松辽盆地庆安地区白垩纪沉积体系和目的层地球化学特征及与铀矿化的关系

本在分析松辽盆地所处大地构造背景和构造演化特征的前提下，着重研究了松辽盆地庆安地区白垩系的沉积特点、沉积体系特点和泉头组目的层地球化学特征，初步论述该地区砂岩型铀矿成矿特点及与白垩纪地层的关系，并提出了该地区可能产出的铀矿床类型。     

南海季风试验与东亚夏季风

南海季风试验是一次国际性大气与海洋的联合试验 ,旨在更好地了解南海季风的爆发、维持与变化 ,以改进东亚和东南亚地区的季风预报。 1998年 5～ 8月进行的外场试验取得了圆满成功 ,获得了大量气象与海洋资料。不少国家对这些资料进行四维资料同化 ,并改进数值模拟和预报 ;同时也为东亚与南海地区季风的研究提供了必要的资料集。文中总结了中国科学家在这方面的主要研究成果 ,共包括 6个方面 :(1)南海夏季风的爆发过程与机理 ;(2 )南海季风爆发过程中对流与中尺度系统的发展及其与大尺度环流的相互作用 ;(3)低频振荡与遥相关作用 ;(4 )南海海 气通量的测量及其与季风活动的关系 ;(5 )夏季风时期南海海洋的热力结构、环流和中尺度涡旋及其与ENSO事件的关系 ;(6 )南海与东亚季风的数值模拟。     

Combined study between the chromospheric flare models and hard X-ray observation

By comparison between SMM HXRBS observation and ground observation of H and Caii K lines for the 2B flare on February 3, 1983, we found that there was a temporal correlation between H intensity and hard X-ray flux at the early stage of the impulsive phase while different peaks in the hard X-ray flux curve represented bursts at different locations. When we combined SMM HXRBS observation with chromospheric flare models, we further found that the temporal coincidence between H intensity and hard X-ray flux could be explained quantitatively by the fact that the H flare was indeed due to the heating by non-thermal electron beams responsible for the emission of hard X-rays. Together with the discussion on coronal density based on chromospheric flare models, it was also shown that the source of electrons seemed to be situated around the top of the flare loop and the column density at the top of the chromosphere in semi-empirical flare models could not be taken as the total material above the top of the chromosphere.     

Heat oscillation in the upper ocean of the southern South China Sea

Data used in this study are temperature/depth profiles taken over the upper 400 m of the ocean in the southern South China Sea (4°-14° N, 106°-120° E) for the period 1961-1973. The data are analyzed on the grid 2 (latitude) by 2 (longitude) in space and bimonthly in time. The vertically averaged temperature (TAV) over the upper 100 m of the ocean is calculated as the estimate of the heat content in the upper ocean.The TAV is cooler in the northwest region of the study area and warmer in the southeast in the annual and seasonal mean figures. The first EOF (Empirical Orthogonal Function) of anomalous TAV accounts for 41 % of the total variance for the period 1961-1973. The time function associated with it displays a significant interannual changes in the heat content, with 2-4 a oscillation period and associated with the ENSO events. During ENSO event TAV increases with the tendency of increasing towards equator along the basin. This anomalous states also exist in the water layers below 100 m depth. T     

冲绳海槽浮岩岩浆活动模式浅析

本文根据部冲绳海槽的地下结构、地温场特征、以及浮岩中斑晶矿物的结晶温度和榴辉岩的熔融相关系等，综合分析了冲绳海槽酸性浮岩岩浆的活动模式。提出：在冲绳海槽中部和东部地下１５ｋｍ以下的地幔物质部分熔融、产生橄榄拉斑玄武质岩浆，而在海槽中部地壳一结构层中（７－１５ｋｍ）熔融产生少量安山质岩浆。因此，在冲绳海槽地下存在有双层岩浆房结构，并且二者之间中部有岩浆通道。来自地幔的拉斑玄武质岩资源下部地壳中一方面     

陡峭S形柔性管初始形状计算

本文采用悬链线方程的解，推导出陡峭Ｓ形柔形管初始形状的计算公式，计算出柔性管的初始形状、张力和弯矩，与国外资料的实例计算进行对比表明，结果相当一致。     

珠江口台风增水对热带气旋参数改变的反响

通过计算，研究热带风暴中心气压下降示度、最大风速半径、热带气旋登陆地点、热带气旋登陆时的入射角、热带气旋移动速度等参数改变条件下，珠江口５个测站风暴潮的变化。结果表明，各站的反响很不一致，在风暴潮预报中对地形的特点、热带气旋移动速度及热带气旋登陆地点等应给予足够的重视。     

An Overview of Researches on Land-Atmosphere Interaction over Semi-Arid Region Under Global Changes

The semi-arid region, as a key part of global land, plays an important role in climate change. In the process of modern climate change, the semi-arid region is significantly affected by local human activities, showing remarkable expansion and obvious decadal variations. In this paper, we summarized the studies of the land-atmosphere interaction in the semi-arid regions in recent years, and major land surface observation plans. We put emphasis on energy balance, water cycle, carbon cycle in land-atmosphere interaction of climate change, and their performance in historical simulation and future prediction. The prediction results illustrate that new character of land-atmosphere interaction will appear as the drying of drylands in the future. Therefore, it is necessary to deepen the understanding of land-atmosphere interaction and move forward energetically on research in regional climate from different aspects.     

The application of HVSR method in detecting sediment thickness in karst collapse area of Pearl River Delta,China

The microtremor horizontal-to-vertical spectral ratio (HVSR, or H/V spectral ratio) method is an effective tool for detecting sediment thickness. Firstly, single-station microtremor measurements were taken beside 52 boreholes located in Pearl River Delta, China. Sediment thicknesses revealed by those boreholes range from 7.9 to 39.6 m. Then, those microtremor data were analyzed using HVSR method, and peak frequency of each site was extracted. According to those peak frequencies of HVSR and corresponding sediment thicknesses, the frequency-to-thickness fitting (f–Z) equation which is suitable for Pearl River Delta area was established. And this equation was compared with several fitting equations derived from different regions by other researchers. Finally, this fitting equation was applied in a collapse area in Guangzhou city to estimate site sediment thickness. Compared with data from five boreholes in this collapse area, the consistency between estimated sediment thickness and real value was relatively good. Karst sinkholes are generally located in regions where thickness of sediments is shallow. Therefore, the method described in this paper can provide support for delineating potential collapse areas.     

Application of seismic velocity tomography in investigation of karst collapse hazards,Guangzhou, China

This paper describes seismic velocity tomography applied to the investigation and assessment of karst collapse hazards to facilitate accurate characterization of geological conditions of karst sinkhole formation. In the survey areas of Xiamao, Guangzhou, China, and Huangchi, Foshan, China, seismic velocity tomography was used to explore the structures of rock and soil associated with karst collapse. The results show that sand intercalated with clay or clay intercalated with soft soil dominates the cover of these two areas. The overburden is 20–33 m thick and underlain by Carboniferous limestone. In the limestone, there are well-developed karst caves and cracks as well as highly fluctuating bedrock surfaces. The seismic velocities are less than 2500 m/s in the cover, 2500–4500 m/s in the karst fracture zones and caves of Xiamao, and 1500–2000 m/s in the Huangchi collapse area. The karst fracture zones, relief of bedrock surfaces, and variations of soil thicknesses revealed by seismic velocity tomography are well constrained and in agreement with those in the drilling borehole profiles. This paper demonstrates that seismic velocity tomography can delineate anomalies of rock and soil with the advantages of speed, intuitive images, and high resolution.