天体

One of the main works of astrometry is to observe celestial bodies, reduceobservational data and obtain the information of objects.

天体测量学的主要工作之一是利用天文望远镜观测天体，并对所得资料进行分析处理，获取目标天体的有用信息。

One of the main works of astrometry is to observe celestial bodies, reduce observational data and obtain the information of objects.

天体测量学的主要工作之一是利用天文望远镜观测天体，并对所得资料进行分析处理，获取目标天体的有用信息。

The specific research contents include: celestial coordinates The establishment of the Department; Sunday apparent motion of celestial bodies and the anniversary of the apparent motion; celestial parallax, atmospheric refraction, optical aberration, precession, nutation theory and applications; astronomical time measurement principles and time systems; depending on the location of celestial bodies return calculation methods.

具体的研究内容有：天球坐标系的建立；天体的周日视运动和周年视运动；天体的视差、大气折射、光行差、岁差、章动的理论及应用；天文时间计量的原则和时间系统的建立；天体视位置的归算方法等。

Based on the fundamental theory of celestial mechanics and the discussion of two body problem under the action of universal gravitation ,the general model which can be continuously used to calculate the apparent place of celestial body in the solar system was derived. Then ,for the specific celestial body ,the material simulating method and the precision verification was given ,and the reason why the error was caused was analyzed and the corresponding method was offered .

摘 要：基于天体力学的基本理论和对万有引力作用下二体问题的讨论，推导出太阳系天体视位置长期计算的一般模型，然后针对特定天体给出了具体的仿真方法和计算结果的精度检验，深入分析了误差的产生原因并提出了相应的改进办法。

Since the 19th century, classical celestial mechanics system and the formation of planets and the moon Sports theory has become a complete theory of .19 century to the 20th century, 50 years is the period of modern celestial mechanics, improved analytical methods, additional qualitative methods and numerical methods .50 years after the study of celestial mechanics celestial object from the solar system be extended to man-made objects Movement Theory, as well as a few star systems, broadening the field of study.

此后到19世纪末，经典天体力学体系形成，大行星和月球运动理论已成为完善的理论。19世纪末到20世纪50年代是近代天体力学时期，改进了分析方法，新增加了定性方法和数值方法。50年代以后，天体力学的研究对象从太阳系天体扩展到人造天体运动理论以及为数不多的恒星系统，拓宽了研究领域。

The theory of accretion disks are important for many astrophysical phenomena, including Quasars, active galatic nucleic, X-ray binary stars, and young stellar objects. The most important branch of accretion djsk theory is the stability properties of djsks. It is widely considered that the luminosity variations of various astronomical objects are associated with the instability of accretion disk. The viscosity plays an important role in the accretion disk theory, and magnetic field exists commonly in astronomical phenomena. A more realistic analysis of the stabihty of the accretion disk should include both the radjal and azimuthal perturbations because of the strong shear of viscous flow.In this paper, according to the luminosity Variations of Various astronomical objects, we study the radial-azimuthal instability of an isothermal with magnetic field. We find that the radial and azimuthal fields B〓,B〓 are mainly responsible for enhancing the instability of the magneto-acoustic modes and non-axisymmetric modes,and that pulsational oscillations are larger in the radial than in the Z direction. The model may be useful in explaining the periodic light variation of FU orionis and. T Tauri stars.

在许多天体物理现象中，例如活动星系核，X-射线双星和年青的恒星理论中，吸积盘理论起着重要的作用，而吸积盘理论中的一个重要分支是吸积盘的不稳定性理论，普遍认为活动天体的周期，准周期光变现象与吸积盘的不稳定性有关，在吸积盘理论中，粘滞起着重要的作用，而磁场是天体物理中普遍存在的现象，对于几何薄吸积盘不稳定性分析，由于强剪切流的缘故，应该包括径向和环向扰动两个方面，本文结合天体物理中的各种周期，准周期光变现象，研究了含磁场的等温薄吸积盘的径向-环向振荡不稳定性，结果表明：磁场的径向和环向分量对磁声模和非轴对称模的不稳定性的增加起着主要的作用，且径向振荡大于轴向振荡，所得结果有利于解释FU Orionis和T Tauri Stars的周期光变现象。

In this paper, by discussing the basic hypotheses about the continuous orbit and discrete orbit in two research directions of the background medium theory for celestial body motion, the concrete equation forms and their summary of the theoretic frame of celestial body motion are introduced. Future more, by discussing the general form of Binet's equation of celestial body motion orbit and it's solution of the advance of the perihelion of planets, the relations and differences between the continuous orbit theory and Newton's gravitation theory and Einstein's general relativity are given. And by discussing the fractional-dimension expanded equation for the celestial body motion orbits, the concrete equations and the prophesy data of discrete orbit or stable orbits of celestial bodies which included the planets in the Solar system, satellites in the Uranian system, satellites in the Earth system and satellites obtaining the Moon obtaining from discrete orbit theory are given too.

摘 要：通过讨论天体运行背景介质理论的连续轨道及离散轨道这二个研究方向的基础假设，介绍了天体运行轨道的具体方程形式及理论框架概要；进一步地通过讨论天体运行轨道 Binet 方程的一般形式及其行星近日点进动角的解，给出了连续轨道理论与 Newton 理论及 Einstein 广义相对论的联系与区别；通过讨论天体运行轨道的分维扩展方程，给出了包括太阳系行星、天王星卫星、地球卫星、绕月航天器等在内的离散轨道方程及其预言数据。

Pluto is clearly a member of the Kuiper belt population, as can be seen from the fact that there are objects in the same vicinity slightly smaller than Pluto (Quaoar, 2004 DW, Varuna), and then even a larger number slightly smaller than that, and then on down.

冥王星显然是一个柯伊柏带天体，这一点可以从在同一区域存在比冥王星稍小的天体上看出（ Quaoar， 2004 DW， Varuna ），然后恰好有一批更大数目的天体比那个天体稍小，然后一直如此。

In order to making an initial statistical research for the AGNs evolution, we investigated the distribution of the redshift and the spectral index and the flux densities in different wavebands.

从本文统计的谱指数和红移的关系图可以看出gamma波段的谱指数比x波段高，在天体的演化过程中是由高能量天体演化成低能量天体，从而得出一个演化序列：BL Lac天体过渡到低偏振类星体。

A point on the Primum Mobile (the Zodiac for practical purposes) which, in the horoscope of an individual, is occupied by a certain planet, manifests its influence depending on the properties of this planet, and acts on the individual as long as he lives.

第十层天（第十层天：古希腊天文学家托勒密的天动学说中的宇宙的第十层和最外层天体，该天体24小时绕地球自东向西旋转，据信该天体引起其它的九个天体与之一同旋转）上的一点，位于个体的诞生盘上，被某颗行星占据，该行星的特性决定了其影响力，从个体出生开始，就一直在起作用。

It is also known as one of the most poisonous naturally occurring substances.

它也被称为一个最自然发生的有毒物质。

The greatest stress is found at the location on the cross section where V is the largest.

最大应力出现在横截面上V为最大的地方。