越南巴达棱湾沿岸海域周年风和浪的观测分析

基于国内首次在越南巴达棱湾2007年5月—2008年4月的风、浪现场实测资料,对该海区的风和浪的基本特征进行了初步统计分析,得出如下结论:1)海区季风现象明显,冬季(夏季)盛行东北(西南)季风,东北季风强度大于西南季风强度;2)海区波向与风向基本一致,即冬季(夏季)常浪向和强浪向均是E(SSW)向浪;3)海区以风浪为主,波谱表现为多峰结构,主峰多为单峰和双峰结构,东北季风(西南季风)期间,峰值周期对应的波向为E(SSW)向,台风对海域的波谱影响明显。文章结果对认识与我国同纬度的南沙群岛海域的风、浪特点具有一定参考价值。     

印度洋热含量在南海夏季风爆发中的作用

利用Scripps海洋研究所0—400m上层海洋热含量资料和美国环境监测中心/国家大气研究中心(National Centers for Environmental Prediction/National Center for Atmospheric Research,NCEP/NCAR)的再分析资料,运用经验正交分解(empirical orthogonal function,EOF)等统计方法,研究在有ENSO影响和去除ENSO影响的情况下,前期春季印度洋热含量如何影响南海夏季风爆发。结果表明,在没有扣除ENSO信号的情况下,热带印度洋热含量EOF分解第一模态呈东西相反变化的空间分布。印度洋东部热含量为正(负)异常、西部为负(正)异常时,南海夏季风爆发较早(晚),印度洋上层热含量主要通过影响热带印度洋上空大气的垂直运动和高低层辐散辐合,进而影响季风纬向环流的强弱,来影响南海夏季风爆发的早晚。在扣除ENSO信号的情况下,印度洋热含量CEOF(conditional EOF)第一模态的空间分布类似于EOF第一模态的空间分布;第二模态表现为除小部分海区外,热带印度洋热含量呈一致变化的海盆模态。这两个模态对南海夏...     

多孔介质中石油挥发过程研究

根据齐鲁石化地区石油污染特点,模拟天然条件下,多孔介质中石油的挥发过程,通过差减法确定石油挥发量与时间的关系。结果表明,Elovich模型和零级动力学方程分别能很好描述多孔介质中汽油和柴油挥发动力学曲线,且汽油在粗砂中的挥发速率系数较在亚黏土中大,而柴油在亚黏土中的挥发速率系数是在粗砂中的2.0~2.5倍。采用线性方程和二项式分别表达多孔介质中汽油和柴油挥发速率系数随含油率增加而增加的趋势。汽油在亚黏土中较在粗砂中的挥发率低,但挥发率一般均在90%以上;经过10 d挥发后,柴油在亚黏土中挥发率为7.2%~37.8%,在粗砂中的挥发率为5.0%~14.0%。     

OGC WCS系统若干关键实现技术研究

由于栅格数据种类繁多,处理过程复杂,目前还没有一种软件能为他们提供完善的WCS。研究表明,针对具体的数据源设计和实现WCS是比较好的解决方案。研究针对MODIS数据,参照OGC WCS实现规范,在充分分析WCS数据处理与服务流程的基础上,总结了WCS系统实现的技术要点,研究和探讨了系统实现中的若干关键技术问题,包括元数...     

