counterparts to the inner radio/X-ray jets are identified and a clear one-to-one correspondence between the optical,radio and X-ray knots is found.The structure and information on the optical jets are discussed.Physical parameters such as the knots position,flux and size are also presented.Detailed comparison between the multi-wavelength data and radiative and dynamic models of jet will be made in a forthcoming paper.     

由斑点图重建天文图像的方法

首先介绍了斑点图形成机制以及获取方法,并借助计算机模拟了斑点图的生成。然后重点描述斑点图的图像重建方法,包括频率域和空间域重建方法。在频率域重建方法部分依次详细叙述了用于复原模信息的斑点干涉法和用于复原相位信息的由模复原相位法、Knox-Thompson法、斑点掩模法;空间域重建方法部分介绍了典型的LWH法和迭代位移叠加法;另外,盲消卷积法也为斑点图重建提供了新的思路,文章对此方法也做了介绍;特别地,还对国内在该领域的相关工作做了介绍;关于斑点图重建方法在天文学、天体物理学等领域的应用,文章做了有针对性的介绍;最后一章是斑点图图像重建方法的总结。