星系

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。

He used the 100-inch telescope on Mount Wilson in California - at the time, the largest telescope in the world - to measure the distances to other galaxies.

他用的是california wilson山上的100英寸的望远镜－－这是当时最大的望远镜－－来测量星系间的距离。

Meanwhile, astronomers in California were building the largest telescope in the history of the world - a new telescope on top of Mount Wilson, near Pasadena, with a mirror 100 inches (2.5 meters) across. In 1923, Edwin Hubble used this new telescope to prove that some of the nebulae, including the Sombrero, are actually other galaxies similar to our own Milky Way.

期间，天文学家在加利福尼亚建造了当时世界上最大的望远镜，该望远镜在 Pasadena 附近的威尔逊山顶，拥有2.5米的镜面。1923年， Edwin Hubble 用这个新的望远镜证明部分星云包括 Sombrero 实际上是和我们的银河系一样是星系。

During the event, Malachor V was turned into a broken cluster of planetoids that were only tenuously fused together by the gravitational anomalies present in the system.

在此事件中，马拉卓5号星被转化为一团破碎的小行星群，仅仅是因为星系中出现的引力异常，而稍微熔合在一起。

A death world on the edge of the Menazoid Clasp, Epsilon was the site of three shrines to Chaos, designated Primaris, Secundus and Tertius by Imperial tacticians.

伊普斯隆是个飘荡在曼纳佐德星系边际的死亡世界行星，那里坐落着三个混沌祭坛，帝国的情报人员分别将他们命名为"第一""第二"与"第三" ACE：-_-#。。。。。。。。。

Then go with you, she will,|to the Teth system.

那么她就跟你|一起去泰斯星系

The Milky Way galaxy is just one of more than hundreds of billions of galaxies in the visible universe.

银河系仅是我们可见宇宙中数千亿个星系之一。

The thick disk of the Milky Way Galaxy is of great importance to study structure and evolution of our Galaxy and external galaxies as well.

银河系厚盘的发现，对于研究银河系以至星系的结构和演化具有重要意义。

Light from ordinary stars and galaxies comes largely from atoms powered by thermonuclear reactions in the hearts of stars.

来自一般恒星和星系的光，主要是那些受恒星内部的热核反应所激发的原子发射出的。

We started by playing with the size and shape of the orbit and the tilt of the spinning galaxies.

我们开始着手的是轨道的大小和形状以及旋转着的星系的倾斜度。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。