γ射线暴研究概况

γ射线暴(简称γ暴)的研究自1997年以来由于余辉的发现而有了很大的突破。在此，对γ暴的观测作了简要的概述，而对γ暴的理论进展和存在问题进行了较为全面的评述，内容包括γ暴本身、余辉、能源机制、寄主星系、暴周环境、高能粒子和引力波辐射、宇宙学意义等。     

γ射线暴的研究进展（Ⅳ：特强γ射线暴和软γ重复暴

最近CGRO上的仪器观测到了两个迄今为止发现的最强的λ暴GB930131和GB940217,其光子最高能量均达GeV量级;GB930131的峰值计数率达2×10~6个光子s~(-1);而GB940217的持续时间竟长达90min。另外沉寂了多年的软重复暴源SGR1900 14和SGR1806-20的再次爆发也由BATSE发现。一系列的观测还发现这些软重复暴均与X射线源对应且与超新星遗迹成协。文中对特强暴和软重暴(SGR)的性质及研究进展作了较为详细的评述。     

A new radiolarian species Clathrocorys gracilis from northern South China Sea

A new species,Clathrocorys gracilis nov. spec. of Tripocyrtidae (Radiolarians: Nassellaria) from surface water in northern South China Sea, is described in this paper. The new species has four radial beams arising from the cephalic base centre, each foot with cup-shaped structure and ramified bar in the proximal section (near cephalic base), and each wing with a large mesh in the middle, a medium mesh and a small mesh on each side respectively. Project supported by the NSFC (No. 40276044) and the Chinese Academy of Sciences (No. KSCX2-SW-101B).     

瓮安生物群与宽川铺生物群中球形类化石研究

通过对获自瓮安生物群与宽川铺生物群中大量球形类化石的系统研究，建立了便于交流和深入讨论的球形类化石形态分类方案，对各种类型的球形类化石进行了属性探讨，并按形态属描述球形类化石4个新类型(相当于形态属)，8个新种类(相当于形态种)。研究表明球形类化石是一个多源的非正式生物类群，包括动物性和植物性球形类化石。具有丰富的研究内涵，对揭示早期生物的起源、演化、多样性及胚胎发育具有深远意义。     

A New Solar Radio Spectrometer at 1.10-2.06 GHz and First Observational Results

An improved Solar Radio Spectrometer working at 1.10-2.06 GHz with much improved spectral and temporal resolution, has been accomplished by the National Astronomical Observatories and Hebei Semiconductor Research Institute, based on an old spectrometer at 1-2 GHz. The new spectrometer has a spectral resolution of 4 MHz and a temporal resolution of 5ms, with an instantaneous detectable range from 0.02 to 10 times of the quiet Sun flux. It can measure both left and right circular polarization with an accuracy of 10% in degree of polarization. Some results of preliminary observations that could not be recorded by the old spectrometer at 1-2 GHz are presented.     

Propagation of Alfvén waves in multi-layer solar atmosphere model

In this paper, we idealize the actual solar atmosphere as a multi-isothermal-layer system so as to obtain the energy transmittance of the linear Alfvén wave that propagates through such a system in presence of a uniform oblique magnetic filed. The results indicate that the two-layer model is essentially different to the three-layer one. In the two-layer model, the temperature jump acts as a high pass filter. In the three-layer model, resonant transfer will take place and the transmittance undergoes oscillation as the trigonometric function terms dominate its behavior. For actual solar atmosphere, the result reveals that the lower parts of solar atmosphere are more suitable for those Alfvén waves with period of seconds to transfer their energy.     

广东省拖网网囊调查

为实施中华人民共和国国家标准《南海区拖网网囊最小网目尺寸》,对广东省范围内拖网网囊现状进行摸底调查,结果表明,广东省沿海拖网渔船现用网囊网目尺寸(内径)在16.7～35.2 mm范围内,总体平均为27 mm,均未能达到1989年国家技术监督局发布的中华人民共和国国家标准--《南海区拖网网囊最小网目尺寸》--内径39 mm.     

基于GIS的印度洋大眼金枪鱼延绳钓钓获率与水温关系的研究

采用GIS定性分析和数值分析的方法,研究了印度洋大眼金枪鱼延绳钓钓获率与水温的 关系。结果表明,大眼金枪鱼延绳钓高钓获率的出现与印度洋加权水温大面分布存在明显的相互 关系,大眼金枪鱼的渔获适温在14～17℃间。建议测量200m水深处的水温作为海上生产时的参 考。     

丽江高美古台址和2m级望远镜项目(英文)

自 1992年起云南天文台开始了在云南省西北部的天文选址。丽江高美古最终被选择作为未来中国地基天文光学观测的新址点。并且 ,在国家科技部 ,云南省政府 ,以及中科院的支持下 ,2m级天文望远镜项目在 2 0 0 0年 12月获得立项。在文中 ,我们简要的介绍了高美古台址的情况 ,并给出了 2 .4m望远镜的详细情况 ,以及其他相关情况。     

Results from several persistent train spectra intercompared

Some results following from two contemporary photographical programs (Slovakia and Japan) for persistent meteor train spectra are compared. It shows that even though both programs are not too different according to their lenses and films used, the spectral interval detected is very different. In this respect prism as a dispersion element is more favourable than the grating with blaze wavelength near 610 nm. However, some results previously assumed as typicai for presented persistent trains-e.g. the forbidden Herzberg O₂ emission, the NO₂ continuum and OH red emissions-seem to be substanciated especially due to higher and linear dispersion of those grating spectra.