INSTRUMENTATION FOR GEOLOGICAL FIELD WORK ON THE MOON

A human return to the Moon will require that astronauts are well equipped with instrumentation to aid their investigations during geological field work. Two instruments are described in detail. The first is a portable X-ray Spectrometer, which can provide rapid geochemical analyses of rocks and soils, identify lunar resources and aid selection of samples for return to Earth. The second instrument is the Geological and Radiation environment package (GEORAD). This is an instrument package, mounted on a rover, to perform in-situ measurements on the lunar surface. It can be used for bulk geochemical measurements of rocks and soils (particularly identifying KREEP-enriched rocks), prospect for ice in shadowed areas of craters at the poles and characterise the lunar radiation environment.     

WAS THE FORMATION OF A 20-KM-DIAMETER IMPACT CRATER ON THE MOON OBSERVED ON JUNE 18, 1178?

As reported in medieval chronicles, on the evening of June 18, 1178, the upper horn of a new moon split, and from the division a flaming torch sprang up. We interpret this observation in terms of a large impact event which formed the 20-km-diameter crater, Giordano Bruno.     

表面边界位置对太阳ρ模本征振荡频率的影响

本文研究了表面边界位置对太阳ρ模绝热本征振荡频率的影响。数值计算结果表明，对于ｖ４０００μＨｚ的中低阶ｐ模，表面边界置于温度极小点所引起的本征振荡频率的计算误差随着ｖ和ｌ的增大，表面边界点位置对太阳理论振荡频率的影响增大，色球结构对太阳ｐ模振荡频率的影响已变得不可忽略。     

A STUDY OF THE RELATIVE RATES OF METEORITE FALLS ON THE EARTH'S SURFACE

Meteorite camera networks have provided reliable data on typical orbits for meteorites. Using an adopted distribution of 20 orbits we determine the relative rates of meteorite falls over the surface of the earth taking account of the important effects due to the earth's gravity. The data are then used to study the expected variation in rates as a function of daylight, twilight or night conditions; time of day; season of the year; and geographic latitude. The rates of meteorite falls have a deep minimum near the area of the earth facing the earth's apex but a surprisingly broad maximum on the opposite side, facing the antapex. Twilight rates are lower than average and nighttime rates 3% higher than daytime rates. Minimum rates occur near 6^h local time and there is a broad maximum from noon to midnight. Rates are highest near the beginning of spring for either hemisphere and lowest near the beginning of autumn. The decline in rates with increasing latitude is quite moderate. The existing camera networks observe average fall rates at night which are very close to the average rate over the whole earth for the whole year.     

具奇异电流密度面的一维无力场的稳定性

从Ｎｅｗｃｏｍｂ（１９６０） 给出的直线箍缩等离子体的一维能量积分和稳定性定理出发,证明Ｌｏｗ（１９９３） 在圆柱坐标系下找到的具奇异电流密度面的一维无力场是稳定的     

预报大行星,月球掩点源事件的一种方法

以ＪＰＬ提供的太阳系天体数值历表ＤＥ２００／ＬＥ２００和美国海军天文台提供的岁差、章动改正程序为出发点，本文介绍预报大行星、月球掩源的一种方法，本方法分三个步骤：首先给出被掩源所满足的必要条件，并据此进行被掩源的初选；其次预报掩事件的全局情况，即掩发生的始终时刻和比较精确的地球椭球表面上可观测区域边界，在可观测区域边界中，本文发现了文献中未见出现过的出没南北界最后；预报地方见掩情况。     

13.7米射电望远镜谱线观测系统的稳定性与观测时间的优化使用

本文介绍紫金山天文台青海13.7M毫米波射电望远镜谱线观测系统稳定性的测试,并讨论如何根据测试结果选择最佳观测模式与积分时间,以提高望远镜的使用效率。     

COMPARING INVESTIGATIONS ON THE SURFACE STRUCTURES OF IRGHIZITES AND PYROCLASTICS BY SEM

The surface structures of irghizites from the Zhamanshin crater in Kazachstan, USSR, play an important role in the discussion of their genesis. These surface structures were compared with those of typical tektites (australites) and pyroclastics (obsidians, lapilli) based on investigation by electron microscope. The results of these investigations indicate that there are no unambiguous genetical relationships between the morphology of irghizites and the surface features of tektites and pyroclastics. The surface shapes of irghizites result from several simultaneous or successive processes, in the course of which globules of different size melted, stuck together and were eaten into by corrosive gases after their solidification. The assumption that the verrucose swellings were caused by expanding gas bubbles immediately below the surface of the glass bulk can be excluded. The verrucose glass globules are identical in chemical composition to the glass bulk of the irghizites.     

