A CASE STUDY ON SANDSTORM

The favourable synoptic situation and climate background for a sandstorm process,which occurred in theperiod 9—16 April 1988,have been studied through analyzing weather maps,meteorological elements,satellitecloud pictures and sandstorm trajectories.The sand dust origin area,the directions and the paths of sanddust transport,and the extent the sand dust reached are also investigated.The results of measurments andanalysis indicate that the concentration of sand dust particles is 10 times greater than the normal.It is also shownthat the elements in the sand dust are lithophylic and come from natural source through the chemical composi-tion analysis of the sand dust,so that the sand dust has not been polluted by human activities.     

COMPARISON OF AEROSOL CHARACTERISTICS OVER MAINLAND OF CHINA AND WESTERN PACIFIC AND ITS LONG-RANGE TRANSPORT

Based on the aerosol data obtained at Shangdianzi regional background monitoring station together withthe air trajectory analysis,the chemical constituents of the aerosol from the different sources are discussed andcompared with the aerosol samples collected over the western Pacific.The results show that the relative massconcentrations of the crustal and pollutant elements in the aerosol collected over the ocean are higher than thosebeing observed at Shangdianzi in particle size above 4.7 μm and below 0.65μm in diameter.The variationsof the enrichment factors of these elements in marine aerosol with particle size are different from those in shang-dianzi's samples.The former enrichment factors are evidently higher than the latter above 1.1 μm in diameter.On the basis of the comparative research,the long-range transport processes of aerosol particles are discussed.     

正常震群和前兆震群的判定指标

本文采用大森公式ｎ（ｔ）＝Ｋ／（ｔ＋ｃ）＾ｐ求解Ｋ、ｃ、ｐ三个参数，对云南１９６５年以来７１个地震序列进行研究。确定Ｐ＝０．８为前兆震群和正常震群的判定指标。利用Ｋ、ｃ、ｐ三参数计算序列理论曲线得到晚期强余震前差残曲线超出两倍均方差的结果。     

低Peclet数下剪切流中气溶胶粒子的传质率

本文研究了低Péclet数下剪切流中气溶胶粒子的传质率。Péclet数(Pe)是物质浓度的对流输送项对分子扩散项的比。它等于Reynolds数(Re)与Schmidt数的(Sc)之积。本文应用奇异扰动方法得到了无因次传质率Nu(Nusselt数)在小Péclet数条件下的四项渐近展式，因而?改进了前人的结果。     

复杂构造区域的初至波走时计算

有限差分法初至波走时计算是一种十分快速、有效及实用的方法，而且不会碰到传统射线法的阴影区、焦散面等问题．文中指出了ＶａｎＴｒｉｅｒ方法存在的问题，并提出了解决的办法．计算结果表明，方法是有效可行的．对速度变化很大的介质模型，仍能得到较精确的解．     

多频测深初探

在频率域测深的基础上,提出了多频测深方法,实现一机多频同时观测的目的,以提高观测速度。本文讨论了多频观测方法的理论依据及工作特点,并提示实现这种观测的方案。     

震源系统不稳定度指标和强震短临预报

在探讨震源系统不稳定产生的物理基础前提下，应用调制模式提出了利用小震日频次起伏加剧与外因的相关性进行强震的短临时间预报的设想，具体提出了调制小震频次起伏加剧的两个判别震源系统不稳定度的指标λ＿１和λ＿２。前者为单因子调制指标，后者为多因子调制或多因子调制强化指标。关于大震的地点预报，应用立交模式短临阶段出现调制小震通过未来大震的共轭小震活动条带进行预报。     

山西师范大学建筑物的震害预测

在统计、收集山西师范大学各类建筑物资料的基础上，对其各类建筑物进行了震害预测和经济损失估计，给出了各类建筑物在不同烈度下的破坏结果和经济损失值，为地震灾害的综合防御提供了科学依据。     

1932年昌马地震构造力学特征探讨

１９３２年昌马地震构造力学特征探讨郭万武，张范民，邢成起，温增平（国家地震局兰州地震研究所，兰州）ＤＩＳＣＵＳＳＩＯＮＯＮＴＨＥＴＥＣＴＯＮＯＭＥＣＨＡＮＩＣＦＥＡＴＵＲＥＳＯＦ１９３２ＣＨＡＮＧＭＡＥＡＲＴＨＱＵＡＫＥＭｓ７．６￥ＧｕｏＷａｎｗｕ；...