一个中尺度流复合体的环境场、云场的特征分析     

余剑浩 《气象与减灾研究》2003,26(3):27-30

利用常规天气图、物理量诊断分析、逐时红外云图、单站资料等,对2003年4月12日影响鹰潭市的强对流、暴雨天气过程进行分析,认为该过程是在一定的大尺度环流背景下,由不同层次的天气系统共同作用下产生的;其触发机制是冷空气从近地层楔入暖空气中,在高、低空急流、层结不稳定等诸多有利条件下,由几个小尺度对流云团合并发展成1个中尺度对流复合体(MCC).  相似文献   

Synthesis of accelerations of the 1976 Tangshan earthquake(M_S 7.8)in near-and far-field by using semi-empirical method     

罗奇峰  胡聿贤 《地震学报(英文版)》1997,(3)

Ｓｙｎｔｈｅｓｉｓｏｆａｃｃｅｌｅｒａｔｉｏｎｓｏｆｔｈｅ１９７６Ｔａｎｇｓｈａｎｅａｒｔｈｑｕａｋｅ（ＭＳ７．８）ｉｎｎｅａｒａｎｄｆａｒｆｉｅｌｄｂｙｕｓｉｎｇｓｅｍｉｅｍｐｉｒｉｃａｌｍｅｔｈｏｄＱＩＦＥＮＧＬＵＯ１）（罗奇峰）ＹＵ?..  相似文献   

北祁连造山带东段老虎山石英闪长岩成因及其地质意义     

张海瑞  赵姣龙  于汇洋 《高校地质学报》1997,25(5):641

以北祁连造山带东段老虎山石英闪长岩体为研究对象，进行了锆石U-Pb年龄及全岩元素与Sr-Nd同位素组成的系统 测定，据此探讨了岩石的成因及其对北祁连构造演化的启示。锆石LA-ICP-MS U-Pb定年结果表明，石英闪长岩体的形成 年龄为440 Ma。岩石具有亚碱、准铝以及贫钙、镁、铁的特征，碱铝指数（AKI值） 均低于0.85，铝饱和指数（A/NKC 值） 多小于1.0，属钙碱性I型花岗岩类岩石。在稀土和微量元素组成上，岩石富集轻稀土和大离子亲石元素（如Rb、Cs、 Th和U），亏损高场强元素（如Nb和Ta），显示弧岩浆岩的地球化学特征。岩体具有相对均一的Sr-Nd同位素组成，初始Sr同 位素值为0.7058~0.7071，εNd(t)值为-1.06~-0.31。综合分析表明，老虎山石英闪长岩应起源于玄武质下地壳物质的部分熔 融，并在成岩过程中有少量幔源物质的混入。对区内火成岩地质地球化学特征与产出背景的全面分析，表明受北祁连洋俯 冲及随后岛弧与祁连—柴达木陆块碰撞拼贴影响，弧后盆地的北向俯冲消减作用可能是诱发民乐窑沟和老虎山弧岩浆岩以 及导致毛藏寺—老虎山花岗岩带内埃达克质岩石侵位的基本动力机制。  相似文献   

Rb-Sr whole rock and U-Pb zircon datings of the granitic-gabbroic rocks from the Skålfjellet Subgroup, southwest Spitsbergen     

YU. A. BALA&#;OV  J. J. PEUCAT  A. M. TEBEN'KOV  Y. OHTA  A. N. LARIONOV  A. N. SIROTKIN  M. BJORNERUD 《Polar research》1996,15(2):167-181

Recent remapping and new age determinations has shed light on the understanding of Precambrian rocks northwest of Hornsund, southwest Spitsbergen. The Skålfjellet Subgroup has been regarded as the eastern equivalent of the Vimsodden Subgroup, and both of these occur within the Precambrian Eimfjellet Group of southwest Spitsbergen. Although the Eimfjellet Group is considered to be older than the oldest unconformity in the area, the age of the rocks has not been known. The granitic-gabbroic rocks in the Skålfjellet Subgroup have been considered to be the products of granitisation for many years, but recent observations show that they are exotic blocks incorporated into the basic eruptive rocks which are the main constituents of the subgroup. These plutonic rocks have a wide range of compositions, from syenite via granite to gabbroic cumulates, which suggests the existence of a well-differentiated plutonic body at depth.
U-Pb zircon and Pb evaporation datings yielded magmatic ages of ca. 1,100 to 1,200 Ma, and a conformable age has been obtained by Rb-Sr whole rock dating. Detrital zircons from the micaceous schists of the Isbjørnhamna Group, which underlies the Skålfjellet Subgroup, show a poorly defined discordia with an upper intercept age of ca. 2,200 Ma and a lower intercept age of ca. 360 Ma. These dating results define the magmatic age of the granitic-gabbroic rocks as late Mesoproterozoic, early Grenvillian. This age is in broad agreement with that of the metavolcanic rock clasts of the Pyttholmen meta-pyroclastic-conglomeratic unit at Vimsodden, which is considered to be the westernmost occurrence of the Skålfjellet Subgroup.
A Rb-Sr whole rock age determination of the shaly phyllites from the Deilegga Group was performed in order to place constraints on the age of younger Precambrian event; however, no good isochron was obtained.  相似文献   