借助光压将探测器推向月球

若采用圆型限制性三体问题模型，从近地停泊轨道上发射一个月球探测器，其最小初始速度必须使相应的Jacobi常数C小于某一临界值C2。但这仅仅是探测器可能飞向月球的必要条件，而且这样飞向月球耗时过长。若采用Hohmann转移轨道，则需要获得较大的变轨冲量，能量消耗较大。如果需要仔细探测地月空间环境，而又不必很快地飞往月球，那么采用较大的太阳帆板，并使其法向有一特殊指向，可借助太阳光压加速引导探测器在不长的时间内飞向月球。利用相应的分析和计算，证实上述考虑是有效的，而且若使太阳帆板截面积大到一定程度（如果技术上能实现），则无需任何动力，也可借助光压将探测器推向月球，就像一条太空帆船（简称太空帆）。     

关于土卫八运动的轨道解

为了适应星际探测的需求,本文建立了在新的精度要求下土星卫星运动对应的力学模型,具体讨论了土卫八的运动,并针对主要摄动源土卫六的引力作用,建立了轨道变化的分析解,以此表明建立了土卫运动理论该采取的途径和精密定轨宜采用以轨道根数作为状态量的数值定轨方法。     

自引力磁均分和磁守恒吸积盘模型的稳定性分析

对自引力磁均分和磁守恒两种模型的径向振荡稳定性的研究表明：在同时考虑自引力和磁场作用的情况下,吸积盘在磁均分和磁守恒模型中均存在着三种振荡模式,其中粘滞模式总是稳定的,磁声模式是不稳定的,中性模式在图中较长波段范围趋于稳定,在较短波段范围是不稳定的．这些结果有利于解释活动天体的Mark421和Pks2155—304的长周期光变现象．同时阐明了自引力在两种模型中对三种模式的影响有相同的趋势,而对磁场则分别起着相反的作用．这个结论表明磁均分吸积盘模型在解释光变现象时更为有利．     

ON THE ORGANIZATION OF FINE STRUCTURE OF THE SOLAR PHOTOSPHERE

High-quality stratospheric photographs in the continuum were used to investigate spatial scales of the solar granulation field. Two-dimensional intensity power spectra are shown to contain most frequently the modes corresponding to the sizes of granules, protogranules, mesogranules, and supergranules. The place of these four, the most steady formations of the quiet Sun in the global structure of the solar photosphere, is discussed as well as their interconnection and their relation to weak and strong magnetic fields. The protogranulation scale is argued to play an important role in organization of the fine structure of the photosphere and magnetic fields in the quiet and active regions of the Sun.     

引力常数变化对地球自转长期变化的影响

探讨和估计了各种引力常数变化理论对地球角速度和日长变化的影响。各种引力常数变化理论包括了引力常数G随时间、空间以及速度变化等几个方面的影响。另外也估计了对地球自转角速度和日长变化产生的效应。其中有些研究对探讨地球自转变化也有启发意义。     

ON THE EVOLUTION OF FILAMENTS

A statistical large-scale study of filaments has revealed the existence of a functional dependence of the length of filaments (the angular distance between the ends of a filament, measured on a great circle on a sphere) on their inclination to lines of solar latitude. A cluster analysis method has been applied to the study of filament evolution and an evolutionary classification of filaments is proposed. The results depend on the differential velocity of filaments. Different types of evolution sequences were obtained, and the evolution of some particular filaments was specially analyzed.     

太阳系外行星动力演化研究

本文简要地介绍了目前太阳系外行星系统动力演化的研究现状。我们用数值模拟方法和并从分析的角度研究了GJ 876和HD 82 943。通过分析不同的共面和非共面构型 ,我们发现所有的稳定轨道都和2 :1共振有关 ,此外我们还发现在这两个系统内存在近星点共振—对应了两个行星的近星点经度之差在1 80 0或者 0 0附近秤动。这两种机制对维持行星系统的稳定性起了重要作用。     

共振在近地小行星轨道演化中的作用

本文采用了合理的力学模型和可靠的计算方法,研究了近地小行星轨道运动,揭示了共振（轨道共振和长期共振）在其轨道演化中的作用,并初步探讨了近地小行星的起源问题。     

日珥谱线不对称性的研究 Ⅰ.视向速度对谱线轮廓的影响

本文主要从理论上用解析方法讨论日珥视向速度随深度变化对谱线轮廓对称性的影响,得到的结论具有普遍性。第二节的分析表明,日珥的谱线轮廓可表示为二项叠加,其中第一项与源函数无关,只依赖于速度场模型,源函数分布仅通过第二项对谱线轮廓产生影响。然后在源函数不随深度变化的假定下,讨论各种速度场模型的谱线轮廓是否对称。得到的结论为:(1)常源函数与常速度场结合的谱线轮廓为对称轮廓;(2)常源函数与线性对称速度场结合的谱线也是对称轮廓;(3)常源函数与线性非对称速度场结合的谱线轮廓为不对称轮廓。最后,用数值计算对理论分析结果进行了检验。