1984年2月18日耀斑后环系的H_α轮廓不对称场和总辐射

本文通过对1984年2月18日耀斑后环系的太阳分光照相光谱资料进行Hα谱线轮廓不对称因子和Hα总辐射量的计算,定量地给出了该环珥系的轮廓不对称场和Hα辐射分布,计算结果表明:1.环珥系大部份轮廓不对称因子|P|<0.5,说明整个环珥系的Hα谱线轮廓基本上是对称的或近似对称的。2.整个环珥系Hα谱线轮廓主要表观为紫不对称。3.具有红移视向速度的地方谱线轮廓都是紫不对称。4.采用不对称因子P进行谱线轮廓不对称计算,比传统的二等分法更优。5.该环珥系的总辐射能量级为10~(31)尔格。     

1979年9月19日3B级耀斑光谱分析:金属线的不对称性和线心位移

本文研究了1979年9月19日3B级耀斑金属谱线的不对称性和线心位移.结果表明:强金属线红不对称占主要地位,少数弱金属线也有蓝不对称存在;不对称程度极大发生于线心强度极大之前;不对称性有时可由蓝变红;不管不对称程度如何,线心的位移却很小,总体上仅表现为极微弱的蓝移.文中认为,耀斑爆发时色球压缩区的向下扩展及由此引起的温度极小区上下的物质运动这个动力学过程可基本解释这些观测现象.金属线的研究是对H_α和CaIIK线光谱研究的补充.     

施密特照相镜试制的初步结果

一.施密特镜的原理近年来,出现的大型天文望远镜几乎都是反射式的.这是因为反射镜有很多优越于折射镜的地方.但是它也有很多缺点.其中之一就是反射镜具有彗像差.由于这种像差的存在,限制了视野的可用范围.彗差的产生是因为作为反射镜物镜的抛物面镜只对称于通过它顶点与焦点的轴线.只有沿着这一方向射来的平行光束才能聚焦成一个对称的像,而对其他方向射来的平行光束就形成不对称的像.     

由对地全晕状日冕物质抛射诱发的地磁感应电流统计研究

太阳活动会引起输变电系统异常,特别是对超长距离输变电系统的危害尤其明显.根据SOHO/LASCO (Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph)的日冕物质抛射(Coronal Mass Ejection,CME)数据、华北电力大学和芬兰气象研究所获得的地磁感应电流(Geomagnetically Induced Current,GIC)数据以及地磁暴数据,分析研究了与GIC事件有关的对地晕状CME的重要观测特征和物理性质.按照对称性将晕状CME进行分类后,发现造成GIC事件的晕状CME主要有3类:完全对称型、亮度不对称型和外形不对称型.不同类型的全晕状CME驱动的GIC事件在强度、持续时间等方面特征各不相同.其中,亮度不对称型晕状CME很有可能对GIC事件影响最为严重.同时注意到GIC与地磁场随时间的变化率也具有较好的相关性.     

激光参量对CPT铷原子钟稳定度影响的数值分析

为具体分析激光参量对相干布居囚禁(CPT)原子钟的稳定度性能的影响,在(-型三能级原子系统模型的基础上,采用半经典密度矩阵方法,数值模拟计算了不同激光参量对CPT铷原子钟共振谱线信号的影响,并给出了比较分析.结果显示:两束激光强度的不对称对CPT钟信号强度的影响很大,而激光频率失谐对CPT钟信号影响较小;此外,当激光强度不对称与频率失谐同时存在时,荧光信号谱出现不对称,微波辐射信号发生频移.     

坍缩为黑洞前的自引力球对称电磁辐射体系

本文在R.D.sorkin等人工作的基础上对自引力球对称电磁辐射体系坍缩为黑洞前的能量密度及最大熵值作了讨论,得到了一些有意义的结果.     

日珥谱线不对称性的研究——Ⅱ.源函数对谱线轮廓的影响

作为文献[1]中工作的继续,本文用解析方法论证了日珥源函数随深度变化与各种速度场结合对谱线轮廓对称性的影响。得到的结论为:(1)常速度场与源函数随深度任意分布结合的谱线为对称轮廓;(2)源函数自日珥中心向前后边界线性对称增大与速度场为线性对称膨胀结合的谱线轮廓为不对称轮廓,且呈双峰结构,紫峰高于红峰;(3)源函数自日珥中心向前后边界线性增大与速度场为线性对称压缩结合的谱线轮廓是不对称的,且呈双峰结构,红峰高于紫峰;(4)源函数自日珥中心向前后边界对称减少与速度场为线性对称膨胀或线性对称压缩结合的谱线为非对称轮廓,原则上也会出现双峰结构,但可能不明显。最后,用数值计算对理论分析结果作了检验。 本文作为文[1]的继续,将用解析方法讨论源函数随深度变化对日珥谱线轮廓对称性的影响。首先讨论速度场为常数源函数随深度任意变化时谱线轮廓的对称性问题,然后讨论速度场自日珥中心对称膨胀或对称压缩与源函数自日珥中心向外边界对称增大或对称下降相结合的模型中,日珥谱线的对称性问题。     

