数字图像压缩方法在天文上的应用

概述了数字图像压缩技术在天文领域应用的必要性。针对天文观测的特点和研究的需要，经过研究、分析和比较，提出了天文图像压缩的可行方案。通过应用计算机编程及压缩实验并给出相应的结果。     

射电喷流中湍动阿耳芬波对相对论电子的加速

本文通过数值求解带电粒子与Ａｌｆｖｅｎ波湍动相互作用的动力学方程，得到了相对论电子在射电喷流中被加速随时间演化的解．高能电子可以加速到Ｌｏｒｅｎｔｚ因子γｙ～１０６，且形成稳态的幂律谱，尽管其谱指数Ｓ≈ｌ比观测值小，但粒子加速时间约为１０１２－１０１４秒，小于射电斑的寿命１０７年．粒子能谱指数几乎与Ａｌｆｖｅｎ波谱指数和能量损失函数无关．能量损失对加速上限有较大影响．     

中国石油生产的展顾

本文分析了中国石油生产近20年变化的原因,对一些学者认为80年代中国会成为超级产油大国,后又悲观断定80年代中国可能变成石油净进口国作了评述。同时对90年代中国石油生产前景作了初步展望。     

利用地震矩张量反演鲜水河断裂带现今运动学特征

本文探讨了利用地震矩反演断裂形变带运动学参数的基本理论和方法，将其初步应用于鲜水河断裂形变带变形分析和运动机制的研究。结果表明，鲜水河断裂带呈现出走向拉伸、倾向压缩的形变格局，由地震矩反演的断裂带剪切形变速率（１０．９ｍｍ／ａ）与用地质学估算方法（１７ｍｍ／ａ）和现今地壳形变测量（８ｍｍ／ａ）的结果相当。同时，反演出的应变主方向能解释鲜水河断裂现今活动分段性特征以及多种滑动方式共存的现状，从而证明该方法是目前研究区域运动学问题切实有效的手段之一。     

Effects of Different Diets on the Dietary Attractability and Selectivity of Chinese Shrimp, Fenneropenaeus chinensis

Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differences of attractability exist between any two different diets when every two natural diets or all five diets are provided simultaneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion.     

Free radical scavenging abilities of polypeptide from Chlamys farreri

1 INTRODUCTION Active oxygen free radicals can damage cell structure, even kill the cells, causing aging and cer- tain serious diseases (Bors et al., 1989). Usually, the production and scavenging of active oxygen free radicals are in balance in healthy hu…     

球状星团的天体测量(英)

球状星团是银河系中最年老的天体之一，是储存着银河系早期演化珍贵信息的“化石”．球状星团的天体测量，主要包括球状星因天区内恒星相对自行的测定，并由这些相对自行数据采用适当方法定出星团的绝对自行，或者直接测定绝对自行．利用这些自行数据，或者进一步与测光和视向速度数据结合，可以开展与球状星团的距离、运动、动力学状况、质量、年龄、演化等等以及银河系的结构和演化等有关的一系列重要的研究．在本文中对本世纪70年代中期以来在球状星团相对自行测定和成员概率估计、内部运动检测、绝对自行测定和空间运动研究这三方面取得的成果和进展以及存在的问题作了评述．     

The Relationship of Green-Line Transients to White-Light Coronal Mass Ejections

We report observations by the Large Angle Spectrometric Coronagraph (LASCO) on the SOHO spacecraft of three coronal green-line transients that could be clearly associated with coronal mass ejections (CMEs) detected in Thomson-scattered white light. Two of these events, with speeds >25 km s^-1, may be classified as ‘whip-like’ transients. They are associated with the core of the white-light CMEs, identified with erupting prominence material, rather than with the leading edge of the CMEs. The third green-line transient has a markedly different appearance and is more gradual than the other two, with a projected outward speed <10 km s^-1. This event corresponds to the leading edge of a ‘streamer blowout’ type of CME. A dark void is left behind in the emission-line corona following each of the fast eruptions. Both fast emission-line transients start off as a loop structure rising up from close to the solar surface. We suggest that the driving mechanism for these events may be the emergence of new bipolar magnetic regions on the surface of the Sun, which destabilize the ambient corona and cause an eruption. The possible relationship of these events to recent X-ray observations of CMEs is briefly discussed. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1004981125702     

大气垂直折射与时序垂直角值的谱分析

本文介绍了对时序垂直角观测值进行谱分析的方法和所得到的结论。使以往对于大气折射影响及其变化规律的定性认识得以定量化。