青海野马泉矽卡岩铁锌多金属矿区侵入岩、交代岩及矿化蚀变特征

野马泉铁锌多金属矿床位于柴达木盆地西南缘和青海祁漫塔格山之间的盆山结合部位.矿区出露有印支期及海西期侵入岩.矿区内矽卡岩呈层状、似层状产于上石炭统四角羊沟组中,矽卡岩矿物主要是石榴子石、单斜辉石、角闪石、绿帘石、符山石等;金属矿物主要有磁铁矿、黄铜矿、黄铁矿、闪锌矿等.文章基于详细野外地质调查、剖面和钻孔岩芯观察结果,开展了侵入岩和交代岩的岩石地球化学及矽卡岩矿物学的系统研究.结果表明,野马泉矿区闪长岩具有低w(SiO2) (51.90％～59.03％)、高w(MgO) (2.04％～3.44％)、w(TFeO)(5.33％～11.67％),高REE[(318.57×10-6～327.67×10-6)],低LREE/HREE比值(7.36～7.48)的特点;二长花岗岩具有高w(SiO2) (77.36％ ～77.41％)、低w(MgO)(0.04％～0.10％)、w(TFeO) (0.76％～1.08％)的特点,LREE/HREE比值较高(9.14～9.37).透辉石-钾长石交代岩比原岩低w(MgO)(1.17％ ～ 2.86％)、低w(TFeO)(3.89％～7.76％),且具有更强的Eu负异常(δEu=0.07～0.52),LREE/HREE比值更低(3.19～7.87).透辉石-钠长石交代岩相对原岩具有低w(MgO) (0.36％～0.92％)、高w(TFeO)(3.05％ ～8.13％)的特点.野马泉矿区的矽卡岩包括钙矽卡岩和锰质矽卡岩,钙矽卡岩主要产于接触带附近,组成矿物主要为单斜辉石和石榴子石,接近岩体的单斜辉石中透辉石端员组分较高,石榴石主要分布在接触带附近,内环带钙铁榴石组分高于外环带.综合矿物学、岩石地球化学结果,推断野马泉矿区闪长岩具有较大成矿潜力,野马泉矿区钙矽卡岩主要形成于氧化条件,锰质矽卡岩形成于还原条件.     

Phanerozoic Paleomagnetism Characteristics of the Qomolangma Area in Tibet

This paper conducts systematic test research on the 2920 paleomagnetic directional samples taken from Ordovician-Paleogene sedimentary formation in the north slope of Qomolangma in south of Tibet and obtains the primary remanent magnetization component and counts the new data of paleomagnetism the times. Based on the characteristic remanent magnetization component, it calculates the geomagnetic pole position and latitude value of Himalaya block in Ordovician-Paleogene. According to the new data of paleomagnetism, it draws the palaeomagnetic polar wander curve and palaeolatitude change curve of the north slope of Qomolangma in Ordovician-Paleogene. It also makes a preliminary discussion to the structure evolution history and relative movement of Himalaya bloc. The research results show that many clockwise rotation movements had occurred to the Himalaya block in northern slope of Qomolangmain the process of northward drifting in the phanerozoic eon. In Ordovician-late Cretaceous, there the movement of about 20.0° clockwise rotation occurred in the process of northward drifting. However, 0.4° counterclockwise rotation occurred from the end of late Devonian epoch to the beginning of early carboniferous epoch; 6.0° and 8.0° counterclockwise rotation occurred in carboniferous period and early Triassic epoch respectively, which might be related with the tension crack of continental rift valley from late Devonian period to the beginning of early carboniferous epoch, carboniferous period and early Triassic epoch. From the Eocene epoch to Pliocene epoch, the Himalaya block generated about 28.0° clockwise while drifting northward with a relatively rapid speed. This was the result that since the Eocene epoch, due to the continuous expansion of mid-ocean ridge of the India Ocean, the neo-Tethys with the Yarlung Zangbo River as the main ocean basin closed to form orogenic movement and the strong continent-continent collision orogenic movement of the east and west Himalayas generated clockwise movement in the mid-Himalaya area. According to the calculation of palaeolatitude data, the Himalaya continent-continent collusion orogenic movement since the Eocene epoch caused the crustal structure in Indian Plate-Himalaya folded structural belt-Lhasa block to shorten by at least 1000 km. The systematic research on the paleomagnetism of Qomolangma area in the phanerozoic eon provides a scientific basis to further research the evolution of Gondwanaland, formation and extinction history of paleo-Tethys Ocean and uplift mechanism of the Qinghai-Tibet Plateau.     

3DGIS中复合地形纹理生成与应用

3DGIS仅用数字高程模型(DEM)表现地形远达不到三维可视化的要求.在传统3IDGIS中,通常采用数字正射影像(DOM)作为DEM的纹理表达地面景观,但其逼真性往往会受到影像分辨率的限制.该文借鉴Mipmap思想,提出一种新的纹理生成方法来解决上述问题,即通过对DOM和二维矢量数据赋予投影信息,将多幅影像及相关矢量数据作为生成3DGIS地形的纹理数据源,生成不同分辨率、不同详细程度的金字塔纹理,动态表现地面景观,并对生成的金字塔模型数据进行高效的索引、存储与管理.上述方法在实际应用中取得了满意的访问效率和视觉效果.