北京集中绿化区气温对夏季高温天气的响应

利用自动气象站风、温、湿观测资料,对北京城市集中绿地缓解夏季高温(最高气温≥35 ℃)的效果进行了初步研究.研究结果表明:1)所研究的集中绿地都具有缩短高温持续时间的作用,但对最高气温的调节存在很大差异,有些集中绿地对最高气温几乎没有缓解作用,甚至有增温的可能.因此为发挥集中绿地缓解高温的效果,应尽可能提高绿地的通风条件.2)对北京城来说,集中绿地面积≥20 hm2时,降温效果比较显著.3)在高温天气情况下,集中绿地对高温的缓解作用对人体舒适度的改善,可能会由于集中绿地相对湿度较高而被抵消.     

济南市一次持续大雾过程分析

利用常规气象观测资料对2007年12月20-23日济南市一次持续大雾天气过程的大尺度天气背景、地面气压场、温度对数压力图以及单站气象要素进行了分析,结果表明:雾是在稳定的大气层结下出现的天气现象,根据大气稳定层结的状况及变化,可以判断大雾天气的有无及生消时间;近地面逆温和低空逆温同时存在,表明大气层结非常稳定,近地面逆温有利于近地面层水汽积累,低空逆温使近地面层水汽不易扩散而聚集,有利于近地面层维持潮湿,持续几天出现大雾;连续几天大气层结都处于稳定状态,地面风力很小,这些都限制了近地面层的水汽向外耗散,底层相对湿度较大,为大雾的形成提供了充沛的水汽条件.     

利用VB语言开发县级MICAPS 2.0资料本地化接收系统

针对县级无法及时、完全接收卫星资料的问题,利用VB语言开发了县级MICAPS2.0资料本地化接收系统,使县级气象台站能够共用地(市)级的卫星单收站接收的资料.     

湘鄂西中生代弧形叠加扩展的变形记录

通过对湘鄂西构造带进行大量的构造形迹测量、解析,结合研究区内构造变形年龄数据的统计分析.明确燕山中期(J3—K1)早期弧形构造弧顶方向为330°,并向两侧发散状分布,以大别山、黔中、黄陵隆起为约束点,湘鄂西形成了由南东侧至北东侧构造迹线由NE→NEE→EW→NWW逐渐偏转的弧形构造,最大主应力方向偏转近114°.同时早...     

GIS中河网空间数据模型

河网通常是由多条河流组成的,河网的空间形态结构特征由各条河流的几何特征和河流之间的相互关系决定,为了完整表示河网的空间形态结构特征,本文提出了基于河网空间形态结构特征的河网空间数据模型,并阐述了该模型的建立、维护等方法。     

Investigation of fractal distribution law for the trace number of random and grouped fractures in a geological mass

A fractal study method of the number of geological mass fractures is introduced in detail in this paper. Three main aspects of the problem were studied: (1) The random distribution of fractures in a geological mass was in good agreement with the fractal law. The size scale of the studied geological mass ranged from 2400 m to 1 mm for the length of each side, and the geological mass samples were taken from 13 coal areas in China. (2) The geological mass fractures were evidently directional and anisotropic, having originated from tectonic movement. Observation and statistics for the data from the Xuangang, Fenxi and Dongshan coal areas in Shanxi, China, demonstrated that the fracture distribution of each group, classified by the strike of the strata, still follow the fractal law, even though the fractal dimension varies to a certain extent with different strikes. (3) The sedimentary strata containing the coal seams, as a geological mass, underwent almost similar tectonic movements in their geological history. The mechanical experiments on geological mass samples from Fenxi and Jiexiu in Shanxi demonstrated that the fractal dimension of the number of fractures in the same strata is in good power function with the product of strength and elastic modulus. The larger the product of the strength of the elastic modulus is, the larger is the fractal dimension, and vice versa.     

New biostratigraphic data from the Cretaceous Bolinxiala Formation in Zanda, southwestern Tibet of China, and their paleogeographic and paleoceanographic implications

Planktonic foraminiferal fossil assemblages identified from the Bolinxiala Formation in Bolin, Zanda, southwestern Tibet of China, determine its age from latest Albian to Maastrichtian. The fossil contents of the Bolinxiala Formation allow its correlation with successions across a platform-to-basin transect of the Late Cretaceous Tethyan Himalaya passive margin. The ocean anoxic event at the Cenomanian–Turonian transition (OAE2) is located at the Whiteinella archaeocretacaea biozone in Zanda, but lithologically it is characterized by grey and bioturbated limestone, implying that during the OAE2 the shallow-water environments of the Tethyan Himalayan carbonate platform remained oxic. Paleogeographic reconstruction indicates that the Upper Cretaceous Oceanic Red Beds (CORBs) in southern Tibet are restricted to the slope and basinal environments but they are entirely missing in the shelf environments. This phenomenon suggests the formation of CORBs by oxidation of Fe(II)-enriched anoxic deep ocean seawater at the chemocline that separated the oxic surface ocean from anoxic deep ocean. For depositional environments above the chemocline, no CORBs would be expected. Because of the chemocline instability across different sedimentary basins, CORBs may be significantly diachronous, consistent with the occurrence of CORBs documented from global sedimentary basins.     

潍北-莱州湾凹陷郯庐断裂带新生代走滑特征

横切潍北-莱州湾凹陷郯庐断裂带的地震反射剖面和断裂带内的凹陷断层、沉积相和油气特征,直接或间接显示了郯庐断裂带的延伸、运动性质和活动时限。郯庐断裂带在海域和陆上的几何形态及其组合基本一致,根据切过断裂带的剖面和平面上断层的组合特征,判断其为兼具垂直位移的走滑运动断层系。走滑断裂带的活动控制着凹陷内同构造沉积以及构造样式,表明郯庐断裂带的活动时限具分段性,相当于渤海湾盆地孔店组(E1?2k)-沙四段(E2?3s4)沉积期(古新世-早始新世)-孔店组-沙二段(E2?3s2)沉积期(古新世-始新世)-孔店组-沙一段(E2?3s1)(古新世-渐新世)沉积时期,走滑拉分活动由南向北迁移; 活动方式也由古新世-早始新世的左旋走滑活动,被早始新世之后的右旋走滑活动所替代。