雷暴型风切变及其对飞机飞行影响的初步探讨   总被引：1，自引：0，他引：1  

王学永  金维明  洪钟祥 《大气科学》1986,10(1):55-67

本文利用北京320米气象观测塔的实测资料和715测雨雷达回波图片.对1980年8月31日晚影响北京地区的两次雷暴天气过程对塔层各要素和参量的影响情况进行了综合分析.结果表明,尽管两次雷暴天气过程的主体路径偏北,但塔层资料仍然明显地反映出雷暴冷性外流气流的存在.冷外流前沿离雷暴云体20公里左右.两次雷暴天气过程的外流气流中都出现了大于0.2秒的严重风切变.这足以使飞机纵向运动发生不稳定而危及安全.为此提出,应把飞机远离雷暴云主体20—30公里飞行作为一个重要的安全措施,不要侥幸地去抢飞这一危险空域.  相似文献   

夏季月份赤道西风的变动及其与低纬环流的关系     

喻世华  洪天宝  刘智远 《气象学报》1986,44(2):166-173

本文利用1979年5—8月的FGGE网格点资料,设计了一个判别指数|v/u|,用来确定赤道西风的存在及其演变特征。分析表明,赤道西风是印度洋低纬地区的一支重要的基本气流。文中分析了这支基本气流的三维结构,并粗略地论述了它与该地区环流的关系。  相似文献   

岩石结构分形维数与岩石压缩强度关系的探讨   总被引：1，自引：0，他引：1  

张玉三  李太任 《煤田地质与勘探》1995,23(3):22-25

运用分形几何学的理论和方法研究煤层顶板岩石的结构，发现岩石的粒度结构和孔隙结构均具有自相似性，粒度分形维数和孔隙分形维数与岩石压缩强度之间有良好的相关关系，故可以用岩石结构的分形维数定量表述岩石的压缩强度。  相似文献   

五寨4.8ML地震宏观考察与震害评估     

Survey Group of Wuzhai Earthquake 《山西地震》1995,(2):42-47

本文介绍了对１９９３的９月１１日五寨４．８ＭＬ地震的考察情况，确定宏观震中在五寨县丰兑坡与河曲县土沟村一带，震中烈度为６度。计算得出本次地震的总经济损失约１５万元。  相似文献   

The Evolutionary History of Ore-forming Processes of Metallic Ore Deposits in Northern Guangxi     

Chen Yuchuan  Mao Jinwen  Wang Ping''an Chinese Academy of Geological Sciences  Beijing Fei Zhenbi 《《地质学报》英文版》1995,69(2)

The northern Guangxi region is an important rare metal, rare earth metal and polymetallic metallogenic province. In the region there exist five metallogenic series and two metallogenic subseries, whose metallogenesis shows features of polycyclic spiral evolution throughout the geological history. As far as various cycles are concerned, mantle-derived ore substances were reduced while crust-derived ore substances increased from early to late timesfin the whole geological evolutionary history, mantle-derived substances decreased gradually while crust-derived ones increased. Meanwhile ore element associations became more and more varied. In terms of space, mineralization migrated from the old basement outwards, i.e. from west to east during the Precambrian, and from north to south during the Phanerozoic, and again from east to west during the Yanshanian.  相似文献   

金川露天矿高边坡的反射地震CT探测研究     

赵永贵  王超凡 《工程地质学报》1995,3(4):62-68

高边坡的岩体结构和稳定性研究是工程地质研究的一个重要课题。本次探测使用高分辨率数字地震仪和反射地震CT方法,对金川露天矿高边坡的岩体结构进行了深入细致的探测与研究,清楚地揭示了边坡岩体中优势结构面的产状和组合关系,以及边坡表层松动带厚度分布,未发现顺坡软弱岩层。  相似文献   

鄂尔多斯盆地南部昆虫化石   总被引：5，自引：0，他引：5  

洪友崇 《甘肃地质》1995,4(1):1-13,T004

鄂尔多斯盆地南部下白垩统环河－华池组昆虫化石，共有９个属种，其中有３个新属５个新种，包括未正式发表的１个属种的模式标本。这些昆虫化石在鄂尔多斯盆地是首次发现与公布的，不但丰富了该盆地的化石门类，也为地层划分与对比提供了新资料。  相似文献   

西藏羌塘南部地区的冰海杂砾岩及其成因     

李才  程立人  胡克  洪裕荣 《吉林大学学报(地球科学版)》1995,(4)

青藏高原及邻区广泛分布的漂砾层、杂砾岩、含砾板岩是一种特殊的冰海相沉积岩，称为冰海杂砾岩（Ｉｃｅ－ｓｅａＭｉｘ－ｃｏｎｇｌｏｍｅｒａｔｅｓ）。它们和一起产出的冷水型动物群、耐冷植物群视为这一地区冈瓦纳相最典型的标志，代表着冈瓦纳大陆上塔尔切尔（Ｔａｌｃｈｉｒ）冰期所影响的时间和空间。除“标准型”冰海杂砾岩外，羌塘腹地发现了蛇绿质和钙质冰海杂砾岩。这两种冰海杂砾岩的发现，不但丰富了冰海杂砾岩的家族成员，同时也为冰海沉积、物质来源问题、冈瓦纳大陆北界及特提斯演化研究提供了新的信息。经研究，冰海杂砾岩中的砾石来自印度半岛──冈瓦纳大陆本体，以冰筏为载体融冰落石成因。  相似文献   

Magnetostratieraphy of the Red Beds in the Hengyang Basin     

Hsu Vindell  A.Baksi 《《地质学报》英文版》1995,69(2)

This paper discusses the Cretaceous-Tertiary magnetic polarity sequence of the the Hengyang Basin on the basis of magnetostratigraphic study. The age of each stratigraphic unit has been determined with the magnetic polarity time scale combined with 39Ar/40Ar dating, thus providing evidence for determining the geological ages of different formations. The authors assign the age of the Dongjing Formation of the Hengyang Basin to Early Cretaceous, the Shenhuangshan Formation to Early-Late Cretaceous, the Daijiaping Formation to Late Cretaceous, and the Dongtang and Xialiushi formations to Palaeocene.  相似文献   

Fluid Inclusion Geochemistry of Metallic Ore Deposits in the South- Central Sector of theDa Hinggan Mountains in China     

Sheng Jifu  Zhang Dequan  Li YanInstitute of Mineral Deposits  Chinese Academy of Geological Sciences  Beijing Jiang M inxi 《《地质学报》英文版》1995,69(3):289-302

Physicochemical parameters of mineralization such as temperature, pressure, salinity, density, composition and boiling of ore fluids as well as pH, Eh, fo2 and reducing parameter in theprocess of mineralization of major ore deposits in the study district have been obtained by the authors through systematic observation and determination of characteristics and phase changes of fluid inclusions at different temperatures and analysis of gaseous and liquid phase compositions of the inclusions, thus providing a scientific basis for the division of mineralization-alteration stages, types of mineral deposits and minerogenetic series and the deepening of the knowledge about the ore-forming processes and mechanisms of mineral deposits. It is indicated that the deposits of the same type have similar fluid inclusion geochemical features and physicochemical parameters though they belong to different minerogenetic series, while the compositions of inclusions are not conditioned by deposit types but closely related to  相似文献