AN APPARENT TEMPERATURE MODEL BASED ON THERMAL EQUILIBRIUM          下载免费PDF全文

YU Bo  LIU Mei  YAO Kemin 《Acta Meteorologica Sinica》2004,18(1):117-128

In this paper,a comprehensive analysis and review of the advances in the research of human body comfort degree is made.Based on the studies of human thermal equilibrium theories contributed by previous researchers,different apparent temperature models corresponding to different environments are set up in accordance with the current situation and the characteristics of metabolism in different groups of people in China.After case studies and comparison with present dominant human body comfort degree statistical models,it is proved that the apparent temperature models have high rationality and wide adaptability.Furthermore,the comfort scaling standard according to apparent temperature is suggested,which is suitable for the middle latitude regions in China.  相似文献   

嫩江断裂构造及其与地震活动的关系   总被引：4，自引：0，他引：4  

陈洪洲  余中元  许晓艳  陶汝朋  高峰 《东北地震研究》2004,20(4):43-49

本文从卫片解译、钻孔资料、地球物理场特征等方面阐述了嫩江断裂的存在标志，同时对该断裂的性质、活动时代及其与地震的关系进行了讨论。认为沿该带分布的北西向及东西向断裂活动与地震关系密切，尤其是存在的地震围空区值得密切关注。  相似文献   

ANALYSIS OF THE RELATIONSHIP BETWEEN THE CHINA ANOMALOUS CLIMATE VARIATION AND ENSO CYCLE ON THE QUASI-FOUR-YEAR SCALE     

朱艳峰  陈隆勋  宇如聪 《热带气象学报(英文版)》2004,10(1):1-13

1 INTRODUCTION Much work has been done addressing the relationship between anomalous climate changes and ENSO in China and the results vary much. For instance, Li et al. (1987) [1] think that the Mei-yu (sustained rain) starts later, lasts shorter and pre…  相似文献   

商丘市烟草花叶病发病的气象条件     

余卫东董博  陈爱荣 《河南气象》2004,(2):30-31

通过对商丘市1986—2000年烟草花叶病发病资料和气象资料的分析，找出了影响商丘市烟草花叶病发病的气象因子，并应用模糊数学原理建立了预报方程，在实际预报工作中应用效果较好。  相似文献   

洛阳市2003年夏季多雨环流特征及汛期降水预报     

马淑玲盛建萍  禹东晖 《河南气象》2004,(3):20-21

分析了2003年洛阳夏季多雨环流特征，探讨了汛期降水偏多的预报因子，并用副高特征量因子建立了汛期降水预测模型。  相似文献   

新疆北部晚古生代埃达克岩、富铌玄武岩组合：古亚洲洋板块南向俯冲的证据   总被引：50，自引：0，他引：50  

张海祥  牛贺才  Hiroaki Sato  单强  于学元  Jun'ichi Ito  张旗 《高校地质学报》2004,10(1):106-113

地球化学研究结果表明，新疆北部富蕴县境内的晚古生代下泥盆统托让格库都克组的安山质岩石具有与埃达克岩非常相似的地球化学特征，它们具有较高的Al2O3，Na2O和Sr含量以及Sr/Y比值；明显亏损重稀土和Y，它们的MORB标准化微量元素蛛网图表现为明显的Nb，Ta负异常和Sr正异常，同时强烈亏损高场强元素。与埃达克岩共生的玄武岩的地球化学特征则与富铌玄武岩一致，表现为Si过饱和及富Na的特征，同时具有较高的Nb，TiO2和P2O5含量，并富集高场强元素。由于埃达克岩和富铌玄武岩的形成均与板块俯冲有关，因此，它们的存在表明，古亚洲洋在早-中泥盆世向南(哈萨克斯坦-准噶尔板块)发生了一次洋壳俯冲作用。  相似文献