喻京川太空美术作品选登

霉动赤道仪,采用接口31.’7mm高品质纯双对称全金属目镜、棱镜式反射镜,31.’7mm全金属增倍镜。统一零售价:1喻京川太空美术作品选登     

对称多步法的适用范围

本文对对称多步法作了一些注解,通过具体的数值计算,给出了对称多步法的局限性及它的适用范围。     

太阳活动的不对称性研究

从三方面概述了太阳活动不对称的进展;不对称性的特征及其演化行为、周期性和可能的解释。太阳活动的南北半球及东西半球人发布是不均匀的,且在南北半球上分布不对称;但目前仍无法确定东西半球分布不对称。在众多的解释太阳活动不对称的理论中,没有一种理论被广泛接受。对将来开展太阳活动不对称性研究工作提出了一些看法。     

Finite source effect on the polarization degree induced by a single microlens

We investigate the effect of a single microlens on Stokes parameters. Semi-analytical formulae of the microlensed Stokes parameters are derived. The formulae not only reduce the double integrals in the estimations of those quantities but can also be approximated to a useful form in the bypass case. By using our formulation, we show that a combination of polarimetric data with photometric data enables us to estimate not only the finite source effect but also the direction of the microlens motion.     

Chemical enrichment by Wolf–Rayet stars: non-solar metallicities

Following on from our recent Paper I, we present theoretical models of Wolf–Rayet (WR) stars for non-solar metallicities from   Z = 0.03  to 0.0001 by mass fraction with different mass-loss rate assumptions. We find that some single WR stars may still form even at the lowest metallicities, but whether this occurs or not depends critically on the upper cut-off point of the initial mass function used. As at solar metallicity, a population of binaries is required to fully reproduce WR star observations. For most scenarios, these binaries dominate the low-metallicity WR population but probably not the enrichment. We find comparable carbon enrichment from single WR stars to that from asymptotic giant branch stars at all metallicities for which data are available, but which of them is the dominant source of carbon depends strongly on the set of asymptotic giant branch yields adopted and the assumed initial mass function. We find an increase in carbon enrichment with increasing metallicity but a decrease in oxygen enrichment, as confirmed by observation.     

A New Analysis of Fireball Data from the Meteorite Observation and Recovery Project (MORP)

Sixty fireball cameras operated in Western Canada from 1971 to 1985. Over one thousand (1016) fireballs were recorded at more than one station, but only 367 were reduced, of which 285 have been published, including that of the Innisfree meteorite. Digitization of all the data is underway, and procedures are being developed which will allow the automatic reduction of events not previously examined. The results of the analysis of 80 fireballs reduced but not previously published are presented. When the new analysis is complete, the MORP archive will be a valuable source of information on meteoroid orbits.     

New theoretical approaches to black holes

Quite recently, some new mathematical approaches to black holes have appeared in the literature. They do not rely on the classical concept of event horizon—which is very global, but on the local concept of hypersurfaces foliated by trapped surfaces. After a brief introduction to these new horizons, we focus on a viscous fluid analogy that can be developed to describe their dynamics, in a fashion similar to the membrane paradigm introduced for event horizons in the seventies, but with a significant change of sign of the bulk viscosity.     

Intrinsic Variables as Components of Close Binaries

I review the current knowledge on binarity accompanying intrinsic variability of different types, according to the existing classification scheme. In many cases, binary nature not only accompanies but causes intrinsic variability.     

Euler solution of a kinematic equation for nearly-parabolic Keplerian motion

In celestial mechanics the kinematic equation connecting the time and position in orbit is important. This equation is investigated in detail, but the case of nearly-parabolic motion remains little studied. The universal equations were derived by Euler, but he did not investigate then in detail. We present the solution in the form of series with respect to the small Euler parameter, with coefficients depending on time, and we solve the problem on determining the convergence domain of this series that occurs to be more complicated problem.     

Stellar flares

Different aspects of stellar flares as one of the events of stellar activity with different levels of similarity to solar-activity phenomena are briefly discussed: those which are understandable by means of scaling of solar events, those that do not occur on the Sun but general solar features allow us to understand them, and such stellar events that have not been understood as yet.     

On the relation between the Sun's (geocentric) angular diameter and the observed (topocentric) ‘drift time’

It is pointed out that the relation between the Sun's geocentric diameter and the so-called drift time observed on the Earth's surface does not depend on topocentric data (distance, declination, parallax, refraction), but only on the geocentric values of distance, declination, and variation of right ascension.     

A comparison between the Hubble diagrams of type-I Seyfert galaxies and low-redshift,radio-weak quasars

We took 30 low-redshift, radio-weak quasars with 2 or more forbidden lines, and 16 Type-I Seyfert galaxies of the non-violent subtype, and compared their Hubble diagrams. We found that they each have a high correlation on the diagram, but they do not fall on a continuous line. This suggests that, contrary to the surmise by some people, they are not the same type of object. If quasars do evolve into Seyferts, then the transition must be very brief and rapid.